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btrfs: submit superblock io with REQ_META and REQ_PRIO
[mirror_ubuntu-bionic-kernel.git] / fs / btrfs / inode.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/kernel.h>
20 #include <linux/bio.h>
21 #include <linux/buffer_head.h>
22 #include <linux/file.h>
23 #include <linux/fs.h>
24 #include <linux/pagemap.h>
25 #include <linux/highmem.h>
26 #include <linux/time.h>
27 #include <linux/init.h>
28 #include <linux/string.h>
29 #include <linux/backing-dev.h>
30 #include <linux/mpage.h>
31 #include <linux/swap.h>
32 #include <linux/writeback.h>
33 #include <linux/compat.h>
34 #include <linux/bit_spinlock.h>
35 #include <linux/xattr.h>
36 #include <linux/posix_acl.h>
37 #include <linux/falloc.h>
38 #include <linux/slab.h>
39 #include <linux/ratelimit.h>
40 #include <linux/mount.h>
41 #include <linux/btrfs.h>
42 #include <linux/blkdev.h>
43 #include <linux/posix_acl_xattr.h>
44 #include <linux/uio.h>
45 #include "ctree.h"
46 #include "disk-io.h"
47 #include "transaction.h"
48 #include "btrfs_inode.h"
49 #include "print-tree.h"
50 #include "ordered-data.h"
51 #include "xattr.h"
52 #include "tree-log.h"
53 #include "volumes.h"
54 #include "compression.h"
55 #include "locking.h"
56 #include "free-space-cache.h"
57 #include "inode-map.h"
58 #include "backref.h"
59 #include "hash.h"
60 #include "props.h"
61 #include "qgroup.h"
62 #include "dedupe.h"
63
64 struct btrfs_iget_args {
65 struct btrfs_key *location;
66 struct btrfs_root *root;
67 };
68
69 struct btrfs_dio_data {
70 u64 outstanding_extents;
71 u64 reserve;
72 u64 unsubmitted_oe_range_start;
73 u64 unsubmitted_oe_range_end;
74 int overwrite;
75 };
76
77 static const struct inode_operations btrfs_dir_inode_operations;
78 static const struct inode_operations btrfs_symlink_inode_operations;
79 static const struct inode_operations btrfs_dir_ro_inode_operations;
80 static const struct inode_operations btrfs_special_inode_operations;
81 static const struct inode_operations btrfs_file_inode_operations;
82 static const struct address_space_operations btrfs_aops;
83 static const struct address_space_operations btrfs_symlink_aops;
84 static const struct file_operations btrfs_dir_file_operations;
85 static const struct extent_io_ops btrfs_extent_io_ops;
86
87 static struct kmem_cache *btrfs_inode_cachep;
88 struct kmem_cache *btrfs_trans_handle_cachep;
89 struct kmem_cache *btrfs_path_cachep;
90 struct kmem_cache *btrfs_free_space_cachep;
91
92 #define S_SHIFT 12
93 static const unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
94 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
95 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
96 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
97 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
98 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
99 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
100 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
101 };
102
103 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
104 static int btrfs_truncate(struct inode *inode);
105 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
106 static noinline int cow_file_range(struct inode *inode,
107 struct page *locked_page,
108 u64 start, u64 end, u64 delalloc_end,
109 int *page_started, unsigned long *nr_written,
110 int unlock, struct btrfs_dedupe_hash *hash);
111 static struct extent_map *create_io_em(struct inode *inode, u64 start, u64 len,
112 u64 orig_start, u64 block_start,
113 u64 block_len, u64 orig_block_len,
114 u64 ram_bytes, int compress_type,
115 int type);
116
117 static void __endio_write_update_ordered(struct inode *inode,
118 const u64 offset, const u64 bytes,
119 const bool uptodate);
120
121 /*
122 * Cleanup all submitted ordered extents in specified range to handle errors
123 * from the fill_dellaloc() callback.
124 *
125 * NOTE: caller must ensure that when an error happens, it can not call
126 * extent_clear_unlock_delalloc() to clear both the bits EXTENT_DO_ACCOUNTING
127 * and EXTENT_DELALLOC simultaneously, because that causes the reserved metadata
128 * to be released, which we want to happen only when finishing the ordered
129 * extent (btrfs_finish_ordered_io()). Also note that the caller of the
130 * fill_delalloc() callback already does proper cleanup for the first page of
131 * the range, that is, it invokes the callback writepage_end_io_hook() for the
132 * range of the first page.
133 */
134 static inline void btrfs_cleanup_ordered_extents(struct inode *inode,
135 const u64 offset,
136 const u64 bytes)
137 {
138 return __endio_write_update_ordered(inode, offset + PAGE_SIZE,
139 bytes - PAGE_SIZE, false);
140 }
141
142 static int btrfs_dirty_inode(struct inode *inode);
143
144 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
145 void btrfs_test_inode_set_ops(struct inode *inode)
146 {
147 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
148 }
149 #endif
150
151 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
152 struct inode *inode, struct inode *dir,
153 const struct qstr *qstr)
154 {
155 int err;
156
157 err = btrfs_init_acl(trans, inode, dir);
158 if (!err)
159 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
160 return err;
161 }
162
163 /*
164 * this does all the hard work for inserting an inline extent into
165 * the btree. The caller should have done a btrfs_drop_extents so that
166 * no overlapping inline items exist in the btree
167 */
168 static int insert_inline_extent(struct btrfs_trans_handle *trans,
169 struct btrfs_path *path, int extent_inserted,
170 struct btrfs_root *root, struct inode *inode,
171 u64 start, size_t size, size_t compressed_size,
172 int compress_type,
173 struct page **compressed_pages)
174 {
175 struct extent_buffer *leaf;
176 struct page *page = NULL;
177 char *kaddr;
178 unsigned long ptr;
179 struct btrfs_file_extent_item *ei;
180 int ret;
181 size_t cur_size = size;
182 unsigned long offset;
183
184 if (compressed_size && compressed_pages)
185 cur_size = compressed_size;
186
187 inode_add_bytes(inode, size);
188
189 if (!extent_inserted) {
190 struct btrfs_key key;
191 size_t datasize;
192
193 key.objectid = btrfs_ino(BTRFS_I(inode));
194 key.offset = start;
195 key.type = BTRFS_EXTENT_DATA_KEY;
196
197 datasize = btrfs_file_extent_calc_inline_size(cur_size);
198 path->leave_spinning = 1;
199 ret = btrfs_insert_empty_item(trans, root, path, &key,
200 datasize);
201 if (ret)
202 goto fail;
203 }
204 leaf = path->nodes[0];
205 ei = btrfs_item_ptr(leaf, path->slots[0],
206 struct btrfs_file_extent_item);
207 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
208 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
209 btrfs_set_file_extent_encryption(leaf, ei, 0);
210 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
211 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
212 ptr = btrfs_file_extent_inline_start(ei);
213
214 if (compress_type != BTRFS_COMPRESS_NONE) {
215 struct page *cpage;
216 int i = 0;
217 while (compressed_size > 0) {
218 cpage = compressed_pages[i];
219 cur_size = min_t(unsigned long, compressed_size,
220 PAGE_SIZE);
221
222 kaddr = kmap_atomic(cpage);
223 write_extent_buffer(leaf, kaddr, ptr, cur_size);
224 kunmap_atomic(kaddr);
225
226 i++;
227 ptr += cur_size;
228 compressed_size -= cur_size;
229 }
230 btrfs_set_file_extent_compression(leaf, ei,
231 compress_type);
232 } else {
233 page = find_get_page(inode->i_mapping,
234 start >> PAGE_SHIFT);
235 btrfs_set_file_extent_compression(leaf, ei, 0);
236 kaddr = kmap_atomic(page);
237 offset = start & (PAGE_SIZE - 1);
238 write_extent_buffer(leaf, kaddr + offset, ptr, size);
239 kunmap_atomic(kaddr);
240 put_page(page);
241 }
242 btrfs_mark_buffer_dirty(leaf);
243 btrfs_release_path(path);
244
245 /*
246 * we're an inline extent, so nobody can
247 * extend the file past i_size without locking
248 * a page we already have locked.
249 *
250 * We must do any isize and inode updates
251 * before we unlock the pages. Otherwise we
252 * could end up racing with unlink.
253 */
254 BTRFS_I(inode)->disk_i_size = inode->i_size;
255 ret = btrfs_update_inode(trans, root, inode);
256
257 fail:
258 return ret;
259 }
260
261
262 /*
263 * conditionally insert an inline extent into the file. This
264 * does the checks required to make sure the data is small enough
265 * to fit as an inline extent.
266 */
267 static noinline int cow_file_range_inline(struct btrfs_root *root,
268 struct inode *inode, u64 start,
269 u64 end, size_t compressed_size,
270 int compress_type,
271 struct page **compressed_pages)
272 {
273 struct btrfs_fs_info *fs_info = root->fs_info;
274 struct btrfs_trans_handle *trans;
275 u64 isize = i_size_read(inode);
276 u64 actual_end = min(end + 1, isize);
277 u64 inline_len = actual_end - start;
278 u64 aligned_end = ALIGN(end, fs_info->sectorsize);
279 u64 data_len = inline_len;
280 int ret;
281 struct btrfs_path *path;
282 int extent_inserted = 0;
283 u32 extent_item_size;
284
285 if (compressed_size)
286 data_len = compressed_size;
287
288 if (start > 0 ||
289 actual_end > fs_info->sectorsize ||
290 data_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info) ||
291 (!compressed_size &&
292 (actual_end & (fs_info->sectorsize - 1)) == 0) ||
293 end + 1 < isize ||
294 data_len > fs_info->max_inline) {
295 return 1;
296 }
297
298 path = btrfs_alloc_path();
299 if (!path)
300 return -ENOMEM;
301
302 trans = btrfs_join_transaction(root);
303 if (IS_ERR(trans)) {
304 btrfs_free_path(path);
305 return PTR_ERR(trans);
306 }
307 trans->block_rsv = &fs_info->delalloc_block_rsv;
308
309 if (compressed_size && compressed_pages)
310 extent_item_size = btrfs_file_extent_calc_inline_size(
311 compressed_size);
312 else
313 extent_item_size = btrfs_file_extent_calc_inline_size(
314 inline_len);
315
316 ret = __btrfs_drop_extents(trans, root, inode, path,
317 start, aligned_end, NULL,
318 1, 1, extent_item_size, &extent_inserted);
319 if (ret) {
320 btrfs_abort_transaction(trans, ret);
321 goto out;
322 }
323
324 if (isize > actual_end)
325 inline_len = min_t(u64, isize, actual_end);
326 ret = insert_inline_extent(trans, path, extent_inserted,
327 root, inode, start,
328 inline_len, compressed_size,
329 compress_type, compressed_pages);
330 if (ret && ret != -ENOSPC) {
331 btrfs_abort_transaction(trans, ret);
332 goto out;
333 } else if (ret == -ENOSPC) {
334 ret = 1;
335 goto out;
336 }
337
338 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
339 btrfs_delalloc_release_metadata(BTRFS_I(inode), end + 1 - start);
340 btrfs_drop_extent_cache(BTRFS_I(inode), start, aligned_end - 1, 0);
341 out:
342 /*
343 * Don't forget to free the reserved space, as for inlined extent
344 * it won't count as data extent, free them directly here.
345 * And at reserve time, it's always aligned to page size, so
346 * just free one page here.
347 */
348 btrfs_qgroup_free_data(inode, NULL, 0, PAGE_SIZE);
349 btrfs_free_path(path);
350 btrfs_end_transaction(trans);
351 return ret;
352 }
353
354 struct async_extent {
355 u64 start;
356 u64 ram_size;
357 u64 compressed_size;
358 struct page **pages;
359 unsigned long nr_pages;
360 int compress_type;
361 struct list_head list;
362 };
363
364 struct async_cow {
365 struct inode *inode;
366 struct btrfs_root *root;
367 struct page *locked_page;
368 u64 start;
369 u64 end;
370 struct list_head extents;
371 struct btrfs_work work;
372 };
373
374 static noinline int add_async_extent(struct async_cow *cow,
375 u64 start, u64 ram_size,
376 u64 compressed_size,
377 struct page **pages,
378 unsigned long nr_pages,
379 int compress_type)
380 {
381 struct async_extent *async_extent;
382
383 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
384 BUG_ON(!async_extent); /* -ENOMEM */
385 async_extent->start = start;
386 async_extent->ram_size = ram_size;
387 async_extent->compressed_size = compressed_size;
388 async_extent->pages = pages;
389 async_extent->nr_pages = nr_pages;
390 async_extent->compress_type = compress_type;
391 list_add_tail(&async_extent->list, &cow->extents);
392 return 0;
393 }
394
395 static inline int inode_need_compress(struct inode *inode, u64 start, u64 end)
396 {
397 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
398
399 /* force compress */
400 if (btrfs_test_opt(fs_info, FORCE_COMPRESS))
401 return 1;
402 /* defrag ioctl */
403 if (BTRFS_I(inode)->defrag_compress)
404 return 1;
405 /* bad compression ratios */
406 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
407 return 0;
408 if (btrfs_test_opt(fs_info, COMPRESS) ||
409 BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
410 BTRFS_I(inode)->prop_compress)
411 return btrfs_compress_heuristic(inode, start, end);
412 return 0;
413 }
414
415 static inline void inode_should_defrag(struct btrfs_inode *inode,
416 u64 start, u64 end, u64 num_bytes, u64 small_write)
417 {
418 /* If this is a small write inside eof, kick off a defrag */
419 if (num_bytes < small_write &&
420 (start > 0 || end + 1 < inode->disk_i_size))
421 btrfs_add_inode_defrag(NULL, inode);
422 }
423
424 /*
425 * we create compressed extents in two phases. The first
426 * phase compresses a range of pages that have already been
427 * locked (both pages and state bits are locked).
428 *
429 * This is done inside an ordered work queue, and the compression
430 * is spread across many cpus. The actual IO submission is step
431 * two, and the ordered work queue takes care of making sure that
432 * happens in the same order things were put onto the queue by
433 * writepages and friends.
434 *
435 * If this code finds it can't get good compression, it puts an
436 * entry onto the work queue to write the uncompressed bytes. This
437 * makes sure that both compressed inodes and uncompressed inodes
438 * are written in the same order that the flusher thread sent them
439 * down.
440 */
441 static noinline void compress_file_range(struct inode *inode,
442 struct page *locked_page,
443 u64 start, u64 end,
444 struct async_cow *async_cow,
445 int *num_added)
446 {
447 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
448 struct btrfs_root *root = BTRFS_I(inode)->root;
449 u64 num_bytes;
450 u64 blocksize = fs_info->sectorsize;
451 u64 actual_end;
452 u64 isize = i_size_read(inode);
453 int ret = 0;
454 struct page **pages = NULL;
455 unsigned long nr_pages;
456 unsigned long total_compressed = 0;
457 unsigned long total_in = 0;
458 int i;
459 int will_compress;
460 int compress_type = fs_info->compress_type;
461 int redirty = 0;
462
463 inode_should_defrag(BTRFS_I(inode), start, end, end - start + 1,
464 SZ_16K);
465
466 actual_end = min_t(u64, isize, end + 1);
467 again:
468 will_compress = 0;
469 nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
470 BUILD_BUG_ON((BTRFS_MAX_COMPRESSED % PAGE_SIZE) != 0);
471 nr_pages = min_t(unsigned long, nr_pages,
472 BTRFS_MAX_COMPRESSED / PAGE_SIZE);
473
474 /*
475 * we don't want to send crud past the end of i_size through
476 * compression, that's just a waste of CPU time. So, if the
477 * end of the file is before the start of our current
478 * requested range of bytes, we bail out to the uncompressed
479 * cleanup code that can deal with all of this.
480 *
481 * It isn't really the fastest way to fix things, but this is a
482 * very uncommon corner.
483 */
484 if (actual_end <= start)
485 goto cleanup_and_bail_uncompressed;
486
487 total_compressed = actual_end - start;
488
489 /*
490 * skip compression for a small file range(<=blocksize) that
491 * isn't an inline extent, since it doesn't save disk space at all.
492 */
493 if (total_compressed <= blocksize &&
494 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
495 goto cleanup_and_bail_uncompressed;
496
497 total_compressed = min_t(unsigned long, total_compressed,
498 BTRFS_MAX_UNCOMPRESSED);
499 num_bytes = ALIGN(end - start + 1, blocksize);
500 num_bytes = max(blocksize, num_bytes);
501 total_in = 0;
502 ret = 0;
503
504 /*
505 * we do compression for mount -o compress and when the
506 * inode has not been flagged as nocompress. This flag can
507 * change at any time if we discover bad compression ratios.
508 */
509 if (inode_need_compress(inode, start, end)) {
510 WARN_ON(pages);
511 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
512 if (!pages) {
513 /* just bail out to the uncompressed code */
514 goto cont;
515 }
516
517 if (BTRFS_I(inode)->defrag_compress)
518 compress_type = BTRFS_I(inode)->defrag_compress;
519 else if (BTRFS_I(inode)->prop_compress)
520 compress_type = BTRFS_I(inode)->prop_compress;
521
522 /*
523 * we need to call clear_page_dirty_for_io on each
524 * page in the range. Otherwise applications with the file
525 * mmap'd can wander in and change the page contents while
526 * we are compressing them.
527 *
528 * If the compression fails for any reason, we set the pages
529 * dirty again later on.
530 */
531 extent_range_clear_dirty_for_io(inode, start, end);
532 redirty = 1;
533 ret = btrfs_compress_pages(compress_type,
534 inode->i_mapping, start,
535 pages,
536 &nr_pages,
537 &total_in,
538 &total_compressed);
539
540 if (!ret) {
541 unsigned long offset = total_compressed &
542 (PAGE_SIZE - 1);
543 struct page *page = pages[nr_pages - 1];
544 char *kaddr;
545
546 /* zero the tail end of the last page, we might be
547 * sending it down to disk
548 */
549 if (offset) {
550 kaddr = kmap_atomic(page);
551 memset(kaddr + offset, 0,
552 PAGE_SIZE - offset);
553 kunmap_atomic(kaddr);
554 }
555 will_compress = 1;
556 }
557 }
558 cont:
559 if (start == 0) {
560 /* lets try to make an inline extent */
561 if (ret || total_in < (actual_end - start)) {
562 /* we didn't compress the entire range, try
563 * to make an uncompressed inline extent.
564 */
565 ret = cow_file_range_inline(root, inode, start, end,
566 0, BTRFS_COMPRESS_NONE, NULL);
567 } else {
568 /* try making a compressed inline extent */
569 ret = cow_file_range_inline(root, inode, start, end,
570 total_compressed,
571 compress_type, pages);
572 }
573 if (ret <= 0) {
574 unsigned long clear_flags = EXTENT_DELALLOC |
575 EXTENT_DELALLOC_NEW | EXTENT_DEFRAG;
576 unsigned long page_error_op;
577
578 clear_flags |= (ret < 0) ? EXTENT_DO_ACCOUNTING : 0;
579 page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
580
581 /*
582 * inline extent creation worked or returned error,
583 * we don't need to create any more async work items.
584 * Unlock and free up our temp pages.
585 */
586 extent_clear_unlock_delalloc(inode, start, end, end,
587 NULL, clear_flags,
588 PAGE_UNLOCK |
589 PAGE_CLEAR_DIRTY |
590 PAGE_SET_WRITEBACK |
591 page_error_op |
592 PAGE_END_WRITEBACK);
593 if (ret == 0)
594 btrfs_free_reserved_data_space_noquota(inode,
595 start,
596 end - start + 1);
597 goto free_pages_out;
598 }
599 }
600
601 if (will_compress) {
602 /*
603 * we aren't doing an inline extent round the compressed size
604 * up to a block size boundary so the allocator does sane
605 * things
606 */
607 total_compressed = ALIGN(total_compressed, blocksize);
608
609 /*
610 * one last check to make sure the compression is really a
611 * win, compare the page count read with the blocks on disk,
612 * compression must free at least one sector size
613 */
614 total_in = ALIGN(total_in, PAGE_SIZE);
615 if (total_compressed + blocksize <= total_in) {
616 num_bytes = total_in;
617 *num_added += 1;
618
619 /*
620 * The async work queues will take care of doing actual
621 * allocation on disk for these compressed pages, and
622 * will submit them to the elevator.
623 */
624 add_async_extent(async_cow, start, num_bytes,
625 total_compressed, pages, nr_pages,
626 compress_type);
627
628 if (start + num_bytes < end) {
629 start += num_bytes;
630 pages = NULL;
631 cond_resched();
632 goto again;
633 }
634 return;
635 }
636 }
637 if (pages) {
638 /*
639 * the compression code ran but failed to make things smaller,
640 * free any pages it allocated and our page pointer array
641 */
642 for (i = 0; i < nr_pages; i++) {
643 WARN_ON(pages[i]->mapping);
644 put_page(pages[i]);
645 }
646 kfree(pages);
647 pages = NULL;
648 total_compressed = 0;
649 nr_pages = 0;
650
651 /* flag the file so we don't compress in the future */
652 if (!btrfs_test_opt(fs_info, FORCE_COMPRESS) &&
653 !(BTRFS_I(inode)->prop_compress)) {
654 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
655 }
656 }
657 cleanup_and_bail_uncompressed:
658 /*
659 * No compression, but we still need to write the pages in the file
660 * we've been given so far. redirty the locked page if it corresponds
661 * to our extent and set things up for the async work queue to run
662 * cow_file_range to do the normal delalloc dance.
663 */
664 if (page_offset(locked_page) >= start &&
665 page_offset(locked_page) <= end)
666 __set_page_dirty_nobuffers(locked_page);
667 /* unlocked later on in the async handlers */
668
669 if (redirty)
670 extent_range_redirty_for_io(inode, start, end);
671 add_async_extent(async_cow, start, end - start + 1, 0, NULL, 0,
672 BTRFS_COMPRESS_NONE);
673 *num_added += 1;
674
675 return;
676
677 free_pages_out:
678 for (i = 0; i < nr_pages; i++) {
679 WARN_ON(pages[i]->mapping);
680 put_page(pages[i]);
681 }
682 kfree(pages);
683 }
684
685 static void free_async_extent_pages(struct async_extent *async_extent)
686 {
687 int i;
688
689 if (!async_extent->pages)
690 return;
691
692 for (i = 0; i < async_extent->nr_pages; i++) {
693 WARN_ON(async_extent->pages[i]->mapping);
694 put_page(async_extent->pages[i]);
695 }
696 kfree(async_extent->pages);
697 async_extent->nr_pages = 0;
698 async_extent->pages = NULL;
699 }
700
701 /*
702 * phase two of compressed writeback. This is the ordered portion
703 * of the code, which only gets called in the order the work was
704 * queued. We walk all the async extents created by compress_file_range
705 * and send them down to the disk.
706 */
707 static noinline void submit_compressed_extents(struct inode *inode,
708 struct async_cow *async_cow)
709 {
710 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
711 struct async_extent *async_extent;
712 u64 alloc_hint = 0;
713 struct btrfs_key ins;
714 struct extent_map *em;
715 struct btrfs_root *root = BTRFS_I(inode)->root;
716 struct extent_io_tree *io_tree;
717 int ret = 0;
718
719 again:
720 while (!list_empty(&async_cow->extents)) {
721 async_extent = list_entry(async_cow->extents.next,
722 struct async_extent, list);
723 list_del(&async_extent->list);
724
725 io_tree = &BTRFS_I(inode)->io_tree;
726
727 retry:
728 /* did the compression code fall back to uncompressed IO? */
729 if (!async_extent->pages) {
730 int page_started = 0;
731 unsigned long nr_written = 0;
732
733 lock_extent(io_tree, async_extent->start,
734 async_extent->start +
735 async_extent->ram_size - 1);
736
737 /* allocate blocks */
738 ret = cow_file_range(inode, async_cow->locked_page,
739 async_extent->start,
740 async_extent->start +
741 async_extent->ram_size - 1,
742 async_extent->start +
743 async_extent->ram_size - 1,
744 &page_started, &nr_written, 0,
745 NULL);
746
747 /* JDM XXX */
748
749 /*
750 * if page_started, cow_file_range inserted an
751 * inline extent and took care of all the unlocking
752 * and IO for us. Otherwise, we need to submit
753 * all those pages down to the drive.
754 */
755 if (!page_started && !ret)
756 extent_write_locked_range(io_tree,
757 inode, async_extent->start,
758 async_extent->start +
759 async_extent->ram_size - 1,
760 btrfs_get_extent,
761 WB_SYNC_ALL);
762 else if (ret)
763 unlock_page(async_cow->locked_page);
764 kfree(async_extent);
765 cond_resched();
766 continue;
767 }
768
769 lock_extent(io_tree, async_extent->start,
770 async_extent->start + async_extent->ram_size - 1);
771
772 ret = btrfs_reserve_extent(root, async_extent->ram_size,
773 async_extent->compressed_size,
774 async_extent->compressed_size,
775 0, alloc_hint, &ins, 1, 1);
776 if (ret) {
777 free_async_extent_pages(async_extent);
778
779 if (ret == -ENOSPC) {
780 unlock_extent(io_tree, async_extent->start,
781 async_extent->start +
782 async_extent->ram_size - 1);
783
784 /*
785 * we need to redirty the pages if we decide to
786 * fallback to uncompressed IO, otherwise we
787 * will not submit these pages down to lower
788 * layers.
789 */
790 extent_range_redirty_for_io(inode,
791 async_extent->start,
792 async_extent->start +
793 async_extent->ram_size - 1);
794
795 goto retry;
796 }
797 goto out_free;
798 }
799 /*
800 * here we're doing allocation and writeback of the
801 * compressed pages
802 */
803 em = create_io_em(inode, async_extent->start,
804 async_extent->ram_size, /* len */
805 async_extent->start, /* orig_start */
806 ins.objectid, /* block_start */
807 ins.offset, /* block_len */
808 ins.offset, /* orig_block_len */
809 async_extent->ram_size, /* ram_bytes */
810 async_extent->compress_type,
811 BTRFS_ORDERED_COMPRESSED);
812 if (IS_ERR(em))
813 /* ret value is not necessary due to void function */
814 goto out_free_reserve;
815 free_extent_map(em);
816
817 ret = btrfs_add_ordered_extent_compress(inode,
818 async_extent->start,
819 ins.objectid,
820 async_extent->ram_size,
821 ins.offset,
822 BTRFS_ORDERED_COMPRESSED,
823 async_extent->compress_type);
824 if (ret) {
825 btrfs_drop_extent_cache(BTRFS_I(inode),
826 async_extent->start,
827 async_extent->start +
828 async_extent->ram_size - 1, 0);
829 goto out_free_reserve;
830 }
831 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
832
833 /*
834 * clear dirty, set writeback and unlock the pages.
835 */
836 extent_clear_unlock_delalloc(inode, async_extent->start,
837 async_extent->start +
838 async_extent->ram_size - 1,
839 async_extent->start +
840 async_extent->ram_size - 1,
841 NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
842 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
843 PAGE_SET_WRITEBACK);
844 if (btrfs_submit_compressed_write(inode,
845 async_extent->start,
846 async_extent->ram_size,
847 ins.objectid,
848 ins.offset, async_extent->pages,
849 async_extent->nr_pages)) {
850 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
851 struct page *p = async_extent->pages[0];
852 const u64 start = async_extent->start;
853 const u64 end = start + async_extent->ram_size - 1;
854
855 p->mapping = inode->i_mapping;
856 tree->ops->writepage_end_io_hook(p, start, end,
857 NULL, 0);
858 p->mapping = NULL;
859 extent_clear_unlock_delalloc(inode, start, end, end,
860 NULL, 0,
861 PAGE_END_WRITEBACK |
862 PAGE_SET_ERROR);
863 free_async_extent_pages(async_extent);
864 }
865 alloc_hint = ins.objectid + ins.offset;
866 kfree(async_extent);
867 cond_resched();
868 }
869 return;
870 out_free_reserve:
871 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
872 btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
873 out_free:
874 extent_clear_unlock_delalloc(inode, async_extent->start,
875 async_extent->start +
876 async_extent->ram_size - 1,
877 async_extent->start +
878 async_extent->ram_size - 1,
879 NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
880 EXTENT_DELALLOC_NEW |
881 EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
882 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
883 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
884 PAGE_SET_ERROR);
885 free_async_extent_pages(async_extent);
886 kfree(async_extent);
887 goto again;
888 }
889
890 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
891 u64 num_bytes)
892 {
893 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
894 struct extent_map *em;
895 u64 alloc_hint = 0;
896
897 read_lock(&em_tree->lock);
898 em = search_extent_mapping(em_tree, start, num_bytes);
899 if (em) {
900 /*
901 * if block start isn't an actual block number then find the
902 * first block in this inode and use that as a hint. If that
903 * block is also bogus then just don't worry about it.
904 */
905 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
906 free_extent_map(em);
907 em = search_extent_mapping(em_tree, 0, 0);
908 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
909 alloc_hint = em->block_start;
910 if (em)
911 free_extent_map(em);
912 } else {
913 alloc_hint = em->block_start;
914 free_extent_map(em);
915 }
916 }
917 read_unlock(&em_tree->lock);
918
919 return alloc_hint;
920 }
921
922 /*
923 * when extent_io.c finds a delayed allocation range in the file,
924 * the call backs end up in this code. The basic idea is to
925 * allocate extents on disk for the range, and create ordered data structs
926 * in ram to track those extents.
927 *
928 * locked_page is the page that writepage had locked already. We use
929 * it to make sure we don't do extra locks or unlocks.
930 *
931 * *page_started is set to one if we unlock locked_page and do everything
932 * required to start IO on it. It may be clean and already done with
933 * IO when we return.
934 */
935 static noinline int cow_file_range(struct inode *inode,
936 struct page *locked_page,
937 u64 start, u64 end, u64 delalloc_end,
938 int *page_started, unsigned long *nr_written,
939 int unlock, struct btrfs_dedupe_hash *hash)
940 {
941 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
942 struct btrfs_root *root = BTRFS_I(inode)->root;
943 u64 alloc_hint = 0;
944 u64 num_bytes;
945 unsigned long ram_size;
946 u64 disk_num_bytes;
947 u64 cur_alloc_size = 0;
948 u64 blocksize = fs_info->sectorsize;
949 struct btrfs_key ins;
950 struct extent_map *em;
951 unsigned clear_bits;
952 unsigned long page_ops;
953 bool extent_reserved = false;
954 int ret = 0;
955
956 if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
957 WARN_ON_ONCE(1);
958 ret = -EINVAL;
959 goto out_unlock;
960 }
961
962 num_bytes = ALIGN(end - start + 1, blocksize);
963 num_bytes = max(blocksize, num_bytes);
964 disk_num_bytes = num_bytes;
965
966 inode_should_defrag(BTRFS_I(inode), start, end, num_bytes, SZ_64K);
967
968 if (start == 0) {
969 /* lets try to make an inline extent */
970 ret = cow_file_range_inline(root, inode, start, end, 0,
971 BTRFS_COMPRESS_NONE, NULL);
972 if (ret == 0) {
973 extent_clear_unlock_delalloc(inode, start, end,
974 delalloc_end, NULL,
975 EXTENT_LOCKED | EXTENT_DELALLOC |
976 EXTENT_DELALLOC_NEW |
977 EXTENT_DEFRAG, PAGE_UNLOCK |
978 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
979 PAGE_END_WRITEBACK);
980 btrfs_free_reserved_data_space_noquota(inode, start,
981 end - start + 1);
982 *nr_written = *nr_written +
983 (end - start + PAGE_SIZE) / PAGE_SIZE;
984 *page_started = 1;
985 goto out;
986 } else if (ret < 0) {
987 goto out_unlock;
988 }
989 }
990
991 BUG_ON(disk_num_bytes >
992 btrfs_super_total_bytes(fs_info->super_copy));
993
994 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
995 btrfs_drop_extent_cache(BTRFS_I(inode), start,
996 start + num_bytes - 1, 0);
997
998 while (disk_num_bytes > 0) {
999 cur_alloc_size = disk_num_bytes;
1000 ret = btrfs_reserve_extent(root, cur_alloc_size, cur_alloc_size,
1001 fs_info->sectorsize, 0, alloc_hint,
1002 &ins, 1, 1);
1003 if (ret < 0)
1004 goto out_unlock;
1005 cur_alloc_size = ins.offset;
1006 extent_reserved = true;
1007
1008 ram_size = ins.offset;
1009 em = create_io_em(inode, start, ins.offset, /* len */
1010 start, /* orig_start */
1011 ins.objectid, /* block_start */
1012 ins.offset, /* block_len */
1013 ins.offset, /* orig_block_len */
1014 ram_size, /* ram_bytes */
1015 BTRFS_COMPRESS_NONE, /* compress_type */
1016 BTRFS_ORDERED_REGULAR /* type */);
1017 if (IS_ERR(em))
1018 goto out_reserve;
1019 free_extent_map(em);
1020
1021 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
1022 ram_size, cur_alloc_size, 0);
1023 if (ret)
1024 goto out_drop_extent_cache;
1025
1026 if (root->root_key.objectid ==
1027 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1028 ret = btrfs_reloc_clone_csums(inode, start,
1029 cur_alloc_size);
1030 /*
1031 * Only drop cache here, and process as normal.
1032 *
1033 * We must not allow extent_clear_unlock_delalloc()
1034 * at out_unlock label to free meta of this ordered
1035 * extent, as its meta should be freed by
1036 * btrfs_finish_ordered_io().
1037 *
1038 * So we must continue until @start is increased to
1039 * skip current ordered extent.
1040 */
1041 if (ret)
1042 btrfs_drop_extent_cache(BTRFS_I(inode), start,
1043 start + ram_size - 1, 0);
1044 }
1045
1046 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
1047
1048 /* we're not doing compressed IO, don't unlock the first
1049 * page (which the caller expects to stay locked), don't
1050 * clear any dirty bits and don't set any writeback bits
1051 *
1052 * Do set the Private2 bit so we know this page was properly
1053 * setup for writepage
1054 */
1055 page_ops = unlock ? PAGE_UNLOCK : 0;
1056 page_ops |= PAGE_SET_PRIVATE2;
1057
1058 extent_clear_unlock_delalloc(inode, start,
1059 start + ram_size - 1,
1060 delalloc_end, locked_page,
1061 EXTENT_LOCKED | EXTENT_DELALLOC,
1062 page_ops);
1063 if (disk_num_bytes < cur_alloc_size)
1064 disk_num_bytes = 0;
1065 else
1066 disk_num_bytes -= cur_alloc_size;
1067 num_bytes -= cur_alloc_size;
1068 alloc_hint = ins.objectid + ins.offset;
1069 start += cur_alloc_size;
1070 extent_reserved = false;
1071
1072 /*
1073 * btrfs_reloc_clone_csums() error, since start is increased
1074 * extent_clear_unlock_delalloc() at out_unlock label won't
1075 * free metadata of current ordered extent, we're OK to exit.
1076 */
1077 if (ret)
1078 goto out_unlock;
1079 }
1080 out:
1081 return ret;
1082
1083 out_drop_extent_cache:
1084 btrfs_drop_extent_cache(BTRFS_I(inode), start, start + ram_size - 1, 0);
1085 out_reserve:
1086 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
1087 btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
1088 out_unlock:
1089 clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
1090 EXTENT_DEFRAG | EXTENT_CLEAR_META_RESV;
1091 page_ops = PAGE_UNLOCK | PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
1092 PAGE_END_WRITEBACK;
1093 /*
1094 * If we reserved an extent for our delalloc range (or a subrange) and
1095 * failed to create the respective ordered extent, then it means that
1096 * when we reserved the extent we decremented the extent's size from
1097 * the data space_info's bytes_may_use counter and incremented the
1098 * space_info's bytes_reserved counter by the same amount. We must make
1099 * sure extent_clear_unlock_delalloc() does not try to decrement again
1100 * the data space_info's bytes_may_use counter, therefore we do not pass
1101 * it the flag EXTENT_CLEAR_DATA_RESV.
1102 */
1103 if (extent_reserved) {
1104 extent_clear_unlock_delalloc(inode, start,
1105 start + cur_alloc_size,
1106 start + cur_alloc_size,
1107 locked_page,
1108 clear_bits,
1109 page_ops);
1110 start += cur_alloc_size;
1111 if (start >= end)
1112 goto out;
1113 }
1114 extent_clear_unlock_delalloc(inode, start, end, delalloc_end,
1115 locked_page,
1116 clear_bits | EXTENT_CLEAR_DATA_RESV,
1117 page_ops);
1118 goto out;
1119 }
1120
1121 /*
1122 * work queue call back to started compression on a file and pages
1123 */
1124 static noinline void async_cow_start(struct btrfs_work *work)
1125 {
1126 struct async_cow *async_cow;
1127 int num_added = 0;
1128 async_cow = container_of(work, struct async_cow, work);
1129
1130 compress_file_range(async_cow->inode, async_cow->locked_page,
1131 async_cow->start, async_cow->end, async_cow,
1132 &num_added);
1133 if (num_added == 0) {
1134 btrfs_add_delayed_iput(async_cow->inode);
1135 async_cow->inode = NULL;
1136 }
1137 }
1138
1139 /*
1140 * work queue call back to submit previously compressed pages
1141 */
1142 static noinline void async_cow_submit(struct btrfs_work *work)
1143 {
1144 struct btrfs_fs_info *fs_info;
1145 struct async_cow *async_cow;
1146 struct btrfs_root *root;
1147 unsigned long nr_pages;
1148
1149 async_cow = container_of(work, struct async_cow, work);
1150
1151 root = async_cow->root;
1152 fs_info = root->fs_info;
1153 nr_pages = (async_cow->end - async_cow->start + PAGE_SIZE) >>
1154 PAGE_SHIFT;
1155
1156 /*
1157 * atomic_sub_return implies a barrier for waitqueue_active
1158 */
1159 if (atomic_sub_return(nr_pages, &fs_info->async_delalloc_pages) <
1160 5 * SZ_1M &&
1161 waitqueue_active(&fs_info->async_submit_wait))
1162 wake_up(&fs_info->async_submit_wait);
1163
1164 if (async_cow->inode)
1165 submit_compressed_extents(async_cow->inode, async_cow);
1166 }
1167
1168 static noinline void async_cow_free(struct btrfs_work *work)
1169 {
1170 struct async_cow *async_cow;
1171 async_cow = container_of(work, struct async_cow, work);
1172 if (async_cow->inode)
1173 btrfs_add_delayed_iput(async_cow->inode);
1174 kfree(async_cow);
1175 }
1176
1177 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1178 u64 start, u64 end, int *page_started,
1179 unsigned long *nr_written)
1180 {
1181 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1182 struct async_cow *async_cow;
1183 struct btrfs_root *root = BTRFS_I(inode)->root;
1184 unsigned long nr_pages;
1185 u64 cur_end;
1186
1187 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1188 1, 0, NULL, GFP_NOFS);
1189 while (start < end) {
1190 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1191 BUG_ON(!async_cow); /* -ENOMEM */
1192 async_cow->inode = igrab(inode);
1193 async_cow->root = root;
1194 async_cow->locked_page = locked_page;
1195 async_cow->start = start;
1196
1197 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
1198 !btrfs_test_opt(fs_info, FORCE_COMPRESS))
1199 cur_end = end;
1200 else
1201 cur_end = min(end, start + SZ_512K - 1);
1202
1203 async_cow->end = cur_end;
1204 INIT_LIST_HEAD(&async_cow->extents);
1205
1206 btrfs_init_work(&async_cow->work,
1207 btrfs_delalloc_helper,
1208 async_cow_start, async_cow_submit,
1209 async_cow_free);
1210
1211 nr_pages = (cur_end - start + PAGE_SIZE) >>
1212 PAGE_SHIFT;
1213 atomic_add(nr_pages, &fs_info->async_delalloc_pages);
1214
1215 btrfs_queue_work(fs_info->delalloc_workers, &async_cow->work);
1216
1217 while (atomic_read(&fs_info->async_submit_draining) &&
1218 atomic_read(&fs_info->async_delalloc_pages)) {
1219 wait_event(fs_info->async_submit_wait,
1220 (atomic_read(&fs_info->async_delalloc_pages) ==
1221 0));
1222 }
1223
1224 *nr_written += nr_pages;
1225 start = cur_end + 1;
1226 }
1227 *page_started = 1;
1228 return 0;
1229 }
1230
1231 static noinline int csum_exist_in_range(struct btrfs_fs_info *fs_info,
1232 u64 bytenr, u64 num_bytes)
1233 {
1234 int ret;
1235 struct btrfs_ordered_sum *sums;
1236 LIST_HEAD(list);
1237
1238 ret = btrfs_lookup_csums_range(fs_info->csum_root, bytenr,
1239 bytenr + num_bytes - 1, &list, 0);
1240 if (ret == 0 && list_empty(&list))
1241 return 0;
1242
1243 while (!list_empty(&list)) {
1244 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1245 list_del(&sums->list);
1246 kfree(sums);
1247 }
1248 return 1;
1249 }
1250
1251 /*
1252 * when nowcow writeback call back. This checks for snapshots or COW copies
1253 * of the extents that exist in the file, and COWs the file as required.
1254 *
1255 * If no cow copies or snapshots exist, we write directly to the existing
1256 * blocks on disk
1257 */
1258 static noinline int run_delalloc_nocow(struct inode *inode,
1259 struct page *locked_page,
1260 u64 start, u64 end, int *page_started, int force,
1261 unsigned long *nr_written)
1262 {
1263 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1264 struct btrfs_root *root = BTRFS_I(inode)->root;
1265 struct extent_buffer *leaf;
1266 struct btrfs_path *path;
1267 struct btrfs_file_extent_item *fi;
1268 struct btrfs_key found_key;
1269 struct extent_map *em;
1270 u64 cow_start;
1271 u64 cur_offset;
1272 u64 extent_end;
1273 u64 extent_offset;
1274 u64 disk_bytenr;
1275 u64 num_bytes;
1276 u64 disk_num_bytes;
1277 u64 ram_bytes;
1278 int extent_type;
1279 int ret, err;
1280 int type;
1281 int nocow;
1282 int check_prev = 1;
1283 bool nolock;
1284 u64 ino = btrfs_ino(BTRFS_I(inode));
1285
1286 path = btrfs_alloc_path();
1287 if (!path) {
1288 extent_clear_unlock_delalloc(inode, start, end, end,
1289 locked_page,
1290 EXTENT_LOCKED | EXTENT_DELALLOC |
1291 EXTENT_DO_ACCOUNTING |
1292 EXTENT_DEFRAG, PAGE_UNLOCK |
1293 PAGE_CLEAR_DIRTY |
1294 PAGE_SET_WRITEBACK |
1295 PAGE_END_WRITEBACK);
1296 return -ENOMEM;
1297 }
1298
1299 nolock = btrfs_is_free_space_inode(BTRFS_I(inode));
1300
1301 cow_start = (u64)-1;
1302 cur_offset = start;
1303 while (1) {
1304 ret = btrfs_lookup_file_extent(NULL, root, path, ino,
1305 cur_offset, 0);
1306 if (ret < 0)
1307 goto error;
1308 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1309 leaf = path->nodes[0];
1310 btrfs_item_key_to_cpu(leaf, &found_key,
1311 path->slots[0] - 1);
1312 if (found_key.objectid == ino &&
1313 found_key.type == BTRFS_EXTENT_DATA_KEY)
1314 path->slots[0]--;
1315 }
1316 check_prev = 0;
1317 next_slot:
1318 leaf = path->nodes[0];
1319 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1320 ret = btrfs_next_leaf(root, path);
1321 if (ret < 0)
1322 goto error;
1323 if (ret > 0)
1324 break;
1325 leaf = path->nodes[0];
1326 }
1327
1328 nocow = 0;
1329 disk_bytenr = 0;
1330 num_bytes = 0;
1331 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1332
1333 if (found_key.objectid > ino)
1334 break;
1335 if (WARN_ON_ONCE(found_key.objectid < ino) ||
1336 found_key.type < BTRFS_EXTENT_DATA_KEY) {
1337 path->slots[0]++;
1338 goto next_slot;
1339 }
1340 if (found_key.type > BTRFS_EXTENT_DATA_KEY ||
1341 found_key.offset > end)
1342 break;
1343
1344 if (found_key.offset > cur_offset) {
1345 extent_end = found_key.offset;
1346 extent_type = 0;
1347 goto out_check;
1348 }
1349
1350 fi = btrfs_item_ptr(leaf, path->slots[0],
1351 struct btrfs_file_extent_item);
1352 extent_type = btrfs_file_extent_type(leaf, fi);
1353
1354 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1355 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1356 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1357 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1358 extent_offset = btrfs_file_extent_offset(leaf, fi);
1359 extent_end = found_key.offset +
1360 btrfs_file_extent_num_bytes(leaf, fi);
1361 disk_num_bytes =
1362 btrfs_file_extent_disk_num_bytes(leaf, fi);
1363 if (extent_end <= start) {
1364 path->slots[0]++;
1365 goto next_slot;
1366 }
1367 if (disk_bytenr == 0)
1368 goto out_check;
1369 if (btrfs_file_extent_compression(leaf, fi) ||
1370 btrfs_file_extent_encryption(leaf, fi) ||
1371 btrfs_file_extent_other_encoding(leaf, fi))
1372 goto out_check;
1373 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1374 goto out_check;
1375 if (btrfs_extent_readonly(fs_info, disk_bytenr))
1376 goto out_check;
1377 if (btrfs_cross_ref_exist(root, ino,
1378 found_key.offset -
1379 extent_offset, disk_bytenr))
1380 goto out_check;
1381 disk_bytenr += extent_offset;
1382 disk_bytenr += cur_offset - found_key.offset;
1383 num_bytes = min(end + 1, extent_end) - cur_offset;
1384 /*
1385 * if there are pending snapshots for this root,
1386 * we fall into common COW way.
