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Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[deliverable/linux.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/statfs.h>
34 #include <linux/compat.h>
35 #include <linux/bit_spinlock.h>
36 #include <linux/xattr.h>
37 #include <linux/posix_acl.h>
38 #include <linux/falloc.h>
39 #include <linux/slab.h>
40 #include <linux/ratelimit.h>
41 #include <linux/mount.h>
42 #include <linux/btrfs.h>
43 #include <linux/blkdev.h>
44 #include <linux/posix_acl_xattr.h>
45 #include <linux/uio.h>
46 #include "ctree.h"
47 #include "disk-io.h"
48 #include "transaction.h"
49 #include "btrfs_inode.h"
50 #include "print-tree.h"
51 #include "ordered-data.h"
52 #include "xattr.h"
53 #include "tree-log.h"
54 #include "volumes.h"
55 #include "compression.h"
56 #include "locking.h"
57 #include "free-space-cache.h"
58 #include "inode-map.h"
59 #include "backref.h"
60 #include "hash.h"
61 #include "props.h"
62 #include "qgroup.h"
63
64 struct btrfs_iget_args {
65 struct btrfs_key *location;
66 struct btrfs_root *root;
67 };
68
69 static const struct inode_operations btrfs_dir_inode_operations;
70 static const struct inode_operations btrfs_symlink_inode_operations;
71 static const struct inode_operations btrfs_dir_ro_inode_operations;
72 static const struct inode_operations btrfs_special_inode_operations;
73 static const struct inode_operations btrfs_file_inode_operations;
74 static const struct address_space_operations btrfs_aops;
75 static const struct address_space_operations btrfs_symlink_aops;
76 static const struct file_operations btrfs_dir_file_operations;
77 static struct extent_io_ops btrfs_extent_io_ops;
78
79 static struct kmem_cache *btrfs_inode_cachep;
80 static struct kmem_cache *btrfs_delalloc_work_cachep;
81 struct kmem_cache *btrfs_trans_handle_cachep;
82 struct kmem_cache *btrfs_transaction_cachep;
83 struct kmem_cache *btrfs_path_cachep;
84 struct kmem_cache *btrfs_free_space_cachep;
85
86 #define S_SHIFT 12
87 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
88 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
89 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
90 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
91 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
92 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
93 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
94 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
95 };
96
97 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
98 static int btrfs_truncate(struct inode *inode);
99 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
100 static noinline int cow_file_range(struct inode *inode,
101 struct page *locked_page,
102 u64 start, u64 end, int *page_started,
103 unsigned long *nr_written, int unlock);
104 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
105 u64 len, u64 orig_start,
106 u64 block_start, u64 block_len,
107 u64 orig_block_len, u64 ram_bytes,
108 int type);
109
110 static int btrfs_dirty_inode(struct inode *inode);
111
112 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
113 void btrfs_test_inode_set_ops(struct inode *inode)
114 {
115 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
116 }
117 #endif
118
119 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
120 struct inode *inode, struct inode *dir,
121 const struct qstr *qstr)
122 {
123 int err;
124
125 err = btrfs_init_acl(trans, inode, dir);
126 if (!err)
127 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
128 return err;
129 }
130
131 /*
132 * this does all the hard work for inserting an inline extent into
133 * the btree. The caller should have done a btrfs_drop_extents so that
134 * no overlapping inline items exist in the btree
135 */
136 static int insert_inline_extent(struct btrfs_trans_handle *trans,
137 struct btrfs_path *path, int extent_inserted,
138 struct btrfs_root *root, struct inode *inode,
139 u64 start, size_t size, size_t compressed_size,
140 int compress_type,
141 struct page **compressed_pages)
142 {
143 struct extent_buffer *leaf;
144 struct page *page = NULL;
145 char *kaddr;
146 unsigned long ptr;
147 struct btrfs_file_extent_item *ei;
148 int err = 0;
149 int ret;
150 size_t cur_size = size;
151 unsigned long offset;
152
153 if (compressed_size && compressed_pages)
154 cur_size = compressed_size;
155
156 inode_add_bytes(inode, size);
157
158 if (!extent_inserted) {
159 struct btrfs_key key;
160 size_t datasize;
161
162 key.objectid = btrfs_ino(inode);
163 key.offset = start;
164 key.type = BTRFS_EXTENT_DATA_KEY;
165
166 datasize = btrfs_file_extent_calc_inline_size(cur_size);
167 path->leave_spinning = 1;
168 ret = btrfs_insert_empty_item(trans, root, path, &key,
169 datasize);
170 if (ret) {
171 err = ret;
172 goto fail;
173 }
174 }
175 leaf = path->nodes[0];
176 ei = btrfs_item_ptr(leaf, path->slots[0],
177 struct btrfs_file_extent_item);
178 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
179 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
180 btrfs_set_file_extent_encryption(leaf, ei, 0);
181 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
182 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
183 ptr = btrfs_file_extent_inline_start(ei);
184
185 if (compress_type != BTRFS_COMPRESS_NONE) {
186 struct page *cpage;
187 int i = 0;
188 while (compressed_size > 0) {
189 cpage = compressed_pages[i];
190 cur_size = min_t(unsigned long, compressed_size,
191 PAGE_CACHE_SIZE);
192
193 kaddr = kmap_atomic(cpage);
194 write_extent_buffer(leaf, kaddr, ptr, cur_size);
195 kunmap_atomic(kaddr);
196
197 i++;
198 ptr += cur_size;
199 compressed_size -= cur_size;
200 }
201 btrfs_set_file_extent_compression(leaf, ei,
202 compress_type);
203 } else {
204 page = find_get_page(inode->i_mapping,
205 start >> PAGE_CACHE_SHIFT);
206 btrfs_set_file_extent_compression(leaf, ei, 0);
207 kaddr = kmap_atomic(page);
208 offset = start & (PAGE_CACHE_SIZE - 1);
209 write_extent_buffer(leaf, kaddr + offset, ptr, size);
210 kunmap_atomic(kaddr);
211 page_cache_release(page);
212 }
213 btrfs_mark_buffer_dirty(leaf);
214 btrfs_release_path(path);
215
216 /*
217 * we're an inline extent, so nobody can
218 * extend the file past i_size without locking
219 * a page we already have locked.
220 *
221 * We must do any isize and inode updates
222 * before we unlock the pages. Otherwise we
223 * could end up racing with unlink.
224 */
225 BTRFS_I(inode)->disk_i_size = inode->i_size;
226 ret = btrfs_update_inode(trans, root, inode);
227
228 return ret;
229 fail:
230 return err;
231 }
232
233
234 /*
235 * conditionally insert an inline extent into the file. This
236 * does the checks required to make sure the data is small enough
237 * to fit as an inline extent.
238 */
239 static noinline int cow_file_range_inline(struct btrfs_root *root,
240 struct inode *inode, u64 start,
241 u64 end, size_t compressed_size,
242 int compress_type,
243 struct page **compressed_pages)
244 {
245 struct btrfs_trans_handle *trans;
246 u64 isize = i_size_read(inode);
247 u64 actual_end = min(end + 1, isize);
248 u64 inline_len = actual_end - start;
249 u64 aligned_end = ALIGN(end, root->sectorsize);
250 u64 data_len = inline_len;
251 int ret;
252 struct btrfs_path *path;
253 int extent_inserted = 0;
254 u32 extent_item_size;
255
256 if (compressed_size)
257 data_len = compressed_size;
258
259 if (start > 0 ||
260 actual_end > PAGE_CACHE_SIZE ||
261 data_len > BTRFS_MAX_INLINE_DATA_SIZE(root) ||
262 (!compressed_size &&
263 (actual_end & (root->sectorsize - 1)) == 0) ||
264 end + 1 < isize ||
265 data_len > root->fs_info->max_inline) {
266 return 1;
267 }
268
269 path = btrfs_alloc_path();
270 if (!path)
271 return -ENOMEM;
272
273 trans = btrfs_join_transaction(root);
274 if (IS_ERR(trans)) {
275 btrfs_free_path(path);
276 return PTR_ERR(trans);
277 }
278 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
279
280 if (compressed_size && compressed_pages)
281 extent_item_size = btrfs_file_extent_calc_inline_size(
282 compressed_size);
283 else
284 extent_item_size = btrfs_file_extent_calc_inline_size(
285 inline_len);
286
287 ret = __btrfs_drop_extents(trans, root, inode, path,
288 start, aligned_end, NULL,
289 1, 1, extent_item_size, &extent_inserted);
290 if (ret) {
291 btrfs_abort_transaction(trans, root, ret);
292 goto out;
293 }
294
295 if (isize > actual_end)
296 inline_len = min_t(u64, isize, actual_end);
297 ret = insert_inline_extent(trans, path, extent_inserted,
298 root, inode, start,
299 inline_len, compressed_size,
300 compress_type, compressed_pages);
301 if (ret && ret != -ENOSPC) {
302 btrfs_abort_transaction(trans, root, ret);
303 goto out;
304 } else if (ret == -ENOSPC) {
305 ret = 1;
306 goto out;
307 }
308
309 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
310 btrfs_delalloc_release_metadata(inode, end + 1 - start);
311 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
312 out:
313 /*
314 * Don't forget to free the reserved space, as for inlined extent
315 * it won't count as data extent, free them directly here.
316 * And at reserve time, it's always aligned to page size, so
317 * just free one page here.
318 */
319 btrfs_qgroup_free_data(inode, 0, PAGE_CACHE_SIZE);
320 btrfs_free_path(path);
321 btrfs_end_transaction(trans, root);
322 return ret;
323 }
324
325 struct async_extent {
326 u64 start;
327 u64 ram_size;
328 u64 compressed_size;
329 struct page **pages;
330 unsigned long nr_pages;
331 int compress_type;
332 struct list_head list;
333 };
334
335 struct async_cow {
336 struct inode *inode;
337 struct btrfs_root *root;
338 struct page *locked_page;
339 u64 start;
340 u64 end;
341 struct list_head extents;
342 struct btrfs_work work;
343 };
344
345 static noinline int add_async_extent(struct async_cow *cow,
346 u64 start, u64 ram_size,
347 u64 compressed_size,
348 struct page **pages,
349 unsigned long nr_pages,
350 int compress_type)
351 {
352 struct async_extent *async_extent;
353
354 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
355 BUG_ON(!async_extent); /* -ENOMEM */
356 async_extent->start = start;
357 async_extent->ram_size = ram_size;
358 async_extent->compressed_size = compressed_size;
359 async_extent->pages = pages;
360 async_extent->nr_pages = nr_pages;
361 async_extent->compress_type = compress_type;
362 list_add_tail(&async_extent->list, &cow->extents);
363 return 0;
364 }
365
366 static inline int inode_need_compress(struct inode *inode)
367 {
368 struct btrfs_root *root = BTRFS_I(inode)->root;
369
370 /* force compress */
371 if (btrfs_test_opt(root, FORCE_COMPRESS))
372 return 1;
373 /* bad compression ratios */
374 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
375 return 0;
376 if (btrfs_test_opt(root, COMPRESS) ||
377 BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
378 BTRFS_I(inode)->force_compress)
379 return 1;
380 return 0;
381 }
382
383 /*
384 * we create compressed extents in two phases. The first
385 * phase compresses a range of pages that have already been
386 * locked (both pages and state bits are locked).
387 *
388 * This is done inside an ordered work queue, and the compression
389 * is spread across many cpus. The actual IO submission is step
390 * two, and the ordered work queue takes care of making sure that
391 * happens in the same order things were put onto the queue by
392 * writepages and friends.
393 *
394 * If this code finds it can't get good compression, it puts an
395 * entry onto the work queue to write the uncompressed bytes. This
396 * makes sure that both compressed inodes and uncompressed inodes
397 * are written in the same order that the flusher thread sent them
398 * down.
399 */
400 static noinline void compress_file_range(struct inode *inode,
401 struct page *locked_page,
402 u64 start, u64 end,
403 struct async_cow *async_cow,
404 int *num_added)
405 {
406 struct btrfs_root *root = BTRFS_I(inode)->root;
407 u64 num_bytes;
408 u64 blocksize = root->sectorsize;
409 u64 actual_end;
410 u64 isize = i_size_read(inode);
411 int ret = 0;
412 struct page **pages = NULL;
413 unsigned long nr_pages;
414 unsigned long nr_pages_ret = 0;
415 unsigned long total_compressed = 0;
416 unsigned long total_in = 0;
417 unsigned long max_compressed = 128 * 1024;
418 unsigned long max_uncompressed = 128 * 1024;
419 int i;
420 int will_compress;
421 int compress_type = root->fs_info->compress_type;
422 int redirty = 0;
423
424 /* if this is a small write inside eof, kick off a defrag */
425 if ((end - start + 1) < 16 * 1024 &&
426 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
427 btrfs_add_inode_defrag(NULL, inode);
428
429 actual_end = min_t(u64, isize, end + 1);
430 again:
431 will_compress = 0;
432 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
433 nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
434
435 /*
436 * we don't want to send crud past the end of i_size through
437 * compression, that's just a waste of CPU time. So, if the
438 * end of the file is before the start of our current
439 * requested range of bytes, we bail out to the uncompressed
440 * cleanup code that can deal with all of this.
441 *
442 * It isn't really the fastest way to fix things, but this is a
443 * very uncommon corner.
444 */
445 if (actual_end <= start)
446 goto cleanup_and_bail_uncompressed;
447
448 total_compressed = actual_end - start;
449
450 /*
451 * skip compression for a small file range(<=blocksize) that
452 * isn't an inline extent, since it dosen't save disk space at all.
453 */
454 if (total_compressed <= blocksize &&
455 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
456 goto cleanup_and_bail_uncompressed;
457
458 /* we want to make sure that amount of ram required to uncompress
459 * an extent is reasonable, so we limit the total size in ram
460 * of a compressed extent to 128k. This is a crucial number
461 * because it also controls how easily we can spread reads across
462 * cpus for decompression.
463 *
464 * We also want to make sure the amount of IO required to do
465 * a random read is reasonably small, so we limit the size of
466 * a compressed extent to 128k.
467 */
468 total_compressed = min(total_compressed, max_uncompressed);
469 num_bytes = ALIGN(end - start + 1, blocksize);
470 num_bytes = max(blocksize, num_bytes);
471 total_in = 0;
472 ret = 0;
473
474 /*
475 * we do compression for mount -o compress and when the
476 * inode has not been flagged as nocompress. This flag can
477 * change at any time if we discover bad compression ratios.
478 */
479 if (inode_need_compress(inode)) {
480 WARN_ON(pages);
481 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
482 if (!pages) {
483 /* just bail out to the uncompressed code */
484 goto cont;
485 }
486
487 if (BTRFS_I(inode)->force_compress)
488 compress_type = BTRFS_I(inode)->force_compress;
489
490 /*
491 * we need to call clear_page_dirty_for_io on each
492 * page in the range. Otherwise applications with the file
493 * mmap'd can wander in and change the page contents while
494 * we are compressing them.
495 *
496 * If the compression fails for any reason, we set the pages
497 * dirty again later on.
498 */
499 extent_range_clear_dirty_for_io(inode, start, end);
500 redirty = 1;
501 ret = btrfs_compress_pages(compress_type,
502 inode->i_mapping, start,
503 total_compressed, pages,
504 nr_pages, &nr_pages_ret,
505 &total_in,
506 &total_compressed,
507 max_compressed);
508
509 if (!ret) {
510 unsigned long offset = total_compressed &
511 (PAGE_CACHE_SIZE - 1);
512 struct page *page = pages[nr_pages_ret - 1];
513 char *kaddr;
514
515 /* zero the tail end of the last page, we might be
516 * sending it down to disk
517 */
518 if (offset) {
519 kaddr = kmap_atomic(page);
520 memset(kaddr + offset, 0,
521 PAGE_CACHE_SIZE - offset);
522 kunmap_atomic(kaddr);
523 }
524 will_compress = 1;
525 }
526 }
527 cont:
528 if (start == 0) {
529 /* lets try to make an inline extent */
530 if (ret || total_in < (actual_end - start)) {
531 /* we didn't compress the entire range, try
532 * to make an uncompressed inline extent.
533 */
534 ret = cow_file_range_inline(root, inode, start, end,
535 0, 0, NULL);
536 } else {
537 /* try making a compressed inline extent */
538 ret = cow_file_range_inline(root, inode, start, end,
539 total_compressed,
540 compress_type, pages);
541 }
542 if (ret <= 0) {
543 unsigned long clear_flags = EXTENT_DELALLOC |
544 EXTENT_DEFRAG;
545 unsigned long page_error_op;
546
547 clear_flags |= (ret < 0) ? EXTENT_DO_ACCOUNTING : 0;
548 page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
549
550 /*
551 * inline extent creation worked or returned error,
552 * we don't need to create any more async work items.
553 * Unlock and free up our temp pages.
554 */
555 extent_clear_unlock_delalloc(inode, start, end, NULL,
556 clear_flags, PAGE_UNLOCK |
557 PAGE_CLEAR_DIRTY |
558 PAGE_SET_WRITEBACK |
559 page_error_op |
560 PAGE_END_WRITEBACK);
561 goto free_pages_out;
562 }
563 }
564
565 if (will_compress) {
566 /*
567 * we aren't doing an inline extent round the compressed size
568 * up to a block size boundary so the allocator does sane
569 * things
570 */
571 total_compressed = ALIGN(total_compressed, blocksize);
572
573 /*
574 * one last check to make sure the compression is really a
575 * win, compare the page count read with the blocks on disk
576 */
577 total_in = ALIGN(total_in, PAGE_CACHE_SIZE);
578 if (total_compressed >= total_in) {
579 will_compress = 0;
580 } else {
581 num_bytes = total_in;
582 }
583 }
584 if (!will_compress && pages) {
585 /*
586 * the compression code ran but failed to make things smaller,
587 * free any pages it allocated and our page pointer array
588 */
589 for (i = 0; i < nr_pages_ret; i++) {
590 WARN_ON(pages[i]->mapping);
591 page_cache_release(pages[i]);
592 }
593 kfree(pages);
594 pages = NULL;
595 total_compressed = 0;
596 nr_pages_ret = 0;
597
598 /* flag the file so we don't compress in the future */
599 if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
600 !(BTRFS_I(inode)->force_compress)) {
601 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
602 }
603 }
604 if (will_compress) {
605 *num_added += 1;
606
607 /* the async work queues will take care of doing actual
608 * allocation on disk for these compressed pages,
609 * and will submit them to the elevator.
610 */
611 add_async_extent(async_cow, start, num_bytes,
612 total_compressed, pages, nr_pages_ret,
613 compress_type);
614
615 if (start + num_bytes < end) {
616 start += num_bytes;
617 pages = NULL;
618 cond_resched();
619 goto again;
620 }
621 } else {
622 cleanup_and_bail_uncompressed:
623 /*
624 * No compression, but we still need to write the pages in
625 * the file we've been given so far. redirty the locked
626 * page if it corresponds to our extent and set things up
627 * for the async work queue to run cow_file_range to do
628 * the normal delalloc dance
629 */
630 if (page_offset(locked_page) >= start &&
631 page_offset(locked_page) <= end) {
632 __set_page_dirty_nobuffers(locked_page);
633 /* unlocked later on in the async handlers */
634 }
635 if (redirty)
636 extent_range_redirty_for_io(inode, start, end);
637 add_async_extent(async_cow, start, end - start + 1,
638 0, NULL, 0, BTRFS_COMPRESS_NONE);
639 *num_added += 1;
640 }
641
642 return;
643
644 free_pages_out:
645 for (i = 0; i < nr_pages_ret; i++) {
646 WARN_ON(pages[i]->mapping);
647 page_cache_release(pages[i]);
648 }
649 kfree(pages);
650 }
651
652 static void free_async_extent_pages(struct async_extent *async_extent)
653 {
654 int i;
655
656 if (!async_extent->pages)
657 return;
658
659 for (i = 0; i < async_extent->nr_pages; i++) {
660 WARN_ON(async_extent->pages[i]->mapping);
661 page_cache_release(async_extent->pages[i]);
662 }
663 kfree(async_extent->pages);
664 async_extent->nr_pages = 0;
665 async_extent->pages = NULL;
666 }
667
668 /*
669 * phase two of compressed writeback. This is the ordered portion
670 * of the code, which only gets called in the order the work was
671 * queued. We walk all the async extents created by compress_file_range
672 * and send them down to the disk.
673 */
674 static noinline void submit_compressed_extents(struct inode *inode,
675 struct async_cow *async_cow)
676 {
677 struct async_extent *async_extent;
678 u64 alloc_hint = 0;
679 struct btrfs_key ins;
680 struct extent_map *em;
681 struct btrfs_root *root = BTRFS_I(inode)->root;
682 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
683 struct extent_io_tree *io_tree;
684 int ret = 0;
685
686 again:
687 while (!list_empty(&async_cow->extents)) {
688 async_extent = list_entry(async_cow->extents.next,
689 struct async_extent, list);
690 list_del(&async_extent->list);
691
692 io_tree = &BTRFS_I(inode)->io_tree;
693
694 retry:
695 /* did the compression code fall back to uncompressed IO? */
696 if (!async_extent->pages) {
697 int page_started = 0;
698 unsigned long nr_written = 0;
699
700 lock_extent(io_tree, async_extent->start,
701 async_extent->start +
702 async_extent->ram_size - 1);
703
704 /* allocate blocks */
705 ret = cow_file_range(inode, async_cow->locked_page,
706 async_extent->start,
707 async_extent->start +
708 async_extent->ram_size - 1,
709 &page_started, &nr_written, 0);
710
711 /* JDM XXX */
712
713 /*
714 * if page_started, cow_file_range inserted an
715 * inline extent and took care of all the unlocking
716 * and IO for us. Otherwise, we need to submit
717 * all those pages down to the drive.
718 */
719 if (!page_started && !ret)
720 extent_write_locked_range(io_tree,
721 inode, async_extent->start,
722 async_extent->start +
723 async_extent->ram_size - 1,
724 btrfs_get_extent,
725 WB_SYNC_ALL);
726 else if (ret)
727 unlock_page(async_cow->locked_page);
728 kfree(async_extent);
729 cond_resched();
730 continue;
731 }
732
733 lock_extent(io_tree, async_extent->start,
734 async_extent->start + async_extent->ram_size - 1);
735
736 ret = btrfs_reserve_extent(root,
737 async_extent->compressed_size,
738 async_extent->compressed_size,
739 0, alloc_hint, &ins, 1, 1);
740 if (ret) {
741 free_async_extent_pages(async_extent);
742
743 if (ret == -ENOSPC) {
744 unlock_extent(io_tree, async_extent->start,
745 async_extent->start +
746 async_extent->ram_size - 1);
747
748 /*
749 * we need to redirty the pages if we decide to
750 * fallback to uncompressed IO, otherwise we
751 * will not submit these pages down to lower
752 * layers.
753 */
754 extent_range_redirty_for_io(inode,
755 async_extent->start,
756 async_extent->start +
757 async_extent->ram_size - 1);
758
759 goto retry;
760 }
761 goto out_free;
762 }
763 /*
764 * here we're doing allocation and writeback of the
765 * compressed pages
766 */
767 btrfs_drop_extent_cache(inode, async_extent->start,
768 async_extent->start +
769 async_extent->ram_size - 1, 0);
770
771 em = alloc_extent_map();
772 if (!em) {
773 ret = -ENOMEM;
774 goto out_free_reserve;
775 }
776 em->start = async_extent->start;
777 em->len = async_extent->ram_size;
778 em->orig_start = em->start;
779 em->mod_start = em->start;
780 em->mod_len = em->len;
781
782 em->block_start = ins.objectid;
783 em->block_len = ins.offset;
784 em->orig_block_len = ins.offset;
785 em->ram_bytes = async_extent->ram_size;
786 em->bdev = root->fs_info->fs_devices->latest_bdev;
787 em->compress_type = async_extent->compress_type;
788 set_bit(EXTENT_FLAG_PINNED, &em->flags);
789 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
790 em->generation = -1;
791
792 while (1) {
793 write_lock(&em_tree->lock);
794 ret = add_extent_mapping(em_tree, em, 1);
795 write_unlock(&em_tree->lock);
796 if (ret != -EEXIST) {
797 free_extent_map(em);
798 break;
799 }
800 btrfs_drop_extent_cache(inode, async_extent->start,
801 async_extent->start +
802 async_extent->ram_size - 1, 0);
803 }
804
805 if (ret)
806 goto out_free_reserve;
807
808 ret = btrfs_add_ordered_extent_compress(inode,
809 async_extent->start,
810 ins.objectid,
811 async_extent->ram_size,
812 ins.offset,
813 BTRFS_ORDERED_COMPRESSED,
814 async_extent->compress_type);
815 if (ret) {
816 btrfs_drop_extent_cache(inode, async_extent->start,
817 async_extent->start +
818 async_extent->ram_size - 1, 0);
819 goto out_free_reserve;
820 }
821
822 /*
823 * clear dirty, set writeback and unlock the pages.
824 */
825 extent_clear_unlock_delalloc(inode, async_extent->start,
826 async_extent->start +
827 async_extent->ram_size - 1,
828 NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
829 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
830 PAGE_SET_WRITEBACK);
831 ret = btrfs_submit_compressed_write(inode,
832 async_extent->start,
833 async_extent->ram_size,
834 ins.objectid,
835 ins.offset, async_extent->pages,
836 async_extent->nr_pages);
837 if (ret) {
838 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
839 struct page *p = async_extent->pages[0];
840 const u64 start = async_extent->start;
841 const u64 end = start + async_extent->ram_size - 1;
842
843 p->mapping = inode->i_mapping;
844 tree->ops->writepage_end_io_hook(p, start, end,
845 NULL, 0);
846 p->mapping = NULL;
847 extent_clear_unlock_delalloc(inode, start, end, NULL, 0,
848 PAGE_END_WRITEBACK |
849 PAGE_SET_ERROR);
850 free_async_extent_pages(async_extent);
851 }
852 alloc_hint = ins.objectid + ins.offset;
853 kfree(async_extent);
854 cond_resched();
855 }
856 return;
857 out_free_reserve:
858 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
859 out_free:
860 extent_clear_unlock_delalloc(inode, async_extent->start,
861 async_extent->start +
862 async_extent->ram_size - 1,
863 NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
864 EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
865 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
866 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
867 PAGE_SET_ERROR);
868 free_async_extent_pages(async_extent);
869 kfree(async_extent);
870 goto again;
871 }
872
873 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
874 u64 num_bytes)
875 {
876 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
877 struct extent_map *em;
878 u64 alloc_hint = 0;
879
880 read_lock(&em_tree->lock);
881 em = search_extent_mapping(em_tree, start, num_bytes);
882 if (em) {
883 /*
884 * if block start isn't an actual block number then find the
885 * first block in this inode and use that as a hint. If that
886 * block is also bogus then just don't worry about it.
887 */
888 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
889 free_extent_map(em);
890 em = search_extent_mapping(em_tree, 0, 0);
891 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
892 alloc_hint = em->block_start;
893 if (em)
894 free_extent_map(em);
895 } else {
896 alloc_hint = em->block_start;
897 free_extent_map(em);
898 }
899 }
900 read_unlock(&em_tree->lock);
901
902 return alloc_hint;
903 }
904
905 /*
906 * when extent_io.c finds a delayed allocation range in the file,
907 * the call backs end up in this code. The basic idea is to
908 * allocate extents on disk for the range, and create ordered data structs
909 * in ram to track those extents.
910 *
911 * locked_page is the page that writepage had locked already. We use
912 * it to make sure we don't do extra locks or unlocks.
913 *
914 * *page_started is set to one if we unlock locked_page and do everything
915 * required to start IO on it. It may be clean and already done with
916 * IO when we return.
917 */
918 static noinline int cow_file_range(struct inode *inode,
919 struct page *locked_page,
920 u64 start, u64 end, int *page_started,
921 unsigned long *nr_written,
922 int unlock)
923 {
924 struct btrfs_root *root = BTRFS_I(inode)->root;
925 u64 alloc_hint = 0;
926 u64 num_bytes;
927 unsigned long ram_size;
928 u64 disk_num_bytes;
929 u64 cur_alloc_size;
930 u64 blocksize = root->sectorsize;
931 struct btrfs_key ins;
932 struct extent_map *em;
933 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
934 int ret = 0;
935
936 if (btrfs_is_free_space_inode(inode)) {
937 WARN_ON_ONCE(1);
938 ret = -EINVAL;
939 goto out_unlock;
940 }
941
942 num_bytes = ALIGN(end - start + 1, blocksize);
943 num_bytes = max(blocksize, num_bytes);
944 disk_num_bytes = num_bytes;
945
946 /* if this is a small write inside eof, kick off defrag */
947 if (num_bytes < 64 * 1024 &&
948 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
949 btrfs_add_inode_defrag(NULL, inode);
950
951 if (start == 0) {
952 /* lets try to make an inline extent */
953 ret = cow_file_range_inline(root, inode, start, end, 0, 0,
954 NULL);
955 if (ret == 0) {
956 extent_clear_unlock_delalloc(inode, start, end, NULL,
957 EXTENT_LOCKED | EXTENT_DELALLOC |
958 EXTENT_DEFRAG, PAGE_UNLOCK |
959 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
960 PAGE_END_WRITEBACK);
961
962 *nr_written = *nr_written +
963 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
964 *page_started = 1;
965 goto out;
966 } else if (ret < 0) {
967 goto out_unlock;
968 }
969 }
970
971 BUG_ON(disk_num_bytes >
972 btrfs_super_total_bytes(root->fs_info->super_copy));
973
974 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
975 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
976
977 while (disk_num_bytes > 0) {
978 unsigned long op;
979
980 cur_alloc_size = disk_num_bytes;
981 ret = btrfs_reserve_extent(root, cur_alloc_size,
982 root->sectorsize, 0, alloc_hint,
983 &ins, 1, 1);
984 if (ret < 0)
985 goto out_unlock;
986
987 em = alloc_extent_map();
988 if (!em) {
989 ret = -ENOMEM;
990 goto out_reserve;
991 }
992 em->start = start;
993 em->orig_start = em->start;
994 ram_size = ins.offset;
995 em->len = ins.offset;
996 em->mod_start = em->start;
997 em->mod_len = em->len;
998
999 em->block_start = ins.objectid;
1000 em->block_len = ins.offset;
1001 em->orig_block_len = ins.offset;
1002 em->ram_bytes = ram_size;
1003 em->bdev = root->fs_info->fs_devices->latest_bdev;
1004 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1005 em->generation = -1;
1006
1007 while (1) {
1008 write_lock(&em_tree->lock);
1009 ret = add_extent_mapping(em_tree, em, 1);
1010 write_unlock(&em_tree->lock);
1011 if (ret != -EEXIST) {
1012 free_extent_map(em);
1013 break;
1014 }
1015 btrfs_drop_extent_cache(inode, start,
1016 start + ram_size - 1, 0);
1017 }
1018 if (ret)
1019 goto out_reserve;
1020
1021 cur_alloc_size = ins.offset;
1022 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
1023 ram_size, cur_alloc_size, 0);
1024 if (ret)
1025 goto out_drop_extent_cache;
1026
1027 if (root->root_key.objectid ==
1028 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1029 ret = btrfs_reloc_clone_csums(inode, start,
1030 cur_alloc_size);
1031 if (ret)
1032 goto out_drop_extent_cache;
1033 }
1034
1035 if (disk_num_bytes < cur_alloc_size)
1036 break;
1037
1038 /* we're not doing compressed IO, don't unlock the first
1039 * page (which the caller expects to stay locked), don't
1040 * clear any dirty bits and don't set any writeback bits
1041 *
1042 * Do set the Private2 bit so we know this page was properly
1043 * setup for writepage
1044 */
1045 op = unlock ? PAGE_UNLOCK : 0;
1046 op |= PAGE_SET_PRIVATE2;
1047
1048 extent_clear_unlock_delalloc(inode, start,
1049 start + ram_size - 1, locked_page,
1050 EXTENT_LOCKED | EXTENT_DELALLOC,
1051 op);
1052 disk_num_bytes -= cur_alloc_size;
1053 num_bytes -= cur_alloc_size;
1054 alloc_hint = ins.objectid + ins.offset;
1055 start += cur_alloc_size;
1056 }
1057 out:
1058 return ret;
1059
1060 out_drop_extent_cache:
1061 btrfs_drop_extent_cache(inode, start, start + ram_size - 1, 0);
1062 out_reserve:
1063 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
1064 out_unlock:
1065 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1066 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
1067 EXTENT_DELALLOC | EXTENT_DEFRAG,
1068 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
1069 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK);
1070 goto out;
1071 }
1072
1073 /*
1074 * work queue call back to started compression on a file and pages
1075 */
1076 static noinline void async_cow_start(struct btrfs_work *work)
1077 {
1078 struct async_cow *async_cow;
1079 int num_added = 0;
1080 async_cow = container_of(work, struct async_cow, work);
1081
1082 compress_file_range(async_cow->inode, async_cow->locked_page,
1083 async_cow->start, async_cow->end, async_cow,
1084 &num_added);
1085 if (num_added == 0) {
1086 btrfs_add_delayed_iput(async_cow->inode);
1087 async_cow->inode = NULL;
1088 }
1089 }
1090
1091 /*
1092 * work queue call back to submit previously compressed pages
1093 */
1094 static noinline void async_cow_submit(struct btrfs_work *work)
1095 {
1096 struct async_cow *async_cow;
1097 struct btrfs_root *root;
1098 unsigned long nr_pages;
1099
1100 async_cow = container_of(work, struct async_cow, work);
1101
1102 root = async_cow->root;
1103 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
1104 PAGE_CACHE_SHIFT;
1105
1106 /*
1107 * atomic_sub_return implies a barrier for waitqueue_active
1108 */
1109 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
1110 5 * 1024 * 1024 &&
1111 waitqueue_active(&root->fs_info->async_submit_wait))
1112 wake_up(&root->fs_info->async_submit_wait);
1113
1114 if (async_cow->inode)
1115 submit_compressed_extents(async_cow->inode, async_cow);
1116 }
1117
1118 static noinline void async_cow_free(struct btrfs_work *work)
1119 {
1120 struct async_cow *async_cow;
1121 async_cow = container_of(work, struct async_cow, work);
1122 if (async_cow->inode)
1123 btrfs_add_delayed_iput(async_cow->inode);
1124 kfree(async_cow);
1125 }
1126
1127 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1128 u64 start, u64 end, int *page_started,
1129 unsigned long *nr_written)
1130 {
1131 struct async_cow *async_cow;
1132 struct btrfs_root *root = BTRFS_I(inode)->root;
1133 unsigned long nr_pages;
1134 u64 cur_end;
1135 int limit = 10 * 1024 * 1024;
1136
1137 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1138 1, 0, NULL, GFP_NOFS);
1139 while (start < end) {
1140 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1141 BUG_ON(!async_cow); /* -ENOMEM */
1142 async_cow->inode = igrab(inode);
1143 async_cow->root = root;
1144 async_cow->locked_page = locked_page;
1145 async_cow->start = start;
1146
1147 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
1148 !btrfs_test_opt(root, FORCE_COMPRESS))
1149 cur_end = end;
1150 else
1151 cur_end = min(end, start + 512 * 1024 - 1);
1152
1153 async_cow->end = cur_end;
1154 INIT_LIST_HEAD(&async_cow->extents);
1155
1156 btrfs_init_work(&async_cow->work,
1157 btrfs_delalloc_helper,
1158 async_cow_start, async_cow_submit,
1159 async_cow_free);
1160
1161 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
1162 PAGE_CACHE_SHIFT;
1163 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
1164
1165 btrfs_queue_work(root->fs_info->delalloc_workers,
1166 &async_cow->work);
1167
1168 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
1169 wait_event(root->fs_info->async_submit_wait,
1170 (atomic_read(&root->fs_info->async_delalloc_pages) <
1171 limit));
1172 }
1173
1174 while (atomic_read(&root->fs_info->async_submit_draining) &&
1175 atomic_read(&root->fs_info->async_delalloc_pages)) {
1176 wait_event(root->fs_info->async_submit_wait,
1177 (atomic_read(&root->fs_info->async_delalloc_pages) ==
1178 0));
1179 }
1180
1181 *nr_written += nr_pages;
1182 start = cur_end + 1;
1183 }
1184 *page_started = 1;
1185 return 0;
1186 }
1187
1188 static noinline int csum_exist_in_range(struct btrfs_root *root,
1189 u64 bytenr, u64 num_bytes)
1190 {
1191 int ret;
1192 struct btrfs_ordered_sum *sums;
1193 LIST_HEAD(list);
1194
1195 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1196 bytenr + num_bytes - 1, &list, 0);
1197 if (ret == 0 && list_empty(&list))
1198 return 0;
1199
1200 while (!list_empty(&list)) {
1201 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1202 list_del(&sums->list);
1203 kfree(sums);
1204 }
1205 return 1;
1206 }
1207
1208 /*
1209 * when nowcow writeback call back. This checks for snapshots or COW copies
1210 * of the extents that exist in the file, and COWs the file as required.
