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[mirror_ubuntu-hirsute-kernel.git] / fs / btrfs / inode.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2007 Oracle. All rights reserved.
4 */
5
6 #include <linux/kernel.h>
7 #include <linux/bio.h>
8 #include <linux/buffer_head.h>
9 #include <linux/file.h>
10 #include <linux/fs.h>
11 #include <linux/pagemap.h>
12 #include <linux/highmem.h>
13 #include <linux/time.h>
14 #include <linux/init.h>
15 #include <linux/string.h>
16 #include <linux/backing-dev.h>
17 #include <linux/mpage.h>
18 #include <linux/swap.h>
19 #include <linux/writeback.h>
20 #include <linux/compat.h>
21 #include <linux/bit_spinlock.h>
22 #include <linux/xattr.h>
23 #include <linux/posix_acl.h>
24 #include <linux/falloc.h>
25 #include <linux/slab.h>
26 #include <linux/ratelimit.h>
27 #include <linux/mount.h>
28 #include <linux/btrfs.h>
29 #include <linux/blkdev.h>
30 #include <linux/posix_acl_xattr.h>
31 #include <linux/uio.h>
32 #include <linux/magic.h>
33 #include <linux/iversion.h>
34 #include <asm/unaligned.h>
35 #include "ctree.h"
36 #include "disk-io.h"
37 #include "transaction.h"
38 #include "btrfs_inode.h"
39 #include "print-tree.h"
40 #include "ordered-data.h"
41 #include "xattr.h"
42 #include "tree-log.h"
43 #include "volumes.h"
44 #include "compression.h"
45 #include "locking.h"
46 #include "free-space-cache.h"
47 #include "inode-map.h"
48 #include "backref.h"
49 #include "props.h"
50 #include "qgroup.h"
51 #include "dedupe.h"
52
53 struct btrfs_iget_args {
54 struct btrfs_key *location;
55 struct btrfs_root *root;
56 };
57
58 struct btrfs_dio_data {
59 u64 reserve;
60 u64 unsubmitted_oe_range_start;
61 u64 unsubmitted_oe_range_end;
62 int overwrite;
63 };
64
65 static const struct inode_operations btrfs_dir_inode_operations;
66 static const struct inode_operations btrfs_symlink_inode_operations;
67 static const struct inode_operations btrfs_dir_ro_inode_operations;
68 static const struct inode_operations btrfs_special_inode_operations;
69 static const struct inode_operations btrfs_file_inode_operations;
70 static const struct address_space_operations btrfs_aops;
71 static const struct address_space_operations btrfs_symlink_aops;
72 static const struct file_operations btrfs_dir_file_operations;
73 static const struct extent_io_ops btrfs_extent_io_ops;
74
75 static struct kmem_cache *btrfs_inode_cachep;
76 struct kmem_cache *btrfs_trans_handle_cachep;
77 struct kmem_cache *btrfs_path_cachep;
78 struct kmem_cache *btrfs_free_space_cachep;
79
80 #define S_SHIFT 12
81 static const unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
82 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
83 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
84 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
85 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
86 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
87 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
88 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
89 };
90
91 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
92 static int btrfs_truncate(struct inode *inode, bool skip_writeback);
93 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
94 static noinline int cow_file_range(struct inode *inode,
95 struct page *locked_page,
96 u64 start, u64 end, u64 delalloc_end,
97 int *page_started, unsigned long *nr_written,
98 int unlock, struct btrfs_dedupe_hash *hash);
99 static struct extent_map *create_io_em(struct inode *inode, u64 start, u64 len,
100 u64 orig_start, u64 block_start,
101 u64 block_len, u64 orig_block_len,
102 u64 ram_bytes, int compress_type,
103 int type);
104
105 static void __endio_write_update_ordered(struct inode *inode,
106 const u64 offset, const u64 bytes,
107 const bool uptodate);
108
109 /*
110 * Cleanup all submitted ordered extents in specified range to handle errors
111 * from the fill_dellaloc() callback.
112 *
113 * NOTE: caller must ensure that when an error happens, it can not call
114 * extent_clear_unlock_delalloc() to clear both the bits EXTENT_DO_ACCOUNTING
115 * and EXTENT_DELALLOC simultaneously, because that causes the reserved metadata
116 * to be released, which we want to happen only when finishing the ordered
117 * extent (btrfs_finish_ordered_io()). Also note that the caller of the
118 * fill_delalloc() callback already does proper cleanup for the first page of
119 * the range, that is, it invokes the callback writepage_end_io_hook() for the
120 * range of the first page.
121 */
122 static inline void btrfs_cleanup_ordered_extents(struct inode *inode,
123 const u64 offset,
124 const u64 bytes)
125 {
126 unsigned long index = offset >> PAGE_SHIFT;
127 unsigned long end_index = (offset + bytes - 1) >> PAGE_SHIFT;
128 struct page *page;
129
130 while (index <= end_index) {
131 page = find_get_page(inode->i_mapping, index);
132 index++;
133 if (!page)
134 continue;
135 ClearPagePrivate2(page);
136 put_page(page);
137 }
138 return __endio_write_update_ordered(inode, offset + PAGE_SIZE,
139 bytes - PAGE_SIZE, false);
140 }
141
142 static int btrfs_dirty_inode(struct inode *inode);
143
144 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
145 void btrfs_test_inode_set_ops(struct inode *inode)
146 {
147 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
148 }
149 #endif
150
151 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
152 struct inode *inode, struct inode *dir,
153 const struct qstr *qstr)
154 {
155 int err;
156
157 err = btrfs_init_acl(trans, inode, dir);
158 if (!err)
159 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
160 return err;
161 }
162
163 /*
164 * this does all the hard work for inserting an inline extent into
165 * the btree. The caller should have done a btrfs_drop_extents so that
166 * no overlapping inline items exist in the btree
167 */
168 static int insert_inline_extent(struct btrfs_trans_handle *trans,
169 struct btrfs_path *path, int extent_inserted,
170 struct btrfs_root *root, struct inode *inode,
171 u64 start, size_t size, size_t compressed_size,
172 int compress_type,
173 struct page **compressed_pages)
174 {
175 struct extent_buffer *leaf;
176 struct page *page = NULL;
177 char *kaddr;
178 unsigned long ptr;
179 struct btrfs_file_extent_item *ei;
180 int ret;
181 size_t cur_size = size;
182 unsigned long offset;
183
184 if (compressed_size && compressed_pages)
185 cur_size = compressed_size;
186
187 inode_add_bytes(inode, size);
188
189 if (!extent_inserted) {
190 struct btrfs_key key;
191 size_t datasize;
192
193 key.objectid = btrfs_ino(BTRFS_I(inode));
194 key.offset = start;
195 key.type = BTRFS_EXTENT_DATA_KEY;
196
197 datasize = btrfs_file_extent_calc_inline_size(cur_size);
198 path->leave_spinning = 1;
199 ret = btrfs_insert_empty_item(trans, root, path, &key,
200 datasize);
201 if (ret)
202 goto fail;
203 }
204 leaf = path->nodes[0];
205 ei = btrfs_item_ptr(leaf, path->slots[0],
206 struct btrfs_file_extent_item);
207 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
208 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
209 btrfs_set_file_extent_encryption(leaf, ei, 0);
210 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
211 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
212 ptr = btrfs_file_extent_inline_start(ei);
213
214 if (compress_type != BTRFS_COMPRESS_NONE) {
215 struct page *cpage;
216 int i = 0;
217 while (compressed_size > 0) {
218 cpage = compressed_pages[i];
219 cur_size = min_t(unsigned long, compressed_size,
220 PAGE_SIZE);
221
222 kaddr = kmap_atomic(cpage);
223 write_extent_buffer(leaf, kaddr, ptr, cur_size);
224 kunmap_atomic(kaddr);
225
226 i++;
227 ptr += cur_size;
228 compressed_size -= cur_size;
229 }
230 btrfs_set_file_extent_compression(leaf, ei,
231 compress_type);
232 } else {
233 page = find_get_page(inode->i_mapping,
234 start >> PAGE_SHIFT);
235 btrfs_set_file_extent_compression(leaf, ei, 0);
236 kaddr = kmap_atomic(page);
237 offset = start & (PAGE_SIZE - 1);
238 write_extent_buffer(leaf, kaddr + offset, ptr, size);
239 kunmap_atomic(kaddr);
240 put_page(page);
241 }
242 btrfs_mark_buffer_dirty(leaf);
243 btrfs_release_path(path);
244
245 /*
246 * we're an inline extent, so nobody can
247 * extend the file past i_size without locking
248 * a page we already have locked.
249 *
250 * We must do any isize and inode updates
251 * before we unlock the pages. Otherwise we
252 * could end up racing with unlink.
253 */
254 BTRFS_I(inode)->disk_i_size = inode->i_size;
255 ret = btrfs_update_inode(trans, root, inode);
256
257 fail:
258 return ret;
259 }
260
261
262 /*
263 * conditionally insert an inline extent into the file. This
264 * does the checks required to make sure the data is small enough
265 * to fit as an inline extent.
266 */
267 static noinline int cow_file_range_inline(struct inode *inode, u64 start,
268 u64 end, size_t compressed_size,
269 int compress_type,
270 struct page **compressed_pages)
271 {
272 struct btrfs_root *root = BTRFS_I(inode)->root;
273 struct btrfs_fs_info *fs_info = root->fs_info;
274 struct btrfs_trans_handle *trans;
275 u64 isize = i_size_read(inode);
276 u64 actual_end = min(end + 1, isize);
277 u64 inline_len = actual_end - start;
278 u64 aligned_end = ALIGN(end, fs_info->sectorsize);
279 u64 data_len = inline_len;
280 int ret;
281 struct btrfs_path *path;
282 int extent_inserted = 0;
283 u32 extent_item_size;
284
285 if (compressed_size)
286 data_len = compressed_size;
287
288 if (start > 0 ||
289 actual_end > fs_info->sectorsize ||
290 data_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info) ||
291 (!compressed_size &&
292 (actual_end & (fs_info->sectorsize - 1)) == 0) ||
293 end + 1 < isize ||
294 data_len > fs_info->max_inline) {
295 return 1;
296 }
297
298 path = btrfs_alloc_path();
299 if (!path)
300 return -ENOMEM;
301
302 trans = btrfs_join_transaction(root);
303 if (IS_ERR(trans)) {
304 btrfs_free_path(path);
305 return PTR_ERR(trans);
306 }
307 trans->block_rsv = &BTRFS_I(inode)->block_rsv;
308
309 if (compressed_size && compressed_pages)
310 extent_item_size = btrfs_file_extent_calc_inline_size(
311 compressed_size);
312 else
313 extent_item_size = btrfs_file_extent_calc_inline_size(
314 inline_len);
315
316 ret = __btrfs_drop_extents(trans, root, inode, path,
317 start, aligned_end, NULL,
318 1, 1, extent_item_size, &extent_inserted);
319 if (ret) {
320 btrfs_abort_transaction(trans, ret);
321 goto out;
322 }
323
324 if (isize > actual_end)
325 inline_len = min_t(u64, isize, actual_end);
326 ret = insert_inline_extent(trans, path, extent_inserted,
327 root, inode, start,
328 inline_len, compressed_size,
329 compress_type, compressed_pages);
330 if (ret && ret != -ENOSPC) {
331 btrfs_abort_transaction(trans, ret);
332 goto out;
333 } else if (ret == -ENOSPC) {
334 ret = 1;
335 goto out;
336 }
337
338 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
339 btrfs_drop_extent_cache(BTRFS_I(inode), start, aligned_end - 1, 0);
340 out:
341 /*
342 * Don't forget to free the reserved space, as for inlined extent
343 * it won't count as data extent, free them directly here.
344 * And at reserve time, it's always aligned to page size, so
345 * just free one page here.
346 */
347 btrfs_qgroup_free_data(inode, NULL, 0, PAGE_SIZE);
348 btrfs_free_path(path);
349 btrfs_end_transaction(trans);
350 return ret;
351 }
352
353 struct async_extent {
354 u64 start;
355 u64 ram_size;
356 u64 compressed_size;
357 struct page **pages;
358 unsigned long nr_pages;
359 int compress_type;
360 struct list_head list;
361 };
362
363 struct async_cow {
364 struct inode *inode;
365 struct btrfs_root *root;
366 struct page *locked_page;
367 u64 start;
368 u64 end;
369 unsigned int write_flags;
370 struct list_head extents;
371 struct btrfs_work work;
372 };
373
374 static noinline int add_async_extent(struct async_cow *cow,
375 u64 start, u64 ram_size,
376 u64 compressed_size,
377 struct page **pages,
378 unsigned long nr_pages,
379 int compress_type)
380 {
381 struct async_extent *async_extent;
382
383 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
384 BUG_ON(!async_extent); /* -ENOMEM */
385 async_extent->start = start;
386 async_extent->ram_size = ram_size;
387 async_extent->compressed_size = compressed_size;
388 async_extent->pages = pages;
389 async_extent->nr_pages = nr_pages;
390 async_extent->compress_type = compress_type;
391 list_add_tail(&async_extent->list, &cow->extents);
392 return 0;
393 }
394
395 static inline int inode_need_compress(struct inode *inode, u64 start, u64 end)
396 {
397 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
398
399 /* force compress */
400 if (btrfs_test_opt(fs_info, FORCE_COMPRESS))
401 return 1;
402 /* defrag ioctl */
403 if (BTRFS_I(inode)->defrag_compress)
404 return 1;
405 /* bad compression ratios */
406 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
407 return 0;
408 if (btrfs_test_opt(fs_info, COMPRESS) ||
409 BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
410 BTRFS_I(inode)->prop_compress)
411 return btrfs_compress_heuristic(inode, start, end);
412 return 0;
413 }
414
415 static inline void inode_should_defrag(struct btrfs_inode *inode,
416 u64 start, u64 end, u64 num_bytes, u64 small_write)
417 {
418 /* If this is a small write inside eof, kick off a defrag */
419 if (num_bytes < small_write &&
420 (start > 0 || end + 1 < inode->disk_i_size))
421 btrfs_add_inode_defrag(NULL, inode);
422 }
423
424 /*
425 * we create compressed extents in two phases. The first
426 * phase compresses a range of pages that have already been
427 * locked (both pages and state bits are locked).
428 *
429 * This is done inside an ordered work queue, and the compression
430 * is spread across many cpus. The actual IO submission is step
431 * two, and the ordered work queue takes care of making sure that
432 * happens in the same order things were put onto the queue by
433 * writepages and friends.
434 *
435 * If this code finds it can't get good compression, it puts an
436 * entry onto the work queue to write the uncompressed bytes. This
437 * makes sure that both compressed inodes and uncompressed inodes
438 * are written in the same order that the flusher thread sent them
439 * down.
440 */
441 static noinline void compress_file_range(struct inode *inode,
442 struct page *locked_page,
443 u64 start, u64 end,
444 struct async_cow *async_cow,
445 int *num_added)
446 {
447 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
448 u64 blocksize = fs_info->sectorsize;
449 u64 actual_end;
450 u64 isize = i_size_read(inode);
451 int ret = 0;
452 struct page **pages = NULL;
453 unsigned long nr_pages;
454 unsigned long total_compressed = 0;
455 unsigned long total_in = 0;
456 int i;
457 int will_compress;
458 int compress_type = fs_info->compress_type;
459 int redirty = 0;
460
461 inode_should_defrag(BTRFS_I(inode), start, end, end - start + 1,
462 SZ_16K);
463
464 actual_end = min_t(u64, isize, end + 1);
465 again:
466 will_compress = 0;
467 nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
468 BUILD_BUG_ON((BTRFS_MAX_COMPRESSED % PAGE_SIZE) != 0);
469 nr_pages = min_t(unsigned long, nr_pages,
470 BTRFS_MAX_COMPRESSED / PAGE_SIZE);
471
472 /*
473 * we don't want to send crud past the end of i_size through
474 * compression, that's just a waste of CPU time. So, if the
475 * end of the file is before the start of our current
476 * requested range of bytes, we bail out to the uncompressed
477 * cleanup code that can deal with all of this.
478 *
479 * It isn't really the fastest way to fix things, but this is a
480 * very uncommon corner.
481 */
482 if (actual_end <= start)
483 goto cleanup_and_bail_uncompressed;
484
485 total_compressed = actual_end - start;
486
487 /*
488 * skip compression for a small file range(<=blocksize) that
489 * isn't an inline extent, since it doesn't save disk space at all.
490 */
491 if (total_compressed <= blocksize &&
492 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
493 goto cleanup_and_bail_uncompressed;
494
495 total_compressed = min_t(unsigned long, total_compressed,
496 BTRFS_MAX_UNCOMPRESSED);
497 total_in = 0;
498 ret = 0;
499
500 /*
501 * we do compression for mount -o compress and when the
502 * inode has not been flagged as nocompress. This flag can
503 * change at any time if we discover bad compression ratios.
504 */
505 if (inode_need_compress(inode, start, end)) {
506 WARN_ON(pages);
507 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
508 if (!pages) {
509 /* just bail out to the uncompressed code */
510 goto cont;
511 }
512
513 if (BTRFS_I(inode)->defrag_compress)
514 compress_type = BTRFS_I(inode)->defrag_compress;
515 else if (BTRFS_I(inode)->prop_compress)
516 compress_type = BTRFS_I(inode)->prop_compress;
517
518 /*
519 * we need to call clear_page_dirty_for_io on each
520 * page in the range. Otherwise applications with the file
521 * mmap'd can wander in and change the page contents while
522 * we are compressing them.
523 *
524 * If the compression fails for any reason, we set the pages
525 * dirty again later on.
526 *
527 * Note that the remaining part is redirtied, the start pointer
528 * has moved, the end is the original one.
529 */
530 if (!redirty) {
531 extent_range_clear_dirty_for_io(inode, start, end);
532 redirty = 1;
533 }
534
535 /* Compression level is applied here and only here */
536 ret = btrfs_compress_pages(
537 compress_type | (fs_info->compress_level << 4),
538 inode->i_mapping, start,
539 pages,
540 &nr_pages,
541 &total_in,
542 &total_compressed);
543
544 if (!ret) {
545 unsigned long offset = total_compressed &
546 (PAGE_SIZE - 1);
547 struct page *page = pages[nr_pages - 1];
548 char *kaddr;
549
550 /* zero the tail end of the last page, we might be
551 * sending it down to disk
552 */
553 if (offset) {
554 kaddr = kmap_atomic(page);
555 memset(kaddr + offset, 0,
556 PAGE_SIZE - offset);
557 kunmap_atomic(kaddr);
558 }
559 will_compress = 1;
560 }
561 }
562 cont:
563 if (start == 0) {
564 /* lets try to make an inline extent */
565 if (ret || total_in < actual_end) {
566 /* we didn't compress the entire range, try
567 * to make an uncompressed inline extent.
568 */
569 ret = cow_file_range_inline(inode, start, end, 0,
570 BTRFS_COMPRESS_NONE, NULL);
571 } else {
572 /* try making a compressed inline extent */
573 ret = cow_file_range_inline(inode, start, end,
574 total_compressed,
575 compress_type, pages);
576 }
577 if (ret <= 0) {
578 unsigned long clear_flags = EXTENT_DELALLOC |
579 EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
580 EXTENT_DO_ACCOUNTING;
581 unsigned long page_error_op;
582
583 page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
584
585 /*
586 * inline extent creation worked or returned error,
587 * we don't need to create any more async work items.
588 * Unlock and free up our temp pages.
589 *
590 * We use DO_ACCOUNTING here because we need the
591 * delalloc_release_metadata to be done _after_ we drop
592 * our outstanding extent for clearing delalloc for this
593 * range.
594 */
595 extent_clear_unlock_delalloc(inode, start, end, end,
596 NULL, clear_flags,
597 PAGE_UNLOCK |
598 PAGE_CLEAR_DIRTY |
599 PAGE_SET_WRITEBACK |
600 page_error_op |
601 PAGE_END_WRITEBACK);
602 goto free_pages_out;
603 }
604 }
605
606 if (will_compress) {
607 /*
608 * we aren't doing an inline extent round the compressed size
609 * up to a block size boundary so the allocator does sane
610 * things
611 */
612 total_compressed = ALIGN(total_compressed, blocksize);
613
614 /*
615 * one last check to make sure the compression is really a
616 * win, compare the page count read with the blocks on disk,
617 * compression must free at least one sector size
618 */
619 total_in = ALIGN(total_in, PAGE_SIZE);
620 if (total_compressed + blocksize <= total_in) {
621 *num_added += 1;
622
623 /*
624 * The async work queues will take care of doing actual
625 * allocation on disk for these compressed pages, and
626 * will submit them to the elevator.
627 */
628 add_async_extent(async_cow, start, total_in,
629 total_compressed, pages, nr_pages,
630 compress_type);
631
632 if (start + total_in < end) {
633 start += total_in;
634 pages = NULL;
635 cond_resched();
636 goto again;
637 }
638 return;
639 }
640 }
641 if (pages) {
642 /*
643 * the compression code ran but failed to make things smaller,
644 * free any pages it allocated and our page pointer array
645 */
646 for (i = 0; i < nr_pages; i++) {
647 WARN_ON(pages[i]->mapping);
648 put_page(pages[i]);
649 }
650 kfree(pages);
651 pages = NULL;
652 total_compressed = 0;
653 nr_pages = 0;
654
655 /* flag the file so we don't compress in the future */
656 if (!btrfs_test_opt(fs_info, FORCE_COMPRESS) &&
657 !(BTRFS_I(inode)->prop_compress)) {
658 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
659 }
660 }
661 cleanup_and_bail_uncompressed:
662 /*
663 * No compression, but we still need to write the pages in the file
664 * we've been given so far. redirty the locked page if it corresponds
665 * to our extent and set things up for the async work queue to run
666 * cow_file_range to do the normal delalloc dance.
667 */
668 if (page_offset(locked_page) >= start &&
669 page_offset(locked_page) <= end)
670 __set_page_dirty_nobuffers(locked_page);
671 /* unlocked later on in the async handlers */
672
673 if (redirty)
674 extent_range_redirty_for_io(inode, start, end);
675 add_async_extent(async_cow, start, end - start + 1, 0, NULL, 0,
676 BTRFS_COMPRESS_NONE);
677 *num_added += 1;
678
679 return;
680
681 free_pages_out:
682 for (i = 0; i < nr_pages; i++) {
683 WARN_ON(pages[i]->mapping);
684 put_page(pages[i]);
685 }
686 kfree(pages);
687 }
688
689 static void free_async_extent_pages(struct async_extent *async_extent)
690 {
691 int i;
692
693 if (!async_extent->pages)
694 return;
695
696 for (i = 0; i < async_extent->nr_pages; i++) {
697 WARN_ON(async_extent->pages[i]->mapping);
698 put_page(async_extent->pages[i]);
699 }
700 kfree(async_extent->pages);
701 async_extent->nr_pages = 0;
702 async_extent->pages = NULL;
703 }
704
705 /*
706 * phase two of compressed writeback. This is the ordered portion
707 * of the code, which only gets called in the order the work was
708 * queued. We walk all the async extents created by compress_file_range
709 * and send them down to the disk.
710 */
711 static noinline void submit_compressed_extents(struct inode *inode,
712 struct async_cow *async_cow)
713 {
714 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
715 struct async_extent *async_extent;
716 u64 alloc_hint = 0;
717 struct btrfs_key ins;
718 struct extent_map *em;
719 struct btrfs_root *root = BTRFS_I(inode)->root;
720 struct extent_io_tree *io_tree;
721 int ret = 0;
722
723 again:
724 while (!list_empty(&async_cow->extents)) {
725 async_extent = list_entry(async_cow->extents.next,
726 struct async_extent, list);
727 list_del(&async_extent->list);
728
729 io_tree = &BTRFS_I(inode)->io_tree;
730
731 retry:
732 /* did the compression code fall back to uncompressed IO? */
733 if (!async_extent->pages) {
734 int page_started = 0;
735 unsigned long nr_written = 0;
736
737 lock_extent(io_tree, async_extent->start,
738 async_extent->start +
739 async_extent->ram_size - 1);
740
741 /* allocate blocks */
742 ret = cow_file_range(inode, async_cow->locked_page,
743 async_extent->start,
744 async_extent->start +
745 async_extent->ram_size - 1,
746 async_extent->start +
747 async_extent->ram_size - 1,
748 &page_started, &nr_written, 0,
749 NULL);
750
751 /* JDM XXX */
752
753 /*
754 * if page_started, cow_file_range inserted an
755 * inline extent and took care of all the unlocking
756 * and IO for us. Otherwise, we need to submit
757 * all those pages down to the drive.
758 */
759 if (!page_started && !ret)
760 extent_write_locked_range(inode,
761 async_extent->start,
762 async_extent->start +
763 async_extent->ram_size - 1,
764 WB_SYNC_ALL);
765 else if (ret)
766 unlock_page(async_cow->locked_page);
767 kfree(async_extent);
768 cond_resched();
769 continue;
770 }
771
772 lock_extent(io_tree, async_extent->start,
773 async_extent->start + async_extent->ram_size - 1);
774
775 ret = btrfs_reserve_extent(root, async_extent->ram_size,
776 async_extent->compressed_size,
777 async_extent->compressed_size,
778 0, alloc_hint, &ins, 1, 1);
779 if (ret) {
780 free_async_extent_pages(async_extent);
781
782 if (ret == -ENOSPC) {
783 unlock_extent(io_tree, async_extent->start,
784 async_extent->start +
785 async_extent->ram_size - 1);
786
787 /*
788 * we need to redirty the pages if we decide to
789 * fallback to uncompressed IO, otherwise we
790 * will not submit these pages down to lower
791 * layers.
792 */
793 extent_range_redirty_for_io(inode,
794 async_extent->start,
795 async_extent->start +
796 async_extent->ram_size - 1);
797
798 goto retry;
799 }
800 goto out_free;
801 }
802 /*
803 * here we're doing allocation and writeback of the
804 * compressed pages
805 */
806 em = create_io_em(inode, async_extent->start,
807 async_extent->ram_size, /* len */
808 async_extent->start, /* orig_start */
809 ins.objectid, /* block_start */
810 ins.offset, /* block_len */
811 ins.offset, /* orig_block_len */
812 async_extent->ram_size, /* ram_bytes */
813 async_extent->compress_type,
814 BTRFS_ORDERED_COMPRESSED);
815 if (IS_ERR(em))
816 /* ret value is not necessary due to void function */
817 goto out_free_reserve;
818 free_extent_map(em);
819
820 ret = btrfs_add_ordered_extent_compress(inode,
821 async_extent->start,
822 ins.objectid,
823 async_extent->ram_size,
824 ins.offset,
825 BTRFS_ORDERED_COMPRESSED,
826 async_extent->compress_type);
827 if (ret) {
828 btrfs_drop_extent_cache(BTRFS_I(inode),
829 async_extent->start,
830 async_extent->start +
831 async_extent->ram_size - 1, 0);
832 goto out_free_reserve;
833 }
834 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
835
836 /*
837 * clear dirty, set writeback and unlock the pages.
838 */
839 extent_clear_unlock_delalloc(inode, async_extent->start,
840 async_extent->start +
841 async_extent->ram_size - 1,
842 async_extent->start +
843 async_extent->ram_size - 1,
844 NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
845 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
846 PAGE_SET_WRITEBACK);
847 if (btrfs_submit_compressed_write(inode,
848 async_extent->start,
849 async_extent->ram_size,
850 ins.objectid,
851 ins.offset, async_extent->pages,
852 async_extent->nr_pages,
853 async_cow->write_flags)) {
854 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
855 struct page *p = async_extent->pages[0];
856 const u64 start = async_extent->start;
857 const u64 end = start + async_extent->ram_size - 1;
858
859 p->mapping = inode->i_mapping;
860 tree->ops->writepage_end_io_hook(p, start, end,
861 NULL, 0);
862 p->mapping = NULL;
863 extent_clear_unlock_delalloc(inode, start, end, end,
864 NULL, 0,
865 PAGE_END_WRITEBACK |
866 PAGE_SET_ERROR);
867 free_async_extent_pages(async_extent);
868 }
869 alloc_hint = ins.objectid + ins.offset;
870 kfree(async_extent);
871 cond_resched();
872 }
873 return;
874 out_free_reserve:
875 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
876 btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
877 out_free:
878 extent_clear_unlock_delalloc(inode, async_extent->start,
879 async_extent->start +
880 async_extent->ram_size - 1,
881 async_extent->start +
882 async_extent->ram_size - 1,
883 NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
884 EXTENT_DELALLOC_NEW |
885 EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
886 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
887 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
888 PAGE_SET_ERROR);
889 free_async_extent_pages(async_extent);
890 kfree(async_extent);
891 goto again;
892 }
893
894 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
895 u64 num_bytes)
896 {
897 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
898 struct extent_map *em;
899 u64 alloc_hint = 0;
900
901 read_lock(&em_tree->lock);
902 em = search_extent_mapping(em_tree, start, num_bytes);
903 if (em) {
904 /*
905 * if block start isn't an actual block number then find the
906 * first block in this inode and use that as a hint. If that
907 * block is also bogus then just don't worry about it.
908 */
909 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
910 free_extent_map(em);
911 em = search_extent_mapping(em_tree, 0, 0);
912 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
913 alloc_hint = em->block_start;
914 if (em)
915 free_extent_map(em);
916 } else {
917 alloc_hint = em->block_start;
918 free_extent_map(em);
919 }
920 }
921 read_unlock(&em_tree->lock);
922
923 return alloc_hint;
924 }
925
926 /*
927 * when extent_io.c finds a delayed allocation range in the file,
928 * the call backs end up in this code. The basic idea is to
929 * allocate extents on disk for the range, and create ordered data structs
930 * in ram to track those extents.
931 *
932 * locked_page is the page that writepage had locked already. We use
933 * it to make sure we don't do extra locks or unlocks.
934 *
935 * *page_started is set to one if we unlock locked_page and do everything
936 * required to start IO on it. It may be clean and already done with
937 * IO when we return.
938 */
939 static noinline int cow_file_range(struct inode *inode,
940 struct page *locked_page,
941 u64 start, u64 end, u64 delalloc_end,
942 int *page_started, unsigned long *nr_written,
943 int unlock, struct btrfs_dedupe_hash *hash)
944 {
945 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
946 struct btrfs_root *root = BTRFS_I(inode)->root;
947 u64 alloc_hint = 0;
948 u64 num_bytes;
949 unsigned long ram_size;
950 u64 cur_alloc_size = 0;
951 u64 blocksize = fs_info->sectorsize;
952 struct btrfs_key ins;
953 struct extent_map *em;
954 unsigned clear_bits;
955 unsigned long page_ops;
956 bool extent_reserved = false;
957 int ret = 0;
958
959 if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
960 WARN_ON_ONCE(1);
961 ret = -EINVAL;
962 goto out_unlock;
963 }
964
965 num_bytes = ALIGN(end - start + 1, blocksize);
966 num_bytes = max(blocksize, num_bytes);
967 ASSERT(num_bytes <= btrfs_super_total_bytes(fs_info->super_copy));
968
969 inode_should_defrag(BTRFS_I(inode), start, end, num_bytes, SZ_64K);
970
971 if (start == 0) {
972 /* lets try to make an inline extent */
973 ret = cow_file_range_inline(inode, start, end, 0,
974 BTRFS_COMPRESS_NONE, NULL);
975 if (ret == 0) {
976 /*
977 * We use DO_ACCOUNTING here because we need the
978 * delalloc_release_metadata to be run _after_ we drop
979 * our outstanding extent for clearing delalloc for this
980 * range.
981 */
982 extent_clear_unlock_delalloc(inode, start, end,
983 delalloc_end, NULL,
984 EXTENT_LOCKED | EXTENT_DELALLOC |
985 EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
986 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
987 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
988 PAGE_END_WRITEBACK);
989 *nr_written = *nr_written +
990 (end - start + PAGE_SIZE) / PAGE_SIZE;
991 *page_started = 1;
992 goto out;
993 } else if (ret < 0) {
994 goto out_unlock;
995 }
996 }
997
998 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
999 btrfs_drop_extent_cache(BTRFS_I(inode), start,
1000 start + num_bytes - 1, 0);
1001
1002 while (num_bytes > 0) {
1003 cur_alloc_size = num_bytes;
1004 ret = btrfs_reserve_extent(root, cur_alloc_size, cur_alloc_size,
1005 fs_info->sectorsize, 0, alloc_hint,
1006 &ins, 1, 1);
1007 if (ret < 0)
1008 goto out_unlock;
1009 cur_alloc_size = ins.offset;
1010 extent_reserved = true;
1011
1012 ram_size = ins.offset;
1013 em = create_io_em(inode, start, ins.offset, /* len */
1014 start, /* orig_start */
1015 ins.objectid, /* block_start */
1016 ins.offset, /* block_len */
1017 ins.offset, /* orig_block_len */
1018 ram_size, /* ram_bytes */
1019 BTRFS_COMPRESS_NONE, /* compress_type */
1020 BTRFS_ORDERED_REGULAR /* type */);
1021 if (IS_ERR(em))
1022 goto out_reserve;
1023 free_extent_map(em);
1024
1025 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
1026 ram_size, cur_alloc_size, 0);
1027 if (ret)
1028 goto out_drop_extent_cache;
1029
1030 if (root->root_key.objectid ==
1031 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1032 ret = btrfs_reloc_clone_csums(inode, start,
1033 cur_alloc_size);
1034 /*
1035 * Only drop cache here, and process as normal.
1036 *
1037 * We must not allow extent_clear_unlock_delalloc()
1038 * at out_unlock label to free meta of this ordered
1039 * extent, as its meta should be freed by
1040 * btrfs_finish_ordered_io().
1041 *
1042 * So we must continue until @start is increased to
1043 * skip current ordered extent.
1044 */
1045 if (ret)
1046 btrfs_drop_extent_cache(BTRFS_I(inode), start,
1047 start + ram_size - 1, 0);
1048 }
1049
1050 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
1051
1052 /* we're not doing compressed IO, don't unlock the first
1053 * page (which the caller expects to stay locked), don't
1054 * clear any dirty bits and don't set any writeback bits
1055 *
1056 * Do set the Private2 bit so we know this page was properly
1057 * setup for writepage
1058 */
1059 page_ops = unlock ? PAGE_UNLOCK : 0;
1060 page_ops |= PAGE_SET_PRIVATE2;
1061
1062 extent_clear_unlock_delalloc(inode, start,
1063 start + ram_size - 1,
1064 delalloc_end, locked_page,
1065 EXTENT_LOCKED | EXTENT_DELALLOC,
1066 page_ops);
1067 if (num_bytes < cur_alloc_size)
1068 num_bytes = 0;
1069 else
1070 num_bytes -= cur_alloc_size;
1071 alloc_hint = ins.objectid + ins.offset;
1072 start += cur_alloc_size;
1073 extent_reserved = false;
1074
1075 /*
1076 * btrfs_reloc_clone_csums() error, since start is increased
1077 * extent_clear_unlock_delalloc() at out_unlock label won't
1078 * free metadata of current ordered extent, we're OK to exit.
1079 */
1080 if (ret)
1081 goto out_unlock;
1082 }
1083 out:
1084 return ret;
1085
1086 out_drop_extent_cache:
1087 btrfs_drop_extent_cache(BTRFS_I(inode), start, start + ram_size - 1, 0);
1088 out_reserve:
1089 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
1090 btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
1091 out_unlock:
1092 clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
1093 EXTENT_DEFRAG | EXTENT_CLEAR_META_RESV;
1094 page_ops = PAGE_UNLOCK | PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
1095 PAGE_END_WRITEBACK;
1096 /*
1097 * If we reserved an extent for our delalloc range (or a subrange) and
1098 * failed to create the respective ordered extent, then it means that
1099 * when we reserved the extent we decremented the extent's size from
1100 * the data space_info's bytes_may_use counter and incremented the
1101 * space_info's bytes_reserved counter by the same amount. We must make
1102 * sure extent_clear_unlock_delalloc() does not try to decrement again
1103 * the data space_info's bytes_may_use counter, therefore we do not pass
1104 * it the flag EXTENT_CLEAR_DATA_RESV.
1105 */
1106 if (extent_reserved) {
1107 extent_clear_unlock_delalloc(inode, start,
1108 start + cur_alloc_size,
1109 start + cur_alloc_size,
1110 locked_page,
1111 clear_bits,
1112 page_ops);
1113 start += cur_alloc_size;
1114 if (start >= end)
1115 goto out;
1116 }
1117 extent_clear_unlock_delalloc(inode, start, end, delalloc_end,
1118 locked_page,
1119 clear_bits | EXTENT_CLEAR_DATA_RESV,
1120 page_ops);
1121 goto out;
1122 }
1123
1124 /*
1125 * work queue call back to started compression on a file and pages
1126 */
1127 static noinline void async_cow_start(struct btrfs_work *work)
1128 {
1129 struct async_cow *async_cow;
1130 int num_added = 0;
1131 async_cow = container_of(work, struct async_cow, work);
1132
1133 compress_file_range(async_cow->inode, async_cow->locked_page,
1134 async_cow->start, async_cow->end, async_cow,
1135 &num_added);
1136 if (num_added == 0) {
1137 btrfs_add_delayed_iput(async_cow->inode);
1138 async_cow->inode = NULL;
1139 }
1140 }
1141
1142 /*
1143 * work queue call back to submit previously compressed pages
1144 */
1145 static noinline void async_cow_submit(struct btrfs_work *work)
1146 {
1147 struct btrfs_fs_info *fs_info;
1148 struct async_cow *async_cow;
1149 struct btrfs_root *root;
1150 unsigned long nr_pages;
1151
1152 async_cow = container_of(work, struct async_cow, work);
1153
1154 root = async_cow->root;
1155 fs_info = root->fs_info;
1156 nr_pages = (async_cow->end - async_cow->start + PAGE_SIZE) >>
1157 PAGE_SHIFT;
1158
1159 /* atomic_sub_return implies a barrier */
1160 if (atomic_sub_return(nr_pages, &fs_info->async_delalloc_pages) <
1161 5 * SZ_1M)
1162 cond_wake_up_nomb(&fs_info->async_submit_wait);
1163
1164 if (async_cow->inode)
1165 submit_compressed_extents(async_cow->inode, async_cow);
1166 }
1167
1168 static noinline void async_cow_free(struct btrfs_work *work)
1169 {
1170 struct async_cow *async_cow;
1171 async_cow = container_of(work, struct async_cow, work);
1172 if (async_cow->inode)
1173 btrfs_add_delayed_iput(async_cow->inode);
1174 kfree(async_cow);
1175 }
1176
1177 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1178 u64 start, u64 end, int *page_started,
1179 unsigned long *nr_written,
1180 unsigned int write_flags)
1181 {
1182 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1183 struct async_cow *async_cow;
1184 struct btrfs_root *root = BTRFS_I(inode)->root;
1185 unsigned long nr_pages;
1186 u64 cur_end;
1187
1188 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1189 1, 0, NULL);
1190 while (start < end) {
1191 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1192 BUG_ON(!async_cow); /* -ENOMEM */
1193 async_cow->inode = igrab(inode);
1194 async_cow->root = root;
1195 async_cow->locked_page = locked_page;
1196 async_cow->start = start;
1197 async_cow->write_flags = write_flags;
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 *nr_written += nr_pages;
1220 start = cur_end + 1;
1221 }
1222 *page_started = 1;
1223 return 0;
1224 }
1225
1226 static noinline int csum_exist_in_range(struct btrfs_fs_info *fs_info,
1227 u64 bytenr, u64 num_bytes)
1228 {
1229 int ret;
1230 struct btrfs_ordered_sum *sums;
1231 LIST_HEAD(list);
1232
1233 ret = btrfs_lookup_csums_range(fs_info->csum_root, bytenr,
1234 bytenr + num_bytes - 1, &list, 0);
1235 if (ret == 0 && list_empty(&list))
1236 return 0;
1237
1238 while (!list_empty(&list)) {
1239 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1240 list_del(&sums->list);
1241 kfree(sums);
1242 }
1243 if (ret < 0)
1244 return ret;
1245 return 1;
1246 }
1247
1248 /*
1249 * when nowcow writeback call back. This checks for snapshots or COW copies
1250 * of the extents that exist in the file, and COWs the file as required.
1251 *
1252 * If no cow copies or snapshots exist, we write directly to the existing
1253 * blocks on disk
1254 */
1255 static noinline int run_delalloc_nocow(struct inode *inode,
1256 struct page *locked_page,
1257 u64 start, u64 end, int *page_started, int force,
1258 unsigned long *nr_written)
1259 {
1260 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1261 struct btrfs_root *root = BTRFS_I(inode)->root;
1262 struct extent_buffer *leaf;
1263 struct btrfs_path *path;
1264 struct btrfs_file_extent_item *fi;
1265 struct btrfs_key found_key;
1266 struct extent_map *em;
1267 u64 cow_start;
1268 u64 cur_offset;
1269 u64 extent_end;
1270 u64 extent_offset;
1271 u64 disk_bytenr;
1272 u64 num_bytes;
1273 u64 disk_num_bytes;
1274 u64 ram_bytes;
1275 int extent_type;
1276 int ret, err;
1277 int type;
1278 int nocow;
1279 int check_prev = 1;
1280 bool nolock;
1281 u64 ino = btrfs_ino(BTRFS_I(inode));
1282
1283 path = btrfs_alloc_path();
1284 if (!path) {
1285 extent_clear_unlock_delalloc(inode, start, end, end,
1286 locked_page,
1287 EXTENT_LOCKED | EXTENT_DELALLOC |
1288 EXTENT_DO_ACCOUNTING |
1289 EXTENT_DEFRAG, PAGE_UNLOCK |
1290 PAGE_CLEAR_DIRTY |
1291 PAGE_SET_WRITEBACK |
1292 PAGE_END_WRITEBACK);
1293 return -ENOMEM;
1294 }
1295
1296 nolock = btrfs_is_free_space_inode(BTRFS_I(inode));
1297
1298 cow_start = (u64)-1;
1299 cur_offset = start;
1300 while (1) {
1301 ret = btrfs_lookup_file_extent(NULL, root, path, ino,
1302 cur_offset, 0);
1303 if (ret < 0)
1304 goto error;
1305 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1306 leaf = path->nodes[0];
1307 btrfs_item_key_to_cpu(leaf, &found_key,
1308 path->slots[0] - 1);
1309 if (found_key.objectid == ino &&
1310 found_key.type == BTRFS_EXTENT_DATA_KEY)
1311 path->slots[0]--;
1312 }
1313 check_prev = 0;
1314 next_slot:
1315 leaf = path->nodes[0];
1316 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1317 ret = btrfs_next_leaf(root, path);
1318 if (ret < 0) {
1319 if (cow_start != (u64)-1)
1320 cur_offset = cow_start;
1321 goto error;
1322 }
1323 if (ret > 0)
1324 break;
1325 leaf = path->nodes[0];
1326 }
1327
1328 nocow = 0;
1329 disk_bytenr = 0;
1330 num_bytes = 0;
1331 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1332
1333 if (found_key.objectid > ino)
1334 break;
1335 if (WARN_ON_ONCE(found_key.objectid < ino) ||
1336 found_key.type < BTRFS_EXTENT_DATA_KEY) {
1337 path->slots[0]++;
1338 goto next_slot;
1339 }
1340 if (found_key.type > BTRFS_EXTENT_DATA_KEY ||
1341 found_key.offset > end)
1342 break;
1343
1344 if (found_key.offset > cur_offset) {
1345 extent_end = found_key.offset;
1346 extent_type = 0;
1347 goto out_check;
1348 }
1349
1350 fi = btrfs_item_ptr(leaf, path->slots[0],
1351 struct btrfs_file_extent_item);
1352 extent_type = btrfs_file_extent_type(leaf, fi);
1353
1354 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1355 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1356 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1357 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1358 extent_offset = btrfs_file_extent_offset(leaf, fi);
1359 extent_end = found_key.offset +
1360 btrfs_file_extent_num_bytes(leaf, fi);
1361 disk_num_bytes =
1362 btrfs_file_extent_disk_num_bytes(leaf, fi);
1363 if (extent_end <= start) {
1364 path->slots[0]++;
1365 goto next_slot;
1366 }
1367 if (disk_bytenr == 0)
1368 goto out_check;
1369 if (btrfs_file_extent_compression(leaf, fi) ||
1370 btrfs_file_extent_encryption(leaf, fi) ||
1371 btrfs_file_extent_other_encoding(leaf, fi))
1372 goto out_check;
1373 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1374 goto out_check;
1375 if (btrfs_extent_readonly(fs_info, disk_bytenr))
1376 goto out_check;
1377 ret = btrfs_cross_ref_exist(root, ino,
1378 found_key.offset -
1379 extent_offset, disk_bytenr);
1380 if (ret) {
1381 /*
1382 * ret could be -EIO if the above fails to read
1383 * metadata.