1387 */
1388 if (!nolock) {
1389 err = btrfs_start_write_no_snapshotting(root);
1390 if (!err)
1391 goto out_check;
1392 }
1393 /*
1394 * force cow if csum exists in the range.
1395 * this ensure that csum for a given extent are
1396 * either valid or do not exist.
1397 */
1398 if (csum_exist_in_range(fs_info, disk_bytenr,
1399 num_bytes)) {
1400 if (!nolock)
1401 btrfs_end_write_no_snapshotting(root);
1402 goto out_check;
1403 }
1404 if (!btrfs_inc_nocow_writers(fs_info, disk_bytenr)) {
1405 if (!nolock)
1406 btrfs_end_write_no_snapshotting(root);
1407 goto out_check;
1408 }
1409 nocow = 1;
1410 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1411 extent_end = found_key.offset +
1412 btrfs_file_extent_inline_len(leaf,
1413 path->slots[0], fi);
1414 extent_end = ALIGN(extent_end,
1415 fs_info->sectorsize);
1416 } else {
1417 BUG_ON(1);
1418 }
1419 out_check:
1420 if (extent_end <= start) {
1421 path->slots[0]++;
1422 if (!nolock && nocow)
1423 btrfs_end_write_no_snapshotting(root);
1424 if (nocow)
1425 btrfs_dec_nocow_writers(fs_info, disk_bytenr);
1426 goto next_slot;
1427 }
1428 if (!nocow) {
1429 if (cow_start == (u64)-1)
1430 cow_start = cur_offset;
1431 cur_offset = extent_end;
1432 if (cur_offset > end)
1433 break;
1434 path->slots[0]++;
1435 goto next_slot;
1436 }
1437
1438 btrfs_release_path(path);
1439 if (cow_start != (u64)-1) {
1440 ret = cow_file_range(inode, locked_page,
1441 cow_start, found_key.offset - 1,
1442 end, page_started, nr_written, 1,
1443 NULL);
1444 if (ret) {
1445 if (!nolock && nocow)
1446 btrfs_end_write_no_snapshotting(root);
1447 if (nocow)
1448 btrfs_dec_nocow_writers(fs_info,
1449 disk_bytenr);
1450 goto error;
1451 }
1452 cow_start = (u64)-1;
1453 }
1454
1455 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1456 u64 orig_start = found_key.offset - extent_offset;
1457
1458 em = create_io_em(inode, cur_offset, num_bytes,
1459 orig_start,
1460 disk_bytenr, /* block_start */
1461 num_bytes, /* block_len */
1462 disk_num_bytes, /* orig_block_len */
1463 ram_bytes, BTRFS_COMPRESS_NONE,
1464 BTRFS_ORDERED_PREALLOC);
1465 if (IS_ERR(em)) {
1466 if (!nolock && nocow)
1467 btrfs_end_write_no_snapshotting(root);
1468 if (nocow)
1469 btrfs_dec_nocow_writers(fs_info,
1470 disk_bytenr);
1471 ret = PTR_ERR(em);
1472 goto error;
1473 }
1474 free_extent_map(em);
1475 }
1476
1477 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1478 type = BTRFS_ORDERED_PREALLOC;
1479 } else {
1480 type = BTRFS_ORDERED_NOCOW;
1481 }
1482
1483 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1484 num_bytes, num_bytes, type);
1485 if (nocow)
1486 btrfs_dec_nocow_writers(fs_info, disk_bytenr);
1487 BUG_ON(ret); /* -ENOMEM */
1488
1489 if (root->root_key.objectid ==
1490 BTRFS_DATA_RELOC_TREE_OBJECTID)
1491 /*
1492 * Error handled later, as we must prevent
1493 * extent_clear_unlock_delalloc() in error handler
1494 * from freeing metadata of created ordered extent.
1495 */
1496 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1497 num_bytes);
1498
1499 extent_clear_unlock_delalloc(inode, cur_offset,
1500 cur_offset + num_bytes - 1, end,
1501 locked_page, EXTENT_LOCKED |
1502 EXTENT_DELALLOC |
1503 EXTENT_CLEAR_DATA_RESV,
1504 PAGE_UNLOCK | PAGE_SET_PRIVATE2);
1505
1506 if (!nolock && nocow)
1507 btrfs_end_write_no_snapshotting(root);
1508 cur_offset = extent_end;
1509
1510 /*
1511 * btrfs_reloc_clone_csums() error, now we're OK to call error
1512 * handler, as metadata for created ordered extent will only
1513 * be freed by btrfs_finish_ordered_io().
1514 */
1515 if (ret)
1516 goto error;
1517 if (cur_offset > end)
1518 break;
1519 }
1520 btrfs_release_path(path);
1521
1522 if (cur_offset <= end && cow_start == (u64)-1) {
1523 cow_start = cur_offset;
1524 cur_offset = end;
1525 }
1526
1527 if (cow_start != (u64)-1) {
1528 ret = cow_file_range(inode, locked_page, cow_start, end, end,
1529 page_started, nr_written, 1, NULL);
1530 if (ret)
1531 goto error;
1532 }
1533
1534 error:
1535 if (ret && cur_offset < end)
1536 extent_clear_unlock_delalloc(inode, cur_offset, end, end,
1537 locked_page, EXTENT_LOCKED |
1538 EXTENT_DELALLOC | EXTENT_DEFRAG |
1539 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1540 PAGE_CLEAR_DIRTY |
1541 PAGE_SET_WRITEBACK |
1542 PAGE_END_WRITEBACK);
1543 btrfs_free_path(path);
1544 return ret;
1545 }
1546
1547 static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
1548 {
1549
1550 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
1551 !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC))
1552 return 0;
1553
1554 /*
1555 * @defrag_bytes is a hint value, no spinlock held here,
1556 * if is not zero, it means the file is defragging.
1557 * Force cow if given extent needs to be defragged.
1558 */
1559 if (BTRFS_I(inode)->defrag_bytes &&
1560 test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
1561 EXTENT_DEFRAG, 0, NULL))
1562 return 1;
1563
1564 return 0;
1565 }
1566
1567 /*
1568 * extent_io.c call back to do delayed allocation processing
1569 */
1570 static int run_delalloc_range(void *private_data, struct page *locked_page,
1571 u64 start, u64 end, int *page_started,
1572 unsigned long *nr_written)
1573 {
1574 struct inode *inode = private_data;
1575 int ret;
1576 int force_cow = need_force_cow(inode, start, end);
1577
1578 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
1579 ret = run_delalloc_nocow(inode, locked_page, start, end,
1580 page_started, 1, nr_written);
1581 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
1582 ret = run_delalloc_nocow(inode, locked_page, start, end,
1583 page_started, 0, nr_written);
1584 } else if (!inode_need_compress(inode, start, end)) {
1585 ret = cow_file_range(inode, locked_page, start, end, end,
1586 page_started, nr_written, 1, NULL);
1587 } else {
1588 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1589 &BTRFS_I(inode)->runtime_flags);
1590 ret = cow_file_range_async(inode, locked_page, start, end,
1591 page_started, nr_written);
1592 }
1593 if (ret)
1594 btrfs_cleanup_ordered_extents(inode, start, end - start + 1);
1595 return ret;
1596 }
1597
1598 static void btrfs_split_extent_hook(void *private_data,
1599 struct extent_state *orig, u64 split)
1600 {
1601 struct inode *inode = private_data;
1602 u64 size;
1603
1604 /* not delalloc, ignore it */
1605 if (!(orig->state & EXTENT_DELALLOC))
1606 return;
1607
1608 size = orig->end - orig->start + 1;
1609 if (size > BTRFS_MAX_EXTENT_SIZE) {
1610 u32 num_extents;
1611 u64 new_size;
1612
1613 /*
1614 * See the explanation in btrfs_merge_extent_hook, the same
1615 * applies here, just in reverse.
1616 */
1617 new_size = orig->end - split + 1;
1618 num_extents = count_max_extents(new_size);
1619 new_size = split - orig->start;
1620 num_extents += count_max_extents(new_size);
1621 if (count_max_extents(size) >= num_extents)
1622 return;
1623 }
1624
1625 spin_lock(&BTRFS_I(inode)->lock);
1626 BTRFS_I(inode)->outstanding_extents++;
1627 spin_unlock(&BTRFS_I(inode)->lock);
1628 }
1629
1630 /*
1631 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1632 * extents so we can keep track of new extents that are just merged onto old
1633 * extents, such as when we are doing sequential writes, so we can properly
1634 * account for the metadata space we'll need.
1635 */
1636 static void btrfs_merge_extent_hook(void *private_data,
1637 struct extent_state *new,
1638 struct extent_state *other)
1639 {
1640 struct inode *inode = private_data;
1641 u64 new_size, old_size;
1642 u32 num_extents;
1643
1644 /* not delalloc, ignore it */
1645 if (!(other->state & EXTENT_DELALLOC))
1646 return;
1647
1648 if (new->start > other->start)
1649 new_size = new->end - other->start + 1;
1650 else
1651 new_size = other->end - new->start + 1;
1652
1653 /* we're not bigger than the max, unreserve the space and go */
1654 if (new_size <= BTRFS_MAX_EXTENT_SIZE) {
1655 spin_lock(&BTRFS_I(inode)->lock);
1656 BTRFS_I(inode)->outstanding_extents--;
1657 spin_unlock(&BTRFS_I(inode)->lock);
1658 return;
1659 }
1660
1661 /*
1662 * We have to add up either side to figure out how many extents were
1663 * accounted for before we merged into one big extent. If the number of
1664 * extents we accounted for is <= the amount we need for the new range
1665 * then we can return, otherwise drop. Think of it like this
1666 *
1667 * [ 4k][MAX_SIZE]
1668 *
1669 * So we've grown the extent by a MAX_SIZE extent, this would mean we
1670 * need 2 outstanding extents, on one side we have 1 and the other side
1671 * we have 1 so they are == and we can return. But in this case
1672 *
1673 * [MAX_SIZE+4k][MAX_SIZE+4k]
1674 *
1675 * Each range on their own accounts for 2 extents, but merged together
1676 * they are only 3 extents worth of accounting, so we need to drop in
1677 * this case.
1678 */
1679 old_size = other->end - other->start + 1;
1680 num_extents = count_max_extents(old_size);
1681 old_size = new->end - new->start + 1;
1682 num_extents += count_max_extents(old_size);
1683 if (count_max_extents(new_size) >= num_extents)
1684 return;
1685
1686 spin_lock(&BTRFS_I(inode)->lock);
1687 BTRFS_I(inode)->outstanding_extents--;
1688 spin_unlock(&BTRFS_I(inode)->lock);
1689 }
1690
1691 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1692 struct inode *inode)
1693 {
1694 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1695
1696 spin_lock(&root->delalloc_lock);
1697 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1698 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1699 &root->delalloc_inodes);
1700 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1701 &BTRFS_I(inode)->runtime_flags);
1702 root->nr_delalloc_inodes++;
1703 if (root->nr_delalloc_inodes == 1) {
1704 spin_lock(&fs_info->delalloc_root_lock);
1705 BUG_ON(!list_empty(&root->delalloc_root));
1706 list_add_tail(&root->delalloc_root,
1707 &fs_info->delalloc_roots);
1708 spin_unlock(&fs_info->delalloc_root_lock);
1709 }
1710 }
1711 spin_unlock(&root->delalloc_lock);
1712 }
1713
1714 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1715 struct btrfs_inode *inode)
1716 {
1717 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
1718
1719 spin_lock(&root->delalloc_lock);
1720 if (!list_empty(&inode->delalloc_inodes)) {
1721 list_del_init(&inode->delalloc_inodes);
1722 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1723 &inode->runtime_flags);
1724 root->nr_delalloc_inodes--;
1725 if (!root->nr_delalloc_inodes) {
1726 spin_lock(&fs_info->delalloc_root_lock);
1727 BUG_ON(list_empty(&root->delalloc_root));
1728 list_del_init(&root->delalloc_root);
1729 spin_unlock(&fs_info->delalloc_root_lock);
1730 }
1731 }
1732 spin_unlock(&root->delalloc_lock);
1733 }
1734
1735 /*
1736 * extent_io.c set_bit_hook, used to track delayed allocation
1737 * bytes in this file, and to maintain the list of inodes that
1738 * have pending delalloc work to be done.
1739 */
1740 static void btrfs_set_bit_hook(void *private_data,
1741 struct extent_state *state, unsigned *bits)
1742 {
1743 struct inode *inode = private_data;
1744
1745 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1746
1747 if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
1748 WARN_ON(1);
1749 /*
1750 * set_bit and clear bit hooks normally require _irqsave/restore
1751 * but in this case, we are only testing for the DELALLOC
1752 * bit, which is only set or cleared with irqs on
1753 */
1754 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1755 struct btrfs_root *root = BTRFS_I(inode)->root;
1756 u64 len = state->end + 1 - state->start;
1757 bool do_list = !btrfs_is_free_space_inode(BTRFS_I(inode));
1758
1759 if (*bits & EXTENT_FIRST_DELALLOC) {
1760 *bits &= ~EXTENT_FIRST_DELALLOC;
1761 } else {
1762 spin_lock(&BTRFS_I(inode)->lock);
1763 BTRFS_I(inode)->outstanding_extents++;
1764 spin_unlock(&BTRFS_I(inode)->lock);
1765 }
1766
1767 /* For sanity tests */
1768 if (btrfs_is_testing(fs_info))
1769 return;
1770
1771 percpu_counter_add_batch(&fs_info->delalloc_bytes, len,
1772 fs_info->delalloc_batch);
1773 spin_lock(&BTRFS_I(inode)->lock);
1774 BTRFS_I(inode)->delalloc_bytes += len;
1775 if (*bits & EXTENT_DEFRAG)
1776 BTRFS_I(inode)->defrag_bytes += len;
1777 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1778 &BTRFS_I(inode)->runtime_flags))
1779 btrfs_add_delalloc_inodes(root, inode);
1780 spin_unlock(&BTRFS_I(inode)->lock);
1781 }
1782
1783 if (!(state->state & EXTENT_DELALLOC_NEW) &&
1784 (*bits & EXTENT_DELALLOC_NEW)) {
1785 spin_lock(&BTRFS_I(inode)->lock);
1786 BTRFS_I(inode)->new_delalloc_bytes += state->end + 1 -
1787 state->start;
1788 spin_unlock(&BTRFS_I(inode)->lock);
1789 }
1790 }
1791
1792 /*
1793 * extent_io.c clear_bit_hook, see set_bit_hook for why
1794 */
1795 static void btrfs_clear_bit_hook(void *private_data,
1796 struct extent_state *state,
1797 unsigned *bits)
1798 {
1799 struct btrfs_inode *inode = BTRFS_I((struct inode *)private_data);
1800 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
1801 u64 len = state->end + 1 - state->start;
1802 u32 num_extents = count_max_extents(len);
1803
1804 if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG)) {
1805 spin_lock(&inode->lock);
1806 inode->defrag_bytes -= len;
1807 spin_unlock(&inode->lock);
1808 }
1809
1810 /*
1811 * set_bit and clear bit hooks normally require _irqsave/restore
1812 * but in this case, we are only testing for the DELALLOC
1813 * bit, which is only set or cleared with irqs on
1814 */
1815 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1816 struct btrfs_root *root = inode->root;
1817 bool do_list = !btrfs_is_free_space_inode(inode);
1818
1819 if (*bits & EXTENT_FIRST_DELALLOC) {
1820 *bits &= ~EXTENT_FIRST_DELALLOC;
1821 } else if (!(*bits & EXTENT_CLEAR_META_RESV)) {
1822 spin_lock(&inode->lock);
1823 inode->outstanding_extents -= num_extents;
1824 spin_unlock(&inode->lock);
1825 }
1826
1827 /*
1828 * We don't reserve metadata space for space cache inodes so we
1829 * don't need to call dellalloc_release_metadata if there is an
1830 * error.
1831 */
1832 if (*bits & EXTENT_CLEAR_META_RESV &&
1833 root != fs_info->tree_root)
1834 btrfs_delalloc_release_metadata(inode, len);
1835
1836 /* For sanity tests. */
1837 if (btrfs_is_testing(fs_info))
1838 return;
1839
1840 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID &&
1841 do_list && !(state->state & EXTENT_NORESERVE) &&
1842 (*bits & EXTENT_CLEAR_DATA_RESV))
1843 btrfs_free_reserved_data_space_noquota(
1844 &inode->vfs_inode,
1845 state->start, len);
1846
1847 percpu_counter_add_batch(&fs_info->delalloc_bytes, -len,
1848 fs_info->delalloc_batch);
1849 spin_lock(&inode->lock);
1850 inode->delalloc_bytes -= len;
1851 if (do_list && inode->delalloc_bytes == 0 &&
1852 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1853 &inode->runtime_flags))
1854 btrfs_del_delalloc_inode(root, inode);
1855 spin_unlock(&inode->lock);
1856 }
1857
1858 if ((state->state & EXTENT_DELALLOC_NEW) &&
1859 (*bits & EXTENT_DELALLOC_NEW)) {
1860 spin_lock(&inode->lock);
1861 ASSERT(inode->new_delalloc_bytes >= len);
1862 inode->new_delalloc_bytes -= len;
1863 spin_unlock(&inode->lock);
1864 }
1865 }
1866
1867 /*
1868 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1869 * we don't create bios that span stripes or chunks
1870 *
1871 * return 1 if page cannot be merged to bio
1872 * return 0 if page can be merged to bio
1873 * return error otherwise
1874 */
1875 int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
1876 size_t size, struct bio *bio,
1877 unsigned long bio_flags)
1878 {
1879 struct inode *inode = page->mapping->host;
1880 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1881 u64 logical = (u64)bio->bi_iter.bi_sector << 9;
1882 u64 length = 0;
1883 u64 map_length;
1884 int ret;
1885
1886 if (bio_flags & EXTENT_BIO_COMPRESSED)
1887 return 0;
1888
1889 length = bio->bi_iter.bi_size;
1890 map_length = length;
1891 ret = btrfs_map_block(fs_info, btrfs_op(bio), logical, &map_length,
1892 NULL, 0);
1893 if (ret < 0)
1894 return ret;
1895 if (map_length < length + size)
1896 return 1;
1897 return 0;
1898 }
1899
1900 /*
1901 * in order to insert checksums into the metadata in large chunks,
1902 * we wait until bio submission time. All the pages in the bio are
1903 * checksummed and sums are attached onto the ordered extent record.
1904 *
1905 * At IO completion time the cums attached on the ordered extent record
1906 * are inserted into the btree
1907 */
1908 static blk_status_t __btrfs_submit_bio_start(void *private_data, struct bio *bio,
1909 int mirror_num, unsigned long bio_flags,
1910 u64 bio_offset)
1911 {
1912 struct inode *inode = private_data;
1913 blk_status_t ret = 0;
1914
1915 ret = btrfs_csum_one_bio(inode, bio, 0, 0);
1916 BUG_ON(ret); /* -ENOMEM */
1917 return 0;
1918 }
1919
1920 /*
1921 * in order to insert checksums into the metadata in large chunks,
1922 * we wait until bio submission time. All the pages in the bio are
1923 * checksummed and sums are attached onto the ordered extent record.
1924 *
1925 * At IO completion time the cums attached on the ordered extent record
1926 * are inserted into the btree
1927 */
1928 static blk_status_t __btrfs_submit_bio_done(void *private_data, struct bio *bio,
1929 int mirror_num, unsigned long bio_flags,
1930 u64 bio_offset)
1931 {
1932 struct inode *inode = private_data;
1933 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1934 blk_status_t ret;
1935
1936 ret = btrfs_map_bio(fs_info, bio, mirror_num, 1);
1937 if (ret) {
1938 bio->bi_status = ret;
1939 bio_endio(bio);
1940 }
1941 return ret;
1942 }
1943
1944 /*
1945 * extent_io.c submission hook. This does the right thing for csum calculation
1946 * on write, or reading the csums from the tree before a read
1947 */
1948 static blk_status_t btrfs_submit_bio_hook(void *private_data, struct bio *bio,
1949 int mirror_num, unsigned long bio_flags,
1950 u64 bio_offset)
1951 {
1952 struct inode *inode = private_data;
1953 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1954 struct btrfs_root *root = BTRFS_I(inode)->root;
1955 enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA;
1956 blk_status_t ret = 0;
1957 int skip_sum;
1958 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1959
1960 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1961
1962 if (btrfs_is_free_space_inode(BTRFS_I(inode)))
1963 metadata = BTRFS_WQ_ENDIO_FREE_SPACE;
1964
1965 if (bio_op(bio) != REQ_OP_WRITE) {
1966 ret = btrfs_bio_wq_end_io(fs_info, bio, metadata);
1967 if (ret)
1968 goto out;
1969
1970 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1971 ret = btrfs_submit_compressed_read(inode, bio,
1972 mirror_num,
1973 bio_flags);
1974 goto out;
1975 } else if (!skip_sum) {
1976 ret = btrfs_lookup_bio_sums(inode, bio, NULL);
1977 if (ret)
1978 goto out;
1979 }
1980 goto mapit;
1981 } else if (async && !skip_sum) {
1982 /* csum items have already been cloned */
1983 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1984 goto mapit;
1985 /* we're doing a write, do the async checksumming */
1986 ret = btrfs_wq_submit_bio(fs_info, bio, mirror_num, bio_flags,
1987 bio_offset, inode,
1988 __btrfs_submit_bio_start,
1989 __btrfs_submit_bio_done);
1990 goto out;
1991 } else if (!skip_sum) {
1992 ret = btrfs_csum_one_bio(inode, bio, 0, 0);
1993 if (ret)
1994 goto out;
1995 }
1996
1997 mapit:
1998 ret = btrfs_map_bio(fs_info, bio, mirror_num, 0);
1999
2000 out:
2001 if (ret) {
2002 bio->bi_status = ret;
2003 bio_endio(bio);
2004 }
2005 return ret;
2006 }
2007
2008 /*
2009 * given a list of ordered sums record them in the inode. This happens
2010 * at IO completion time based on sums calculated at bio submission time.
2011 */
2012 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
2013 struct inode *inode, struct list_head *list)
2014 {
2015 struct btrfs_ordered_sum *sum;
2016
2017 list_for_each_entry(sum, list, list) {
2018 trans->adding_csums = 1;
2019 btrfs_csum_file_blocks(trans,
2020 BTRFS_I(inode)->root->fs_info->csum_root, sum);
2021 trans->adding_csums = 0;
2022 }
2023 return 0;
2024 }
2025
2026 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
2027 struct extent_state **cached_state, int dedupe)
2028 {
2029 WARN_ON((end & (PAGE_SIZE - 1)) == 0);
2030 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
2031 cached_state);
2032 }
2033
2034 /* see btrfs_writepage_start_hook for details on why this is required */
2035 struct btrfs_writepage_fixup {
2036 struct page *page;
2037 struct btrfs_work work;
2038 };
2039
2040 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
2041 {
2042 struct btrfs_writepage_fixup *fixup;
2043 struct btrfs_ordered_extent *ordered;
2044 struct extent_state *cached_state = NULL;
2045 struct extent_changeset *data_reserved = NULL;
2046 struct page *page;
2047 struct inode *inode;
2048 u64 page_start;
2049 u64 page_end;
2050 int ret;
2051
2052 fixup = container_of(work, struct btrfs_writepage_fixup, work);
2053 page = fixup->page;
2054 again:
2055 lock_page(page);
2056 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
2057 ClearPageChecked(page);
2058 goto out_page;
2059 }
2060
2061 inode = page->mapping->host;
2062 page_start = page_offset(page);
2063 page_end = page_offset(page) + PAGE_SIZE - 1;
2064
2065 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end,
2066 &cached_state);
2067
2068 /* already ordered? We're done */
2069 if (PagePrivate2(page))
2070 goto out;
2071
2072 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start,
2073 PAGE_SIZE);
2074 if (ordered) {
2075 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
2076 page_end, &cached_state, GFP_NOFS);
2077 unlock_page(page);
2078 btrfs_start_ordered_extent(inode, ordered, 1);
2079 btrfs_put_ordered_extent(ordered);
2080 goto again;
2081 }
2082
2083 ret = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start,
2084 PAGE_SIZE);
2085 if (ret) {
2086 mapping_set_error(page->mapping, ret);
2087 end_extent_writepage(page, ret, page_start, page_end);
2088 ClearPageChecked(page);
2089 goto out;
2090 }
2091
2092 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state,
2093 0);
2094 ClearPageChecked(page);
2095 set_page_dirty(page);
2096 out:
2097 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
2098 &cached_state, GFP_NOFS);
2099 out_page:
2100 unlock_page(page);
2101 put_page(page);
2102 kfree(fixup);
2103 extent_changeset_free(data_reserved);
2104 }
2105
2106 /*
2107 * There are a few paths in the higher layers of the kernel that directly
2108 * set the page dirty bit without asking the filesystem if it is a
2109 * good idea. This causes problems because we want to make sure COW
2110 * properly happens and the data=ordered rules are followed.
2111 *
2112 * In our case any range that doesn't have the ORDERED bit set
2113 * hasn't been properly setup for IO. We kick off an async process
2114 * to fix it up. The async helper will wait for ordered extents, set
2115 * the delalloc bit and make it safe to write the page.
2116 */
2117 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
2118 {
2119 struct inode *inode = page->mapping->host;
2120 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2121 struct btrfs_writepage_fixup *fixup;
2122
2123 /* this page is properly in the ordered list */
2124 if (TestClearPagePrivate2(page))
2125 return 0;
2126
2127 if (PageChecked(page))
2128 return -EAGAIN;
2129
2130 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
2131 if (!fixup)
2132 return -EAGAIN;
2133
2134 SetPageChecked(page);
2135 get_page(page);
2136 btrfs_init_work(&fixup->work, btrfs_fixup_helper,
2137 btrfs_writepage_fixup_worker, NULL, NULL);
2138 fixup->page = page;
2139 btrfs_queue_work(fs_info->fixup_workers, &fixup->work);
2140 return -EBUSY;
2141 }
2142
2143 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
2144 struct inode *inode, u64 file_pos,
2145 u64 disk_bytenr, u64 disk_num_bytes,
2146 u64 num_bytes, u64 ram_bytes,
2147 u8 compression, u8 encryption,
2148 u16 other_encoding, int extent_type)
2149 {
2150 struct btrfs_root *root = BTRFS_I(inode)->root;
2151 struct btrfs_file_extent_item *fi;
2152 struct btrfs_path *path;
2153 struct extent_buffer *leaf;
2154 struct btrfs_key ins;
2155 u64 qg_released;
2156 int extent_inserted = 0;
2157 int ret;
2158
2159 path = btrfs_alloc_path();
2160 if (!path)
2161 return -ENOMEM;
2162
2163 /*
2164 * we may be replacing one extent in the tree with another.
2165 * The new extent is pinned in the extent map, and we don't want
2166 * to drop it from the cache until it is completely in the btree.
2167 *
2168 * So, tell btrfs_drop_extents to leave this extent in the cache.
2169 * the caller is expected to unpin it and allow it to be merged
2170 * with the others.
2171 */
2172 ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
2173 file_pos + num_bytes, NULL, 0,
2174 1, sizeof(*fi), &extent_inserted);
2175 if (ret)
2176 goto out;
2177
2178 if (!extent_inserted) {
2179 ins.objectid = btrfs_ino(BTRFS_I(inode));
2180 ins.offset = file_pos;
2181 ins.type = BTRFS_EXTENT_DATA_KEY;
2182
2183 path->leave_spinning = 1;
2184 ret = btrfs_insert_empty_item(trans, root, path, &ins,
2185 sizeof(*fi));
2186 if (ret)
2187 goto out;
2188 }
2189 leaf = path->nodes[0];
2190 fi = btrfs_item_ptr(leaf, path->slots[0],
2191 struct btrfs_file_extent_item);
2192 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
2193 btrfs_set_file_extent_type(leaf, fi, extent_type);
2194 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
2195 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
2196 btrfs_set_file_extent_offset(leaf, fi, 0);
2197 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2198 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
2199 btrfs_set_file_extent_compression(leaf, fi, compression);
2200 btrfs_set_file_extent_encryption(leaf, fi, encryption);
2201 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
2202
2203 btrfs_mark_buffer_dirty(leaf);
2204 btrfs_release_path(path);
2205
2206 inode_add_bytes(inode, num_bytes);
2207
2208 ins.objectid = disk_bytenr;
2209 ins.offset = disk_num_bytes;
2210 ins.type = BTRFS_EXTENT_ITEM_KEY;
2211
2212 /*
2213 * Release the reserved range from inode dirty range map, as it is
2214 * already moved into delayed_ref_head
2215 */
2216 ret = btrfs_qgroup_release_data(inode, file_pos, ram_bytes);
2217 if (ret < 0)
2218 goto out;
2219 qg_released = ret;
2220 ret = btrfs_alloc_reserved_file_extent(trans, root->root_key.objectid,
2221 btrfs_ino(BTRFS_I(inode)), file_pos, qg_released, &ins);
2222 out:
2223 btrfs_free_path(path);
2224
2225 return ret;
2226 }
2227
2228 /* snapshot-aware defrag */
2229 struct sa_defrag_extent_backref {
2230 struct rb_node node;
2231 struct old_sa_defrag_extent *old;
2232 u64 root_id;
2233 u64 inum;
2234 u64 file_pos;
2235 u64 extent_offset;
2236 u64 num_bytes;
2237 u64 generation;
2238 };
2239
2240 struct old_sa_defrag_extent {
2241 struct list_head list;
2242 struct new_sa_defrag_extent *new;
2243
2244 u64 extent_offset;
2245 u64 bytenr;
2246 u64 offset;
2247 u64 len;
2248 int count;
2249 };
2250
2251 struct new_sa_defrag_extent {
2252 struct rb_root root;
2253 struct list_head head;
2254 struct btrfs_path *path;
2255 struct inode *inode;
2256 u64 file_pos;
2257 u64 len;
2258 u64 bytenr;
2259 u64 disk_len;
2260 u8 compress_type;
2261 };
2262
2263 static int backref_comp(struct sa_defrag_extent_backref *b1,
2264 struct sa_defrag_extent_backref *b2)
2265 {
2266 if (b1->root_id < b2->root_id)
2267 return -1;
2268 else if (b1->root_id > b2->root_id)
2269 return 1;
2270
2271 if (b1->inum < b2->inum)
2272 return -1;
2273 else if (b1->inum > b2->inum)
2274 return 1;
2275
2276 if (b1->file_pos < b2->file_pos)
2277 return -1;
2278 else if (b1->file_pos > b2->file_pos)
2279 return 1;
2280
2281 /*
2282 * [------------------------------] ===> (a range of space)
2283 * |<--->| |<---->| =============> (fs/file tree A)
2284 * |<---------------------------->| ===> (fs/file tree B)
2285 *
2286 * A range of space can refer to two file extents in one tree while
2287 * refer to only one file extent in another tree.
2288 *
2289 * So we may process a disk offset more than one time(two extents in A)
2290 * and locate at the same extent(one extent in B), then insert two same
2291 * backrefs(both refer to the extent in B).
2292 */
2293 return 0;
2294 }
2295
2296 static void backref_insert(struct rb_root *root,
2297 struct sa_defrag_extent_backref *backref)
2298 {
2299 struct rb_node **p = &root->rb_node;
2300 struct rb_node *parent = NULL;
2301 struct sa_defrag_extent_backref *entry;
2302 int ret;
2303
2304 while (*p) {
2305 parent = *p;
2306 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2307
2308 ret = backref_comp(backref, entry);
2309 if (ret < 0)
2310 p = &(*p)->rb_left;
2311 else
2312 p = &(*p)->rb_right;
2313 }
2314
2315 rb_link_node(&backref->node, parent, p);
2316 rb_insert_color(&backref->node, root);
2317 }
2318
2319 /*
2320 * Note the backref might has changed, and in this case we just return 0.
2321 */
2322 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2323 void *ctx)
2324 {
2325 struct btrfs_file_extent_item *extent;
2326 struct old_sa_defrag_extent *old = ctx;
2327 struct new_sa_defrag_extent *new = old->new;
2328 struct btrfs_path *path = new->path;
2329 struct btrfs_key key;
2330 struct btrfs_root *root;
2331 struct sa_defrag_extent_backref *backref;
2332 struct extent_buffer *leaf;
2333 struct inode *inode = new->inode;
2334 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2335 int slot;
2336 int ret;
2337 u64 extent_offset;
2338 u64 num_bytes;
2339
2340 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2341 inum == btrfs_ino(BTRFS_I(inode)))
2342 return 0;
2343
2344 key.objectid = root_id;
2345 key.type = BTRFS_ROOT_ITEM_KEY;
2346 key.offset = (u64)-1;
2347
2348 root = btrfs_read_fs_root_no_name(fs_info, &key);
2349 if (IS_ERR(root)) {
2350 if (PTR_ERR(root) == -ENOENT)
2351 return 0;
2352 WARN_ON(1);
2353 btrfs_debug(fs_info, "inum=%llu, offset=%llu, root_id=%llu",
2354 inum, offset, root_id);
2355 return PTR_ERR(root);
2356 }
2357
2358 key.objectid = inum;
2359 key.type = BTRFS_EXTENT_DATA_KEY;
2360 if (offset > (u64)-1 << 32)
2361 key.offset = 0;
2362 else
2363 key.offset = offset;
2364
2365 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2366 if (WARN_ON(ret < 0))
2367 return ret;
2368 ret = 0;
2369
2370 while (1) {
2371 cond_resched();
2372
2373 leaf = path->nodes[0];
2374 slot = path->slots[0];
2375
2376 if (slot >= btrfs_header_nritems(leaf)) {
2377 ret = btrfs_next_leaf(root, path);
2378 if (ret < 0) {
2379 goto out;
2380 } else if (ret > 0) {
2381 ret = 0;
2382 goto out;
2383 }
2384 continue;
2385 }
2386
2387 path->slots[0]++;
2388
2389 btrfs_item_key_to_cpu(leaf, &key, slot);
2390
2391 if (key.objectid > inum)
2392 goto out;
2393
2394 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2395 continue;
2396
2397 extent = btrfs_item_ptr(leaf, slot,
2398 struct btrfs_file_extent_item);
2399
2400 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2401 continue;
2402
2403 /*
2404 * 'offset' refers to the exact key.offset,
2405 * NOT the 'offset' field in btrfs_extent_data_ref, ie.
2406 * (key.offset - extent_offset).
2407 */
2408 if (key.offset != offset)
2409 continue;
2410
2411 extent_offset = btrfs_file_extent_offset(leaf, extent);
2412 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2413
2414 if (extent_offset >= old->extent_offset + old->offset +
2415 old->len || extent_offset + num_bytes <=
2416 old->extent_offset + old->offset)
2417 continue;
2418 break;
2419 }
2420
2421 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2422 if (!backref) {
2423 ret = -ENOENT;
2424 goto out;
2425 }
2426
2427 backref->root_id = root_id;
2428 backref->inum = inum;
2429 backref->file_pos = offset;
2430 backref->num_bytes = num_bytes;
2431 backref->extent_offset = extent_offset;
2432 backref->generation = btrfs_file_extent_generation(leaf, extent);
2433 backref->old = old;
2434 backref_insert(&new->root, backref);
2435 old->count++;
2436 out:
2437 btrfs_release_path(path);
2438 WARN_ON(ret);
2439 return ret;
2440 }
2441
2442 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2443 struct new_sa_defrag_extent *new)
2444 {
2445 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2446 struct old_sa_defrag_extent *old, *tmp;
2447 int ret;
2448
2449 new->path = path;
2450
2451 list_for_each_entry_safe(old, tmp, &new->head, list) {
2452 ret = iterate_inodes_from_logical(old->bytenr +
2453 old->extent_offset, fs_info,
2454 path, record_one_backref,
2455 old);
2456 if (ret < 0 && ret != -ENOENT)
2457 return false;
2458
2459 /* no backref to be processed for this extent */
2460 if (!old->count) {
2461 list_del(&old->list);
2462 kfree(old);
2463 }
2464 }
2465
2466 if (list_empty(&new->head))
2467 return false;
2468
2469 return true;
2470 }
2471
2472 static int relink_is_mergable(struct extent_buffer *leaf,
2473 struct btrfs_file_extent_item *fi,
2474 struct new_sa_defrag_extent *new)
2475 {
2476 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
2477 return 0;
2478
2479 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2480 return 0;
2481
2482 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
2483 return 0;
2484
2485 if (btrfs_file_extent_encryption(leaf, fi) ||
2486 btrfs_file_extent_other_encoding(leaf, fi))
2487 return 0;
2488
2489 return 1;
2490 }
2491
2492 /*
2493 * Note the backref might has changed, and in this case we just return 0.
2494 */
2495 static noinline int relink_extent_backref(struct btrfs_path *path,
2496 struct sa_defrag_extent_backref *prev,
2497 struct sa_defrag_extent_backref *backref)
2498 {
2499 struct btrfs_file_extent_item *extent;
2500 struct btrfs_file_extent_item *item;
2501 struct btrfs_ordered_extent *ordered;
2502 struct btrfs_trans_handle *trans;
2503 struct btrfs_root *root;
2504 struct btrfs_key key;
2505 struct extent_buffer *leaf;
2506 struct old_sa_defrag_extent *old = backref->old;
2507 struct new_sa_defrag_extent *new = old->new;
2508 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2509 struct inode *inode;
2510 struct extent_state *cached = NULL;
2511 int ret = 0;
2512 u64 start;
2513 u64 len;
2514 u64 lock_start;
2515 u64 lock_end;
2516 bool merge = false;
2517 int index;
2518
2519 if (prev && prev->root_id == backref->root_id &&
2520 prev->inum == backref->inum &&
2521 prev->file_pos + prev->num_bytes == backref->file_pos)
2522 merge = true;
2523
2524 /* step 1: get root */
2525 key.objectid = backref->root_id;
2526 key.type = BTRFS_ROOT_ITEM_KEY;
2527 key.offset = (u64)-1;
2528
2529 index = srcu_read_lock(&fs_info->subvol_srcu);
2530
2531 root = btrfs_read_fs_root_no_name(fs_info, &key);
2532 if (IS_ERR(root)) {
2533 srcu_read_unlock(&fs_info->subvol_srcu, index);
2534 if (PTR_ERR(root) == -ENOENT)
2535 return 0;
2536 return PTR_ERR(root);
2537 }
2538
2539 if (btrfs_root_readonly(root)) {
2540 srcu_read_unlock(&fs_info->subvol_srcu, index);
2541 return 0;
2542 }
2543
2544 /* step 2: get inode */
2545 key.objectid = backref->inum;
2546 key.type = BTRFS_INODE_ITEM_KEY;
2547 key.offset = 0;
2548
2549 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2550 if (IS_ERR(inode)) {
2551 srcu_read_unlock(&fs_info->subvol_srcu, index);
2552 return 0;
2553 }
2554
2555 srcu_read_unlock(&fs_info->subvol_srcu, index);
2556
2557 /* step 3: relink backref */
2558 lock_start = backref->file_pos;
2559 lock_end = backref->file_pos + backref->num_bytes - 1;
2560 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2561 &cached);
2562
2563 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2564 if (ordered) {
2565 btrfs_put_ordered_extent(ordered);
2566 goto out_unlock;
2567 }
2568
2569 trans = btrfs_join_transaction(root);
2570 if (IS_ERR(trans)) {
2571 ret = PTR_ERR(trans);
2572 goto out_unlock;
2573 }
2574
2575 key.objectid = backref->inum;
2576 key.type = BTRFS_EXTENT_DATA_KEY;
2577 key.offset = backref->file_pos;
2578
2579 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2580 if (ret < 0) {
2581 goto out_free_path;
2582 } else if (ret > 0) {
2583 ret = 0;
2584 goto out_free_path;
2585 }
2586
2587 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2588 struct btrfs_file_extent_item);
2589
2590 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2591 backref->generation)
2592 goto out_free_path;
2593
2594 btrfs_release_path(path);
2595
2596 start = backref->file_pos;
2597 if (backref->extent_offset < old->extent_offset + old->offset)
2598 start += old->extent_offset + old->offset -
2599 backref->extent_offset;
2600
2601 len = min(backref->extent_offset + backref->num_bytes,
2602 old->extent_offset + old->offset + old->len);
2603 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2604
2605 ret = btrfs_drop_extents(trans, root, inode, start,
2606 start + len, 1);
2607 if (ret)
2608 goto out_free_path;
2609 again:
2610 key.objectid = btrfs_ino(BTRFS_I(inode));
2611 key.type = BTRFS_EXTENT_DATA_KEY;
2612 key.offset = start;
2613
2614 path->leave_spinning = 1;
2615 if (merge) {
2616 struct btrfs_file_extent_item *fi;
2617 u64 extent_len;
2618 struct btrfs_key found_key;
2619
2620 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2621 if (ret < 0)
2622 goto out_free_path;
2623
2624 path->slots[0]--;
2625 leaf = path->nodes[0];
2626 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2627
2628 fi = btrfs_item_ptr(leaf, path->slots[0],
2629 struct btrfs_file_extent_item);
2630 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2631
2632 if (extent_len + found_key.offset == start &&
2633 relink_is_mergable(leaf, fi, new)) {
2634 btrfs_set_file_extent_num_bytes(leaf, fi,
2635 extent_len + len);
2636 btrfs_mark_buffer_dirty(leaf);
2637 inode_add_bytes(inode, len);
2638
2639 ret = 1;
2640 goto out_free_path;
2641 } else {
2642 merge = false;
2643 btrfs_release_path(path);
2644 goto again;
2645 }
2646 }
2647
2648 ret = btrfs_insert_empty_item(trans, root, path, &key,
2649 sizeof(*extent));
2650 if (ret) {
2651 btrfs_abort_transaction(trans, ret);
2652 goto out_free_path;
2653 }
2654
2655 leaf = path->nodes[0];
2656 item = btrfs_item_ptr(leaf, path->slots[0],
2657 struct btrfs_file_extent_item);
2658 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2659 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2660 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2661 btrfs_set_file_extent_num_bytes(leaf, item, len);
2662 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2663 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2664 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2665 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2666 btrfs_set_file_extent_encryption(leaf, item, 0);
2667 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2668
2669 btrfs_mark_buffer_dirty(leaf);
2670 inode_add_bytes(inode, len);
2671 btrfs_release_path(path);
2672
2673 ret = btrfs_inc_extent_ref(trans, fs_info, new->bytenr,
2674 new->disk_len, 0,
2675 backref->root_id, backref->inum,
2676 new->file_pos); /* start - extent_offset */
2677 if (ret) {
2678 btrfs_abort_transaction(trans, ret);
2679 goto out_free_path;
2680 }
2681
2682 ret = 1;
2683 out_free_path:
2684 btrfs_release_path(path);
2685 path->leave_spinning = 0;
2686 btrfs_end_transaction(trans);
2687 out_unlock:
2688 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2689 &cached, GFP_NOFS);
2690 iput(inode);
2691 return ret;
2692 }
2693
2694 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
2695 {
2696 struct old_sa_defrag_extent *old, *tmp;
2697
2698 if (!new)
2699 return;
2700
2701 list_for_each_entry_safe(old, tmp, &new->head, list) {
2702 kfree(old);
2703 }
2704 kfree(new);
2705 }
2706
2707 static void relink_file_extents(struct new_sa_defrag_extent *new)
2708 {
2709 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2710 struct btrfs_path *path;
2711 struct sa_defrag_extent_backref *backref;
2712 struct sa_defrag_extent_backref *prev = NULL;
2713 struct inode *inode;
2714 struct btrfs_root *root;
2715 struct rb_node *node;
2716 int ret;
2717
2718 inode = new->inode;
2719 root = BTRFS_I(inode)->root;
2720
2721 path = btrfs_alloc_path();
2722 if (!path)
2723 return;
2724
2725 if (!record_extent_backrefs(path, new)) {
2726 btrfs_free_path(path);
2727 goto out;
2728 }
2729 btrfs_release_path(path);
2730
2731 while (1) {
2732 node = rb_first(&new->root);
2733 if (!node)
2734 break;
2735 rb_erase(node, &new->root);
2736
2737 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2738
2739 ret = relink_extent_backref(path, prev, backref);
2740 WARN_ON(ret < 0);
2741
2742 kfree(prev);
2743
2744 if (ret == 1)
2745 prev = backref;
2746 else
2747 prev = NULL;
2748 cond_resched();
2749 }
2750 kfree(prev);
2751
2752 btrfs_free_path(path);
2753 out:
2754 free_sa_defrag_extent(new);
2755
2756 atomic_dec(&fs_info->defrag_running);
2757 wake_up(&fs_info->transaction_wait);
2758 }
2759
2760 static struct new_sa_defrag_extent *
2761 record_old_file_extents(struct inode *inode,
2762 struct btrfs_ordered_extent *ordered)
2763 {
2764 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2765 struct btrfs_root *root = BTRFS_I(inode)->root;
2766 struct btrfs_path *path;
2767 struct btrfs_key key;
2768 struct old_sa_defrag_extent *old;
2769 struct new_sa_defrag_extent *new;
2770 int ret;
2771
2772 new = kmalloc(sizeof(*new), GFP_NOFS);
2773 if (!new)
2774 return NULL;
2775
2776 new->inode = inode;
2777 new->file_pos = ordered->file_offset;
2778 new->len = ordered->len;
2779 new->bytenr = ordered->start;
2780 new->disk_len = ordered->disk_len;
2781 new->compress_type = ordered->compress_type;
2782 new->root = RB_ROOT;
2783 INIT_LIST_HEAD(&new->head);
2784
2785 path = btrfs_alloc_path();
2786 if (!path)
2787 goto out_kfree;
2788
2789 key.objectid = btrfs_ino(BTRFS_I(inode));
2790 key.type = BTRFS_EXTENT_DATA_KEY;
2791 key.offset = new->file_pos;
2792
2793 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2794 if (ret < 0)
2795 goto out_free_path;
2796 if (ret > 0 && path->slots[0] > 0)
2797 path->slots[0]--;
2798
2799 /* find out all the old extents for the file range */
2800 while (1) {
2801 struct btrfs_file_extent_item *extent;
2802 struct extent_buffer *l;
2803 int slot;
2804 u64 num_bytes;
2805 u64 offset;
2806 u64 end;
2807 u64 disk_bytenr;
2808 u64 extent_offset;
2809
2810 l = path->nodes[0];
2811 slot = path->slots[0];
2812
2813 if (slot >= btrfs_header_nritems(l)) {
2814 ret = btrfs_next_leaf(root, path);
2815 if (ret < 0)
2816 goto out_free_path;
2817 else if (ret > 0)
2818 break;
2819 continue;
2820 }
2821
2822 btrfs_item_key_to_cpu(l, &key, slot);
2823
2824 if (key.objectid != btrfs_ino(BTRFS_I(inode)))
2825 break;
2826 if (key.type != BTRFS_EXTENT_DATA_KEY)
2827 break;
2828 if (key.offset >= new->file_pos + new->len)
2829 break;
2830
2831 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2832
2833 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2834 if (key.offset + num_bytes < new->file_pos)
2835 goto next;
2836
2837 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2838 if (!disk_bytenr)
2839 goto next;
2840
2841 extent_offset = btrfs_file_extent_offset(l, extent);
2842
2843 old = kmalloc(sizeof(*old), GFP_NOFS);
2844 if (!old)
2845 goto out_free_path;
2846
2847 offset = max(new->file_pos, key.offset);
2848 end = min(new->file_pos + new->len, key.offset + num_bytes);
2849
2850 old->bytenr = disk_bytenr;
2851 old->extent_offset = extent_offset;
2852 old->offset = offset - key.offset;
2853 old->len = end - offset;
2854 old->new = new;
2855 old->count = 0;
2856 list_add_tail(&old->list, &new->head);
2857 next:
2858 path->slots[0]++;
2859 cond_resched();
2860 }
2861
2862 btrfs_free_path(path);
2863 atomic_inc(&fs_info->defrag_running);
2864
2865 return new;
2866
2867 out_free_path:
2868 btrfs_free_path(path);
2869 out_kfree:
2870 free_sa_defrag_extent(new);
2871 return NULL;
2872 }
2873
2874 static void btrfs_release_delalloc_bytes(struct btrfs_fs_info *fs_info,
2875 u64 start, u64 len)
2876 {
2877 struct btrfs_block_group_cache *cache;
2878
2879 cache = btrfs_lookup_block_group(fs_info, start);
2880 ASSERT(cache);
2881
2882 spin_lock(&cache->lock);
2883 cache->delalloc_bytes -= len;
2884 spin_unlock(&cache->lock);
2885
2886 btrfs_put_block_group(cache);
2887 }
2888
2889 /* as ordered data IO finishes, this gets called so we can finish
2890 * an ordered extent if the range of bytes in the file it covers are
2891 * fully written.
