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Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[mirror_ubuntu-bionic-kernel.git] / fs / btrfs / inode.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/kernel.h>
20 #include <linux/bio.h>
21 #include <linux/buffer_head.h>
22 #include <linux/file.h>
23 #include <linux/fs.h>
24 #include <linux/pagemap.h>
25 #include <linux/highmem.h>
26 #include <linux/time.h>
27 #include <linux/init.h>
28 #include <linux/string.h>
29 #include <linux/backing-dev.h>
30 #include <linux/mpage.h>
31 #include <linux/swap.h>
32 #include <linux/writeback.h>
33 #include <linux/compat.h>
34 #include <linux/bit_spinlock.h>
35 #include <linux/xattr.h>
36 #include <linux/posix_acl.h>
37 #include <linux/falloc.h>
38 #include <linux/slab.h>
39 #include <linux/ratelimit.h>
40 #include <linux/mount.h>
41 #include <linux/btrfs.h>
42 #include <linux/blkdev.h>
43 #include <linux/posix_acl_xattr.h>
44 #include <linux/uio.h>
45 #include "ctree.h"
46 #include "disk-io.h"
47 #include "transaction.h"
48 #include "btrfs_inode.h"
49 #include "print-tree.h"
50 #include "ordered-data.h"
51 #include "xattr.h"
52 #include "tree-log.h"
53 #include "volumes.h"
54 #include "compression.h"
55 #include "locking.h"
56 #include "free-space-cache.h"
57 #include "inode-map.h"
58 #include "backref.h"
59 #include "hash.h"
60 #include "props.h"
61 #include "qgroup.h"
62 #include "dedupe.h"
63
64 struct btrfs_iget_args {
65 struct btrfs_key *location;
66 struct btrfs_root *root;
67 };
68
69 struct btrfs_dio_data {
70 u64 outstanding_extents;
71 u64 reserve;
72 u64 unsubmitted_oe_range_start;
73 u64 unsubmitted_oe_range_end;
74 };
75
76 static const struct inode_operations btrfs_dir_inode_operations;
77 static const struct inode_operations btrfs_symlink_inode_operations;
78 static const struct inode_operations btrfs_dir_ro_inode_operations;
79 static const struct inode_operations btrfs_special_inode_operations;
80 static const struct inode_operations btrfs_file_inode_operations;
81 static const struct address_space_operations btrfs_aops;
82 static const struct address_space_operations btrfs_symlink_aops;
83 static const struct file_operations btrfs_dir_file_operations;
84 static const struct extent_io_ops btrfs_extent_io_ops;
85
86 static struct kmem_cache *btrfs_inode_cachep;
87 struct kmem_cache *btrfs_trans_handle_cachep;
88 struct kmem_cache *btrfs_transaction_cachep;
89 struct kmem_cache *btrfs_path_cachep;
90 struct kmem_cache *btrfs_free_space_cachep;
91
92 #define S_SHIFT 12
93 static const unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
94 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
95 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
96 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
97 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
98 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
99 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
100 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
101 };
102
103 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
104 static int btrfs_truncate(struct inode *inode);
105 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
106 static noinline int cow_file_range(struct inode *inode,
107 struct page *locked_page,
108 u64 start, u64 end, u64 delalloc_end,
109 int *page_started, unsigned long *nr_written,
110 int unlock, struct btrfs_dedupe_hash *hash);
111 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
112 u64 len, u64 orig_start,
113 u64 block_start, u64 block_len,
114 u64 orig_block_len, u64 ram_bytes,
115 int type);
116
117 static int btrfs_dirty_inode(struct inode *inode);
118
119 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
120 void btrfs_test_inode_set_ops(struct inode *inode)
121 {
122 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
123 }
124 #endif
125
126 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
127 struct inode *inode, struct inode *dir,
128 const struct qstr *qstr)
129 {
130 int err;
131
132 err = btrfs_init_acl(trans, inode, dir);
133 if (!err)
134 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
135 return err;
136 }
137
138 /*
139 * this does all the hard work for inserting an inline extent into
140 * the btree. The caller should have done a btrfs_drop_extents so that
141 * no overlapping inline items exist in the btree
142 */
143 static int insert_inline_extent(struct btrfs_trans_handle *trans,
144 struct btrfs_path *path, int extent_inserted,
145 struct btrfs_root *root, struct inode *inode,
146 u64 start, size_t size, size_t compressed_size,
147 int compress_type,
148 struct page **compressed_pages)
149 {
150 struct extent_buffer *leaf;
151 struct page *page = NULL;
152 char *kaddr;
153 unsigned long ptr;
154 struct btrfs_file_extent_item *ei;
155 int err = 0;
156 int ret;
157 size_t cur_size = size;
158 unsigned long offset;
159
160 if (compressed_size && compressed_pages)
161 cur_size = compressed_size;
162
163 inode_add_bytes(inode, size);
164
165 if (!extent_inserted) {
166 struct btrfs_key key;
167 size_t datasize;
168
169 key.objectid = btrfs_ino(inode);
170 key.offset = start;
171 key.type = BTRFS_EXTENT_DATA_KEY;
172
173 datasize = btrfs_file_extent_calc_inline_size(cur_size);
174 path->leave_spinning = 1;
175 ret = btrfs_insert_empty_item(trans, root, path, &key,
176 datasize);
177 if (ret) {
178 err = ret;
179 goto fail;
180 }
181 }
182 leaf = path->nodes[0];
183 ei = btrfs_item_ptr(leaf, path->slots[0],
184 struct btrfs_file_extent_item);
185 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
186 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
187 btrfs_set_file_extent_encryption(leaf, ei, 0);
188 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
189 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
190 ptr = btrfs_file_extent_inline_start(ei);
191
192 if (compress_type != BTRFS_COMPRESS_NONE) {
193 struct page *cpage;
194 int i = 0;
195 while (compressed_size > 0) {
196 cpage = compressed_pages[i];
197 cur_size = min_t(unsigned long, compressed_size,
198 PAGE_SIZE);
199
200 kaddr = kmap_atomic(cpage);
201 write_extent_buffer(leaf, kaddr, ptr, cur_size);
202 kunmap_atomic(kaddr);
203
204 i++;
205 ptr += cur_size;
206 compressed_size -= cur_size;
207 }
208 btrfs_set_file_extent_compression(leaf, ei,
209 compress_type);
210 } else {
211 page = find_get_page(inode->i_mapping,
212 start >> PAGE_SHIFT);
213 btrfs_set_file_extent_compression(leaf, ei, 0);
214 kaddr = kmap_atomic(page);
215 offset = start & (PAGE_SIZE - 1);
216 write_extent_buffer(leaf, kaddr + offset, ptr, size);
217 kunmap_atomic(kaddr);
218 put_page(page);
219 }
220 btrfs_mark_buffer_dirty(leaf);
221 btrfs_release_path(path);
222
223 /*
224 * we're an inline extent, so nobody can
225 * extend the file past i_size without locking
226 * a page we already have locked.
227 *
228 * We must do any isize and inode updates
229 * before we unlock the pages. Otherwise we
230 * could end up racing with unlink.
231 */
232 BTRFS_I(inode)->disk_i_size = inode->i_size;
233 ret = btrfs_update_inode(trans, root, inode);
234
235 return ret;
236 fail:
237 return err;
238 }
239
240
241 /*
242 * conditionally insert an inline extent into the file. This
243 * does the checks required to make sure the data is small enough
244 * to fit as an inline extent.
245 */
246 static noinline int cow_file_range_inline(struct btrfs_root *root,
247 struct inode *inode, u64 start,
248 u64 end, size_t compressed_size,
249 int compress_type,
250 struct page **compressed_pages)
251 {
252 struct btrfs_fs_info *fs_info = root->fs_info;
253 struct btrfs_trans_handle *trans;
254 u64 isize = i_size_read(inode);
255 u64 actual_end = min(end + 1, isize);
256 u64 inline_len = actual_end - start;
257 u64 aligned_end = ALIGN(end, fs_info->sectorsize);
258 u64 data_len = inline_len;
259 int ret;
260 struct btrfs_path *path;
261 int extent_inserted = 0;
262 u32 extent_item_size;
263
264 if (compressed_size)
265 data_len = compressed_size;
266
267 if (start > 0 ||
268 actual_end > fs_info->sectorsize ||
269 data_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info) ||
270 (!compressed_size &&
271 (actual_end & (fs_info->sectorsize - 1)) == 0) ||
272 end + 1 < isize ||
273 data_len > fs_info->max_inline) {
274 return 1;
275 }
276
277 path = btrfs_alloc_path();
278 if (!path)
279 return -ENOMEM;
280
281 trans = btrfs_join_transaction(root);
282 if (IS_ERR(trans)) {
283 btrfs_free_path(path);
284 return PTR_ERR(trans);
285 }
286 trans->block_rsv = &fs_info->delalloc_block_rsv;
287
288 if (compressed_size && compressed_pages)
289 extent_item_size = btrfs_file_extent_calc_inline_size(
290 compressed_size);
291 else
292 extent_item_size = btrfs_file_extent_calc_inline_size(
293 inline_len);
294
295 ret = __btrfs_drop_extents(trans, root, inode, path,
296 start, aligned_end, NULL,
297 1, 1, extent_item_size, &extent_inserted);
298 if (ret) {
299 btrfs_abort_transaction(trans, ret);
300 goto out;
301 }
302
303 if (isize > actual_end)
304 inline_len = min_t(u64, isize, actual_end);
305 ret = insert_inline_extent(trans, path, extent_inserted,
306 root, inode, start,
307 inline_len, compressed_size,
308 compress_type, compressed_pages);
309 if (ret && ret != -ENOSPC) {
310 btrfs_abort_transaction(trans, ret);
311 goto out;
312 } else if (ret == -ENOSPC) {
313 ret = 1;
314 goto out;
315 }
316
317 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
318 btrfs_delalloc_release_metadata(inode, end + 1 - start);
319 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
320 out:
321 /*
322 * Don't forget to free the reserved space, as for inlined extent
323 * it won't count as data extent, free them directly here.
324 * And at reserve time, it's always aligned to page size, so
325 * just free one page here.
326 */
327 btrfs_qgroup_free_data(inode, 0, PAGE_SIZE);
328 btrfs_free_path(path);
329 btrfs_end_transaction(trans);
330 return ret;
331 }
332
333 struct async_extent {
334 u64 start;
335 u64 ram_size;
336 u64 compressed_size;
337 struct page **pages;
338 unsigned long nr_pages;
339 int compress_type;
340 struct list_head list;
341 };
342
343 struct async_cow {
344 struct inode *inode;
345 struct btrfs_root *root;
346 struct page *locked_page;
347 u64 start;
348 u64 end;
349 struct list_head extents;
350 struct btrfs_work work;
351 };
352
353 static noinline int add_async_extent(struct async_cow *cow,
354 u64 start, u64 ram_size,
355 u64 compressed_size,
356 struct page **pages,
357 unsigned long nr_pages,
358 int compress_type)
359 {
360 struct async_extent *async_extent;
361
362 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
363 BUG_ON(!async_extent); /* -ENOMEM */
364 async_extent->start = start;
365 async_extent->ram_size = ram_size;
366 async_extent->compressed_size = compressed_size;
367 async_extent->pages = pages;
368 async_extent->nr_pages = nr_pages;
369 async_extent->compress_type = compress_type;
370 list_add_tail(&async_extent->list, &cow->extents);
371 return 0;
372 }
373
374 static inline int inode_need_compress(struct inode *inode)
375 {
376 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
377
378 /* force compress */
379 if (btrfs_test_opt(fs_info, FORCE_COMPRESS))
380 return 1;
381 /* bad compression ratios */
382 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
383 return 0;
384 if (btrfs_test_opt(fs_info, COMPRESS) ||
385 BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
386 BTRFS_I(inode)->force_compress)
387 return 1;
388 return 0;
389 }
390
391 /*
392 * we create compressed extents in two phases. The first
393 * phase compresses a range of pages that have already been
394 * locked (both pages and state bits are locked).
395 *
396 * This is done inside an ordered work queue, and the compression
397 * is spread across many cpus. The actual IO submission is step
398 * two, and the ordered work queue takes care of making sure that
399 * happens in the same order things were put onto the queue by
400 * writepages and friends.
401 *
402 * If this code finds it can't get good compression, it puts an
403 * entry onto the work queue to write the uncompressed bytes. This
404 * makes sure that both compressed inodes and uncompressed inodes
405 * are written in the same order that the flusher thread sent them
406 * down.
407 */
408 static noinline void compress_file_range(struct inode *inode,
409 struct page *locked_page,
410 u64 start, u64 end,
411 struct async_cow *async_cow,
412 int *num_added)
413 {
414 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
415 struct btrfs_root *root = BTRFS_I(inode)->root;
416 u64 num_bytes;
417 u64 blocksize = fs_info->sectorsize;
418 u64 actual_end;
419 u64 isize = i_size_read(inode);
420 int ret = 0;
421 struct page **pages = NULL;
422 unsigned long nr_pages;
423 unsigned long nr_pages_ret = 0;
424 unsigned long total_compressed = 0;
425 unsigned long total_in = 0;
426 unsigned long max_compressed = SZ_128K;
427 unsigned long max_uncompressed = SZ_128K;
428 int i;
429 int will_compress;
430 int compress_type = fs_info->compress_type;
431 int redirty = 0;
432
433 /* if this is a small write inside eof, kick off a defrag */
434 if ((end - start + 1) < SZ_16K &&
435 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
436 btrfs_add_inode_defrag(NULL, inode);
437
438 actual_end = min_t(u64, isize, end + 1);
439 again:
440 will_compress = 0;
441 nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
442 nr_pages = min_t(unsigned long, nr_pages, SZ_128K / PAGE_SIZE);
443
444 /*
445 * we don't want to send crud past the end of i_size through
446 * compression, that's just a waste of CPU time. So, if the
447 * end of the file is before the start of our current
448 * requested range of bytes, we bail out to the uncompressed
449 * cleanup code that can deal with all of this.
450 *
451 * It isn't really the fastest way to fix things, but this is a
452 * very uncommon corner.
453 */
454 if (actual_end <= start)
455 goto cleanup_and_bail_uncompressed;
456
457 total_compressed = actual_end - start;
458
459 /*
460 * skip compression for a small file range(<=blocksize) that
461 * isn't an inline extent, since it doesn't save disk space at all.
462 */
463 if (total_compressed <= blocksize &&
464 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
465 goto cleanup_and_bail_uncompressed;
466
467 /* we want to make sure that amount of ram required to uncompress
468 * an extent is reasonable, so we limit the total size in ram
469 * of a compressed extent to 128k. This is a crucial number
470 * because it also controls how easily we can spread reads across
471 * cpus for decompression.
472 *
473 * We also want to make sure the amount of IO required to do
474 * a random read is reasonably small, so we limit the size of
475 * a compressed extent to 128k.
476 */
477 total_compressed = min(total_compressed, max_uncompressed);
478 num_bytes = ALIGN(end - start + 1, blocksize);
479 num_bytes = max(blocksize, num_bytes);
480 total_in = 0;
481 ret = 0;
482
483 /*
484 * we do compression for mount -o compress and when the
485 * inode has not been flagged as nocompress. This flag can
486 * change at any time if we discover bad compression ratios.
487 */
488 if (inode_need_compress(inode)) {
489 WARN_ON(pages);
490 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
491 if (!pages) {
492 /* just bail out to the uncompressed code */
493 goto cont;
494 }
495
496 if (BTRFS_I(inode)->force_compress)
497 compress_type = BTRFS_I(inode)->force_compress;
498
499 /*
500 * we need to call clear_page_dirty_for_io on each
501 * page in the range. Otherwise applications with the file
502 * mmap'd can wander in and change the page contents while
503 * we are compressing them.
504 *
505 * If the compression fails for any reason, we set the pages
506 * dirty again later on.
507 */
508 extent_range_clear_dirty_for_io(inode, start, end);
509 redirty = 1;
510 ret = btrfs_compress_pages(compress_type,
511 inode->i_mapping, start,
512 total_compressed, pages,
513 nr_pages, &nr_pages_ret,
514 &total_in,
515 &total_compressed,
516 max_compressed);
517
518 if (!ret) {
519 unsigned long offset = total_compressed &
520 (PAGE_SIZE - 1);
521 struct page *page = pages[nr_pages_ret - 1];
522 char *kaddr;
523
524 /* zero the tail end of the last page, we might be
525 * sending it down to disk
526 */
527 if (offset) {
528 kaddr = kmap_atomic(page);
529 memset(kaddr + offset, 0,
530 PAGE_SIZE - offset);
531 kunmap_atomic(kaddr);
532 }
533 will_compress = 1;
534 }
535 }
536 cont:
537 if (start == 0) {
538 /* lets try to make an inline extent */
539 if (ret || total_in < (actual_end - start)) {
540 /* we didn't compress the entire range, try
541 * to make an uncompressed inline extent.
542 */
543 ret = cow_file_range_inline(root, inode, start, end,
544 0, 0, NULL);
545 } else {
546 /* try making a compressed inline extent */
547 ret = cow_file_range_inline(root, inode, start, end,
548 total_compressed,
549 compress_type, pages);
550 }
551 if (ret <= 0) {
552 unsigned long clear_flags = EXTENT_DELALLOC |
553 EXTENT_DEFRAG;
554 unsigned long page_error_op;
555
556 clear_flags |= (ret < 0) ? EXTENT_DO_ACCOUNTING : 0;
557 page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
558
559 /*
560 * inline extent creation worked or returned error,
561 * we don't need to create any more async work items.
562 * Unlock and free up our temp pages.
563 */
564 extent_clear_unlock_delalloc(inode, start, end, end,
565 NULL, clear_flags,
566 PAGE_UNLOCK |
567 PAGE_CLEAR_DIRTY |
568 PAGE_SET_WRITEBACK |
569 page_error_op |
570 PAGE_END_WRITEBACK);
571 btrfs_free_reserved_data_space_noquota(inode, start,
572 end - start + 1);
573 goto free_pages_out;
574 }
575 }
576
577 if (will_compress) {
578 /*
579 * we aren't doing an inline extent round the compressed size
580 * up to a block size boundary so the allocator does sane
581 * things
582 */
583 total_compressed = ALIGN(total_compressed, blocksize);
584
585 /*
586 * one last check to make sure the compression is really a
587 * win, compare the page count read with the blocks on disk
588 */
589 total_in = ALIGN(total_in, PAGE_SIZE);
590 if (total_compressed >= total_in) {
591 will_compress = 0;
592 } else {
593 num_bytes = total_in;
594 *num_added += 1;
595
596 /*
597 * The async work queues will take care of doing actual
598 * allocation on disk for these compressed pages, and
599 * will submit them to the elevator.
600 */
601 add_async_extent(async_cow, start, num_bytes,
602 total_compressed, pages, nr_pages_ret,
603 compress_type);
604
605 if (start + num_bytes < end) {
606 start += num_bytes;
607 pages = NULL;
608 cond_resched();
609 goto again;
610 }
611 return;
612 }
613 }
614 if (pages) {
615 /*
616 * the compression code ran but failed to make things smaller,
617 * free any pages it allocated and our page pointer array
618 */
619 for (i = 0; i < nr_pages_ret; i++) {
620 WARN_ON(pages[i]->mapping);
621 put_page(pages[i]);
622 }
623 kfree(pages);
624 pages = NULL;
625 total_compressed = 0;
626 nr_pages_ret = 0;
627
628 /* flag the file so we don't compress in the future */
629 if (!btrfs_test_opt(fs_info, FORCE_COMPRESS) &&
630 !(BTRFS_I(inode)->force_compress)) {
631 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
632 }
633 }
634 cleanup_and_bail_uncompressed:
635 /*
636 * No compression, but we still need to write the pages in the file
637 * we've been given so far. redirty the locked page if it corresponds
638 * to our extent and set things up for the async work queue to run
639 * cow_file_range to do the normal delalloc dance.
640 */
641 if (page_offset(locked_page) >= start &&
642 page_offset(locked_page) <= end)
643 __set_page_dirty_nobuffers(locked_page);
644 /* unlocked later on in the async handlers */
645
646 if (redirty)
647 extent_range_redirty_for_io(inode, start, end);
648 add_async_extent(async_cow, start, end - start + 1, 0, NULL, 0,
649 BTRFS_COMPRESS_NONE);
650 *num_added += 1;
651
652 return;
653
654 free_pages_out:
655 for (i = 0; i < nr_pages_ret; i++) {
656 WARN_ON(pages[i]->mapping);
657 put_page(pages[i]);
658 }
659 kfree(pages);
660 }
661
662 static void free_async_extent_pages(struct async_extent *async_extent)
663 {
664 int i;
665
666 if (!async_extent->pages)
667 return;
668
669 for (i = 0; i < async_extent->nr_pages; i++) {
670 WARN_ON(async_extent->pages[i]->mapping);
671 put_page(async_extent->pages[i]);
672 }
673 kfree(async_extent->pages);
674 async_extent->nr_pages = 0;
675 async_extent->pages = NULL;
676 }
677
678 /*
679 * phase two of compressed writeback. This is the ordered portion
680 * of the code, which only gets called in the order the work was
681 * queued. We walk all the async extents created by compress_file_range
682 * and send them down to the disk.
683 */
684 static noinline void submit_compressed_extents(struct inode *inode,
685 struct async_cow *async_cow)
686 {
687 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
688 struct async_extent *async_extent;
689 u64 alloc_hint = 0;
690 struct btrfs_key ins;
691 struct extent_map *em;
692 struct btrfs_root *root = BTRFS_I(inode)->root;
693 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
694 struct extent_io_tree *io_tree;
695 int ret = 0;
696
697 again:
698 while (!list_empty(&async_cow->extents)) {
699 async_extent = list_entry(async_cow->extents.next,
700 struct async_extent, list);
701 list_del(&async_extent->list);
702
703 io_tree = &BTRFS_I(inode)->io_tree;
704
705 retry:
706 /* did the compression code fall back to uncompressed IO? */
707 if (!async_extent->pages) {
708 int page_started = 0;
709 unsigned long nr_written = 0;
710
711 lock_extent(io_tree, async_extent->start,
712 async_extent->start +
713 async_extent->ram_size - 1);
714
715 /* allocate blocks */
716 ret = cow_file_range(inode, async_cow->locked_page,
717 async_extent->start,
718 async_extent->start +
719 async_extent->ram_size - 1,
720 async_extent->start +
721 async_extent->ram_size - 1,
722 &page_started, &nr_written, 0,
723 NULL);
724
725 /* JDM XXX */
726
727 /*
728 * if page_started, cow_file_range inserted an
729 * inline extent and took care of all the unlocking
730 * and IO for us. Otherwise, we need to submit
731 * all those pages down to the drive.
732 */
733 if (!page_started && !ret)
734 extent_write_locked_range(io_tree,
735 inode, async_extent->start,
736 async_extent->start +
737 async_extent->ram_size - 1,
738 btrfs_get_extent,
739 WB_SYNC_ALL);
740 else if (ret)
741 unlock_page(async_cow->locked_page);
742 kfree(async_extent);
743 cond_resched();
744 continue;
745 }
746
747 lock_extent(io_tree, async_extent->start,
748 async_extent->start + async_extent->ram_size - 1);
749
750 ret = btrfs_reserve_extent(root, async_extent->ram_size,
751 async_extent->compressed_size,
752 async_extent->compressed_size,
753 0, alloc_hint, &ins, 1, 1);
754 if (ret) {
755 free_async_extent_pages(async_extent);
756
757 if (ret == -ENOSPC) {
758 unlock_extent(io_tree, async_extent->start,
759 async_extent->start +
760 async_extent->ram_size - 1);
761
762 /*
763 * we need to redirty the pages if we decide to
764 * fallback to uncompressed IO, otherwise we
765 * will not submit these pages down to lower
766 * layers.
767 */
768 extent_range_redirty_for_io(inode,
769 async_extent->start,
770 async_extent->start +
771 async_extent->ram_size - 1);
772
773 goto retry;
774 }
775 goto out_free;
776 }
777 /*
778 * here we're doing allocation and writeback of the
779 * compressed pages
780 */
781 btrfs_drop_extent_cache(inode, async_extent->start,
782 async_extent->start +
783 async_extent->ram_size - 1, 0);
784
785 em = alloc_extent_map();
786 if (!em) {
787 ret = -ENOMEM;
788 goto out_free_reserve;
789 }
790 em->start = async_extent->start;
791 em->len = async_extent->ram_size;
792 em->orig_start = em->start;
793 em->mod_start = em->start;
794 em->mod_len = em->len;
795
796 em->block_start = ins.objectid;
797 em->block_len = ins.offset;
798 em->orig_block_len = ins.offset;
799 em->ram_bytes = async_extent->ram_size;
800 em->bdev = fs_info->fs_devices->latest_bdev;
801 em->compress_type = async_extent->compress_type;
802 set_bit(EXTENT_FLAG_PINNED, &em->flags);
803 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
804 em->generation = -1;
805
806 while (1) {
807 write_lock(&em_tree->lock);
808 ret = add_extent_mapping(em_tree, em, 1);
809 write_unlock(&em_tree->lock);
810 if (ret != -EEXIST) {
811 free_extent_map(em);
812 break;
813 }
814 btrfs_drop_extent_cache(inode, async_extent->start,
815 async_extent->start +
816 async_extent->ram_size - 1, 0);
817 }
818
819 if (ret)
820 goto out_free_reserve;
821
822 ret = btrfs_add_ordered_extent_compress(inode,
823 async_extent->start,
824 ins.objectid,
825 async_extent->ram_size,
826 ins.offset,
827 BTRFS_ORDERED_COMPRESSED,
828 async_extent->compress_type);
829 if (ret) {
830 btrfs_drop_extent_cache(inode, async_extent->start,
831 async_extent->start +
832 async_extent->ram_size - 1, 0);
833 goto out_free_reserve;
834 }
835 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
836
837 /*
838 * clear dirty, set writeback and unlock the pages.
839 */
840 extent_clear_unlock_delalloc(inode, async_extent->start,
841 async_extent->start +
842 async_extent->ram_size - 1,
843 async_extent->start +
844 async_extent->ram_size - 1,
845 NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
846 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
847 PAGE_SET_WRITEBACK);
848 ret = btrfs_submit_compressed_write(inode,
849 async_extent->start,
850 async_extent->ram_size,
851 ins.objectid,
852 ins.offset, async_extent->pages,
853 async_extent->nr_pages);
854 if (ret) {
855 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
856 struct page *p = async_extent->pages[0];
857 const u64 start = async_extent->start;
858 const u64 end = start + async_extent->ram_size - 1;
859
860 p->mapping = inode->i_mapping;
861 tree->ops->writepage_end_io_hook(p, start, end,
862 NULL, 0);
863 p->mapping = NULL;
864 extent_clear_unlock_delalloc(inode, start, end, end,
865 NULL, 0,
866 PAGE_END_WRITEBACK |
867 PAGE_SET_ERROR);
868 free_async_extent_pages(async_extent);
869 }
870 alloc_hint = ins.objectid + ins.offset;
871 kfree(async_extent);
872 cond_resched();
873 }
874 return;
875 out_free_reserve:
876 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
877 btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
878 out_free:
879 extent_clear_unlock_delalloc(inode, async_extent->start,
880 async_extent->start +
881 async_extent->ram_size - 1,
882 async_extent->start +
883 async_extent->ram_size - 1,
884 NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
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 disk_num_bytes;
951 u64 cur_alloc_size;
952 u64 blocksize = fs_info->sectorsize;
953 struct btrfs_key ins;
954 struct extent_map *em;
955 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
956 int ret = 0;
957
958 if (btrfs_is_free_space_inode(inode)) {
959 WARN_ON_ONCE(1);
960 ret = -EINVAL;
961 goto out_unlock;
962 }
963
964 num_bytes = ALIGN(end - start + 1, blocksize);
965 num_bytes = max(blocksize, num_bytes);
966 disk_num_bytes = num_bytes;
967
968 /* if this is a small write inside eof, kick off defrag */
969 if (num_bytes < SZ_64K &&
970 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
971 btrfs_add_inode_defrag(NULL, inode);
972
973 if (start == 0) {
974 /* lets try to make an inline extent */
975 ret = cow_file_range_inline(root, inode, start, end, 0, 0,
976 NULL);
977 if (ret == 0) {
978 extent_clear_unlock_delalloc(inode, start, end,
979 delalloc_end, NULL,
980 EXTENT_LOCKED | EXTENT_DELALLOC |
981 EXTENT_DEFRAG, PAGE_UNLOCK |
982 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
983 PAGE_END_WRITEBACK);
984 btrfs_free_reserved_data_space_noquota(inode, start,
985 end - start + 1);
986 *nr_written = *nr_written +
987 (end - start + PAGE_SIZE) / PAGE_SIZE;
988 *page_started = 1;
989 goto out;
990 } else if (ret < 0) {
991 goto out_unlock;
992 }
993 }
994
995 BUG_ON(disk_num_bytes >
996 btrfs_super_total_bytes(fs_info->super_copy));
997
998 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
999 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
1000
1001 while (disk_num_bytes > 0) {
1002 unsigned long op;
1003
1004 cur_alloc_size = disk_num_bytes;
1005 ret = btrfs_reserve_extent(root, cur_alloc_size, cur_alloc_size,
1006 fs_info->sectorsize, 0, alloc_hint,
1007 &ins, 1, 1);
1008 if (ret < 0)
1009 goto out_unlock;
1010
1011 em = alloc_extent_map();
1012 if (!em) {
1013 ret = -ENOMEM;
1014 goto out_reserve;
1015 }
1016 em->start = start;
1017 em->orig_start = em->start;
1018 ram_size = ins.offset;
1019 em->len = ins.offset;
1020 em->mod_start = em->start;
1021 em->mod_len = em->len;
1022
1023 em->block_start = ins.objectid;
1024 em->block_len = ins.offset;
1025 em->orig_block_len = ins.offset;
1026 em->ram_bytes = ram_size;
1027 em->bdev = fs_info->fs_devices->latest_bdev;
1028 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1029 em->generation = -1;
1030
1031 while (1) {
1032 write_lock(&em_tree->lock);
1033 ret = add_extent_mapping(em_tree, em, 1);
1034 write_unlock(&em_tree->lock);
1035 if (ret != -EEXIST) {
1036 free_extent_map(em);
1037 break;
1038 }
1039 btrfs_drop_extent_cache(inode, start,
1040 start + ram_size - 1, 0);
1041 }
1042 if (ret)
1043 goto out_reserve;
1044
1045 cur_alloc_size = ins.offset;
1046 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
1047 ram_size, cur_alloc_size, 0);
1048 if (ret)
1049 goto out_drop_extent_cache;
1050
1051 if (root->root_key.objectid ==
1052 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1053 ret = btrfs_reloc_clone_csums(inode, start,
1054 cur_alloc_size);
1055 if (ret)
1056 goto out_drop_extent_cache;
1057 }
1058
1059 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
1060
1061 if (disk_num_bytes < cur_alloc_size)
1062 break;
1063
1064 /* we're not doing compressed IO, don't unlock the first
1065 * page (which the caller expects to stay locked), don't
1066 * clear any dirty bits and don't set any writeback bits
1067 *
1068 * Do set the Private2 bit so we know this page was properly
1069 * setup for writepage
1070 */
1071 op = unlock ? PAGE_UNLOCK : 0;
1072 op |= PAGE_SET_PRIVATE2;
1073
1074 extent_clear_unlock_delalloc(inode, start,
1075 start + ram_size - 1,
1076 delalloc_end, locked_page,
1077 EXTENT_LOCKED | EXTENT_DELALLOC,
1078 op);
1079 disk_num_bytes -= cur_alloc_size;
1080 num_bytes -= cur_alloc_size;
1081 alloc_hint = ins.objectid + ins.offset;
1082 start += cur_alloc_size;
1083 }
1084 out:
1085 return ret;
1086
1087 out_drop_extent_cache:
1088 btrfs_drop_extent_cache(inode, start, start + ram_size - 1, 0);
1089 out_reserve:
1090 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
1091 btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
1092 out_unlock:
1093 extent_clear_unlock_delalloc(inode, start, end, delalloc_end,
1094 locked_page,
1095 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
1096 EXTENT_DELALLOC | EXTENT_DEFRAG,
1097 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
1098 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK);
1099 goto out;
1100 }
1101
1102 /*
1103 * work queue call back to started compression on a file and pages
1104 */
1105 static noinline void async_cow_start(struct btrfs_work *work)
1106 {
1107 struct async_cow *async_cow;
1108 int num_added = 0;
1109 async_cow = container_of(work, struct async_cow, work);
1110
1111 compress_file_range(async_cow->inode, async_cow->locked_page,
1112 async_cow->start, async_cow->end, async_cow,
1113 &num_added);
1114 if (num_added == 0) {
1115 btrfs_add_delayed_iput(async_cow->inode);
1116 async_cow->inode = NULL;
1117 }
1118 }
1119
1120 /*
1121 * work queue call back to submit previously compressed pages
1122 */
1123 static noinline void async_cow_submit(struct btrfs_work *work)
1124 {
1125 struct btrfs_fs_info *fs_info;
1126 struct async_cow *async_cow;
1127 struct btrfs_root *root;
1128 unsigned long nr_pages;
1129
1130 async_cow = container_of(work, struct async_cow, work);
1131
1132 root = async_cow->root;
1133 fs_info = root->fs_info;
1134 nr_pages = (async_cow->end - async_cow->start + PAGE_SIZE) >>
1135 PAGE_SHIFT;
1136
1137 /*
1138 * atomic_sub_return implies a barrier for waitqueue_active
1139 */
1140 if (atomic_sub_return(nr_pages, &fs_info->async_delalloc_pages) <
1141 5 * SZ_1M &&
1142 waitqueue_active(&fs_info->async_submit_wait))
1143 wake_up(&fs_info->async_submit_wait);
1144
1145 if (async_cow->inode)
1146 submit_compressed_extents(async_cow->inode, async_cow);
1147 }
1148
1149 static noinline void async_cow_free(struct btrfs_work *work)
1150 {
1151 struct async_cow *async_cow;
1152 async_cow = container_of(work, struct async_cow, work);
1153 if (async_cow->inode)
1154 btrfs_add_delayed_iput(async_cow->inode);
1155 kfree(async_cow);
1156 }
1157
1158 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1159 u64 start, u64 end, int *page_started,
1160 unsigned long *nr_written)
1161 {
1162 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1163 struct async_cow *async_cow;
1164 struct btrfs_root *root = BTRFS_I(inode)->root;
1165 unsigned long nr_pages;
1166 u64 cur_end;
1167 int limit = 10 * SZ_1M;
1168
1169 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1170 1, 0, NULL, GFP_NOFS);
1171 while (start < end) {
1172 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1173 BUG_ON(!async_cow); /* -ENOMEM */
1174 async_cow->inode = igrab(inode);
1175 async_cow->root = root;
1176 async_cow->locked_page = locked_page;
1177 async_cow->start = start;
1178
1179 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
1180 !btrfs_test_opt(fs_info, FORCE_COMPRESS))
1181 cur_end = end;
1182 else
1183 cur_end = min(end, start + SZ_512K - 1);
1184
1185 async_cow->end = cur_end;
1186 INIT_LIST_HEAD(&async_cow->extents);
1187
1188 btrfs_init_work(&async_cow->work,
1189 btrfs_delalloc_helper,
1190 async_cow_start, async_cow_submit,
1191 async_cow_free);
1192
1193 nr_pages = (cur_end - start + PAGE_SIZE) >>
1194 PAGE_SHIFT;
1195 atomic_add(nr_pages, &fs_info->async_delalloc_pages);
1196
1197 btrfs_queue_work(fs_info->delalloc_workers, &async_cow->work);
1198
1199 if (atomic_read(&fs_info->async_delalloc_pages) > limit) {
1200 wait_event(fs_info->async_submit_wait,
1201 (atomic_read(&fs_info->async_delalloc_pages) <
1202 limit));
1203 }
1204
1205 while (atomic_read(&fs_info->async_submit_draining) &&
1206 atomic_read(&fs_info->async_delalloc_pages)) {
1207 wait_event(fs_info->async_submit_wait,
1208 (atomic_read(&fs_info->async_delalloc_pages) ==
1209 0));
1210 }
1211
1212 *nr_written += nr_pages;
1213 start = cur_end + 1;
1214 }
1215 *page_started = 1;
1216 return 0;
1217 }
1218
1219 static noinline int csum_exist_in_range(struct btrfs_fs_info *fs_info,
1220 u64 bytenr, u64 num_bytes)
1221 {
1222 int ret;
1223 struct btrfs_ordered_sum *sums;
1224 LIST_HEAD(list);
1225
1226 ret = btrfs_lookup_csums_range(fs_info->csum_root, bytenr,
1227 bytenr + num_bytes - 1, &list, 0);
1228 if (ret == 0 && list_empty(&list))
1229 return 0;
1230
1231 while (!list_empty(&list)) {
1232 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1233 list_del(&sums->list);
1234 kfree(sums);
1235 }
1236 return 1;
1237 }
1238
1239 /*
1240 * when nowcow writeback call back. This checks for snapshots or COW copies
1241 * of the extents that exist in the file, and COWs the file as required.
1242 *
1243 * If no cow copies or snapshots exist, we write directly to the existing
1244 * blocks on disk
1245 */
1246 static noinline int run_delalloc_nocow(struct inode *inode,
1247 struct page *locked_page,
1248 u64 start, u64 end, int *page_started, int force,
1249 unsigned long *nr_written)
1250 {
1251 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1252 struct btrfs_root *root = BTRFS_I(inode)->root;
1253 struct btrfs_trans_handle *trans;
1254 struct extent_buffer *leaf;
1255 struct btrfs_path *path;
1256 struct btrfs_file_extent_item *fi;
1257 struct btrfs_key found_key;
1258 u64 cow_start;
1259 u64 cur_offset;
1260 u64 extent_end;
1261 u64 extent_offset;
1262 u64 disk_bytenr;
1263 u64 num_bytes;
1264 u64 disk_num_bytes;
1265 u64 ram_bytes;
1266 int extent_type;
1267 int ret, err;
1268 int type;
1269 int nocow;
1270 int check_prev = 1;
1271 bool nolock;
1272 u64 ino = btrfs_ino(inode);
1273
1274 path = btrfs_alloc_path();
1275 if (!path) {
1276 extent_clear_unlock_delalloc(inode, start, end, end,
1277 locked_page,
1278 EXTENT_LOCKED | EXTENT_DELALLOC |
1279 EXTENT_DO_ACCOUNTING |
1280 EXTENT_DEFRAG, PAGE_UNLOCK |
1281 PAGE_CLEAR_DIRTY |
1282 PAGE_SET_WRITEBACK |
1283 PAGE_END_WRITEBACK);
1284 return -ENOMEM;
1285 }
1286
1287 nolock = btrfs_is_free_space_inode(inode);
1288
1289 if (nolock)
1290 trans = btrfs_join_transaction_nolock(root);
1291 else
1292 trans = btrfs_join_transaction(root);
1293
1294 if (IS_ERR(trans)) {
1295 extent_clear_unlock_delalloc(inode, start, end, end,
1296 locked_page,
1297 EXTENT_LOCKED | EXTENT_DELALLOC |
1298 EXTENT_DO_ACCOUNTING |
1299 EXTENT_DEFRAG, PAGE_UNLOCK |
1300 PAGE_CLEAR_DIRTY |
1301 PAGE_SET_WRITEBACK |
1302 PAGE_END_WRITEBACK);
1303 btrfs_free_path(path);
1304 return PTR_ERR(trans);
1305 }
1306
1307 trans->block_rsv = &fs_info->delalloc_block_rsv;
1308
1309 cow_start = (u64)-1;
1310 cur_offset = start;
1311 while (1) {
1312 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1313 cur_offset, 0);
1314 if (ret < 0)
1315 goto error;
1316 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1317 leaf = path->nodes[0];
1318 btrfs_item_key_to_cpu(leaf, &found_key,
1319 path->slots[0] - 1);
1320 if (found_key.objectid == ino &&
1321 found_key.type == BTRFS_EXTENT_DATA_KEY)
1322 path->slots[0]--;
1323 }
1324 check_prev = 0;
1325 next_slot:
1326 leaf = path->nodes[0];
1327 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1328 ret = btrfs_next_leaf(root, path);
1329 if (ret < 0)
1330 goto error;
1331 if (ret > 0)
1332 break;
1333 leaf = path->nodes[0];
1334 }
1335
1336 nocow = 0;
1337 disk_bytenr = 0;
1338 num_bytes = 0;
1339 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1340
1341 if (found_key.objectid > ino)
1342 break;
1343 if (WARN_ON_ONCE(found_key.objectid < ino) ||
1344 found_key.type < BTRFS_EXTENT_DATA_KEY) {
1345 path->slots[0]++;
1346 goto next_slot;
1347 }
1348 if (found_key.type > BTRFS_EXTENT_DATA_KEY ||
1349 found_key.offset > end)
1350 break;
1351
1352 if (found_key.offset > cur_offset) {
1353 extent_end = found_key.offset;
1354 extent_type = 0;
1355 goto out_check;
1356 }
1357
1358 fi = btrfs_item_ptr(leaf, path->slots[0],
1359 struct btrfs_file_extent_item);
1360 extent_type = btrfs_file_extent_type(leaf, fi);
1361
1362 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1363 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1364 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1365 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1366 extent_offset = btrfs_file_extent_offset(leaf, fi);
1367 extent_end = found_key.offset +
1368 btrfs_file_extent_num_bytes(leaf, fi);
1369 disk_num_bytes =
1370 btrfs_file_extent_disk_num_bytes(leaf, fi);
1371 if (extent_end <= start) {
1372 path->slots[0]++;
1373 goto next_slot;
1374 }
1375 if (disk_bytenr == 0)
1376 goto out_check;
1377 if (btrfs_file_extent_compression(leaf, fi) ||
1378 btrfs_file_extent_encryption(leaf, fi) ||
1379 btrfs_file_extent_other_encoding(leaf, fi))
1380 goto out_check;
1381 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1382 goto out_check;
1383 if (btrfs_extent_readonly(fs_info, disk_bytenr))
1384 goto out_check;
1385 if (btrfs_cross_ref_exist(trans, root, ino,
1386 found_key.offset -
1387 extent_offset, disk_bytenr))
1388 goto out_check;
1389 disk_bytenr += extent_offset;
1390 disk_bytenr += cur_offset - found_key.offset;
1391 num_bytes = min(end + 1, extent_end) - cur_offset;
1392 /*
1393 * if there are pending snapshots for this root,
1394 * we fall into common COW way.
1395 */
1396 if (!nolock) {
1397 err = btrfs_start_write_no_snapshoting(root);
1398 if (!err)
1399 goto out_check;
1400 }
1401 /*
1402 * force cow if csum exists in the range.
1403 * this ensure that csum for a given extent are
1404 * either valid or do not exist.