1384 */
1385 if (ret < 0) {
1386 if (cow_start != (u64)-1)
1387 cur_offset = cow_start;
1388 goto error;
1389 }
1390
1391 WARN_ON_ONCE(nolock);
1392 goto out_check;
1393 }
1394 disk_bytenr += extent_offset;
1395 disk_bytenr += cur_offset - found_key.offset;
1396 num_bytes = min(end + 1, extent_end) - cur_offset;
1397 /*
1398 * if there are pending snapshots for this root,
1399 * we fall into common COW way.
1400 */
1401 if (!nolock) {
1402 err = btrfs_start_write_no_snapshotting(root);
1403 if (!err)
1404 goto out_check;
1405 }
1406 /*
1407 * force cow if csum exists in the range.
1408 * this ensure that csum for a given extent are
1409 * either valid or do not exist.
1410 */
1411 ret = csum_exist_in_range(fs_info, disk_bytenr,
1412 num_bytes);
1413 if (ret) {
1414 if (!nolock)
1415 btrfs_end_write_no_snapshotting(root);
1416
1417 /*
1418 * ret could be -EIO if the above fails to read
1419 * metadata.
1420 */
1421 if (ret < 0) {
1422 if (cow_start != (u64)-1)
1423 cur_offset = cow_start;
1424 goto error;
1425 }
1426 WARN_ON_ONCE(nolock);
1427 goto out_check;
1428 }
1429 if (!btrfs_inc_nocow_writers(fs_info, disk_bytenr)) {
1430 if (!nolock)
1431 btrfs_end_write_no_snapshotting(root);
1432 goto out_check;
1433 }
1434 nocow = 1;
1435 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1436 extent_end = found_key.offset +
1437 btrfs_file_extent_inline_len(leaf,
1438 path->slots[0], fi);
1439 extent_end = ALIGN(extent_end,
1440 fs_info->sectorsize);
1441 } else {
1442 BUG_ON(1);
1443 }
1444 out_check:
1445 if (extent_end <= start) {
1446 path->slots[0]++;
1447 if (!nolock && nocow)
1448 btrfs_end_write_no_snapshotting(root);
1449 if (nocow)
1450 btrfs_dec_nocow_writers(fs_info, disk_bytenr);
1451 goto next_slot;
1452 }
1453 if (!nocow) {
1454 if (cow_start == (u64)-1)
1455 cow_start = cur_offset;
1456 cur_offset = extent_end;
1457 if (cur_offset > end)
1458 break;
1459 path->slots[0]++;
1460 goto next_slot;
1461 }
1462
1463 btrfs_release_path(path);
1464 if (cow_start != (u64)-1) {
1465 ret = cow_file_range(inode, locked_page,
1466 cow_start, found_key.offset - 1,
1467 end, page_started, nr_written, 1,
1468 NULL);
1469 if (ret) {
1470 if (!nolock && nocow)
1471 btrfs_end_write_no_snapshotting(root);
1472 if (nocow)
1473 btrfs_dec_nocow_writers(fs_info,
1474 disk_bytenr);
1475 goto error;
1476 }
1477 cow_start = (u64)-1;
1478 }
1479
1480 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1481 u64 orig_start = found_key.offset - extent_offset;
1482
1483 em = create_io_em(inode, cur_offset, num_bytes,
1484 orig_start,
1485 disk_bytenr, /* block_start */
1486 num_bytes, /* block_len */
1487 disk_num_bytes, /* orig_block_len */
1488 ram_bytes, BTRFS_COMPRESS_NONE,
1489 BTRFS_ORDERED_PREALLOC);
1490 if (IS_ERR(em)) {
1491 if (!nolock && nocow)
1492 btrfs_end_write_no_snapshotting(root);
1493 if (nocow)
1494 btrfs_dec_nocow_writers(fs_info,
1495 disk_bytenr);
1496 ret = PTR_ERR(em);
1497 goto error;
1498 }
1499 free_extent_map(em);
1500 }
1501
1502 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1503 type = BTRFS_ORDERED_PREALLOC;
1504 } else {
1505 type = BTRFS_ORDERED_NOCOW;
1506 }
1507
1508 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1509 num_bytes, num_bytes, type);
1510 if (nocow)
1511 btrfs_dec_nocow_writers(fs_info, disk_bytenr);
1512 BUG_ON(ret); /* -ENOMEM */
1513
1514 if (root->root_key.objectid ==
1515 BTRFS_DATA_RELOC_TREE_OBJECTID)
1516 /*
1517 * Error handled later, as we must prevent
1518 * extent_clear_unlock_delalloc() in error handler
1519 * from freeing metadata of created ordered extent.
1520 */
1521 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1522 num_bytes);
1523
1524 extent_clear_unlock_delalloc(inode, cur_offset,
1525 cur_offset + num_bytes - 1, end,
1526 locked_page, EXTENT_LOCKED |
1527 EXTENT_DELALLOC |
1528 EXTENT_CLEAR_DATA_RESV,
1529 PAGE_UNLOCK | PAGE_SET_PRIVATE2);
1530
1531 if (!nolock && nocow)
1532 btrfs_end_write_no_snapshotting(root);
1533 cur_offset = extent_end;
1534
1535 /*
1536 * btrfs_reloc_clone_csums() error, now we're OK to call error
1537 * handler, as metadata for created ordered extent will only
1538 * be freed by btrfs_finish_ordered_io().
1539 */
1540 if (ret)
1541 goto error;
1542 if (cur_offset > end)
1543 break;
1544 }
1545 btrfs_release_path(path);
1546
1547 if (cur_offset <= end && cow_start == (u64)-1) {
1548 cow_start = cur_offset;
1549 cur_offset = end;
1550 }
1551
1552 if (cow_start != (u64)-1) {
1553 ret = cow_file_range(inode, locked_page, cow_start, end, end,
1554 page_started, nr_written, 1, NULL);
1555 if (ret)
1556 goto error;
1557 }
1558
1559 error:
1560 if (ret && cur_offset < end)
1561 extent_clear_unlock_delalloc(inode, cur_offset, end, end,
1562 locked_page, EXTENT_LOCKED |
1563 EXTENT_DELALLOC | EXTENT_DEFRAG |
1564 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1565 PAGE_CLEAR_DIRTY |
1566 PAGE_SET_WRITEBACK |
1567 PAGE_END_WRITEBACK);
1568 btrfs_free_path(path);
1569 return ret;
1570 }
1571
1572 static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
1573 {
1574
1575 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
1576 !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC))
1577 return 0;
1578
1579 /*
1580 * @defrag_bytes is a hint value, no spinlock held here,
1581 * if is not zero, it means the file is defragging.
1582 * Force cow if given extent needs to be defragged.
1583 */
1584 if (BTRFS_I(inode)->defrag_bytes &&
1585 test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
1586 EXTENT_DEFRAG, 0, NULL))
1587 return 1;
1588
1589 return 0;
1590 }
1591
1592 /*
1593 * extent_io.c call back to do delayed allocation processing
1594 */
1595 static int run_delalloc_range(void *private_data, struct page *locked_page,
1596 u64 start, u64 end, int *page_started,
1597 unsigned long *nr_written,
1598 struct writeback_control *wbc)
1599 {
1600 struct inode *inode = private_data;
1601 int ret;
1602 int force_cow = need_force_cow(inode, start, end);
1603 unsigned int write_flags = wbc_to_write_flags(wbc);
1604
1605 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
1606 ret = run_delalloc_nocow(inode, locked_page, start, end,
1607 page_started, 1, nr_written);
1608 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
1609 ret = run_delalloc_nocow(inode, locked_page, start, end,
1610 page_started, 0, nr_written);
1611 } else if (!inode_need_compress(inode, start, end)) {
1612 ret = cow_file_range(inode, locked_page, start, end, end,
1613 page_started, nr_written, 1, NULL);
1614 } else {
1615 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1616 &BTRFS_I(inode)->runtime_flags);
1617 ret = cow_file_range_async(inode, locked_page, start, end,
1618 page_started, nr_written,
1619 write_flags);
1620 }
1621 if (ret)
1622 btrfs_cleanup_ordered_extents(inode, start, end - start + 1);
1623 return ret;
1624 }
1625
1626 static void btrfs_split_extent_hook(void *private_data,
1627 struct extent_state *orig, u64 split)
1628 {
1629 struct inode *inode = private_data;
1630 u64 size;
1631
1632 /* not delalloc, ignore it */
1633 if (!(orig->state & EXTENT_DELALLOC))
1634 return;
1635
1636 size = orig->end - orig->start + 1;
1637 if (size > BTRFS_MAX_EXTENT_SIZE) {
1638 u32 num_extents;
1639 u64 new_size;
1640
1641 /*
1642 * See the explanation in btrfs_merge_extent_hook, the same
1643 * applies here, just in reverse.
1644 */
1645 new_size = orig->end - split + 1;
1646 num_extents = count_max_extents(new_size);
1647 new_size = split - orig->start;
1648 num_extents += count_max_extents(new_size);
1649 if (count_max_extents(size) >= num_extents)
1650 return;
1651 }
1652
1653 spin_lock(&BTRFS_I(inode)->lock);
1654 btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
1655 spin_unlock(&BTRFS_I(inode)->lock);
1656 }
1657
1658 /*
1659 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1660 * extents so we can keep track of new extents that are just merged onto old
1661 * extents, such as when we are doing sequential writes, so we can properly
1662 * account for the metadata space we'll need.
1663 */
1664 static void btrfs_merge_extent_hook(void *private_data,
1665 struct extent_state *new,
1666 struct extent_state *other)
1667 {
1668 struct inode *inode = private_data;
1669 u64 new_size, old_size;
1670 u32 num_extents;
1671
1672 /* not delalloc, ignore it */
1673 if (!(other->state & EXTENT_DELALLOC))
1674 return;
1675
1676 if (new->start > other->start)
1677 new_size = new->end - other->start + 1;
1678 else
1679 new_size = other->end - new->start + 1;
1680
1681 /* we're not bigger than the max, unreserve the space and go */
1682 if (new_size <= BTRFS_MAX_EXTENT_SIZE) {
1683 spin_lock(&BTRFS_I(inode)->lock);
1684 btrfs_mod_outstanding_extents(BTRFS_I(inode), -1);
1685 spin_unlock(&BTRFS_I(inode)->lock);
1686 return;
1687 }
1688
1689 /*
1690 * We have to add up either side to figure out how many extents were
1691 * accounted for before we merged into one big extent. If the number of
1692 * extents we accounted for is <= the amount we need for the new range
1693 * then we can return, otherwise drop. Think of it like this
1694 *
1695 * [ 4k][MAX_SIZE]
1696 *
1697 * So we've grown the extent by a MAX_SIZE extent, this would mean we
1698 * need 2 outstanding extents, on one side we have 1 and the other side
1699 * we have 1 so they are == and we can return. But in this case
1700 *
1701 * [MAX_SIZE+4k][MAX_SIZE+4k]
1702 *
1703 * Each range on their own accounts for 2 extents, but merged together
1704 * they are only 3 extents worth of accounting, so we need to drop in
1705 * this case.
1706 */
1707 old_size = other->end - other->start + 1;
1708 num_extents = count_max_extents(old_size);
1709 old_size = new->end - new->start + 1;
1710 num_extents += count_max_extents(old_size);
1711 if (count_max_extents(new_size) >= num_extents)
1712 return;
1713
1714 spin_lock(&BTRFS_I(inode)->lock);
1715 btrfs_mod_outstanding_extents(BTRFS_I(inode), -1);
1716 spin_unlock(&BTRFS_I(inode)->lock);
1717 }
1718
1719 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1720 struct inode *inode)
1721 {
1722 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1723
1724 spin_lock(&root->delalloc_lock);
1725 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1726 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1727 &root->delalloc_inodes);
1728 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1729 &BTRFS_I(inode)->runtime_flags);
1730 root->nr_delalloc_inodes++;
1731 if (root->nr_delalloc_inodes == 1) {
1732 spin_lock(&fs_info->delalloc_root_lock);
1733 BUG_ON(!list_empty(&root->delalloc_root));
1734 list_add_tail(&root->delalloc_root,
1735 &fs_info->delalloc_roots);
1736 spin_unlock(&fs_info->delalloc_root_lock);
1737 }
1738 }
1739 spin_unlock(&root->delalloc_lock);
1740 }
1741
1742
1743 void __btrfs_del_delalloc_inode(struct btrfs_root *root,
1744 struct btrfs_inode *inode)
1745 {
1746 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
1747
1748 if (!list_empty(&inode->delalloc_inodes)) {
1749 list_del_init(&inode->delalloc_inodes);
1750 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1751 &inode->runtime_flags);
1752 root->nr_delalloc_inodes--;
1753 if (!root->nr_delalloc_inodes) {
1754 ASSERT(list_empty(&root->delalloc_inodes));
1755 spin_lock(&fs_info->delalloc_root_lock);
1756 BUG_ON(list_empty(&root->delalloc_root));
1757 list_del_init(&root->delalloc_root);
1758 spin_unlock(&fs_info->delalloc_root_lock);
1759 }
1760 }
1761 }
1762
1763 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1764 struct btrfs_inode *inode)
1765 {
1766 spin_lock(&root->delalloc_lock);
1767 __btrfs_del_delalloc_inode(root, inode);
1768 spin_unlock(&root->delalloc_lock);
1769 }
1770
1771 /*
1772 * extent_io.c set_bit_hook, used to track delayed allocation
1773 * bytes in this file, and to maintain the list of inodes that
1774 * have pending delalloc work to be done.
1775 */
1776 static void btrfs_set_bit_hook(void *private_data,
1777 struct extent_state *state, unsigned *bits)
1778 {
1779 struct inode *inode = private_data;
1780
1781 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1782
1783 if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
1784 WARN_ON(1);
1785 /*
1786 * set_bit and clear bit hooks normally require _irqsave/restore
1787 * but in this case, we are only testing for the DELALLOC
1788 * bit, which is only set or cleared with irqs on
1789 */
1790 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1791 struct btrfs_root *root = BTRFS_I(inode)->root;
1792 u64 len = state->end + 1 - state->start;
1793 u32 num_extents = count_max_extents(len);
1794 bool do_list = !btrfs_is_free_space_inode(BTRFS_I(inode));
1795
1796 spin_lock(&BTRFS_I(inode)->lock);
1797 btrfs_mod_outstanding_extents(BTRFS_I(inode), num_extents);
1798 spin_unlock(&BTRFS_I(inode)->lock);
1799
1800 /* For sanity tests */
1801 if (btrfs_is_testing(fs_info))
1802 return;
1803
1804 percpu_counter_add_batch(&fs_info->delalloc_bytes, len,
1805 fs_info->delalloc_batch);
1806 spin_lock(&BTRFS_I(inode)->lock);
1807 BTRFS_I(inode)->delalloc_bytes += len;
1808 if (*bits & EXTENT_DEFRAG)
1809 BTRFS_I(inode)->defrag_bytes += len;
1810 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1811 &BTRFS_I(inode)->runtime_flags))
1812 btrfs_add_delalloc_inodes(root, inode);
1813 spin_unlock(&BTRFS_I(inode)->lock);
1814 }
1815
1816 if (!(state->state & EXTENT_DELALLOC_NEW) &&
1817 (*bits & EXTENT_DELALLOC_NEW)) {
1818 spin_lock(&BTRFS_I(inode)->lock);
1819 BTRFS_I(inode)->new_delalloc_bytes += state->end + 1 -
1820 state->start;
1821 spin_unlock(&BTRFS_I(inode)->lock);
1822 }
1823 }
1824
1825 /*
1826 * extent_io.c clear_bit_hook, see set_bit_hook for why
1827 */
1828 static void btrfs_clear_bit_hook(void *private_data,
1829 struct extent_state *state,
1830 unsigned *bits)
1831 {
1832 struct btrfs_inode *inode = BTRFS_I((struct inode *)private_data);
1833 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
1834 u64 len = state->end + 1 - state->start;
1835 u32 num_extents = count_max_extents(len);
1836
1837 if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG)) {
1838 spin_lock(&inode->lock);
1839 inode->defrag_bytes -= len;
1840 spin_unlock(&inode->lock);
1841 }
1842
1843 /*
1844 * set_bit and clear bit hooks normally require _irqsave/restore
1845 * but in this case, we are only testing for the DELALLOC
1846 * bit, which is only set or cleared with irqs on
1847 */
1848 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1849 struct btrfs_root *root = inode->root;
1850 bool do_list = !btrfs_is_free_space_inode(inode);
1851
1852 spin_lock(&inode->lock);
1853 btrfs_mod_outstanding_extents(inode, -num_extents);
1854 spin_unlock(&inode->lock);
1855
1856 /*
1857 * We don't reserve metadata space for space cache inodes so we
1858 * don't need to call dellalloc_release_metadata if there is an
1859 * error.
1860 */
1861 if (*bits & EXTENT_CLEAR_META_RESV &&
1862 root != fs_info->tree_root)
1863 btrfs_delalloc_release_metadata(inode, len, false);
1864
1865 /* For sanity tests. */
1866 if (btrfs_is_testing(fs_info))
1867 return;
1868
1869 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID &&
1870 do_list && !(state->state & EXTENT_NORESERVE) &&
1871 (*bits & EXTENT_CLEAR_DATA_RESV))
1872 btrfs_free_reserved_data_space_noquota(
1873 &inode->vfs_inode,
1874 state->start, len);
1875
1876 percpu_counter_add_batch(&fs_info->delalloc_bytes, -len,
1877 fs_info->delalloc_batch);
1878 spin_lock(&inode->lock);
1879 inode->delalloc_bytes -= len;
1880 if (do_list && inode->delalloc_bytes == 0 &&
1881 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1882 &inode->runtime_flags))
1883 btrfs_del_delalloc_inode(root, inode);
1884 spin_unlock(&inode->lock);
1885 }
1886
1887 if ((state->state & EXTENT_DELALLOC_NEW) &&
1888 (*bits & EXTENT_DELALLOC_NEW)) {
1889 spin_lock(&inode->lock);
1890 ASSERT(inode->new_delalloc_bytes >= len);
1891 inode->new_delalloc_bytes -= len;
1892 spin_unlock(&inode->lock);
1893 }
1894 }
1895
1896 /*
1897 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1898 * we don't create bios that span stripes or chunks
1899 *
1900 * return 1 if page cannot be merged to bio
1901 * return 0 if page can be merged to bio
1902 * return error otherwise
1903 */
1904 int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
1905 size_t size, struct bio *bio,
1906 unsigned long bio_flags)
1907 {
1908 struct inode *inode = page->mapping->host;
1909 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1910 u64 logical = (u64)bio->bi_iter.bi_sector << 9;
1911 u64 length = 0;
1912 u64 map_length;
1913 int ret;
1914
1915 if (bio_flags & EXTENT_BIO_COMPRESSED)
1916 return 0;
1917
1918 length = bio->bi_iter.bi_size;
1919 map_length = length;
1920 ret = btrfs_map_block(fs_info, btrfs_op(bio), logical, &map_length,
1921 NULL, 0);
1922 if (ret < 0)
1923 return ret;
1924 if (map_length < length + size)
1925 return 1;
1926 return 0;
1927 }
1928
1929 /*
1930 * in order to insert checksums into the metadata in large chunks,
1931 * we wait until bio submission time. All the pages in the bio are
1932 * checksummed and sums are attached onto the ordered extent record.
1933 *
1934 * At IO completion time the cums attached on the ordered extent record
1935 * are inserted into the btree
1936 */
1937 static blk_status_t btrfs_submit_bio_start(void *private_data, struct bio *bio,
1938 u64 bio_offset)
1939 {
1940 struct inode *inode = private_data;
1941 blk_status_t ret = 0;
1942
1943 ret = btrfs_csum_one_bio(inode, bio, 0, 0);
1944 BUG_ON(ret); /* -ENOMEM */
1945 return 0;
1946 }
1947
1948 /*
1949 * in order to insert checksums into the metadata in large chunks,
1950 * we wait until bio submission time. All the pages in the bio are
1951 * checksummed and sums are attached onto the ordered extent record.
1952 *
1953 * At IO completion time the cums attached on the ordered extent record
1954 * are inserted into the btree
1955 */
1956 static blk_status_t btrfs_submit_bio_done(void *private_data, struct bio *bio,
1957 int mirror_num)
1958 {
1959 struct inode *inode = private_data;
1960 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1961 blk_status_t ret;
1962
1963 ret = btrfs_map_bio(fs_info, bio, mirror_num, 1);
1964 if (ret) {
1965 bio->bi_status = ret;
1966 bio_endio(bio);
1967 }
1968 return ret;
1969 }
1970
1971 /*
1972 * extent_io.c submission hook. This does the right thing for csum calculation
1973 * on write, or reading the csums from the tree before a read.
1974 *
1975 * Rules about async/sync submit,
1976 * a) read: sync submit
1977 *
1978 * b) write without checksum: sync submit
1979 *
1980 * c) write with checksum:
1981 * c-1) if bio is issued by fsync: sync submit
1982 * (sync_writers != 0)
1983 *
1984 * c-2) if root is reloc root: sync submit
1985 * (only in case of buffered IO)
1986 *
1987 * c-3) otherwise: async submit
1988 */
1989 static blk_status_t btrfs_submit_bio_hook(void *private_data, struct bio *bio,
1990 int mirror_num, unsigned long bio_flags,
1991 u64 bio_offset)
1992 {
1993 struct inode *inode = private_data;
1994 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1995 struct btrfs_root *root = BTRFS_I(inode)->root;
1996 enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA;
1997 blk_status_t ret = 0;
1998 int skip_sum;
1999 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
2000
2001 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
2002
2003 if (btrfs_is_free_space_inode(BTRFS_I(inode)))
2004 metadata = BTRFS_WQ_ENDIO_FREE_SPACE;
2005
2006 if (bio_op(bio) != REQ_OP_WRITE) {
2007 ret = btrfs_bio_wq_end_io(fs_info, bio, metadata);
2008 if (ret)
2009 goto out;
2010
2011 if (bio_flags & EXTENT_BIO_COMPRESSED) {
2012 ret = btrfs_submit_compressed_read(inode, bio,
2013 mirror_num,
2014 bio_flags);
2015 goto out;
2016 } else if (!skip_sum) {
2017 ret = btrfs_lookup_bio_sums(inode, bio, NULL);
2018 if (ret)
2019 goto out;
2020 }
2021 goto mapit;
2022 } else if (async && !skip_sum) {
2023 /* csum items have already been cloned */
2024 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
2025 goto mapit;
2026 /* we're doing a write, do the async checksumming */
2027 ret = btrfs_wq_submit_bio(fs_info, bio, mirror_num, bio_flags,
2028 bio_offset, inode,
2029 btrfs_submit_bio_start,
2030 btrfs_submit_bio_done);
2031 goto out;
2032 } else if (!skip_sum) {
2033 ret = btrfs_csum_one_bio(inode, bio, 0, 0);
2034 if (ret)
2035 goto out;
2036 }
2037
2038 mapit:
2039 ret = btrfs_map_bio(fs_info, bio, mirror_num, 0);
2040
2041 out:
2042 if (ret) {
2043 bio->bi_status = ret;
2044 bio_endio(bio);
2045 }
2046 return ret;
2047 }
2048
2049 /*
2050 * given a list of ordered sums record them in the inode. This happens
2051 * at IO completion time based on sums calculated at bio submission time.
2052 */
2053 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
2054 struct inode *inode, struct list_head *list)
2055 {
2056 struct btrfs_ordered_sum *sum;
2057 int ret;
2058
2059 list_for_each_entry(sum, list, list) {
2060 trans->adding_csums = true;
2061 ret = btrfs_csum_file_blocks(trans,
2062 BTRFS_I(inode)->root->fs_info->csum_root, sum);
2063 trans->adding_csums = false;
2064 if (ret)
2065 return ret;
2066 }
2067 return 0;
2068 }
2069
2070 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
2071 unsigned int extra_bits,
2072 struct extent_state **cached_state, int dedupe)
2073 {
2074 WARN_ON((end & (PAGE_SIZE - 1)) == 0);
2075 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
2076 extra_bits, cached_state);
2077 }
2078
2079 /* see btrfs_writepage_start_hook for details on why this is required */
2080 struct btrfs_writepage_fixup {
2081 struct page *page;
2082 struct btrfs_work work;
2083 };
2084
2085 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
2086 {
2087 struct btrfs_writepage_fixup *fixup;
2088 struct btrfs_ordered_extent *ordered;
2089 struct extent_state *cached_state = NULL;
2090 struct extent_changeset *data_reserved = NULL;
2091 struct page *page;
2092 struct inode *inode;
2093 u64 page_start;
2094 u64 page_end;
2095 int ret;
2096
2097 fixup = container_of(work, struct btrfs_writepage_fixup, work);
2098 page = fixup->page;
2099 again:
2100 lock_page(page);
2101 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
2102 ClearPageChecked(page);
2103 goto out_page;
2104 }
2105
2106 inode = page->mapping->host;
2107 page_start = page_offset(page);
2108 page_end = page_offset(page) + PAGE_SIZE - 1;
2109
2110 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end,
2111 &cached_state);
2112
2113 /* already ordered? We're done */
2114 if (PagePrivate2(page))
2115 goto out;
2116
2117 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start,
2118 PAGE_SIZE);
2119 if (ordered) {
2120 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
2121 page_end, &cached_state);
2122 unlock_page(page);
2123 btrfs_start_ordered_extent(inode, ordered, 1);
2124 btrfs_put_ordered_extent(ordered);
2125 goto again;
2126 }
2127
2128 ret = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start,
2129 PAGE_SIZE);
2130 if (ret) {
2131 mapping_set_error(page->mapping, ret);
2132 end_extent_writepage(page, ret, page_start, page_end);
2133 ClearPageChecked(page);
2134 goto out;
2135 }
2136
2137 ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 0,
2138 &cached_state, 0);
2139 if (ret) {
2140 mapping_set_error(page->mapping, ret);
2141 end_extent_writepage(page, ret, page_start, page_end);
2142 ClearPageChecked(page);
2143 goto out;
2144 }
2145
2146 ClearPageChecked(page);
2147 set_page_dirty(page);
2148 btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE, false);
2149 out:
2150 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
2151 &cached_state);
2152 out_page:
2153 unlock_page(page);
2154 put_page(page);
2155 kfree(fixup);
2156 extent_changeset_free(data_reserved);
2157 }
2158
2159 /*
2160 * There are a few paths in the higher layers of the kernel that directly
2161 * set the page dirty bit without asking the filesystem if it is a
2162 * good idea. This causes problems because we want to make sure COW
2163 * properly happens and the data=ordered rules are followed.
2164 *
2165 * In our case any range that doesn't have the ORDERED bit set
2166 * hasn't been properly setup for IO. We kick off an async process
2167 * to fix it up. The async helper will wait for ordered extents, set
2168 * the delalloc bit and make it safe to write the page.
2169 */
2170 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
2171 {
2172 struct inode *inode = page->mapping->host;
2173 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2174 struct btrfs_writepage_fixup *fixup;
2175
2176 /* this page is properly in the ordered list */
2177 if (TestClearPagePrivate2(page))
2178 return 0;
2179
2180 if (PageChecked(page))
2181 return -EAGAIN;
2182
2183 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
2184 if (!fixup)
2185 return -EAGAIN;
2186
2187 SetPageChecked(page);
2188 get_page(page);
2189 btrfs_init_work(&fixup->work, btrfs_fixup_helper,
2190 btrfs_writepage_fixup_worker, NULL, NULL);
2191 fixup->page = page;
2192 btrfs_queue_work(fs_info->fixup_workers, &fixup->work);
2193 return -EBUSY;
2194 }
2195
2196 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
2197 struct inode *inode, u64 file_pos,
2198 u64 disk_bytenr, u64 disk_num_bytes,
2199 u64 num_bytes, u64 ram_bytes,
2200 u8 compression, u8 encryption,
2201 u16 other_encoding, int extent_type)
2202 {
2203 struct btrfs_root *root = BTRFS_I(inode)->root;
2204 struct btrfs_file_extent_item *fi;
2205 struct btrfs_path *path;
2206 struct extent_buffer *leaf;
2207 struct btrfs_key ins;
2208 u64 qg_released;
2209 int extent_inserted = 0;
2210 int ret;
2211
2212 path = btrfs_alloc_path();
2213 if (!path)
2214 return -ENOMEM;
2215
2216 /*
2217 * we may be replacing one extent in the tree with another.
2218 * The new extent is pinned in the extent map, and we don't want
2219 * to drop it from the cache until it is completely in the btree.
2220 *
2221 * So, tell btrfs_drop_extents to leave this extent in the cache.
2222 * the caller is expected to unpin it and allow it to be merged
2223 * with the others.
2224 */
2225 ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
2226 file_pos + num_bytes, NULL, 0,
2227 1, sizeof(*fi), &extent_inserted);
2228 if (ret)
2229 goto out;
2230
2231 if (!extent_inserted) {
2232 ins.objectid = btrfs_ino(BTRFS_I(inode));
2233 ins.offset = file_pos;
2234 ins.type = BTRFS_EXTENT_DATA_KEY;
2235
2236 path->leave_spinning = 1;
2237 ret = btrfs_insert_empty_item(trans, root, path, &ins,
2238 sizeof(*fi));
2239 if (ret)
2240 goto out;
2241 }
2242 leaf = path->nodes[0];
2243 fi = btrfs_item_ptr(leaf, path->slots[0],
2244 struct btrfs_file_extent_item);
2245 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
2246 btrfs_set_file_extent_type(leaf, fi, extent_type);
2247 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
2248 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
2249 btrfs_set_file_extent_offset(leaf, fi, 0);
2250 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2251 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
2252 btrfs_set_file_extent_compression(leaf, fi, compression);
2253 btrfs_set_file_extent_encryption(leaf, fi, encryption);
2254 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
2255
2256 btrfs_mark_buffer_dirty(leaf);
2257 btrfs_release_path(path);
2258
2259 inode_add_bytes(inode, num_bytes);
2260
2261 ins.objectid = disk_bytenr;
2262 ins.offset = disk_num_bytes;
2263 ins.type = BTRFS_EXTENT_ITEM_KEY;
2264
2265 /*
2266 * Release the reserved range from inode dirty range map, as it is
2267 * already moved into delayed_ref_head
2268 */
2269 ret = btrfs_qgroup_release_data(inode, file_pos, ram_bytes);
2270 if (ret < 0)
2271 goto out;
2272 qg_released = ret;
2273 ret = btrfs_alloc_reserved_file_extent(trans, root,
2274 btrfs_ino(BTRFS_I(inode)),
2275 file_pos, qg_released, &ins);
2276 out:
2277 btrfs_free_path(path);
2278
2279 return ret;
2280 }
2281
2282 /* snapshot-aware defrag */
2283 struct sa_defrag_extent_backref {
2284 struct rb_node node;
2285 struct old_sa_defrag_extent *old;
2286 u64 root_id;
2287 u64 inum;
2288 u64 file_pos;
2289 u64 extent_offset;
2290 u64 num_bytes;
2291 u64 generation;
2292 };
2293
2294 struct old_sa_defrag_extent {
2295 struct list_head list;
2296 struct new_sa_defrag_extent *new;
2297
2298 u64 extent_offset;
2299 u64 bytenr;
2300 u64 offset;
2301 u64 len;
2302 int count;
2303 };
2304
2305 struct new_sa_defrag_extent {
2306 struct rb_root root;
2307 struct list_head head;
2308 struct btrfs_path *path;
2309 struct inode *inode;
2310 u64 file_pos;
2311 u64 len;
2312 u64 bytenr;
2313 u64 disk_len;
2314 u8 compress_type;
2315 };
2316
2317 static int backref_comp(struct sa_defrag_extent_backref *b1,
2318 struct sa_defrag_extent_backref *b2)
2319 {
2320 if (b1->root_id < b2->root_id)
2321 return -1;
2322 else if (b1->root_id > b2->root_id)
2323 return 1;
2324
2325 if (b1->inum < b2->inum)
2326 return -1;
2327 else if (b1->inum > b2->inum)
2328 return 1;
2329
2330 if (b1->file_pos < b2->file_pos)
2331 return -1;
2332 else if (b1->file_pos > b2->file_pos)
2333 return 1;
2334
2335 /*
2336 * [------------------------------] ===> (a range of space)
2337 * |<--->| |<---->| =============> (fs/file tree A)
2338 * |<---------------------------->| ===> (fs/file tree B)
2339 *
2340 * A range of space can refer to two file extents in one tree while
2341 * refer to only one file extent in another tree.
2342 *
2343 * So we may process a disk offset more than one time(two extents in A)
2344 * and locate at the same extent(one extent in B), then insert two same
2345 * backrefs(both refer to the extent in B).
2346 */
2347 return 0;
2348 }
2349
2350 static void backref_insert(struct rb_root *root,
2351 struct sa_defrag_extent_backref *backref)
2352 {
2353 struct rb_node **p = &root->rb_node;
2354 struct rb_node *parent = NULL;
2355 struct sa_defrag_extent_backref *entry;
2356 int ret;
2357
2358 while (*p) {
2359 parent = *p;
2360 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2361
2362 ret = backref_comp(backref, entry);
2363 if (ret < 0)
2364 p = &(*p)->rb_left;
2365 else
2366 p = &(*p)->rb_right;
2367 }
2368
2369 rb_link_node(&backref->node, parent, p);
2370 rb_insert_color(&backref->node, root);
2371 }
2372
2373 /*
2374 * Note the backref might has changed, and in this case we just return 0.
2375 */
2376 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2377 void *ctx)
2378 {
2379 struct btrfs_file_extent_item *extent;
2380 struct old_sa_defrag_extent *old = ctx;
2381 struct new_sa_defrag_extent *new = old->new;
2382 struct btrfs_path *path = new->path;
2383 struct btrfs_key key;
2384 struct btrfs_root *root;
2385 struct sa_defrag_extent_backref *backref;
2386 struct extent_buffer *leaf;
2387 struct inode *inode = new->inode;
2388 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2389 int slot;
2390 int ret;
2391 u64 extent_offset;
2392 u64 num_bytes;
2393
2394 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2395 inum == btrfs_ino(BTRFS_I(inode)))
2396 return 0;
2397
2398 key.objectid = root_id;
2399 key.type = BTRFS_ROOT_ITEM_KEY;
2400 key.offset = (u64)-1;
2401
2402 root = btrfs_read_fs_root_no_name(fs_info, &key);
2403 if (IS_ERR(root)) {
2404 if (PTR_ERR(root) == -ENOENT)
2405 return 0;
2406 WARN_ON(1);
2407 btrfs_debug(fs_info, "inum=%llu, offset=%llu, root_id=%llu",
2408 inum, offset, root_id);
2409 return PTR_ERR(root);
2410 }
2411
2412 key.objectid = inum;
2413 key.type = BTRFS_EXTENT_DATA_KEY;
2414 if (offset > (u64)-1 << 32)
2415 key.offset = 0;
2416 else
2417 key.offset = offset;
2418
2419 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2420 if (WARN_ON(ret < 0))
2421 return ret;
2422 ret = 0;
2423
2424 while (1) {
2425 cond_resched();
2426
2427 leaf = path->nodes[0];
2428 slot = path->slots[0];
2429
2430 if (slot >= btrfs_header_nritems(leaf)) {
2431 ret = btrfs_next_leaf(root, path);
2432 if (ret < 0) {
2433 goto out;
2434 } else if (ret > 0) {
2435 ret = 0;
2436 goto out;
2437 }
2438 continue;
2439 }
2440
2441 path->slots[0]++;
2442
2443 btrfs_item_key_to_cpu(leaf, &key, slot);
2444
2445 if (key.objectid > inum)
2446 goto out;
2447
2448 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2449 continue;
2450
2451 extent = btrfs_item_ptr(leaf, slot,
2452 struct btrfs_file_extent_item);
2453
2454 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2455 continue;
2456
2457 /*
2458 * 'offset' refers to the exact key.offset,
2459 * NOT the 'offset' field in btrfs_extent_data_ref, ie.
2460 * (key.offset - extent_offset).
2461 */
2462 if (key.offset != offset)
2463 continue;
2464
2465 extent_offset = btrfs_file_extent_offset(leaf, extent);
2466 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2467
2468 if (extent_offset >= old->extent_offset + old->offset +
2469 old->len || extent_offset + num_bytes <=
2470 old->extent_offset + old->offset)
2471 continue;
2472 break;
2473 }
2474
2475 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2476 if (!backref) {
2477 ret = -ENOENT;
2478 goto out;
2479 }
2480
2481 backref->root_id = root_id;
2482 backref->inum = inum;
2483 backref->file_pos = offset;
2484 backref->num_bytes = num_bytes;
2485 backref->extent_offset = extent_offset;
2486 backref->generation = btrfs_file_extent_generation(leaf, extent);
2487 backref->old = old;
2488 backref_insert(&new->root, backref);
2489 old->count++;
2490 out:
2491 btrfs_release_path(path);
2492 WARN_ON(ret);
2493 return ret;
2494 }
2495
2496 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2497 struct new_sa_defrag_extent *new)
2498 {
2499 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2500 struct old_sa_defrag_extent *old, *tmp;
2501 int ret;
2502
2503 new->path = path;
2504
2505 list_for_each_entry_safe(old, tmp, &new->head, list) {
2506 ret = iterate_inodes_from_logical(old->bytenr +
2507 old->extent_offset, fs_info,
2508 path, record_one_backref,
2509 old, false);
2510 if (ret < 0 && ret != -ENOENT)
2511 return false;
2512
2513 /* no backref to be processed for this extent */
2514 if (!old->count) {
2515 list_del(&old->list);
2516 kfree(old);
2517 }
2518 }
2519
2520 if (list_empty(&new->head))
2521 return false;
2522
2523 return true;
2524 }
2525
2526 static int relink_is_mergable(struct extent_buffer *leaf,
2527 struct btrfs_file_extent_item *fi,
2528 struct new_sa_defrag_extent *new)
2529 {
2530 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
2531 return 0;
2532
2533 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2534 return 0;
2535
2536 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
2537 return 0;
2538
2539 if (btrfs_file_extent_encryption(leaf, fi) ||
2540 btrfs_file_extent_other_encoding(leaf, fi))
2541 return 0;
2542
2543 return 1;
2544 }
2545
2546 /*
2547 * Note the backref might has changed, and in this case we just return 0.
2548 */
2549 static noinline int relink_extent_backref(struct btrfs_path *path,
2550 struct sa_defrag_extent_backref *prev,
2551 struct sa_defrag_extent_backref *backref)
2552 {
2553 struct btrfs_file_extent_item *extent;
2554 struct btrfs_file_extent_item *item;
2555 struct btrfs_ordered_extent *ordered;
2556 struct btrfs_trans_handle *trans;
2557 struct btrfs_root *root;
2558 struct btrfs_key key;
2559 struct extent_buffer *leaf;
2560 struct old_sa_defrag_extent *old = backref->old;
2561 struct new_sa_defrag_extent *new = old->new;
2562 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2563 struct inode *inode;
2564 struct extent_state *cached = NULL;
2565 int ret = 0;
2566 u64 start;
2567 u64 len;
2568 u64 lock_start;
2569 u64 lock_end;
2570 bool merge = false;
2571 int index;
2572
2573 if (prev && prev->root_id == backref->root_id &&
2574 prev->inum == backref->inum &&
2575 prev->file_pos + prev->num_bytes == backref->file_pos)
2576 merge = true;
2577
2578 /* step 1: get root */
2579 key.objectid = backref->root_id;
2580 key.type = BTRFS_ROOT_ITEM_KEY;
2581 key.offset = (u64)-1;
2582
2583 index = srcu_read_lock(&fs_info->subvol_srcu);
2584
2585 root = btrfs_read_fs_root_no_name(fs_info, &key);
2586 if (IS_ERR(root)) {
2587 srcu_read_unlock(&fs_info->subvol_srcu, index);
2588 if (PTR_ERR(root) == -ENOENT)
2589 return 0;
2590 return PTR_ERR(root);
2591 }
2592
2593 if (btrfs_root_readonly(root)) {
2594 srcu_read_unlock(&fs_info->subvol_srcu, index);
2595 return 0;
2596 }
2597
2598 /* step 2: get inode */
2599 key.objectid = backref->inum;
2600 key.type = BTRFS_INODE_ITEM_KEY;
2601 key.offset = 0;
2602
2603 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2604 if (IS_ERR(inode)) {
2605 srcu_read_unlock(&fs_info->subvol_srcu, index);
2606 return 0;
2607 }
2608
2609 srcu_read_unlock(&fs_info->subvol_srcu, index);
2610
2611 /* step 3: relink backref */
2612 lock_start = backref->file_pos;
2613 lock_end = backref->file_pos + backref->num_bytes - 1;
2614 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2615 &cached);
2616
2617 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2618 if (ordered) {
2619 btrfs_put_ordered_extent(ordered);
2620 goto out_unlock;
2621 }
2622
2623 trans = btrfs_join_transaction(root);
2624 if (IS_ERR(trans)) {
2625 ret = PTR_ERR(trans);
2626 goto out_unlock;
2627 }
2628
2629 key.objectid = backref->inum;
2630 key.type = BTRFS_EXTENT_DATA_KEY;
2631 key.offset = backref->file_pos;
2632
2633 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2634 if (ret < 0) {
2635 goto out_free_path;
2636 } else if (ret > 0) {
2637 ret = 0;
2638 goto out_free_path;
2639 }
2640
2641 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2642 struct btrfs_file_extent_item);
2643
2644 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2645 backref->generation)
2646 goto out_free_path;
2647
2648 btrfs_release_path(path);
2649
2650 start = backref->file_pos;
2651 if (backref->extent_offset < old->extent_offset + old->offset)
2652 start += old->extent_offset + old->offset -
2653 backref->extent_offset;
2654
2655 len = min(backref->extent_offset + backref->num_bytes,
2656 old->extent_offset + old->offset + old->len);
2657 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2658
2659 ret = btrfs_drop_extents(trans, root, inode, start,
2660 start + len, 1);
2661 if (ret)
2662 goto out_free_path;
2663 again:
2664 key.objectid = btrfs_ino(BTRFS_I(inode));
2665 key.type = BTRFS_EXTENT_DATA_KEY;
2666 key.offset = start;
2667
2668 path->leave_spinning = 1;
2669 if (merge) {
2670 struct btrfs_file_extent_item *fi;
2671 u64 extent_len;
2672 struct btrfs_key found_key;
2673
2674 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2675 if (ret < 0)
2676 goto out_free_path;
2677
2678 path->slots[0]--;
2679 leaf = path->nodes[0];
2680 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2681
2682 fi = btrfs_item_ptr(leaf, path->slots[0],
2683 struct btrfs_file_extent_item);
2684 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2685
2686 if (extent_len + found_key.offset == start &&
2687 relink_is_mergable(leaf, fi, new)) {
2688 btrfs_set_file_extent_num_bytes(leaf, fi,
2689 extent_len + len);
2690 btrfs_mark_buffer_dirty(leaf);
2691 inode_add_bytes(inode, len);
2692
2693 ret = 1;
2694 goto out_free_path;
2695 } else {
2696 merge = false;
2697 btrfs_release_path(path);
2698 goto again;
2699 }
2700 }
2701
2702 ret = btrfs_insert_empty_item(trans, root, path, &key,
2703 sizeof(*extent));
2704 if (ret) {
2705 btrfs_abort_transaction(trans, ret);
2706 goto out_free_path;
2707 }
2708
2709 leaf = path->nodes[0];
2710 item = btrfs_item_ptr(leaf, path->slots[0],
2711 struct btrfs_file_extent_item);
2712 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2713 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2714 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2715 btrfs_set_file_extent_num_bytes(leaf, item, len);
2716 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2717 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2718 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2719 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2720 btrfs_set_file_extent_encryption(leaf, item, 0);
2721 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2722
2723 btrfs_mark_buffer_dirty(leaf);
2724 inode_add_bytes(inode, len);
2725 btrfs_release_path(path);
2726
2727 ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
2728 new->disk_len, 0,
2729 backref->root_id, backref->inum,
2730 new->file_pos); /* start - extent_offset */
2731 if (ret) {
2732 btrfs_abort_transaction(trans, ret);
2733 goto out_free_path;
2734 }
2735
2736 ret = 1;
2737 out_free_path:
2738 btrfs_release_path(path);
2739 path->leave_spinning = 0;
2740 btrfs_end_transaction(trans);
2741 out_unlock:
2742 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2743 &cached);
2744 iput(inode);
2745 return ret;
2746 }
2747
2748 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
2749 {
2750 struct old_sa_defrag_extent *old, *tmp;
2751
2752 if (!new)
2753 return;
2754
2755 list_for_each_entry_safe(old, tmp, &new->head, list) {
2756 kfree(old);
2757 }
2758 kfree(new);
2759 }
2760
2761 static void relink_file_extents(struct new_sa_defrag_extent *new)
2762 {
2763 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2764 struct btrfs_path *path;
2765 struct sa_defrag_extent_backref *backref;
2766 struct sa_defrag_extent_backref *prev = NULL;
2767 struct inode *inode;
2768 struct rb_node *node;
2769 int ret;
2770
2771 inode = new->inode;
2772
2773 path = btrfs_alloc_path();
2774 if (!path)
2775 return;
2776
2777 if (!record_extent_backrefs(path, new)) {
2778 btrfs_free_path(path);
2779 goto out;
2780 }
2781 btrfs_release_path(path);
2782
2783 while (1) {
2784 node = rb_first(&new->root);
2785 if (!node)
2786 break;
2787 rb_erase(node, &new->root);
2788
2789 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2790
2791 ret = relink_extent_backref(path, prev, backref);
2792 WARN_ON(ret < 0);
2793
2794 kfree(prev);
2795
2796 if (ret == 1)
2797 prev = backref;
2798 else
2799 prev = NULL;
2800 cond_resched();
2801 }
2802 kfree(prev);
2803
2804 btrfs_free_path(path);
2805 out:
2806 free_sa_defrag_extent(new);
2807
2808 atomic_dec(&fs_info->defrag_running);
2809 wake_up(&fs_info->transaction_wait);
2810 }
2811
2812 static struct new_sa_defrag_extent *
2813 record_old_file_extents(struct inode *inode,
2814 struct btrfs_ordered_extent *ordered)
2815 {
2816 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2817 struct btrfs_root *root = BTRFS_I(inode)->root;
2818 struct btrfs_path *path;
2819 struct btrfs_key key;
2820 struct old_sa_defrag_extent *old;
2821 struct new_sa_defrag_extent *new;
2822 int ret;
2823
2824 new = kmalloc(sizeof(*new), GFP_NOFS);
2825 if (!new)
2826 return NULL;
2827
2828 new->inode = inode;
2829 new->file_pos = ordered->file_offset;
2830 new->len = ordered->len;
2831 new->bytenr = ordered->start;
2832 new->disk_len = ordered->disk_len;
2833 new->compress_type = ordered->compress_type;
2834 new->root = RB_ROOT;
2835 INIT_LIST_HEAD(&new->head);
2836
2837 path = btrfs_alloc_path();
2838 if (!path)
2839 goto out_kfree;
2840
2841 key.objectid = btrfs_ino(BTRFS_I(inode));
2842 key.type = BTRFS_EXTENT_DATA_KEY;
2843 key.offset = new->file_pos;
2844
2845 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2846 if (ret < 0)
2847 goto out_free_path;
2848 if (ret > 0 && path->slots[0] > 0)
2849 path->slots[0]--;
2850
2851 /* find out all the old extents for the file range */
2852 while (1) {
2853 struct btrfs_file_extent_item *extent;
2854 struct extent_buffer *l;
2855 int slot;
2856 u64 num_bytes;
2857 u64 offset;
2858 u64 end;
2859 u64 disk_bytenr;
2860 u64 extent_offset;
2861
2862 l = path->nodes[0];
2863 slot = path->slots[0];
2864
2865 if (slot >= btrfs_header_nritems(l)) {
2866 ret = btrfs_next_leaf(root, path);
2867 if (ret < 0)
2868 goto out_free_path;
2869 else if (ret > 0)
2870 break;
2871 continue;
2872 }
2873
2874 btrfs_item_key_to_cpu(l, &key, slot);
2875
2876 if (key.objectid != btrfs_ino(BTRFS_I(inode)))
2877 break;
2878 if (key.type != BTRFS_EXTENT_DATA_KEY)
2879 break;
2880 if (key.offset >= new->file_pos + new->len)
2881 break;
2882
2883 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2884
2885 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2886 if (key.offset + num_bytes < new->file_pos)
2887 goto next;
2888
2889 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2890 if (!disk_bytenr)
2891 goto next;
2892
2893 extent_offset = btrfs_file_extent_offset(l, extent);
2894
2895 old = kmalloc(sizeof(*old), GFP_NOFS);
2896 if (!old)
2897 goto out_free_path;
2898
2899 offset = max(new->file_pos, key.offset);
2900 end = min(new->file_pos + new->len, key.offset + num_bytes);
2901
2902 old->bytenr = disk_bytenr;
2903 old->extent_offset = extent_offset;
2904 old->offset = offset - key.offset;
2905 old->len = end - offset;
2906 old->new = new;
2907 old->count = 0;
2908 list_add_tail(&old->list, &new->head);
2909 next:
2910 path->slots[0]++;
2911 cond_resched();
2912 }
2913
2914 btrfs_free_path(path);
2915 atomic_inc(&fs_info->defrag_running);
2916
2917 return new;
2918
2919 out_free_path:
2920 btrfs_free_path(path);
2921 out_kfree:
2922 free_sa_defrag_extent(new);
2923 return NULL;
2924 }
2925
2926 static void btrfs_release_delalloc_bytes(struct btrfs_fs_info *fs_info,
2927 u64 start, u64 len)
2928 {
2929 struct btrfs_block_group_cache *cache;
2930
2931 cache = btrfs_lookup_block_group(fs_info, start);
2932 ASSERT(cache);
2933
2934 spin_lock(&cache->lock);
2935 cache->delalloc_bytes -= len;
2936 spin_unlock(&cache->lock);
2937
2938 btrfs_put_block_group(cache);
2939 }
2940
2941 /* as ordered data IO finishes, this gets called so we can finish
2942 * an ordered extent if the range of bytes in the file it covers are
2943 * fully written.