2892 */
2893 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2894 {
2895 struct inode *inode = ordered_extent->inode;
2896 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2897 struct btrfs_root *root = BTRFS_I(inode)->root;
2898 struct btrfs_trans_handle *trans = NULL;
2899 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2900 struct extent_state *cached_state = NULL;
2901 struct new_sa_defrag_extent *new = NULL;
2902 int compress_type = 0;
2903 int ret = 0;
2904 u64 logical_len = ordered_extent->len;
2905 bool nolock;
2906 bool truncated = false;
2907 bool range_locked = false;
2908 bool clear_new_delalloc_bytes = false;
2909
2910 if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
2911 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags) &&
2912 !test_bit(BTRFS_ORDERED_DIRECT, &ordered_extent->flags))
2913 clear_new_delalloc_bytes = true;
2914
2915 nolock = btrfs_is_free_space_inode(BTRFS_I(inode));
2916
2917 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2918 ret = -EIO;
2919 goto out;
2920 }
2921
2922 btrfs_free_io_failure_record(BTRFS_I(inode),
2923 ordered_extent->file_offset,
2924 ordered_extent->file_offset +
2925 ordered_extent->len - 1);
2926
2927 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
2928 truncated = true;
2929 logical_len = ordered_extent->truncated_len;
2930 /* Truncated the entire extent, don't bother adding */
2931 if (!logical_len)
2932 goto out;
2933 }
2934
2935 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2936 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2937
2938 /*
2939 * For mwrite(mmap + memset to write) case, we still reserve
2940 * space for NOCOW range.
2941 * As NOCOW won't cause a new delayed ref, just free the space
2942 */
2943 btrfs_qgroup_free_data(inode, NULL, ordered_extent->file_offset,
2944 ordered_extent->len);
2945 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2946 if (nolock)
2947 trans = btrfs_join_transaction_nolock(root);
2948 else
2949 trans = btrfs_join_transaction(root);
2950 if (IS_ERR(trans)) {
2951 ret = PTR_ERR(trans);
2952 trans = NULL;
2953 goto out;
2954 }
2955 trans->block_rsv = &fs_info->delalloc_block_rsv;
2956 ret = btrfs_update_inode_fallback(trans, root, inode);
2957 if (ret) /* -ENOMEM or corruption */
2958 btrfs_abort_transaction(trans, ret);
2959 goto out;
2960 }
2961
2962 range_locked = true;
2963 lock_extent_bits(io_tree, ordered_extent->file_offset,
2964 ordered_extent->file_offset + ordered_extent->len - 1,
2965 &cached_state);
2966
2967 ret = test_range_bit(io_tree, ordered_extent->file_offset,
2968 ordered_extent->file_offset + ordered_extent->len - 1,
2969 EXTENT_DEFRAG, 0, cached_state);
2970 if (ret) {
2971 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2972 if (0 && last_snapshot >= BTRFS_I(inode)->generation)
2973 /* the inode is shared */
2974 new = record_old_file_extents(inode, ordered_extent);
2975
2976 clear_extent_bit(io_tree, ordered_extent->file_offset,
2977 ordered_extent->file_offset + ordered_extent->len - 1,
2978 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
2979 }
2980
2981 if (nolock)
2982 trans = btrfs_join_transaction_nolock(root);
2983 else
2984 trans = btrfs_join_transaction(root);
2985 if (IS_ERR(trans)) {
2986 ret = PTR_ERR(trans);
2987 trans = NULL;
2988 goto out;
2989 }
2990
2991 trans->block_rsv = &fs_info->delalloc_block_rsv;
2992
2993 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
2994 compress_type = ordered_extent->compress_type;
2995 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
2996 BUG_ON(compress_type);
2997 ret = btrfs_mark_extent_written(trans, BTRFS_I(inode),
2998 ordered_extent->file_offset,
2999 ordered_extent->file_offset +
3000 logical_len);
3001 } else {
3002 BUG_ON(root == fs_info->tree_root);
3003 ret = insert_reserved_file_extent(trans, inode,
3004 ordered_extent->file_offset,
3005 ordered_extent->start,
3006 ordered_extent->disk_len,
3007 logical_len, logical_len,
3008 compress_type, 0, 0,
3009 BTRFS_FILE_EXTENT_REG);
3010 if (!ret)
3011 btrfs_release_delalloc_bytes(fs_info,
3012 ordered_extent->start,
3013 ordered_extent->disk_len);
3014 }
3015 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
3016 ordered_extent->file_offset, ordered_extent->len,
3017 trans->transid);
3018 if (ret < 0) {
3019 btrfs_abort_transaction(trans, ret);
3020 goto out;
3021 }
3022
3023 add_pending_csums(trans, inode, &ordered_extent->list);
3024
3025 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
3026 ret = btrfs_update_inode_fallback(trans, root, inode);
3027 if (ret) { /* -ENOMEM or corruption */
3028 btrfs_abort_transaction(trans, ret);
3029 goto out;
3030 }
3031 ret = 0;
3032 out:
3033 if (range_locked || clear_new_delalloc_bytes) {
3034 unsigned int clear_bits = 0;
3035
3036 if (range_locked)
3037 clear_bits |= EXTENT_LOCKED;
3038 if (clear_new_delalloc_bytes)
3039 clear_bits |= EXTENT_DELALLOC_NEW;
3040 clear_extent_bit(&BTRFS_I(inode)->io_tree,
3041 ordered_extent->file_offset,
3042 ordered_extent->file_offset +
3043 ordered_extent->len - 1,
3044 clear_bits,
3045 (clear_bits & EXTENT_LOCKED) ? 1 : 0,
3046 0, &cached_state, GFP_NOFS);
3047 }
3048
3049 if (root != fs_info->tree_root)
3050 btrfs_delalloc_release_metadata(BTRFS_I(inode),
3051 ordered_extent->len);
3052 if (trans)
3053 btrfs_end_transaction(trans);
3054
3055 if (ret || truncated) {
3056 u64 start, end;
3057
3058 if (truncated)
3059 start = ordered_extent->file_offset + logical_len;
3060 else
3061 start = ordered_extent->file_offset;
3062 end = ordered_extent->file_offset + ordered_extent->len - 1;
3063 clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS);
3064
3065 /* Drop the cache for the part of the extent we didn't write. */
3066 btrfs_drop_extent_cache(BTRFS_I(inode), start, end, 0);
3067
3068 /*
3069 * If the ordered extent had an IOERR or something else went
3070 * wrong we need to return the space for this ordered extent
3071 * back to the allocator. We only free the extent in the
3072 * truncated case if we didn't write out the extent at all.
3073 */
3074 if ((ret || !logical_len) &&
3075 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
3076 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
3077 btrfs_free_reserved_extent(fs_info,
3078 ordered_extent->start,
3079 ordered_extent->disk_len, 1);
3080 }
3081
3082
3083 /*
3084 * This needs to be done to make sure anybody waiting knows we are done
3085 * updating everything for this ordered extent.
3086 */
3087 btrfs_remove_ordered_extent(inode, ordered_extent);
3088
3089 /* for snapshot-aware defrag */
3090 if (new) {
3091 if (ret) {
3092 free_sa_defrag_extent(new);
3093 atomic_dec(&fs_info->defrag_running);
3094 } else {
3095 relink_file_extents(new);
3096 }
3097 }
3098
3099 /* once for us */
3100 btrfs_put_ordered_extent(ordered_extent);
3101 /* once for the tree */
3102 btrfs_put_ordered_extent(ordered_extent);
3103
3104 return ret;
3105 }
3106
3107 static void finish_ordered_fn(struct btrfs_work *work)
3108 {
3109 struct btrfs_ordered_extent *ordered_extent;
3110 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
3111 btrfs_finish_ordered_io(ordered_extent);
3112 }
3113
3114 static void btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
3115 struct extent_state *state, int uptodate)
3116 {
3117 struct inode *inode = page->mapping->host;
3118 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3119 struct btrfs_ordered_extent *ordered_extent = NULL;
3120 struct btrfs_workqueue *wq;
3121 btrfs_work_func_t func;
3122
3123 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
3124
3125 ClearPagePrivate2(page);
3126 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
3127 end - start + 1, uptodate))
3128 return;
3129
3130 if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
3131 wq = fs_info->endio_freespace_worker;
3132 func = btrfs_freespace_write_helper;
3133 } else {
3134 wq = fs_info->endio_write_workers;
3135 func = btrfs_endio_write_helper;
3136 }
3137
3138 btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL,
3139 NULL);
3140 btrfs_queue_work(wq, &ordered_extent->work);
3141 }
3142
3143 static int __readpage_endio_check(struct inode *inode,
3144 struct btrfs_io_bio *io_bio,
3145 int icsum, struct page *page,
3146 int pgoff, u64 start, size_t len)
3147 {
3148 char *kaddr;
3149 u32 csum_expected;
3150 u32 csum = ~(u32)0;
3151
3152 csum_expected = *(((u32 *)io_bio->csum) + icsum);
3153
3154 kaddr = kmap_atomic(page);
3155 csum = btrfs_csum_data(kaddr + pgoff, csum, len);
3156 btrfs_csum_final(csum, (u8 *)&csum);
3157 if (csum != csum_expected)
3158 goto zeroit;
3159
3160 kunmap_atomic(kaddr);
3161 return 0;
3162 zeroit:
3163 btrfs_print_data_csum_error(BTRFS_I(inode), start, csum, csum_expected,
3164 io_bio->mirror_num);
3165 memset(kaddr + pgoff, 1, len);
3166 flush_dcache_page(page);
3167 kunmap_atomic(kaddr);
3168 return -EIO;
3169 }
3170
3171 /*
3172 * when reads are done, we need to check csums to verify the data is correct
3173 * if there's a match, we allow the bio to finish. If not, the code in
3174 * extent_io.c will try to find good copies for us.
3175 */
3176 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
3177 u64 phy_offset, struct page *page,
3178 u64 start, u64 end, int mirror)
3179 {
3180 size_t offset = start - page_offset(page);
3181 struct inode *inode = page->mapping->host;
3182 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3183 struct btrfs_root *root = BTRFS_I(inode)->root;
3184
3185 if (PageChecked(page)) {
3186 ClearPageChecked(page);
3187 return 0;
3188 }
3189
3190 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
3191 return 0;
3192
3193 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
3194 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
3195 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM);
3196 return 0;
3197 }
3198
3199 phy_offset >>= inode->i_sb->s_blocksize_bits;
3200 return __readpage_endio_check(inode, io_bio, phy_offset, page, offset,
3201 start, (size_t)(end - start + 1));
3202 }
3203
3204 void btrfs_add_delayed_iput(struct inode *inode)
3205 {
3206 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3207 struct btrfs_inode *binode = BTRFS_I(inode);
3208
3209 if (atomic_add_unless(&inode->i_count, -1, 1))
3210 return;
3211
3212 spin_lock(&fs_info->delayed_iput_lock);
3213 if (binode->delayed_iput_count == 0) {
3214 ASSERT(list_empty(&binode->delayed_iput));
3215 list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs);
3216 } else {
3217 binode->delayed_iput_count++;
3218 }
3219 spin_unlock(&fs_info->delayed_iput_lock);
3220 }
3221
3222 void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info)
3223 {
3224
3225 spin_lock(&fs_info->delayed_iput_lock);
3226 while (!list_empty(&fs_info->delayed_iputs)) {
3227 struct btrfs_inode *inode;
3228
3229 inode = list_first_entry(&fs_info->delayed_iputs,
3230 struct btrfs_inode, delayed_iput);
3231 if (inode->delayed_iput_count) {
3232 inode->delayed_iput_count--;
3233 list_move_tail(&inode->delayed_iput,
3234 &fs_info->delayed_iputs);
3235 } else {
3236 list_del_init(&inode->delayed_iput);
3237 }
3238 spin_unlock(&fs_info->delayed_iput_lock);
3239 iput(&inode->vfs_inode);
3240 spin_lock(&fs_info->delayed_iput_lock);
3241 }
3242 spin_unlock(&fs_info->delayed_iput_lock);
3243 }
3244
3245 /*
3246 * This is called in transaction commit time. If there are no orphan
3247 * files in the subvolume, it removes orphan item and frees block_rsv
3248 * structure.
3249 */
3250 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
3251 struct btrfs_root *root)
3252 {
3253 struct btrfs_fs_info *fs_info = root->fs_info;
3254 struct btrfs_block_rsv *block_rsv;
3255 int ret;
3256
3257 if (atomic_read(&root->orphan_inodes) ||
3258 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
3259 return;
3260
3261 spin_lock(&root->orphan_lock);
3262 if (atomic_read(&root->orphan_inodes)) {
3263 spin_unlock(&root->orphan_lock);
3264 return;
3265 }
3266
3267 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
3268 spin_unlock(&root->orphan_lock);
3269 return;
3270 }
3271
3272 block_rsv = root->orphan_block_rsv;
3273 root->orphan_block_rsv = NULL;
3274 spin_unlock(&root->orphan_lock);
3275
3276 if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) &&
3277 btrfs_root_refs(&root->root_item) > 0) {
3278 ret = btrfs_del_orphan_item(trans, fs_info->tree_root,
3279 root->root_key.objectid);
3280 if (ret)
3281 btrfs_abort_transaction(trans, ret);
3282 else
3283 clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
3284 &root->state);
3285 }
3286
3287 if (block_rsv) {
3288 WARN_ON(block_rsv->size > 0);
3289 btrfs_free_block_rsv(fs_info, block_rsv);
3290 }
3291 }
3292
3293 /*
3294 * This creates an orphan entry for the given inode in case something goes
3295 * wrong in the middle of an unlink/truncate.
3296 *
3297 * NOTE: caller of this function should reserve 5 units of metadata for
3298 * this function.
3299 */
3300 int btrfs_orphan_add(struct btrfs_trans_handle *trans,
3301 struct btrfs_inode *inode)
3302 {
3303 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
3304 struct btrfs_root *root = inode->root;
3305 struct btrfs_block_rsv *block_rsv = NULL;
3306 int reserve = 0;
3307 int insert = 0;
3308 int ret;
3309
3310 if (!root->orphan_block_rsv) {
3311 block_rsv = btrfs_alloc_block_rsv(fs_info,
3312 BTRFS_BLOCK_RSV_TEMP);
3313 if (!block_rsv)
3314 return -ENOMEM;
3315 }
3316
3317 spin_lock(&root->orphan_lock);
3318 if (!root->orphan_block_rsv) {
3319 root->orphan_block_rsv = block_rsv;
3320 } else if (block_rsv) {
3321 btrfs_free_block_rsv(fs_info, block_rsv);
3322 block_rsv = NULL;
3323 }
3324
3325 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3326 &inode->runtime_flags)) {
3327 #if 0
3328 /*
3329 * For proper ENOSPC handling, we should do orphan
3330 * cleanup when mounting. But this introduces backward
3331 * compatibility issue.
3332 */
3333 if (!xchg(&root->orphan_item_inserted, 1))
3334 insert = 2;
3335 else
3336 insert = 1;
3337 #endif
3338 insert = 1;
3339 atomic_inc(&root->orphan_inodes);
3340 }
3341
3342 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3343 &inode->runtime_flags))
3344 reserve = 1;
3345 spin_unlock(&root->orphan_lock);
3346
3347 /* grab metadata reservation from transaction handle */
3348 if (reserve) {
3349 ret = btrfs_orphan_reserve_metadata(trans, inode);
3350 ASSERT(!ret);
3351 if (ret) {
3352 atomic_dec(&root->orphan_inodes);
3353 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3354 &inode->runtime_flags);
3355 if (insert)
3356 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3357 &inode->runtime_flags);
3358 return ret;
3359 }
3360 }
3361
3362 /* insert an orphan item to track this unlinked/truncated file */
3363 if (insert >= 1) {
3364 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3365 if (ret) {
3366 atomic_dec(&root->orphan_inodes);
3367 if (reserve) {
3368 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3369 &inode->runtime_flags);
3370 btrfs_orphan_release_metadata(inode);
3371 }
3372 if (ret != -EEXIST) {
3373 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3374 &inode->runtime_flags);
3375 btrfs_abort_transaction(trans, ret);
3376 return ret;
3377 }
3378 }
3379 ret = 0;
3380 }
3381
3382 /* insert an orphan item to track subvolume contains orphan files */
3383 if (insert >= 2) {
3384 ret = btrfs_insert_orphan_item(trans, fs_info->tree_root,
3385 root->root_key.objectid);
3386 if (ret && ret != -EEXIST) {
3387 btrfs_abort_transaction(trans, ret);
3388 return ret;
3389 }
3390 }
3391 return 0;
3392 }
3393
3394 /*
3395 * We have done the truncate/delete so we can go ahead and remove the orphan
3396 * item for this particular inode.
3397 */
3398 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3399 struct btrfs_inode *inode)
3400 {
3401 struct btrfs_root *root = inode->root;
3402 int delete_item = 0;
3403 int release_rsv = 0;
3404 int ret = 0;
3405
3406 spin_lock(&root->orphan_lock);
3407 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3408 &inode->runtime_flags))
3409 delete_item = 1;
3410
3411 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3412 &inode->runtime_flags))
3413 release_rsv = 1;
3414 spin_unlock(&root->orphan_lock);
3415
3416 if (delete_item) {
3417 atomic_dec(&root->orphan_inodes);
3418 if (trans)
3419 ret = btrfs_del_orphan_item(trans, root,
3420 btrfs_ino(inode));
3421 }
3422
3423 if (release_rsv)
3424 btrfs_orphan_release_metadata(inode);
3425
3426 return ret;
3427 }
3428
3429 /*
3430 * this cleans up any orphans that may be left on the list from the last use
3431 * of this root.
3432 */
3433 int btrfs_orphan_cleanup(struct btrfs_root *root)
3434 {
3435 struct btrfs_fs_info *fs_info = root->fs_info;
3436 struct btrfs_path *path;
3437 struct extent_buffer *leaf;
3438 struct btrfs_key key, found_key;
3439 struct btrfs_trans_handle *trans;
3440 struct inode *inode;
3441 u64 last_objectid = 0;
3442 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3443
3444 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3445 return 0;
3446
3447 path = btrfs_alloc_path();
3448 if (!path) {
3449 ret = -ENOMEM;
3450 goto out;
3451 }
3452 path->reada = READA_BACK;
3453
3454 key.objectid = BTRFS_ORPHAN_OBJECTID;
3455 key.type = BTRFS_ORPHAN_ITEM_KEY;
3456 key.offset = (u64)-1;
3457
3458 while (1) {
3459 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3460 if (ret < 0)
3461 goto out;
3462
3463 /*
3464 * if ret == 0 means we found what we were searching for, which
3465 * is weird, but possible, so only screw with path if we didn't
3466 * find the key and see if we have stuff that matches
3467 */
3468 if (ret > 0) {
3469 ret = 0;
3470 if (path->slots[0] == 0)
3471 break;
3472 path->slots[0]--;
3473 }
3474
3475 /* pull out the item */
3476 leaf = path->nodes[0];
3477 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3478
3479 /* make sure the item matches what we want */
3480 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3481 break;
3482 if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
3483 break;
3484
3485 /* release the path since we're done with it */
3486 btrfs_release_path(path);
3487
3488 /*
3489 * this is where we are basically btrfs_lookup, without the
3490 * crossing root thing. we store the inode number in the
3491 * offset of the orphan item.
3492 */
3493
3494 if (found_key.offset == last_objectid) {
3495 btrfs_err(fs_info,
3496 "Error removing orphan entry, stopping orphan cleanup");
3497 ret = -EINVAL;
3498 goto out;
3499 }
3500
3501 last_objectid = found_key.offset;
3502
3503 found_key.objectid = found_key.offset;
3504 found_key.type = BTRFS_INODE_ITEM_KEY;
3505 found_key.offset = 0;
3506 inode = btrfs_iget(fs_info->sb, &found_key, root, NULL);
3507 ret = PTR_ERR_OR_ZERO(inode);
3508 if (ret && ret != -ENOENT)
3509 goto out;
3510
3511 if (ret == -ENOENT && root == fs_info->tree_root) {
3512 struct btrfs_root *dead_root;
3513 struct btrfs_fs_info *fs_info = root->fs_info;
3514 int is_dead_root = 0;
3515
3516 /*
3517 * this is an orphan in the tree root. Currently these
3518 * could come from 2 sources:
3519 * a) a snapshot deletion in progress
3520 * b) a free space cache inode
3521 * We need to distinguish those two, as the snapshot
3522 * orphan must not get deleted.
3523 * find_dead_roots already ran before us, so if this
3524 * is a snapshot deletion, we should find the root
3525 * in the dead_roots list
3526 */
3527 spin_lock(&fs_info->trans_lock);
3528 list_for_each_entry(dead_root, &fs_info->dead_roots,
3529 root_list) {
3530 if (dead_root->root_key.objectid ==
3531 found_key.objectid) {
3532 is_dead_root = 1;
3533 break;
3534 }
3535 }
3536 spin_unlock(&fs_info->trans_lock);
3537 if (is_dead_root) {
3538 /* prevent this orphan from being found again */
3539 key.offset = found_key.objectid - 1;
3540 continue;
3541 }
3542 }
3543 /*
3544 * Inode is already gone but the orphan item is still there,
3545 * kill the orphan item.
3546 */
3547 if (ret == -ENOENT) {
3548 trans = btrfs_start_transaction(root, 1);
3549 if (IS_ERR(trans)) {
3550 ret = PTR_ERR(trans);
3551 goto out;
3552 }
3553 btrfs_debug(fs_info, "auto deleting %Lu",
3554 found_key.objectid);
3555 ret = btrfs_del_orphan_item(trans, root,
3556 found_key.objectid);
3557 btrfs_end_transaction(trans);
3558 if (ret)
3559 goto out;
3560 continue;
3561 }
3562
3563 /*
3564 * add this inode to the orphan list so btrfs_orphan_del does
3565 * the proper thing when we hit it
3566 */
3567 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3568 &BTRFS_I(inode)->runtime_flags);
3569 atomic_inc(&root->orphan_inodes);
3570
3571 /* if we have links, this was a truncate, lets do that */
3572 if (inode->i_nlink) {
3573 if (WARN_ON(!S_ISREG(inode->i_mode))) {
3574 iput(inode);
3575 continue;
3576 }
3577 nr_truncate++;
3578
3579 /* 1 for the orphan item deletion. */
3580 trans = btrfs_start_transaction(root, 1);
3581 if (IS_ERR(trans)) {
3582 iput(inode);
3583 ret = PTR_ERR(trans);
3584 goto out;
3585 }
3586 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
3587 btrfs_end_transaction(trans);
3588 if (ret) {
3589 iput(inode);
3590 goto out;
3591 }
3592
3593 ret = btrfs_truncate(inode);
3594 if (ret)
3595 btrfs_orphan_del(NULL, BTRFS_I(inode));
3596 } else {
3597 nr_unlink++;
3598 }
3599
3600 /* this will do delete_inode and everything for us */
3601 iput(inode);
3602 if (ret)
3603 goto out;
3604 }
3605 /* release the path since we're done with it */
3606 btrfs_release_path(path);
3607
3608 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3609
3610 if (root->orphan_block_rsv)
3611 btrfs_block_rsv_release(fs_info, root->orphan_block_rsv,
3612 (u64)-1);
3613
3614 if (root->orphan_block_rsv ||
3615 test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
3616 trans = btrfs_join_transaction(root);
3617 if (!IS_ERR(trans))
3618 btrfs_end_transaction(trans);
3619 }
3620
3621 if (nr_unlink)
3622 btrfs_debug(fs_info, "unlinked %d orphans", nr_unlink);
3623 if (nr_truncate)
3624 btrfs_debug(fs_info, "truncated %d orphans", nr_truncate);
3625
3626 out:
3627 if (ret)
3628 btrfs_err(fs_info, "could not do orphan cleanup %d", ret);
3629 btrfs_free_path(path);
3630 return ret;
3631 }
3632
3633 /*
3634 * very simple check to peek ahead in the leaf looking for xattrs. If we
3635 * don't find any xattrs, we know there can't be any acls.
3636 *
3637 * slot is the slot the inode is in, objectid is the objectid of the inode
3638 */
3639 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3640 int slot, u64 objectid,
3641 int *first_xattr_slot)
3642 {
3643 u32 nritems = btrfs_header_nritems(leaf);
3644 struct btrfs_key found_key;
3645 static u64 xattr_access = 0;
3646 static u64 xattr_default = 0;
3647 int scanned = 0;
3648
3649 if (!xattr_access) {
3650 xattr_access = btrfs_name_hash(XATTR_NAME_POSIX_ACL_ACCESS,
3651 strlen(XATTR_NAME_POSIX_ACL_ACCESS));
3652 xattr_default = btrfs_name_hash(XATTR_NAME_POSIX_ACL_DEFAULT,
3653 strlen(XATTR_NAME_POSIX_ACL_DEFAULT));
3654 }
3655
3656 slot++;
3657 *first_xattr_slot = -1;
3658 while (slot < nritems) {
3659 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3660
3661 /* we found a different objectid, there must not be acls */
3662 if (found_key.objectid != objectid)
3663 return 0;
3664
3665 /* we found an xattr, assume we've got an acl */
3666 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3667 if (*first_xattr_slot == -1)
3668 *first_xattr_slot = slot;
3669 if (found_key.offset == xattr_access ||
3670 found_key.offset == xattr_default)
3671 return 1;
3672 }
3673
3674 /*
3675 * we found a key greater than an xattr key, there can't
3676 * be any acls later on
3677 */
3678 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3679 return 0;
3680
3681 slot++;
3682 scanned++;
3683
3684 /*
3685 * it goes inode, inode backrefs, xattrs, extents,
3686 * so if there are a ton of hard links to an inode there can
3687 * be a lot of backrefs. Don't waste time searching too hard,
3688 * this is just an optimization
3689 */
3690 if (scanned >= 8)
3691 break;
3692 }
3693 /* we hit the end of the leaf before we found an xattr or
3694 * something larger than an xattr. We have to assume the inode
3695 * has acls
3696 */
3697 if (*first_xattr_slot == -1)
3698 *first_xattr_slot = slot;
3699 return 1;
3700 }
3701
3702 /*
3703 * read an inode from the btree into the in-memory inode
3704 */
3705 static int btrfs_read_locked_inode(struct inode *inode)
3706 {
3707 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3708 struct btrfs_path *path;
3709 struct extent_buffer *leaf;
3710 struct btrfs_inode_item *inode_item;
3711 struct btrfs_root *root = BTRFS_I(inode)->root;
3712 struct btrfs_key location;
3713 unsigned long ptr;
3714 int maybe_acls;
3715 u32 rdev;
3716 int ret;
3717 bool filled = false;
3718 int first_xattr_slot;
3719
3720 ret = btrfs_fill_inode(inode, &rdev);
3721 if (!ret)
3722 filled = true;
3723
3724 path = btrfs_alloc_path();
3725 if (!path) {
3726 ret = -ENOMEM;
3727 goto make_bad;
3728 }
3729
3730 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3731
3732 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3733 if (ret) {
3734 if (ret > 0)
3735 ret = -ENOENT;
3736 goto make_bad;
3737 }
3738
3739 leaf = path->nodes[0];
3740
3741 if (filled)
3742 goto cache_index;
3743
3744 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3745 struct btrfs_inode_item);
3746 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3747 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3748 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3749 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3750 btrfs_i_size_write(BTRFS_I(inode), btrfs_inode_size(leaf, inode_item));
3751
3752 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
3753 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
3754
3755 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
3756 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
3757
3758 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
3759 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
3760
3761 BTRFS_I(inode)->i_otime.tv_sec =
3762 btrfs_timespec_sec(leaf, &inode_item->otime);
3763 BTRFS_I(inode)->i_otime.tv_nsec =
3764 btrfs_timespec_nsec(leaf, &inode_item->otime);
3765
3766 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3767 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3768 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3769
3770 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
3771 inode->i_generation = BTRFS_I(inode)->generation;
3772 inode->i_rdev = 0;
3773 rdev = btrfs_inode_rdev(leaf, inode_item);
3774
3775 BTRFS_I(inode)->index_cnt = (u64)-1;
3776 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3777
3778 cache_index:
3779 /*
3780 * If we were modified in the current generation and evicted from memory
3781 * and then re-read we need to do a full sync since we don't have any
3782 * idea about which extents were modified before we were evicted from
3783 * cache.
3784 *
3785 * This is required for both inode re-read from disk and delayed inode
3786 * in delayed_nodes_tree.
3787 */
3788 if (BTRFS_I(inode)->last_trans == fs_info->generation)
3789 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3790 &BTRFS_I(inode)->runtime_flags);
3791
3792 /*
3793 * We don't persist the id of the transaction where an unlink operation
3794 * against the inode was last made. So here we assume the inode might
3795 * have been evicted, and therefore the exact value of last_unlink_trans
3796 * lost, and set it to last_trans to avoid metadata inconsistencies
3797 * between the inode and its parent if the inode is fsync'ed and the log
3798 * replayed. For example, in the scenario:
3799 *
3800 * touch mydir/foo
3801 * ln mydir/foo mydir/bar
3802 * sync
3803 * unlink mydir/bar
3804 * echo 2 > /proc/sys/vm/drop_caches # evicts inode
3805 * xfs_io -c fsync mydir/foo
3806 * <power failure>
3807 * mount fs, triggers fsync log replay
3808 *
3809 * We must make sure that when we fsync our inode foo we also log its
3810 * parent inode, otherwise after log replay the parent still has the
3811 * dentry with the "bar" name but our inode foo has a link count of 1
3812 * and doesn't have an inode ref with the name "bar" anymore.
3813 *
3814 * Setting last_unlink_trans to last_trans is a pessimistic approach,
3815 * but it guarantees correctness at the expense of occasional full
3816 * transaction commits on fsync if our inode is a directory, or if our
3817 * inode is not a directory, logging its parent unnecessarily.
3818 */
3819 BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans;
3820
3821 path->slots[0]++;
3822 if (inode->i_nlink != 1 ||
3823 path->slots[0] >= btrfs_header_nritems(leaf))
3824 goto cache_acl;
3825
3826 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
3827 if (location.objectid != btrfs_ino(BTRFS_I(inode)))
3828 goto cache_acl;
3829
3830 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3831 if (location.type == BTRFS_INODE_REF_KEY) {
3832 struct btrfs_inode_ref *ref;
3833
3834 ref = (struct btrfs_inode_ref *)ptr;
3835 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
3836 } else if (location.type == BTRFS_INODE_EXTREF_KEY) {
3837 struct btrfs_inode_extref *extref;
3838
3839 extref = (struct btrfs_inode_extref *)ptr;
3840 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
3841 extref);
3842 }
3843 cache_acl:
3844 /*
3845 * try to precache a NULL acl entry for files that don't have
3846 * any xattrs or acls
3847 */
3848 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3849 btrfs_ino(BTRFS_I(inode)), &first_xattr_slot);
3850 if (first_xattr_slot != -1) {
3851 path->slots[0] = first_xattr_slot;
3852 ret = btrfs_load_inode_props(inode, path);
3853 if (ret)
3854 btrfs_err(fs_info,
3855 "error loading props for ino %llu (root %llu): %d",
3856 btrfs_ino(BTRFS_I(inode)),
3857 root->root_key.objectid, ret);
3858 }
3859 btrfs_free_path(path);
3860
3861 if (!maybe_acls)
3862 cache_no_acl(inode);
3863
3864 switch (inode->i_mode & S_IFMT) {
3865 case S_IFREG:
3866 inode->i_mapping->a_ops = &btrfs_aops;
3867 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3868 inode->i_fop = &btrfs_file_operations;
3869 inode->i_op = &btrfs_file_inode_operations;
3870 break;
3871 case S_IFDIR:
3872 inode->i_fop = &btrfs_dir_file_operations;
3873 inode->i_op = &btrfs_dir_inode_operations;
3874 break;
3875 case S_IFLNK:
3876 inode->i_op = &btrfs_symlink_inode_operations;
3877 inode_nohighmem(inode);
3878 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3879 break;
3880 default:
3881 inode->i_op = &btrfs_special_inode_operations;
3882 init_special_inode(inode, inode->i_mode, rdev);
3883 break;
3884 }
3885
3886 btrfs_update_iflags(inode);
3887 return 0;
3888
3889 make_bad:
3890 btrfs_free_path(path);
3891 make_bad_inode(inode);
3892 return ret;
3893 }
3894
3895 /*
3896 * given a leaf and an inode, copy the inode fields into the leaf
3897 */
3898 static void fill_inode_item(struct btrfs_trans_handle *trans,
3899 struct extent_buffer *leaf,
3900 struct btrfs_inode_item *item,
3901 struct inode *inode)
3902 {
3903 struct btrfs_map_token token;
3904
3905 btrfs_init_map_token(&token);
3906
3907 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3908 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3909 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3910 &token);
3911 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3912 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3913
3914 btrfs_set_token_timespec_sec(leaf, &item->atime,
3915 inode->i_atime.tv_sec, &token);
3916 btrfs_set_token_timespec_nsec(leaf, &item->atime,
3917 inode->i_atime.tv_nsec, &token);
3918
3919 btrfs_set_token_timespec_sec(leaf, &item->mtime,
3920 inode->i_mtime.tv_sec, &token);
3921 btrfs_set_token_timespec_nsec(leaf, &item->mtime,
3922 inode->i_mtime.tv_nsec, &token);
3923
3924 btrfs_set_token_timespec_sec(leaf, &item->ctime,
3925 inode->i_ctime.tv_sec, &token);
3926 btrfs_set_token_timespec_nsec(leaf, &item->ctime,
3927 inode->i_ctime.tv_nsec, &token);
3928
3929 btrfs_set_token_timespec_sec(leaf, &item->otime,
3930 BTRFS_I(inode)->i_otime.tv_sec, &token);
3931 btrfs_set_token_timespec_nsec(leaf, &item->otime,
3932 BTRFS_I(inode)->i_otime.tv_nsec, &token);
3933
3934 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3935 &token);
3936 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3937 &token);
3938 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3939 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3940 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3941 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3942 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3943 }
3944
3945 /*
3946 * copy everything in the in-memory inode into the btree.
3947 */
3948 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3949 struct btrfs_root *root, struct inode *inode)
3950 {
3951 struct btrfs_inode_item *inode_item;
3952 struct btrfs_path *path;
3953 struct extent_buffer *leaf;
3954 int ret;
3955
3956 path = btrfs_alloc_path();
3957 if (!path)
3958 return -ENOMEM;
3959
3960 path->leave_spinning = 1;
3961 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3962 1);
3963 if (ret) {
3964 if (ret > 0)
3965 ret = -ENOENT;
3966 goto failed;
3967 }
3968
3969 leaf = path->nodes[0];
3970 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3971 struct btrfs_inode_item);
3972
3973 fill_inode_item(trans, leaf, inode_item, inode);
3974 btrfs_mark_buffer_dirty(leaf);
3975 btrfs_set_inode_last_trans(trans, inode);
3976 ret = 0;
3977 failed:
3978 btrfs_free_path(path);
3979 return ret;
3980 }
3981
3982 /*
3983 * copy everything in the in-memory inode into the btree.
3984 */
3985 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3986 struct btrfs_root *root, struct inode *inode)
3987 {
3988 struct btrfs_fs_info *fs_info = root->fs_info;
3989 int ret;
3990
3991 /*
3992 * If the inode is a free space inode, we can deadlock during commit
3993 * if we put it into the delayed code.
3994 *
3995 * The data relocation inode should also be directly updated
3996 * without delay
3997 */
3998 if (!btrfs_is_free_space_inode(BTRFS_I(inode))
3999 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
4000 && !test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) {
4001 btrfs_update_root_times(trans, root);
4002
4003 ret = btrfs_delayed_update_inode(trans, root, inode);
4004 if (!ret)
4005 btrfs_set_inode_last_trans(trans, inode);
4006 return ret;
4007 }
4008
4009 return btrfs_update_inode_item(trans, root, inode);
4010 }
4011
4012 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
4013 struct btrfs_root *root,
4014 struct inode *inode)
4015 {
4016 int ret;
4017
4018 ret = btrfs_update_inode(trans, root, inode);
4019 if (ret == -ENOSPC)
4020 return btrfs_update_inode_item(trans, root, inode);
4021 return ret;
4022 }
4023
4024 /*
4025 * unlink helper that gets used here in inode.c and in the tree logging
4026 * recovery code. It remove a link in a directory with a given name, and
4027 * also drops the back refs in the inode to the directory
4028 */
4029 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4030 struct btrfs_root *root,
4031 struct btrfs_inode *dir,
4032 struct btrfs_inode *inode,
4033 const char *name, int name_len)
4034 {
4035 struct btrfs_fs_info *fs_info = root->fs_info;
4036 struct btrfs_path *path;
4037 int ret = 0;
4038 struct extent_buffer *leaf;
4039 struct btrfs_dir_item *di;
4040 struct btrfs_key key;
4041 u64 index;
4042 u64 ino = btrfs_ino(inode);
4043 u64 dir_ino = btrfs_ino(dir);
4044
4045 path = btrfs_alloc_path();
4046 if (!path) {
4047 ret = -ENOMEM;
4048 goto out;
4049 }
4050
4051 path->leave_spinning = 1;
4052 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4053 name, name_len, -1);
4054 if (IS_ERR(di)) {
4055 ret = PTR_ERR(di);
4056 goto err;
4057 }
4058 if (!di) {
4059 ret = -ENOENT;
4060 goto err;
4061 }
4062 leaf = path->nodes[0];
4063 btrfs_dir_item_key_to_cpu(leaf, di, &key);
4064 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4065 if (ret)
4066 goto err;
4067 btrfs_release_path(path);
4068
4069 /*
4070 * If we don't have dir index, we have to get it by looking up
4071 * the inode ref, since we get the inode ref, remove it directly,
4072 * it is unnecessary to do delayed deletion.
4073 *
4074 * But if we have dir index, needn't search inode ref to get it.
4075 * Since the inode ref is close to the inode item, it is better
4076 * that we delay to delete it, and just do this deletion when
4077 * we update the inode item.
4078 */
4079 if (inode->dir_index) {
4080 ret = btrfs_delayed_delete_inode_ref(inode);
4081 if (!ret) {
4082 index = inode->dir_index;
4083 goto skip_backref;
4084 }
4085 }
4086
4087 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
4088 dir_ino, &index);
4089 if (ret) {
4090 btrfs_info(fs_info,
4091 "failed to delete reference to %.*s, inode %llu parent %llu",
4092 name_len, name, ino, dir_ino);
4093 btrfs_abort_transaction(trans, ret);
4094 goto err;
4095 }
4096 skip_backref:
4097 ret = btrfs_delete_delayed_dir_index(trans, fs_info, dir, index);
4098 if (ret) {
4099 btrfs_abort_transaction(trans, ret);
4100 goto err;
4101 }
4102
4103 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len, inode,
4104 dir_ino);
4105 if (ret != 0 && ret != -ENOENT) {
4106 btrfs_abort_transaction(trans, ret);
4107 goto err;
4108 }
4109
4110 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len, dir,
4111 index);
4112 if (ret == -ENOENT)
4113 ret = 0;
4114 else if (ret)
4115 btrfs_abort_transaction(trans, ret);
4116 err:
4117 btrfs_free_path(path);
4118 if (ret)
4119 goto out;
4120
4121 btrfs_i_size_write(dir, dir->vfs_inode.i_size - name_len * 2);
4122 inode_inc_iversion(&inode->vfs_inode);
4123 inode_inc_iversion(&dir->vfs_inode);
4124 inode->vfs_inode.i_ctime = dir->vfs_inode.i_mtime =
4125 dir->vfs_inode.i_ctime = current_time(&inode->vfs_inode);
4126 ret = btrfs_update_inode(trans, root, &dir->vfs_inode);
4127 out:
4128 return ret;
4129 }
4130
4131 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4132 struct btrfs_root *root,
4133 struct btrfs_inode *dir, struct btrfs_inode *inode,
4134 const char *name, int name_len)
4135 {
4136 int ret;
4137 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
4138 if (!ret) {
4139 drop_nlink(&inode->vfs_inode);
4140 ret = btrfs_update_inode(trans, root, &inode->vfs_inode);
4141 }
4142 return ret;
4143 }
4144
4145 /*
4146 * helper to start transaction for unlink and rmdir.
4147 *
4148 * unlink and rmdir are special in btrfs, they do not always free space, so
4149 * if we cannot make our reservations the normal way try and see if there is
4150 * plenty of slack room in the global reserve to migrate, otherwise we cannot
4151 * allow the unlink to occur.