1405 */
1406 if (csum_exist_in_range(fs_info, disk_bytenr,
1407 num_bytes))
1408 goto out_check;
1409 if (!btrfs_inc_nocow_writers(fs_info, disk_bytenr))
1410 goto out_check;
1411 nocow = 1;
1412 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1413 extent_end = found_key.offset +
1414 btrfs_file_extent_inline_len(leaf,
1415 path->slots[0], fi);
1416 extent_end = ALIGN(extent_end,
1417 fs_info->sectorsize);
1418 } else {
1419 BUG_ON(1);
1420 }
1421 out_check:
1422 if (extent_end <= start) {
1423 path->slots[0]++;
1424 if (!nolock && nocow)
1425 btrfs_end_write_no_snapshoting(root);
1426 if (nocow)
1427 btrfs_dec_nocow_writers(fs_info, disk_bytenr);
1428 goto next_slot;
1429 }
1430 if (!nocow) {
1431 if (cow_start == (u64)-1)
1432 cow_start = cur_offset;
1433 cur_offset = extent_end;
1434 if (cur_offset > end)
1435 break;
1436 path->slots[0]++;
1437 goto next_slot;
1438 }
1439
1440 btrfs_release_path(path);
1441 if (cow_start != (u64)-1) {
1442 ret = cow_file_range(inode, locked_page,
1443 cow_start, found_key.offset - 1,
1444 end, page_started, nr_written, 1,
1445 NULL);
1446 if (ret) {
1447 if (!nolock && nocow)
1448 btrfs_end_write_no_snapshoting(root);
1449 if (nocow)
1450 btrfs_dec_nocow_writers(fs_info,
1451 disk_bytenr);
1452 goto error;
1453 }
1454 cow_start = (u64)-1;
1455 }
1456
1457 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1458 struct extent_map *em;
1459 struct extent_map_tree *em_tree;
1460 em_tree = &BTRFS_I(inode)->extent_tree;
1461 em = alloc_extent_map();
1462 BUG_ON(!em); /* -ENOMEM */
1463 em->start = cur_offset;
1464 em->orig_start = found_key.offset - extent_offset;
1465 em->len = num_bytes;
1466 em->block_len = num_bytes;
1467 em->block_start = disk_bytenr;
1468 em->orig_block_len = disk_num_bytes;
1469 em->ram_bytes = ram_bytes;
1470 em->bdev = fs_info->fs_devices->latest_bdev;
1471 em->mod_start = em->start;
1472 em->mod_len = em->len;
1473 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1474 set_bit(EXTENT_FLAG_FILLING, &em->flags);
1475 em->generation = -1;
1476 while (1) {
1477 write_lock(&em_tree->lock);
1478 ret = add_extent_mapping(em_tree, em, 1);
1479 write_unlock(&em_tree->lock);
1480 if (ret != -EEXIST) {
1481 free_extent_map(em);
1482 break;
1483 }
1484 btrfs_drop_extent_cache(inode, em->start,
1485 em->start + em->len - 1, 0);
1486 }
1487 type = BTRFS_ORDERED_PREALLOC;
1488 } else {
1489 type = BTRFS_ORDERED_NOCOW;
1490 }
1491
1492 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1493 num_bytes, num_bytes, type);
1494 if (nocow)
1495 btrfs_dec_nocow_writers(fs_info, disk_bytenr);
1496 BUG_ON(ret); /* -ENOMEM */
1497
1498 if (root->root_key.objectid ==
1499 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1500 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1501 num_bytes);
1502 if (ret) {
1503 if (!nolock && nocow)
1504 btrfs_end_write_no_snapshoting(root);
1505 goto error;
1506 }
1507 }
1508
1509 extent_clear_unlock_delalloc(inode, cur_offset,
1510 cur_offset + num_bytes - 1, end,
1511 locked_page, EXTENT_LOCKED |
1512 EXTENT_DELALLOC |
1513 EXTENT_CLEAR_DATA_RESV,
1514 PAGE_UNLOCK | PAGE_SET_PRIVATE2);
1515
1516 if (!nolock && nocow)
1517 btrfs_end_write_no_snapshoting(root);
1518 cur_offset = extent_end;
1519 if (cur_offset > end)
1520 break;
1521 }
1522 btrfs_release_path(path);
1523
1524 if (cur_offset <= end && cow_start == (u64)-1) {
1525 cow_start = cur_offset;
1526 cur_offset = end;
1527 }
1528
1529 if (cow_start != (u64)-1) {
1530 ret = cow_file_range(inode, locked_page, cow_start, end, end,
1531 page_started, nr_written, 1, NULL);
1532 if (ret)
1533 goto error;
1534 }
1535
1536 error:
1537 err = btrfs_end_transaction(trans);
1538 if (!ret)
1539 ret = err;
1540
1541 if (ret && cur_offset < end)
1542 extent_clear_unlock_delalloc(inode, cur_offset, end, end,
1543 locked_page, EXTENT_LOCKED |
1544 EXTENT_DELALLOC | EXTENT_DEFRAG |
1545 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1546 PAGE_CLEAR_DIRTY |
1547 PAGE_SET_WRITEBACK |
1548 PAGE_END_WRITEBACK);
1549 btrfs_free_path(path);
1550 return ret;
1551 }
1552
1553 static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
1554 {
1555
1556 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
1557 !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC))
1558 return 0;
1559
1560 /*
1561 * @defrag_bytes is a hint value, no spinlock held here,
1562 * if is not zero, it means the file is defragging.
1563 * Force cow if given extent needs to be defragged.
1564 */
1565 if (BTRFS_I(inode)->defrag_bytes &&
1566 test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
1567 EXTENT_DEFRAG, 0, NULL))
1568 return 1;
1569
1570 return 0;
1571 }
1572
1573 /*
1574 * extent_io.c call back to do delayed allocation processing
1575 */
1576 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1577 u64 start, u64 end, int *page_started,
1578 unsigned long *nr_written)
1579 {
1580 int ret;
1581 int force_cow = need_force_cow(inode, start, end);
1582
1583 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
1584 ret = run_delalloc_nocow(inode, locked_page, start, end,
1585 page_started, 1, nr_written);
1586 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
1587 ret = run_delalloc_nocow(inode, locked_page, start, end,
1588 page_started, 0, nr_written);
1589 } else if (!inode_need_compress(inode)) {
1590 ret = cow_file_range(inode, locked_page, start, end, end,
1591 page_started, nr_written, 1, NULL);
1592 } else {
1593 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1594 &BTRFS_I(inode)->runtime_flags);
1595 ret = cow_file_range_async(inode, locked_page, start, end,
1596 page_started, nr_written);
1597 }
1598 return ret;
1599 }
1600
1601 static void btrfs_split_extent_hook(struct inode *inode,
1602 struct extent_state *orig, u64 split)
1603 {
1604 u64 size;
1605
1606 /* not delalloc, ignore it */
1607 if (!(orig->state & EXTENT_DELALLOC))
1608 return;
1609
1610 size = orig->end - orig->start + 1;
1611 if (size > BTRFS_MAX_EXTENT_SIZE) {
1612 u64 num_extents;
1613 u64 new_size;
1614
1615 /*
1616 * See the explanation in btrfs_merge_extent_hook, the same
1617 * applies here, just in reverse.
1618 */
1619 new_size = orig->end - split + 1;
1620 num_extents = div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1621 BTRFS_MAX_EXTENT_SIZE);
1622 new_size = split - orig->start;
1623 num_extents += div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1624 BTRFS_MAX_EXTENT_SIZE);
1625 if (div64_u64(size + BTRFS_MAX_EXTENT_SIZE - 1,
1626 BTRFS_MAX_EXTENT_SIZE) >= num_extents)
1627 return;
1628 }
1629
1630 spin_lock(&BTRFS_I(inode)->lock);
1631 BTRFS_I(inode)->outstanding_extents++;
1632 spin_unlock(&BTRFS_I(inode)->lock);
1633 }
1634
1635 /*
1636 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1637 * extents so we can keep track of new extents that are just merged onto old
1638 * extents, such as when we are doing sequential writes, so we can properly
1639 * account for the metadata space we'll need.
1640 */
1641 static void btrfs_merge_extent_hook(struct inode *inode,
1642 struct extent_state *new,
1643 struct extent_state *other)
1644 {
1645 u64 new_size, old_size;
1646 u64 num_extents;
1647
1648 /* not delalloc, ignore it */
1649 if (!(other->state & EXTENT_DELALLOC))
1650 return;
1651
1652 if (new->start > other->start)
1653 new_size = new->end - other->start + 1;
1654 else
1655 new_size = other->end - new->start + 1;
1656
1657 /* we're not bigger than the max, unreserve the space and go */
1658 if (new_size <= BTRFS_MAX_EXTENT_SIZE) {
1659 spin_lock(&BTRFS_I(inode)->lock);
1660 BTRFS_I(inode)->outstanding_extents--;
1661 spin_unlock(&BTRFS_I(inode)->lock);
1662 return;
1663 }
1664
1665 /*
1666 * We have to add up either side to figure out how many extents were
1667 * accounted for before we merged into one big extent. If the number of
1668 * extents we accounted for is <= the amount we need for the new range
1669 * then we can return, otherwise drop. Think of it like this
1670 *
1671 * [ 4k][MAX_SIZE]
1672 *
1673 * So we've grown the extent by a MAX_SIZE extent, this would mean we
1674 * need 2 outstanding extents, on one side we have 1 and the other side
1675 * we have 1 so they are == and we can return. But in this case
1676 *
1677 * [MAX_SIZE+4k][MAX_SIZE+4k]
1678 *
1679 * Each range on their own accounts for 2 extents, but merged together
1680 * they are only 3 extents worth of accounting, so we need to drop in
1681 * this case.
1682 */
1683 old_size = other->end - other->start + 1;
1684 num_extents = div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
1685 BTRFS_MAX_EXTENT_SIZE);
1686 old_size = new->end - new->start + 1;
1687 num_extents += div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
1688 BTRFS_MAX_EXTENT_SIZE);
1689
1690 if (div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1691 BTRFS_MAX_EXTENT_SIZE) >= num_extents)
1692 return;
1693
1694 spin_lock(&BTRFS_I(inode)->lock);
1695 BTRFS_I(inode)->outstanding_extents--;
1696 spin_unlock(&BTRFS_I(inode)->lock);
1697 }
1698
1699 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1700 struct inode *inode)
1701 {
1702 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1703
1704 spin_lock(&root->delalloc_lock);
1705 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1706 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1707 &root->delalloc_inodes);
1708 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1709 &BTRFS_I(inode)->runtime_flags);
1710 root->nr_delalloc_inodes++;
1711 if (root->nr_delalloc_inodes == 1) {
1712 spin_lock(&fs_info->delalloc_root_lock);
1713 BUG_ON(!list_empty(&root->delalloc_root));
1714 list_add_tail(&root->delalloc_root,
1715 &fs_info->delalloc_roots);
1716 spin_unlock(&fs_info->delalloc_root_lock);
1717 }
1718 }
1719 spin_unlock(&root->delalloc_lock);
1720 }
1721
1722 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1723 struct inode *inode)
1724 {
1725 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1726
1727 spin_lock(&root->delalloc_lock);
1728 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1729 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1730 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1731 &BTRFS_I(inode)->runtime_flags);
1732 root->nr_delalloc_inodes--;
1733 if (!root->nr_delalloc_inodes) {
1734 spin_lock(&fs_info->delalloc_root_lock);
1735 BUG_ON(list_empty(&root->delalloc_root));
1736 list_del_init(&root->delalloc_root);
1737 spin_unlock(&fs_info->delalloc_root_lock);
1738 }
1739 }
1740 spin_unlock(&root->delalloc_lock);
1741 }
1742
1743 /*
1744 * extent_io.c set_bit_hook, used to track delayed allocation
1745 * bytes in this file, and to maintain the list of inodes that
1746 * have pending delalloc work to be done.
1747 */
1748 static void btrfs_set_bit_hook(struct inode *inode,
1749 struct extent_state *state, unsigned *bits)
1750 {
1751
1752 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1753
1754 if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
1755 WARN_ON(1);
1756 /*
1757 * set_bit and clear bit hooks normally require _irqsave/restore
1758 * but in this case, we are only testing for the DELALLOC
1759 * bit, which is only set or cleared with irqs on
1760 */
1761 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1762 struct btrfs_root *root = BTRFS_I(inode)->root;
1763 u64 len = state->end + 1 - state->start;
1764 bool do_list = !btrfs_is_free_space_inode(inode);
1765
1766 if (*bits & EXTENT_FIRST_DELALLOC) {
1767 *bits &= ~EXTENT_FIRST_DELALLOC;
1768 } else {
1769 spin_lock(&BTRFS_I(inode)->lock);
1770 BTRFS_I(inode)->outstanding_extents++;
1771 spin_unlock(&BTRFS_I(inode)->lock);
1772 }
1773
1774 /* For sanity tests */
1775 if (btrfs_is_testing(fs_info))
1776 return;
1777
1778 __percpu_counter_add(&fs_info->delalloc_bytes, len,
1779 fs_info->delalloc_batch);
1780 spin_lock(&BTRFS_I(inode)->lock);
1781 BTRFS_I(inode)->delalloc_bytes += len;
1782 if (*bits & EXTENT_DEFRAG)
1783 BTRFS_I(inode)->defrag_bytes += len;
1784 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1785 &BTRFS_I(inode)->runtime_flags))
1786 btrfs_add_delalloc_inodes(root, inode);
1787 spin_unlock(&BTRFS_I(inode)->lock);
1788 }
1789 }
1790
1791 /*
1792 * extent_io.c clear_bit_hook, see set_bit_hook for why
1793 */
1794 static void btrfs_clear_bit_hook(struct inode *inode,
1795 struct extent_state *state,
1796 unsigned *bits)
1797 {
1798 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1799 u64 len = state->end + 1 - state->start;
1800 u64 num_extents = div64_u64(len + BTRFS_MAX_EXTENT_SIZE -1,
1801 BTRFS_MAX_EXTENT_SIZE);
1802
1803 spin_lock(&BTRFS_I(inode)->lock);
1804 if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG))
1805 BTRFS_I(inode)->defrag_bytes -= len;
1806 spin_unlock(&BTRFS_I(inode)->lock);
1807
1808 /*
1809 * set_bit and clear bit hooks normally require _irqsave/restore
1810 * but in this case, we are only testing for the DELALLOC
1811 * bit, which is only set or cleared with irqs on
1812 */
1813 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1814 struct btrfs_root *root = BTRFS_I(inode)->root;
1815 bool do_list = !btrfs_is_free_space_inode(inode);
1816
1817 if (*bits & EXTENT_FIRST_DELALLOC) {
1818 *bits &= ~EXTENT_FIRST_DELALLOC;
1819 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1820 spin_lock(&BTRFS_I(inode)->lock);
1821 BTRFS_I(inode)->outstanding_extents -= num_extents;
1822 spin_unlock(&BTRFS_I(inode)->lock);
1823 }
1824
1825 /*
1826 * We don't reserve metadata space for space cache inodes so we
1827 * don't need to call dellalloc_release_metadata if there is an
1828 * error.
1829 */
1830 if (*bits & EXTENT_DO_ACCOUNTING &&
1831 root != fs_info->tree_root)
1832 btrfs_delalloc_release_metadata(inode, len);
1833
1834 /* For sanity tests. */
1835 if (btrfs_is_testing(fs_info))
1836 return;
1837
1838 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1839 && do_list && !(state->state & EXTENT_NORESERVE)
1840 && (*bits & (EXTENT_DO_ACCOUNTING |
1841 EXTENT_CLEAR_DATA_RESV)))
1842 btrfs_free_reserved_data_space_noquota(inode,
1843 state->start, len);
1844
1845 __percpu_counter_add(&fs_info->delalloc_bytes, -len,
1846 fs_info->delalloc_batch);
1847 spin_lock(&BTRFS_I(inode)->lock);
1848 BTRFS_I(inode)->delalloc_bytes -= len;
1849 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1850 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1851 &BTRFS_I(inode)->runtime_flags))
1852 btrfs_del_delalloc_inode(root, inode);
1853 spin_unlock(&BTRFS_I(inode)->lock);
1854 }
1855 }
1856
1857 /*
1858 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1859 * we don't create bios that span stripes or chunks
1860 *
1861 * return 1 if page cannot be merged to bio
1862 * return 0 if page can be merged to bio
1863 * return error otherwise
1864 */
1865 int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
1866 size_t size, struct bio *bio,
1867 unsigned long bio_flags)
1868 {
1869 struct inode *inode = page->mapping->host;
1870 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1871 u64 logical = (u64)bio->bi_iter.bi_sector << 9;
1872 u64 length = 0;
1873 u64 map_length;
1874 int ret;
1875
1876 if (bio_flags & EXTENT_BIO_COMPRESSED)
1877 return 0;
1878
1879 length = bio->bi_iter.bi_size;
1880 map_length = length;
1881 ret = btrfs_map_block(fs_info, btrfs_op(bio), logical, &map_length,
1882 NULL, 0);
1883 if (ret < 0)
1884 return ret;
1885 if (map_length < length + size)
1886 return 1;
1887 return 0;
1888 }
1889
1890 /*
1891 * in order to insert checksums into the metadata in large chunks,
1892 * we wait until bio submission time. All the pages in the bio are
1893 * checksummed and sums are attached onto the ordered extent record.
1894 *
1895 * At IO completion time the cums attached on the ordered extent record
1896 * are inserted into the btree
1897 */
1898 static int __btrfs_submit_bio_start(struct inode *inode, struct bio *bio,
1899 int mirror_num, unsigned long bio_flags,
1900 u64 bio_offset)
1901 {
1902 int ret = 0;
1903
1904 ret = btrfs_csum_one_bio(inode, bio, 0, 0);
1905 BUG_ON(ret); /* -ENOMEM */
1906 return 0;
1907 }
1908
1909 /*
1910 * in order to insert checksums into the metadata in large chunks,
1911 * we wait until bio submission time. All the pages in the bio are
1912 * checksummed and sums are attached onto the ordered extent record.
1913 *
1914 * At IO completion time the cums attached on the ordered extent record
1915 * are inserted into the btree
1916 */
1917 static int __btrfs_submit_bio_done(struct inode *inode, struct bio *bio,
1918 int mirror_num, unsigned long bio_flags,
1919 u64 bio_offset)
1920 {
1921 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1922 int ret;
1923
1924 ret = btrfs_map_bio(fs_info, bio, mirror_num, 1);
1925 if (ret) {
1926 bio->bi_error = ret;
1927 bio_endio(bio);
1928 }
1929 return ret;
1930 }
1931
1932 /*
1933 * extent_io.c submission hook. This does the right thing for csum calculation
1934 * on write, or reading the csums from the tree before a read
1935 */
1936 static int btrfs_submit_bio_hook(struct inode *inode, struct bio *bio,
1937 int mirror_num, unsigned long bio_flags,
1938 u64 bio_offset)
1939 {
1940 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1941 struct btrfs_root *root = BTRFS_I(inode)->root;
1942 enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA;
1943 int ret = 0;
1944 int skip_sum;
1945 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1946
1947 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1948
1949 if (btrfs_is_free_space_inode(inode))
1950 metadata = BTRFS_WQ_ENDIO_FREE_SPACE;
1951
1952 if (bio_op(bio) != REQ_OP_WRITE) {
1953 ret = btrfs_bio_wq_end_io(fs_info, bio, metadata);
1954 if (ret)
1955 goto out;
1956
1957 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1958 ret = btrfs_submit_compressed_read(inode, bio,
1959 mirror_num,
1960 bio_flags);
1961 goto out;
1962 } else if (!skip_sum) {
1963 ret = btrfs_lookup_bio_sums(inode, bio, NULL);
1964 if (ret)
1965 goto out;
1966 }
1967 goto mapit;
1968 } else if (async && !skip_sum) {
1969 /* csum items have already been cloned */
1970 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1971 goto mapit;
1972 /* we're doing a write, do the async checksumming */
1973 ret = btrfs_wq_submit_bio(fs_info, inode, bio, mirror_num,
1974 bio_flags, bio_offset,
1975 __btrfs_submit_bio_start,
1976 __btrfs_submit_bio_done);
1977 goto out;
1978 } else if (!skip_sum) {
1979 ret = btrfs_csum_one_bio(inode, bio, 0, 0);
1980 if (ret)
1981 goto out;
1982 }
1983
1984 mapit:
1985 ret = btrfs_map_bio(fs_info, bio, mirror_num, 0);
1986
1987 out:
1988 if (ret < 0) {
1989 bio->bi_error = ret;
1990 bio_endio(bio);
1991 }
1992 return ret;
1993 }
1994
1995 /*
1996 * given a list of ordered sums record them in the inode. This happens
1997 * at IO completion time based on sums calculated at bio submission time.
1998 */
1999 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
2000 struct inode *inode, u64 file_offset,
2001 struct list_head *list)
2002 {
2003 struct btrfs_ordered_sum *sum;
2004
2005 list_for_each_entry(sum, list, list) {
2006 trans->adding_csums = 1;
2007 btrfs_csum_file_blocks(trans,
2008 BTRFS_I(inode)->root->fs_info->csum_root, sum);
2009 trans->adding_csums = 0;
2010 }
2011 return 0;
2012 }
2013
2014 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
2015 struct extent_state **cached_state, int dedupe)
2016 {
2017 WARN_ON((end & (PAGE_SIZE - 1)) == 0);
2018 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
2019 cached_state);
2020 }
2021
2022 /* see btrfs_writepage_start_hook for details on why this is required */
2023 struct btrfs_writepage_fixup {
2024 struct page *page;
2025 struct btrfs_work work;
2026 };
2027
2028 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
2029 {
2030 struct btrfs_writepage_fixup *fixup;
2031 struct btrfs_ordered_extent *ordered;
2032 struct extent_state *cached_state = NULL;
2033 struct page *page;
2034 struct inode *inode;
2035 u64 page_start;
2036 u64 page_end;
2037 int ret;
2038
2039 fixup = container_of(work, struct btrfs_writepage_fixup, work);
2040 page = fixup->page;
2041 again:
2042 lock_page(page);
2043 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
2044 ClearPageChecked(page);
2045 goto out_page;
2046 }
2047
2048 inode = page->mapping->host;
2049 page_start = page_offset(page);
2050 page_end = page_offset(page) + PAGE_SIZE - 1;
2051
2052 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end,
2053 &cached_state);
2054
2055 /* already ordered? We're done */
2056 if (PagePrivate2(page))
2057 goto out;
2058
2059 ordered = btrfs_lookup_ordered_range(inode, page_start,
2060 PAGE_SIZE);
2061 if (ordered) {
2062 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
2063 page_end, &cached_state, GFP_NOFS);
2064 unlock_page(page);
2065 btrfs_start_ordered_extent(inode, ordered, 1);
2066 btrfs_put_ordered_extent(ordered);
2067 goto again;
2068 }
2069
2070 ret = btrfs_delalloc_reserve_space(inode, page_start,
2071 PAGE_SIZE);
2072 if (ret) {
2073 mapping_set_error(page->mapping, ret);
2074 end_extent_writepage(page, ret, page_start, page_end);
2075 ClearPageChecked(page);
2076 goto out;
2077 }
2078
2079 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state,
2080 0);
2081 ClearPageChecked(page);
2082 set_page_dirty(page);
2083 out:
2084 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
2085 &cached_state, GFP_NOFS);
2086 out_page:
2087 unlock_page(page);
2088 put_page(page);
2089 kfree(fixup);
2090 }
2091
2092 /*
2093 * There are a few paths in the higher layers of the kernel that directly
2094 * set the page dirty bit without asking the filesystem if it is a
2095 * good idea. This causes problems because we want to make sure COW
2096 * properly happens and the data=ordered rules are followed.
2097 *
2098 * In our case any range that doesn't have the ORDERED bit set
2099 * hasn't been properly setup for IO. We kick off an async process
2100 * to fix it up. The async helper will wait for ordered extents, set
2101 * the delalloc bit and make it safe to write the page.
2102 */
2103 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
2104 {
2105 struct inode *inode = page->mapping->host;
2106 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2107 struct btrfs_writepage_fixup *fixup;
2108
2109 /* this page is properly in the ordered list */
2110 if (TestClearPagePrivate2(page))
2111 return 0;
2112
2113 if (PageChecked(page))
2114 return -EAGAIN;
2115
2116 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
2117 if (!fixup)
2118 return -EAGAIN;
2119
2120 SetPageChecked(page);
2121 get_page(page);
2122 btrfs_init_work(&fixup->work, btrfs_fixup_helper,
2123 btrfs_writepage_fixup_worker, NULL, NULL);
2124 fixup->page = page;
2125 btrfs_queue_work(fs_info->fixup_workers, &fixup->work);
2126 return -EBUSY;
2127 }
2128
2129 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
2130 struct inode *inode, u64 file_pos,
2131 u64 disk_bytenr, u64 disk_num_bytes,
2132 u64 num_bytes, u64 ram_bytes,
2133 u8 compression, u8 encryption,
2134 u16 other_encoding, int extent_type)
2135 {
2136 struct btrfs_root *root = BTRFS_I(inode)->root;
2137 struct btrfs_file_extent_item *fi;
2138 struct btrfs_path *path;
2139 struct extent_buffer *leaf;
2140 struct btrfs_key ins;
2141 int extent_inserted = 0;
2142 int ret;
2143
2144 path = btrfs_alloc_path();
2145 if (!path)
2146 return -ENOMEM;
2147
2148 /*
2149 * we may be replacing one extent in the tree with another.
2150 * The new extent is pinned in the extent map, and we don't want
2151 * to drop it from the cache until it is completely in the btree.
2152 *
2153 * So, tell btrfs_drop_extents to leave this extent in the cache.
2154 * the caller is expected to unpin it and allow it to be merged
2155 * with the others.
2156 */
2157 ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
2158 file_pos + num_bytes, NULL, 0,
2159 1, sizeof(*fi), &extent_inserted);
2160 if (ret)
2161 goto out;
2162
2163 if (!extent_inserted) {
2164 ins.objectid = btrfs_ino(inode);
2165 ins.offset = file_pos;
2166 ins.type = BTRFS_EXTENT_DATA_KEY;
2167
2168 path->leave_spinning = 1;
2169 ret = btrfs_insert_empty_item(trans, root, path, &ins,
2170 sizeof(*fi));
2171 if (ret)
2172 goto out;
2173 }
2174 leaf = path->nodes[0];
2175 fi = btrfs_item_ptr(leaf, path->slots[0],
2176 struct btrfs_file_extent_item);
2177 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
2178 btrfs_set_file_extent_type(leaf, fi, extent_type);
2179 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
2180 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
2181 btrfs_set_file_extent_offset(leaf, fi, 0);
2182 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2183 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
2184 btrfs_set_file_extent_compression(leaf, fi, compression);
2185 btrfs_set_file_extent_encryption(leaf, fi, encryption);
2186 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
2187
2188 btrfs_mark_buffer_dirty(leaf);
2189 btrfs_release_path(path);
2190
2191 inode_add_bytes(inode, num_bytes);
2192
2193 ins.objectid = disk_bytenr;
2194 ins.offset = disk_num_bytes;
2195 ins.type = BTRFS_EXTENT_ITEM_KEY;
2196 ret = btrfs_alloc_reserved_file_extent(trans, root->root_key.objectid,
2197 btrfs_ino(inode), file_pos,
2198 ram_bytes, &ins);
2199 /*
2200 * Release the reserved range from inode dirty range map, as it is
2201 * already moved into delayed_ref_head
2202 */
2203 btrfs_qgroup_release_data(inode, file_pos, ram_bytes);
2204 out:
2205 btrfs_free_path(path);
2206
2207 return ret;
2208 }
2209
2210 /* snapshot-aware defrag */
2211 struct sa_defrag_extent_backref {
2212 struct rb_node node;
2213 struct old_sa_defrag_extent *old;
2214 u64 root_id;
2215 u64 inum;
2216 u64 file_pos;
2217 u64 extent_offset;
2218 u64 num_bytes;
2219 u64 generation;
2220 };
2221
2222 struct old_sa_defrag_extent {
2223 struct list_head list;
2224 struct new_sa_defrag_extent *new;
2225
2226 u64 extent_offset;
2227 u64 bytenr;
2228 u64 offset;
2229 u64 len;
2230 int count;
2231 };
2232
2233 struct new_sa_defrag_extent {
2234 struct rb_root root;
2235 struct list_head head;
2236 struct btrfs_path *path;
2237 struct inode *inode;
2238 u64 file_pos;
2239 u64 len;
2240 u64 bytenr;
2241 u64 disk_len;
2242 u8 compress_type;
2243 };
2244
2245 static int backref_comp(struct sa_defrag_extent_backref *b1,
2246 struct sa_defrag_extent_backref *b2)
2247 {
2248 if (b1->root_id < b2->root_id)
2249 return -1;
2250 else if (b1->root_id > b2->root_id)
2251 return 1;
2252
2253 if (b1->inum < b2->inum)
2254 return -1;
2255 else if (b1->inum > b2->inum)
2256 return 1;
2257
2258 if (b1->file_pos < b2->file_pos)
2259 return -1;
2260 else if (b1->file_pos > b2->file_pos)
2261 return 1;
2262
2263 /*
2264 * [------------------------------] ===> (a range of space)
2265 * |<--->| |<---->| =============> (fs/file tree A)
2266 * |<---------------------------->| ===> (fs/file tree B)
2267 *
2268 * A range of space can refer to two file extents in one tree while
2269 * refer to only one file extent in another tree.
2270 *
2271 * So we may process a disk offset more than one time(two extents in A)
2272 * and locate at the same extent(one extent in B), then insert two same
2273 * backrefs(both refer to the extent in B).
2274 */
2275 return 0;
2276 }
2277
2278 static void backref_insert(struct rb_root *root,
2279 struct sa_defrag_extent_backref *backref)
2280 {
2281 struct rb_node **p = &root->rb_node;
2282 struct rb_node *parent = NULL;
2283 struct sa_defrag_extent_backref *entry;
2284 int ret;
2285
2286 while (*p) {
2287 parent = *p;
2288 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2289
2290 ret = backref_comp(backref, entry);
2291 if (ret < 0)
2292 p = &(*p)->rb_left;
2293 else
2294 p = &(*p)->rb_right;
2295 }
2296
2297 rb_link_node(&backref->node, parent, p);
2298 rb_insert_color(&backref->node, root);
2299 }
2300
2301 /*
2302 * Note the backref might has changed, and in this case we just return 0.
2303 */
2304 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2305 void *ctx)
2306 {
2307 struct btrfs_file_extent_item *extent;
2308 struct old_sa_defrag_extent *old = ctx;
2309 struct new_sa_defrag_extent *new = old->new;
2310 struct btrfs_path *path = new->path;
2311 struct btrfs_key key;
2312 struct btrfs_root *root;
2313 struct sa_defrag_extent_backref *backref;
2314 struct extent_buffer *leaf;
2315 struct inode *inode = new->inode;
2316 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2317 int slot;
2318 int ret;
2319 u64 extent_offset;
2320 u64 num_bytes;
2321
2322 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2323 inum == btrfs_ino(inode))
2324 return 0;
2325
2326 key.objectid = root_id;
2327 key.type = BTRFS_ROOT_ITEM_KEY;
2328 key.offset = (u64)-1;
2329
2330 root = btrfs_read_fs_root_no_name(fs_info, &key);
2331 if (IS_ERR(root)) {
2332 if (PTR_ERR(root) == -ENOENT)
2333 return 0;
2334 WARN_ON(1);
2335 btrfs_debug(fs_info, "inum=%llu, offset=%llu, root_id=%llu",
2336 inum, offset, root_id);
2337 return PTR_ERR(root);
2338 }
2339
2340 key.objectid = inum;
2341 key.type = BTRFS_EXTENT_DATA_KEY;
2342 if (offset > (u64)-1 << 32)
2343 key.offset = 0;
2344 else
2345 key.offset = offset;
2346
2347 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2348 if (WARN_ON(ret < 0))
2349 return ret;
2350 ret = 0;
2351
2352 while (1) {
2353 cond_resched();
2354
2355 leaf = path->nodes[0];
2356 slot = path->slots[0];
2357
2358 if (slot >= btrfs_header_nritems(leaf)) {
2359 ret = btrfs_next_leaf(root, path);
2360 if (ret < 0) {
2361 goto out;
2362 } else if (ret > 0) {
2363 ret = 0;
2364 goto out;
2365 }
2366 continue;
2367 }
2368
2369 path->slots[0]++;
2370
2371 btrfs_item_key_to_cpu(leaf, &key, slot);
2372
2373 if (key.objectid > inum)
2374 goto out;
2375
2376 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2377 continue;
2378
2379 extent = btrfs_item_ptr(leaf, slot,
2380 struct btrfs_file_extent_item);
2381
2382 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2383 continue;
2384
2385 /*
2386 * 'offset' refers to the exact key.offset,
2387 * NOT the 'offset' field in btrfs_extent_data_ref, ie.
2388 * (key.offset - extent_offset).
2389 */
2390 if (key.offset != offset)
2391 continue;
2392
2393 extent_offset = btrfs_file_extent_offset(leaf, extent);
2394 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2395
2396 if (extent_offset >= old->extent_offset + old->offset +
2397 old->len || extent_offset + num_bytes <=
2398 old->extent_offset + old->offset)
2399 continue;
2400 break;
2401 }
2402
2403 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2404 if (!backref) {
2405 ret = -ENOENT;
2406 goto out;
2407 }
2408
2409 backref->root_id = root_id;
2410 backref->inum = inum;
2411 backref->file_pos = offset;
2412 backref->num_bytes = num_bytes;
2413 backref->extent_offset = extent_offset;
2414 backref->generation = btrfs_file_extent_generation(leaf, extent);
2415 backref->old = old;
2416 backref_insert(&new->root, backref);
2417 old->count++;
2418 out:
2419 btrfs_release_path(path);
2420 WARN_ON(ret);
2421 return ret;
2422 }
2423
2424 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2425 struct new_sa_defrag_extent *new)
2426 {
2427 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2428 struct old_sa_defrag_extent *old, *tmp;
2429 int ret;
2430
2431 new->path = path;
2432
2433 list_for_each_entry_safe(old, tmp, &new->head, list) {
2434 ret = iterate_inodes_from_logical(old->bytenr +
2435 old->extent_offset, fs_info,
2436 path, record_one_backref,
2437 old);
2438 if (ret < 0 && ret != -ENOENT)
2439 return false;
2440
2441 /* no backref to be processed for this extent */
2442 if (!old->count) {
2443 list_del(&old->list);
2444 kfree(old);
2445 }
2446 }
2447
2448 if (list_empty(&new->head))
2449 return false;
2450
2451 return true;
2452 }
2453
2454 static int relink_is_mergable(struct extent_buffer *leaf,
2455 struct btrfs_file_extent_item *fi,
2456 struct new_sa_defrag_extent *new)
2457 {
2458 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
2459 return 0;
2460
2461 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2462 return 0;
2463
2464 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
2465 return 0;
2466
2467 if (btrfs_file_extent_encryption(leaf, fi) ||
2468 btrfs_file_extent_other_encoding(leaf, fi))
2469 return 0;
2470
2471 return 1;
2472 }
2473
2474 /*
2475 * Note the backref might has changed, and in this case we just return 0.
2476 */
2477 static noinline int relink_extent_backref(struct btrfs_path *path,
2478 struct sa_defrag_extent_backref *prev,
2479 struct sa_defrag_extent_backref *backref)
2480 {
2481 struct btrfs_file_extent_item *extent;
2482 struct btrfs_file_extent_item *item;
2483 struct btrfs_ordered_extent *ordered;
2484 struct btrfs_trans_handle *trans;
2485 struct btrfs_root *root;
2486 struct btrfs_key key;
2487 struct extent_buffer *leaf;
2488 struct old_sa_defrag_extent *old = backref->old;
2489 struct new_sa_defrag_extent *new = old->new;
2490 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2491 struct inode *inode;
2492 struct extent_state *cached = NULL;
2493 int ret = 0;
2494 u64 start;
2495 u64 len;
2496 u64 lock_start;
2497 u64 lock_end;
2498 bool merge = false;
2499 int index;
2500
2501 if (prev && prev->root_id == backref->root_id &&
2502 prev->inum == backref->inum &&
2503 prev->file_pos + prev->num_bytes == backref->file_pos)
2504 merge = true;
2505
2506 /* step 1: get root */
2507 key.objectid = backref->root_id;
2508 key.type = BTRFS_ROOT_ITEM_KEY;
2509 key.offset = (u64)-1;
2510
2511 index = srcu_read_lock(&fs_info->subvol_srcu);
2512
2513 root = btrfs_read_fs_root_no_name(fs_info, &key);
2514 if (IS_ERR(root)) {
2515 srcu_read_unlock(&fs_info->subvol_srcu, index);
2516 if (PTR_ERR(root) == -ENOENT)
2517 return 0;
2518 return PTR_ERR(root);
2519 }
2520
2521 if (btrfs_root_readonly(root)) {
2522 srcu_read_unlock(&fs_info->subvol_srcu, index);
2523 return 0;
2524 }
2525
2526 /* step 2: get inode */
2527 key.objectid = backref->inum;
2528 key.type = BTRFS_INODE_ITEM_KEY;
2529 key.offset = 0;
2530
2531 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2532 if (IS_ERR(inode)) {
2533 srcu_read_unlock(&fs_info->subvol_srcu, index);
2534 return 0;
2535 }
2536
2537 srcu_read_unlock(&fs_info->subvol_srcu, index);
2538
2539 /* step 3: relink backref */
2540 lock_start = backref->file_pos;
2541 lock_end = backref->file_pos + backref->num_bytes - 1;
2542 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2543 &cached);
2544
2545 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2546 if (ordered) {
2547 btrfs_put_ordered_extent(ordered);
2548 goto out_unlock;
2549 }
2550
2551 trans = btrfs_join_transaction(root);
2552 if (IS_ERR(trans)) {
2553 ret = PTR_ERR(trans);
2554 goto out_unlock;
2555 }
2556
2557 key.objectid = backref->inum;
2558 key.type = BTRFS_EXTENT_DATA_KEY;
2559 key.offset = backref->file_pos;
2560
2561 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2562 if (ret < 0) {
2563 goto out_free_path;
2564 } else if (ret > 0) {
2565 ret = 0;
2566 goto out_free_path;
2567 }
2568
2569 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2570 struct btrfs_file_extent_item);
2571
2572 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2573 backref->generation)
2574 goto out_free_path;
2575
2576 btrfs_release_path(path);
2577
2578 start = backref->file_pos;
2579 if (backref->extent_offset < old->extent_offset + old->offset)
2580 start += old->extent_offset + old->offset -
2581 backref->extent_offset;
2582
2583 len = min(backref->extent_offset + backref->num_bytes,
2584 old->extent_offset + old->offset + old->len);
2585 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2586
2587 ret = btrfs_drop_extents(trans, root, inode, start,
2588 start + len, 1);
2589 if (ret)
2590 goto out_free_path;
2591 again:
2592 key.objectid = btrfs_ino(inode);
2593 key.type = BTRFS_EXTENT_DATA_KEY;
2594 key.offset = start;
2595
2596 path->leave_spinning = 1;
2597 if (merge) {
2598 struct btrfs_file_extent_item *fi;
2599 u64 extent_len;
2600 struct btrfs_key found_key;
2601
2602 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2603 if (ret < 0)
2604 goto out_free_path;
2605
2606 path->slots[0]--;
2607 leaf = path->nodes[0];
2608 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2609
2610 fi = btrfs_item_ptr(leaf, path->slots[0],
2611 struct btrfs_file_extent_item);
2612 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2613
2614 if (extent_len + found_key.offset == start &&
2615 relink_is_mergable(leaf, fi, new)) {
2616 btrfs_set_file_extent_num_bytes(leaf, fi,
2617 extent_len + len);
2618 btrfs_mark_buffer_dirty(leaf);
2619 inode_add_bytes(inode, len);
2620
2621 ret = 1;
2622 goto out_free_path;
2623 } else {
2624 merge = false;
2625 btrfs_release_path(path);
2626 goto again;
2627 }
2628 }
2629
2630 ret = btrfs_insert_empty_item(trans, root, path, &key,
2631 sizeof(*extent));
2632 if (ret) {
2633 btrfs_abort_transaction(trans, ret);
2634 goto out_free_path;
2635 }
2636
2637 leaf = path->nodes[0];
2638 item = btrfs_item_ptr(leaf, path->slots[0],
2639 struct btrfs_file_extent_item);
2640 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2641 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2642 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2643 btrfs_set_file_extent_num_bytes(leaf, item, len);
2644 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2645 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2646 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2647 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2648 btrfs_set_file_extent_encryption(leaf, item, 0);
2649 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2650
2651 btrfs_mark_buffer_dirty(leaf);
2652 inode_add_bytes(inode, len);
2653 btrfs_release_path(path);
2654
2655 ret = btrfs_inc_extent_ref(trans, fs_info, new->bytenr,
2656 new->disk_len, 0,
2657 backref->root_id, backref->inum,
2658 new->file_pos); /* start - extent_offset */
2659 if (ret) {
2660 btrfs_abort_transaction(trans, ret);
2661 goto out_free_path;
2662 }
2663
2664 ret = 1;
2665 out_free_path:
2666 btrfs_release_path(path);
2667 path->leave_spinning = 0;
2668 btrfs_end_transaction(trans);
2669 out_unlock:
2670 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2671 &cached, GFP_NOFS);
2672 iput(inode);
2673 return ret;
2674 }
2675
2676 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
2677 {
2678 struct old_sa_defrag_extent *old, *tmp;
2679
2680 if (!new)
2681 return;
2682
2683 list_for_each_entry_safe(old, tmp, &new->head, list) {
2684 kfree(old);
2685 }
2686 kfree(new);
2687 }
2688
2689 static void relink_file_extents(struct new_sa_defrag_extent *new)
2690 {
2691 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2692 struct btrfs_path *path;
2693 struct sa_defrag_extent_backref *backref;
2694 struct sa_defrag_extent_backref *prev = NULL;
2695 struct inode *inode;
2696 struct btrfs_root *root;
2697 struct rb_node *node;
2698 int ret;
2699
2700 inode = new->inode;
2701 root = BTRFS_I(inode)->root;
2702
2703 path = btrfs_alloc_path();
2704 if (!path)
2705 return;
2706
2707 if (!record_extent_backrefs(path, new)) {
2708 btrfs_free_path(path);
2709 goto out;
2710 }
2711 btrfs_release_path(path);
2712
2713 while (1) {
2714 node = rb_first(&new->root);
2715 if (!node)
2716 break;
2717 rb_erase(node, &new->root);
2718
2719 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2720
2721 ret = relink_extent_backref(path, prev, backref);
2722 WARN_ON(ret < 0);
2723
2724 kfree(prev);
2725
2726 if (ret == 1)
2727 prev = backref;
2728 else
2729 prev = NULL;
2730 cond_resched();
2731 }
2732 kfree(prev);
2733
2734 btrfs_free_path(path);
2735 out:
2736 free_sa_defrag_extent(new);
2737
2738 atomic_dec(&fs_info->defrag_running);
2739 wake_up(&fs_info->transaction_wait);
2740 }
2741
2742 static struct new_sa_defrag_extent *
2743 record_old_file_extents(struct inode *inode,
2744 struct btrfs_ordered_extent *ordered)
2745 {
2746 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2747 struct btrfs_root *root = BTRFS_I(inode)->root;
2748 struct btrfs_path *path;
2749 struct btrfs_key key;
2750 struct old_sa_defrag_extent *old;
2751 struct new_sa_defrag_extent *new;
2752 int ret;
2753
2754 new = kmalloc(sizeof(*new), GFP_NOFS);
2755 if (!new)
2756 return NULL;
2757
2758 new->inode = inode;
2759 new->file_pos = ordered->file_offset;
2760 new->len = ordered->len;
2761 new->bytenr = ordered->start;
2762 new->disk_len = ordered->disk_len;
2763 new->compress_type = ordered->compress_type;
2764 new->root = RB_ROOT;
2765 INIT_LIST_HEAD(&new->head);
2766
2767 path = btrfs_alloc_path();
2768 if (!path)
2769 goto out_kfree;
2770
2771 key.objectid = btrfs_ino(inode);
2772 key.type = BTRFS_EXTENT_DATA_KEY;
2773 key.offset = new->file_pos;
2774
2775 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2776 if (ret < 0)
2777 goto out_free_path;
2778 if (ret > 0 && path->slots[0] > 0)
2779 path->slots[0]--;
2780
2781 /* find out all the old extents for the file range */
2782 while (1) {
2783 struct btrfs_file_extent_item *extent;
2784 struct extent_buffer *l;
2785 int slot;
2786 u64 num_bytes;
2787 u64 offset;
2788 u64 end;
2789 u64 disk_bytenr;
2790 u64 extent_offset;
2791
2792 l = path->nodes[0];
2793 slot = path->slots[0];
2794
2795 if (slot >= btrfs_header_nritems(l)) {
2796 ret = btrfs_next_leaf(root, path);
2797 if (ret < 0)
2798 goto out_free_path;
2799 else if (ret > 0)
2800 break;
2801 continue;
2802 }
2803
2804 btrfs_item_key_to_cpu(l, &key, slot);
2805
2806 if (key.objectid != btrfs_ino(inode))
2807 break;
2808 if (key.type != BTRFS_EXTENT_DATA_KEY)
2809 break;
2810 if (key.offset >= new->file_pos + new->len)
2811 break;
2812
2813 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2814
2815 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2816 if (key.offset + num_bytes < new->file_pos)
2817 goto next;
2818
2819 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2820 if (!disk_bytenr)
2821 goto next;
2822
2823 extent_offset = btrfs_file_extent_offset(l, extent);
2824
2825 old = kmalloc(sizeof(*old), GFP_NOFS);
2826 if (!old)
2827 goto out_free_path;
2828
2829 offset = max(new->file_pos, key.offset);
2830 end = min(new->file_pos + new->len, key.offset + num_bytes);
2831
2832 old->bytenr = disk_bytenr;
2833 old->extent_offset = extent_offset;
2834 old->offset = offset - key.offset;
2835 old->len = end - offset;
2836 old->new = new;
2837 old->count = 0;
2838 list_add_tail(&old->list, &new->head);
2839 next:
2840 path->slots[0]++;
2841 cond_resched();
2842 }
2843
2844 btrfs_free_path(path);
2845 atomic_inc(&fs_info->defrag_running);
2846
2847 return new;
2848
2849 out_free_path:
2850 btrfs_free_path(path);
2851 out_kfree:
2852 free_sa_defrag_extent(new);
2853 return NULL;
2854 }
2855
2856 static void btrfs_release_delalloc_bytes(struct btrfs_fs_info *fs_info,
2857 u64 start, u64 len)
2858 {
2859 struct btrfs_block_group_cache *cache;
2860
2861 cache = btrfs_lookup_block_group(fs_info, start);
2862 ASSERT(cache);
2863
2864 spin_lock(&cache->lock);
2865 cache->delalloc_bytes -= len;
2866 spin_unlock(&cache->lock);
2867
2868 btrfs_put_block_group(cache);
2869 }
2870
2871 /* as ordered data IO finishes, this gets called so we can finish
2872 * an ordered extent if the range of bytes in the file it covers are
2873 * fully written.