2944 */
2945 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2946 {
2947 struct inode *inode = ordered_extent->inode;
2948 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2949 struct btrfs_root *root = BTRFS_I(inode)->root;
2950 struct btrfs_trans_handle *trans = NULL;
2951 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2952 struct extent_state *cached_state = NULL;
2953 struct new_sa_defrag_extent *new = NULL;
2954 int compress_type = 0;
2955 int ret = 0;
2956 u64 logical_len = ordered_extent->len;
2957 bool nolock;
2958 bool truncated = false;
2959 bool range_locked = false;
2960 bool clear_new_delalloc_bytes = false;
2961
2962 if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
2963 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags) &&
2964 !test_bit(BTRFS_ORDERED_DIRECT, &ordered_extent->flags))
2965 clear_new_delalloc_bytes = true;
2966
2967 nolock = btrfs_is_free_space_inode(BTRFS_I(inode));
2968
2969 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2970 ret = -EIO;
2971 goto out;
2972 }
2973
2974 btrfs_free_io_failure_record(BTRFS_I(inode),
2975 ordered_extent->file_offset,
2976 ordered_extent->file_offset +
2977 ordered_extent->len - 1);
2978
2979 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
2980 truncated = true;
2981 logical_len = ordered_extent->truncated_len;
2982 /* Truncated the entire extent, don't bother adding */
2983 if (!logical_len)
2984 goto out;
2985 }
2986
2987 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2988 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2989
2990 /*
2991 * For mwrite(mmap + memset to write) case, we still reserve
2992 * space for NOCOW range.
2993 * As NOCOW won't cause a new delayed ref, just free the space
2994 */
2995 btrfs_qgroup_free_data(inode, NULL, ordered_extent->file_offset,
2996 ordered_extent->len);
2997 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2998 if (nolock)
2999 trans = btrfs_join_transaction_nolock(root);
3000 else
3001 trans = btrfs_join_transaction(root);
3002 if (IS_ERR(trans)) {
3003 ret = PTR_ERR(trans);
3004 trans = NULL;
3005 goto out;
3006 }
3007 trans->block_rsv = &BTRFS_I(inode)->block_rsv;
3008 ret = btrfs_update_inode_fallback(trans, root, inode);
3009 if (ret) /* -ENOMEM or corruption */
3010 btrfs_abort_transaction(trans, ret);
3011 goto out;
3012 }
3013
3014 range_locked = true;
3015 lock_extent_bits(io_tree, ordered_extent->file_offset,
3016 ordered_extent->file_offset + ordered_extent->len - 1,
3017 &cached_state);
3018
3019 ret = test_range_bit(io_tree, ordered_extent->file_offset,
3020 ordered_extent->file_offset + ordered_extent->len - 1,
3021 EXTENT_DEFRAG, 0, cached_state);
3022 if (ret) {
3023 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
3024 if (0 && last_snapshot >= BTRFS_I(inode)->generation)
3025 /* the inode is shared */
3026 new = record_old_file_extents(inode, ordered_extent);
3027
3028 clear_extent_bit(io_tree, ordered_extent->file_offset,
3029 ordered_extent->file_offset + ordered_extent->len - 1,
3030 EXTENT_DEFRAG, 0, 0, &cached_state);
3031 }
3032
3033 if (nolock)
3034 trans = btrfs_join_transaction_nolock(root);
3035 else
3036 trans = btrfs_join_transaction(root);
3037 if (IS_ERR(trans)) {
3038 ret = PTR_ERR(trans);
3039 trans = NULL;
3040 goto out;
3041 }
3042
3043 trans->block_rsv = &BTRFS_I(inode)->block_rsv;
3044
3045 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
3046 compress_type = ordered_extent->compress_type;
3047 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
3048 BUG_ON(compress_type);
3049 btrfs_qgroup_free_data(inode, NULL, ordered_extent->file_offset,
3050 ordered_extent->len);
3051 ret = btrfs_mark_extent_written(trans, BTRFS_I(inode),
3052 ordered_extent->file_offset,
3053 ordered_extent->file_offset +
3054 logical_len);
3055 } else {
3056 BUG_ON(root == fs_info->tree_root);
3057 ret = insert_reserved_file_extent(trans, inode,
3058 ordered_extent->file_offset,
3059 ordered_extent->start,
3060 ordered_extent->disk_len,
3061 logical_len, logical_len,
3062 compress_type, 0, 0,
3063 BTRFS_FILE_EXTENT_REG);
3064 if (!ret)
3065 btrfs_release_delalloc_bytes(fs_info,
3066 ordered_extent->start,
3067 ordered_extent->disk_len);
3068 }
3069 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
3070 ordered_extent->file_offset, ordered_extent->len,
3071 trans->transid);
3072 if (ret < 0) {
3073 btrfs_abort_transaction(trans, ret);
3074 goto out;
3075 }
3076
3077 ret = add_pending_csums(trans, inode, &ordered_extent->list);
3078 if (ret) {
3079 btrfs_abort_transaction(trans, ret);
3080 goto out;
3081 }
3082
3083 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
3084 ret = btrfs_update_inode_fallback(trans, root, inode);
3085 if (ret) { /* -ENOMEM or corruption */
3086 btrfs_abort_transaction(trans, ret);
3087 goto out;
3088 }
3089 ret = 0;
3090 out:
3091 if (range_locked || clear_new_delalloc_bytes) {
3092 unsigned int clear_bits = 0;
3093
3094 if (range_locked)
3095 clear_bits |= EXTENT_LOCKED;
3096 if (clear_new_delalloc_bytes)
3097 clear_bits |= EXTENT_DELALLOC_NEW;
3098 clear_extent_bit(&BTRFS_I(inode)->io_tree,
3099 ordered_extent->file_offset,
3100 ordered_extent->file_offset +
3101 ordered_extent->len - 1,
3102 clear_bits,
3103 (clear_bits & EXTENT_LOCKED) ? 1 : 0,
3104 0, &cached_state);
3105 }
3106
3107 if (trans)
3108 btrfs_end_transaction(trans);
3109
3110 if (ret || truncated) {
3111 u64 start, end;
3112
3113 if (truncated)
3114 start = ordered_extent->file_offset + logical_len;
3115 else
3116 start = ordered_extent->file_offset;
3117 end = ordered_extent->file_offset + ordered_extent->len - 1;
3118 clear_extent_uptodate(io_tree, start, end, NULL);
3119
3120 /* Drop the cache for the part of the extent we didn't write. */
3121 btrfs_drop_extent_cache(BTRFS_I(inode), start, end, 0);
3122
3123 /*
3124 * If the ordered extent had an IOERR or something else went
3125 * wrong we need to return the space for this ordered extent
3126 * back to the allocator. We only free the extent in the
3127 * truncated case if we didn't write out the extent at all.
3128 */
3129 if ((ret || !logical_len) &&
3130 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
3131 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
3132 btrfs_free_reserved_extent(fs_info,
3133 ordered_extent->start,
3134 ordered_extent->disk_len, 1);
3135 }
3136
3137
3138 /*
3139 * This needs to be done to make sure anybody waiting knows we are done
3140 * updating everything for this ordered extent.
3141 */
3142 btrfs_remove_ordered_extent(inode, ordered_extent);
3143
3144 /* for snapshot-aware defrag */
3145 if (new) {
3146 if (ret) {
3147 free_sa_defrag_extent(new);
3148 atomic_dec(&fs_info->defrag_running);
3149 } else {
3150 relink_file_extents(new);
3151 }
3152 }
3153
3154 /* once for us */
3155 btrfs_put_ordered_extent(ordered_extent);
3156 /* once for the tree */
3157 btrfs_put_ordered_extent(ordered_extent);
3158
3159 return ret;
3160 }
3161
3162 static void finish_ordered_fn(struct btrfs_work *work)
3163 {
3164 struct btrfs_ordered_extent *ordered_extent;
3165 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
3166 btrfs_finish_ordered_io(ordered_extent);
3167 }
3168
3169 static void btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
3170 struct extent_state *state, int uptodate)
3171 {
3172 struct inode *inode = page->mapping->host;
3173 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3174 struct btrfs_ordered_extent *ordered_extent = NULL;
3175 struct btrfs_workqueue *wq;
3176 btrfs_work_func_t func;
3177
3178 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
3179
3180 ClearPagePrivate2(page);
3181 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
3182 end - start + 1, uptodate))
3183 return;
3184
3185 if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
3186 wq = fs_info->endio_freespace_worker;
3187 func = btrfs_freespace_write_helper;
3188 } else {
3189 wq = fs_info->endio_write_workers;
3190 func = btrfs_endio_write_helper;
3191 }
3192
3193 btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL,
3194 NULL);
3195 btrfs_queue_work(wq, &ordered_extent->work);
3196 }
3197
3198 static int __readpage_endio_check(struct inode *inode,
3199 struct btrfs_io_bio *io_bio,
3200 int icsum, struct page *page,
3201 int pgoff, u64 start, size_t len)
3202 {
3203 char *kaddr;
3204 u32 csum_expected;
3205 u32 csum = ~(u32)0;
3206
3207 csum_expected = *(((u32 *)io_bio->csum) + icsum);
3208
3209 kaddr = kmap_atomic(page);
3210 csum = btrfs_csum_data(kaddr + pgoff, csum, len);
3211 btrfs_csum_final(csum, (u8 *)&csum);
3212 if (csum != csum_expected)
3213 goto zeroit;
3214
3215 kunmap_atomic(kaddr);
3216 return 0;
3217 zeroit:
3218 btrfs_print_data_csum_error(BTRFS_I(inode), start, csum, csum_expected,
3219 io_bio->mirror_num);
3220 memset(kaddr + pgoff, 1, len);
3221 flush_dcache_page(page);
3222 kunmap_atomic(kaddr);
3223 return -EIO;
3224 }
3225
3226 /*
3227 * when reads are done, we need to check csums to verify the data is correct
3228 * if there's a match, we allow the bio to finish. If not, the code in
3229 * extent_io.c will try to find good copies for us.
3230 */
3231 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
3232 u64 phy_offset, struct page *page,
3233 u64 start, u64 end, int mirror)
3234 {
3235 size_t offset = start - page_offset(page);
3236 struct inode *inode = page->mapping->host;
3237 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3238 struct btrfs_root *root = BTRFS_I(inode)->root;
3239
3240 if (PageChecked(page)) {
3241 ClearPageChecked(page);
3242 return 0;
3243 }
3244
3245 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
3246 return 0;
3247
3248 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
3249 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
3250 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM);
3251 return 0;
3252 }
3253
3254 phy_offset >>= inode->i_sb->s_blocksize_bits;
3255 return __readpage_endio_check(inode, io_bio, phy_offset, page, offset,
3256 start, (size_t)(end - start + 1));
3257 }
3258
3259 /*
3260 * btrfs_add_delayed_iput - perform a delayed iput on @inode
3261 *
3262 * @inode: The inode we want to perform iput on
3263 *
3264 * This function uses the generic vfs_inode::i_count to track whether we should
3265 * just decrement it (in case it's > 1) or if this is the last iput then link
3266 * the inode to the delayed iput machinery. Delayed iputs are processed at
3267 * transaction commit time/superblock commit/cleaner kthread.
3268 */
3269 void btrfs_add_delayed_iput(struct inode *inode)
3270 {
3271 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3272 struct btrfs_inode *binode = BTRFS_I(inode);
3273
3274 if (atomic_add_unless(&inode->i_count, -1, 1))
3275 return;
3276
3277 spin_lock(&fs_info->delayed_iput_lock);
3278 ASSERT(list_empty(&binode->delayed_iput));
3279 list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs);
3280 spin_unlock(&fs_info->delayed_iput_lock);
3281 }
3282
3283 void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info)
3284 {
3285
3286 spin_lock(&fs_info->delayed_iput_lock);
3287 while (!list_empty(&fs_info->delayed_iputs)) {
3288 struct btrfs_inode *inode;
3289
3290 inode = list_first_entry(&fs_info->delayed_iputs,
3291 struct btrfs_inode, delayed_iput);
3292 list_del_init(&inode->delayed_iput);
3293 spin_unlock(&fs_info->delayed_iput_lock);
3294 iput(&inode->vfs_inode);
3295 spin_lock(&fs_info->delayed_iput_lock);
3296 }
3297 spin_unlock(&fs_info->delayed_iput_lock);
3298 }
3299
3300 /*
3301 * This is called in transaction commit time. If there are no orphan
3302 * files in the subvolume, it removes orphan item and frees block_rsv
3303 * structure.
3304 */
3305 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
3306 struct btrfs_root *root)
3307 {
3308 struct btrfs_fs_info *fs_info = root->fs_info;
3309 struct btrfs_block_rsv *block_rsv;
3310 int ret;
3311
3312 if (atomic_read(&root->orphan_inodes) ||
3313 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
3314 return;
3315
3316 spin_lock(&root->orphan_lock);
3317 if (atomic_read(&root->orphan_inodes)) {
3318 spin_unlock(&root->orphan_lock);
3319 return;
3320 }
3321
3322 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
3323 spin_unlock(&root->orphan_lock);
3324 return;
3325 }
3326
3327 block_rsv = root->orphan_block_rsv;
3328 root->orphan_block_rsv = NULL;
3329 spin_unlock(&root->orphan_lock);
3330
3331 if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) &&
3332 btrfs_root_refs(&root->root_item) > 0) {
3333 ret = btrfs_del_orphan_item(trans, fs_info->tree_root,
3334 root->root_key.objectid);
3335 if (ret)
3336 btrfs_abort_transaction(trans, ret);
3337 else
3338 clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
3339 &root->state);
3340 }
3341
3342 if (block_rsv) {
3343 WARN_ON(block_rsv->size > 0);
3344 btrfs_free_block_rsv(fs_info, block_rsv);
3345 }
3346 }
3347
3348 /*
3349 * This creates an orphan entry for the given inode in case something goes
3350 * wrong in the middle of an unlink/truncate.
3351 *
3352 * NOTE: caller of this function should reserve 5 units of metadata for
3353 * this function.
3354 */
3355 int btrfs_orphan_add(struct btrfs_trans_handle *trans,
3356 struct btrfs_inode *inode)
3357 {
3358 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
3359 struct btrfs_root *root = inode->root;
3360 struct btrfs_block_rsv *block_rsv = NULL;
3361 int reserve = 0;
3362 bool insert = false;
3363 int ret;
3364
3365 if (!root->orphan_block_rsv) {
3366 block_rsv = btrfs_alloc_block_rsv(fs_info,
3367 BTRFS_BLOCK_RSV_TEMP);
3368 if (!block_rsv)
3369 return -ENOMEM;
3370 }
3371
3372 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3373 &inode->runtime_flags))
3374 insert = true;
3375
3376 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3377 &inode->runtime_flags))
3378 reserve = 1;
3379
3380 spin_lock(&root->orphan_lock);
3381 /* If someone has created ->orphan_block_rsv, be happy to use it. */
3382 if (!root->orphan_block_rsv) {
3383 root->orphan_block_rsv = block_rsv;
3384 } else if (block_rsv) {
3385 btrfs_free_block_rsv(fs_info, block_rsv);
3386 block_rsv = NULL;
3387 }
3388
3389 if (insert)
3390 atomic_inc(&root->orphan_inodes);
3391 spin_unlock(&root->orphan_lock);
3392
3393 /* grab metadata reservation from transaction handle */
3394 if (reserve) {
3395 ret = btrfs_orphan_reserve_metadata(trans, inode);
3396 ASSERT(!ret);
3397 if (ret) {
3398 /*
3399 * dec doesn't need spin_lock as ->orphan_block_rsv
3400 * would be released only if ->orphan_inodes is
3401 * zero.
3402 */
3403 atomic_dec(&root->orphan_inodes);
3404 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3405 &inode->runtime_flags);
3406 if (insert)
3407 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3408 &inode->runtime_flags);
3409 return ret;
3410 }
3411 }
3412
3413 /* insert an orphan item to track this unlinked/truncated file */
3414 if (insert) {
3415 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3416 if (ret) {
3417 if (reserve) {
3418 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3419 &inode->runtime_flags);
3420 btrfs_orphan_release_metadata(inode);
3421 }
3422 /*
3423 * btrfs_orphan_commit_root may race with us and set
3424 * ->orphan_block_rsv to zero, in order to avoid that,
3425 * decrease ->orphan_inodes after everything is done.
3426 */
3427 atomic_dec(&root->orphan_inodes);
3428 if (ret != -EEXIST) {
3429 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3430 &inode->runtime_flags);
3431 btrfs_abort_transaction(trans, ret);
3432 return ret;
3433 }
3434 }
3435 ret = 0;
3436 }
3437
3438 return 0;
3439 }
3440
3441 /*
3442 * We have done the truncate/delete so we can go ahead and remove the orphan
3443 * item for this particular inode.
3444 */
3445 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3446 struct btrfs_inode *inode)
3447 {
3448 struct btrfs_root *root = inode->root;
3449 int delete_item = 0;
3450 int ret = 0;
3451
3452 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3453 &inode->runtime_flags))
3454 delete_item = 1;
3455
3456 if (delete_item && trans)
3457 ret = btrfs_del_orphan_item(trans, root, btrfs_ino(inode));
3458
3459 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3460 &inode->runtime_flags))
3461 btrfs_orphan_release_metadata(inode);
3462
3463 /*
3464 * btrfs_orphan_commit_root may race with us and set ->orphan_block_rsv
3465 * to zero, in order to avoid that, decrease ->orphan_inodes after
3466 * everything is done.
3467 */
3468 if (delete_item)
3469 atomic_dec(&root->orphan_inodes);
3470
3471 return ret;
3472 }
3473
3474 /*
3475 * this cleans up any orphans that may be left on the list from the last use
3476 * of this root.
3477 */
3478 int btrfs_orphan_cleanup(struct btrfs_root *root)
3479 {
3480 struct btrfs_fs_info *fs_info = root->fs_info;
3481 struct btrfs_path *path;
3482 struct extent_buffer *leaf;
3483 struct btrfs_key key, found_key;
3484 struct btrfs_trans_handle *trans;
3485 struct inode *inode;
3486 u64 last_objectid = 0;
3487 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3488
3489 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3490 return 0;
3491
3492 path = btrfs_alloc_path();
3493 if (!path) {
3494 ret = -ENOMEM;
3495 goto out;
3496 }
3497 path->reada = READA_BACK;
3498
3499 key.objectid = BTRFS_ORPHAN_OBJECTID;
3500 key.type = BTRFS_ORPHAN_ITEM_KEY;
3501 key.offset = (u64)-1;
3502
3503 while (1) {
3504 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3505 if (ret < 0)
3506 goto out;
3507
3508 /*
3509 * if ret == 0 means we found what we were searching for, which
3510 * is weird, but possible, so only screw with path if we didn't
3511 * find the key and see if we have stuff that matches
3512 */
3513 if (ret > 0) {
3514 ret = 0;
3515 if (path->slots[0] == 0)
3516 break;
3517 path->slots[0]--;
3518 }
3519
3520 /* pull out the item */
3521 leaf = path->nodes[0];
3522 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3523
3524 /* make sure the item matches what we want */
3525 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3526 break;
3527 if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
3528 break;
3529
3530 /* release the path since we're done with it */
3531 btrfs_release_path(path);
3532
3533 /*
3534 * this is where we are basically btrfs_lookup, without the
3535 * crossing root thing. we store the inode number in the
3536 * offset of the orphan item.
3537 */
3538
3539 if (found_key.offset == last_objectid) {
3540 btrfs_err(fs_info,
3541 "Error removing orphan entry, stopping orphan cleanup");
3542 ret = -EINVAL;
3543 goto out;
3544 }
3545
3546 last_objectid = found_key.offset;
3547
3548 found_key.objectid = found_key.offset;
3549 found_key.type = BTRFS_INODE_ITEM_KEY;
3550 found_key.offset = 0;
3551 inode = btrfs_iget(fs_info->sb, &found_key, root, NULL);
3552 ret = PTR_ERR_OR_ZERO(inode);
3553 if (ret && ret != -ENOENT)
3554 goto out;
3555
3556 if (ret == -ENOENT && root == fs_info->tree_root) {
3557 struct btrfs_root *dead_root;
3558 struct btrfs_fs_info *fs_info = root->fs_info;
3559 int is_dead_root = 0;
3560
3561 /*
3562 * this is an orphan in the tree root. Currently these
3563 * could come from 2 sources:
3564 * a) a snapshot deletion in progress
3565 * b) a free space cache inode
3566 * We need to distinguish those two, as the snapshot
3567 * orphan must not get deleted.
3568 * find_dead_roots already ran before us, so if this
3569 * is a snapshot deletion, we should find the root
3570 * in the dead_roots list
3571 */
3572 spin_lock(&fs_info->trans_lock);
3573 list_for_each_entry(dead_root, &fs_info->dead_roots,
3574 root_list) {
3575 if (dead_root->root_key.objectid ==
3576 found_key.objectid) {
3577 is_dead_root = 1;
3578 break;
3579 }
3580 }
3581 spin_unlock(&fs_info->trans_lock);
3582 if (is_dead_root) {
3583 /* prevent this orphan from being found again */
3584 key.offset = found_key.objectid - 1;
3585 continue;
3586 }
3587 }
3588 /*
3589 * Inode is already gone but the orphan item is still there,
3590 * kill the orphan item.
3591 */
3592 if (ret == -ENOENT) {
3593 trans = btrfs_start_transaction(root, 1);
3594 if (IS_ERR(trans)) {
3595 ret = PTR_ERR(trans);
3596 goto out;
3597 }
3598 btrfs_debug(fs_info, "auto deleting %Lu",
3599 found_key.objectid);
3600 ret = btrfs_del_orphan_item(trans, root,
3601 found_key.objectid);
3602 btrfs_end_transaction(trans);
3603 if (ret)
3604 goto out;
3605 continue;
3606 }
3607
3608 /*
3609 * add this inode to the orphan list so btrfs_orphan_del does
3610 * the proper thing when we hit it
3611 */
3612 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3613 &BTRFS_I(inode)->runtime_flags);
3614 atomic_inc(&root->orphan_inodes);
3615
3616 /* if we have links, this was a truncate, lets do that */
3617 if (inode->i_nlink) {
3618 if (WARN_ON(!S_ISREG(inode->i_mode))) {
3619 iput(inode);
3620 continue;
3621 }
3622 nr_truncate++;
3623
3624 /* 1 for the orphan item deletion. */
3625 trans = btrfs_start_transaction(root, 1);
3626 if (IS_ERR(trans)) {
3627 iput(inode);
3628 ret = PTR_ERR(trans);
3629 goto out;
3630 }
3631 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
3632 btrfs_end_transaction(trans);
3633 if (ret) {
3634 iput(inode);
3635 goto out;
3636 }
3637
3638 ret = btrfs_truncate(inode, false);
3639 if (ret)
3640 btrfs_orphan_del(NULL, BTRFS_I(inode));
3641 } else {
3642 nr_unlink++;
3643 }
3644
3645 /* this will do delete_inode and everything for us */
3646 iput(inode);
3647 if (ret)
3648 goto out;
3649 }
3650 /* release the path since we're done with it */
3651 btrfs_release_path(path);
3652
3653 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3654
3655 if (root->orphan_block_rsv)
3656 btrfs_block_rsv_release(fs_info, root->orphan_block_rsv,
3657 (u64)-1);
3658
3659 if (root->orphan_block_rsv ||
3660 test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
3661 trans = btrfs_join_transaction(root);
3662 if (!IS_ERR(trans))
3663 btrfs_end_transaction(trans);
3664 }
3665
3666 if (nr_unlink)
3667 btrfs_debug(fs_info, "unlinked %d orphans", nr_unlink);
3668 if (nr_truncate)
3669 btrfs_debug(fs_info, "truncated %d orphans", nr_truncate);
3670
3671 out:
3672 if (ret)
3673 btrfs_err(fs_info, "could not do orphan cleanup %d", ret);
3674 btrfs_free_path(path);
3675 return ret;
3676 }
3677
3678 /*
3679 * very simple check to peek ahead in the leaf looking for xattrs. If we
3680 * don't find any xattrs, we know there can't be any acls.
3681 *
3682 * slot is the slot the inode is in, objectid is the objectid of the inode
3683 */
3684 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3685 int slot, u64 objectid,
3686 int *first_xattr_slot)
3687 {
3688 u32 nritems = btrfs_header_nritems(leaf);
3689 struct btrfs_key found_key;
3690 static u64 xattr_access = 0;
3691 static u64 xattr_default = 0;
3692 int scanned = 0;
3693
3694 if (!xattr_access) {
3695 xattr_access = btrfs_name_hash(XATTR_NAME_POSIX_ACL_ACCESS,
3696 strlen(XATTR_NAME_POSIX_ACL_ACCESS));
3697 xattr_default = btrfs_name_hash(XATTR_NAME_POSIX_ACL_DEFAULT,
3698 strlen(XATTR_NAME_POSIX_ACL_DEFAULT));
3699 }
3700
3701 slot++;
3702 *first_xattr_slot = -1;
3703 while (slot < nritems) {
3704 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3705
3706 /* we found a different objectid, there must not be acls */
3707 if (found_key.objectid != objectid)
3708 return 0;
3709
3710 /* we found an xattr, assume we've got an acl */
3711 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3712 if (*first_xattr_slot == -1)
3713 *first_xattr_slot = slot;
3714 if (found_key.offset == xattr_access ||
3715 found_key.offset == xattr_default)
3716 return 1;
3717 }
3718
3719 /*
3720 * we found a key greater than an xattr key, there can't
3721 * be any acls later on
3722 */
3723 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3724 return 0;
3725
3726 slot++;
3727 scanned++;
3728
3729 /*
3730 * it goes inode, inode backrefs, xattrs, extents,
3731 * so if there are a ton of hard links to an inode there can
3732 * be a lot of backrefs. Don't waste time searching too hard,
3733 * this is just an optimization
3734 */
3735 if (scanned >= 8)
3736 break;
3737 }
3738 /* we hit the end of the leaf before we found an xattr or
3739 * something larger than an xattr. We have to assume the inode
3740 * has acls
3741 */
3742 if (*first_xattr_slot == -1)
3743 *first_xattr_slot = slot;
3744 return 1;
3745 }
3746
3747 /*
3748 * read an inode from the btree into the in-memory inode
3749 */
3750 static int btrfs_read_locked_inode(struct inode *inode)
3751 {
3752 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3753 struct btrfs_path *path;
3754 struct extent_buffer *leaf;
3755 struct btrfs_inode_item *inode_item;
3756 struct btrfs_root *root = BTRFS_I(inode)->root;
3757 struct btrfs_key location;
3758 unsigned long ptr;
3759 int maybe_acls;
3760 u32 rdev;
3761 int ret;
3762 bool filled = false;
3763 int first_xattr_slot;
3764
3765 ret = btrfs_fill_inode(inode, &rdev);
3766 if (!ret)
3767 filled = true;
3768
3769 path = btrfs_alloc_path();
3770 if (!path) {
3771 ret = -ENOMEM;
3772 goto make_bad;
3773 }
3774
3775 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3776
3777 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3778 if (ret) {
3779 if (ret > 0)
3780 ret = -ENOENT;
3781 goto make_bad;
3782 }
3783
3784 leaf = path->nodes[0];
3785
3786 if (filled)
3787 goto cache_index;
3788
3789 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3790 struct btrfs_inode_item);
3791 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3792 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3793 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3794 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3795 btrfs_i_size_write(BTRFS_I(inode), btrfs_inode_size(leaf, inode_item));
3796
3797 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
3798 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
3799
3800 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
3801 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
3802
3803 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
3804 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
3805
3806 BTRFS_I(inode)->i_otime.tv_sec =
3807 btrfs_timespec_sec(leaf, &inode_item->otime);
3808 BTRFS_I(inode)->i_otime.tv_nsec =
3809 btrfs_timespec_nsec(leaf, &inode_item->otime);
3810
3811 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3812 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3813 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3814
3815 inode_set_iversion_queried(inode,
3816 btrfs_inode_sequence(leaf, inode_item));
3817 inode->i_generation = BTRFS_I(inode)->generation;
3818 inode->i_rdev = 0;
3819 rdev = btrfs_inode_rdev(leaf, inode_item);
3820
3821 BTRFS_I(inode)->index_cnt = (u64)-1;
3822 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3823
3824 cache_index:
3825 /*
3826 * If we were modified in the current generation and evicted from memory
3827 * and then re-read we need to do a full sync since we don't have any
3828 * idea about which extents were modified before we were evicted from
3829 * cache.
3830 *
3831 * This is required for both inode re-read from disk and delayed inode
3832 * in delayed_nodes_tree.
3833 */
3834 if (BTRFS_I(inode)->last_trans == fs_info->generation)
3835 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3836 &BTRFS_I(inode)->runtime_flags);
3837
3838 /*
3839 * We don't persist the id of the transaction where an unlink operation
3840 * against the inode was last made. So here we assume the inode might
3841 * have been evicted, and therefore the exact value of last_unlink_trans
3842 * lost, and set it to last_trans to avoid metadata inconsistencies
3843 * between the inode and its parent if the inode is fsync'ed and the log
3844 * replayed. For example, in the scenario:
3845 *
3846 * touch mydir/foo
3847 * ln mydir/foo mydir/bar
3848 * sync
3849 * unlink mydir/bar
3850 * echo 2 > /proc/sys/vm/drop_caches # evicts inode
3851 * xfs_io -c fsync mydir/foo
3852 * <power failure>
3853 * mount fs, triggers fsync log replay
3854 *
3855 * We must make sure that when we fsync our inode foo we also log its
3856 * parent inode, otherwise after log replay the parent still has the
3857 * dentry with the "bar" name but our inode foo has a link count of 1
3858 * and doesn't have an inode ref with the name "bar" anymore.
3859 *
3860 * Setting last_unlink_trans to last_trans is a pessimistic approach,
3861 * but it guarantees correctness at the expense of occasional full
3862 * transaction commits on fsync if our inode is a directory, or if our
3863 * inode is not a directory, logging its parent unnecessarily.
3864 */
3865 BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans;
3866
3867 path->slots[0]++;
3868 if (inode->i_nlink != 1 ||
3869 path->slots[0] >= btrfs_header_nritems(leaf))
3870 goto cache_acl;
3871
3872 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
3873 if (location.objectid != btrfs_ino(BTRFS_I(inode)))
3874 goto cache_acl;
3875
3876 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3877 if (location.type == BTRFS_INODE_REF_KEY) {
3878 struct btrfs_inode_ref *ref;
3879
3880 ref = (struct btrfs_inode_ref *)ptr;
3881 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
3882 } else if (location.type == BTRFS_INODE_EXTREF_KEY) {
3883 struct btrfs_inode_extref *extref;
3884
3885 extref = (struct btrfs_inode_extref *)ptr;
3886 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
3887 extref);
3888 }
3889 cache_acl:
3890 /*
3891 * try to precache a NULL acl entry for files that don't have
3892 * any xattrs or acls
3893 */
3894 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3895 btrfs_ino(BTRFS_I(inode)), &first_xattr_slot);
3896 if (first_xattr_slot != -1) {
3897 path->slots[0] = first_xattr_slot;
3898 ret = btrfs_load_inode_props(inode, path);
3899 if (ret)
3900 btrfs_err(fs_info,
3901 "error loading props for ino %llu (root %llu): %d",
3902 btrfs_ino(BTRFS_I(inode)),
3903 root->root_key.objectid, ret);
3904 }
3905 btrfs_free_path(path);
3906
3907 if (!maybe_acls)
3908 cache_no_acl(inode);
3909
3910 switch (inode->i_mode & S_IFMT) {
3911 case S_IFREG:
3912 inode->i_mapping->a_ops = &btrfs_aops;
3913 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3914 inode->i_fop = &btrfs_file_operations;
3915 inode->i_op = &btrfs_file_inode_operations;
3916 break;
3917 case S_IFDIR:
3918 inode->i_fop = &btrfs_dir_file_operations;
3919 inode->i_op = &btrfs_dir_inode_operations;
3920 break;
3921 case S_IFLNK:
3922 inode->i_op = &btrfs_symlink_inode_operations;
3923 inode_nohighmem(inode);
3924 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3925 break;
3926 default:
3927 inode->i_op = &btrfs_special_inode_operations;
3928 init_special_inode(inode, inode->i_mode, rdev);
3929 break;
3930 }
3931
3932 btrfs_sync_inode_flags_to_i_flags(inode);
3933 return 0;
3934
3935 make_bad:
3936 btrfs_free_path(path);
3937 make_bad_inode(inode);
3938 return ret;
3939 }
3940
3941 /*
3942 * given a leaf and an inode, copy the inode fields into the leaf
3943 */
3944 static void fill_inode_item(struct btrfs_trans_handle *trans,
3945 struct extent_buffer *leaf,
3946 struct btrfs_inode_item *item,
3947 struct inode *inode)
3948 {
3949 struct btrfs_map_token token;
3950
3951 btrfs_init_map_token(&token);
3952
3953 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3954 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3955 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3956 &token);
3957 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3958 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3959
3960 btrfs_set_token_timespec_sec(leaf, &item->atime,
3961 inode->i_atime.tv_sec, &token);
3962 btrfs_set_token_timespec_nsec(leaf, &item->atime,
3963 inode->i_atime.tv_nsec, &token);
3964
3965 btrfs_set_token_timespec_sec(leaf, &item->mtime,
3966 inode->i_mtime.tv_sec, &token);
3967 btrfs_set_token_timespec_nsec(leaf, &item->mtime,
3968 inode->i_mtime.tv_nsec, &token);
3969
3970 btrfs_set_token_timespec_sec(leaf, &item->ctime,
3971 inode->i_ctime.tv_sec, &token);
3972 btrfs_set_token_timespec_nsec(leaf, &item->ctime,
3973 inode->i_ctime.tv_nsec, &token);
3974
3975 btrfs_set_token_timespec_sec(leaf, &item->otime,
3976 BTRFS_I(inode)->i_otime.tv_sec, &token);
3977 btrfs_set_token_timespec_nsec(leaf, &item->otime,
3978 BTRFS_I(inode)->i_otime.tv_nsec, &token);
3979
3980 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3981 &token);
3982 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3983 &token);
3984 btrfs_set_token_inode_sequence(leaf, item, inode_peek_iversion(inode),
3985 &token);
3986 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3987 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3988 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3989 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3990 }
3991
3992 /*
3993 * copy everything in the in-memory inode into the btree.
3994 */
3995 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3996 struct btrfs_root *root, struct inode *inode)
3997 {
3998 struct btrfs_inode_item *inode_item;
3999 struct btrfs_path *path;
4000 struct extent_buffer *leaf;
4001 int ret;
4002
4003 path = btrfs_alloc_path();
4004 if (!path)
4005 return -ENOMEM;
4006
4007 path->leave_spinning = 1;
4008 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
4009 1);
4010 if (ret) {
4011 if (ret > 0)
4012 ret = -ENOENT;
4013 goto failed;
4014 }
4015
4016 leaf = path->nodes[0];
4017 inode_item = btrfs_item_ptr(leaf, path->slots[0],
4018 struct btrfs_inode_item);
4019
4020 fill_inode_item(trans, leaf, inode_item, inode);
4021 btrfs_mark_buffer_dirty(leaf);
4022 btrfs_set_inode_last_trans(trans, inode);
4023 ret = 0;
4024 failed:
4025 btrfs_free_path(path);
4026 return ret;
4027 }
4028
4029 /*
4030 * copy everything in the in-memory inode into the btree.
4031 */
4032 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
4033 struct btrfs_root *root, struct inode *inode)
4034 {
4035 struct btrfs_fs_info *fs_info = root->fs_info;
4036 int ret;
4037
4038 /*
4039 * If the inode is a free space inode, we can deadlock during commit
4040 * if we put it into the delayed code.
4041 *
4042 * The data relocation inode should also be directly updated
4043 * without delay
4044 */
4045 if (!btrfs_is_free_space_inode(BTRFS_I(inode))
4046 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
4047 && !test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) {
4048 btrfs_update_root_times(trans, root);
4049
4050 ret = btrfs_delayed_update_inode(trans, root, inode);
4051 if (!ret)
4052 btrfs_set_inode_last_trans(trans, inode);
4053 return ret;
4054 }
4055
4056 return btrfs_update_inode_item(trans, root, inode);
4057 }
4058
4059 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
4060 struct btrfs_root *root,
4061 struct inode *inode)
4062 {
4063 int ret;
4064
4065 ret = btrfs_update_inode(trans, root, inode);
4066 if (ret == -ENOSPC)
4067 return btrfs_update_inode_item(trans, root, inode);
4068 return ret;
4069 }
4070
4071 /*
4072 * unlink helper that gets used here in inode.c and in the tree logging
4073 * recovery code. It remove a link in a directory with a given name, and
4074 * also drops the back refs in the inode to the directory
4075 */
4076 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4077 struct btrfs_root *root,
4078 struct btrfs_inode *dir,
4079 struct btrfs_inode *inode,
4080 const char *name, int name_len)
4081 {
4082 struct btrfs_fs_info *fs_info = root->fs_info;
4083 struct btrfs_path *path;
4084 int ret = 0;
4085 struct extent_buffer *leaf;
4086 struct btrfs_dir_item *di;
4087 struct btrfs_key key;
4088 u64 index;
4089 u64 ino = btrfs_ino(inode);
4090 u64 dir_ino = btrfs_ino(dir);
4091
4092 path = btrfs_alloc_path();
4093 if (!path) {
4094 ret = -ENOMEM;
4095 goto out;
4096 }
4097
4098 path->leave_spinning = 1;
4099 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4100 name, name_len, -1);
4101 if (IS_ERR(di)) {
4102 ret = PTR_ERR(di);
4103 goto err;
4104 }
4105 if (!di) {
4106 ret = -ENOENT;
4107 goto err;
4108 }
4109 leaf = path->nodes[0];
4110 btrfs_dir_item_key_to_cpu(leaf, di, &key);
4111 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4112 if (ret)
4113 goto err;
4114 btrfs_release_path(path);
4115
4116 /*
4117 * If we don't have dir index, we have to get it by looking up
4118 * the inode ref, since we get the inode ref, remove it directly,
4119 * it is unnecessary to do delayed deletion.
4120 *
4121 * But if we have dir index, needn't search inode ref to get it.
4122 * Since the inode ref is close to the inode item, it is better
4123 * that we delay to delete it, and just do this deletion when
4124 * we update the inode item.
4125 */
4126 if (inode->dir_index) {
4127 ret = btrfs_delayed_delete_inode_ref(inode);
4128 if (!ret) {
4129 index = inode->dir_index;
4130 goto skip_backref;
4131 }
4132 }
4133
4134 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
4135 dir_ino, &index);
4136 if (ret) {
4137 btrfs_info(fs_info,
4138 "failed to delete reference to %.*s, inode %llu parent %llu",
4139 name_len, name, ino, dir_ino);
4140 btrfs_abort_transaction(trans, ret);
4141 goto err;
4142 }
4143 skip_backref:
4144 ret = btrfs_delete_delayed_dir_index(trans, fs_info, dir, index);
4145 if (ret) {
4146 btrfs_abort_transaction(trans, ret);
4147 goto err;
4148 }
4149
4150 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len, inode,
4151 dir_ino);
4152 if (ret != 0 && ret != -ENOENT) {
4153 btrfs_abort_transaction(trans, ret);
4154 goto err;
4155 }
4156
4157 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len, dir,
4158 index);
4159 if (ret == -ENOENT)
4160 ret = 0;
4161 else if (ret)
4162 btrfs_abort_transaction(trans, ret);
4163 err:
4164 btrfs_free_path(path);
4165 if (ret)
4166 goto out;
4167
4168 btrfs_i_size_write(dir, dir->vfs_inode.i_size - name_len * 2);
4169 inode_inc_iversion(&inode->vfs_inode);
4170 inode_inc_iversion(&dir->vfs_inode);
4171 inode->vfs_inode.i_ctime = dir->vfs_inode.i_mtime =
4172 dir->vfs_inode.i_ctime = current_time(&inode->vfs_inode);
4173 ret = btrfs_update_inode(trans, root, &dir->vfs_inode);
4174 out:
4175 return ret;
4176 }
4177
4178 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4179 struct btrfs_root *root,
4180 struct btrfs_inode *dir, struct btrfs_inode *inode,
4181 const char *name, int name_len)
4182 {
4183 int ret;
4184 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
4185 if (!ret) {
4186 drop_nlink(&inode->vfs_inode);
4187 ret = btrfs_update_inode(trans, root, &inode->vfs_inode);
4188 }
4189 return ret;
4190 }
4191
4192 /*
4193 * helper to start transaction for unlink and rmdir.