1211 *
1212 * If no cow copies or snapshots exist, we write directly to the existing
1213 * blocks on disk
1214 */
1215 static noinline int run_delalloc_nocow(struct inode *inode,
1216 struct page *locked_page,
1217 u64 start, u64 end, int *page_started, int force,
1218 unsigned long *nr_written)
1219 {
1220 struct btrfs_root *root = BTRFS_I(inode)->root;
1221 struct btrfs_trans_handle *trans;
1222 struct extent_buffer *leaf;
1223 struct btrfs_path *path;
1224 struct btrfs_file_extent_item *fi;
1225 struct btrfs_key found_key;
1226 u64 cow_start;
1227 u64 cur_offset;
1228 u64 extent_end;
1229 u64 extent_offset;
1230 u64 disk_bytenr;
1231 u64 num_bytes;
1232 u64 disk_num_bytes;
1233 u64 ram_bytes;
1234 int extent_type;
1235 int ret, err;
1236 int type;
1237 int nocow;
1238 int check_prev = 1;
1239 bool nolock;
1240 u64 ino = btrfs_ino(inode);
1241
1242 path = btrfs_alloc_path();
1243 if (!path) {
1244 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1245 EXTENT_LOCKED | EXTENT_DELALLOC |
1246 EXTENT_DO_ACCOUNTING |
1247 EXTENT_DEFRAG, PAGE_UNLOCK |
1248 PAGE_CLEAR_DIRTY |
1249 PAGE_SET_WRITEBACK |
1250 PAGE_END_WRITEBACK);
1251 return -ENOMEM;
1252 }
1253
1254 nolock = btrfs_is_free_space_inode(inode);
1255
1256 if (nolock)
1257 trans = btrfs_join_transaction_nolock(root);
1258 else
1259 trans = btrfs_join_transaction(root);
1260
1261 if (IS_ERR(trans)) {
1262 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1263 EXTENT_LOCKED | EXTENT_DELALLOC |
1264 EXTENT_DO_ACCOUNTING |
1265 EXTENT_DEFRAG, PAGE_UNLOCK |
1266 PAGE_CLEAR_DIRTY |
1267 PAGE_SET_WRITEBACK |
1268 PAGE_END_WRITEBACK);
1269 btrfs_free_path(path);
1270 return PTR_ERR(trans);
1271 }
1272
1273 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1274
1275 cow_start = (u64)-1;
1276 cur_offset = start;
1277 while (1) {
1278 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1279 cur_offset, 0);
1280 if (ret < 0)
1281 goto error;
1282 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1283 leaf = path->nodes[0];
1284 btrfs_item_key_to_cpu(leaf, &found_key,
1285 path->slots[0] - 1);
1286 if (found_key.objectid == ino &&
1287 found_key.type == BTRFS_EXTENT_DATA_KEY)
1288 path->slots[0]--;
1289 }
1290 check_prev = 0;
1291 next_slot:
1292 leaf = path->nodes[0];
1293 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1294 ret = btrfs_next_leaf(root, path);
1295 if (ret < 0)
1296 goto error;
1297 if (ret > 0)
1298 break;
1299 leaf = path->nodes[0];
1300 }
1301
1302 nocow = 0;
1303 disk_bytenr = 0;
1304 num_bytes = 0;
1305 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1306
1307 if (found_key.objectid > ino)
1308 break;
1309 if (WARN_ON_ONCE(found_key.objectid < ino) ||
1310 found_key.type < BTRFS_EXTENT_DATA_KEY) {
1311 path->slots[0]++;
1312 goto next_slot;
1313 }
1314 if (found_key.type > BTRFS_EXTENT_DATA_KEY ||
1315 found_key.offset > end)
1316 break;
1317
1318 if (found_key.offset > cur_offset) {
1319 extent_end = found_key.offset;
1320 extent_type = 0;
1321 goto out_check;
1322 }
1323
1324 fi = btrfs_item_ptr(leaf, path->slots[0],
1325 struct btrfs_file_extent_item);
1326 extent_type = btrfs_file_extent_type(leaf, fi);
1327
1328 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1329 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1330 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1331 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1332 extent_offset = btrfs_file_extent_offset(leaf, fi);
1333 extent_end = found_key.offset +
1334 btrfs_file_extent_num_bytes(leaf, fi);
1335 disk_num_bytes =
1336 btrfs_file_extent_disk_num_bytes(leaf, fi);
1337 if (extent_end <= start) {
1338 path->slots[0]++;
1339 goto next_slot;
1340 }
1341 if (disk_bytenr == 0)
1342 goto out_check;
1343 if (btrfs_file_extent_compression(leaf, fi) ||
1344 btrfs_file_extent_encryption(leaf, fi) ||
1345 btrfs_file_extent_other_encoding(leaf, fi))
1346 goto out_check;
1347 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1348 goto out_check;
1349 if (btrfs_extent_readonly(root, disk_bytenr))
1350 goto out_check;
1351 if (btrfs_cross_ref_exist(trans, root, ino,
1352 found_key.offset -
1353 extent_offset, disk_bytenr))
1354 goto out_check;
1355 disk_bytenr += extent_offset;
1356 disk_bytenr += cur_offset - found_key.offset;
1357 num_bytes = min(end + 1, extent_end) - cur_offset;
1358 /*
1359 * if there are pending snapshots for this root,
1360 * we fall into common COW way.
1361 */
1362 if (!nolock) {
1363 err = btrfs_start_write_no_snapshoting(root);
1364 if (!err)
1365 goto out_check;
1366 }
1367 /*
1368 * force cow if csum exists in the range.
1369 * this ensure that csum for a given extent are
1370 * either valid or do not exist.
1371 */
1372 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1373 goto out_check;
1374 nocow = 1;
1375 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1376 extent_end = found_key.offset +
1377 btrfs_file_extent_inline_len(leaf,
1378 path->slots[0], fi);
1379 extent_end = ALIGN(extent_end, root->sectorsize);
1380 } else {
1381 BUG_ON(1);
1382 }
1383 out_check:
1384 if (extent_end <= start) {
1385 path->slots[0]++;
1386 if (!nolock && nocow)
1387 btrfs_end_write_no_snapshoting(root);
1388 goto next_slot;
1389 }
1390 if (!nocow) {
1391 if (cow_start == (u64)-1)
1392 cow_start = cur_offset;
1393 cur_offset = extent_end;
1394 if (cur_offset > end)
1395 break;
1396 path->slots[0]++;
1397 goto next_slot;
1398 }
1399
1400 btrfs_release_path(path);
1401 if (cow_start != (u64)-1) {
1402 ret = cow_file_range(inode, locked_page,
1403 cow_start, found_key.offset - 1,
1404 page_started, nr_written, 1);
1405 if (ret) {
1406 if (!nolock && nocow)
1407 btrfs_end_write_no_snapshoting(root);
1408 goto error;
1409 }
1410 cow_start = (u64)-1;
1411 }
1412
1413 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1414 struct extent_map *em;
1415 struct extent_map_tree *em_tree;
1416 em_tree = &BTRFS_I(inode)->extent_tree;
1417 em = alloc_extent_map();
1418 BUG_ON(!em); /* -ENOMEM */
1419 em->start = cur_offset;
1420 em->orig_start = found_key.offset - extent_offset;
1421 em->len = num_bytes;
1422 em->block_len = num_bytes;
1423 em->block_start = disk_bytenr;
1424 em->orig_block_len = disk_num_bytes;
1425 em->ram_bytes = ram_bytes;
1426 em->bdev = root->fs_info->fs_devices->latest_bdev;
1427 em->mod_start = em->start;
1428 em->mod_len = em->len;
1429 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1430 set_bit(EXTENT_FLAG_FILLING, &em->flags);
1431 em->generation = -1;
1432 while (1) {
1433 write_lock(&em_tree->lock);
1434 ret = add_extent_mapping(em_tree, em, 1);
1435 write_unlock(&em_tree->lock);
1436 if (ret != -EEXIST) {
1437 free_extent_map(em);
1438 break;
1439 }
1440 btrfs_drop_extent_cache(inode, em->start,
1441 em->start + em->len - 1, 0);
1442 }
1443 type = BTRFS_ORDERED_PREALLOC;
1444 } else {
1445 type = BTRFS_ORDERED_NOCOW;
1446 }
1447
1448 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1449 num_bytes, num_bytes, type);
1450 BUG_ON(ret); /* -ENOMEM */
1451
1452 if (root->root_key.objectid ==
1453 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1454 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1455 num_bytes);
1456 if (ret) {
1457 if (!nolock && nocow)
1458 btrfs_end_write_no_snapshoting(root);
1459 goto error;
1460 }
1461 }
1462
1463 extent_clear_unlock_delalloc(inode, cur_offset,
1464 cur_offset + num_bytes - 1,
1465 locked_page, EXTENT_LOCKED |
1466 EXTENT_DELALLOC, PAGE_UNLOCK |
1467 PAGE_SET_PRIVATE2);
1468 if (!nolock && nocow)
1469 btrfs_end_write_no_snapshoting(root);
1470 cur_offset = extent_end;
1471 if (cur_offset > end)
1472 break;
1473 }
1474 btrfs_release_path(path);
1475
1476 if (cur_offset <= end && cow_start == (u64)-1) {
1477 cow_start = cur_offset;
1478 cur_offset = end;
1479 }
1480
1481 if (cow_start != (u64)-1) {
1482 ret = cow_file_range(inode, locked_page, cow_start, end,
1483 page_started, nr_written, 1);
1484 if (ret)
1485 goto error;
1486 }
1487
1488 error:
1489 err = btrfs_end_transaction(trans, root);
1490 if (!ret)
1491 ret = err;
1492
1493 if (ret && cur_offset < end)
1494 extent_clear_unlock_delalloc(inode, cur_offset, end,
1495 locked_page, EXTENT_LOCKED |
1496 EXTENT_DELALLOC | EXTENT_DEFRAG |
1497 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1498 PAGE_CLEAR_DIRTY |
1499 PAGE_SET_WRITEBACK |
1500 PAGE_END_WRITEBACK);
1501 btrfs_free_path(path);
1502 return ret;
1503 }
1504
1505 static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
1506 {
1507
1508 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
1509 !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC))
1510 return 0;
1511
1512 /*
1513 * @defrag_bytes is a hint value, no spinlock held here,
1514 * if is not zero, it means the file is defragging.
1515 * Force cow if given extent needs to be defragged.
1516 */
1517 if (BTRFS_I(inode)->defrag_bytes &&
1518 test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
1519 EXTENT_DEFRAG, 0, NULL))
1520 return 1;
1521
1522 return 0;
1523 }
1524
1525 /*
1526 * extent_io.c call back to do delayed allocation processing
1527 */
1528 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1529 u64 start, u64 end, int *page_started,
1530 unsigned long *nr_written)
1531 {
1532 int ret;
1533 int force_cow = need_force_cow(inode, start, end);
1534
1535 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
1536 ret = run_delalloc_nocow(inode, locked_page, start, end,
1537 page_started, 1, nr_written);
1538 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
1539 ret = run_delalloc_nocow(inode, locked_page, start, end,
1540 page_started, 0, nr_written);
1541 } else if (!inode_need_compress(inode)) {
1542 ret = cow_file_range(inode, locked_page, start, end,
1543 page_started, nr_written, 1);
1544 } else {
1545 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1546 &BTRFS_I(inode)->runtime_flags);
1547 ret = cow_file_range_async(inode, locked_page, start, end,
1548 page_started, nr_written);
1549 }
1550 return ret;
1551 }
1552
1553 static void btrfs_split_extent_hook(struct inode *inode,
1554 struct extent_state *orig, u64 split)
1555 {
1556 u64 size;
1557
1558 /* not delalloc, ignore it */
1559 if (!(orig->state & EXTENT_DELALLOC))
1560 return;
1561
1562 size = orig->end - orig->start + 1;
1563 if (size > BTRFS_MAX_EXTENT_SIZE) {
1564 u64 num_extents;
1565 u64 new_size;
1566
1567 /*
1568 * See the explanation in btrfs_merge_extent_hook, the same
1569 * applies here, just in reverse.
1570 */
1571 new_size = orig->end - split + 1;
1572 num_extents = div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1573 BTRFS_MAX_EXTENT_SIZE);
1574 new_size = split - orig->start;
1575 num_extents += div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1576 BTRFS_MAX_EXTENT_SIZE);
1577 if (div64_u64(size + BTRFS_MAX_EXTENT_SIZE - 1,
1578 BTRFS_MAX_EXTENT_SIZE) >= num_extents)
1579 return;
1580 }
1581
1582 spin_lock(&BTRFS_I(inode)->lock);
1583 BTRFS_I(inode)->outstanding_extents++;
1584 spin_unlock(&BTRFS_I(inode)->lock);
1585 }
1586
1587 /*
1588 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1589 * extents so we can keep track of new extents that are just merged onto old
1590 * extents, such as when we are doing sequential writes, so we can properly
1591 * account for the metadata space we'll need.
1592 */
1593 static void btrfs_merge_extent_hook(struct inode *inode,
1594 struct extent_state *new,
1595 struct extent_state *other)
1596 {
1597 u64 new_size, old_size;
1598 u64 num_extents;
1599
1600 /* not delalloc, ignore it */
1601 if (!(other->state & EXTENT_DELALLOC))
1602 return;
1603
1604 if (new->start > other->start)
1605 new_size = new->end - other->start + 1;
1606 else
1607 new_size = other->end - new->start + 1;
1608
1609 /* we're not bigger than the max, unreserve the space and go */
1610 if (new_size <= BTRFS_MAX_EXTENT_SIZE) {
1611 spin_lock(&BTRFS_I(inode)->lock);
1612 BTRFS_I(inode)->outstanding_extents--;
1613 spin_unlock(&BTRFS_I(inode)->lock);
1614 return;
1615 }
1616
1617 /*
1618 * We have to add up either side to figure out how many extents were
1619 * accounted for before we merged into one big extent. If the number of
1620 * extents we accounted for is <= the amount we need for the new range
1621 * then we can return, otherwise drop. Think of it like this
1622 *
1623 * [ 4k][MAX_SIZE]
1624 *
1625 * So we've grown the extent by a MAX_SIZE extent, this would mean we
1626 * need 2 outstanding extents, on one side we have 1 and the other side
1627 * we have 1 so they are == and we can return. But in this case
1628 *
1629 * [MAX_SIZE+4k][MAX_SIZE+4k]
1630 *
1631 * Each range on their own accounts for 2 extents, but merged together
1632 * they are only 3 extents worth of accounting, so we need to drop in
1633 * this case.
1634 */
1635 old_size = other->end - other->start + 1;
1636 num_extents = div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
1637 BTRFS_MAX_EXTENT_SIZE);
1638 old_size = new->end - new->start + 1;
1639 num_extents += div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
1640 BTRFS_MAX_EXTENT_SIZE);
1641
1642 if (div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1643 BTRFS_MAX_EXTENT_SIZE) >= num_extents)
1644 return;
1645
1646 spin_lock(&BTRFS_I(inode)->lock);
1647 BTRFS_I(inode)->outstanding_extents--;
1648 spin_unlock(&BTRFS_I(inode)->lock);
1649 }
1650
1651 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1652 struct inode *inode)
1653 {
1654 spin_lock(&root->delalloc_lock);
1655 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1656 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1657 &root->delalloc_inodes);
1658 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1659 &BTRFS_I(inode)->runtime_flags);
1660 root->nr_delalloc_inodes++;
1661 if (root->nr_delalloc_inodes == 1) {
1662 spin_lock(&root->fs_info->delalloc_root_lock);
1663 BUG_ON(!list_empty(&root->delalloc_root));
1664 list_add_tail(&root->delalloc_root,
1665 &root->fs_info->delalloc_roots);
1666 spin_unlock(&root->fs_info->delalloc_root_lock);
1667 }
1668 }
1669 spin_unlock(&root->delalloc_lock);
1670 }
1671
1672 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1673 struct inode *inode)
1674 {
1675 spin_lock(&root->delalloc_lock);
1676 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1677 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1678 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1679 &BTRFS_I(inode)->runtime_flags);
1680 root->nr_delalloc_inodes--;
1681 if (!root->nr_delalloc_inodes) {
1682 spin_lock(&root->fs_info->delalloc_root_lock);
1683 BUG_ON(list_empty(&root->delalloc_root));
1684 list_del_init(&root->delalloc_root);
1685 spin_unlock(&root->fs_info->delalloc_root_lock);
1686 }
1687 }
1688 spin_unlock(&root->delalloc_lock);
1689 }
1690
1691 /*
1692 * extent_io.c set_bit_hook, used to track delayed allocation
1693 * bytes in this file, and to maintain the list of inodes that
1694 * have pending delalloc work to be done.
1695 */
1696 static void btrfs_set_bit_hook(struct inode *inode,
1697 struct extent_state *state, unsigned *bits)
1698 {
1699
1700 if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
1701 WARN_ON(1);
1702 /*
1703 * set_bit and clear bit hooks normally require _irqsave/restore
1704 * but in this case, we are only testing for the DELALLOC
1705 * bit, which is only set or cleared with irqs on
1706 */
1707 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1708 struct btrfs_root *root = BTRFS_I(inode)->root;
1709 u64 len = state->end + 1 - state->start;
1710 bool do_list = !btrfs_is_free_space_inode(inode);
1711
1712 if (*bits & EXTENT_FIRST_DELALLOC) {
1713 *bits &= ~EXTENT_FIRST_DELALLOC;
1714 } else {
1715 spin_lock(&BTRFS_I(inode)->lock);
1716 BTRFS_I(inode)->outstanding_extents++;
1717 spin_unlock(&BTRFS_I(inode)->lock);
1718 }
1719
1720 /* For sanity tests */
1721 if (btrfs_test_is_dummy_root(root))
1722 return;
1723
1724 __percpu_counter_add(&root->fs_info->delalloc_bytes, len,
1725 root->fs_info->delalloc_batch);
1726 spin_lock(&BTRFS_I(inode)->lock);
1727 BTRFS_I(inode)->delalloc_bytes += len;
1728 if (*bits & EXTENT_DEFRAG)
1729 BTRFS_I(inode)->defrag_bytes += len;
1730 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1731 &BTRFS_I(inode)->runtime_flags))
1732 btrfs_add_delalloc_inodes(root, inode);
1733 spin_unlock(&BTRFS_I(inode)->lock);
1734 }
1735 }
1736
1737 /*
1738 * extent_io.c clear_bit_hook, see set_bit_hook for why
1739 */
1740 static void btrfs_clear_bit_hook(struct inode *inode,
1741 struct extent_state *state,
1742 unsigned *bits)
1743 {
1744 u64 len = state->end + 1 - state->start;
1745 u64 num_extents = div64_u64(len + BTRFS_MAX_EXTENT_SIZE -1,
1746 BTRFS_MAX_EXTENT_SIZE);
1747
1748 spin_lock(&BTRFS_I(inode)->lock);
1749 if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG))
1750 BTRFS_I(inode)->defrag_bytes -= len;
1751 spin_unlock(&BTRFS_I(inode)->lock);
1752
1753 /*
1754 * set_bit and clear bit hooks normally require _irqsave/restore
1755 * but in this case, we are only testing for the DELALLOC
1756 * bit, which is only set or cleared with irqs on
1757 */
1758 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1759 struct btrfs_root *root = BTRFS_I(inode)->root;
1760 bool do_list = !btrfs_is_free_space_inode(inode);
1761
1762 if (*bits & EXTENT_FIRST_DELALLOC) {
1763 *bits &= ~EXTENT_FIRST_DELALLOC;
1764 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1765 spin_lock(&BTRFS_I(inode)->lock);
1766 BTRFS_I(inode)->outstanding_extents -= num_extents;
1767 spin_unlock(&BTRFS_I(inode)->lock);
1768 }
1769
1770 /*
1771 * We don't reserve metadata space for space cache inodes so we
1772 * don't need to call dellalloc_release_metadata if there is an
1773 * error.
1774 */
1775 if (*bits & EXTENT_DO_ACCOUNTING &&
1776 root != root->fs_info->tree_root)
1777 btrfs_delalloc_release_metadata(inode, len);
1778
1779 /* For sanity tests. */
1780 if (btrfs_test_is_dummy_root(root))
1781 return;
1782
1783 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1784 && do_list && !(state->state & EXTENT_NORESERVE))
1785 btrfs_free_reserved_data_space_noquota(inode,
1786 state->start, len);
1787
1788 __percpu_counter_add(&root->fs_info->delalloc_bytes, -len,
1789 root->fs_info->delalloc_batch);
1790 spin_lock(&BTRFS_I(inode)->lock);
1791 BTRFS_I(inode)->delalloc_bytes -= len;
1792 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1793 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1794 &BTRFS_I(inode)->runtime_flags))
1795 btrfs_del_delalloc_inode(root, inode);
1796 spin_unlock(&BTRFS_I(inode)->lock);
1797 }
1798 }
1799
1800 /*
1801 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1802 * we don't create bios that span stripes or chunks
1803 */
1804 int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset,
1805 size_t size, struct bio *bio,
1806 unsigned long bio_flags)
1807 {
1808 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1809 u64 logical = (u64)bio->bi_iter.bi_sector << 9;
1810 u64 length = 0;
1811 u64 map_length;
1812 int ret;
1813
1814 if (bio_flags & EXTENT_BIO_COMPRESSED)
1815 return 0;
1816
1817 length = bio->bi_iter.bi_size;
1818 map_length = length;
1819 ret = btrfs_map_block(root->fs_info, rw, logical,
1820 &map_length, NULL, 0);
1821 /* Will always return 0 with map_multi == NULL */
1822 BUG_ON(ret < 0);
1823 if (map_length < length + size)
1824 return 1;
1825 return 0;
1826 }
1827
1828 /*
1829 * in order to insert checksums into the metadata in large chunks,
1830 * we wait until bio submission time. All the pages in the bio are
1831 * checksummed and sums are attached onto the ordered extent record.
1832 *
1833 * At IO completion time the cums attached on the ordered extent record
1834 * are inserted into the btree
1835 */
1836 static int __btrfs_submit_bio_start(struct inode *inode, int rw,
1837 struct bio *bio, int mirror_num,
1838 unsigned long bio_flags,
1839 u64 bio_offset)
1840 {
1841 struct btrfs_root *root = BTRFS_I(inode)->root;
1842 int ret = 0;
1843
1844 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1845 BUG_ON(ret); /* -ENOMEM */
1846 return 0;
1847 }
1848
1849 /*
1850 * in order to insert checksums into the metadata in large chunks,
1851 * we wait until bio submission time. All the pages in the bio are
1852 * checksummed and sums are attached onto the ordered extent record.
1853 *
1854 * At IO completion time the cums attached on the ordered extent record
1855 * are inserted into the btree
1856 */
1857 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1858 int mirror_num, unsigned long bio_flags,
1859 u64 bio_offset)
1860 {
1861 struct btrfs_root *root = BTRFS_I(inode)->root;
1862 int ret;
1863
1864 ret = btrfs_map_bio(root, rw, bio, mirror_num, 1);
1865 if (ret) {
1866 bio->bi_error = ret;
1867 bio_endio(bio);
1868 }
1869 return ret;
1870 }
1871
1872 /*
1873 * extent_io.c submission hook. This does the right thing for csum calculation
1874 * on write, or reading the csums from the tree before a read
1875 */
1876 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1877 int mirror_num, unsigned long bio_flags,
1878 u64 bio_offset)
1879 {
1880 struct btrfs_root *root = BTRFS_I(inode)->root;
1881 enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA;
1882 int ret = 0;
1883 int skip_sum;
1884 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1885
1886 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1887
1888 if (btrfs_is_free_space_inode(inode))
1889 metadata = BTRFS_WQ_ENDIO_FREE_SPACE;
1890
1891 if (!(rw & REQ_WRITE)) {
1892 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
1893 if (ret)
1894 goto out;
1895
1896 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1897 ret = btrfs_submit_compressed_read(inode, bio,
1898 mirror_num,
1899 bio_flags);
1900 goto out;
1901 } else if (!skip_sum) {
1902 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1903 if (ret)
1904 goto out;
1905 }
1906 goto mapit;
1907 } else if (async && !skip_sum) {
1908 /* csum items have already been cloned */
1909 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1910 goto mapit;
1911 /* we're doing a write, do the async checksumming */
1912 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1913 inode, rw, bio, mirror_num,
1914 bio_flags, bio_offset,
1915 __btrfs_submit_bio_start,
1916 __btrfs_submit_bio_done);
1917 goto out;
1918 } else if (!skip_sum) {
1919 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1920 if (ret)
1921 goto out;
1922 }
1923
1924 mapit:
1925 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
1926
1927 out:
1928 if (ret < 0) {
1929 bio->bi_error = ret;
1930 bio_endio(bio);
1931 }
1932 return ret;
1933 }
1934
1935 /*
1936 * given a list of ordered sums record them in the inode. This happens
1937 * at IO completion time based on sums calculated at bio submission time.
1938 */
1939 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1940 struct inode *inode, u64 file_offset,
1941 struct list_head *list)
1942 {
1943 struct btrfs_ordered_sum *sum;
1944
1945 list_for_each_entry(sum, list, list) {
1946 trans->adding_csums = 1;
1947 btrfs_csum_file_blocks(trans,
1948 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1949 trans->adding_csums = 0;
1950 }
1951 return 0;
1952 }
1953
1954 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1955 struct extent_state **cached_state)
1956 {
1957 WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0);
1958 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1959 cached_state, GFP_NOFS);
1960 }
1961
1962 /* see btrfs_writepage_start_hook for details on why this is required */
1963 struct btrfs_writepage_fixup {
1964 struct page *page;
1965 struct btrfs_work work;
1966 };
1967
1968 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1969 {
1970 struct btrfs_writepage_fixup *fixup;
1971 struct btrfs_ordered_extent *ordered;
1972 struct extent_state *cached_state = NULL;
1973 struct page *page;
1974 struct inode *inode;
1975 u64 page_start;
1976 u64 page_end;
1977 int ret;
1978
1979 fixup = container_of(work, struct btrfs_writepage_fixup, work);
1980 page = fixup->page;
1981 again:
1982 lock_page(page);
1983 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
1984 ClearPageChecked(page);
1985 goto out_page;
1986 }
1987
1988 inode = page->mapping->host;
1989 page_start = page_offset(page);
1990 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
1991
1992 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0,
1993 &cached_state);
1994
1995 /* already ordered? We're done */
1996 if (PagePrivate2(page))
1997 goto out;
1998
1999 ordered = btrfs_lookup_ordered_extent(inode, page_start);
2000 if (ordered) {
2001 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
2002 page_end, &cached_state, GFP_NOFS);
2003 unlock_page(page);
2004 btrfs_start_ordered_extent(inode, ordered, 1);
2005 btrfs_put_ordered_extent(ordered);
2006 goto again;
2007 }
2008
2009 ret = btrfs_delalloc_reserve_space(inode, page_start,
2010 PAGE_CACHE_SIZE);
2011 if (ret) {
2012 mapping_set_error(page->mapping, ret);
2013 end_extent_writepage(page, ret, page_start, page_end);
2014 ClearPageChecked(page);
2015 goto out;
2016 }
2017
2018 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
2019 ClearPageChecked(page);
2020 set_page_dirty(page);
2021 out:
2022 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
2023 &cached_state, GFP_NOFS);
2024 out_page:
2025 unlock_page(page);
2026 page_cache_release(page);
2027 kfree(fixup);
2028 }
2029
2030 /*
2031 * There are a few paths in the higher layers of the kernel that directly
2032 * set the page dirty bit without asking the filesystem if it is a
2033 * good idea. This causes problems because we want to make sure COW
2034 * properly happens and the data=ordered rules are followed.
2035 *
2036 * In our case any range that doesn't have the ORDERED bit set
2037 * hasn't been properly setup for IO. We kick off an async process
2038 * to fix it up. The async helper will wait for ordered extents, set
2039 * the delalloc bit and make it safe to write the page.
2040 */
2041 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
2042 {
2043 struct inode *inode = page->mapping->host;
2044 struct btrfs_writepage_fixup *fixup;
2045 struct btrfs_root *root = BTRFS_I(inode)->root;
2046
2047 /* this page is properly in the ordered list */
2048 if (TestClearPagePrivate2(page))
2049 return 0;
2050
2051 if (PageChecked(page))
2052 return -EAGAIN;
2053
2054 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
2055 if (!fixup)
2056 return -EAGAIN;
2057
2058 SetPageChecked(page);
2059 page_cache_get(page);
2060 btrfs_init_work(&fixup->work, btrfs_fixup_helper,
2061 btrfs_writepage_fixup_worker, NULL, NULL);
2062 fixup->page = page;
2063 btrfs_queue_work(root->fs_info->fixup_workers, &fixup->work);
2064 return -EBUSY;
2065 }
2066
2067 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
2068 struct inode *inode, u64 file_pos,
2069 u64 disk_bytenr, u64 disk_num_bytes,
2070 u64 num_bytes, u64 ram_bytes,
2071 u8 compression, u8 encryption,
2072 u16 other_encoding, int extent_type)
2073 {
2074 struct btrfs_root *root = BTRFS_I(inode)->root;
2075 struct btrfs_file_extent_item *fi;
2076 struct btrfs_path *path;
2077 struct extent_buffer *leaf;
2078 struct btrfs_key ins;
2079 int extent_inserted = 0;
2080 int ret;
2081
2082 path = btrfs_alloc_path();
2083 if (!path)
2084 return -ENOMEM;
2085
2086 /*
2087 * we may be replacing one extent in the tree with another.
2088 * The new extent is pinned in the extent map, and we don't want
2089 * to drop it from the cache until it is completely in the btree.
2090 *
2091 * So, tell btrfs_drop_extents to leave this extent in the cache.
2092 * the caller is expected to unpin it and allow it to be merged
2093 * with the others.
2094 */
2095 ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
2096 file_pos + num_bytes, NULL, 0,
2097 1, sizeof(*fi), &extent_inserted);
2098 if (ret)
2099 goto out;
2100
2101 if (!extent_inserted) {
2102 ins.objectid = btrfs_ino(inode);
2103 ins.offset = file_pos;
2104 ins.type = BTRFS_EXTENT_DATA_KEY;
2105
2106 path->leave_spinning = 1;
2107 ret = btrfs_insert_empty_item(trans, root, path, &ins,
2108 sizeof(*fi));
2109 if (ret)
2110 goto out;
2111 }
2112 leaf = path->nodes[0];
2113 fi = btrfs_item_ptr(leaf, path->slots[0],
2114 struct btrfs_file_extent_item);
2115 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
2116 btrfs_set_file_extent_type(leaf, fi, extent_type);
2117 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
2118 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
2119 btrfs_set_file_extent_offset(leaf, fi, 0);
2120 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2121 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
2122 btrfs_set_file_extent_compression(leaf, fi, compression);
2123 btrfs_set_file_extent_encryption(leaf, fi, encryption);
2124 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
2125
2126 btrfs_mark_buffer_dirty(leaf);
2127 btrfs_release_path(path);
2128
2129 inode_add_bytes(inode, num_bytes);
2130
2131 ins.objectid = disk_bytenr;
2132 ins.offset = disk_num_bytes;
2133 ins.type = BTRFS_EXTENT_ITEM_KEY;
2134 ret = btrfs_alloc_reserved_file_extent(trans, root,
2135 root->root_key.objectid,
2136 btrfs_ino(inode), file_pos,
2137 ram_bytes, &ins);
2138 /*
2139 * Release the reserved range from inode dirty range map, as it is
2140 * already moved into delayed_ref_head
2141 */
2142 btrfs_qgroup_release_data(inode, file_pos, ram_bytes);
2143 out:
2144 btrfs_free_path(path);
2145
2146 return ret;
2147 }
2148
2149 /* snapshot-aware defrag */
2150 struct sa_defrag_extent_backref {
2151 struct rb_node node;
2152 struct old_sa_defrag_extent *old;
2153 u64 root_id;
2154 u64 inum;
2155 u64 file_pos;
2156 u64 extent_offset;
2157 u64 num_bytes;
2158 u64 generation;
2159 };
2160
2161 struct old_sa_defrag_extent {
2162 struct list_head list;
2163 struct new_sa_defrag_extent *new;
2164
2165 u64 extent_offset;
2166 u64 bytenr;
2167 u64 offset;
2168 u64 len;
2169 int count;
2170 };
2171
2172 struct new_sa_defrag_extent {
2173 struct rb_root root;
2174 struct list_head head;
2175 struct btrfs_path *path;
2176 struct inode *inode;
2177 u64 file_pos;
2178 u64 len;
2179 u64 bytenr;
2180 u64 disk_len;
2181 u8 compress_type;
2182 };
2183
2184 static int backref_comp(struct sa_defrag_extent_backref *b1,
2185 struct sa_defrag_extent_backref *b2)
2186 {
2187 if (b1->root_id < b2->root_id)
2188 return -1;
2189 else if (b1->root_id > b2->root_id)
2190 return 1;
2191
2192 if (b1->inum < b2->inum)
2193 return -1;
2194 else if (b1->inum > b2->inum)
2195 return 1;
2196
2197 if (b1->file_pos < b2->file_pos)
2198 return -1;
2199 else if (b1->file_pos > b2->file_pos)
2200 return 1;
2201
2202 /*
2203 * [------------------------------] ===> (a range of space)
2204 * |<--->| |<---->| =============> (fs/file tree A)
2205 * |<---------------------------->| ===> (fs/file tree B)
2206 *
2207 * A range of space can refer to two file extents in one tree while
2208 * refer to only one file extent in another tree.