4152 */
4153 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
4154 {
4155 struct btrfs_root *root = BTRFS_I(dir)->root;
4156
4157 /*
4158 * 1 for the possible orphan item
4159 * 1 for the dir item
4160 * 1 for the dir index
4161 * 1 for the inode ref
4162 * 1 for the inode
4163 */
4164 return btrfs_start_transaction_fallback_global_rsv(root, 5, 5);
4165 }
4166
4167 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
4168 {
4169 struct btrfs_root *root = BTRFS_I(dir)->root;
4170 struct btrfs_trans_handle *trans;
4171 struct inode *inode = d_inode(dentry);
4172 int ret;
4173
4174 trans = __unlink_start_trans(dir);
4175 if (IS_ERR(trans))
4176 return PTR_ERR(trans);
4177
4178 btrfs_record_unlink_dir(trans, BTRFS_I(dir), BTRFS_I(d_inode(dentry)),
4179 0);
4180
4181 ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
4182 BTRFS_I(d_inode(dentry)), dentry->d_name.name,
4183 dentry->d_name.len);
4184 if (ret)
4185 goto out;
4186
4187 if (inode->i_nlink == 0) {
4188 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
4189 if (ret)
4190 goto out;
4191 }
4192
4193 out:
4194 btrfs_end_transaction(trans);
4195 btrfs_btree_balance_dirty(root->fs_info);
4196 return ret;
4197 }
4198
4199 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
4200 struct btrfs_root *root,
4201 struct inode *dir, u64 objectid,
4202 const char *name, int name_len)
4203 {
4204 struct btrfs_fs_info *fs_info = root->fs_info;
4205 struct btrfs_path *path;
4206 struct extent_buffer *leaf;
4207 struct btrfs_dir_item *di;
4208 struct btrfs_key key;
4209 u64 index;
4210 int ret;
4211 u64 dir_ino = btrfs_ino(BTRFS_I(dir));
4212
4213 path = btrfs_alloc_path();
4214 if (!path)
4215 return -ENOMEM;
4216
4217 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4218 name, name_len, -1);
4219 if (IS_ERR_OR_NULL(di)) {
4220 if (!di)
4221 ret = -ENOENT;
4222 else
4223 ret = PTR_ERR(di);
4224 goto out;
4225 }
4226
4227 leaf = path->nodes[0];
4228 btrfs_dir_item_key_to_cpu(leaf, di, &key);
4229 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
4230 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4231 if (ret) {
4232 btrfs_abort_transaction(trans, ret);
4233 goto out;
4234 }
4235 btrfs_release_path(path);
4236
4237 ret = btrfs_del_root_ref(trans, fs_info, objectid,
4238 root->root_key.objectid, dir_ino,
4239 &index, name, name_len);
4240 if (ret < 0) {
4241 if (ret != -ENOENT) {
4242 btrfs_abort_transaction(trans, ret);
4243 goto out;
4244 }
4245 di = btrfs_search_dir_index_item(root, path, dir_ino,
4246 name, name_len);
4247 if (IS_ERR_OR_NULL(di)) {
4248 if (!di)
4249 ret = -ENOENT;
4250 else
4251 ret = PTR_ERR(di);
4252 btrfs_abort_transaction(trans, ret);
4253 goto out;
4254 }
4255
4256 leaf = path->nodes[0];
4257 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4258 btrfs_release_path(path);
4259 index = key.offset;
4260 }
4261 btrfs_release_path(path);
4262
4263 ret = btrfs_delete_delayed_dir_index(trans, fs_info, BTRFS_I(dir), index);
4264 if (ret) {
4265 btrfs_abort_transaction(trans, ret);
4266 goto out;
4267 }
4268
4269 btrfs_i_size_write(BTRFS_I(dir), dir->i_size - name_len * 2);
4270 inode_inc_iversion(dir);
4271 dir->i_mtime = dir->i_ctime = current_time(dir);
4272 ret = btrfs_update_inode_fallback(trans, root, dir);
4273 if (ret)
4274 btrfs_abort_transaction(trans, ret);
4275 out:
4276 btrfs_free_path(path);
4277 return ret;
4278 }
4279
4280 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
4281 {
4282 struct inode *inode = d_inode(dentry);
4283 int err = 0;
4284 struct btrfs_root *root = BTRFS_I(dir)->root;
4285 struct btrfs_trans_handle *trans;
4286 u64 last_unlink_trans;
4287
4288 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
4289 return -ENOTEMPTY;
4290 if (btrfs_ino(BTRFS_I(inode)) == BTRFS_FIRST_FREE_OBJECTID)
4291 return -EPERM;
4292
4293 trans = __unlink_start_trans(dir);
4294 if (IS_ERR(trans))
4295 return PTR_ERR(trans);
4296
4297 if (unlikely(btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
4298 err = btrfs_unlink_subvol(trans, root, dir,
4299 BTRFS_I(inode)->location.objectid,
4300 dentry->d_name.name,
4301 dentry->d_name.len);
4302 goto out;
4303 }
4304
4305 err = btrfs_orphan_add(trans, BTRFS_I(inode));
4306 if (err)
4307 goto out;
4308
4309 last_unlink_trans = BTRFS_I(inode)->last_unlink_trans;
4310
4311 /* now the directory is empty */
4312 err = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
4313 BTRFS_I(d_inode(dentry)), dentry->d_name.name,
4314 dentry->d_name.len);
4315 if (!err) {
4316 btrfs_i_size_write(BTRFS_I(inode), 0);
4317 /*
4318 * Propagate the last_unlink_trans value of the deleted dir to
4319 * its parent directory. This is to prevent an unrecoverable
4320 * log tree in the case we do something like this:
4321 * 1) create dir foo
4322 * 2) create snapshot under dir foo
4323 * 3) delete the snapshot
4324 * 4) rmdir foo
4325 * 5) mkdir foo
4326 * 6) fsync foo or some file inside foo
4327 */
4328 if (last_unlink_trans >= trans->transid)
4329 BTRFS_I(dir)->last_unlink_trans = last_unlink_trans;
4330 }
4331 out:
4332 btrfs_end_transaction(trans);
4333 btrfs_btree_balance_dirty(root->fs_info);
4334
4335 return err;
4336 }
4337
4338 static int truncate_space_check(struct btrfs_trans_handle *trans,
4339 struct btrfs_root *root,
4340 u64 bytes_deleted)
4341 {
4342 struct btrfs_fs_info *fs_info = root->fs_info;
4343 int ret;
4344
4345 /*
4346 * This is only used to apply pressure to the enospc system, we don't
4347 * intend to use this reservation at all.
4348 */
4349 bytes_deleted = btrfs_csum_bytes_to_leaves(fs_info, bytes_deleted);
4350 bytes_deleted *= fs_info->nodesize;
4351 ret = btrfs_block_rsv_add(root, &fs_info->trans_block_rsv,
4352 bytes_deleted, BTRFS_RESERVE_NO_FLUSH);
4353 if (!ret) {
4354 trace_btrfs_space_reservation(fs_info, "transaction",
4355 trans->transid,
4356 bytes_deleted, 1);
4357 trans->bytes_reserved += bytes_deleted;
4358 }
4359 return ret;
4360
4361 }
4362
4363 static int truncate_inline_extent(struct inode *inode,
4364 struct btrfs_path *path,
4365 struct btrfs_key *found_key,
4366 const u64 item_end,
4367 const u64 new_size)
4368 {
4369 struct extent_buffer *leaf = path->nodes[0];
4370 int slot = path->slots[0];
4371 struct btrfs_file_extent_item *fi;
4372 u32 size = (u32)(new_size - found_key->offset);
4373 struct btrfs_root *root = BTRFS_I(inode)->root;
4374
4375 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
4376
4377 if (btrfs_file_extent_compression(leaf, fi) != BTRFS_COMPRESS_NONE) {
4378 loff_t offset = new_size;
4379 loff_t page_end = ALIGN(offset, PAGE_SIZE);
4380
4381 /*
4382 * Zero out the remaining of the last page of our inline extent,
4383 * instead of directly truncating our inline extent here - that
4384 * would be much more complex (decompressing all the data, then
4385 * compressing the truncated data, which might be bigger than
4386 * the size of the inline extent, resize the extent, etc).
4387 * We release the path because to get the page we might need to
4388 * read the extent item from disk (data not in the page cache).
4389 */
4390 btrfs_release_path(path);
4391 return btrfs_truncate_block(inode, offset, page_end - offset,
4392 0);
4393 }
4394
4395 btrfs_set_file_extent_ram_bytes(leaf, fi, size);
4396 size = btrfs_file_extent_calc_inline_size(size);
4397 btrfs_truncate_item(root->fs_info, path, size, 1);
4398
4399 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4400 inode_sub_bytes(inode, item_end + 1 - new_size);
4401
4402 return 0;
4403 }
4404
4405 /*
4406 * this can truncate away extent items, csum items and directory items.
4407 * It starts at a high offset and removes keys until it can't find
4408 * any higher than new_size
4409 *
4410 * csum items that cross the new i_size are truncated to the new size
4411 * as well.
4412 *
4413 * min_type is the minimum key type to truncate down to. If set to 0, this
4414 * will kill all the items on this inode, including the INODE_ITEM_KEY.
4415 */
4416 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
4417 struct btrfs_root *root,
4418 struct inode *inode,
4419 u64 new_size, u32 min_type)
4420 {
4421 struct btrfs_fs_info *fs_info = root->fs_info;
4422 struct btrfs_path *path;
4423 struct extent_buffer *leaf;
4424 struct btrfs_file_extent_item *fi;
4425 struct btrfs_key key;
4426 struct btrfs_key found_key;
4427 u64 extent_start = 0;
4428 u64 extent_num_bytes = 0;
4429 u64 extent_offset = 0;
4430 u64 item_end = 0;
4431 u64 last_size = new_size;
4432 u32 found_type = (u8)-1;
4433 int found_extent;
4434 int del_item;
4435 int pending_del_nr = 0;
4436 int pending_del_slot = 0;
4437 int extent_type = -1;
4438 int ret;
4439 int err = 0;
4440 u64 ino = btrfs_ino(BTRFS_I(inode));
4441 u64 bytes_deleted = 0;
4442 bool be_nice = 0;
4443 bool should_throttle = 0;
4444 bool should_end = 0;
4445
4446 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
4447
4448 /*
4449 * for non-free space inodes and ref cows, we want to back off from
4450 * time to time
4451 */
4452 if (!btrfs_is_free_space_inode(BTRFS_I(inode)) &&
4453 test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4454 be_nice = 1;
4455
4456 path = btrfs_alloc_path();
4457 if (!path)
4458 return -ENOMEM;
4459 path->reada = READA_BACK;
4460
4461 /*
4462 * We want to drop from the next block forward in case this new size is
4463 * not block aligned since we will be keeping the last block of the
4464 * extent just the way it is.
4465 */
4466 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4467 root == fs_info->tree_root)
4468 btrfs_drop_extent_cache(BTRFS_I(inode), ALIGN(new_size,
4469 fs_info->sectorsize),
4470 (u64)-1, 0);
4471
4472 /*
4473 * This function is also used to drop the items in the log tree before
4474 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4475 * it is used to drop the loged items. So we shouldn't kill the delayed
4476 * items.
4477 */
4478 if (min_type == 0 && root == BTRFS_I(inode)->root)
4479 btrfs_kill_delayed_inode_items(BTRFS_I(inode));
4480
4481 key.objectid = ino;
4482 key.offset = (u64)-1;
4483 key.type = (u8)-1;
4484
4485 search_again:
4486 /*
4487 * with a 16K leaf size and 128MB extents, you can actually queue
4488 * up a huge file in a single leaf. Most of the time that
4489 * bytes_deleted is > 0, it will be huge by the time we get here
4490 */
4491 if (be_nice && bytes_deleted > SZ_32M) {
4492 if (btrfs_should_end_transaction(trans)) {
4493 err = -EAGAIN;
4494 goto error;
4495 }
4496 }
4497
4498
4499 path->leave_spinning = 1;
4500 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4501 if (ret < 0) {
4502 err = ret;
4503 goto out;
4504 }
4505
4506 if (ret > 0) {
4507 /* there are no items in the tree for us to truncate, we're
4508 * done
4509 */
4510 if (path->slots[0] == 0)
4511 goto out;
4512 path->slots[0]--;
4513 }
4514
4515 while (1) {
4516 fi = NULL;
4517 leaf = path->nodes[0];
4518 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4519 found_type = found_key.type;
4520
4521 if (found_key.objectid != ino)
4522 break;
4523
4524 if (found_type < min_type)
4525 break;
4526
4527 item_end = found_key.offset;
4528 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4529 fi = btrfs_item_ptr(leaf, path->slots[0],
4530 struct btrfs_file_extent_item);
4531 extent_type = btrfs_file_extent_type(leaf, fi);
4532 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4533 item_end +=
4534 btrfs_file_extent_num_bytes(leaf, fi);
4535
4536 trace_btrfs_truncate_show_fi_regular(
4537 BTRFS_I(inode), leaf, fi,
4538 found_key.offset);
4539 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4540 item_end += btrfs_file_extent_inline_len(leaf,
4541 path->slots[0], fi);
4542
4543 trace_btrfs_truncate_show_fi_inline(
4544 BTRFS_I(inode), leaf, fi, path->slots[0],
4545 found_key.offset);
4546 }
4547 item_end--;
4548 }
4549 if (found_type > min_type) {
4550 del_item = 1;
4551 } else {
4552 if (item_end < new_size)
4553 break;
4554 if (found_key.offset >= new_size)
4555 del_item = 1;
4556 else
4557 del_item = 0;
4558 }
4559 found_extent = 0;
4560 /* FIXME, shrink the extent if the ref count is only 1 */
4561 if (found_type != BTRFS_EXTENT_DATA_KEY)
4562 goto delete;
4563
4564 if (del_item)
4565 last_size = found_key.offset;
4566 else
4567 last_size = new_size;
4568
4569 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4570 u64 num_dec;
4571 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4572 if (!del_item) {
4573 u64 orig_num_bytes =
4574 btrfs_file_extent_num_bytes(leaf, fi);
4575 extent_num_bytes = ALIGN(new_size -
4576 found_key.offset,
4577 fs_info->sectorsize);
4578 btrfs_set_file_extent_num_bytes(leaf, fi,
4579 extent_num_bytes);
4580 num_dec = (orig_num_bytes -
4581 extent_num_bytes);
4582 if (test_bit(BTRFS_ROOT_REF_COWS,
4583 &root->state) &&
4584 extent_start != 0)
4585 inode_sub_bytes(inode, num_dec);
4586 btrfs_mark_buffer_dirty(leaf);
4587 } else {
4588 extent_num_bytes =
4589 btrfs_file_extent_disk_num_bytes(leaf,
4590 fi);
4591 extent_offset = found_key.offset -
4592 btrfs_file_extent_offset(leaf, fi);
4593
4594 /* FIXME blocksize != 4096 */
4595 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4596 if (extent_start != 0) {
4597 found_extent = 1;
4598 if (test_bit(BTRFS_ROOT_REF_COWS,
4599 &root->state))
4600 inode_sub_bytes(inode, num_dec);
4601 }
4602 }
4603 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4604 /*
4605 * we can't truncate inline items that have had
4606 * special encodings
4607 */
4608 if (!del_item &&
4609 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4610 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
4611
4612 /*
4613 * Need to release path in order to truncate a
4614 * compressed extent. So delete any accumulated
4615 * extent items so far.
4616 */
4617 if (btrfs_file_extent_compression(leaf, fi) !=
4618 BTRFS_COMPRESS_NONE && pending_del_nr) {
4619 err = btrfs_del_items(trans, root, path,
4620 pending_del_slot,
4621 pending_del_nr);
4622 if (err) {
4623 btrfs_abort_transaction(trans,
4624 err);
4625 goto error;
4626 }
4627 pending_del_nr = 0;
4628 }
4629
4630 err = truncate_inline_extent(inode, path,
4631 &found_key,
4632 item_end,
4633 new_size);
4634 if (err) {
4635 btrfs_abort_transaction(trans, err);
4636 goto error;
4637 }
4638 } else if (test_bit(BTRFS_ROOT_REF_COWS,
4639 &root->state)) {
4640 inode_sub_bytes(inode, item_end + 1 - new_size);
4641 }
4642 }
4643 delete:
4644 if (del_item) {
4645 if (!pending_del_nr) {
4646 /* no pending yet, add ourselves */
4647 pending_del_slot = path->slots[0];
4648 pending_del_nr = 1;
4649 } else if (pending_del_nr &&
4650 path->slots[0] + 1 == pending_del_slot) {
4651 /* hop on the pending chunk */
4652 pending_del_nr++;
4653 pending_del_slot = path->slots[0];
4654 } else {
4655 BUG();
4656 }
4657 } else {
4658 break;
4659 }
4660 should_throttle = 0;
4661
4662 if (found_extent &&
4663 (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4664 root == fs_info->tree_root)) {
4665 btrfs_set_path_blocking(path);
4666 bytes_deleted += extent_num_bytes;
4667 ret = btrfs_free_extent(trans, fs_info, extent_start,
4668 extent_num_bytes, 0,
4669 btrfs_header_owner(leaf),
4670 ino, extent_offset);
4671 BUG_ON(ret);
4672 if (btrfs_should_throttle_delayed_refs(trans, fs_info))
4673 btrfs_async_run_delayed_refs(fs_info,
4674 trans->delayed_ref_updates * 2,
4675 trans->transid, 0);
4676 if (be_nice) {
4677 if (truncate_space_check(trans, root,
4678 extent_num_bytes)) {
4679 should_end = 1;
4680 }
4681 if (btrfs_should_throttle_delayed_refs(trans,
4682 fs_info))
4683 should_throttle = 1;
4684 }
4685 }
4686
4687 if (found_type == BTRFS_INODE_ITEM_KEY)
4688 break;
4689
4690 if (path->slots[0] == 0 ||
4691 path->slots[0] != pending_del_slot ||
4692 should_throttle || should_end) {
4693 if (pending_del_nr) {
4694 ret = btrfs_del_items(trans, root, path,
4695 pending_del_slot,
4696 pending_del_nr);
4697 if (ret) {
4698 btrfs_abort_transaction(trans, ret);
4699 goto error;
4700 }
4701 pending_del_nr = 0;
4702 }
4703 btrfs_release_path(path);
4704 if (should_throttle) {
4705 unsigned long updates = trans->delayed_ref_updates;
4706 if (updates) {
4707 trans->delayed_ref_updates = 0;
4708 ret = btrfs_run_delayed_refs(trans,
4709 fs_info,
4710 updates * 2);
4711 if (ret && !err)
4712 err = ret;
4713 }
4714 }
4715 /*
4716 * if we failed to refill our space rsv, bail out
4717 * and let the transaction restart
4718 */
4719 if (should_end) {
4720 err = -EAGAIN;
4721 goto error;
4722 }
4723 goto search_again;
4724 } else {
4725 path->slots[0]--;
4726 }
4727 }
4728 out:
4729 if (pending_del_nr) {
4730 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4731 pending_del_nr);
4732 if (ret)
4733 btrfs_abort_transaction(trans, ret);
4734 }
4735 error:
4736 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
4737 ASSERT(last_size >= new_size);
4738 if (!err && last_size > new_size)
4739 last_size = new_size;
4740 btrfs_ordered_update_i_size(inode, last_size, NULL);
4741 }
4742
4743 btrfs_free_path(path);
4744
4745 if (be_nice && bytes_deleted > SZ_32M) {
4746 unsigned long updates = trans->delayed_ref_updates;
4747 if (updates) {
4748 trans->delayed_ref_updates = 0;
4749 ret = btrfs_run_delayed_refs(trans, fs_info,
4750 updates * 2);
4751 if (ret && !err)
4752 err = ret;
4753 }
4754 }
4755 return err;
4756 }
4757
4758 /*
4759 * btrfs_truncate_block - read, zero a chunk and write a block
4760 * @inode - inode that we're zeroing
4761 * @from - the offset to start zeroing
4762 * @len - the length to zero, 0 to zero the entire range respective to the
4763 * offset
4764 * @front - zero up to the offset instead of from the offset on
4765 *
4766 * This will find the block for the "from" offset and cow the block and zero the
4767 * part we want to zero. This is used with truncate and hole punching.
4768 */
4769 int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len,
4770 int front)
4771 {
4772 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4773 struct address_space *mapping = inode->i_mapping;
4774 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4775 struct btrfs_ordered_extent *ordered;
4776 struct extent_state *cached_state = NULL;
4777 struct extent_changeset *data_reserved = NULL;
4778 char *kaddr;
4779 u32 blocksize = fs_info->sectorsize;
4780 pgoff_t index = from >> PAGE_SHIFT;
4781 unsigned offset = from & (blocksize - 1);
4782 struct page *page;
4783 gfp_t mask = btrfs_alloc_write_mask(mapping);
4784 int ret = 0;
4785 u64 block_start;
4786 u64 block_end;
4787
4788 if ((offset & (blocksize - 1)) == 0 &&
4789 (!len || ((len & (blocksize - 1)) == 0)))
4790 goto out;
4791
4792 ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
4793 round_down(from, blocksize), blocksize);
4794 if (ret)
4795 goto out;
4796
4797 again:
4798 page = find_or_create_page(mapping, index, mask);
4799 if (!page) {
4800 btrfs_delalloc_release_space(inode, data_reserved,
4801 round_down(from, blocksize),
4802 blocksize);
4803 ret = -ENOMEM;
4804 goto out;
4805 }
4806
4807 block_start = round_down(from, blocksize);
4808 block_end = block_start + blocksize - 1;
4809
4810 if (!PageUptodate(page)) {
4811 ret = btrfs_readpage(NULL, page);
4812 lock_page(page);
4813 if (page->mapping != mapping) {
4814 unlock_page(page);
4815 put_page(page);
4816 goto again;
4817 }
4818 if (!PageUptodate(page)) {
4819 ret = -EIO;
4820 goto out_unlock;
4821 }
4822 }
4823 wait_on_page_writeback(page);
4824
4825 lock_extent_bits(io_tree, block_start, block_end, &cached_state);
4826 set_page_extent_mapped(page);
4827
4828 ordered = btrfs_lookup_ordered_extent(inode, block_start);
4829 if (ordered) {
4830 unlock_extent_cached(io_tree, block_start, block_end,
4831 &cached_state, GFP_NOFS);
4832 unlock_page(page);
4833 put_page(page);
4834 btrfs_start_ordered_extent(inode, ordered, 1);
4835 btrfs_put_ordered_extent(ordered);
4836 goto again;
4837 }
4838
4839 clear_extent_bit(&BTRFS_I(inode)->io_tree, block_start, block_end,
4840 EXTENT_DIRTY | EXTENT_DELALLOC |
4841 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4842 0, 0, &cached_state, GFP_NOFS);
4843
4844 ret = btrfs_set_extent_delalloc(inode, block_start, block_end,
4845 &cached_state, 0);
4846 if (ret) {
4847 unlock_extent_cached(io_tree, block_start, block_end,
4848 &cached_state, GFP_NOFS);
4849 goto out_unlock;
4850 }
4851
4852 if (offset != blocksize) {
4853 if (!len)
4854 len = blocksize - offset;
4855 kaddr = kmap(page);
4856 if (front)
4857 memset(kaddr + (block_start - page_offset(page)),
4858 0, offset);
4859 else
4860 memset(kaddr + (block_start - page_offset(page)) + offset,
4861 0, len);
4862 flush_dcache_page(page);
4863 kunmap(page);
4864 }
4865 ClearPageChecked(page);
4866 set_page_dirty(page);
4867 unlock_extent_cached(io_tree, block_start, block_end, &cached_state,
4868 GFP_NOFS);
4869
4870 out_unlock:
4871 if (ret)
4872 btrfs_delalloc_release_space(inode, data_reserved, block_start,
4873 blocksize);
4874 unlock_page(page);
4875 put_page(page);
4876 out:
4877 extent_changeset_free(data_reserved);
4878 return ret;
4879 }
4880
4881 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
4882 u64 offset, u64 len)
4883 {
4884 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4885 struct btrfs_trans_handle *trans;
4886 int ret;
4887
4888 /*
4889 * Still need to make sure the inode looks like it's been updated so
4890 * that any holes get logged if we fsync.
4891 */
4892 if (btrfs_fs_incompat(fs_info, NO_HOLES)) {
4893 BTRFS_I(inode)->last_trans = fs_info->generation;
4894 BTRFS_I(inode)->last_sub_trans = root->log_transid;
4895 BTRFS_I(inode)->last_log_commit = root->last_log_commit;
4896 return 0;
4897 }
4898
4899 /*
4900 * 1 - for the one we're dropping
4901 * 1 - for the one we're adding
4902 * 1 - for updating the inode.
4903 */
4904 trans = btrfs_start_transaction(root, 3);
4905 if (IS_ERR(trans))
4906 return PTR_ERR(trans);
4907
4908 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
4909 if (ret) {
4910 btrfs_abort_transaction(trans, ret);
4911 btrfs_end_transaction(trans);
4912 return ret;
4913 }
4914
4915 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(BTRFS_I(inode)),
4916 offset, 0, 0, len, 0, len, 0, 0, 0);
4917 if (ret)
4918 btrfs_abort_transaction(trans, ret);
4919 else
4920 btrfs_update_inode(trans, root, inode);
4921 btrfs_end_transaction(trans);
4922 return ret;
4923 }
4924
4925 /*
4926 * This function puts in dummy file extents for the area we're creating a hole
4927 * for. So if we are truncating this file to a larger size we need to insert
4928 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4929 * the range between oldsize and size
4930 */
4931 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4932 {
4933 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4934 struct btrfs_root *root = BTRFS_I(inode)->root;
4935 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4936 struct extent_map *em = NULL;
4937 struct extent_state *cached_state = NULL;
4938 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4939 u64 hole_start = ALIGN(oldsize, fs_info->sectorsize);
4940 u64 block_end = ALIGN(size, fs_info->sectorsize);
4941 u64 last_byte;
4942 u64 cur_offset;
4943 u64 hole_size;
4944 int err = 0;
4945
4946 /*
4947 * If our size started in the middle of a block we need to zero out the
4948 * rest of the block before we expand the i_size, otherwise we could
4949 * expose stale data.
4950 */
4951 err = btrfs_truncate_block(inode, oldsize, 0, 0);
4952 if (err)
4953 return err;
4954
4955 if (size <= hole_start)
4956 return 0;
4957
4958 while (1) {
4959 struct btrfs_ordered_extent *ordered;
4960
4961 lock_extent_bits(io_tree, hole_start, block_end - 1,
4962 &cached_state);
4963 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), hole_start,
4964 block_end - hole_start);
4965 if (!ordered)
4966 break;
4967 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4968 &cached_state, GFP_NOFS);
4969 btrfs_start_ordered_extent(inode, ordered, 1);
4970 btrfs_put_ordered_extent(ordered);
4971 }
4972
4973 cur_offset = hole_start;
4974 while (1) {
4975 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur_offset,
4976 block_end - cur_offset, 0);
4977 if (IS_ERR(em)) {
4978 err = PTR_ERR(em);
4979 em = NULL;
4980 break;
4981 }
4982 last_byte = min(extent_map_end(em), block_end);
4983 last_byte = ALIGN(last_byte, fs_info->sectorsize);
4984 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4985 struct extent_map *hole_em;
4986 hole_size = last_byte - cur_offset;
4987
4988 err = maybe_insert_hole(root, inode, cur_offset,
4989 hole_size);
4990 if (err)
4991 break;
4992 btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
4993 cur_offset + hole_size - 1, 0);
4994 hole_em = alloc_extent_map();
4995 if (!hole_em) {
4996 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4997 &BTRFS_I(inode)->runtime_flags);
4998 goto next;
4999 }
5000 hole_em->start = cur_offset;
5001 hole_em->len = hole_size;
5002 hole_em->orig_start = cur_offset;
5003
5004 hole_em->block_start = EXTENT_MAP_HOLE;
5005 hole_em->block_len = 0;
5006 hole_em->orig_block_len = 0;
5007 hole_em->ram_bytes = hole_size;
5008 hole_em->bdev = fs_info->fs_devices->latest_bdev;
5009 hole_em->compress_type = BTRFS_COMPRESS_NONE;
5010 hole_em->generation = fs_info->generation;
5011
5012 while (1) {
5013 write_lock(&em_tree->lock);
5014 err = add_extent_mapping(em_tree, hole_em, 1);
5015 write_unlock(&em_tree->lock);
5016 if (err != -EEXIST)
5017 break;
5018 btrfs_drop_extent_cache(BTRFS_I(inode),
5019 cur_offset,
5020 cur_offset +
5021 hole_size - 1, 0);
5022 }
5023 free_extent_map(hole_em);
5024 }
5025 next:
5026 free_extent_map(em);
5027 em = NULL;
5028 cur_offset = last_byte;
5029 if (cur_offset >= block_end)
5030 break;
5031 }
5032 free_extent_map(em);
5033 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
5034 GFP_NOFS);
5035 return err;
5036 }
5037
5038 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
5039 {
5040 struct btrfs_root *root = BTRFS_I(inode)->root;
5041 struct btrfs_trans_handle *trans;
5042 loff_t oldsize = i_size_read(inode);
5043 loff_t newsize = attr->ia_size;
5044 int mask = attr->ia_valid;
5045 int ret;
5046
5047 /*
5048 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
5049 * special case where we need to update the times despite not having
5050 * these flags set. For all other operations the VFS set these flags
5051 * explicitly if it wants a timestamp update.
5052 */
5053 if (newsize != oldsize) {
5054 inode_inc_iversion(inode);
5055 if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
5056 inode->i_ctime = inode->i_mtime =
5057 current_time(inode);
5058 }
5059
5060 if (newsize > oldsize) {
5061 /*
5062 * Don't do an expanding truncate while snapshotting is ongoing.
5063 * This is to ensure the snapshot captures a fully consistent
5064 * state of this file - if the snapshot captures this expanding
5065 * truncation, it must capture all writes that happened before
5066 * this truncation.
5067 */
5068 btrfs_wait_for_snapshot_creation(root);
5069 ret = btrfs_cont_expand(inode, oldsize, newsize);
5070 if (ret) {
5071 btrfs_end_write_no_snapshotting(root);
5072 return ret;
5073 }
5074
5075 trans = btrfs_start_transaction(root, 1);
5076 if (IS_ERR(trans)) {
5077 btrfs_end_write_no_snapshotting(root);
5078 return PTR_ERR(trans);
5079 }
5080
5081 i_size_write(inode, newsize);
5082 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
5083 pagecache_isize_extended(inode, oldsize, newsize);
5084 ret = btrfs_update_inode(trans, root, inode);
5085 btrfs_end_write_no_snapshotting(root);
5086 btrfs_end_transaction(trans);
5087 } else {
5088
5089 /*
5090 * We're truncating a file that used to have good data down to
5091 * zero. Make sure it gets into the ordered flush list so that
5092 * any new writes get down to disk quickly.
5093 */
5094 if (newsize == 0)
5095 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
5096 &BTRFS_I(inode)->runtime_flags);
5097
5098 /*
5099 * 1 for the orphan item we're going to add
5100 * 1 for the orphan item deletion.
5101 */
5102 trans = btrfs_start_transaction(root, 2);
5103 if (IS_ERR(trans))
5104 return PTR_ERR(trans);
5105
5106 /*
5107 * We need to do this in case we fail at _any_ point during the
5108 * actual truncate. Once we do the truncate_setsize we could
5109 * invalidate pages which forces any outstanding ordered io to
5110 * be instantly completed which will give us extents that need
5111 * to be truncated. If we fail to get an orphan inode down we
5112 * could have left over extents that were never meant to live,
5113 * so we need to guarantee from this point on that everything
5114 * will be consistent.
5115 */
5116 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
5117 btrfs_end_transaction(trans);
5118 if (ret)
5119 return ret;
5120
5121 /* we don't support swapfiles, so vmtruncate shouldn't fail */
5122 truncate_setsize(inode, newsize);
5123
5124 /* Disable nonlocked read DIO to avoid the end less truncate */
5125 btrfs_inode_block_unlocked_dio(BTRFS_I(inode));
5126 inode_dio_wait(inode);
5127 btrfs_inode_resume_unlocked_dio(BTRFS_I(inode));
5128
5129 ret = btrfs_truncate(inode);
5130 if (ret && inode->i_nlink) {
5131 int err;
5132
5133 /* To get a stable disk_i_size */
5134 err = btrfs_wait_ordered_range(inode, 0, (u64)-1);
5135 if (err) {
5136 btrfs_orphan_del(NULL, BTRFS_I(inode));
5137 return err;
5138 }
5139
5140 /*
5141 * failed to truncate, disk_i_size is only adjusted down
5142 * as we remove extents, so it should represent the true
5143 * size of the inode, so reset the in memory size and
5144 * delete our orphan entry.
5145 */
5146 trans = btrfs_join_transaction(root);
5147 if (IS_ERR(trans)) {
5148 btrfs_orphan_del(NULL, BTRFS_I(inode));
5149 return ret;
5150 }
5151 i_size_write(inode, BTRFS_I(inode)->disk_i_size);
5152 err = btrfs_orphan_del(trans, BTRFS_I(inode));
5153 if (err)
5154 btrfs_abort_transaction(trans, err);
5155 btrfs_end_transaction(trans);
5156 }
5157 }
5158
5159 return ret;
5160 }
5161
5162 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
5163 {
5164 struct inode *inode = d_inode(dentry);
5165 struct btrfs_root *root = BTRFS_I(inode)->root;
5166 int err;
5167
5168 if (btrfs_root_readonly(root))
5169 return -EROFS;
5170
5171 err = setattr_prepare(dentry, attr);
5172 if (err)
5173 return err;
5174
5175 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
5176 err = btrfs_setsize(inode, attr);
5177 if (err)
5178 return err;
5179 }
5180
5181 if (attr->ia_valid) {
5182 setattr_copy(inode, attr);
5183 inode_inc_iversion(inode);
5184 err = btrfs_dirty_inode(inode);
5185
5186 if (!err && attr->ia_valid & ATTR_MODE)
5187 err = posix_acl_chmod(inode, inode->i_mode);
5188 }
5189
5190 return err;
5191 }
5192
5193 /*
5194 * While truncating the inode pages during eviction, we get the VFS calling
5195 * btrfs_invalidatepage() against each page of the inode. This is slow because
5196 * the calls to btrfs_invalidatepage() result in a huge amount of calls to
5197 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
5198 * extent_state structures over and over, wasting lots of time.
5199 *
5200 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
5201 * those expensive operations on a per page basis and do only the ordered io
5202 * finishing, while we release here the extent_map and extent_state structures,
5203 * without the excessive merging and splitting.
5204 */
5205 static void evict_inode_truncate_pages(struct inode *inode)
5206 {
5207 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5208 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
5209 struct rb_node *node;
5210
5211 ASSERT(inode->i_state & I_FREEING);
5212 truncate_inode_pages_final(&inode->i_data);
5213
5214 write_lock(&map_tree->lock);
5215 while (!RB_EMPTY_ROOT(&map_tree->map)) {
5216 struct extent_map *em;
5217
5218 node = rb_first(&map_tree->map);
5219 em = rb_entry(node, struct extent_map, rb_node);
5220 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
5221 clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
5222 remove_extent_mapping(map_tree, em);
5223 free_extent_map(em);
5224 if (need_resched()) {
5225 write_unlock(&map_tree->lock);
5226 cond_resched();
5227 write_lock(&map_tree->lock);
5228 }
5229 }
5230 write_unlock(&map_tree->lock);
5231
5232 /*
5233 * Keep looping until we have no more ranges in the io tree.
5234 * We can have ongoing bios started by readpages (called from readahead)
5235 * that have their endio callback (extent_io.c:end_bio_extent_readpage)
5236 * still in progress (unlocked the pages in the bio but did not yet
5237 * unlocked the ranges in the io tree). Therefore this means some
5238 * ranges can still be locked and eviction started because before
5239 * submitting those bios, which are executed by a separate task (work
5240 * queue kthread), inode references (inode->i_count) were not taken
5241 * (which would be dropped in the end io callback of each bio).
5242 * Therefore here we effectively end up waiting for those bios and
5243 * anyone else holding locked ranges without having bumped the inode's
5244 * reference count - if we don't do it, when they access the inode's
5245 * io_tree to unlock a range it may be too late, leading to an
5246 * use-after-free issue.
5247 */
5248 spin_lock(&io_tree->lock);
5249 while (!RB_EMPTY_ROOT(&io_tree->state)) {
5250 struct extent_state *state;
5251 struct extent_state *cached_state = NULL;
5252 u64 start;
5253 u64 end;
5254
5255 node = rb_first(&io_tree->state);
5256 state = rb_entry(node, struct extent_state, rb_node);
5257 start = state->start;
5258 end = state->end;
5259 spin_unlock(&io_tree->lock);
5260
5261 lock_extent_bits(io_tree, start, end, &cached_state);
5262
5263 /*
5264 * If still has DELALLOC flag, the extent didn't reach disk,
5265 * and its reserved space won't be freed by delayed_ref.
5266 * So we need to free its reserved space here.
5267 * (Refer to comment in btrfs_invalidatepage, case 2)
5268 *
5269 * Note, end is the bytenr of last byte, so we need + 1 here.
5270 */
5271 if (state->state & EXTENT_DELALLOC)
5272 btrfs_qgroup_free_data(inode, NULL, start, end - start + 1);
5273
5274 clear_extent_bit(io_tree, start, end,
5275 EXTENT_LOCKED | EXTENT_DIRTY |
5276 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
5277 EXTENT_DEFRAG, 1, 1,
5278 &cached_state, GFP_NOFS);
5279
5280 cond_resched();
5281 spin_lock(&io_tree->lock);
5282 }
5283 spin_unlock(&io_tree->lock);
5284 }
5285
5286 void btrfs_evict_inode(struct inode *inode)
5287 {
5288 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5289 struct btrfs_trans_handle *trans;
5290 struct btrfs_root *root = BTRFS_I(inode)->root;
5291 struct btrfs_block_rsv *rsv, *global_rsv;
5292 int steal_from_global = 0;
5293 u64 min_size;
5294 int ret;
5295
5296 trace_btrfs_inode_evict(inode);
5297
5298 if (!root) {
5299 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
5300 return;
5301 }
5302
5303 min_size = btrfs_calc_trunc_metadata_size(fs_info, 1);
5304
5305 evict_inode_truncate_pages(inode);
5306
5307 if (inode->i_nlink &&
5308 ((btrfs_root_refs(&root->root_item) != 0 &&
5309 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
5310 btrfs_is_free_space_inode(BTRFS_I(inode))))
5311 goto no_delete;
5312
5313 if (is_bad_inode(inode)) {
5314 btrfs_orphan_del(NULL, BTRFS_I(inode));
5315 goto no_delete;
5316 }
5317 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
5318 if (!special_file(inode->i_mode))
5319 btrfs_wait_ordered_range(inode, 0, (u64)-1);
5320
5321 btrfs_free_io_failure_record(BTRFS_I(inode), 0, (u64)-1);
5322
5323 if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) {
5324 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
5325 &BTRFS_I(inode)->runtime_flags));
5326 goto no_delete;
5327 }
5328
5329 if (inode->i_nlink > 0) {
5330 BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
5331 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
5332 goto no_delete;
5333 }
5334
5335 ret = btrfs_commit_inode_delayed_inode(BTRFS_I(inode));
5336 if (ret) {
5337 btrfs_orphan_del(NULL, BTRFS_I(inode));
5338 goto no_delete;
5339 }
5340
5341 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
5342 if (!rsv) {
5343 btrfs_orphan_del(NULL, BTRFS_I(inode));
5344 goto no_delete;
5345 }
5346 rsv->size = min_size;
5347 rsv->failfast = 1;
5348 global_rsv = &fs_info->global_block_rsv;
5349
5350 btrfs_i_size_write(BTRFS_I(inode), 0);
5351
5352 /*
5353 * This is a bit simpler than btrfs_truncate since we've already
5354 * reserved our space for our orphan item in the unlink, so we just
5355 * need to reserve some slack space in case we add bytes and update
5356 * inode item when doing the truncate.
5357 */
5358 while (1) {
5359 ret = btrfs_block_rsv_refill(root, rsv, min_size,
5360 BTRFS_RESERVE_FLUSH_LIMIT);
5361
5362 /*
5363 * Try and steal from the global reserve since we will
5364 * likely not use this space anyway, we want to try as
5365 * hard as possible to get this to work.
5366 */
5367 if (ret)
5368 steal_from_global++;
5369 else
5370 steal_from_global = 0;
5371 ret = 0;
5372
5373 /*
5374 * steal_from_global == 0: we reserved stuff, hooray!
5375 * steal_from_global == 1: we didn't reserve stuff, boo!
5376 * steal_from_global == 2: we've committed, still not a lot of
5377 * room but maybe we'll have room in the global reserve this
5378 * time.
5379 * steal_from_global == 3: abandon all hope!
5380 */
5381 if (steal_from_global > 2) {
5382 btrfs_warn(fs_info,
5383 "Could not get space for a delete, will truncate on mount %d",
5384 ret);
5385 btrfs_orphan_del(NULL, BTRFS_I(inode));
5386 btrfs_free_block_rsv(fs_info, rsv);
5387 goto no_delete;
5388 }
5389
5390 trans = btrfs_join_transaction(root);
5391 if (IS_ERR(trans)) {
5392 btrfs_orphan_del(NULL, BTRFS_I(inode));
5393 btrfs_free_block_rsv(fs_info, rsv);
5394 goto no_delete;
5395 }
5396
5397 /*
5398 * We can't just steal from the global reserve, we need to make
5399 * sure there is room to do it, if not we need to commit and try
5400 * again.
5401 */
5402 if (steal_from_global) {
5403 if (!btrfs_check_space_for_delayed_refs(trans, fs_info))
5404 ret = btrfs_block_rsv_migrate(global_rsv, rsv,
5405 min_size, 0);
5406 else
5407 ret = -ENOSPC;
5408 }
5409
5410 /*
5411 * Couldn't steal from the global reserve, we have too much
5412 * pending stuff built up, commit the transaction and try it
5413 * again.
5414 */
5415 if (ret) {
5416 ret = btrfs_commit_transaction(trans);
5417 if (ret) {
5418 btrfs_orphan_del(NULL, BTRFS_I(inode));
5419 btrfs_free_block_rsv(fs_info, rsv);
5420 goto no_delete;
5421 }
5422 continue;
5423 } else {
5424 steal_from_global = 0;
5425 }
5426
5427 trans->block_rsv = rsv;
5428
5429 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
5430 if (ret != -ENOSPC && ret != -EAGAIN)
5431 break;
5432
5433 trans->block_rsv = &fs_info->trans_block_rsv;
5434 btrfs_end_transaction(trans);
5435 trans = NULL;
5436 btrfs_btree_balance_dirty(fs_info);
5437 }
5438
5439 btrfs_free_block_rsv(fs_info, rsv);
5440
5441 /*
5442 * Errors here aren't a big deal, it just means we leave orphan items
5443 * in the tree. They will be cleaned up on the next mount.
5444 */
5445 if (ret == 0) {
5446 trans->block_rsv = root->orphan_block_rsv;
5447 btrfs_orphan_del(trans, BTRFS_I(inode));
5448 } else {
5449 btrfs_orphan_del(NULL, BTRFS_I(inode));
5450 }
5451
5452 trans->block_rsv = &fs_info->trans_block_rsv;
5453 if (!(root == fs_info->tree_root ||
5454 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
5455 btrfs_return_ino(root, btrfs_ino(BTRFS_I(inode)));
5456
5457 btrfs_end_transaction(trans);
5458 btrfs_btree_balance_dirty(fs_info);
5459 no_delete:
5460 btrfs_remove_delayed_node(BTRFS_I(inode));
5461 clear_inode(inode);
5462 }
5463
5464 /*
5465 * this returns the key found in the dir entry in the location pointer.
5466 * If no dir entries were found, location->objectid is 0.
5467 */
5468 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
5469 struct btrfs_key *location)
5470 {
5471 const char *name = dentry->d_name.name;
5472 int namelen = dentry->d_name.len;
5473 struct btrfs_dir_item *di;
5474 struct btrfs_path *path;
5475 struct btrfs_root *root = BTRFS_I(dir)->root;
5476 int ret = 0;
5477
5478 path = btrfs_alloc_path();
5479 if (!path)
5480 return -ENOMEM;
5481
5482 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(BTRFS_I(dir)),
5483 name, namelen, 0);
5484 if (IS_ERR(di))
5485 ret = PTR_ERR(di);
5486
5487 if (IS_ERR_OR_NULL(di))
5488 goto out_err;
5489
5490 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
5491 out:
5492 btrfs_free_path(path);
5493 return ret;
5494 out_err:
5495 location->objectid = 0;
5496 goto out;
5497 }
5498
5499 /*
5500 * when we hit a tree root in a directory, the btrfs part of the inode
5501 * needs to be changed to reflect the root directory of the tree root. This
5502 * is kind of like crossing a mount point.