4194 *
4195 * unlink and rmdir are special in btrfs, they do not always free space, so
4196 * if we cannot make our reservations the normal way try and see if there is
4197 * plenty of slack room in the global reserve to migrate, otherwise we cannot
4198 * allow the unlink to occur.
4199 */
4200 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
4201 {
4202 struct btrfs_root *root = BTRFS_I(dir)->root;
4203
4204 /*
4205 * 1 for the possible orphan item
4206 * 1 for the dir item
4207 * 1 for the dir index
4208 * 1 for the inode ref
4209 * 1 for the inode
4210 */
4211 return btrfs_start_transaction_fallback_global_rsv(root, 5, 5);
4212 }
4213
4214 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
4215 {
4216 struct btrfs_root *root = BTRFS_I(dir)->root;
4217 struct btrfs_trans_handle *trans;
4218 struct inode *inode = d_inode(dentry);
4219 int ret;
4220
4221 trans = __unlink_start_trans(dir);
4222 if (IS_ERR(trans))
4223 return PTR_ERR(trans);
4224
4225 btrfs_record_unlink_dir(trans, BTRFS_I(dir), BTRFS_I(d_inode(dentry)),
4226 0);
4227
4228 ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
4229 BTRFS_I(d_inode(dentry)), dentry->d_name.name,
4230 dentry->d_name.len);
4231 if (ret)
4232 goto out;
4233
4234 if (inode->i_nlink == 0) {
4235 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
4236 if (ret)
4237 goto out;
4238 }
4239
4240 out:
4241 btrfs_end_transaction(trans);
4242 btrfs_btree_balance_dirty(root->fs_info);
4243 return ret;
4244 }
4245
4246 static int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
4247 struct btrfs_root *root,
4248 struct inode *dir, u64 objectid,
4249 const char *name, int name_len)
4250 {
4251 struct btrfs_fs_info *fs_info = root->fs_info;
4252 struct btrfs_path *path;
4253 struct extent_buffer *leaf;
4254 struct btrfs_dir_item *di;
4255 struct btrfs_key key;
4256 u64 index;
4257 int ret;
4258 u64 dir_ino = btrfs_ino(BTRFS_I(dir));
4259
4260 path = btrfs_alloc_path();
4261 if (!path)
4262 return -ENOMEM;
4263
4264 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4265 name, name_len, -1);
4266 if (IS_ERR_OR_NULL(di)) {
4267 if (!di)
4268 ret = -ENOENT;
4269 else
4270 ret = PTR_ERR(di);
4271 goto out;
4272 }
4273
4274 leaf = path->nodes[0];
4275 btrfs_dir_item_key_to_cpu(leaf, di, &key);
4276 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
4277 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4278 if (ret) {
4279 btrfs_abort_transaction(trans, ret);
4280 goto out;
4281 }
4282 btrfs_release_path(path);
4283
4284 ret = btrfs_del_root_ref(trans, fs_info, objectid,
4285 root->root_key.objectid, dir_ino,
4286 &index, name, name_len);
4287 if (ret < 0) {
4288 if (ret != -ENOENT) {
4289 btrfs_abort_transaction(trans, ret);
4290 goto out;
4291 }
4292 di = btrfs_search_dir_index_item(root, path, dir_ino,
4293 name, name_len);
4294 if (IS_ERR_OR_NULL(di)) {
4295 if (!di)
4296 ret = -ENOENT;
4297 else
4298 ret = PTR_ERR(di);
4299 btrfs_abort_transaction(trans, ret);
4300 goto out;
4301 }
4302
4303 leaf = path->nodes[0];
4304 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4305 btrfs_release_path(path);
4306 index = key.offset;
4307 }
4308 btrfs_release_path(path);
4309
4310 ret = btrfs_delete_delayed_dir_index(trans, fs_info, BTRFS_I(dir), index);
4311 if (ret) {
4312 btrfs_abort_transaction(trans, ret);
4313 goto out;
4314 }
4315
4316 btrfs_i_size_write(BTRFS_I(dir), dir->i_size - name_len * 2);
4317 inode_inc_iversion(dir);
4318 dir->i_mtime = dir->i_ctime = current_time(dir);
4319 ret = btrfs_update_inode_fallback(trans, root, dir);
4320 if (ret)
4321 btrfs_abort_transaction(trans, ret);
4322 out:
4323 btrfs_free_path(path);
4324 return ret;
4325 }
4326
4327 /*
4328 * Helper to check if the subvolume references other subvolumes or if it's
4329 * default.
4330 */
4331 static noinline int may_destroy_subvol(struct btrfs_root *root)
4332 {
4333 struct btrfs_fs_info *fs_info = root->fs_info;
4334 struct btrfs_path *path;
4335 struct btrfs_dir_item *di;
4336 struct btrfs_key key;
4337 u64 dir_id;
4338 int ret;
4339
4340 path = btrfs_alloc_path();
4341 if (!path)
4342 return -ENOMEM;
4343
4344 /* Make sure this root isn't set as the default subvol */
4345 dir_id = btrfs_super_root_dir(fs_info->super_copy);
4346 di = btrfs_lookup_dir_item(NULL, fs_info->tree_root, path,
4347 dir_id, "default", 7, 0);
4348 if (di && !IS_ERR(di)) {
4349 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
4350 if (key.objectid == root->root_key.objectid) {
4351 ret = -EPERM;
4352 btrfs_err(fs_info,
4353 "deleting default subvolume %llu is not allowed",
4354 key.objectid);
4355 goto out;
4356 }
4357 btrfs_release_path(path);
4358 }
4359
4360 key.objectid = root->root_key.objectid;
4361 key.type = BTRFS_ROOT_REF_KEY;
4362 key.offset = (u64)-1;
4363
4364 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
4365 if (ret < 0)
4366 goto out;
4367 BUG_ON(ret == 0);
4368
4369 ret = 0;
4370 if (path->slots[0] > 0) {
4371 path->slots[0]--;
4372 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
4373 if (key.objectid == root->root_key.objectid &&
4374 key.type == BTRFS_ROOT_REF_KEY)
4375 ret = -ENOTEMPTY;
4376 }
4377 out:
4378 btrfs_free_path(path);
4379 return ret;
4380 }
4381
4382 /* Delete all dentries for inodes belonging to the root */
4383 static void btrfs_prune_dentries(struct btrfs_root *root)
4384 {
4385 struct btrfs_fs_info *fs_info = root->fs_info;
4386 struct rb_node *node;
4387 struct rb_node *prev;
4388 struct btrfs_inode *entry;
4389 struct inode *inode;
4390 u64 objectid = 0;
4391
4392 if (!test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
4393 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
4394
4395 spin_lock(&root->inode_lock);
4396 again:
4397 node = root->inode_tree.rb_node;
4398 prev = NULL;
4399 while (node) {
4400 prev = node;
4401 entry = rb_entry(node, struct btrfs_inode, rb_node);
4402
4403 if (objectid < btrfs_ino(BTRFS_I(&entry->vfs_inode)))
4404 node = node->rb_left;
4405 else if (objectid > btrfs_ino(BTRFS_I(&entry->vfs_inode)))
4406 node = node->rb_right;
4407 else
4408 break;
4409 }
4410 if (!node) {
4411 while (prev) {
4412 entry = rb_entry(prev, struct btrfs_inode, rb_node);
4413 if (objectid <= btrfs_ino(BTRFS_I(&entry->vfs_inode))) {
4414 node = prev;
4415 break;
4416 }
4417 prev = rb_next(prev);
4418 }
4419 }
4420 while (node) {
4421 entry = rb_entry(node, struct btrfs_inode, rb_node);
4422 objectid = btrfs_ino(BTRFS_I(&entry->vfs_inode)) + 1;
4423 inode = igrab(&entry->vfs_inode);
4424 if (inode) {
4425 spin_unlock(&root->inode_lock);
4426 if (atomic_read(&inode->i_count) > 1)
4427 d_prune_aliases(inode);
4428 /*
4429 * btrfs_drop_inode will have it removed from the inode
4430 * cache when its usage count hits zero.
4431 */
4432 iput(inode);
4433 cond_resched();
4434 spin_lock(&root->inode_lock);
4435 goto again;
4436 }
4437
4438 if (cond_resched_lock(&root->inode_lock))
4439 goto again;
4440
4441 node = rb_next(node);
4442 }
4443 spin_unlock(&root->inode_lock);
4444 }
4445
4446 int btrfs_delete_subvolume(struct inode *dir, struct dentry *dentry)
4447 {
4448 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
4449 struct btrfs_root *root = BTRFS_I(dir)->root;
4450 struct inode *inode = d_inode(dentry);
4451 struct btrfs_root *dest = BTRFS_I(inode)->root;
4452 struct btrfs_trans_handle *trans;
4453 struct btrfs_block_rsv block_rsv;
4454 u64 root_flags;
4455 u64 qgroup_reserved;
4456 int ret;
4457 int err;
4458
4459 /*
4460 * Don't allow to delete a subvolume with send in progress. This is
4461 * inside the inode lock so the error handling that has to drop the bit
4462 * again is not run concurrently.
4463 */
4464 spin_lock(&dest->root_item_lock);
4465 root_flags = btrfs_root_flags(&dest->root_item);
4466 if (dest->send_in_progress == 0) {
4467 btrfs_set_root_flags(&dest->root_item,
4468 root_flags | BTRFS_ROOT_SUBVOL_DEAD);
4469 spin_unlock(&dest->root_item_lock);
4470 } else {
4471 spin_unlock(&dest->root_item_lock);
4472 btrfs_warn(fs_info,
4473 "attempt to delete subvolume %llu during send",
4474 dest->root_key.objectid);
4475 return -EPERM;
4476 }
4477
4478 down_write(&fs_info->subvol_sem);
4479
4480 err = may_destroy_subvol(dest);
4481 if (err)
4482 goto out_up_write;
4483
4484 btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
4485 /*
4486 * One for dir inode,
4487 * two for dir entries,
4488 * two for root ref/backref.
4489 */
4490 err = btrfs_subvolume_reserve_metadata(root, &block_rsv,
4491 5, &qgroup_reserved, true);
4492 if (err)
4493 goto out_up_write;
4494
4495 trans = btrfs_start_transaction(root, 0);
4496 if (IS_ERR(trans)) {
4497 err = PTR_ERR(trans);
4498 goto out_release;
4499 }
4500 trans->block_rsv = &block_rsv;
4501 trans->bytes_reserved = block_rsv.size;
4502
4503 btrfs_record_snapshot_destroy(trans, BTRFS_I(dir));
4504
4505 ret = btrfs_unlink_subvol(trans, root, dir,
4506 dest->root_key.objectid,
4507 dentry->d_name.name,
4508 dentry->d_name.len);
4509 if (ret) {
4510 err = ret;
4511 btrfs_abort_transaction(trans, ret);
4512 goto out_end_trans;
4513 }
4514
4515 btrfs_record_root_in_trans(trans, dest);
4516
4517 memset(&dest->root_item.drop_progress, 0,
4518 sizeof(dest->root_item.drop_progress));
4519 dest->root_item.drop_level = 0;
4520 btrfs_set_root_refs(&dest->root_item, 0);
4521
4522 if (!test_and_set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &dest->state)) {
4523 ret = btrfs_insert_orphan_item(trans,
4524 fs_info->tree_root,
4525 dest->root_key.objectid);
4526 if (ret) {
4527 btrfs_abort_transaction(trans, ret);
4528 err = ret;
4529 goto out_end_trans;
4530 }
4531 }
4532
4533 ret = btrfs_uuid_tree_rem(trans, fs_info, dest->root_item.uuid,
4534 BTRFS_UUID_KEY_SUBVOL,
4535 dest->root_key.objectid);
4536 if (ret && ret != -ENOENT) {
4537 btrfs_abort_transaction(trans, ret);
4538 err = ret;
4539 goto out_end_trans;
4540 }
4541 if (!btrfs_is_empty_uuid(dest->root_item.received_uuid)) {
4542 ret = btrfs_uuid_tree_rem(trans, fs_info,
4543 dest->root_item.received_uuid,
4544 BTRFS_UUID_KEY_RECEIVED_SUBVOL,
4545 dest->root_key.objectid);
4546 if (ret && ret != -ENOENT) {
4547 btrfs_abort_transaction(trans, ret);
4548 err = ret;
4549 goto out_end_trans;
4550 }
4551 }
4552
4553 out_end_trans:
4554 trans->block_rsv = NULL;
4555 trans->bytes_reserved = 0;
4556 ret = btrfs_end_transaction(trans);
4557 if (ret && !err)
4558 err = ret;
4559 inode->i_flags |= S_DEAD;
4560 out_release:
4561 btrfs_subvolume_release_metadata(fs_info, &block_rsv);
4562 out_up_write:
4563 up_write(&fs_info->subvol_sem);
4564 if (err) {
4565 spin_lock(&dest->root_item_lock);
4566 root_flags = btrfs_root_flags(&dest->root_item);
4567 btrfs_set_root_flags(&dest->root_item,
4568 root_flags & ~BTRFS_ROOT_SUBVOL_DEAD);
4569 spin_unlock(&dest->root_item_lock);
4570 } else {
4571 d_invalidate(dentry);
4572 btrfs_prune_dentries(dest);
4573 ASSERT(dest->send_in_progress == 0);
4574
4575 /* the last ref */
4576 if (dest->ino_cache_inode) {
4577 iput(dest->ino_cache_inode);
4578 dest->ino_cache_inode = NULL;
4579 }
4580 }
4581
4582 return err;
4583 }
4584
4585 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
4586 {
4587 struct inode *inode = d_inode(dentry);
4588 int err = 0;
4589 struct btrfs_root *root = BTRFS_I(dir)->root;
4590 struct btrfs_trans_handle *trans;
4591 u64 last_unlink_trans;
4592
4593 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
4594 return -ENOTEMPTY;
4595 if (btrfs_ino(BTRFS_I(inode)) == BTRFS_FIRST_FREE_OBJECTID)
4596 return btrfs_delete_subvolume(dir, dentry);
4597
4598 trans = __unlink_start_trans(dir);
4599 if (IS_ERR(trans))
4600 return PTR_ERR(trans);
4601
4602 if (unlikely(btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
4603 err = btrfs_unlink_subvol(trans, root, dir,
4604 BTRFS_I(inode)->location.objectid,
4605 dentry->d_name.name,
4606 dentry->d_name.len);
4607 goto out;
4608 }
4609
4610 err = btrfs_orphan_add(trans, BTRFS_I(inode));
4611 if (err)
4612 goto out;
4613
4614 last_unlink_trans = BTRFS_I(inode)->last_unlink_trans;
4615
4616 /* now the directory is empty */
4617 err = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
4618 BTRFS_I(d_inode(dentry)), dentry->d_name.name,
4619 dentry->d_name.len);
4620 if (!err) {
4621 btrfs_i_size_write(BTRFS_I(inode), 0);
4622 /*
4623 * Propagate the last_unlink_trans value of the deleted dir to
4624 * its parent directory. This is to prevent an unrecoverable
4625 * log tree in the case we do something like this:
4626 * 1) create dir foo
4627 * 2) create snapshot under dir foo
4628 * 3) delete the snapshot
4629 * 4) rmdir foo
4630 * 5) mkdir foo
4631 * 6) fsync foo or some file inside foo
4632 */
4633 if (last_unlink_trans >= trans->transid)
4634 BTRFS_I(dir)->last_unlink_trans = last_unlink_trans;
4635 }
4636 out:
4637 btrfs_end_transaction(trans);
4638 btrfs_btree_balance_dirty(root->fs_info);
4639
4640 return err;
4641 }
4642
4643 static int truncate_space_check(struct btrfs_trans_handle *trans,
4644 struct btrfs_root *root,
4645 u64 bytes_deleted)
4646 {
4647 struct btrfs_fs_info *fs_info = root->fs_info;
4648 int ret;
4649
4650 /*
4651 * This is only used to apply pressure to the enospc system, we don't
4652 * intend to use this reservation at all.
4653 */
4654 bytes_deleted = btrfs_csum_bytes_to_leaves(fs_info, bytes_deleted);
4655 bytes_deleted *= fs_info->nodesize;
4656 ret = btrfs_block_rsv_add(root, &fs_info->trans_block_rsv,
4657 bytes_deleted, BTRFS_RESERVE_NO_FLUSH);
4658 if (!ret) {
4659 trace_btrfs_space_reservation(fs_info, "transaction",
4660 trans->transid,
4661 bytes_deleted, 1);
4662 trans->bytes_reserved += bytes_deleted;
4663 }
4664 return ret;
4665
4666 }
4667
4668 /*
4669 * Return this if we need to call truncate_block for the last bit of the
4670 * truncate.
4671 */
4672 #define NEED_TRUNCATE_BLOCK 1
4673
4674 /*
4675 * this can truncate away extent items, csum items and directory items.
4676 * It starts at a high offset and removes keys until it can't find
4677 * any higher than new_size
4678 *
4679 * csum items that cross the new i_size are truncated to the new size
4680 * as well.
4681 *
4682 * min_type is the minimum key type to truncate down to. If set to 0, this
4683 * will kill all the items on this inode, including the INODE_ITEM_KEY.
4684 */
4685 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
4686 struct btrfs_root *root,
4687 struct inode *inode,
4688 u64 new_size, u32 min_type)
4689 {
4690 struct btrfs_fs_info *fs_info = root->fs_info;
4691 struct btrfs_path *path;
4692 struct extent_buffer *leaf;
4693 struct btrfs_file_extent_item *fi;
4694 struct btrfs_key key;
4695 struct btrfs_key found_key;
4696 u64 extent_start = 0;
4697 u64 extent_num_bytes = 0;
4698 u64 extent_offset = 0;
4699 u64 item_end = 0;
4700 u64 last_size = new_size;
4701 u32 found_type = (u8)-1;
4702 int found_extent;
4703 int del_item;
4704 int pending_del_nr = 0;
4705 int pending_del_slot = 0;
4706 int extent_type = -1;
4707 int ret;
4708 int err = 0;
4709 u64 ino = btrfs_ino(BTRFS_I(inode));
4710 u64 bytes_deleted = 0;
4711 bool be_nice = false;
4712 bool should_throttle = false;
4713 bool should_end = false;
4714
4715 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
4716
4717 /*
4718 * for non-free space inodes and ref cows, we want to back off from
4719 * time to time
4720 */
4721 if (!btrfs_is_free_space_inode(BTRFS_I(inode)) &&
4722 test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4723 be_nice = true;
4724
4725 path = btrfs_alloc_path();
4726 if (!path)
4727 return -ENOMEM;
4728 path->reada = READA_BACK;
4729
4730 /*
4731 * We want to drop from the next block forward in case this new size is
4732 * not block aligned since we will be keeping the last block of the
4733 * extent just the way it is.
4734 */
4735 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4736 root == fs_info->tree_root)
4737 btrfs_drop_extent_cache(BTRFS_I(inode), ALIGN(new_size,
4738 fs_info->sectorsize),
4739 (u64)-1, 0);
4740
4741 /*
4742 * This function is also used to drop the items in the log tree before
4743 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4744 * it is used to drop the loged items. So we shouldn't kill the delayed
4745 * items.
4746 */
4747 if (min_type == 0 && root == BTRFS_I(inode)->root)
4748 btrfs_kill_delayed_inode_items(BTRFS_I(inode));
4749
4750 key.objectid = ino;
4751 key.offset = (u64)-1;
4752 key.type = (u8)-1;
4753
4754 search_again:
4755 /*
4756 * with a 16K leaf size and 128MB extents, you can actually queue
4757 * up a huge file in a single leaf. Most of the time that
4758 * bytes_deleted is > 0, it will be huge by the time we get here
4759 */
4760 if (be_nice && bytes_deleted > SZ_32M) {
4761 if (btrfs_should_end_transaction(trans)) {
4762 err = -EAGAIN;
4763 goto error;
4764 }
4765 }
4766
4767
4768 path->leave_spinning = 1;
4769 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4770 if (ret < 0) {
4771 err = ret;
4772 goto out;
4773 }
4774
4775 if (ret > 0) {
4776 /* there are no items in the tree for us to truncate, we're
4777 * done
4778 */
4779 if (path->slots[0] == 0)
4780 goto out;
4781 path->slots[0]--;
4782 }
4783
4784 while (1) {
4785 fi = NULL;
4786 leaf = path->nodes[0];
4787 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4788 found_type = found_key.type;
4789
4790 if (found_key.objectid != ino)
4791 break;
4792
4793 if (found_type < min_type)
4794 break;
4795
4796 item_end = found_key.offset;
4797 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4798 fi = btrfs_item_ptr(leaf, path->slots[0],
4799 struct btrfs_file_extent_item);
4800 extent_type = btrfs_file_extent_type(leaf, fi);
4801 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4802 item_end +=
4803 btrfs_file_extent_num_bytes(leaf, fi);
4804
4805 trace_btrfs_truncate_show_fi_regular(
4806 BTRFS_I(inode), leaf, fi,
4807 found_key.offset);
4808 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4809 item_end += btrfs_file_extent_inline_len(leaf,
4810 path->slots[0], fi);
4811
4812 trace_btrfs_truncate_show_fi_inline(
4813 BTRFS_I(inode), leaf, fi, path->slots[0],
4814 found_key.offset);
4815 }
4816 item_end--;
4817 }
4818 if (found_type > min_type) {
4819 del_item = 1;
4820 } else {
4821 if (item_end < new_size)
4822 break;
4823 if (found_key.offset >= new_size)
4824 del_item = 1;
4825 else
4826 del_item = 0;
4827 }
4828 found_extent = 0;
4829 /* FIXME, shrink the extent if the ref count is only 1 */
4830 if (found_type != BTRFS_EXTENT_DATA_KEY)
4831 goto delete;
4832
4833 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4834 u64 num_dec;
4835 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4836 if (!del_item) {
4837 u64 orig_num_bytes =
4838 btrfs_file_extent_num_bytes(leaf, fi);
4839 extent_num_bytes = ALIGN(new_size -
4840 found_key.offset,
4841 fs_info->sectorsize);
4842 btrfs_set_file_extent_num_bytes(leaf, fi,
4843 extent_num_bytes);
4844 num_dec = (orig_num_bytes -
4845 extent_num_bytes);
4846 if (test_bit(BTRFS_ROOT_REF_COWS,
4847 &root->state) &&
4848 extent_start != 0)
4849 inode_sub_bytes(inode, num_dec);
4850 btrfs_mark_buffer_dirty(leaf);
4851 } else {
4852 extent_num_bytes =
4853 btrfs_file_extent_disk_num_bytes(leaf,
4854 fi);
4855 extent_offset = found_key.offset -
4856 btrfs_file_extent_offset(leaf, fi);
4857
4858 /* FIXME blocksize != 4096 */
4859 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4860 if (extent_start != 0) {
4861 found_extent = 1;
4862 if (test_bit(BTRFS_ROOT_REF_COWS,
4863 &root->state))
4864 inode_sub_bytes(inode, num_dec);
4865 }
4866 }
4867 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4868 /*
4869 * we can't truncate inline items that have had
4870 * special encodings
4871 */
4872 if (!del_item &&
4873 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4874 btrfs_file_extent_other_encoding(leaf, fi) == 0 &&
4875 btrfs_file_extent_compression(leaf, fi) == 0) {
4876 u32 size = (u32)(new_size - found_key.offset);
4877
4878 btrfs_set_file_extent_ram_bytes(leaf, fi, size);
4879 size = btrfs_file_extent_calc_inline_size(size);
4880 btrfs_truncate_item(root->fs_info, path, size, 1);
4881 } else if (!del_item) {
4882 /*
4883 * We have to bail so the last_size is set to
4884 * just before this extent.
4885 */
4886 err = NEED_TRUNCATE_BLOCK;
4887 break;
4888 }
4889
4890 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4891 inode_sub_bytes(inode, item_end + 1 - new_size);
4892 }
4893 delete:
4894 if (del_item)
4895 last_size = found_key.offset;
4896 else
4897 last_size = new_size;
4898 if (del_item) {
4899 if (!pending_del_nr) {
4900 /* no pending yet, add ourselves */
4901 pending_del_slot = path->slots[0];
4902 pending_del_nr = 1;
4903 } else if (pending_del_nr &&
4904 path->slots[0] + 1 == pending_del_slot) {
4905 /* hop on the pending chunk */
4906 pending_del_nr++;
4907 pending_del_slot = path->slots[0];
4908 } else {
4909 BUG();
4910 }
4911 } else {
4912 break;
4913 }
4914 should_throttle = false;
4915
4916 if (found_extent &&
4917 (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4918 root == fs_info->tree_root)) {
4919 btrfs_set_path_blocking(path);
4920 bytes_deleted += extent_num_bytes;
4921 ret = btrfs_free_extent(trans, root, extent_start,
4922 extent_num_bytes, 0,
4923 btrfs_header_owner(leaf),
4924 ino, extent_offset);
4925 BUG_ON(ret);
4926 if (btrfs_should_throttle_delayed_refs(trans, fs_info))
4927 btrfs_async_run_delayed_refs(fs_info,
4928 trans->delayed_ref_updates * 2,
4929 trans->transid, 0);
4930 if (be_nice) {
4931 if (truncate_space_check(trans, root,
4932 extent_num_bytes)) {
4933 should_end = true;
4934 }
4935 if (btrfs_should_throttle_delayed_refs(trans,
4936 fs_info))
4937 should_throttle = true;
4938 }
4939 }
4940
4941 if (found_type == BTRFS_INODE_ITEM_KEY)
4942 break;
4943
4944 if (path->slots[0] == 0 ||
4945 path->slots[0] != pending_del_slot ||
4946 should_throttle || should_end) {
4947 if (pending_del_nr) {
4948 ret = btrfs_del_items(trans, root, path,
4949 pending_del_slot,
4950 pending_del_nr);
4951 if (ret) {
4952 btrfs_abort_transaction(trans, ret);
4953 goto error;
4954 }
4955 pending_del_nr = 0;
4956 }
4957 btrfs_release_path(path);
4958 if (should_throttle) {
4959 unsigned long updates = trans->delayed_ref_updates;
4960 if (updates) {
4961 trans->delayed_ref_updates = 0;
4962 ret = btrfs_run_delayed_refs(trans,
4963 updates * 2);
4964 if (ret && !err)
4965 err = ret;
4966 }
4967 }
4968 /*
4969 * if we failed to refill our space rsv, bail out
4970 * and let the transaction restart
4971 */
4972 if (should_end) {
4973 err = -EAGAIN;
4974 goto error;
4975 }
4976 goto search_again;
4977 } else {
4978 path->slots[0]--;
4979 }
4980 }
4981 out:
4982 if (pending_del_nr) {
4983 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4984 pending_del_nr);
4985 if (ret)
4986 btrfs_abort_transaction(trans, ret);
4987 }
4988 error:
4989 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
4990 ASSERT(last_size >= new_size);
4991 if (!err && last_size > new_size)
4992 last_size = new_size;
4993 btrfs_ordered_update_i_size(inode, last_size, NULL);
4994 }
4995
4996 btrfs_free_path(path);
4997
4998 if (be_nice && bytes_deleted > SZ_32M) {
4999 unsigned long updates = trans->delayed_ref_updates;
5000 if (updates) {
5001 trans->delayed_ref_updates = 0;
5002 ret = btrfs_run_delayed_refs(trans, updates * 2);
5003 if (ret && !err)
5004 err = ret;
5005 }
5006 }
5007 return err;
5008 }
5009
5010 /*
5011 * btrfs_truncate_block - read, zero a chunk and write a block
5012 * @inode - inode that we're zeroing
5013 * @from - the offset to start zeroing
5014 * @len - the length to zero, 0 to zero the entire range respective to the
5015 * offset
5016 * @front - zero up to the offset instead of from the offset on
5017 *
5018 * This will find the block for the "from" offset and cow the block and zero the
5019 * part we want to zero. This is used with truncate and hole punching.
5020 */
5021 int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len,
5022 int front)
5023 {
5024 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5025 struct address_space *mapping = inode->i_mapping;
5026 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5027 struct btrfs_ordered_extent *ordered;
5028 struct extent_state *cached_state = NULL;
5029 struct extent_changeset *data_reserved = NULL;
5030 char *kaddr;
5031 u32 blocksize = fs_info->sectorsize;
5032 pgoff_t index = from >> PAGE_SHIFT;
5033 unsigned offset = from & (blocksize - 1);
5034 struct page *page;
5035 gfp_t mask = btrfs_alloc_write_mask(mapping);
5036 int ret = 0;
5037 u64 block_start;
5038 u64 block_end;
5039
5040 if (IS_ALIGNED(offset, blocksize) &&
5041 (!len || IS_ALIGNED(len, blocksize)))
5042 goto out;
5043
5044 block_start = round_down(from, blocksize);
5045 block_end = block_start + blocksize - 1;
5046
5047 ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
5048 block_start, blocksize);
5049 if (ret)
5050 goto out;
5051
5052 again:
5053 page = find_or_create_page(mapping, index, mask);
5054 if (!page) {
5055 btrfs_delalloc_release_space(inode, data_reserved,
5056 block_start, blocksize, true);
5057 btrfs_delalloc_release_extents(BTRFS_I(inode), blocksize, true);
5058 ret = -ENOMEM;
5059 goto out;
5060 }
5061
5062 if (!PageUptodate(page)) {
5063 ret = btrfs_readpage(NULL, page);
5064 lock_page(page);
5065 if (page->mapping != mapping) {
5066 unlock_page(page);
5067 put_page(page);
5068 goto again;
5069 }
5070 if (!PageUptodate(page)) {
5071 ret = -EIO;
5072 goto out_unlock;
5073 }
5074 }
5075 wait_on_page_writeback(page);
5076
5077 lock_extent_bits(io_tree, block_start, block_end, &cached_state);
5078 set_page_extent_mapped(page);
5079
5080 ordered = btrfs_lookup_ordered_extent(inode, block_start);
5081 if (ordered) {
5082 unlock_extent_cached(io_tree, block_start, block_end,
5083 &cached_state);
5084 unlock_page(page);
5085 put_page(page);
5086 btrfs_start_ordered_extent(inode, ordered, 1);
5087 btrfs_put_ordered_extent(ordered);
5088 goto again;
5089 }
5090
5091 clear_extent_bit(&BTRFS_I(inode)->io_tree, block_start, block_end,
5092 EXTENT_DIRTY | EXTENT_DELALLOC |
5093 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
5094 0, 0, &cached_state);
5095
5096 ret = btrfs_set_extent_delalloc(inode, block_start, block_end, 0,
5097 &cached_state, 0);
5098 if (ret) {
5099 unlock_extent_cached(io_tree, block_start, block_end,
5100 &cached_state);
5101 goto out_unlock;
5102 }
5103
5104 if (offset != blocksize) {
5105 if (!len)
5106 len = blocksize - offset;
5107 kaddr = kmap(page);
5108 if (front)
5109 memset(kaddr + (block_start - page_offset(page)),
5110 0, offset);
5111 else
5112 memset(kaddr + (block_start - page_offset(page)) + offset,
5113 0, len);
5114 flush_dcache_page(page);
5115 kunmap(page);
5116 }
5117 ClearPageChecked(page);
5118 set_page_dirty(page);
5119 unlock_extent_cached(io_tree, block_start, block_end, &cached_state);
5120
5121 out_unlock:
5122 if (ret)
5123 btrfs_delalloc_release_space(inode, data_reserved, block_start,
5124 blocksize, true);
5125 btrfs_delalloc_release_extents(BTRFS_I(inode), blocksize, (ret != 0));
5126 unlock_page(page);
5127 put_page(page);
5128 out:
5129 extent_changeset_free(data_reserved);
5130 return ret;
5131 }
5132
5133 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
5134 u64 offset, u64 len)
5135 {
5136 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5137 struct btrfs_trans_handle *trans;
5138 int ret;
5139
5140 /*
5141 * Still need to make sure the inode looks like it's been updated so
5142 * that any holes get logged if we fsync.
5143 */
5144 if (btrfs_fs_incompat(fs_info, NO_HOLES)) {
5145 BTRFS_I(inode)->last_trans = fs_info->generation;
5146 BTRFS_I(inode)->last_sub_trans = root->log_transid;
5147 BTRFS_I(inode)->last_log_commit = root->last_log_commit;
5148 return 0;
5149 }
5150
5151 /*
5152 * 1 - for the one we're dropping
5153 * 1 - for the one we're adding
5154 * 1 - for updating the inode.
5155 */
5156 trans = btrfs_start_transaction(root, 3);
5157 if (IS_ERR(trans))
5158 return PTR_ERR(trans);
5159
5160 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
5161 if (ret) {
5162 btrfs_abort_transaction(trans, ret);
5163 btrfs_end_transaction(trans);
5164 return ret;
5165 }
5166
5167 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(BTRFS_I(inode)),
5168 offset, 0, 0, len, 0, len, 0, 0, 0);
5169 if (ret)
5170 btrfs_abort_transaction(trans, ret);
5171 else
5172 btrfs_update_inode(trans, root, inode);
5173 btrfs_end_transaction(trans);
5174 return ret;
5175 }
5176
5177 /*
5178 * This function puts in dummy file extents for the area we're creating a hole
5179 * for. So if we are truncating this file to a larger size we need to insert
5180 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
5181 * the range between oldsize and size
5182 */
5183 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
5184 {
5185 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5186 struct btrfs_root *root = BTRFS_I(inode)->root;
5187 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5188 struct extent_map *em = NULL;
5189 struct extent_state *cached_state = NULL;
5190 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
5191 u64 hole_start = ALIGN(oldsize, fs_info->sectorsize);
5192 u64 block_end = ALIGN(size, fs_info->sectorsize);
5193 u64 last_byte;
5194 u64 cur_offset;
5195 u64 hole_size;
5196 int err = 0;
5197
5198 /*
5199 * If our size started in the middle of a block we need to zero out the
5200 * rest of the block before we expand the i_size, otherwise we could
5201 * expose stale data.
5202 */
5203 err = btrfs_truncate_block(inode, oldsize, 0, 0);
5204 if (err)
5205 return err;
5206
5207 if (size <= hole_start)
5208 return 0;
5209
5210 while (1) {
5211 struct btrfs_ordered_extent *ordered;
5212
5213 lock_extent_bits(io_tree, hole_start, block_end - 1,
5214 &cached_state);
5215 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), hole_start,
5216 block_end - hole_start);
5217 if (!ordered)
5218 break;
5219 unlock_extent_cached(io_tree, hole_start, block_end - 1,
5220 &cached_state);
5221 btrfs_start_ordered_extent(inode, ordered, 1);
5222 btrfs_put_ordered_extent(ordered);
5223 }
5224
5225 cur_offset = hole_start;
5226 while (1) {
5227 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur_offset,
5228 block_end - cur_offset, 0);
5229 if (IS_ERR(em)) {
5230 err = PTR_ERR(em);
5231 em = NULL;
5232 break;
5233 }
5234 last_byte = min(extent_map_end(em), block_end);
5235 last_byte = ALIGN(last_byte, fs_info->sectorsize);
5236 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
5237 struct extent_map *hole_em;
5238 hole_size = last_byte - cur_offset;
5239
5240 err = maybe_insert_hole(root, inode, cur_offset,
5241 hole_size);
5242 if (err)
5243 break;
5244 btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
5245 cur_offset + hole_size - 1, 0);
5246 hole_em = alloc_extent_map();
5247 if (!hole_em) {
5248 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
5249 &BTRFS_I(inode)->runtime_flags);
5250 goto next;
5251 }
5252 hole_em->start = cur_offset;
5253 hole_em->len = hole_size;
5254 hole_em->orig_start = cur_offset;
5255
5256 hole_em->block_start = EXTENT_MAP_HOLE;
5257 hole_em->block_len = 0;
5258 hole_em->orig_block_len = 0;
5259 hole_em->ram_bytes = hole_size;
5260 hole_em->bdev = fs_info->fs_devices->latest_bdev;
5261 hole_em->compress_type = BTRFS_COMPRESS_NONE;
5262 hole_em->generation = fs_info->generation;
5263
5264 while (1) {
5265 write_lock(&em_tree->lock);
5266 err = add_extent_mapping(em_tree, hole_em, 1);
5267 write_unlock(&em_tree->lock);
5268 if (err != -EEXIST)
5269 break;
5270 btrfs_drop_extent_cache(BTRFS_I(inode),
5271 cur_offset,
5272 cur_offset +
5273 hole_size - 1, 0);
5274 }
5275 free_extent_map(hole_em);
5276 }
5277 next:
5278 free_extent_map(em);
5279 em = NULL;
5280 cur_offset = last_byte;
5281 if (cur_offset >= block_end)
5282 break;
5283 }
5284 free_extent_map(em);
5285 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state);
5286 return err;
5287 }
5288
5289 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
5290 {
5291 struct btrfs_root *root = BTRFS_I(inode)->root;
5292 struct btrfs_trans_handle *trans;
5293 loff_t oldsize = i_size_read(inode);
5294 loff_t newsize = attr->ia_size;
5295 int mask = attr->ia_valid;
5296 int ret;
5297
5298 /*
5299 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
5300 * special case where we need to update the times despite not having
5301 * these flags set. For all other operations the VFS set these flags
5302 * explicitly if it wants a timestamp update.
5303 */
5304 if (newsize != oldsize) {
5305 inode_inc_iversion(inode);
5306 if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
5307 inode->i_ctime = inode->i_mtime =
5308 current_time(inode);
5309 }
5310
5311 if (newsize > oldsize) {
5312 /*
5313 * Don't do an expanding truncate while snapshotting is ongoing.
5314 * This is to ensure the snapshot captures a fully consistent
5315 * state of this file - if the snapshot captures this expanding
5316 * truncation, it must capture all writes that happened before
5317 * this truncation.
5318 */
5319 btrfs_wait_for_snapshot_creation(root);
5320 ret = btrfs_cont_expand(inode, oldsize, newsize);
5321 if (ret) {
5322 btrfs_end_write_no_snapshotting(root);
5323 return ret;
5324 }
5325
5326 trans = btrfs_start_transaction(root, 1);
5327 if (IS_ERR(trans)) {
5328 btrfs_end_write_no_snapshotting(root);
5329 return PTR_ERR(trans);
5330 }
5331
5332 i_size_write(inode, newsize);
5333 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
5334 pagecache_isize_extended(inode, oldsize, newsize);
5335 ret = btrfs_update_inode(trans, root, inode);
5336 btrfs_end_write_no_snapshotting(root);
5337 btrfs_end_transaction(trans);
5338 } else {
5339
5340 /*
5341 * We're truncating a file that used to have good data down to
5342 * zero. Make sure it gets into the ordered flush list so that
5343 * any new writes get down to disk quickly.
5344 */
5345 if (newsize == 0)
5346 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
5347 &BTRFS_I(inode)->runtime_flags);
5348
5349 /*
5350 * 1 for the orphan item we're going to add
5351 * 1 for the orphan item deletion.
5352 */
5353 trans = btrfs_start_transaction(root, 2);
5354 if (IS_ERR(trans))
5355 return PTR_ERR(trans);
5356
5357 /*
5358 * We need to do this in case we fail at _any_ point during the
5359 * actual truncate. Once we do the truncate_setsize we could
5360 * invalidate pages which forces any outstanding ordered io to
5361 * be instantly completed which will give us extents that need
5362 * to be truncated. If we fail to get an orphan inode down we
5363 * could have left over extents that were never meant to live,
5364 * so we need to guarantee from this point on that everything
5365 * will be consistent.
5366 */
5367 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
5368 btrfs_end_transaction(trans);
5369 if (ret)
5370 return ret;
5371
5372 /* we don't support swapfiles, so vmtruncate shouldn't fail */
5373 truncate_setsize(inode, newsize);
5374
5375 /* Disable nonlocked read DIO to avoid the end less truncate */
5376 btrfs_inode_block_unlocked_dio(BTRFS_I(inode));
5377 inode_dio_wait(inode);
5378 btrfs_inode_resume_unlocked_dio(BTRFS_I(inode));
5379
5380 ret = btrfs_truncate(inode, newsize == oldsize);
5381 if (ret && inode->i_nlink) {
5382 int err;
5383
5384 /* To get a stable disk_i_size */
5385 err = btrfs_wait_ordered_range(inode, 0, (u64)-1);
5386 if (err) {
5387 btrfs_orphan_del(NULL, BTRFS_I(inode));
5388 return err;
5389 }
5390
5391 /*
5392 * failed to truncate, disk_i_size is only adjusted down
5393 * as we remove extents, so it should represent the true
5394 * size of the inode, so reset the in memory size and
5395 * delete our orphan entry.
5396 */
5397 trans = btrfs_join_transaction(root);
5398 if (IS_ERR(trans)) {
5399 btrfs_orphan_del(NULL, BTRFS_I(inode));
5400 return ret;
5401 }
5402 i_size_write(inode, BTRFS_I(inode)->disk_i_size);
5403 err = btrfs_orphan_del(trans, BTRFS_I(inode));
5404 if (err)
5405 btrfs_abort_transaction(trans, err);
5406 btrfs_end_transaction(trans);
5407 }
5408 }
5409
5410 return ret;
5411 }
5412
5413 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
5414 {
5415 struct inode *inode = d_inode(dentry);
5416 struct btrfs_root *root = BTRFS_I(inode)->root;
5417 int err;
5418
5419 if (btrfs_root_readonly(root))
5420 return -EROFS;
5421
5422 err = setattr_prepare(dentry, attr);
5423 if (err)
5424 return err;
5425
5426 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
5427 err = btrfs_setsize(inode, attr);
5428 if (err)
5429 return err;
5430 }
5431
5432 if (attr->ia_valid) {
5433 setattr_copy(inode, attr);
5434 inode_inc_iversion(inode);
5435 err = btrfs_dirty_inode(inode);
5436
5437 if (!err && attr->ia_valid & ATTR_MODE)
5438 err = posix_acl_chmod(inode, inode->i_mode);
5439 }
5440
5441 return err;
5442 }
5443
5444 /*
5445 * While truncating the inode pages during eviction, we get the VFS calling
5446 * btrfs_invalidatepage() against each page of the inode. This is slow because
5447 * the calls to btrfs_invalidatepage() result in a huge amount of calls to
5448 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
5449 * extent_state structures over and over, wasting lots of time.
5450 *
5451 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
5452 * those expensive operations on a per page basis and do only the ordered io
5453 * finishing, while we release here the extent_map and extent_state structures,
5454 * without the excessive merging and splitting.
5455 */
5456 static void evict_inode_truncate_pages(struct inode *inode)
5457 {
5458 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5459 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
5460 struct rb_node *node;
5461
5462 ASSERT(inode->i_state & I_FREEING);
5463 truncate_inode_pages_final(&inode->i_data);
5464
5465 write_lock(&map_tree->lock);
5466 while (!RB_EMPTY_ROOT(&map_tree->map)) {
5467 struct extent_map *em;
5468
5469 node = rb_first(&map_tree->map);
5470 em = rb_entry(node, struct extent_map, rb_node);
5471 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
5472 clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
5473 remove_extent_mapping(map_tree, em);
5474 free_extent_map(em);
5475 if (need_resched()) {
5476 write_unlock(&map_tree->lock);
5477 cond_resched();
5478 write_lock(&map_tree->lock);
5479 }
5480 }
5481 write_unlock(&map_tree->lock);
5482
5483 /*
5484 * Keep looping until we have no more ranges in the io tree.
5485 * We can have ongoing bios started by readpages (called from readahead)
5486 * that have their endio callback (extent_io.c:end_bio_extent_readpage)
5487 * still in progress (unlocked the pages in the bio but did not yet
5488 * unlocked the ranges in the io tree). Therefore this means some
5489 * ranges can still be locked and eviction started because before
5490 * submitting those bios, which are executed by a separate task (work
5491 * queue kthread), inode references (inode->i_count) were not taken
5492 * (which would be dropped in the end io callback of each bio).
5493 * Therefore here we effectively end up waiting for those bios and
5494 * anyone else holding locked ranges without having bumped the inode's
5495 * reference count - if we don't do it, when they access the inode's
5496 * io_tree to unlock a range it may be too late, leading to an
5497 * use-after-free issue.