2209 *
2210 * So we may process a disk offset more than one time(two extents in A)
2211 * and locate at the same extent(one extent in B), then insert two same
2212 * backrefs(both refer to the extent in B).
2213 */
2214 return 0;
2215 }
2216
2217 static void backref_insert(struct rb_root *root,
2218 struct sa_defrag_extent_backref *backref)
2219 {
2220 struct rb_node **p = &root->rb_node;
2221 struct rb_node *parent = NULL;
2222 struct sa_defrag_extent_backref *entry;
2223 int ret;
2224
2225 while (*p) {
2226 parent = *p;
2227 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2228
2229 ret = backref_comp(backref, entry);
2230 if (ret < 0)
2231 p = &(*p)->rb_left;
2232 else
2233 p = &(*p)->rb_right;
2234 }
2235
2236 rb_link_node(&backref->node, parent, p);
2237 rb_insert_color(&backref->node, root);
2238 }
2239
2240 /*
2241 * Note the backref might has changed, and in this case we just return 0.
2242 */
2243 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2244 void *ctx)
2245 {
2246 struct btrfs_file_extent_item *extent;
2247 struct btrfs_fs_info *fs_info;
2248 struct old_sa_defrag_extent *old = ctx;
2249 struct new_sa_defrag_extent *new = old->new;
2250 struct btrfs_path *path = new->path;
2251 struct btrfs_key key;
2252 struct btrfs_root *root;
2253 struct sa_defrag_extent_backref *backref;
2254 struct extent_buffer *leaf;
2255 struct inode *inode = new->inode;
2256 int slot;
2257 int ret;
2258 u64 extent_offset;
2259 u64 num_bytes;
2260
2261 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2262 inum == btrfs_ino(inode))
2263 return 0;
2264
2265 key.objectid = root_id;
2266 key.type = BTRFS_ROOT_ITEM_KEY;
2267 key.offset = (u64)-1;
2268
2269 fs_info = BTRFS_I(inode)->root->fs_info;
2270 root = btrfs_read_fs_root_no_name(fs_info, &key);
2271 if (IS_ERR(root)) {
2272 if (PTR_ERR(root) == -ENOENT)
2273 return 0;
2274 WARN_ON(1);
2275 pr_debug("inum=%llu, offset=%llu, root_id=%llu\n",
2276 inum, offset, root_id);
2277 return PTR_ERR(root);
2278 }
2279
2280 key.objectid = inum;
2281 key.type = BTRFS_EXTENT_DATA_KEY;
2282 if (offset > (u64)-1 << 32)
2283 key.offset = 0;
2284 else
2285 key.offset = offset;
2286
2287 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2288 if (WARN_ON(ret < 0))
2289 return ret;
2290 ret = 0;
2291
2292 while (1) {
2293 cond_resched();
2294
2295 leaf = path->nodes[0];
2296 slot = path->slots[0];
2297
2298 if (slot >= btrfs_header_nritems(leaf)) {
2299 ret = btrfs_next_leaf(root, path);
2300 if (ret < 0) {
2301 goto out;
2302 } else if (ret > 0) {
2303 ret = 0;
2304 goto out;
2305 }
2306 continue;
2307 }
2308
2309 path->slots[0]++;
2310
2311 btrfs_item_key_to_cpu(leaf, &key, slot);
2312
2313 if (key.objectid > inum)
2314 goto out;
2315
2316 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2317 continue;
2318
2319 extent = btrfs_item_ptr(leaf, slot,
2320 struct btrfs_file_extent_item);
2321
2322 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2323 continue;
2324
2325 /*
2326 * 'offset' refers to the exact key.offset,
2327 * NOT the 'offset' field in btrfs_extent_data_ref, ie.
2328 * (key.offset - extent_offset).
2329 */
2330 if (key.offset != offset)
2331 continue;
2332
2333 extent_offset = btrfs_file_extent_offset(leaf, extent);
2334 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2335
2336 if (extent_offset >= old->extent_offset + old->offset +
2337 old->len || extent_offset + num_bytes <=
2338 old->extent_offset + old->offset)
2339 continue;
2340 break;
2341 }
2342
2343 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2344 if (!backref) {
2345 ret = -ENOENT;
2346 goto out;
2347 }
2348
2349 backref->root_id = root_id;
2350 backref->inum = inum;
2351 backref->file_pos = offset;
2352 backref->num_bytes = num_bytes;
2353 backref->extent_offset = extent_offset;
2354 backref->generation = btrfs_file_extent_generation(leaf, extent);
2355 backref->old = old;
2356 backref_insert(&new->root, backref);
2357 old->count++;
2358 out:
2359 btrfs_release_path(path);
2360 WARN_ON(ret);
2361 return ret;
2362 }
2363
2364 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2365 struct new_sa_defrag_extent *new)
2366 {
2367 struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info;
2368 struct old_sa_defrag_extent *old, *tmp;
2369 int ret;
2370
2371 new->path = path;
2372
2373 list_for_each_entry_safe(old, tmp, &new->head, list) {
2374 ret = iterate_inodes_from_logical(old->bytenr +
2375 old->extent_offset, fs_info,
2376 path, record_one_backref,
2377 old);
2378 if (ret < 0 && ret != -ENOENT)
2379 return false;
2380
2381 /* no backref to be processed for this extent */
2382 if (!old->count) {
2383 list_del(&old->list);
2384 kfree(old);
2385 }
2386 }
2387
2388 if (list_empty(&new->head))
2389 return false;
2390
2391 return true;
2392 }
2393
2394 static int relink_is_mergable(struct extent_buffer *leaf,
2395 struct btrfs_file_extent_item *fi,
2396 struct new_sa_defrag_extent *new)
2397 {
2398 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
2399 return 0;
2400
2401 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2402 return 0;
2403
2404 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
2405 return 0;
2406
2407 if (btrfs_file_extent_encryption(leaf, fi) ||
2408 btrfs_file_extent_other_encoding(leaf, fi))
2409 return 0;
2410
2411 return 1;
2412 }
2413
2414 /*
2415 * Note the backref might has changed, and in this case we just return 0.
2416 */
2417 static noinline int relink_extent_backref(struct btrfs_path *path,
2418 struct sa_defrag_extent_backref *prev,
2419 struct sa_defrag_extent_backref *backref)
2420 {
2421 struct btrfs_file_extent_item *extent;
2422 struct btrfs_file_extent_item *item;
2423 struct btrfs_ordered_extent *ordered;
2424 struct btrfs_trans_handle *trans;
2425 struct btrfs_fs_info *fs_info;
2426 struct btrfs_root *root;
2427 struct btrfs_key key;
2428 struct extent_buffer *leaf;
2429 struct old_sa_defrag_extent *old = backref->old;
2430 struct new_sa_defrag_extent *new = old->new;
2431 struct inode *src_inode = new->inode;
2432 struct inode *inode;
2433 struct extent_state *cached = NULL;
2434 int ret = 0;
2435 u64 start;
2436 u64 len;
2437 u64 lock_start;
2438 u64 lock_end;
2439 bool merge = false;
2440 int index;
2441
2442 if (prev && prev->root_id == backref->root_id &&
2443 prev->inum == backref->inum &&
2444 prev->file_pos + prev->num_bytes == backref->file_pos)
2445 merge = true;
2446
2447 /* step 1: get root */
2448 key.objectid = backref->root_id;
2449 key.type = BTRFS_ROOT_ITEM_KEY;
2450 key.offset = (u64)-1;
2451
2452 fs_info = BTRFS_I(src_inode)->root->fs_info;
2453 index = srcu_read_lock(&fs_info->subvol_srcu);
2454
2455 root = btrfs_read_fs_root_no_name(fs_info, &key);
2456 if (IS_ERR(root)) {
2457 srcu_read_unlock(&fs_info->subvol_srcu, index);
2458 if (PTR_ERR(root) == -ENOENT)
2459 return 0;
2460 return PTR_ERR(root);
2461 }
2462
2463 if (btrfs_root_readonly(root)) {
2464 srcu_read_unlock(&fs_info->subvol_srcu, index);
2465 return 0;
2466 }
2467
2468 /* step 2: get inode */
2469 key.objectid = backref->inum;
2470 key.type = BTRFS_INODE_ITEM_KEY;
2471 key.offset = 0;
2472
2473 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2474 if (IS_ERR(inode)) {
2475 srcu_read_unlock(&fs_info->subvol_srcu, index);
2476 return 0;
2477 }
2478
2479 srcu_read_unlock(&fs_info->subvol_srcu, index);
2480
2481 /* step 3: relink backref */
2482 lock_start = backref->file_pos;
2483 lock_end = backref->file_pos + backref->num_bytes - 1;
2484 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2485 0, &cached);
2486
2487 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2488 if (ordered) {
2489 btrfs_put_ordered_extent(ordered);
2490 goto out_unlock;
2491 }
2492
2493 trans = btrfs_join_transaction(root);
2494 if (IS_ERR(trans)) {
2495 ret = PTR_ERR(trans);
2496 goto out_unlock;
2497 }
2498
2499 key.objectid = backref->inum;
2500 key.type = BTRFS_EXTENT_DATA_KEY;
2501 key.offset = backref->file_pos;
2502
2503 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2504 if (ret < 0) {
2505 goto out_free_path;
2506 } else if (ret > 0) {
2507 ret = 0;
2508 goto out_free_path;
2509 }
2510
2511 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2512 struct btrfs_file_extent_item);
2513
2514 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2515 backref->generation)
2516 goto out_free_path;
2517
2518 btrfs_release_path(path);
2519
2520 start = backref->file_pos;
2521 if (backref->extent_offset < old->extent_offset + old->offset)
2522 start += old->extent_offset + old->offset -
2523 backref->extent_offset;
2524
2525 len = min(backref->extent_offset + backref->num_bytes,
2526 old->extent_offset + old->offset + old->len);
2527 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2528
2529 ret = btrfs_drop_extents(trans, root, inode, start,
2530 start + len, 1);
2531 if (ret)
2532 goto out_free_path;
2533 again:
2534 key.objectid = btrfs_ino(inode);
2535 key.type = BTRFS_EXTENT_DATA_KEY;
2536 key.offset = start;
2537
2538 path->leave_spinning = 1;
2539 if (merge) {
2540 struct btrfs_file_extent_item *fi;
2541 u64 extent_len;
2542 struct btrfs_key found_key;
2543
2544 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2545 if (ret < 0)
2546 goto out_free_path;
2547
2548 path->slots[0]--;
2549 leaf = path->nodes[0];
2550 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2551
2552 fi = btrfs_item_ptr(leaf, path->slots[0],
2553 struct btrfs_file_extent_item);
2554 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2555
2556 if (extent_len + found_key.offset == start &&
2557 relink_is_mergable(leaf, fi, new)) {
2558 btrfs_set_file_extent_num_bytes(leaf, fi,
2559 extent_len + len);
2560 btrfs_mark_buffer_dirty(leaf);
2561 inode_add_bytes(inode, len);
2562
2563 ret = 1;
2564 goto out_free_path;
2565 } else {
2566 merge = false;
2567 btrfs_release_path(path);
2568 goto again;
2569 }
2570 }
2571
2572 ret = btrfs_insert_empty_item(trans, root, path, &key,
2573 sizeof(*extent));
2574 if (ret) {
2575 btrfs_abort_transaction(trans, root, ret);
2576 goto out_free_path;
2577 }
2578
2579 leaf = path->nodes[0];
2580 item = btrfs_item_ptr(leaf, path->slots[0],
2581 struct btrfs_file_extent_item);
2582 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2583 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2584 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2585 btrfs_set_file_extent_num_bytes(leaf, item, len);
2586 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2587 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2588 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2589 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2590 btrfs_set_file_extent_encryption(leaf, item, 0);
2591 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2592
2593 btrfs_mark_buffer_dirty(leaf);
2594 inode_add_bytes(inode, len);
2595 btrfs_release_path(path);
2596
2597 ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
2598 new->disk_len, 0,
2599 backref->root_id, backref->inum,
2600 new->file_pos); /* start - extent_offset */
2601 if (ret) {
2602 btrfs_abort_transaction(trans, root, ret);
2603 goto out_free_path;
2604 }
2605
2606 ret = 1;
2607 out_free_path:
2608 btrfs_release_path(path);
2609 path->leave_spinning = 0;
2610 btrfs_end_transaction(trans, root);
2611 out_unlock:
2612 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2613 &cached, GFP_NOFS);
2614 iput(inode);
2615 return ret;
2616 }
2617
2618 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
2619 {
2620 struct old_sa_defrag_extent *old, *tmp;
2621
2622 if (!new)
2623 return;
2624
2625 list_for_each_entry_safe(old, tmp, &new->head, list) {
2626 kfree(old);
2627 }
2628 kfree(new);
2629 }
2630
2631 static void relink_file_extents(struct new_sa_defrag_extent *new)
2632 {
2633 struct btrfs_path *path;
2634 struct sa_defrag_extent_backref *backref;
2635 struct sa_defrag_extent_backref *prev = NULL;
2636 struct inode *inode;
2637 struct btrfs_root *root;
2638 struct rb_node *node;
2639 int ret;
2640
2641 inode = new->inode;
2642 root = BTRFS_I(inode)->root;
2643
2644 path = btrfs_alloc_path();
2645 if (!path)
2646 return;
2647
2648 if (!record_extent_backrefs(path, new)) {
2649 btrfs_free_path(path);
2650 goto out;
2651 }
2652 btrfs_release_path(path);
2653
2654 while (1) {
2655 node = rb_first(&new->root);
2656 if (!node)
2657 break;
2658 rb_erase(node, &new->root);
2659
2660 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2661
2662 ret = relink_extent_backref(path, prev, backref);
2663 WARN_ON(ret < 0);
2664
2665 kfree(prev);
2666
2667 if (ret == 1)
2668 prev = backref;
2669 else
2670 prev = NULL;
2671 cond_resched();
2672 }
2673 kfree(prev);
2674
2675 btrfs_free_path(path);
2676 out:
2677 free_sa_defrag_extent(new);
2678
2679 atomic_dec(&root->fs_info->defrag_running);
2680 wake_up(&root->fs_info->transaction_wait);
2681 }
2682
2683 static struct new_sa_defrag_extent *
2684 record_old_file_extents(struct inode *inode,
2685 struct btrfs_ordered_extent *ordered)
2686 {
2687 struct btrfs_root *root = BTRFS_I(inode)->root;
2688 struct btrfs_path *path;
2689 struct btrfs_key key;
2690 struct old_sa_defrag_extent *old;
2691 struct new_sa_defrag_extent *new;
2692 int ret;
2693
2694 new = kmalloc(sizeof(*new), GFP_NOFS);
2695 if (!new)
2696 return NULL;
2697
2698 new->inode = inode;
2699 new->file_pos = ordered->file_offset;
2700 new->len = ordered->len;
2701 new->bytenr = ordered->start;
2702 new->disk_len = ordered->disk_len;
2703 new->compress_type = ordered->compress_type;
2704 new->root = RB_ROOT;
2705 INIT_LIST_HEAD(&new->head);
2706
2707 path = btrfs_alloc_path();
2708 if (!path)
2709 goto out_kfree;
2710
2711 key.objectid = btrfs_ino(inode);
2712 key.type = BTRFS_EXTENT_DATA_KEY;
2713 key.offset = new->file_pos;
2714
2715 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2716 if (ret < 0)
2717 goto out_free_path;
2718 if (ret > 0 && path->slots[0] > 0)
2719 path->slots[0]--;
2720
2721 /* find out all the old extents for the file range */
2722 while (1) {
2723 struct btrfs_file_extent_item *extent;
2724 struct extent_buffer *l;
2725 int slot;
2726 u64 num_bytes;
2727 u64 offset;
2728 u64 end;
2729 u64 disk_bytenr;
2730 u64 extent_offset;
2731
2732 l = path->nodes[0];
2733 slot = path->slots[0];
2734
2735 if (slot >= btrfs_header_nritems(l)) {
2736 ret = btrfs_next_leaf(root, path);
2737 if (ret < 0)
2738 goto out_free_path;
2739 else if (ret > 0)
2740 break;
2741 continue;
2742 }
2743
2744 btrfs_item_key_to_cpu(l, &key, slot);
2745
2746 if (key.objectid != btrfs_ino(inode))
2747 break;
2748 if (key.type != BTRFS_EXTENT_DATA_KEY)
2749 break;
2750 if (key.offset >= new->file_pos + new->len)
2751 break;
2752
2753 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2754
2755 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2756 if (key.offset + num_bytes < new->file_pos)
2757 goto next;
2758
2759 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2760 if (!disk_bytenr)
2761 goto next;
2762
2763 extent_offset = btrfs_file_extent_offset(l, extent);
2764
2765 old = kmalloc(sizeof(*old), GFP_NOFS);
2766 if (!old)
2767 goto out_free_path;
2768
2769 offset = max(new->file_pos, key.offset);
2770 end = min(new->file_pos + new->len, key.offset + num_bytes);
2771
2772 old->bytenr = disk_bytenr;
2773 old->extent_offset = extent_offset;
2774 old->offset = offset - key.offset;
2775 old->len = end - offset;
2776 old->new = new;
2777 old->count = 0;
2778 list_add_tail(&old->list, &new->head);
2779 next:
2780 path->slots[0]++;
2781 cond_resched();
2782 }
2783
2784 btrfs_free_path(path);
2785 atomic_inc(&root->fs_info->defrag_running);
2786
2787 return new;
2788
2789 out_free_path:
2790 btrfs_free_path(path);
2791 out_kfree:
2792 free_sa_defrag_extent(new);
2793 return NULL;
2794 }
2795
2796 static void btrfs_release_delalloc_bytes(struct btrfs_root *root,
2797 u64 start, u64 len)
2798 {
2799 struct btrfs_block_group_cache *cache;
2800
2801 cache = btrfs_lookup_block_group(root->fs_info, start);
2802 ASSERT(cache);
2803
2804 spin_lock(&cache->lock);
2805 cache->delalloc_bytes -= len;
2806 spin_unlock(&cache->lock);
2807
2808 btrfs_put_block_group(cache);
2809 }
2810
2811 /* as ordered data IO finishes, this gets called so we can finish
2812 * an ordered extent if the range of bytes in the file it covers are
2813 * fully written.
2814 */
2815 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2816 {
2817 struct inode *inode = ordered_extent->inode;
2818 struct btrfs_root *root = BTRFS_I(inode)->root;
2819 struct btrfs_trans_handle *trans = NULL;
2820 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2821 struct extent_state *cached_state = NULL;
2822 struct new_sa_defrag_extent *new = NULL;
2823 int compress_type = 0;
2824 int ret = 0;
2825 u64 logical_len = ordered_extent->len;
2826 bool nolock;
2827 bool truncated = false;
2828
2829 nolock = btrfs_is_free_space_inode(inode);
2830
2831 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2832 ret = -EIO;
2833 goto out;
2834 }
2835
2836 btrfs_free_io_failure_record(inode, ordered_extent->file_offset,
2837 ordered_extent->file_offset +
2838 ordered_extent->len - 1);
2839
2840 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
2841 truncated = true;
2842 logical_len = ordered_extent->truncated_len;
2843 /* Truncated the entire extent, don't bother adding */
2844 if (!logical_len)
2845 goto out;
2846 }
2847
2848 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2849 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2850
2851 /*
2852 * For mwrite(mmap + memset to write) case, we still reserve
2853 * space for NOCOW range.
2854 * As NOCOW won't cause a new delayed ref, just free the space
2855 */
2856 btrfs_qgroup_free_data(inode, ordered_extent->file_offset,
2857 ordered_extent->len);
2858 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2859 if (nolock)
2860 trans = btrfs_join_transaction_nolock(root);
2861 else
2862 trans = btrfs_join_transaction(root);
2863 if (IS_ERR(trans)) {
2864 ret = PTR_ERR(trans);
2865 trans = NULL;
2866 goto out;
2867 }
2868 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2869 ret = btrfs_update_inode_fallback(trans, root, inode);
2870 if (ret) /* -ENOMEM or corruption */
2871 btrfs_abort_transaction(trans, root, ret);
2872 goto out;
2873 }
2874
2875 lock_extent_bits(io_tree, ordered_extent->file_offset,
2876 ordered_extent->file_offset + ordered_extent->len - 1,
2877 0, &cached_state);
2878
2879 ret = test_range_bit(io_tree, ordered_extent->file_offset,
2880 ordered_extent->file_offset + ordered_extent->len - 1,
2881 EXTENT_DEFRAG, 1, cached_state);
2882 if (ret) {
2883 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2884 if (0 && last_snapshot >= BTRFS_I(inode)->generation)
2885 /* the inode is shared */
2886 new = record_old_file_extents(inode, ordered_extent);
2887
2888 clear_extent_bit(io_tree, ordered_extent->file_offset,
2889 ordered_extent->file_offset + ordered_extent->len - 1,
2890 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
2891 }
2892
2893 if (nolock)
2894 trans = btrfs_join_transaction_nolock(root);
2895 else
2896 trans = btrfs_join_transaction(root);
2897 if (IS_ERR(trans)) {
2898 ret = PTR_ERR(trans);
2899 trans = NULL;
2900 goto out_unlock;
2901 }
2902
2903 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2904
2905 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
2906 compress_type = ordered_extent->compress_type;
2907 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
2908 BUG_ON(compress_type);
2909 ret = btrfs_mark_extent_written(trans, inode,
2910 ordered_extent->file_offset,
2911 ordered_extent->file_offset +
2912 logical_len);
2913 } else {
2914 BUG_ON(root == root->fs_info->tree_root);
2915 ret = insert_reserved_file_extent(trans, inode,
2916 ordered_extent->file_offset,
2917 ordered_extent->start,
2918 ordered_extent->disk_len,
2919 logical_len, logical_len,
2920 compress_type, 0, 0,
2921 BTRFS_FILE_EXTENT_REG);
2922 if (!ret)
2923 btrfs_release_delalloc_bytes(root,
2924 ordered_extent->start,
2925 ordered_extent->disk_len);
2926 }
2927 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
2928 ordered_extent->file_offset, ordered_extent->len,
2929 trans->transid);
2930 if (ret < 0) {
2931 btrfs_abort_transaction(trans, root, ret);
2932 goto out_unlock;
2933 }
2934
2935 add_pending_csums(trans, inode, ordered_extent->file_offset,
2936 &ordered_extent->list);
2937
2938 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2939 ret = btrfs_update_inode_fallback(trans, root, inode);
2940 if (ret) { /* -ENOMEM or corruption */
2941 btrfs_abort_transaction(trans, root, ret);
2942 goto out_unlock;
2943 }
2944 ret = 0;
2945 out_unlock:
2946 unlock_extent_cached(io_tree, ordered_extent->file_offset,
2947 ordered_extent->file_offset +
2948 ordered_extent->len - 1, &cached_state, GFP_NOFS);
2949 out:
2950 if (root != root->fs_info->tree_root)
2951 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
2952 if (trans)
2953 btrfs_end_transaction(trans, root);
2954
2955 if (ret || truncated) {
2956 u64 start, end;
2957
2958 if (truncated)
2959 start = ordered_extent->file_offset + logical_len;
2960 else
2961 start = ordered_extent->file_offset;
2962 end = ordered_extent->file_offset + ordered_extent->len - 1;
2963 clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS);
2964
2965 /* Drop the cache for the part of the extent we didn't write. */
2966 btrfs_drop_extent_cache(inode, start, end, 0);
2967
2968 /*
2969 * If the ordered extent had an IOERR or something else went
2970 * wrong we need to return the space for this ordered extent
2971 * back to the allocator. We only free the extent in the
2972 * truncated case if we didn't write out the extent at all.
2973 */
2974 if ((ret || !logical_len) &&
2975 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
2976 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
2977 btrfs_free_reserved_extent(root, ordered_extent->start,
2978 ordered_extent->disk_len, 1);
2979 }
2980
2981
2982 /*
2983 * This needs to be done to make sure anybody waiting knows we are done
2984 * updating everything for this ordered extent.
2985 */
2986 btrfs_remove_ordered_extent(inode, ordered_extent);
2987
2988 /* for snapshot-aware defrag */
2989 if (new) {
2990 if (ret) {
2991 free_sa_defrag_extent(new);
2992 atomic_dec(&root->fs_info->defrag_running);
2993 } else {
2994 relink_file_extents(new);
2995 }
2996 }
2997
2998 /* once for us */
2999 btrfs_put_ordered_extent(ordered_extent);
3000 /* once for the tree */
3001 btrfs_put_ordered_extent(ordered_extent);
3002
3003 return ret;
3004 }
3005
3006 static void finish_ordered_fn(struct btrfs_work *work)
3007 {
3008 struct btrfs_ordered_extent *ordered_extent;
3009 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
3010 btrfs_finish_ordered_io(ordered_extent);
3011 }
3012
3013 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
3014 struct extent_state *state, int uptodate)
3015 {
3016 struct inode *inode = page->mapping->host;
3017 struct btrfs_root *root = BTRFS_I(inode)->root;
3018 struct btrfs_ordered_extent *ordered_extent = NULL;
3019 struct btrfs_workqueue *wq;
3020 btrfs_work_func_t func;
3021
3022 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
3023
3024 ClearPagePrivate2(page);
3025 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
3026 end - start + 1, uptodate))
3027 return 0;
3028
3029 if (btrfs_is_free_space_inode(inode)) {
3030 wq = root->fs_info->endio_freespace_worker;
3031 func = btrfs_freespace_write_helper;
3032 } else {
3033 wq = root->fs_info->endio_write_workers;
3034 func = btrfs_endio_write_helper;
3035 }
3036
3037 btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL,
3038 NULL);
3039 btrfs_queue_work(wq, &ordered_extent->work);
3040
3041 return 0;
3042 }
3043
3044 static int __readpage_endio_check(struct inode *inode,
3045 struct btrfs_io_bio *io_bio,
3046 int icsum, struct page *page,
3047 int pgoff, u64 start, size_t len)
3048 {
3049 char *kaddr;
3050 u32 csum_expected;
3051 u32 csum = ~(u32)0;
3052
3053 csum_expected = *(((u32 *)io_bio->csum) + icsum);
3054
3055 kaddr = kmap_atomic(page);
3056 csum = btrfs_csum_data(kaddr + pgoff, csum, len);
3057 btrfs_csum_final(csum, (char *)&csum);
3058 if (csum != csum_expected)
3059 goto zeroit;
3060
3061 kunmap_atomic(kaddr);
3062 return 0;
3063 zeroit:
3064 btrfs_warn_rl(BTRFS_I(inode)->root->fs_info,
3065 "csum failed ino %llu off %llu csum %u expected csum %u",
3066 btrfs_ino(inode), start, csum, csum_expected);
3067 memset(kaddr + pgoff, 1, len);
3068 flush_dcache_page(page);
3069 kunmap_atomic(kaddr);
3070 if (csum_expected == 0)
3071 return 0;
3072 return -EIO;
3073 }
3074
3075 /*
3076 * when reads are done, we need to check csums to verify the data is correct
3077 * if there's a match, we allow the bio to finish. If not, the code in
3078 * extent_io.c will try to find good copies for us.
3079 */
3080 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
3081 u64 phy_offset, struct page *page,
3082 u64 start, u64 end, int mirror)
3083 {
3084 size_t offset = start - page_offset(page);
3085 struct inode *inode = page->mapping->host;
3086 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3087 struct btrfs_root *root = BTRFS_I(inode)->root;
3088
3089 if (PageChecked(page)) {
3090 ClearPageChecked(page);
3091 return 0;
3092 }
3093
3094 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
3095 return 0;
3096
3097 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
3098 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
3099 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
3100 GFP_NOFS);
3101 return 0;
3102 }
3103
3104 phy_offset >>= inode->i_sb->s_blocksize_bits;
3105 return __readpage_endio_check(inode, io_bio, phy_offset, page, offset,
3106 start, (size_t)(end - start + 1));
3107 }
3108
3109 struct delayed_iput {
3110 struct list_head list;
3111 struct inode *inode;
3112 };
3113
3114 /* JDM: If this is fs-wide, why can't we add a pointer to
3115 * btrfs_inode instead and avoid the allocation? */
3116 void btrfs_add_delayed_iput(struct inode *inode)
3117 {
3118 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
3119 struct delayed_iput *delayed;
3120
3121 if (atomic_add_unless(&inode->i_count, -1, 1))
3122 return;
3123
3124 delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL);
3125 delayed->inode = inode;
3126
3127 spin_lock(&fs_info->delayed_iput_lock);
3128 list_add_tail(&delayed->list, &fs_info->delayed_iputs);
3129 spin_unlock(&fs_info->delayed_iput_lock);
3130 }
3131
3132 void btrfs_run_delayed_iputs(struct btrfs_root *root)
3133 {
3134 LIST_HEAD(list);
3135 struct btrfs_fs_info *fs_info = root->fs_info;
3136 struct delayed_iput *delayed;
3137 int empty;
3138
3139 spin_lock(&fs_info->delayed_iput_lock);
3140 empty = list_empty(&fs_info->delayed_iputs);
3141 spin_unlock(&fs_info->delayed_iput_lock);
3142 if (empty)
3143 return;
3144
3145 down_read(&fs_info->delayed_iput_sem);
3146
3147 spin_lock(&fs_info->delayed_iput_lock);
3148 list_splice_init(&fs_info->delayed_iputs, &list);
3149 spin_unlock(&fs_info->delayed_iput_lock);
3150
3151 while (!list_empty(&list)) {
3152 delayed = list_entry(list.next, struct delayed_iput, list);
3153 list_del(&delayed->list);
3154 iput(delayed->inode);
3155 kfree(delayed);
3156 }
3157
3158 up_read(&root->fs_info->delayed_iput_sem);
3159 }
3160
3161 /*
3162 * This is called in transaction commit time. If there are no orphan
3163 * files in the subvolume, it removes orphan item and frees block_rsv
3164 * structure.
3165 */
3166 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
3167 struct btrfs_root *root)
3168 {
3169 struct btrfs_block_rsv *block_rsv;
3170 int ret;
3171
3172 if (atomic_read(&root->orphan_inodes) ||
3173 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
3174 return;
3175
3176 spin_lock(&root->orphan_lock);
3177 if (atomic_read(&root->orphan_inodes)) {
3178 spin_unlock(&root->orphan_lock);
3179 return;
3180 }
3181
3182 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
3183 spin_unlock(&root->orphan_lock);
3184 return;
3185 }
3186
3187 block_rsv = root->orphan_block_rsv;
3188 root->orphan_block_rsv = NULL;
3189 spin_unlock(&root->orphan_lock);
3190
3191 if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) &&
3192 btrfs_root_refs(&root->root_item) > 0) {
3193 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
3194 root->root_key.objectid);
3195 if (ret)
3196 btrfs_abort_transaction(trans, root, ret);
3197 else
3198 clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
3199 &root->state);
3200 }
3201
3202 if (block_rsv) {
3203 WARN_ON(block_rsv->size > 0);
3204 btrfs_free_block_rsv(root, block_rsv);
3205 }
3206 }
3207
3208 /*
3209 * This creates an orphan entry for the given inode in case something goes
3210 * wrong in the middle of an unlink/truncate.
3211 *
3212 * NOTE: caller of this function should reserve 5 units of metadata for
3213 * this function.
3214 */
3215 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
3216 {
3217 struct btrfs_root *root = BTRFS_I(inode)->root;
3218 struct btrfs_block_rsv *block_rsv = NULL;
3219 int reserve = 0;
3220 int insert = 0;
3221 int ret;
3222
3223 if (!root->orphan_block_rsv) {
3224 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
3225 if (!block_rsv)
3226 return -ENOMEM;
3227 }
3228
3229 spin_lock(&root->orphan_lock);
3230 if (!root->orphan_block_rsv) {
3231 root->orphan_block_rsv = block_rsv;
3232 } else if (block_rsv) {
3233 btrfs_free_block_rsv(root, block_rsv);
3234 block_rsv = NULL;
3235 }
3236
3237 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3238 &BTRFS_I(inode)->runtime_flags)) {
3239 #if 0
3240 /*
3241 * For proper ENOSPC handling, we should do orphan
3242 * cleanup when mounting. But this introduces backward
3243 * compatibility issue.
3244 */
3245 if (!xchg(&root->orphan_item_inserted, 1))
3246 insert = 2;
3247 else
3248 insert = 1;
3249 #endif
3250 insert = 1;
3251 atomic_inc(&root->orphan_inodes);
3252 }
3253
3254 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3255 &BTRFS_I(inode)->runtime_flags))
3256 reserve = 1;
3257 spin_unlock(&root->orphan_lock);
3258
3259 /* grab metadata reservation from transaction handle */
3260 if (reserve) {
3261 ret = btrfs_orphan_reserve_metadata(trans, inode);
3262 BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */
3263 }
3264
3265 /* insert an orphan item to track this unlinked/truncated file */
3266 if (insert >= 1) {
3267 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3268 if (ret) {
3269 atomic_dec(&root->orphan_inodes);
3270 if (reserve) {
3271 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3272 &BTRFS_I(inode)->runtime_flags);
3273 btrfs_orphan_release_metadata(inode);
3274 }
3275 if (ret != -EEXIST) {
3276 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3277 &BTRFS_I(inode)->runtime_flags);
3278 btrfs_abort_transaction(trans, root, ret);
3279 return ret;
3280 }
3281 }
3282 ret = 0;
3283 }
3284
3285 /* insert an orphan item to track subvolume contains orphan files */
3286 if (insert >= 2) {
3287 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
3288 root->root_key.objectid);
3289 if (ret && ret != -EEXIST) {
3290 btrfs_abort_transaction(trans, root, ret);
3291 return ret;
3292 }
3293 }
3294 return 0;
3295 }
3296
3297 /*
3298 * We have done the truncate/delete so we can go ahead and remove the orphan
3299 * item for this particular inode.