2874 */
2875 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2876 {
2877 struct inode *inode = ordered_extent->inode;
2878 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2879 struct btrfs_root *root = BTRFS_I(inode)->root;
2880 struct btrfs_trans_handle *trans = NULL;
2881 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2882 struct extent_state *cached_state = NULL;
2883 struct new_sa_defrag_extent *new = NULL;
2884 int compress_type = 0;
2885 int ret = 0;
2886 u64 logical_len = ordered_extent->len;
2887 bool nolock;
2888 bool truncated = false;
2889
2890 nolock = btrfs_is_free_space_inode(inode);
2891
2892 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2893 ret = -EIO;
2894 goto out;
2895 }
2896
2897 btrfs_free_io_failure_record(inode, ordered_extent->file_offset,
2898 ordered_extent->file_offset +
2899 ordered_extent->len - 1);
2900
2901 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
2902 truncated = true;
2903 logical_len = ordered_extent->truncated_len;
2904 /* Truncated the entire extent, don't bother adding */
2905 if (!logical_len)
2906 goto out;
2907 }
2908
2909 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2910 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2911
2912 /*
2913 * For mwrite(mmap + memset to write) case, we still reserve
2914 * space for NOCOW range.
2915 * As NOCOW won't cause a new delayed ref, just free the space
2916 */
2917 btrfs_qgroup_free_data(inode, ordered_extent->file_offset,
2918 ordered_extent->len);
2919 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2920 if (nolock)
2921 trans = btrfs_join_transaction_nolock(root);
2922 else
2923 trans = btrfs_join_transaction(root);
2924 if (IS_ERR(trans)) {
2925 ret = PTR_ERR(trans);
2926 trans = NULL;
2927 goto out;
2928 }
2929 trans->block_rsv = &fs_info->delalloc_block_rsv;
2930 ret = btrfs_update_inode_fallback(trans, root, inode);
2931 if (ret) /* -ENOMEM or corruption */
2932 btrfs_abort_transaction(trans, ret);
2933 goto out;
2934 }
2935
2936 lock_extent_bits(io_tree, ordered_extent->file_offset,
2937 ordered_extent->file_offset + ordered_extent->len - 1,
2938 &cached_state);
2939
2940 ret = test_range_bit(io_tree, ordered_extent->file_offset,
2941 ordered_extent->file_offset + ordered_extent->len - 1,
2942 EXTENT_DEFRAG, 1, cached_state);
2943 if (ret) {
2944 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2945 if (0 && last_snapshot >= BTRFS_I(inode)->generation)
2946 /* the inode is shared */
2947 new = record_old_file_extents(inode, ordered_extent);
2948
2949 clear_extent_bit(io_tree, ordered_extent->file_offset,
2950 ordered_extent->file_offset + ordered_extent->len - 1,
2951 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
2952 }
2953
2954 if (nolock)
2955 trans = btrfs_join_transaction_nolock(root);
2956 else
2957 trans = btrfs_join_transaction(root);
2958 if (IS_ERR(trans)) {
2959 ret = PTR_ERR(trans);
2960 trans = NULL;
2961 goto out_unlock;
2962 }
2963
2964 trans->block_rsv = &fs_info->delalloc_block_rsv;
2965
2966 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
2967 compress_type = ordered_extent->compress_type;
2968 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
2969 BUG_ON(compress_type);
2970 ret = btrfs_mark_extent_written(trans, inode,
2971 ordered_extent->file_offset,
2972 ordered_extent->file_offset +
2973 logical_len);
2974 } else {
2975 BUG_ON(root == fs_info->tree_root);
2976 ret = insert_reserved_file_extent(trans, inode,
2977 ordered_extent->file_offset,
2978 ordered_extent->start,
2979 ordered_extent->disk_len,
2980 logical_len, logical_len,
2981 compress_type, 0, 0,
2982 BTRFS_FILE_EXTENT_REG);
2983 if (!ret)
2984 btrfs_release_delalloc_bytes(fs_info,
2985 ordered_extent->start,
2986 ordered_extent->disk_len);
2987 }
2988 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
2989 ordered_extent->file_offset, ordered_extent->len,
2990 trans->transid);
2991 if (ret < 0) {
2992 btrfs_abort_transaction(trans, ret);
2993 goto out_unlock;
2994 }
2995
2996 add_pending_csums(trans, inode, ordered_extent->file_offset,
2997 &ordered_extent->list);
2998
2999 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
3000 ret = btrfs_update_inode_fallback(trans, root, inode);
3001 if (ret) { /* -ENOMEM or corruption */
3002 btrfs_abort_transaction(trans, ret);
3003 goto out_unlock;
3004 }
3005 ret = 0;
3006 out_unlock:
3007 unlock_extent_cached(io_tree, ordered_extent->file_offset,
3008 ordered_extent->file_offset +
3009 ordered_extent->len - 1, &cached_state, GFP_NOFS);
3010 out:
3011 if (root != fs_info->tree_root)
3012 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
3013 if (trans)
3014 btrfs_end_transaction(trans);
3015
3016 if (ret || truncated) {
3017 u64 start, end;
3018
3019 if (truncated)
3020 start = ordered_extent->file_offset + logical_len;
3021 else
3022 start = ordered_extent->file_offset;
3023 end = ordered_extent->file_offset + ordered_extent->len - 1;
3024 clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS);
3025
3026 /* Drop the cache for the part of the extent we didn't write. */
3027 btrfs_drop_extent_cache(inode, start, end, 0);
3028
3029 /*
3030 * If the ordered extent had an IOERR or something else went
3031 * wrong we need to return the space for this ordered extent
3032 * back to the allocator. We only free the extent in the
3033 * truncated case if we didn't write out the extent at all.
3034 */
3035 if ((ret || !logical_len) &&
3036 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
3037 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
3038 btrfs_free_reserved_extent(fs_info,
3039 ordered_extent->start,
3040 ordered_extent->disk_len, 1);
3041 }
3042
3043
3044 /*
3045 * This needs to be done to make sure anybody waiting knows we are done
3046 * updating everything for this ordered extent.
3047 */
3048 btrfs_remove_ordered_extent(inode, ordered_extent);
3049
3050 /* for snapshot-aware defrag */
3051 if (new) {
3052 if (ret) {
3053 free_sa_defrag_extent(new);
3054 atomic_dec(&fs_info->defrag_running);
3055 } else {
3056 relink_file_extents(new);
3057 }
3058 }
3059
3060 /* once for us */
3061 btrfs_put_ordered_extent(ordered_extent);
3062 /* once for the tree */
3063 btrfs_put_ordered_extent(ordered_extent);
3064
3065 return ret;
3066 }
3067
3068 static void finish_ordered_fn(struct btrfs_work *work)
3069 {
3070 struct btrfs_ordered_extent *ordered_extent;
3071 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
3072 btrfs_finish_ordered_io(ordered_extent);
3073 }
3074
3075 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
3076 struct extent_state *state, int uptodate)
3077 {
3078 struct inode *inode = page->mapping->host;
3079 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3080 struct btrfs_ordered_extent *ordered_extent = NULL;
3081 struct btrfs_workqueue *wq;
3082 btrfs_work_func_t func;
3083
3084 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
3085
3086 ClearPagePrivate2(page);
3087 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
3088 end - start + 1, uptodate))
3089 return 0;
3090
3091 if (btrfs_is_free_space_inode(inode)) {
3092 wq = fs_info->endio_freespace_worker;
3093 func = btrfs_freespace_write_helper;
3094 } else {
3095 wq = fs_info->endio_write_workers;
3096 func = btrfs_endio_write_helper;
3097 }
3098
3099 btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL,
3100 NULL);
3101 btrfs_queue_work(wq, &ordered_extent->work);
3102
3103 return 0;
3104 }
3105
3106 static int __readpage_endio_check(struct inode *inode,
3107 struct btrfs_io_bio *io_bio,
3108 int icsum, struct page *page,
3109 int pgoff, u64 start, size_t len)
3110 {
3111 char *kaddr;
3112 u32 csum_expected;
3113 u32 csum = ~(u32)0;
3114
3115 csum_expected = *(((u32 *)io_bio->csum) + icsum);
3116
3117 kaddr = kmap_atomic(page);
3118 csum = btrfs_csum_data(kaddr + pgoff, csum, len);
3119 btrfs_csum_final(csum, (u8 *)&csum);
3120 if (csum != csum_expected)
3121 goto zeroit;
3122
3123 kunmap_atomic(kaddr);
3124 return 0;
3125 zeroit:
3126 btrfs_warn_rl(BTRFS_I(inode)->root->fs_info,
3127 "csum failed ino %llu off %llu csum %u expected csum %u",
3128 btrfs_ino(inode), start, csum, csum_expected);
3129 memset(kaddr + pgoff, 1, len);
3130 flush_dcache_page(page);
3131 kunmap_atomic(kaddr);
3132 if (csum_expected == 0)
3133 return 0;
3134 return -EIO;
3135 }
3136
3137 /*
3138 * when reads are done, we need to check csums to verify the data is correct
3139 * if there's a match, we allow the bio to finish. If not, the code in
3140 * extent_io.c will try to find good copies for us.
3141 */
3142 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
3143 u64 phy_offset, struct page *page,
3144 u64 start, u64 end, int mirror)
3145 {
3146 size_t offset = start - page_offset(page);
3147 struct inode *inode = page->mapping->host;
3148 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3149 struct btrfs_root *root = BTRFS_I(inode)->root;
3150
3151 if (PageChecked(page)) {
3152 ClearPageChecked(page);
3153 return 0;
3154 }
3155
3156 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
3157 return 0;
3158
3159 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
3160 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
3161 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM);
3162 return 0;
3163 }
3164
3165 phy_offset >>= inode->i_sb->s_blocksize_bits;
3166 return __readpage_endio_check(inode, io_bio, phy_offset, page, offset,
3167 start, (size_t)(end - start + 1));
3168 }
3169
3170 void btrfs_add_delayed_iput(struct inode *inode)
3171 {
3172 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3173 struct btrfs_inode *binode = BTRFS_I(inode);
3174
3175 if (atomic_add_unless(&inode->i_count, -1, 1))
3176 return;
3177
3178 spin_lock(&fs_info->delayed_iput_lock);
3179 if (binode->delayed_iput_count == 0) {
3180 ASSERT(list_empty(&binode->delayed_iput));
3181 list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs);
3182 } else {
3183 binode->delayed_iput_count++;
3184 }
3185 spin_unlock(&fs_info->delayed_iput_lock);
3186 }
3187
3188 void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info)
3189 {
3190
3191 spin_lock(&fs_info->delayed_iput_lock);
3192 while (!list_empty(&fs_info->delayed_iputs)) {
3193 struct btrfs_inode *inode;
3194
3195 inode = list_first_entry(&fs_info->delayed_iputs,
3196 struct btrfs_inode, delayed_iput);
3197 if (inode->delayed_iput_count) {
3198 inode->delayed_iput_count--;
3199 list_move_tail(&inode->delayed_iput,
3200 &fs_info->delayed_iputs);
3201 } else {
3202 list_del_init(&inode->delayed_iput);
3203 }
3204 spin_unlock(&fs_info->delayed_iput_lock);
3205 iput(&inode->vfs_inode);
3206 spin_lock(&fs_info->delayed_iput_lock);
3207 }
3208 spin_unlock(&fs_info->delayed_iput_lock);
3209 }
3210
3211 /*
3212 * This is called in transaction commit time. If there are no orphan
3213 * files in the subvolume, it removes orphan item and frees block_rsv
3214 * structure.
3215 */
3216 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
3217 struct btrfs_root *root)
3218 {
3219 struct btrfs_fs_info *fs_info = root->fs_info;
3220 struct btrfs_block_rsv *block_rsv;
3221 int ret;
3222
3223 if (atomic_read(&root->orphan_inodes) ||
3224 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
3225 return;
3226
3227 spin_lock(&root->orphan_lock);
3228 if (atomic_read(&root->orphan_inodes)) {
3229 spin_unlock(&root->orphan_lock);
3230 return;
3231 }
3232
3233 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
3234 spin_unlock(&root->orphan_lock);
3235 return;
3236 }
3237
3238 block_rsv = root->orphan_block_rsv;
3239 root->orphan_block_rsv = NULL;
3240 spin_unlock(&root->orphan_lock);
3241
3242 if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) &&
3243 btrfs_root_refs(&root->root_item) > 0) {
3244 ret = btrfs_del_orphan_item(trans, fs_info->tree_root,
3245 root->root_key.objectid);
3246 if (ret)
3247 btrfs_abort_transaction(trans, ret);
3248 else
3249 clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
3250 &root->state);
3251 }
3252
3253 if (block_rsv) {
3254 WARN_ON(block_rsv->size > 0);
3255 btrfs_free_block_rsv(fs_info, block_rsv);
3256 }
3257 }
3258
3259 /*
3260 * This creates an orphan entry for the given inode in case something goes
3261 * wrong in the middle of an unlink/truncate.
3262 *
3263 * NOTE: caller of this function should reserve 5 units of metadata for
3264 * this function.
3265 */
3266 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
3267 {
3268 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3269 struct btrfs_root *root = BTRFS_I(inode)->root;
3270 struct btrfs_block_rsv *block_rsv = NULL;
3271 int reserve = 0;
3272 int insert = 0;
3273 int ret;
3274
3275 if (!root->orphan_block_rsv) {
3276 block_rsv = btrfs_alloc_block_rsv(fs_info,
3277 BTRFS_BLOCK_RSV_TEMP);
3278 if (!block_rsv)
3279 return -ENOMEM;
3280 }
3281
3282 spin_lock(&root->orphan_lock);
3283 if (!root->orphan_block_rsv) {
3284 root->orphan_block_rsv = block_rsv;
3285 } else if (block_rsv) {
3286 btrfs_free_block_rsv(fs_info, block_rsv);
3287 block_rsv = NULL;
3288 }
3289
3290 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3291 &BTRFS_I(inode)->runtime_flags)) {
3292 #if 0
3293 /*
3294 * For proper ENOSPC handling, we should do orphan
3295 * cleanup when mounting. But this introduces backward
3296 * compatibility issue.
3297 */
3298 if (!xchg(&root->orphan_item_inserted, 1))
3299 insert = 2;
3300 else
3301 insert = 1;
3302 #endif
3303 insert = 1;
3304 atomic_inc(&root->orphan_inodes);
3305 }
3306
3307 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3308 &BTRFS_I(inode)->runtime_flags))
3309 reserve = 1;
3310 spin_unlock(&root->orphan_lock);
3311
3312 /* grab metadata reservation from transaction handle */
3313 if (reserve) {
3314 ret = btrfs_orphan_reserve_metadata(trans, inode);
3315 ASSERT(!ret);
3316 if (ret) {
3317 atomic_dec(&root->orphan_inodes);
3318 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3319 &BTRFS_I(inode)->runtime_flags);
3320 if (insert)
3321 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3322 &BTRFS_I(inode)->runtime_flags);
3323 return ret;
3324 }
3325 }
3326
3327 /* insert an orphan item to track this unlinked/truncated file */
3328 if (insert >= 1) {
3329 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3330 if (ret) {
3331 atomic_dec(&root->orphan_inodes);
3332 if (reserve) {
3333 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3334 &BTRFS_I(inode)->runtime_flags);
3335 btrfs_orphan_release_metadata(inode);
3336 }
3337 if (ret != -EEXIST) {
3338 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3339 &BTRFS_I(inode)->runtime_flags);
3340 btrfs_abort_transaction(trans, ret);
3341 return ret;
3342 }
3343 }
3344 ret = 0;
3345 }
3346
3347 /* insert an orphan item to track subvolume contains orphan files */
3348 if (insert >= 2) {
3349 ret = btrfs_insert_orphan_item(trans, fs_info->tree_root,
3350 root->root_key.objectid);
3351 if (ret && ret != -EEXIST) {
3352 btrfs_abort_transaction(trans, ret);
3353 return ret;
3354 }
3355 }
3356 return 0;
3357 }
3358
3359 /*
3360 * We have done the truncate/delete so we can go ahead and remove the orphan
3361 * item for this particular inode.
3362 */
3363 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3364 struct inode *inode)
3365 {
3366 struct btrfs_root *root = BTRFS_I(inode)->root;
3367 int delete_item = 0;
3368 int release_rsv = 0;
3369 int ret = 0;
3370
3371 spin_lock(&root->orphan_lock);
3372 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3373 &BTRFS_I(inode)->runtime_flags))
3374 delete_item = 1;
3375
3376 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3377 &BTRFS_I(inode)->runtime_flags))
3378 release_rsv = 1;
3379 spin_unlock(&root->orphan_lock);
3380
3381 if (delete_item) {
3382 atomic_dec(&root->orphan_inodes);
3383 if (trans)
3384 ret = btrfs_del_orphan_item(trans, root,
3385 btrfs_ino(inode));
3386 }
3387
3388 if (release_rsv)
3389 btrfs_orphan_release_metadata(inode);
3390
3391 return ret;
3392 }
3393
3394 /*
3395 * this cleans up any orphans that may be left on the list from the last use
3396 * of this root.
3397 */
3398 int btrfs_orphan_cleanup(struct btrfs_root *root)
3399 {
3400 struct btrfs_fs_info *fs_info = root->fs_info;
3401 struct btrfs_path *path;
3402 struct extent_buffer *leaf;
3403 struct btrfs_key key, found_key;
3404 struct btrfs_trans_handle *trans;
3405 struct inode *inode;
3406 u64 last_objectid = 0;
3407 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3408
3409 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3410 return 0;
3411
3412 path = btrfs_alloc_path();
3413 if (!path) {
3414 ret = -ENOMEM;
3415 goto out;
3416 }
3417 path->reada = READA_BACK;
3418
3419 key.objectid = BTRFS_ORPHAN_OBJECTID;
3420 key.type = BTRFS_ORPHAN_ITEM_KEY;
3421 key.offset = (u64)-1;
3422
3423 while (1) {
3424 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3425 if (ret < 0)
3426 goto out;
3427
3428 /*
3429 * if ret == 0 means we found what we were searching for, which
3430 * is weird, but possible, so only screw with path if we didn't
3431 * find the key and see if we have stuff that matches
3432 */
3433 if (ret > 0) {
3434 ret = 0;
3435 if (path->slots[0] == 0)
3436 break;
3437 path->slots[0]--;
3438 }
3439
3440 /* pull out the item */
3441 leaf = path->nodes[0];
3442 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3443
3444 /* make sure the item matches what we want */
3445 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3446 break;
3447 if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
3448 break;
3449
3450 /* release the path since we're done with it */
3451 btrfs_release_path(path);
3452
3453 /*
3454 * this is where we are basically btrfs_lookup, without the
3455 * crossing root thing. we store the inode number in the
3456 * offset of the orphan item.
3457 */
3458
3459 if (found_key.offset == last_objectid) {
3460 btrfs_err(fs_info,
3461 "Error removing orphan entry, stopping orphan cleanup");
3462 ret = -EINVAL;
3463 goto out;
3464 }
3465
3466 last_objectid = found_key.offset;
3467
3468 found_key.objectid = found_key.offset;
3469 found_key.type = BTRFS_INODE_ITEM_KEY;
3470 found_key.offset = 0;
3471 inode = btrfs_iget(fs_info->sb, &found_key, root, NULL);
3472 ret = PTR_ERR_OR_ZERO(inode);
3473 if (ret && ret != -ENOENT)
3474 goto out;
3475
3476 if (ret == -ENOENT && root == fs_info->tree_root) {
3477 struct btrfs_root *dead_root;
3478 struct btrfs_fs_info *fs_info = root->fs_info;
3479 int is_dead_root = 0;
3480
3481 /*
3482 * this is an orphan in the tree root. Currently these
3483 * could come from 2 sources:
3484 * a) a snapshot deletion in progress
3485 * b) a free space cache inode
3486 * We need to distinguish those two, as the snapshot
3487 * orphan must not get deleted.
3488 * find_dead_roots already ran before us, so if this
3489 * is a snapshot deletion, we should find the root
3490 * in the dead_roots list
3491 */
3492 spin_lock(&fs_info->trans_lock);
3493 list_for_each_entry(dead_root, &fs_info->dead_roots,
3494 root_list) {
3495 if (dead_root->root_key.objectid ==
3496 found_key.objectid) {
3497 is_dead_root = 1;
3498 break;
3499 }
3500 }
3501 spin_unlock(&fs_info->trans_lock);
3502 if (is_dead_root) {
3503 /* prevent this orphan from being found again */
3504 key.offset = found_key.objectid - 1;
3505 continue;
3506 }
3507 }
3508 /*
3509 * Inode is already gone but the orphan item is still there,
3510 * kill the orphan item.
3511 */
3512 if (ret == -ENOENT) {
3513 trans = btrfs_start_transaction(root, 1);
3514 if (IS_ERR(trans)) {
3515 ret = PTR_ERR(trans);
3516 goto out;
3517 }
3518 btrfs_debug(fs_info, "auto deleting %Lu",
3519 found_key.objectid);
3520 ret = btrfs_del_orphan_item(trans, root,
3521 found_key.objectid);
3522 btrfs_end_transaction(trans);
3523 if (ret)
3524 goto out;
3525 continue;
3526 }
3527
3528 /*
3529 * add this inode to the orphan list so btrfs_orphan_del does
3530 * the proper thing when we hit it
3531 */
3532 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3533 &BTRFS_I(inode)->runtime_flags);
3534 atomic_inc(&root->orphan_inodes);
3535
3536 /* if we have links, this was a truncate, lets do that */
3537 if (inode->i_nlink) {
3538 if (WARN_ON(!S_ISREG(inode->i_mode))) {
3539 iput(inode);
3540 continue;
3541 }
3542 nr_truncate++;
3543
3544 /* 1 for the orphan item deletion. */
3545 trans = btrfs_start_transaction(root, 1);
3546 if (IS_ERR(trans)) {
3547 iput(inode);
3548 ret = PTR_ERR(trans);
3549 goto out;
3550 }
3551 ret = btrfs_orphan_add(trans, inode);
3552 btrfs_end_transaction(trans);
3553 if (ret) {
3554 iput(inode);
3555 goto out;
3556 }
3557
3558 ret = btrfs_truncate(inode);
3559 if (ret)
3560 btrfs_orphan_del(NULL, inode);
3561 } else {
3562 nr_unlink++;
3563 }
3564
3565 /* this will do delete_inode and everything for us */
3566 iput(inode);
3567 if (ret)
3568 goto out;
3569 }
3570 /* release the path since we're done with it */
3571 btrfs_release_path(path);
3572
3573 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3574
3575 if (root->orphan_block_rsv)
3576 btrfs_block_rsv_release(fs_info, root->orphan_block_rsv,
3577 (u64)-1);
3578
3579 if (root->orphan_block_rsv ||
3580 test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
3581 trans = btrfs_join_transaction(root);
3582 if (!IS_ERR(trans))
3583 btrfs_end_transaction(trans);
3584 }
3585
3586 if (nr_unlink)
3587 btrfs_debug(fs_info, "unlinked %d orphans", nr_unlink);
3588 if (nr_truncate)
3589 btrfs_debug(fs_info, "truncated %d orphans", nr_truncate);
3590
3591 out:
3592 if (ret)
3593 btrfs_err(fs_info, "could not do orphan cleanup %d", ret);
3594 btrfs_free_path(path);
3595 return ret;
3596 }
3597
3598 /*
3599 * very simple check to peek ahead in the leaf looking for xattrs. If we
3600 * don't find any xattrs, we know there can't be any acls.
3601 *
3602 * slot is the slot the inode is in, objectid is the objectid of the inode
3603 */
3604 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3605 int slot, u64 objectid,
3606 int *first_xattr_slot)
3607 {
3608 u32 nritems = btrfs_header_nritems(leaf);
3609 struct btrfs_key found_key;
3610 static u64 xattr_access = 0;
3611 static u64 xattr_default = 0;
3612 int scanned = 0;
3613
3614 if (!xattr_access) {
3615 xattr_access = btrfs_name_hash(XATTR_NAME_POSIX_ACL_ACCESS,
3616 strlen(XATTR_NAME_POSIX_ACL_ACCESS));
3617 xattr_default = btrfs_name_hash(XATTR_NAME_POSIX_ACL_DEFAULT,
3618 strlen(XATTR_NAME_POSIX_ACL_DEFAULT));
3619 }
3620
3621 slot++;
3622 *first_xattr_slot = -1;
3623 while (slot < nritems) {
3624 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3625
3626 /* we found a different objectid, there must not be acls */
3627 if (found_key.objectid != objectid)
3628 return 0;
3629
3630 /* we found an xattr, assume we've got an acl */
3631 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3632 if (*first_xattr_slot == -1)
3633 *first_xattr_slot = slot;
3634 if (found_key.offset == xattr_access ||
3635 found_key.offset == xattr_default)
3636 return 1;
3637 }
3638
3639 /*
3640 * we found a key greater than an xattr key, there can't
3641 * be any acls later on
3642 */
3643 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3644 return 0;
3645
3646 slot++;
3647 scanned++;
3648
3649 /*
3650 * it goes inode, inode backrefs, xattrs, extents,
3651 * so if there are a ton of hard links to an inode there can
3652 * be a lot of backrefs. Don't waste time searching too hard,
3653 * this is just an optimization
3654 */
3655 if (scanned >= 8)
3656 break;
3657 }
3658 /* we hit the end of the leaf before we found an xattr or
3659 * something larger than an xattr. We have to assume the inode
3660 * has acls
3661 */
3662 if (*first_xattr_slot == -1)
3663 *first_xattr_slot = slot;
3664 return 1;
3665 }
3666
3667 /*
3668 * read an inode from the btree into the in-memory inode
3669 */
3670 static int btrfs_read_locked_inode(struct inode *inode)
3671 {
3672 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3673 struct btrfs_path *path;
3674 struct extent_buffer *leaf;
3675 struct btrfs_inode_item *inode_item;
3676 struct btrfs_root *root = BTRFS_I(inode)->root;
3677 struct btrfs_key location;
3678 unsigned long ptr;
3679 int maybe_acls;
3680 u32 rdev;
3681 int ret;
3682 bool filled = false;
3683 int first_xattr_slot;
3684
3685 ret = btrfs_fill_inode(inode, &rdev);
3686 if (!ret)
3687 filled = true;
3688
3689 path = btrfs_alloc_path();
3690 if (!path) {
3691 ret = -ENOMEM;
3692 goto make_bad;
3693 }
3694
3695 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3696
3697 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3698 if (ret) {
3699 if (ret > 0)
3700 ret = -ENOENT;
3701 goto make_bad;
3702 }
3703
3704 leaf = path->nodes[0];
3705
3706 if (filled)
3707 goto cache_index;
3708
3709 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3710 struct btrfs_inode_item);
3711 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3712 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3713 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3714 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3715 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
3716
3717 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
3718 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
3719
3720 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
3721 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
3722
3723 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
3724 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
3725
3726 BTRFS_I(inode)->i_otime.tv_sec =
3727 btrfs_timespec_sec(leaf, &inode_item->otime);
3728 BTRFS_I(inode)->i_otime.tv_nsec =
3729 btrfs_timespec_nsec(leaf, &inode_item->otime);
3730
3731 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3732 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3733 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3734
3735 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
3736 inode->i_generation = BTRFS_I(inode)->generation;
3737 inode->i_rdev = 0;
3738 rdev = btrfs_inode_rdev(leaf, inode_item);
3739
3740 BTRFS_I(inode)->index_cnt = (u64)-1;
3741 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3742
3743 cache_index:
3744 /*
3745 * If we were modified in the current generation and evicted from memory
3746 * and then re-read we need to do a full sync since we don't have any
3747 * idea about which extents were modified before we were evicted from
3748 * cache.
3749 *
3750 * This is required for both inode re-read from disk and delayed inode
3751 * in delayed_nodes_tree.
3752 */
3753 if (BTRFS_I(inode)->last_trans == fs_info->generation)
3754 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3755 &BTRFS_I(inode)->runtime_flags);
3756
3757 /*
3758 * We don't persist the id of the transaction where an unlink operation
3759 * against the inode was last made. So here we assume the inode might
3760 * have been evicted, and therefore the exact value of last_unlink_trans
3761 * lost, and set it to last_trans to avoid metadata inconsistencies
3762 * between the inode and its parent if the inode is fsync'ed and the log
3763 * replayed. For example, in the scenario:
3764 *
3765 * touch mydir/foo
3766 * ln mydir/foo mydir/bar
3767 * sync
3768 * unlink mydir/bar
3769 * echo 2 > /proc/sys/vm/drop_caches # evicts inode
3770 * xfs_io -c fsync mydir/foo
3771 * <power failure>
3772 * mount fs, triggers fsync log replay
3773 *
3774 * We must make sure that when we fsync our inode foo we also log its
3775 * parent inode, otherwise after log replay the parent still has the
3776 * dentry with the "bar" name but our inode foo has a link count of 1
3777 * and doesn't have an inode ref with the name "bar" anymore.
3778 *
3779 * Setting last_unlink_trans to last_trans is a pessimistic approach,
3780 * but it guarantees correctness at the expense of occasional full
3781 * transaction commits on fsync if our inode is a directory, or if our
3782 * inode is not a directory, logging its parent unnecessarily.
3783 */
3784 BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans;
3785
3786 path->slots[0]++;
3787 if (inode->i_nlink != 1 ||
3788 path->slots[0] >= btrfs_header_nritems(leaf))
3789 goto cache_acl;
3790
3791 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
3792 if (location.objectid != btrfs_ino(inode))
3793 goto cache_acl;
3794
3795 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3796 if (location.type == BTRFS_INODE_REF_KEY) {
3797 struct btrfs_inode_ref *ref;
3798
3799 ref = (struct btrfs_inode_ref *)ptr;
3800 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
3801 } else if (location.type == BTRFS_INODE_EXTREF_KEY) {
3802 struct btrfs_inode_extref *extref;
3803
3804 extref = (struct btrfs_inode_extref *)ptr;
3805 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
3806 extref);
3807 }
3808 cache_acl:
3809 /*
3810 * try to precache a NULL acl entry for files that don't have
3811 * any xattrs or acls
3812 */
3813 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3814 btrfs_ino(inode), &first_xattr_slot);
3815 if (first_xattr_slot != -1) {
3816 path->slots[0] = first_xattr_slot;
3817 ret = btrfs_load_inode_props(inode, path);
3818 if (ret)
3819 btrfs_err(fs_info,
3820 "error loading props for ino %llu (root %llu): %d",
3821 btrfs_ino(inode),
3822 root->root_key.objectid, ret);
3823 }
3824 btrfs_free_path(path);
3825
3826 if (!maybe_acls)
3827 cache_no_acl(inode);
3828
3829 switch (inode->i_mode & S_IFMT) {
3830 case S_IFREG:
3831 inode->i_mapping->a_ops = &btrfs_aops;
3832 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3833 inode->i_fop = &btrfs_file_operations;
3834 inode->i_op = &btrfs_file_inode_operations;
3835 break;
3836 case S_IFDIR:
3837 inode->i_fop = &btrfs_dir_file_operations;
3838 if (root == fs_info->tree_root)
3839 inode->i_op = &btrfs_dir_ro_inode_operations;
3840 else
3841 inode->i_op = &btrfs_dir_inode_operations;
3842 break;
3843 case S_IFLNK:
3844 inode->i_op = &btrfs_symlink_inode_operations;
3845 inode_nohighmem(inode);
3846 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3847 break;
3848 default:
3849 inode->i_op = &btrfs_special_inode_operations;
3850 init_special_inode(inode, inode->i_mode, rdev);
3851 break;
3852 }
3853
3854 btrfs_update_iflags(inode);
3855 return 0;
3856
3857 make_bad:
3858 btrfs_free_path(path);
3859 make_bad_inode(inode);
3860 return ret;
3861 }
3862
3863 /*
3864 * given a leaf and an inode, copy the inode fields into the leaf
3865 */
3866 static void fill_inode_item(struct btrfs_trans_handle *trans,
3867 struct extent_buffer *leaf,
3868 struct btrfs_inode_item *item,
3869 struct inode *inode)
3870 {
3871 struct btrfs_map_token token;
3872
3873 btrfs_init_map_token(&token);
3874
3875 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3876 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3877 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3878 &token);
3879 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3880 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3881
3882 btrfs_set_token_timespec_sec(leaf, &item->atime,
3883 inode->i_atime.tv_sec, &token);
3884 btrfs_set_token_timespec_nsec(leaf, &item->atime,
3885 inode->i_atime.tv_nsec, &token);
3886
3887 btrfs_set_token_timespec_sec(leaf, &item->mtime,
3888 inode->i_mtime.tv_sec, &token);
3889 btrfs_set_token_timespec_nsec(leaf, &item->mtime,
3890 inode->i_mtime.tv_nsec, &token);
3891
3892 btrfs_set_token_timespec_sec(leaf, &item->ctime,
3893 inode->i_ctime.tv_sec, &token);
3894 btrfs_set_token_timespec_nsec(leaf, &item->ctime,
3895 inode->i_ctime.tv_nsec, &token);
3896
3897 btrfs_set_token_timespec_sec(leaf, &item->otime,
3898 BTRFS_I(inode)->i_otime.tv_sec, &token);
3899 btrfs_set_token_timespec_nsec(leaf, &item->otime,
3900 BTRFS_I(inode)->i_otime.tv_nsec, &token);
3901
3902 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3903 &token);
3904 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3905 &token);
3906 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3907 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3908 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3909 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3910 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3911 }
3912
3913 /*
3914 * copy everything in the in-memory inode into the btree.
3915 */
3916 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3917 struct btrfs_root *root, struct inode *inode)
3918 {
3919 struct btrfs_inode_item *inode_item;
3920 struct btrfs_path *path;
3921 struct extent_buffer *leaf;
3922 int ret;
3923
3924 path = btrfs_alloc_path();
3925 if (!path)
3926 return -ENOMEM;
3927
3928 path->leave_spinning = 1;
3929 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3930 1);
3931 if (ret) {
3932 if (ret > 0)
3933 ret = -ENOENT;
3934 goto failed;
3935 }
3936
3937 leaf = path->nodes[0];
3938 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3939 struct btrfs_inode_item);
3940
3941 fill_inode_item(trans, leaf, inode_item, inode);
3942 btrfs_mark_buffer_dirty(leaf);
3943 btrfs_set_inode_last_trans(trans, inode);
3944 ret = 0;
3945 failed:
3946 btrfs_free_path(path);
3947 return ret;
3948 }
3949
3950 /*
3951 * copy everything in the in-memory inode into the btree.
3952 */
3953 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3954 struct btrfs_root *root, struct inode *inode)
3955 {
3956 struct btrfs_fs_info *fs_info = root->fs_info;
3957 int ret;
3958
3959 /*
3960 * If the inode is a free space inode, we can deadlock during commit
3961 * if we put it into the delayed code.
3962 *
3963 * The data relocation inode should also be directly updated
3964 * without delay
3965 */
3966 if (!btrfs_is_free_space_inode(inode)
3967 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
3968 && !test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) {
3969 btrfs_update_root_times(trans, root);
3970
3971 ret = btrfs_delayed_update_inode(trans, root, inode);
3972 if (!ret)
3973 btrfs_set_inode_last_trans(trans, inode);
3974 return ret;
3975 }
3976
3977 return btrfs_update_inode_item(trans, root, inode);
3978 }
3979
3980 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
3981 struct btrfs_root *root,
3982 struct inode *inode)
3983 {
3984 int ret;
3985
3986 ret = btrfs_update_inode(trans, root, inode);
3987 if (ret == -ENOSPC)
3988 return btrfs_update_inode_item(trans, root, inode);
3989 return ret;
3990 }
3991
3992 /*
3993 * unlink helper that gets used here in inode.c and in the tree logging
3994 * recovery code. It remove a link in a directory with a given name, and
3995 * also drops the back refs in the inode to the directory
3996 */
3997 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3998 struct btrfs_root *root,
3999 struct inode *dir, struct inode *inode,
4000 const char *name, int name_len)
4001 {
4002 struct btrfs_fs_info *fs_info = root->fs_info;
4003 struct btrfs_path *path;
4004 int ret = 0;
4005 struct extent_buffer *leaf;
4006 struct btrfs_dir_item *di;
4007 struct btrfs_key key;
4008 u64 index;
4009 u64 ino = btrfs_ino(inode);
4010 u64 dir_ino = btrfs_ino(dir);
4011
4012 path = btrfs_alloc_path();
4013 if (!path) {
4014 ret = -ENOMEM;
4015 goto out;
4016 }
4017
4018 path->leave_spinning = 1;
4019 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4020 name, name_len, -1);
4021 if (IS_ERR(di)) {
4022 ret = PTR_ERR(di);
4023 goto err;
4024 }
4025 if (!di) {
4026 ret = -ENOENT;
4027 goto err;
4028 }
4029 leaf = path->nodes[0];
4030 btrfs_dir_item_key_to_cpu(leaf, di, &key);
4031 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4032 if (ret)
4033 goto err;
4034 btrfs_release_path(path);
4035
4036 /*
4037 * If we don't have dir index, we have to get it by looking up
4038 * the inode ref, since we get the inode ref, remove it directly,
4039 * it is unnecessary to do delayed deletion.
4040 *
4041 * But if we have dir index, needn't search inode ref to get it.
4042 * Since the inode ref is close to the inode item, it is better
4043 * that we delay to delete it, and just do this deletion when
4044 * we update the inode item.
4045 */
4046 if (BTRFS_I(inode)->dir_index) {
4047 ret = btrfs_delayed_delete_inode_ref(inode);
4048 if (!ret) {
4049 index = BTRFS_I(inode)->dir_index;
4050 goto skip_backref;
4051 }
4052 }
4053
4054 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
4055 dir_ino, &index);
4056 if (ret) {
4057 btrfs_info(fs_info,
4058 "failed to delete reference to %.*s, inode %llu parent %llu",
4059 name_len, name, ino, dir_ino);
4060 btrfs_abort_transaction(trans, ret);
4061 goto err;
4062 }
4063 skip_backref:
4064 ret = btrfs_delete_delayed_dir_index(trans, fs_info, dir, index);
4065 if (ret) {
4066 btrfs_abort_transaction(trans, ret);
4067 goto err;
4068 }
4069
4070 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
4071 inode, dir_ino);
4072 if (ret != 0 && ret != -ENOENT) {
4073 btrfs_abort_transaction(trans, ret);
4074 goto err;
4075 }
4076
4077 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
4078 dir, index);
4079 if (ret == -ENOENT)
4080 ret = 0;
4081 else if (ret)
4082 btrfs_abort_transaction(trans, ret);
4083 err:
4084 btrfs_free_path(path);
4085 if (ret)
4086 goto out;
4087
4088 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
4089 inode_inc_iversion(inode);
4090 inode_inc_iversion(dir);
4091 inode->i_ctime = dir->i_mtime =
4092 dir->i_ctime = current_time(inode);
4093 ret = btrfs_update_inode(trans, root, dir);
4094 out:
4095 return ret;
4096 }
4097
4098 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4099 struct btrfs_root *root,
4100 struct inode *dir, struct inode *inode,
4101 const char *name, int name_len)
4102 {
4103 int ret;
4104 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
4105 if (!ret) {
4106 drop_nlink(inode);
4107 ret = btrfs_update_inode(trans, root, inode);
4108 }
4109 return ret;
4110 }
4111
4112 /*
4113 * helper to start transaction for unlink and rmdir.