5498 */
5499 spin_lock(&io_tree->lock);
5500 while (!RB_EMPTY_ROOT(&io_tree->state)) {
5501 struct extent_state *state;
5502 struct extent_state *cached_state = NULL;
5503 u64 start;
5504 u64 end;
5505
5506 node = rb_first(&io_tree->state);
5507 state = rb_entry(node, struct extent_state, rb_node);
5508 start = state->start;
5509 end = state->end;
5510 spin_unlock(&io_tree->lock);
5511
5512 lock_extent_bits(io_tree, start, end, &cached_state);
5513
5514 /*
5515 * If still has DELALLOC flag, the extent didn't reach disk,
5516 * and its reserved space won't be freed by delayed_ref.
5517 * So we need to free its reserved space here.
5518 * (Refer to comment in btrfs_invalidatepage, case 2)
5519 *
5520 * Note, end is the bytenr of last byte, so we need + 1 here.
5521 */
5522 if (state->state & EXTENT_DELALLOC)
5523 btrfs_qgroup_free_data(inode, NULL, start, end - start + 1);
5524
5525 clear_extent_bit(io_tree, start, end,
5526 EXTENT_LOCKED | EXTENT_DIRTY |
5527 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
5528 EXTENT_DEFRAG, 1, 1, &cached_state);
5529
5530 cond_resched();
5531 spin_lock(&io_tree->lock);
5532 }
5533 spin_unlock(&io_tree->lock);
5534 }
5535
5536 void btrfs_evict_inode(struct inode *inode)
5537 {
5538 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5539 struct btrfs_trans_handle *trans;
5540 struct btrfs_root *root = BTRFS_I(inode)->root;
5541 struct btrfs_block_rsv *rsv, *global_rsv;
5542 int steal_from_global = 0;
5543 u64 min_size;
5544 int ret;
5545
5546 trace_btrfs_inode_evict(inode);
5547
5548 if (!root) {
5549 clear_inode(inode);
5550 return;
5551 }
5552
5553 min_size = btrfs_calc_trunc_metadata_size(fs_info, 1);
5554
5555 evict_inode_truncate_pages(inode);
5556
5557 if (inode->i_nlink &&
5558 ((btrfs_root_refs(&root->root_item) != 0 &&
5559 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
5560 btrfs_is_free_space_inode(BTRFS_I(inode))))
5561 goto no_delete;
5562
5563 if (is_bad_inode(inode)) {
5564 btrfs_orphan_del(NULL, BTRFS_I(inode));
5565 goto no_delete;
5566 }
5567 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
5568 if (!special_file(inode->i_mode))
5569 btrfs_wait_ordered_range(inode, 0, (u64)-1);
5570
5571 btrfs_free_io_failure_record(BTRFS_I(inode), 0, (u64)-1);
5572
5573 if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) {
5574 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
5575 &BTRFS_I(inode)->runtime_flags));
5576 goto no_delete;
5577 }
5578
5579 if (inode->i_nlink > 0) {
5580 BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
5581 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
5582 goto no_delete;
5583 }
5584
5585 ret = btrfs_commit_inode_delayed_inode(BTRFS_I(inode));
5586 if (ret) {
5587 btrfs_orphan_del(NULL, BTRFS_I(inode));
5588 goto no_delete;
5589 }
5590
5591 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
5592 if (!rsv) {
5593 btrfs_orphan_del(NULL, BTRFS_I(inode));
5594 goto no_delete;
5595 }
5596 rsv->size = min_size;
5597 rsv->failfast = 1;
5598 global_rsv = &fs_info->global_block_rsv;
5599
5600 btrfs_i_size_write(BTRFS_I(inode), 0);
5601
5602 /*
5603 * This is a bit simpler than btrfs_truncate since we've already
5604 * reserved our space for our orphan item in the unlink, so we just
5605 * need to reserve some slack space in case we add bytes and update
5606 * inode item when doing the truncate.
5607 */
5608 while (1) {
5609 ret = btrfs_block_rsv_refill(root, rsv, min_size,
5610 BTRFS_RESERVE_FLUSH_LIMIT);
5611
5612 /*
5613 * Try and steal from the global reserve since we will
5614 * likely not use this space anyway, we want to try as
5615 * hard as possible to get this to work.
5616 */
5617 if (ret)
5618 steal_from_global++;
5619 else
5620 steal_from_global = 0;
5621 ret = 0;
5622
5623 /*
5624 * steal_from_global == 0: we reserved stuff, hooray!
5625 * steal_from_global == 1: we didn't reserve stuff, boo!
5626 * steal_from_global == 2: we've committed, still not a lot of
5627 * room but maybe we'll have room in the global reserve this
5628 * time.
5629 * steal_from_global == 3: abandon all hope!
5630 */
5631 if (steal_from_global > 2) {
5632 btrfs_warn(fs_info,
5633 "Could not get space for a delete, will truncate on mount %d",
5634 ret);
5635 btrfs_orphan_del(NULL, BTRFS_I(inode));
5636 btrfs_free_block_rsv(fs_info, rsv);
5637 goto no_delete;
5638 }
5639
5640 trans = btrfs_join_transaction(root);
5641 if (IS_ERR(trans)) {
5642 btrfs_orphan_del(NULL, BTRFS_I(inode));
5643 btrfs_free_block_rsv(fs_info, rsv);
5644 goto no_delete;
5645 }
5646
5647 /*
5648 * We can't just steal from the global reserve, we need to make
5649 * sure there is room to do it, if not we need to commit and try
5650 * again.
5651 */
5652 if (steal_from_global) {
5653 if (!btrfs_check_space_for_delayed_refs(trans, fs_info))
5654 ret = btrfs_block_rsv_migrate(global_rsv, rsv,
5655 min_size, 0);
5656 else
5657 ret = -ENOSPC;
5658 }
5659
5660 /*
5661 * Couldn't steal from the global reserve, we have too much
5662 * pending stuff built up, commit the transaction and try it
5663 * again.
5664 */
5665 if (ret) {
5666 ret = btrfs_commit_transaction(trans);
5667 if (ret) {
5668 btrfs_orphan_del(NULL, BTRFS_I(inode));
5669 btrfs_free_block_rsv(fs_info, rsv);
5670 goto no_delete;
5671 }
5672 continue;
5673 } else {
5674 steal_from_global = 0;
5675 }
5676
5677 trans->block_rsv = rsv;
5678
5679 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
5680 if (ret != -ENOSPC && ret != -EAGAIN)
5681 break;
5682
5683 trans->block_rsv = &fs_info->trans_block_rsv;
5684 btrfs_end_transaction(trans);
5685 trans = NULL;
5686 btrfs_btree_balance_dirty(fs_info);
5687 }
5688
5689 btrfs_free_block_rsv(fs_info, rsv);
5690
5691 /*
5692 * Errors here aren't a big deal, it just means we leave orphan items
5693 * in the tree. They will be cleaned up on the next mount.
5694 */
5695 if (ret == 0) {
5696 trans->block_rsv = root->orphan_block_rsv;
5697 btrfs_orphan_del(trans, BTRFS_I(inode));
5698 } else {
5699 btrfs_orphan_del(NULL, BTRFS_I(inode));
5700 }
5701
5702 trans->block_rsv = &fs_info->trans_block_rsv;
5703 if (!(root == fs_info->tree_root ||
5704 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
5705 btrfs_return_ino(root, btrfs_ino(BTRFS_I(inode)));
5706
5707 btrfs_end_transaction(trans);
5708 btrfs_btree_balance_dirty(fs_info);
5709 no_delete:
5710 btrfs_remove_delayed_node(BTRFS_I(inode));
5711 clear_inode(inode);
5712 }
5713
5714 /*
5715 * this returns the key found in the dir entry in the location pointer.
5716 * If no dir entries were found, returns -ENOENT.
5717 * If found a corrupted location in dir entry, returns -EUCLEAN.
5718 */
5719 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
5720 struct btrfs_key *location)
5721 {
5722 const char *name = dentry->d_name.name;
5723 int namelen = dentry->d_name.len;
5724 struct btrfs_dir_item *di;
5725 struct btrfs_path *path;
5726 struct btrfs_root *root = BTRFS_I(dir)->root;
5727 int ret = 0;
5728
5729 path = btrfs_alloc_path();
5730 if (!path)
5731 return -ENOMEM;
5732
5733 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(BTRFS_I(dir)),
5734 name, namelen, 0);
5735 if (!di) {
5736 ret = -ENOENT;
5737 goto out;
5738 }
5739 if (IS_ERR(di)) {
5740 ret = PTR_ERR(di);
5741 goto out;
5742 }
5743
5744 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
5745 if (location->type != BTRFS_INODE_ITEM_KEY &&
5746 location->type != BTRFS_ROOT_ITEM_KEY) {
5747 ret = -EUCLEAN;
5748 btrfs_warn(root->fs_info,
5749 "%s gets something invalid in DIR_ITEM (name %s, directory ino %llu, location(%llu %u %llu))",
5750 __func__, name, btrfs_ino(BTRFS_I(dir)),
5751 location->objectid, location->type, location->offset);
5752 }
5753 out:
5754 btrfs_free_path(path);
5755 return ret;
5756 }
5757
5758 /*
5759 * when we hit a tree root in a directory, the btrfs part of the inode
5760 * needs to be changed to reflect the root directory of the tree root. This
5761 * is kind of like crossing a mount point.
5762 */
5763 static int fixup_tree_root_location(struct btrfs_fs_info *fs_info,
5764 struct inode *dir,
5765 struct dentry *dentry,
5766 struct btrfs_key *location,
5767 struct btrfs_root **sub_root)
5768 {
5769 struct btrfs_path *path;
5770 struct btrfs_root *new_root;
5771 struct btrfs_root_ref *ref;
5772 struct extent_buffer *leaf;
5773 struct btrfs_key key;
5774 int ret;
5775 int err = 0;
5776
5777 path = btrfs_alloc_path();
5778 if (!path) {
5779 err = -ENOMEM;
5780 goto out;
5781 }
5782
5783 err = -ENOENT;
5784 key.objectid = BTRFS_I(dir)->root->root_key.objectid;
5785 key.type = BTRFS_ROOT_REF_KEY;
5786 key.offset = location->objectid;
5787
5788 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
5789 if (ret) {
5790 if (ret < 0)
5791 err = ret;
5792 goto out;
5793 }
5794
5795 leaf = path->nodes[0];
5796 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
5797 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(BTRFS_I(dir)) ||
5798 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
5799 goto out;
5800
5801 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
5802 (unsigned long)(ref + 1),
5803 dentry->d_name.len);
5804 if (ret)
5805 goto out;
5806
5807 btrfs_release_path(path);
5808
5809 new_root = btrfs_read_fs_root_no_name(fs_info, location);
5810 if (IS_ERR(new_root)) {
5811 err = PTR_ERR(new_root);
5812 goto out;
5813 }
5814
5815 *sub_root = new_root;
5816 location->objectid = btrfs_root_dirid(&new_root->root_item);
5817 location->type = BTRFS_INODE_ITEM_KEY;
5818 location->offset = 0;
5819 err = 0;
5820 out:
5821 btrfs_free_path(path);
5822 return err;
5823 }
5824
5825 static void inode_tree_add(struct inode *inode)
5826 {
5827 struct btrfs_root *root = BTRFS_I(inode)->root;
5828 struct btrfs_inode *entry;
5829 struct rb_node **p;
5830 struct rb_node *parent;
5831 struct rb_node *new = &BTRFS_I(inode)->rb_node;
5832 u64 ino = btrfs_ino(BTRFS_I(inode));
5833
5834 if (inode_unhashed(inode))
5835 return;
5836 parent = NULL;
5837 spin_lock(&root->inode_lock);
5838 p = &root->inode_tree.rb_node;
5839 while (*p) {
5840 parent = *p;
5841 entry = rb_entry(parent, struct btrfs_inode, rb_node);
5842
5843 if (ino < btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5844 p = &parent->rb_left;
5845 else if (ino > btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5846 p = &parent->rb_right;
5847 else {
5848 WARN_ON(!(entry->vfs_inode.i_state &
5849 (I_WILL_FREE | I_FREEING)));
5850 rb_replace_node(parent, new, &root->inode_tree);
5851 RB_CLEAR_NODE(parent);
5852 spin_unlock(&root->inode_lock);
5853 return;
5854 }
5855 }
5856 rb_link_node(new, parent, p);
5857 rb_insert_color(new, &root->inode_tree);
5858 spin_unlock(&root->inode_lock);
5859 }
5860
5861 static void inode_tree_del(struct inode *inode)
5862 {
5863 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5864 struct btrfs_root *root = BTRFS_I(inode)->root;
5865 int empty = 0;
5866
5867 spin_lock(&root->inode_lock);
5868 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
5869 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
5870 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
5871 empty = RB_EMPTY_ROOT(&root->inode_tree);
5872 }
5873 spin_unlock(&root->inode_lock);
5874
5875 if (empty && btrfs_root_refs(&root->root_item) == 0) {
5876 synchronize_srcu(&fs_info->subvol_srcu);
5877 spin_lock(&root->inode_lock);
5878 empty = RB_EMPTY_ROOT(&root->inode_tree);
5879 spin_unlock(&root->inode_lock);
5880 if (empty)
5881 btrfs_add_dead_root(root);
5882 }
5883 }
5884
5885
5886 static int btrfs_init_locked_inode(struct inode *inode, void *p)
5887 {
5888 struct btrfs_iget_args *args = p;
5889 inode->i_ino = args->location->objectid;
5890 memcpy(&BTRFS_I(inode)->location, args->location,
5891 sizeof(*args->location));
5892 BTRFS_I(inode)->root = args->root;
5893 return 0;
5894 }
5895
5896 static int btrfs_find_actor(struct inode *inode, void *opaque)
5897 {
5898 struct btrfs_iget_args *args = opaque;
5899 return args->location->objectid == BTRFS_I(inode)->location.objectid &&
5900 args->root == BTRFS_I(inode)->root;
5901 }
5902
5903 static struct inode *btrfs_iget_locked(struct super_block *s,
5904 struct btrfs_key *location,
5905 struct btrfs_root *root)
5906 {
5907 struct inode *inode;
5908 struct btrfs_iget_args args;
5909 unsigned long hashval = btrfs_inode_hash(location->objectid, root);
5910
5911 args.location = location;
5912 args.root = root;
5913
5914 inode = iget5_locked(s, hashval, btrfs_find_actor,
5915 btrfs_init_locked_inode,
5916 (void *)&args);
5917 return inode;
5918 }
5919
5920 /* Get an inode object given its location and corresponding root.
5921 * Returns in *is_new if the inode was read from disk
5922 */
5923 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
5924 struct btrfs_root *root, int *new)
5925 {
5926 struct inode *inode;
5927
5928 inode = btrfs_iget_locked(s, location, root);
5929 if (!inode)
5930 return ERR_PTR(-ENOMEM);
5931
5932 if (inode->i_state & I_NEW) {
5933 int ret;
5934
5935 ret = btrfs_read_locked_inode(inode);
5936 if (!is_bad_inode(inode)) {
5937 inode_tree_add(inode);
5938 unlock_new_inode(inode);
5939 if (new)
5940 *new = 1;
5941 } else {
5942 unlock_new_inode(inode);
5943 iput(inode);
5944 ASSERT(ret < 0);
5945 inode = ERR_PTR(ret < 0 ? ret : -ESTALE);
5946 }
5947 }
5948
5949 return inode;
5950 }
5951
5952 static struct inode *new_simple_dir(struct super_block *s,
5953 struct btrfs_key *key,
5954 struct btrfs_root *root)
5955 {
5956 struct inode *inode = new_inode(s);
5957
5958 if (!inode)
5959 return ERR_PTR(-ENOMEM);
5960
5961 BTRFS_I(inode)->root = root;
5962 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5963 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5964
5965 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5966 inode->i_op = &btrfs_dir_ro_inode_operations;
5967 inode->i_opflags &= ~IOP_XATTR;
5968 inode->i_fop = &simple_dir_operations;
5969 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5970 inode->i_mtime = current_time(inode);
5971 inode->i_atime = inode->i_mtime;
5972 inode->i_ctime = inode->i_mtime;
5973 BTRFS_I(inode)->i_otime = inode->i_mtime;
5974
5975 return inode;
5976 }
5977
5978 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5979 {
5980 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
5981 struct inode *inode;
5982 struct btrfs_root *root = BTRFS_I(dir)->root;
5983 struct btrfs_root *sub_root = root;
5984 struct btrfs_key location;
5985 int index;
5986 int ret = 0;
5987
5988 if (dentry->d_name.len > BTRFS_NAME_LEN)
5989 return ERR_PTR(-ENAMETOOLONG);
5990
5991 ret = btrfs_inode_by_name(dir, dentry, &location);
5992 if (ret < 0)
5993 return ERR_PTR(ret);
5994
5995 if (location.type == BTRFS_INODE_ITEM_KEY) {
5996 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5997 return inode;
5998 }
5999
6000 index = srcu_read_lock(&fs_info->subvol_srcu);
6001 ret = fixup_tree_root_location(fs_info, dir, dentry,
6002 &location, &sub_root);
6003 if (ret < 0) {
6004 if (ret != -ENOENT)
6005 inode = ERR_PTR(ret);
6006 else
6007 inode = new_simple_dir(dir->i_sb, &location, sub_root);
6008 } else {
6009 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
6010 }
6011 srcu_read_unlock(&fs_info->subvol_srcu, index);
6012
6013 if (!IS_ERR(inode) && root != sub_root) {
6014 down_read(&fs_info->cleanup_work_sem);
6015 if (!sb_rdonly(inode->i_sb))
6016 ret = btrfs_orphan_cleanup(sub_root);
6017 up_read(&fs_info->cleanup_work_sem);
6018 if (ret) {
6019 iput(inode);
6020 inode = ERR_PTR(ret);
6021 }
6022 }
6023
6024 return inode;
6025 }
6026
6027 static int btrfs_dentry_delete(const struct dentry *dentry)
6028 {
6029 struct btrfs_root *root;
6030 struct inode *inode = d_inode(dentry);
6031
6032 if (!inode && !IS_ROOT(dentry))
6033 inode = d_inode(dentry->d_parent);
6034
6035 if (inode) {
6036 root = BTRFS_I(inode)->root;
6037 if (btrfs_root_refs(&root->root_item) == 0)
6038 return 1;
6039
6040 if (btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
6041 return 1;
6042 }
6043 return 0;
6044 }
6045
6046 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
6047 unsigned int flags)
6048 {
6049 struct inode *inode;
6050
6051 inode = btrfs_lookup_dentry(dir, dentry);
6052 if (IS_ERR(inode)) {
6053 if (PTR_ERR(inode) == -ENOENT)
6054 inode = NULL;
6055 else
6056 return ERR_CAST(inode);
6057 }
6058
6059 return d_splice_alias(inode, dentry);
6060 }
6061
6062 unsigned char btrfs_filetype_table[] = {
6063 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
6064 };
6065
6066 /*
6067 * All this infrastructure exists because dir_emit can fault, and we are holding
6068 * the tree lock when doing readdir. For now just allocate a buffer and copy
6069 * our information into that, and then dir_emit from the buffer. This is
6070 * similar to what NFS does, only we don't keep the buffer around in pagecache
6071 * because I'm afraid I'll mess that up. Long term we need to make filldir do
6072 * copy_to_user_inatomic so we don't have to worry about page faulting under the
6073 * tree lock.
6074 */
6075 static int btrfs_opendir(struct inode *inode, struct file *file)
6076 {
6077 struct btrfs_file_private *private;
6078
6079 private = kzalloc(sizeof(struct btrfs_file_private), GFP_KERNEL);
6080 if (!private)
6081 return -ENOMEM;
6082 private->filldir_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
6083 if (!private->filldir_buf) {
6084 kfree(private);
6085 return -ENOMEM;
6086 }
6087 file->private_data = private;
6088 return 0;
6089 }
6090
6091 struct dir_entry {
6092 u64 ino;
6093 u64 offset;
6094 unsigned type;
6095 int name_len;
6096 };
6097
6098 static int btrfs_filldir(void *addr, int entries, struct dir_context *ctx)
6099 {
6100 while (entries--) {
6101 struct dir_entry *entry = addr;
6102 char *name = (char *)(entry + 1);
6103
6104 ctx->pos = get_unaligned(&entry->offset);
6105 if (!dir_emit(ctx, name, get_unaligned(&entry->name_len),
6106 get_unaligned(&entry->ino),
6107 get_unaligned(&entry->type)))
6108 return 1;
6109 addr += sizeof(struct dir_entry) +
6110 get_unaligned(&entry->name_len);
6111 ctx->pos++;
6112 }
6113 return 0;
6114 }
6115
6116 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
6117 {
6118 struct inode *inode = file_inode(file);
6119 struct btrfs_root *root = BTRFS_I(inode)->root;
6120 struct btrfs_file_private *private = file->private_data;
6121 struct btrfs_dir_item *di;
6122 struct btrfs_key key;
6123 struct btrfs_key found_key;
6124 struct btrfs_path *path;
6125 void *addr;
6126 struct list_head ins_list;
6127 struct list_head del_list;
6128 int ret;
6129 struct extent_buffer *leaf;
6130 int slot;
6131 char *name_ptr;
6132 int name_len;
6133 int entries = 0;
6134 int total_len = 0;
6135 bool put = false;
6136 struct btrfs_key location;
6137
6138 if (!dir_emit_dots(file, ctx))
6139 return 0;
6140
6141 path = btrfs_alloc_path();
6142 if (!path)
6143 return -ENOMEM;
6144
6145 addr = private->filldir_buf;
6146 path->reada = READA_FORWARD;
6147
6148 INIT_LIST_HEAD(&ins_list);
6149 INIT_LIST_HEAD(&del_list);
6150 put = btrfs_readdir_get_delayed_items(inode, &ins_list, &del_list);
6151
6152 again:
6153 key.type = BTRFS_DIR_INDEX_KEY;
6154 key.offset = ctx->pos;
6155 key.objectid = btrfs_ino(BTRFS_I(inode));
6156
6157 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6158 if (ret < 0)
6159 goto err;
6160
6161 while (1) {
6162 struct dir_entry *entry;
6163
6164 leaf = path->nodes[0];
6165 slot = path->slots[0];
6166 if (slot >= btrfs_header_nritems(leaf)) {
6167 ret = btrfs_next_leaf(root, path);
6168 if (ret < 0)
6169 goto err;
6170 else if (ret > 0)
6171 break;
6172 continue;
6173 }
6174
6175 btrfs_item_key_to_cpu(leaf, &found_key, slot);
6176
6177 if (found_key.objectid != key.objectid)
6178 break;
6179 if (found_key.type != BTRFS_DIR_INDEX_KEY)
6180 break;
6181 if (found_key.offset < ctx->pos)
6182 goto next;
6183 if (btrfs_should_delete_dir_index(&del_list, found_key.offset))
6184 goto next;
6185 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
6186 name_len = btrfs_dir_name_len(leaf, di);
6187 if ((total_len + sizeof(struct dir_entry) + name_len) >=
6188 PAGE_SIZE) {
6189 btrfs_release_path(path);
6190 ret = btrfs_filldir(private->filldir_buf, entries, ctx);
6191 if (ret)
6192 goto nopos;
6193 addr = private->filldir_buf;
6194 entries = 0;
6195 total_len = 0;
6196 goto again;
6197 }
6198
6199 entry = addr;
6200 put_unaligned(name_len, &entry->name_len);
6201 name_ptr = (char *)(entry + 1);
6202 read_extent_buffer(leaf, name_ptr, (unsigned long)(di + 1),
6203 name_len);
6204 put_unaligned(btrfs_filetype_table[btrfs_dir_type(leaf, di)],
6205 &entry->type);
6206 btrfs_dir_item_key_to_cpu(leaf, di, &location);
6207 put_unaligned(location.objectid, &entry->ino);
6208 put_unaligned(found_key.offset, &entry->offset);
6209 entries++;
6210 addr += sizeof(struct dir_entry) + name_len;
6211 total_len += sizeof(struct dir_entry) + name_len;
6212 next:
6213 path->slots[0]++;
6214 }
6215 btrfs_release_path(path);
6216
6217 ret = btrfs_filldir(private->filldir_buf, entries, ctx);
6218 if (ret)
6219 goto nopos;
6220
6221 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
6222 if (ret)
6223 goto nopos;
6224
6225 /*
6226 * Stop new entries from being returned after we return the last
6227 * entry.
6228 *
6229 * New directory entries are assigned a strictly increasing
6230 * offset. This means that new entries created during readdir
6231 * are *guaranteed* to be seen in the future by that readdir.
6232 * This has broken buggy programs which operate on names as
6233 * they're returned by readdir. Until we re-use freed offsets
6234 * we have this hack to stop new entries from being returned
6235 * under the assumption that they'll never reach this huge
6236 * offset.
6237 *
6238 * This is being careful not to overflow 32bit loff_t unless the
6239 * last entry requires it because doing so has broken 32bit apps
6240 * in the past.
6241 */
6242 if (ctx->pos >= INT_MAX)
6243 ctx->pos = LLONG_MAX;
6244 else
6245 ctx->pos = INT_MAX;
6246 nopos:
6247 ret = 0;
6248 err:
6249 if (put)
6250 btrfs_readdir_put_delayed_items(inode, &ins_list, &del_list);
6251 btrfs_free_path(path);
6252 return ret;
6253 }
6254
6255 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
6256 {
6257 struct btrfs_root *root = BTRFS_I(inode)->root;
6258 struct btrfs_trans_handle *trans;
6259 int ret = 0;
6260 bool nolock = false;
6261
6262 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
6263 return 0;
6264
6265 if (btrfs_fs_closing(root->fs_info) &&
6266 btrfs_is_free_space_inode(BTRFS_I(inode)))
6267 nolock = true;
6268
6269 if (wbc->sync_mode == WB_SYNC_ALL) {
6270 if (nolock)
6271 trans = btrfs_join_transaction_nolock(root);
6272 else
6273 trans = btrfs_join_transaction(root);
6274 if (IS_ERR(trans))
6275 return PTR_ERR(trans);
6276 ret = btrfs_commit_transaction(trans);
6277 }
6278 return ret;
6279 }
6280
6281 /*
6282 * This is somewhat expensive, updating the tree every time the
6283 * inode changes. But, it is most likely to find the inode in cache.
6284 * FIXME, needs more benchmarking...there are no reasons other than performance
6285 * to keep or drop this code.
6286 */
6287 static int btrfs_dirty_inode(struct inode *inode)
6288 {
6289 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
6290 struct btrfs_root *root = BTRFS_I(inode)->root;
6291 struct btrfs_trans_handle *trans;
6292 int ret;
6293
6294 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
6295 return 0;
6296
6297 trans = btrfs_join_transaction(root);
6298 if (IS_ERR(trans))
6299 return PTR_ERR(trans);
6300
6301 ret = btrfs_update_inode(trans, root, inode);
6302 if (ret && ret == -ENOSPC) {
6303 /* whoops, lets try again with the full transaction */
6304 btrfs_end_transaction(trans);
6305 trans = btrfs_start_transaction(root, 1);
6306 if (IS_ERR(trans))
6307 return PTR_ERR(trans);
6308
6309 ret = btrfs_update_inode(trans, root, inode);
6310 }
6311 btrfs_end_transaction(trans);
6312 if (BTRFS_I(inode)->delayed_node)
6313 btrfs_balance_delayed_items(fs_info);
6314
6315 return ret;
6316 }
6317
6318 /*
6319 * This is a copy of file_update_time. We need this so we can return error on
6320 * ENOSPC for updating the inode in the case of file write and mmap writes.
6321 */
6322 static int btrfs_update_time(struct inode *inode, struct timespec *now,
6323 int flags)
6324 {
6325 struct btrfs_root *root = BTRFS_I(inode)->root;
6326 bool dirty = flags & ~S_VERSION;
6327
6328 if (btrfs_root_readonly(root))
6329 return -EROFS;
6330
6331 if (flags & S_VERSION)
6332 dirty |= inode_maybe_inc_iversion(inode, dirty);
6333 if (flags & S_CTIME)
6334 inode->i_ctime = *now;
6335 if (flags & S_MTIME)
6336 inode->i_mtime = *now;
6337 if (flags & S_ATIME)
6338 inode->i_atime = *now;
6339 return dirty ? btrfs_dirty_inode(inode) : 0;
6340 }
6341
6342 /*
6343 * find the highest existing sequence number in a directory
6344 * and then set the in-memory index_cnt variable to reflect
6345 * free sequence numbers
6346 */
6347 static int btrfs_set_inode_index_count(struct btrfs_inode *inode)
6348 {
6349 struct btrfs_root *root = inode->root;
6350 struct btrfs_key key, found_key;
6351 struct btrfs_path *path;
6352 struct extent_buffer *leaf;
6353 int ret;
6354
6355 key.objectid = btrfs_ino(inode);
6356 key.type = BTRFS_DIR_INDEX_KEY;
6357 key.offset = (u64)-1;
6358
6359 path = btrfs_alloc_path();
6360 if (!path)
6361 return -ENOMEM;
6362
6363 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6364 if (ret < 0)
6365 goto out;
6366 /* FIXME: we should be able to handle this */
6367 if (ret == 0)
6368 goto out;
6369 ret = 0;
6370
6371 /*
6372 * MAGIC NUMBER EXPLANATION:
6373 * since we search a directory based on f_pos we have to start at 2
6374 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
6375 * else has to start at 2
6376 */
6377 if (path->slots[0] == 0) {
6378 inode->index_cnt = 2;
6379 goto out;
6380 }
6381
6382 path->slots[0]--;
6383
6384 leaf = path->nodes[0];
6385 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6386
6387 if (found_key.objectid != btrfs_ino(inode) ||
6388 found_key.type != BTRFS_DIR_INDEX_KEY) {
6389 inode->index_cnt = 2;
6390 goto out;
6391 }
6392
6393 inode->index_cnt = found_key.offset + 1;
6394 out:
6395 btrfs_free_path(path);
6396 return ret;
6397 }
6398
6399 /*
6400 * helper to find a free sequence number in a given directory. This current
6401 * code is very simple, later versions will do smarter things in the btree
6402 */
6403 int btrfs_set_inode_index(struct btrfs_inode *dir, u64 *index)
6404 {
6405 int ret = 0;
6406
6407 if (dir->index_cnt == (u64)-1) {
6408 ret = btrfs_inode_delayed_dir_index_count(dir);
6409 if (ret) {
6410 ret = btrfs_set_inode_index_count(dir);
6411 if (ret)
6412 return ret;
6413 }
6414 }
6415
6416 *index = dir->index_cnt;
6417 dir->index_cnt++;
6418
6419 return ret;
6420 }
6421
6422 static int btrfs_insert_inode_locked(struct inode *inode)
6423 {
6424 struct btrfs_iget_args args;
6425 args.location = &BTRFS_I(inode)->location;
6426 args.root = BTRFS_I(inode)->root;
6427
6428 return insert_inode_locked4(inode,
6429 btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
6430 btrfs_find_actor, &args);
6431 }
6432
6433 /*
6434 * Inherit flags from the parent inode.
6435 *
6436 * Currently only the compression flags and the cow flags are inherited.
6437 */
6438 static void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
6439 {
6440 unsigned int flags;
6441
6442 if (!dir)
6443 return;
6444
6445 flags = BTRFS_I(dir)->flags;
6446
6447 if (flags & BTRFS_INODE_NOCOMPRESS) {
6448 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
6449 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
6450 } else if (flags & BTRFS_INODE_COMPRESS) {
6451 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
6452 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
6453 }
6454
6455 if (flags & BTRFS_INODE_NODATACOW) {
6456 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
6457 if (S_ISREG(inode->i_mode))
6458 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6459 }
6460
6461 btrfs_sync_inode_flags_to_i_flags(inode);
6462 }
6463
6464 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
6465 struct btrfs_root *root,
6466 struct inode *dir,
6467 const char *name, int name_len,
6468 u64 ref_objectid, u64 objectid,
6469 umode_t mode, u64 *index)
6470 {
6471 struct btrfs_fs_info *fs_info = root->fs_info;
6472 struct inode *inode;
6473 struct btrfs_inode_item *inode_item;
6474 struct btrfs_key *location;
6475 struct btrfs_path *path;
6476 struct btrfs_inode_ref *ref;
6477 struct btrfs_key key[2];
6478 u32 sizes[2];
6479 int nitems = name ? 2 : 1;
6480 unsigned long ptr;
6481 int ret;
6482
6483 path = btrfs_alloc_path();
6484 if (!path)
6485 return ERR_PTR(-ENOMEM);
6486
6487 inode = new_inode(fs_info->sb);
6488 if (!inode) {
6489 btrfs_free_path(path);
6490 return ERR_PTR(-ENOMEM);
6491 }
6492
6493 /*
6494 * O_TMPFILE, set link count to 0, so that after this point,
6495 * we fill in an inode item with the correct link count.
6496 */
6497 if (!name)
6498 set_nlink(inode, 0);
6499
6500 /*
6501 * we have to initialize this early, so we can reclaim the inode
6502 * number if we fail afterwards in this function.
6503 */
6504 inode->i_ino = objectid;
6505
6506 if (dir && name) {
6507 trace_btrfs_inode_request(dir);
6508
6509 ret = btrfs_set_inode_index(BTRFS_I(dir), index);
6510 if (ret) {
6511 btrfs_free_path(path);
6512 iput(inode);
6513 return ERR_PTR(ret);
6514 }
6515 } else if (dir) {
6516 *index = 0;
6517 }
6518 /*
6519 * index_cnt is ignored for everything but a dir,
6520 * btrfs_set_inode_index_count has an explanation for the magic
6521 * number
6522 */
6523 BTRFS_I(inode)->index_cnt = 2;
6524 BTRFS_I(inode)->dir_index = *index;
6525 BTRFS_I(inode)->root = root;
6526 BTRFS_I(inode)->generation = trans->transid;
6527 inode->i_generation = BTRFS_I(inode)->generation;
6528
6529 /*
6530 * We could have gotten an inode number from somebody who was fsynced
6531 * and then removed in this same transaction, so let's just set full
6532 * sync since it will be a full sync anyway and this will blow away the
6533 * old info in the log.
6534 */
6535 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
6536
6537 key[0].objectid = objectid;
6538 key[0].type = BTRFS_INODE_ITEM_KEY;
6539 key[0].offset = 0;
6540
6541 sizes[0] = sizeof(struct btrfs_inode_item);
6542
6543 if (name) {
6544 /*
6545 * Start new inodes with an inode_ref. This is slightly more
6546 * efficient for small numbers of hard links since they will
6547 * be packed into one item. Extended refs will kick in if we
6548 * add more hard links than can fit in the ref item.
6549 */
6550 key[1].objectid = objectid;
6551 key[1].type = BTRFS_INODE_REF_KEY;
6552 key[1].offset = ref_objectid;
6553
6554 sizes[1] = name_len + sizeof(*ref);
6555 }
6556
6557 location = &BTRFS_I(inode)->location;
6558 location->objectid = objectid;
6559 location->offset = 0;
6560 location->type = BTRFS_INODE_ITEM_KEY;
6561
6562 ret = btrfs_insert_inode_locked(inode);
6563 if (ret < 0)
6564 goto fail;
6565
6566 path->leave_spinning = 1;
6567 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
6568 if (ret != 0)
6569 goto fail_unlock;
6570
6571 inode_init_owner(inode, dir, mode);
6572 inode_set_bytes(inode, 0);
6573
6574 inode->i_mtime = current_time(inode);
6575 inode->i_atime = inode->i_mtime;
6576 inode->i_ctime = inode->i_mtime;
6577 BTRFS_I(inode)->i_otime = inode->i_mtime;
6578
6579 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
6580 struct btrfs_inode_item);
6581 memzero_extent_buffer(path->nodes[0], (unsigned long)inode_item,
6582 sizeof(*inode_item));
6583 fill_inode_item(trans, path->nodes[0], inode_item, inode);
6584
6585 if (name) {
6586 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
6587 struct btrfs_inode_ref);
6588 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
6589 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
6590 ptr = (unsigned long)(ref + 1);
6591 write_extent_buffer(path->nodes[0], name, ptr, name_len);
6592 }
6593
6594 btrfs_mark_buffer_dirty(path->nodes[0]);
6595 btrfs_free_path(path);
6596
6597 btrfs_inherit_iflags(inode, dir);
6598
6599 if (S_ISREG(mode)) {
6600 if (btrfs_test_opt(fs_info, NODATASUM))
6601 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6602 if (btrfs_test_opt(fs_info, NODATACOW))
6603 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
6604 BTRFS_INODE_NODATASUM;
6605 }
6606
6607 inode_tree_add(inode);
6608
6609 trace_btrfs_inode_new(inode);
6610 btrfs_set_inode_last_trans(trans, inode);
6611
6612 btrfs_update_root_times(trans, root);
6613
6614 ret = btrfs_inode_inherit_props(trans, inode, dir);
6615 if (ret)
6616 btrfs_err(fs_info,
6617 "error inheriting props for ino %llu (root %llu): %d",
6618 btrfs_ino(BTRFS_I(inode)), root->root_key.objectid, ret);
6619
6620 return inode;
6621
6622 fail_unlock:
6623 unlock_new_inode(inode);
6624 fail:
6625 if (dir && name)
6626 BTRFS_I(dir)->index_cnt--;
6627 btrfs_free_path(path);
6628 iput(inode);
6629 return ERR_PTR(ret);
6630 }
6631
6632 static inline u8 btrfs_inode_type(struct inode *inode)
6633 {
6634 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
6635 }
6636
6637 /*
6638 * utility function to add 'inode' into 'parent_inode' with
6639 * a give name and a given sequence number.
6640 * if 'add_backref' is true, also insert a backref from the
6641 * inode to the parent directory.
6642 */
6643 int btrfs_add_link(struct btrfs_trans_handle *trans,
6644 struct btrfs_inode *parent_inode, struct btrfs_inode *inode,
6645 const char *name, int name_len, int add_backref, u64 index)
6646 {
6647 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
6648 int ret = 0;
6649 struct btrfs_key key;
6650 struct btrfs_root *root = parent_inode->root;
6651 u64 ino = btrfs_ino(inode);
6652 u64 parent_ino = btrfs_ino(parent_inode);
6653
6654 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6655 memcpy(&key, &inode->root->root_key, sizeof(key));
6656 } else {
6657 key.objectid = ino;
6658 key.type = BTRFS_INODE_ITEM_KEY;
6659 key.offset = 0;
6660 }
6661
6662 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6663 ret = btrfs_add_root_ref(trans, fs_info, key.objectid,
6664 root->root_key.objectid, parent_ino,
6665 index, name, name_len);
6666 } else if (add_backref) {
6667 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
6668 parent_ino, index);
6669 }
6670
6671 /* Nothing to clean up yet */
6672 if (ret)
6673 return ret;
6674
6675 ret = btrfs_insert_dir_item(trans, root, name, name_len,
6676 parent_inode, &key,
6677 btrfs_inode_type(&inode->vfs_inode), index);
6678 if (ret == -EEXIST || ret == -EOVERFLOW)
6679 goto fail_dir_item;
6680 else if (ret) {
6681 btrfs_abort_transaction(trans, ret);
6682 return ret;
6683 }
6684
6685 btrfs_i_size_write(parent_inode, parent_inode->vfs_inode.i_size +
6686 name_len * 2);
6687 inode_inc_iversion(&parent_inode->vfs_inode);
6688 parent_inode->vfs_inode.i_mtime = parent_inode->vfs_inode.i_ctime =
6689 current_time(&parent_inode->vfs_inode);
6690 ret = btrfs_update_inode(trans, root, &parent_inode->vfs_inode);
6691 if (ret)
6692 btrfs_abort_transaction(trans, ret);
6693 return ret;
6694
6695 fail_dir_item:
6696 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6697 u64 local_index;
6698 int err;
6699 err = btrfs_del_root_ref(trans, fs_info, key.objectid,
6700 root->root_key.objectid, parent_ino,
6701 &local_index, name, name_len);
6702
6703 } else if (add_backref) {
6704 u64 local_index;
6705 int err;
6706
6707 err = btrfs_del_inode_ref(trans, root, name, name_len,
6708 ino, parent_ino, &local_index);
6709 }
6710 return ret;
6711 }
6712
6713 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
6714 struct btrfs_inode *dir, struct dentry *dentry,
6715 struct btrfs_inode *inode, int backref, u64 index)
6716 {
6717 int err = btrfs_add_link(trans, dir, inode,
6718 dentry->d_name.name, dentry->d_name.len,
6719 backref, index);
6720 if (err > 0)
6721 err = -EEXIST;
6722 return err;
6723 }
6724
6725 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
6726 umode_t mode, dev_t rdev)
6727 {
6728 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6729 struct btrfs_trans_handle *trans;
6730 struct btrfs_root *root = BTRFS_I(dir)->root;
6731 struct inode *inode = NULL;
6732 int err;
6733 int drop_inode = 0;
6734 u64 objectid;
6735 u64 index = 0;
6736
6737 /*
6738 * 2 for inode item and ref
6739 * 2 for dir items
6740 * 1 for xattr if selinux is on
6741 */
6742 trans = btrfs_start_transaction(root, 5);
6743 if (IS_ERR(trans))
6744 return PTR_ERR(trans);
6745
6746 err = btrfs_find_free_ino(root, &objectid);
6747 if (err)
6748 goto out_unlock;
6749
6750 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6751 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6752 mode, &index);
6753 if (IS_ERR(inode)) {
6754 err = PTR_ERR(inode);
6755 goto out_unlock;
6756 }
6757
6758 /*
6759 * If the active LSM wants to access the inode during
6760 * d_instantiate it needs these. Smack checks to see
6761 * if the filesystem supports xattrs by looking at the
6762 * ops vector.
6763 */
6764 inode->i_op = &btrfs_special_inode_operations;
6765 init_special_inode(inode, inode->i_mode, rdev);
6766
6767 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6768 if (err)
6769 goto out_unlock_inode;
6770
6771 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6772 0, index);
6773 if (err) {
6774 goto out_unlock_inode;
6775 } else {
6776 btrfs_update_inode(trans, root, inode);
6777 d_instantiate_new(dentry, inode);
6778 }
6779
6780 out_unlock:
6781 btrfs_end_transaction(trans);
6782 btrfs_btree_balance_dirty(fs_info);
6783 if (drop_inode) {
6784 inode_dec_link_count(inode);
6785 iput(inode);
6786 }
6787 return err;
6788
6789 out_unlock_inode:
6790 drop_inode = 1;
6791 unlock_new_inode(inode);
6792 goto out_unlock;
6793
6794 }
6795
6796 static int btrfs_create(struct inode *dir, struct dentry *dentry,
6797 umode_t mode, bool excl)
6798 {
6799 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6800 struct btrfs_trans_handle *trans;
6801 struct btrfs_root *root = BTRFS_I(dir)->root;
6802 struct inode *inode = NULL;
6803 int drop_inode_on_err = 0;
6804 int err;
6805 u64 objectid;
6806 u64 index = 0;
6807
6808 /*
6809 * 2 for inode item and ref
6810 * 2 for dir items
6811 * 1 for xattr if selinux is on
6812 */
6813 trans = btrfs_start_transaction(root, 5);
6814 if (IS_ERR(trans))
6815 return PTR_ERR(trans);
6816
6817 err = btrfs_find_free_ino(root, &objectid);
6818 if (err)
6819 goto out_unlock;
6820
6821 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6822 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6823 mode, &index);
6824 if (IS_ERR(inode)) {
6825 err = PTR_ERR(inode);
6826 goto out_unlock;
6827 }
6828 drop_inode_on_err = 1;
6829 /*
6830 * If the active LSM wants to access the inode during
6831 * d_instantiate it needs these. Smack checks to see
6832 * if the filesystem supports xattrs by looking at the
6833 * ops vector.
6834 */
6835 inode->i_fop = &btrfs_file_operations;
6836 inode->i_op = &btrfs_file_inode_operations;
6837 inode->i_mapping->a_ops = &btrfs_aops;
6838
6839 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6840 if (err)
6841 goto out_unlock_inode;
6842
6843 err = btrfs_update_inode(trans, root, inode);
6844 if (err)
6845 goto out_unlock_inode;
6846
6847 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6848 0, index);
6849 if (err)
6850 goto out_unlock_inode;
6851
6852 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
6853 d_instantiate_new(dentry, inode);
6854
6855 out_unlock:
6856 btrfs_end_transaction(trans);
6857 if (err && drop_inode_on_err) {
6858 inode_dec_link_count(inode);
6859 iput(inode);
6860 }
6861 btrfs_btree_balance_dirty(fs_info);
6862 return err;
6863
6864 out_unlock_inode:
6865 unlock_new_inode(inode);
6866 goto out_unlock;
6867
6868 }
6869
6870 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
6871 struct dentry *dentry)
6872 {
6873 struct btrfs_trans_handle *trans = NULL;
6874 struct btrfs_root *root = BTRFS_I(dir)->root;
6875 struct inode *inode = d_inode(old_dentry);
6876 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
6877 u64 index;
6878 int err;
6879 int drop_inode = 0;
6880
6881 /* do not allow sys_link's with other subvols of the same device */
6882 if (root->objectid != BTRFS_I(inode)->root->objectid)
6883 return -EXDEV;
6884
6885 if (inode->i_nlink >= BTRFS_LINK_MAX)
6886 return -EMLINK;
6887
6888 err = btrfs_set_inode_index(BTRFS_I(dir), &index);
6889 if (err)
6890 goto fail;
6891
6892 /*
6893 * 2 items for inode and inode ref
6894 * 2 items for dir items
6895 * 1 item for parent inode
6896 */
6897 trans = btrfs_start_transaction(root, 5);
6898 if (IS_ERR(trans)) {
6899 err = PTR_ERR(trans);
6900 trans = NULL;
6901 goto fail;
6902 }
6903
6904 /* There are several dir indexes for this inode, clear the cache. */
6905 BTRFS_I(inode)->dir_index = 0ULL;
6906 inc_nlink(inode);
6907 inode_inc_iversion(inode);
6908 inode->i_ctime = current_time(inode);
6909 ihold(inode);
6910 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
6911
6912 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6913 1, index);
6914
6915 if (err) {
6916 drop_inode = 1;
6917 } else {
6918 struct dentry *parent = dentry->d_parent;
6919 err = btrfs_update_inode(trans, root, inode);
6920 if (err)
6921 goto fail;
6922 if (inode->i_nlink == 1) {
6923 /*
6924 * If new hard link count is 1, it's a file created
6925 * with open(2) O_TMPFILE flag.