3300 */
3301 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3302 struct inode *inode)
3303 {
3304 struct btrfs_root *root = BTRFS_I(inode)->root;
3305 int delete_item = 0;
3306 int release_rsv = 0;
3307 int ret = 0;
3308
3309 spin_lock(&root->orphan_lock);
3310 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3311 &BTRFS_I(inode)->runtime_flags))
3312 delete_item = 1;
3313
3314 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3315 &BTRFS_I(inode)->runtime_flags))
3316 release_rsv = 1;
3317 spin_unlock(&root->orphan_lock);
3318
3319 if (delete_item) {
3320 atomic_dec(&root->orphan_inodes);
3321 if (trans)
3322 ret = btrfs_del_orphan_item(trans, root,
3323 btrfs_ino(inode));
3324 }
3325
3326 if (release_rsv)
3327 btrfs_orphan_release_metadata(inode);
3328
3329 return ret;
3330 }
3331
3332 /*
3333 * this cleans up any orphans that may be left on the list from the last use
3334 * of this root.
3335 */
3336 int btrfs_orphan_cleanup(struct btrfs_root *root)
3337 {
3338 struct btrfs_path *path;
3339 struct extent_buffer *leaf;
3340 struct btrfs_key key, found_key;
3341 struct btrfs_trans_handle *trans;
3342 struct inode *inode;
3343 u64 last_objectid = 0;
3344 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3345
3346 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3347 return 0;
3348
3349 path = btrfs_alloc_path();
3350 if (!path) {
3351 ret = -ENOMEM;
3352 goto out;
3353 }
3354 path->reada = -1;
3355
3356 key.objectid = BTRFS_ORPHAN_OBJECTID;
3357 key.type = BTRFS_ORPHAN_ITEM_KEY;
3358 key.offset = (u64)-1;
3359
3360 while (1) {
3361 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3362 if (ret < 0)
3363 goto out;
3364
3365 /*
3366 * if ret == 0 means we found what we were searching for, which
3367 * is weird, but possible, so only screw with path if we didn't
3368 * find the key and see if we have stuff that matches
3369 */
3370 if (ret > 0) {
3371 ret = 0;
3372 if (path->slots[0] == 0)
3373 break;
3374 path->slots[0]--;
3375 }
3376
3377 /* pull out the item */
3378 leaf = path->nodes[0];
3379 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3380
3381 /* make sure the item matches what we want */
3382 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3383 break;
3384 if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
3385 break;
3386
3387 /* release the path since we're done with it */
3388 btrfs_release_path(path);
3389
3390 /*
3391 * this is where we are basically btrfs_lookup, without the
3392 * crossing root thing. we store the inode number in the
3393 * offset of the orphan item.
3394 */
3395
3396 if (found_key.offset == last_objectid) {
3397 btrfs_err(root->fs_info,
3398 "Error removing orphan entry, stopping orphan cleanup");
3399 ret = -EINVAL;
3400 goto out;
3401 }
3402
3403 last_objectid = found_key.offset;
3404
3405 found_key.objectid = found_key.offset;
3406 found_key.type = BTRFS_INODE_ITEM_KEY;
3407 found_key.offset = 0;
3408 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
3409 ret = PTR_ERR_OR_ZERO(inode);
3410 if (ret && ret != -ESTALE)
3411 goto out;
3412
3413 if (ret == -ESTALE && root == root->fs_info->tree_root) {
3414 struct btrfs_root *dead_root;
3415 struct btrfs_fs_info *fs_info = root->fs_info;
3416 int is_dead_root = 0;
3417
3418 /*
3419 * this is an orphan in the tree root. Currently these
3420 * could come from 2 sources:
3421 * a) a snapshot deletion in progress
3422 * b) a free space cache inode
3423 * We need to distinguish those two, as the snapshot
3424 * orphan must not get deleted.
3425 * find_dead_roots already ran before us, so if this
3426 * is a snapshot deletion, we should find the root
3427 * in the dead_roots list
3428 */
3429 spin_lock(&fs_info->trans_lock);
3430 list_for_each_entry(dead_root, &fs_info->dead_roots,
3431 root_list) {
3432 if (dead_root->root_key.objectid ==
3433 found_key.objectid) {
3434 is_dead_root = 1;
3435 break;
3436 }
3437 }
3438 spin_unlock(&fs_info->trans_lock);
3439 if (is_dead_root) {
3440 /* prevent this orphan from being found again */
3441 key.offset = found_key.objectid - 1;
3442 continue;
3443 }
3444 }
3445 /*
3446 * Inode is already gone but the orphan item is still there,
3447 * kill the orphan item.
3448 */
3449 if (ret == -ESTALE) {
3450 trans = btrfs_start_transaction(root, 1);
3451 if (IS_ERR(trans)) {
3452 ret = PTR_ERR(trans);
3453 goto out;
3454 }
3455 btrfs_debug(root->fs_info, "auto deleting %Lu",
3456 found_key.objectid);
3457 ret = btrfs_del_orphan_item(trans, root,
3458 found_key.objectid);
3459 btrfs_end_transaction(trans, root);
3460 if (ret)
3461 goto out;
3462 continue;
3463 }
3464
3465 /*
3466 * add this inode to the orphan list so btrfs_orphan_del does
3467 * the proper thing when we hit it
3468 */
3469 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3470 &BTRFS_I(inode)->runtime_flags);
3471 atomic_inc(&root->orphan_inodes);
3472
3473 /* if we have links, this was a truncate, lets do that */
3474 if (inode->i_nlink) {
3475 if (WARN_ON(!S_ISREG(inode->i_mode))) {
3476 iput(inode);
3477 continue;
3478 }
3479 nr_truncate++;
3480
3481 /* 1 for the orphan item deletion. */
3482 trans = btrfs_start_transaction(root, 1);
3483 if (IS_ERR(trans)) {
3484 iput(inode);
3485 ret = PTR_ERR(trans);
3486 goto out;
3487 }
3488 ret = btrfs_orphan_add(trans, inode);
3489 btrfs_end_transaction(trans, root);
3490 if (ret) {
3491 iput(inode);
3492 goto out;
3493 }
3494
3495 ret = btrfs_truncate(inode);
3496 if (ret)
3497 btrfs_orphan_del(NULL, inode);
3498 } else {
3499 nr_unlink++;
3500 }
3501
3502 /* this will do delete_inode and everything for us */
3503 iput(inode);
3504 if (ret)
3505 goto out;
3506 }
3507 /* release the path since we're done with it */
3508 btrfs_release_path(path);
3509
3510 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3511
3512 if (root->orphan_block_rsv)
3513 btrfs_block_rsv_release(root, root->orphan_block_rsv,
3514 (u64)-1);
3515
3516 if (root->orphan_block_rsv ||
3517 test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
3518 trans = btrfs_join_transaction(root);
3519 if (!IS_ERR(trans))
3520 btrfs_end_transaction(trans, root);
3521 }
3522
3523 if (nr_unlink)
3524 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink);
3525 if (nr_truncate)
3526 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate);
3527
3528 out:
3529 if (ret)
3530 btrfs_err(root->fs_info,
3531 "could not do orphan cleanup %d", ret);
3532 btrfs_free_path(path);
3533 return ret;
3534 }
3535
3536 /*
3537 * very simple check to peek ahead in the leaf looking for xattrs. If we
3538 * don't find any xattrs, we know there can't be any acls.
3539 *
3540 * slot is the slot the inode is in, objectid is the objectid of the inode
3541 */
3542 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3543 int slot, u64 objectid,
3544 int *first_xattr_slot)
3545 {
3546 u32 nritems = btrfs_header_nritems(leaf);
3547 struct btrfs_key found_key;
3548 static u64 xattr_access = 0;
3549 static u64 xattr_default = 0;
3550 int scanned = 0;
3551
3552 if (!xattr_access) {
3553 xattr_access = btrfs_name_hash(POSIX_ACL_XATTR_ACCESS,
3554 strlen(POSIX_ACL_XATTR_ACCESS));
3555 xattr_default = btrfs_name_hash(POSIX_ACL_XATTR_DEFAULT,
3556 strlen(POSIX_ACL_XATTR_DEFAULT));
3557 }
3558
3559 slot++;
3560 *first_xattr_slot = -1;
3561 while (slot < nritems) {
3562 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3563
3564 /* we found a different objectid, there must not be acls */
3565 if (found_key.objectid != objectid)
3566 return 0;
3567
3568 /* we found an xattr, assume we've got an acl */
3569 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3570 if (*first_xattr_slot == -1)
3571 *first_xattr_slot = slot;
3572 if (found_key.offset == xattr_access ||
3573 found_key.offset == xattr_default)
3574 return 1;
3575 }
3576
3577 /*
3578 * we found a key greater than an xattr key, there can't
3579 * be any acls later on
3580 */
3581 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3582 return 0;
3583
3584 slot++;
3585 scanned++;
3586
3587 /*
3588 * it goes inode, inode backrefs, xattrs, extents,
3589 * so if there are a ton of hard links to an inode there can
3590 * be a lot of backrefs. Don't waste time searching too hard,
3591 * this is just an optimization
3592 */
3593 if (scanned >= 8)
3594 break;
3595 }
3596 /* we hit the end of the leaf before we found an xattr or
3597 * something larger than an xattr. We have to assume the inode
3598 * has acls
3599 */
3600 if (*first_xattr_slot == -1)
3601 *first_xattr_slot = slot;
3602 return 1;
3603 }
3604
3605 /*
3606 * read an inode from the btree into the in-memory inode
3607 */
3608 static void btrfs_read_locked_inode(struct inode *inode)
3609 {
3610 struct btrfs_path *path;
3611 struct extent_buffer *leaf;
3612 struct btrfs_inode_item *inode_item;
3613 struct btrfs_root *root = BTRFS_I(inode)->root;
3614 struct btrfs_key location;
3615 unsigned long ptr;
3616 int maybe_acls;
3617 u32 rdev;
3618 int ret;
3619 bool filled = false;
3620 int first_xattr_slot;
3621
3622 ret = btrfs_fill_inode(inode, &rdev);
3623 if (!ret)
3624 filled = true;
3625
3626 path = btrfs_alloc_path();
3627 if (!path)
3628 goto make_bad;
3629
3630 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3631
3632 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3633 if (ret)
3634 goto make_bad;
3635
3636 leaf = path->nodes[0];
3637
3638 if (filled)
3639 goto cache_index;
3640
3641 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3642 struct btrfs_inode_item);
3643 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3644 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3645 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3646 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3647 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
3648
3649 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
3650 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
3651
3652 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
3653 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
3654
3655 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
3656 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
3657
3658 BTRFS_I(inode)->i_otime.tv_sec =
3659 btrfs_timespec_sec(leaf, &inode_item->otime);
3660 BTRFS_I(inode)->i_otime.tv_nsec =
3661 btrfs_timespec_nsec(leaf, &inode_item->otime);
3662
3663 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3664 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3665 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3666
3667 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
3668 inode->i_generation = BTRFS_I(inode)->generation;
3669 inode->i_rdev = 0;
3670 rdev = btrfs_inode_rdev(leaf, inode_item);
3671
3672 BTRFS_I(inode)->index_cnt = (u64)-1;
3673 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3674
3675 cache_index:
3676 /*
3677 * If we were modified in the current generation and evicted from memory
3678 * and then re-read we need to do a full sync since we don't have any
3679 * idea about which extents were modified before we were evicted from
3680 * cache.
3681 *
3682 * This is required for both inode re-read from disk and delayed inode
3683 * in delayed_nodes_tree.
3684 */
3685 if (BTRFS_I(inode)->last_trans == root->fs_info->generation)
3686 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3687 &BTRFS_I(inode)->runtime_flags);
3688
3689 /*
3690 * We don't persist the id of the transaction where an unlink operation
3691 * against the inode was last made. So here we assume the inode might
3692 * have been evicted, and therefore the exact value of last_unlink_trans
3693 * lost, and set it to last_trans to avoid metadata inconsistencies
3694 * between the inode and its parent if the inode is fsync'ed and the log
3695 * replayed. For example, in the scenario:
3696 *
3697 * touch mydir/foo
3698 * ln mydir/foo mydir/bar
3699 * sync
3700 * unlink mydir/bar
3701 * echo 2 > /proc/sys/vm/drop_caches # evicts inode
3702 * xfs_io -c fsync mydir/foo
3703 * <power failure>
3704 * mount fs, triggers fsync log replay
3705 *
3706 * We must make sure that when we fsync our inode foo we also log its
3707 * parent inode, otherwise after log replay the parent still has the
3708 * dentry with the "bar" name but our inode foo has a link count of 1
3709 * and doesn't have an inode ref with the name "bar" anymore.
3710 *
3711 * Setting last_unlink_trans to last_trans is a pessimistic approach,
3712 * but it guarantees correctness at the expense of ocassional full
3713 * transaction commits on fsync if our inode is a directory, or if our
3714 * inode is not a directory, logging its parent unnecessarily.
3715 */
3716 BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans;
3717
3718 path->slots[0]++;
3719 if (inode->i_nlink != 1 ||
3720 path->slots[0] >= btrfs_header_nritems(leaf))
3721 goto cache_acl;
3722
3723 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
3724 if (location.objectid != btrfs_ino(inode))
3725 goto cache_acl;
3726
3727 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3728 if (location.type == BTRFS_INODE_REF_KEY) {
3729 struct btrfs_inode_ref *ref;
3730
3731 ref = (struct btrfs_inode_ref *)ptr;
3732 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
3733 } else if (location.type == BTRFS_INODE_EXTREF_KEY) {
3734 struct btrfs_inode_extref *extref;
3735
3736 extref = (struct btrfs_inode_extref *)ptr;
3737 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
3738 extref);
3739 }
3740 cache_acl:
3741 /*
3742 * try to precache a NULL acl entry for files that don't have
3743 * any xattrs or acls
3744 */
3745 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3746 btrfs_ino(inode), &first_xattr_slot);
3747 if (first_xattr_slot != -1) {
3748 path->slots[0] = first_xattr_slot;
3749 ret = btrfs_load_inode_props(inode, path);
3750 if (ret)
3751 btrfs_err(root->fs_info,
3752 "error loading props for ino %llu (root %llu): %d",
3753 btrfs_ino(inode),
3754 root->root_key.objectid, ret);
3755 }
3756 btrfs_free_path(path);
3757
3758 if (!maybe_acls)
3759 cache_no_acl(inode);
3760
3761 switch (inode->i_mode & S_IFMT) {
3762 case S_IFREG:
3763 inode->i_mapping->a_ops = &btrfs_aops;
3764 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3765 inode->i_fop = &btrfs_file_operations;
3766 inode->i_op = &btrfs_file_inode_operations;
3767 break;
3768 case S_IFDIR:
3769 inode->i_fop = &btrfs_dir_file_operations;
3770 if (root == root->fs_info->tree_root)
3771 inode->i_op = &btrfs_dir_ro_inode_operations;
3772 else
3773 inode->i_op = &btrfs_dir_inode_operations;
3774 break;
3775 case S_IFLNK:
3776 inode->i_op = &btrfs_symlink_inode_operations;
3777 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3778 break;
3779 default:
3780 inode->i_op = &btrfs_special_inode_operations;
3781 init_special_inode(inode, inode->i_mode, rdev);
3782 break;
3783 }
3784
3785 btrfs_update_iflags(inode);
3786 return;
3787
3788 make_bad:
3789 btrfs_free_path(path);
3790 make_bad_inode(inode);
3791 }
3792
3793 /*
3794 * given a leaf and an inode, copy the inode fields into the leaf
3795 */
3796 static void fill_inode_item(struct btrfs_trans_handle *trans,
3797 struct extent_buffer *leaf,
3798 struct btrfs_inode_item *item,
3799 struct inode *inode)
3800 {
3801 struct btrfs_map_token token;
3802
3803 btrfs_init_map_token(&token);
3804
3805 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3806 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3807 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3808 &token);
3809 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3810 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3811
3812 btrfs_set_token_timespec_sec(leaf, &item->atime,
3813 inode->i_atime.tv_sec, &token);
3814 btrfs_set_token_timespec_nsec(leaf, &item->atime,
3815 inode->i_atime.tv_nsec, &token);
3816
3817 btrfs_set_token_timespec_sec(leaf, &item->mtime,
3818 inode->i_mtime.tv_sec, &token);
3819 btrfs_set_token_timespec_nsec(leaf, &item->mtime,
3820 inode->i_mtime.tv_nsec, &token);
3821
3822 btrfs_set_token_timespec_sec(leaf, &item->ctime,
3823 inode->i_ctime.tv_sec, &token);
3824 btrfs_set_token_timespec_nsec(leaf, &item->ctime,
3825 inode->i_ctime.tv_nsec, &token);
3826
3827 btrfs_set_token_timespec_sec(leaf, &item->otime,
3828 BTRFS_I(inode)->i_otime.tv_sec, &token);
3829 btrfs_set_token_timespec_nsec(leaf, &item->otime,
3830 BTRFS_I(inode)->i_otime.tv_nsec, &token);
3831
3832 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3833 &token);
3834 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3835 &token);
3836 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3837 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3838 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3839 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3840 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3841 }
3842
3843 /*
3844 * copy everything in the in-memory inode into the btree.
3845 */
3846 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3847 struct btrfs_root *root, struct inode *inode)
3848 {
3849 struct btrfs_inode_item *inode_item;
3850 struct btrfs_path *path;
3851 struct extent_buffer *leaf;
3852 int ret;
3853
3854 path = btrfs_alloc_path();
3855 if (!path)
3856 return -ENOMEM;
3857
3858 path->leave_spinning = 1;
3859 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3860 1);
3861 if (ret) {
3862 if (ret > 0)
3863 ret = -ENOENT;
3864 goto failed;
3865 }
3866
3867 leaf = path->nodes[0];
3868 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3869 struct btrfs_inode_item);
3870
3871 fill_inode_item(trans, leaf, inode_item, inode);
3872 btrfs_mark_buffer_dirty(leaf);
3873 btrfs_set_inode_last_trans(trans, inode);
3874 ret = 0;
3875 failed:
3876 btrfs_free_path(path);
3877 return ret;
3878 }
3879
3880 /*
3881 * copy everything in the in-memory inode into the btree.
3882 */
3883 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3884 struct btrfs_root *root, struct inode *inode)
3885 {
3886 int ret;
3887
3888 /*
3889 * If the inode is a free space inode, we can deadlock during commit
3890 * if we put it into the delayed code.
3891 *
3892 * The data relocation inode should also be directly updated
3893 * without delay
3894 */
3895 if (!btrfs_is_free_space_inode(inode)
3896 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
3897 && !root->fs_info->log_root_recovering) {
3898 btrfs_update_root_times(trans, root);
3899
3900 ret = btrfs_delayed_update_inode(trans, root, inode);
3901 if (!ret)
3902 btrfs_set_inode_last_trans(trans, inode);
3903 return ret;
3904 }
3905
3906 return btrfs_update_inode_item(trans, root, inode);
3907 }
3908
3909 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
3910 struct btrfs_root *root,
3911 struct inode *inode)
3912 {
3913 int ret;
3914
3915 ret = btrfs_update_inode(trans, root, inode);
3916 if (ret == -ENOSPC)
3917 return btrfs_update_inode_item(trans, root, inode);
3918 return ret;
3919 }
3920
3921 /*
3922 * unlink helper that gets used here in inode.c and in the tree logging
3923 * recovery code. It remove a link in a directory with a given name, and
3924 * also drops the back refs in the inode to the directory
3925 */
3926 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3927 struct btrfs_root *root,
3928 struct inode *dir, struct inode *inode,
3929 const char *name, int name_len)
3930 {
3931 struct btrfs_path *path;
3932 int ret = 0;
3933 struct extent_buffer *leaf;
3934 struct btrfs_dir_item *di;
3935 struct btrfs_key key;
3936 u64 index;
3937 u64 ino = btrfs_ino(inode);
3938 u64 dir_ino = btrfs_ino(dir);
3939
3940 path = btrfs_alloc_path();
3941 if (!path) {
3942 ret = -ENOMEM;
3943 goto out;
3944 }
3945
3946 path->leave_spinning = 1;
3947 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3948 name, name_len, -1);
3949 if (IS_ERR(di)) {
3950 ret = PTR_ERR(di);
3951 goto err;
3952 }
3953 if (!di) {
3954 ret = -ENOENT;
3955 goto err;
3956 }
3957 leaf = path->nodes[0];
3958 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3959 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3960 if (ret)
3961 goto err;
3962 btrfs_release_path(path);
3963
3964 /*
3965 * If we don't have dir index, we have to get it by looking up
3966 * the inode ref, since we get the inode ref, remove it directly,
3967 * it is unnecessary to do delayed deletion.
3968 *
3969 * But if we have dir index, needn't search inode ref to get it.
3970 * Since the inode ref is close to the inode item, it is better
3971 * that we delay to delete it, and just do this deletion when
3972 * we update the inode item.
3973 */
3974 if (BTRFS_I(inode)->dir_index) {
3975 ret = btrfs_delayed_delete_inode_ref(inode);
3976 if (!ret) {
3977 index = BTRFS_I(inode)->dir_index;
3978 goto skip_backref;
3979 }
3980 }
3981
3982 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
3983 dir_ino, &index);
3984 if (ret) {
3985 btrfs_info(root->fs_info,
3986 "failed to delete reference to %.*s, inode %llu parent %llu",
3987 name_len, name, ino, dir_ino);
3988 btrfs_abort_transaction(trans, root, ret);
3989 goto err;
3990 }
3991 skip_backref:
3992 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3993 if (ret) {
3994 btrfs_abort_transaction(trans, root, ret);
3995 goto err;
3996 }
3997
3998 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
3999 inode, dir_ino);
4000 if (ret != 0 && ret != -ENOENT) {
4001 btrfs_abort_transaction(trans, root, ret);
4002 goto err;
4003 }
4004
4005 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
4006 dir, index);
4007 if (ret == -ENOENT)
4008 ret = 0;
4009 else if (ret)
4010 btrfs_abort_transaction(trans, root, ret);
4011 err:
4012 btrfs_free_path(path);
4013 if (ret)
4014 goto out;
4015
4016 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
4017 inode_inc_iversion(inode);
4018 inode_inc_iversion(dir);
4019 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
4020 ret = btrfs_update_inode(trans, root, dir);
4021 out:
4022 return ret;
4023 }
4024
4025 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4026 struct btrfs_root *root,
4027 struct inode *dir, struct inode *inode,
4028 const char *name, int name_len)
4029 {
4030 int ret;
4031 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
4032 if (!ret) {
4033 drop_nlink(inode);
4034 ret = btrfs_update_inode(trans, root, inode);
4035 }
4036 return ret;
4037 }
4038
4039 /*
4040 * helper to start transaction for unlink and rmdir.
4041 *
4042 * unlink and rmdir are special in btrfs, they do not always free space, so
4043 * if we cannot make our reservations the normal way try and see if there is
4044 * plenty of slack room in the global reserve to migrate, otherwise we cannot
4045 * allow the unlink to occur.
4046 */
4047 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
4048 {
4049 struct btrfs_trans_handle *trans;
4050 struct btrfs_root *root = BTRFS_I(dir)->root;
4051 int ret;
4052
4053 /*
4054 * 1 for the possible orphan item
4055 * 1 for the dir item
4056 * 1 for the dir index
4057 * 1 for the inode ref
4058 * 1 for the inode
4059 */
4060 trans = btrfs_start_transaction(root, 5);
4061 if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
4062 return trans;
4063
4064 if (PTR_ERR(trans) == -ENOSPC) {
4065 u64 num_bytes = btrfs_calc_trans_metadata_size(root, 5);
4066
4067 trans = btrfs_start_transaction(root, 0);
4068 if (IS_ERR(trans))
4069 return trans;
4070 ret = btrfs_cond_migrate_bytes(root->fs_info,
4071 &root->fs_info->trans_block_rsv,
4072 num_bytes, 5);
4073 if (ret) {
4074 btrfs_end_transaction(trans, root);
4075 return ERR_PTR(ret);
4076 }
4077 trans->block_rsv = &root->fs_info->trans_block_rsv;
4078 trans->bytes_reserved = num_bytes;
4079 }
4080 return trans;
4081 }
4082
4083 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
4084 {
4085 struct btrfs_root *root = BTRFS_I(dir)->root;
4086 struct btrfs_trans_handle *trans;
4087 struct inode *inode = d_inode(dentry);
4088 int ret;
4089
4090 trans = __unlink_start_trans(dir);
4091 if (IS_ERR(trans))
4092 return PTR_ERR(trans);
4093
4094 btrfs_record_unlink_dir(trans, dir, d_inode(dentry), 0);
4095
4096 ret = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
4097 dentry->d_name.name, dentry->d_name.len);
4098 if (ret)
4099 goto out;
4100
4101 if (inode->i_nlink == 0) {
4102 ret = btrfs_orphan_add(trans, inode);
4103 if (ret)
4104 goto out;
4105 }
4106
4107 out:
4108 btrfs_end_transaction(trans, root);
4109 btrfs_btree_balance_dirty(root);
4110 return ret;
4111 }
4112
4113 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
4114 struct btrfs_root *root,
4115 struct inode *dir, u64 objectid,
4116 const char *name, int name_len)
4117 {
4118 struct btrfs_path *path;
4119 struct extent_buffer *leaf;
4120 struct btrfs_dir_item *di;
4121 struct btrfs_key key;
4122 u64 index;
4123 int ret;
4124 u64 dir_ino = btrfs_ino(dir);
4125
4126 path = btrfs_alloc_path();
4127 if (!path)
4128 return -ENOMEM;
4129
4130 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4131 name, name_len, -1);
4132 if (IS_ERR_OR_NULL(di)) {
4133 if (!di)
4134 ret = -ENOENT;
4135 else
4136 ret = PTR_ERR(di);
4137 goto out;
4138 }
4139
4140 leaf = path->nodes[0];
4141 btrfs_dir_item_key_to_cpu(leaf, di, &key);
4142 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
4143 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4144 if (ret) {
4145 btrfs_abort_transaction(trans, root, ret);
4146 goto out;
4147 }
4148 btrfs_release_path(path);
4149
4150 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
4151 objectid, root->root_key.objectid,
4152 dir_ino, &index, name, name_len);
4153 if (ret < 0) {
4154 if (ret != -ENOENT) {
4155 btrfs_abort_transaction(trans, root, ret);
4156 goto out;
4157 }
4158 di = btrfs_search_dir_index_item(root, path, dir_ino,
4159 name, name_len);
4160 if (IS_ERR_OR_NULL(di)) {
4161 if (!di)
4162 ret = -ENOENT;
4163 else
4164 ret = PTR_ERR(di);
4165 btrfs_abort_transaction(trans, root, ret);
4166 goto out;
4167 }
4168
4169 leaf = path->nodes[0];
4170 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4171 btrfs_release_path(path);
4172 index = key.offset;
4173 }
4174 btrfs_release_path(path);
4175
4176 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
4177 if (ret) {
4178 btrfs_abort_transaction(trans, root, ret);
4179 goto out;
4180 }
4181
4182 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
4183 inode_inc_iversion(dir);
4184 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
4185 ret = btrfs_update_inode_fallback(trans, root, dir);
4186 if (ret)
4187 btrfs_abort_transaction(trans, root, ret);
4188 out:
4189 btrfs_free_path(path);
4190 return ret;
4191 }
4192
4193 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
4194 {
4195 struct inode *inode = d_inode(dentry);
4196 int err = 0;
4197 struct btrfs_root *root = BTRFS_I(dir)->root;
4198 struct btrfs_trans_handle *trans;
4199
4200 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
4201 return -ENOTEMPTY;
4202 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
4203 return -EPERM;
4204
4205 trans = __unlink_start_trans(dir);
4206 if (IS_ERR(trans))
4207 return PTR_ERR(trans);
4208
4209 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
4210 err = btrfs_unlink_subvol(trans, root, dir,
4211 BTRFS_I(inode)->location.objectid,
4212 dentry->d_name.name,
4213 dentry->d_name.len);
4214 goto out;
4215 }
4216
4217 err = btrfs_orphan_add(trans, inode);
4218 if (err)
4219 goto out;
4220
4221 /* now the directory is empty */
4222 err = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
4223 dentry->d_name.name, dentry->d_name.len);
4224 if (!err)
4225 btrfs_i_size_write(inode, 0);
4226 out:
4227 btrfs_end_transaction(trans, root);
4228 btrfs_btree_balance_dirty(root);
4229
4230 return err;
4231 }
4232
4233 static int truncate_space_check(struct btrfs_trans_handle *trans,
4234 struct btrfs_root *root,
4235 u64 bytes_deleted)
4236 {
4237 int ret;
4238
4239 bytes_deleted = btrfs_csum_bytes_to_leaves(root, bytes_deleted);
4240 ret = btrfs_block_rsv_add(root, &root->fs_info->trans_block_rsv,
4241 bytes_deleted, BTRFS_RESERVE_NO_FLUSH);
4242 if (!ret)
4243 trans->bytes_reserved += bytes_deleted;
4244 return ret;
4245
4246 }
4247
4248 static int truncate_inline_extent(struct inode *inode,
4249 struct btrfs_path *path,
4250 struct btrfs_key *found_key,
4251 const u64 item_end,
4252 const u64 new_size)
4253 {
4254 struct extent_buffer *leaf = path->nodes[0];
4255 int slot = path->slots[0];
4256 struct btrfs_file_extent_item *fi;
4257 u32 size = (u32)(new_size - found_key->offset);
4258 struct btrfs_root *root = BTRFS_I(inode)->root;
4259
4260 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
4261
4262 if (btrfs_file_extent_compression(leaf, fi) != BTRFS_COMPRESS_NONE) {
4263 loff_t offset = new_size;
4264 loff_t page_end = ALIGN(offset, PAGE_CACHE_SIZE);
4265
4266 /*
4267 * Zero out the remaining of the last page of our inline extent,
4268 * instead of directly truncating our inline extent here - that
4269 * would be much more complex (decompressing all the data, then
4270 * compressing the truncated data, which might be bigger than
4271 * the size of the inline extent, resize the extent, etc).
4272 * We release the path because to get the page we might need to
4273 * read the extent item from disk (data not in the page cache).
4274 */
4275 btrfs_release_path(path);
4276 return btrfs_truncate_page(inode, offset, page_end - offset, 0);
4277 }
4278
4279 btrfs_set_file_extent_ram_bytes(leaf, fi, size);
4280 size = btrfs_file_extent_calc_inline_size(size);
4281 btrfs_truncate_item(root, path, size, 1);
4282
4283 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4284 inode_sub_bytes(inode, item_end + 1 - new_size);
4285
4286 return 0;
4287 }
4288
4289 /*
4290 * this can truncate away extent items, csum items and directory items.
4291 * It starts at a high offset and removes keys until it can't find
4292 * any higher than new_size
4293 *
4294 * csum items that cross the new i_size are truncated to the new size
4295 * as well.
4296 *
4297 * min_type is the minimum key type to truncate down to. If set to 0, this
4298 * will kill all the items on this inode, including the INODE_ITEM_KEY.
4299 */
4300 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
4301 struct btrfs_root *root,
4302 struct inode *inode,
4303 u64 new_size, u32 min_type)
4304 {
4305 struct btrfs_path *path;
4306 struct extent_buffer *leaf;
4307 struct btrfs_file_extent_item *fi;
4308 struct btrfs_key key;
4309 struct btrfs_key found_key;
4310 u64 extent_start = 0;
4311 u64 extent_num_bytes = 0;
4312 u64 extent_offset = 0;
4313 u64 item_end = 0;
4314 u64 last_size = new_size;
4315 u32 found_type = (u8)-1;
4316 int found_extent;
4317 int del_item;
4318 int pending_del_nr = 0;
4319 int pending_del_slot = 0;
4320 int extent_type = -1;
4321 int ret;
4322 int err = 0;
4323 u64 ino = btrfs_ino(inode);
4324 u64 bytes_deleted = 0;
4325 bool be_nice = 0;
4326 bool should_throttle = 0;
4327 bool should_end = 0;
4328
4329 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
4330
4331 /*
4332 * for non-free space inodes and ref cows, we want to back off from
4333 * time to time
4334 */
4335 if (!btrfs_is_free_space_inode(inode) &&
4336 test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4337 be_nice = 1;
4338
4339 path = btrfs_alloc_path();
4340 if (!path)
4341 return -ENOMEM;
4342 path->reada = -1;
4343
4344 /*
4345 * We want to drop from the next block forward in case this new size is
4346 * not block aligned since we will be keeping the last block of the
4347 * extent just the way it is.
4348 */
4349 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4350 root == root->fs_info->tree_root)
4351 btrfs_drop_extent_cache(inode, ALIGN(new_size,
4352 root->sectorsize), (u64)-1, 0);
4353
4354 /*
4355 * This function is also used to drop the items in the log tree before
4356 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4357 * it is used to drop the loged items. So we shouldn't kill the delayed
4358 * items.