5503 */
5504 static int fixup_tree_root_location(struct btrfs_fs_info *fs_info,
5505 struct inode *dir,
5506 struct dentry *dentry,
5507 struct btrfs_key *location,
5508 struct btrfs_root **sub_root)
5509 {
5510 struct btrfs_path *path;
5511 struct btrfs_root *new_root;
5512 struct btrfs_root_ref *ref;
5513 struct extent_buffer *leaf;
5514 struct btrfs_key key;
5515 int ret;
5516 int err = 0;
5517
5518 path = btrfs_alloc_path();
5519 if (!path) {
5520 err = -ENOMEM;
5521 goto out;
5522 }
5523
5524 err = -ENOENT;
5525 key.objectid = BTRFS_I(dir)->root->root_key.objectid;
5526 key.type = BTRFS_ROOT_REF_KEY;
5527 key.offset = location->objectid;
5528
5529 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
5530 if (ret) {
5531 if (ret < 0)
5532 err = ret;
5533 goto out;
5534 }
5535
5536 leaf = path->nodes[0];
5537 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
5538 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(BTRFS_I(dir)) ||
5539 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
5540 goto out;
5541
5542 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
5543 (unsigned long)(ref + 1),
5544 dentry->d_name.len);
5545 if (ret)
5546 goto out;
5547
5548 btrfs_release_path(path);
5549
5550 new_root = btrfs_read_fs_root_no_name(fs_info, location);
5551 if (IS_ERR(new_root)) {
5552 err = PTR_ERR(new_root);
5553 goto out;
5554 }
5555
5556 *sub_root = new_root;
5557 location->objectid = btrfs_root_dirid(&new_root->root_item);
5558 location->type = BTRFS_INODE_ITEM_KEY;
5559 location->offset = 0;
5560 err = 0;
5561 out:
5562 btrfs_free_path(path);
5563 return err;
5564 }
5565
5566 static void inode_tree_add(struct inode *inode)
5567 {
5568 struct btrfs_root *root = BTRFS_I(inode)->root;
5569 struct btrfs_inode *entry;
5570 struct rb_node **p;
5571 struct rb_node *parent;
5572 struct rb_node *new = &BTRFS_I(inode)->rb_node;
5573 u64 ino = btrfs_ino(BTRFS_I(inode));
5574
5575 if (inode_unhashed(inode))
5576 return;
5577 parent = NULL;
5578 spin_lock(&root->inode_lock);
5579 p = &root->inode_tree.rb_node;
5580 while (*p) {
5581 parent = *p;
5582 entry = rb_entry(parent, struct btrfs_inode, rb_node);
5583
5584 if (ino < btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5585 p = &parent->rb_left;
5586 else if (ino > btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5587 p = &parent->rb_right;
5588 else {
5589 WARN_ON(!(entry->vfs_inode.i_state &
5590 (I_WILL_FREE | I_FREEING)));
5591 rb_replace_node(parent, new, &root->inode_tree);
5592 RB_CLEAR_NODE(parent);
5593 spin_unlock(&root->inode_lock);
5594 return;
5595 }
5596 }
5597 rb_link_node(new, parent, p);
5598 rb_insert_color(new, &root->inode_tree);
5599 spin_unlock(&root->inode_lock);
5600 }
5601
5602 static void inode_tree_del(struct inode *inode)
5603 {
5604 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5605 struct btrfs_root *root = BTRFS_I(inode)->root;
5606 int empty = 0;
5607
5608 spin_lock(&root->inode_lock);
5609 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
5610 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
5611 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
5612 empty = RB_EMPTY_ROOT(&root->inode_tree);
5613 }
5614 spin_unlock(&root->inode_lock);
5615
5616 if (empty && btrfs_root_refs(&root->root_item) == 0) {
5617 synchronize_srcu(&fs_info->subvol_srcu);
5618 spin_lock(&root->inode_lock);
5619 empty = RB_EMPTY_ROOT(&root->inode_tree);
5620 spin_unlock(&root->inode_lock);
5621 if (empty)
5622 btrfs_add_dead_root(root);
5623 }
5624 }
5625
5626 void btrfs_invalidate_inodes(struct btrfs_root *root)
5627 {
5628 struct btrfs_fs_info *fs_info = root->fs_info;
5629 struct rb_node *node;
5630 struct rb_node *prev;
5631 struct btrfs_inode *entry;
5632 struct inode *inode;
5633 u64 objectid = 0;
5634
5635 if (!test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
5636 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
5637
5638 spin_lock(&root->inode_lock);
5639 again:
5640 node = root->inode_tree.rb_node;
5641 prev = NULL;
5642 while (node) {
5643 prev = node;
5644 entry = rb_entry(node, struct btrfs_inode, rb_node);
5645
5646 if (objectid < btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5647 node = node->rb_left;
5648 else if (objectid > btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5649 node = node->rb_right;
5650 else
5651 break;
5652 }
5653 if (!node) {
5654 while (prev) {
5655 entry = rb_entry(prev, struct btrfs_inode, rb_node);
5656 if (objectid <= btrfs_ino(BTRFS_I(&entry->vfs_inode))) {
5657 node = prev;
5658 break;
5659 }
5660 prev = rb_next(prev);
5661 }
5662 }
5663 while (node) {
5664 entry = rb_entry(node, struct btrfs_inode, rb_node);
5665 objectid = btrfs_ino(BTRFS_I(&entry->vfs_inode)) + 1;
5666 inode = igrab(&entry->vfs_inode);
5667 if (inode) {
5668 spin_unlock(&root->inode_lock);
5669 if (atomic_read(&inode->i_count) > 1)
5670 d_prune_aliases(inode);
5671 /*
5672 * btrfs_drop_inode will have it removed from
5673 * the inode cache when its usage count
5674 * hits zero.
5675 */
5676 iput(inode);
5677 cond_resched();
5678 spin_lock(&root->inode_lock);
5679 goto again;
5680 }
5681
5682 if (cond_resched_lock(&root->inode_lock))
5683 goto again;
5684
5685 node = rb_next(node);
5686 }
5687 spin_unlock(&root->inode_lock);
5688 }
5689
5690 static int btrfs_init_locked_inode(struct inode *inode, void *p)
5691 {
5692 struct btrfs_iget_args *args = p;
5693 inode->i_ino = args->location->objectid;
5694 memcpy(&BTRFS_I(inode)->location, args->location,
5695 sizeof(*args->location));
5696 BTRFS_I(inode)->root = args->root;
5697 return 0;
5698 }
5699
5700 static int btrfs_find_actor(struct inode *inode, void *opaque)
5701 {
5702 struct btrfs_iget_args *args = opaque;
5703 return args->location->objectid == BTRFS_I(inode)->location.objectid &&
5704 args->root == BTRFS_I(inode)->root;
5705 }
5706
5707 static struct inode *btrfs_iget_locked(struct super_block *s,
5708 struct btrfs_key *location,
5709 struct btrfs_root *root)
5710 {
5711 struct inode *inode;
5712 struct btrfs_iget_args args;
5713 unsigned long hashval = btrfs_inode_hash(location->objectid, root);
5714
5715 args.location = location;
5716 args.root = root;
5717
5718 inode = iget5_locked(s, hashval, btrfs_find_actor,
5719 btrfs_init_locked_inode,
5720 (void *)&args);
5721 return inode;
5722 }
5723
5724 /* Get an inode object given its location and corresponding root.
5725 * Returns in *is_new if the inode was read from disk
5726 */
5727 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
5728 struct btrfs_root *root, int *new)
5729 {
5730 struct inode *inode;
5731
5732 inode = btrfs_iget_locked(s, location, root);
5733 if (!inode)
5734 return ERR_PTR(-ENOMEM);
5735
5736 if (inode->i_state & I_NEW) {
5737 int ret;
5738
5739 ret = btrfs_read_locked_inode(inode);
5740 if (!is_bad_inode(inode)) {
5741 inode_tree_add(inode);
5742 unlock_new_inode(inode);
5743 if (new)
5744 *new = 1;
5745 } else {
5746 unlock_new_inode(inode);
5747 iput(inode);
5748 ASSERT(ret < 0);
5749 inode = ERR_PTR(ret < 0 ? ret : -ESTALE);
5750 }
5751 }
5752
5753 return inode;
5754 }
5755
5756 static struct inode *new_simple_dir(struct super_block *s,
5757 struct btrfs_key *key,
5758 struct btrfs_root *root)
5759 {
5760 struct inode *inode = new_inode(s);
5761
5762 if (!inode)
5763 return ERR_PTR(-ENOMEM);
5764
5765 BTRFS_I(inode)->root = root;
5766 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5767 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5768
5769 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5770 inode->i_op = &btrfs_dir_ro_inode_operations;
5771 inode->i_opflags &= ~IOP_XATTR;
5772 inode->i_fop = &simple_dir_operations;
5773 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5774 inode->i_mtime = current_time(inode);
5775 inode->i_atime = inode->i_mtime;
5776 inode->i_ctime = inode->i_mtime;
5777 BTRFS_I(inode)->i_otime = inode->i_mtime;
5778
5779 return inode;
5780 }
5781
5782 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5783 {
5784 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
5785 struct inode *inode;
5786 struct btrfs_root *root = BTRFS_I(dir)->root;
5787 struct btrfs_root *sub_root = root;
5788 struct btrfs_key location;
5789 int index;
5790 int ret = 0;
5791
5792 if (dentry->d_name.len > BTRFS_NAME_LEN)
5793 return ERR_PTR(-ENAMETOOLONG);
5794
5795 ret = btrfs_inode_by_name(dir, dentry, &location);
5796 if (ret < 0)
5797 return ERR_PTR(ret);
5798
5799 if (location.objectid == 0)
5800 return ERR_PTR(-ENOENT);
5801
5802 if (location.type == BTRFS_INODE_ITEM_KEY) {
5803 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5804 return inode;
5805 }
5806
5807 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
5808
5809 index = srcu_read_lock(&fs_info->subvol_srcu);
5810 ret = fixup_tree_root_location(fs_info, dir, dentry,
5811 &location, &sub_root);
5812 if (ret < 0) {
5813 if (ret != -ENOENT)
5814 inode = ERR_PTR(ret);
5815 else
5816 inode = new_simple_dir(dir->i_sb, &location, sub_root);
5817 } else {
5818 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
5819 }
5820 srcu_read_unlock(&fs_info->subvol_srcu, index);
5821
5822 if (!IS_ERR(inode) && root != sub_root) {
5823 down_read(&fs_info->cleanup_work_sem);
5824 if (!(inode->i_sb->s_flags & MS_RDONLY))
5825 ret = btrfs_orphan_cleanup(sub_root);
5826 up_read(&fs_info->cleanup_work_sem);
5827 if (ret) {
5828 iput(inode);
5829 inode = ERR_PTR(ret);
5830 }
5831 }
5832
5833 return inode;
5834 }
5835
5836 static int btrfs_dentry_delete(const struct dentry *dentry)
5837 {
5838 struct btrfs_root *root;
5839 struct inode *inode = d_inode(dentry);
5840
5841 if (!inode && !IS_ROOT(dentry))
5842 inode = d_inode(dentry->d_parent);
5843
5844 if (inode) {
5845 root = BTRFS_I(inode)->root;
5846 if (btrfs_root_refs(&root->root_item) == 0)
5847 return 1;
5848
5849 if (btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5850 return 1;
5851 }
5852 return 0;
5853 }
5854
5855 static void btrfs_dentry_release(struct dentry *dentry)
5856 {
5857 kfree(dentry->d_fsdata);
5858 }
5859
5860 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5861 unsigned int flags)
5862 {
5863 struct inode *inode;
5864
5865 inode = btrfs_lookup_dentry(dir, dentry);
5866 if (IS_ERR(inode)) {
5867 if (PTR_ERR(inode) == -ENOENT)
5868 inode = NULL;
5869 else
5870 return ERR_CAST(inode);
5871 }
5872
5873 return d_splice_alias(inode, dentry);
5874 }
5875
5876 unsigned char btrfs_filetype_table[] = {
5877 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5878 };
5879
5880 /*
5881 * All this infrastructure exists because dir_emit can fault, and we are holding
5882 * the tree lock when doing readdir. For now just allocate a buffer and copy
5883 * our information into that, and then dir_emit from the buffer. This is
5884 * similar to what NFS does, only we don't keep the buffer around in pagecache
5885 * because I'm afraid I'll mess that up. Long term we need to make filldir do
5886 * copy_to_user_inatomic so we don't have to worry about page faulting under the
5887 * tree lock.
5888 */
5889 static int btrfs_opendir(struct inode *inode, struct file *file)
5890 {
5891 struct btrfs_file_private *private;
5892
5893 private = kzalloc(sizeof(struct btrfs_file_private), GFP_KERNEL);
5894 if (!private)
5895 return -ENOMEM;
5896 private->filldir_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
5897 if (!private->filldir_buf) {
5898 kfree(private);
5899 return -ENOMEM;
5900 }
5901 file->private_data = private;
5902 return 0;
5903 }
5904
5905 struct dir_entry {
5906 u64 ino;
5907 u64 offset;
5908 unsigned type;
5909 int name_len;
5910 };
5911
5912 static int btrfs_filldir(void *addr, int entries, struct dir_context *ctx)
5913 {
5914 while (entries--) {
5915 struct dir_entry *entry = addr;
5916 char *name = (char *)(entry + 1);
5917
5918 ctx->pos = entry->offset;
5919 if (!dir_emit(ctx, name, entry->name_len, entry->ino,
5920 entry->type))
5921 return 1;
5922 addr += sizeof(struct dir_entry) + entry->name_len;
5923 ctx->pos++;
5924 }
5925 return 0;
5926 }
5927
5928 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
5929 {
5930 struct inode *inode = file_inode(file);
5931 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5932 struct btrfs_root *root = BTRFS_I(inode)->root;
5933 struct btrfs_file_private *private = file->private_data;
5934 struct btrfs_dir_item *di;
5935 struct btrfs_key key;
5936 struct btrfs_key found_key;
5937 struct btrfs_path *path;
5938 void *addr;
5939 struct list_head ins_list;
5940 struct list_head del_list;
5941 int ret;
5942 struct extent_buffer *leaf;
5943 int slot;
5944 char *name_ptr;
5945 int name_len;
5946 int entries = 0;
5947 int total_len = 0;
5948 bool put = false;
5949 struct btrfs_key location;
5950
5951 if (!dir_emit_dots(file, ctx))
5952 return 0;
5953
5954 path = btrfs_alloc_path();
5955 if (!path)
5956 return -ENOMEM;
5957
5958 addr = private->filldir_buf;
5959 path->reada = READA_FORWARD;
5960
5961 INIT_LIST_HEAD(&ins_list);
5962 INIT_LIST_HEAD(&del_list);
5963 put = btrfs_readdir_get_delayed_items(inode, &ins_list, &del_list);
5964
5965 again:
5966 key.type = BTRFS_DIR_INDEX_KEY;
5967 key.offset = ctx->pos;
5968 key.objectid = btrfs_ino(BTRFS_I(inode));
5969
5970 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5971 if (ret < 0)
5972 goto err;
5973
5974 while (1) {
5975 struct dir_entry *entry;
5976
5977 leaf = path->nodes[0];
5978 slot = path->slots[0];
5979 if (slot >= btrfs_header_nritems(leaf)) {
5980 ret = btrfs_next_leaf(root, path);
5981 if (ret < 0)
5982 goto err;
5983 else if (ret > 0)
5984 break;
5985 continue;
5986 }
5987
5988 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5989
5990 if (found_key.objectid != key.objectid)
5991 break;
5992 if (found_key.type != BTRFS_DIR_INDEX_KEY)
5993 break;
5994 if (found_key.offset < ctx->pos)
5995 goto next;
5996 if (btrfs_should_delete_dir_index(&del_list, found_key.offset))
5997 goto next;
5998 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5999 if (verify_dir_item(fs_info, leaf, slot, di))
6000 goto next;
6001
6002 name_len = btrfs_dir_name_len(leaf, di);
6003 if ((total_len + sizeof(struct dir_entry) + name_len) >=
6004 PAGE_SIZE) {
6005 btrfs_release_path(path);
6006 ret = btrfs_filldir(private->filldir_buf, entries, ctx);
6007 if (ret)
6008 goto nopos;
6009 addr = private->filldir_buf;
6010 entries = 0;
6011 total_len = 0;
6012 goto again;
6013 }
6014
6015 entry = addr;
6016 entry->name_len = name_len;
6017 name_ptr = (char *)(entry + 1);
6018 read_extent_buffer(leaf, name_ptr, (unsigned long)(di + 1),
6019 name_len);
6020 entry->type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
6021 btrfs_dir_item_key_to_cpu(leaf, di, &location);
6022 entry->ino = location.objectid;
6023 entry->offset = found_key.offset;
6024 entries++;
6025 addr += sizeof(struct dir_entry) + name_len;
6026 total_len += sizeof(struct dir_entry) + name_len;
6027 next:
6028 path->slots[0]++;
6029 }
6030 btrfs_release_path(path);
6031
6032 ret = btrfs_filldir(private->filldir_buf, entries, ctx);
6033 if (ret)
6034 goto nopos;
6035
6036 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
6037 if (ret)
6038 goto nopos;
6039
6040 /*
6041 * Stop new entries from being returned after we return the last
6042 * entry.
6043 *
6044 * New directory entries are assigned a strictly increasing
6045 * offset. This means that new entries created during readdir
6046 * are *guaranteed* to be seen in the future by that readdir.
6047 * This has broken buggy programs which operate on names as
6048 * they're returned by readdir. Until we re-use freed offsets
6049 * we have this hack to stop new entries from being returned
6050 * under the assumption that they'll never reach this huge
6051 * offset.
6052 *
6053 * This is being careful not to overflow 32bit loff_t unless the
6054 * last entry requires it because doing so has broken 32bit apps
6055 * in the past.
6056 */
6057 if (ctx->pos >= INT_MAX)
6058 ctx->pos = LLONG_MAX;
6059 else
6060 ctx->pos = INT_MAX;
6061 nopos:
6062 ret = 0;
6063 err:
6064 if (put)
6065 btrfs_readdir_put_delayed_items(inode, &ins_list, &del_list);
6066 btrfs_free_path(path);
6067 return ret;
6068 }
6069
6070 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
6071 {
6072 struct btrfs_root *root = BTRFS_I(inode)->root;
6073 struct btrfs_trans_handle *trans;
6074 int ret = 0;
6075 bool nolock = false;
6076
6077 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
6078 return 0;
6079
6080 if (btrfs_fs_closing(root->fs_info) &&
6081 btrfs_is_free_space_inode(BTRFS_I(inode)))
6082 nolock = true;
6083
6084 if (wbc->sync_mode == WB_SYNC_ALL) {
6085 if (nolock)
6086 trans = btrfs_join_transaction_nolock(root);
6087 else
6088 trans = btrfs_join_transaction(root);
6089 if (IS_ERR(trans))
6090 return PTR_ERR(trans);
6091 ret = btrfs_commit_transaction(trans);
6092 }
6093 return ret;
6094 }
6095
6096 /*
6097 * This is somewhat expensive, updating the tree every time the
6098 * inode changes. But, it is most likely to find the inode in cache.
6099 * FIXME, needs more benchmarking...there are no reasons other than performance
6100 * to keep or drop this code.
6101 */
6102 static int btrfs_dirty_inode(struct inode *inode)
6103 {
6104 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
6105 struct btrfs_root *root = BTRFS_I(inode)->root;
6106 struct btrfs_trans_handle *trans;
6107 int ret;
6108
6109 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
6110 return 0;
6111
6112 trans = btrfs_join_transaction(root);
6113 if (IS_ERR(trans))
6114 return PTR_ERR(trans);
6115
6116 ret = btrfs_update_inode(trans, root, inode);
6117 if (ret && ret == -ENOSPC) {
6118 /* whoops, lets try again with the full transaction */
6119 btrfs_end_transaction(trans);
6120 trans = btrfs_start_transaction(root, 1);
6121 if (IS_ERR(trans))
6122 return PTR_ERR(trans);
6123
6124 ret = btrfs_update_inode(trans, root, inode);
6125 }
6126 btrfs_end_transaction(trans);
6127 if (BTRFS_I(inode)->delayed_node)
6128 btrfs_balance_delayed_items(fs_info);
6129
6130 return ret;
6131 }
6132
6133 /*
6134 * This is a copy of file_update_time. We need this so we can return error on
6135 * ENOSPC for updating the inode in the case of file write and mmap writes.
6136 */
6137 static int btrfs_update_time(struct inode *inode, struct timespec *now,
6138 int flags)
6139 {
6140 struct btrfs_root *root = BTRFS_I(inode)->root;
6141
6142 if (btrfs_root_readonly(root))
6143 return -EROFS;
6144
6145 if (flags & S_VERSION)
6146 inode_inc_iversion(inode);
6147 if (flags & S_CTIME)
6148 inode->i_ctime = *now;
6149 if (flags & S_MTIME)
6150 inode->i_mtime = *now;
6151 if (flags & S_ATIME)
6152 inode->i_atime = *now;
6153 return btrfs_dirty_inode(inode);
6154 }
6155
6156 /*
6157 * find the highest existing sequence number in a directory
6158 * and then set the in-memory index_cnt variable to reflect
6159 * free sequence numbers
6160 */
6161 static int btrfs_set_inode_index_count(struct btrfs_inode *inode)
6162 {
6163 struct btrfs_root *root = inode->root;
6164 struct btrfs_key key, found_key;
6165 struct btrfs_path *path;
6166 struct extent_buffer *leaf;
6167 int ret;
6168
6169 key.objectid = btrfs_ino(inode);
6170 key.type = BTRFS_DIR_INDEX_KEY;
6171 key.offset = (u64)-1;
6172
6173 path = btrfs_alloc_path();
6174 if (!path)
6175 return -ENOMEM;
6176
6177 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6178 if (ret < 0)
6179 goto out;
6180 /* FIXME: we should be able to handle this */
6181 if (ret == 0)
6182 goto out;
6183 ret = 0;
6184
6185 /*
6186 * MAGIC NUMBER EXPLANATION:
6187 * since we search a directory based on f_pos we have to start at 2
6188 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
6189 * else has to start at 2
6190 */
6191 if (path->slots[0] == 0) {
6192 inode->index_cnt = 2;
6193 goto out;
6194 }
6195
6196 path->slots[0]--;
6197
6198 leaf = path->nodes[0];
6199 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6200
6201 if (found_key.objectid != btrfs_ino(inode) ||
6202 found_key.type != BTRFS_DIR_INDEX_KEY) {
6203 inode->index_cnt = 2;
6204 goto out;
6205 }
6206
6207 inode->index_cnt = found_key.offset + 1;
6208 out:
6209 btrfs_free_path(path);
6210 return ret;
6211 }
6212
6213 /*
6214 * helper to find a free sequence number in a given directory. This current
6215 * code is very simple, later versions will do smarter things in the btree
6216 */
6217 int btrfs_set_inode_index(struct btrfs_inode *dir, u64 *index)
6218 {
6219 int ret = 0;
6220
6221 if (dir->index_cnt == (u64)-1) {
6222 ret = btrfs_inode_delayed_dir_index_count(dir);
6223 if (ret) {
6224 ret = btrfs_set_inode_index_count(dir);
6225 if (ret)
6226 return ret;
6227 }
6228 }
6229
6230 *index = dir->index_cnt;
6231 dir->index_cnt++;
6232
6233 return ret;
6234 }
6235
6236 static int btrfs_insert_inode_locked(struct inode *inode)
6237 {
6238 struct btrfs_iget_args args;
6239 args.location = &BTRFS_I(inode)->location;
6240 args.root = BTRFS_I(inode)->root;
6241
6242 return insert_inode_locked4(inode,
6243 btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
6244 btrfs_find_actor, &args);
6245 }
6246
6247 /*
6248 * Inherit flags from the parent inode.
6249 *
6250 * Currently only the compression flags and the cow flags are inherited.
6251 */
6252 static void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
6253 {
6254 unsigned int flags;
6255
6256 if (!dir)
6257 return;
6258
6259 flags = BTRFS_I(dir)->flags;
6260
6261 if (flags & BTRFS_INODE_NOCOMPRESS) {
6262 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
6263 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
6264 } else if (flags & BTRFS_INODE_COMPRESS) {
6265 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
6266 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
6267 }
6268
6269 if (flags & BTRFS_INODE_NODATACOW) {
6270 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
6271 if (S_ISREG(inode->i_mode))
6272 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6273 }
6274
6275 btrfs_update_iflags(inode);
6276 }
6277
6278 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
6279 struct btrfs_root *root,
6280 struct inode *dir,
6281 const char *name, int name_len,
6282 u64 ref_objectid, u64 objectid,
6283 umode_t mode, u64 *index)
6284 {
6285 struct btrfs_fs_info *fs_info = root->fs_info;
6286 struct inode *inode;
6287 struct btrfs_inode_item *inode_item;
6288 struct btrfs_key *location;
6289 struct btrfs_path *path;
6290 struct btrfs_inode_ref *ref;
6291 struct btrfs_key key[2];
6292 u32 sizes[2];
6293 int nitems = name ? 2 : 1;
6294 unsigned long ptr;
6295 int ret;
6296
6297 path = btrfs_alloc_path();
6298 if (!path)
6299 return ERR_PTR(-ENOMEM);
6300
6301 inode = new_inode(fs_info->sb);
6302 if (!inode) {
6303 btrfs_free_path(path);
6304 return ERR_PTR(-ENOMEM);
6305 }
6306
6307 /*
6308 * O_TMPFILE, set link count to 0, so that after this point,
6309 * we fill in an inode item with the correct link count.
6310 */
6311 if (!name)
6312 set_nlink(inode, 0);
6313
6314 /*
6315 * we have to initialize this early, so we can reclaim the inode
6316 * number if we fail afterwards in this function.
6317 */
6318 inode->i_ino = objectid;
6319
6320 if (dir && name) {
6321 trace_btrfs_inode_request(dir);
6322
6323 ret = btrfs_set_inode_index(BTRFS_I(dir), index);
6324 if (ret) {
6325 btrfs_free_path(path);
6326 iput(inode);
6327 return ERR_PTR(ret);
6328 }
6329 } else if (dir) {
6330 *index = 0;
6331 }
6332 /*
6333 * index_cnt is ignored for everything but a dir,
6334 * btrfs_get_inode_index_count has an explanation for the magic
6335 * number
6336 */
6337 BTRFS_I(inode)->index_cnt = 2;
6338 BTRFS_I(inode)->dir_index = *index;
6339 BTRFS_I(inode)->root = root;
6340 BTRFS_I(inode)->generation = trans->transid;
6341 inode->i_generation = BTRFS_I(inode)->generation;
6342
6343 /*
6344 * We could have gotten an inode number from somebody who was fsynced
6345 * and then removed in this same transaction, so let's just set full
6346 * sync since it will be a full sync anyway and this will blow away the
6347 * old info in the log.
6348 */
6349 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
6350
6351 key[0].objectid = objectid;
6352 key[0].type = BTRFS_INODE_ITEM_KEY;
6353 key[0].offset = 0;
6354
6355 sizes[0] = sizeof(struct btrfs_inode_item);
6356
6357 if (name) {
6358 /*
6359 * Start new inodes with an inode_ref. This is slightly more
6360 * efficient for small numbers of hard links since they will
6361 * be packed into one item. Extended refs will kick in if we
6362 * add more hard links than can fit in the ref item.
6363 */
6364 key[1].objectid = objectid;
6365 key[1].type = BTRFS_INODE_REF_KEY;
6366 key[1].offset = ref_objectid;
6367
6368 sizes[1] = name_len + sizeof(*ref);
6369 }
6370
6371 location = &BTRFS_I(inode)->location;
6372 location->objectid = objectid;
6373 location->offset = 0;
6374 location->type = BTRFS_INODE_ITEM_KEY;
6375
6376 ret = btrfs_insert_inode_locked(inode);
6377 if (ret < 0)
6378 goto fail;
6379
6380 path->leave_spinning = 1;
6381 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
6382 if (ret != 0)
6383 goto fail_unlock;
6384
6385 inode_init_owner(inode, dir, mode);
6386 inode_set_bytes(inode, 0);
6387
6388 inode->i_mtime = current_time(inode);
6389 inode->i_atime = inode->i_mtime;
6390 inode->i_ctime = inode->i_mtime;
6391 BTRFS_I(inode)->i_otime = inode->i_mtime;
6392
6393 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
6394 struct btrfs_inode_item);
6395 memzero_extent_buffer(path->nodes[0], (unsigned long)inode_item,
6396 sizeof(*inode_item));
6397 fill_inode_item(trans, path->nodes[0], inode_item, inode);
6398
6399 if (name) {
6400 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
6401 struct btrfs_inode_ref);
6402 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
6403 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
6404 ptr = (unsigned long)(ref + 1);
6405 write_extent_buffer(path->nodes[0], name, ptr, name_len);
6406 }
6407
6408 btrfs_mark_buffer_dirty(path->nodes[0]);
6409 btrfs_free_path(path);
6410
6411 btrfs_inherit_iflags(inode, dir);
6412
6413 if (S_ISREG(mode)) {
6414 if (btrfs_test_opt(fs_info, NODATASUM))
6415 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6416 if (btrfs_test_opt(fs_info, NODATACOW))
6417 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
6418 BTRFS_INODE_NODATASUM;
6419 }
6420
6421 inode_tree_add(inode);
6422
6423 trace_btrfs_inode_new(inode);
6424 btrfs_set_inode_last_trans(trans, inode);
6425
6426 btrfs_update_root_times(trans, root);
6427
6428 ret = btrfs_inode_inherit_props(trans, inode, dir);
6429 if (ret)
6430 btrfs_err(fs_info,
6431 "error inheriting props for ino %llu (root %llu): %d",
6432 btrfs_ino(BTRFS_I(inode)), root->root_key.objectid, ret);
6433
6434 return inode;
6435
6436 fail_unlock:
6437 unlock_new_inode(inode);
6438 fail:
6439 if (dir && name)
6440 BTRFS_I(dir)->index_cnt--;
6441 btrfs_free_path(path);
6442 iput(inode);
6443 return ERR_PTR(ret);
6444 }
6445
6446 static inline u8 btrfs_inode_type(struct inode *inode)
6447 {
6448 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
6449 }
6450
6451 /*
6452 * utility function to add 'inode' into 'parent_inode' with
6453 * a give name and a given sequence number.
6454 * if 'add_backref' is true, also insert a backref from the
6455 * inode to the parent directory.
6456 */
6457 int btrfs_add_link(struct btrfs_trans_handle *trans,
6458 struct btrfs_inode *parent_inode, struct btrfs_inode *inode,
6459 const char *name, int name_len, int add_backref, u64 index)
6460 {
6461 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
6462 int ret = 0;
6463 struct btrfs_key key;
6464 struct btrfs_root *root = parent_inode->root;
6465 u64 ino = btrfs_ino(inode);
6466 u64 parent_ino = btrfs_ino(parent_inode);
6467
6468 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6469 memcpy(&key, &inode->root->root_key, sizeof(key));
6470 } else {
6471 key.objectid = ino;
6472 key.type = BTRFS_INODE_ITEM_KEY;
6473 key.offset = 0;
6474 }
6475
6476 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6477 ret = btrfs_add_root_ref(trans, fs_info, key.objectid,
6478 root->root_key.objectid, parent_ino,
6479 index, name, name_len);
6480 } else if (add_backref) {
6481 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
6482 parent_ino, index);
6483 }
6484
6485 /* Nothing to clean up yet */
6486 if (ret)
6487 return ret;
6488
6489 ret = btrfs_insert_dir_item(trans, root, name, name_len,
6490 parent_inode, &key,
6491 btrfs_inode_type(&inode->vfs_inode), index);
6492 if (ret == -EEXIST || ret == -EOVERFLOW)
6493 goto fail_dir_item;
6494 else if (ret) {
6495 btrfs_abort_transaction(trans, ret);
6496 return ret;
6497 }
6498
6499 btrfs_i_size_write(parent_inode, parent_inode->vfs_inode.i_size +
6500 name_len * 2);
6501 inode_inc_iversion(&parent_inode->vfs_inode);
6502 parent_inode->vfs_inode.i_mtime = parent_inode->vfs_inode.i_ctime =
6503 current_time(&parent_inode->vfs_inode);
6504 ret = btrfs_update_inode(trans, root, &parent_inode->vfs_inode);
6505 if (ret)
6506 btrfs_abort_transaction(trans, ret);
6507 return ret;
6508
6509 fail_dir_item:
6510 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6511 u64 local_index;
6512 int err;
6513 err = btrfs_del_root_ref(trans, fs_info, key.objectid,
6514 root->root_key.objectid, parent_ino,
6515 &local_index, name, name_len);
6516
6517 } else if (add_backref) {
6518 u64 local_index;
6519 int err;
6520
6521 err = btrfs_del_inode_ref(trans, root, name, name_len,
6522 ino, parent_ino, &local_index);
6523 }
6524 return ret;
6525 }
6526
6527 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
6528 struct btrfs_inode *dir, struct dentry *dentry,
6529 struct btrfs_inode *inode, int backref, u64 index)
6530 {
6531 int err = btrfs_add_link(trans, dir, inode,
6532 dentry->d_name.name, dentry->d_name.len,
6533 backref, index);
6534 if (err > 0)
6535 err = -EEXIST;
6536 return err;
6537 }
6538
6539 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
6540 umode_t mode, dev_t rdev)
6541 {
6542 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6543 struct btrfs_trans_handle *trans;
6544 struct btrfs_root *root = BTRFS_I(dir)->root;
6545 struct inode *inode = NULL;
6546 int err;
6547 int drop_inode = 0;
6548 u64 objectid;
6549 u64 index = 0;
6550
6551 /*
6552 * 2 for inode item and ref
6553 * 2 for dir items
6554 * 1 for xattr if selinux is on
6555 */
6556 trans = btrfs_start_transaction(root, 5);
6557 if (IS_ERR(trans))
6558 return PTR_ERR(trans);
6559
6560 err = btrfs_find_free_ino(root, &objectid);
6561 if (err)
6562 goto out_unlock;
6563
6564 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6565 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6566 mode, &index);
6567 if (IS_ERR(inode)) {
6568 err = PTR_ERR(inode);
6569 goto out_unlock;
6570 }
6571
6572 /*
6573 * If the active LSM wants to access the inode during
6574 * d_instantiate it needs these. Smack checks to see
6575 * if the filesystem supports xattrs by looking at the
6576 * ops vector.
6577 */
6578 inode->i_op = &btrfs_special_inode_operations;
6579 init_special_inode(inode, inode->i_mode, rdev);
6580
6581 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6582 if (err)
6583 goto out_unlock_inode;
6584
6585 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6586 0, index);
6587 if (err) {
6588 goto out_unlock_inode;
6589 } else {
6590 btrfs_update_inode(trans, root, inode);
6591 unlock_new_inode(inode);
6592 d_instantiate(dentry, inode);
6593 }
6594
6595 out_unlock:
6596 btrfs_end_transaction(trans);
6597 btrfs_balance_delayed_items(fs_info);
6598 btrfs_btree_balance_dirty(fs_info);
6599 if (drop_inode) {
6600 inode_dec_link_count(inode);
6601 iput(inode);
6602 }
6603 return err;
6604
6605 out_unlock_inode:
6606 drop_inode = 1;
6607 unlock_new_inode(inode);
6608 goto out_unlock;
6609
6610 }
6611
6612 static int btrfs_create(struct inode *dir, struct dentry *dentry,
6613 umode_t mode, bool excl)
6614 {
6615 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6616 struct btrfs_trans_handle *trans;
6617 struct btrfs_root *root = BTRFS_I(dir)->root;
6618 struct inode *inode = NULL;
6619 int drop_inode_on_err = 0;
6620 int err;
6621 u64 objectid;
6622 u64 index = 0;
6623
6624 /*
6625 * 2 for inode item and ref
6626 * 2 for dir items
6627 * 1 for xattr if selinux is on
6628 */
6629 trans = btrfs_start_transaction(root, 5);
6630 if (IS_ERR(trans))
6631 return PTR_ERR(trans);
6632
6633 err = btrfs_find_free_ino(root, &objectid);
6634 if (err)
6635 goto out_unlock;
6636
6637 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6638 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6639 mode, &index);
6640 if (IS_ERR(inode)) {
6641 err = PTR_ERR(inode);
6642 goto out_unlock;
6643 }
6644 drop_inode_on_err = 1;
6645 /*
6646 * If the active LSM wants to access the inode during
6647 * d_instantiate it needs these. Smack checks to see
6648 * if the filesystem supports xattrs by looking at the
6649 * ops vector.
6650 */
6651 inode->i_fop = &btrfs_file_operations;
6652 inode->i_op = &btrfs_file_inode_operations;
6653 inode->i_mapping->a_ops = &btrfs_aops;
6654
6655 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6656 if (err)
6657 goto out_unlock_inode;
6658
6659 err = btrfs_update_inode(trans, root, inode);
6660 if (err)
6661 goto out_unlock_inode;
6662
6663 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6664 0, index);
6665 if (err)
6666 goto out_unlock_inode;
6667
6668 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
6669 unlock_new_inode(inode);
6670 d_instantiate(dentry, inode);
6671
6672 out_unlock:
6673 btrfs_end_transaction(trans);
6674 if (err && drop_inode_on_err) {
6675 inode_dec_link_count(inode);
6676 iput(inode);
6677 }
6678 btrfs_balance_delayed_items(fs_info);
6679 btrfs_btree_balance_dirty(fs_info);
6680 return err;
6681
6682 out_unlock_inode:
6683 unlock_new_inode(inode);
6684 goto out_unlock;
6685
6686 }
6687
6688 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
6689 struct dentry *dentry)
6690 {
6691 struct btrfs_trans_handle *trans = NULL;
6692 struct btrfs_root *root = BTRFS_I(dir)->root;
6693 struct inode *inode = d_inode(old_dentry);
6694 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
6695 u64 index;
6696 int err;
6697 int drop_inode = 0;
6698
6699 /* do not allow sys_link's with other subvols of the same device */
6700 if (root->objectid != BTRFS_I(inode)->root->objectid)
6701 return -EXDEV;
6702
6703 if (inode->i_nlink >= BTRFS_LINK_MAX)
6704 return -EMLINK;
6705
6706 err = btrfs_set_inode_index(BTRFS_I(dir), &index);
6707 if (err)
6708 goto fail;
6709
6710 /*
6711 * 2 items for inode and inode ref
6712 * 2 items for dir items
6713 * 1 item for parent inode
6714 */
6715 trans = btrfs_start_transaction(root, 5);
6716 if (IS_ERR(trans)) {
6717 err = PTR_ERR(trans);
6718 trans = NULL;
6719 goto fail;
6720 }
6721
6722 /* There are several dir indexes for this inode, clear the cache. */
6723 BTRFS_I(inode)->dir_index = 0ULL;
6724 inc_nlink(inode);
6725 inode_inc_iversion(inode);
6726 inode->i_ctime = current_time(inode);
6727 ihold(inode);
6728 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
6729
6730 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6731 1, index);
6732
6733 if (err) {
6734 drop_inode = 1;
6735 } else {
6736 struct dentry *parent = dentry->d_parent;
6737 err = btrfs_update_inode(trans, root, inode);
6738 if (err)
6739 goto fail;
6740 if (inode->i_nlink == 1) {
6741 /*
6742 * If new hard link count is 1, it's a file created
6743 * with open(2) O_TMPFILE flag.
6744 */
6745 err = btrfs_orphan_del(trans, BTRFS_I(inode));
6746 if (err)
6747 goto fail;
6748 }
6749 d_instantiate(dentry, inode);
6750 btrfs_log_new_name(trans, BTRFS_I(inode), NULL, parent);
6751 }
6752
6753 btrfs_balance_delayed_items(fs_info);
6754 fail:
6755 if (trans)
6756 btrfs_end_transaction(trans);
6757 if (drop_inode) {
6758 inode_dec_link_count(inode);
6759 iput(inode);
6760 }
6761 btrfs_btree_balance_dirty(fs_info);
6762 return err;
6763 }
6764
6765 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
6766 {
6767 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6768 struct inode *inode = NULL;
6769 struct btrfs_trans_handle *trans;
6770 struct btrfs_root *root = BTRFS_I(dir)->root;
6771 int err = 0;
6772 int drop_on_err = 0;
6773 u64 objectid = 0;
6774 u64 index = 0;
6775
6776 /*
6777 * 2 items for inode and ref
6778 * 2 items for dir items
6779 * 1 for xattr if selinux is on
6780 */
6781 trans = btrfs_start_transaction(root, 5);
6782 if (IS_ERR(trans))
6783 return PTR_ERR(trans);
6784
6785 err = btrfs_find_free_ino(root, &objectid);
6786 if (err)
6787 goto out_fail;
6788
6789 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6790 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6791 S_IFDIR | mode, &index);
6792 if (IS_ERR(inode)) {
6793 err = PTR_ERR(inode);
6794 goto out_fail;
6795 }
6796
6797 drop_on_err = 1;
6798 /* these must be set before we unlock the inode */
6799 inode->i_op = &btrfs_dir_inode_operations;
6800 inode->i_fop = &btrfs_dir_file_operations;
6801
6802 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6803 if (err)
6804 goto out_fail_inode;
6805
6806 btrfs_i_size_write(BTRFS_I(inode), 0);
6807 err = btrfs_update_inode(trans, root, inode);
6808 if (err)
6809 goto out_fail_inode;
6810
6811 err = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode),
6812 dentry->d_name.name,
6813 dentry->d_name.len, 0, index);
6814 if (err)
6815 goto out_fail_inode;
6816
6817 d_instantiate(dentry, inode);
6818 /*
6819 * mkdir is special. We're unlocking after we call d_instantiate
6820 * to avoid a race with nfsd calling d_instantiate.
6821 */
6822 unlock_new_inode(inode);
6823 drop_on_err = 0;
6824
6825 out_fail:
6826 btrfs_end_transaction(trans);
6827 if (drop_on_err) {
6828 inode_dec_link_count(inode);
6829 iput(inode);
6830 }
6831 btrfs_balance_delayed_items(fs_info);
6832 btrfs_btree_balance_dirty(fs_info);
6833 return err;
6834
6835 out_fail_inode:
6836 unlock_new_inode(inode);
6837 goto out_fail;
6838 }
6839
6840 /* Find next extent map of a given extent map, caller needs to ensure locks */
6841 static struct extent_map *next_extent_map(struct extent_map *em)
6842 {
6843 struct rb_node *next;
6844
6845 next = rb_next(&em->rb_node);
6846 if (!next)
6847 return NULL;
6848 return container_of(next, struct extent_map, rb_node);
6849 }
6850
6851 static struct extent_map *prev_extent_map(struct extent_map *em)
6852 {
6853 struct rb_node *prev;
6854
6855 prev = rb_prev(&em->rb_node);
6856 if (!prev)
6857 return NULL;
6858 return container_of(prev, struct extent_map, rb_node);
6859 }
6860
6861 /* helper for btfs_get_extent. Given an existing extent in the tree,
6862 * the existing extent is the nearest extent to map_start,
6863 * and an extent that you want to insert, deal with overlap and insert
6864 * the best fitted new extent into the tree.
6865 */
6866 static int merge_extent_mapping(struct extent_map_tree *em_tree,
6867 struct extent_map *existing,
6868 struct extent_map *em,
6869 u64 map_start)
6870 {
6871 struct extent_map *prev;
6872 struct extent_map *next;
6873 u64 start;
6874 u64 end;
6875 u64 start_diff;
6876
6877 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
6878
6879 if (existing->start > map_start) {
6880 next = existing;
6881 prev = prev_extent_map(next);
6882 } else {
6883 prev = existing;
6884 next = next_extent_map(prev);
6885 }
6886
6887 start = prev ? extent_map_end(prev) : em->start;
6888 start = max_t(u64, start, em->start);
6889 end = next ? next->start : extent_map_end(em);
6890 end = min_t(u64, end, extent_map_end(em));
6891 start_diff = start - em->start;
6892 em->start = start;
6893 em->len = end - start;
6894 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
6895 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
6896 em->block_start += start_diff;
6897 em->block_len -= start_diff;
6898 }
6899 return add_extent_mapping(em_tree, em, 0);
6900 }
6901
6902 static noinline int uncompress_inline(struct btrfs_path *path,
6903 struct page *page,
6904 size_t pg_offset, u64 extent_offset,
6905 struct btrfs_file_extent_item *item)
6906 {
6907 int ret;
6908 struct extent_buffer *leaf = path->nodes[0];
6909 char *tmp;
6910 size_t max_size;
6911 unsigned long inline_size;
6912 unsigned long ptr;
6913 int compress_type;
6914
6915 WARN_ON(pg_offset != 0);
6916 compress_type = btrfs_file_extent_compression(leaf, item);
6917 max_size = btrfs_file_extent_ram_bytes(leaf, item);
6918 inline_size = btrfs_file_extent_inline_item_len(leaf,
6919 btrfs_item_nr(path->slots[0]));
6920 tmp = kmalloc(inline_size, GFP_NOFS);
6921 if (!tmp)
6922 return -ENOMEM;
6923 ptr = btrfs_file_extent_inline_start(item);
6924
6925 read_extent_buffer(leaf, tmp, ptr, inline_size);
6926
6927 max_size = min_t(unsigned long, PAGE_SIZE, max_size);
6928 ret = btrfs_decompress(compress_type, tmp, page,
6929 extent_offset, inline_size, max_size);
6930
6931 /*
6932 * decompression code contains a memset to fill in any space between the end
6933 * of the uncompressed data and the end of max_size in case the decompressed
6934 * data ends up shorter than ram_bytes. That doesn't cover the hole between
6935 * the end of an inline extent and the beginning of the next block, so we
6936 * cover that region here.