4114 *
4115 * unlink and rmdir are special in btrfs, they do not always free space, so
4116 * if we cannot make our reservations the normal way try and see if there is
4117 * plenty of slack room in the global reserve to migrate, otherwise we cannot
4118 * allow the unlink to occur.
4119 */
4120 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
4121 {
4122 struct btrfs_root *root = BTRFS_I(dir)->root;
4123
4124 /*
4125 * 1 for the possible orphan item
4126 * 1 for the dir item
4127 * 1 for the dir index
4128 * 1 for the inode ref
4129 * 1 for the inode
4130 */
4131 return btrfs_start_transaction_fallback_global_rsv(root, 5, 5);
4132 }
4133
4134 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
4135 {
4136 struct btrfs_root *root = BTRFS_I(dir)->root;
4137 struct btrfs_trans_handle *trans;
4138 struct inode *inode = d_inode(dentry);
4139 int ret;
4140
4141 trans = __unlink_start_trans(dir);
4142 if (IS_ERR(trans))
4143 return PTR_ERR(trans);
4144
4145 btrfs_record_unlink_dir(trans, dir, d_inode(dentry), 0);
4146
4147 ret = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
4148 dentry->d_name.name, dentry->d_name.len);
4149 if (ret)
4150 goto out;
4151
4152 if (inode->i_nlink == 0) {
4153 ret = btrfs_orphan_add(trans, inode);
4154 if (ret)
4155 goto out;
4156 }
4157
4158 out:
4159 btrfs_end_transaction(trans);
4160 btrfs_btree_balance_dirty(root->fs_info);
4161 return ret;
4162 }
4163
4164 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
4165 struct btrfs_root *root,
4166 struct inode *dir, u64 objectid,
4167 const char *name, int name_len)
4168 {
4169 struct btrfs_fs_info *fs_info = root->fs_info;
4170 struct btrfs_path *path;
4171 struct extent_buffer *leaf;
4172 struct btrfs_dir_item *di;
4173 struct btrfs_key key;
4174 u64 index;
4175 int ret;
4176 u64 dir_ino = btrfs_ino(dir);
4177
4178 path = btrfs_alloc_path();
4179 if (!path)
4180 return -ENOMEM;
4181
4182 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4183 name, name_len, -1);
4184 if (IS_ERR_OR_NULL(di)) {
4185 if (!di)
4186 ret = -ENOENT;
4187 else
4188 ret = PTR_ERR(di);
4189 goto out;
4190 }
4191
4192 leaf = path->nodes[0];
4193 btrfs_dir_item_key_to_cpu(leaf, di, &key);
4194 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
4195 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4196 if (ret) {
4197 btrfs_abort_transaction(trans, ret);
4198 goto out;
4199 }
4200 btrfs_release_path(path);
4201
4202 ret = btrfs_del_root_ref(trans, fs_info, objectid,
4203 root->root_key.objectid, dir_ino,
4204 &index, name, name_len);
4205 if (ret < 0) {
4206 if (ret != -ENOENT) {
4207 btrfs_abort_transaction(trans, ret);
4208 goto out;
4209 }
4210 di = btrfs_search_dir_index_item(root, path, dir_ino,
4211 name, name_len);
4212 if (IS_ERR_OR_NULL(di)) {
4213 if (!di)
4214 ret = -ENOENT;
4215 else
4216 ret = PTR_ERR(di);
4217 btrfs_abort_transaction(trans, ret);
4218 goto out;
4219 }
4220
4221 leaf = path->nodes[0];
4222 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4223 btrfs_release_path(path);
4224 index = key.offset;
4225 }
4226 btrfs_release_path(path);
4227
4228 ret = btrfs_delete_delayed_dir_index(trans, fs_info, dir, index);
4229 if (ret) {
4230 btrfs_abort_transaction(trans, ret);
4231 goto out;
4232 }
4233
4234 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
4235 inode_inc_iversion(dir);
4236 dir->i_mtime = dir->i_ctime = current_time(dir);
4237 ret = btrfs_update_inode_fallback(trans, root, dir);
4238 if (ret)
4239 btrfs_abort_transaction(trans, ret);
4240 out:
4241 btrfs_free_path(path);
4242 return ret;
4243 }
4244
4245 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
4246 {
4247 struct inode *inode = d_inode(dentry);
4248 int err = 0;
4249 struct btrfs_root *root = BTRFS_I(dir)->root;
4250 struct btrfs_trans_handle *trans;
4251 u64 last_unlink_trans;
4252
4253 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
4254 return -ENOTEMPTY;
4255 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
4256 return -EPERM;
4257
4258 trans = __unlink_start_trans(dir);
4259 if (IS_ERR(trans))
4260 return PTR_ERR(trans);
4261
4262 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
4263 err = btrfs_unlink_subvol(trans, root, dir,
4264 BTRFS_I(inode)->location.objectid,
4265 dentry->d_name.name,
4266 dentry->d_name.len);
4267 goto out;
4268 }
4269
4270 err = btrfs_orphan_add(trans, inode);
4271 if (err)
4272 goto out;
4273
4274 last_unlink_trans = BTRFS_I(inode)->last_unlink_trans;
4275
4276 /* now the directory is empty */
4277 err = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
4278 dentry->d_name.name, dentry->d_name.len);
4279 if (!err) {
4280 btrfs_i_size_write(inode, 0);
4281 /*
4282 * Propagate the last_unlink_trans value of the deleted dir to
4283 * its parent directory. This is to prevent an unrecoverable
4284 * log tree in the case we do something like this:
4285 * 1) create dir foo
4286 * 2) create snapshot under dir foo
4287 * 3) delete the snapshot
4288 * 4) rmdir foo
4289 * 5) mkdir foo
4290 * 6) fsync foo or some file inside foo
4291 */
4292 if (last_unlink_trans >= trans->transid)
4293 BTRFS_I(dir)->last_unlink_trans = last_unlink_trans;
4294 }
4295 out:
4296 btrfs_end_transaction(trans);
4297 btrfs_btree_balance_dirty(root->fs_info);
4298
4299 return err;
4300 }
4301
4302 static int truncate_space_check(struct btrfs_trans_handle *trans,
4303 struct btrfs_root *root,
4304 u64 bytes_deleted)
4305 {
4306 struct btrfs_fs_info *fs_info = root->fs_info;
4307 int ret;
4308
4309 /*
4310 * This is only used to apply pressure to the enospc system, we don't
4311 * intend to use this reservation at all.
4312 */
4313 bytes_deleted = btrfs_csum_bytes_to_leaves(fs_info, bytes_deleted);
4314 bytes_deleted *= fs_info->nodesize;
4315 ret = btrfs_block_rsv_add(root, &fs_info->trans_block_rsv,
4316 bytes_deleted, BTRFS_RESERVE_NO_FLUSH);
4317 if (!ret) {
4318 trace_btrfs_space_reservation(fs_info, "transaction",
4319 trans->transid,
4320 bytes_deleted, 1);
4321 trans->bytes_reserved += bytes_deleted;
4322 }
4323 return ret;
4324
4325 }
4326
4327 static int truncate_inline_extent(struct inode *inode,
4328 struct btrfs_path *path,
4329 struct btrfs_key *found_key,
4330 const u64 item_end,
4331 const u64 new_size)
4332 {
4333 struct extent_buffer *leaf = path->nodes[0];
4334 int slot = path->slots[0];
4335 struct btrfs_file_extent_item *fi;
4336 u32 size = (u32)(new_size - found_key->offset);
4337 struct btrfs_root *root = BTRFS_I(inode)->root;
4338
4339 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
4340
4341 if (btrfs_file_extent_compression(leaf, fi) != BTRFS_COMPRESS_NONE) {
4342 loff_t offset = new_size;
4343 loff_t page_end = ALIGN(offset, PAGE_SIZE);
4344
4345 /*
4346 * Zero out the remaining of the last page of our inline extent,
4347 * instead of directly truncating our inline extent here - that
4348 * would be much more complex (decompressing all the data, then
4349 * compressing the truncated data, which might be bigger than
4350 * the size of the inline extent, resize the extent, etc).
4351 * We release the path because to get the page we might need to
4352 * read the extent item from disk (data not in the page cache).
4353 */
4354 btrfs_release_path(path);
4355 return btrfs_truncate_block(inode, offset, page_end - offset,
4356 0);
4357 }
4358
4359 btrfs_set_file_extent_ram_bytes(leaf, fi, size);
4360 size = btrfs_file_extent_calc_inline_size(size);
4361 btrfs_truncate_item(root->fs_info, path, size, 1);
4362
4363 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4364 inode_sub_bytes(inode, item_end + 1 - new_size);
4365
4366 return 0;
4367 }
4368
4369 /*
4370 * this can truncate away extent items, csum items and directory items.
4371 * It starts at a high offset and removes keys until it can't find
4372 * any higher than new_size
4373 *
4374 * csum items that cross the new i_size are truncated to the new size
4375 * as well.
4376 *
4377 * min_type is the minimum key type to truncate down to. If set to 0, this
4378 * will kill all the items on this inode, including the INODE_ITEM_KEY.
4379 */
4380 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
4381 struct btrfs_root *root,
4382 struct inode *inode,
4383 u64 new_size, u32 min_type)
4384 {
4385 struct btrfs_fs_info *fs_info = root->fs_info;
4386 struct btrfs_path *path;
4387 struct extent_buffer *leaf;
4388 struct btrfs_file_extent_item *fi;
4389 struct btrfs_key key;
4390 struct btrfs_key found_key;
4391 u64 extent_start = 0;
4392 u64 extent_num_bytes = 0;
4393 u64 extent_offset = 0;
4394 u64 item_end = 0;
4395 u64 last_size = new_size;
4396 u32 found_type = (u8)-1;
4397 int found_extent;
4398 int del_item;
4399 int pending_del_nr = 0;
4400 int pending_del_slot = 0;
4401 int extent_type = -1;
4402 int ret;
4403 int err = 0;
4404 u64 ino = btrfs_ino(inode);
4405 u64 bytes_deleted = 0;
4406 bool be_nice = 0;
4407 bool should_throttle = 0;
4408 bool should_end = 0;
4409
4410 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
4411
4412 /*
4413 * for non-free space inodes and ref cows, we want to back off from
4414 * time to time
4415 */
4416 if (!btrfs_is_free_space_inode(inode) &&
4417 test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4418 be_nice = 1;
4419
4420 path = btrfs_alloc_path();
4421 if (!path)
4422 return -ENOMEM;
4423 path->reada = READA_BACK;
4424
4425 /*
4426 * We want to drop from the next block forward in case this new size is
4427 * not block aligned since we will be keeping the last block of the
4428 * extent just the way it is.
4429 */
4430 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4431 root == fs_info->tree_root)
4432 btrfs_drop_extent_cache(inode, ALIGN(new_size,
4433 fs_info->sectorsize),
4434 (u64)-1, 0);
4435
4436 /*
4437 * This function is also used to drop the items in the log tree before
4438 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4439 * it is used to drop the loged items. So we shouldn't kill the delayed
4440 * items.
4441 */
4442 if (min_type == 0 && root == BTRFS_I(inode)->root)
4443 btrfs_kill_delayed_inode_items(inode);
4444
4445 key.objectid = ino;
4446 key.offset = (u64)-1;
4447 key.type = (u8)-1;
4448
4449 search_again:
4450 /*
4451 * with a 16K leaf size and 128MB extents, you can actually queue
4452 * up a huge file in a single leaf. Most of the time that
4453 * bytes_deleted is > 0, it will be huge by the time we get here
4454 */
4455 if (be_nice && bytes_deleted > SZ_32M) {
4456 if (btrfs_should_end_transaction(trans)) {
4457 err = -EAGAIN;
4458 goto error;
4459 }
4460 }
4461
4462
4463 path->leave_spinning = 1;
4464 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4465 if (ret < 0) {
4466 err = ret;
4467 goto out;
4468 }
4469
4470 if (ret > 0) {
4471 /* there are no items in the tree for us to truncate, we're
4472 * done
4473 */
4474 if (path->slots[0] == 0)
4475 goto out;
4476 path->slots[0]--;
4477 }
4478
4479 while (1) {
4480 fi = NULL;
4481 leaf = path->nodes[0];
4482 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4483 found_type = found_key.type;
4484
4485 if (found_key.objectid != ino)
4486 break;
4487
4488 if (found_type < min_type)
4489 break;
4490
4491 item_end = found_key.offset;
4492 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4493 fi = btrfs_item_ptr(leaf, path->slots[0],
4494 struct btrfs_file_extent_item);
4495 extent_type = btrfs_file_extent_type(leaf, fi);
4496 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4497 item_end +=
4498 btrfs_file_extent_num_bytes(leaf, fi);
4499 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4500 item_end += btrfs_file_extent_inline_len(leaf,
4501 path->slots[0], fi);
4502 }
4503 item_end--;
4504 }
4505 if (found_type > min_type) {
4506 del_item = 1;
4507 } else {
4508 if (item_end < new_size)
4509 break;
4510 if (found_key.offset >= new_size)
4511 del_item = 1;
4512 else
4513 del_item = 0;
4514 }
4515 found_extent = 0;
4516 /* FIXME, shrink the extent if the ref count is only 1 */
4517 if (found_type != BTRFS_EXTENT_DATA_KEY)
4518 goto delete;
4519
4520 if (del_item)
4521 last_size = found_key.offset;
4522 else
4523 last_size = new_size;
4524
4525 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4526 u64 num_dec;
4527 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4528 if (!del_item) {
4529 u64 orig_num_bytes =
4530 btrfs_file_extent_num_bytes(leaf, fi);
4531 extent_num_bytes = ALIGN(new_size -
4532 found_key.offset,
4533 fs_info->sectorsize);
4534 btrfs_set_file_extent_num_bytes(leaf, fi,
4535 extent_num_bytes);
4536 num_dec = (orig_num_bytes -
4537 extent_num_bytes);
4538 if (test_bit(BTRFS_ROOT_REF_COWS,
4539 &root->state) &&
4540 extent_start != 0)
4541 inode_sub_bytes(inode, num_dec);
4542 btrfs_mark_buffer_dirty(leaf);
4543 } else {
4544 extent_num_bytes =
4545 btrfs_file_extent_disk_num_bytes(leaf,
4546 fi);
4547 extent_offset = found_key.offset -
4548 btrfs_file_extent_offset(leaf, fi);
4549
4550 /* FIXME blocksize != 4096 */
4551 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4552 if (extent_start != 0) {
4553 found_extent = 1;
4554 if (test_bit(BTRFS_ROOT_REF_COWS,
4555 &root->state))
4556 inode_sub_bytes(inode, num_dec);
4557 }
4558 }
4559 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4560 /*
4561 * we can't truncate inline items that have had
4562 * special encodings
4563 */
4564 if (!del_item &&
4565 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4566 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
4567
4568 /*
4569 * Need to release path in order to truncate a
4570 * compressed extent. So delete any accumulated
4571 * extent items so far.
4572 */
4573 if (btrfs_file_extent_compression(leaf, fi) !=
4574 BTRFS_COMPRESS_NONE && pending_del_nr) {
4575 err = btrfs_del_items(trans, root, path,
4576 pending_del_slot,
4577 pending_del_nr);
4578 if (err) {
4579 btrfs_abort_transaction(trans,
4580 err);
4581 goto error;
4582 }
4583 pending_del_nr = 0;
4584 }
4585
4586 err = truncate_inline_extent(inode, path,
4587 &found_key,
4588 item_end,
4589 new_size);
4590 if (err) {
4591 btrfs_abort_transaction(trans, err);
4592 goto error;
4593 }
4594 } else if (test_bit(BTRFS_ROOT_REF_COWS,
4595 &root->state)) {
4596 inode_sub_bytes(inode, item_end + 1 - new_size);
4597 }
4598 }
4599 delete:
4600 if (del_item) {
4601 if (!pending_del_nr) {
4602 /* no pending yet, add ourselves */
4603 pending_del_slot = path->slots[0];
4604 pending_del_nr = 1;
4605 } else if (pending_del_nr &&
4606 path->slots[0] + 1 == pending_del_slot) {
4607 /* hop on the pending chunk */
4608 pending_del_nr++;
4609 pending_del_slot = path->slots[0];
4610 } else {
4611 BUG();
4612 }
4613 } else {
4614 break;
4615 }
4616 should_throttle = 0;
4617
4618 if (found_extent &&
4619 (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4620 root == fs_info->tree_root)) {
4621 btrfs_set_path_blocking(path);
4622 bytes_deleted += extent_num_bytes;
4623 ret = btrfs_free_extent(trans, fs_info, extent_start,
4624 extent_num_bytes, 0,
4625 btrfs_header_owner(leaf),
4626 ino, extent_offset);
4627 BUG_ON(ret);
4628 if (btrfs_should_throttle_delayed_refs(trans, fs_info))
4629 btrfs_async_run_delayed_refs(fs_info,
4630 trans->delayed_ref_updates * 2,
4631 trans->transid, 0);
4632 if (be_nice) {
4633 if (truncate_space_check(trans, root,
4634 extent_num_bytes)) {
4635 should_end = 1;
4636 }
4637 if (btrfs_should_throttle_delayed_refs(trans,
4638 fs_info))
4639 should_throttle = 1;
4640 }
4641 }
4642
4643 if (found_type == BTRFS_INODE_ITEM_KEY)
4644 break;
4645
4646 if (path->slots[0] == 0 ||
4647 path->slots[0] != pending_del_slot ||
4648 should_throttle || should_end) {
4649 if (pending_del_nr) {
4650 ret = btrfs_del_items(trans, root, path,
4651 pending_del_slot,
4652 pending_del_nr);
4653 if (ret) {
4654 btrfs_abort_transaction(trans, ret);
4655 goto error;
4656 }
4657 pending_del_nr = 0;
4658 }
4659 btrfs_release_path(path);
4660 if (should_throttle) {
4661 unsigned long updates = trans->delayed_ref_updates;
4662 if (updates) {
4663 trans->delayed_ref_updates = 0;
4664 ret = btrfs_run_delayed_refs(trans,
4665 fs_info,
4666 updates * 2);
4667 if (ret && !err)
4668 err = ret;
4669 }
4670 }
4671 /*
4672 * if we failed to refill our space rsv, bail out
4673 * and let the transaction restart
4674 */
4675 if (should_end) {
4676 err = -EAGAIN;
4677 goto error;
4678 }
4679 goto search_again;
4680 } else {
4681 path->slots[0]--;
4682 }
4683 }
4684 out:
4685 if (pending_del_nr) {
4686 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4687 pending_del_nr);
4688 if (ret)
4689 btrfs_abort_transaction(trans, ret);
4690 }
4691 error:
4692 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
4693 btrfs_ordered_update_i_size(inode, last_size, NULL);
4694
4695 btrfs_free_path(path);
4696
4697 if (be_nice && bytes_deleted > SZ_32M) {
4698 unsigned long updates = trans->delayed_ref_updates;
4699 if (updates) {
4700 trans->delayed_ref_updates = 0;
4701 ret = btrfs_run_delayed_refs(trans, fs_info,
4702 updates * 2);
4703 if (ret && !err)
4704 err = ret;
4705 }
4706 }
4707 return err;
4708 }
4709
4710 /*
4711 * btrfs_truncate_block - read, zero a chunk and write a block
4712 * @inode - inode that we're zeroing
4713 * @from - the offset to start zeroing
4714 * @len - the length to zero, 0 to zero the entire range respective to the
4715 * offset
4716 * @front - zero up to the offset instead of from the offset on
4717 *
4718 * This will find the block for the "from" offset and cow the block and zero the
4719 * part we want to zero. This is used with truncate and hole punching.
4720 */
4721 int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len,
4722 int front)
4723 {
4724 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4725 struct address_space *mapping = inode->i_mapping;
4726 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4727 struct btrfs_ordered_extent *ordered;
4728 struct extent_state *cached_state = NULL;
4729 char *kaddr;
4730 u32 blocksize = fs_info->sectorsize;
4731 pgoff_t index = from >> PAGE_SHIFT;
4732 unsigned offset = from & (blocksize - 1);
4733 struct page *page;
4734 gfp_t mask = btrfs_alloc_write_mask(mapping);
4735 int ret = 0;
4736 u64 block_start;
4737 u64 block_end;
4738
4739 if ((offset & (blocksize - 1)) == 0 &&
4740 (!len || ((len & (blocksize - 1)) == 0)))
4741 goto out;
4742
4743 ret = btrfs_delalloc_reserve_space(inode,
4744 round_down(from, blocksize), blocksize);
4745 if (ret)
4746 goto out;
4747
4748 again:
4749 page = find_or_create_page(mapping, index, mask);
4750 if (!page) {
4751 btrfs_delalloc_release_space(inode,
4752 round_down(from, blocksize),
4753 blocksize);
4754 ret = -ENOMEM;
4755 goto out;
4756 }
4757
4758 block_start = round_down(from, blocksize);
4759 block_end = block_start + blocksize - 1;
4760
4761 if (!PageUptodate(page)) {
4762 ret = btrfs_readpage(NULL, page);
4763 lock_page(page);
4764 if (page->mapping != mapping) {
4765 unlock_page(page);
4766 put_page(page);
4767 goto again;
4768 }
4769 if (!PageUptodate(page)) {
4770 ret = -EIO;
4771 goto out_unlock;
4772 }
4773 }
4774 wait_on_page_writeback(page);
4775
4776 lock_extent_bits(io_tree, block_start, block_end, &cached_state);
4777 set_page_extent_mapped(page);
4778
4779 ordered = btrfs_lookup_ordered_extent(inode, block_start);
4780 if (ordered) {
4781 unlock_extent_cached(io_tree, block_start, block_end,
4782 &cached_state, GFP_NOFS);
4783 unlock_page(page);
4784 put_page(page);
4785 btrfs_start_ordered_extent(inode, ordered, 1);
4786 btrfs_put_ordered_extent(ordered);
4787 goto again;
4788 }
4789
4790 clear_extent_bit(&BTRFS_I(inode)->io_tree, block_start, block_end,
4791 EXTENT_DIRTY | EXTENT_DELALLOC |
4792 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4793 0, 0, &cached_state, GFP_NOFS);
4794
4795 ret = btrfs_set_extent_delalloc(inode, block_start, block_end,
4796 &cached_state, 0);
4797 if (ret) {
4798 unlock_extent_cached(io_tree, block_start, block_end,
4799 &cached_state, GFP_NOFS);
4800 goto out_unlock;
4801 }
4802
4803 if (offset != blocksize) {
4804 if (!len)
4805 len = blocksize - offset;
4806 kaddr = kmap(page);
4807 if (front)
4808 memset(kaddr + (block_start - page_offset(page)),
4809 0, offset);
4810 else
4811 memset(kaddr + (block_start - page_offset(page)) + offset,
4812 0, len);
4813 flush_dcache_page(page);
4814 kunmap(page);
4815 }
4816 ClearPageChecked(page);
4817 set_page_dirty(page);
4818 unlock_extent_cached(io_tree, block_start, block_end, &cached_state,
4819 GFP_NOFS);
4820
4821 out_unlock:
4822 if (ret)
4823 btrfs_delalloc_release_space(inode, block_start,
4824 blocksize);
4825 unlock_page(page);
4826 put_page(page);
4827 out:
4828 return ret;
4829 }
4830
4831 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
4832 u64 offset, u64 len)
4833 {
4834 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4835 struct btrfs_trans_handle *trans;
4836 int ret;
4837
4838 /*
4839 * Still need to make sure the inode looks like it's been updated so
4840 * that any holes get logged if we fsync.
4841 */
4842 if (btrfs_fs_incompat(fs_info, NO_HOLES)) {
4843 BTRFS_I(inode)->last_trans = fs_info->generation;
4844 BTRFS_I(inode)->last_sub_trans = root->log_transid;
4845 BTRFS_I(inode)->last_log_commit = root->last_log_commit;
4846 return 0;
4847 }
4848
4849 /*
4850 * 1 - for the one we're dropping
4851 * 1 - for the one we're adding
4852 * 1 - for updating the inode.
4853 */
4854 trans = btrfs_start_transaction(root, 3);
4855 if (IS_ERR(trans))
4856 return PTR_ERR(trans);
4857
4858 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
4859 if (ret) {
4860 btrfs_abort_transaction(trans, ret);
4861 btrfs_end_transaction(trans);
4862 return ret;
4863 }
4864
4865 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset,
4866 0, 0, len, 0, len, 0, 0, 0);
4867 if (ret)
4868 btrfs_abort_transaction(trans, ret);
4869 else
4870 btrfs_update_inode(trans, root, inode);
4871 btrfs_end_transaction(trans);
4872 return ret;
4873 }
4874
4875 /*
4876 * This function puts in dummy file extents for the area we're creating a hole
4877 * for. So if we are truncating this file to a larger size we need to insert
4878 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4879 * the range between oldsize and size
4880 */
4881 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4882 {
4883 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4884 struct btrfs_root *root = BTRFS_I(inode)->root;
4885 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4886 struct extent_map *em = NULL;
4887 struct extent_state *cached_state = NULL;
4888 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4889 u64 hole_start = ALIGN(oldsize, fs_info->sectorsize);
4890 u64 block_end = ALIGN(size, fs_info->sectorsize);
4891 u64 last_byte;
4892 u64 cur_offset;
4893 u64 hole_size;
4894 int err = 0;
4895
4896 /*
4897 * If our size started in the middle of a block we need to zero out the
4898 * rest of the block before we expand the i_size, otherwise we could
4899 * expose stale data.
4900 */
4901 err = btrfs_truncate_block(inode, oldsize, 0, 0);
4902 if (err)
4903 return err;
4904
4905 if (size <= hole_start)
4906 return 0;
4907
4908 while (1) {
4909 struct btrfs_ordered_extent *ordered;
4910
4911 lock_extent_bits(io_tree, hole_start, block_end - 1,
4912 &cached_state);
4913 ordered = btrfs_lookup_ordered_range(inode, hole_start,
4914 block_end - hole_start);
4915 if (!ordered)
4916 break;
4917 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4918 &cached_state, GFP_NOFS);
4919 btrfs_start_ordered_extent(inode, ordered, 1);
4920 btrfs_put_ordered_extent(ordered);
4921 }
4922
4923 cur_offset = hole_start;
4924 while (1) {
4925 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
4926 block_end - cur_offset, 0);
4927 if (IS_ERR(em)) {
4928 err = PTR_ERR(em);
4929 em = NULL;
4930 break;
4931 }
4932 last_byte = min(extent_map_end(em), block_end);
4933 last_byte = ALIGN(last_byte, fs_info->sectorsize);
4934 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4935 struct extent_map *hole_em;
4936 hole_size = last_byte - cur_offset;
4937
4938 err = maybe_insert_hole(root, inode, cur_offset,
4939 hole_size);
4940 if (err)
4941 break;
4942 btrfs_drop_extent_cache(inode, cur_offset,
4943 cur_offset + hole_size - 1, 0);
4944 hole_em = alloc_extent_map();
4945 if (!hole_em) {
4946 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4947 &BTRFS_I(inode)->runtime_flags);
4948 goto next;
4949 }
4950 hole_em->start = cur_offset;
4951 hole_em->len = hole_size;
4952 hole_em->orig_start = cur_offset;
4953
4954 hole_em->block_start = EXTENT_MAP_HOLE;
4955 hole_em->block_len = 0;
4956 hole_em->orig_block_len = 0;
4957 hole_em->ram_bytes = hole_size;
4958 hole_em->bdev = fs_info->fs_devices->latest_bdev;
4959 hole_em->compress_type = BTRFS_COMPRESS_NONE;
4960 hole_em->generation = fs_info->generation;
4961
4962 while (1) {
4963 write_lock(&em_tree->lock);
4964 err = add_extent_mapping(em_tree, hole_em, 1);
4965 write_unlock(&em_tree->lock);
4966 if (err != -EEXIST)
4967 break;
4968 btrfs_drop_extent_cache(inode, cur_offset,
4969 cur_offset +
4970 hole_size - 1, 0);
4971 }
4972 free_extent_map(hole_em);
4973 }
4974 next:
4975 free_extent_map(em);
4976 em = NULL;
4977 cur_offset = last_byte;
4978 if (cur_offset >= block_end)
4979 break;
4980 }
4981 free_extent_map(em);
4982 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
4983 GFP_NOFS);
4984 return err;
4985 }
4986
4987 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
4988 {
4989 struct btrfs_root *root = BTRFS_I(inode)->root;
4990 struct btrfs_trans_handle *trans;
4991 loff_t oldsize = i_size_read(inode);
4992 loff_t newsize = attr->ia_size;
4993 int mask = attr->ia_valid;
4994 int ret;
4995
4996 /*
4997 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
4998 * special case where we need to update the times despite not having
4999 * these flags set. For all other operations the VFS set these flags
5000 * explicitly if it wants a timestamp update.
5001 */
5002 if (newsize != oldsize) {
5003 inode_inc_iversion(inode);
5004 if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
5005 inode->i_ctime = inode->i_mtime =
5006 current_time(inode);
5007 }
5008
5009 if (newsize > oldsize) {
5010 /*
5011 * Don't do an expanding truncate while snapshoting is ongoing.
5012 * This is to ensure the snapshot captures a fully consistent
5013 * state of this file - if the snapshot captures this expanding
5014 * truncation, it must capture all writes that happened before
5015 * this truncation.
5016 */
5017 btrfs_wait_for_snapshot_creation(root);
5018 ret = btrfs_cont_expand(inode, oldsize, newsize);
5019 if (ret) {
5020 btrfs_end_write_no_snapshoting(root);
5021 return ret;
5022 }
5023
5024 trans = btrfs_start_transaction(root, 1);
5025 if (IS_ERR(trans)) {
5026 btrfs_end_write_no_snapshoting(root);
5027 return PTR_ERR(trans);
5028 }
5029
5030 i_size_write(inode, newsize);
5031 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
5032 pagecache_isize_extended(inode, oldsize, newsize);
5033 ret = btrfs_update_inode(trans, root, inode);
5034 btrfs_end_write_no_snapshoting(root);
5035 btrfs_end_transaction(trans);
5036 } else {
5037
5038 /*
5039 * We're truncating a file that used to have good data down to
5040 * zero. Make sure it gets into the ordered flush list so that
5041 * any new writes get down to disk quickly.
5042 */
5043 if (newsize == 0)
5044 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
5045 &BTRFS_I(inode)->runtime_flags);
5046
5047 /*
5048 * 1 for the orphan item we're going to add
5049 * 1 for the orphan item deletion.
5050 */
5051 trans = btrfs_start_transaction(root, 2);
5052 if (IS_ERR(trans))
5053 return PTR_ERR(trans);
5054
5055 /*
5056 * We need to do this in case we fail at _any_ point during the
5057 * actual truncate. Once we do the truncate_setsize we could
5058 * invalidate pages which forces any outstanding ordered io to
5059 * be instantly completed which will give us extents that need
5060 * to be truncated. If we fail to get an orphan inode down we
5061 * could have left over extents that were never meant to live,
5062 * so we need to guarantee from this point on that everything
5063 * will be consistent.
5064 */
5065 ret = btrfs_orphan_add(trans, inode);
5066 btrfs_end_transaction(trans);
5067 if (ret)
5068 return ret;
5069
5070 /* we don't support swapfiles, so vmtruncate shouldn't fail */
5071 truncate_setsize(inode, newsize);
5072
5073 /* Disable nonlocked read DIO to avoid the end less truncate */
5074 btrfs_inode_block_unlocked_dio(inode);
5075 inode_dio_wait(inode);
5076 btrfs_inode_resume_unlocked_dio(inode);
5077
5078 ret = btrfs_truncate(inode);
5079 if (ret && inode->i_nlink) {
5080 int err;
5081
5082 /*
5083 * failed to truncate, disk_i_size is only adjusted down
5084 * as we remove extents, so it should represent the true
5085 * size of the inode, so reset the in memory size and
5086 * delete our orphan entry.
5087 */
5088 trans = btrfs_join_transaction(root);
5089 if (IS_ERR(trans)) {
5090 btrfs_orphan_del(NULL, inode);
5091 return ret;
5092 }
5093 i_size_write(inode, BTRFS_I(inode)->disk_i_size);
5094 err = btrfs_orphan_del(trans, inode);
5095 if (err)
5096 btrfs_abort_transaction(trans, err);
5097 btrfs_end_transaction(trans);
5098 }
5099 }
5100
5101 return ret;
5102 }
5103
5104 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
5105 {
5106 struct inode *inode = d_inode(dentry);
5107 struct btrfs_root *root = BTRFS_I(inode)->root;
5108 int err;
5109
5110 if (btrfs_root_readonly(root))
5111 return -EROFS;
5112
5113 err = setattr_prepare(dentry, attr);
5114 if (err)
5115 return err;
5116
5117 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
5118 err = btrfs_setsize(inode, attr);
5119 if (err)
5120 return err;
5121 }
5122
5123 if (attr->ia_valid) {
5124 setattr_copy(inode, attr);
5125 inode_inc_iversion(inode);
5126 err = btrfs_dirty_inode(inode);
5127
5128 if (!err && attr->ia_valid & ATTR_MODE)
5129 err = posix_acl_chmod(inode, inode->i_mode);
5130 }
5131
5132 return err;
5133 }
5134
5135 /*
5136 * While truncating the inode pages during eviction, we get the VFS calling
5137 * btrfs_invalidatepage() against each page of the inode. This is slow because
5138 * the calls to btrfs_invalidatepage() result in a huge amount of calls to
5139 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
5140 * extent_state structures over and over, wasting lots of time.
5141 *
5142 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
5143 * those expensive operations on a per page basis and do only the ordered io
5144 * finishing, while we release here the extent_map and extent_state structures,
5145 * without the excessive merging and splitting.
5146 */
5147 static void evict_inode_truncate_pages(struct inode *inode)
5148 {
5149 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5150 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
5151 struct rb_node *node;
5152
5153 ASSERT(inode->i_state & I_FREEING);
5154 truncate_inode_pages_final(&inode->i_data);
5155
5156 write_lock(&map_tree->lock);
5157 while (!RB_EMPTY_ROOT(&map_tree->map)) {
5158 struct extent_map *em;
5159
5160 node = rb_first(&map_tree->map);
5161 em = rb_entry(node, struct extent_map, rb_node);
5162 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
5163 clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
5164 remove_extent_mapping(map_tree, em);
5165 free_extent_map(em);
5166 if (need_resched()) {
5167 write_unlock(&map_tree->lock);
5168 cond_resched();
5169 write_lock(&map_tree->lock);
5170 }
5171 }
5172 write_unlock(&map_tree->lock);
5173
5174 /*
5175 * Keep looping until we have no more ranges in the io tree.
5176 * We can have ongoing bios started by readpages (called from readahead)
5177 * that have their endio callback (extent_io.c:end_bio_extent_readpage)
5178 * still in progress (unlocked the pages in the bio but did not yet
5179 * unlocked the ranges in the io tree). Therefore this means some
5180 * ranges can still be locked and eviction started because before
5181 * submitting those bios, which are executed by a separate task (work
5182 * queue kthread), inode references (inode->i_count) were not taken
5183 * (which would be dropped in the end io callback of each bio).
5184 * Therefore here we effectively end up waiting for those bios and
5185 * anyone else holding locked ranges without having bumped the inode's
5186 * reference count - if we don't do it, when they access the inode's
5187 * io_tree to unlock a range it may be too late, leading to an
5188 * use-after-free issue.
5189 */
5190 spin_lock(&io_tree->lock);
5191 while (!RB_EMPTY_ROOT(&io_tree->state)) {
5192 struct extent_state *state;
5193 struct extent_state *cached_state = NULL;
5194 u64 start;
5195 u64 end;
5196
5197 node = rb_first(&io_tree->state);
5198 state = rb_entry(node, struct extent_state, rb_node);
5199 start = state->start;
5200 end = state->end;
5201 spin_unlock(&io_tree->lock);
5202
5203 lock_extent_bits(io_tree, start, end, &cached_state);
5204
5205 /*
5206 * If still has DELALLOC flag, the extent didn't reach disk,
5207 * and its reserved space won't be freed by delayed_ref.
5208 * So we need to free its reserved space here.
5209 * (Refer to comment in btrfs_invalidatepage, case 2)
5210 *
5211 * Note, end is the bytenr of last byte, so we need + 1 here.
5212 */
5213 if (state->state & EXTENT_DELALLOC)
5214 btrfs_qgroup_free_data(inode, start, end - start + 1);
5215
5216 clear_extent_bit(io_tree, start, end,
5217 EXTENT_LOCKED | EXTENT_DIRTY |
5218 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
5219 EXTENT_DEFRAG, 1, 1,
5220 &cached_state, GFP_NOFS);
5221
5222 cond_resched();
5223 spin_lock(&io_tree->lock);
5224 }
5225 spin_unlock(&io_tree->lock);
5226 }
5227
5228 void btrfs_evict_inode(struct inode *inode)
5229 {
5230 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5231 struct btrfs_trans_handle *trans;
5232 struct btrfs_root *root = BTRFS_I(inode)->root;
5233 struct btrfs_block_rsv *rsv, *global_rsv;
5234 int steal_from_global = 0;
5235 u64 min_size;
5236 int ret;
5237
5238 trace_btrfs_inode_evict(inode);
5239
5240 if (!root) {
5241 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
5242 return;
5243 }
5244
5245 min_size = btrfs_calc_trunc_metadata_size(fs_info, 1);
5246
5247 evict_inode_truncate_pages(inode);
5248
5249 if (inode->i_nlink &&
5250 ((btrfs_root_refs(&root->root_item) != 0 &&
5251 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
5252 btrfs_is_free_space_inode(inode)))
5253 goto no_delete;
5254
5255 if (is_bad_inode(inode)) {
5256 btrfs_orphan_del(NULL, inode);
5257 goto no_delete;
5258 }
5259 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
5260 if (!special_file(inode->i_mode))
5261 btrfs_wait_ordered_range(inode, 0, (u64)-1);
5262
5263 btrfs_free_io_failure_record(inode, 0, (u64)-1);
5264
5265 if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) {
5266 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
5267 &BTRFS_I(inode)->runtime_flags));
5268 goto no_delete;
5269 }
5270
5271 if (inode->i_nlink > 0) {
5272 BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
5273 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
5274 goto no_delete;
5275 }
5276
5277 ret = btrfs_commit_inode_delayed_inode(inode);
5278 if (ret) {
5279 btrfs_orphan_del(NULL, inode);
5280 goto no_delete;
5281 }
5282
5283 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
5284 if (!rsv) {
5285 btrfs_orphan_del(NULL, inode);
5286 goto no_delete;
5287 }
5288 rsv->size = min_size;
5289 rsv->failfast = 1;
5290 global_rsv = &fs_info->global_block_rsv;
5291
5292 btrfs_i_size_write(inode, 0);
5293
5294 /*
5295 * This is a bit simpler than btrfs_truncate since we've already
5296 * reserved our space for our orphan item in the unlink, so we just
5297 * need to reserve some slack space in case we add bytes and update
5298 * inode item when doing the truncate.
5299 */
5300 while (1) {
5301 ret = btrfs_block_rsv_refill(root, rsv, min_size,
5302 BTRFS_RESERVE_FLUSH_LIMIT);
5303
5304 /*
5305 * Try and steal from the global reserve since we will
5306 * likely not use this space anyway, we want to try as
5307 * hard as possible to get this to work.
5308 */
5309 if (ret)
5310 steal_from_global++;
5311 else
5312 steal_from_global = 0;
5313 ret = 0;
5314
5315 /*
5316 * steal_from_global == 0: we reserved stuff, hooray!
5317 * steal_from_global == 1: we didn't reserve stuff, boo!
5318 * steal_from_global == 2: we've committed, still not a lot of
5319 * room but maybe we'll have room in the global reserve this
5320 * time.
5321 * steal_from_global == 3: abandon all hope!
5322 */
5323 if (steal_from_global > 2) {
5324 btrfs_warn(fs_info,
5325 "Could not get space for a delete, will truncate on mount %d",
5326 ret);
5327 btrfs_orphan_del(NULL, inode);
5328 btrfs_free_block_rsv(fs_info, rsv);
5329 goto no_delete;
5330 }
5331
5332 trans = btrfs_join_transaction(root);
5333 if (IS_ERR(trans)) {
5334 btrfs_orphan_del(NULL, inode);
5335 btrfs_free_block_rsv(fs_info, rsv);
5336 goto no_delete;
5337 }
5338
5339 /*
5340 * We can't just steal from the global reserve, we need to make
5341 * sure there is room to do it, if not we need to commit and try
5342 * again.
5343 */
5344 if (steal_from_global) {
5345 if (!btrfs_check_space_for_delayed_refs(trans, fs_info))
5346 ret = btrfs_block_rsv_migrate(global_rsv, rsv,
5347 min_size, 0);
5348 else
5349 ret = -ENOSPC;
5350 }
5351
5352 /*
5353 * Couldn't steal from the global reserve, we have too much
5354 * pending stuff built up, commit the transaction and try it
5355 * again.
5356 */
5357 if (ret) {
5358 ret = btrfs_commit_transaction(trans);
5359 if (ret) {
5360 btrfs_orphan_del(NULL, inode);
5361 btrfs_free_block_rsv(fs_info, rsv);
5362 goto no_delete;
5363 }
5364 continue;
5365 } else {
5366 steal_from_global = 0;
5367 }
5368
5369 trans->block_rsv = rsv;
5370
5371 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
5372 if (ret != -ENOSPC && ret != -EAGAIN)
5373 break;
5374
5375 trans->block_rsv = &fs_info->trans_block_rsv;
5376 btrfs_end_transaction(trans);
5377 trans = NULL;
5378 btrfs_btree_balance_dirty(fs_info);
5379 }
5380
5381 btrfs_free_block_rsv(fs_info, rsv);
5382
5383 /*
5384 * Errors here aren't a big deal, it just means we leave orphan items
5385 * in the tree. They will be cleaned up on the next mount.
5386 */
5387 if (ret == 0) {
5388 trans->block_rsv = root->orphan_block_rsv;
5389 btrfs_orphan_del(trans, inode);
5390 } else {
5391 btrfs_orphan_del(NULL, inode);
5392 }
5393
5394 trans->block_rsv = &fs_info->trans_block_rsv;
5395 if (!(root == fs_info->tree_root ||
5396 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
5397 btrfs_return_ino(root, btrfs_ino(inode));
5398
5399 btrfs_end_transaction(trans);
5400 btrfs_btree_balance_dirty(fs_info);
5401 no_delete:
5402 btrfs_remove_delayed_node(inode);
5403 clear_inode(inode);
5404 }
5405
5406 /*
5407 * this returns the key found in the dir entry in the location pointer.
5408 * If no dir entries were found, location->objectid is 0.