4359 */
4360 if (min_type == 0 && root == BTRFS_I(inode)->root)
4361 btrfs_kill_delayed_inode_items(inode);
4362
4363 key.objectid = ino;
4364 key.offset = (u64)-1;
4365 key.type = (u8)-1;
4366
4367 search_again:
4368 /*
4369 * with a 16K leaf size and 128MB extents, you can actually queue
4370 * up a huge file in a single leaf. Most of the time that
4371 * bytes_deleted is > 0, it will be huge by the time we get here
4372 */
4373 if (be_nice && bytes_deleted > 32 * 1024 * 1024) {
4374 if (btrfs_should_end_transaction(trans, root)) {
4375 err = -EAGAIN;
4376 goto error;
4377 }
4378 }
4379
4380
4381 path->leave_spinning = 1;
4382 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4383 if (ret < 0) {
4384 err = ret;
4385 goto out;
4386 }
4387
4388 if (ret > 0) {
4389 /* there are no items in the tree for us to truncate, we're
4390 * done
4391 */
4392 if (path->slots[0] == 0)
4393 goto out;
4394 path->slots[0]--;
4395 }
4396
4397 while (1) {
4398 fi = NULL;
4399 leaf = path->nodes[0];
4400 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4401 found_type = found_key.type;
4402
4403 if (found_key.objectid != ino)
4404 break;
4405
4406 if (found_type < min_type)
4407 break;
4408
4409 item_end = found_key.offset;
4410 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4411 fi = btrfs_item_ptr(leaf, path->slots[0],
4412 struct btrfs_file_extent_item);
4413 extent_type = btrfs_file_extent_type(leaf, fi);
4414 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4415 item_end +=
4416 btrfs_file_extent_num_bytes(leaf, fi);
4417 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4418 item_end += btrfs_file_extent_inline_len(leaf,
4419 path->slots[0], fi);
4420 }
4421 item_end--;
4422 }
4423 if (found_type > min_type) {
4424 del_item = 1;
4425 } else {
4426 if (item_end < new_size)
4427 break;
4428 if (found_key.offset >= new_size)
4429 del_item = 1;
4430 else
4431 del_item = 0;
4432 }
4433 found_extent = 0;
4434 /* FIXME, shrink the extent if the ref count is only 1 */
4435 if (found_type != BTRFS_EXTENT_DATA_KEY)
4436 goto delete;
4437
4438 if (del_item)
4439 last_size = found_key.offset;
4440 else
4441 last_size = new_size;
4442
4443 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4444 u64 num_dec;
4445 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4446 if (!del_item) {
4447 u64 orig_num_bytes =
4448 btrfs_file_extent_num_bytes(leaf, fi);
4449 extent_num_bytes = ALIGN(new_size -
4450 found_key.offset,
4451 root->sectorsize);
4452 btrfs_set_file_extent_num_bytes(leaf, fi,
4453 extent_num_bytes);
4454 num_dec = (orig_num_bytes -
4455 extent_num_bytes);
4456 if (test_bit(BTRFS_ROOT_REF_COWS,
4457 &root->state) &&
4458 extent_start != 0)
4459 inode_sub_bytes(inode, num_dec);
4460 btrfs_mark_buffer_dirty(leaf);
4461 } else {
4462 extent_num_bytes =
4463 btrfs_file_extent_disk_num_bytes(leaf,
4464 fi);
4465 extent_offset = found_key.offset -
4466 btrfs_file_extent_offset(leaf, fi);
4467
4468 /* FIXME blocksize != 4096 */
4469 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4470 if (extent_start != 0) {
4471 found_extent = 1;
4472 if (test_bit(BTRFS_ROOT_REF_COWS,
4473 &root->state))
4474 inode_sub_bytes(inode, num_dec);
4475 }
4476 }
4477 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4478 /*
4479 * we can't truncate inline items that have had
4480 * special encodings
4481 */
4482 if (!del_item &&
4483 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4484 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
4485
4486 /*
4487 * Need to release path in order to truncate a
4488 * compressed extent. So delete any accumulated
4489 * extent items so far.
4490 */
4491 if (btrfs_file_extent_compression(leaf, fi) !=
4492 BTRFS_COMPRESS_NONE && pending_del_nr) {
4493 err = btrfs_del_items(trans, root, path,
4494 pending_del_slot,
4495 pending_del_nr);
4496 if (err) {
4497 btrfs_abort_transaction(trans,
4498 root,
4499 err);
4500 goto error;
4501 }
4502 pending_del_nr = 0;
4503 }
4504
4505 err = truncate_inline_extent(inode, path,
4506 &found_key,
4507 item_end,
4508 new_size);
4509 if (err) {
4510 btrfs_abort_transaction(trans,
4511 root, err);
4512 goto error;
4513 }
4514 } else if (test_bit(BTRFS_ROOT_REF_COWS,
4515 &root->state)) {
4516 inode_sub_bytes(inode, item_end + 1 - new_size);
4517 }
4518 }
4519 delete:
4520 if (del_item) {
4521 if (!pending_del_nr) {
4522 /* no pending yet, add ourselves */
4523 pending_del_slot = path->slots[0];
4524 pending_del_nr = 1;
4525 } else if (pending_del_nr &&
4526 path->slots[0] + 1 == pending_del_slot) {
4527 /* hop on the pending chunk */
4528 pending_del_nr++;
4529 pending_del_slot = path->slots[0];
4530 } else {
4531 BUG();
4532 }
4533 } else {
4534 break;
4535 }
4536 should_throttle = 0;
4537
4538 if (found_extent &&
4539 (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4540 root == root->fs_info->tree_root)) {
4541 btrfs_set_path_blocking(path);
4542 bytes_deleted += extent_num_bytes;
4543 ret = btrfs_free_extent(trans, root, extent_start,
4544 extent_num_bytes, 0,
4545 btrfs_header_owner(leaf),
4546 ino, extent_offset);
4547 BUG_ON(ret);
4548 if (btrfs_should_throttle_delayed_refs(trans, root))
4549 btrfs_async_run_delayed_refs(root,
4550 trans->delayed_ref_updates * 2, 0);
4551 if (be_nice) {
4552 if (truncate_space_check(trans, root,
4553 extent_num_bytes)) {
4554 should_end = 1;
4555 }
4556 if (btrfs_should_throttle_delayed_refs(trans,
4557 root)) {
4558 should_throttle = 1;
4559 }
4560 }
4561 }
4562
4563 if (found_type == BTRFS_INODE_ITEM_KEY)
4564 break;
4565
4566 if (path->slots[0] == 0 ||
4567 path->slots[0] != pending_del_slot ||
4568 should_throttle || should_end) {
4569 if (pending_del_nr) {
4570 ret = btrfs_del_items(trans, root, path,
4571 pending_del_slot,
4572 pending_del_nr);
4573 if (ret) {
4574 btrfs_abort_transaction(trans,
4575 root, ret);
4576 goto error;
4577 }
4578 pending_del_nr = 0;
4579 }
4580 btrfs_release_path(path);
4581 if (should_throttle) {
4582 unsigned long updates = trans->delayed_ref_updates;
4583 if (updates) {
4584 trans->delayed_ref_updates = 0;
4585 ret = btrfs_run_delayed_refs(trans, root, updates * 2);
4586 if (ret && !err)
4587 err = ret;
4588 }
4589 }
4590 /*
4591 * if we failed to refill our space rsv, bail out
4592 * and let the transaction restart
4593 */
4594 if (should_end) {
4595 err = -EAGAIN;
4596 goto error;
4597 }
4598 goto search_again;
4599 } else {
4600 path->slots[0]--;
4601 }
4602 }
4603 out:
4604 if (pending_del_nr) {
4605 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4606 pending_del_nr);
4607 if (ret)
4608 btrfs_abort_transaction(trans, root, ret);
4609 }
4610 error:
4611 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
4612 btrfs_ordered_update_i_size(inode, last_size, NULL);
4613
4614 btrfs_free_path(path);
4615
4616 if (be_nice && bytes_deleted > 32 * 1024 * 1024) {
4617 unsigned long updates = trans->delayed_ref_updates;
4618 if (updates) {
4619 trans->delayed_ref_updates = 0;
4620 ret = btrfs_run_delayed_refs(trans, root, updates * 2);
4621 if (ret && !err)
4622 err = ret;
4623 }
4624 }
4625 return err;
4626 }
4627
4628 /*
4629 * btrfs_truncate_page - read, zero a chunk and write a page
4630 * @inode - inode that we're zeroing
4631 * @from - the offset to start zeroing
4632 * @len - the length to zero, 0 to zero the entire range respective to the
4633 * offset
4634 * @front - zero up to the offset instead of from the offset on
4635 *
4636 * This will find the page for the "from" offset and cow the page and zero the
4637 * part we want to zero. This is used with truncate and hole punching.
4638 */
4639 int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len,
4640 int front)
4641 {
4642 struct address_space *mapping = inode->i_mapping;
4643 struct btrfs_root *root = BTRFS_I(inode)->root;
4644 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4645 struct btrfs_ordered_extent *ordered;
4646 struct extent_state *cached_state = NULL;
4647 char *kaddr;
4648 u32 blocksize = root->sectorsize;
4649 pgoff_t index = from >> PAGE_CACHE_SHIFT;
4650 unsigned offset = from & (PAGE_CACHE_SIZE-1);
4651 struct page *page;
4652 gfp_t mask = btrfs_alloc_write_mask(mapping);
4653 int ret = 0;
4654 u64 page_start;
4655 u64 page_end;
4656
4657 if ((offset & (blocksize - 1)) == 0 &&
4658 (!len || ((len & (blocksize - 1)) == 0)))
4659 goto out;
4660 ret = btrfs_delalloc_reserve_space(inode,
4661 round_down(from, PAGE_CACHE_SIZE), PAGE_CACHE_SIZE);
4662 if (ret)
4663 goto out;
4664
4665 again:
4666 page = find_or_create_page(mapping, index, mask);
4667 if (!page) {
4668 btrfs_delalloc_release_space(inode,
4669 round_down(from, PAGE_CACHE_SIZE),
4670 PAGE_CACHE_SIZE);
4671 ret = -ENOMEM;
4672 goto out;
4673 }
4674
4675 page_start = page_offset(page);
4676 page_end = page_start + PAGE_CACHE_SIZE - 1;
4677
4678 if (!PageUptodate(page)) {
4679 ret = btrfs_readpage(NULL, page);
4680 lock_page(page);
4681 if (page->mapping != mapping) {
4682 unlock_page(page);
4683 page_cache_release(page);
4684 goto again;
4685 }
4686 if (!PageUptodate(page)) {
4687 ret = -EIO;
4688 goto out_unlock;
4689 }
4690 }
4691 wait_on_page_writeback(page);
4692
4693 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
4694 set_page_extent_mapped(page);
4695
4696 ordered = btrfs_lookup_ordered_extent(inode, page_start);
4697 if (ordered) {
4698 unlock_extent_cached(io_tree, page_start, page_end,
4699 &cached_state, GFP_NOFS);
4700 unlock_page(page);
4701 page_cache_release(page);
4702 btrfs_start_ordered_extent(inode, ordered, 1);
4703 btrfs_put_ordered_extent(ordered);
4704 goto again;
4705 }
4706
4707 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
4708 EXTENT_DIRTY | EXTENT_DELALLOC |
4709 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4710 0, 0, &cached_state, GFP_NOFS);
4711
4712 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
4713 &cached_state);
4714 if (ret) {
4715 unlock_extent_cached(io_tree, page_start, page_end,
4716 &cached_state, GFP_NOFS);
4717 goto out_unlock;
4718 }
4719
4720 if (offset != PAGE_CACHE_SIZE) {
4721 if (!len)
4722 len = PAGE_CACHE_SIZE - offset;
4723 kaddr = kmap(page);
4724 if (front)
4725 memset(kaddr, 0, offset);
4726 else
4727 memset(kaddr + offset, 0, len);
4728 flush_dcache_page(page);
4729 kunmap(page);
4730 }
4731 ClearPageChecked(page);
4732 set_page_dirty(page);
4733 unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
4734 GFP_NOFS);
4735
4736 out_unlock:
4737 if (ret)
4738 btrfs_delalloc_release_space(inode, page_start,
4739 PAGE_CACHE_SIZE);
4740 unlock_page(page);
4741 page_cache_release(page);
4742 out:
4743 return ret;
4744 }
4745
4746 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
4747 u64 offset, u64 len)
4748 {
4749 struct btrfs_trans_handle *trans;
4750 int ret;
4751
4752 /*
4753 * Still need to make sure the inode looks like it's been updated so
4754 * that any holes get logged if we fsync.
4755 */
4756 if (btrfs_fs_incompat(root->fs_info, NO_HOLES)) {
4757 BTRFS_I(inode)->last_trans = root->fs_info->generation;
4758 BTRFS_I(inode)->last_sub_trans = root->log_transid;
4759 BTRFS_I(inode)->last_log_commit = root->last_log_commit;
4760 return 0;
4761 }
4762
4763 /*
4764 * 1 - for the one we're dropping
4765 * 1 - for the one we're adding
4766 * 1 - for updating the inode.
4767 */
4768 trans = btrfs_start_transaction(root, 3);
4769 if (IS_ERR(trans))
4770 return PTR_ERR(trans);
4771
4772 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
4773 if (ret) {
4774 btrfs_abort_transaction(trans, root, ret);
4775 btrfs_end_transaction(trans, root);
4776 return ret;
4777 }
4778
4779 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset,
4780 0, 0, len, 0, len, 0, 0, 0);
4781 if (ret)
4782 btrfs_abort_transaction(trans, root, ret);
4783 else
4784 btrfs_update_inode(trans, root, inode);
4785 btrfs_end_transaction(trans, root);
4786 return ret;
4787 }
4788
4789 /*
4790 * This function puts in dummy file extents for the area we're creating a hole
4791 * for. So if we are truncating this file to a larger size we need to insert
4792 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4793 * the range between oldsize and size
4794 */
4795 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4796 {
4797 struct btrfs_root *root = BTRFS_I(inode)->root;
4798 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4799 struct extent_map *em = NULL;
4800 struct extent_state *cached_state = NULL;
4801 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4802 u64 hole_start = ALIGN(oldsize, root->sectorsize);
4803 u64 block_end = ALIGN(size, root->sectorsize);
4804 u64 last_byte;
4805 u64 cur_offset;
4806 u64 hole_size;
4807 int err = 0;
4808
4809 /*
4810 * If our size started in the middle of a page we need to zero out the
4811 * rest of the page before we expand the i_size, otherwise we could
4812 * expose stale data.
4813 */
4814 err = btrfs_truncate_page(inode, oldsize, 0, 0);
4815 if (err)
4816 return err;
4817
4818 if (size <= hole_start)
4819 return 0;
4820
4821 while (1) {
4822 struct btrfs_ordered_extent *ordered;
4823
4824 lock_extent_bits(io_tree, hole_start, block_end - 1, 0,
4825 &cached_state);
4826 ordered = btrfs_lookup_ordered_range(inode, hole_start,
4827 block_end - hole_start);
4828 if (!ordered)
4829 break;
4830 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4831 &cached_state, GFP_NOFS);
4832 btrfs_start_ordered_extent(inode, ordered, 1);
4833 btrfs_put_ordered_extent(ordered);
4834 }
4835
4836 cur_offset = hole_start;
4837 while (1) {
4838 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
4839 block_end - cur_offset, 0);
4840 if (IS_ERR(em)) {
4841 err = PTR_ERR(em);
4842 em = NULL;
4843 break;
4844 }
4845 last_byte = min(extent_map_end(em), block_end);
4846 last_byte = ALIGN(last_byte , root->sectorsize);
4847 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4848 struct extent_map *hole_em;
4849 hole_size = last_byte - cur_offset;
4850
4851 err = maybe_insert_hole(root, inode, cur_offset,
4852 hole_size);
4853 if (err)
4854 break;
4855 btrfs_drop_extent_cache(inode, cur_offset,
4856 cur_offset + hole_size - 1, 0);
4857 hole_em = alloc_extent_map();
4858 if (!hole_em) {
4859 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4860 &BTRFS_I(inode)->runtime_flags);
4861 goto next;
4862 }
4863 hole_em->start = cur_offset;
4864 hole_em->len = hole_size;
4865 hole_em->orig_start = cur_offset;
4866
4867 hole_em->block_start = EXTENT_MAP_HOLE;
4868 hole_em->block_len = 0;
4869 hole_em->orig_block_len = 0;
4870 hole_em->ram_bytes = hole_size;
4871 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
4872 hole_em->compress_type = BTRFS_COMPRESS_NONE;
4873 hole_em->generation = root->fs_info->generation;
4874
4875 while (1) {
4876 write_lock(&em_tree->lock);
4877 err = add_extent_mapping(em_tree, hole_em, 1);
4878 write_unlock(&em_tree->lock);
4879 if (err != -EEXIST)
4880 break;
4881 btrfs_drop_extent_cache(inode, cur_offset,
4882 cur_offset +
4883 hole_size - 1, 0);
4884 }
4885 free_extent_map(hole_em);
4886 }
4887 next:
4888 free_extent_map(em);
4889 em = NULL;
4890 cur_offset = last_byte;
4891 if (cur_offset >= block_end)
4892 break;
4893 }
4894 free_extent_map(em);
4895 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
4896 GFP_NOFS);
4897 return err;
4898 }
4899
4900 static int wait_snapshoting_atomic_t(atomic_t *a)
4901 {
4902 schedule();
4903 return 0;
4904 }
4905
4906 static void wait_for_snapshot_creation(struct btrfs_root *root)
4907 {
4908 while (true) {
4909 int ret;
4910
4911 ret = btrfs_start_write_no_snapshoting(root);
4912 if (ret)
4913 break;
4914 wait_on_atomic_t(&root->will_be_snapshoted,
4915 wait_snapshoting_atomic_t,
4916 TASK_UNINTERRUPTIBLE);
4917 }
4918 }
4919
4920 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
4921 {
4922 struct btrfs_root *root = BTRFS_I(inode)->root;
4923 struct btrfs_trans_handle *trans;
4924 loff_t oldsize = i_size_read(inode);
4925 loff_t newsize = attr->ia_size;
4926 int mask = attr->ia_valid;
4927 int ret;
4928
4929 /*
4930 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
4931 * special case where we need to update the times despite not having
4932 * these flags set. For all other operations the VFS set these flags
4933 * explicitly if it wants a timestamp update.
4934 */
4935 if (newsize != oldsize) {
4936 inode_inc_iversion(inode);
4937 if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
4938 inode->i_ctime = inode->i_mtime =
4939 current_fs_time(inode->i_sb);
4940 }
4941
4942 if (newsize > oldsize) {
4943 truncate_pagecache(inode, newsize);
4944 /*
4945 * Don't do an expanding truncate while snapshoting is ongoing.
4946 * This is to ensure the snapshot captures a fully consistent
4947 * state of this file - if the snapshot captures this expanding
4948 * truncation, it must capture all writes that happened before
4949 * this truncation.
4950 */
4951 wait_for_snapshot_creation(root);
4952 ret = btrfs_cont_expand(inode, oldsize, newsize);
4953 if (ret) {
4954 btrfs_end_write_no_snapshoting(root);
4955 return ret;
4956 }
4957
4958 trans = btrfs_start_transaction(root, 1);
4959 if (IS_ERR(trans)) {
4960 btrfs_end_write_no_snapshoting(root);
4961 return PTR_ERR(trans);
4962 }
4963
4964 i_size_write(inode, newsize);
4965 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
4966 ret = btrfs_update_inode(trans, root, inode);
4967 btrfs_end_write_no_snapshoting(root);
4968 btrfs_end_transaction(trans, root);
4969 } else {
4970
4971 /*
4972 * We're truncating a file that used to have good data down to
4973 * zero. Make sure it gets into the ordered flush list so that
4974 * any new writes get down to disk quickly.
4975 */
4976 if (newsize == 0)
4977 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
4978 &BTRFS_I(inode)->runtime_flags);
4979
4980 /*
4981 * 1 for the orphan item we're going to add
4982 * 1 for the orphan item deletion.
4983 */
4984 trans = btrfs_start_transaction(root, 2);
4985 if (IS_ERR(trans))
4986 return PTR_ERR(trans);
4987
4988 /*
4989 * We need to do this in case we fail at _any_ point during the
4990 * actual truncate. Once we do the truncate_setsize we could
4991 * invalidate pages which forces any outstanding ordered io to
4992 * be instantly completed which will give us extents that need
4993 * to be truncated. If we fail to get an orphan inode down we
4994 * could have left over extents that were never meant to live,
4995 * so we need to garuntee from this point on that everything
4996 * will be consistent.
4997 */
4998 ret = btrfs_orphan_add(trans, inode);
4999 btrfs_end_transaction(trans, root);
5000 if (ret)
5001 return ret;
5002
5003 /* we don't support swapfiles, so vmtruncate shouldn't fail */
5004 truncate_setsize(inode, newsize);
5005
5006 /* Disable nonlocked read DIO to avoid the end less truncate */
5007 btrfs_inode_block_unlocked_dio(inode);
5008 inode_dio_wait(inode);
5009 btrfs_inode_resume_unlocked_dio(inode);
5010
5011 ret = btrfs_truncate(inode);
5012 if (ret && inode->i_nlink) {
5013 int err;
5014
5015 /*
5016 * failed to truncate, disk_i_size is only adjusted down
5017 * as we remove extents, so it should represent the true
5018 * size of the inode, so reset the in memory size and
5019 * delete our orphan entry.
5020 */
5021 trans = btrfs_join_transaction(root);
5022 if (IS_ERR(trans)) {
5023 btrfs_orphan_del(NULL, inode);
5024 return ret;
5025 }
5026 i_size_write(inode, BTRFS_I(inode)->disk_i_size);
5027 err = btrfs_orphan_del(trans, inode);
5028 if (err)
5029 btrfs_abort_transaction(trans, root, err);
5030 btrfs_end_transaction(trans, root);
5031 }
5032 }
5033
5034 return ret;
5035 }
5036
5037 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
5038 {
5039 struct inode *inode = d_inode(dentry);
5040 struct btrfs_root *root = BTRFS_I(inode)->root;
5041 int err;
5042
5043 if (btrfs_root_readonly(root))
5044 return -EROFS;
5045
5046 err = inode_change_ok(inode, attr);
5047 if (err)
5048 return err;
5049
5050 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
5051 err = btrfs_setsize(inode, attr);
5052 if (err)
5053 return err;
5054 }
5055
5056 if (attr->ia_valid) {
5057 setattr_copy(inode, attr);
5058 inode_inc_iversion(inode);
5059 err = btrfs_dirty_inode(inode);
5060
5061 if (!err && attr->ia_valid & ATTR_MODE)
5062 err = posix_acl_chmod(inode, inode->i_mode);
5063 }
5064
5065 return err;
5066 }
5067
5068 /*
5069 * While truncating the inode pages during eviction, we get the VFS calling
5070 * btrfs_invalidatepage() against each page of the inode. This is slow because
5071 * the calls to btrfs_invalidatepage() result in a huge amount of calls to
5072 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
5073 * extent_state structures over and over, wasting lots of time.
5074 *
5075 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
5076 * those expensive operations on a per page basis and do only the ordered io
5077 * finishing, while we release here the extent_map and extent_state structures,
5078 * without the excessive merging and splitting.
5079 */
5080 static void evict_inode_truncate_pages(struct inode *inode)
5081 {
5082 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5083 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
5084 struct rb_node *node;
5085
5086 ASSERT(inode->i_state & I_FREEING);
5087 truncate_inode_pages_final(&inode->i_data);
5088
5089 write_lock(&map_tree->lock);
5090 while (!RB_EMPTY_ROOT(&map_tree->map)) {
5091 struct extent_map *em;
5092
5093 node = rb_first(&map_tree->map);
5094 em = rb_entry(node, struct extent_map, rb_node);
5095 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
5096 clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
5097 remove_extent_mapping(map_tree, em);
5098 free_extent_map(em);
5099 if (need_resched()) {
5100 write_unlock(&map_tree->lock);
5101 cond_resched();
5102 write_lock(&map_tree->lock);
5103 }
5104 }
5105 write_unlock(&map_tree->lock);
5106
5107 /*
5108 * Keep looping until we have no more ranges in the io tree.
5109 * We can have ongoing bios started by readpages (called from readahead)
5110 * that have their endio callback (extent_io.c:end_bio_extent_readpage)
5111 * still in progress (unlocked the pages in the bio but did not yet
5112 * unlocked the ranges in the io tree). Therefore this means some
5113 * ranges can still be locked and eviction started because before
5114 * submitting those bios, which are executed by a separate task (work
5115 * queue kthread), inode references (inode->i_count) were not taken
5116 * (which would be dropped in the end io callback of each bio).
5117 * Therefore here we effectively end up waiting for those bios and
5118 * anyone else holding locked ranges without having bumped the inode's
5119 * reference count - if we don't do it, when they access the inode's
5120 * io_tree to unlock a range it may be too late, leading to an
5121 * use-after-free issue.
5122 */
5123 spin_lock(&io_tree->lock);
5124 while (!RB_EMPTY_ROOT(&io_tree->state)) {
5125 struct extent_state *state;
5126 struct extent_state *cached_state = NULL;
5127 u64 start;
5128 u64 end;
5129
5130 node = rb_first(&io_tree->state);
5131 state = rb_entry(node, struct extent_state, rb_node);
5132 start = state->start;
5133 end = state->end;
5134 spin_unlock(&io_tree->lock);
5135
5136 lock_extent_bits(io_tree, start, end, 0, &cached_state);
5137
5138 /*
5139 * If still has DELALLOC flag, the extent didn't reach disk,
5140 * and its reserved space won't be freed by delayed_ref.
5141 * So we need to free its reserved space here.
5142 * (Refer to comment in btrfs_invalidatepage, case 2)
5143 *
5144 * Note, end is the bytenr of last byte, so we need + 1 here.
5145 */
5146 if (state->state & EXTENT_DELALLOC)
5147 btrfs_qgroup_free_data(inode, start, end - start + 1);
5148
5149 clear_extent_bit(io_tree, start, end,
5150 EXTENT_LOCKED | EXTENT_DIRTY |
5151 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
5152 EXTENT_DEFRAG, 1, 1,
5153 &cached_state, GFP_NOFS);
5154
5155 cond_resched();
5156 spin_lock(&io_tree->lock);
5157 }
5158 spin_unlock(&io_tree->lock);
5159 }
5160
5161 void btrfs_evict_inode(struct inode *inode)
5162 {
5163 struct btrfs_trans_handle *trans;
5164 struct btrfs_root *root = BTRFS_I(inode)->root;
5165 struct btrfs_block_rsv *rsv, *global_rsv;
5166 int steal_from_global = 0;
5167 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
5168 int ret;
5169
5170 trace_btrfs_inode_evict(inode);
5171
5172 evict_inode_truncate_pages(inode);
5173
5174 if (inode->i_nlink &&
5175 ((btrfs_root_refs(&root->root_item) != 0 &&
5176 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
5177 btrfs_is_free_space_inode(inode)))
5178 goto no_delete;
5179
5180 if (is_bad_inode(inode)) {
5181 btrfs_orphan_del(NULL, inode);
5182 goto no_delete;
5183 }
5184 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
5185 if (!special_file(inode->i_mode))
5186 btrfs_wait_ordered_range(inode, 0, (u64)-1);
5187
5188 btrfs_free_io_failure_record(inode, 0, (u64)-1);
5189
5190 if (root->fs_info->log_root_recovering) {
5191 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
5192 &BTRFS_I(inode)->runtime_flags));
5193 goto no_delete;
5194 }
5195
5196 if (inode->i_nlink > 0) {
5197 BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
5198 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
5199 goto no_delete;
5200 }
5201
5202 ret = btrfs_commit_inode_delayed_inode(inode);
5203 if (ret) {
5204 btrfs_orphan_del(NULL, inode);
5205 goto no_delete;
5206 }
5207
5208 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
5209 if (!rsv) {
5210 btrfs_orphan_del(NULL, inode);
5211 goto no_delete;
5212 }
5213 rsv->size = min_size;
5214 rsv->failfast = 1;
5215 global_rsv = &root->fs_info->global_block_rsv;
5216
5217 btrfs_i_size_write(inode, 0);
5218
5219 /*
5220 * This is a bit simpler than btrfs_truncate since we've already
5221 * reserved our space for our orphan item in the unlink, so we just
5222 * need to reserve some slack space in case we add bytes and update
5223 * inode item when doing the truncate.
5224 */
5225 while (1) {
5226 ret = btrfs_block_rsv_refill(root, rsv, min_size,
5227 BTRFS_RESERVE_FLUSH_LIMIT);
5228
5229 /*
5230 * Try and steal from the global reserve since we will
5231 * likely not use this space anyway, we want to try as
5232 * hard as possible to get this to work.
5233 */
5234 if (ret)
5235 steal_from_global++;
5236 else
5237 steal_from_global = 0;
5238 ret = 0;
5239
5240 /*
5241 * steal_from_global == 0: we reserved stuff, hooray!
5242 * steal_from_global == 1: we didn't reserve stuff, boo!
5243 * steal_from_global == 2: we've committed, still not a lot of
5244 * room but maybe we'll have room in the global reserve this
5245 * time.
5246 * steal_from_global == 3: abandon all hope!
5247 */
5248 if (steal_from_global > 2) {
5249 btrfs_warn(root->fs_info,
5250 "Could not get space for a delete, will truncate on mount %d",
5251 ret);
5252 btrfs_orphan_del(NULL, inode);
5253 btrfs_free_block_rsv(root, rsv);
5254 goto no_delete;
5255 }
5256
5257 trans = btrfs_join_transaction(root);
5258 if (IS_ERR(trans)) {
5259 btrfs_orphan_del(NULL, inode);
5260 btrfs_free_block_rsv(root, rsv);
5261 goto no_delete;
5262 }
5263
5264 /*
5265 * We can't just steal from the global reserve, we need tomake
5266 * sure there is room to do it, if not we need to commit and try
5267 * again.
5268 */
5269 if (steal_from_global) {
5270 if (!btrfs_check_space_for_delayed_refs(trans, root))
5271 ret = btrfs_block_rsv_migrate(global_rsv, rsv,
5272 min_size);
5273 else
5274 ret = -ENOSPC;
5275 }
5276
5277 /*
5278 * Couldn't steal from the global reserve, we have too much
5279 * pending stuff built up, commit the transaction and try it
5280 * again.
5281 */
5282 if (ret) {
5283 ret = btrfs_commit_transaction(trans, root);
5284 if (ret) {
5285 btrfs_orphan_del(NULL, inode);
5286 btrfs_free_block_rsv(root, rsv);
5287 goto no_delete;
5288 }
5289 continue;
5290 } else {
5291 steal_from_global = 0;
5292 }
5293
5294 trans->block_rsv = rsv;
5295
5296 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
5297 if (ret != -ENOSPC && ret != -EAGAIN)
5298 break;
5299
5300 trans->block_rsv = &root->fs_info->trans_block_rsv;
5301 btrfs_end_transaction(trans, root);
5302 trans = NULL;
5303 btrfs_btree_balance_dirty(root);
5304 }
5305
5306 btrfs_free_block_rsv(root, rsv);
5307
5308 /*
5309 * Errors here aren't a big deal, it just means we leave orphan items
5310 * in the tree. They will be cleaned up on the next mount.
5311 */
5312 if (ret == 0) {
5313 trans->block_rsv = root->orphan_block_rsv;
5314 btrfs_orphan_del(trans, inode);
5315 } else {
5316 btrfs_orphan_del(NULL, inode);
5317 }
5318
5319 trans->block_rsv = &root->fs_info->trans_block_rsv;
5320 if (!(root == root->fs_info->tree_root ||
5321 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
5322 btrfs_return_ino(root, btrfs_ino(inode));
5323
5324 btrfs_end_transaction(trans, root);
5325 btrfs_btree_balance_dirty(root);
5326 no_delete:
5327 btrfs_remove_delayed_node(inode);
5328 clear_inode(inode);
5329 return;
5330 }
5331
5332 /*
5333 * this returns the key found in the dir entry in the location pointer.
5334 * If no dir entries were found, location->objectid is 0.
5335 */
5336 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
5337 struct btrfs_key *location)
5338 {
5339 const char *name = dentry->d_name.name;
5340 int namelen = dentry->d_name.len;
5341 struct btrfs_dir_item *di;
5342 struct btrfs_path *path;
5343 struct btrfs_root *root = BTRFS_I(dir)->root;
5344 int ret = 0;
5345
5346 path = btrfs_alloc_path();
5347 if (!path)
5348 return -ENOMEM;
5349
5350 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
5351 namelen, 0);
5352 if (IS_ERR(di))
5353 ret = PTR_ERR(di);
5354
5355 if (IS_ERR_OR_NULL(di))
5356 goto out_err;
5357
5358 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
5359 out:
5360 btrfs_free_path(path);
5361 return ret;
5362 out_err:
5363 location->objectid = 0;
5364 goto out;
5365 }
5366
5367 /*
5368 * when we hit a tree root in a directory, the btrfs part of the inode
5369 * needs to be changed to reflect the root directory of the tree root. This
5370 * is kind of like crossing a mount point.
5371 */
5372 static int fixup_tree_root_location(struct btrfs_root *root,
5373 struct inode *dir,
5374 struct dentry *dentry,
5375 struct btrfs_key *location,
5376 struct btrfs_root **sub_root)
5377 {
5378 struct btrfs_path *path;
5379 struct btrfs_root *new_root;
5380 struct btrfs_root_ref *ref;
5381 struct extent_buffer *leaf;
5382 struct btrfs_key key;
5383 int ret;
5384 int err = 0;
5385
5386 path = btrfs_alloc_path();
5387 if (!path) {
5388 err = -ENOMEM;
5389 goto out;
5390 }
5391
5392 err = -ENOENT;
5393 key.objectid = BTRFS_I(dir)->root->root_key.objectid;
5394 key.type = BTRFS_ROOT_REF_KEY;
5395 key.offset = location->objectid;
5396
5397 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key, path,
5398 0, 0);
5399 if (ret) {
5400 if (ret < 0)
5401 err = ret;
5402 goto out;
5403 }
5404
5405 leaf = path->nodes[0];
5406 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
5407 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
5408 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
5409 goto out;
5410
5411 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
5412 (unsigned long)(ref + 1),
5413 dentry->d_name.len);
5414 if (ret)
5415 goto out;
5416
5417 btrfs_release_path(path);
5418
5419 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
5420 if (IS_ERR(new_root)) {
5421 err = PTR_ERR(new_root);
5422 goto out;
5423 }
5424
5425 *sub_root = new_root;
5426 location->objectid = btrfs_root_dirid(&new_root->root_item);
5427 location->type = BTRFS_INODE_ITEM_KEY;
5428 location->offset = 0;
5429 err = 0;
5430 out:
5431 btrfs_free_path(path);
5432 return err;
5433 }
5434
5435 static void inode_tree_add(struct inode *inode)
5436 {
5437 struct btrfs_root *root = BTRFS_I(inode)->root;
5438 struct btrfs_inode *entry;
5439 struct rb_node **p;
5440 struct rb_node *parent;
5441 struct rb_node *new = &BTRFS_I(inode)->rb_node;
5442 u64 ino = btrfs_ino(inode);
5443
5444 if (inode_unhashed(inode))
5445 return;
5446 parent = NULL;
5447 spin_lock(&root->inode_lock);
5448 p = &root->inode_tree.rb_node;
5449 while (*p) {
5450 parent = *p;
5451 entry = rb_entry(parent, struct btrfs_inode, rb_node);
5452
5453 if (ino < btrfs_ino(&entry->vfs_inode))
5454 p = &parent->rb_left;
5455 else if (ino > btrfs_ino(&entry->vfs_inode))
5456 p = &parent->rb_right;
5457 else {
5458 WARN_ON(!(entry->vfs_inode.i_state &
5459 (I_WILL_FREE | I_FREEING)));
5460 rb_replace_node(parent, new, &root->inode_tree);
5461 RB_CLEAR_NODE(parent);
5462 spin_unlock(&root->inode_lock);
5463 return;
5464 }
5465 }
5466 rb_link_node(new, parent, p);
5467 rb_insert_color(new, &root->inode_tree);
5468 spin_unlock(&root->inode_lock);
5469 }
5470
5471 static void inode_tree_del(struct inode *inode)
5472 {
5473 struct btrfs_root *root = BTRFS_I(inode)->root;
5474 int empty = 0;
5475
5476 spin_lock(&root->inode_lock);
5477 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
5478 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
5479 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
5480 empty = RB_EMPTY_ROOT(&root->inode_tree);
5481 }
5482 spin_unlock(&root->inode_lock);
5483
5484 if (empty && btrfs_root_refs(&root->root_item) == 0) {
5485 synchronize_srcu(&root->fs_info->subvol_srcu);
5486 spin_lock(&root->inode_lock);
5487 empty = RB_EMPTY_ROOT(&root->inode_tree);
5488 spin_unlock(&root->inode_lock);
5489 if (empty)
5490 btrfs_add_dead_root(root);
5491 }
5492 }
5493
5494 void btrfs_invalidate_inodes(struct btrfs_root *root)
5495 {
5496 struct rb_node *node;
5497 struct rb_node *prev;
5498 struct btrfs_inode *entry;
5499 struct inode *inode;
5500 u64 objectid = 0;
5501
5502 if (!test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
5503 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
5504
5505 spin_lock(&root->inode_lock);
5506 again:
5507 node = root->inode_tree.rb_node;
5508 prev = NULL;
5509 while (node) {
5510 prev = node;
5511 entry = rb_entry(node, struct btrfs_inode, rb_node);
5512
5513 if (objectid < btrfs_ino(&entry->vfs_inode))
5514 node = node->rb_left;
5515 else if (objectid > btrfs_ino(&entry->vfs_inode))
5516 node = node->rb_right;
5517 else
5518 break;
5519 }
5520 if (!node) {
5521 while (prev) {
5522 entry = rb_entry(prev, struct btrfs_inode, rb_node);
5523 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
5524 node = prev;
5525 break;
5526 }
5527 prev = rb_next(prev);
5528 }
5529 }
5530 while (node) {
5531 entry = rb_entry(node, struct btrfs_inode, rb_node);
5532 objectid = btrfs_ino(&entry->vfs_inode) + 1;
5533 inode = igrab(&entry->vfs_inode);
5534 if (inode) {
5535 spin_unlock(&root->inode_lock);
5536 if (atomic_read(&inode->i_count) > 1)
5537 d_prune_aliases(inode);
5538 /*
5539 * btrfs_drop_inode will have it removed from
5540 * the inode cache when its usage count
5541 * hits zero.