6926 */
6927 err = btrfs_orphan_del(trans, BTRFS_I(inode));
6928 if (err)
6929 goto fail;
6930 }
6931 d_instantiate(dentry, inode);
6932 btrfs_log_new_name(trans, BTRFS_I(inode), NULL, parent);
6933 }
6934
6935 fail:
6936 if (trans)
6937 btrfs_end_transaction(trans);
6938 if (drop_inode) {
6939 inode_dec_link_count(inode);
6940 iput(inode);
6941 }
6942 btrfs_btree_balance_dirty(fs_info);
6943 return err;
6944 }
6945
6946 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
6947 {
6948 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6949 struct inode *inode = NULL;
6950 struct btrfs_trans_handle *trans;
6951 struct btrfs_root *root = BTRFS_I(dir)->root;
6952 int err = 0;
6953 int drop_on_err = 0;
6954 u64 objectid = 0;
6955 u64 index = 0;
6956
6957 /*
6958 * 2 items for inode and ref
6959 * 2 items for dir items
6960 * 1 for xattr if selinux is on
6961 */
6962 trans = btrfs_start_transaction(root, 5);
6963 if (IS_ERR(trans))
6964 return PTR_ERR(trans);
6965
6966 err = btrfs_find_free_ino(root, &objectid);
6967 if (err)
6968 goto out_fail;
6969
6970 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6971 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6972 S_IFDIR | mode, &index);
6973 if (IS_ERR(inode)) {
6974 err = PTR_ERR(inode);
6975 goto out_fail;
6976 }
6977
6978 drop_on_err = 1;
6979 /* these must be set before we unlock the inode */
6980 inode->i_op = &btrfs_dir_inode_operations;
6981 inode->i_fop = &btrfs_dir_file_operations;
6982
6983 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6984 if (err)
6985 goto out_fail_inode;
6986
6987 btrfs_i_size_write(BTRFS_I(inode), 0);
6988 err = btrfs_update_inode(trans, root, inode);
6989 if (err)
6990 goto out_fail_inode;
6991
6992 err = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode),
6993 dentry->d_name.name,
6994 dentry->d_name.len, 0, index);
6995 if (err)
6996 goto out_fail_inode;
6997
6998 d_instantiate_new(dentry, inode);
6999 drop_on_err = 0;
7000
7001 out_fail:
7002 btrfs_end_transaction(trans);
7003 if (drop_on_err) {
7004 inode_dec_link_count(inode);
7005 iput(inode);
7006 }
7007 btrfs_btree_balance_dirty(fs_info);
7008 return err;
7009
7010 out_fail_inode:
7011 unlock_new_inode(inode);
7012 goto out_fail;
7013 }
7014
7015 static noinline int uncompress_inline(struct btrfs_path *path,
7016 struct page *page,
7017 size_t pg_offset, u64 extent_offset,
7018 struct btrfs_file_extent_item *item)
7019 {
7020 int ret;
7021 struct extent_buffer *leaf = path->nodes[0];
7022 char *tmp;
7023 size_t max_size;
7024 unsigned long inline_size;
7025 unsigned long ptr;
7026 int compress_type;
7027
7028 WARN_ON(pg_offset != 0);
7029 compress_type = btrfs_file_extent_compression(leaf, item);
7030 max_size = btrfs_file_extent_ram_bytes(leaf, item);
7031 inline_size = btrfs_file_extent_inline_item_len(leaf,
7032 btrfs_item_nr(path->slots[0]));
7033 tmp = kmalloc(inline_size, GFP_NOFS);
7034 if (!tmp)
7035 return -ENOMEM;
7036 ptr = btrfs_file_extent_inline_start(item);
7037
7038 read_extent_buffer(leaf, tmp, ptr, inline_size);
7039
7040 max_size = min_t(unsigned long, PAGE_SIZE, max_size);
7041 ret = btrfs_decompress(compress_type, tmp, page,
7042 extent_offset, inline_size, max_size);
7043
7044 /*
7045 * decompression code contains a memset to fill in any space between the end
7046 * of the uncompressed data and the end of max_size in case the decompressed
7047 * data ends up shorter than ram_bytes. That doesn't cover the hole between
7048 * the end of an inline extent and the beginning of the next block, so we
7049 * cover that region here.
7050 */
7051
7052 if (max_size + pg_offset < PAGE_SIZE) {
7053 char *map = kmap(page);
7054 memset(map + pg_offset + max_size, 0, PAGE_SIZE - max_size - pg_offset);
7055 kunmap(page);
7056 }
7057 kfree(tmp);
7058 return ret;
7059 }
7060
7061 /*
7062 * a bit scary, this does extent mapping from logical file offset to the disk.
7063 * the ugly parts come from merging extents from the disk with the in-ram
7064 * representation. This gets more complex because of the data=ordered code,
7065 * where the in-ram extents might be locked pending data=ordered completion.
7066 *
7067 * This also copies inline extents directly into the page.
7068 */
7069 struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
7070 struct page *page,
7071 size_t pg_offset, u64 start, u64 len,
7072 int create)
7073 {
7074 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
7075 int ret;
7076 int err = 0;
7077 u64 extent_start = 0;
7078 u64 extent_end = 0;
7079 u64 objectid = btrfs_ino(inode);
7080 u32 found_type;
7081 struct btrfs_path *path = NULL;
7082 struct btrfs_root *root = inode->root;
7083 struct btrfs_file_extent_item *item;
7084 struct extent_buffer *leaf;
7085 struct btrfs_key found_key;
7086 struct extent_map *em = NULL;
7087 struct extent_map_tree *em_tree = &inode->extent_tree;
7088 struct extent_io_tree *io_tree = &inode->io_tree;
7089 const bool new_inline = !page || create;
7090
7091 read_lock(&em_tree->lock);
7092 em = lookup_extent_mapping(em_tree, start, len);
7093 if (em)
7094 em->bdev = fs_info->fs_devices->latest_bdev;
7095 read_unlock(&em_tree->lock);
7096
7097 if (em) {
7098 if (em->start > start || em->start + em->len <= start)
7099 free_extent_map(em);
7100 else if (em->block_start == EXTENT_MAP_INLINE && page)
7101 free_extent_map(em);
7102 else
7103 goto out;
7104 }
7105 em = alloc_extent_map();
7106 if (!em) {
7107 err = -ENOMEM;
7108 goto out;
7109 }
7110 em->bdev = fs_info->fs_devices->latest_bdev;
7111 em->start = EXTENT_MAP_HOLE;
7112 em->orig_start = EXTENT_MAP_HOLE;
7113 em->len = (u64)-1;
7114 em->block_len = (u64)-1;
7115
7116 if (!path) {
7117 path = btrfs_alloc_path();
7118 if (!path) {
7119 err = -ENOMEM;
7120 goto out;
7121 }
7122 /*
7123 * Chances are we'll be called again, so go ahead and do
7124 * readahead
7125 */
7126 path->reada = READA_FORWARD;
7127 }
7128
7129 ret = btrfs_lookup_file_extent(NULL, root, path, objectid, start, 0);
7130 if (ret < 0) {
7131 err = ret;
7132 goto out;
7133 }
7134
7135 if (ret != 0) {
7136 if (path->slots[0] == 0)
7137 goto not_found;
7138 path->slots[0]--;
7139 }
7140
7141 leaf = path->nodes[0];
7142 item = btrfs_item_ptr(leaf, path->slots[0],
7143 struct btrfs_file_extent_item);
7144 /* are we inside the extent that was found? */
7145 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
7146 found_type = found_key.type;
7147 if (found_key.objectid != objectid ||
7148 found_type != BTRFS_EXTENT_DATA_KEY) {
7149 /*
7150 * If we backup past the first extent we want to move forward
7151 * and see if there is an extent in front of us, otherwise we'll
7152 * say there is a hole for our whole search range which can
7153 * cause problems.
7154 */
7155 extent_end = start;
7156 goto next;
7157 }
7158
7159 found_type = btrfs_file_extent_type(leaf, item);
7160 extent_start = found_key.offset;
7161 if (found_type == BTRFS_FILE_EXTENT_REG ||
7162 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7163 extent_end = extent_start +
7164 btrfs_file_extent_num_bytes(leaf, item);
7165
7166 trace_btrfs_get_extent_show_fi_regular(inode, leaf, item,
7167 extent_start);
7168 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
7169 size_t size;
7170 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
7171 extent_end = ALIGN(extent_start + size,
7172 fs_info->sectorsize);
7173
7174 trace_btrfs_get_extent_show_fi_inline(inode, leaf, item,
7175 path->slots[0],
7176 extent_start);
7177 }
7178 next:
7179 if (start >= extent_end) {
7180 path->slots[0]++;
7181 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
7182 ret = btrfs_next_leaf(root, path);
7183 if (ret < 0) {
7184 err = ret;
7185 goto out;
7186 }
7187 if (ret > 0)
7188 goto not_found;
7189 leaf = path->nodes[0];
7190 }
7191 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
7192 if (found_key.objectid != objectid ||
7193 found_key.type != BTRFS_EXTENT_DATA_KEY)
7194 goto not_found;
7195 if (start + len <= found_key.offset)
7196 goto not_found;
7197 if (start > found_key.offset)
7198 goto next;
7199 em->start = start;
7200 em->orig_start = start;
7201 em->len = found_key.offset - start;
7202 goto not_found_em;
7203 }
7204
7205 btrfs_extent_item_to_extent_map(inode, path, item,
7206 new_inline, em);
7207
7208 if (found_type == BTRFS_FILE_EXTENT_REG ||
7209 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7210 goto insert;
7211 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
7212 unsigned long ptr;
7213 char *map;
7214 size_t size;
7215 size_t extent_offset;
7216 size_t copy_size;
7217
7218 if (new_inline)
7219 goto out;
7220
7221 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
7222 extent_offset = page_offset(page) + pg_offset - extent_start;
7223 copy_size = min_t(u64, PAGE_SIZE - pg_offset,
7224 size - extent_offset);
7225 em->start = extent_start + extent_offset;
7226 em->len = ALIGN(copy_size, fs_info->sectorsize);
7227 em->orig_block_len = em->len;
7228 em->orig_start = em->start;
7229 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
7230 if (!PageUptodate(page)) {
7231 if (btrfs_file_extent_compression(leaf, item) !=
7232 BTRFS_COMPRESS_NONE) {
7233 ret = uncompress_inline(path, page, pg_offset,
7234 extent_offset, item);
7235 if (ret) {
7236 err = ret;
7237 goto out;
7238 }
7239 } else {
7240 map = kmap(page);
7241 read_extent_buffer(leaf, map + pg_offset, ptr,
7242 copy_size);
7243 if (pg_offset + copy_size < PAGE_SIZE) {
7244 memset(map + pg_offset + copy_size, 0,
7245 PAGE_SIZE - pg_offset -
7246 copy_size);
7247 }
7248 kunmap(page);
7249 }
7250 flush_dcache_page(page);
7251 }
7252 set_extent_uptodate(io_tree, em->start,
7253 extent_map_end(em) - 1, NULL, GFP_NOFS);
7254 goto insert;
7255 }
7256 not_found:
7257 em->start = start;
7258 em->orig_start = start;
7259 em->len = len;
7260 not_found_em:
7261 em->block_start = EXTENT_MAP_HOLE;
7262 insert:
7263 btrfs_release_path(path);
7264 if (em->start > start || extent_map_end(em) <= start) {
7265 btrfs_err(fs_info,
7266 "bad extent! em: [%llu %llu] passed [%llu %llu]",
7267 em->start, em->len, start, len);
7268 err = -EIO;
7269 goto out;
7270 }
7271
7272 err = 0;
7273 write_lock(&em_tree->lock);
7274 err = btrfs_add_extent_mapping(fs_info, em_tree, &em, start, len);
7275 write_unlock(&em_tree->lock);
7276 out:
7277
7278 trace_btrfs_get_extent(root, inode, em);
7279
7280 btrfs_free_path(path);
7281 if (err) {
7282 free_extent_map(em);
7283 return ERR_PTR(err);
7284 }
7285 BUG_ON(!em); /* Error is always set */
7286 return em;
7287 }
7288
7289 struct extent_map *btrfs_get_extent_fiemap(struct btrfs_inode *inode,
7290 struct page *page,
7291 size_t pg_offset, u64 start, u64 len,
7292 int create)
7293 {
7294 struct extent_map *em;
7295 struct extent_map *hole_em = NULL;
7296 u64 range_start = start;
7297 u64 end;
7298 u64 found;
7299 u64 found_end;
7300 int err = 0;
7301
7302 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
7303 if (IS_ERR(em))
7304 return em;
7305 /*
7306 * If our em maps to:
7307 * - a hole or
7308 * - a pre-alloc extent,
7309 * there might actually be delalloc bytes behind it.
7310 */
7311 if (em->block_start != EXTENT_MAP_HOLE &&
7312 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7313 return em;
7314 else
7315 hole_em = em;
7316
7317 /* check to see if we've wrapped (len == -1 or similar) */
7318 end = start + len;
7319 if (end < start)
7320 end = (u64)-1;
7321 else
7322 end -= 1;
7323
7324 em = NULL;
7325
7326 /* ok, we didn't find anything, lets look for delalloc */
7327 found = count_range_bits(&inode->io_tree, &range_start,
7328 end, len, EXTENT_DELALLOC, 1);
7329 found_end = range_start + found;
7330 if (found_end < range_start)
7331 found_end = (u64)-1;
7332
7333 /*
7334 * we didn't find anything useful, return
7335 * the original results from get_extent()
7336 */
7337 if (range_start > end || found_end <= start) {
7338 em = hole_em;
7339 hole_em = NULL;
7340 goto out;
7341 }
7342
7343 /* adjust the range_start to make sure it doesn't
7344 * go backwards from the start they passed in
7345 */
7346 range_start = max(start, range_start);
7347 found = found_end - range_start;
7348
7349 if (found > 0) {
7350 u64 hole_start = start;
7351 u64 hole_len = len;
7352
7353 em = alloc_extent_map();
7354 if (!em) {
7355 err = -ENOMEM;
7356 goto out;
7357 }
7358 /*
7359 * when btrfs_get_extent can't find anything it
7360 * returns one huge hole
7361 *
7362 * make sure what it found really fits our range, and
7363 * adjust to make sure it is based on the start from
7364 * the caller
7365 */
7366 if (hole_em) {
7367 u64 calc_end = extent_map_end(hole_em);
7368
7369 if (calc_end <= start || (hole_em->start > end)) {
7370 free_extent_map(hole_em);
7371 hole_em = NULL;
7372 } else {
7373 hole_start = max(hole_em->start, start);
7374 hole_len = calc_end - hole_start;
7375 }
7376 }
7377 em->bdev = NULL;
7378 if (hole_em && range_start > hole_start) {
7379 /* our hole starts before our delalloc, so we
7380 * have to return just the parts of the hole
7381 * that go until the delalloc starts
7382 */
7383 em->len = min(hole_len,
7384 range_start - hole_start);
7385 em->start = hole_start;
7386 em->orig_start = hole_start;
7387 /*
7388 * don't adjust block start at all,
7389 * it is fixed at EXTENT_MAP_HOLE
7390 */
7391 em->block_start = hole_em->block_start;
7392 em->block_len = hole_len;
7393 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
7394 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
7395 } else {
7396 em->start = range_start;
7397 em->len = found;
7398 em->orig_start = range_start;
7399 em->block_start = EXTENT_MAP_DELALLOC;
7400 em->block_len = found;
7401 }
7402 } else {
7403 return hole_em;
7404 }
7405 out:
7406
7407 free_extent_map(hole_em);
7408 if (err) {
7409 free_extent_map(em);
7410 return ERR_PTR(err);
7411 }
7412 return em;
7413 }
7414
7415 static struct extent_map *btrfs_create_dio_extent(struct inode *inode,
7416 const u64 start,
7417 const u64 len,
7418 const u64 orig_start,
7419 const u64 block_start,
7420 const u64 block_len,
7421 const u64 orig_block_len,
7422 const u64 ram_bytes,
7423 const int type)
7424 {
7425 struct extent_map *em = NULL;
7426 int ret;
7427
7428 if (type != BTRFS_ORDERED_NOCOW) {
7429 em = create_io_em(inode, start, len, orig_start,
7430 block_start, block_len, orig_block_len,
7431 ram_bytes,
7432 BTRFS_COMPRESS_NONE, /* compress_type */
7433 type);
7434 if (IS_ERR(em))
7435 goto out;
7436 }
7437 ret = btrfs_add_ordered_extent_dio(inode, start, block_start,
7438 len, block_len, type);
7439 if (ret) {
7440 if (em) {
7441 free_extent_map(em);
7442 btrfs_drop_extent_cache(BTRFS_I(inode), start,
7443 start + len - 1, 0);
7444 }
7445 em = ERR_PTR(ret);
7446 }
7447 out:
7448
7449 return em;
7450 }
7451
7452 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
7453 u64 start, u64 len)
7454 {
7455 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7456 struct btrfs_root *root = BTRFS_I(inode)->root;
7457 struct extent_map *em;
7458 struct btrfs_key ins;
7459 u64 alloc_hint;
7460 int ret;
7461
7462 alloc_hint = get_extent_allocation_hint(inode, start, len);
7463 ret = btrfs_reserve_extent(root, len, len, fs_info->sectorsize,
7464 0, alloc_hint, &ins, 1, 1);
7465 if (ret)
7466 return ERR_PTR(ret);
7467
7468 em = btrfs_create_dio_extent(inode, start, ins.offset, start,
7469 ins.objectid, ins.offset, ins.offset,
7470 ins.offset, BTRFS_ORDERED_REGULAR);
7471 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
7472 if (IS_ERR(em))
7473 btrfs_free_reserved_extent(fs_info, ins.objectid,
7474 ins.offset, 1);
7475
7476 return em;
7477 }
7478
7479 /*
7480 * returns 1 when the nocow is safe, < 1 on error, 0 if the
7481 * block must be cow'd
7482 */
7483 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
7484 u64 *orig_start, u64 *orig_block_len,
7485 u64 *ram_bytes)
7486 {
7487 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7488 struct btrfs_path *path;
7489 int ret;
7490 struct extent_buffer *leaf;
7491 struct btrfs_root *root = BTRFS_I(inode)->root;
7492 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7493 struct btrfs_file_extent_item *fi;
7494 struct btrfs_key key;
7495 u64 disk_bytenr;
7496 u64 backref_offset;
7497 u64 extent_end;
7498 u64 num_bytes;
7499 int slot;
7500 int found_type;
7501 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
7502
7503 path = btrfs_alloc_path();
7504 if (!path)
7505 return -ENOMEM;
7506
7507 ret = btrfs_lookup_file_extent(NULL, root, path,
7508 btrfs_ino(BTRFS_I(inode)), offset, 0);
7509 if (ret < 0)
7510 goto out;
7511
7512 slot = path->slots[0];
7513 if (ret == 1) {
7514 if (slot == 0) {
7515 /* can't find the item, must cow */
7516 ret = 0;
7517 goto out;
7518 }
7519 slot--;
7520 }
7521 ret = 0;
7522 leaf = path->nodes[0];
7523 btrfs_item_key_to_cpu(leaf, &key, slot);
7524 if (key.objectid != btrfs_ino(BTRFS_I(inode)) ||
7525 key.type != BTRFS_EXTENT_DATA_KEY) {
7526 /* not our file or wrong item type, must cow */
7527 goto out;
7528 }
7529
7530 if (key.offset > offset) {
7531 /* Wrong offset, must cow */
7532 goto out;
7533 }
7534
7535 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
7536 found_type = btrfs_file_extent_type(leaf, fi);
7537 if (found_type != BTRFS_FILE_EXTENT_REG &&
7538 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
7539 /* not a regular extent, must cow */
7540 goto out;
7541 }
7542
7543 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
7544 goto out;
7545
7546 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
7547 if (extent_end <= offset)
7548 goto out;
7549
7550 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
7551 if (disk_bytenr == 0)
7552 goto out;
7553
7554 if (btrfs_file_extent_compression(leaf, fi) ||
7555 btrfs_file_extent_encryption(leaf, fi) ||
7556 btrfs_file_extent_other_encoding(leaf, fi))
7557 goto out;
7558
7559 backref_offset = btrfs_file_extent_offset(leaf, fi);
7560
7561 if (orig_start) {
7562 *orig_start = key.offset - backref_offset;
7563 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
7564 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
7565 }
7566
7567 if (btrfs_extent_readonly(fs_info, disk_bytenr))
7568 goto out;
7569
7570 num_bytes = min(offset + *len, extent_end) - offset;
7571 if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7572 u64 range_end;
7573
7574 range_end = round_up(offset + num_bytes,
7575 root->fs_info->sectorsize) - 1;
7576 ret = test_range_bit(io_tree, offset, range_end,
7577 EXTENT_DELALLOC, 0, NULL);
7578 if (ret) {
7579 ret = -EAGAIN;
7580 goto out;
7581 }
7582 }
7583
7584 btrfs_release_path(path);
7585
7586 /*
7587 * look for other files referencing this extent, if we
7588 * find any we must cow
7589 */
7590
7591 ret = btrfs_cross_ref_exist(root, btrfs_ino(BTRFS_I(inode)),
7592 key.offset - backref_offset, disk_bytenr);
7593 if (ret) {
7594 ret = 0;
7595 goto out;
7596 }
7597
7598 /*
7599 * adjust disk_bytenr and num_bytes to cover just the bytes
7600 * in this extent we are about to write. If there
7601 * are any csums in that range we have to cow in order
7602 * to keep the csums correct
7603 */
7604 disk_bytenr += backref_offset;
7605 disk_bytenr += offset - key.offset;
7606 if (csum_exist_in_range(fs_info, disk_bytenr, num_bytes))
7607 goto out;
7608 /*
7609 * all of the above have passed, it is safe to overwrite this extent
7610 * without cow
7611 */
7612 *len = num_bytes;
7613 ret = 1;
7614 out:
7615 btrfs_free_path(path);
7616 return ret;
7617 }
7618
7619 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
7620 struct extent_state **cached_state, int writing)
7621 {
7622 struct btrfs_ordered_extent *ordered;
7623 int ret = 0;
7624
7625 while (1) {
7626 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7627 cached_state);
7628 /*
7629 * We're concerned with the entire range that we're going to be
7630 * doing DIO to, so we need to make sure there's no ordered
7631 * extents in this range.
7632 */
7633 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), lockstart,
7634 lockend - lockstart + 1);
7635
7636 /*
7637 * We need to make sure there are no buffered pages in this
7638 * range either, we could have raced between the invalidate in
7639 * generic_file_direct_write and locking the extent. The
7640 * invalidate needs to happen so that reads after a write do not
7641 * get stale data.
7642 */
7643 if (!ordered &&
7644 (!writing || !filemap_range_has_page(inode->i_mapping,
7645 lockstart, lockend)))
7646 break;
7647
7648 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7649 cached_state);
7650
7651 if (ordered) {
7652 /*
7653 * If we are doing a DIO read and the ordered extent we
7654 * found is for a buffered write, we can not wait for it
7655 * to complete and retry, because if we do so we can
7656 * deadlock with concurrent buffered writes on page
7657 * locks. This happens only if our DIO read covers more
7658 * than one extent map, if at this point has already
7659 * created an ordered extent for a previous extent map
7660 * and locked its range in the inode's io tree, and a
7661 * concurrent write against that previous extent map's
7662 * range and this range started (we unlock the ranges
7663 * in the io tree only when the bios complete and
7664 * buffered writes always lock pages before attempting
7665 * to lock range in the io tree).
7666 */
7667 if (writing ||
7668 test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags))
7669 btrfs_start_ordered_extent(inode, ordered, 1);
7670 else
7671 ret = -ENOTBLK;
7672 btrfs_put_ordered_extent(ordered);
7673 } else {
7674 /*
7675 * We could trigger writeback for this range (and wait
7676 * for it to complete) and then invalidate the pages for
7677 * this range (through invalidate_inode_pages2_range()),
7678 * but that can lead us to a deadlock with a concurrent
7679 * call to readpages() (a buffered read or a defrag call
7680 * triggered a readahead) on a page lock due to an
7681 * ordered dio extent we created before but did not have
7682 * yet a corresponding bio submitted (whence it can not
7683 * complete), which makes readpages() wait for that
7684 * ordered extent to complete while holding a lock on
7685 * that page.
7686 */
7687 ret = -ENOTBLK;
7688 }
7689
7690 if (ret)
7691 break;
7692
7693 cond_resched();
7694 }
7695
7696 return ret;
7697 }
7698
7699 /* The callers of this must take lock_extent() */
7700 static struct extent_map *create_io_em(struct inode *inode, u64 start, u64 len,
7701 u64 orig_start, u64 block_start,
7702 u64 block_len, u64 orig_block_len,
7703 u64 ram_bytes, int compress_type,
7704 int type)
7705 {
7706 struct extent_map_tree *em_tree;
7707 struct extent_map *em;
7708 struct btrfs_root *root = BTRFS_I(inode)->root;
7709 int ret;
7710
7711 ASSERT(type == BTRFS_ORDERED_PREALLOC ||
7712 type == BTRFS_ORDERED_COMPRESSED ||
7713 type == BTRFS_ORDERED_NOCOW ||
7714 type == BTRFS_ORDERED_REGULAR);
7715
7716 em_tree = &BTRFS_I(inode)->extent_tree;
7717 em = alloc_extent_map();
7718 if (!em)
7719 return ERR_PTR(-ENOMEM);
7720
7721 em->start = start;
7722 em->orig_start = orig_start;
7723 em->len = len;
7724 em->block_len = block_len;
7725 em->block_start = block_start;
7726 em->bdev = root->fs_info->fs_devices->latest_bdev;
7727 em->orig_block_len = orig_block_len;
7728 em->ram_bytes = ram_bytes;
7729 em->generation = -1;
7730 set_bit(EXTENT_FLAG_PINNED, &em->flags);
7731 if (type == BTRFS_ORDERED_PREALLOC) {
7732 set_bit(EXTENT_FLAG_FILLING, &em->flags);
7733 } else if (type == BTRFS_ORDERED_COMPRESSED) {
7734 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
7735 em->compress_type = compress_type;
7736 }
7737
7738 do {
7739 btrfs_drop_extent_cache(BTRFS_I(inode), em->start,
7740 em->start + em->len - 1, 0);
7741 write_lock(&em_tree->lock);
7742 ret = add_extent_mapping(em_tree, em, 1);
7743 write_unlock(&em_tree->lock);
7744 /*
7745 * The caller has taken lock_extent(), who could race with us
7746 * to add em?
7747 */
7748 } while (ret == -EEXIST);
7749
7750 if (ret) {
7751 free_extent_map(em);
7752 return ERR_PTR(ret);
7753 }
7754
7755 /* em got 2 refs now, callers needs to do free_extent_map once. */
7756 return em;
7757 }
7758
7759 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
7760 struct buffer_head *bh_result, int create)
7761 {
7762 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7763 struct extent_map *em;
7764 struct extent_state *cached_state = NULL;
7765 struct btrfs_dio_data *dio_data = NULL;
7766 u64 start = iblock << inode->i_blkbits;
7767 u64 lockstart, lockend;
7768 u64 len = bh_result->b_size;
7769 int unlock_bits = EXTENT_LOCKED;
7770 int ret = 0;
7771
7772 if (create)
7773 unlock_bits |= EXTENT_DIRTY;
7774 else
7775 len = min_t(u64, len, fs_info->sectorsize);
7776
7777 lockstart = start;
7778 lockend = start + len - 1;
7779
7780 if (current->journal_info) {
7781 /*
7782 * Need to pull our outstanding extents and set journal_info to NULL so
7783 * that anything that needs to check if there's a transaction doesn't get
7784 * confused.
7785 */
7786 dio_data = current->journal_info;
7787 current->journal_info = NULL;
7788 }
7789
7790 /*
7791 * If this errors out it's because we couldn't invalidate pagecache for
7792 * this range and we need to fallback to buffered.
7793 */
7794 if (lock_extent_direct(inode, lockstart, lockend, &cached_state,
7795 create)) {
7796 ret = -ENOTBLK;
7797 goto err;
7798 }
7799
7800 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
7801 if (IS_ERR(em)) {
7802 ret = PTR_ERR(em);
7803 goto unlock_err;
7804 }
7805
7806 /*
7807 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
7808 * io. INLINE is special, and we could probably kludge it in here, but
7809 * it's still buffered so for safety lets just fall back to the generic
7810 * buffered path.
7811 *
7812 * For COMPRESSED we _have_ to read the entire extent in so we can
7813 * decompress it, so there will be buffering required no matter what we
7814 * do, so go ahead and fallback to buffered.
7815 *
7816 * We return -ENOTBLK because that's what makes DIO go ahead and go back
7817 * to buffered IO. Don't blame me, this is the price we pay for using
7818 * the generic code.
7819 */
7820 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
7821 em->block_start == EXTENT_MAP_INLINE) {
7822 free_extent_map(em);
7823 ret = -ENOTBLK;
7824 goto unlock_err;
7825 }
7826
7827 /* Just a good old fashioned hole, return */
7828 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
7829 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
7830 free_extent_map(em);
7831 goto unlock_err;
7832 }
7833
7834 /*
7835 * We don't allocate a new extent in the following cases
7836 *
7837 * 1) The inode is marked as NODATACOW. In this case we'll just use the
7838 * existing extent.
7839 * 2) The extent is marked as PREALLOC. We're good to go here and can
7840 * just use the extent.
7841 *
7842 */
7843 if (!create) {
7844 len = min(len, em->len - (start - em->start));
7845 lockstart = start + len;
7846 goto unlock;
7847 }
7848
7849 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
7850 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
7851 em->block_start != EXTENT_MAP_HOLE)) {
7852 int type;
7853 u64 block_start, orig_start, orig_block_len, ram_bytes;
7854
7855 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7856 type = BTRFS_ORDERED_PREALLOC;
7857 else
7858 type = BTRFS_ORDERED_NOCOW;
7859 len = min(len, em->len - (start - em->start));
7860 block_start = em->block_start + (start - em->start);
7861
7862 if (can_nocow_extent(inode, start, &len, &orig_start,
7863 &orig_block_len, &ram_bytes) == 1 &&
7864 btrfs_inc_nocow_writers(fs_info, block_start)) {
7865 struct extent_map *em2;
7866
7867 em2 = btrfs_create_dio_extent(inode, start, len,
7868 orig_start, block_start,
7869 len, orig_block_len,
7870 ram_bytes, type);
7871 btrfs_dec_nocow_writers(fs_info, block_start);
7872 if (type == BTRFS_ORDERED_PREALLOC) {
7873 free_extent_map(em);
7874 em = em2;
7875 }
7876 if (em2 && IS_ERR(em2)) {
7877 ret = PTR_ERR(em2);
7878 goto unlock_err;
7879 }
7880 /*
7881 * For inode marked NODATACOW or extent marked PREALLOC,
7882 * use the existing or preallocated extent, so does not
7883 * need to adjust btrfs_space_info's bytes_may_use.
7884 */
7885 btrfs_free_reserved_data_space_noquota(inode,
7886 start, len);
7887 goto unlock;
7888 }
7889 }
7890
7891 /*
7892 * this will cow the extent, reset the len in case we changed
7893 * it above
7894 */
7895 len = bh_result->b_size;
7896 free_extent_map(em);
7897 em = btrfs_new_extent_direct(inode, start, len);
7898 if (IS_ERR(em)) {
7899 ret = PTR_ERR(em);
7900 goto unlock_err;
7901 }
7902 len = min(len, em->len - (start - em->start));
7903 unlock:
7904 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
7905 inode->i_blkbits;
7906 bh_result->b_size = len;
7907 bh_result->b_bdev = em->bdev;
7908 set_buffer_mapped(bh_result);
7909 if (create) {
7910 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7911 set_buffer_new(bh_result);
7912
7913 /*
7914 * Need to update the i_size under the extent lock so buffered
7915 * readers will get the updated i_size when we unlock.
7916 */
7917 if (!dio_data->overwrite && start + len > i_size_read(inode))
7918 i_size_write(inode, start + len);
7919
7920 WARN_ON(dio_data->reserve < len);
7921 dio_data->reserve -= len;
7922 dio_data->unsubmitted_oe_range_end = start + len;
7923 current->journal_info = dio_data;
7924 }
7925
7926 /*
7927 * In the case of write we need to clear and unlock the entire range,
7928 * in the case of read we need to unlock only the end area that we
7929 * aren't using if there is any left over space.
7930 */
7931 if (lockstart < lockend) {
7932 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
7933 lockend, unlock_bits, 1, 0,
7934 &cached_state);
7935 } else {
7936 free_extent_state(cached_state);
7937 }
7938
7939 free_extent_map(em);
7940
7941 return 0;
7942
7943 unlock_err:
7944 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7945 unlock_bits, 1, 0, &cached_state);
7946 err:
7947 if (dio_data)
7948 current->journal_info = dio_data;
7949 return ret;
7950 }
7951
7952 static inline blk_status_t submit_dio_repair_bio(struct inode *inode,
7953 struct bio *bio,
7954 int mirror_num)
7955 {
7956 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7957 blk_status_t ret;
7958
7959 BUG_ON(bio_op(bio) == REQ_OP_WRITE);
7960
7961 ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DIO_REPAIR);
7962 if (ret)
7963 return ret;
7964
7965 ret = btrfs_map_bio(fs_info, bio, mirror_num, 0);
7966
7967 return ret;
7968 }
7969
7970 static int btrfs_check_dio_repairable(struct inode *inode,
7971 struct bio *failed_bio,
7972 struct io_failure_record *failrec,
7973 int failed_mirror)
7974 {
7975 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7976 int num_copies;
7977
7978 num_copies = btrfs_num_copies(fs_info, failrec->logical, failrec->len);
7979 if (num_copies == 1) {
7980 /*
7981 * we only have a single copy of the data, so don't bother with
7982 * all the retry and error correction code that follows. no
7983 * matter what the error is, it is very likely to persist.
7984 */
7985 btrfs_debug(fs_info,
7986 "Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d",
7987 num_copies, failrec->this_mirror, failed_mirror);
7988 return 0;
7989 }
7990
7991 failrec->failed_mirror = failed_mirror;
7992 failrec->this_mirror++;
7993 if (failrec->this_mirror == failed_mirror)
7994 failrec->this_mirror++;
7995
7996 if (failrec->this_mirror > num_copies) {
7997 btrfs_debug(fs_info,
7998 "Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d",
7999 num_copies, failrec->this_mirror, failed_mirror);
8000 return 0;
8001 }
8002
8003 return 1;
8004 }
8005
8006 static blk_status_t dio_read_error(struct inode *inode, struct bio *failed_bio,
8007 struct page *page, unsigned int pgoff,
8008 u64 start, u64 end, int failed_mirror,
8009 bio_end_io_t *repair_endio, void *repair_arg)
8010 {
8011 struct io_failure_record *failrec;
8012 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
8013 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
8014 struct bio *bio;
8015 int isector;
8016 unsigned int read_mode = 0;
8017 int segs;
8018 int ret;
8019 blk_status_t status;
8020 struct bio_vec bvec;
8021
8022 BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
8023
8024 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
8025 if (ret)
8026 return errno_to_blk_status(ret);
8027
8028 ret = btrfs_check_dio_repairable(inode, failed_bio, failrec,
8029 failed_mirror);
8030 if (!ret) {
8031 free_io_failure(failure_tree, io_tree, failrec);
8032 return BLK_STS_IOERR;
8033 }
8034
8035 segs = bio_segments(failed_bio);
8036 bio_get_first_bvec(failed_bio, &bvec);
8037 if (segs > 1 ||
8038 (bvec.bv_len > btrfs_inode_sectorsize(inode)))
8039 read_mode |= REQ_FAILFAST_DEV;
8040
8041 isector = start - btrfs_io_bio(failed_bio)->logical;
8042 isector >>= inode->i_sb->s_blocksize_bits;
8043 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
8044 pgoff, isector, repair_endio, repair_arg);
8045 bio_set_op_attrs(bio, REQ_OP_READ, read_mode);
8046
8047 btrfs_debug(BTRFS_I(inode)->root->fs_info,
8048 "repair DIO read error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d",
8049 read_mode, failrec->this_mirror, failrec->in_validation);
8050
8051 status = submit_dio_repair_bio(inode, bio, failrec->this_mirror);
8052 if (status) {
8053 free_io_failure(failure_tree, io_tree, failrec);
8054 bio_put(bio);
8055 }
8056
8057 return status;
8058 }
8059
8060 struct btrfs_retry_complete {
8061 struct completion done;
8062 struct inode *inode;
8063 u64 start;
8064 int uptodate;
8065 };
8066
8067 static void btrfs_retry_endio_nocsum(struct bio *bio)
8068 {
8069 struct btrfs_retry_complete *done = bio->bi_private;
8070 struct inode *inode = done->inode;
8071 struct bio_vec *bvec;
8072 struct extent_io_tree *io_tree, *failure_tree;
8073 int i;
8074
8075 if (bio->bi_status)
8076 goto end;
8077
8078 ASSERT(bio->bi_vcnt == 1);
8079 io_tree = &BTRFS_I(inode)->io_tree;
8080 failure_tree = &BTRFS_I(inode)->io_failure_tree;
8081 ASSERT(bio_first_bvec_all(bio)->bv_len == btrfs_inode_sectorsize(inode));
8082
8083 done->uptodate = 1;
8084 ASSERT(!bio_flagged(bio, BIO_CLONED));
8085 bio_for_each_segment_all(bvec, bio, i)
8086 clean_io_failure(BTRFS_I(inode)->root->fs_info, failure_tree,
8087 io_tree, done->start, bvec->bv_page,
8088 btrfs_ino(BTRFS_I(inode)), 0);
8089 end:
8090 complete(&done->done);
8091 bio_put(bio);
8092 }
8093
8094 static blk_status_t __btrfs_correct_data_nocsum(struct inode *inode,
8095 struct btrfs_io_bio *io_bio)
8096 {
8097 struct btrfs_fs_info *fs_info;
8098 struct bio_vec bvec;
8099 struct bvec_iter iter;
8100 struct btrfs_retry_complete done;
8101 u64 start;
8102 unsigned int pgoff;
8103 u32 sectorsize;
8104 int nr_sectors;
8105 blk_status_t ret;
8106 blk_status_t err = BLK_STS_OK;
8107
8108 fs_info = BTRFS_I(inode)->root->fs_info;
8109 sectorsize = fs_info->sectorsize;
8110
8111 start = io_bio->logical;
8112 done.inode = inode;
8113 io_bio->bio.bi_iter = io_bio->iter;
8114
8115 bio_for_each_segment(bvec, &io_bio->bio, iter) {
8116 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec.bv_len);
8117 pgoff = bvec.bv_offset;
8118
8119 next_block_or_try_again:
8120 done.uptodate = 0;
8121 done.start = start;
8122 init_completion(&done.done);
8123
8124 ret = dio_read_error(inode, &io_bio->bio, bvec.bv_page,
8125 pgoff, start, start + sectorsize - 1,
8126 io_bio->mirror_num,
8127 btrfs_retry_endio_nocsum, &done);
8128 if (ret) {
8129 err = ret;
8130 goto next;
8131 }
8132
8133 wait_for_completion_io(&done.done);
8134
8135 if (!done.uptodate) {
8136 /* We might have another mirror, so try again */
8137 goto next_block_or_try_again;
8138 }
8139
8140 next:
8141 start += sectorsize;
8142
8143 nr_sectors--;
8144 if (nr_sectors) {
8145 pgoff += sectorsize;
8146 ASSERT(pgoff < PAGE_SIZE);
8147 goto next_block_or_try_again;
8148 }
8149 }
8150
8151 return err;
8152 }
8153
8154 static void btrfs_retry_endio(struct bio *bio)
8155 {
8156 struct btrfs_retry_complete *done = bio->bi_private;
8157 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8158 struct extent_io_tree *io_tree, *failure_tree;
8159 struct inode *inode = done->inode;
8160 struct bio_vec *bvec;
8161 int uptodate;
8162 int ret;
8163 int i;
8164
8165 if (bio->bi_status)
8166 goto end;
8167
8168 uptodate = 1;
8169
8170 ASSERT(bio->bi_vcnt == 1);
8171 ASSERT(bio_first_bvec_all(bio)->bv_len == btrfs_inode_sectorsize(done->inode));
8172
8173 io_tree = &BTRFS_I(inode)->io_tree;
8174 failure_tree = &BTRFS_I(inode)->io_failure_tree;
8175
8176 ASSERT(!bio_flagged(bio, BIO_CLONED));
8177 bio_for_each_segment_all(bvec, bio, i) {
8178 ret = __readpage_endio_check(inode, io_bio, i, bvec->bv_page,
8179 bvec->bv_offset, done->start,
8180 bvec->bv_len);
8181 if (!ret)
8182 clean_io_failure(BTRFS_I(inode)->root->fs_info,
8183 failure_tree, io_tree, done->start,
8184 bvec->bv_page,
8185 btrfs_ino(BTRFS_I(inode)),
8186 bvec->bv_offset);
8187 else
8188 uptodate = 0;
8189 }
8190
8191 done->uptodate = uptodate;
8192 end:
8193 complete(&done->done);
8194 bio_put(bio);
8195 }
8196
8197 static blk_status_t __btrfs_subio_endio_read(struct inode *inode,
8198 struct btrfs_io_bio *io_bio, blk_status_t err)
8199 {
8200 struct btrfs_fs_info *fs_info;
8201 struct bio_vec bvec;
8202 struct bvec_iter iter;
8203 struct btrfs_retry_complete done;
8204 u64 start;
8205 u64 offset = 0;
8206 u32 sectorsize;
8207 int nr_sectors;
8208 unsigned int pgoff;
8209 int csum_pos;
8210 bool uptodate = (err == 0);
8211 int ret;
8212 blk_status_t status;
8213
8214 fs_info = BTRFS_I(inode)->root->fs_info;
8215 sectorsize = fs_info->sectorsize;
8216
8217 err = BLK_STS_OK;
8218 start = io_bio->logical;
8219 done.inode = inode;
8220 io_bio->bio.bi_iter = io_bio->iter;
8221
8222 bio_for_each_segment(bvec, &io_bio->bio, iter) {
8223 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec.bv_len);
8224
8225 pgoff = bvec.bv_offset;
8226 next_block:
8227 if (uptodate) {
8228 csum_pos = BTRFS_BYTES_TO_BLKS(fs_info, offset);
8229 ret = __readpage_endio_check(inode, io_bio, csum_pos,
8230 bvec.bv_page, pgoff, start, sectorsize);
8231 if (likely(!ret))
8232 goto next;
8233 }
8234 try_again:
8235 done.uptodate = 0;
8236 done.start = start;
8237 init_completion(&done.done);
8238
8239 status = dio_read_error(inode, &io_bio->bio, bvec.bv_page,
8240 pgoff, start, start + sectorsize - 1,
8241 io_bio->mirror_num, btrfs_retry_endio,
8242 &done);
8243 if (status) {
8244 err = status;
8245 goto next;
8246 }
8247
8248 wait_for_completion_io(&done.done);
8249
8250 if (!done.uptodate) {
8251 /* We might have another mirror, so try again */
8252 goto try_again;
8253 }
8254 next:
8255 offset += sectorsize;
8256 start += sectorsize;
8257
8258 ASSERT(nr_sectors);
8259
8260 nr_sectors--;
8261 if (nr_sectors) {
8262 pgoff += sectorsize;
8263 ASSERT(pgoff < PAGE_SIZE);
8264 goto next_block;
8265 }
8266 }
8267
8268 return err;
8269 }
8270
8271 static blk_status_t btrfs_subio_endio_read(struct inode *inode,
8272 struct btrfs_io_bio *io_bio, blk_status_t err)
8273 {
8274 bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8275
8276 if (skip_csum) {
8277 if (unlikely(err))
8278 return __btrfs_correct_data_nocsum(inode, io_bio);
8279 else
8280 return BLK_STS_OK;
8281 } else {
8282 return __btrfs_subio_endio_read(inode, io_bio, err);
8283 }
8284 }
8285
8286 static void btrfs_endio_direct_read(struct bio *bio)
8287 {
8288 struct btrfs_dio_private *dip = bio->bi_private;
8289 struct inode *inode = dip->inode;
8290 struct bio *dio_bio;
8291 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8292 blk_status_t err = bio->bi_status;
8293
8294 if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED)
8295 err = btrfs_subio_endio_read(inode, io_bio, err);
8296
8297 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
8298 dip->logical_offset + dip->bytes - 1);
8299 dio_bio = dip->dio_bio;
8300
8301 kfree(dip);
8302
8303 dio_bio->bi_status = err;
8304 dio_end_io(dio_bio);
8305
8306 if (io_bio->end_io)
8307 io_bio->end_io(io_bio, blk_status_to_errno(err));
8308 bio_put(bio);
8309 }
8310
8311 static void __endio_write_update_ordered(struct inode *inode,
8312 const u64 offset, const u64 bytes,
8313 const bool uptodate)
8314 {
8315 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8316 struct btrfs_ordered_extent *ordered = NULL;
8317 struct btrfs_workqueue *wq;
8318 btrfs_work_func_t func;
8319 u64 ordered_offset = offset;
8320 u64 ordered_bytes = bytes;
8321 u64 last_offset;
8322
8323 if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
8324 wq = fs_info->endio_freespace_worker;
8325 func = btrfs_freespace_write_helper;
8326 } else {
8327 wq = fs_info->endio_write_workers;
8328 func = btrfs_endio_write_helper;
8329 }
8330
8331 while (ordered_offset < offset + bytes) {
8332 last_offset = ordered_offset;
8333 if (btrfs_dec_test_first_ordered_pending(inode, &ordered,
8334 &ordered_offset,
8335 ordered_bytes,
8336 uptodate)) {
8337 btrfs_init_work(&ordered->work, func,
8338 finish_ordered_fn,
8339 NULL, NULL);
8340 btrfs_queue_work(wq, &ordered->work);
8341 }
8342 /*
8343 * If btrfs_dec_test_ordered_pending does not find any ordered
8344 * extent in the range, we can exit.
