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