5542 */
5543 iput(inode);
5544 cond_resched();
5545 spin_lock(&root->inode_lock);
5546 goto again;
5547 }
5548
5549 if (cond_resched_lock(&root->inode_lock))
5550 goto again;
5551
5552 node = rb_next(node);
5553 }
5554 spin_unlock(&root->inode_lock);
5555 }
5556
5557 static int btrfs_init_locked_inode(struct inode *inode, void *p)
5558 {
5559 struct btrfs_iget_args *args = p;
5560 inode->i_ino = args->location->objectid;
5561 memcpy(&BTRFS_I(inode)->location, args->location,
5562 sizeof(*args->location));
5563 BTRFS_I(inode)->root = args->root;
5564 return 0;
5565 }
5566
5567 static int btrfs_find_actor(struct inode *inode, void *opaque)
5568 {
5569 struct btrfs_iget_args *args = opaque;
5570 return args->location->objectid == BTRFS_I(inode)->location.objectid &&
5571 args->root == BTRFS_I(inode)->root;
5572 }
5573
5574 static struct inode *btrfs_iget_locked(struct super_block *s,
5575 struct btrfs_key *location,
5576 struct btrfs_root *root)
5577 {
5578 struct inode *inode;
5579 struct btrfs_iget_args args;
5580 unsigned long hashval = btrfs_inode_hash(location->objectid, root);
5581
5582 args.location = location;
5583 args.root = root;
5584
5585 inode = iget5_locked(s, hashval, btrfs_find_actor,
5586 btrfs_init_locked_inode,
5587 (void *)&args);
5588 return inode;
5589 }
5590
5591 /* Get an inode object given its location and corresponding root.
5592 * Returns in *is_new if the inode was read from disk
5593 */
5594 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
5595 struct btrfs_root *root, int *new)
5596 {
5597 struct inode *inode;
5598
5599 inode = btrfs_iget_locked(s, location, root);
5600 if (!inode)
5601 return ERR_PTR(-ENOMEM);
5602
5603 if (inode->i_state & I_NEW) {
5604 btrfs_read_locked_inode(inode);
5605 if (!is_bad_inode(inode)) {
5606 inode_tree_add(inode);
5607 unlock_new_inode(inode);
5608 if (new)
5609 *new = 1;
5610 } else {
5611 unlock_new_inode(inode);
5612 iput(inode);
5613 inode = ERR_PTR(-ESTALE);
5614 }
5615 }
5616
5617 return inode;
5618 }
5619
5620 static struct inode *new_simple_dir(struct super_block *s,
5621 struct btrfs_key *key,
5622 struct btrfs_root *root)
5623 {
5624 struct inode *inode = new_inode(s);
5625
5626 if (!inode)
5627 return ERR_PTR(-ENOMEM);
5628
5629 BTRFS_I(inode)->root = root;
5630 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5631 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5632
5633 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5634 inode->i_op = &btrfs_dir_ro_inode_operations;
5635 inode->i_fop = &simple_dir_operations;
5636 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5637 inode->i_mtime = CURRENT_TIME;
5638 inode->i_atime = inode->i_mtime;
5639 inode->i_ctime = inode->i_mtime;
5640 BTRFS_I(inode)->i_otime = inode->i_mtime;
5641
5642 return inode;
5643 }
5644
5645 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5646 {
5647 struct inode *inode;
5648 struct btrfs_root *root = BTRFS_I(dir)->root;
5649 struct btrfs_root *sub_root = root;
5650 struct btrfs_key location;
5651 int index;
5652 int ret = 0;
5653
5654 if (dentry->d_name.len > BTRFS_NAME_LEN)
5655 return ERR_PTR(-ENAMETOOLONG);
5656
5657 ret = btrfs_inode_by_name(dir, dentry, &location);
5658 if (ret < 0)
5659 return ERR_PTR(ret);
5660
5661 if (location.objectid == 0)
5662 return ERR_PTR(-ENOENT);
5663
5664 if (location.type == BTRFS_INODE_ITEM_KEY) {
5665 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5666 return inode;
5667 }
5668
5669 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
5670
5671 index = srcu_read_lock(&root->fs_info->subvol_srcu);
5672 ret = fixup_tree_root_location(root, dir, dentry,
5673 &location, &sub_root);
5674 if (ret < 0) {
5675 if (ret != -ENOENT)
5676 inode = ERR_PTR(ret);
5677 else
5678 inode = new_simple_dir(dir->i_sb, &location, sub_root);
5679 } else {
5680 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
5681 }
5682 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
5683
5684 if (!IS_ERR(inode) && root != sub_root) {
5685 down_read(&root->fs_info->cleanup_work_sem);
5686 if (!(inode->i_sb->s_flags & MS_RDONLY))
5687 ret = btrfs_orphan_cleanup(sub_root);
5688 up_read(&root->fs_info->cleanup_work_sem);
5689 if (ret) {
5690 iput(inode);
5691 inode = ERR_PTR(ret);
5692 }
5693 }
5694
5695 return inode;
5696 }
5697
5698 static int btrfs_dentry_delete(const struct dentry *dentry)
5699 {
5700 struct btrfs_root *root;
5701 struct inode *inode = d_inode(dentry);
5702
5703 if (!inode && !IS_ROOT(dentry))
5704 inode = d_inode(dentry->d_parent);
5705
5706 if (inode) {
5707 root = BTRFS_I(inode)->root;
5708 if (btrfs_root_refs(&root->root_item) == 0)
5709 return 1;
5710
5711 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5712 return 1;
5713 }
5714 return 0;
5715 }
5716
5717 static void btrfs_dentry_release(struct dentry *dentry)
5718 {
5719 kfree(dentry->d_fsdata);
5720 }
5721
5722 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5723 unsigned int flags)
5724 {
5725 struct inode *inode;
5726
5727 inode = btrfs_lookup_dentry(dir, dentry);
5728 if (IS_ERR(inode)) {
5729 if (PTR_ERR(inode) == -ENOENT)
5730 inode = NULL;
5731 else
5732 return ERR_CAST(inode);
5733 }
5734
5735 return d_splice_alias(inode, dentry);
5736 }
5737
5738 unsigned char btrfs_filetype_table[] = {
5739 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5740 };
5741
5742 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
5743 {
5744 struct inode *inode = file_inode(file);
5745 struct btrfs_root *root = BTRFS_I(inode)->root;
5746 struct btrfs_item *item;
5747 struct btrfs_dir_item *di;
5748 struct btrfs_key key;
5749 struct btrfs_key found_key;
5750 struct btrfs_path *path;
5751 struct list_head ins_list;
5752 struct list_head del_list;
5753 int ret;
5754 struct extent_buffer *leaf;
5755 int slot;
5756 unsigned char d_type;
5757 int over = 0;
5758 u32 di_cur;
5759 u32 di_total;
5760 u32 di_len;
5761 int key_type = BTRFS_DIR_INDEX_KEY;
5762 char tmp_name[32];
5763 char *name_ptr;
5764 int name_len;
5765 int is_curr = 0; /* ctx->pos points to the current index? */
5766
5767 /* FIXME, use a real flag for deciding about the key type */
5768 if (root->fs_info->tree_root == root)
5769 key_type = BTRFS_DIR_ITEM_KEY;
5770
5771 if (!dir_emit_dots(file, ctx))
5772 return 0;
5773
5774 path = btrfs_alloc_path();
5775 if (!path)
5776 return -ENOMEM;
5777
5778 path->reada = 1;
5779
5780 if (key_type == BTRFS_DIR_INDEX_KEY) {
5781 INIT_LIST_HEAD(&ins_list);
5782 INIT_LIST_HEAD(&del_list);
5783 btrfs_get_delayed_items(inode, &ins_list, &del_list);
5784 }
5785
5786 key.type = key_type;
5787 key.offset = ctx->pos;
5788 key.objectid = btrfs_ino(inode);
5789
5790 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5791 if (ret < 0)
5792 goto err;
5793
5794 while (1) {
5795 leaf = path->nodes[0];
5796 slot = path->slots[0];
5797 if (slot >= btrfs_header_nritems(leaf)) {
5798 ret = btrfs_next_leaf(root, path);
5799 if (ret < 0)
5800 goto err;
5801 else if (ret > 0)
5802 break;
5803 continue;
5804 }
5805
5806 item = btrfs_item_nr(slot);
5807 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5808
5809 if (found_key.objectid != key.objectid)
5810 break;
5811 if (found_key.type != key_type)
5812 break;
5813 if (found_key.offset < ctx->pos)
5814 goto next;
5815 if (key_type == BTRFS_DIR_INDEX_KEY &&
5816 btrfs_should_delete_dir_index(&del_list,
5817 found_key.offset))
5818 goto next;
5819
5820 ctx->pos = found_key.offset;
5821 is_curr = 1;
5822
5823 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5824 di_cur = 0;
5825 di_total = btrfs_item_size(leaf, item);
5826
5827 while (di_cur < di_total) {
5828 struct btrfs_key location;
5829
5830 if (verify_dir_item(root, leaf, di))
5831 break;
5832
5833 name_len = btrfs_dir_name_len(leaf, di);
5834 if (name_len <= sizeof(tmp_name)) {
5835 name_ptr = tmp_name;
5836 } else {
5837 name_ptr = kmalloc(name_len, GFP_NOFS);
5838 if (!name_ptr) {
5839 ret = -ENOMEM;
5840 goto err;
5841 }
5842 }
5843 read_extent_buffer(leaf, name_ptr,
5844 (unsigned long)(di + 1), name_len);
5845
5846 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
5847 btrfs_dir_item_key_to_cpu(leaf, di, &location);
5848
5849
5850 /* is this a reference to our own snapshot? If so
5851 * skip it.
5852 *
5853 * In contrast to old kernels, we insert the snapshot's
5854 * dir item and dir index after it has been created, so
5855 * we won't find a reference to our own snapshot. We
5856 * still keep the following code for backward
5857 * compatibility.
5858 */
5859 if (location.type == BTRFS_ROOT_ITEM_KEY &&
5860 location.objectid == root->root_key.objectid) {
5861 over = 0;
5862 goto skip;
5863 }
5864 over = !dir_emit(ctx, name_ptr, name_len,
5865 location.objectid, d_type);
5866
5867 skip:
5868 if (name_ptr != tmp_name)
5869 kfree(name_ptr);
5870
5871 if (over)
5872 goto nopos;
5873 di_len = btrfs_dir_name_len(leaf, di) +
5874 btrfs_dir_data_len(leaf, di) + sizeof(*di);
5875 di_cur += di_len;
5876 di = (struct btrfs_dir_item *)((char *)di + di_len);
5877 }
5878 next:
5879 path->slots[0]++;
5880 }
5881
5882 if (key_type == BTRFS_DIR_INDEX_KEY) {
5883 if (is_curr)
5884 ctx->pos++;
5885 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
5886 if (ret)
5887 goto nopos;
5888 }
5889
5890 /* Reached end of directory/root. Bump pos past the last item. */
5891 ctx->pos++;
5892
5893 /*
5894 * Stop new entries from being returned after we return the last
5895 * entry.
5896 *
5897 * New directory entries are assigned a strictly increasing
5898 * offset. This means that new entries created during readdir
5899 * are *guaranteed* to be seen in the future by that readdir.
5900 * This has broken buggy programs which operate on names as
5901 * they're returned by readdir. Until we re-use freed offsets
5902 * we have this hack to stop new entries from being returned
5903 * under the assumption that they'll never reach this huge
5904 * offset.
5905 *
5906 * This is being careful not to overflow 32bit loff_t unless the
5907 * last entry requires it because doing so has broken 32bit apps
5908 * in the past.
5909 */
5910 if (key_type == BTRFS_DIR_INDEX_KEY) {
5911 if (ctx->pos >= INT_MAX)
5912 ctx->pos = LLONG_MAX;
5913 else
5914 ctx->pos = INT_MAX;
5915 }
5916 nopos:
5917 ret = 0;
5918 err:
5919 if (key_type == BTRFS_DIR_INDEX_KEY)
5920 btrfs_put_delayed_items(&ins_list, &del_list);
5921 btrfs_free_path(path);
5922 return ret;
5923 }
5924
5925 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
5926 {
5927 struct btrfs_root *root = BTRFS_I(inode)->root;
5928 struct btrfs_trans_handle *trans;
5929 int ret = 0;
5930 bool nolock = false;
5931
5932 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5933 return 0;
5934
5935 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
5936 nolock = true;
5937
5938 if (wbc->sync_mode == WB_SYNC_ALL) {
5939 if (nolock)
5940 trans = btrfs_join_transaction_nolock(root);
5941 else
5942 trans = btrfs_join_transaction(root);
5943 if (IS_ERR(trans))
5944 return PTR_ERR(trans);
5945 ret = btrfs_commit_transaction(trans, root);
5946 }
5947 return ret;
5948 }
5949
5950 /*
5951 * This is somewhat expensive, updating the tree every time the
5952 * inode changes. But, it is most likely to find the inode in cache.
5953 * FIXME, needs more benchmarking...there are no reasons other than performance
5954 * to keep or drop this code.
5955 */
5956 static int btrfs_dirty_inode(struct inode *inode)
5957 {
5958 struct btrfs_root *root = BTRFS_I(inode)->root;
5959 struct btrfs_trans_handle *trans;
5960 int ret;
5961
5962 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5963 return 0;
5964
5965 trans = btrfs_join_transaction(root);
5966 if (IS_ERR(trans))
5967 return PTR_ERR(trans);
5968
5969 ret = btrfs_update_inode(trans, root, inode);
5970 if (ret && ret == -ENOSPC) {
5971 /* whoops, lets try again with the full transaction */
5972 btrfs_end_transaction(trans, root);
5973 trans = btrfs_start_transaction(root, 1);
5974 if (IS_ERR(trans))
5975 return PTR_ERR(trans);
5976
5977 ret = btrfs_update_inode(trans, root, inode);
5978 }
5979 btrfs_end_transaction(trans, root);
5980 if (BTRFS_I(inode)->delayed_node)
5981 btrfs_balance_delayed_items(root);
5982
5983 return ret;
5984 }
5985
5986 /*
5987 * This is a copy of file_update_time. We need this so we can return error on
5988 * ENOSPC for updating the inode in the case of file write and mmap writes.
5989 */
5990 static int btrfs_update_time(struct inode *inode, struct timespec *now,
5991 int flags)
5992 {
5993 struct btrfs_root *root = BTRFS_I(inode)->root;
5994
5995 if (btrfs_root_readonly(root))
5996 return -EROFS;
5997
5998 if (flags & S_VERSION)
5999 inode_inc_iversion(inode);
6000 if (flags & S_CTIME)
6001 inode->i_ctime = *now;
6002 if (flags & S_MTIME)
6003 inode->i_mtime = *now;
6004 if (flags & S_ATIME)
6005 inode->i_atime = *now;
6006 return btrfs_dirty_inode(inode);
6007 }
6008
6009 /*
6010 * find the highest existing sequence number in a directory
6011 * and then set the in-memory index_cnt variable to reflect
6012 * free sequence numbers
6013 */
6014 static int btrfs_set_inode_index_count(struct inode *inode)
6015 {
6016 struct btrfs_root *root = BTRFS_I(inode)->root;
6017 struct btrfs_key key, found_key;
6018 struct btrfs_path *path;
6019 struct extent_buffer *leaf;
6020 int ret;
6021
6022 key.objectid = btrfs_ino(inode);
6023 key.type = BTRFS_DIR_INDEX_KEY;
6024 key.offset = (u64)-1;
6025
6026 path = btrfs_alloc_path();
6027 if (!path)
6028 return -ENOMEM;
6029
6030 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6031 if (ret < 0)
6032 goto out;
6033 /* FIXME: we should be able to handle this */
6034 if (ret == 0)
6035 goto out;
6036 ret = 0;
6037
6038 /*
6039 * MAGIC NUMBER EXPLANATION:
6040 * since we search a directory based on f_pos we have to start at 2
6041 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
6042 * else has to start at 2
6043 */
6044 if (path->slots[0] == 0) {
6045 BTRFS_I(inode)->index_cnt = 2;
6046 goto out;
6047 }
6048
6049 path->slots[0]--;
6050
6051 leaf = path->nodes[0];
6052 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6053
6054 if (found_key.objectid != btrfs_ino(inode) ||
6055 found_key.type != BTRFS_DIR_INDEX_KEY) {
6056 BTRFS_I(inode)->index_cnt = 2;
6057 goto out;
6058 }
6059
6060 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
6061 out:
6062 btrfs_free_path(path);
6063 return ret;
6064 }
6065
6066 /*
6067 * helper to find a free sequence number in a given directory. This current
6068 * code is very simple, later versions will do smarter things in the btree
6069 */
6070 int btrfs_set_inode_index(struct inode *dir, u64 *index)
6071 {
6072 int ret = 0;
6073
6074 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
6075 ret = btrfs_inode_delayed_dir_index_count(dir);
6076 if (ret) {
6077 ret = btrfs_set_inode_index_count(dir);
6078 if (ret)
6079 return ret;
6080 }
6081 }
6082
6083 *index = BTRFS_I(dir)->index_cnt;
6084 BTRFS_I(dir)->index_cnt++;
6085
6086 return ret;
6087 }
6088
6089 static int btrfs_insert_inode_locked(struct inode *inode)
6090 {
6091 struct btrfs_iget_args args;
6092 args.location = &BTRFS_I(inode)->location;
6093 args.root = BTRFS_I(inode)->root;
6094
6095 return insert_inode_locked4(inode,
6096 btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
6097 btrfs_find_actor, &args);
6098 }
6099
6100 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
6101 struct btrfs_root *root,
6102 struct inode *dir,
6103 const char *name, int name_len,
6104 u64 ref_objectid, u64 objectid,
6105 umode_t mode, u64 *index)
6106 {
6107 struct inode *inode;
6108 struct btrfs_inode_item *inode_item;
6109 struct btrfs_key *location;
6110 struct btrfs_path *path;
6111 struct btrfs_inode_ref *ref;
6112 struct btrfs_key key[2];
6113 u32 sizes[2];
6114 int nitems = name ? 2 : 1;
6115 unsigned long ptr;
6116 int ret;
6117
6118 path = btrfs_alloc_path();
6119 if (!path)
6120 return ERR_PTR(-ENOMEM);
6121
6122 inode = new_inode(root->fs_info->sb);
6123 if (!inode) {
6124 btrfs_free_path(path);
6125 return ERR_PTR(-ENOMEM);
6126 }
6127
6128 /*
6129 * O_TMPFILE, set link count to 0, so that after this point,
6130 * we fill in an inode item with the correct link count.
6131 */
6132 if (!name)
6133 set_nlink(inode, 0);
6134
6135 /*
6136 * we have to initialize this early, so we can reclaim the inode
6137 * number if we fail afterwards in this function.
6138 */
6139 inode->i_ino = objectid;
6140
6141 if (dir && name) {
6142 trace_btrfs_inode_request(dir);
6143
6144 ret = btrfs_set_inode_index(dir, index);
6145 if (ret) {
6146 btrfs_free_path(path);
6147 iput(inode);
6148 return ERR_PTR(ret);
6149 }
6150 } else if (dir) {
6151 *index = 0;
6152 }
6153 /*
6154 * index_cnt is ignored for everything but a dir,
6155 * btrfs_get_inode_index_count has an explanation for the magic
6156 * number
6157 */
6158 BTRFS_I(inode)->index_cnt = 2;
6159 BTRFS_I(inode)->dir_index = *index;
6160 BTRFS_I(inode)->root = root;
6161 BTRFS_I(inode)->generation = trans->transid;
6162 inode->i_generation = BTRFS_I(inode)->generation;
6163
6164 /*
6165 * We could have gotten an inode number from somebody who was fsynced
6166 * and then removed in this same transaction, so let's just set full
6167 * sync since it will be a full sync anyway and this will blow away the
6168 * old info in the log.
6169 */
6170 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
6171
6172 key[0].objectid = objectid;
6173 key[0].type = BTRFS_INODE_ITEM_KEY;
6174 key[0].offset = 0;
6175
6176 sizes[0] = sizeof(struct btrfs_inode_item);
6177
6178 if (name) {
6179 /*
6180 * Start new inodes with an inode_ref. This is slightly more
6181 * efficient for small numbers of hard links since they will
6182 * be packed into one item. Extended refs will kick in if we
6183 * add more hard links than can fit in the ref item.
6184 */
6185 key[1].objectid = objectid;
6186 key[1].type = BTRFS_INODE_REF_KEY;
6187 key[1].offset = ref_objectid;
6188
6189 sizes[1] = name_len + sizeof(*ref);
6190 }
6191
6192 location = &BTRFS_I(inode)->location;
6193 location->objectid = objectid;
6194 location->offset = 0;
6195 location->type = BTRFS_INODE_ITEM_KEY;
6196
6197 ret = btrfs_insert_inode_locked(inode);
6198 if (ret < 0)
6199 goto fail;
6200
6201 path->leave_spinning = 1;
6202 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
6203 if (ret != 0)
6204 goto fail_unlock;
6205
6206 inode_init_owner(inode, dir, mode);
6207 inode_set_bytes(inode, 0);
6208
6209 inode->i_mtime = CURRENT_TIME;
6210 inode->i_atime = inode->i_mtime;
6211 inode->i_ctime = inode->i_mtime;
6212 BTRFS_I(inode)->i_otime = inode->i_mtime;
6213
6214 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
6215 struct btrfs_inode_item);
6216 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
6217 sizeof(*inode_item));
6218 fill_inode_item(trans, path->nodes[0], inode_item, inode);
6219
6220 if (name) {
6221 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
6222 struct btrfs_inode_ref);
6223 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
6224 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
6225 ptr = (unsigned long)(ref + 1);
6226 write_extent_buffer(path->nodes[0], name, ptr, name_len);
6227 }
6228
6229 btrfs_mark_buffer_dirty(path->nodes[0]);
6230 btrfs_free_path(path);
6231
6232 btrfs_inherit_iflags(inode, dir);
6233
6234 if (S_ISREG(mode)) {
6235 if (btrfs_test_opt(root, NODATASUM))
6236 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6237 if (btrfs_test_opt(root, NODATACOW))
6238 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
6239 BTRFS_INODE_NODATASUM;
6240 }
6241
6242 inode_tree_add(inode);
6243
6244 trace_btrfs_inode_new(inode);
6245 btrfs_set_inode_last_trans(trans, inode);
6246
6247 btrfs_update_root_times(trans, root);
6248
6249 ret = btrfs_inode_inherit_props(trans, inode, dir);
6250 if (ret)
6251 btrfs_err(root->fs_info,
6252 "error inheriting props for ino %llu (root %llu): %d",
6253 btrfs_ino(inode), root->root_key.objectid, ret);
6254
6255 return inode;
6256
6257 fail_unlock:
6258 unlock_new_inode(inode);
6259 fail:
6260 if (dir && name)
6261 BTRFS_I(dir)->index_cnt--;
6262 btrfs_free_path(path);
6263 iput(inode);
6264 return ERR_PTR(ret);
6265 }
6266
6267 static inline u8 btrfs_inode_type(struct inode *inode)
6268 {
6269 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
6270 }
6271
6272 /*
6273 * utility function to add 'inode' into 'parent_inode' with
6274 * a give name and a given sequence number.
6275 * if 'add_backref' is true, also insert a backref from the
6276 * inode to the parent directory.
6277 */
6278 int btrfs_add_link(struct btrfs_trans_handle *trans,
6279 struct inode *parent_inode, struct inode *inode,
6280 const char *name, int name_len, int add_backref, u64 index)
6281 {
6282 int ret = 0;
6283 struct btrfs_key key;
6284 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
6285 u64 ino = btrfs_ino(inode);
6286 u64 parent_ino = btrfs_ino(parent_inode);
6287
6288 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6289 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
6290 } else {
6291 key.objectid = ino;
6292 key.type = BTRFS_INODE_ITEM_KEY;
6293 key.offset = 0;
6294 }
6295
6296 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6297 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
6298 key.objectid, root->root_key.objectid,
6299 parent_ino, index, name, name_len);
6300 } else if (add_backref) {
6301 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
6302 parent_ino, index);
6303 }
6304
6305 /* Nothing to clean up yet */
6306 if (ret)
6307 return ret;
6308
6309 ret = btrfs_insert_dir_item(trans, root, name, name_len,
6310 parent_inode, &key,
6311 btrfs_inode_type(inode), index);
6312 if (ret == -EEXIST || ret == -EOVERFLOW)
6313 goto fail_dir_item;
6314 else if (ret) {
6315 btrfs_abort_transaction(trans, root, ret);
6316 return ret;
6317 }
6318
6319 btrfs_i_size_write(parent_inode, parent_inode->i_size +
6320 name_len * 2);
6321 inode_inc_iversion(parent_inode);
6322 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
6323 ret = btrfs_update_inode(trans, root, parent_inode);
6324 if (ret)
6325 btrfs_abort_transaction(trans, root, ret);
6326 return ret;
6327
6328 fail_dir_item:
6329 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6330 u64 local_index;
6331 int err;
6332 err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
6333 key.objectid, root->root_key.objectid,
6334 parent_ino, &local_index, name, name_len);
6335
6336 } else if (add_backref) {
6337 u64 local_index;
6338 int err;
6339
6340 err = btrfs_del_inode_ref(trans, root, name, name_len,
6341 ino, parent_ino, &local_index);
6342 }
6343 return ret;
6344 }
6345
6346 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
6347 struct inode *dir, struct dentry *dentry,
6348 struct inode *inode, int backref, u64 index)
6349 {
6350 int err = btrfs_add_link(trans, dir, inode,
6351 dentry->d_name.name, dentry->d_name.len,
6352 backref, index);
6353 if (err > 0)
6354 err = -EEXIST;
6355 return err;
6356 }
6357
6358 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
6359 umode_t mode, dev_t rdev)
6360 {
6361 struct btrfs_trans_handle *trans;
6362 struct btrfs_root *root = BTRFS_I(dir)->root;
6363 struct inode *inode = NULL;
6364 int err;
6365 int drop_inode = 0;
6366 u64 objectid;
6367 u64 index = 0;
6368
6369 /*
6370 * 2 for inode item and ref
6371 * 2 for dir items
6372 * 1 for xattr if selinux is on
6373 */
6374 trans = btrfs_start_transaction(root, 5);
6375 if (IS_ERR(trans))
6376 return PTR_ERR(trans);
6377
6378 err = btrfs_find_free_ino(root, &objectid);
6379 if (err)
6380 goto out_unlock;
6381
6382 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6383 dentry->d_name.len, btrfs_ino(dir), objectid,
6384 mode, &index);
6385 if (IS_ERR(inode)) {
6386 err = PTR_ERR(inode);
6387 goto out_unlock;
6388 }
6389
6390 /*
6391 * If the active LSM wants to access the inode during
6392 * d_instantiate it needs these. Smack checks to see
6393 * if the filesystem supports xattrs by looking at the
6394 * ops vector.
6395 */
6396 inode->i_op = &btrfs_special_inode_operations;
6397 init_special_inode(inode, inode->i_mode, rdev);
6398
6399 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6400 if (err)
6401 goto out_unlock_inode;
6402
6403 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
6404 if (err) {
6405 goto out_unlock_inode;
6406 } else {
6407 btrfs_update_inode(trans, root, inode);
6408 unlock_new_inode(inode);
6409 d_instantiate(dentry, inode);
6410 }
6411
6412 out_unlock:
6413 btrfs_end_transaction(trans, root);
6414 btrfs_balance_delayed_items(root);
6415 btrfs_btree_balance_dirty(root);
6416 if (drop_inode) {
6417 inode_dec_link_count(inode);
6418 iput(inode);
6419 }
6420 return err;
6421
6422 out_unlock_inode:
6423 drop_inode = 1;
6424 unlock_new_inode(inode);
6425 goto out_unlock;
6426
6427 }
6428
6429 static int btrfs_create(struct inode *dir, struct dentry *dentry,
6430 umode_t mode, bool excl)
6431 {
6432 struct btrfs_trans_handle *trans;
6433 struct btrfs_root *root = BTRFS_I(dir)->root;
6434 struct inode *inode = NULL;
6435 int drop_inode_on_err = 0;
6436 int err;
6437 u64 objectid;
6438 u64 index = 0;
6439
6440 /*
6441 * 2 for inode item and ref
6442 * 2 for dir items
6443 * 1 for xattr if selinux is on
6444 */
6445 trans = btrfs_start_transaction(root, 5);
6446 if (IS_ERR(trans))
6447 return PTR_ERR(trans);
6448
6449 err = btrfs_find_free_ino(root, &objectid);
6450 if (err)
6451 goto out_unlock;
6452
6453 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6454 dentry->d_name.len, btrfs_ino(dir), objectid,
6455 mode, &index);
6456 if (IS_ERR(inode)) {
6457 err = PTR_ERR(inode);
6458 goto out_unlock;
6459 }
6460 drop_inode_on_err = 1;
6461 /*
6462 * If the active LSM wants to access the inode during
6463 * d_instantiate it needs these. Smack checks to see
6464 * if the filesystem supports xattrs by looking at the
6465 * ops vector.
6466 */
6467 inode->i_fop = &btrfs_file_operations;
6468 inode->i_op = &btrfs_file_inode_operations;
6469 inode->i_mapping->a_ops = &btrfs_aops;
6470
6471 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6472 if (err)
6473 goto out_unlock_inode;
6474
6475 err = btrfs_update_inode(trans, root, inode);
6476 if (err)
6477 goto out_unlock_inode;
6478
6479 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
6480 if (err)
6481 goto out_unlock_inode;
6482
6483 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
6484 unlock_new_inode(inode);
6485 d_instantiate(dentry, inode);
6486
6487 out_unlock:
6488 btrfs_end_transaction(trans, root);
6489 if (err && drop_inode_on_err) {
6490 inode_dec_link_count(inode);
6491 iput(inode);
6492 }
6493 btrfs_balance_delayed_items(root);
6494 btrfs_btree_balance_dirty(root);
6495 return err;
6496
6497 out_unlock_inode:
6498 unlock_new_inode(inode);
6499 goto out_unlock;
6500
6501 }
6502
6503 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
6504 struct dentry *dentry)
6505 {
6506 struct btrfs_trans_handle *trans;
6507 struct btrfs_root *root = BTRFS_I(dir)->root;
6508 struct inode *inode = d_inode(old_dentry);
6509 u64 index;
6510 int err;
6511 int drop_inode = 0;
6512
6513 /* do not allow sys_link's with other subvols of the same device */
6514 if (root->objectid != BTRFS_I(inode)->root->objectid)
6515 return -EXDEV;
6516
6517 if (inode->i_nlink >= BTRFS_LINK_MAX)
6518 return -EMLINK;
6519
6520 err = btrfs_set_inode_index(dir, &index);
6521 if (err)
6522 goto fail;
6523
6524 /*
6525 * 2 items for inode and inode ref
6526 * 2 items for dir items
6527 * 1 item for parent inode
6528 */
6529 trans = btrfs_start_transaction(root, 5);
6530 if (IS_ERR(trans)) {
6531 err = PTR_ERR(trans);
6532 goto fail;
6533 }
6534
6535 /* There are several dir indexes for this inode, clear the cache. */
6536 BTRFS_I(inode)->dir_index = 0ULL;
6537 inc_nlink(inode);
6538 inode_inc_iversion(inode);
6539 inode->i_ctime = CURRENT_TIME;
6540 ihold(inode);
6541 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
6542
6543 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
6544
6545 if (err) {
6546 drop_inode = 1;
6547 } else {
6548 struct dentry *parent = dentry->d_parent;
6549 err = btrfs_update_inode(trans, root, inode);
6550 if (err)
6551 goto fail;
6552 if (inode->i_nlink == 1) {
6553 /*
6554 * If new hard link count is 1, it's a file created
6555 * with open(2) O_TMPFILE flag.