5409 */
5410 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
5411 struct btrfs_key *location)
5412 {
5413 const char *name = dentry->d_name.name;
5414 int namelen = dentry->d_name.len;
5415 struct btrfs_dir_item *di;
5416 struct btrfs_path *path;
5417 struct btrfs_root *root = BTRFS_I(dir)->root;
5418 int ret = 0;
5419
5420 path = btrfs_alloc_path();
5421 if (!path)
5422 return -ENOMEM;
5423
5424 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
5425 namelen, 0);
5426 if (IS_ERR(di))
5427 ret = PTR_ERR(di);
5428
5429 if (IS_ERR_OR_NULL(di))
5430 goto out_err;
5431
5432 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
5433 out:
5434 btrfs_free_path(path);
5435 return ret;
5436 out_err:
5437 location->objectid = 0;
5438 goto out;
5439 }
5440
5441 /*
5442 * when we hit a tree root in a directory, the btrfs part of the inode
5443 * needs to be changed to reflect the root directory of the tree root. This
5444 * is kind of like crossing a mount point.
5445 */
5446 static int fixup_tree_root_location(struct btrfs_fs_info *fs_info,
5447 struct inode *dir,
5448 struct dentry *dentry,
5449 struct btrfs_key *location,
5450 struct btrfs_root **sub_root)
5451 {
5452 struct btrfs_path *path;
5453 struct btrfs_root *new_root;
5454 struct btrfs_root_ref *ref;
5455 struct extent_buffer *leaf;
5456 struct btrfs_key key;
5457 int ret;
5458 int err = 0;
5459
5460 path = btrfs_alloc_path();
5461 if (!path) {
5462 err = -ENOMEM;
5463 goto out;
5464 }
5465
5466 err = -ENOENT;
5467 key.objectid = BTRFS_I(dir)->root->root_key.objectid;
5468 key.type = BTRFS_ROOT_REF_KEY;
5469 key.offset = location->objectid;
5470
5471 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
5472 if (ret) {
5473 if (ret < 0)
5474 err = ret;
5475 goto out;
5476 }
5477
5478 leaf = path->nodes[0];
5479 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
5480 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
5481 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
5482 goto out;
5483
5484 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
5485 (unsigned long)(ref + 1),
5486 dentry->d_name.len);
5487 if (ret)
5488 goto out;
5489
5490 btrfs_release_path(path);
5491
5492 new_root = btrfs_read_fs_root_no_name(fs_info, location);
5493 if (IS_ERR(new_root)) {
5494 err = PTR_ERR(new_root);
5495 goto out;
5496 }
5497
5498 *sub_root = new_root;
5499 location->objectid = btrfs_root_dirid(&new_root->root_item);
5500 location->type = BTRFS_INODE_ITEM_KEY;
5501 location->offset = 0;
5502 err = 0;
5503 out:
5504 btrfs_free_path(path);
5505 return err;
5506 }
5507
5508 static void inode_tree_add(struct inode *inode)
5509 {
5510 struct btrfs_root *root = BTRFS_I(inode)->root;
5511 struct btrfs_inode *entry;
5512 struct rb_node **p;
5513 struct rb_node *parent;
5514 struct rb_node *new = &BTRFS_I(inode)->rb_node;
5515 u64 ino = btrfs_ino(inode);
5516
5517 if (inode_unhashed(inode))
5518 return;
5519 parent = NULL;
5520 spin_lock(&root->inode_lock);
5521 p = &root->inode_tree.rb_node;
5522 while (*p) {
5523 parent = *p;
5524 entry = rb_entry(parent, struct btrfs_inode, rb_node);
5525
5526 if (ino < btrfs_ino(&entry->vfs_inode))
5527 p = &parent->rb_left;
5528 else if (ino > btrfs_ino(&entry->vfs_inode))
5529 p = &parent->rb_right;
5530 else {
5531 WARN_ON(!(entry->vfs_inode.i_state &
5532 (I_WILL_FREE | I_FREEING)));
5533 rb_replace_node(parent, new, &root->inode_tree);
5534 RB_CLEAR_NODE(parent);
5535 spin_unlock(&root->inode_lock);
5536 return;
5537 }
5538 }
5539 rb_link_node(new, parent, p);
5540 rb_insert_color(new, &root->inode_tree);
5541 spin_unlock(&root->inode_lock);
5542 }
5543
5544 static void inode_tree_del(struct inode *inode)
5545 {
5546 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5547 struct btrfs_root *root = BTRFS_I(inode)->root;
5548 int empty = 0;
5549
5550 spin_lock(&root->inode_lock);
5551 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
5552 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
5553 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
5554 empty = RB_EMPTY_ROOT(&root->inode_tree);
5555 }
5556 spin_unlock(&root->inode_lock);
5557
5558 if (empty && btrfs_root_refs(&root->root_item) == 0) {
5559 synchronize_srcu(&fs_info->subvol_srcu);
5560 spin_lock(&root->inode_lock);
5561 empty = RB_EMPTY_ROOT(&root->inode_tree);
5562 spin_unlock(&root->inode_lock);
5563 if (empty)
5564 btrfs_add_dead_root(root);
5565 }
5566 }
5567
5568 void btrfs_invalidate_inodes(struct btrfs_root *root)
5569 {
5570 struct btrfs_fs_info *fs_info = root->fs_info;
5571 struct rb_node *node;
5572 struct rb_node *prev;
5573 struct btrfs_inode *entry;
5574 struct inode *inode;
5575 u64 objectid = 0;
5576
5577 if (!test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
5578 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
5579
5580 spin_lock(&root->inode_lock);
5581 again:
5582 node = root->inode_tree.rb_node;
5583 prev = NULL;
5584 while (node) {
5585 prev = node;
5586 entry = rb_entry(node, struct btrfs_inode, rb_node);
5587
5588 if (objectid < btrfs_ino(&entry->vfs_inode))
5589 node = node->rb_left;
5590 else if (objectid > btrfs_ino(&entry->vfs_inode))
5591 node = node->rb_right;
5592 else
5593 break;
5594 }
5595 if (!node) {
5596 while (prev) {
5597 entry = rb_entry(prev, struct btrfs_inode, rb_node);
5598 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
5599 node = prev;
5600 break;
5601 }
5602 prev = rb_next(prev);
5603 }
5604 }
5605 while (node) {
5606 entry = rb_entry(node, struct btrfs_inode, rb_node);
5607 objectid = btrfs_ino(&entry->vfs_inode) + 1;
5608 inode = igrab(&entry->vfs_inode);
5609 if (inode) {
5610 spin_unlock(&root->inode_lock);
5611 if (atomic_read(&inode->i_count) > 1)
5612 d_prune_aliases(inode);
5613 /*
5614 * btrfs_drop_inode will have it removed from
5615 * the inode cache when its usage count
5616 * hits zero.
5617 */
5618 iput(inode);
5619 cond_resched();
5620 spin_lock(&root->inode_lock);
5621 goto again;
5622 }
5623
5624 if (cond_resched_lock(&root->inode_lock))
5625 goto again;
5626
5627 node = rb_next(node);
5628 }
5629 spin_unlock(&root->inode_lock);
5630 }
5631
5632 static int btrfs_init_locked_inode(struct inode *inode, void *p)
5633 {
5634 struct btrfs_iget_args *args = p;
5635 inode->i_ino = args->location->objectid;
5636 memcpy(&BTRFS_I(inode)->location, args->location,
5637 sizeof(*args->location));
5638 BTRFS_I(inode)->root = args->root;
5639 return 0;
5640 }
5641
5642 static int btrfs_find_actor(struct inode *inode, void *opaque)
5643 {
5644 struct btrfs_iget_args *args = opaque;
5645 return args->location->objectid == BTRFS_I(inode)->location.objectid &&
5646 args->root == BTRFS_I(inode)->root;
5647 }
5648
5649 static struct inode *btrfs_iget_locked(struct super_block *s,
5650 struct btrfs_key *location,
5651 struct btrfs_root *root)
5652 {
5653 struct inode *inode;
5654 struct btrfs_iget_args args;
5655 unsigned long hashval = btrfs_inode_hash(location->objectid, root);
5656
5657 args.location = location;
5658 args.root = root;
5659
5660 inode = iget5_locked(s, hashval, btrfs_find_actor,
5661 btrfs_init_locked_inode,
5662 (void *)&args);
5663 return inode;
5664 }
5665
5666 /* Get an inode object given its location and corresponding root.
5667 * Returns in *is_new if the inode was read from disk
5668 */
5669 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
5670 struct btrfs_root *root, int *new)
5671 {
5672 struct inode *inode;
5673
5674 inode = btrfs_iget_locked(s, location, root);
5675 if (!inode)
5676 return ERR_PTR(-ENOMEM);
5677
5678 if (inode->i_state & I_NEW) {
5679 int ret;
5680
5681 ret = btrfs_read_locked_inode(inode);
5682 if (!is_bad_inode(inode)) {
5683 inode_tree_add(inode);
5684 unlock_new_inode(inode);
5685 if (new)
5686 *new = 1;
5687 } else {
5688 unlock_new_inode(inode);
5689 iput(inode);
5690 ASSERT(ret < 0);
5691 inode = ERR_PTR(ret < 0 ? ret : -ESTALE);
5692 }
5693 }
5694
5695 return inode;
5696 }
5697
5698 static struct inode *new_simple_dir(struct super_block *s,
5699 struct btrfs_key *key,
5700 struct btrfs_root *root)
5701 {
5702 struct inode *inode = new_inode(s);
5703
5704 if (!inode)
5705 return ERR_PTR(-ENOMEM);
5706
5707 BTRFS_I(inode)->root = root;
5708 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5709 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5710
5711 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5712 inode->i_op = &btrfs_dir_ro_inode_operations;
5713 inode->i_fop = &simple_dir_operations;
5714 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5715 inode->i_mtime = current_time(inode);
5716 inode->i_atime = inode->i_mtime;
5717 inode->i_ctime = inode->i_mtime;
5718 BTRFS_I(inode)->i_otime = inode->i_mtime;
5719
5720 return inode;
5721 }
5722
5723 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5724 {
5725 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
5726 struct inode *inode;
5727 struct btrfs_root *root = BTRFS_I(dir)->root;
5728 struct btrfs_root *sub_root = root;
5729 struct btrfs_key location;
5730 int index;
5731 int ret = 0;
5732
5733 if (dentry->d_name.len > BTRFS_NAME_LEN)
5734 return ERR_PTR(-ENAMETOOLONG);
5735
5736 ret = btrfs_inode_by_name(dir, dentry, &location);
5737 if (ret < 0)
5738 return ERR_PTR(ret);
5739
5740 if (location.objectid == 0)
5741 return ERR_PTR(-ENOENT);
5742
5743 if (location.type == BTRFS_INODE_ITEM_KEY) {
5744 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5745 return inode;
5746 }
5747
5748 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
5749
5750 index = srcu_read_lock(&fs_info->subvol_srcu);
5751 ret = fixup_tree_root_location(fs_info, dir, dentry,
5752 &location, &sub_root);
5753 if (ret < 0) {
5754 if (ret != -ENOENT)
5755 inode = ERR_PTR(ret);
5756 else
5757 inode = new_simple_dir(dir->i_sb, &location, sub_root);
5758 } else {
5759 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
5760 }
5761 srcu_read_unlock(&fs_info->subvol_srcu, index);
5762
5763 if (!IS_ERR(inode) && root != sub_root) {
5764 down_read(&fs_info->cleanup_work_sem);
5765 if (!(inode->i_sb->s_flags & MS_RDONLY))
5766 ret = btrfs_orphan_cleanup(sub_root);
5767 up_read(&fs_info->cleanup_work_sem);
5768 if (ret) {
5769 iput(inode);
5770 inode = ERR_PTR(ret);
5771 }
5772 }
5773
5774 return inode;
5775 }
5776
5777 static int btrfs_dentry_delete(const struct dentry *dentry)
5778 {
5779 struct btrfs_root *root;
5780 struct inode *inode = d_inode(dentry);
5781
5782 if (!inode && !IS_ROOT(dentry))
5783 inode = d_inode(dentry->d_parent);
5784
5785 if (inode) {
5786 root = BTRFS_I(inode)->root;
5787 if (btrfs_root_refs(&root->root_item) == 0)
5788 return 1;
5789
5790 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5791 return 1;
5792 }
5793 return 0;
5794 }
5795
5796 static void btrfs_dentry_release(struct dentry *dentry)
5797 {
5798 kfree(dentry->d_fsdata);
5799 }
5800
5801 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5802 unsigned int flags)
5803 {
5804 struct inode *inode;
5805
5806 inode = btrfs_lookup_dentry(dir, dentry);
5807 if (IS_ERR(inode)) {
5808 if (PTR_ERR(inode) == -ENOENT)
5809 inode = NULL;
5810 else
5811 return ERR_CAST(inode);
5812 }
5813
5814 return d_splice_alias(inode, dentry);
5815 }
5816
5817 unsigned char btrfs_filetype_table[] = {
5818 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5819 };
5820
5821 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
5822 {
5823 struct inode *inode = file_inode(file);
5824 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5825 struct btrfs_root *root = BTRFS_I(inode)->root;
5826 struct btrfs_item *item;
5827 struct btrfs_dir_item *di;
5828 struct btrfs_key key;
5829 struct btrfs_key found_key;
5830 struct btrfs_path *path;
5831 struct list_head ins_list;
5832 struct list_head del_list;
5833 int ret;
5834 struct extent_buffer *leaf;
5835 int slot;
5836 unsigned char d_type;
5837 int over = 0;
5838 char tmp_name[32];
5839 char *name_ptr;
5840 int name_len;
5841 bool put = false;
5842 struct btrfs_key location;
5843
5844 if (!dir_emit_dots(file, ctx))
5845 return 0;
5846
5847 path = btrfs_alloc_path();
5848 if (!path)
5849 return -ENOMEM;
5850
5851 path->reada = READA_FORWARD;
5852
5853 INIT_LIST_HEAD(&ins_list);
5854 INIT_LIST_HEAD(&del_list);
5855 put = btrfs_readdir_get_delayed_items(inode, &ins_list, &del_list);
5856
5857 key.type = BTRFS_DIR_INDEX_KEY;
5858 key.offset = ctx->pos;
5859 key.objectid = btrfs_ino(inode);
5860
5861 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5862 if (ret < 0)
5863 goto err;
5864
5865 while (1) {
5866 leaf = path->nodes[0];
5867 slot = path->slots[0];
5868 if (slot >= btrfs_header_nritems(leaf)) {
5869 ret = btrfs_next_leaf(root, path);
5870 if (ret < 0)
5871 goto err;
5872 else if (ret > 0)
5873 break;
5874 continue;
5875 }
5876
5877 item = btrfs_item_nr(slot);
5878 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5879
5880 if (found_key.objectid != key.objectid)
5881 break;
5882 if (found_key.type != BTRFS_DIR_INDEX_KEY)
5883 break;
5884 if (found_key.offset < ctx->pos)
5885 goto next;
5886 if (btrfs_should_delete_dir_index(&del_list, found_key.offset))
5887 goto next;
5888
5889 ctx->pos = found_key.offset;
5890
5891 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5892 if (verify_dir_item(fs_info, leaf, di))
5893 goto next;
5894
5895 name_len = btrfs_dir_name_len(leaf, di);
5896 if (name_len <= sizeof(tmp_name)) {
5897 name_ptr = tmp_name;
5898 } else {
5899 name_ptr = kmalloc(name_len, GFP_KERNEL);
5900 if (!name_ptr) {
5901 ret = -ENOMEM;
5902 goto err;
5903 }
5904 }
5905 read_extent_buffer(leaf, name_ptr, (unsigned long)(di + 1),
5906 name_len);
5907
5908 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
5909 btrfs_dir_item_key_to_cpu(leaf, di, &location);
5910
5911 over = !dir_emit(ctx, name_ptr, name_len, location.objectid,
5912 d_type);
5913
5914 if (name_ptr != tmp_name)
5915 kfree(name_ptr);
5916
5917 if (over)
5918 goto nopos;
5919 ctx->pos++;
5920 next:
5921 path->slots[0]++;
5922 }
5923
5924 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
5925 if (ret)
5926 goto nopos;
5927
5928 /*
5929 * Stop new entries from being returned after we return the last
5930 * entry.
5931 *
5932 * New directory entries are assigned a strictly increasing
5933 * offset. This means that new entries created during readdir
5934 * are *guaranteed* to be seen in the future by that readdir.
5935 * This has broken buggy programs which operate on names as
5936 * they're returned by readdir. Until we re-use freed offsets
5937 * we have this hack to stop new entries from being returned
5938 * under the assumption that they'll never reach this huge
5939 * offset.
5940 *
5941 * This is being careful not to overflow 32bit loff_t unless the
5942 * last entry requires it because doing so has broken 32bit apps
5943 * in the past.
5944 */
5945 if (ctx->pos >= INT_MAX)
5946 ctx->pos = LLONG_MAX;
5947 else
5948 ctx->pos = INT_MAX;
5949 nopos:
5950 ret = 0;
5951 err:
5952 if (put)
5953 btrfs_readdir_put_delayed_items(inode, &ins_list, &del_list);
5954 btrfs_free_path(path);
5955 return ret;
5956 }
5957
5958 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
5959 {
5960 struct btrfs_root *root = BTRFS_I(inode)->root;
5961 struct btrfs_trans_handle *trans;
5962 int ret = 0;
5963 bool nolock = false;
5964
5965 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5966 return 0;
5967
5968 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
5969 nolock = true;
5970
5971 if (wbc->sync_mode == WB_SYNC_ALL) {
5972 if (nolock)
5973 trans = btrfs_join_transaction_nolock(root);
5974 else
5975 trans = btrfs_join_transaction(root);
5976 if (IS_ERR(trans))
5977 return PTR_ERR(trans);
5978 ret = btrfs_commit_transaction(trans);
5979 }
5980 return ret;
5981 }
5982
5983 /*
5984 * This is somewhat expensive, updating the tree every time the
5985 * inode changes. But, it is most likely to find the inode in cache.
5986 * FIXME, needs more benchmarking...there are no reasons other than performance
5987 * to keep or drop this code.
5988 */
5989 static int btrfs_dirty_inode(struct inode *inode)
5990 {
5991 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5992 struct btrfs_root *root = BTRFS_I(inode)->root;
5993 struct btrfs_trans_handle *trans;
5994 int ret;
5995
5996 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5997 return 0;
5998
5999 trans = btrfs_join_transaction(root);
6000 if (IS_ERR(trans))
6001 return PTR_ERR(trans);
6002
6003 ret = btrfs_update_inode(trans, root, inode);
6004 if (ret && ret == -ENOSPC) {
6005 /* whoops, lets try again with the full transaction */
6006 btrfs_end_transaction(trans);
6007 trans = btrfs_start_transaction(root, 1);
6008 if (IS_ERR(trans))
6009 return PTR_ERR(trans);
6010
6011 ret = btrfs_update_inode(trans, root, inode);
6012 }
6013 btrfs_end_transaction(trans);
6014 if (BTRFS_I(inode)->delayed_node)
6015 btrfs_balance_delayed_items(fs_info);
6016
6017 return ret;
6018 }
6019
6020 /*
6021 * This is a copy of file_update_time. We need this so we can return error on
6022 * ENOSPC for updating the inode in the case of file write and mmap writes.
6023 */
6024 static int btrfs_update_time(struct inode *inode, struct timespec *now,
6025 int flags)
6026 {
6027 struct btrfs_root *root = BTRFS_I(inode)->root;
6028
6029 if (btrfs_root_readonly(root))
6030 return -EROFS;
6031
6032 if (flags & S_VERSION)
6033 inode_inc_iversion(inode);
6034 if (flags & S_CTIME)
6035 inode->i_ctime = *now;
6036 if (flags & S_MTIME)
6037 inode->i_mtime = *now;
6038 if (flags & S_ATIME)
6039 inode->i_atime = *now;
6040 return btrfs_dirty_inode(inode);
6041 }
6042
6043 /*
6044 * find the highest existing sequence number in a directory
6045 * and then set the in-memory index_cnt variable to reflect
6046 * free sequence numbers
6047 */
6048 static int btrfs_set_inode_index_count(struct inode *inode)
6049 {
6050 struct btrfs_root *root = BTRFS_I(inode)->root;
6051 struct btrfs_key key, found_key;
6052 struct btrfs_path *path;
6053 struct extent_buffer *leaf;
6054 int ret;
6055
6056 key.objectid = btrfs_ino(inode);
6057 key.type = BTRFS_DIR_INDEX_KEY;
6058 key.offset = (u64)-1;
6059
6060 path = btrfs_alloc_path();
6061 if (!path)
6062 return -ENOMEM;
6063
6064 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6065 if (ret < 0)
6066 goto out;
6067 /* FIXME: we should be able to handle this */
6068 if (ret == 0)
6069 goto out;
6070 ret = 0;
6071
6072 /*
6073 * MAGIC NUMBER EXPLANATION:
6074 * since we search a directory based on f_pos we have to start at 2
6075 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
6076 * else has to start at 2
6077 */
6078 if (path->slots[0] == 0) {
6079 BTRFS_I(inode)->index_cnt = 2;
6080 goto out;
6081 }
6082
6083 path->slots[0]--;
6084
6085 leaf = path->nodes[0];
6086 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6087
6088 if (found_key.objectid != btrfs_ino(inode) ||
6089 found_key.type != BTRFS_DIR_INDEX_KEY) {
6090 BTRFS_I(inode)->index_cnt = 2;
6091 goto out;
6092 }
6093
6094 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
6095 out:
6096 btrfs_free_path(path);
6097 return ret;
6098 }
6099
6100 /*
6101 * helper to find a free sequence number in a given directory. This current
6102 * code is very simple, later versions will do smarter things in the btree
6103 */
6104 int btrfs_set_inode_index(struct inode *dir, u64 *index)
6105 {
6106 int ret = 0;
6107
6108 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
6109 ret = btrfs_inode_delayed_dir_index_count(dir);
6110 if (ret) {
6111 ret = btrfs_set_inode_index_count(dir);
6112 if (ret)
6113 return ret;
6114 }
6115 }
6116
6117 *index = BTRFS_I(dir)->index_cnt;
6118 BTRFS_I(dir)->index_cnt++;
6119
6120 return ret;
6121 }
6122
6123 static int btrfs_insert_inode_locked(struct inode *inode)
6124 {
6125 struct btrfs_iget_args args;
6126 args.location = &BTRFS_I(inode)->location;
6127 args.root = BTRFS_I(inode)->root;
6128
6129 return insert_inode_locked4(inode,
6130 btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
6131 btrfs_find_actor, &args);
6132 }
6133
6134 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
6135 struct btrfs_root *root,
6136 struct inode *dir,
6137 const char *name, int name_len,
6138 u64 ref_objectid, u64 objectid,
6139 umode_t mode, u64 *index)
6140 {
6141 struct btrfs_fs_info *fs_info = root->fs_info;
6142 struct inode *inode;
6143 struct btrfs_inode_item *inode_item;
6144 struct btrfs_key *location;
6145 struct btrfs_path *path;
6146 struct btrfs_inode_ref *ref;
6147 struct btrfs_key key[2];
6148 u32 sizes[2];
6149 int nitems = name ? 2 : 1;
6150 unsigned long ptr;
6151 int ret;
6152
6153 path = btrfs_alloc_path();
6154 if (!path)
6155 return ERR_PTR(-ENOMEM);
6156
6157 inode = new_inode(fs_info->sb);
6158 if (!inode) {
6159 btrfs_free_path(path);
6160 return ERR_PTR(-ENOMEM);
6161 }
6162
6163 /*
6164 * O_TMPFILE, set link count to 0, so that after this point,
6165 * we fill in an inode item with the correct link count.
6166 */
6167 if (!name)
6168 set_nlink(inode, 0);
6169
6170 /*
6171 * we have to initialize this early, so we can reclaim the inode
6172 * number if we fail afterwards in this function.
6173 */
6174 inode->i_ino = objectid;
6175
6176 if (dir && name) {
6177 trace_btrfs_inode_request(dir);
6178
6179 ret = btrfs_set_inode_index(dir, index);
6180 if (ret) {
6181 btrfs_free_path(path);
6182 iput(inode);
6183 return ERR_PTR(ret);
6184 }
6185 } else if (dir) {
6186 *index = 0;
6187 }
6188 /*
6189 * index_cnt is ignored for everything but a dir,
6190 * btrfs_get_inode_index_count has an explanation for the magic
6191 * number
6192 */
6193 BTRFS_I(inode)->index_cnt = 2;
6194 BTRFS_I(inode)->dir_index = *index;
6195 BTRFS_I(inode)->root = root;
6196 BTRFS_I(inode)->generation = trans->transid;
6197 inode->i_generation = BTRFS_I(inode)->generation;
6198
6199 /*
6200 * We could have gotten an inode number from somebody who was fsynced
6201 * and then removed in this same transaction, so let's just set full
6202 * sync since it will be a full sync anyway and this will blow away the
6203 * old info in the log.
6204 */
6205 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
6206
6207 key[0].objectid = objectid;
6208 key[0].type = BTRFS_INODE_ITEM_KEY;
6209 key[0].offset = 0;
6210
6211 sizes[0] = sizeof(struct btrfs_inode_item);
6212
6213 if (name) {
6214 /*
6215 * Start new inodes with an inode_ref. This is slightly more
6216 * efficient for small numbers of hard links since they will
6217 * be packed into one item. Extended refs will kick in if we
6218 * add more hard links than can fit in the ref item.
6219 */
6220 key[1].objectid = objectid;
6221 key[1].type = BTRFS_INODE_REF_KEY;
6222 key[1].offset = ref_objectid;
6223
6224 sizes[1] = name_len + sizeof(*ref);
6225 }
6226
6227 location = &BTRFS_I(inode)->location;
6228 location->objectid = objectid;
6229 location->offset = 0;
6230 location->type = BTRFS_INODE_ITEM_KEY;
6231
6232 ret = btrfs_insert_inode_locked(inode);
6233 if (ret < 0)
6234 goto fail;
6235
6236 path->leave_spinning = 1;
6237 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
6238 if (ret != 0)
6239 goto fail_unlock;
6240
6241 inode_init_owner(inode, dir, mode);
6242 inode_set_bytes(inode, 0);
6243
6244 inode->i_mtime = current_time(inode);
6245 inode->i_atime = inode->i_mtime;
6246 inode->i_ctime = inode->i_mtime;
6247 BTRFS_I(inode)->i_otime = inode->i_mtime;
6248
6249 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
6250 struct btrfs_inode_item);
6251 memzero_extent_buffer(path->nodes[0], (unsigned long)inode_item,
6252 sizeof(*inode_item));
6253 fill_inode_item(trans, path->nodes[0], inode_item, inode);
6254
6255 if (name) {
6256 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
6257 struct btrfs_inode_ref);
6258 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
6259 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
6260 ptr = (unsigned long)(ref + 1);
6261 write_extent_buffer(path->nodes[0], name, ptr, name_len);
6262 }
6263
6264 btrfs_mark_buffer_dirty(path->nodes[0]);
6265 btrfs_free_path(path);
6266
6267 btrfs_inherit_iflags(inode, dir);
6268
6269 if (S_ISREG(mode)) {
6270 if (btrfs_test_opt(fs_info, NODATASUM))
6271 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6272 if (btrfs_test_opt(fs_info, NODATACOW))
6273 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
6274 BTRFS_INODE_NODATASUM;
6275 }
6276
6277 inode_tree_add(inode);
6278
6279 trace_btrfs_inode_new(inode);
6280 btrfs_set_inode_last_trans(trans, inode);
6281
6282 btrfs_update_root_times(trans, root);
6283
6284 ret = btrfs_inode_inherit_props(trans, inode, dir);
6285 if (ret)
6286 btrfs_err(fs_info,
6287 "error inheriting props for ino %llu (root %llu): %d",
6288 btrfs_ino(inode), root->root_key.objectid, ret);
6289
6290 return inode;
6291
6292 fail_unlock:
6293 unlock_new_inode(inode);
6294 fail:
6295 if (dir && name)
6296 BTRFS_I(dir)->index_cnt--;
6297 btrfs_free_path(path);
6298 iput(inode);
6299 return ERR_PTR(ret);
6300 }
6301
6302 static inline u8 btrfs_inode_type(struct inode *inode)
6303 {
6304 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
6305 }
6306
6307 /*
6308 * utility function to add 'inode' into 'parent_inode' with
6309 * a give name and a given sequence number.
6310 * if 'add_backref' is true, also insert a backref from the
6311 * inode to the parent directory.
6312 */
6313 int btrfs_add_link(struct btrfs_trans_handle *trans,
6314 struct inode *parent_inode, struct inode *inode,
6315 const char *name, int name_len, int add_backref, u64 index)
6316 {
6317 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
6318 int ret = 0;
6319 struct btrfs_key key;
6320 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
6321 u64 ino = btrfs_ino(inode);
6322 u64 parent_ino = btrfs_ino(parent_inode);
6323
6324 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6325 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
6326 } else {
6327 key.objectid = ino;
6328 key.type = BTRFS_INODE_ITEM_KEY;
6329 key.offset = 0;
6330 }
6331
6332 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6333 ret = btrfs_add_root_ref(trans, fs_info, key.objectid,
6334 root->root_key.objectid, parent_ino,
6335 index, name, name_len);
6336 } else if (add_backref) {
6337 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
6338 parent_ino, index);
6339 }
6340
6341 /* Nothing to clean up yet */
6342 if (ret)
6343 return ret;
6344
6345 ret = btrfs_insert_dir_item(trans, root, name, name_len,
6346 parent_inode, &key,
6347 btrfs_inode_type(inode), index);
6348 if (ret == -EEXIST || ret == -EOVERFLOW)
6349 goto fail_dir_item;
6350 else if (ret) {
6351 btrfs_abort_transaction(trans, ret);
6352 return ret;
6353 }
6354
6355 btrfs_i_size_write(parent_inode, parent_inode->i_size +
6356 name_len * 2);
6357 inode_inc_iversion(parent_inode);
6358 parent_inode->i_mtime = parent_inode->i_ctime =
6359 current_time(parent_inode);
6360 ret = btrfs_update_inode(trans, root, parent_inode);
6361 if (ret)
6362 btrfs_abort_transaction(trans, ret);
6363 return ret;
6364
6365 fail_dir_item:
6366 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6367 u64 local_index;
6368 int err;
6369 err = btrfs_del_root_ref(trans, fs_info, key.objectid,
6370 root->root_key.objectid, parent_ino,
6371 &local_index, name, name_len);
6372
6373 } else if (add_backref) {
6374 u64 local_index;
6375 int err;
6376
6377 err = btrfs_del_inode_ref(trans, root, name, name_len,
6378 ino, parent_ino, &local_index);
6379 }
6380 return ret;
6381 }
6382
6383 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
6384 struct inode *dir, struct dentry *dentry,
6385 struct inode *inode, int backref, u64 index)
6386 {
6387 int err = btrfs_add_link(trans, dir, inode,
6388 dentry->d_name.name, dentry->d_name.len,
6389 backref, index);
6390 if (err > 0)
6391 err = -EEXIST;
6392 return err;
6393 }
6394
6395 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
6396 umode_t mode, dev_t rdev)
6397 {
6398 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6399 struct btrfs_trans_handle *trans;
6400 struct btrfs_root *root = BTRFS_I(dir)->root;
6401 struct inode *inode = NULL;
6402 int err;
6403 int drop_inode = 0;
6404 u64 objectid;
6405 u64 index = 0;
6406
6407 /*
6408 * 2 for inode item and ref
6409 * 2 for dir items
6410 * 1 for xattr if selinux is on
6411 */
6412 trans = btrfs_start_transaction(root, 5);
6413 if (IS_ERR(trans))
6414 return PTR_ERR(trans);
6415
6416 err = btrfs_find_free_ino(root, &objectid);
6417 if (err)
6418 goto out_unlock;
6419
6420 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6421 dentry->d_name.len, btrfs_ino(dir), objectid,
6422 mode, &index);
6423 if (IS_ERR(inode)) {
6424 err = PTR_ERR(inode);
6425 goto out_unlock;
6426 }
6427
6428 /*
6429 * If the active LSM wants to access the inode during
6430 * d_instantiate it needs these. Smack checks to see
6431 * if the filesystem supports xattrs by looking at the
6432 * ops vector.
6433 */
6434 inode->i_op = &btrfs_special_inode_operations;
6435 init_special_inode(inode, inode->i_mode, rdev);
6436
6437 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6438 if (err)
6439 goto out_unlock_inode;
6440
6441 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
6442 if (err) {
6443 goto out_unlock_inode;
6444 } else {
6445 btrfs_update_inode(trans, root, inode);
6446 unlock_new_inode(inode);
6447 d_instantiate(dentry, inode);
6448 }
6449
6450 out_unlock:
6451 btrfs_end_transaction(trans);
6452 btrfs_balance_delayed_items(fs_info);
6453 btrfs_btree_balance_dirty(fs_info);
6454 if (drop_inode) {
6455 inode_dec_link_count(inode);
6456 iput(inode);
6457 }
6458 return err;
6459
6460 out_unlock_inode:
6461 drop_inode = 1;
6462 unlock_new_inode(inode);
6463 goto out_unlock;
6464
6465 }
6466
6467 static int btrfs_create(struct inode *dir, struct dentry *dentry,
6468 umode_t mode, bool excl)
6469 {
6470 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6471 struct btrfs_trans_handle *trans;
6472 struct btrfs_root *root = BTRFS_I(dir)->root;
6473 struct inode *inode = NULL;
6474 int drop_inode_on_err = 0;
6475 int err;
6476 u64 objectid;
6477 u64 index = 0;
6478
6479 /*
6480 * 2 for inode item and ref
6481 * 2 for dir items
6482 * 1 for xattr if selinux is on
6483 */
6484 trans = btrfs_start_transaction(root, 5);
6485 if (IS_ERR(trans))
6486 return PTR_ERR(trans);
6487
6488 err = btrfs_find_free_ino(root, &objectid);
6489 if (err)
6490 goto out_unlock;
6491
6492 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6493 dentry->d_name.len, btrfs_ino(dir), objectid,
6494 mode, &index);
6495 if (IS_ERR(inode)) {
6496 err = PTR_ERR(inode);
6497 goto out_unlock;
6498 }
6499 drop_inode_on_err = 1;
6500 /*
6501 * If the active LSM wants to access the inode during
6502 * d_instantiate it needs these. Smack checks to see
6503 * if the filesystem supports xattrs by looking at the
6504 * ops vector.
6505 */
6506 inode->i_fop = &btrfs_file_operations;
6507 inode->i_op = &btrfs_file_inode_operations;
6508 inode->i_mapping->a_ops = &btrfs_aops;
6509
6510 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6511 if (err)
6512 goto out_unlock_inode;
6513
6514 err = btrfs_update_inode(trans, root, inode);
6515 if (err)
6516 goto out_unlock_inode;
6517
6518 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
6519 if (err)
6520 goto out_unlock_inode;
6521
6522 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
6523 unlock_new_inode(inode);
6524 d_instantiate(dentry, inode);
6525
6526 out_unlock:
6527 btrfs_end_transaction(trans);
6528 if (err && drop_inode_on_err) {
6529 inode_dec_link_count(inode);
6530 iput(inode);
6531 }
6532 btrfs_balance_delayed_items(fs_info);
6533 btrfs_btree_balance_dirty(fs_info);
6534 return err;
6535
6536 out_unlock_inode:
6537 unlock_new_inode(inode);
6538 goto out_unlock;
6539
6540 }
6541
6542 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
6543 struct dentry *dentry)
6544 {
6545 struct btrfs_trans_handle *trans = NULL;
6546 struct btrfs_root *root = BTRFS_I(dir)->root;
6547 struct inode *inode = d_inode(old_dentry);
6548 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
6549 u64 index;
6550 int err;
6551 int drop_inode = 0;
6552
6553 /* do not allow sys_link's with other subvols of the same device */
6554 if (root->objectid != BTRFS_I(inode)->root->objectid)
6555 return -EXDEV;
6556
6557 if (inode->i_nlink >= BTRFS_LINK_MAX)
6558 return -EMLINK;
6559
6560 err = btrfs_set_inode_index(dir, &index);
6561 if (err)
6562 goto fail;
6563
6564 /*
6565 * 2 items for inode and inode ref
6566 * 2 items for dir items
6567 * 1 item for parent inode
6568 */
6569 trans = btrfs_start_transaction(root, 5);
6570 if (IS_ERR(trans)) {
6571 err = PTR_ERR(trans);
6572 trans = NULL;
6573 goto fail;
6574 }
6575
6576 /* There are several dir indexes for this inode, clear the cache. */
6577 BTRFS_I(inode)->dir_index = 0ULL;
6578 inc_nlink(inode);
6579 inode_inc_iversion(inode);
6580 inode->i_ctime = current_time(inode);
6581 ihold(inode);
6582 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
6583
6584 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
6585
6586 if (err) {
6587 drop_inode = 1;
6588 } else {
6589 struct dentry *parent = dentry->d_parent;
6590 err = btrfs_update_inode(trans, root, inode);
6591 if (err)
6592 goto fail;
6593 if (inode->i_nlink == 1) {
6594 /*
6595 * If new hard link count is 1, it's a file created
6596 * with open(2) O_TMPFILE flag.
6597 */
6598 err = btrfs_orphan_del(trans, inode);
6599 if (err)
6600 goto fail;
6601 }
6602 d_instantiate(dentry, inode);
6603 btrfs_log_new_name(trans, inode, NULL, parent);
6604 }
6605
6606 btrfs_balance_delayed_items(fs_info);
6607 fail:
6608 if (trans)
6609 btrfs_end_transaction(trans);
6610 if (drop_inode) {
6611 inode_dec_link_count(inode);
6612 iput(inode);
6613 }
6614 btrfs_btree_balance_dirty(fs_info);
6615 return err;
6616 }
6617
6618 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
6619 {
6620 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6621 struct inode *inode = NULL;
6622 struct btrfs_trans_handle *trans;
6623 struct btrfs_root *root = BTRFS_I(dir)->root;
6624 int err = 0;
6625 int drop_on_err = 0;
6626 u64 objectid = 0;
6627 u64 index = 0;
6628
6629 /*
6630 * 2 items for inode and ref
6631 * 2 items for dir items
6632 * 1 for xattr if selinux is on
6633 */
6634 trans = btrfs_start_transaction(root, 5);
6635 if (IS_ERR(trans))
6636 return PTR_ERR(trans);
6637
6638 err = btrfs_find_free_ino(root, &objectid);
6639 if (err)
6640 goto out_fail;
6641
6642 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6643 dentry->d_name.len, btrfs_ino(dir), objectid,
6644 S_IFDIR | mode, &index);
6645 if (IS_ERR(inode)) {
6646 err = PTR_ERR(inode);
6647 goto out_fail;
6648 }
6649
6650 drop_on_err = 1;
6651 /* these must be set before we unlock the inode */
6652 inode->i_op = &btrfs_dir_inode_operations;
6653 inode->i_fop = &btrfs_dir_file_operations;
6654
6655 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6656 if (err)
6657 goto out_fail_inode;
6658
6659 btrfs_i_size_write(inode, 0);
6660 err = btrfs_update_inode(trans, root, inode);
6661 if (err)
6662 goto out_fail_inode;
6663
6664 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
6665 dentry->d_name.len, 0, index);
6666 if (err)
6667 goto out_fail_inode;
6668
6669 d_instantiate(dentry, inode);
6670 /*
6671 * mkdir is special. We're unlocking after we call d_instantiate
6672 * to avoid a race with nfsd calling d_instantiate.
6673 */
6674 unlock_new_inode(inode);
6675 drop_on_err = 0;
6676
6677 out_fail:
6678 btrfs_end_transaction(trans);
6679 if (drop_on_err) {
6680 inode_dec_link_count(inode);
6681 iput(inode);
6682 }
6683 btrfs_balance_delayed_items(fs_info);
6684 btrfs_btree_balance_dirty(fs_info);
6685 return err;
6686
6687 out_fail_inode:
6688 unlock_new_inode(inode);
6689 goto out_fail;
6690 }
6691
6692 /* Find next extent map of a given extent map, caller needs to ensure locks */
6693 static struct extent_map *next_extent_map(struct extent_map *em)
6694 {
6695 struct rb_node *next;
6696
6697 next = rb_next(&em->rb_node);
6698 if (!next)
6699 return NULL;
6700 return container_of(next, struct extent_map, rb_node);
6701 }
6702
6703 static struct extent_map *prev_extent_map(struct extent_map *em)
6704 {
6705 struct rb_node *prev;
6706
6707 prev = rb_prev(&em->rb_node);
6708 if (!prev)
6709 return NULL;
6710 return container_of(prev, struct extent_map, rb_node);
6711 }
6712
6713 /* helper for btfs_get_extent. Given an existing extent in the tree,
6714 * the existing extent is the nearest extent to map_start,
6715 * and an extent that you want to insert, deal with overlap and insert
6716 * the best fitted new extent into the tree.
6717 */
6718 static int merge_extent_mapping(struct extent_map_tree *em_tree,
6719 struct extent_map *existing,
6720 struct extent_map *em,
6721 u64 map_start)
6722 {
6723 struct extent_map *prev;
6724 struct extent_map *next;
6725 u64 start;
6726 u64 end;
6727 u64 start_diff;
6728
6729 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
6730
6731 if (existing->start > map_start) {
6732 next = existing;
6733 prev = prev_extent_map(next);
6734 } else {
6735 prev = existing;
6736 next = next_extent_map(prev);
6737 }
6738
6739 start = prev ? extent_map_end(prev) : em->start;
6740 start = max_t(u64, start, em->start);
6741 end = next ? next->start : extent_map_end(em);
6742 end = min_t(u64, end, extent_map_end(em));
6743 start_diff = start - em->start;
6744 em->start = start;
6745 em->len = end - start;
6746 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
6747 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
6748 em->block_start += start_diff;
6749 em->block_len -= start_diff;
6750 }
6751 return add_extent_mapping(em_tree, em, 0);
6752 }
6753
6754 static noinline int uncompress_inline(struct btrfs_path *path,
6755 struct page *page,
6756 size_t pg_offset, u64 extent_offset,
6757 struct btrfs_file_extent_item *item)
6758 {
6759 int ret;
6760 struct extent_buffer *leaf = path->nodes[0];
6761 char *tmp;
6762 size_t max_size;
6763 unsigned long inline_size;
6764 unsigned long ptr;
6765 int compress_type;
6766
6767 WARN_ON(pg_offset != 0);
6768 compress_type = btrfs_file_extent_compression(leaf, item);
6769 max_size = btrfs_file_extent_ram_bytes(leaf, item);
6770 inline_size = btrfs_file_extent_inline_item_len(leaf,
6771 btrfs_item_nr(path->slots[0]));
6772 tmp = kmalloc(inline_size, GFP_NOFS);
6773 if (!tmp)
6774 return -ENOMEM;
6775 ptr = btrfs_file_extent_inline_start(item);
6776
6777 read_extent_buffer(leaf, tmp, ptr, inline_size);
6778
6779 max_size = min_t(unsigned long, PAGE_SIZE, max_size);
6780 ret = btrfs_decompress(compress_type, tmp, page,
6781 extent_offset, inline_size, max_size);
6782 kfree(tmp);
6783 return ret;
6784 }
6785
6786 /*
6787 * a bit scary, this does extent mapping from logical file offset to the disk.