8345 */
8346 if (ordered_offset == last_offset)
8347 return;
8348 /*
8349 * Our bio might span multiple ordered extents. In this case
8350 * we keep goin until we have accounted the whole dio.
8351 */
8352 if (ordered_offset < offset + bytes) {
8353 ordered_bytes = offset + bytes - ordered_offset;
8354 ordered = NULL;
8355 }
8356 }
8357 }
8358
8359 static void btrfs_endio_direct_write(struct bio *bio)
8360 {
8361 struct btrfs_dio_private *dip = bio->bi_private;
8362 struct bio *dio_bio = dip->dio_bio;
8363
8364 __endio_write_update_ordered(dip->inode, dip->logical_offset,
8365 dip->bytes, !bio->bi_status);
8366
8367 kfree(dip);
8368
8369 dio_bio->bi_status = bio->bi_status;
8370 dio_end_io(dio_bio);
8371 bio_put(bio);
8372 }
8373
8374 static blk_status_t btrfs_submit_bio_start_direct_io(void *private_data,
8375 struct bio *bio, u64 offset)
8376 {
8377 struct inode *inode = private_data;
8378 blk_status_t ret;
8379 ret = btrfs_csum_one_bio(inode, bio, offset, 1);
8380 BUG_ON(ret); /* -ENOMEM */
8381 return 0;
8382 }
8383
8384 static void btrfs_end_dio_bio(struct bio *bio)
8385 {
8386 struct btrfs_dio_private *dip = bio->bi_private;
8387 blk_status_t err = bio->bi_status;
8388
8389 if (err)
8390 btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
8391 "direct IO failed ino %llu rw %d,%u sector %#Lx len %u err no %d",
8392 btrfs_ino(BTRFS_I(dip->inode)), bio_op(bio),
8393 bio->bi_opf,
8394 (unsigned long long)bio->bi_iter.bi_sector,
8395 bio->bi_iter.bi_size, err);
8396
8397 if (dip->subio_endio)
8398 err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err);
8399
8400 if (err) {
8401 /*
8402 * We want to perceive the errors flag being set before
8403 * decrementing the reference count. We don't need a barrier
8404 * since atomic operations with a return value are fully
8405 * ordered as per atomic_t.txt
8406 */
8407 dip->errors = 1;
8408 }
8409
8410 /* if there are more bios still pending for this dio, just exit */
8411 if (!atomic_dec_and_test(&dip->pending_bios))
8412 goto out;
8413
8414 if (dip->errors) {
8415 bio_io_error(dip->orig_bio);
8416 } else {
8417 dip->dio_bio->bi_status = BLK_STS_OK;
8418 bio_endio(dip->orig_bio);
8419 }
8420 out:
8421 bio_put(bio);
8422 }
8423
8424 static inline blk_status_t btrfs_lookup_and_bind_dio_csum(struct inode *inode,
8425 struct btrfs_dio_private *dip,
8426 struct bio *bio,
8427 u64 file_offset)
8428 {
8429 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8430 struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio);
8431 blk_status_t ret;
8432
8433 /*
8434 * We load all the csum data we need when we submit
8435 * the first bio to reduce the csum tree search and
8436 * contention.
8437 */
8438 if (dip->logical_offset == file_offset) {
8439 ret = btrfs_lookup_bio_sums_dio(inode, dip->orig_bio,
8440 file_offset);
8441 if (ret)
8442 return ret;
8443 }
8444
8445 if (bio == dip->orig_bio)
8446 return 0;
8447
8448 file_offset -= dip->logical_offset;
8449 file_offset >>= inode->i_sb->s_blocksize_bits;
8450 io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset);
8451
8452 return 0;
8453 }
8454
8455 static inline blk_status_t btrfs_submit_dio_bio(struct bio *bio,
8456 struct inode *inode, u64 file_offset, int async_submit)
8457 {
8458 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8459 struct btrfs_dio_private *dip = bio->bi_private;
8460 bool write = bio_op(bio) == REQ_OP_WRITE;
8461 blk_status_t ret;
8462
8463 /* Check btrfs_submit_bio_hook() for rules about async submit. */
8464 if (async_submit)
8465 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
8466
8467 if (!write) {
8468 ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DATA);
8469 if (ret)
8470 goto err;
8471 }
8472
8473 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
8474 goto map;
8475
8476 if (write && async_submit) {
8477 ret = btrfs_wq_submit_bio(fs_info, bio, 0, 0,
8478 file_offset, inode,
8479 btrfs_submit_bio_start_direct_io,
8480 btrfs_submit_bio_done);
8481 goto err;
8482 } else if (write) {
8483 /*
8484 * If we aren't doing async submit, calculate the csum of the
8485 * bio now.
8486 */
8487 ret = btrfs_csum_one_bio(inode, bio, file_offset, 1);
8488 if (ret)
8489 goto err;
8490 } else {
8491 ret = btrfs_lookup_and_bind_dio_csum(inode, dip, bio,
8492 file_offset);
8493 if (ret)
8494 goto err;
8495 }
8496 map:
8497 ret = btrfs_map_bio(fs_info, bio, 0, 0);
8498 err:
8499 return ret;
8500 }
8501
8502 static int btrfs_submit_direct_hook(struct btrfs_dio_private *dip)
8503 {
8504 struct inode *inode = dip->inode;
8505 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8506 struct bio *bio;
8507 struct bio *orig_bio = dip->orig_bio;
8508 u64 start_sector = orig_bio->bi_iter.bi_sector;
8509 u64 file_offset = dip->logical_offset;
8510 u64 map_length;
8511 int async_submit = 0;
8512 u64 submit_len;
8513 int clone_offset = 0;
8514 int clone_len;
8515 int ret;
8516 blk_status_t status;
8517
8518 map_length = orig_bio->bi_iter.bi_size;
8519 submit_len = map_length;
8520 ret = btrfs_map_block(fs_info, btrfs_op(orig_bio), start_sector << 9,
8521 &map_length, NULL, 0);
8522 if (ret)
8523 return -EIO;
8524
8525 if (map_length >= submit_len) {
8526 bio = orig_bio;
8527 dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED;
8528 goto submit;
8529 }
8530
8531 /* async crcs make it difficult to collect full stripe writes. */
8532 if (btrfs_data_alloc_profile(fs_info) & BTRFS_BLOCK_GROUP_RAID56_MASK)
8533 async_submit = 0;
8534 else
8535 async_submit = 1;
8536
8537 /* bio split */
8538 ASSERT(map_length <= INT_MAX);
8539 atomic_inc(&dip->pending_bios);
8540 do {
8541 clone_len = min_t(int, submit_len, map_length);
8542
8543 /*
8544 * This will never fail as it's passing GPF_NOFS and
8545 * the allocation is backed by btrfs_bioset.
8546 */
8547 bio = btrfs_bio_clone_partial(orig_bio, clone_offset,
8548 clone_len);
8549 bio->bi_private = dip;
8550 bio->bi_end_io = btrfs_end_dio_bio;
8551 btrfs_io_bio(bio)->logical = file_offset;
8552
8553 ASSERT(submit_len >= clone_len);
8554 submit_len -= clone_len;
8555 if (submit_len == 0)
8556 break;
8557
8558 /*
8559 * Increase the count before we submit the bio so we know
8560 * the end IO handler won't happen before we increase the
8561 * count. Otherwise, the dip might get freed before we're
8562 * done setting it up.
8563 */
8564 atomic_inc(&dip->pending_bios);
8565
8566 status = btrfs_submit_dio_bio(bio, inode, file_offset,
8567 async_submit);
8568 if (status) {
8569 bio_put(bio);
8570 atomic_dec(&dip->pending_bios);
8571 goto out_err;
8572 }
8573
8574 clone_offset += clone_len;
8575 start_sector += clone_len >> 9;
8576 file_offset += clone_len;
8577
8578 map_length = submit_len;
8579 ret = btrfs_map_block(fs_info, btrfs_op(orig_bio),
8580 start_sector << 9, &map_length, NULL, 0);
8581 if (ret)
8582 goto out_err;
8583 } while (submit_len > 0);
8584
8585 submit:
8586 status = btrfs_submit_dio_bio(bio, inode, file_offset, async_submit);
8587 if (!status)
8588 return 0;
8589
8590 bio_put(bio);
8591 out_err:
8592 dip->errors = 1;
8593 /*
8594 * Before atomic variable goto zero, we must make sure dip->errors is
8595 * perceived to be set. This ordering is ensured by the fact that an
8596 * atomic operations with a return value are fully ordered as per
8597 * atomic_t.txt
8598 */
8599 if (atomic_dec_and_test(&dip->pending_bios))
8600 bio_io_error(dip->orig_bio);
8601
8602 /* bio_end_io() will handle error, so we needn't return it */
8603 return 0;
8604 }
8605
8606 static void btrfs_submit_direct(struct bio *dio_bio, struct inode *inode,
8607 loff_t file_offset)
8608 {
8609 struct btrfs_dio_private *dip = NULL;
8610 struct bio *bio = NULL;
8611 struct btrfs_io_bio *io_bio;
8612 bool write = (bio_op(dio_bio) == REQ_OP_WRITE);
8613 int ret = 0;
8614
8615 bio = btrfs_bio_clone(dio_bio);
8616
8617 dip = kzalloc(sizeof(*dip), GFP_NOFS);
8618 if (!dip) {
8619 ret = -ENOMEM;
8620 goto free_ordered;
8621 }
8622
8623 dip->private = dio_bio->bi_private;
8624 dip->inode = inode;
8625 dip->logical_offset = file_offset;
8626 dip->bytes = dio_bio->bi_iter.bi_size;
8627 dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
8628 bio->bi_private = dip;
8629 dip->orig_bio = bio;
8630 dip->dio_bio = dio_bio;
8631 atomic_set(&dip->pending_bios, 0);
8632 io_bio = btrfs_io_bio(bio);
8633 io_bio->logical = file_offset;
8634
8635 if (write) {
8636 bio->bi_end_io = btrfs_endio_direct_write;
8637 } else {
8638 bio->bi_end_io = btrfs_endio_direct_read;
8639 dip->subio_endio = btrfs_subio_endio_read;
8640 }
8641
8642 /*
8643 * Reset the range for unsubmitted ordered extents (to a 0 length range)
8644 * even if we fail to submit a bio, because in such case we do the
8645 * corresponding error handling below and it must not be done a second
8646 * time by btrfs_direct_IO().
8647 */
8648 if (write) {
8649 struct btrfs_dio_data *dio_data = current->journal_info;
8650
8651 dio_data->unsubmitted_oe_range_end = dip->logical_offset +
8652 dip->bytes;
8653 dio_data->unsubmitted_oe_range_start =
8654 dio_data->unsubmitted_oe_range_end;
8655 }
8656
8657 ret = btrfs_submit_direct_hook(dip);
8658 if (!ret)
8659 return;
8660
8661 if (io_bio->end_io)
8662 io_bio->end_io(io_bio, ret);
8663
8664 free_ordered:
8665 /*
8666 * If we arrived here it means either we failed to submit the dip
8667 * or we either failed to clone the dio_bio or failed to allocate the
8668 * dip. If we cloned the dio_bio and allocated the dip, we can just
8669 * call bio_endio against our io_bio so that we get proper resource
8670 * cleanup if we fail to submit the dip, otherwise, we must do the
8671 * same as btrfs_endio_direct_[write|read] because we can't call these
8672 * callbacks - they require an allocated dip and a clone of dio_bio.
8673 */
8674 if (bio && dip) {
8675 bio_io_error(bio);
8676 /*
8677 * The end io callbacks free our dip, do the final put on bio
8678 * and all the cleanup and final put for dio_bio (through
8679 * dio_end_io()).
8680 */
8681 dip = NULL;
8682 bio = NULL;
8683 } else {
8684 if (write)
8685 __endio_write_update_ordered(inode,
8686 file_offset,
8687 dio_bio->bi_iter.bi_size,
8688 false);
8689 else
8690 unlock_extent(&BTRFS_I(inode)->io_tree, file_offset,
8691 file_offset + dio_bio->bi_iter.bi_size - 1);
8692
8693 dio_bio->bi_status = BLK_STS_IOERR;
8694 /*
8695 * Releases and cleans up our dio_bio, no need to bio_put()
8696 * nor bio_endio()/bio_io_error() against dio_bio.
8697 */
8698 dio_end_io(dio_bio);
8699 }
8700 if (bio)
8701 bio_put(bio);
8702 kfree(dip);
8703 }
8704
8705 static ssize_t check_direct_IO(struct btrfs_fs_info *fs_info,
8706 const struct iov_iter *iter, loff_t offset)
8707 {
8708 int seg;
8709 int i;
8710 unsigned int blocksize_mask = fs_info->sectorsize - 1;
8711 ssize_t retval = -EINVAL;
8712
8713 if (offset & blocksize_mask)
8714 goto out;
8715
8716 if (iov_iter_alignment(iter) & blocksize_mask)
8717 goto out;
8718
8719 /* If this is a write we don't need to check anymore */
8720 if (iov_iter_rw(iter) != READ || !iter_is_iovec(iter))
8721 return 0;
8722 /*
8723 * Check to make sure we don't have duplicate iov_base's in this
8724 * iovec, if so return EINVAL, otherwise we'll get csum errors
8725 * when reading back.
8726 */
8727 for (seg = 0; seg < iter->nr_segs; seg++) {
8728 for (i = seg + 1; i < iter->nr_segs; i++) {
8729 if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
8730 goto out;
8731 }
8732 }
8733 retval = 0;
8734 out:
8735 return retval;
8736 }
8737
8738 static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
8739 {
8740 struct file *file = iocb->ki_filp;
8741 struct inode *inode = file->f_mapping->host;
8742 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8743 struct btrfs_dio_data dio_data = { 0 };
8744 struct extent_changeset *data_reserved = NULL;
8745 loff_t offset = iocb->ki_pos;
8746 size_t count = 0;
8747 int flags = 0;
8748 bool wakeup = true;
8749 bool relock = false;
8750 ssize_t ret;
8751
8752 if (check_direct_IO(fs_info, iter, offset))
8753 return 0;
8754
8755 inode_dio_begin(inode);
8756
8757 /*
8758 * The generic stuff only does filemap_write_and_wait_range, which
8759 * isn't enough if we've written compressed pages to this area, so
8760 * we need to flush the dirty pages again to make absolutely sure
8761 * that any outstanding dirty pages are on disk.
8762 */
8763 count = iov_iter_count(iter);
8764 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
8765 &BTRFS_I(inode)->runtime_flags))
8766 filemap_fdatawrite_range(inode->i_mapping, offset,
8767 offset + count - 1);
8768
8769 if (iov_iter_rw(iter) == WRITE) {
8770 /*
8771 * If the write DIO is beyond the EOF, we need update
8772 * the isize, but it is protected by i_mutex. So we can
8773 * not unlock the i_mutex at this case.
8774 */
8775 if (offset + count <= inode->i_size) {
8776 dio_data.overwrite = 1;
8777 inode_unlock(inode);
8778 relock = true;
8779 } else if (iocb->ki_flags & IOCB_NOWAIT) {
8780 ret = -EAGAIN;
8781 goto out;
8782 }
8783 ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
8784 offset, count);
8785 if (ret)
8786 goto out;
8787
8788 /*
8789 * We need to know how many extents we reserved so that we can
8790 * do the accounting properly if we go over the number we
8791 * originally calculated. Abuse current->journal_info for this.
8792 */
8793 dio_data.reserve = round_up(count,
8794 fs_info->sectorsize);
8795 dio_data.unsubmitted_oe_range_start = (u64)offset;
8796 dio_data.unsubmitted_oe_range_end = (u64)offset;
8797 current->journal_info = &dio_data;
8798 down_read(&BTRFS_I(inode)->dio_sem);
8799 } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
8800 &BTRFS_I(inode)->runtime_flags)) {
8801 inode_dio_end(inode);
8802 flags = DIO_LOCKING | DIO_SKIP_HOLES;
8803 wakeup = false;
8804 }
8805
8806 ret = __blockdev_direct_IO(iocb, inode,
8807 fs_info->fs_devices->latest_bdev,
8808 iter, btrfs_get_blocks_direct, NULL,
8809 btrfs_submit_direct, flags);
8810 if (iov_iter_rw(iter) == WRITE) {
8811 up_read(&BTRFS_I(inode)->dio_sem);
8812 current->journal_info = NULL;
8813 if (ret < 0 && ret != -EIOCBQUEUED) {
8814 if (dio_data.reserve)
8815 btrfs_delalloc_release_space(inode, data_reserved,
8816 offset, dio_data.reserve, true);
8817 /*
8818 * On error we might have left some ordered extents
8819 * without submitting corresponding bios for them, so
8820 * cleanup them up to avoid other tasks getting them
8821 * and waiting for them to complete forever.
8822 */
8823 if (dio_data.unsubmitted_oe_range_start <
8824 dio_data.unsubmitted_oe_range_end)
8825 __endio_write_update_ordered(inode,
8826 dio_data.unsubmitted_oe_range_start,
8827 dio_data.unsubmitted_oe_range_end -
8828 dio_data.unsubmitted_oe_range_start,
8829 false);
8830 } else if (ret >= 0 && (size_t)ret < count)
8831 btrfs_delalloc_release_space(inode, data_reserved,
8832 offset, count - (size_t)ret, true);
8833 btrfs_delalloc_release_extents(BTRFS_I(inode), count, false);
8834 }
8835 out:
8836 if (wakeup)
8837 inode_dio_end(inode);
8838 if (relock)
8839 inode_lock(inode);
8840
8841 extent_changeset_free(data_reserved);
8842 return ret;
8843 }
8844
8845 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
8846
8847 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
8848 __u64 start, __u64 len)
8849 {
8850 int ret;
8851
8852 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
8853 if (ret)
8854 return ret;
8855
8856 return extent_fiemap(inode, fieinfo, start, len);
8857 }
8858
8859 int btrfs_readpage(struct file *file, struct page *page)
8860 {
8861 struct extent_io_tree *tree;
8862 tree = &BTRFS_I(page->mapping->host)->io_tree;
8863 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
8864 }
8865
8866 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
8867 {
8868 struct inode *inode = page->mapping->host;
8869 int ret;
8870
8871 if (current->flags & PF_MEMALLOC) {
8872 redirty_page_for_writepage(wbc, page);
8873 unlock_page(page);
8874 return 0;
8875 }
8876
8877 /*
8878 * If we are under memory pressure we will call this directly from the
8879 * VM, we need to make sure we have the inode referenced for the ordered
8880 * extent. If not just return like we didn't do anything.
8881 */
8882 if (!igrab(inode)) {
8883 redirty_page_for_writepage(wbc, page);
8884 return AOP_WRITEPAGE_ACTIVATE;
8885 }
8886 ret = extent_write_full_page(page, wbc);
8887 btrfs_add_delayed_iput(inode);
8888 return ret;
8889 }
8890
8891 static int btrfs_writepages(struct address_space *mapping,
8892 struct writeback_control *wbc)
8893 {
8894 return extent_writepages(mapping, wbc);
8895 }
8896
8897 static int
8898 btrfs_readpages(struct file *file, struct address_space *mapping,
8899 struct list_head *pages, unsigned nr_pages)
8900 {
8901 return extent_readpages(mapping, pages, nr_pages);
8902 }
8903
8904 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8905 {
8906 int ret = try_release_extent_mapping(page, gfp_flags);
8907 if (ret == 1) {
8908 ClearPagePrivate(page);
8909 set_page_private(page, 0);
8910 put_page(page);
8911 }
8912 return ret;
8913 }
8914
8915 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8916 {
8917 if (PageWriteback(page) || PageDirty(page))
8918 return 0;
8919 return __btrfs_releasepage(page, gfp_flags);
8920 }
8921
8922 static void btrfs_invalidatepage(struct page *page, unsigned int offset,
8923 unsigned int length)
8924 {
8925 struct inode *inode = page->mapping->host;
8926 struct extent_io_tree *tree;
8927 struct btrfs_ordered_extent *ordered;
8928 struct extent_state *cached_state = NULL;
8929 u64 page_start = page_offset(page);
8930 u64 page_end = page_start + PAGE_SIZE - 1;
8931 u64 start;
8932 u64 end;
8933 int inode_evicting = inode->i_state & I_FREEING;
8934
8935 /*
8936 * we have the page locked, so new writeback can't start,
8937 * and the dirty bit won't be cleared while we are here.
8938 *
8939 * Wait for IO on this page so that we can safely clear
8940 * the PagePrivate2 bit and do ordered accounting
8941 */
8942 wait_on_page_writeback(page);
8943
8944 tree = &BTRFS_I(inode)->io_tree;
8945 if (offset) {
8946 btrfs_releasepage(page, GFP_NOFS);
8947 return;
8948 }
8949
8950 if (!inode_evicting)
8951 lock_extent_bits(tree, page_start, page_end, &cached_state);
8952 again:
8953 start = page_start;
8954 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), start,
8955 page_end - start + 1);
8956 if (ordered) {
8957 end = min(page_end, ordered->file_offset + ordered->len - 1);
8958 /*
8959 * IO on this page will never be started, so we need
8960 * to account for any ordered extents now
8961 */
8962 if (!inode_evicting)
8963 clear_extent_bit(tree, start, end,
8964 EXTENT_DIRTY | EXTENT_DELALLOC |
8965 EXTENT_DELALLOC_NEW |
8966 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
8967 EXTENT_DEFRAG, 1, 0, &cached_state);
8968 /*
8969 * whoever cleared the private bit is responsible
8970 * for the finish_ordered_io
8971 */
8972 if (TestClearPagePrivate2(page)) {
8973 struct btrfs_ordered_inode_tree *tree;
8974 u64 new_len;
8975
8976 tree = &BTRFS_I(inode)->ordered_tree;
8977
8978 spin_lock_irq(&tree->lock);
8979 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
8980 new_len = start - ordered->file_offset;
8981 if (new_len < ordered->truncated_len)
8982 ordered->truncated_len = new_len;
8983 spin_unlock_irq(&tree->lock);
8984
8985 if (btrfs_dec_test_ordered_pending(inode, &ordered,
8986 start,
8987 end - start + 1, 1))
8988 btrfs_finish_ordered_io(ordered);
8989 }
8990 btrfs_put_ordered_extent(ordered);
8991 if (!inode_evicting) {
8992 cached_state = NULL;
8993 lock_extent_bits(tree, start, end,
8994 &cached_state);
8995 }
8996
8997 start = end + 1;
8998 if (start < page_end)
8999 goto again;
9000 }
9001
9002 /*
9003 * Qgroup reserved space handler
9004 * Page here will be either
9005 * 1) Already written to disk
9006 * In this case, its reserved space is released from data rsv map
9007 * and will be freed by delayed_ref handler finally.
9008 * So even we call qgroup_free_data(), it won't decrease reserved
9009 * space.
9010 * 2) Not written to disk
9011 * This means the reserved space should be freed here. However,
9012 * if a truncate invalidates the page (by clearing PageDirty)
9013 * and the page is accounted for while allocating extent
9014 * in btrfs_check_data_free_space() we let delayed_ref to
9015 * free the entire extent.
9016 */
9017 if (PageDirty(page))
9018 btrfs_qgroup_free_data(inode, NULL, page_start, PAGE_SIZE);
9019 if (!inode_evicting) {
9020 clear_extent_bit(tree, page_start, page_end,
9021 EXTENT_LOCKED | EXTENT_DIRTY |
9022 EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
9023 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1,
9024 &cached_state);
9025
9026 __btrfs_releasepage(page, GFP_NOFS);
9027 }
9028
9029 ClearPageChecked(page);
9030 if (PagePrivate(page)) {
9031 ClearPagePrivate(page);
9032 set_page_private(page, 0);
9033 put_page(page);
9034 }
9035 }
9036
9037 /*
9038 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
9039 * called from a page fault handler when a page is first dirtied. Hence we must
9040 * be careful to check for EOF conditions here. We set the page up correctly
9041 * for a written page which means we get ENOSPC checking when writing into
9042 * holes and correct delalloc and unwritten extent mapping on filesystems that
9043 * support these features.
9044 *
9045 * We are not allowed to take the i_mutex here so we have to play games to
9046 * protect against truncate races as the page could now be beyond EOF. Because
9047 * vmtruncate() writes the inode size before removing pages, once we have the
9048 * page lock we can determine safely if the page is beyond EOF. If it is not
9049 * beyond EOF, then the page is guaranteed safe against truncation until we
9050 * unlock the page.
9051 */
9052 int btrfs_page_mkwrite(struct vm_fault *vmf)
9053 {
9054 struct page *page = vmf->page;
9055 struct inode *inode = file_inode(vmf->vma->vm_file);
9056 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
9057 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
9058 struct btrfs_ordered_extent *ordered;
9059 struct extent_state *cached_state = NULL;
9060 struct extent_changeset *data_reserved = NULL;
9061 char *kaddr;
9062 unsigned long zero_start;
9063 loff_t size;
9064 int ret;
9065 int reserved = 0;
9066 u64 reserved_space;
9067 u64 page_start;
9068 u64 page_end;
9069 u64 end;
9070
9071 reserved_space = PAGE_SIZE;
9072
9073 sb_start_pagefault(inode->i_sb);
9074 page_start = page_offset(page);
9075 page_end = page_start + PAGE_SIZE - 1;
9076 end = page_end;
9077
9078 /*
9079 * Reserving delalloc space after obtaining the page lock can lead to
9080 * deadlock. For example, if a dirty page is locked by this function
9081 * and the call to btrfs_delalloc_reserve_space() ends up triggering
9082 * dirty page write out, then the btrfs_writepage() function could
9083 * end up waiting indefinitely to get a lock on the page currently
9084 * being processed by btrfs_page_mkwrite() function.
9085 */
9086 ret = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start,
9087 reserved_space);
9088 if (!ret) {
9089 ret = file_update_time(vmf->vma->vm_file);
9090 reserved = 1;
9091 }
9092 if (ret) {
9093 if (ret == -ENOMEM)
9094 ret = VM_FAULT_OOM;
9095 else /* -ENOSPC, -EIO, etc */
9096 ret = VM_FAULT_SIGBUS;
9097 if (reserved)
9098 goto out;
9099 goto out_noreserve;
9100 }
9101
9102 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
9103 again:
9104 lock_page(page);
9105 size = i_size_read(inode);
9106
9107 if ((page->mapping != inode->i_mapping) ||
9108 (page_start >= size)) {
9109 /* page got truncated out from underneath us */
9110 goto out_unlock;
9111 }
9112 wait_on_page_writeback(page);
9113
9114 lock_extent_bits(io_tree, page_start, page_end, &cached_state);
9115 set_page_extent_mapped(page);
9116
9117 /*
9118 * we can't set the delalloc bits if there are pending ordered
9119 * extents. Drop our locks and wait for them to finish
9120 */
9121 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start,
9122 PAGE_SIZE);
9123 if (ordered) {
9124 unlock_extent_cached(io_tree, page_start, page_end,
9125 &cached_state);
9126 unlock_page(page);
9127 btrfs_start_ordered_extent(inode, ordered, 1);
9128 btrfs_put_ordered_extent(ordered);
9129 goto again;
9130 }
9131
9132 if (page->index == ((size - 1) >> PAGE_SHIFT)) {
9133 reserved_space = round_up(size - page_start,
9134 fs_info->sectorsize);
9135 if (reserved_space < PAGE_SIZE) {
9136 end = page_start + reserved_space - 1;
9137 btrfs_delalloc_release_space(inode, data_reserved,
9138 page_start, PAGE_SIZE - reserved_space,
9139 true);
9140 }
9141 }
9142
9143 /*
9144 * page_mkwrite gets called when the page is firstly dirtied after it's
9145 * faulted in, but write(2) could also dirty a page and set delalloc
9146 * bits, thus in this case for space account reason, we still need to
9147 * clear any delalloc bits within this page range since we have to
9148 * reserve data&meta space before lock_page() (see above comments).
9149 */
9150 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end,
9151 EXTENT_DIRTY | EXTENT_DELALLOC |
9152 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
9153 0, 0, &cached_state);
9154
9155 ret = btrfs_set_extent_delalloc(inode, page_start, end, 0,
9156 &cached_state, 0);
9157 if (ret) {
9158 unlock_extent_cached(io_tree, page_start, page_end,
9159 &cached_state);
9160 ret = VM_FAULT_SIGBUS;
9161 goto out_unlock;
9162 }
9163 ret = 0;
9164
9165 /* page is wholly or partially inside EOF */
9166 if (page_start + PAGE_SIZE > size)
9167 zero_start = size & ~PAGE_MASK;
9168 else
9169 zero_start = PAGE_SIZE;
9170
9171 if (zero_start != PAGE_SIZE) {
9172 kaddr = kmap(page);
9173 memset(kaddr + zero_start, 0, PAGE_SIZE - zero_start);
9174 flush_dcache_page(page);
9175 kunmap(page);
9176 }
9177 ClearPageChecked(page);
9178 set_page_dirty(page);
9179 SetPageUptodate(page);
9180
9181 BTRFS_I(inode)->last_trans = fs_info->generation;
9182 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
9183 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
9184
9185 unlock_extent_cached(io_tree, page_start, page_end, &cached_state);
9186
9187 out_unlock:
9188 if (!ret) {
9189 btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE, true);
9190 sb_end_pagefault(inode->i_sb);
9191 extent_changeset_free(data_reserved);
9192 return VM_FAULT_LOCKED;
9193 }
9194 unlock_page(page);
9195 out:
9196 btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE, (ret != 0));
9197 btrfs_delalloc_release_space(inode, data_reserved, page_start,
9198 reserved_space, (ret != 0));
9199 out_noreserve:
9200 sb_end_pagefault(inode->i_sb);
9201 extent_changeset_free(data_reserved);
9202 return ret;
9203 }
9204
9205 static int btrfs_truncate(struct inode *inode, bool skip_writeback)
9206 {
9207 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
9208 struct btrfs_root *root = BTRFS_I(inode)->root;
9209 struct btrfs_block_rsv *rsv;
9210 int ret = 0;
9211 int err = 0;
9212 struct btrfs_trans_handle *trans;
9213 u64 mask = fs_info->sectorsize - 1;
9214 u64 min_size = btrfs_calc_trunc_metadata_size(fs_info, 1);
9215
9216 if (!skip_writeback) {
9217 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
9218 (u64)-1);
9219 if (ret)
9220 return ret;
9221 }
9222
9223 /*
9224 * Yes ladies and gentlemen, this is indeed ugly. The fact is we have
9225 * 3 things going on here
9226 *
9227 * 1) We need to reserve space for our orphan item and the space to
9228 * delete our orphan item. Lord knows we don't want to have a dangling
9229 * orphan item because we didn't reserve space to remove it.
9230 *
9231 * 2) We need to reserve space to update our inode.
9232 *
9233 * 3) We need to have something to cache all the space that is going to
9234 * be free'd up by the truncate operation, but also have some slack
9235 * space reserved in case it uses space during the truncate (thank you
9236 * very much snapshotting).
9237 *
9238 * And we need these to all be separate. The fact is we can use a lot of
9239 * space doing the truncate, and we have no earthly idea how much space
9240 * we will use, so we need the truncate reservation to be separate so it
9241 * doesn't end up using space reserved for updating the inode or
9242 * removing the orphan item. We also need to be able to stop the
9243 * transaction and start a new one, which means we need to be able to
9244 * update the inode several times, and we have no idea of knowing how
9245 * many times that will be, so we can't just reserve 1 item for the
9246 * entirety of the operation, so that has to be done separately as well.
9247 * Then there is the orphan item, which does indeed need to be held on
9248 * to for the whole operation, and we need nobody to touch this reserved
9249 * space except the orphan code.
9250 *
9251 * So that leaves us with
9252 *
9253 * 1) root->orphan_block_rsv - for the orphan deletion.
9254 * 2) rsv - for the truncate reservation, which we will steal from the
9255 * transaction reservation.
9256 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
9257 * updating the inode.
9258 */
9259 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
9260 if (!rsv)
9261 return -ENOMEM;
9262 rsv->size = min_size;
9263 rsv->failfast = 1;
9264
9265 /*
9266 * 1 for the truncate slack space
9267 * 1 for updating the inode.
9268 */
9269 trans = btrfs_start_transaction(root, 2);
9270 if (IS_ERR(trans)) {
9271 err = PTR_ERR(trans);
9272 goto out;
9273 }
9274
9275 /* Migrate the slack space for the truncate to our reserve */
9276 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
9277 min_size, 0);
9278 BUG_ON(ret);
9279
9280 /*
9281 * So if we truncate and then write and fsync we normally would just
9282 * write the extents that changed, which is a problem if we need to
9283 * first truncate that entire inode. So set this flag so we write out
9284 * all of the extents in the inode to the sync log so we're completely
9285 * safe.
9286 */
9287 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
9288 trans->block_rsv = rsv;
9289
9290 while (1) {
9291 ret = btrfs_truncate_inode_items(trans, root, inode,
9292 inode->i_size,
9293 BTRFS_EXTENT_DATA_KEY);
9294 trans->block_rsv = &fs_info->trans_block_rsv;
9295 if (ret != -ENOSPC && ret != -EAGAIN) {
9296 if (ret < 0)
9297 err = ret;
9298 break;
9299 }
9300
9301 ret = btrfs_update_inode(trans, root, inode);
9302 if (ret) {
9303 err = ret;
9304 break;
9305 }
9306
9307 btrfs_end_transaction(trans);
9308 btrfs_btree_balance_dirty(fs_info);
9309
9310 trans = btrfs_start_transaction(root, 2);
9311 if (IS_ERR(trans)) {
9312 ret = err = PTR_ERR(trans);
9313 trans = NULL;
9314 break;
9315 }
9316
9317 btrfs_block_rsv_release(fs_info, rsv, -1);
9318 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
9319 rsv, min_size, 0);
9320 BUG_ON(ret); /* shouldn't happen */
9321 trans->block_rsv = rsv;
9322 }
9323
9324 /*
9325 * We can't call btrfs_truncate_block inside a trans handle as we could
9326 * deadlock with freeze, if we got NEED_TRUNCATE_BLOCK then we know
9327 * we've truncated everything except the last little bit, and can do
9328 * btrfs_truncate_block and then update the disk_i_size.
9329 */
9330 if (ret == NEED_TRUNCATE_BLOCK) {
9331 btrfs_end_transaction(trans);
9332 btrfs_btree_balance_dirty(fs_info);
9333
9334 ret = btrfs_truncate_block(inode, inode->i_size, 0, 0);
9335 if (ret)
9336 goto out;
9337 trans = btrfs_start_transaction(root, 1);
9338 if (IS_ERR(trans)) {
9339 ret = PTR_ERR(trans);
9340 goto out;
9341 }
9342 btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
9343 }
9344
9345 if (ret == 0 && inode->i_nlink > 0) {
9346 trans->block_rsv = root->orphan_block_rsv;
9347 ret = btrfs_orphan_del(trans, BTRFS_I(inode));
9348 if (ret)
9349 err = ret;
9350 }
9351
9352 if (trans) {
9353 trans->block_rsv = &fs_info->trans_block_rsv;
9354 ret = btrfs_update_inode(trans, root, inode);
9355 if (ret && !err)
9356 err = ret;
9357
9358 ret = btrfs_end_transaction(trans);
9359 btrfs_btree_balance_dirty(fs_info);
9360 }
9361 out:
9362 btrfs_free_block_rsv(fs_info, rsv);
9363
9364 if (ret && !err)
9365 err = ret;
9366
9367 return err;
9368 }
9369
9370 /*
9371 * create a new subvolume directory/inode (helper for the ioctl).
9372 */
9373 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
9374 struct btrfs_root *new_root,
9375 struct btrfs_root *parent_root,
9376 u64 new_dirid)
9377 {
9378 struct inode *inode;
9379 int err;
9380 u64 index = 0;
9381
9382 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
9383 new_dirid, new_dirid,
9384 S_IFDIR | (~current_umask() & S_IRWXUGO),
9385 &index);
9386 if (IS_ERR(inode))
9387 return PTR_ERR(inode);
9388 inode->i_op = &btrfs_dir_inode_operations;
9389 inode->i_fop = &btrfs_dir_file_operations;
9390
9391 set_nlink(inode, 1);
9392 btrfs_i_size_write(BTRFS_I(inode), 0);
9393 unlock_new_inode(inode);
9394
9395 err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
9396 if (err)
9397 btrfs_err(new_root->fs_info,
9398 "error inheriting subvolume %llu properties: %d",
9399 new_root->root_key.objectid, err);
9400
9401 err = btrfs_update_inode(trans, new_root, inode);
9402
9403 iput(inode);
9404 return err;
9405 }
9406
9407 struct inode *btrfs_alloc_inode(struct super_block *sb)
9408 {
9409 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
9410 struct btrfs_inode *ei;
9411 struct inode *inode;
9412
9413 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_KERNEL);
9414 if (!ei)
9415 return NULL;
9416
9417 ei->root = NULL;
9418 ei->generation = 0;
9419 ei->last_trans = 0;
9420 ei->last_sub_trans = 0;
9421 ei->logged_trans = 0;
9422 ei->delalloc_bytes = 0;
9423 ei->new_delalloc_bytes = 0;
9424 ei->defrag_bytes = 0;
9425 ei->disk_i_size = 0;
9426 ei->flags = 0;
9427 ei->csum_bytes = 0;
9428 ei->index_cnt = (u64)-1;
9429 ei->dir_index = 0;
9430 ei->last_unlink_trans = 0;
9431 ei->last_log_commit = 0;
9432
9433 spin_lock_init(&ei->lock);
9434 ei->outstanding_extents = 0;
9435 if (sb->s_magic != BTRFS_TEST_MAGIC)
9436 btrfs_init_metadata_block_rsv(fs_info, &ei->block_rsv,
9437 BTRFS_BLOCK_RSV_DELALLOC);
9438 ei->runtime_flags = 0;
9439 ei->prop_compress = BTRFS_COMPRESS_NONE;
9440 ei->defrag_compress = BTRFS_COMPRESS_NONE;
9441
9442 ei->delayed_node = NULL;
9443
9444 ei->i_otime.tv_sec = 0;
9445 ei->i_otime.tv_nsec = 0;
9446
9447 inode = &ei->vfs_inode;
9448 extent_map_tree_init(&ei->extent_tree);
9449 extent_io_tree_init(&ei->io_tree, inode);
9450 extent_io_tree_init(&ei->io_failure_tree, inode);
9451 ei->io_tree.track_uptodate = 1;
9452 ei->io_failure_tree.track_uptodate = 1;
9453 atomic_set(&ei->sync_writers, 0);
9454 mutex_init(&ei->log_mutex);
9455 mutex_init(&ei->delalloc_mutex);
9456 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
9457 INIT_LIST_HEAD(&ei->delalloc_inodes);
9458 INIT_LIST_HEAD(&ei->delayed_iput);
9459 RB_CLEAR_NODE(&ei->rb_node);
9460 init_rwsem(&ei->dio_sem);
9461
9462 return inode;
9463 }
9464
9465 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
9466 void btrfs_test_destroy_inode(struct inode *inode)
9467 {
9468 btrfs_drop_extent_cache(BTRFS_I(inode), 0, (u64)-1, 0);
9469 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9470 }
9471 #endif
9472
9473 static void btrfs_i_callback(struct rcu_head *head)
9474 {
9475 struct inode *inode = container_of(head, struct inode, i_rcu);
9476 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9477 }
9478
9479 void btrfs_destroy_inode(struct inode *inode)
9480 {
9481 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
9482 struct btrfs_ordered_extent *ordered;
9483 struct btrfs_root *root = BTRFS_I(inode)->root;
9484
9485 WARN_ON(!hlist_empty(&inode->i_dentry));
9486 WARN_ON(inode->i_data.nrpages);
9487 WARN_ON(BTRFS_I(inode)->block_rsv.reserved);
9488 WARN_ON(BTRFS_I(inode)->block_rsv.size);
9489 WARN_ON(BTRFS_I(inode)->outstanding_extents);
9490 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
9491 WARN_ON(BTRFS_I(inode)->new_delalloc_bytes);
9492 WARN_ON(BTRFS_I(inode)->csum_bytes);
9493 WARN_ON(BTRFS_I(inode)->defrag_bytes);
9494
9495 /*
9496 * This can happen where we create an inode, but somebody else also
9497 * created the same inode and we need to destroy the one we already
9498 * created.
9499 */
9500 if (!root)
9501 goto free;
9502
9503 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
9504 &BTRFS_I(inode)->runtime_flags)) {
9505 btrfs_info(fs_info, "inode %llu still on the orphan list",
9506 btrfs_ino(BTRFS_I(inode)));
9507 atomic_dec(&root->orphan_inodes);
9508 }
9509
9510 while (1) {
9511 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
9512 if (!ordered)
9513 break;
9514 else {
9515 btrfs_err(fs_info,
9516 "found ordered extent %llu %llu on inode cleanup",
9517 ordered->file_offset, ordered->len);
9518 btrfs_remove_ordered_extent(inode, ordered);
9519 btrfs_put_ordered_extent(ordered);
9520 btrfs_put_ordered_extent(ordered);
9521 }
9522 }
9523 btrfs_qgroup_check_reserved_leak(inode);
9524 inode_tree_del(inode);
9525 btrfs_drop_extent_cache(BTRFS_I(inode), 0, (u64)-1, 0);
9526 free:
9527 call_rcu(&inode->i_rcu, btrfs_i_callback);
9528 }
9529
9530 int btrfs_drop_inode(struct inode *inode)
9531 {
9532 struct btrfs_root *root = BTRFS_I(inode)->root;
9533
9534 if (root == NULL)
9535 return 1;
9536
9537 /* the snap/subvol tree is on deleting */
9538 if (btrfs_root_refs(&root->root_item) == 0)
9539 return 1;
9540 else
9541 return generic_drop_inode(inode);
9542 }
9543
9544 static void init_once(void *foo)
9545 {
9546 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
9547
9548 inode_init_once(&ei->vfs_inode);
9549 }
9550
9551 void __cold btrfs_destroy_cachep(void)
9552 {
9553 /*
9554 * Make sure all delayed rcu free inodes are flushed before we
9555 * destroy cache.