6556 */
6557 err = btrfs_orphan_del(trans, inode);
6558 if (err)
6559 goto fail;
6560 }
6561 d_instantiate(dentry, inode);
6562 btrfs_log_new_name(trans, inode, NULL, parent);
6563 }
6564
6565 btrfs_end_transaction(trans, root);
6566 btrfs_balance_delayed_items(root);
6567 fail:
6568 if (drop_inode) {
6569 inode_dec_link_count(inode);
6570 iput(inode);
6571 }
6572 btrfs_btree_balance_dirty(root);
6573 return err;
6574 }
6575
6576 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
6577 {
6578 struct inode *inode = NULL;
6579 struct btrfs_trans_handle *trans;
6580 struct btrfs_root *root = BTRFS_I(dir)->root;
6581 int err = 0;
6582 int drop_on_err = 0;
6583 u64 objectid = 0;
6584 u64 index = 0;
6585
6586 /*
6587 * 2 items for inode and ref
6588 * 2 items for dir items
6589 * 1 for xattr if selinux is on
6590 */
6591 trans = btrfs_start_transaction(root, 5);
6592 if (IS_ERR(trans))
6593 return PTR_ERR(trans);
6594
6595 err = btrfs_find_free_ino(root, &objectid);
6596 if (err)
6597 goto out_fail;
6598
6599 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6600 dentry->d_name.len, btrfs_ino(dir), objectid,
6601 S_IFDIR | mode, &index);
6602 if (IS_ERR(inode)) {
6603 err = PTR_ERR(inode);
6604 goto out_fail;
6605 }
6606
6607 drop_on_err = 1;
6608 /* these must be set before we unlock the inode */
6609 inode->i_op = &btrfs_dir_inode_operations;
6610 inode->i_fop = &btrfs_dir_file_operations;
6611
6612 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6613 if (err)
6614 goto out_fail_inode;
6615
6616 btrfs_i_size_write(inode, 0);
6617 err = btrfs_update_inode(trans, root, inode);
6618 if (err)
6619 goto out_fail_inode;
6620
6621 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
6622 dentry->d_name.len, 0, index);
6623 if (err)
6624 goto out_fail_inode;
6625
6626 d_instantiate(dentry, inode);
6627 /*
6628 * mkdir is special. We're unlocking after we call d_instantiate
6629 * to avoid a race with nfsd calling d_instantiate.
6630 */
6631 unlock_new_inode(inode);
6632 drop_on_err = 0;
6633
6634 out_fail:
6635 btrfs_end_transaction(trans, root);
6636 if (drop_on_err) {
6637 inode_dec_link_count(inode);
6638 iput(inode);
6639 }
6640 btrfs_balance_delayed_items(root);
6641 btrfs_btree_balance_dirty(root);
6642 return err;
6643
6644 out_fail_inode:
6645 unlock_new_inode(inode);
6646 goto out_fail;
6647 }
6648
6649 /* Find next extent map of a given extent map, caller needs to ensure locks */
6650 static struct extent_map *next_extent_map(struct extent_map *em)
6651 {
6652 struct rb_node *next;
6653
6654 next = rb_next(&em->rb_node);
6655 if (!next)
6656 return NULL;
6657 return container_of(next, struct extent_map, rb_node);
6658 }
6659
6660 static struct extent_map *prev_extent_map(struct extent_map *em)
6661 {
6662 struct rb_node *prev;
6663
6664 prev = rb_prev(&em->rb_node);
6665 if (!prev)
6666 return NULL;
6667 return container_of(prev, struct extent_map, rb_node);
6668 }
6669
6670 /* helper for btfs_get_extent. Given an existing extent in the tree,
6671 * the existing extent is the nearest extent to map_start,
6672 * and an extent that you want to insert, deal with overlap and insert
6673 * the best fitted new extent into the tree.
6674 */
6675 static int merge_extent_mapping(struct extent_map_tree *em_tree,
6676 struct extent_map *existing,
6677 struct extent_map *em,
6678 u64 map_start)
6679 {
6680 struct extent_map *prev;
6681 struct extent_map *next;
6682 u64 start;
6683 u64 end;
6684 u64 start_diff;
6685
6686 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
6687
6688 if (existing->start > map_start) {
6689 next = existing;
6690 prev = prev_extent_map(next);
6691 } else {
6692 prev = existing;
6693 next = next_extent_map(prev);
6694 }
6695
6696 start = prev ? extent_map_end(prev) : em->start;
6697 start = max_t(u64, start, em->start);
6698 end = next ? next->start : extent_map_end(em);
6699 end = min_t(u64, end, extent_map_end(em));
6700 start_diff = start - em->start;
6701 em->start = start;
6702 em->len = end - start;
6703 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
6704 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
6705 em->block_start += start_diff;
6706 em->block_len -= start_diff;
6707 }
6708 return add_extent_mapping(em_tree, em, 0);
6709 }
6710
6711 static noinline int uncompress_inline(struct btrfs_path *path,
6712 struct inode *inode, struct page *page,
6713 size_t pg_offset, u64 extent_offset,
6714 struct btrfs_file_extent_item *item)
6715 {
6716 int ret;
6717 struct extent_buffer *leaf = path->nodes[0];
6718 char *tmp;
6719 size_t max_size;
6720 unsigned long inline_size;
6721 unsigned long ptr;
6722 int compress_type;
6723
6724 WARN_ON(pg_offset != 0);
6725 compress_type = btrfs_file_extent_compression(leaf, item);
6726 max_size = btrfs_file_extent_ram_bytes(leaf, item);
6727 inline_size = btrfs_file_extent_inline_item_len(leaf,
6728 btrfs_item_nr(path->slots[0]));
6729 tmp = kmalloc(inline_size, GFP_NOFS);
6730 if (!tmp)
6731 return -ENOMEM;
6732 ptr = btrfs_file_extent_inline_start(item);
6733
6734 read_extent_buffer(leaf, tmp, ptr, inline_size);
6735
6736 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
6737 ret = btrfs_decompress(compress_type, tmp, page,
6738 extent_offset, inline_size, max_size);
6739 kfree(tmp);
6740 return ret;
6741 }
6742
6743 /*
6744 * a bit scary, this does extent mapping from logical file offset to the disk.
6745 * the ugly parts come from merging extents from the disk with the in-ram
6746 * representation. This gets more complex because of the data=ordered code,
6747 * where the in-ram extents might be locked pending data=ordered completion.
6748 *
6749 * This also copies inline extents directly into the page.
6750 */
6751
6752 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
6753 size_t pg_offset, u64 start, u64 len,
6754 int create)
6755 {
6756 int ret;
6757 int err = 0;
6758 u64 extent_start = 0;
6759 u64 extent_end = 0;
6760 u64 objectid = btrfs_ino(inode);
6761 u32 found_type;
6762 struct btrfs_path *path = NULL;
6763 struct btrfs_root *root = BTRFS_I(inode)->root;
6764 struct btrfs_file_extent_item *item;
6765 struct extent_buffer *leaf;
6766 struct btrfs_key found_key;
6767 struct extent_map *em = NULL;
6768 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
6769 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6770 struct btrfs_trans_handle *trans = NULL;
6771 const bool new_inline = !page || create;
6772
6773 again:
6774 read_lock(&em_tree->lock);
6775 em = lookup_extent_mapping(em_tree, start, len);
6776 if (em)
6777 em->bdev = root->fs_info->fs_devices->latest_bdev;
6778 read_unlock(&em_tree->lock);
6779
6780 if (em) {
6781 if (em->start > start || em->start + em->len <= start)
6782 free_extent_map(em);
6783 else if (em->block_start == EXTENT_MAP_INLINE && page)
6784 free_extent_map(em);
6785 else
6786 goto out;
6787 }
6788 em = alloc_extent_map();
6789 if (!em) {
6790 err = -ENOMEM;
6791 goto out;
6792 }
6793 em->bdev = root->fs_info->fs_devices->latest_bdev;
6794 em->start = EXTENT_MAP_HOLE;
6795 em->orig_start = EXTENT_MAP_HOLE;
6796 em->len = (u64)-1;
6797 em->block_len = (u64)-1;
6798
6799 if (!path) {
6800 path = btrfs_alloc_path();
6801 if (!path) {
6802 err = -ENOMEM;
6803 goto out;
6804 }
6805 /*
6806 * Chances are we'll be called again, so go ahead and do
6807 * readahead
6808 */
6809 path->reada = 1;
6810 }
6811
6812 ret = btrfs_lookup_file_extent(trans, root, path,
6813 objectid, start, trans != NULL);
6814 if (ret < 0) {
6815 err = ret;
6816 goto out;
6817 }
6818
6819 if (ret != 0) {
6820 if (path->slots[0] == 0)
6821 goto not_found;
6822 path->slots[0]--;
6823 }
6824
6825 leaf = path->nodes[0];
6826 item = btrfs_item_ptr(leaf, path->slots[0],
6827 struct btrfs_file_extent_item);
6828 /* are we inside the extent that was found? */
6829 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6830 found_type = found_key.type;
6831 if (found_key.objectid != objectid ||
6832 found_type != BTRFS_EXTENT_DATA_KEY) {
6833 /*
6834 * If we backup past the first extent we want to move forward
6835 * and see if there is an extent in front of us, otherwise we'll
6836 * say there is a hole for our whole search range which can
6837 * cause problems.
6838 */
6839 extent_end = start;
6840 goto next;
6841 }
6842
6843 found_type = btrfs_file_extent_type(leaf, item);
6844 extent_start = found_key.offset;
6845 if (found_type == BTRFS_FILE_EXTENT_REG ||
6846 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6847 extent_end = extent_start +
6848 btrfs_file_extent_num_bytes(leaf, item);
6849 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6850 size_t size;
6851 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6852 extent_end = ALIGN(extent_start + size, root->sectorsize);
6853 }
6854 next:
6855 if (start >= extent_end) {
6856 path->slots[0]++;
6857 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
6858 ret = btrfs_next_leaf(root, path);
6859 if (ret < 0) {
6860 err = ret;
6861 goto out;
6862 }
6863 if (ret > 0)
6864 goto not_found;
6865 leaf = path->nodes[0];
6866 }
6867 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6868 if (found_key.objectid != objectid ||
6869 found_key.type != BTRFS_EXTENT_DATA_KEY)
6870 goto not_found;
6871 if (start + len <= found_key.offset)
6872 goto not_found;
6873 if (start > found_key.offset)
6874 goto next;
6875 em->start = start;
6876 em->orig_start = start;
6877 em->len = found_key.offset - start;
6878 goto not_found_em;
6879 }
6880
6881 btrfs_extent_item_to_extent_map(inode, path, item, new_inline, em);
6882
6883 if (found_type == BTRFS_FILE_EXTENT_REG ||
6884 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6885 goto insert;
6886 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6887 unsigned long ptr;
6888 char *map;
6889 size_t size;
6890 size_t extent_offset;
6891 size_t copy_size;
6892
6893 if (new_inline)
6894 goto out;
6895
6896 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6897 extent_offset = page_offset(page) + pg_offset - extent_start;
6898 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
6899 size - extent_offset);
6900 em->start = extent_start + extent_offset;
6901 em->len = ALIGN(copy_size, root->sectorsize);
6902 em->orig_block_len = em->len;
6903 em->orig_start = em->start;
6904 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
6905 if (create == 0 && !PageUptodate(page)) {
6906 if (btrfs_file_extent_compression(leaf, item) !=
6907 BTRFS_COMPRESS_NONE) {
6908 ret = uncompress_inline(path, inode, page,
6909 pg_offset,
6910 extent_offset, item);
6911 if (ret) {
6912 err = ret;
6913 goto out;
6914 }
6915 } else {
6916 map = kmap(page);
6917 read_extent_buffer(leaf, map + pg_offset, ptr,
6918 copy_size);
6919 if (pg_offset + copy_size < PAGE_CACHE_SIZE) {
6920 memset(map + pg_offset + copy_size, 0,
6921 PAGE_CACHE_SIZE - pg_offset -
6922 copy_size);
6923 }
6924 kunmap(page);
6925 }
6926 flush_dcache_page(page);
6927 } else if (create && PageUptodate(page)) {
6928 BUG();
6929 if (!trans) {
6930 kunmap(page);
6931 free_extent_map(em);
6932 em = NULL;
6933
6934 btrfs_release_path(path);
6935 trans = btrfs_join_transaction(root);
6936
6937 if (IS_ERR(trans))
6938 return ERR_CAST(trans);
6939 goto again;
6940 }
6941 map = kmap(page);
6942 write_extent_buffer(leaf, map + pg_offset, ptr,
6943 copy_size);
6944 kunmap(page);
6945 btrfs_mark_buffer_dirty(leaf);
6946 }
6947 set_extent_uptodate(io_tree, em->start,
6948 extent_map_end(em) - 1, NULL, GFP_NOFS);
6949 goto insert;
6950 }
6951 not_found:
6952 em->start = start;
6953 em->orig_start = start;
6954 em->len = len;
6955 not_found_em:
6956 em->block_start = EXTENT_MAP_HOLE;
6957 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
6958 insert:
6959 btrfs_release_path(path);
6960 if (em->start > start || extent_map_end(em) <= start) {
6961 btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]",
6962 em->start, em->len, start, len);
6963 err = -EIO;
6964 goto out;
6965 }
6966
6967 err = 0;
6968 write_lock(&em_tree->lock);
6969 ret = add_extent_mapping(em_tree, em, 0);
6970 /* it is possible that someone inserted the extent into the tree
6971 * while we had the lock dropped. It is also possible that
6972 * an overlapping map exists in the tree
6973 */
6974 if (ret == -EEXIST) {
6975 struct extent_map *existing;
6976
6977 ret = 0;
6978
6979 existing = search_extent_mapping(em_tree, start, len);
6980 /*
6981 * existing will always be non-NULL, since there must be
6982 * extent causing the -EEXIST.
6983 */
6984 if (start >= extent_map_end(existing) ||
6985 start <= existing->start) {
6986 /*
6987 * The existing extent map is the one nearest to
6988 * the [start, start + len) range which overlaps
6989 */
6990 err = merge_extent_mapping(em_tree, existing,
6991 em, start);
6992 free_extent_map(existing);
6993 if (err) {
6994 free_extent_map(em);
6995 em = NULL;
6996 }
6997 } else {
6998 free_extent_map(em);
6999 em = existing;
7000 err = 0;
7001 }
7002 }
7003 write_unlock(&em_tree->lock);
7004 out:
7005
7006 trace_btrfs_get_extent(root, em);
7007
7008 btrfs_free_path(path);
7009 if (trans) {
7010 ret = btrfs_end_transaction(trans, root);
7011 if (!err)
7012 err = ret;
7013 }
7014 if (err) {
7015 free_extent_map(em);
7016 return ERR_PTR(err);
7017 }
7018 BUG_ON(!em); /* Error is always set */
7019 return em;
7020 }
7021
7022 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
7023 size_t pg_offset, u64 start, u64 len,
7024 int create)
7025 {
7026 struct extent_map *em;
7027 struct extent_map *hole_em = NULL;
7028 u64 range_start = start;
7029 u64 end;
7030 u64 found;
7031 u64 found_end;
7032 int err = 0;
7033
7034 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
7035 if (IS_ERR(em))
7036 return em;
7037 if (em) {
7038 /*
7039 * if our em maps to
7040 * - a hole or
7041 * - a pre-alloc extent,
7042 * there might actually be delalloc bytes behind it.
7043 */
7044 if (em->block_start != EXTENT_MAP_HOLE &&
7045 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7046 return em;
7047 else
7048 hole_em = em;
7049 }
7050
7051 /* check to see if we've wrapped (len == -1 or similar) */
7052 end = start + len;
7053 if (end < start)
7054 end = (u64)-1;
7055 else
7056 end -= 1;
7057
7058 em = NULL;
7059
7060 /* ok, we didn't find anything, lets look for delalloc */
7061 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
7062 end, len, EXTENT_DELALLOC, 1);
7063 found_end = range_start + found;
7064 if (found_end < range_start)
7065 found_end = (u64)-1;
7066
7067 /*
7068 * we didn't find anything useful, return
7069 * the original results from get_extent()
7070 */
7071 if (range_start > end || found_end <= start) {
7072 em = hole_em;
7073 hole_em = NULL;
7074 goto out;
7075 }
7076
7077 /* adjust the range_start to make sure it doesn't
7078 * go backwards from the start they passed in
7079 */
7080 range_start = max(start, range_start);
7081 found = found_end - range_start;
7082
7083 if (found > 0) {
7084 u64 hole_start = start;
7085 u64 hole_len = len;
7086
7087 em = alloc_extent_map();
7088 if (!em) {
7089 err = -ENOMEM;
7090 goto out;
7091 }
7092 /*
7093 * when btrfs_get_extent can't find anything it
7094 * returns one huge hole
7095 *
7096 * make sure what it found really fits our range, and
7097 * adjust to make sure it is based on the start from
7098 * the caller
7099 */
7100 if (hole_em) {
7101 u64 calc_end = extent_map_end(hole_em);
7102
7103 if (calc_end <= start || (hole_em->start > end)) {
7104 free_extent_map(hole_em);
7105 hole_em = NULL;
7106 } else {
7107 hole_start = max(hole_em->start, start);
7108 hole_len = calc_end - hole_start;
7109 }
7110 }
7111 em->bdev = NULL;
7112 if (hole_em && range_start > hole_start) {
7113 /* our hole starts before our delalloc, so we
7114 * have to return just the parts of the hole
7115 * that go until the delalloc starts
7116 */
7117 em->len = min(hole_len,
7118 range_start - hole_start);
7119 em->start = hole_start;
7120 em->orig_start = hole_start;
7121 /*
7122 * don't adjust block start at all,
7123 * it is fixed at EXTENT_MAP_HOLE
7124 */
7125 em->block_start = hole_em->block_start;
7126 em->block_len = hole_len;
7127 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
7128 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
7129 } else {
7130 em->start = range_start;
7131 em->len = found;
7132 em->orig_start = range_start;
7133 em->block_start = EXTENT_MAP_DELALLOC;
7134 em->block_len = found;
7135 }
7136 } else if (hole_em) {
7137 return hole_em;
7138 }
7139 out:
7140
7141 free_extent_map(hole_em);
7142 if (err) {
7143 free_extent_map(em);
7144 return ERR_PTR(err);
7145 }
7146 return em;
7147 }
7148
7149 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
7150 u64 start, u64 len)
7151 {
7152 struct btrfs_root *root = BTRFS_I(inode)->root;
7153 struct extent_map *em;
7154 struct btrfs_key ins;
7155 u64 alloc_hint;
7156 int ret;
7157
7158 alloc_hint = get_extent_allocation_hint(inode, start, len);
7159 ret = btrfs_reserve_extent(root, len, root->sectorsize, 0,
7160 alloc_hint, &ins, 1, 1);
7161 if (ret)
7162 return ERR_PTR(ret);
7163
7164 em = create_pinned_em(inode, start, ins.offset, start, ins.objectid,
7165 ins.offset, ins.offset, ins.offset, 0);
7166 if (IS_ERR(em)) {
7167 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
7168 return em;
7169 }
7170
7171 ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
7172 ins.offset, ins.offset, 0);
7173 if (ret) {
7174 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
7175 free_extent_map(em);
7176 return ERR_PTR(ret);
7177 }
7178
7179 return em;
7180 }
7181
7182 /*
7183 * returns 1 when the nocow is safe, < 1 on error, 0 if the
7184 * block must be cow'd
7185 */
7186 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
7187 u64 *orig_start, u64 *orig_block_len,
7188 u64 *ram_bytes)
7189 {
7190 struct btrfs_trans_handle *trans;
7191 struct btrfs_path *path;
7192 int ret;
7193 struct extent_buffer *leaf;
7194 struct btrfs_root *root = BTRFS_I(inode)->root;
7195 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7196 struct btrfs_file_extent_item *fi;
7197 struct btrfs_key key;
7198 u64 disk_bytenr;
7199 u64 backref_offset;
7200 u64 extent_end;
7201 u64 num_bytes;
7202 int slot;
7203 int found_type;
7204 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
7205
7206 path = btrfs_alloc_path();
7207 if (!path)
7208 return -ENOMEM;
7209
7210 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode),
7211 offset, 0);
7212 if (ret < 0)
7213 goto out;
7214
7215 slot = path->slots[0];
7216 if (ret == 1) {
7217 if (slot == 0) {
7218 /* can't find the item, must cow */
7219 ret = 0;
7220 goto out;
7221 }
7222 slot--;
7223 }
7224 ret = 0;
7225 leaf = path->nodes[0];
7226 btrfs_item_key_to_cpu(leaf, &key, slot);
7227 if (key.objectid != btrfs_ino(inode) ||
7228 key.type != BTRFS_EXTENT_DATA_KEY) {
7229 /* not our file or wrong item type, must cow */
7230 goto out;
7231 }
7232
7233 if (key.offset > offset) {
7234 /* Wrong offset, must cow */
7235 goto out;
7236 }
7237
7238 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
7239 found_type = btrfs_file_extent_type(leaf, fi);
7240 if (found_type != BTRFS_FILE_EXTENT_REG &&
7241 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
7242 /* not a regular extent, must cow */
7243 goto out;
7244 }
7245
7246 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
7247 goto out;
7248
7249 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
7250 if (extent_end <= offset)
7251 goto out;
7252
7253 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
7254 if (disk_bytenr == 0)
7255 goto out;
7256
7257 if (btrfs_file_extent_compression(leaf, fi) ||
7258 btrfs_file_extent_encryption(leaf, fi) ||
7259 btrfs_file_extent_other_encoding(leaf, fi))
7260 goto out;
7261
7262 backref_offset = btrfs_file_extent_offset(leaf, fi);
7263
7264 if (orig_start) {
7265 *orig_start = key.offset - backref_offset;
7266 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
7267 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
7268 }
7269
7270 if (btrfs_extent_readonly(root, disk_bytenr))
7271 goto out;
7272
7273 num_bytes = min(offset + *len, extent_end) - offset;
7274 if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7275 u64 range_end;
7276
7277 range_end = round_up(offset + num_bytes, root->sectorsize) - 1;
7278 ret = test_range_bit(io_tree, offset, range_end,
7279 EXTENT_DELALLOC, 0, NULL);
7280 if (ret) {
7281 ret = -EAGAIN;
7282 goto out;
7283 }
7284 }
7285
7286 btrfs_release_path(path);
7287
7288 /*
7289 * look for other files referencing this extent, if we
7290 * find any we must cow
7291 */
7292 trans = btrfs_join_transaction(root);
7293 if (IS_ERR(trans)) {
7294 ret = 0;
7295 goto out;
7296 }
7297
7298 ret = btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
7299 key.offset - backref_offset, disk_bytenr);
7300 btrfs_end_transaction(trans, root);
7301 if (ret) {
7302 ret = 0;
7303 goto out;
7304 }
7305
7306 /*
7307 * adjust disk_bytenr and num_bytes to cover just the bytes
7308 * in this extent we are about to write. If there
7309 * are any csums in that range we have to cow in order
7310 * to keep the csums correct
7311 */
7312 disk_bytenr += backref_offset;
7313 disk_bytenr += offset - key.offset;
7314 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
7315 goto out;
7316 /*
7317 * all of the above have passed, it is safe to overwrite this extent
7318 * without cow
7319 */
7320 *len = num_bytes;
7321 ret = 1;
7322 out:
7323 btrfs_free_path(path);
7324 return ret;
7325 }
7326
7327 bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end)
7328 {
7329 struct radix_tree_root *root = &inode->i_mapping->page_tree;
7330 int found = false;
7331 void **pagep = NULL;
7332 struct page *page = NULL;
7333 int start_idx;
7334 int end_idx;
7335
7336 start_idx = start >> PAGE_CACHE_SHIFT;
7337
7338 /*
7339 * end is the last byte in the last page. end == start is legal
7340 */
7341 end_idx = end >> PAGE_CACHE_SHIFT;
7342
7343 rcu_read_lock();
7344
7345 /* Most of the code in this while loop is lifted from
7346 * find_get_page. It's been modified to begin searching from a
7347 * page and return just the first page found in that range. If the
7348 * found idx is less than or equal to the end idx then we know that
7349 * a page exists. If no pages are found or if those pages are
7350 * outside of the range then we're fine (yay!) */
7351 while (page == NULL &&
7352 radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) {
7353 page = radix_tree_deref_slot(pagep);
7354 if (unlikely(!page))
7355 break;
7356
7357 if (radix_tree_exception(page)) {
7358 if (radix_tree_deref_retry(page)) {
7359 page = NULL;
7360 continue;
7361 }
7362 /*
7363 * Otherwise, shmem/tmpfs must be storing a swap entry
7364 * here as an exceptional entry: so return it without
7365 * attempting to raise page count.
7366 */
7367 page = NULL;
7368 break; /* TODO: Is this relevant for this use case? */
7369 }
7370
7371 if (!page_cache_get_speculative(page)) {
7372 page = NULL;
7373 continue;
7374 }
7375
7376 /*
7377 * Has the page moved?
7378 * This is part of the lockless pagecache protocol. See
7379 * include/linux/pagemap.h for details.
7380 */
7381 if (unlikely(page != *pagep)) {
7382 page_cache_release(page);
7383 page = NULL;
7384 }
7385 }
7386
7387 if (page) {
7388 if (page->index <= end_idx)
7389 found = true;
7390 page_cache_release(page);
7391 }
7392
7393 rcu_read_unlock();
7394 return found;
7395 }
7396
7397 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
7398 struct extent_state **cached_state, int writing)
7399 {
7400 struct btrfs_ordered_extent *ordered;
7401 int ret = 0;
7402
7403 while (1) {
7404 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7405 0, cached_state);
7406 /*
7407 * We're concerned with the entire range that we're going to be
7408 * doing DIO to, so we need to make sure theres no ordered
7409 * extents in this range.
7410 */
7411 ordered = btrfs_lookup_ordered_range(inode, lockstart,
7412 lockend - lockstart + 1);
7413
7414 /*
7415 * We need to make sure there are no buffered pages in this
7416 * range either, we could have raced between the invalidate in
7417 * generic_file_direct_write and locking the extent. The
7418 * invalidate needs to happen so that reads after a write do not
7419 * get stale data.
7420 */
7421 if (!ordered &&
7422 (!writing ||
7423 !btrfs_page_exists_in_range(inode, lockstart, lockend)))
7424 break;
7425
7426 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7427 cached_state, GFP_NOFS);
7428
7429 if (ordered) {
7430 btrfs_start_ordered_extent(inode, ordered, 1);
7431 btrfs_put_ordered_extent(ordered);
7432 } else {
7433 /* Screw you mmap */
7434 ret = btrfs_fdatawrite_range(inode, lockstart, lockend);
7435 if (ret)
7436 break;
7437 ret = filemap_fdatawait_range(inode->i_mapping,
7438 lockstart,
7439 lockend);
7440 if (ret)
7441 break;
7442
7443 /*
7444 * If we found a page that couldn't be invalidated just
7445 * fall back to buffered.
7446 */
7447 ret = invalidate_inode_pages2_range(inode->i_mapping,
7448 lockstart >> PAGE_CACHE_SHIFT,
7449 lockend >> PAGE_CACHE_SHIFT);
7450 if (ret)
7451 break;
7452 }
7453
7454 cond_resched();
7455 }
7456
7457 return ret;
7458 }
7459
7460 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
7461 u64 len, u64 orig_start,
7462 u64 block_start, u64 block_len,
7463 u64 orig_block_len, u64 ram_bytes,
7464 int type)
7465 {
7466 struct extent_map_tree *em_tree;
7467 struct extent_map *em;
7468 struct btrfs_root *root = BTRFS_I(inode)->root;
7469 int ret;
7470
7471 em_tree = &BTRFS_I(inode)->extent_tree;
7472 em = alloc_extent_map();
7473 if (!em)
7474 return ERR_PTR(-ENOMEM);
7475
7476 em->start = start;
7477 em->orig_start = orig_start;
7478 em->mod_start = start;
7479 em->mod_len = len;
7480 em->len = len;
7481 em->block_len = block_len;
7482 em->block_start = block_start;
7483 em->bdev = root->fs_info->fs_devices->latest_bdev;
7484 em->orig_block_len = orig_block_len;
7485 em->ram_bytes = ram_bytes;
7486 em->generation = -1;
7487 set_bit(EXTENT_FLAG_PINNED, &em->flags);
7488 if (type == BTRFS_ORDERED_PREALLOC)
7489 set_bit(EXTENT_FLAG_FILLING, &em->flags);
7490
7491 do {
7492 btrfs_drop_extent_cache(inode, em->start,
7493 em->start + em->len - 1, 0);
7494 write_lock(&em_tree->lock);
7495 ret = add_extent_mapping(em_tree, em, 1);
7496 write_unlock(&em_tree->lock);
7497 } while (ret == -EEXIST);
7498
7499 if (ret) {
7500 free_extent_map(em);
7501 return ERR_PTR(ret);
7502 }
7503
7504 return em;
7505 }
7506
7507 struct btrfs_dio_data {
7508 u64 outstanding_extents;
7509 u64 reserve;
7510 };
7511
7512 static void adjust_dio_outstanding_extents(struct inode *inode,
7513 struct btrfs_dio_data *dio_data,
7514 const u64 len)
7515 {
7516 unsigned num_extents;
7517
7518 num_extents = (unsigned) div64_u64(len + BTRFS_MAX_EXTENT_SIZE - 1,
7519 BTRFS_MAX_EXTENT_SIZE);
7520 /*
7521 * If we have an outstanding_extents count still set then we're
7522 * within our reservation, otherwise we need to adjust our inode
7523 * counter appropriately.
7524 */
7525 if (dio_data->outstanding_extents) {
7526 dio_data->outstanding_extents -= num_extents;
7527 } else {
7528 spin_lock(&BTRFS_I(inode)->lock);
7529 BTRFS_I(inode)->outstanding_extents += num_extents;
7530 spin_unlock(&BTRFS_I(inode)->lock);
7531 }
7532 }
7533
7534 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
7535 struct buffer_head *bh_result, int create)
7536 {
7537 struct extent_map *em;
7538 struct btrfs_root *root = BTRFS_I(inode)->root;
7539 struct extent_state *cached_state = NULL;
7540 struct btrfs_dio_data *dio_data = NULL;
7541 u64 start = iblock << inode->i_blkbits;
7542 u64 lockstart, lockend;
7543 u64 len = bh_result->b_size;
7544 int unlock_bits = EXTENT_LOCKED;
7545 int ret = 0;
7546
7547 if (create)
7548 unlock_bits |= EXTENT_DIRTY;
7549 else
7550 len = min_t(u64, len, root->sectorsize);
7551
7552 lockstart = start;
7553 lockend = start + len - 1;
7554
7555 if (current->journal_info) {
7556 /*
7557 * Need to pull our outstanding extents and set journal_info to NULL so
7558 * that anything that needs to check if there's a transction doesn't get
7559 * confused.
7560 */
7561 dio_data = current->journal_info;
7562 current->journal_info = NULL;
7563 }
7564
7565 /*
7566 * If this errors out it's because we couldn't invalidate pagecache for
7567 * this range and we need to fallback to buffered.
7568 */
7569 if (lock_extent_direct(inode, lockstart, lockend, &cached_state,
7570 create)) {
7571 ret = -ENOTBLK;
7572 goto err;
7573 }
7574
7575 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
7576 if (IS_ERR(em)) {
7577 ret = PTR_ERR(em);
7578 goto unlock_err;
7579 }
7580
7581 /*
7582 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
7583 * io. INLINE is special, and we could probably kludge it in here, but
7584 * it's still buffered so for safety lets just fall back to the generic
7585 * buffered path.
7586 *
7587 * For COMPRESSED we _have_ to read the entire extent in so we can
7588 * decompress it, so there will be buffering required no matter what we
7589 * do, so go ahead and fallback to buffered.
7590 *
7591 * We return -ENOTBLK because thats what makes DIO go ahead and go back
7592 * to buffered IO. Don't blame me, this is the price we pay for using
7593 * the generic code.
7594 */
7595 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
7596 em->block_start == EXTENT_MAP_INLINE) {
7597 free_extent_map(em);
7598 ret = -ENOTBLK;
7599 goto unlock_err;
7600 }
7601
7602 /* Just a good old fashioned hole, return */
7603 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
7604 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
7605 free_extent_map(em);
7606 goto unlock_err;
7607 }
7608
7609 /*
7610 * We don't allocate a new extent in the following cases
7611 *
7612 * 1) The inode is marked as NODATACOW. In this case we'll just use the
7613 * existing extent.
7614 * 2) The extent is marked as PREALLOC. We're good to go here and can
7615 * just use the extent.
7616 *
7617 */
7618 if (!create) {
7619 len = min(len, em->len - (start - em->start));
7620 lockstart = start + len;
7621 goto unlock;
7622 }
7623
7624 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
7625 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
7626 em->block_start != EXTENT_MAP_HOLE)) {
7627 int type;
7628 u64 block_start, orig_start, orig_block_len, ram_bytes;
7629
7630 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7631 type = BTRFS_ORDERED_PREALLOC;
7632 else
7633 type = BTRFS_ORDERED_NOCOW;
7634 len = min(len, em->len - (start - em->start));
7635 block_start = em->block_start + (start - em->start);
7636
7637 if (can_nocow_extent(inode, start, &len, &orig_start,
7638 &orig_block_len, &ram_bytes) == 1) {
7639 if (type == BTRFS_ORDERED_PREALLOC) {
7640 free_extent_map(em);
7641 em = create_pinned_em(inode, start, len,
7642 orig_start,
7643 block_start, len,
7644 orig_block_len,
7645 ram_bytes, type);
7646 if (IS_ERR(em)) {
7647 ret = PTR_ERR(em);
7648 goto unlock_err;
7649 }
7650 }
7651
7652 ret = btrfs_add_ordered_extent_dio(inode, start,
7653 block_start, len, len, type);
7654 if (ret) {
7655 free_extent_map(em);
7656 goto unlock_err;
7657 }
7658 goto unlock;
7659 }
7660 }
7661
7662 /*
7663 * this will cow the extent, reset the len in case we changed
7664 * it above
7665 */
7666 len = bh_result->b_size;
7667 free_extent_map(em);
7668 em = btrfs_new_extent_direct(inode, start, len);
7669 if (IS_ERR(em)) {
7670 ret = PTR_ERR(em);
7671 goto unlock_err;
7672 }
7673 len = min(len, em->len - (start - em->start));
7674 unlock:
7675 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
7676 inode->i_blkbits;
7677 bh_result->b_size = len;
7678 bh_result->b_bdev = em->bdev;
7679 set_buffer_mapped(bh_result);
7680 if (create) {
7681 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7682 set_buffer_new(bh_result);
7683
7684 /*
7685 * Need to update the i_size under the extent lock so buffered
7686 * readers will get the updated i_size when we unlock.