6937 */
6938
6939 if (max_size + pg_offset < PAGE_SIZE) {
6940 char *map = kmap(page);
6941 memset(map + pg_offset + max_size, 0, PAGE_SIZE - max_size - pg_offset);
6942 kunmap(page);
6943 }
6944 kfree(tmp);
6945 return ret;
6946 }
6947
6948 /*
6949 * a bit scary, this does extent mapping from logical file offset to the disk.
6950 * the ugly parts come from merging extents from the disk with the in-ram
6951 * representation. This gets more complex because of the data=ordered code,
6952 * where the in-ram extents might be locked pending data=ordered completion.
6953 *
6954 * This also copies inline extents directly into the page.
6955 */
6956 struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
6957 struct page *page,
6958 size_t pg_offset, u64 start, u64 len,
6959 int create)
6960 {
6961 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
6962 int ret;
6963 int err = 0;
6964 u64 extent_start = 0;
6965 u64 extent_end = 0;
6966 u64 objectid = btrfs_ino(inode);
6967 u32 found_type;
6968 struct btrfs_path *path = NULL;
6969 struct btrfs_root *root = inode->root;
6970 struct btrfs_file_extent_item *item;
6971 struct extent_buffer *leaf;
6972 struct btrfs_key found_key;
6973 struct extent_map *em = NULL;
6974 struct extent_map_tree *em_tree = &inode->extent_tree;
6975 struct extent_io_tree *io_tree = &inode->io_tree;
6976 struct btrfs_trans_handle *trans = NULL;
6977 const bool new_inline = !page || create;
6978
6979 again:
6980 read_lock(&em_tree->lock);
6981 em = lookup_extent_mapping(em_tree, start, len);
6982 if (em)
6983 em->bdev = fs_info->fs_devices->latest_bdev;
6984 read_unlock(&em_tree->lock);
6985
6986 if (em) {
6987 if (em->start > start || em->start + em->len <= start)
6988 free_extent_map(em);
6989 else if (em->block_start == EXTENT_MAP_INLINE && page)
6990 free_extent_map(em);
6991 else
6992 goto out;
6993 }
6994 em = alloc_extent_map();
6995 if (!em) {
6996 err = -ENOMEM;
6997 goto out;
6998 }
6999 em->bdev = fs_info->fs_devices->latest_bdev;
7000 em->start = EXTENT_MAP_HOLE;
7001 em->orig_start = EXTENT_MAP_HOLE;
7002 em->len = (u64)-1;
7003 em->block_len = (u64)-1;
7004
7005 if (!path) {
7006 path = btrfs_alloc_path();
7007 if (!path) {
7008 err = -ENOMEM;
7009 goto out;
7010 }
7011 /*
7012 * Chances are we'll be called again, so go ahead and do
7013 * readahead
7014 */
7015 path->reada = READA_FORWARD;
7016 }
7017
7018 ret = btrfs_lookup_file_extent(trans, root, path,
7019 objectid, start, trans != NULL);
7020 if (ret < 0) {
7021 err = ret;
7022 goto out;
7023 }
7024
7025 if (ret != 0) {
7026 if (path->slots[0] == 0)
7027 goto not_found;
7028 path->slots[0]--;
7029 }
7030
7031 leaf = path->nodes[0];
7032 item = btrfs_item_ptr(leaf, path->slots[0],
7033 struct btrfs_file_extent_item);
7034 /* are we inside the extent that was found? */
7035 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
7036 found_type = found_key.type;
7037 if (found_key.objectid != objectid ||
7038 found_type != BTRFS_EXTENT_DATA_KEY) {
7039 /*
7040 * If we backup past the first extent we want to move forward
7041 * and see if there is an extent in front of us, otherwise we'll
7042 * say there is a hole for our whole search range which can
7043 * cause problems.
7044 */
7045 extent_end = start;
7046 goto next;
7047 }
7048
7049 found_type = btrfs_file_extent_type(leaf, item);
7050 extent_start = found_key.offset;
7051 if (found_type == BTRFS_FILE_EXTENT_REG ||
7052 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7053 extent_end = extent_start +
7054 btrfs_file_extent_num_bytes(leaf, item);
7055
7056 trace_btrfs_get_extent_show_fi_regular(inode, leaf, item,
7057 extent_start);
7058 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
7059 size_t size;
7060 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
7061 extent_end = ALIGN(extent_start + size,
7062 fs_info->sectorsize);
7063
7064 trace_btrfs_get_extent_show_fi_inline(inode, leaf, item,
7065 path->slots[0],
7066 extent_start);
7067 }
7068 next:
7069 if (start >= extent_end) {
7070 path->slots[0]++;
7071 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
7072 ret = btrfs_next_leaf(root, path);
7073 if (ret < 0) {
7074 err = ret;
7075 goto out;
7076 }
7077 if (ret > 0)
7078 goto not_found;
7079 leaf = path->nodes[0];
7080 }
7081 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
7082 if (found_key.objectid != objectid ||
7083 found_key.type != BTRFS_EXTENT_DATA_KEY)
7084 goto not_found;
7085 if (start + len <= found_key.offset)
7086 goto not_found;
7087 if (start > found_key.offset)
7088 goto next;
7089 em->start = start;
7090 em->orig_start = start;
7091 em->len = found_key.offset - start;
7092 goto not_found_em;
7093 }
7094
7095 btrfs_extent_item_to_extent_map(inode, path, item,
7096 new_inline, em);
7097
7098 if (found_type == BTRFS_FILE_EXTENT_REG ||
7099 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7100 goto insert;
7101 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
7102 unsigned long ptr;
7103 char *map;
7104 size_t size;
7105 size_t extent_offset;
7106 size_t copy_size;
7107
7108 if (new_inline)
7109 goto out;
7110
7111 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
7112 extent_offset = page_offset(page) + pg_offset - extent_start;
7113 copy_size = min_t(u64, PAGE_SIZE - pg_offset,
7114 size - extent_offset);
7115 em->start = extent_start + extent_offset;
7116 em->len = ALIGN(copy_size, fs_info->sectorsize);
7117 em->orig_block_len = em->len;
7118 em->orig_start = em->start;
7119 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
7120 if (create == 0 && !PageUptodate(page)) {
7121 if (btrfs_file_extent_compression(leaf, item) !=
7122 BTRFS_COMPRESS_NONE) {
7123 ret = uncompress_inline(path, page, pg_offset,
7124 extent_offset, item);
7125 if (ret) {
7126 err = ret;
7127 goto out;
7128 }
7129 } else {
7130 map = kmap(page);
7131 read_extent_buffer(leaf, map + pg_offset, ptr,
7132 copy_size);
7133 if (pg_offset + copy_size < PAGE_SIZE) {
7134 memset(map + pg_offset + copy_size, 0,
7135 PAGE_SIZE - pg_offset -
7136 copy_size);
7137 }
7138 kunmap(page);
7139 }
7140 flush_dcache_page(page);
7141 } else if (create && PageUptodate(page)) {
7142 BUG();
7143 if (!trans) {
7144 kunmap(page);
7145 free_extent_map(em);
7146 em = NULL;
7147
7148 btrfs_release_path(path);
7149 trans = btrfs_join_transaction(root);
7150
7151 if (IS_ERR(trans))
7152 return ERR_CAST(trans);
7153 goto again;
7154 }
7155 map = kmap(page);
7156 write_extent_buffer(leaf, map + pg_offset, ptr,
7157 copy_size);
7158 kunmap(page);
7159 btrfs_mark_buffer_dirty(leaf);
7160 }
7161 set_extent_uptodate(io_tree, em->start,
7162 extent_map_end(em) - 1, NULL, GFP_NOFS);
7163 goto insert;
7164 }
7165 not_found:
7166 em->start = start;
7167 em->orig_start = start;
7168 em->len = len;
7169 not_found_em:
7170 em->block_start = EXTENT_MAP_HOLE;
7171 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
7172 insert:
7173 btrfs_release_path(path);
7174 if (em->start > start || extent_map_end(em) <= start) {
7175 btrfs_err(fs_info,
7176 "bad extent! em: [%llu %llu] passed [%llu %llu]",
7177 em->start, em->len, start, len);
7178 err = -EIO;
7179 goto out;
7180 }
7181
7182 err = 0;
7183 write_lock(&em_tree->lock);
7184 ret = add_extent_mapping(em_tree, em, 0);
7185 /* it is possible that someone inserted the extent into the tree
7186 * while we had the lock dropped. It is also possible that
7187 * an overlapping map exists in the tree
7188 */
7189 if (ret == -EEXIST) {
7190 struct extent_map *existing;
7191
7192 ret = 0;
7193
7194 existing = search_extent_mapping(em_tree, start, len);
7195 /*
7196 * existing will always be non-NULL, since there must be
7197 * extent causing the -EEXIST.
7198 */
7199 if (existing->start == em->start &&
7200 extent_map_end(existing) >= extent_map_end(em) &&
7201 em->block_start == existing->block_start) {
7202 /*
7203 * The existing extent map already encompasses the
7204 * entire extent map we tried to add.
7205 */
7206 free_extent_map(em);
7207 em = existing;
7208 err = 0;
7209
7210 } else if (start >= extent_map_end(existing) ||
7211 start <= existing->start) {
7212 /*
7213 * The existing extent map is the one nearest to
7214 * the [start, start + len) range which overlaps
7215 */
7216 err = merge_extent_mapping(em_tree, existing,
7217 em, start);
7218 free_extent_map(existing);
7219 if (err) {
7220 free_extent_map(em);
7221 em = NULL;
7222 }
7223 } else {
7224 free_extent_map(em);
7225 em = existing;
7226 err = 0;
7227 }
7228 }
7229 write_unlock(&em_tree->lock);
7230 out:
7231
7232 trace_btrfs_get_extent(root, inode, em);
7233
7234 btrfs_free_path(path);
7235 if (trans) {
7236 ret = btrfs_end_transaction(trans);
7237 if (!err)
7238 err = ret;
7239 }
7240 if (err) {
7241 free_extent_map(em);
7242 return ERR_PTR(err);
7243 }
7244 BUG_ON(!em); /* Error is always set */
7245 return em;
7246 }
7247
7248 struct extent_map *btrfs_get_extent_fiemap(struct btrfs_inode *inode,
7249 struct page *page,
7250 size_t pg_offset, u64 start, u64 len,
7251 int create)
7252 {
7253 struct extent_map *em;
7254 struct extent_map *hole_em = NULL;
7255 u64 range_start = start;
7256 u64 end;
7257 u64 found;
7258 u64 found_end;
7259 int err = 0;
7260
7261 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
7262 if (IS_ERR(em))
7263 return em;
7264 /*
7265 * If our em maps to:
7266 * - a hole or
7267 * - a pre-alloc extent,
7268 * there might actually be delalloc bytes behind it.
7269 */
7270 if (em->block_start != EXTENT_MAP_HOLE &&
7271 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7272 return em;
7273 else
7274 hole_em = em;
7275
7276 /* check to see if we've wrapped (len == -1 or similar) */
7277 end = start + len;
7278 if (end < start)
7279 end = (u64)-1;
7280 else
7281 end -= 1;
7282
7283 em = NULL;
7284
7285 /* ok, we didn't find anything, lets look for delalloc */
7286 found = count_range_bits(&inode->io_tree, &range_start,
7287 end, len, EXTENT_DELALLOC, 1);
7288 found_end = range_start + found;
7289 if (found_end < range_start)
7290 found_end = (u64)-1;
7291
7292 /*
7293 * we didn't find anything useful, return
7294 * the original results from get_extent()
7295 */
7296 if (range_start > end || found_end <= start) {
7297 em = hole_em;
7298 hole_em = NULL;
7299 goto out;
7300 }
7301
7302 /* adjust the range_start to make sure it doesn't
7303 * go backwards from the start they passed in
7304 */
7305 range_start = max(start, range_start);
7306 found = found_end - range_start;
7307
7308 if (found > 0) {
7309 u64 hole_start = start;
7310 u64 hole_len = len;
7311
7312 em = alloc_extent_map();
7313 if (!em) {
7314 err = -ENOMEM;
7315 goto out;
7316 }
7317 /*
7318 * when btrfs_get_extent can't find anything it
7319 * returns one huge hole
7320 *
7321 * make sure what it found really fits our range, and
7322 * adjust to make sure it is based on the start from
7323 * the caller
7324 */
7325 if (hole_em) {
7326 u64 calc_end = extent_map_end(hole_em);
7327
7328 if (calc_end <= start || (hole_em->start > end)) {
7329 free_extent_map(hole_em);
7330 hole_em = NULL;
7331 } else {
7332 hole_start = max(hole_em->start, start);
7333 hole_len = calc_end - hole_start;
7334 }
7335 }
7336 em->bdev = NULL;
7337 if (hole_em && range_start > hole_start) {
7338 /* our hole starts before our delalloc, so we
7339 * have to return just the parts of the hole
7340 * that go until the delalloc starts
7341 */
7342 em->len = min(hole_len,
7343 range_start - hole_start);
7344 em->start = hole_start;
7345 em->orig_start = hole_start;
7346 /*
7347 * don't adjust block start at all,
7348 * it is fixed at EXTENT_MAP_HOLE
7349 */
7350 em->block_start = hole_em->block_start;
7351 em->block_len = hole_len;
7352 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
7353 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
7354 } else {
7355 em->start = range_start;
7356 em->len = found;
7357 em->orig_start = range_start;
7358 em->block_start = EXTENT_MAP_DELALLOC;
7359 em->block_len = found;
7360 }
7361 } else if (hole_em) {
7362 return hole_em;
7363 }
7364 out:
7365
7366 free_extent_map(hole_em);
7367 if (err) {
7368 free_extent_map(em);
7369 return ERR_PTR(err);
7370 }
7371 return em;
7372 }
7373
7374 static struct extent_map *btrfs_create_dio_extent(struct inode *inode,
7375 const u64 start,
7376 const u64 len,
7377 const u64 orig_start,
7378 const u64 block_start,
7379 const u64 block_len,
7380 const u64 orig_block_len,
7381 const u64 ram_bytes,
7382 const int type)
7383 {
7384 struct extent_map *em = NULL;
7385 int ret;
7386
7387 if (type != BTRFS_ORDERED_NOCOW) {
7388 em = create_io_em(inode, start, len, orig_start,
7389 block_start, block_len, orig_block_len,
7390 ram_bytes,
7391 BTRFS_COMPRESS_NONE, /* compress_type */
7392 type);
7393 if (IS_ERR(em))
7394 goto out;
7395 }
7396 ret = btrfs_add_ordered_extent_dio(inode, start, block_start,
7397 len, block_len, type);
7398 if (ret) {
7399 if (em) {
7400 free_extent_map(em);
7401 btrfs_drop_extent_cache(BTRFS_I(inode), start,
7402 start + len - 1, 0);
7403 }
7404 em = ERR_PTR(ret);
7405 }
7406 out:
7407
7408 return em;
7409 }
7410
7411 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
7412 u64 start, u64 len)
7413 {
7414 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7415 struct btrfs_root *root = BTRFS_I(inode)->root;
7416 struct extent_map *em;
7417 struct btrfs_key ins;
7418 u64 alloc_hint;
7419 int ret;
7420
7421 alloc_hint = get_extent_allocation_hint(inode, start, len);
7422 ret = btrfs_reserve_extent(root, len, len, fs_info->sectorsize,
7423 0, alloc_hint, &ins, 1, 1);
7424 if (ret)
7425 return ERR_PTR(ret);
7426
7427 em = btrfs_create_dio_extent(inode, start, ins.offset, start,
7428 ins.objectid, ins.offset, ins.offset,
7429 ins.offset, BTRFS_ORDERED_REGULAR);
7430 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
7431 if (IS_ERR(em))
7432 btrfs_free_reserved_extent(fs_info, ins.objectid,
7433 ins.offset, 1);
7434
7435 return em;
7436 }
7437
7438 /*
7439 * returns 1 when the nocow is safe, < 1 on error, 0 if the
7440 * block must be cow'd
7441 */
7442 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
7443 u64 *orig_start, u64 *orig_block_len,
7444 u64 *ram_bytes)
7445 {
7446 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7447 struct btrfs_path *path;
7448 int ret;
7449 struct extent_buffer *leaf;
7450 struct btrfs_root *root = BTRFS_I(inode)->root;
7451 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7452 struct btrfs_file_extent_item *fi;
7453 struct btrfs_key key;
7454 u64 disk_bytenr;
7455 u64 backref_offset;
7456 u64 extent_end;
7457 u64 num_bytes;
7458 int slot;
7459 int found_type;
7460 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
7461
7462 path = btrfs_alloc_path();
7463 if (!path)
7464 return -ENOMEM;
7465
7466 ret = btrfs_lookup_file_extent(NULL, root, path,
7467 btrfs_ino(BTRFS_I(inode)), offset, 0);
7468 if (ret < 0)
7469 goto out;
7470
7471 slot = path->slots[0];
7472 if (ret == 1) {
7473 if (slot == 0) {
7474 /* can't find the item, must cow */
7475 ret = 0;
7476 goto out;
7477 }
7478 slot--;
7479 }
7480 ret = 0;
7481 leaf = path->nodes[0];
7482 btrfs_item_key_to_cpu(leaf, &key, slot);
7483 if (key.objectid != btrfs_ino(BTRFS_I(inode)) ||
7484 key.type != BTRFS_EXTENT_DATA_KEY) {
7485 /* not our file or wrong item type, must cow */
7486 goto out;
7487 }
7488
7489 if (key.offset > offset) {
7490 /* Wrong offset, must cow */
7491 goto out;
7492 }
7493
7494 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
7495 found_type = btrfs_file_extent_type(leaf, fi);
7496 if (found_type != BTRFS_FILE_EXTENT_REG &&
7497 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
7498 /* not a regular extent, must cow */
7499 goto out;
7500 }
7501
7502 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
7503 goto out;
7504
7505 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
7506 if (extent_end <= offset)
7507 goto out;
7508
7509 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
7510 if (disk_bytenr == 0)
7511 goto out;
7512
7513 if (btrfs_file_extent_compression(leaf, fi) ||
7514 btrfs_file_extent_encryption(leaf, fi) ||
7515 btrfs_file_extent_other_encoding(leaf, fi))
7516 goto out;
7517
7518 backref_offset = btrfs_file_extent_offset(leaf, fi);
7519
7520 if (orig_start) {
7521 *orig_start = key.offset - backref_offset;
7522 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
7523 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
7524 }
7525
7526 if (btrfs_extent_readonly(fs_info, disk_bytenr))
7527 goto out;
7528
7529 num_bytes = min(offset + *len, extent_end) - offset;
7530 if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7531 u64 range_end;
7532
7533 range_end = round_up(offset + num_bytes,
7534 root->fs_info->sectorsize) - 1;
7535 ret = test_range_bit(io_tree, offset, range_end,
7536 EXTENT_DELALLOC, 0, NULL);
7537 if (ret) {
7538 ret = -EAGAIN;
7539 goto out;
7540 }
7541 }
7542
7543 btrfs_release_path(path);
7544
7545 /*
7546 * look for other files referencing this extent, if we
7547 * find any we must cow
7548 */
7549
7550 ret = btrfs_cross_ref_exist(root, btrfs_ino(BTRFS_I(inode)),
7551 key.offset - backref_offset, disk_bytenr);
7552 if (ret) {
7553 ret = 0;
7554 goto out;
7555 }
7556
7557 /*
7558 * adjust disk_bytenr and num_bytes to cover just the bytes
7559 * in this extent we are about to write. If there
7560 * are any csums in that range we have to cow in order
7561 * to keep the csums correct
7562 */
7563 disk_bytenr += backref_offset;
7564 disk_bytenr += offset - key.offset;
7565 if (csum_exist_in_range(fs_info, disk_bytenr, num_bytes))
7566 goto out;
7567 /*
7568 * all of the above have passed, it is safe to overwrite this extent
7569 * without cow
7570 */
7571 *len = num_bytes;
7572 ret = 1;
7573 out:
7574 btrfs_free_path(path);
7575 return ret;
7576 }
7577
7578 bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end)
7579 {
7580 struct radix_tree_root *root = &inode->i_mapping->page_tree;
7581 bool found = false;
7582 void **pagep = NULL;
7583 struct page *page = NULL;
7584 unsigned long start_idx;
7585 unsigned long end_idx;
7586
7587 start_idx = start >> PAGE_SHIFT;
7588
7589 /*
7590 * end is the last byte in the last page. end == start is legal
7591 */
7592 end_idx = end >> PAGE_SHIFT;
7593
7594 rcu_read_lock();
7595
7596 /* Most of the code in this while loop is lifted from
7597 * find_get_page. It's been modified to begin searching from a
7598 * page and return just the first page found in that range. If the
7599 * found idx is less than or equal to the end idx then we know that
7600 * a page exists. If no pages are found or if those pages are
7601 * outside of the range then we're fine (yay!) */
7602 while (page == NULL &&
7603 radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) {
7604 page = radix_tree_deref_slot(pagep);
7605 if (unlikely(!page))
7606 break;
7607
7608 if (radix_tree_exception(page)) {
7609 if (radix_tree_deref_retry(page)) {
7610 page = NULL;
7611 continue;
7612 }
7613 /*
7614 * Otherwise, shmem/tmpfs must be storing a swap entry
7615 * here as an exceptional entry: so return it without
7616 * attempting to raise page count.
7617 */
7618 page = NULL;
7619 break; /* TODO: Is this relevant for this use case? */
7620 }
7621
7622 if (!page_cache_get_speculative(page)) {
7623 page = NULL;
7624 continue;
7625 }
7626
7627 /*
7628 * Has the page moved?
7629 * This is part of the lockless pagecache protocol. See
7630 * include/linux/pagemap.h for details.
7631 */
7632 if (unlikely(page != *pagep)) {
7633 put_page(page);
7634 page = NULL;
7635 }
7636 }
7637
7638 if (page) {
7639 if (page->index <= end_idx)
7640 found = true;
7641 put_page(page);
7642 }
7643
7644 rcu_read_unlock();
7645 return found;
7646 }
7647
7648 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
7649 struct extent_state **cached_state, int writing)
7650 {
7651 struct btrfs_ordered_extent *ordered;
7652 int ret = 0;
7653
7654 while (1) {
7655 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7656 cached_state);
7657 /*
7658 * We're concerned with the entire range that we're going to be
7659 * doing DIO to, so we need to make sure there's no ordered
7660 * extents in this range.
7661 */
7662 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), lockstart,
7663 lockend - lockstart + 1);
7664
7665 /*
7666 * We need to make sure there are no buffered pages in this
7667 * range either, we could have raced between the invalidate in
7668 * generic_file_direct_write and locking the extent. The
7669 * invalidate needs to happen so that reads after a write do not
7670 * get stale data.
7671 */
7672 if (!ordered &&
7673 (!writing ||
7674 !btrfs_page_exists_in_range(inode, lockstart, lockend)))
7675 break;
7676
7677 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7678 cached_state, GFP_NOFS);
7679
7680 if (ordered) {
7681 /*
7682 * If we are doing a DIO read and the ordered extent we
7683 * found is for a buffered write, we can not wait for it
7684 * to complete and retry, because if we do so we can
7685 * deadlock with concurrent buffered writes on page
7686 * locks. This happens only if our DIO read covers more
7687 * than one extent map, if at this point has already
7688 * created an ordered extent for a previous extent map
7689 * and locked its range in the inode's io tree, and a
7690 * concurrent write against that previous extent map's
7691 * range and this range started (we unlock the ranges
7692 * in the io tree only when the bios complete and
7693 * buffered writes always lock pages before attempting
7694 * to lock range in the io tree).
7695 */
7696 if (writing ||
7697 test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags))
7698 btrfs_start_ordered_extent(inode, ordered, 1);
7699 else
7700 ret = -ENOTBLK;
7701 btrfs_put_ordered_extent(ordered);
7702 } else {
7703 /*
7704 * We could trigger writeback for this range (and wait
7705 * for it to complete) and then invalidate the pages for
7706 * this range (through invalidate_inode_pages2_range()),
7707 * but that can lead us to a deadlock with a concurrent
7708 * call to readpages() (a buffered read or a defrag call
7709 * triggered a readahead) on a page lock due to an
7710 * ordered dio extent we created before but did not have
7711 * yet a corresponding bio submitted (whence it can not
7712 * complete), which makes readpages() wait for that
7713 * ordered extent to complete while holding a lock on
7714 * that page.
7715 */
7716 ret = -ENOTBLK;
7717 }
7718
7719 if (ret)
7720 break;
7721
7722 cond_resched();
7723 }
7724
7725 return ret;
7726 }
7727
7728 /* The callers of this must take lock_extent() */
7729 static struct extent_map *create_io_em(struct inode *inode, u64 start, u64 len,
7730 u64 orig_start, u64 block_start,
7731 u64 block_len, u64 orig_block_len,
7732 u64 ram_bytes, int compress_type,
7733 int type)
7734 {
7735 struct extent_map_tree *em_tree;
7736 struct extent_map *em;
7737 struct btrfs_root *root = BTRFS_I(inode)->root;
7738 int ret;
7739
7740 ASSERT(type == BTRFS_ORDERED_PREALLOC ||
7741 type == BTRFS_ORDERED_COMPRESSED ||
7742 type == BTRFS_ORDERED_NOCOW ||
7743 type == BTRFS_ORDERED_REGULAR);
7744
7745 em_tree = &BTRFS_I(inode)->extent_tree;
7746 em = alloc_extent_map();
7747 if (!em)
7748 return ERR_PTR(-ENOMEM);
7749
7750 em->start = start;
7751 em->orig_start = orig_start;
7752 em->len = len;
7753 em->block_len = block_len;
7754 em->block_start = block_start;
7755 em->bdev = root->fs_info->fs_devices->latest_bdev;
7756 em->orig_block_len = orig_block_len;
7757 em->ram_bytes = ram_bytes;
7758 em->generation = -1;
7759 set_bit(EXTENT_FLAG_PINNED, &em->flags);
7760 if (type == BTRFS_ORDERED_PREALLOC) {
7761 set_bit(EXTENT_FLAG_FILLING, &em->flags);
7762 } else if (type == BTRFS_ORDERED_COMPRESSED) {
7763 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
7764 em->compress_type = compress_type;
7765 }
7766
7767 do {
7768 btrfs_drop_extent_cache(BTRFS_I(inode), em->start,
7769 em->start + em->len - 1, 0);
7770 write_lock(&em_tree->lock);
7771 ret = add_extent_mapping(em_tree, em, 1);
7772 write_unlock(&em_tree->lock);
7773 /*
7774 * The caller has taken lock_extent(), who could race with us
7775 * to add em?
7776 */
7777 } while (ret == -EEXIST);
7778
7779 if (ret) {
7780 free_extent_map(em);
7781 return ERR_PTR(ret);
7782 }
7783
7784 /* em got 2 refs now, callers needs to do free_extent_map once. */
7785 return em;
7786 }
7787
7788 static void adjust_dio_outstanding_extents(struct inode *inode,
7789 struct btrfs_dio_data *dio_data,
7790 const u64 len)
7791 {
7792 unsigned num_extents = count_max_extents(len);
7793
7794 /*
7795 * If we have an outstanding_extents count still set then we're
7796 * within our reservation, otherwise we need to adjust our inode
7797 * counter appropriately.
7798 */
7799 if (dio_data->outstanding_extents >= num_extents) {
7800 dio_data->outstanding_extents -= num_extents;
7801 } else {
7802 /*
7803 * If dio write length has been split due to no large enough
7804 * contiguous space, we need to compensate our inode counter
7805 * appropriately.
7806 */
7807 u64 num_needed = num_extents - dio_data->outstanding_extents;
7808
7809 spin_lock(&BTRFS_I(inode)->lock);
7810 BTRFS_I(inode)->outstanding_extents += num_needed;
7811 spin_unlock(&BTRFS_I(inode)->lock);
7812 }
7813 }
7814
7815 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
7816 struct buffer_head *bh_result, int create)
7817 {
7818 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7819 struct extent_map *em;
7820 struct extent_state *cached_state = NULL;
7821 struct btrfs_dio_data *dio_data = NULL;
7822 u64 start = iblock << inode->i_blkbits;
7823 u64 lockstart, lockend;
7824 u64 len = bh_result->b_size;
7825 int unlock_bits = EXTENT_LOCKED;
7826 int ret = 0;
7827
7828 if (create)
7829 unlock_bits |= EXTENT_DIRTY;
7830 else
7831 len = min_t(u64, len, fs_info->sectorsize);
7832
7833 lockstart = start;
7834 lockend = start + len - 1;
7835
7836 if (current->journal_info) {
7837 /*
7838 * Need to pull our outstanding extents and set journal_info to NULL so
7839 * that anything that needs to check if there's a transaction doesn't get
7840 * confused.
7841 */
7842 dio_data = current->journal_info;
7843 current->journal_info = NULL;
7844 }
7845
7846 /*
7847 * If this errors out it's because we couldn't invalidate pagecache for
7848 * this range and we need to fallback to buffered.
7849 */
7850 if (lock_extent_direct(inode, lockstart, lockend, &cached_state,
7851 create)) {
7852 ret = -ENOTBLK;
7853 goto err;
7854 }
7855
7856 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
7857 if (IS_ERR(em)) {
7858 ret = PTR_ERR(em);
7859 goto unlock_err;
7860 }
7861
7862 /*
7863 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
7864 * io. INLINE is special, and we could probably kludge it in here, but
7865 * it's still buffered so for safety lets just fall back to the generic
7866 * buffered path.
7867 *
7868 * For COMPRESSED we _have_ to read the entire extent in so we can
7869 * decompress it, so there will be buffering required no matter what we
7870 * do, so go ahead and fallback to buffered.
7871 *
7872 * We return -ENOTBLK because that's what makes DIO go ahead and go back
7873 * to buffered IO. Don't blame me, this is the price we pay for using
7874 * the generic code.
7875 */
7876 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
7877 em->block_start == EXTENT_MAP_INLINE) {
7878 free_extent_map(em);
7879 ret = -ENOTBLK;
7880 goto unlock_err;
7881 }
7882
7883 /* Just a good old fashioned hole, return */
7884 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
7885 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
7886 free_extent_map(em);
7887 goto unlock_err;
7888 }
7889
7890 /*
7891 * We don't allocate a new extent in the following cases
7892 *
7893 * 1) The inode is marked as NODATACOW. In this case we'll just use the
7894 * existing extent.
7895 * 2) The extent is marked as PREALLOC. We're good to go here and can
7896 * just use the extent.
7897 *
7898 */
7899 if (!create) {
7900 len = min(len, em->len - (start - em->start));
7901 lockstart = start + len;
7902 goto unlock;
7903 }
7904
7905 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
7906 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
7907 em->block_start != EXTENT_MAP_HOLE)) {
7908 int type;
7909 u64 block_start, orig_start, orig_block_len, ram_bytes;
7910
7911 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7912 type = BTRFS_ORDERED_PREALLOC;
7913 else
7914 type = BTRFS_ORDERED_NOCOW;
7915 len = min(len, em->len - (start - em->start));
7916 block_start = em->block_start + (start - em->start);
7917
7918 if (can_nocow_extent(inode, start, &len, &orig_start,
7919 &orig_block_len, &ram_bytes) == 1 &&
7920 btrfs_inc_nocow_writers(fs_info, block_start)) {
7921 struct extent_map *em2;
7922
7923 em2 = btrfs_create_dio_extent(inode, start, len,
7924 orig_start, block_start,
7925 len, orig_block_len,
7926 ram_bytes, type);
7927 btrfs_dec_nocow_writers(fs_info, block_start);
7928 if (type == BTRFS_ORDERED_PREALLOC) {
7929 free_extent_map(em);
7930 em = em2;
7931 }
7932 if (em2 && IS_ERR(em2)) {
7933 ret = PTR_ERR(em2);
7934 goto unlock_err;
7935 }
7936 /*
7937 * For inode marked NODATACOW or extent marked PREALLOC,
7938 * use the existing or preallocated extent, so does not
7939 * need to adjust btrfs_space_info's bytes_may_use.
7940 */
7941 btrfs_free_reserved_data_space_noquota(inode,
7942 start, len);
7943 goto unlock;
7944 }
7945 }
7946
7947 /*
7948 * this will cow the extent, reset the len in case we changed
7949 * it above
7950 */
7951 len = bh_result->b_size;
7952 free_extent_map(em);
7953 em = btrfs_new_extent_direct(inode, start, len);
7954 if (IS_ERR(em)) {
7955 ret = PTR_ERR(em);
7956 goto unlock_err;
7957 }
7958 len = min(len, em->len - (start - em->start));
7959 unlock:
7960 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
7961 inode->i_blkbits;
7962 bh_result->b_size = len;
7963 bh_result->b_bdev = em->bdev;
7964 set_buffer_mapped(bh_result);
7965 if (create) {
7966 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7967 set_buffer_new(bh_result);
7968
7969 /*
7970 * Need to update the i_size under the extent lock so buffered
7971 * readers will get the updated i_size when we unlock.
7972 */
7973 if (!dio_data->overwrite && start + len > i_size_read(inode))
7974 i_size_write(inode, start + len);
7975
7976 adjust_dio_outstanding_extents(inode, dio_data, len);
7977 WARN_ON(dio_data->reserve < len);
7978 dio_data->reserve -= len;
7979 dio_data->unsubmitted_oe_range_end = start + len;
7980 current->journal_info = dio_data;
7981 }
7982
7983 /*
7984 * In the case of write we need to clear and unlock the entire range,
7985 * in the case of read we need to unlock only the end area that we
7986 * aren't using if there is any left over space.
7987 */
7988 if (lockstart < lockend) {
7989 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
7990 lockend, unlock_bits, 1, 0,
7991 &cached_state, GFP_NOFS);
7992 } else {
7993 free_extent_state(cached_state);
7994 }
7995
7996 free_extent_map(em);
7997
7998 return 0;
7999
8000 unlock_err:
8001 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
8002 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
8003 err:
8004 if (dio_data)
8005 current->journal_info = dio_data;
8006 /*
8007 * Compensate the delalloc release we do in btrfs_direct_IO() when we
8008 * write less data then expected, so that we don't underflow our inode's
8009 * outstanding extents counter.
8010 */
8011 if (create && dio_data)
8012 adjust_dio_outstanding_extents(inode, dio_data, len);
8013
8014 return ret;
8015 }
8016
8017 static inline int submit_dio_repair_bio(struct inode *inode, struct bio *bio,
8018 int mirror_num)
8019 {
8020 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8021 int ret;
8022
8023 BUG_ON(bio_op(bio) == REQ_OP_WRITE);
8024
8025 bio_get(bio);
8026
8027 ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DIO_REPAIR);
8028 if (ret)
8029 goto err;
8030
8031 ret = btrfs_map_bio(fs_info, bio, mirror_num, 0);
8032 err:
8033 bio_put(bio);
8034 return ret;
8035 }
8036
8037 static int btrfs_check_dio_repairable(struct inode *inode,
8038 struct bio *failed_bio,
8039 struct io_failure_record *failrec,
8040 int failed_mirror)
8041 {
8042 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8043 int num_copies;
8044
8045 num_copies = btrfs_num_copies(fs_info, failrec->logical, failrec->len);
8046 if (num_copies == 1) {
8047 /*
8048 * we only have a single copy of the data, so don't bother with
8049 * all the retry and error correction code that follows. no
8050 * matter what the error is, it is very likely to persist.
8051 */
8052 btrfs_debug(fs_info,
8053 "Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d",
8054 num_copies, failrec->this_mirror, failed_mirror);
8055 return 0;
8056 }
8057
8058 failrec->failed_mirror = failed_mirror;
8059 failrec->this_mirror++;
8060 if (failrec->this_mirror == failed_mirror)
8061 failrec->this_mirror++;
8062
8063 if (failrec->this_mirror > num_copies) {
8064 btrfs_debug(fs_info,
8065 "Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d",
8066 num_copies, failrec->this_mirror, failed_mirror);
8067 return 0;
8068 }
8069
8070 return 1;
8071 }
8072
8073 static int dio_read_error(struct inode *inode, struct bio *failed_bio,
8074 struct page *page, unsigned int pgoff,
8075 u64 start, u64 end, int failed_mirror,
8076 bio_end_io_t *repair_endio, void *repair_arg)
8077 {
8078 struct io_failure_record *failrec;
8079 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
8080 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
8081 struct bio *bio;
8082 int isector;
8083 unsigned int read_mode = 0;
8084 int segs;
8085 int ret;
8086
8087 BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
8088
8089 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
8090 if (ret)
8091 return ret;
8092
8093 ret = btrfs_check_dio_repairable(inode, failed_bio, failrec,
8094 failed_mirror);
8095 if (!ret) {
8096 free_io_failure(failure_tree, io_tree, failrec);
8097 return -EIO;
8098 }
8099
8100 segs = bio_segments(failed_bio);
8101 if (segs > 1 ||
8102 (failed_bio->bi_io_vec->bv_len > btrfs_inode_sectorsize(inode)))
8103 read_mode |= REQ_FAILFAST_DEV;
8104
8105 isector = start - btrfs_io_bio(failed_bio)->logical;
8106 isector >>= inode->i_sb->s_blocksize_bits;
8107 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
8108 pgoff, isector, repair_endio, repair_arg);
8109 bio_set_op_attrs(bio, REQ_OP_READ, read_mode);
8110
8111 btrfs_debug(BTRFS_I(inode)->root->fs_info,
8112 "repair DIO read error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d",
8113 read_mode, failrec->this_mirror, failrec->in_validation);
8114
8115 ret = submit_dio_repair_bio(inode, bio, failrec->this_mirror);
8116 if (ret) {
8117 free_io_failure(failure_tree, io_tree, failrec);
8118 bio_put(bio);
8119 }
8120
8121 return ret;
8122 }
8123
8124 struct btrfs_retry_complete {
8125 struct completion done;
8126 struct inode *inode;
8127 u64 start;
8128 int uptodate;
8129 };
8130
8131 static void btrfs_retry_endio_nocsum(struct bio *bio)
8132 {
8133 struct btrfs_retry_complete *done = bio->bi_private;
8134 struct inode *inode = done->inode;
8135 struct bio_vec *bvec;
8136 struct extent_io_tree *io_tree, *failure_tree;
8137 int i;
8138
8139 if (bio->bi_status)
8140 goto end;
8141
8142 ASSERT(bio->bi_vcnt == 1);
8143 io_tree = &BTRFS_I(inode)->io_tree;
8144 failure_tree = &BTRFS_I(inode)->io_failure_tree;
8145 ASSERT(bio->bi_io_vec->bv_len == btrfs_inode_sectorsize(inode));
8146
8147 done->uptodate = 1;
8148 ASSERT(!bio_flagged(bio, BIO_CLONED));
8149 bio_for_each_segment_all(bvec, bio, i)
8150 clean_io_failure(BTRFS_I(inode)->root->fs_info, failure_tree,
8151 io_tree, done->start, bvec->bv_page,
8152 btrfs_ino(BTRFS_I(inode)), 0);
8153 end:
8154 complete(&done->done);
8155 bio_put(bio);
8156 }
8157
8158 static int __btrfs_correct_data_nocsum(struct inode *inode,
8159 struct btrfs_io_bio *io_bio)
8160 {
8161 struct btrfs_fs_info *fs_info;
8162 struct bio_vec bvec;
8163 struct bvec_iter iter;
8164 struct btrfs_retry_complete done;
8165 u64 start;
8166 unsigned int pgoff;
8167 u32 sectorsize;
8168 int nr_sectors;
8169 int ret;
8170 int err = 0;
8171
8172 fs_info = BTRFS_I(inode)->root->fs_info;
8173 sectorsize = fs_info->sectorsize;
8174
8175 start = io_bio->logical;
8176 done.inode = inode;
8177 io_bio->bio.bi_iter = io_bio->iter;
8178
8179 bio_for_each_segment(bvec, &io_bio->bio, iter) {
8180 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec.bv_len);
8181 pgoff = bvec.bv_offset;
8182
8183 next_block_or_try_again:
8184 done.uptodate = 0;
8185 done.start = start;
8186 init_completion(&done.done);
8187
8188 ret = dio_read_error(inode, &io_bio->bio, bvec.bv_page,
8189 pgoff, start, start + sectorsize - 1,
8190 io_bio->mirror_num,
8191 btrfs_retry_endio_nocsum, &done);
8192 if (ret) {
8193 err = ret;
8194 goto next;
8195 }
8196
8197 wait_for_completion_io(&done.done);
8198
8199 if (!done.uptodate) {
8200 /* We might have another mirror, so try again */
8201 goto next_block_or_try_again;
8202 }
8203
8204 next:
8205 start += sectorsize;
8206
8207 nr_sectors--;
8208 if (nr_sectors) {
8209 pgoff += sectorsize;
8210 ASSERT(pgoff < PAGE_SIZE);
8211 goto next_block_or_try_again;
8212 }
8213 }
8214
8215 return err;
8216 }
8217
8218 static void btrfs_retry_endio(struct bio *bio)
8219 {
8220 struct btrfs_retry_complete *done = bio->bi_private;
8221 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8222 struct extent_io_tree *io_tree, *failure_tree;
8223 struct inode *inode = done->inode;
8224 struct bio_vec *bvec;
8225 int uptodate;
8226 int ret;
8227 int i;
8228
8229 if (bio->bi_status)
8230 goto end;
8231
8232 uptodate = 1;
8233
8234 ASSERT(bio->bi_vcnt == 1);
8235 ASSERT(bio->bi_io_vec->bv_len == btrfs_inode_sectorsize(done->inode));
8236
8237 io_tree = &BTRFS_I(inode)->io_tree;
8238 failure_tree = &BTRFS_I(inode)->io_failure_tree;
8239
8240 ASSERT(!bio_flagged(bio, BIO_CLONED));
8241 bio_for_each_segment_all(bvec, bio, i) {
8242 ret = __readpage_endio_check(inode, io_bio, i, bvec->bv_page,
8243 bvec->bv_offset, done->start,
8244 bvec->bv_len);
8245 if (!ret)
8246 clean_io_failure(BTRFS_I(inode)->root->fs_info,
8247 failure_tree, io_tree, done->start,
8248 bvec->bv_page,
8249 btrfs_ino(BTRFS_I(inode)),
8250 bvec->bv_offset);
8251 else
8252 uptodate = 0;
8253 }
8254
8255 done->uptodate = uptodate;
8256 end:
8257 complete(&done->done);
8258 bio_put(bio);
8259 }
8260
8261 static blk_status_t __btrfs_subio_endio_read(struct inode *inode,
8262 struct btrfs_io_bio *io_bio, blk_status_t err)
8263 {
8264 struct btrfs_fs_info *fs_info;
8265 struct bio_vec bvec;
8266 struct bvec_iter iter;
8267 struct btrfs_retry_complete done;
8268 u64 start;
8269 u64 offset = 0;
8270 u32 sectorsize;
8271 int nr_sectors;
8272 unsigned int pgoff;
8273 int csum_pos;
8274 bool uptodate = (err == 0);
8275 int ret;
8276
8277 fs_info = BTRFS_I(inode)->root->fs_info;
8278 sectorsize = fs_info->sectorsize;
8279
8280 err = 0;
8281 start = io_bio->logical;
8282 done.inode = inode;
8283 io_bio->bio.bi_iter = io_bio->iter;
8284
8285 bio_for_each_segment(bvec, &io_bio->bio, iter) {
8286 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec.bv_len);
8287
8288 pgoff = bvec.bv_offset;
8289 next_block:
8290 if (uptodate) {
8291 csum_pos = BTRFS_BYTES_TO_BLKS(fs_info, offset);
8292 ret = __readpage_endio_check(inode, io_bio, csum_pos,
8293 bvec.bv_page, pgoff, start, sectorsize);
8294 if (likely(!ret))
8295 goto next;
8296 }
8297 try_again:
8298 done.uptodate = 0;
8299 done.start = start;
8300 init_completion(&done.done);
8301
8302 ret = dio_read_error(inode, &io_bio->bio, bvec.bv_page,
8303 pgoff, start, start + sectorsize - 1,
8304 io_bio->mirror_num,
8305 btrfs_retry_endio, &done);
8306 if (ret) {
8307 err = errno_to_blk_status(ret);
8308 goto next;
8309 }
8310
8311 wait_for_completion_io(&done.done);
8312
8313 if (!done.uptodate) {
8314 /* We might have another mirror, so try again */
8315 goto try_again;
8316 }
8317 next:
8318 offset += sectorsize;
8319 start += sectorsize;
8320
8321 ASSERT(nr_sectors);
8322
8323 nr_sectors--;
8324 if (nr_sectors) {
8325 pgoff += sectorsize;
8326 ASSERT(pgoff < PAGE_SIZE);
8327 goto next_block;
8328 }
8329 }
8330
8331 return err;
8332 }
8333
8334 static blk_status_t btrfs_subio_endio_read(struct inode *inode,
8335 struct btrfs_io_bio *io_bio, blk_status_t err)
8336 {
8337 bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8338
8339 if (skip_csum) {
8340 if (unlikely(err))
8341 return __btrfs_correct_data_nocsum(inode, io_bio);
8342 else
8343 return 0;
8344 } else {
8345 return __btrfs_subio_endio_read(inode, io_bio, err);
8346 }
8347 }
8348
8349 static void btrfs_endio_direct_read(struct bio *bio)
8350 {
8351 struct btrfs_dio_private *dip = bio->bi_private;
8352 struct inode *inode = dip->inode;
8353 struct bio *dio_bio;
8354 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8355 blk_status_t err = bio->bi_status;
8356
8357 if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED) {
8358 err = btrfs_subio_endio_read(inode, io_bio, err);
8359 if (!err)
8360 bio->bi_status = 0;
8361 }
8362
8363 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
8364 dip->logical_offset + dip->bytes - 1);
8365 dio_bio = dip->dio_bio;
8366
8367 kfree(dip);
8368
8369 dio_bio->bi_status = bio->bi_status;
8370 dio_end_io(dio_bio);
8371
8372 if (io_bio->end_io)
8373 io_bio->end_io(io_bio, blk_status_to_errno(err));
8374 bio_put(bio);
8375 }
8376
8377 static void __endio_write_update_ordered(struct inode *inode,
8378 const u64 offset, const u64 bytes,
8379 const bool uptodate)
8380 {
8381 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8382 struct btrfs_ordered_extent *ordered = NULL;
8383 struct btrfs_workqueue *wq;
8384 btrfs_work_func_t func;
8385 u64 ordered_offset = offset;
8386 u64 ordered_bytes = bytes;
8387 int ret;
8388
8389 if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
8390 wq = fs_info->endio_freespace_worker;
8391 func = btrfs_freespace_write_helper;
8392 } else {
8393 wq = fs_info->endio_write_workers;
8394 func = btrfs_endio_write_helper;
8395 }
8396
8397 again:
8398 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
8399 &ordered_offset,
8400 ordered_bytes,
8401 uptodate);
8402 if (!ret)
8403 goto out_test;
8404
8405 btrfs_init_work(&ordered->work, func, finish_ordered_fn, NULL, NULL);
8406 btrfs_queue_work(wq, &ordered->work);
8407 out_test:
8408 /*
8409 * our bio might span multiple ordered extents. If we haven't
8410 * completed the accounting for the whole dio, go back and try again
8411 */
8412 if (ordered_offset < offset + bytes) {
8413 ordered_bytes = offset + bytes - ordered_offset;
8414 ordered = NULL;
8415 goto again;
8416 }
8417 }
8418
8419 static void btrfs_endio_direct_write(struct bio *bio)
8420 {
8421 struct btrfs_dio_private *dip = bio->bi_private;
8422 struct bio *dio_bio = dip->dio_bio;
8423
8424 __endio_write_update_ordered(dip->inode, dip->logical_offset,
8425 dip->bytes, !bio->bi_status);
8426
8427 kfree(dip);
8428
8429 dio_bio->bi_status = bio->bi_status;
8430 dio_end_io(dio_bio);
8431 bio_put(bio);
8432 }
8433
8434 static blk_status_t __btrfs_submit_bio_start_direct_io(void *private_data,
8435 struct bio *bio, int mirror_num,
8436 unsigned long bio_flags, u64 offset)
8437 {
8438 struct inode *inode = private_data;
8439 blk_status_t ret;
8440 ret = btrfs_csum_one_bio(inode, bio, offset, 1);
8441 BUG_ON(ret); /* -ENOMEM */
8442 return 0;
8443 }
8444
8445 static void btrfs_end_dio_bio(struct bio *bio)
8446 {
8447 struct btrfs_dio_private *dip = bio->bi_private;
8448 blk_status_t err = bio->bi_status;
8449
8450 if (err)
8451 btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
8452 "direct IO failed ino %llu rw %d,%u sector %#Lx len %u err no %d",
8453 btrfs_ino(BTRFS_I(dip->inode)), bio_op(bio),
8454 bio->bi_opf,
8455 (unsigned long long)bio->bi_iter.bi_sector,
8456 bio->bi_iter.bi_size, err);
8457
8458 if (dip->subio_endio)
8459 err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err);
8460
8461 if (err) {
8462 dip->errors = 1;
8463
8464 /*
8465 * before atomic variable goto zero, we must make sure
8466 * dip->errors is perceived to be set.