6788 * the ugly parts come from merging extents from the disk with the in-ram
6789 * representation. This gets more complex because of the data=ordered code,
6790 * where the in-ram extents might be locked pending data=ordered completion.
6791 *
6792 * This also copies inline extents directly into the page.
6793 */
6794
6795 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
6796 size_t pg_offset, u64 start, u64 len,
6797 int create)
6798 {
6799 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
6800 int ret;
6801 int err = 0;
6802 u64 extent_start = 0;
6803 u64 extent_end = 0;
6804 u64 objectid = btrfs_ino(inode);
6805 u32 found_type;
6806 struct btrfs_path *path = NULL;
6807 struct btrfs_root *root = BTRFS_I(inode)->root;
6808 struct btrfs_file_extent_item *item;
6809 struct extent_buffer *leaf;
6810 struct btrfs_key found_key;
6811 struct extent_map *em = NULL;
6812 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
6813 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6814 struct btrfs_trans_handle *trans = NULL;
6815 const bool new_inline = !page || create;
6816
6817 again:
6818 read_lock(&em_tree->lock);
6819 em = lookup_extent_mapping(em_tree, start, len);
6820 if (em)
6821 em->bdev = fs_info->fs_devices->latest_bdev;
6822 read_unlock(&em_tree->lock);
6823
6824 if (em) {
6825 if (em->start > start || em->start + em->len <= start)
6826 free_extent_map(em);
6827 else if (em->block_start == EXTENT_MAP_INLINE && page)
6828 free_extent_map(em);
6829 else
6830 goto out;
6831 }
6832 em = alloc_extent_map();
6833 if (!em) {
6834 err = -ENOMEM;
6835 goto out;
6836 }
6837 em->bdev = fs_info->fs_devices->latest_bdev;
6838 em->start = EXTENT_MAP_HOLE;
6839 em->orig_start = EXTENT_MAP_HOLE;
6840 em->len = (u64)-1;
6841 em->block_len = (u64)-1;
6842
6843 if (!path) {
6844 path = btrfs_alloc_path();
6845 if (!path) {
6846 err = -ENOMEM;
6847 goto out;
6848 }
6849 /*
6850 * Chances are we'll be called again, so go ahead and do
6851 * readahead
6852 */
6853 path->reada = READA_FORWARD;
6854 }
6855
6856 ret = btrfs_lookup_file_extent(trans, root, path,
6857 objectid, start, trans != NULL);
6858 if (ret < 0) {
6859 err = ret;
6860 goto out;
6861 }
6862
6863 if (ret != 0) {
6864 if (path->slots[0] == 0)
6865 goto not_found;
6866 path->slots[0]--;
6867 }
6868
6869 leaf = path->nodes[0];
6870 item = btrfs_item_ptr(leaf, path->slots[0],
6871 struct btrfs_file_extent_item);
6872 /* are we inside the extent that was found? */
6873 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6874 found_type = found_key.type;
6875 if (found_key.objectid != objectid ||
6876 found_type != BTRFS_EXTENT_DATA_KEY) {
6877 /*
6878 * If we backup past the first extent we want to move forward
6879 * and see if there is an extent in front of us, otherwise we'll
6880 * say there is a hole for our whole search range which can
6881 * cause problems.
6882 */
6883 extent_end = start;
6884 goto next;
6885 }
6886
6887 found_type = btrfs_file_extent_type(leaf, item);
6888 extent_start = found_key.offset;
6889 if (found_type == BTRFS_FILE_EXTENT_REG ||
6890 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6891 extent_end = extent_start +
6892 btrfs_file_extent_num_bytes(leaf, item);
6893 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6894 size_t size;
6895 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6896 extent_end = ALIGN(extent_start + size,
6897 fs_info->sectorsize);
6898 }
6899 next:
6900 if (start >= extent_end) {
6901 path->slots[0]++;
6902 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
6903 ret = btrfs_next_leaf(root, path);
6904 if (ret < 0) {
6905 err = ret;
6906 goto out;
6907 }
6908 if (ret > 0)
6909 goto not_found;
6910 leaf = path->nodes[0];
6911 }
6912 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6913 if (found_key.objectid != objectid ||
6914 found_key.type != BTRFS_EXTENT_DATA_KEY)
6915 goto not_found;
6916 if (start + len <= found_key.offset)
6917 goto not_found;
6918 if (start > found_key.offset)
6919 goto next;
6920 em->start = start;
6921 em->orig_start = start;
6922 em->len = found_key.offset - start;
6923 goto not_found_em;
6924 }
6925
6926 btrfs_extent_item_to_extent_map(inode, path, item, new_inline, em);
6927
6928 if (found_type == BTRFS_FILE_EXTENT_REG ||
6929 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6930 goto insert;
6931 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6932 unsigned long ptr;
6933 char *map;
6934 size_t size;
6935 size_t extent_offset;
6936 size_t copy_size;
6937
6938 if (new_inline)
6939 goto out;
6940
6941 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6942 extent_offset = page_offset(page) + pg_offset - extent_start;
6943 copy_size = min_t(u64, PAGE_SIZE - pg_offset,
6944 size - extent_offset);
6945 em->start = extent_start + extent_offset;
6946 em->len = ALIGN(copy_size, fs_info->sectorsize);
6947 em->orig_block_len = em->len;
6948 em->orig_start = em->start;
6949 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
6950 if (create == 0 && !PageUptodate(page)) {
6951 if (btrfs_file_extent_compression(leaf, item) !=
6952 BTRFS_COMPRESS_NONE) {
6953 ret = uncompress_inline(path, page, pg_offset,
6954 extent_offset, item);
6955 if (ret) {
6956 err = ret;
6957 goto out;
6958 }
6959 } else {
6960 map = kmap(page);
6961 read_extent_buffer(leaf, map + pg_offset, ptr,
6962 copy_size);
6963 if (pg_offset + copy_size < PAGE_SIZE) {
6964 memset(map + pg_offset + copy_size, 0,
6965 PAGE_SIZE - pg_offset -
6966 copy_size);
6967 }
6968 kunmap(page);
6969 }
6970 flush_dcache_page(page);
6971 } else if (create && PageUptodate(page)) {
6972 BUG();
6973 if (!trans) {
6974 kunmap(page);
6975 free_extent_map(em);
6976 em = NULL;
6977
6978 btrfs_release_path(path);
6979 trans = btrfs_join_transaction(root);
6980
6981 if (IS_ERR(trans))
6982 return ERR_CAST(trans);
6983 goto again;
6984 }
6985 map = kmap(page);
6986 write_extent_buffer(leaf, map + pg_offset, ptr,
6987 copy_size);
6988 kunmap(page);
6989 btrfs_mark_buffer_dirty(leaf);
6990 }
6991 set_extent_uptodate(io_tree, em->start,
6992 extent_map_end(em) - 1, NULL, GFP_NOFS);
6993 goto insert;
6994 }
6995 not_found:
6996 em->start = start;
6997 em->orig_start = start;
6998 em->len = len;
6999 not_found_em:
7000 em->block_start = EXTENT_MAP_HOLE;
7001 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
7002 insert:
7003 btrfs_release_path(path);
7004 if (em->start > start || extent_map_end(em) <= start) {
7005 btrfs_err(fs_info,
7006 "bad extent! em: [%llu %llu] passed [%llu %llu]",
7007 em->start, em->len, start, len);
7008 err = -EIO;
7009 goto out;
7010 }
7011
7012 err = 0;
7013 write_lock(&em_tree->lock);
7014 ret = add_extent_mapping(em_tree, em, 0);
7015 /* it is possible that someone inserted the extent into the tree
7016 * while we had the lock dropped. It is also possible that
7017 * an overlapping map exists in the tree
7018 */
7019 if (ret == -EEXIST) {
7020 struct extent_map *existing;
7021
7022 ret = 0;
7023
7024 existing = search_extent_mapping(em_tree, start, len);
7025 /*
7026 * existing will always be non-NULL, since there must be
7027 * extent causing the -EEXIST.
7028 */
7029 if (existing->start == em->start &&
7030 extent_map_end(existing) >= extent_map_end(em) &&
7031 em->block_start == existing->block_start) {
7032 /*
7033 * The existing extent map already encompasses the
7034 * entire extent map we tried to add.
7035 */
7036 free_extent_map(em);
7037 em = existing;
7038 err = 0;
7039
7040 } else if (start >= extent_map_end(existing) ||
7041 start <= existing->start) {
7042 /*
7043 * The existing extent map is the one nearest to
7044 * the [start, start + len) range which overlaps
7045 */
7046 err = merge_extent_mapping(em_tree, existing,
7047 em, start);
7048 free_extent_map(existing);
7049 if (err) {
7050 free_extent_map(em);
7051 em = NULL;
7052 }
7053 } else {
7054 free_extent_map(em);
7055 em = existing;
7056 err = 0;
7057 }
7058 }
7059 write_unlock(&em_tree->lock);
7060 out:
7061
7062 trace_btrfs_get_extent(root, em);
7063
7064 btrfs_free_path(path);
7065 if (trans) {
7066 ret = btrfs_end_transaction(trans);
7067 if (!err)
7068 err = ret;
7069 }
7070 if (err) {
7071 free_extent_map(em);
7072 return ERR_PTR(err);
7073 }
7074 BUG_ON(!em); /* Error is always set */
7075 return em;
7076 }
7077
7078 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
7079 size_t pg_offset, u64 start, u64 len,
7080 int create)
7081 {
7082 struct extent_map *em;
7083 struct extent_map *hole_em = NULL;
7084 u64 range_start = start;
7085 u64 end;
7086 u64 found;
7087 u64 found_end;
7088 int err = 0;
7089
7090 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
7091 if (IS_ERR(em))
7092 return em;
7093 if (em) {
7094 /*
7095 * if our em maps to
7096 * - a hole or
7097 * - a pre-alloc extent,
7098 * there might actually be delalloc bytes behind it.
7099 */
7100 if (em->block_start != EXTENT_MAP_HOLE &&
7101 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7102 return em;
7103 else
7104 hole_em = em;
7105 }
7106
7107 /* check to see if we've wrapped (len == -1 or similar) */
7108 end = start + len;
7109 if (end < start)
7110 end = (u64)-1;
7111 else
7112 end -= 1;
7113
7114 em = NULL;
7115
7116 /* ok, we didn't find anything, lets look for delalloc */
7117 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
7118 end, len, EXTENT_DELALLOC, 1);
7119 found_end = range_start + found;
7120 if (found_end < range_start)
7121 found_end = (u64)-1;
7122
7123 /*
7124 * we didn't find anything useful, return
7125 * the original results from get_extent()
7126 */
7127 if (range_start > end || found_end <= start) {
7128 em = hole_em;
7129 hole_em = NULL;
7130 goto out;
7131 }
7132
7133 /* adjust the range_start to make sure it doesn't
7134 * go backwards from the start they passed in
7135 */
7136 range_start = max(start, range_start);
7137 found = found_end - range_start;
7138
7139 if (found > 0) {
7140 u64 hole_start = start;
7141 u64 hole_len = len;
7142
7143 em = alloc_extent_map();
7144 if (!em) {
7145 err = -ENOMEM;
7146 goto out;
7147 }
7148 /*
7149 * when btrfs_get_extent can't find anything it
7150 * returns one huge hole
7151 *
7152 * make sure what it found really fits our range, and
7153 * adjust to make sure it is based on the start from
7154 * the caller
7155 */
7156 if (hole_em) {
7157 u64 calc_end = extent_map_end(hole_em);
7158
7159 if (calc_end <= start || (hole_em->start > end)) {
7160 free_extent_map(hole_em);
7161 hole_em = NULL;
7162 } else {
7163 hole_start = max(hole_em->start, start);
7164 hole_len = calc_end - hole_start;
7165 }
7166 }
7167 em->bdev = NULL;
7168 if (hole_em && range_start > hole_start) {
7169 /* our hole starts before our delalloc, so we
7170 * have to return just the parts of the hole
7171 * that go until the delalloc starts
7172 */
7173 em->len = min(hole_len,
7174 range_start - hole_start);
7175 em->start = hole_start;
7176 em->orig_start = hole_start;
7177 /*
7178 * don't adjust block start at all,
7179 * it is fixed at EXTENT_MAP_HOLE
7180 */
7181 em->block_start = hole_em->block_start;
7182 em->block_len = hole_len;
7183 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
7184 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
7185 } else {
7186 em->start = range_start;
7187 em->len = found;
7188 em->orig_start = range_start;
7189 em->block_start = EXTENT_MAP_DELALLOC;
7190 em->block_len = found;
7191 }
7192 } else if (hole_em) {
7193 return hole_em;
7194 }
7195 out:
7196
7197 free_extent_map(hole_em);
7198 if (err) {
7199 free_extent_map(em);
7200 return ERR_PTR(err);
7201 }
7202 return em;
7203 }
7204
7205 static struct extent_map *btrfs_create_dio_extent(struct inode *inode,
7206 const u64 start,
7207 const u64 len,
7208 const u64 orig_start,
7209 const u64 block_start,
7210 const u64 block_len,
7211 const u64 orig_block_len,
7212 const u64 ram_bytes,
7213 const int type)
7214 {
7215 struct extent_map *em = NULL;
7216 int ret;
7217
7218 down_read(&BTRFS_I(inode)->dio_sem);
7219 if (type != BTRFS_ORDERED_NOCOW) {
7220 em = create_pinned_em(inode, start, len, orig_start,
7221 block_start, block_len, orig_block_len,
7222 ram_bytes, type);
7223 if (IS_ERR(em))
7224 goto out;
7225 }
7226 ret = btrfs_add_ordered_extent_dio(inode, start, block_start,
7227 len, block_len, type);
7228 if (ret) {
7229 if (em) {
7230 free_extent_map(em);
7231 btrfs_drop_extent_cache(inode, start,
7232 start + len - 1, 0);
7233 }
7234 em = ERR_PTR(ret);
7235 }
7236 out:
7237 up_read(&BTRFS_I(inode)->dio_sem);
7238
7239 return em;
7240 }
7241
7242 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
7243 u64 start, u64 len)
7244 {
7245 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7246 struct btrfs_root *root = BTRFS_I(inode)->root;
7247 struct extent_map *em;
7248 struct btrfs_key ins;
7249 u64 alloc_hint;
7250 int ret;
7251
7252 alloc_hint = get_extent_allocation_hint(inode, start, len);
7253 ret = btrfs_reserve_extent(root, len, len, fs_info->sectorsize,
7254 0, alloc_hint, &ins, 1, 1);
7255 if (ret)
7256 return ERR_PTR(ret);
7257
7258 em = btrfs_create_dio_extent(inode, start, ins.offset, start,
7259 ins.objectid, ins.offset, ins.offset,
7260 ins.offset, 0);
7261 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
7262 if (IS_ERR(em))
7263 btrfs_free_reserved_extent(fs_info, ins.objectid,
7264 ins.offset, 1);
7265
7266 return em;
7267 }
7268
7269 /*
7270 * returns 1 when the nocow is safe, < 1 on error, 0 if the
7271 * block must be cow'd
7272 */
7273 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
7274 u64 *orig_start, u64 *orig_block_len,
7275 u64 *ram_bytes)
7276 {
7277 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7278 struct btrfs_trans_handle *trans;
7279 struct btrfs_path *path;
7280 int ret;
7281 struct extent_buffer *leaf;
7282 struct btrfs_root *root = BTRFS_I(inode)->root;
7283 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7284 struct btrfs_file_extent_item *fi;
7285 struct btrfs_key key;
7286 u64 disk_bytenr;
7287 u64 backref_offset;
7288 u64 extent_end;
7289 u64 num_bytes;
7290 int slot;
7291 int found_type;
7292 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
7293
7294 path = btrfs_alloc_path();
7295 if (!path)
7296 return -ENOMEM;
7297
7298 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode),
7299 offset, 0);
7300 if (ret < 0)
7301 goto out;
7302
7303 slot = path->slots[0];
7304 if (ret == 1) {
7305 if (slot == 0) {
7306 /* can't find the item, must cow */
7307 ret = 0;
7308 goto out;
7309 }
7310 slot--;
7311 }
7312 ret = 0;
7313 leaf = path->nodes[0];
7314 btrfs_item_key_to_cpu(leaf, &key, slot);
7315 if (key.objectid != btrfs_ino(inode) ||
7316 key.type != BTRFS_EXTENT_DATA_KEY) {
7317 /* not our file or wrong item type, must cow */
7318 goto out;
7319 }
7320
7321 if (key.offset > offset) {
7322 /* Wrong offset, must cow */
7323 goto out;
7324 }
7325
7326 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
7327 found_type = btrfs_file_extent_type(leaf, fi);
7328 if (found_type != BTRFS_FILE_EXTENT_REG &&
7329 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
7330 /* not a regular extent, must cow */
7331 goto out;
7332 }
7333
7334 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
7335 goto out;
7336
7337 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
7338 if (extent_end <= offset)
7339 goto out;
7340
7341 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
7342 if (disk_bytenr == 0)
7343 goto out;
7344
7345 if (btrfs_file_extent_compression(leaf, fi) ||
7346 btrfs_file_extent_encryption(leaf, fi) ||
7347 btrfs_file_extent_other_encoding(leaf, fi))
7348 goto out;
7349
7350 backref_offset = btrfs_file_extent_offset(leaf, fi);
7351
7352 if (orig_start) {
7353 *orig_start = key.offset - backref_offset;
7354 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
7355 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
7356 }
7357
7358 if (btrfs_extent_readonly(fs_info, disk_bytenr))
7359 goto out;
7360
7361 num_bytes = min(offset + *len, extent_end) - offset;
7362 if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7363 u64 range_end;
7364
7365 range_end = round_up(offset + num_bytes,
7366 root->fs_info->sectorsize) - 1;
7367 ret = test_range_bit(io_tree, offset, range_end,
7368 EXTENT_DELALLOC, 0, NULL);
7369 if (ret) {
7370 ret = -EAGAIN;
7371 goto out;
7372 }
7373 }
7374
7375 btrfs_release_path(path);
7376
7377 /*
7378 * look for other files referencing this extent, if we
7379 * find any we must cow
7380 */
7381 trans = btrfs_join_transaction(root);
7382 if (IS_ERR(trans)) {
7383 ret = 0;
7384 goto out;
7385 }
7386
7387 ret = btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
7388 key.offset - backref_offset, disk_bytenr);
7389 btrfs_end_transaction(trans);
7390 if (ret) {
7391 ret = 0;
7392 goto out;
7393 }
7394
7395 /*
7396 * adjust disk_bytenr and num_bytes to cover just the bytes
7397 * in this extent we are about to write. If there
7398 * are any csums in that range we have to cow in order
7399 * to keep the csums correct
7400 */
7401 disk_bytenr += backref_offset;
7402 disk_bytenr += offset - key.offset;
7403 if (csum_exist_in_range(fs_info, disk_bytenr, num_bytes))
7404 goto out;
7405 /*
7406 * all of the above have passed, it is safe to overwrite this extent
7407 * without cow
7408 */
7409 *len = num_bytes;
7410 ret = 1;
7411 out:
7412 btrfs_free_path(path);
7413 return ret;
7414 }
7415
7416 bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end)
7417 {
7418 struct radix_tree_root *root = &inode->i_mapping->page_tree;
7419 int found = false;
7420 void **pagep = NULL;
7421 struct page *page = NULL;
7422 int start_idx;
7423 int end_idx;
7424
7425 start_idx = start >> PAGE_SHIFT;
7426
7427 /*
7428 * end is the last byte in the last page. end == start is legal
7429 */
7430 end_idx = end >> PAGE_SHIFT;
7431
7432 rcu_read_lock();
7433
7434 /* Most of the code in this while loop is lifted from
7435 * find_get_page. It's been modified to begin searching from a
7436 * page and return just the first page found in that range. If the
7437 * found idx is less than or equal to the end idx then we know that
7438 * a page exists. If no pages are found or if those pages are
7439 * outside of the range then we're fine (yay!) */
7440 while (page == NULL &&
7441 radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) {
7442 page = radix_tree_deref_slot(pagep);
7443 if (unlikely(!page))
7444 break;
7445
7446 if (radix_tree_exception(page)) {
7447 if (radix_tree_deref_retry(page)) {
7448 page = NULL;
7449 continue;
7450 }
7451 /*
7452 * Otherwise, shmem/tmpfs must be storing a swap entry
7453 * here as an exceptional entry: so return it without
7454 * attempting to raise page count.
7455 */
7456 page = NULL;
7457 break; /* TODO: Is this relevant for this use case? */
7458 }
7459
7460 if (!page_cache_get_speculative(page)) {
7461 page = NULL;
7462 continue;
7463 }
7464
7465 /*
7466 * Has the page moved?
7467 * This is part of the lockless pagecache protocol. See
7468 * include/linux/pagemap.h for details.
7469 */
7470 if (unlikely(page != *pagep)) {
7471 put_page(page);
7472 page = NULL;
7473 }
7474 }
7475
7476 if (page) {
7477 if (page->index <= end_idx)
7478 found = true;
7479 put_page(page);
7480 }
7481
7482 rcu_read_unlock();
7483 return found;
7484 }
7485
7486 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
7487 struct extent_state **cached_state, int writing)
7488 {
7489 struct btrfs_ordered_extent *ordered;
7490 int ret = 0;
7491
7492 while (1) {
7493 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7494 cached_state);
7495 /*
7496 * We're concerned with the entire range that we're going to be
7497 * doing DIO to, so we need to make sure there's no ordered
7498 * extents in this range.
7499 */
7500 ordered = btrfs_lookup_ordered_range(inode, lockstart,
7501 lockend - lockstart + 1);
7502
7503 /*
7504 * We need to make sure there are no buffered pages in this
7505 * range either, we could have raced between the invalidate in
7506 * generic_file_direct_write and locking the extent. The
7507 * invalidate needs to happen so that reads after a write do not
7508 * get stale data.
7509 */
7510 if (!ordered &&
7511 (!writing ||
7512 !btrfs_page_exists_in_range(inode, lockstart, lockend)))
7513 break;
7514
7515 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7516 cached_state, GFP_NOFS);
7517
7518 if (ordered) {
7519 /*
7520 * If we are doing a DIO read and the ordered extent we
7521 * found is for a buffered write, we can not wait for it
7522 * to complete and retry, because if we do so we can
7523 * deadlock with concurrent buffered writes on page
7524 * locks. This happens only if our DIO read covers more
7525 * than one extent map, if at this point has already
7526 * created an ordered extent for a previous extent map
7527 * and locked its range in the inode's io tree, and a
7528 * concurrent write against that previous extent map's
7529 * range and this range started (we unlock the ranges
7530 * in the io tree only when the bios complete and
7531 * buffered writes always lock pages before attempting
7532 * to lock range in the io tree).
7533 */
7534 if (writing ||
7535 test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags))
7536 btrfs_start_ordered_extent(inode, ordered, 1);
7537 else
7538 ret = -ENOTBLK;
7539 btrfs_put_ordered_extent(ordered);
7540 } else {
7541 /*
7542 * We could trigger writeback for this range (and wait
7543 * for it to complete) and then invalidate the pages for
7544 * this range (through invalidate_inode_pages2_range()),
7545 * but that can lead us to a deadlock with a concurrent
7546 * call to readpages() (a buffered read or a defrag call
7547 * triggered a readahead) on a page lock due to an
7548 * ordered dio extent we created before but did not have
7549 * yet a corresponding bio submitted (whence it can not
7550 * complete), which makes readpages() wait for that
7551 * ordered extent to complete while holding a lock on
7552 * that page.
7553 */
7554 ret = -ENOTBLK;
7555 }
7556
7557 if (ret)
7558 break;
7559
7560 cond_resched();
7561 }
7562
7563 return ret;
7564 }
7565
7566 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
7567 u64 len, u64 orig_start,
7568 u64 block_start, u64 block_len,
7569 u64 orig_block_len, u64 ram_bytes,
7570 int type)
7571 {
7572 struct extent_map_tree *em_tree;
7573 struct extent_map *em;
7574 struct btrfs_root *root = BTRFS_I(inode)->root;
7575 int ret;
7576
7577 em_tree = &BTRFS_I(inode)->extent_tree;
7578 em = alloc_extent_map();
7579 if (!em)
7580 return ERR_PTR(-ENOMEM);
7581
7582 em->start = start;
7583 em->orig_start = orig_start;
7584 em->mod_start = start;
7585 em->mod_len = len;
7586 em->len = len;
7587 em->block_len = block_len;
7588 em->block_start = block_start;
7589 em->bdev = root->fs_info->fs_devices->latest_bdev;
7590 em->orig_block_len = orig_block_len;
7591 em->ram_bytes = ram_bytes;
7592 em->generation = -1;
7593 set_bit(EXTENT_FLAG_PINNED, &em->flags);
7594 if (type == BTRFS_ORDERED_PREALLOC)
7595 set_bit(EXTENT_FLAG_FILLING, &em->flags);
7596
7597 do {
7598 btrfs_drop_extent_cache(inode, em->start,
7599 em->start + em->len - 1, 0);
7600 write_lock(&em_tree->lock);
7601 ret = add_extent_mapping(em_tree, em, 1);
7602 write_unlock(&em_tree->lock);
7603 } while (ret == -EEXIST);
7604
7605 if (ret) {
7606 free_extent_map(em);
7607 return ERR_PTR(ret);
7608 }
7609
7610 return em;
7611 }
7612
7613 static void adjust_dio_outstanding_extents(struct inode *inode,
7614 struct btrfs_dio_data *dio_data,
7615 const u64 len)
7616 {
7617 unsigned num_extents;
7618
7619 num_extents = (unsigned) div64_u64(len + BTRFS_MAX_EXTENT_SIZE - 1,
7620 BTRFS_MAX_EXTENT_SIZE);
7621 /*
7622 * If we have an outstanding_extents count still set then we're
7623 * within our reservation, otherwise we need to adjust our inode
7624 * counter appropriately.
7625 */
7626 if (dio_data->outstanding_extents) {
7627 dio_data->outstanding_extents -= num_extents;
7628 } else {
7629 spin_lock(&BTRFS_I(inode)->lock);
7630 BTRFS_I(inode)->outstanding_extents += num_extents;
7631 spin_unlock(&BTRFS_I(inode)->lock);
7632 }
7633 }
7634
7635 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
7636 struct buffer_head *bh_result, int create)
7637 {
7638 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7639 struct extent_map *em;
7640 struct extent_state *cached_state = NULL;
7641 struct btrfs_dio_data *dio_data = NULL;
7642 u64 start = iblock << inode->i_blkbits;
7643 u64 lockstart, lockend;
7644 u64 len = bh_result->b_size;
7645 int unlock_bits = EXTENT_LOCKED;
7646 int ret = 0;
7647
7648 if (create)
7649 unlock_bits |= EXTENT_DIRTY;
7650 else
7651 len = min_t(u64, len, fs_info->sectorsize);
7652
7653 lockstart = start;
7654 lockend = start + len - 1;
7655
7656 if (current->journal_info) {
7657 /*
7658 * Need to pull our outstanding extents and set journal_info to NULL so
7659 * that anything that needs to check if there's a transaction doesn't get
7660 * confused.
7661 */
7662 dio_data = current->journal_info;
7663 current->journal_info = NULL;
7664 }
7665
7666 /*
7667 * If this errors out it's because we couldn't invalidate pagecache for
7668 * this range and we need to fallback to buffered.
7669 */
7670 if (lock_extent_direct(inode, lockstart, lockend, &cached_state,
7671 create)) {
7672 ret = -ENOTBLK;
7673 goto err;
7674 }
7675
7676 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
7677 if (IS_ERR(em)) {
7678 ret = PTR_ERR(em);
7679 goto unlock_err;
7680 }
7681
7682 /*
7683 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
7684 * io. INLINE is special, and we could probably kludge it in here, but
7685 * it's still buffered so for safety lets just fall back to the generic
7686 * buffered path.
7687 *
7688 * For COMPRESSED we _have_ to read the entire extent in so we can
7689 * decompress it, so there will be buffering required no matter what we
7690 * do, so go ahead and fallback to buffered.
7691 *
7692 * We return -ENOTBLK because that's what makes DIO go ahead and go back
7693 * to buffered IO. Don't blame me, this is the price we pay for using
7694 * the generic code.
7695 */
7696 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
7697 em->block_start == EXTENT_MAP_INLINE) {
7698 free_extent_map(em);
7699 ret = -ENOTBLK;
7700 goto unlock_err;
7701 }
7702
7703 /* Just a good old fashioned hole, return */
7704 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
7705 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
7706 free_extent_map(em);
7707 goto unlock_err;
7708 }
7709
7710 /*
7711 * We don't allocate a new extent in the following cases
7712 *
7713 * 1) The inode is marked as NODATACOW. In this case we'll just use the
7714 * existing extent.
7715 * 2) The extent is marked as PREALLOC. We're good to go here and can
7716 * just use the extent.
7717 *
7718 */
7719 if (!create) {
7720 len = min(len, em->len - (start - em->start));
7721 lockstart = start + len;
7722 goto unlock;
7723 }
7724
7725 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
7726 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
7727 em->block_start != EXTENT_MAP_HOLE)) {
7728 int type;
7729 u64 block_start, orig_start, orig_block_len, ram_bytes;
7730
7731 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7732 type = BTRFS_ORDERED_PREALLOC;
7733 else
7734 type = BTRFS_ORDERED_NOCOW;
7735 len = min(len, em->len - (start - em->start));
7736 block_start = em->block_start + (start - em->start);
7737
7738 if (can_nocow_extent(inode, start, &len, &orig_start,
7739 &orig_block_len, &ram_bytes) == 1 &&
7740 btrfs_inc_nocow_writers(fs_info, block_start)) {
7741 struct extent_map *em2;
7742
7743 em2 = btrfs_create_dio_extent(inode, start, len,
7744 orig_start, block_start,
7745 len, orig_block_len,
7746 ram_bytes, type);
7747 btrfs_dec_nocow_writers(fs_info, block_start);
7748 if (type == BTRFS_ORDERED_PREALLOC) {
7749 free_extent_map(em);
7750 em = em2;
7751 }
7752 if (em2 && IS_ERR(em2)) {
7753 ret = PTR_ERR(em2);
7754 goto unlock_err;
7755 }
7756 /*
7757 * For inode marked NODATACOW or extent marked PREALLOC,
7758 * use the existing or preallocated extent, so does not
7759 * need to adjust btrfs_space_info's bytes_may_use.
7760 */
7761 btrfs_free_reserved_data_space_noquota(inode,
7762 start, len);
7763 goto unlock;
7764 }
7765 }
7766
7767 /*
7768 * this will cow the extent, reset the len in case we changed
7769 * it above
7770 */
7771 len = bh_result->b_size;
7772 free_extent_map(em);
7773 em = btrfs_new_extent_direct(inode, start, len);
7774 if (IS_ERR(em)) {
7775 ret = PTR_ERR(em);
7776 goto unlock_err;
7777 }
7778 len = min(len, em->len - (start - em->start));
7779 unlock:
7780 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
7781 inode->i_blkbits;
7782 bh_result->b_size = len;
7783 bh_result->b_bdev = em->bdev;
7784 set_buffer_mapped(bh_result);
7785 if (create) {
7786 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7787 set_buffer_new(bh_result);
7788
7789 /*
7790 * Need to update the i_size under the extent lock so buffered
7791 * readers will get the updated i_size when we unlock.
7792 */
7793 if (start + len > i_size_read(inode))
7794 i_size_write(inode, start + len);
7795
7796 adjust_dio_outstanding_extents(inode, dio_data, len);
7797 WARN_ON(dio_data->reserve < len);
7798 dio_data->reserve -= len;
7799 dio_data->unsubmitted_oe_range_end = start + len;
7800 current->journal_info = dio_data;
7801 }
7802
7803 /*
7804 * In the case of write we need to clear and unlock the entire range,
7805 * in the case of read we need to unlock only the end area that we
7806 * aren't using if there is any left over space.
7807 */
7808 if (lockstart < lockend) {
7809 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
7810 lockend, unlock_bits, 1, 0,
7811 &cached_state, GFP_NOFS);
7812 } else {
7813 free_extent_state(cached_state);
7814 }
7815
7816 free_extent_map(em);
7817
7818 return 0;
7819
7820 unlock_err:
7821 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7822 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
7823 err:
7824 if (dio_data)
7825 current->journal_info = dio_data;
7826 /*
7827 * Compensate the delalloc release we do in btrfs_direct_IO() when we
7828 * write less data then expected, so that we don't underflow our inode's
7829 * outstanding extents counter.
7830 */
7831 if (create && dio_data)
7832 adjust_dio_outstanding_extents(inode, dio_data, len);
7833
7834 return ret;
7835 }
7836
7837 static inline int submit_dio_repair_bio(struct inode *inode, struct bio *bio,
7838 int mirror_num)
7839 {
7840 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7841 int ret;
7842
7843 BUG_ON(bio_op(bio) == REQ_OP_WRITE);
7844
7845 bio_get(bio);
7846
7847 ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DIO_REPAIR);
7848 if (ret)
7849 goto err;
7850
7851 ret = btrfs_map_bio(fs_info, bio, mirror_num, 0);
7852 err:
7853 bio_put(bio);
7854 return ret;
7855 }
7856
7857 static int btrfs_check_dio_repairable(struct inode *inode,
7858 struct bio *failed_bio,
7859 struct io_failure_record *failrec,
7860 int failed_mirror)
7861 {
7862 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7863 int num_copies;
7864
7865 num_copies = btrfs_num_copies(fs_info, failrec->logical, failrec->len);
7866 if (num_copies == 1) {
7867 /*
7868 * we only have a single copy of the data, so don't bother with
7869 * all the retry and error correction code that follows. no
7870 * matter what the error is, it is very likely to persist.
7871 */
7872 btrfs_debug(fs_info,
7873 "Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d",
7874 num_copies, failrec->this_mirror, failed_mirror);
7875 return 0;
7876 }
7877
7878 failrec->failed_mirror = failed_mirror;
7879 failrec->this_mirror++;
7880 if (failrec->this_mirror == failed_mirror)
7881 failrec->this_mirror++;
7882
7883 if (failrec->this_mirror > num_copies) {
7884 btrfs_debug(fs_info,
7885 "Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d",
7886 num_copies, failrec->this_mirror, failed_mirror);
7887 return 0;
7888 }
7889
7890 return 1;
7891 }
7892
7893 static int dio_read_error(struct inode *inode, struct bio *failed_bio,
7894 struct page *page, unsigned int pgoff,
7895 u64 start, u64 end, int failed_mirror,
7896 bio_end_io_t *repair_endio, void *repair_arg)
7897 {
7898 struct io_failure_record *failrec;
7899 struct bio *bio;
7900 int isector;
7901 int read_mode = 0;
7902 int ret;
7903
7904 BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
7905
7906 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
7907 if (ret)
7908 return ret;
7909
7910 ret = btrfs_check_dio_repairable(inode, failed_bio, failrec,
7911 failed_mirror);
7912 if (!ret) {
7913 free_io_failure(inode, failrec);
7914 return -EIO;
7915 }
7916
7917 if ((failed_bio->bi_vcnt > 1)
7918 || (failed_bio->bi_io_vec->bv_len
7919 > btrfs_inode_sectorsize(inode)))
7920 read_mode |= REQ_FAILFAST_DEV;
7921
7922 isector = start - btrfs_io_bio(failed_bio)->logical;
7923 isector >>= inode->i_sb->s_blocksize_bits;
7924 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
7925 pgoff, isector, repair_endio, repair_arg);
7926 if (!bio) {
7927 free_io_failure(inode, failrec);
7928 return -EIO;
7929 }
7930 bio_set_op_attrs(bio, REQ_OP_READ, read_mode);
7931
7932 btrfs_debug(BTRFS_I(inode)->root->fs_info,
7933 "Repair DIO Read Error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d\n",
7934 read_mode, failrec->this_mirror, failrec->in_validation);
7935
7936 ret = submit_dio_repair_bio(inode, bio, failrec->this_mirror);
7937 if (ret) {
7938 free_io_failure(inode, failrec);
7939 bio_put(bio);
7940 }
7941
7942 return ret;
7943 }
7944
7945 struct btrfs_retry_complete {
7946 struct completion done;
7947 struct inode *inode;
7948 u64 start;
7949 int uptodate;
7950 };
7951
7952 static void btrfs_retry_endio_nocsum(struct bio *bio)
7953 {
7954 struct btrfs_retry_complete *done = bio->bi_private;
7955 struct inode *inode;
7956 struct bio_vec *bvec;
7957 int i;
7958
7959 if (bio->bi_error)
7960 goto end;
7961
7962 ASSERT(bio->bi_vcnt == 1);
7963 inode = bio->bi_io_vec->bv_page->mapping->host;
7964 ASSERT(bio->bi_io_vec->bv_len == btrfs_inode_sectorsize(inode));
7965
7966 done->uptodate = 1;
7967 bio_for_each_segment_all(bvec, bio, i)
7968 clean_io_failure(done->inode, done->start, bvec->bv_page, 0);
7969 end:
7970 complete(&done->done);
7971 bio_put(bio);
7972 }
7973
7974 static int __btrfs_correct_data_nocsum(struct inode *inode,
7975 struct btrfs_io_bio *io_bio)
7976 {
7977 struct btrfs_fs_info *fs_info;
7978 struct bio_vec *bvec;
7979 struct btrfs_retry_complete done;
7980 u64 start;
7981 unsigned int pgoff;
7982 u32 sectorsize;
7983 int nr_sectors;
7984 int i;
7985 int ret;
7986
7987 fs_info = BTRFS_I(inode)->root->fs_info;
7988 sectorsize = fs_info->sectorsize;
7989
7990 start = io_bio->logical;
7991 done.inode = inode;
7992
7993 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
7994 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len);
7995 pgoff = bvec->bv_offset;
7996
7997 next_block_or_try_again:
7998 done.uptodate = 0;
7999 done.start = start;
8000 init_completion(&done.done);
8001
8002 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page,
8003 pgoff, start, start + sectorsize - 1,
8004 io_bio->mirror_num,
8005 btrfs_retry_endio_nocsum, &done);
8006 if (ret)
8007 return ret;
8008
8009 wait_for_completion(&done.done);
8010
8011 if (!done.uptodate) {
8012 /* We might have another mirror, so try again */
8013 goto next_block_or_try_again;
8014 }
8015
8016 start += sectorsize;
8017
8018 if (nr_sectors--) {
8019 pgoff += sectorsize;
8020 goto next_block_or_try_again;
8021 }
8022 }
8023
8024 return 0;
8025 }
8026
8027 static void btrfs_retry_endio(struct bio *bio)
8028 {
8029 struct btrfs_retry_complete *done = bio->bi_private;
8030 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8031 struct inode *inode;
8032 struct bio_vec *bvec;
8033 u64 start;
8034 int uptodate;
8035 int ret;
8036 int i;
8037
8038 if (bio->bi_error)
8039 goto end;
8040
8041 uptodate = 1;
8042
8043 start = done->start;
8044
8045 ASSERT(bio->bi_vcnt == 1);
8046 inode = bio->bi_io_vec->bv_page->mapping->host;
8047 ASSERT(bio->bi_io_vec->bv_len == btrfs_inode_sectorsize(inode));
8048
8049 bio_for_each_segment_all(bvec, bio, i) {
8050 ret = __readpage_endio_check(done->inode, io_bio, i,
8051 bvec->bv_page, bvec->bv_offset,
8052 done->start, bvec->bv_len);
8053 if (!ret)
8054 clean_io_failure(done->inode, done->start,
8055 bvec->bv_page, bvec->bv_offset);
8056 else
8057 uptodate = 0;
8058 }
8059
8060 done->uptodate = uptodate;
8061 end:
8062 complete(&done->done);
8063 bio_put(bio);
8064 }
8065
8066 static int __btrfs_subio_endio_read(struct inode *inode,
8067 struct btrfs_io_bio *io_bio, int err)
8068 {
8069 struct btrfs_fs_info *fs_info;
8070 struct bio_vec *bvec;
8071 struct btrfs_retry_complete done;
8072 u64 start;
8073 u64 offset = 0;
8074 u32 sectorsize;
8075 int nr_sectors;
8076 unsigned int pgoff;
8077 int csum_pos;
8078 int i;
8079 int ret;
8080
8081 fs_info = BTRFS_I(inode)->root->fs_info;
8082 sectorsize = fs_info->sectorsize;
8083
8084 err = 0;
8085 start = io_bio->logical;
8086 done.inode = inode;
8087
8088 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
8089 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len);
8090
8091 pgoff = bvec->bv_offset;
8092 next_block:
8093 csum_pos = BTRFS_BYTES_TO_BLKS(fs_info, offset);
8094 ret = __readpage_endio_check(inode, io_bio, csum_pos,
8095 bvec->bv_page, pgoff, start,
8096 sectorsize);
8097 if (likely(!ret))
8098 goto next;
8099 try_again:
8100 done.uptodate = 0;
8101 done.start = start;
8102 init_completion(&done.done);
8103
8104 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page,
8105 pgoff, start, start + sectorsize - 1,
8106 io_bio->mirror_num,
8107 btrfs_retry_endio, &done);
8108 if (ret) {
8109 err = ret;
8110 goto next;
8111 }
8112
8113 wait_for_completion(&done.done);
8114
8115 if (!done.uptodate) {
8116 /* We might have another mirror, so try again */
8117 goto try_again;
8118 }
8119 next:
8120 offset += sectorsize;
8121 start += sectorsize;
8122
8123 ASSERT(nr_sectors);
8124
8125 if (--nr_sectors) {
8126 pgoff += sectorsize;
8127 goto next_block;
8128 }
8129 }
8130
8131 return err;
8132 }
8133
8134 static int btrfs_subio_endio_read(struct inode *inode,
8135 struct btrfs_io_bio *io_bio, int err)
8136 {
8137 bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8138
8139 if (skip_csum) {
8140 if (unlikely(err))
8141 return __btrfs_correct_data_nocsum(inode, io_bio);
8142 else
8143 return 0;
8144 } else {
8145 return __btrfs_subio_endio_read(inode, io_bio, err);
8146 }
8147 }
8148
8149 static void btrfs_endio_direct_read(struct bio *bio)
8150 {
8151 struct btrfs_dio_private *dip = bio->bi_private;
8152 struct inode *inode = dip->inode;
8153 struct bio *dio_bio;
8154 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8155 int err = bio->bi_error;
8156
8157 if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED)
8158 err = btrfs_subio_endio_read(inode, io_bio, err);
8159
8160 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
8161 dip->logical_offset + dip->bytes - 1);
8162 dio_bio = dip->dio_bio;
8163
8164 kfree(dip);
8165
8166 dio_bio->bi_error = bio->bi_error;
8167 dio_end_io(dio_bio, bio->bi_error);
8168
8169 if (io_bio->end_io)
8170 io_bio->end_io(io_bio, err);
8171 bio_put(bio);
8172 }
8173
8174 static void btrfs_endio_direct_write_update_ordered(struct inode *inode,
8175 const u64 offset,
8176 const u64 bytes,
8177 const int uptodate)
8178 {
8179 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8180 struct btrfs_ordered_extent *ordered = NULL;
8181 u64 ordered_offset = offset;
8182 u64 ordered_bytes = bytes;
8183 int ret;
8184
8185 again:
8186 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
8187 &ordered_offset,
8188 ordered_bytes,
8189 uptodate);
8190 if (!ret)
8191 goto out_test;
8192
8193 btrfs_init_work(&ordered->work, btrfs_endio_write_helper,
8194 finish_ordered_fn, NULL, NULL);
8195 btrfs_queue_work(fs_info->endio_write_workers, &ordered->work);
8196 out_test:
8197 /*
8198 * our bio might span multiple ordered extents. If we haven't
8199 * completed the accounting for the whole dio, go back and try again
8200 */
8201 if (ordered_offset < offset + bytes) {
8202 ordered_bytes = offset + bytes - ordered_offset;
8203 ordered = NULL;
8204 goto again;
8205 }
8206 }
8207
8208 static void btrfs_endio_direct_write(struct bio *bio)
8209 {
8210 struct btrfs_dio_private *dip = bio->bi_private;
8211 struct bio *dio_bio = dip->dio_bio;
8212
8213 btrfs_endio_direct_write_update_ordered(dip->inode,
8214 dip->logical_offset,
8215 dip->bytes,
8216 !bio->bi_error);
8217
8218 kfree(dip);
8219
8220 dio_bio->bi_error = bio->bi_error;
8221 dio_end_io(dio_bio, bio->bi_error);
8222 bio_put(bio);
8223 }
8224
8225 static int __btrfs_submit_bio_start_direct_io(struct inode *inode,
8226 struct bio *bio, int mirror_num,
8227 unsigned long bio_flags, u64 offset)
8228 {
8229 int ret;
8230 ret = btrfs_csum_one_bio(inode, bio, offset, 1);
8231 BUG_ON(ret); /* -ENOMEM */
8232 return 0;
8233 }
8234
8235 static void btrfs_end_dio_bio(struct bio *bio)
8236 {
8237 struct btrfs_dio_private *dip = bio->bi_private;
8238 int err = bio->bi_error;
8239
8240 if (err)
8241 btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
8242 "direct IO failed ino %llu rw %d,%u sector %#Lx len %u err no %d",
8243 btrfs_ino(dip->inode), bio_op(bio), bio->bi_opf,
8244 (unsigned long long)bio->bi_iter.bi_sector,
8245 bio->bi_iter.bi_size, err);
8246
8247 if (dip->subio_endio)
8248 err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err);
8249
8250 if (err) {
8251 dip->errors = 1;
8252
8253 /*
8254 * before atomic variable goto zero, we must make sure
8255 * dip->errors is perceived to be set.