9556 */
9557 rcu_barrier();
9558 kmem_cache_destroy(btrfs_inode_cachep);
9559 kmem_cache_destroy(btrfs_trans_handle_cachep);
9560 kmem_cache_destroy(btrfs_path_cachep);
9561 kmem_cache_destroy(btrfs_free_space_cachep);
9562 }
9563
9564 int __init btrfs_init_cachep(void)
9565 {
9566 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
9567 sizeof(struct btrfs_inode), 0,
9568 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT,
9569 init_once);
9570 if (!btrfs_inode_cachep)
9571 goto fail;
9572
9573 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
9574 sizeof(struct btrfs_trans_handle), 0,
9575 SLAB_TEMPORARY | SLAB_MEM_SPREAD, NULL);
9576 if (!btrfs_trans_handle_cachep)
9577 goto fail;
9578
9579 btrfs_path_cachep = kmem_cache_create("btrfs_path",
9580 sizeof(struct btrfs_path), 0,
9581 SLAB_MEM_SPREAD, NULL);
9582 if (!btrfs_path_cachep)
9583 goto fail;
9584
9585 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
9586 sizeof(struct btrfs_free_space), 0,
9587 SLAB_MEM_SPREAD, NULL);
9588 if (!btrfs_free_space_cachep)
9589 goto fail;
9590
9591 return 0;
9592 fail:
9593 btrfs_destroy_cachep();
9594 return -ENOMEM;
9595 }
9596
9597 static int btrfs_getattr(const struct path *path, struct kstat *stat,
9598 u32 request_mask, unsigned int flags)
9599 {
9600 u64 delalloc_bytes;
9601 struct inode *inode = d_inode(path->dentry);
9602 u32 blocksize = inode->i_sb->s_blocksize;
9603 u32 bi_flags = BTRFS_I(inode)->flags;
9604
9605 stat->result_mask |= STATX_BTIME;
9606 stat->btime.tv_sec = BTRFS_I(inode)->i_otime.tv_sec;
9607 stat->btime.tv_nsec = BTRFS_I(inode)->i_otime.tv_nsec;
9608 if (bi_flags & BTRFS_INODE_APPEND)
9609 stat->attributes |= STATX_ATTR_APPEND;
9610 if (bi_flags & BTRFS_INODE_COMPRESS)
9611 stat->attributes |= STATX_ATTR_COMPRESSED;
9612 if (bi_flags & BTRFS_INODE_IMMUTABLE)
9613 stat->attributes |= STATX_ATTR_IMMUTABLE;
9614 if (bi_flags & BTRFS_INODE_NODUMP)
9615 stat->attributes |= STATX_ATTR_NODUMP;
9616
9617 stat->attributes_mask |= (STATX_ATTR_APPEND |
9618 STATX_ATTR_COMPRESSED |
9619 STATX_ATTR_IMMUTABLE |
9620 STATX_ATTR_NODUMP);
9621
9622 generic_fillattr(inode, stat);
9623 stat->dev = BTRFS_I(inode)->root->anon_dev;
9624
9625 spin_lock(&BTRFS_I(inode)->lock);
9626 delalloc_bytes = BTRFS_I(inode)->new_delalloc_bytes;
9627 spin_unlock(&BTRFS_I(inode)->lock);
9628 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
9629 ALIGN(delalloc_bytes, blocksize)) >> 9;
9630 return 0;
9631 }
9632
9633 static int btrfs_rename_exchange(struct inode *old_dir,
9634 struct dentry *old_dentry,
9635 struct inode *new_dir,
9636 struct dentry *new_dentry)
9637 {
9638 struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
9639 struct btrfs_trans_handle *trans;
9640 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9641 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9642 struct inode *new_inode = new_dentry->d_inode;
9643 struct inode *old_inode = old_dentry->d_inode;
9644 struct timespec ctime = current_time(old_inode);
9645 struct dentry *parent;
9646 u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
9647 u64 new_ino = btrfs_ino(BTRFS_I(new_inode));
9648 u64 old_idx = 0;
9649 u64 new_idx = 0;
9650 u64 root_objectid;
9651 int ret;
9652 bool root_log_pinned = false;
9653 bool dest_log_pinned = false;
9654
9655 /* we only allow rename subvolume link between subvolumes */
9656 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9657 return -EXDEV;
9658
9659 /* close the race window with snapshot create/destroy ioctl */
9660 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9661 down_read(&fs_info->subvol_sem);
9662 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9663 down_read(&fs_info->subvol_sem);
9664
9665 /*
9666 * We want to reserve the absolute worst case amount of items. So if
9667 * both inodes are subvols and we need to unlink them then that would
9668 * require 4 item modifications, but if they are both normal inodes it
9669 * would require 5 item modifications, so we'll assume their normal
9670 * inodes. So 5 * 2 is 10, plus 2 for the new links, so 12 total items
9671 * should cover the worst case number of items we'll modify.
9672 */
9673 trans = btrfs_start_transaction(root, 12);
9674 if (IS_ERR(trans)) {
9675 ret = PTR_ERR(trans);
9676 goto out_notrans;
9677 }
9678
9679 /*
9680 * We need to find a free sequence number both in the source and
9681 * in the destination directory for the exchange.
9682 */
9683 ret = btrfs_set_inode_index(BTRFS_I(new_dir), &old_idx);
9684 if (ret)
9685 goto out_fail;
9686 ret = btrfs_set_inode_index(BTRFS_I(old_dir), &new_idx);
9687 if (ret)
9688 goto out_fail;
9689
9690 BTRFS_I(old_inode)->dir_index = 0ULL;
9691 BTRFS_I(new_inode)->dir_index = 0ULL;
9692
9693 /* Reference for the source. */
9694 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9695 /* force full log commit if subvolume involved. */
9696 btrfs_set_log_full_commit(fs_info, trans);
9697 } else {
9698 btrfs_pin_log_trans(root);
9699 root_log_pinned = true;
9700 ret = btrfs_insert_inode_ref(trans, dest,
9701 new_dentry->d_name.name,
9702 new_dentry->d_name.len,
9703 old_ino,
9704 btrfs_ino(BTRFS_I(new_dir)),
9705 old_idx);
9706 if (ret)
9707 goto out_fail;
9708 }
9709
9710 /* And now for the dest. */
9711 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9712 /* force full log commit if subvolume involved. */
9713 btrfs_set_log_full_commit(fs_info, trans);
9714 } else {
9715 btrfs_pin_log_trans(dest);
9716 dest_log_pinned = true;
9717 ret = btrfs_insert_inode_ref(trans, root,
9718 old_dentry->d_name.name,
9719 old_dentry->d_name.len,
9720 new_ino,
9721 btrfs_ino(BTRFS_I(old_dir)),
9722 new_idx);
9723 if (ret)
9724 goto out_fail;
9725 }
9726
9727 /* Update inode version and ctime/mtime. */
9728 inode_inc_iversion(old_dir);
9729 inode_inc_iversion(new_dir);
9730 inode_inc_iversion(old_inode);
9731 inode_inc_iversion(new_inode);
9732 old_dir->i_ctime = old_dir->i_mtime = ctime;
9733 new_dir->i_ctime = new_dir->i_mtime = ctime;
9734 old_inode->i_ctime = ctime;
9735 new_inode->i_ctime = ctime;
9736
9737 if (old_dentry->d_parent != new_dentry->d_parent) {
9738 btrfs_record_unlink_dir(trans, BTRFS_I(old_dir),
9739 BTRFS_I(old_inode), 1);
9740 btrfs_record_unlink_dir(trans, BTRFS_I(new_dir),
9741 BTRFS_I(new_inode), 1);
9742 }
9743
9744 /* src is a subvolume */
9745 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9746 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9747 ret = btrfs_unlink_subvol(trans, root, old_dir,
9748 root_objectid,
9749 old_dentry->d_name.name,
9750 old_dentry->d_name.len);
9751 } else { /* src is an inode */
9752 ret = __btrfs_unlink_inode(trans, root, BTRFS_I(old_dir),
9753 BTRFS_I(old_dentry->d_inode),
9754 old_dentry->d_name.name,
9755 old_dentry->d_name.len);
9756 if (!ret)
9757 ret = btrfs_update_inode(trans, root, old_inode);
9758 }
9759 if (ret) {
9760 btrfs_abort_transaction(trans, ret);
9761 goto out_fail;
9762 }
9763
9764 /* dest is a subvolume */
9765 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9766 root_objectid = BTRFS_I(new_inode)->root->root_key.objectid;
9767 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9768 root_objectid,
9769 new_dentry->d_name.name,
9770 new_dentry->d_name.len);
9771 } else { /* dest is an inode */
9772 ret = __btrfs_unlink_inode(trans, dest, BTRFS_I(new_dir),
9773 BTRFS_I(new_dentry->d_inode),
9774 new_dentry->d_name.name,
9775 new_dentry->d_name.len);
9776 if (!ret)
9777 ret = btrfs_update_inode(trans, dest, new_inode);
9778 }
9779 if (ret) {
9780 btrfs_abort_transaction(trans, ret);
9781 goto out_fail;
9782 }
9783
9784 ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
9785 new_dentry->d_name.name,
9786 new_dentry->d_name.len, 0, old_idx);
9787 if (ret) {
9788 btrfs_abort_transaction(trans, ret);
9789 goto out_fail;
9790 }
9791
9792 ret = btrfs_add_link(trans, BTRFS_I(old_dir), BTRFS_I(new_inode),
9793 old_dentry->d_name.name,
9794 old_dentry->d_name.len, 0, new_idx);
9795 if (ret) {
9796 btrfs_abort_transaction(trans, ret);
9797 goto out_fail;
9798 }
9799
9800 if (old_inode->i_nlink == 1)
9801 BTRFS_I(old_inode)->dir_index = old_idx;
9802 if (new_inode->i_nlink == 1)
9803 BTRFS_I(new_inode)->dir_index = new_idx;
9804
9805 if (root_log_pinned) {
9806 parent = new_dentry->d_parent;
9807 btrfs_log_new_name(trans, BTRFS_I(old_inode), BTRFS_I(old_dir),
9808 parent);
9809 btrfs_end_log_trans(root);
9810 root_log_pinned = false;
9811 }
9812 if (dest_log_pinned) {
9813 parent = old_dentry->d_parent;
9814 btrfs_log_new_name(trans, BTRFS_I(new_inode), BTRFS_I(new_dir),
9815 parent);
9816 btrfs_end_log_trans(dest);
9817 dest_log_pinned = false;
9818 }
9819 out_fail:
9820 /*
9821 * If we have pinned a log and an error happened, we unpin tasks
9822 * trying to sync the log and force them to fallback to a transaction
9823 * commit if the log currently contains any of the inodes involved in
9824 * this rename operation (to ensure we do not persist a log with an
9825 * inconsistent state for any of these inodes or leading to any
9826 * inconsistencies when replayed). If the transaction was aborted, the
9827 * abortion reason is propagated to userspace when attempting to commit
9828 * the transaction. If the log does not contain any of these inodes, we
9829 * allow the tasks to sync it.
9830 */
9831 if (ret && (root_log_pinned || dest_log_pinned)) {
9832 if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) ||
9833 btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) ||
9834 btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) ||
9835 (new_inode &&
9836 btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation)))
9837 btrfs_set_log_full_commit(fs_info, trans);
9838
9839 if (root_log_pinned) {
9840 btrfs_end_log_trans(root);
9841 root_log_pinned = false;
9842 }
9843 if (dest_log_pinned) {
9844 btrfs_end_log_trans(dest);
9845 dest_log_pinned = false;
9846 }
9847 }
9848 ret = btrfs_end_transaction(trans);
9849 out_notrans:
9850 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9851 up_read(&fs_info->subvol_sem);
9852 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9853 up_read(&fs_info->subvol_sem);
9854
9855 return ret;
9856 }
9857
9858 static int btrfs_whiteout_for_rename(struct btrfs_trans_handle *trans,
9859 struct btrfs_root *root,
9860 struct inode *dir,
9861 struct dentry *dentry)
9862 {
9863 int ret;
9864 struct inode *inode;
9865 u64 objectid;
9866 u64 index;
9867
9868 ret = btrfs_find_free_ino(root, &objectid);
9869 if (ret)
9870 return ret;
9871
9872 inode = btrfs_new_inode(trans, root, dir,
9873 dentry->d_name.name,
9874 dentry->d_name.len,
9875 btrfs_ino(BTRFS_I(dir)),
9876 objectid,
9877 S_IFCHR | WHITEOUT_MODE,
9878 &index);
9879
9880 if (IS_ERR(inode)) {
9881 ret = PTR_ERR(inode);
9882 return ret;
9883 }
9884
9885 inode->i_op = &btrfs_special_inode_operations;
9886 init_special_inode(inode, inode->i_mode,
9887 WHITEOUT_DEV);
9888
9889 ret = btrfs_init_inode_security(trans, inode, dir,
9890 &dentry->d_name);
9891 if (ret)
9892 goto out;
9893
9894 ret = btrfs_add_nondir(trans, BTRFS_I(dir), dentry,
9895 BTRFS_I(inode), 0, index);
9896 if (ret)
9897 goto out;
9898
9899 ret = btrfs_update_inode(trans, root, inode);
9900 out:
9901 unlock_new_inode(inode);
9902 if (ret)
9903 inode_dec_link_count(inode);
9904 iput(inode);
9905
9906 return ret;
9907 }
9908
9909 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
9910 struct inode *new_dir, struct dentry *new_dentry,
9911 unsigned int flags)
9912 {
9913 struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
9914 struct btrfs_trans_handle *trans;
9915 unsigned int trans_num_items;
9916 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9917 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9918 struct inode *new_inode = d_inode(new_dentry);
9919 struct inode *old_inode = d_inode(old_dentry);
9920 u64 index = 0;
9921 u64 root_objectid;
9922 int ret;
9923 u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
9924 bool log_pinned = false;
9925
9926 if (btrfs_ino(BTRFS_I(new_dir)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
9927 return -EPERM;
9928
9929 /* we only allow rename subvolume link between subvolumes */
9930 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9931 return -EXDEV;
9932
9933 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
9934 (new_inode && btrfs_ino(BTRFS_I(new_inode)) == BTRFS_FIRST_FREE_OBJECTID))
9935 return -ENOTEMPTY;
9936
9937 if (S_ISDIR(old_inode->i_mode) && new_inode &&
9938 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
9939 return -ENOTEMPTY;
9940
9941
9942 /* check for collisions, even if the name isn't there */
9943 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
9944 new_dentry->d_name.name,
9945 new_dentry->d_name.len);
9946
9947 if (ret) {
9948 if (ret == -EEXIST) {
9949 /* we shouldn't get
9950 * eexist without a new_inode */
9951 if (WARN_ON(!new_inode)) {
9952 return ret;
9953 }
9954 } else {
9955 /* maybe -EOVERFLOW */
9956 return ret;
9957 }
9958 }
9959 ret = 0;
9960
9961 /*
9962 * we're using rename to replace one file with another. Start IO on it
9963 * now so we don't add too much work to the end of the transaction
9964 */
9965 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
9966 filemap_flush(old_inode->i_mapping);
9967
9968 /* close the racy window with snapshot create/destroy ioctl */
9969 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9970 down_read(&fs_info->subvol_sem);
9971 /*
9972 * We want to reserve the absolute worst case amount of items. So if
9973 * both inodes are subvols and we need to unlink them then that would
9974 * require 4 item modifications, but if they are both normal inodes it
9975 * would require 5 item modifications, so we'll assume they are normal
9976 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
9977 * should cover the worst case number of items we'll modify.
9978 * If our rename has the whiteout flag, we need more 5 units for the
9979 * new inode (1 inode item, 1 inode ref, 2 dir items and 1 xattr item
9980 * when selinux is enabled).
9981 */
9982 trans_num_items = 11;
9983 if (flags & RENAME_WHITEOUT)
9984 trans_num_items += 5;
9985 trans = btrfs_start_transaction(root, trans_num_items);
9986 if (IS_ERR(trans)) {
9987 ret = PTR_ERR(trans);
9988 goto out_notrans;
9989 }
9990
9991 if (dest != root)
9992 btrfs_record_root_in_trans(trans, dest);
9993
9994 ret = btrfs_set_inode_index(BTRFS_I(new_dir), &index);
9995 if (ret)
9996 goto out_fail;
9997
9998 BTRFS_I(old_inode)->dir_index = 0ULL;
9999 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
10000 /* force full log commit if subvolume involved. */
10001 btrfs_set_log_full_commit(fs_info, trans);
10002 } else {
10003 btrfs_pin_log_trans(root);
10004 log_pinned = true;
10005 ret = btrfs_insert_inode_ref(trans, dest,
10006 new_dentry->d_name.name,
10007 new_dentry->d_name.len,
10008 old_ino,
10009 btrfs_ino(BTRFS_I(new_dir)), index);
10010 if (ret)
10011 goto out_fail;
10012 }
10013
10014 inode_inc_iversion(old_dir);
10015 inode_inc_iversion(new_dir);
10016 inode_inc_iversion(old_inode);
10017 old_dir->i_ctime = old_dir->i_mtime =
10018 new_dir->i_ctime = new_dir->i_mtime =
10019 old_inode->i_ctime = current_time(old_dir);
10020
10021 if (old_dentry->d_parent != new_dentry->d_parent)
10022 btrfs_record_unlink_dir(trans, BTRFS_I(old_dir),
10023 BTRFS_I(old_inode), 1);
10024
10025 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
10026 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
10027 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
10028 old_dentry->d_name.name,
10029 old_dentry->d_name.len);
10030 } else {
10031 ret = __btrfs_unlink_inode(trans, root, BTRFS_I(old_dir),
10032 BTRFS_I(d_inode(old_dentry)),
10033 old_dentry->d_name.name,
10034 old_dentry->d_name.len);
10035 if (!ret)
10036 ret = btrfs_update_inode(trans, root, old_inode);
10037 }
10038 if (ret) {
10039 btrfs_abort_transaction(trans, ret);
10040 goto out_fail;
10041 }
10042
10043 if (new_inode) {
10044 inode_inc_iversion(new_inode);
10045 new_inode->i_ctime = current_time(new_inode);
10046 if (unlikely(btrfs_ino(BTRFS_I(new_inode)) ==
10047 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
10048 root_objectid = BTRFS_I(new_inode)->location.objectid;
10049 ret = btrfs_unlink_subvol(trans, dest, new_dir,
10050 root_objectid,
10051 new_dentry->d_name.name,
10052 new_dentry->d_name.len);
10053 BUG_ON(new_inode->i_nlink == 0);
10054 } else {
10055 ret = btrfs_unlink_inode(trans, dest, BTRFS_I(new_dir),
10056 BTRFS_I(d_inode(new_dentry)),
10057 new_dentry->d_name.name,
10058 new_dentry->d_name.len);
10059 }
10060 if (!ret && new_inode->i_nlink == 0)
10061 ret = btrfs_orphan_add(trans,
10062 BTRFS_I(d_inode(new_dentry)));
10063 if (ret) {
10064 btrfs_abort_transaction(trans, ret);
10065 goto out_fail;
10066 }
10067 }
10068
10069 ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
10070 new_dentry->d_name.name,
10071 new_dentry->d_name.len, 0, index);
10072 if (ret) {
10073 btrfs_abort_transaction(trans, ret);
10074 goto out_fail;
10075 }
10076
10077 if (old_inode->i_nlink == 1)
10078 BTRFS_I(old_inode)->dir_index = index;
10079
10080 if (log_pinned) {
10081 struct dentry *parent = new_dentry->d_parent;
10082
10083 btrfs_log_new_name(trans, BTRFS_I(old_inode), BTRFS_I(old_dir),
10084 parent);
10085 btrfs_end_log_trans(root);
10086 log_pinned = false;
10087 }
10088
10089 if (flags & RENAME_WHITEOUT) {
10090 ret = btrfs_whiteout_for_rename(trans, root, old_dir,
10091 old_dentry);
10092
10093 if (ret) {
10094 btrfs_abort_transaction(trans, ret);
10095 goto out_fail;
10096 }
10097 }
10098 out_fail:
10099 /*
10100 * If we have pinned the log and an error happened, we unpin tasks
10101 * trying to sync the log and force them to fallback to a transaction
10102 * commit if the log currently contains any of the inodes involved in
10103 * this rename operation (to ensure we do not persist a log with an
10104 * inconsistent state for any of these inodes or leading to any
10105 * inconsistencies when replayed). If the transaction was aborted, the
10106 * abortion reason is propagated to userspace when attempting to commit
10107 * the transaction. If the log does not contain any of these inodes, we
10108 * allow the tasks to sync it.
10109 */
10110 if (ret && log_pinned) {
10111 if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) ||
10112 btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) ||
10113 btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) ||
10114 (new_inode &&
10115 btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation)))
10116 btrfs_set_log_full_commit(fs_info, trans);
10117
10118 btrfs_end_log_trans(root);
10119 log_pinned = false;
10120 }
10121 btrfs_end_transaction(trans);
10122 out_notrans:
10123 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
10124 up_read(&fs_info->subvol_sem);
10125
10126 return ret;
10127 }
10128
10129 static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
10130 struct inode *new_dir, struct dentry *new_dentry,
10131 unsigned int flags)
10132 {
10133 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
10134 return -EINVAL;
10135
10136 if (flags & RENAME_EXCHANGE)
10137 return btrfs_rename_exchange(old_dir, old_dentry, new_dir,
10138 new_dentry);
10139
10140 return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
10141 }
10142
10143 struct btrfs_delalloc_work {
10144 struct inode *inode;
10145 struct completion completion;
10146 struct list_head list;
10147 struct btrfs_work work;
10148 };
10149
10150 static void btrfs_run_delalloc_work(struct btrfs_work *work)
10151 {
10152 struct btrfs_delalloc_work *delalloc_work;
10153 struct inode *inode;
10154
10155 delalloc_work = container_of(work, struct btrfs_delalloc_work,
10156 work);
10157 inode = delalloc_work->inode;
10158 filemap_flush(inode->i_mapping);
10159 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
10160 &BTRFS_I(inode)->runtime_flags))
10161 filemap_flush(inode->i_mapping);
10162
10163 iput(inode);
10164 complete(&delalloc_work->completion);
10165 }
10166
10167 static struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode)
10168 {
10169 struct btrfs_delalloc_work *work;
10170
10171 work = kmalloc(sizeof(*work), GFP_NOFS);
10172 if (!work)
10173 return NULL;
10174
10175 init_completion(&work->completion);
10176 INIT_LIST_HEAD(&work->list);
10177 work->inode = inode;
10178 WARN_ON_ONCE(!inode);
10179 btrfs_init_work(&work->work, btrfs_flush_delalloc_helper,
10180 btrfs_run_delalloc_work, NULL, NULL);
10181
10182 return work;
10183 }
10184
10185 /*
10186 * some fairly slow code that needs optimization. This walks the list
10187 * of all the inodes with pending delalloc and forces them to disk.
10188 */
10189 static int start_delalloc_inodes(struct btrfs_root *root, int nr)
10190 {
10191 struct btrfs_inode *binode;
10192 struct inode *inode;
10193 struct btrfs_delalloc_work *work, *next;
10194 struct list_head works;
10195 struct list_head splice;
10196 int ret = 0;
10197
10198 INIT_LIST_HEAD(&works);
10199 INIT_LIST_HEAD(&splice);
10200
10201 mutex_lock(&root->delalloc_mutex);
10202 spin_lock(&root->delalloc_lock);
10203 list_splice_init(&root->delalloc_inodes, &splice);
10204 while (!list_empty(&splice)) {
10205 binode = list_entry(splice.next, struct btrfs_inode,
10206 delalloc_inodes);
10207
10208 list_move_tail(&binode->delalloc_inodes,
10209 &root->delalloc_inodes);
10210 inode = igrab(&binode->vfs_inode);
10211 if (!inode) {
10212 cond_resched_lock(&root->delalloc_lock);
10213 continue;
10214 }
10215 spin_unlock(&root->delalloc_lock);
10216
10217 work = btrfs_alloc_delalloc_work(inode);
10218 if (!work) {
10219 iput(inode);
10220 ret = -ENOMEM;
10221 goto out;
10222 }
10223 list_add_tail(&work->list, &works);
10224 btrfs_queue_work(root->fs_info->flush_workers,
10225 &work->work);
10226 ret++;
10227 if (nr != -1 && ret >= nr)
10228 goto out;
10229 cond_resched();
10230 spin_lock(&root->delalloc_lock);
10231 }
10232 spin_unlock(&root->delalloc_lock);
10233
10234 out:
10235 list_for_each_entry_safe(work, next, &works, list) {
10236 list_del_init(&work->list);
10237 wait_for_completion(&work->completion);
10238 kfree(work);
10239 }
10240
10241 if (!list_empty(&splice)) {
10242 spin_lock(&root->delalloc_lock);
10243 list_splice_tail(&splice, &root->delalloc_inodes);
10244 spin_unlock(&root->delalloc_lock);
10245 }
10246 mutex_unlock(&root->delalloc_mutex);
10247 return ret;
10248 }
10249
10250 int btrfs_start_delalloc_inodes(struct btrfs_root *root)
10251 {
10252 struct btrfs_fs_info *fs_info = root->fs_info;
10253 int ret;
10254
10255 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
10256 return -EROFS;
10257
10258 ret = start_delalloc_inodes(root, -1);
10259 if (ret > 0)
10260 ret = 0;
10261 return ret;
10262 }
10263
10264 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int nr)
10265 {
10266 struct btrfs_root *root;
10267 struct list_head splice;
10268 int ret;
10269
10270 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
10271 return -EROFS;
10272
10273 INIT_LIST_HEAD(&splice);
10274
10275 mutex_lock(&fs_info->delalloc_root_mutex);
10276 spin_lock(&fs_info->delalloc_root_lock);
10277 list_splice_init(&fs_info->delalloc_roots, &splice);
10278 while (!list_empty(&splice) && nr) {
10279 root = list_first_entry(&splice, struct btrfs_root,
10280 delalloc_root);
10281 root = btrfs_grab_fs_root(root);
10282 BUG_ON(!root);
10283 list_move_tail(&root->delalloc_root,
10284 &fs_info->delalloc_roots);
10285 spin_unlock(&fs_info->delalloc_root_lock);
10286
10287 ret = start_delalloc_inodes(root, nr);
10288 btrfs_put_fs_root(root);
10289 if (ret < 0)
10290 goto out;
10291
10292 if (nr != -1) {
10293 nr -= ret;
10294 WARN_ON(nr < 0);
10295 }
10296 spin_lock(&fs_info->delalloc_root_lock);
10297 }
10298 spin_unlock(&fs_info->delalloc_root_lock);
10299
10300 ret = 0;
10301 out:
10302 if (!list_empty(&splice)) {
10303 spin_lock(&fs_info->delalloc_root_lock);
10304 list_splice_tail(&splice, &fs_info->delalloc_roots);
10305 spin_unlock(&fs_info->delalloc_root_lock);
10306 }
10307 mutex_unlock(&fs_info->delalloc_root_mutex);
10308 return ret;
10309 }
10310
10311 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
10312 const char *symname)
10313 {
10314 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
10315 struct btrfs_trans_handle *trans;
10316 struct btrfs_root *root = BTRFS_I(dir)->root;
10317 struct btrfs_path *path;
10318 struct btrfs_key key;
10319 struct inode *inode = NULL;
10320 int err;
10321 int drop_inode = 0;
10322 u64 objectid;
10323 u64 index = 0;
10324 int name_len;
10325 int datasize;
10326 unsigned long ptr;
10327 struct btrfs_file_extent_item *ei;
10328 struct extent_buffer *leaf;
10329
10330 name_len = strlen(symname);
10331 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info))
10332 return -ENAMETOOLONG;
10333
10334 /*
10335 * 2 items for inode item and ref
10336 * 2 items for dir items
10337 * 1 item for updating parent inode item
10338 * 1 item for the inline extent item
10339 * 1 item for xattr if selinux is on
10340 */
10341 trans = btrfs_start_transaction(root, 7);
10342 if (IS_ERR(trans))
10343 return PTR_ERR(trans);
10344
10345 err = btrfs_find_free_ino(root, &objectid);
10346 if (err)
10347 goto out_unlock;
10348
10349 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
10350 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)),
10351 objectid, S_IFLNK|S_IRWXUGO, &index);
10352 if (IS_ERR(inode)) {
10353 err = PTR_ERR(inode);
10354 goto out_unlock;
10355 }
10356
10357 /*
10358 * If the active LSM wants to access the inode during
10359 * d_instantiate it needs these. Smack checks to see
10360 * if the filesystem supports xattrs by looking at the
10361 * ops vector.
10362 */
10363 inode->i_fop = &btrfs_file_operations;
10364 inode->i_op = &btrfs_file_inode_operations;
10365 inode->i_mapping->a_ops = &btrfs_aops;
10366 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10367
10368 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
10369 if (err)
10370 goto out_unlock_inode;
10371
10372 path = btrfs_alloc_path();
10373 if (!path) {
10374 err = -ENOMEM;
10375 goto out_unlock_inode;
10376 }
10377 key.objectid = btrfs_ino(BTRFS_I(inode));
10378 key.offset = 0;
10379 key.type = BTRFS_EXTENT_DATA_KEY;
10380 datasize = btrfs_file_extent_calc_inline_size(name_len);
10381 err = btrfs_insert_empty_item(trans, root, path, &key,
10382 datasize);
10383 if (err) {
10384 btrfs_free_path(path);
10385 goto out_unlock_inode;
10386 }
10387 leaf = path->nodes[0];
10388 ei = btrfs_item_ptr(leaf, path->slots[0],
10389 struct btrfs_file_extent_item);
10390 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
10391 btrfs_set_file_extent_type(leaf, ei,
10392 BTRFS_FILE_EXTENT_INLINE);
10393 btrfs_set_file_extent_encryption(leaf, ei, 0);
10394 btrfs_set_file_extent_compression(leaf, ei, 0);
10395 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
10396 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
10397
10398 ptr = btrfs_file_extent_inline_start(ei);
10399 write_extent_buffer(leaf, symname, ptr, name_len);
10400 btrfs_mark_buffer_dirty(leaf);
10401 btrfs_free_path(path);
10402
10403 inode->i_op = &btrfs_symlink_inode_operations;
10404 inode_nohighmem(inode);
10405 inode->i_mapping->a_ops = &btrfs_symlink_aops;
10406 inode_set_bytes(inode, name_len);
10407 btrfs_i_size_write(BTRFS_I(inode), name_len);
10408 err = btrfs_update_inode(trans, root, inode);
10409 /*
10410 * Last step, add directory indexes for our symlink inode. This is the
10411 * last step to avoid extra cleanup of these indexes if an error happens
10412 * elsewhere above.
10413 */
10414 if (!err)
10415 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry,
10416 BTRFS_I(inode), 0, index);
10417 if (err) {
10418 drop_inode = 1;
10419 goto out_unlock_inode;
10420 }
10421
10422 d_instantiate_new(dentry, inode);
10423
10424 out_unlock:
10425 btrfs_end_transaction(trans);
10426 if (drop_inode) {
10427 inode_dec_link_count(inode);
10428 iput(inode);
10429 }
10430 btrfs_btree_balance_dirty(fs_info);
10431 return err;
10432
10433 out_unlock_inode:
10434 drop_inode = 1;
10435 unlock_new_inode(inode);
10436 goto out_unlock;
10437 }
10438
10439 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
10440 u64 start, u64 num_bytes, u64 min_size,
10441 loff_t actual_len, u64 *alloc_hint,
10442 struct btrfs_trans_handle *trans)
10443 {
10444 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
10445 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
10446 struct extent_map *em;
10447 struct btrfs_root *root = BTRFS_I(inode)->root;
10448 struct btrfs_key ins;
10449 u64 cur_offset = start;
10450 u64 i_size;
10451 u64 cur_bytes;
10452 u64 last_alloc = (u64)-1;
10453 int ret = 0;
10454 bool own_trans = true;
10455 u64 end = start + num_bytes - 1;
10456
10457 if (trans)
10458 own_trans = false;
10459 while (num_bytes > 0) {
10460 if (own_trans) {
10461 trans = btrfs_start_transaction(root, 3);
10462 if (IS_ERR(trans)) {
10463 ret = PTR_ERR(trans);
10464 break;
10465 }
10466 }
10467
10468 cur_bytes = min_t(u64, num_bytes, SZ_256M);
10469 cur_bytes = max(cur_bytes, min_size);
10470 /*
10471 * If we are severely fragmented we could end up with really
10472 * small allocations, so if the allocator is returning small
10473 * chunks lets make its job easier by only searching for those
10474 * sized chunks.
10475 */
10476 cur_bytes = min(cur_bytes, last_alloc);
10477 ret = btrfs_reserve_extent(root, cur_bytes, cur_bytes,
10478 min_size, 0, *alloc_hint, &ins, 1, 0);
10479 if (ret) {
10480 if (own_trans)
10481 btrfs_end_transaction(trans);
10482 break;
10483 }
10484 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
10485
10486 last_alloc = ins.offset;
10487 ret = insert_reserved_file_extent(trans, inode,
10488 cur_offset, ins.objectid,
10489 ins.offset, ins.offset,
10490 ins.offset, 0, 0, 0,
10491 BTRFS_FILE_EXTENT_PREALLOC);
10492 if (ret) {
10493 btrfs_free_reserved_extent(fs_info, ins.objectid,
10494 ins.offset, 0);
10495 btrfs_abort_transaction(trans, ret);
10496 if (own_trans)
10497 btrfs_end_transaction(trans);
10498 break;
10499 }
10500
10501 btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
10502 cur_offset + ins.offset -1, 0);
10503
10504 em = alloc_extent_map();
10505 if (!em) {
10506 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
10507 &BTRFS_I(inode)->runtime_flags);
10508 goto next;
10509 }
10510
10511 em->start = cur_offset;
10512 em->orig_start = cur_offset;
10513 em->len = ins.offset;
10514 em->block_start = ins.objectid;
10515 em->block_len = ins.offset;
10516 em->orig_block_len = ins.offset;
10517 em->ram_bytes = ins.offset;
10518 em->bdev = fs_info->fs_devices->latest_bdev;
10519 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
10520 em->generation = trans->transid;
10521
10522 while (1) {
10523 write_lock(&em_tree->lock);
10524 ret = add_extent_mapping(em_tree, em, 1);
10525 write_unlock(&em_tree->lock);
10526 if (ret != -EEXIST)
10527 break;
10528 btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
10529 cur_offset + ins.offset - 1,
10530 0);
10531 }
10532 free_extent_map(em);
10533 next:
10534 num_bytes -= ins.offset;
10535 cur_offset += ins.offset;
10536 *alloc_hint = ins.objectid + ins.offset;
10537
10538 inode_inc_iversion(inode);
10539 inode->i_ctime = current_time(inode);
10540 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
10541 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
10542 (actual_len > inode->i_size) &&
10543 (cur_offset > inode->i_size)) {
10544 if (cur_offset > actual_len)
10545 i_size = actual_len;
10546 else
10547 i_size = cur_offset;
10548 i_size_write(inode, i_size);
10549 btrfs_ordered_update_i_size(inode, i_size, NULL);
10550 }
10551
10552 ret = btrfs_update_inode(trans, root, inode);
10553
10554 if (ret) {
10555 btrfs_abort_transaction(trans, ret);
10556 if (own_trans)
10557 btrfs_end_transaction(trans);
10558 break;
10559 }
10560
10561 if (own_trans)
10562 btrfs_end_transaction(trans);
10563 }
10564 if (cur_offset < end)
10565 btrfs_free_reserved_data_space(inode, NULL, cur_offset,
10566 end - cur_offset + 1);
10567 return ret;
10568 }
10569
10570 int btrfs_prealloc_file_range(struct inode *inode, int mode,
10571 u64 start, u64 num_bytes, u64 min_size,
10572 loff_t actual_len, u64 *alloc_hint)
10573 {
10574 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10575 min_size, actual_len, alloc_hint,
10576 NULL);
10577 }
10578
10579 int btrfs_prealloc_file_range_trans(struct inode *inode,
10580 struct btrfs_trans_handle *trans, int mode,
10581 u64 start, u64 num_bytes, u64 min_size,
10582 loff_t actual_len, u64 *alloc_hint)
10583 {
10584 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10585 min_size, actual_len, alloc_hint, trans);
10586 }
10587
10588 static int btrfs_set_page_dirty(struct page *page)
10589 {
10590 return __set_page_dirty_nobuffers(page);
10591 }
10592
10593 static int btrfs_permission(struct inode *inode, int mask)
10594 {
10595 struct btrfs_root *root = BTRFS_I(inode)->root;
10596 umode_t mode = inode->i_mode;
10597
10598 if (mask & MAY_WRITE &&
10599 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
10600 if (btrfs_root_readonly(root))
10601 return -EROFS;
10602 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
10603 return -EACCES;
10604 }
10605 return generic_permission(inode, mask);
10606 }
10607
10608 static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
10609 {
10610 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
10611 struct btrfs_trans_handle *trans;
10612 struct btrfs_root *root = BTRFS_I(dir)->root;
10613 struct inode *inode = NULL;
10614 u64 objectid;
10615 u64 index;
10616 int ret = 0;
10617
10618 /*
10619 * 5 units required for adding orphan entry
10620 */
10621 trans = btrfs_start_transaction(root, 5);
10622 if (IS_ERR(trans))
10623 return PTR_ERR(trans);
10624
10625 ret = btrfs_find_free_ino(root, &objectid);
10626 if (ret)
10627 goto out;
10628
10629 inode = btrfs_new_inode(trans, root, dir, NULL, 0,
10630 btrfs_ino(BTRFS_I(dir)), objectid, mode, &index);
10631 if (IS_ERR(inode)) {
10632 ret = PTR_ERR(inode);
10633 inode = NULL;
10634 goto out;
10635 }
10636
10637 inode->i_fop = &btrfs_file_operations;
10638 inode->i_op = &btrfs_file_inode_operations;
10639
10640 inode->i_mapping->a_ops = &btrfs_aops;
10641 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10642
10643 ret = btrfs_init_inode_security(trans, inode, dir, NULL);
10644 if (ret)
10645 goto out_inode;
10646
10647 ret = btrfs_update_inode(trans, root, inode);
10648 if (ret)
10649 goto out_inode;
10650 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
10651 if (ret)
10652 goto out_inode;
10653
10654 /*
10655 * We set number of links to 0 in btrfs_new_inode(), and here we set
10656 * it to 1 because d_tmpfile() will issue a warning if the count is 0,
10657 * through:
10658 *
10659 * d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
10660 */
10661 set_nlink(inode, 1);
10662 unlock_new_inode(inode);
10663 d_tmpfile(dentry, inode);
10664 mark_inode_dirty(inode);
10665
10666 out:
10667 btrfs_end_transaction(trans);
10668 if (ret)
10669 iput(inode);
10670 btrfs_btree_balance_dirty(fs_info);
10671 return ret;
10672
10673 out_inode:
10674 unlock_new_inode(inode);
10675 goto out;
10676
10677 }
10678
10679 __attribute__((const))
10680 static int btrfs_readpage_io_failed_hook(struct page *page, int failed_mirror)
10681 {
10682 return -EAGAIN;
10683 }
10684
10685 static struct btrfs_fs_info *iotree_fs_info(void *private_data)
10686 {
10687 struct inode *inode = private_data;
10688 return btrfs_sb(inode->i_sb);
10689 }
10690
10691 static void btrfs_check_extent_io_range(void *private_data, const char *caller,
10692 u64 start, u64 end)
10693 {
10694 struct inode *inode = private_data;
10695 u64 isize;
10696
10697 isize = i_size_read(inode);
10698 if (end >= PAGE_SIZE && (end % 2) == 0 && end != isize - 1) {
10699 btrfs_debug_rl(BTRFS_I(inode)->root->fs_info,
10700 "%s: ino %llu isize %llu odd range [%llu,%llu]",
10701 caller, btrfs_ino(BTRFS_I(inode)), isize, start, end);
10702 }
10703 }
10704
10705 void btrfs_set_range_writeback(void *private_data, u64 start, u64 end)
10706 {
10707 struct inode *inode = private_data;
10708 unsigned long index = start >> PAGE_SHIFT;
10709 unsigned long end_index = end >> PAGE_SHIFT;
10710 struct page *page;
10711
10712 while (index <= end_index) {
10713 page = find_get_page(inode->i_mapping, index);
10714 ASSERT(page); /* Pages should be in the extent_io_tree */
10715 set_page_writeback(page);
10716 put_page(page);
10717 index++;
10718 }
10719 }
10720
10721 static const struct inode_operations btrfs_dir_inode_operations = {
10722 .getattr = btrfs_getattr,
10723 .lookup = btrfs_lookup,
10724 .create = btrfs_create,
10725 .unlink = btrfs_unlink,
10726 .link = btrfs_link,
10727 .mkdir = btrfs_mkdir,
10728 .rmdir = btrfs_rmdir,
10729 .rename = btrfs_rename2,
10730 .symlink = btrfs_symlink,
10731 .setattr = btrfs_setattr,
10732 .mknod = btrfs_mknod,
10733 .listxattr = btrfs_listxattr,
10734 .permission = btrfs_permission,
10735 .get_acl = btrfs_get_acl,
10736 .set_acl = btrfs_set_acl,
10737 .update_time = btrfs_update_time,
10738 .tmpfile = btrfs_tmpfile,
10739 };
10740 static const struct inode_operations btrfs_dir_ro_inode_operations = {
10741 .lookup = btrfs_lookup,
10742 .permission = btrfs_permission,
10743 .update_time = btrfs_update_time,
10744 };
10745
10746 static const struct file_operations btrfs_dir_file_operations = {
10747 .llseek = generic_file_llseek,
10748 .read = generic_read_dir,
10749 .iterate_shared = btrfs_real_readdir,
10750 .open = btrfs_opendir,
10751 .unlocked_ioctl = btrfs_ioctl,
10752 #ifdef CONFIG_COMPAT
10753 .compat_ioctl = btrfs_compat_ioctl,
10754 #endif
10755 .release = btrfs_release_file,
10756 .fsync = btrfs_sync_file,
10757 };
10758
10759 static const struct extent_io_ops btrfs_extent_io_ops = {
10760 /* mandatory callbacks */
10761 .submit_bio_hook = btrfs_submit_bio_hook,
10762 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
10763 .merge_bio_hook = btrfs_merge_bio_hook,
10764 .readpage_io_failed_hook = btrfs_readpage_io_failed_hook,
10765 .tree_fs_info = iotree_fs_info,
10766 .set_range_writeback = btrfs_set_range_writeback,
10767
10768 /* optional callbacks */
10769 .fill_delalloc = run_delalloc_range,
10770 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
10771 .writepage_start_hook = btrfs_writepage_start_hook,
10772 .set_bit_hook = btrfs_set_bit_hook,
10773 .clear_bit_hook = btrfs_clear_bit_hook,
10774 .merge_extent_hook = btrfs_merge_extent_hook,
10775 .split_extent_hook = btrfs_split_extent_hook,
10776 .check_extent_io_range = btrfs_check_extent_io_range,
10777 };
10778
10779 /*
10780 * btrfs doesn't support the bmap operation because swapfiles
10781 * use bmap to make a mapping of extents in the file. They assume
10782 * these extents won't change over the life of the file and they
10783 * use the bmap result to do IO directly to the drive.
10784 *
10785 * the btrfs bmap call would return logical addresses that aren't
10786 * suitable for IO and they also will change frequently as COW
10787 * operations happen. So, swapfile + btrfs == corruption.
10788 *
10789 * For now we're avoiding this by dropping bmap.
10790 */
10791 static const struct address_space_operations btrfs_aops = {
10792 .readpage = btrfs_readpage,
10793 .writepage = btrfs_writepage,
10794 .writepages = btrfs_writepages,
10795 .readpages = btrfs_readpages,
10796 .direct_IO = btrfs_direct_IO,
10797 .invalidatepage = btrfs_invalidatepage,
10798 .releasepage = btrfs_releasepage,
10799 .set_page_dirty = btrfs_set_page_dirty,
10800 .error_remove_page = generic_error_remove_page,
10801 };
10802
10803 static const struct address_space_operations btrfs_symlink_aops = {
10804 .readpage = btrfs_readpage,
10805 .writepage = btrfs_writepage,
10806 .invalidatepage = btrfs_invalidatepage,
10807 .releasepage = btrfs_releasepage,
10808 };
10809
10810 static const struct inode_operations btrfs_file_inode_operations = {
10811 .getattr = btrfs_getattr,
10812 .setattr = btrfs_setattr,
10813 .listxattr = btrfs_listxattr,
10814 .permission = btrfs_permission,
10815 .fiemap = btrfs_fiemap,
10816 .get_acl = btrfs_get_acl,
10817 .set_acl = btrfs_set_acl,
10818 .update_time = btrfs_update_time,
10819 };
10820 static const struct inode_operations btrfs_special_inode_operations = {
10821 .getattr = btrfs_getattr,
10822 .setattr = btrfs_setattr,
10823 .permission = btrfs_permission,
10824 .listxattr = btrfs_listxattr,
10825 .get_acl = btrfs_get_acl,
10826 .set_acl = btrfs_set_acl,
10827 .update_time = btrfs_update_time,
10828 };
10829 static const struct inode_operations btrfs_symlink_inode_operations = {
10830 .get_link = page_get_link,
10831 .getattr = btrfs_getattr,
10832 .setattr = btrfs_setattr,
10833 .permission = btrfs_permission,
10834 .listxattr = btrfs_listxattr,
10835 .update_time = btrfs_update_time,
10836 };
10837
10838 const struct dentry_operations btrfs_dentry_operations = {
10839 .d_delete = btrfs_dentry_delete,
10840 };
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