8467 */
8468 smp_mb__before_atomic();
8469 }
8470
8471 /* if there are more bios still pending for this dio, just exit */
8472 if (!atomic_dec_and_test(&dip->pending_bios))
8473 goto out;
8474
8475 if (dip->errors) {
8476 bio_io_error(dip->orig_bio);
8477 } else {
8478 dip->dio_bio->bi_status = 0;
8479 bio_endio(dip->orig_bio);
8480 }
8481 out:
8482 bio_put(bio);
8483 }
8484
8485 static inline blk_status_t btrfs_lookup_and_bind_dio_csum(struct inode *inode,
8486 struct btrfs_dio_private *dip,
8487 struct bio *bio,
8488 u64 file_offset)
8489 {
8490 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8491 struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio);
8492 blk_status_t ret;
8493
8494 /*
8495 * We load all the csum data we need when we submit
8496 * the first bio to reduce the csum tree search and
8497 * contention.
8498 */
8499 if (dip->logical_offset == file_offset) {
8500 ret = btrfs_lookup_bio_sums_dio(inode, dip->orig_bio,
8501 file_offset);
8502 if (ret)
8503 return ret;
8504 }
8505
8506 if (bio == dip->orig_bio)
8507 return 0;
8508
8509 file_offset -= dip->logical_offset;
8510 file_offset >>= inode->i_sb->s_blocksize_bits;
8511 io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset);
8512
8513 return 0;
8514 }
8515
8516 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
8517 u64 file_offset, int async_submit)
8518 {
8519 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8520 struct btrfs_dio_private *dip = bio->bi_private;
8521 bool write = bio_op(bio) == REQ_OP_WRITE;
8522 blk_status_t ret;
8523
8524 if (async_submit)
8525 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
8526
8527 bio_get(bio);
8528
8529 if (!write) {
8530 ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DATA);
8531 if (ret)
8532 goto err;
8533 }
8534
8535 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
8536 goto map;
8537
8538 if (write && async_submit) {
8539 ret = btrfs_wq_submit_bio(fs_info, bio, 0, 0,
8540 file_offset, inode,
8541 __btrfs_submit_bio_start_direct_io,
8542 __btrfs_submit_bio_done);
8543 goto err;
8544 } else if (write) {
8545 /*
8546 * If we aren't doing async submit, calculate the csum of the
8547 * bio now.
8548 */
8549 ret = btrfs_csum_one_bio(inode, bio, file_offset, 1);
8550 if (ret)
8551 goto err;
8552 } else {
8553 ret = btrfs_lookup_and_bind_dio_csum(inode, dip, bio,
8554 file_offset);
8555 if (ret)
8556 goto err;
8557 }
8558 map:
8559 ret = btrfs_map_bio(fs_info, bio, 0, async_submit);
8560 err:
8561 bio_put(bio);
8562 return ret;
8563 }
8564
8565 static int btrfs_submit_direct_hook(struct btrfs_dio_private *dip)
8566 {
8567 struct inode *inode = dip->inode;
8568 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8569 struct bio *bio;
8570 struct bio *orig_bio = dip->orig_bio;
8571 u64 start_sector = orig_bio->bi_iter.bi_sector;
8572 u64 file_offset = dip->logical_offset;
8573 u64 map_length;
8574 int async_submit = 0;
8575 u64 submit_len;
8576 int clone_offset = 0;
8577 int clone_len;
8578 int ret;
8579
8580 map_length = orig_bio->bi_iter.bi_size;
8581 submit_len = map_length;
8582 ret = btrfs_map_block(fs_info, btrfs_op(orig_bio), start_sector << 9,
8583 &map_length, NULL, 0);
8584 if (ret)
8585 return -EIO;
8586
8587 if (map_length >= submit_len) {
8588 bio = orig_bio;
8589 dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED;
8590 goto submit;
8591 }
8592
8593 /* async crcs make it difficult to collect full stripe writes. */
8594 if (btrfs_data_alloc_profile(fs_info) & BTRFS_BLOCK_GROUP_RAID56_MASK)
8595 async_submit = 0;
8596 else
8597 async_submit = 1;
8598
8599 /* bio split */
8600 ASSERT(map_length <= INT_MAX);
8601 atomic_inc(&dip->pending_bios);
8602 do {
8603 clone_len = min_t(int, submit_len, map_length);
8604
8605 /*
8606 * This will never fail as it's passing GPF_NOFS and
8607 * the allocation is backed by btrfs_bioset.
8608 */
8609 bio = btrfs_bio_clone_partial(orig_bio, clone_offset,
8610 clone_len);
8611 bio->bi_private = dip;
8612 bio->bi_end_io = btrfs_end_dio_bio;
8613 btrfs_io_bio(bio)->logical = file_offset;
8614
8615 ASSERT(submit_len >= clone_len);
8616 submit_len -= clone_len;
8617 if (submit_len == 0)
8618 break;
8619
8620 /*
8621 * Increase the count before we submit the bio so we know
8622 * the end IO handler won't happen before we increase the
8623 * count. Otherwise, the dip might get freed before we're
8624 * done setting it up.
8625 */
8626 atomic_inc(&dip->pending_bios);
8627
8628 ret = __btrfs_submit_dio_bio(bio, inode, file_offset,
8629 async_submit);
8630 if (ret) {
8631 bio_put(bio);
8632 atomic_dec(&dip->pending_bios);
8633 goto out_err;
8634 }
8635
8636 clone_offset += clone_len;
8637 start_sector += clone_len >> 9;
8638 file_offset += clone_len;
8639
8640 map_length = submit_len;
8641 ret = btrfs_map_block(fs_info, btrfs_op(orig_bio),
8642 start_sector << 9, &map_length, NULL, 0);
8643 if (ret)
8644 goto out_err;
8645 } while (submit_len > 0);
8646
8647 submit:
8648 ret = __btrfs_submit_dio_bio(bio, inode, file_offset, async_submit);
8649 if (!ret)
8650 return 0;
8651
8652 bio_put(bio);
8653 out_err:
8654 dip->errors = 1;
8655 /*
8656 * before atomic variable goto zero, we must
8657 * make sure dip->errors is perceived to be set.
8658 */
8659 smp_mb__before_atomic();
8660 if (atomic_dec_and_test(&dip->pending_bios))
8661 bio_io_error(dip->orig_bio);
8662
8663 /* bio_end_io() will handle error, so we needn't return it */
8664 return 0;
8665 }
8666
8667 static void btrfs_submit_direct(struct bio *dio_bio, struct inode *inode,
8668 loff_t file_offset)
8669 {
8670 struct btrfs_dio_private *dip = NULL;
8671 struct bio *bio = NULL;
8672 struct btrfs_io_bio *io_bio;
8673 bool write = (bio_op(dio_bio) == REQ_OP_WRITE);
8674 int ret = 0;
8675
8676 bio = btrfs_bio_clone(dio_bio);
8677
8678 dip = kzalloc(sizeof(*dip), GFP_NOFS);
8679 if (!dip) {
8680 ret = -ENOMEM;
8681 goto free_ordered;
8682 }
8683
8684 dip->private = dio_bio->bi_private;
8685 dip->inode = inode;
8686 dip->logical_offset = file_offset;
8687 dip->bytes = dio_bio->bi_iter.bi_size;
8688 dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
8689 bio->bi_private = dip;
8690 dip->orig_bio = bio;
8691 dip->dio_bio = dio_bio;
8692 atomic_set(&dip->pending_bios, 0);
8693 io_bio = btrfs_io_bio(bio);
8694 io_bio->logical = file_offset;
8695
8696 if (write) {
8697 bio->bi_end_io = btrfs_endio_direct_write;
8698 } else {
8699 bio->bi_end_io = btrfs_endio_direct_read;
8700 dip->subio_endio = btrfs_subio_endio_read;
8701 }
8702
8703 /*
8704 * Reset the range for unsubmitted ordered extents (to a 0 length range)
8705 * even if we fail to submit a bio, because in such case we do the
8706 * corresponding error handling below and it must not be done a second
8707 * time by btrfs_direct_IO().
8708 */
8709 if (write) {
8710 struct btrfs_dio_data *dio_data = current->journal_info;
8711
8712 dio_data->unsubmitted_oe_range_end = dip->logical_offset +
8713 dip->bytes;
8714 dio_data->unsubmitted_oe_range_start =
8715 dio_data->unsubmitted_oe_range_end;
8716 }
8717
8718 ret = btrfs_submit_direct_hook(dip);
8719 if (!ret)
8720 return;
8721
8722 if (io_bio->end_io)
8723 io_bio->end_io(io_bio, ret);
8724
8725 free_ordered:
8726 /*
8727 * If we arrived here it means either we failed to submit the dip
8728 * or we either failed to clone the dio_bio or failed to allocate the
8729 * dip. If we cloned the dio_bio and allocated the dip, we can just
8730 * call bio_endio against our io_bio so that we get proper resource
8731 * cleanup if we fail to submit the dip, otherwise, we must do the
8732 * same as btrfs_endio_direct_[write|read] because we can't call these
8733 * callbacks - they require an allocated dip and a clone of dio_bio.
8734 */
8735 if (bio && dip) {
8736 bio_io_error(bio);
8737 /*
8738 * The end io callbacks free our dip, do the final put on bio
8739 * and all the cleanup and final put for dio_bio (through
8740 * dio_end_io()).
8741 */
8742 dip = NULL;
8743 bio = NULL;
8744 } else {
8745 if (write)
8746 __endio_write_update_ordered(inode,
8747 file_offset,
8748 dio_bio->bi_iter.bi_size,
8749 false);
8750 else
8751 unlock_extent(&BTRFS_I(inode)->io_tree, file_offset,
8752 file_offset + dio_bio->bi_iter.bi_size - 1);
8753
8754 dio_bio->bi_status = BLK_STS_IOERR;
8755 /*
8756 * Releases and cleans up our dio_bio, no need to bio_put()
8757 * nor bio_endio()/bio_io_error() against dio_bio.
8758 */
8759 dio_end_io(dio_bio);
8760 }
8761 if (bio)
8762 bio_put(bio);
8763 kfree(dip);
8764 }
8765
8766 static ssize_t check_direct_IO(struct btrfs_fs_info *fs_info,
8767 struct kiocb *iocb,
8768 const struct iov_iter *iter, loff_t offset)
8769 {
8770 int seg;
8771 int i;
8772 unsigned int blocksize_mask = fs_info->sectorsize - 1;
8773 ssize_t retval = -EINVAL;
8774
8775 if (offset & blocksize_mask)
8776 goto out;
8777
8778 if (iov_iter_alignment(iter) & blocksize_mask)
8779 goto out;
8780
8781 /* If this is a write we don't need to check anymore */
8782 if (iov_iter_rw(iter) != READ || !iter_is_iovec(iter))
8783 return 0;
8784 /*
8785 * Check to make sure we don't have duplicate iov_base's in this
8786 * iovec, if so return EINVAL, otherwise we'll get csum errors
8787 * when reading back.
8788 */
8789 for (seg = 0; seg < iter->nr_segs; seg++) {
8790 for (i = seg + 1; i < iter->nr_segs; i++) {
8791 if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
8792 goto out;
8793 }
8794 }
8795 retval = 0;
8796 out:
8797 return retval;
8798 }
8799
8800 static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
8801 {
8802 struct file *file = iocb->ki_filp;
8803 struct inode *inode = file->f_mapping->host;
8804 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8805 struct btrfs_dio_data dio_data = { 0 };
8806 struct extent_changeset *data_reserved = NULL;
8807 loff_t offset = iocb->ki_pos;
8808 size_t count = 0;
8809 int flags = 0;
8810 bool wakeup = true;
8811 bool relock = false;
8812 ssize_t ret;
8813
8814 if (check_direct_IO(fs_info, iocb, iter, offset))
8815 return 0;
8816
8817 inode_dio_begin(inode);
8818
8819 /*
8820 * The generic stuff only does filemap_write_and_wait_range, which
8821 * isn't enough if we've written compressed pages to this area, so
8822 * we need to flush the dirty pages again to make absolutely sure
8823 * that any outstanding dirty pages are on disk.
8824 */
8825 count = iov_iter_count(iter);
8826 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
8827 &BTRFS_I(inode)->runtime_flags))
8828 filemap_fdatawrite_range(inode->i_mapping, offset,
8829 offset + count - 1);
8830
8831 if (iov_iter_rw(iter) == WRITE) {
8832 /*
8833 * If the write DIO is beyond the EOF, we need update
8834 * the isize, but it is protected by i_mutex. So we can
8835 * not unlock the i_mutex at this case.
8836 */
8837 if (offset + count <= inode->i_size) {
8838 dio_data.overwrite = 1;
8839 inode_unlock(inode);
8840 relock = true;
8841 } else if (iocb->ki_flags & IOCB_NOWAIT) {
8842 ret = -EAGAIN;
8843 goto out;
8844 }
8845 ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
8846 offset, count);
8847 if (ret)
8848 goto out;
8849 dio_data.outstanding_extents = count_max_extents(count);
8850
8851 /*
8852 * We need to know how many extents we reserved so that we can
8853 * do the accounting properly if we go over the number we
8854 * originally calculated. Abuse current->journal_info for this.
8855 */
8856 dio_data.reserve = round_up(count,
8857 fs_info->sectorsize);
8858 dio_data.unsubmitted_oe_range_start = (u64)offset;
8859 dio_data.unsubmitted_oe_range_end = (u64)offset;
8860 current->journal_info = &dio_data;
8861 down_read(&BTRFS_I(inode)->dio_sem);
8862 } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
8863 &BTRFS_I(inode)->runtime_flags)) {
8864 inode_dio_end(inode);
8865 flags = DIO_LOCKING | DIO_SKIP_HOLES;
8866 wakeup = false;
8867 }
8868
8869 ret = __blockdev_direct_IO(iocb, inode,
8870 fs_info->fs_devices->latest_bdev,
8871 iter, btrfs_get_blocks_direct, NULL,
8872 btrfs_submit_direct, flags);
8873 if (iov_iter_rw(iter) == WRITE) {
8874 up_read(&BTRFS_I(inode)->dio_sem);
8875 current->journal_info = NULL;
8876 if (ret < 0 && ret != -EIOCBQUEUED) {
8877 if (dio_data.reserve)
8878 btrfs_delalloc_release_space(inode, data_reserved,
8879 offset, dio_data.reserve);
8880 /*
8881 * On error we might have left some ordered extents
8882 * without submitting corresponding bios for them, so
8883 * cleanup them up to avoid other tasks getting them
8884 * and waiting for them to complete forever.
8885 */
8886 if (dio_data.unsubmitted_oe_range_start <
8887 dio_data.unsubmitted_oe_range_end)
8888 __endio_write_update_ordered(inode,
8889 dio_data.unsubmitted_oe_range_start,
8890 dio_data.unsubmitted_oe_range_end -
8891 dio_data.unsubmitted_oe_range_start,
8892 false);
8893 } else if (ret >= 0 && (size_t)ret < count)
8894 btrfs_delalloc_release_space(inode, data_reserved,
8895 offset, count - (size_t)ret);
8896 }
8897 out:
8898 if (wakeup)
8899 inode_dio_end(inode);
8900 if (relock)
8901 inode_lock(inode);
8902
8903 extent_changeset_free(data_reserved);
8904 return ret;
8905 }
8906
8907 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
8908
8909 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
8910 __u64 start, __u64 len)
8911 {
8912 int ret;
8913
8914 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
8915 if (ret)
8916 return ret;
8917
8918 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
8919 }
8920
8921 int btrfs_readpage(struct file *file, struct page *page)
8922 {
8923 struct extent_io_tree *tree;
8924 tree = &BTRFS_I(page->mapping->host)->io_tree;
8925 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
8926 }
8927
8928 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
8929 {
8930 struct extent_io_tree *tree;
8931 struct inode *inode = page->mapping->host;
8932 int ret;
8933
8934 if (current->flags & PF_MEMALLOC) {
8935 redirty_page_for_writepage(wbc, page);
8936 unlock_page(page);
8937 return 0;
8938 }
8939
8940 /*
8941 * If we are under memory pressure we will call this directly from the
8942 * VM, we need to make sure we have the inode referenced for the ordered
8943 * extent. If not just return like we didn't do anything.
8944 */
8945 if (!igrab(inode)) {
8946 redirty_page_for_writepage(wbc, page);
8947 return AOP_WRITEPAGE_ACTIVATE;
8948 }
8949 tree = &BTRFS_I(page->mapping->host)->io_tree;
8950 ret = extent_write_full_page(tree, page, btrfs_get_extent, wbc);
8951 btrfs_add_delayed_iput(inode);
8952 return ret;
8953 }
8954
8955 static int btrfs_writepages(struct address_space *mapping,
8956 struct writeback_control *wbc)
8957 {
8958 struct extent_io_tree *tree;
8959
8960 tree = &BTRFS_I(mapping->host)->io_tree;
8961 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
8962 }
8963
8964 static int
8965 btrfs_readpages(struct file *file, struct address_space *mapping,
8966 struct list_head *pages, unsigned nr_pages)
8967 {
8968 struct extent_io_tree *tree;
8969 tree = &BTRFS_I(mapping->host)->io_tree;
8970 return extent_readpages(tree, mapping, pages, nr_pages,
8971 btrfs_get_extent);
8972 }
8973 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8974 {
8975 struct extent_io_tree *tree;
8976 struct extent_map_tree *map;
8977 int ret;
8978
8979 tree = &BTRFS_I(page->mapping->host)->io_tree;
8980 map = &BTRFS_I(page->mapping->host)->extent_tree;
8981 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
8982 if (ret == 1) {
8983 ClearPagePrivate(page);
8984 set_page_private(page, 0);
8985 put_page(page);
8986 }
8987 return ret;
8988 }
8989
8990 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8991 {
8992 if (PageWriteback(page) || PageDirty(page))
8993 return 0;
8994 return __btrfs_releasepage(page, gfp_flags);
8995 }
8996
8997 static void btrfs_invalidatepage(struct page *page, unsigned int offset,
8998 unsigned int length)
8999 {
9000 struct inode *inode = page->mapping->host;
9001 struct extent_io_tree *tree;
9002 struct btrfs_ordered_extent *ordered;
9003 struct extent_state *cached_state = NULL;
9004 u64 page_start = page_offset(page);
9005 u64 page_end = page_start + PAGE_SIZE - 1;
9006 u64 start;
9007 u64 end;
9008 int inode_evicting = inode->i_state & I_FREEING;
9009
9010 /*
9011 * we have the page locked, so new writeback can't start,
9012 * and the dirty bit won't be cleared while we are here.
9013 *
9014 * Wait for IO on this page so that we can safely clear
9015 * the PagePrivate2 bit and do ordered accounting
9016 */
9017 wait_on_page_writeback(page);
9018
9019 tree = &BTRFS_I(inode)->io_tree;
9020 if (offset) {
9021 btrfs_releasepage(page, GFP_NOFS);
9022 return;
9023 }
9024
9025 if (!inode_evicting)
9026 lock_extent_bits(tree, page_start, page_end, &cached_state);
9027 again:
9028 start = page_start;
9029 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), start,
9030 page_end - start + 1);
9031 if (ordered) {
9032 end = min(page_end, ordered->file_offset + ordered->len - 1);
9033 /*
9034 * IO on this page will never be started, so we need
9035 * to account for any ordered extents now
9036 */
9037 if (!inode_evicting)
9038 clear_extent_bit(tree, start, end,
9039 EXTENT_DIRTY | EXTENT_DELALLOC |
9040 EXTENT_DELALLOC_NEW |
9041 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
9042 EXTENT_DEFRAG, 1, 0, &cached_state,
9043 GFP_NOFS);
9044 /*
9045 * whoever cleared the private bit is responsible
9046 * for the finish_ordered_io
9047 */
9048 if (TestClearPagePrivate2(page)) {
9049 struct btrfs_ordered_inode_tree *tree;
9050 u64 new_len;
9051
9052 tree = &BTRFS_I(inode)->ordered_tree;
9053
9054 spin_lock_irq(&tree->lock);
9055 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
9056 new_len = start - ordered->file_offset;
9057 if (new_len < ordered->truncated_len)
9058 ordered->truncated_len = new_len;
9059 spin_unlock_irq(&tree->lock);
9060
9061 if (btrfs_dec_test_ordered_pending(inode, &ordered,
9062 start,
9063 end - start + 1, 1))
9064 btrfs_finish_ordered_io(ordered);
9065 }
9066 btrfs_put_ordered_extent(ordered);
9067 if (!inode_evicting) {
9068 cached_state = NULL;
9069 lock_extent_bits(tree, start, end,
9070 &cached_state);
9071 }
9072
9073 start = end + 1;
9074 if (start < page_end)
9075 goto again;
9076 }
9077
9078 /*
9079 * Qgroup reserved space handler
9080 * Page here will be either
9081 * 1) Already written to disk
9082 * In this case, its reserved space is released from data rsv map
9083 * and will be freed by delayed_ref handler finally.
9084 * So even we call qgroup_free_data(), it won't decrease reserved
9085 * space.
9086 * 2) Not written to disk
9087 * This means the reserved space should be freed here. However,
9088 * if a truncate invalidates the page (by clearing PageDirty)
9089 * and the page is accounted for while allocating extent
9090 * in btrfs_check_data_free_space() we let delayed_ref to
9091 * free the entire extent.
9092 */
9093 if (PageDirty(page))
9094 btrfs_qgroup_free_data(inode, NULL, page_start, PAGE_SIZE);
9095 if (!inode_evicting) {
9096 clear_extent_bit(tree, page_start, page_end,
9097 EXTENT_LOCKED | EXTENT_DIRTY |
9098 EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
9099 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1,
9100 &cached_state, GFP_NOFS);
9101
9102 __btrfs_releasepage(page, GFP_NOFS);
9103 }
9104
9105 ClearPageChecked(page);
9106 if (PagePrivate(page)) {
9107 ClearPagePrivate(page);
9108 set_page_private(page, 0);
9109 put_page(page);
9110 }
9111 }
9112
9113 /*
9114 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
9115 * called from a page fault handler when a page is first dirtied. Hence we must
9116 * be careful to check for EOF conditions here. We set the page up correctly
9117 * for a written page which means we get ENOSPC checking when writing into
9118 * holes and correct delalloc and unwritten extent mapping on filesystems that
9119 * support these features.
9120 *
9121 * We are not allowed to take the i_mutex here so we have to play games to
9122 * protect against truncate races as the page could now be beyond EOF. Because
9123 * vmtruncate() writes the inode size before removing pages, once we have the
9124 * page lock we can determine safely if the page is beyond EOF. If it is not
9125 * beyond EOF, then the page is guaranteed safe against truncation until we
9126 * unlock the page.
9127 */
9128 int btrfs_page_mkwrite(struct vm_fault *vmf)
9129 {
9130 struct page *page = vmf->page;
9131 struct inode *inode = file_inode(vmf->vma->vm_file);
9132 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
9133 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
9134 struct btrfs_ordered_extent *ordered;
9135 struct extent_state *cached_state = NULL;
9136 struct extent_changeset *data_reserved = NULL;
9137 char *kaddr;
9138 unsigned long zero_start;
9139 loff_t size;
9140 int ret;
9141 int reserved = 0;
9142 u64 reserved_space;
9143 u64 page_start;
9144 u64 page_end;
9145 u64 end;
9146
9147 reserved_space = PAGE_SIZE;
9148
9149 sb_start_pagefault(inode->i_sb);
9150 page_start = page_offset(page);
9151 page_end = page_start + PAGE_SIZE - 1;
9152 end = page_end;
9153
9154 /*
9155 * Reserving delalloc space after obtaining the page lock can lead to
9156 * deadlock. For example, if a dirty page is locked by this function
9157 * and the call to btrfs_delalloc_reserve_space() ends up triggering
9158 * dirty page write out, then the btrfs_writepage() function could
9159 * end up waiting indefinitely to get a lock on the page currently
9160 * being processed by btrfs_page_mkwrite() function.
9161 */
9162 ret = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start,
9163 reserved_space);
9164 if (!ret) {
9165 ret = file_update_time(vmf->vma->vm_file);
9166 reserved = 1;
9167 }
9168 if (ret) {
9169 if (ret == -ENOMEM)
9170 ret = VM_FAULT_OOM;
9171 else /* -ENOSPC, -EIO, etc */
9172 ret = VM_FAULT_SIGBUS;
9173 if (reserved)
9174 goto out;
9175 goto out_noreserve;
9176 }
9177
9178 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
9179 again:
9180 lock_page(page);
9181 size = i_size_read(inode);
9182
9183 if ((page->mapping != inode->i_mapping) ||
9184 (page_start >= size)) {
9185 /* page got truncated out from underneath us */
9186 goto out_unlock;
9187 }
9188 wait_on_page_writeback(page);
9189
9190 lock_extent_bits(io_tree, page_start, page_end, &cached_state);
9191 set_page_extent_mapped(page);
9192
9193 /*
9194 * we can't set the delalloc bits if there are pending ordered
9195 * extents. Drop our locks and wait for them to finish
9196 */
9197 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start,
9198 PAGE_SIZE);
9199 if (ordered) {
9200 unlock_extent_cached(io_tree, page_start, page_end,
9201 &cached_state, GFP_NOFS);
9202 unlock_page(page);
9203 btrfs_start_ordered_extent(inode, ordered, 1);
9204 btrfs_put_ordered_extent(ordered);
9205 goto again;
9206 }
9207
9208 if (page->index == ((size - 1) >> PAGE_SHIFT)) {
9209 reserved_space = round_up(size - page_start,
9210 fs_info->sectorsize);
9211 if (reserved_space < PAGE_SIZE) {
9212 end = page_start + reserved_space - 1;
9213 spin_lock(&BTRFS_I(inode)->lock);
9214 BTRFS_I(inode)->outstanding_extents++;
9215 spin_unlock(&BTRFS_I(inode)->lock);
9216 btrfs_delalloc_release_space(inode, data_reserved,
9217 page_start, PAGE_SIZE - reserved_space);
9218 }
9219 }
9220
9221 /*
9222 * page_mkwrite gets called when the page is firstly dirtied after it's
9223 * faulted in, but write(2) could also dirty a page and set delalloc
9224 * bits, thus in this case for space account reason, we still need to
9225 * clear any delalloc bits within this page range since we have to
9226 * reserve data&meta space before lock_page() (see above comments).
9227 */
9228 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end,
9229 EXTENT_DIRTY | EXTENT_DELALLOC |
9230 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
9231 0, 0, &cached_state, GFP_NOFS);
9232
9233 ret = btrfs_set_extent_delalloc(inode, page_start, end,
9234 &cached_state, 0);
9235 if (ret) {
9236 unlock_extent_cached(io_tree, page_start, page_end,
9237 &cached_state, GFP_NOFS);
9238 ret = VM_FAULT_SIGBUS;
9239 goto out_unlock;
9240 }
9241 ret = 0;
9242
9243 /* page is wholly or partially inside EOF */
9244 if (page_start + PAGE_SIZE > size)
9245 zero_start = size & ~PAGE_MASK;
9246 else
9247 zero_start = PAGE_SIZE;
9248
9249 if (zero_start != PAGE_SIZE) {
9250 kaddr = kmap(page);
9251 memset(kaddr + zero_start, 0, PAGE_SIZE - zero_start);
9252 flush_dcache_page(page);
9253 kunmap(page);
9254 }
9255 ClearPageChecked(page);
9256 set_page_dirty(page);
9257 SetPageUptodate(page);
9258
9259 BTRFS_I(inode)->last_trans = fs_info->generation;
9260 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
9261 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
9262
9263 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
9264
9265 out_unlock:
9266 if (!ret) {
9267 sb_end_pagefault(inode->i_sb);
9268 extent_changeset_free(data_reserved);
9269 return VM_FAULT_LOCKED;
9270 }
9271 unlock_page(page);
9272 out:
9273 btrfs_delalloc_release_space(inode, data_reserved, page_start,
9274 reserved_space);
9275 out_noreserve:
9276 sb_end_pagefault(inode->i_sb);
9277 extent_changeset_free(data_reserved);
9278 return ret;
9279 }
9280
9281 static int btrfs_truncate(struct inode *inode)
9282 {
9283 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
9284 struct btrfs_root *root = BTRFS_I(inode)->root;
9285 struct btrfs_block_rsv *rsv;
9286 int ret = 0;
9287 int err = 0;
9288 struct btrfs_trans_handle *trans;
9289 u64 mask = fs_info->sectorsize - 1;
9290 u64 min_size = btrfs_calc_trunc_metadata_size(fs_info, 1);
9291
9292 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
9293 (u64)-1);
9294 if (ret)
9295 return ret;
9296
9297 /*
9298 * Yes ladies and gentlemen, this is indeed ugly. The fact is we have
9299 * 3 things going on here
9300 *
9301 * 1) We need to reserve space for our orphan item and the space to
9302 * delete our orphan item. Lord knows we don't want to have a dangling
9303 * orphan item because we didn't reserve space to remove it.
9304 *
9305 * 2) We need to reserve space to update our inode.
9306 *
9307 * 3) We need to have something to cache all the space that is going to
9308 * be free'd up by the truncate operation, but also have some slack
9309 * space reserved in case it uses space during the truncate (thank you
9310 * very much snapshotting).
9311 *
9312 * And we need these to all be separate. The fact is we can use a lot of
9313 * space doing the truncate, and we have no earthly idea how much space
9314 * we will use, so we need the truncate reservation to be separate so it
9315 * doesn't end up using space reserved for updating the inode or
9316 * removing the orphan item. We also need to be able to stop the
9317 * transaction and start a new one, which means we need to be able to
9318 * update the inode several times, and we have no idea of knowing how
9319 * many times that will be, so we can't just reserve 1 item for the
9320 * entirety of the operation, so that has to be done separately as well.
9321 * Then there is the orphan item, which does indeed need to be held on
9322 * to for the whole operation, and we need nobody to touch this reserved
9323 * space except the orphan code.
9324 *
9325 * So that leaves us with
9326 *
9327 * 1) root->orphan_block_rsv - for the orphan deletion.
9328 * 2) rsv - for the truncate reservation, which we will steal from the
9329 * transaction reservation.
9330 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
9331 * updating the inode.
9332 */
9333 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
9334 if (!rsv)
9335 return -ENOMEM;
9336 rsv->size = min_size;
9337 rsv->failfast = 1;
9338
9339 /*
9340 * 1 for the truncate slack space
9341 * 1 for updating the inode.
9342 */
9343 trans = btrfs_start_transaction(root, 2);
9344 if (IS_ERR(trans)) {
9345 err = PTR_ERR(trans);
9346 goto out;
9347 }
9348
9349 /* Migrate the slack space for the truncate to our reserve */
9350 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
9351 min_size, 0);
9352 BUG_ON(ret);
9353
9354 /*
9355 * So if we truncate and then write and fsync we normally would just
9356 * write the extents that changed, which is a problem if we need to
9357 * first truncate that entire inode. So set this flag so we write out
9358 * all of the extents in the inode to the sync log so we're completely
9359 * safe.
9360 */
9361 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
9362 trans->block_rsv = rsv;
9363
9364 while (1) {
9365 ret = btrfs_truncate_inode_items(trans, root, inode,
9366 inode->i_size,
9367 BTRFS_EXTENT_DATA_KEY);
9368 if (ret != -ENOSPC && ret != -EAGAIN) {
9369 err = ret;
9370 break;
9371 }
9372
9373 trans->block_rsv = &fs_info->trans_block_rsv;
9374 ret = btrfs_update_inode(trans, root, inode);
9375 if (ret) {
9376 err = ret;
9377 break;
9378 }
9379
9380 btrfs_end_transaction(trans);
9381 btrfs_btree_balance_dirty(fs_info);
9382
9383 trans = btrfs_start_transaction(root, 2);
9384 if (IS_ERR(trans)) {
9385 ret = err = PTR_ERR(trans);
9386 trans = NULL;
9387 break;
9388 }
9389
9390 btrfs_block_rsv_release(fs_info, rsv, -1);
9391 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
9392 rsv, min_size, 0);
9393 BUG_ON(ret); /* shouldn't happen */
9394 trans->block_rsv = rsv;
9395 }
9396
9397 if (ret == 0 && inode->i_nlink > 0) {
9398 trans->block_rsv = root->orphan_block_rsv;
9399 ret = btrfs_orphan_del(trans, BTRFS_I(inode));
9400 if (ret)
9401 err = ret;
9402 }
9403
9404 if (trans) {
9405 trans->block_rsv = &fs_info->trans_block_rsv;
9406 ret = btrfs_update_inode(trans, root, inode);
9407 if (ret && !err)
9408 err = ret;
9409
9410 ret = btrfs_end_transaction(trans);
9411 btrfs_btree_balance_dirty(fs_info);
9412 }
9413 out:
9414 btrfs_free_block_rsv(fs_info, rsv);
9415
9416 if (ret && !err)
9417 err = ret;
9418
9419 return err;
9420 }
9421
9422 /*
9423 * create a new subvolume directory/inode (helper for the ioctl).
9424 */
9425 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
9426 struct btrfs_root *new_root,
9427 struct btrfs_root *parent_root,
9428 u64 new_dirid)
9429 {
9430 struct inode *inode;
9431 int err;
9432 u64 index = 0;
9433
9434 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
9435 new_dirid, new_dirid,
9436 S_IFDIR | (~current_umask() & S_IRWXUGO),
9437 &index);
9438 if (IS_ERR(inode))
9439 return PTR_ERR(inode);
9440 inode->i_op = &btrfs_dir_inode_operations;
9441 inode->i_fop = &btrfs_dir_file_operations;
9442
9443 set_nlink(inode, 1);
9444 btrfs_i_size_write(BTRFS_I(inode), 0);
9445 unlock_new_inode(inode);
9446
9447 err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
9448 if (err)
9449 btrfs_err(new_root->fs_info,
9450 "error inheriting subvolume %llu properties: %d",
9451 new_root->root_key.objectid, err);
9452
9453 err = btrfs_update_inode(trans, new_root, inode);
9454
9455 iput(inode);
9456 return err;
9457 }
9458
9459 struct inode *btrfs_alloc_inode(struct super_block *sb)
9460 {
9461 struct btrfs_inode *ei;
9462 struct inode *inode;
9463
9464 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
9465 if (!ei)
9466 return NULL;
9467
9468 ei->root = NULL;
9469 ei->generation = 0;
9470 ei->last_trans = 0;
9471 ei->last_sub_trans = 0;
9472 ei->logged_trans = 0;
9473 ei->delalloc_bytes = 0;
9474 ei->new_delalloc_bytes = 0;
9475 ei->defrag_bytes = 0;
9476 ei->disk_i_size = 0;
9477 ei->flags = 0;
9478 ei->csum_bytes = 0;
9479 ei->index_cnt = (u64)-1;
9480 ei->dir_index = 0;
9481 ei->last_unlink_trans = 0;
9482 ei->last_log_commit = 0;
9483 ei->delayed_iput_count = 0;
9484
9485 spin_lock_init(&ei->lock);
9486 ei->outstanding_extents = 0;
9487 ei->reserved_extents = 0;
9488
9489 ei->runtime_flags = 0;
9490 ei->prop_compress = BTRFS_COMPRESS_NONE;
9491 ei->defrag_compress = BTRFS_COMPRESS_NONE;
9492
9493 ei->delayed_node = NULL;
9494
9495 ei->i_otime.tv_sec = 0;
9496 ei->i_otime.tv_nsec = 0;
9497
9498 inode = &ei->vfs_inode;
9499 extent_map_tree_init(&ei->extent_tree);
9500 extent_io_tree_init(&ei->io_tree, inode);
9501 extent_io_tree_init(&ei->io_failure_tree, inode);
9502 ei->io_tree.track_uptodate = 1;
9503 ei->io_failure_tree.track_uptodate = 1;
9504 atomic_set(&ei->sync_writers, 0);
9505 mutex_init(&ei->log_mutex);
9506 mutex_init(&ei->delalloc_mutex);
9507 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
9508 INIT_LIST_HEAD(&ei->delalloc_inodes);
9509 INIT_LIST_HEAD(&ei->delayed_iput);
9510 RB_CLEAR_NODE(&ei->rb_node);
9511 init_rwsem(&ei->dio_sem);
9512
9513 return inode;
9514 }
9515
9516 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
9517 void btrfs_test_destroy_inode(struct inode *inode)
9518 {
9519 btrfs_drop_extent_cache(BTRFS_I(inode), 0, (u64)-1, 0);
9520 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9521 }
9522 #endif
9523
9524 static void btrfs_i_callback(struct rcu_head *head)
9525 {
9526 struct inode *inode = container_of(head, struct inode, i_rcu);
9527 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9528 }
9529
9530 void btrfs_destroy_inode(struct inode *inode)
9531 {
9532 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
9533 struct btrfs_ordered_extent *ordered;
9534 struct btrfs_root *root = BTRFS_I(inode)->root;
9535
9536 WARN_ON(!hlist_empty(&inode->i_dentry));
9537 WARN_ON(inode->i_data.nrpages);
9538 WARN_ON(BTRFS_I(inode)->outstanding_extents);
9539 WARN_ON(BTRFS_I(inode)->reserved_extents);
9540 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
9541 WARN_ON(BTRFS_I(inode)->new_delalloc_bytes);
9542 WARN_ON(BTRFS_I(inode)->csum_bytes);
9543 WARN_ON(BTRFS_I(inode)->defrag_bytes);
9544
9545 /*
9546 * This can happen where we create an inode, but somebody else also
9547 * created the same inode and we need to destroy the one we already
9548 * created.
9549 */
9550 if (!root)
9551 goto free;
9552
9553 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
9554 &BTRFS_I(inode)->runtime_flags)) {
9555 btrfs_info(fs_info, "inode %llu still on the orphan list",
9556 btrfs_ino(BTRFS_I(inode)));
9557 atomic_dec(&root->orphan_inodes);
9558 }
9559
9560 while (1) {
9561 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
9562 if (!ordered)
9563 break;
9564 else {
9565 btrfs_err(fs_info,
9566 "found ordered extent %llu %llu on inode cleanup",
9567 ordered->file_offset, ordered->len);
9568 btrfs_remove_ordered_extent(inode, ordered);
9569 btrfs_put_ordered_extent(ordered);
9570 btrfs_put_ordered_extent(ordered);
9571 }
9572 }
9573 btrfs_qgroup_check_reserved_leak(inode);
9574 inode_tree_del(inode);
9575 btrfs_drop_extent_cache(BTRFS_I(inode), 0, (u64)-1, 0);
9576 free:
9577 call_rcu(&inode->i_rcu, btrfs_i_callback);
9578 }
9579
9580 int btrfs_drop_inode(struct inode *inode)
9581 {
9582 struct btrfs_root *root = BTRFS_I(inode)->root;
9583
9584 if (root == NULL)
9585 return 1;
9586
9587 /* the snap/subvol tree is on deleting */
9588 if (btrfs_root_refs(&root->root_item) == 0)
9589 return 1;
9590 else
9591 return generic_drop_inode(inode);
9592 }
9593
9594 static void init_once(void *foo)
9595 {
9596 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
9597
9598 inode_init_once(&ei->vfs_inode);
9599 }
9600
9601 void btrfs_destroy_cachep(void)
9602 {
9603 /*
9604 * Make sure all delayed rcu free inodes are flushed before we
9605 * destroy cache.