8256 */
8257 smp_mb__before_atomic();
8258 }
8259
8260 /* if there are more bios still pending for this dio, just exit */
8261 if (!atomic_dec_and_test(&dip->pending_bios))
8262 goto out;
8263
8264 if (dip->errors) {
8265 bio_io_error(dip->orig_bio);
8266 } else {
8267 dip->dio_bio->bi_error = 0;
8268 bio_endio(dip->orig_bio);
8269 }
8270 out:
8271 bio_put(bio);
8272 }
8273
8274 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
8275 u64 first_sector, gfp_t gfp_flags)
8276 {
8277 struct bio *bio;
8278 bio = btrfs_bio_alloc(bdev, first_sector, BIO_MAX_PAGES, gfp_flags);
8279 if (bio)
8280 bio_associate_current(bio);
8281 return bio;
8282 }
8283
8284 static inline int btrfs_lookup_and_bind_dio_csum(struct inode *inode,
8285 struct btrfs_dio_private *dip,
8286 struct bio *bio,
8287 u64 file_offset)
8288 {
8289 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8290 struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio);
8291 int ret;
8292
8293 /*
8294 * We load all the csum data we need when we submit
8295 * the first bio to reduce the csum tree search and
8296 * contention.
8297 */
8298 if (dip->logical_offset == file_offset) {
8299 ret = btrfs_lookup_bio_sums_dio(inode, dip->orig_bio,
8300 file_offset);
8301 if (ret)
8302 return ret;
8303 }
8304
8305 if (bio == dip->orig_bio)
8306 return 0;
8307
8308 file_offset -= dip->logical_offset;
8309 file_offset >>= inode->i_sb->s_blocksize_bits;
8310 io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset);
8311
8312 return 0;
8313 }
8314
8315 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
8316 u64 file_offset, int skip_sum,
8317 int async_submit)
8318 {
8319 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8320 struct btrfs_dio_private *dip = bio->bi_private;
8321 bool write = bio_op(bio) == REQ_OP_WRITE;
8322 int ret;
8323
8324 if (async_submit)
8325 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
8326
8327 bio_get(bio);
8328
8329 if (!write) {
8330 ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DATA);
8331 if (ret)
8332 goto err;
8333 }
8334
8335 if (skip_sum)
8336 goto map;
8337
8338 if (write && async_submit) {
8339 ret = btrfs_wq_submit_bio(fs_info, inode, bio, 0, 0,
8340 file_offset,
8341 __btrfs_submit_bio_start_direct_io,
8342 __btrfs_submit_bio_done);
8343 goto err;
8344 } else if (write) {
8345 /*
8346 * If we aren't doing async submit, calculate the csum of the
8347 * bio now.
8348 */
8349 ret = btrfs_csum_one_bio(inode, bio, file_offset, 1);
8350 if (ret)
8351 goto err;
8352 } else {
8353 ret = btrfs_lookup_and_bind_dio_csum(inode, dip, bio,
8354 file_offset);
8355 if (ret)
8356 goto err;
8357 }
8358 map:
8359 ret = btrfs_map_bio(fs_info, bio, 0, async_submit);
8360 err:
8361 bio_put(bio);
8362 return ret;
8363 }
8364
8365 static int btrfs_submit_direct_hook(struct btrfs_dio_private *dip,
8366 int skip_sum)
8367 {
8368 struct inode *inode = dip->inode;
8369 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8370 struct btrfs_root *root = BTRFS_I(inode)->root;
8371 struct bio *bio;
8372 struct bio *orig_bio = dip->orig_bio;
8373 struct bio_vec *bvec;
8374 u64 start_sector = orig_bio->bi_iter.bi_sector;
8375 u64 file_offset = dip->logical_offset;
8376 u64 submit_len = 0;
8377 u64 map_length;
8378 u32 blocksize = fs_info->sectorsize;
8379 int async_submit = 0;
8380 int nr_sectors;
8381 int ret;
8382 int i, j;
8383
8384 map_length = orig_bio->bi_iter.bi_size;
8385 ret = btrfs_map_block(fs_info, btrfs_op(orig_bio), start_sector << 9,
8386 &map_length, NULL, 0);
8387 if (ret)
8388 return -EIO;
8389
8390 if (map_length >= orig_bio->bi_iter.bi_size) {
8391 bio = orig_bio;
8392 dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED;
8393 goto submit;
8394 }
8395
8396 /* async crcs make it difficult to collect full stripe writes. */
8397 if (btrfs_get_alloc_profile(root, 1) & BTRFS_BLOCK_GROUP_RAID56_MASK)
8398 async_submit = 0;
8399 else
8400 async_submit = 1;
8401
8402 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
8403 if (!bio)
8404 return -ENOMEM;
8405
8406 bio->bi_opf = orig_bio->bi_opf;
8407 bio->bi_private = dip;
8408 bio->bi_end_io = btrfs_end_dio_bio;
8409 btrfs_io_bio(bio)->logical = file_offset;
8410 atomic_inc(&dip->pending_bios);
8411
8412 bio_for_each_segment_all(bvec, orig_bio, j) {
8413 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len);
8414 i = 0;
8415 next_block:
8416 if (unlikely(map_length < submit_len + blocksize ||
8417 bio_add_page(bio, bvec->bv_page, blocksize,
8418 bvec->bv_offset + (i * blocksize)) < blocksize)) {
8419 /*
8420 * inc the count before we submit the bio so
8421 * we know the end IO handler won't happen before
8422 * we inc the count. Otherwise, the dip might get freed
8423 * before we're done setting it up
8424 */
8425 atomic_inc(&dip->pending_bios);
8426 ret = __btrfs_submit_dio_bio(bio, inode,
8427 file_offset, skip_sum,
8428 async_submit);
8429 if (ret) {
8430 bio_put(bio);
8431 atomic_dec(&dip->pending_bios);
8432 goto out_err;
8433 }
8434
8435 start_sector += submit_len >> 9;
8436 file_offset += submit_len;
8437
8438 submit_len = 0;
8439
8440 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
8441 start_sector, GFP_NOFS);
8442 if (!bio)
8443 goto out_err;
8444 bio->bi_opf = orig_bio->bi_opf;
8445 bio->bi_private = dip;
8446 bio->bi_end_io = btrfs_end_dio_bio;
8447 btrfs_io_bio(bio)->logical = file_offset;
8448
8449 map_length = orig_bio->bi_iter.bi_size;
8450 ret = btrfs_map_block(fs_info, btrfs_op(orig_bio),
8451 start_sector << 9,
8452 &map_length, NULL, 0);
8453 if (ret) {
8454 bio_put(bio);
8455 goto out_err;
8456 }
8457
8458 goto next_block;
8459 } else {
8460 submit_len += blocksize;
8461 if (--nr_sectors) {
8462 i++;
8463 goto next_block;
8464 }
8465 }
8466 }
8467
8468 submit:
8469 ret = __btrfs_submit_dio_bio(bio, inode, file_offset, skip_sum,
8470 async_submit);
8471 if (!ret)
8472 return 0;
8473
8474 bio_put(bio);
8475 out_err:
8476 dip->errors = 1;
8477 /*
8478 * before atomic variable goto zero, we must
8479 * make sure dip->errors is perceived to be set.
8480 */
8481 smp_mb__before_atomic();
8482 if (atomic_dec_and_test(&dip->pending_bios))
8483 bio_io_error(dip->orig_bio);
8484
8485 /* bio_end_io() will handle error, so we needn't return it */
8486 return 0;
8487 }
8488
8489 static void btrfs_submit_direct(struct bio *dio_bio, struct inode *inode,
8490 loff_t file_offset)
8491 {
8492 struct btrfs_dio_private *dip = NULL;
8493 struct bio *io_bio = NULL;
8494 struct btrfs_io_bio *btrfs_bio;
8495 int skip_sum;
8496 bool write = (bio_op(dio_bio) == REQ_OP_WRITE);
8497 int ret = 0;
8498
8499 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8500
8501 io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS);
8502 if (!io_bio) {
8503 ret = -ENOMEM;
8504 goto free_ordered;
8505 }
8506
8507 dip = kzalloc(sizeof(*dip), GFP_NOFS);
8508 if (!dip) {
8509 ret = -ENOMEM;
8510 goto free_ordered;
8511 }
8512
8513 dip->private = dio_bio->bi_private;
8514 dip->inode = inode;
8515 dip->logical_offset = file_offset;
8516 dip->bytes = dio_bio->bi_iter.bi_size;
8517 dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
8518 io_bio->bi_private = dip;
8519 dip->orig_bio = io_bio;
8520 dip->dio_bio = dio_bio;
8521 atomic_set(&dip->pending_bios, 0);
8522 btrfs_bio = btrfs_io_bio(io_bio);
8523 btrfs_bio->logical = file_offset;
8524
8525 if (write) {
8526 io_bio->bi_end_io = btrfs_endio_direct_write;
8527 } else {
8528 io_bio->bi_end_io = btrfs_endio_direct_read;
8529 dip->subio_endio = btrfs_subio_endio_read;
8530 }
8531
8532 /*
8533 * Reset the range for unsubmitted ordered extents (to a 0 length range)
8534 * even if we fail to submit a bio, because in such case we do the
8535 * corresponding error handling below and it must not be done a second
8536 * time by btrfs_direct_IO().
8537 */
8538 if (write) {
8539 struct btrfs_dio_data *dio_data = current->journal_info;
8540
8541 dio_data->unsubmitted_oe_range_end = dip->logical_offset +
8542 dip->bytes;
8543 dio_data->unsubmitted_oe_range_start =
8544 dio_data->unsubmitted_oe_range_end;
8545 }
8546
8547 ret = btrfs_submit_direct_hook(dip, skip_sum);
8548 if (!ret)
8549 return;
8550
8551 if (btrfs_bio->end_io)
8552 btrfs_bio->end_io(btrfs_bio, ret);
8553
8554 free_ordered:
8555 /*
8556 * If we arrived here it means either we failed to submit the dip
8557 * or we either failed to clone the dio_bio or failed to allocate the
8558 * dip. If we cloned the dio_bio and allocated the dip, we can just
8559 * call bio_endio against our io_bio so that we get proper resource
8560 * cleanup if we fail to submit the dip, otherwise, we must do the
8561 * same as btrfs_endio_direct_[write|read] because we can't call these
8562 * callbacks - they require an allocated dip and a clone of dio_bio.
8563 */
8564 if (io_bio && dip) {
8565 io_bio->bi_error = -EIO;
8566 bio_endio(io_bio);
8567 /*
8568 * The end io callbacks free our dip, do the final put on io_bio
8569 * and all the cleanup and final put for dio_bio (through
8570 * dio_end_io()).
8571 */
8572 dip = NULL;
8573 io_bio = NULL;
8574 } else {
8575 if (write)
8576 btrfs_endio_direct_write_update_ordered(inode,
8577 file_offset,
8578 dio_bio->bi_iter.bi_size,
8579 0);
8580 else
8581 unlock_extent(&BTRFS_I(inode)->io_tree, file_offset,
8582 file_offset + dio_bio->bi_iter.bi_size - 1);
8583
8584 dio_bio->bi_error = -EIO;
8585 /*
8586 * Releases and cleans up our dio_bio, no need to bio_put()
8587 * nor bio_endio()/bio_io_error() against dio_bio.
8588 */
8589 dio_end_io(dio_bio, ret);
8590 }
8591 if (io_bio)
8592 bio_put(io_bio);
8593 kfree(dip);
8594 }
8595
8596 static ssize_t check_direct_IO(struct btrfs_fs_info *fs_info,
8597 struct kiocb *iocb,
8598 const struct iov_iter *iter, loff_t offset)
8599 {
8600 int seg;
8601 int i;
8602 unsigned int blocksize_mask = fs_info->sectorsize - 1;
8603 ssize_t retval = -EINVAL;
8604
8605 if (offset & blocksize_mask)
8606 goto out;
8607
8608 if (iov_iter_alignment(iter) & blocksize_mask)
8609 goto out;
8610
8611 /* If this is a write we don't need to check anymore */
8612 if (iov_iter_rw(iter) != READ || !iter_is_iovec(iter))
8613 return 0;
8614 /*
8615 * Check to make sure we don't have duplicate iov_base's in this
8616 * iovec, if so return EINVAL, otherwise we'll get csum errors
8617 * when reading back.
8618 */
8619 for (seg = 0; seg < iter->nr_segs; seg++) {
8620 for (i = seg + 1; i < iter->nr_segs; i++) {
8621 if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
8622 goto out;
8623 }
8624 }
8625 retval = 0;
8626 out:
8627 return retval;
8628 }
8629
8630 static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
8631 {
8632 struct file *file = iocb->ki_filp;
8633 struct inode *inode = file->f_mapping->host;
8634 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8635 struct btrfs_dio_data dio_data = { 0 };
8636 loff_t offset = iocb->ki_pos;
8637 size_t count = 0;
8638 int flags = 0;
8639 bool wakeup = true;
8640 bool relock = false;
8641 ssize_t ret;
8642
8643 if (check_direct_IO(fs_info, iocb, iter, offset))
8644 return 0;
8645
8646 inode_dio_begin(inode);
8647 smp_mb__after_atomic();
8648
8649 /*
8650 * The generic stuff only does filemap_write_and_wait_range, which
8651 * isn't enough if we've written compressed pages to this area, so
8652 * we need to flush the dirty pages again to make absolutely sure
8653 * that any outstanding dirty pages are on disk.
8654 */
8655 count = iov_iter_count(iter);
8656 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
8657 &BTRFS_I(inode)->runtime_flags))
8658 filemap_fdatawrite_range(inode->i_mapping, offset,
8659 offset + count - 1);
8660
8661 if (iov_iter_rw(iter) == WRITE) {
8662 /*
8663 * If the write DIO is beyond the EOF, we need update
8664 * the isize, but it is protected by i_mutex. So we can
8665 * not unlock the i_mutex at this case.
8666 */
8667 if (offset + count <= inode->i_size) {
8668 inode_unlock(inode);
8669 relock = true;
8670 }
8671 ret = btrfs_delalloc_reserve_space(inode, offset, count);
8672 if (ret)
8673 goto out;
8674 dio_data.outstanding_extents = div64_u64(count +
8675 BTRFS_MAX_EXTENT_SIZE - 1,
8676 BTRFS_MAX_EXTENT_SIZE);
8677
8678 /*
8679 * We need to know how many extents we reserved so that we can
8680 * do the accounting properly if we go over the number we
8681 * originally calculated. Abuse current->journal_info for this.
8682 */
8683 dio_data.reserve = round_up(count,
8684 fs_info->sectorsize);
8685 dio_data.unsubmitted_oe_range_start = (u64)offset;
8686 dio_data.unsubmitted_oe_range_end = (u64)offset;
8687 current->journal_info = &dio_data;
8688 } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
8689 &BTRFS_I(inode)->runtime_flags)) {
8690 inode_dio_end(inode);
8691 flags = DIO_LOCKING | DIO_SKIP_HOLES;
8692 wakeup = false;
8693 }
8694
8695 ret = __blockdev_direct_IO(iocb, inode,
8696 fs_info->fs_devices->latest_bdev,
8697 iter, btrfs_get_blocks_direct, NULL,
8698 btrfs_submit_direct, flags);
8699 if (iov_iter_rw(iter) == WRITE) {
8700 current->journal_info = NULL;
8701 if (ret < 0 && ret != -EIOCBQUEUED) {
8702 if (dio_data.reserve)
8703 btrfs_delalloc_release_space(inode, offset,
8704 dio_data.reserve);
8705 /*
8706 * On error we might have left some ordered extents
8707 * without submitting corresponding bios for them, so
8708 * cleanup them up to avoid other tasks getting them
8709 * and waiting for them to complete forever.
8710 */
8711 if (dio_data.unsubmitted_oe_range_start <
8712 dio_data.unsubmitted_oe_range_end)
8713 btrfs_endio_direct_write_update_ordered(inode,
8714 dio_data.unsubmitted_oe_range_start,
8715 dio_data.unsubmitted_oe_range_end -
8716 dio_data.unsubmitted_oe_range_start,
8717 0);
8718 } else if (ret >= 0 && (size_t)ret < count)
8719 btrfs_delalloc_release_space(inode, offset,
8720 count - (size_t)ret);
8721 }
8722 out:
8723 if (wakeup)
8724 inode_dio_end(inode);
8725 if (relock)
8726 inode_lock(inode);
8727
8728 return ret;
8729 }
8730
8731 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
8732
8733 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
8734 __u64 start, __u64 len)
8735 {
8736 int ret;
8737
8738 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
8739 if (ret)
8740 return ret;
8741
8742 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
8743 }
8744
8745 int btrfs_readpage(struct file *file, struct page *page)
8746 {
8747 struct extent_io_tree *tree;
8748 tree = &BTRFS_I(page->mapping->host)->io_tree;
8749 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
8750 }
8751
8752 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
8753 {
8754 struct extent_io_tree *tree;
8755 struct inode *inode = page->mapping->host;
8756 int ret;
8757
8758 if (current->flags & PF_MEMALLOC) {
8759 redirty_page_for_writepage(wbc, page);
8760 unlock_page(page);
8761 return 0;
8762 }
8763
8764 /*
8765 * If we are under memory pressure we will call this directly from the
8766 * VM, we need to make sure we have the inode referenced for the ordered
8767 * extent. If not just return like we didn't do anything.
8768 */
8769 if (!igrab(inode)) {
8770 redirty_page_for_writepage(wbc, page);
8771 return AOP_WRITEPAGE_ACTIVATE;
8772 }
8773 tree = &BTRFS_I(page->mapping->host)->io_tree;
8774 ret = extent_write_full_page(tree, page, btrfs_get_extent, wbc);
8775 btrfs_add_delayed_iput(inode);
8776 return ret;
8777 }
8778
8779 static int btrfs_writepages(struct address_space *mapping,
8780 struct writeback_control *wbc)
8781 {
8782 struct extent_io_tree *tree;
8783
8784 tree = &BTRFS_I(mapping->host)->io_tree;
8785 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
8786 }
8787
8788 static int
8789 btrfs_readpages(struct file *file, struct address_space *mapping,
8790 struct list_head *pages, unsigned nr_pages)
8791 {
8792 struct extent_io_tree *tree;
8793 tree = &BTRFS_I(mapping->host)->io_tree;
8794 return extent_readpages(tree, mapping, pages, nr_pages,
8795 btrfs_get_extent);
8796 }
8797 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8798 {
8799 struct extent_io_tree *tree;
8800 struct extent_map_tree *map;
8801 int ret;
8802
8803 tree = &BTRFS_I(page->mapping->host)->io_tree;
8804 map = &BTRFS_I(page->mapping->host)->extent_tree;
8805 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
8806 if (ret == 1) {
8807 ClearPagePrivate(page);
8808 set_page_private(page, 0);
8809 put_page(page);
8810 }
8811 return ret;
8812 }
8813
8814 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8815 {
8816 if (PageWriteback(page) || PageDirty(page))
8817 return 0;
8818 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
8819 }
8820
8821 static void btrfs_invalidatepage(struct page *page, unsigned int offset,
8822 unsigned int length)
8823 {
8824 struct inode *inode = page->mapping->host;
8825 struct extent_io_tree *tree;
8826 struct btrfs_ordered_extent *ordered;
8827 struct extent_state *cached_state = NULL;
8828 u64 page_start = page_offset(page);
8829 u64 page_end = page_start + PAGE_SIZE - 1;
8830 u64 start;
8831 u64 end;
8832 int inode_evicting = inode->i_state & I_FREEING;
8833
8834 /*
8835 * we have the page locked, so new writeback can't start,
8836 * and the dirty bit won't be cleared while we are here.
8837 *
8838 * Wait for IO on this page so that we can safely clear
8839 * the PagePrivate2 bit and do ordered accounting
8840 */
8841 wait_on_page_writeback(page);
8842
8843 tree = &BTRFS_I(inode)->io_tree;
8844 if (offset) {
8845 btrfs_releasepage(page, GFP_NOFS);
8846 return;
8847 }
8848
8849 if (!inode_evicting)
8850 lock_extent_bits(tree, page_start, page_end, &cached_state);
8851 again:
8852 start = page_start;
8853 ordered = btrfs_lookup_ordered_range(inode, start,
8854 page_end - start + 1);
8855 if (ordered) {
8856 end = min(page_end, ordered->file_offset + ordered->len - 1);
8857 /*
8858 * IO on this page will never be started, so we need
8859 * to account for any ordered extents now
8860 */
8861 if (!inode_evicting)
8862 clear_extent_bit(tree, start, end,
8863 EXTENT_DIRTY | EXTENT_DELALLOC |
8864 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
8865 EXTENT_DEFRAG, 1, 0, &cached_state,
8866 GFP_NOFS);
8867 /*
8868 * whoever cleared the private bit is responsible
8869 * for the finish_ordered_io
8870 */
8871 if (TestClearPagePrivate2(page)) {
8872 struct btrfs_ordered_inode_tree *tree;
8873 u64 new_len;
8874
8875 tree = &BTRFS_I(inode)->ordered_tree;
8876
8877 spin_lock_irq(&tree->lock);
8878 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
8879 new_len = start - ordered->file_offset;
8880 if (new_len < ordered->truncated_len)
8881 ordered->truncated_len = new_len;
8882 spin_unlock_irq(&tree->lock);
8883
8884 if (btrfs_dec_test_ordered_pending(inode, &ordered,
8885 start,
8886 end - start + 1, 1))
8887 btrfs_finish_ordered_io(ordered);
8888 }
8889 btrfs_put_ordered_extent(ordered);
8890 if (!inode_evicting) {
8891 cached_state = NULL;
8892 lock_extent_bits(tree, start, end,
8893 &cached_state);
8894 }
8895
8896 start = end + 1;
8897 if (start < page_end)
8898 goto again;
8899 }
8900
8901 /*
8902 * Qgroup reserved space handler
8903 * Page here will be either
8904 * 1) Already written to disk
8905 * In this case, its reserved space is released from data rsv map
8906 * and will be freed by delayed_ref handler finally.
8907 * So even we call qgroup_free_data(), it won't decrease reserved
8908 * space.
8909 * 2) Not written to disk
8910 * This means the reserved space should be freed here. However,
8911 * if a truncate invalidates the page (by clearing PageDirty)
8912 * and the page is accounted for while allocating extent
8913 * in btrfs_check_data_free_space() we let delayed_ref to
8914 * free the entire extent.
8915 */
8916 if (PageDirty(page))
8917 btrfs_qgroup_free_data(inode, page_start, PAGE_SIZE);
8918 if (!inode_evicting) {
8919 clear_extent_bit(tree, page_start, page_end,
8920 EXTENT_LOCKED | EXTENT_DIRTY |
8921 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
8922 EXTENT_DEFRAG, 1, 1,
8923 &cached_state, GFP_NOFS);
8924
8925 __btrfs_releasepage(page, GFP_NOFS);
8926 }
8927
8928 ClearPageChecked(page);
8929 if (PagePrivate(page)) {
8930 ClearPagePrivate(page);
8931 set_page_private(page, 0);
8932 put_page(page);
8933 }
8934 }
8935
8936 /*
8937 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
8938 * called from a page fault handler when a page is first dirtied. Hence we must
8939 * be careful to check for EOF conditions here. We set the page up correctly
8940 * for a written page which means we get ENOSPC checking when writing into
8941 * holes and correct delalloc and unwritten extent mapping on filesystems that
8942 * support these features.
8943 *
8944 * We are not allowed to take the i_mutex here so we have to play games to
8945 * protect against truncate races as the page could now be beyond EOF. Because
8946 * vmtruncate() writes the inode size before removing pages, once we have the
8947 * page lock we can determine safely if the page is beyond EOF. If it is not
8948 * beyond EOF, then the page is guaranteed safe against truncation until we
8949 * unlock the page.
8950 */
8951 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
8952 {
8953 struct page *page = vmf->page;
8954 struct inode *inode = file_inode(vma->vm_file);
8955 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8956 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
8957 struct btrfs_ordered_extent *ordered;
8958 struct extent_state *cached_state = NULL;
8959 char *kaddr;
8960 unsigned long zero_start;
8961 loff_t size;
8962 int ret;
8963 int reserved = 0;
8964 u64 reserved_space;
8965 u64 page_start;
8966 u64 page_end;
8967 u64 end;
8968
8969 reserved_space = PAGE_SIZE;
8970
8971 sb_start_pagefault(inode->i_sb);
8972 page_start = page_offset(page);
8973 page_end = page_start + PAGE_SIZE - 1;
8974 end = page_end;
8975
8976 /*
8977 * Reserving delalloc space after obtaining the page lock can lead to
8978 * deadlock. For example, if a dirty page is locked by this function
8979 * and the call to btrfs_delalloc_reserve_space() ends up triggering
8980 * dirty page write out, then the btrfs_writepage() function could
8981 * end up waiting indefinitely to get a lock on the page currently
8982 * being processed by btrfs_page_mkwrite() function.
8983 */
8984 ret = btrfs_delalloc_reserve_space(inode, page_start,
8985 reserved_space);
8986 if (!ret) {
8987 ret = file_update_time(vma->vm_file);
8988 reserved = 1;
8989 }
8990 if (ret) {
8991 if (ret == -ENOMEM)
8992 ret = VM_FAULT_OOM;
8993 else /* -ENOSPC, -EIO, etc */
8994 ret = VM_FAULT_SIGBUS;
8995 if (reserved)
8996 goto out;
8997 goto out_noreserve;
8998 }
8999
9000 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
9001 again:
9002 lock_page(page);
9003 size = i_size_read(inode);
9004
9005 if ((page->mapping != inode->i_mapping) ||
9006 (page_start >= size)) {
9007 /* page got truncated out from underneath us */
9008 goto out_unlock;
9009 }
9010 wait_on_page_writeback(page);
9011
9012 lock_extent_bits(io_tree, page_start, page_end, &cached_state);
9013 set_page_extent_mapped(page);
9014
9015 /*
9016 * we can't set the delalloc bits if there are pending ordered
9017 * extents. Drop our locks and wait for them to finish
9018 */
9019 ordered = btrfs_lookup_ordered_range(inode, page_start, page_end);
9020 if (ordered) {
9021 unlock_extent_cached(io_tree, page_start, page_end,
9022 &cached_state, GFP_NOFS);
9023 unlock_page(page);
9024 btrfs_start_ordered_extent(inode, ordered, 1);
9025 btrfs_put_ordered_extent(ordered);
9026 goto again;
9027 }
9028
9029 if (page->index == ((size - 1) >> PAGE_SHIFT)) {
9030 reserved_space = round_up(size - page_start,
9031 fs_info->sectorsize);
9032 if (reserved_space < PAGE_SIZE) {
9033 end = page_start + reserved_space - 1;
9034 spin_lock(&BTRFS_I(inode)->lock);
9035 BTRFS_I(inode)->outstanding_extents++;
9036 spin_unlock(&BTRFS_I(inode)->lock);
9037 btrfs_delalloc_release_space(inode, page_start,
9038 PAGE_SIZE - reserved_space);
9039 }
9040 }
9041
9042 /*
9043 * XXX - page_mkwrite gets called every time the page is dirtied, even
9044 * if it was already dirty, so for space accounting reasons we need to
9045 * clear any delalloc bits for the range we are fixing to save. There
9046 * is probably a better way to do this, but for now keep consistent with
9047 * prepare_pages in the normal write path.
9048 */
9049 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end,
9050 EXTENT_DIRTY | EXTENT_DELALLOC |
9051 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
9052 0, 0, &cached_state, GFP_NOFS);
9053
9054 ret = btrfs_set_extent_delalloc(inode, page_start, end,
9055 &cached_state, 0);
9056 if (ret) {
9057 unlock_extent_cached(io_tree, page_start, page_end,
9058 &cached_state, GFP_NOFS);
9059 ret = VM_FAULT_SIGBUS;
9060 goto out_unlock;
9061 }
9062 ret = 0;
9063
9064 /* page is wholly or partially inside EOF */
9065 if (page_start + PAGE_SIZE > size)
9066 zero_start = size & ~PAGE_MASK;
9067 else
9068 zero_start = PAGE_SIZE;
9069
9070 if (zero_start != PAGE_SIZE) {
9071 kaddr = kmap(page);
9072 memset(kaddr + zero_start, 0, PAGE_SIZE - zero_start);
9073 flush_dcache_page(page);
9074 kunmap(page);
9075 }
9076 ClearPageChecked(page);
9077 set_page_dirty(page);
9078 SetPageUptodate(page);
9079
9080 BTRFS_I(inode)->last_trans = fs_info->generation;
9081 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
9082 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
9083
9084 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
9085
9086 out_unlock:
9087 if (!ret) {
9088 sb_end_pagefault(inode->i_sb);
9089 return VM_FAULT_LOCKED;
9090 }
9091 unlock_page(page);
9092 out:
9093 btrfs_delalloc_release_space(inode, page_start, reserved_space);
9094 out_noreserve:
9095 sb_end_pagefault(inode->i_sb);
9096 return ret;
9097 }
9098
9099 static int btrfs_truncate(struct inode *inode)
9100 {
9101 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
9102 struct btrfs_root *root = BTRFS_I(inode)->root;
9103 struct btrfs_block_rsv *rsv;
9104 int ret = 0;
9105 int err = 0;
9106 struct btrfs_trans_handle *trans;
9107 u64 mask = fs_info->sectorsize - 1;
9108 u64 min_size = btrfs_calc_trunc_metadata_size(fs_info, 1);
9109
9110 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
9111 (u64)-1);
9112 if (ret)
9113 return ret;
9114
9115 /*
9116 * Yes ladies and gentlemen, this is indeed ugly. The fact is we have
9117 * 3 things going on here
9118 *
9119 * 1) We need to reserve space for our orphan item and the space to
9120 * delete our orphan item. Lord knows we don't want to have a dangling
9121 * orphan item because we didn't reserve space to remove it.
9122 *
9123 * 2) We need to reserve space to update our inode.
9124 *
9125 * 3) We need to have something to cache all the space that is going to
9126 * be free'd up by the truncate operation, but also have some slack
9127 * space reserved in case it uses space during the truncate (thank you
9128 * very much snapshotting).
9129 *
9130 * And we need these to all be separate. The fact is we can use a lot of
9131 * space doing the truncate, and we have no earthly idea how much space
9132 * we will use, so we need the truncate reservation to be separate so it
9133 * doesn't end up using space reserved for updating the inode or
9134 * removing the orphan item. We also need to be able to stop the
9135 * transaction and start a new one, which means we need to be able to
9136 * update the inode several times, and we have no idea of knowing how
9137 * many times that will be, so we can't just reserve 1 item for the
9138 * entirety of the operation, so that has to be done separately as well.
9139 * Then there is the orphan item, which does indeed need to be held on
9140 * to for the whole operation, and we need nobody to touch this reserved
9141 * space except the orphan code.
9142 *
9143 * So that leaves us with
9144 *
9145 * 1) root->orphan_block_rsv - for the orphan deletion.
9146 * 2) rsv - for the truncate reservation, which we will steal from the
9147 * transaction reservation.
9148 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
9149 * updating the inode.
9150 */
9151 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
9152 if (!rsv)
9153 return -ENOMEM;
9154 rsv->size = min_size;
9155 rsv->failfast = 1;
9156
9157 /*
9158 * 1 for the truncate slack space
9159 * 1 for updating the inode.
9160 */
9161 trans = btrfs_start_transaction(root, 2);
9162 if (IS_ERR(trans)) {
9163 err = PTR_ERR(trans);
9164 goto out;
9165 }
9166
9167 /* Migrate the slack space for the truncate to our reserve */
9168 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
9169 min_size, 0);
9170 BUG_ON(ret);
9171
9172 /*
9173 * So if we truncate and then write and fsync we normally would just
9174 * write the extents that changed, which is a problem if we need to
9175 * first truncate that entire inode. So set this flag so we write out
9176 * all of the extents in the inode to the sync log so we're completely
9177 * safe.
9178 */
9179 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
9180 trans->block_rsv = rsv;
9181
9182 while (1) {
9183 ret = btrfs_truncate_inode_items(trans, root, inode,
9184 inode->i_size,
9185 BTRFS_EXTENT_DATA_KEY);
9186 if (ret != -ENOSPC && ret != -EAGAIN) {
9187 err = ret;
9188 break;
9189 }
9190
9191 trans->block_rsv = &fs_info->trans_block_rsv;
9192 ret = btrfs_update_inode(trans, root, inode);
9193 if (ret) {
9194 err = ret;
9195 break;
9196 }
9197
9198 btrfs_end_transaction(trans);
9199 btrfs_btree_balance_dirty(fs_info);
9200
9201 trans = btrfs_start_transaction(root, 2);
9202 if (IS_ERR(trans)) {
9203 ret = err = PTR_ERR(trans);
9204 trans = NULL;
9205 break;
9206 }
9207
9208 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
9209 rsv, min_size, 0);
9210 BUG_ON(ret); /* shouldn't happen */
9211 trans->block_rsv = rsv;
9212 }
9213
9214 if (ret == 0 && inode->i_nlink > 0) {
9215 trans->block_rsv = root->orphan_block_rsv;
9216 ret = btrfs_orphan_del(trans, inode);
9217 if (ret)
9218 err = ret;
9219 }
9220
9221 if (trans) {
9222 trans->block_rsv = &fs_info->trans_block_rsv;
9223 ret = btrfs_update_inode(trans, root, inode);
9224 if (ret && !err)
9225 err = ret;
9226
9227 ret = btrfs_end_transaction(trans);
9228 btrfs_btree_balance_dirty(fs_info);
9229 }
9230 out:
9231 btrfs_free_block_rsv(fs_info, rsv);
9232
9233 if (ret && !err)
9234 err = ret;
9235
9236 return err;
9237 }
9238
9239 /*
9240 * create a new subvolume directory/inode (helper for the ioctl).
9241 */
9242 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
9243 struct btrfs_root *new_root,
9244 struct btrfs_root *parent_root,
9245 u64 new_dirid)
9246 {
9247 struct inode *inode;
9248 int err;
9249 u64 index = 0;
9250
9251 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
9252 new_dirid, new_dirid,
9253 S_IFDIR | (~current_umask() & S_IRWXUGO),
9254 &index);
9255 if (IS_ERR(inode))
9256 return PTR_ERR(inode);
9257 inode->i_op = &btrfs_dir_inode_operations;
9258 inode->i_fop = &btrfs_dir_file_operations;
9259
9260 set_nlink(inode, 1);
9261 btrfs_i_size_write(inode, 0);
9262 unlock_new_inode(inode);
9263
9264 err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
9265 if (err)
9266 btrfs_err(new_root->fs_info,
9267 "error inheriting subvolume %llu properties: %d",
9268 new_root->root_key.objectid, err);
9269
9270 err = btrfs_update_inode(trans, new_root, inode);
9271
9272 iput(inode);
9273 return err;
9274 }
9275
9276 struct inode *btrfs_alloc_inode(struct super_block *sb)
9277 {
9278 struct btrfs_inode *ei;
9279 struct inode *inode;
9280
9281 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
9282 if (!ei)
9283 return NULL;
9284
9285 ei->root = NULL;
9286 ei->generation = 0;
9287 ei->last_trans = 0;
9288 ei->last_sub_trans = 0;
9289 ei->logged_trans = 0;
9290 ei->delalloc_bytes = 0;
9291 ei->defrag_bytes = 0;
9292 ei->disk_i_size = 0;
9293 ei->flags = 0;
9294 ei->csum_bytes = 0;
9295 ei->index_cnt = (u64)-1;
9296 ei->dir_index = 0;
9297 ei->last_unlink_trans = 0;
9298 ei->last_log_commit = 0;
9299 ei->delayed_iput_count = 0;
9300
9301 spin_lock_init(&ei->lock);
9302 ei->outstanding_extents = 0;
9303 ei->reserved_extents = 0;
9304
9305 ei->runtime_flags = 0;
9306 ei->force_compress = BTRFS_COMPRESS_NONE;
9307
9308 ei->delayed_node = NULL;
9309
9310 ei->i_otime.tv_sec = 0;
9311 ei->i_otime.tv_nsec = 0;
9312
9313 inode = &ei->vfs_inode;
9314 extent_map_tree_init(&ei->extent_tree);
9315 extent_io_tree_init(&ei->io_tree, &inode->i_data);
9316 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
9317 ei->io_tree.track_uptodate = 1;
9318 ei->io_failure_tree.track_uptodate = 1;
9319 atomic_set(&ei->sync_writers, 0);
9320 mutex_init(&ei->log_mutex);
9321 mutex_init(&ei->delalloc_mutex);
9322 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
9323 INIT_LIST_HEAD(&ei->delalloc_inodes);
9324 INIT_LIST_HEAD(&ei->delayed_iput);
9325 RB_CLEAR_NODE(&ei->rb_node);
9326 init_rwsem(&ei->dio_sem);
9327
9328 return inode;
9329 }
9330
9331 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
9332 void btrfs_test_destroy_inode(struct inode *inode)
9333 {
9334 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
9335 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9336 }
9337 #endif
9338
9339 static void btrfs_i_callback(struct rcu_head *head)
9340 {
9341 struct inode *inode = container_of(head, struct inode, i_rcu);
9342 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9343 }
9344
9345 void btrfs_destroy_inode(struct inode *inode)
9346 {
9347 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
9348 struct btrfs_ordered_extent *ordered;
9349 struct btrfs_root *root = BTRFS_I(inode)->root;
9350
9351 WARN_ON(!hlist_empty(&inode->i_dentry));
9352 WARN_ON(inode->i_data.nrpages);
9353 WARN_ON(BTRFS_I(inode)->outstanding_extents);
9354 WARN_ON(BTRFS_I(inode)->reserved_extents);
9355 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
9356 WARN_ON(BTRFS_I(inode)->csum_bytes);
9357 WARN_ON(BTRFS_I(inode)->defrag_bytes);
9358
9359 /*
9360 * This can happen where we create an inode, but somebody else also
9361 * created the same inode and we need to destroy the one we already
9362 * created.
9363 */
9364 if (!root)
9365 goto free;
9366
9367 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
9368 &BTRFS_I(inode)->runtime_flags)) {
9369 btrfs_info(fs_info, "inode %llu still on the orphan list",
9370 btrfs_ino(inode));
9371 atomic_dec(&root->orphan_inodes);
9372 }
9373
9374 while (1) {
9375 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
9376 if (!ordered)
9377 break;
9378 else {
9379 btrfs_err(fs_info,
9380 "found ordered extent %llu %llu on inode cleanup",
9381 ordered->file_offset, ordered->len);
9382 btrfs_remove_ordered_extent(inode, ordered);
9383 btrfs_put_ordered_extent(ordered);
9384 btrfs_put_ordered_extent(ordered);
9385 }
9386 }
9387 btrfs_qgroup_check_reserved_leak(inode);
9388 inode_tree_del(inode);
9389 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
9390 free:
9391 call_rcu(&inode->i_rcu, btrfs_i_callback);
9392 }
9393
9394 int btrfs_drop_inode(struct inode *inode)
9395 {
9396 struct btrfs_root *root = BTRFS_I(inode)->root;
9397
9398 if (root == NULL)
9399 return 1;
9400
9401 /* the snap/subvol tree is on deleting */
9402 if (btrfs_root_refs(&root->root_item) == 0)
9403 return 1;
9404 else
9405 return generic_drop_inode(inode);
9406 }
9407
9408 static void init_once(void *foo)
9409 {
9410 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
9411
9412 inode_init_once(&ei->vfs_inode);
9413 }
9414
9415 void btrfs_destroy_cachep(void)
9416 {
9417 /*
9418 * Make sure all delayed rcu free inodes are flushed before we
9419 * destroy cache.