9606 */
9607 rcu_barrier();
9608 kmem_cache_destroy(btrfs_inode_cachep);
9609 kmem_cache_destroy(btrfs_trans_handle_cachep);
9610 kmem_cache_destroy(btrfs_path_cachep);
9611 kmem_cache_destroy(btrfs_free_space_cachep);
9612 }
9613
9614 int btrfs_init_cachep(void)
9615 {
9616 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
9617 sizeof(struct btrfs_inode), 0,
9618 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT,
9619 init_once);
9620 if (!btrfs_inode_cachep)
9621 goto fail;
9622
9623 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
9624 sizeof(struct btrfs_trans_handle), 0,
9625 SLAB_TEMPORARY | SLAB_MEM_SPREAD, NULL);
9626 if (!btrfs_trans_handle_cachep)
9627 goto fail;
9628
9629 btrfs_path_cachep = kmem_cache_create("btrfs_path",
9630 sizeof(struct btrfs_path), 0,
9631 SLAB_MEM_SPREAD, NULL);
9632 if (!btrfs_path_cachep)
9633 goto fail;
9634
9635 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
9636 sizeof(struct btrfs_free_space), 0,
9637 SLAB_MEM_SPREAD, NULL);
9638 if (!btrfs_free_space_cachep)
9639 goto fail;
9640
9641 return 0;
9642 fail:
9643 btrfs_destroy_cachep();
9644 return -ENOMEM;
9645 }
9646
9647 static int btrfs_getattr(const struct path *path, struct kstat *stat,
9648 u32 request_mask, unsigned int flags)
9649 {
9650 u64 delalloc_bytes;
9651 struct inode *inode = d_inode(path->dentry);
9652 u32 blocksize = inode->i_sb->s_blocksize;
9653 u32 bi_flags = BTRFS_I(inode)->flags;
9654
9655 stat->result_mask |= STATX_BTIME;
9656 stat->btime.tv_sec = BTRFS_I(inode)->i_otime.tv_sec;
9657 stat->btime.tv_nsec = BTRFS_I(inode)->i_otime.tv_nsec;
9658 if (bi_flags & BTRFS_INODE_APPEND)
9659 stat->attributes |= STATX_ATTR_APPEND;
9660 if (bi_flags & BTRFS_INODE_COMPRESS)
9661 stat->attributes |= STATX_ATTR_COMPRESSED;
9662 if (bi_flags & BTRFS_INODE_IMMUTABLE)
9663 stat->attributes |= STATX_ATTR_IMMUTABLE;
9664 if (bi_flags & BTRFS_INODE_NODUMP)
9665 stat->attributes |= STATX_ATTR_NODUMP;
9666
9667 stat->attributes_mask |= (STATX_ATTR_APPEND |
9668 STATX_ATTR_COMPRESSED |
9669 STATX_ATTR_IMMUTABLE |
9670 STATX_ATTR_NODUMP);
9671
9672 generic_fillattr(inode, stat);
9673 stat->dev = BTRFS_I(inode)->root->anon_dev;
9674
9675 spin_lock(&BTRFS_I(inode)->lock);
9676 delalloc_bytes = BTRFS_I(inode)->new_delalloc_bytes;
9677 spin_unlock(&BTRFS_I(inode)->lock);
9678 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
9679 ALIGN(delalloc_bytes, blocksize)) >> 9;
9680 return 0;
9681 }
9682
9683 static int btrfs_rename_exchange(struct inode *old_dir,
9684 struct dentry *old_dentry,
9685 struct inode *new_dir,
9686 struct dentry *new_dentry)
9687 {
9688 struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
9689 struct btrfs_trans_handle *trans;
9690 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9691 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9692 struct inode *new_inode = new_dentry->d_inode;
9693 struct inode *old_inode = old_dentry->d_inode;
9694 struct timespec ctime = current_time(old_inode);
9695 struct dentry *parent;
9696 u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
9697 u64 new_ino = btrfs_ino(BTRFS_I(new_inode));
9698 u64 old_idx = 0;
9699 u64 new_idx = 0;
9700 u64 root_objectid;
9701 int ret;
9702 bool root_log_pinned = false;
9703 bool dest_log_pinned = false;
9704
9705 /* we only allow rename subvolume link between subvolumes */
9706 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9707 return -EXDEV;
9708
9709 /* close the race window with snapshot create/destroy ioctl */
9710 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9711 down_read(&fs_info->subvol_sem);
9712 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9713 down_read(&fs_info->subvol_sem);
9714
9715 /*
9716 * We want to reserve the absolute worst case amount of items. So if
9717 * both inodes are subvols and we need to unlink them then that would
9718 * require 4 item modifications, but if they are both normal inodes it
9719 * would require 5 item modifications, so we'll assume their normal
9720 * inodes. So 5 * 2 is 10, plus 2 for the new links, so 12 total items
9721 * should cover the worst case number of items we'll modify.
9722 */
9723 trans = btrfs_start_transaction(root, 12);
9724 if (IS_ERR(trans)) {
9725 ret = PTR_ERR(trans);
9726 goto out_notrans;
9727 }
9728
9729 /*
9730 * We need to find a free sequence number both in the source and
9731 * in the destination directory for the exchange.
9732 */
9733 ret = btrfs_set_inode_index(BTRFS_I(new_dir), &old_idx);
9734 if (ret)
9735 goto out_fail;
9736 ret = btrfs_set_inode_index(BTRFS_I(old_dir), &new_idx);
9737 if (ret)
9738 goto out_fail;
9739
9740 BTRFS_I(old_inode)->dir_index = 0ULL;
9741 BTRFS_I(new_inode)->dir_index = 0ULL;
9742
9743 /* Reference for the source. */
9744 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9745 /* force full log commit if subvolume involved. */
9746 btrfs_set_log_full_commit(fs_info, trans);
9747 } else {
9748 btrfs_pin_log_trans(root);
9749 root_log_pinned = true;
9750 ret = btrfs_insert_inode_ref(trans, dest,
9751 new_dentry->d_name.name,
9752 new_dentry->d_name.len,
9753 old_ino,
9754 btrfs_ino(BTRFS_I(new_dir)),
9755 old_idx);
9756 if (ret)
9757 goto out_fail;
9758 }
9759
9760 /* And now for the dest. */
9761 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9762 /* force full log commit if subvolume involved. */
9763 btrfs_set_log_full_commit(fs_info, trans);
9764 } else {
9765 btrfs_pin_log_trans(dest);
9766 dest_log_pinned = true;
9767 ret = btrfs_insert_inode_ref(trans, root,
9768 old_dentry->d_name.name,
9769 old_dentry->d_name.len,
9770 new_ino,
9771 btrfs_ino(BTRFS_I(old_dir)),
9772 new_idx);
9773 if (ret)
9774 goto out_fail;
9775 }
9776
9777 /* Update inode version and ctime/mtime. */
9778 inode_inc_iversion(old_dir);
9779 inode_inc_iversion(new_dir);
9780 inode_inc_iversion(old_inode);
9781 inode_inc_iversion(new_inode);
9782 old_dir->i_ctime = old_dir->i_mtime = ctime;
9783 new_dir->i_ctime = new_dir->i_mtime = ctime;
9784 old_inode->i_ctime = ctime;
9785 new_inode->i_ctime = ctime;
9786
9787 if (old_dentry->d_parent != new_dentry->d_parent) {
9788 btrfs_record_unlink_dir(trans, BTRFS_I(old_dir),
9789 BTRFS_I(old_inode), 1);
9790 btrfs_record_unlink_dir(trans, BTRFS_I(new_dir),
9791 BTRFS_I(new_inode), 1);
9792 }
9793
9794 /* src is a subvolume */
9795 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9796 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9797 ret = btrfs_unlink_subvol(trans, root, old_dir,
9798 root_objectid,
9799 old_dentry->d_name.name,
9800 old_dentry->d_name.len);
9801 } else { /* src is an inode */
9802 ret = __btrfs_unlink_inode(trans, root, BTRFS_I(old_dir),
9803 BTRFS_I(old_dentry->d_inode),
9804 old_dentry->d_name.name,
9805 old_dentry->d_name.len);
9806 if (!ret)
9807 ret = btrfs_update_inode(trans, root, old_inode);
9808 }
9809 if (ret) {
9810 btrfs_abort_transaction(trans, ret);
9811 goto out_fail;
9812 }
9813
9814 /* dest is a subvolume */
9815 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9816 root_objectid = BTRFS_I(new_inode)->root->root_key.objectid;
9817 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9818 root_objectid,
9819 new_dentry->d_name.name,
9820 new_dentry->d_name.len);
9821 } else { /* dest is an inode */
9822 ret = __btrfs_unlink_inode(trans, dest, BTRFS_I(new_dir),
9823 BTRFS_I(new_dentry->d_inode),
9824 new_dentry->d_name.name,
9825 new_dentry->d_name.len);
9826 if (!ret)
9827 ret = btrfs_update_inode(trans, dest, new_inode);
9828 }
9829 if (ret) {
9830 btrfs_abort_transaction(trans, ret);
9831 goto out_fail;
9832 }
9833
9834 ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
9835 new_dentry->d_name.name,
9836 new_dentry->d_name.len, 0, old_idx);
9837 if (ret) {
9838 btrfs_abort_transaction(trans, ret);
9839 goto out_fail;
9840 }
9841
9842 ret = btrfs_add_link(trans, BTRFS_I(old_dir), BTRFS_I(new_inode),
9843 old_dentry->d_name.name,
9844 old_dentry->d_name.len, 0, new_idx);
9845 if (ret) {
9846 btrfs_abort_transaction(trans, ret);
9847 goto out_fail;
9848 }
9849
9850 if (old_inode->i_nlink == 1)
9851 BTRFS_I(old_inode)->dir_index = old_idx;
9852 if (new_inode->i_nlink == 1)
9853 BTRFS_I(new_inode)->dir_index = new_idx;
9854
9855 if (root_log_pinned) {
9856 parent = new_dentry->d_parent;
9857 btrfs_log_new_name(trans, BTRFS_I(old_inode), BTRFS_I(old_dir),
9858 parent);
9859 btrfs_end_log_trans(root);
9860 root_log_pinned = false;
9861 }
9862 if (dest_log_pinned) {
9863 parent = old_dentry->d_parent;
9864 btrfs_log_new_name(trans, BTRFS_I(new_inode), BTRFS_I(new_dir),
9865 parent);
9866 btrfs_end_log_trans(dest);
9867 dest_log_pinned = false;
9868 }
9869 out_fail:
9870 /*
9871 * If we have pinned a log and an error happened, we unpin tasks
9872 * trying to sync the log and force them to fallback to a transaction
9873 * commit if the log currently contains any of the inodes involved in
9874 * this rename operation (to ensure we do not persist a log with an
9875 * inconsistent state for any of these inodes or leading to any
9876 * inconsistencies when replayed). If the transaction was aborted, the
9877 * abortion reason is propagated to userspace when attempting to commit
9878 * the transaction. If the log does not contain any of these inodes, we
9879 * allow the tasks to sync it.
9880 */
9881 if (ret && (root_log_pinned || dest_log_pinned)) {
9882 if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) ||
9883 btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) ||
9884 btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) ||
9885 (new_inode &&
9886 btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation)))
9887 btrfs_set_log_full_commit(fs_info, trans);
9888
9889 if (root_log_pinned) {
9890 btrfs_end_log_trans(root);
9891 root_log_pinned = false;
9892 }
9893 if (dest_log_pinned) {
9894 btrfs_end_log_trans(dest);
9895 dest_log_pinned = false;
9896 }
9897 }
9898 ret = btrfs_end_transaction(trans);
9899 out_notrans:
9900 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9901 up_read(&fs_info->subvol_sem);
9902 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9903 up_read(&fs_info->subvol_sem);
9904
9905 return ret;
9906 }
9907
9908 static int btrfs_whiteout_for_rename(struct btrfs_trans_handle *trans,
9909 struct btrfs_root *root,
9910 struct inode *dir,
9911 struct dentry *dentry)
9912 {
9913 int ret;
9914 struct inode *inode;
9915 u64 objectid;
9916 u64 index;
9917
9918 ret = btrfs_find_free_ino(root, &objectid);
9919 if (ret)
9920 return ret;
9921
9922 inode = btrfs_new_inode(trans, root, dir,
9923 dentry->d_name.name,
9924 dentry->d_name.len,
9925 btrfs_ino(BTRFS_I(dir)),
9926 objectid,
9927 S_IFCHR | WHITEOUT_MODE,
9928 &index);
9929
9930 if (IS_ERR(inode)) {
9931 ret = PTR_ERR(inode);
9932 return ret;
9933 }
9934
9935 inode->i_op = &btrfs_special_inode_operations;
9936 init_special_inode(inode, inode->i_mode,
9937 WHITEOUT_DEV);
9938
9939 ret = btrfs_init_inode_security(trans, inode, dir,
9940 &dentry->d_name);
9941 if (ret)
9942 goto out;
9943
9944 ret = btrfs_add_nondir(trans, BTRFS_I(dir), dentry,
9945 BTRFS_I(inode), 0, index);
9946 if (ret)
9947 goto out;
9948
9949 ret = btrfs_update_inode(trans, root, inode);
9950 out:
9951 unlock_new_inode(inode);
9952 if (ret)
9953 inode_dec_link_count(inode);
9954 iput(inode);
9955
9956 return ret;
9957 }
9958
9959 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
9960 struct inode *new_dir, struct dentry *new_dentry,
9961 unsigned int flags)
9962 {
9963 struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
9964 struct btrfs_trans_handle *trans;
9965 unsigned int trans_num_items;
9966 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9967 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9968 struct inode *new_inode = d_inode(new_dentry);
9969 struct inode *old_inode = d_inode(old_dentry);
9970 u64 index = 0;
9971 u64 root_objectid;
9972 int ret;
9973 u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
9974 bool log_pinned = false;
9975
9976 if (btrfs_ino(BTRFS_I(new_dir)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
9977 return -EPERM;
9978
9979 /* we only allow rename subvolume link between subvolumes */
9980 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9981 return -EXDEV;
9982
9983 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
9984 (new_inode && btrfs_ino(BTRFS_I(new_inode)) == BTRFS_FIRST_FREE_OBJECTID))
9985 return -ENOTEMPTY;
9986
9987 if (S_ISDIR(old_inode->i_mode) && new_inode &&
9988 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
9989 return -ENOTEMPTY;
9990
9991
9992 /* check for collisions, even if the name isn't there */
9993 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
9994 new_dentry->d_name.name,
9995 new_dentry->d_name.len);
9996
9997 if (ret) {
9998 if (ret == -EEXIST) {
9999 /* we shouldn't get
10000 * eexist without a new_inode */
10001 if (WARN_ON(!new_inode)) {
10002 return ret;
10003 }
10004 } else {
10005 /* maybe -EOVERFLOW */
10006 return ret;
10007 }
10008 }
10009 ret = 0;
10010
10011 /*
10012 * we're using rename to replace one file with another. Start IO on it
10013 * now so we don't add too much work to the end of the transaction
10014 */
10015 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
10016 filemap_flush(old_inode->i_mapping);
10017
10018 /* close the racy window with snapshot create/destroy ioctl */
10019 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
10020 down_read(&fs_info->subvol_sem);
10021 /*
10022 * We want to reserve the absolute worst case amount of items. So if
10023 * both inodes are subvols and we need to unlink them then that would
10024 * require 4 item modifications, but if they are both normal inodes it
10025 * would require 5 item modifications, so we'll assume they are normal
10026 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
10027 * should cover the worst case number of items we'll modify.
10028 * If our rename has the whiteout flag, we need more 5 units for the
10029 * new inode (1 inode item, 1 inode ref, 2 dir items and 1 xattr item
10030 * when selinux is enabled).
10031 */
10032 trans_num_items = 11;
10033 if (flags & RENAME_WHITEOUT)
10034 trans_num_items += 5;
10035 trans = btrfs_start_transaction(root, trans_num_items);
10036 if (IS_ERR(trans)) {
10037 ret = PTR_ERR(trans);
10038 goto out_notrans;
10039 }
10040
10041 if (dest != root)
10042 btrfs_record_root_in_trans(trans, dest);
10043
10044 ret = btrfs_set_inode_index(BTRFS_I(new_dir), &index);
10045 if (ret)
10046 goto out_fail;
10047
10048 BTRFS_I(old_inode)->dir_index = 0ULL;
10049 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
10050 /* force full log commit if subvolume involved. */
10051 btrfs_set_log_full_commit(fs_info, trans);
10052 } else {
10053 btrfs_pin_log_trans(root);
10054 log_pinned = true;
10055 ret = btrfs_insert_inode_ref(trans, dest,
10056 new_dentry->d_name.name,
10057 new_dentry->d_name.len,
10058 old_ino,
10059 btrfs_ino(BTRFS_I(new_dir)), index);
10060 if (ret)
10061 goto out_fail;
10062 }
10063
10064 inode_inc_iversion(old_dir);
10065 inode_inc_iversion(new_dir);
10066 inode_inc_iversion(old_inode);
10067 old_dir->i_ctime = old_dir->i_mtime =
10068 new_dir->i_ctime = new_dir->i_mtime =
10069 old_inode->i_ctime = current_time(old_dir);
10070
10071 if (old_dentry->d_parent != new_dentry->d_parent)
10072 btrfs_record_unlink_dir(trans, BTRFS_I(old_dir),
10073 BTRFS_I(old_inode), 1);
10074
10075 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
10076 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
10077 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
10078 old_dentry->d_name.name,
10079 old_dentry->d_name.len);
10080 } else {
10081 ret = __btrfs_unlink_inode(trans, root, BTRFS_I(old_dir),
10082 BTRFS_I(d_inode(old_dentry)),
10083 old_dentry->d_name.name,
10084 old_dentry->d_name.len);
10085 if (!ret)
10086 ret = btrfs_update_inode(trans, root, old_inode);
10087 }
10088 if (ret) {
10089 btrfs_abort_transaction(trans, ret);
10090 goto out_fail;
10091 }
10092
10093 if (new_inode) {
10094 inode_inc_iversion(new_inode);
10095 new_inode->i_ctime = current_time(new_inode);
10096 if (unlikely(btrfs_ino(BTRFS_I(new_inode)) ==
10097 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
10098 root_objectid = BTRFS_I(new_inode)->location.objectid;
10099 ret = btrfs_unlink_subvol(trans, dest, new_dir,
10100 root_objectid,
10101 new_dentry->d_name.name,
10102 new_dentry->d_name.len);
10103 BUG_ON(new_inode->i_nlink == 0);
10104 } else {
10105 ret = btrfs_unlink_inode(trans, dest, BTRFS_I(new_dir),
10106 BTRFS_I(d_inode(new_dentry)),
10107 new_dentry->d_name.name,
10108 new_dentry->d_name.len);
10109 }
10110 if (!ret && new_inode->i_nlink == 0)
10111 ret = btrfs_orphan_add(trans,
10112 BTRFS_I(d_inode(new_dentry)));
10113 if (ret) {
10114 btrfs_abort_transaction(trans, ret);
10115 goto out_fail;
10116 }
10117 }
10118
10119 ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
10120 new_dentry->d_name.name,
10121 new_dentry->d_name.len, 0, index);
10122 if (ret) {
10123 btrfs_abort_transaction(trans, ret);
10124 goto out_fail;
10125 }
10126
10127 if (old_inode->i_nlink == 1)
10128 BTRFS_I(old_inode)->dir_index = index;
10129
10130 if (log_pinned) {
10131 struct dentry *parent = new_dentry->d_parent;
10132
10133 btrfs_log_new_name(trans, BTRFS_I(old_inode), BTRFS_I(old_dir),
10134 parent);
10135 btrfs_end_log_trans(root);
10136 log_pinned = false;
10137 }
10138
10139 if (flags & RENAME_WHITEOUT) {
10140 ret = btrfs_whiteout_for_rename(trans, root, old_dir,
10141 old_dentry);
10142
10143 if (ret) {
10144 btrfs_abort_transaction(trans, ret);
10145 goto out_fail;
10146 }
10147 }
10148 out_fail:
10149 /*
10150 * If we have pinned the log and an error happened, we unpin tasks
10151 * trying to sync the log and force them to fallback to a transaction
10152 * commit if the log currently contains any of the inodes involved in
10153 * this rename operation (to ensure we do not persist a log with an
10154 * inconsistent state for any of these inodes or leading to any
10155 * inconsistencies when replayed). If the transaction was aborted, the
10156 * abortion reason is propagated to userspace when attempting to commit
10157 * the transaction. If the log does not contain any of these inodes, we
10158 * allow the tasks to sync it.
10159 */
10160 if (ret && log_pinned) {
10161 if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) ||
10162 btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) ||
10163 btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) ||
10164 (new_inode &&
10165 btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation)))
10166 btrfs_set_log_full_commit(fs_info, trans);
10167
10168 btrfs_end_log_trans(root);
10169 log_pinned = false;
10170 }
10171 btrfs_end_transaction(trans);
10172 out_notrans:
10173 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
10174 up_read(&fs_info->subvol_sem);
10175
10176 return ret;
10177 }
10178
10179 static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
10180 struct inode *new_dir, struct dentry *new_dentry,
10181 unsigned int flags)
10182 {
10183 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
10184 return -EINVAL;
10185
10186 if (flags & RENAME_EXCHANGE)
10187 return btrfs_rename_exchange(old_dir, old_dentry, new_dir,
10188 new_dentry);
10189
10190 return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
10191 }
10192
10193 static void btrfs_run_delalloc_work(struct btrfs_work *work)
10194 {
10195 struct btrfs_delalloc_work *delalloc_work;
10196 struct inode *inode;
10197
10198 delalloc_work = container_of(work, struct btrfs_delalloc_work,
10199 work);
10200 inode = delalloc_work->inode;
10201 filemap_flush(inode->i_mapping);
10202 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
10203 &BTRFS_I(inode)->runtime_flags))
10204 filemap_flush(inode->i_mapping);
10205
10206 if (delalloc_work->delay_iput)
10207 btrfs_add_delayed_iput(inode);
10208 else
10209 iput(inode);
10210 complete(&delalloc_work->completion);
10211 }
10212
10213 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
10214 int delay_iput)
10215 {
10216 struct btrfs_delalloc_work *work;
10217
10218 work = kmalloc(sizeof(*work), GFP_NOFS);
10219 if (!work)
10220 return NULL;
10221
10222 init_completion(&work->completion);
10223 INIT_LIST_HEAD(&work->list);
10224 work->inode = inode;
10225 work->delay_iput = delay_iput;
10226 WARN_ON_ONCE(!inode);
10227 btrfs_init_work(&work->work, btrfs_flush_delalloc_helper,
10228 btrfs_run_delalloc_work, NULL, NULL);
10229
10230 return work;
10231 }
10232
10233 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
10234 {
10235 wait_for_completion(&work->completion);
10236 kfree(work);
10237 }
10238
10239 /*
10240 * some fairly slow code that needs optimization. This walks the list
10241 * of all the inodes with pending delalloc and forces them to disk.
10242 */
10243 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput,
10244 int nr)
10245 {
10246 struct btrfs_inode *binode;
10247 struct inode *inode;
10248 struct btrfs_delalloc_work *work, *next;
10249 struct list_head works;
10250 struct list_head splice;
10251 int ret = 0;
10252
10253 INIT_LIST_HEAD(&works);
10254 INIT_LIST_HEAD(&splice);
10255
10256 mutex_lock(&root->delalloc_mutex);
10257 spin_lock(&root->delalloc_lock);
10258 list_splice_init(&root->delalloc_inodes, &splice);
10259 while (!list_empty(&splice)) {
10260 binode = list_entry(splice.next, struct btrfs_inode,
10261 delalloc_inodes);
10262
10263 list_move_tail(&binode->delalloc_inodes,
10264 &root->delalloc_inodes);
10265 inode = igrab(&binode->vfs_inode);
10266 if (!inode) {
10267 cond_resched_lock(&root->delalloc_lock);
10268 continue;
10269 }
10270 spin_unlock(&root->delalloc_lock);
10271
10272 work = btrfs_alloc_delalloc_work(inode, delay_iput);
10273 if (!work) {
10274 if (delay_iput)
10275 btrfs_add_delayed_iput(inode);
10276 else
10277 iput(inode);
10278 ret = -ENOMEM;
10279 goto out;
10280 }
10281 list_add_tail(&work->list, &works);
10282 btrfs_queue_work(root->fs_info->flush_workers,
10283 &work->work);
10284 ret++;
10285 if (nr != -1 && ret >= nr)
10286 goto out;
10287 cond_resched();
10288 spin_lock(&root->delalloc_lock);
10289 }
10290 spin_unlock(&root->delalloc_lock);
10291
10292 out:
10293 list_for_each_entry_safe(work, next, &works, list) {
10294 list_del_init(&work->list);
10295 btrfs_wait_and_free_delalloc_work(work);
10296 }
10297
10298 if (!list_empty_careful(&splice)) {
10299 spin_lock(&root->delalloc_lock);
10300 list_splice_tail(&splice, &root->delalloc_inodes);
10301 spin_unlock(&root->delalloc_lock);
10302 }
10303 mutex_unlock(&root->delalloc_mutex);
10304 return ret;
10305 }
10306
10307 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
10308 {
10309 struct btrfs_fs_info *fs_info = root->fs_info;
10310 int ret;
10311
10312 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
10313 return -EROFS;
10314
10315 ret = __start_delalloc_inodes(root, delay_iput, -1);
10316 if (ret > 0)
10317 ret = 0;
10318 /*
10319 * the filemap_flush will queue IO into the worker threads, but
10320 * we have to make sure the IO is actually started and that
10321 * ordered extents get created before we return
10322 */
10323 atomic_inc(&fs_info->async_submit_draining);
10324 while (atomic_read(&fs_info->nr_async_submits) ||
10325 atomic_read(&fs_info->async_delalloc_pages)) {
10326 wait_event(fs_info->async_submit_wait,
10327 (atomic_read(&fs_info->nr_async_submits) == 0 &&
10328 atomic_read(&fs_info->async_delalloc_pages) == 0));
10329 }
10330 atomic_dec(&fs_info->async_submit_draining);
10331 return ret;
10332 }
10333
10334 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput,
10335 int nr)
10336 {
10337 struct btrfs_root *root;
10338 struct list_head splice;
10339 int ret;
10340
10341 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
10342 return -EROFS;
10343
10344 INIT_LIST_HEAD(&splice);
10345
10346 mutex_lock(&fs_info->delalloc_root_mutex);
10347 spin_lock(&fs_info->delalloc_root_lock);
10348 list_splice_init(&fs_info->delalloc_roots, &splice);
10349 while (!list_empty(&splice) && nr) {
10350 root = list_first_entry(&splice, struct btrfs_root,
10351 delalloc_root);
10352 root = btrfs_grab_fs_root(root);
10353 BUG_ON(!root);
10354 list_move_tail(&root->delalloc_root,
10355 &fs_info->delalloc_roots);
10356 spin_unlock(&fs_info->delalloc_root_lock);
10357
10358 ret = __start_delalloc_inodes(root, delay_iput, nr);
10359 btrfs_put_fs_root(root);
10360 if (ret < 0)
10361 goto out;
10362
10363 if (nr != -1) {
10364 nr -= ret;
10365 WARN_ON(nr < 0);
10366 }
10367 spin_lock(&fs_info->delalloc_root_lock);
10368 }
10369 spin_unlock(&fs_info->delalloc_root_lock);
10370
10371 ret = 0;
10372 atomic_inc(&fs_info->async_submit_draining);
10373 while (atomic_read(&fs_info->nr_async_submits) ||
10374 atomic_read(&fs_info->async_delalloc_pages)) {
10375 wait_event(fs_info->async_submit_wait,
10376 (atomic_read(&fs_info->nr_async_submits) == 0 &&
10377 atomic_read(&fs_info->async_delalloc_pages) == 0));
10378 }
10379 atomic_dec(&fs_info->async_submit_draining);
10380 out:
10381 if (!list_empty_careful(&splice)) {
10382 spin_lock(&fs_info->delalloc_root_lock);
10383 list_splice_tail(&splice, &fs_info->delalloc_roots);
10384 spin_unlock(&fs_info->delalloc_root_lock);
10385 }
10386 mutex_unlock(&fs_info->delalloc_root_mutex);
10387 return ret;
10388 }
10389
10390 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
10391 const char *symname)
10392 {
10393 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
10394 struct btrfs_trans_handle *trans;
10395 struct btrfs_root *root = BTRFS_I(dir)->root;
10396 struct btrfs_path *path;
10397 struct btrfs_key key;
10398 struct inode *inode = NULL;
10399 int err;
10400 int drop_inode = 0;
10401 u64 objectid;
10402 u64 index = 0;
10403 int name_len;
10404 int datasize;
10405 unsigned long ptr;
10406 struct btrfs_file_extent_item *ei;
10407 struct extent_buffer *leaf;
10408
10409 name_len = strlen(symname);
10410 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info))
10411 return -ENAMETOOLONG;
10412
10413 /*
10414 * 2 items for inode item and ref
10415 * 2 items for dir items
10416 * 1 item for updating parent inode item
10417 * 1 item for the inline extent item
10418 * 1 item for xattr if selinux is on
10419 */
10420 trans = btrfs_start_transaction(root, 7);
10421 if (IS_ERR(trans))
10422 return PTR_ERR(trans);
10423
10424 err = btrfs_find_free_ino(root, &objectid);
10425 if (err)
10426 goto out_unlock;
10427
10428 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
10429 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)),
10430 objectid, S_IFLNK|S_IRWXUGO, &index);
10431 if (IS_ERR(inode)) {
10432 err = PTR_ERR(inode);
10433 goto out_unlock;
10434 }
10435
10436 /*
10437 * If the active LSM wants to access the inode during
10438 * d_instantiate it needs these. Smack checks to see
10439 * if the filesystem supports xattrs by looking at the
10440 * ops vector.
10441 */
10442 inode->i_fop = &btrfs_file_operations;
10443 inode->i_op = &btrfs_file_inode_operations;
10444 inode->i_mapping->a_ops = &btrfs_aops;
10445 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10446
10447 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
10448 if (err)
10449 goto out_unlock_inode;
10450
10451 path = btrfs_alloc_path();
10452 if (!path) {
10453 err = -ENOMEM;
10454 goto out_unlock_inode;
10455 }
10456 key.objectid = btrfs_ino(BTRFS_I(inode));
10457 key.offset = 0;
10458 key.type = BTRFS_EXTENT_DATA_KEY;
10459 datasize = btrfs_file_extent_calc_inline_size(name_len);
10460 err = btrfs_insert_empty_item(trans, root, path, &key,
10461 datasize);
10462 if (err) {
10463 btrfs_free_path(path);
10464 goto out_unlock_inode;
10465 }
10466 leaf = path->nodes[0];
10467 ei = btrfs_item_ptr(leaf, path->slots[0],
10468 struct btrfs_file_extent_item);
10469 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
10470 btrfs_set_file_extent_type(leaf, ei,
10471 BTRFS_FILE_EXTENT_INLINE);
10472 btrfs_set_file_extent_encryption(leaf, ei, 0);
10473 btrfs_set_file_extent_compression(leaf, ei, 0);
10474 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
10475 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
10476
10477 ptr = btrfs_file_extent_inline_start(ei);
10478 write_extent_buffer(leaf, symname, ptr, name_len);
10479 btrfs_mark_buffer_dirty(leaf);
10480 btrfs_free_path(path);
10481
10482 inode->i_op = &btrfs_symlink_inode_operations;
10483 inode_nohighmem(inode);
10484 inode->i_mapping->a_ops = &btrfs_symlink_aops;
10485 inode_set_bytes(inode, name_len);
10486 btrfs_i_size_write(BTRFS_I(inode), name_len);
10487 err = btrfs_update_inode(trans, root, inode);
10488 /*
10489 * Last step, add directory indexes for our symlink inode. This is the
10490 * last step to avoid extra cleanup of these indexes if an error happens
10491 * elsewhere above.
10492 */
10493 if (!err)
10494 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry,
10495 BTRFS_I(inode), 0, index);
10496 if (err) {
10497 drop_inode = 1;
10498 goto out_unlock_inode;
10499 }
10500
10501 unlock_new_inode(inode);
10502 d_instantiate(dentry, inode);
10503
10504 out_unlock:
10505 btrfs_end_transaction(trans);
10506 if (drop_inode) {
10507 inode_dec_link_count(inode);
10508 iput(inode);
10509 }
10510 btrfs_btree_balance_dirty(fs_info);
10511 return err;
10512
10513 out_unlock_inode:
10514 drop_inode = 1;
10515 unlock_new_inode(inode);
10516 goto out_unlock;
10517 }
10518
10519 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
10520 u64 start, u64 num_bytes, u64 min_size,
10521 loff_t actual_len, u64 *alloc_hint,
10522 struct btrfs_trans_handle *trans)
10523 {
10524 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
10525 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
10526 struct extent_map *em;
10527 struct btrfs_root *root = BTRFS_I(inode)->root;
10528 struct btrfs_key ins;
10529 u64 cur_offset = start;
10530 u64 i_size;
10531 u64 cur_bytes;
10532 u64 last_alloc = (u64)-1;
10533 int ret = 0;
10534 bool own_trans = true;
10535 u64 end = start + num_bytes - 1;
10536
10537 if (trans)
10538 own_trans = false;
10539 while (num_bytes > 0) {
10540 if (own_trans) {
10541 trans = btrfs_start_transaction(root, 3);
10542 if (IS_ERR(trans)) {
10543 ret = PTR_ERR(trans);
10544 break;
10545 }
10546 }
10547
10548 cur_bytes = min_t(u64, num_bytes, SZ_256M);
10549 cur_bytes = max(cur_bytes, min_size);
10550 /*
10551 * If we are severely fragmented we could end up with really
10552 * small allocations, so if the allocator is returning small
10553 * chunks lets make its job easier by only searching for those
10554 * sized chunks.
10555 */
10556 cur_bytes = min(cur_bytes, last_alloc);
10557 ret = btrfs_reserve_extent(root, cur_bytes, cur_bytes,
10558 min_size, 0, *alloc_hint, &ins, 1, 0);
10559 if (ret) {
10560 if (own_trans)
10561 btrfs_end_transaction(trans);
10562 break;
10563 }
10564 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
10565
10566 last_alloc = ins.offset;
10567 ret = insert_reserved_file_extent(trans, inode,
10568 cur_offset, ins.objectid,
10569 ins.offset, ins.offset,
10570 ins.offset, 0, 0, 0,
10571 BTRFS_FILE_EXTENT_PREALLOC);
10572 if (ret) {
10573 btrfs_free_reserved_extent(fs_info, ins.objectid,
10574 ins.offset, 0);
10575 btrfs_abort_transaction(trans, ret);
10576 if (own_trans)
10577 btrfs_end_transaction(trans);
10578 break;
10579 }
10580
10581 btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
10582 cur_offset + ins.offset -1, 0);
10583
10584 em = alloc_extent_map();
10585 if (!em) {
10586 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
10587 &BTRFS_I(inode)->runtime_flags);
10588 goto next;
10589 }
10590
10591 em->start = cur_offset;
10592 em->orig_start = cur_offset;
10593 em->len = ins.offset;
10594 em->block_start = ins.objectid;
10595 em->block_len = ins.offset;
10596 em->orig_block_len = ins.offset;
10597 em->ram_bytes = ins.offset;
10598 em->bdev = fs_info->fs_devices->latest_bdev;
10599 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
10600 em->generation = trans->transid;
10601
10602 while (1) {
10603 write_lock(&em_tree->lock);
10604 ret = add_extent_mapping(em_tree, em, 1);
10605 write_unlock(&em_tree->lock);
10606 if (ret != -EEXIST)
10607 break;
10608 btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
10609 cur_offset + ins.offset - 1,
10610 0);
10611 }
10612 free_extent_map(em);
10613 next:
10614 num_bytes -= ins.offset;
10615 cur_offset += ins.offset;
10616 *alloc_hint = ins.objectid + ins.offset;
10617
10618 inode_inc_iversion(inode);
10619 inode->i_ctime = current_time(inode);
10620 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
10621 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
10622 (actual_len > inode->i_size) &&
10623 (cur_offset > inode->i_size)) {
10624 if (cur_offset > actual_len)
10625 i_size = actual_len;
10626 else
10627 i_size = cur_offset;
10628 i_size_write(inode, i_size);
10629 btrfs_ordered_update_i_size(inode, i_size, NULL);
10630 }
10631
10632 ret = btrfs_update_inode(trans, root, inode);
10633
10634 if (ret) {
10635 btrfs_abort_transaction(trans, ret);
10636 if (own_trans)
10637 btrfs_end_transaction(trans);
10638 break;
10639 }
10640
10641 if (own_trans)
10642 btrfs_end_transaction(trans);
10643 }
10644 if (cur_offset < end)
10645 btrfs_free_reserved_data_space(inode, NULL, cur_offset,
10646 end - cur_offset + 1);
10647 return ret;
10648 }
10649
10650 int btrfs_prealloc_file_range(struct inode *inode, int mode,
10651 u64 start, u64 num_bytes, u64 min_size,
10652 loff_t actual_len, u64 *alloc_hint)
10653 {
10654 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10655 min_size, actual_len, alloc_hint,
10656 NULL);
10657 }
10658
10659 int btrfs_prealloc_file_range_trans(struct inode *inode,
10660 struct btrfs_trans_handle *trans, int mode,
10661 u64 start, u64 num_bytes, u64 min_size,
10662 loff_t actual_len, u64 *alloc_hint)
10663 {
10664 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10665 min_size, actual_len, alloc_hint, trans);
10666 }
10667
10668 static int btrfs_set_page_dirty(struct page *page)
10669 {
10670 return __set_page_dirty_nobuffers(page);
10671 }
10672
10673 static int btrfs_permission(struct inode *inode, int mask)
10674 {
10675 struct btrfs_root *root = BTRFS_I(inode)->root;
10676 umode_t mode = inode->i_mode;
10677
10678 if (mask & MAY_WRITE &&
10679 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
10680 if (btrfs_root_readonly(root))
10681 return -EROFS;
10682 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
10683 return -EACCES;
10684 }
10685 return generic_permission(inode, mask);
10686 }
10687
10688 static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
10689 {
10690 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
10691 struct btrfs_trans_handle *trans;
10692 struct btrfs_root *root = BTRFS_I(dir)->root;
10693 struct inode *inode = NULL;
10694 u64 objectid;
10695 u64 index;
10696 int ret = 0;
10697
10698 /*
10699 * 5 units required for adding orphan entry
10700 */
10701 trans = btrfs_start_transaction(root, 5);
10702 if (IS_ERR(trans))
10703 return PTR_ERR(trans);
10704
10705 ret = btrfs_find_free_ino(root, &objectid);
10706 if (ret)
10707 goto out;
10708
10709 inode = btrfs_new_inode(trans, root, dir, NULL, 0,
10710 btrfs_ino(BTRFS_I(dir)), objectid, mode, &index);
10711 if (IS_ERR(inode)) {
10712 ret = PTR_ERR(inode);
10713 inode = NULL;
10714 goto out;
10715 }
10716
10717 inode->i_fop = &btrfs_file_operations;
10718 inode->i_op = &btrfs_file_inode_operations;
10719
10720 inode->i_mapping->a_ops = &btrfs_aops;
10721 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10722
10723 ret = btrfs_init_inode_security(trans, inode, dir, NULL);
10724 if (ret)
10725 goto out_inode;
10726
10727 ret = btrfs_update_inode(trans, root, inode);
10728 if (ret)
10729 goto out_inode;
10730 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
10731 if (ret)
10732 goto out_inode;
10733
10734 /*
10735 * We set number of links to 0 in btrfs_new_inode(), and here we set
10736 * it to 1 because d_tmpfile() will issue a warning if the count is 0,
10737 * through:
10738 *
10739 * d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
10740 */
10741 set_nlink(inode, 1);
10742 unlock_new_inode(inode);
10743 d_tmpfile(dentry, inode);
10744 mark_inode_dirty(inode);
10745
10746 out:
10747 btrfs_end_transaction(trans);
10748 if (ret)
10749 iput(inode);
10750 btrfs_balance_delayed_items(fs_info);
10751 btrfs_btree_balance_dirty(fs_info);
10752 return ret;
10753
10754 out_inode:
10755 unlock_new_inode(inode);
10756 goto out;
10757
10758 }
10759
10760 __attribute__((const))
10761 static int btrfs_readpage_io_failed_hook(struct page *page, int failed_mirror)
10762 {
10763 return -EAGAIN;
10764 }
10765
10766 static struct btrfs_fs_info *iotree_fs_info(void *private_data)
10767 {
10768 struct inode *inode = private_data;
10769 return btrfs_sb(inode->i_sb);
10770 }
10771
10772 static void btrfs_check_extent_io_range(void *private_data, const char *caller,
10773 u64 start, u64 end)
10774 {
10775 struct inode *inode = private_data;
10776 u64 isize;
10777
10778 isize = i_size_read(inode);
10779 if (end >= PAGE_SIZE && (end % 2) == 0 && end != isize - 1) {
10780 btrfs_debug_rl(BTRFS_I(inode)->root->fs_info,
10781 "%s: ino %llu isize %llu odd range [%llu,%llu]",
10782 caller, btrfs_ino(BTRFS_I(inode)), isize, start, end);
10783 }
10784 }
10785
10786 void btrfs_set_range_writeback(void *private_data, u64 start, u64 end)
10787 {
10788 struct inode *inode = private_data;
10789 unsigned long index = start >> PAGE_SHIFT;
10790 unsigned long end_index = end >> PAGE_SHIFT;
10791 struct page *page;
10792
10793 while (index <= end_index) {
10794 page = find_get_page(inode->i_mapping, index);
10795 ASSERT(page); /* Pages should be in the extent_io_tree */
10796 set_page_writeback(page);
10797 put_page(page);
10798 index++;
10799 }
10800 }
10801
10802 static const struct inode_operations btrfs_dir_inode_operations = {
10803 .getattr = btrfs_getattr,
10804 .lookup = btrfs_lookup,
10805 .create = btrfs_create,
10806 .unlink = btrfs_unlink,
10807 .link = btrfs_link,
10808 .mkdir = btrfs_mkdir,
10809 .rmdir = btrfs_rmdir,
10810 .rename = btrfs_rename2,
10811 .symlink = btrfs_symlink,
10812 .setattr = btrfs_setattr,
10813 .mknod = btrfs_mknod,
10814 .listxattr = btrfs_listxattr,
10815 .permission = btrfs_permission,
10816 .get_acl = btrfs_get_acl,
10817 .set_acl = btrfs_set_acl,
10818 .update_time = btrfs_update_time,
10819 .tmpfile = btrfs_tmpfile,
10820 };
10821 static const struct inode_operations btrfs_dir_ro_inode_operations = {
10822 .lookup = btrfs_lookup,
10823 .permission = btrfs_permission,
10824 .update_time = btrfs_update_time,
10825 };
10826
10827 static const struct file_operations btrfs_dir_file_operations = {
10828 .llseek = generic_file_llseek,
10829 .read = generic_read_dir,
10830 .iterate_shared = btrfs_real_readdir,
10831 .open = btrfs_opendir,
10832 .unlocked_ioctl = btrfs_ioctl,
10833 #ifdef CONFIG_COMPAT
10834 .compat_ioctl = btrfs_compat_ioctl,
10835 #endif
10836 .release = btrfs_release_file,
10837 .fsync = btrfs_sync_file,
10838 };
10839
10840 static const struct extent_io_ops btrfs_extent_io_ops = {
10841 /* mandatory callbacks */
10842 .submit_bio_hook = btrfs_submit_bio_hook,
10843 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
10844 .merge_bio_hook = btrfs_merge_bio_hook,
10845 .readpage_io_failed_hook = btrfs_readpage_io_failed_hook,
10846 .tree_fs_info = iotree_fs_info,
10847 .set_range_writeback = btrfs_set_range_writeback,
10848
10849 /* optional callbacks */
10850 .fill_delalloc = run_delalloc_range,
10851 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
10852 .writepage_start_hook = btrfs_writepage_start_hook,
10853 .set_bit_hook = btrfs_set_bit_hook,
10854 .clear_bit_hook = btrfs_clear_bit_hook,
10855 .merge_extent_hook = btrfs_merge_extent_hook,
10856 .split_extent_hook = btrfs_split_extent_hook,
10857 .check_extent_io_range = btrfs_check_extent_io_range,
10858 };
10859
10860 /*
10861 * btrfs doesn't support the bmap operation because swapfiles
10862 * use bmap to make a mapping of extents in the file. They assume
10863 * these extents won't change over the life of the file and they
10864 * use the bmap result to do IO directly to the drive.
10865 *
10866 * the btrfs bmap call would return logical addresses that aren't
10867 * suitable for IO and they also will change frequently as COW
10868 * operations happen. So, swapfile + btrfs == corruption.
10869 *
10870 * For now we're avoiding this by dropping bmap.
10871 */
10872 static const struct address_space_operations btrfs_aops = {
10873 .readpage = btrfs_readpage,
10874 .writepage = btrfs_writepage,
10875 .writepages = btrfs_writepages,
10876 .readpages = btrfs_readpages,
10877 .direct_IO = btrfs_direct_IO,
10878 .invalidatepage = btrfs_invalidatepage,
10879 .releasepage = btrfs_releasepage,
10880 .set_page_dirty = btrfs_set_page_dirty,
10881 .error_remove_page = generic_error_remove_page,
10882 };
10883
10884 static const struct address_space_operations btrfs_symlink_aops = {
10885 .readpage = btrfs_readpage,
10886 .writepage = btrfs_writepage,
10887 .invalidatepage = btrfs_invalidatepage,
10888 .releasepage = btrfs_releasepage,
10889 };
10890
10891 static const struct inode_operations btrfs_file_inode_operations = {
10892 .getattr = btrfs_getattr,
10893 .setattr = btrfs_setattr,
10894 .listxattr = btrfs_listxattr,
10895 .permission = btrfs_permission,
10896 .fiemap = btrfs_fiemap,
10897 .get_acl = btrfs_get_acl,
10898 .set_acl = btrfs_set_acl,
10899 .update_time = btrfs_update_time,
10900 };
10901 static const struct inode_operations btrfs_special_inode_operations = {
10902 .getattr = btrfs_getattr,
10903 .setattr = btrfs_setattr,
10904 .permission = btrfs_permission,
10905 .listxattr = btrfs_listxattr,
10906 .get_acl = btrfs_get_acl,
10907 .set_acl = btrfs_set_acl,
10908 .update_time = btrfs_update_time,
10909 };
10910 static const struct inode_operations btrfs_symlink_inode_operations = {
10911 .get_link = page_get_link,
10912 .getattr = btrfs_getattr,
10913 .setattr = btrfs_setattr,
10914 .permission = btrfs_permission,
10915 .listxattr = btrfs_listxattr,
10916 .update_time = btrfs_update_time,
10917 };
10918
10919 const struct dentry_operations btrfs_dentry_operations = {
10920 .d_delete = btrfs_dentry_delete,
10921 .d_release = btrfs_dentry_release,
10922 };
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