9420 */
9421 rcu_barrier();
9422 kmem_cache_destroy(btrfs_inode_cachep);
9423 kmem_cache_destroy(btrfs_trans_handle_cachep);
9424 kmem_cache_destroy(btrfs_transaction_cachep);
9425 kmem_cache_destroy(btrfs_path_cachep);
9426 kmem_cache_destroy(btrfs_free_space_cachep);
9427 }
9428
9429 int btrfs_init_cachep(void)
9430 {
9431 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
9432 sizeof(struct btrfs_inode), 0,
9433 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT,
9434 init_once);
9435 if (!btrfs_inode_cachep)
9436 goto fail;
9437
9438 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
9439 sizeof(struct btrfs_trans_handle), 0,
9440 SLAB_TEMPORARY | SLAB_MEM_SPREAD, NULL);
9441 if (!btrfs_trans_handle_cachep)
9442 goto fail;
9443
9444 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
9445 sizeof(struct btrfs_transaction), 0,
9446 SLAB_TEMPORARY | SLAB_MEM_SPREAD, NULL);
9447 if (!btrfs_transaction_cachep)
9448 goto fail;
9449
9450 btrfs_path_cachep = kmem_cache_create("btrfs_path",
9451 sizeof(struct btrfs_path), 0,
9452 SLAB_MEM_SPREAD, NULL);
9453 if (!btrfs_path_cachep)
9454 goto fail;
9455
9456 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
9457 sizeof(struct btrfs_free_space), 0,
9458 SLAB_MEM_SPREAD, NULL);
9459 if (!btrfs_free_space_cachep)
9460 goto fail;
9461
9462 return 0;
9463 fail:
9464 btrfs_destroy_cachep();
9465 return -ENOMEM;
9466 }
9467
9468 static int btrfs_getattr(struct vfsmount *mnt,
9469 struct dentry *dentry, struct kstat *stat)
9470 {
9471 u64 delalloc_bytes;
9472 struct inode *inode = d_inode(dentry);
9473 u32 blocksize = inode->i_sb->s_blocksize;
9474
9475 generic_fillattr(inode, stat);
9476 stat->dev = BTRFS_I(inode)->root->anon_dev;
9477
9478 spin_lock(&BTRFS_I(inode)->lock);
9479 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;
9480 spin_unlock(&BTRFS_I(inode)->lock);
9481 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
9482 ALIGN(delalloc_bytes, blocksize)) >> 9;
9483 return 0;
9484 }
9485
9486 static int btrfs_rename_exchange(struct inode *old_dir,
9487 struct dentry *old_dentry,
9488 struct inode *new_dir,
9489 struct dentry *new_dentry)
9490 {
9491 struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
9492 struct btrfs_trans_handle *trans;
9493 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9494 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9495 struct inode *new_inode = new_dentry->d_inode;
9496 struct inode *old_inode = old_dentry->d_inode;
9497 struct timespec ctime = current_time(old_inode);
9498 struct dentry *parent;
9499 u64 old_ino = btrfs_ino(old_inode);
9500 u64 new_ino = btrfs_ino(new_inode);
9501 u64 old_idx = 0;
9502 u64 new_idx = 0;
9503 u64 root_objectid;
9504 int ret;
9505 bool root_log_pinned = false;
9506 bool dest_log_pinned = false;
9507
9508 /* we only allow rename subvolume link between subvolumes */
9509 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9510 return -EXDEV;
9511
9512 /* close the race window with snapshot create/destroy ioctl */
9513 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9514 down_read(&fs_info->subvol_sem);
9515 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9516 down_read(&fs_info->subvol_sem);
9517
9518 /*
9519 * We want to reserve the absolute worst case amount of items. So if
9520 * both inodes are subvols and we need to unlink them then that would
9521 * require 4 item modifications, but if they are both normal inodes it
9522 * would require 5 item modifications, so we'll assume their normal
9523 * inodes. So 5 * 2 is 10, plus 2 for the new links, so 12 total items
9524 * should cover the worst case number of items we'll modify.
9525 */
9526 trans = btrfs_start_transaction(root, 12);
9527 if (IS_ERR(trans)) {
9528 ret = PTR_ERR(trans);
9529 goto out_notrans;
9530 }
9531
9532 /*
9533 * We need to find a free sequence number both in the source and
9534 * in the destination directory for the exchange.
9535 */
9536 ret = btrfs_set_inode_index(new_dir, &old_idx);
9537 if (ret)
9538 goto out_fail;
9539 ret = btrfs_set_inode_index(old_dir, &new_idx);
9540 if (ret)
9541 goto out_fail;
9542
9543 BTRFS_I(old_inode)->dir_index = 0ULL;
9544 BTRFS_I(new_inode)->dir_index = 0ULL;
9545
9546 /* Reference for the source. */
9547 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9548 /* force full log commit if subvolume involved. */
9549 btrfs_set_log_full_commit(fs_info, trans);
9550 } else {
9551 btrfs_pin_log_trans(root);
9552 root_log_pinned = true;
9553 ret = btrfs_insert_inode_ref(trans, dest,
9554 new_dentry->d_name.name,
9555 new_dentry->d_name.len,
9556 old_ino,
9557 btrfs_ino(new_dir), old_idx);
9558 if (ret)
9559 goto out_fail;
9560 }
9561
9562 /* And now for the dest. */
9563 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9564 /* force full log commit if subvolume involved. */
9565 btrfs_set_log_full_commit(fs_info, trans);
9566 } else {
9567 btrfs_pin_log_trans(dest);
9568 dest_log_pinned = true;
9569 ret = btrfs_insert_inode_ref(trans, root,
9570 old_dentry->d_name.name,
9571 old_dentry->d_name.len,
9572 new_ino,
9573 btrfs_ino(old_dir), new_idx);
9574 if (ret)
9575 goto out_fail;
9576 }
9577
9578 /* Update inode version and ctime/mtime. */
9579 inode_inc_iversion(old_dir);
9580 inode_inc_iversion(new_dir);
9581 inode_inc_iversion(old_inode);
9582 inode_inc_iversion(new_inode);
9583 old_dir->i_ctime = old_dir->i_mtime = ctime;
9584 new_dir->i_ctime = new_dir->i_mtime = ctime;
9585 old_inode->i_ctime = ctime;
9586 new_inode->i_ctime = ctime;
9587
9588 if (old_dentry->d_parent != new_dentry->d_parent) {
9589 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
9590 btrfs_record_unlink_dir(trans, new_dir, new_inode, 1);
9591 }
9592
9593 /* src is a subvolume */
9594 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9595 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9596 ret = btrfs_unlink_subvol(trans, root, old_dir,
9597 root_objectid,
9598 old_dentry->d_name.name,
9599 old_dentry->d_name.len);
9600 } else { /* src is an inode */
9601 ret = __btrfs_unlink_inode(trans, root, old_dir,
9602 old_dentry->d_inode,
9603 old_dentry->d_name.name,
9604 old_dentry->d_name.len);
9605 if (!ret)
9606 ret = btrfs_update_inode(trans, root, old_inode);
9607 }
9608 if (ret) {
9609 btrfs_abort_transaction(trans, ret);
9610 goto out_fail;
9611 }
9612
9613 /* dest is a subvolume */
9614 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9615 root_objectid = BTRFS_I(new_inode)->root->root_key.objectid;
9616 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9617 root_objectid,
9618 new_dentry->d_name.name,
9619 new_dentry->d_name.len);
9620 } else { /* dest is an inode */
9621 ret = __btrfs_unlink_inode(trans, dest, new_dir,
9622 new_dentry->d_inode,
9623 new_dentry->d_name.name,
9624 new_dentry->d_name.len);
9625 if (!ret)
9626 ret = btrfs_update_inode(trans, dest, new_inode);
9627 }
9628 if (ret) {
9629 btrfs_abort_transaction(trans, ret);
9630 goto out_fail;
9631 }
9632
9633 ret = btrfs_add_link(trans, new_dir, old_inode,
9634 new_dentry->d_name.name,
9635 new_dentry->d_name.len, 0, old_idx);
9636 if (ret) {
9637 btrfs_abort_transaction(trans, ret);
9638 goto out_fail;
9639 }
9640
9641 ret = btrfs_add_link(trans, old_dir, new_inode,
9642 old_dentry->d_name.name,
9643 old_dentry->d_name.len, 0, new_idx);
9644 if (ret) {
9645 btrfs_abort_transaction(trans, ret);
9646 goto out_fail;
9647 }
9648
9649 if (old_inode->i_nlink == 1)
9650 BTRFS_I(old_inode)->dir_index = old_idx;
9651 if (new_inode->i_nlink == 1)
9652 BTRFS_I(new_inode)->dir_index = new_idx;
9653
9654 if (root_log_pinned) {
9655 parent = new_dentry->d_parent;
9656 btrfs_log_new_name(trans, old_inode, old_dir, parent);
9657 btrfs_end_log_trans(root);
9658 root_log_pinned = false;
9659 }
9660 if (dest_log_pinned) {
9661 parent = old_dentry->d_parent;
9662 btrfs_log_new_name(trans, new_inode, new_dir, parent);
9663 btrfs_end_log_trans(dest);
9664 dest_log_pinned = false;
9665 }
9666 out_fail:
9667 /*
9668 * If we have pinned a log and an error happened, we unpin tasks
9669 * trying to sync the log and force them to fallback to a transaction
9670 * commit if the log currently contains any of the inodes involved in
9671 * this rename operation (to ensure we do not persist a log with an
9672 * inconsistent state for any of these inodes or leading to any
9673 * inconsistencies when replayed). If the transaction was aborted, the
9674 * abortion reason is propagated to userspace when attempting to commit
9675 * the transaction. If the log does not contain any of these inodes, we
9676 * allow the tasks to sync it.
9677 */
9678 if (ret && (root_log_pinned || dest_log_pinned)) {
9679 if (btrfs_inode_in_log(old_dir, fs_info->generation) ||
9680 btrfs_inode_in_log(new_dir, fs_info->generation) ||
9681 btrfs_inode_in_log(old_inode, fs_info->generation) ||
9682 (new_inode &&
9683 btrfs_inode_in_log(new_inode, fs_info->generation)))
9684 btrfs_set_log_full_commit(fs_info, trans);
9685
9686 if (root_log_pinned) {
9687 btrfs_end_log_trans(root);
9688 root_log_pinned = false;
9689 }
9690 if (dest_log_pinned) {
9691 btrfs_end_log_trans(dest);
9692 dest_log_pinned = false;
9693 }
9694 }
9695 ret = btrfs_end_transaction(trans);
9696 out_notrans:
9697 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9698 up_read(&fs_info->subvol_sem);
9699 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9700 up_read(&fs_info->subvol_sem);
9701
9702 return ret;
9703 }
9704
9705 static int btrfs_whiteout_for_rename(struct btrfs_trans_handle *trans,
9706 struct btrfs_root *root,
9707 struct inode *dir,
9708 struct dentry *dentry)
9709 {
9710 int ret;
9711 struct inode *inode;
9712 u64 objectid;
9713 u64 index;
9714
9715 ret = btrfs_find_free_ino(root, &objectid);
9716 if (ret)
9717 return ret;
9718
9719 inode = btrfs_new_inode(trans, root, dir,
9720 dentry->d_name.name,
9721 dentry->d_name.len,
9722 btrfs_ino(dir),
9723 objectid,
9724 S_IFCHR | WHITEOUT_MODE,
9725 &index);
9726
9727 if (IS_ERR(inode)) {
9728 ret = PTR_ERR(inode);
9729 return ret;
9730 }
9731
9732 inode->i_op = &btrfs_special_inode_operations;
9733 init_special_inode(inode, inode->i_mode,
9734 WHITEOUT_DEV);
9735
9736 ret = btrfs_init_inode_security(trans, inode, dir,
9737 &dentry->d_name);
9738 if (ret)
9739 goto out;
9740
9741 ret = btrfs_add_nondir(trans, dir, dentry,
9742 inode, 0, index);
9743 if (ret)
9744 goto out;
9745
9746 ret = btrfs_update_inode(trans, root, inode);
9747 out:
9748 unlock_new_inode(inode);
9749 if (ret)
9750 inode_dec_link_count(inode);
9751 iput(inode);
9752
9753 return ret;
9754 }
9755
9756 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
9757 struct inode *new_dir, struct dentry *new_dentry,
9758 unsigned int flags)
9759 {
9760 struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
9761 struct btrfs_trans_handle *trans;
9762 unsigned int trans_num_items;
9763 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9764 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9765 struct inode *new_inode = d_inode(new_dentry);
9766 struct inode *old_inode = d_inode(old_dentry);
9767 u64 index = 0;
9768 u64 root_objectid;
9769 int ret;
9770 u64 old_ino = btrfs_ino(old_inode);
9771 bool log_pinned = false;
9772
9773 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
9774 return -EPERM;
9775
9776 /* we only allow rename subvolume link between subvolumes */
9777 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9778 return -EXDEV;
9779
9780 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
9781 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
9782 return -ENOTEMPTY;
9783
9784 if (S_ISDIR(old_inode->i_mode) && new_inode &&
9785 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
9786 return -ENOTEMPTY;
9787
9788
9789 /* check for collisions, even if the name isn't there */
9790 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
9791 new_dentry->d_name.name,
9792 new_dentry->d_name.len);
9793
9794 if (ret) {
9795 if (ret == -EEXIST) {
9796 /* we shouldn't get
9797 * eexist without a new_inode */
9798 if (WARN_ON(!new_inode)) {
9799 return ret;
9800 }
9801 } else {
9802 /* maybe -EOVERFLOW */
9803 return ret;
9804 }
9805 }
9806 ret = 0;
9807
9808 /*
9809 * we're using rename to replace one file with another. Start IO on it
9810 * now so we don't add too much work to the end of the transaction
9811 */
9812 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
9813 filemap_flush(old_inode->i_mapping);
9814
9815 /* close the racy window with snapshot create/destroy ioctl */
9816 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9817 down_read(&fs_info->subvol_sem);
9818 /*
9819 * We want to reserve the absolute worst case amount of items. So if
9820 * both inodes are subvols and we need to unlink them then that would
9821 * require 4 item modifications, but if they are both normal inodes it
9822 * would require 5 item modifications, so we'll assume they are normal
9823 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
9824 * should cover the worst case number of items we'll modify.
9825 * If our rename has the whiteout flag, we need more 5 units for the
9826 * new inode (1 inode item, 1 inode ref, 2 dir items and 1 xattr item
9827 * when selinux is enabled).
9828 */
9829 trans_num_items = 11;
9830 if (flags & RENAME_WHITEOUT)
9831 trans_num_items += 5;
9832 trans = btrfs_start_transaction(root, trans_num_items);
9833 if (IS_ERR(trans)) {
9834 ret = PTR_ERR(trans);
9835 goto out_notrans;
9836 }
9837
9838 if (dest != root)
9839 btrfs_record_root_in_trans(trans, dest);
9840
9841 ret = btrfs_set_inode_index(new_dir, &index);
9842 if (ret)
9843 goto out_fail;
9844
9845 BTRFS_I(old_inode)->dir_index = 0ULL;
9846 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9847 /* force full log commit if subvolume involved. */
9848 btrfs_set_log_full_commit(fs_info, trans);
9849 } else {
9850 btrfs_pin_log_trans(root);
9851 log_pinned = true;
9852 ret = btrfs_insert_inode_ref(trans, dest,
9853 new_dentry->d_name.name,
9854 new_dentry->d_name.len,
9855 old_ino,
9856 btrfs_ino(new_dir), index);
9857 if (ret)
9858 goto out_fail;
9859 }
9860
9861 inode_inc_iversion(old_dir);
9862 inode_inc_iversion(new_dir);
9863 inode_inc_iversion(old_inode);
9864 old_dir->i_ctime = old_dir->i_mtime =
9865 new_dir->i_ctime = new_dir->i_mtime =
9866 old_inode->i_ctime = current_time(old_dir);
9867
9868 if (old_dentry->d_parent != new_dentry->d_parent)
9869 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
9870
9871 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9872 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9873 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
9874 old_dentry->d_name.name,
9875 old_dentry->d_name.len);
9876 } else {
9877 ret = __btrfs_unlink_inode(trans, root, old_dir,
9878 d_inode(old_dentry),
9879 old_dentry->d_name.name,
9880 old_dentry->d_name.len);
9881 if (!ret)
9882 ret = btrfs_update_inode(trans, root, old_inode);
9883 }
9884 if (ret) {
9885 btrfs_abort_transaction(trans, ret);
9886 goto out_fail;
9887 }
9888
9889 if (new_inode) {
9890 inode_inc_iversion(new_inode);
9891 new_inode->i_ctime = current_time(new_inode);
9892 if (unlikely(btrfs_ino(new_inode) ==
9893 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
9894 root_objectid = BTRFS_I(new_inode)->location.objectid;
9895 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9896 root_objectid,
9897 new_dentry->d_name.name,
9898 new_dentry->d_name.len);
9899 BUG_ON(new_inode->i_nlink == 0);
9900 } else {
9901 ret = btrfs_unlink_inode(trans, dest, new_dir,
9902 d_inode(new_dentry),
9903 new_dentry->d_name.name,
9904 new_dentry->d_name.len);
9905 }
9906 if (!ret && new_inode->i_nlink == 0)
9907 ret = btrfs_orphan_add(trans, d_inode(new_dentry));
9908 if (ret) {
9909 btrfs_abort_transaction(trans, ret);
9910 goto out_fail;
9911 }
9912 }
9913
9914 ret = btrfs_add_link(trans, new_dir, old_inode,
9915 new_dentry->d_name.name,
9916 new_dentry->d_name.len, 0, index);
9917 if (ret) {
9918 btrfs_abort_transaction(trans, ret);
9919 goto out_fail;
9920 }
9921
9922 if (old_inode->i_nlink == 1)
9923 BTRFS_I(old_inode)->dir_index = index;
9924
9925 if (log_pinned) {
9926 struct dentry *parent = new_dentry->d_parent;
9927
9928 btrfs_log_new_name(trans, old_inode, old_dir, parent);
9929 btrfs_end_log_trans(root);
9930 log_pinned = false;
9931 }
9932
9933 if (flags & RENAME_WHITEOUT) {
9934 ret = btrfs_whiteout_for_rename(trans, root, old_dir,
9935 old_dentry);
9936
9937 if (ret) {
9938 btrfs_abort_transaction(trans, ret);
9939 goto out_fail;
9940 }
9941 }
9942 out_fail:
9943 /*
9944 * If we have pinned the log and an error happened, we unpin tasks
9945 * trying to sync the log and force them to fallback to a transaction
9946 * commit if the log currently contains any of the inodes involved in
9947 * this rename operation (to ensure we do not persist a log with an
9948 * inconsistent state for any of these inodes or leading to any
9949 * inconsistencies when replayed). If the transaction was aborted, the
9950 * abortion reason is propagated to userspace when attempting to commit
9951 * the transaction. If the log does not contain any of these inodes, we
9952 * allow the tasks to sync it.
9953 */
9954 if (ret && log_pinned) {
9955 if (btrfs_inode_in_log(old_dir, fs_info->generation) ||
9956 btrfs_inode_in_log(new_dir, fs_info->generation) ||
9957 btrfs_inode_in_log(old_inode, fs_info->generation) ||
9958 (new_inode &&
9959 btrfs_inode_in_log(new_inode, fs_info->generation)))
9960 btrfs_set_log_full_commit(fs_info, trans);
9961
9962 btrfs_end_log_trans(root);
9963 log_pinned = false;
9964 }
9965 btrfs_end_transaction(trans);
9966 out_notrans:
9967 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9968 up_read(&fs_info->subvol_sem);
9969
9970 return ret;
9971 }
9972
9973 static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
9974 struct inode *new_dir, struct dentry *new_dentry,
9975 unsigned int flags)
9976 {
9977 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
9978 return -EINVAL;
9979
9980 if (flags & RENAME_EXCHANGE)
9981 return btrfs_rename_exchange(old_dir, old_dentry, new_dir,
9982 new_dentry);
9983
9984 return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
9985 }
9986
9987 static void btrfs_run_delalloc_work(struct btrfs_work *work)
9988 {
9989 struct btrfs_delalloc_work *delalloc_work;
9990 struct inode *inode;
9991
9992 delalloc_work = container_of(work, struct btrfs_delalloc_work,
9993 work);
9994 inode = delalloc_work->inode;
9995 filemap_flush(inode->i_mapping);
9996 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
9997 &BTRFS_I(inode)->runtime_flags))
9998 filemap_flush(inode->i_mapping);
9999
10000 if (delalloc_work->delay_iput)
10001 btrfs_add_delayed_iput(inode);
10002 else
10003 iput(inode);
10004 complete(&delalloc_work->completion);
10005 }
10006
10007 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
10008 int delay_iput)
10009 {
10010 struct btrfs_delalloc_work *work;
10011
10012 work = kmalloc(sizeof(*work), GFP_NOFS);
10013 if (!work)
10014 return NULL;
10015
10016 init_completion(&work->completion);
10017 INIT_LIST_HEAD(&work->list);
10018 work->inode = inode;
10019 work->delay_iput = delay_iput;
10020 WARN_ON_ONCE(!inode);
10021 btrfs_init_work(&work->work, btrfs_flush_delalloc_helper,
10022 btrfs_run_delalloc_work, NULL, NULL);
10023
10024 return work;
10025 }
10026
10027 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
10028 {
10029 wait_for_completion(&work->completion);
10030 kfree(work);
10031 }
10032
10033 /*
10034 * some fairly slow code that needs optimization. This walks the list
10035 * of all the inodes with pending delalloc and forces them to disk.
10036 */
10037 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput,
10038 int nr)
10039 {
10040 struct btrfs_inode *binode;
10041 struct inode *inode;
10042 struct btrfs_delalloc_work *work, *next;
10043 struct list_head works;
10044 struct list_head splice;
10045 int ret = 0;
10046
10047 INIT_LIST_HEAD(&works);
10048 INIT_LIST_HEAD(&splice);
10049
10050 mutex_lock(&root->delalloc_mutex);
10051 spin_lock(&root->delalloc_lock);
10052 list_splice_init(&root->delalloc_inodes, &splice);
10053 while (!list_empty(&splice)) {
10054 binode = list_entry(splice.next, struct btrfs_inode,
10055 delalloc_inodes);
10056
10057 list_move_tail(&binode->delalloc_inodes,
10058 &root->delalloc_inodes);
10059 inode = igrab(&binode->vfs_inode);
10060 if (!inode) {
10061 cond_resched_lock(&root->delalloc_lock);
10062 continue;
10063 }
10064 spin_unlock(&root->delalloc_lock);
10065
10066 work = btrfs_alloc_delalloc_work(inode, delay_iput);
10067 if (!work) {
10068 if (delay_iput)
10069 btrfs_add_delayed_iput(inode);
10070 else
10071 iput(inode);
10072 ret = -ENOMEM;
10073 goto out;
10074 }
10075 list_add_tail(&work->list, &works);
10076 btrfs_queue_work(root->fs_info->flush_workers,
10077 &work->work);
10078 ret++;
10079 if (nr != -1 && ret >= nr)
10080 goto out;
10081 cond_resched();
10082 spin_lock(&root->delalloc_lock);
10083 }
10084 spin_unlock(&root->delalloc_lock);
10085
10086 out:
10087 list_for_each_entry_safe(work, next, &works, list) {
10088 list_del_init(&work->list);
10089 btrfs_wait_and_free_delalloc_work(work);
10090 }
10091
10092 if (!list_empty_careful(&splice)) {
10093 spin_lock(&root->delalloc_lock);
10094 list_splice_tail(&splice, &root->delalloc_inodes);
10095 spin_unlock(&root->delalloc_lock);
10096 }
10097 mutex_unlock(&root->delalloc_mutex);
10098 return ret;
10099 }
10100
10101 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
10102 {
10103 struct btrfs_fs_info *fs_info = root->fs_info;
10104 int ret;
10105
10106 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
10107 return -EROFS;
10108
10109 ret = __start_delalloc_inodes(root, delay_iput, -1);
10110 if (ret > 0)
10111 ret = 0;
10112 /*
10113 * the filemap_flush will queue IO into the worker threads, but
10114 * we have to make sure the IO is actually started and that
10115 * ordered extents get created before we return
10116 */
10117 atomic_inc(&fs_info->async_submit_draining);
10118 while (atomic_read(&fs_info->nr_async_submits) ||
10119 atomic_read(&fs_info->async_delalloc_pages)) {
10120 wait_event(fs_info->async_submit_wait,
10121 (atomic_read(&fs_info->nr_async_submits) == 0 &&
10122 atomic_read(&fs_info->async_delalloc_pages) == 0));
10123 }
10124 atomic_dec(&fs_info->async_submit_draining);
10125 return ret;
10126 }
10127
10128 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput,
10129 int nr)
10130 {
10131 struct btrfs_root *root;
10132 struct list_head splice;
10133 int ret;
10134
10135 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
10136 return -EROFS;
10137
10138 INIT_LIST_HEAD(&splice);
10139
10140 mutex_lock(&fs_info->delalloc_root_mutex);
10141 spin_lock(&fs_info->delalloc_root_lock);
10142 list_splice_init(&fs_info->delalloc_roots, &splice);
10143 while (!list_empty(&splice) && nr) {
10144 root = list_first_entry(&splice, struct btrfs_root,
10145 delalloc_root);
10146 root = btrfs_grab_fs_root(root);
10147 BUG_ON(!root);
10148 list_move_tail(&root->delalloc_root,
10149 &fs_info->delalloc_roots);
10150 spin_unlock(&fs_info->delalloc_root_lock);
10151
10152 ret = __start_delalloc_inodes(root, delay_iput, nr);
10153 btrfs_put_fs_root(root);
10154 if (ret < 0)
10155 goto out;
10156
10157 if (nr != -1) {
10158 nr -= ret;
10159 WARN_ON(nr < 0);
10160 }
10161 spin_lock(&fs_info->delalloc_root_lock);
10162 }
10163 spin_unlock(&fs_info->delalloc_root_lock);
10164
10165 ret = 0;
10166 atomic_inc(&fs_info->async_submit_draining);
10167 while (atomic_read(&fs_info->nr_async_submits) ||
10168 atomic_read(&fs_info->async_delalloc_pages)) {
10169 wait_event(fs_info->async_submit_wait,
10170 (atomic_read(&fs_info->nr_async_submits) == 0 &&
10171 atomic_read(&fs_info->async_delalloc_pages) == 0));
10172 }
10173 atomic_dec(&fs_info->async_submit_draining);
10174 out:
10175 if (!list_empty_careful(&splice)) {
10176 spin_lock(&fs_info->delalloc_root_lock);
10177 list_splice_tail(&splice, &fs_info->delalloc_roots);
10178 spin_unlock(&fs_info->delalloc_root_lock);
10179 }
10180 mutex_unlock(&fs_info->delalloc_root_mutex);
10181 return ret;
10182 }
10183
10184 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
10185 const char *symname)
10186 {
10187 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
10188 struct btrfs_trans_handle *trans;
10189 struct btrfs_root *root = BTRFS_I(dir)->root;
10190 struct btrfs_path *path;
10191 struct btrfs_key key;
10192 struct inode *inode = NULL;
10193 int err;
10194 int drop_inode = 0;
10195 u64 objectid;
10196 u64 index = 0;
10197 int name_len;
10198 int datasize;
10199 unsigned long ptr;
10200 struct btrfs_file_extent_item *ei;
10201 struct extent_buffer *leaf;
10202
10203 name_len = strlen(symname);
10204 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info))
10205 return -ENAMETOOLONG;
10206
10207 /*
10208 * 2 items for inode item and ref
10209 * 2 items for dir items
10210 * 1 item for updating parent inode item
10211 * 1 item for the inline extent item
10212 * 1 item for xattr if selinux is on
10213 */
10214 trans = btrfs_start_transaction(root, 7);
10215 if (IS_ERR(trans))
10216 return PTR_ERR(trans);
10217
10218 err = btrfs_find_free_ino(root, &objectid);
10219 if (err)
10220 goto out_unlock;
10221
10222 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
10223 dentry->d_name.len, btrfs_ino(dir), objectid,
10224 S_IFLNK|S_IRWXUGO, &index);
10225 if (IS_ERR(inode)) {
10226 err = PTR_ERR(inode);
10227 goto out_unlock;
10228 }
10229
10230 /*
10231 * If the active LSM wants to access the inode during
10232 * d_instantiate it needs these. Smack checks to see
10233 * if the filesystem supports xattrs by looking at the
10234 * ops vector.
10235 */
10236 inode->i_fop = &btrfs_file_operations;
10237 inode->i_op = &btrfs_file_inode_operations;
10238 inode->i_mapping->a_ops = &btrfs_aops;
10239 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10240
10241 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
10242 if (err)
10243 goto out_unlock_inode;
10244
10245 path = btrfs_alloc_path();
10246 if (!path) {
10247 err = -ENOMEM;
10248 goto out_unlock_inode;
10249 }
10250 key.objectid = btrfs_ino(inode);
10251 key.offset = 0;
10252 key.type = BTRFS_EXTENT_DATA_KEY;
10253 datasize = btrfs_file_extent_calc_inline_size(name_len);
10254 err = btrfs_insert_empty_item(trans, root, path, &key,
10255 datasize);
10256 if (err) {
10257 btrfs_free_path(path);
10258 goto out_unlock_inode;
10259 }
10260 leaf = path->nodes[0];
10261 ei = btrfs_item_ptr(leaf, path->slots[0],
10262 struct btrfs_file_extent_item);
10263 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
10264 btrfs_set_file_extent_type(leaf, ei,
10265 BTRFS_FILE_EXTENT_INLINE);
10266 btrfs_set_file_extent_encryption(leaf, ei, 0);
10267 btrfs_set_file_extent_compression(leaf, ei, 0);
10268 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
10269 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
10270
10271 ptr = btrfs_file_extent_inline_start(ei);
10272 write_extent_buffer(leaf, symname, ptr, name_len);
10273 btrfs_mark_buffer_dirty(leaf);
10274 btrfs_free_path(path);
10275
10276 inode->i_op = &btrfs_symlink_inode_operations;
10277 inode_nohighmem(inode);
10278 inode->i_mapping->a_ops = &btrfs_symlink_aops;
10279 inode_set_bytes(inode, name_len);
10280 btrfs_i_size_write(inode, name_len);
10281 err = btrfs_update_inode(trans, root, inode);
10282 /*
10283 * Last step, add directory indexes for our symlink inode. This is the
10284 * last step to avoid extra cleanup of these indexes if an error happens
10285 * elsewhere above.
10286 */
10287 if (!err)
10288 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
10289 if (err) {
10290 drop_inode = 1;
10291 goto out_unlock_inode;
10292 }
10293
10294 unlock_new_inode(inode);
10295 d_instantiate(dentry, inode);
10296
10297 out_unlock:
10298 btrfs_end_transaction(trans);
10299 if (drop_inode) {
10300 inode_dec_link_count(inode);
10301 iput(inode);
10302 }
10303 btrfs_btree_balance_dirty(fs_info);
10304 return err;
10305
10306 out_unlock_inode:
10307 drop_inode = 1;
10308 unlock_new_inode(inode);
10309 goto out_unlock;
10310 }
10311
10312 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
10313 u64 start, u64 num_bytes, u64 min_size,
10314 loff_t actual_len, u64 *alloc_hint,
10315 struct btrfs_trans_handle *trans)
10316 {
10317 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
10318 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
10319 struct extent_map *em;
10320 struct btrfs_root *root = BTRFS_I(inode)->root;
10321 struct btrfs_key ins;
10322 u64 cur_offset = start;
10323 u64 i_size;
10324 u64 cur_bytes;
10325 u64 last_alloc = (u64)-1;
10326 int ret = 0;
10327 bool own_trans = true;
10328 u64 end = start + num_bytes - 1;
10329
10330 if (trans)
10331 own_trans = false;
10332 while (num_bytes > 0) {
10333 if (own_trans) {
10334 trans = btrfs_start_transaction(root, 3);
10335 if (IS_ERR(trans)) {
10336 ret = PTR_ERR(trans);
10337 break;
10338 }
10339 }
10340
10341 cur_bytes = min_t(u64, num_bytes, SZ_256M);
10342 cur_bytes = max(cur_bytes, min_size);
10343 /*
10344 * If we are severely fragmented we could end up with really
10345 * small allocations, so if the allocator is returning small
10346 * chunks lets make its job easier by only searching for those
10347 * sized chunks.
10348 */
10349 cur_bytes = min(cur_bytes, last_alloc);
10350 ret = btrfs_reserve_extent(root, cur_bytes, cur_bytes,
10351 min_size, 0, *alloc_hint, &ins, 1, 0);
10352 if (ret) {
10353 if (own_trans)
10354 btrfs_end_transaction(trans);
10355 break;
10356 }
10357 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
10358
10359 last_alloc = ins.offset;
10360 ret = insert_reserved_file_extent(trans, inode,
10361 cur_offset, ins.objectid,
10362 ins.offset, ins.offset,
10363 ins.offset, 0, 0, 0,
10364 BTRFS_FILE_EXTENT_PREALLOC);
10365 if (ret) {
10366 btrfs_free_reserved_extent(fs_info, ins.objectid,
10367 ins.offset, 0);
10368 btrfs_abort_transaction(trans, ret);
10369 if (own_trans)
10370 btrfs_end_transaction(trans);
10371 break;
10372 }
10373
10374 btrfs_drop_extent_cache(inode, cur_offset,
10375 cur_offset + ins.offset -1, 0);
10376
10377 em = alloc_extent_map();
10378 if (!em) {
10379 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
10380 &BTRFS_I(inode)->runtime_flags);
10381 goto next;
10382 }
10383
10384 em->start = cur_offset;
10385 em->orig_start = cur_offset;
10386 em->len = ins.offset;
10387 em->block_start = ins.objectid;
10388 em->block_len = ins.offset;
10389 em->orig_block_len = ins.offset;
10390 em->ram_bytes = ins.offset;
10391 em->bdev = fs_info->fs_devices->latest_bdev;
10392 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
10393 em->generation = trans->transid;
10394
10395 while (1) {
10396 write_lock(&em_tree->lock);
10397 ret = add_extent_mapping(em_tree, em, 1);
10398 write_unlock(&em_tree->lock);
10399 if (ret != -EEXIST)
10400 break;
10401 btrfs_drop_extent_cache(inode, cur_offset,
10402 cur_offset + ins.offset - 1,
10403 0);
10404 }
10405 free_extent_map(em);
10406 next:
10407 num_bytes -= ins.offset;
10408 cur_offset += ins.offset;
10409 *alloc_hint = ins.objectid + ins.offset;
10410
10411 inode_inc_iversion(inode);
10412 inode->i_ctime = current_time(inode);
10413 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
10414 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
10415 (actual_len > inode->i_size) &&
10416 (cur_offset > inode->i_size)) {
10417 if (cur_offset > actual_len)
10418 i_size = actual_len;
10419 else
10420 i_size = cur_offset;
10421 i_size_write(inode, i_size);
10422 btrfs_ordered_update_i_size(inode, i_size, NULL);
10423 }
10424
10425 ret = btrfs_update_inode(trans, root, inode);
10426
10427 if (ret) {
10428 btrfs_abort_transaction(trans, ret);
10429 if (own_trans)
10430 btrfs_end_transaction(trans);
10431 break;
10432 }
10433
10434 if (own_trans)
10435 btrfs_end_transaction(trans);
10436 }
10437 if (cur_offset < end)
10438 btrfs_free_reserved_data_space(inode, cur_offset,
10439 end - cur_offset + 1);
10440 return ret;
10441 }
10442
10443 int btrfs_prealloc_file_range(struct inode *inode, int mode,
10444 u64 start, u64 num_bytes, u64 min_size,
10445 loff_t actual_len, u64 *alloc_hint)
10446 {
10447 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10448 min_size, actual_len, alloc_hint,
10449 NULL);
10450 }
10451
10452 int btrfs_prealloc_file_range_trans(struct inode *inode,
10453 struct btrfs_trans_handle *trans, int mode,
10454 u64 start, u64 num_bytes, u64 min_size,
10455 loff_t actual_len, u64 *alloc_hint)
10456 {
10457 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10458 min_size, actual_len, alloc_hint, trans);
10459 }
10460
10461 static int btrfs_set_page_dirty(struct page *page)
10462 {
10463 return __set_page_dirty_nobuffers(page);
10464 }
10465
10466 static int btrfs_permission(struct inode *inode, int mask)
10467 {
10468 struct btrfs_root *root = BTRFS_I(inode)->root;
10469 umode_t mode = inode->i_mode;
10470
10471 if (mask & MAY_WRITE &&
10472 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
10473 if (btrfs_root_readonly(root))
10474 return -EROFS;
10475 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
10476 return -EACCES;
10477 }
10478 return generic_permission(inode, mask);
10479 }
10480
10481 static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
10482 {
10483 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
10484 struct btrfs_trans_handle *trans;
10485 struct btrfs_root *root = BTRFS_I(dir)->root;
10486 struct inode *inode = NULL;
10487 u64 objectid;
10488 u64 index;
10489 int ret = 0;
10490
10491 /*
10492 * 5 units required for adding orphan entry
10493 */
10494 trans = btrfs_start_transaction(root, 5);
10495 if (IS_ERR(trans))
10496 return PTR_ERR(trans);
10497
10498 ret = btrfs_find_free_ino(root, &objectid);
10499 if (ret)
10500 goto out;
10501
10502 inode = btrfs_new_inode(trans, root, dir, NULL, 0,
10503 btrfs_ino(dir), objectid, mode, &index);
10504 if (IS_ERR(inode)) {
10505 ret = PTR_ERR(inode);
10506 inode = NULL;
10507 goto out;
10508 }
10509
10510 inode->i_fop = &btrfs_file_operations;
10511 inode->i_op = &btrfs_file_inode_operations;
10512
10513 inode->i_mapping->a_ops = &btrfs_aops;
10514 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10515
10516 ret = btrfs_init_inode_security(trans, inode, dir, NULL);
10517 if (ret)
10518 goto out_inode;
10519
10520 ret = btrfs_update_inode(trans, root, inode);
10521 if (ret)
10522 goto out_inode;
10523 ret = btrfs_orphan_add(trans, inode);
10524 if (ret)
10525 goto out_inode;
10526
10527 /*
10528 * We set number of links to 0 in btrfs_new_inode(), and here we set
10529 * it to 1 because d_tmpfile() will issue a warning if the count is 0,
10530 * through:
10531 *
10532 * d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
10533 */
10534 set_nlink(inode, 1);
10535 unlock_new_inode(inode);
10536 d_tmpfile(dentry, inode);
10537 mark_inode_dirty(inode);
10538
10539 out:
10540 btrfs_end_transaction(trans);
10541 if (ret)
10542 iput(inode);
10543 btrfs_balance_delayed_items(fs_info);
10544 btrfs_btree_balance_dirty(fs_info);
10545 return ret;
10546
10547 out_inode:
10548 unlock_new_inode(inode);
10549 goto out;
10550
10551 }
10552
10553 static const struct inode_operations btrfs_dir_inode_operations = {
10554 .getattr = btrfs_getattr,
10555 .lookup = btrfs_lookup,
10556 .create = btrfs_create,
10557 .unlink = btrfs_unlink,
10558 .link = btrfs_link,
10559 .mkdir = btrfs_mkdir,
10560 .rmdir = btrfs_rmdir,
10561 .rename = btrfs_rename2,
10562 .symlink = btrfs_symlink,
10563 .setattr = btrfs_setattr,
10564 .mknod = btrfs_mknod,
10565 .listxattr = btrfs_listxattr,
10566 .permission = btrfs_permission,
10567 .get_acl = btrfs_get_acl,
10568 .set_acl = btrfs_set_acl,
10569 .update_time = btrfs_update_time,
10570 .tmpfile = btrfs_tmpfile,
10571 };
10572 static const struct inode_operations btrfs_dir_ro_inode_operations = {
10573 .lookup = btrfs_lookup,
10574 .permission = btrfs_permission,
10575 .get_acl = btrfs_get_acl,
10576 .set_acl = btrfs_set_acl,
10577 .update_time = btrfs_update_time,
10578 };
10579
10580 static const struct file_operations btrfs_dir_file_operations = {
10581 .llseek = generic_file_llseek,
10582 .read = generic_read_dir,
10583 .iterate_shared = btrfs_real_readdir,
10584 .unlocked_ioctl = btrfs_ioctl,
10585 #ifdef CONFIG_COMPAT
10586 .compat_ioctl = btrfs_compat_ioctl,
10587 #endif
10588 .release = btrfs_release_file,
10589 .fsync = btrfs_sync_file,
10590 };
10591
10592 static const struct extent_io_ops btrfs_extent_io_ops = {
10593 .fill_delalloc = run_delalloc_range,
10594 .submit_bio_hook = btrfs_submit_bio_hook,
10595 .merge_bio_hook = btrfs_merge_bio_hook,
10596 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
10597 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
10598 .writepage_start_hook = btrfs_writepage_start_hook,
10599 .set_bit_hook = btrfs_set_bit_hook,
10600 .clear_bit_hook = btrfs_clear_bit_hook,
10601 .merge_extent_hook = btrfs_merge_extent_hook,
10602 .split_extent_hook = btrfs_split_extent_hook,
10603 };
10604
10605 /*
10606 * btrfs doesn't support the bmap operation because swapfiles
10607 * use bmap to make a mapping of extents in the file. They assume
10608 * these extents won't change over the life of the file and they
10609 * use the bmap result to do IO directly to the drive.
10610 *
10611 * the btrfs bmap call would return logical addresses that aren't
10612 * suitable for IO and they also will change frequently as COW
10613 * operations happen. So, swapfile + btrfs == corruption.
10614 *
10615 * For now we're avoiding this by dropping bmap.
10616 */
10617 static const struct address_space_operations btrfs_aops = {
10618 .readpage = btrfs_readpage,
10619 .writepage = btrfs_writepage,
10620 .writepages = btrfs_writepages,
10621 .readpages = btrfs_readpages,
10622 .direct_IO = btrfs_direct_IO,
10623 .invalidatepage = btrfs_invalidatepage,
10624 .releasepage = btrfs_releasepage,
10625 .set_page_dirty = btrfs_set_page_dirty,
10626 .error_remove_page = generic_error_remove_page,
10627 };
10628
10629 static const struct address_space_operations btrfs_symlink_aops = {
10630 .readpage = btrfs_readpage,
10631 .writepage = btrfs_writepage,
10632 .invalidatepage = btrfs_invalidatepage,
10633 .releasepage = btrfs_releasepage,
10634 };
10635
10636 static const struct inode_operations btrfs_file_inode_operations = {
10637 .getattr = btrfs_getattr,
10638 .setattr = btrfs_setattr,
10639 .listxattr = btrfs_listxattr,
10640 .permission = btrfs_permission,
10641 .fiemap = btrfs_fiemap,
10642 .get_acl = btrfs_get_acl,
10643 .set_acl = btrfs_set_acl,
10644 .update_time = btrfs_update_time,
10645 };
10646 static const struct inode_operations btrfs_special_inode_operations = {
10647 .getattr = btrfs_getattr,
10648 .setattr = btrfs_setattr,
10649 .permission = btrfs_permission,
10650 .listxattr = btrfs_listxattr,
10651 .get_acl = btrfs_get_acl,
10652 .set_acl = btrfs_set_acl,
10653 .update_time = btrfs_update_time,
10654 };
10655 static const struct inode_operations btrfs_symlink_inode_operations = {
10656 .get_link = page_get_link,
10657 .getattr = btrfs_getattr,
10658 .setattr = btrfs_setattr,
10659 .permission = btrfs_permission,
10660 .listxattr = btrfs_listxattr,
10661 .update_time = btrfs_update_time,
10662 };
10663
10664 const struct dentry_operations btrfs_dentry_operations = {
10665 .d_delete = btrfs_dentry_delete,
10666 .d_release = btrfs_dentry_release,
10667 };
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