7687 */
7688 if (start + len > i_size_read(inode))
7689 i_size_write(inode, start + len);
7690
7691 adjust_dio_outstanding_extents(inode, dio_data, len);
7692 btrfs_free_reserved_data_space(inode, start, len);
7693 WARN_ON(dio_data->reserve < len);
7694 dio_data->reserve -= len;
7695 current->journal_info = dio_data;
7696 }
7697
7698 /*
7699 * In the case of write we need to clear and unlock the entire range,
7700 * in the case of read we need to unlock only the end area that we
7701 * aren't using if there is any left over space.
7702 */
7703 if (lockstart < lockend) {
7704 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
7705 lockend, unlock_bits, 1, 0,
7706 &cached_state, GFP_NOFS);
7707 } else {
7708 free_extent_state(cached_state);
7709 }
7710
7711 free_extent_map(em);
7712
7713 return 0;
7714
7715 unlock_err:
7716 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7717 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
7718 err:
7719 if (dio_data)
7720 current->journal_info = dio_data;
7721 /*
7722 * Compensate the delalloc release we do in btrfs_direct_IO() when we
7723 * write less data then expected, so that we don't underflow our inode's
7724 * outstanding extents counter.
7725 */
7726 if (create && dio_data)
7727 adjust_dio_outstanding_extents(inode, dio_data, len);
7728
7729 return ret;
7730 }
7731
7732 static inline int submit_dio_repair_bio(struct inode *inode, struct bio *bio,
7733 int rw, int mirror_num)
7734 {
7735 struct btrfs_root *root = BTRFS_I(inode)->root;
7736 int ret;
7737
7738 BUG_ON(rw & REQ_WRITE);
7739
7740 bio_get(bio);
7741
7742 ret = btrfs_bio_wq_end_io(root->fs_info, bio,
7743 BTRFS_WQ_ENDIO_DIO_REPAIR);
7744 if (ret)
7745 goto err;
7746
7747 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
7748 err:
7749 bio_put(bio);
7750 return ret;
7751 }
7752
7753 static int btrfs_check_dio_repairable(struct inode *inode,
7754 struct bio *failed_bio,
7755 struct io_failure_record *failrec,
7756 int failed_mirror)
7757 {
7758 int num_copies;
7759
7760 num_copies = btrfs_num_copies(BTRFS_I(inode)->root->fs_info,
7761 failrec->logical, failrec->len);
7762 if (num_copies == 1) {
7763 /*
7764 * we only have a single copy of the data, so don't bother with
7765 * all the retry and error correction code that follows. no
7766 * matter what the error is, it is very likely to persist.
7767 */
7768 pr_debug("Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n",
7769 num_copies, failrec->this_mirror, failed_mirror);
7770 return 0;
7771 }
7772
7773 failrec->failed_mirror = failed_mirror;
7774 failrec->this_mirror++;
7775 if (failrec->this_mirror == failed_mirror)
7776 failrec->this_mirror++;
7777
7778 if (failrec->this_mirror > num_copies) {
7779 pr_debug("Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n",
7780 num_copies, failrec->this_mirror, failed_mirror);
7781 return 0;
7782 }
7783
7784 return 1;
7785 }
7786
7787 static int dio_read_error(struct inode *inode, struct bio *failed_bio,
7788 struct page *page, u64 start, u64 end,
7789 int failed_mirror, bio_end_io_t *repair_endio,
7790 void *repair_arg)
7791 {
7792 struct io_failure_record *failrec;
7793 struct bio *bio;
7794 int isector;
7795 int read_mode;
7796 int ret;
7797
7798 BUG_ON(failed_bio->bi_rw & REQ_WRITE);
7799
7800 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
7801 if (ret)
7802 return ret;
7803
7804 ret = btrfs_check_dio_repairable(inode, failed_bio, failrec,
7805 failed_mirror);
7806 if (!ret) {
7807 free_io_failure(inode, failrec);
7808 return -EIO;
7809 }
7810
7811 if (failed_bio->bi_vcnt > 1)
7812 read_mode = READ_SYNC | REQ_FAILFAST_DEV;
7813 else
7814 read_mode = READ_SYNC;
7815
7816 isector = start - btrfs_io_bio(failed_bio)->logical;
7817 isector >>= inode->i_sb->s_blocksize_bits;
7818 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
7819 0, isector, repair_endio, repair_arg);
7820 if (!bio) {
7821 free_io_failure(inode, failrec);
7822 return -EIO;
7823 }
7824
7825 btrfs_debug(BTRFS_I(inode)->root->fs_info,
7826 "Repair DIO Read Error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d\n",
7827 read_mode, failrec->this_mirror, failrec->in_validation);
7828
7829 ret = submit_dio_repair_bio(inode, bio, read_mode,
7830 failrec->this_mirror);
7831 if (ret) {
7832 free_io_failure(inode, failrec);
7833 bio_put(bio);
7834 }
7835
7836 return ret;
7837 }
7838
7839 struct btrfs_retry_complete {
7840 struct completion done;
7841 struct inode *inode;
7842 u64 start;
7843 int uptodate;
7844 };
7845
7846 static void btrfs_retry_endio_nocsum(struct bio *bio)
7847 {
7848 struct btrfs_retry_complete *done = bio->bi_private;
7849 struct bio_vec *bvec;
7850 int i;
7851
7852 if (bio->bi_error)
7853 goto end;
7854
7855 done->uptodate = 1;
7856 bio_for_each_segment_all(bvec, bio, i)
7857 clean_io_failure(done->inode, done->start, bvec->bv_page, 0);
7858 end:
7859 complete(&done->done);
7860 bio_put(bio);
7861 }
7862
7863 static int __btrfs_correct_data_nocsum(struct inode *inode,
7864 struct btrfs_io_bio *io_bio)
7865 {
7866 struct bio_vec *bvec;
7867 struct btrfs_retry_complete done;
7868 u64 start;
7869 int i;
7870 int ret;
7871
7872 start = io_bio->logical;
7873 done.inode = inode;
7874
7875 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
7876 try_again:
7877 done.uptodate = 0;
7878 done.start = start;
7879 init_completion(&done.done);
7880
7881 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page, start,
7882 start + bvec->bv_len - 1,
7883 io_bio->mirror_num,
7884 btrfs_retry_endio_nocsum, &done);
7885 if (ret)
7886 return ret;
7887
7888 wait_for_completion(&done.done);
7889
7890 if (!done.uptodate) {
7891 /* We might have another mirror, so try again */
7892 goto try_again;
7893 }
7894
7895 start += bvec->bv_len;
7896 }
7897
7898 return 0;
7899 }
7900
7901 static void btrfs_retry_endio(struct bio *bio)
7902 {
7903 struct btrfs_retry_complete *done = bio->bi_private;
7904 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
7905 struct bio_vec *bvec;
7906 int uptodate;
7907 int ret;
7908 int i;
7909
7910 if (bio->bi_error)
7911 goto end;
7912
7913 uptodate = 1;
7914 bio_for_each_segment_all(bvec, bio, i) {
7915 ret = __readpage_endio_check(done->inode, io_bio, i,
7916 bvec->bv_page, 0,
7917 done->start, bvec->bv_len);
7918 if (!ret)
7919 clean_io_failure(done->inode, done->start,
7920 bvec->bv_page, 0);
7921 else
7922 uptodate = 0;
7923 }
7924
7925 done->uptodate = uptodate;
7926 end:
7927 complete(&done->done);
7928 bio_put(bio);
7929 }
7930
7931 static int __btrfs_subio_endio_read(struct inode *inode,
7932 struct btrfs_io_bio *io_bio, int err)
7933 {
7934 struct bio_vec *bvec;
7935 struct btrfs_retry_complete done;
7936 u64 start;
7937 u64 offset = 0;
7938 int i;
7939 int ret;
7940
7941 err = 0;
7942 start = io_bio->logical;
7943 done.inode = inode;
7944
7945 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
7946 ret = __readpage_endio_check(inode, io_bio, i, bvec->bv_page,
7947 0, start, bvec->bv_len);
7948 if (likely(!ret))
7949 goto next;
7950 try_again:
7951 done.uptodate = 0;
7952 done.start = start;
7953 init_completion(&done.done);
7954
7955 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page, start,
7956 start + bvec->bv_len - 1,
7957 io_bio->mirror_num,
7958 btrfs_retry_endio, &done);
7959 if (ret) {
7960 err = ret;
7961 goto next;
7962 }
7963
7964 wait_for_completion(&done.done);
7965
7966 if (!done.uptodate) {
7967 /* We might have another mirror, so try again */
7968 goto try_again;
7969 }
7970 next:
7971 offset += bvec->bv_len;
7972 start += bvec->bv_len;
7973 }
7974
7975 return err;
7976 }
7977
7978 static int btrfs_subio_endio_read(struct inode *inode,
7979 struct btrfs_io_bio *io_bio, int err)
7980 {
7981 bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
7982
7983 if (skip_csum) {
7984 if (unlikely(err))
7985 return __btrfs_correct_data_nocsum(inode, io_bio);
7986 else
7987 return 0;
7988 } else {
7989 return __btrfs_subio_endio_read(inode, io_bio, err);
7990 }
7991 }
7992
7993 static void btrfs_endio_direct_read(struct bio *bio)
7994 {
7995 struct btrfs_dio_private *dip = bio->bi_private;
7996 struct inode *inode = dip->inode;
7997 struct bio *dio_bio;
7998 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
7999 int err = bio->bi_error;
8000
8001 if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED)
8002 err = btrfs_subio_endio_read(inode, io_bio, err);
8003
8004 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
8005 dip->logical_offset + dip->bytes - 1);
8006 dio_bio = dip->dio_bio;
8007
8008 kfree(dip);
8009
8010 dio_end_io(dio_bio, bio->bi_error);
8011
8012 if (io_bio->end_io)
8013 io_bio->end_io(io_bio, err);
8014 bio_put(bio);
8015 }
8016
8017 static void btrfs_endio_direct_write(struct bio *bio)
8018 {
8019 struct btrfs_dio_private *dip = bio->bi_private;
8020 struct inode *inode = dip->inode;
8021 struct btrfs_root *root = BTRFS_I(inode)->root;
8022 struct btrfs_ordered_extent *ordered = NULL;
8023 u64 ordered_offset = dip->logical_offset;
8024 u64 ordered_bytes = dip->bytes;
8025 struct bio *dio_bio;
8026 int ret;
8027
8028 again:
8029 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
8030 &ordered_offset,
8031 ordered_bytes,
8032 !bio->bi_error);
8033 if (!ret)
8034 goto out_test;
8035
8036 btrfs_init_work(&ordered->work, btrfs_endio_write_helper,
8037 finish_ordered_fn, NULL, NULL);
8038 btrfs_queue_work(root->fs_info->endio_write_workers,
8039 &ordered->work);
8040 out_test:
8041 /*
8042 * our bio might span multiple ordered extents. If we haven't
8043 * completed the accounting for the whole dio, go back and try again
8044 */
8045 if (ordered_offset < dip->logical_offset + dip->bytes) {
8046 ordered_bytes = dip->logical_offset + dip->bytes -
8047 ordered_offset;
8048 ordered = NULL;
8049 goto again;
8050 }
8051 dio_bio = dip->dio_bio;
8052
8053 kfree(dip);
8054
8055 dio_end_io(dio_bio, bio->bi_error);
8056 bio_put(bio);
8057 }
8058
8059 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
8060 struct bio *bio, int mirror_num,
8061 unsigned long bio_flags, u64 offset)
8062 {
8063 int ret;
8064 struct btrfs_root *root = BTRFS_I(inode)->root;
8065 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
8066 BUG_ON(ret); /* -ENOMEM */
8067 return 0;
8068 }
8069
8070 static void btrfs_end_dio_bio(struct bio *bio)
8071 {
8072 struct btrfs_dio_private *dip = bio->bi_private;
8073 int err = bio->bi_error;
8074
8075 if (err)
8076 btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
8077 "direct IO failed ino %llu rw %lu sector %#Lx len %u err no %d",
8078 btrfs_ino(dip->inode), bio->bi_rw,
8079 (unsigned long long)bio->bi_iter.bi_sector,
8080 bio->bi_iter.bi_size, err);
8081
8082 if (dip->subio_endio)
8083 err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err);
8084
8085 if (err) {
8086 dip->errors = 1;
8087
8088 /*
8089 * before atomic variable goto zero, we must make sure
8090 * dip->errors is perceived to be set.
8091 */
8092 smp_mb__before_atomic();
8093 }
8094
8095 /* if there are more bios still pending for this dio, just exit */
8096 if (!atomic_dec_and_test(&dip->pending_bios))
8097 goto out;
8098
8099 if (dip->errors) {
8100 bio_io_error(dip->orig_bio);
8101 } else {
8102 dip->dio_bio->bi_error = 0;
8103 bio_endio(dip->orig_bio);
8104 }
8105 out:
8106 bio_put(bio);
8107 }
8108
8109 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
8110 u64 first_sector, gfp_t gfp_flags)
8111 {
8112 struct bio *bio;
8113 bio = btrfs_bio_alloc(bdev, first_sector, BIO_MAX_PAGES, gfp_flags);
8114 if (bio)
8115 bio_associate_current(bio);
8116 return bio;
8117 }
8118
8119 static inline int btrfs_lookup_and_bind_dio_csum(struct btrfs_root *root,
8120 struct inode *inode,
8121 struct btrfs_dio_private *dip,
8122 struct bio *bio,
8123 u64 file_offset)
8124 {
8125 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8126 struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio);
8127 int ret;
8128
8129 /*
8130 * We load all the csum data we need when we submit
8131 * the first bio to reduce the csum tree search and
8132 * contention.
8133 */
8134 if (dip->logical_offset == file_offset) {
8135 ret = btrfs_lookup_bio_sums_dio(root, inode, dip->orig_bio,
8136 file_offset);
8137 if (ret)
8138 return ret;
8139 }
8140
8141 if (bio == dip->orig_bio)
8142 return 0;
8143
8144 file_offset -= dip->logical_offset;
8145 file_offset >>= inode->i_sb->s_blocksize_bits;
8146 io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset);
8147
8148 return 0;
8149 }
8150
8151 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
8152 int rw, u64 file_offset, int skip_sum,
8153 int async_submit)
8154 {
8155 struct btrfs_dio_private *dip = bio->bi_private;
8156 int write = rw & REQ_WRITE;
8157 struct btrfs_root *root = BTRFS_I(inode)->root;
8158 int ret;
8159
8160 if (async_submit)
8161 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
8162
8163 bio_get(bio);
8164
8165 if (!write) {
8166 ret = btrfs_bio_wq_end_io(root->fs_info, bio,
8167 BTRFS_WQ_ENDIO_DATA);
8168 if (ret)
8169 goto err;
8170 }
8171
8172 if (skip_sum)
8173 goto map;
8174
8175 if (write && async_submit) {
8176 ret = btrfs_wq_submit_bio(root->fs_info,
8177 inode, rw, bio, 0, 0,
8178 file_offset,
8179 __btrfs_submit_bio_start_direct_io,
8180 __btrfs_submit_bio_done);
8181 goto err;
8182 } else if (write) {
8183 /*
8184 * If we aren't doing async submit, calculate the csum of the
8185 * bio now.
8186 */
8187 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
8188 if (ret)
8189 goto err;
8190 } else {
8191 ret = btrfs_lookup_and_bind_dio_csum(root, inode, dip, bio,
8192 file_offset);
8193 if (ret)
8194 goto err;
8195 }
8196 map:
8197 ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
8198 err:
8199 bio_put(bio);
8200 return ret;
8201 }
8202
8203 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
8204 int skip_sum)
8205 {
8206 struct inode *inode = dip->inode;
8207 struct btrfs_root *root = BTRFS_I(inode)->root;
8208 struct bio *bio;
8209 struct bio *orig_bio = dip->orig_bio;
8210 struct bio_vec *bvec = orig_bio->bi_io_vec;
8211 u64 start_sector = orig_bio->bi_iter.bi_sector;
8212 u64 file_offset = dip->logical_offset;
8213 u64 submit_len = 0;
8214 u64 map_length;
8215 int nr_pages = 0;
8216 int ret;
8217 int async_submit = 0;
8218
8219 map_length = orig_bio->bi_iter.bi_size;
8220 ret = btrfs_map_block(root->fs_info, rw, start_sector << 9,
8221 &map_length, NULL, 0);
8222 if (ret)
8223 return -EIO;
8224
8225 if (map_length >= orig_bio->bi_iter.bi_size) {
8226 bio = orig_bio;
8227 dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED;
8228 goto submit;
8229 }
8230
8231 /* async crcs make it difficult to collect full stripe writes. */
8232 if (btrfs_get_alloc_profile(root, 1) & BTRFS_BLOCK_GROUP_RAID56_MASK)
8233 async_submit = 0;
8234 else
8235 async_submit = 1;
8236
8237 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
8238 if (!bio)
8239 return -ENOMEM;
8240
8241 bio->bi_private = dip;
8242 bio->bi_end_io = btrfs_end_dio_bio;
8243 btrfs_io_bio(bio)->logical = file_offset;
8244 atomic_inc(&dip->pending_bios);
8245
8246 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
8247 if (map_length < submit_len + bvec->bv_len ||
8248 bio_add_page(bio, bvec->bv_page, bvec->bv_len,
8249 bvec->bv_offset) < bvec->bv_len) {
8250 /*
8251 * inc the count before we submit the bio so
8252 * we know the end IO handler won't happen before
8253 * we inc the count. Otherwise, the dip might get freed
8254 * before we're done setting it up
8255 */
8256 atomic_inc(&dip->pending_bios);
8257 ret = __btrfs_submit_dio_bio(bio, inode, rw,
8258 file_offset, skip_sum,
8259 async_submit);
8260 if (ret) {
8261 bio_put(bio);
8262 atomic_dec(&dip->pending_bios);
8263 goto out_err;
8264 }
8265
8266 start_sector += submit_len >> 9;
8267 file_offset += submit_len;
8268
8269 submit_len = 0;
8270 nr_pages = 0;
8271
8272 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
8273 start_sector, GFP_NOFS);
8274 if (!bio)
8275 goto out_err;
8276 bio->bi_private = dip;
8277 bio->bi_end_io = btrfs_end_dio_bio;
8278 btrfs_io_bio(bio)->logical = file_offset;
8279
8280 map_length = orig_bio->bi_iter.bi_size;
8281 ret = btrfs_map_block(root->fs_info, rw,
8282 start_sector << 9,
8283 &map_length, NULL, 0);
8284 if (ret) {
8285 bio_put(bio);
8286 goto out_err;
8287 }
8288 } else {
8289 submit_len += bvec->bv_len;
8290 nr_pages++;
8291 bvec++;
8292 }
8293 }
8294
8295 submit:
8296 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
8297 async_submit);
8298 if (!ret)
8299 return 0;
8300
8301 bio_put(bio);
8302 out_err:
8303 dip->errors = 1;
8304 /*
8305 * before atomic variable goto zero, we must
8306 * make sure dip->errors is perceived to be set.
8307 */
8308 smp_mb__before_atomic();
8309 if (atomic_dec_and_test(&dip->pending_bios))
8310 bio_io_error(dip->orig_bio);
8311
8312 /* bio_end_io() will handle error, so we needn't return it */
8313 return 0;
8314 }
8315
8316 static void btrfs_submit_direct(int rw, struct bio *dio_bio,
8317 struct inode *inode, loff_t file_offset)
8318 {
8319 struct btrfs_dio_private *dip = NULL;
8320 struct bio *io_bio = NULL;
8321 struct btrfs_io_bio *btrfs_bio;
8322 int skip_sum;
8323 int write = rw & REQ_WRITE;
8324 int ret = 0;
8325
8326 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8327
8328 io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS);
8329 if (!io_bio) {
8330 ret = -ENOMEM;
8331 goto free_ordered;
8332 }
8333
8334 dip = kzalloc(sizeof(*dip), GFP_NOFS);
8335 if (!dip) {
8336 ret = -ENOMEM;
8337 goto free_ordered;
8338 }
8339
8340 dip->private = dio_bio->bi_private;
8341 dip->inode = inode;
8342 dip->logical_offset = file_offset;
8343 dip->bytes = dio_bio->bi_iter.bi_size;
8344 dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
8345 io_bio->bi_private = dip;
8346 dip->orig_bio = io_bio;
8347 dip->dio_bio = dio_bio;
8348 atomic_set(&dip->pending_bios, 0);
8349 btrfs_bio = btrfs_io_bio(io_bio);
8350 btrfs_bio->logical = file_offset;
8351
8352 if (write) {
8353 io_bio->bi_end_io = btrfs_endio_direct_write;
8354 } else {
8355 io_bio->bi_end_io = btrfs_endio_direct_read;
8356 dip->subio_endio = btrfs_subio_endio_read;
8357 }
8358
8359 ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
8360 if (!ret)
8361 return;
8362
8363 if (btrfs_bio->end_io)
8364 btrfs_bio->end_io(btrfs_bio, ret);
8365
8366 free_ordered:
8367 /*
8368 * If we arrived here it means either we failed to submit the dip
8369 * or we either failed to clone the dio_bio or failed to allocate the
8370 * dip. If we cloned the dio_bio and allocated the dip, we can just
8371 * call bio_endio against our io_bio so that we get proper resource
8372 * cleanup if we fail to submit the dip, otherwise, we must do the
8373 * same as btrfs_endio_direct_[write|read] because we can't call these
8374 * callbacks - they require an allocated dip and a clone of dio_bio.
8375 */
8376 if (io_bio && dip) {
8377 io_bio->bi_error = -EIO;
8378 bio_endio(io_bio);
8379 /*
8380 * The end io callbacks free our dip, do the final put on io_bio
8381 * and all the cleanup and final put for dio_bio (through
8382 * dio_end_io()).
8383 */
8384 dip = NULL;
8385 io_bio = NULL;
8386 } else {
8387 if (write) {
8388 struct btrfs_ordered_extent *ordered;
8389
8390 ordered = btrfs_lookup_ordered_extent(inode,
8391 file_offset);
8392 set_bit(BTRFS_ORDERED_IOERR, &ordered->flags);
8393 /*
8394 * Decrements our ref on the ordered extent and removes
8395 * the ordered extent from the inode's ordered tree,
8396 * doing all the proper resource cleanup such as for the
8397 * reserved space and waking up any waiters for this
8398 * ordered extent (through btrfs_remove_ordered_extent).
8399 */
8400 btrfs_finish_ordered_io(ordered);
8401 } else {
8402 unlock_extent(&BTRFS_I(inode)->io_tree, file_offset,
8403 file_offset + dio_bio->bi_iter.bi_size - 1);
8404 }
8405 dio_bio->bi_error = -EIO;
8406 /*
8407 * Releases and cleans up our dio_bio, no need to bio_put()
8408 * nor bio_endio()/bio_io_error() against dio_bio.
8409 */
8410 dio_end_io(dio_bio, ret);
8411 }
8412 if (io_bio)
8413 bio_put(io_bio);
8414 kfree(dip);
8415 }
8416
8417 static ssize_t check_direct_IO(struct btrfs_root *root, struct kiocb *iocb,
8418 const struct iov_iter *iter, loff_t offset)
8419 {
8420 int seg;
8421 int i;
8422 unsigned blocksize_mask = root->sectorsize - 1;
8423 ssize_t retval = -EINVAL;
8424
8425 if (offset & blocksize_mask)
8426 goto out;
8427
8428 if (iov_iter_alignment(iter) & blocksize_mask)
8429 goto out;
8430
8431 /* If this is a write we don't need to check anymore */
8432 if (iov_iter_rw(iter) == WRITE)
8433 return 0;
8434 /*
8435 * Check to make sure we don't have duplicate iov_base's in this
8436 * iovec, if so return EINVAL, otherwise we'll get csum errors
8437 * when reading back.
8438 */
8439 for (seg = 0; seg < iter->nr_segs; seg++) {
8440 for (i = seg + 1; i < iter->nr_segs; i++) {
8441 if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
8442 goto out;
8443 }
8444 }
8445 retval = 0;
8446 out:
8447 return retval;
8448 }
8449
8450 static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
8451 loff_t offset)
8452 {
8453 struct file *file = iocb->ki_filp;
8454 struct inode *inode = file->f_mapping->host;
8455 struct btrfs_root *root = BTRFS_I(inode)->root;
8456 struct btrfs_dio_data dio_data = { 0 };
8457 size_t count = 0;
8458 int flags = 0;
8459 bool wakeup = true;
8460 bool relock = false;
8461 ssize_t ret;
8462
8463 if (check_direct_IO(BTRFS_I(inode)->root, iocb, iter, offset))
8464 return 0;
8465
8466 inode_dio_begin(inode);
8467 smp_mb__after_atomic();
8468
8469 /*
8470 * The generic stuff only does filemap_write_and_wait_range, which
8471 * isn't enough if we've written compressed pages to this area, so
8472 * we need to flush the dirty pages again to make absolutely sure
8473 * that any outstanding dirty pages are on disk.
8474 */
8475 count = iov_iter_count(iter);
8476 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
8477 &BTRFS_I(inode)->runtime_flags))
8478 filemap_fdatawrite_range(inode->i_mapping, offset,
8479 offset + count - 1);
8480
8481 if (iov_iter_rw(iter) == WRITE) {
8482 /*
8483 * If the write DIO is beyond the EOF, we need update
8484 * the isize, but it is protected by i_mutex. So we can
8485 * not unlock the i_mutex at this case.
8486 */
8487 if (offset + count <= inode->i_size) {
8488 mutex_unlock(&inode->i_mutex);
8489 relock = true;
8490 }
8491 ret = btrfs_delalloc_reserve_space(inode, offset, count);
8492 if (ret)
8493 goto out;
8494 dio_data.outstanding_extents = div64_u64(count +
8495 BTRFS_MAX_EXTENT_SIZE - 1,
8496 BTRFS_MAX_EXTENT_SIZE);
8497
8498 /*
8499 * We need to know how many extents we reserved so that we can
8500 * do the accounting properly if we go over the number we
8501 * originally calculated. Abuse current->journal_info for this.
8502 */
8503 dio_data.reserve = round_up(count, root->sectorsize);
8504 current->journal_info = &dio_data;
8505 } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
8506 &BTRFS_I(inode)->runtime_flags)) {
8507 inode_dio_end(inode);
8508 flags = DIO_LOCKING | DIO_SKIP_HOLES;
8509 wakeup = false;
8510 }
8511
8512 ret = __blockdev_direct_IO(iocb, inode,
8513 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
8514 iter, offset, btrfs_get_blocks_direct, NULL,
8515 btrfs_submit_direct, flags);
8516 if (iov_iter_rw(iter) == WRITE) {
8517 current->journal_info = NULL;
8518 if (ret < 0 && ret != -EIOCBQUEUED) {
8519 if (dio_data.reserve)
8520 btrfs_delalloc_release_space(inode, offset,
8521 dio_data.reserve);
8522 } else if (ret >= 0 && (size_t)ret < count)
8523 btrfs_delalloc_release_space(inode, offset,
8524 count - (size_t)ret);
8525 }
8526 out:
8527 if (wakeup)
8528 inode_dio_end(inode);
8529 if (relock)
8530 mutex_lock(&inode->i_mutex);
8531
8532 return ret;
8533 }
8534
8535 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
8536
8537 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
8538 __u64 start, __u64 len)
8539 {
8540 int ret;
8541
8542 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
8543 if (ret)
8544 return ret;
8545
8546 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
8547 }
8548
8549 int btrfs_readpage(struct file *file, struct page *page)
8550 {
8551 struct extent_io_tree *tree;
8552 tree = &BTRFS_I(page->mapping->host)->io_tree;
8553 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
8554 }
8555
8556 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
8557 {
8558 struct extent_io_tree *tree;
8559
8560
8561 if (current->flags & PF_MEMALLOC) {
8562 redirty_page_for_writepage(wbc, page);
8563 unlock_page(page);
8564 return 0;
8565 }
8566 tree = &BTRFS_I(page->mapping->host)->io_tree;
8567 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
8568 }
8569
8570 static int btrfs_writepages(struct address_space *mapping,
8571 struct writeback_control *wbc)
8572 {
8573 struct extent_io_tree *tree;
8574
8575 tree = &BTRFS_I(mapping->host)->io_tree;
8576 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
8577 }
8578
8579 static int
8580 btrfs_readpages(struct file *file, struct address_space *mapping,
8581 struct list_head *pages, unsigned nr_pages)
8582 {
8583 struct extent_io_tree *tree;
8584 tree = &BTRFS_I(mapping->host)->io_tree;
8585 return extent_readpages(tree, mapping, pages, nr_pages,
8586 btrfs_get_extent);
8587 }
8588 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8589 {
8590 struct extent_io_tree *tree;
8591 struct extent_map_tree *map;
8592 int ret;
8593
8594 tree = &BTRFS_I(page->mapping->host)->io_tree;
8595 map = &BTRFS_I(page->mapping->host)->extent_tree;
8596 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
8597 if (ret == 1) {
8598 ClearPagePrivate(page);
8599 set_page_private(page, 0);
8600 page_cache_release(page);
8601 }
8602 return ret;
8603 }
8604
8605 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8606 {
8607 if (PageWriteback(page) || PageDirty(page))
8608 return 0;
8609 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
8610 }
8611
8612 static void btrfs_invalidatepage(struct page *page, unsigned int offset,
8613 unsigned int length)
8614 {
8615 struct inode *inode = page->mapping->host;
8616 struct extent_io_tree *tree;
8617 struct btrfs_ordered_extent *ordered;
8618 struct extent_state *cached_state = NULL;
8619 u64 page_start = page_offset(page);
8620 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
8621 int inode_evicting = inode->i_state & I_FREEING;
8622
8623 /*
8624 * we have the page locked, so new writeback can't start,
8625 * and the dirty bit won't be cleared while we are here.
8626 *
8627 * Wait for IO on this page so that we can safely clear
8628 * the PagePrivate2 bit and do ordered accounting
8629 */
8630 wait_on_page_writeback(page);
8631
8632 tree = &BTRFS_I(inode)->io_tree;
8633 if (offset) {
8634 btrfs_releasepage(page, GFP_NOFS);
8635 return;
8636 }
8637
8638 if (!inode_evicting)
8639 lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
8640 ordered = btrfs_lookup_ordered_extent(inode, page_start);
8641 if (ordered) {
8642 /*
8643 * IO on this page will never be started, so we need
8644 * to account for any ordered extents now
8645 */
8646 if (!inode_evicting)
8647 clear_extent_bit(tree, page_start, page_end,
8648 EXTENT_DIRTY | EXTENT_DELALLOC |
8649 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
8650 EXTENT_DEFRAG, 1, 0, &cached_state,
8651 GFP_NOFS);
8652 /*
8653 * whoever cleared the private bit is responsible
8654 * for the finish_ordered_io
8655 */
8656 if (TestClearPagePrivate2(page)) {
8657 struct btrfs_ordered_inode_tree *tree;
8658 u64 new_len;
8659
8660 tree = &BTRFS_I(inode)->ordered_tree;
8661
8662 spin_lock_irq(&tree->lock);
8663 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
8664 new_len = page_start - ordered->file_offset;
8665 if (new_len < ordered->truncated_len)
8666 ordered->truncated_len = new_len;
8667 spin_unlock_irq(&tree->lock);
8668
8669 if (btrfs_dec_test_ordered_pending(inode, &ordered,
8670 page_start,
8671 PAGE_CACHE_SIZE, 1))
8672 btrfs_finish_ordered_io(ordered);
8673 }
8674 btrfs_put_ordered_extent(ordered);
8675 if (!inode_evicting) {
8676 cached_state = NULL;
8677 lock_extent_bits(tree, page_start, page_end, 0,
8678 &cached_state);
8679 }
8680 }
8681
8682 /*
8683 * Qgroup reserved space handler
8684 * Page here will be either
8685 * 1) Already written to disk
8686 * In this case, its reserved space is released from data rsv map
8687 * and will be freed by delayed_ref handler finally.
8688 * So even we call qgroup_free_data(), it won't decrease reserved
8689 * space.
8690 * 2) Not written to disk
8691 * This means the reserved space should be freed here.
8692 */
8693 btrfs_qgroup_free_data(inode, page_start, PAGE_CACHE_SIZE);
8694 if (!inode_evicting) {
8695 clear_extent_bit(tree, page_start, page_end,
8696 EXTENT_LOCKED | EXTENT_DIRTY |
8697 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
8698 EXTENT_DEFRAG, 1, 1,
8699 &cached_state, GFP_NOFS);
8700
8701 __btrfs_releasepage(page, GFP_NOFS);
8702 }
8703
8704 ClearPageChecked(page);
8705 if (PagePrivate(page)) {
8706 ClearPagePrivate(page);
8707 set_page_private(page, 0);
8708 page_cache_release(page);
8709 }
8710 }
8711
8712 /*
8713 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
8714 * called from a page fault handler when a page is first dirtied. Hence we must
8715 * be careful to check for EOF conditions here. We set the page up correctly
8716 * for a written page which means we get ENOSPC checking when writing into
8717 * holes and correct delalloc and unwritten extent mapping on filesystems that
8718 * support these features.
8719 *
8720 * We are not allowed to take the i_mutex here so we have to play games to
8721 * protect against truncate races as the page could now be beyond EOF. Because
8722 * vmtruncate() writes the inode size before removing pages, once we have the
8723 * page lock we can determine safely if the page is beyond EOF. If it is not
8724 * beyond EOF, then the page is guaranteed safe against truncation until we
8725 * unlock the page.
8726 */
8727 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
8728 {
8729 struct page *page = vmf->page;
8730 struct inode *inode = file_inode(vma->vm_file);
8731 struct btrfs_root *root = BTRFS_I(inode)->root;
8732 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
8733 struct btrfs_ordered_extent *ordered;
8734 struct extent_state *cached_state = NULL;
8735 char *kaddr;
8736 unsigned long zero_start;
8737 loff_t size;
8738 int ret;
8739 int reserved = 0;
8740 u64 page_start;
8741 u64 page_end;
8742
8743 sb_start_pagefault(inode->i_sb);
8744 page_start = page_offset(page);
8745 page_end = page_start + PAGE_CACHE_SIZE - 1;
8746
8747 ret = btrfs_delalloc_reserve_space(inode, page_start,
8748 PAGE_CACHE_SIZE);
8749 if (!ret) {
8750 ret = file_update_time(vma->vm_file);
8751 reserved = 1;
8752 }
8753 if (ret) {
8754 if (ret == -ENOMEM)
8755 ret = VM_FAULT_OOM;
8756 else /* -ENOSPC, -EIO, etc */
8757 ret = VM_FAULT_SIGBUS;
8758 if (reserved)
8759 goto out;
8760 goto out_noreserve;
8761 }
8762
8763 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
8764 again:
8765 lock_page(page);
8766 size = i_size_read(inode);
8767
8768 if ((page->mapping != inode->i_mapping) ||
8769 (page_start >= size)) {
8770 /* page got truncated out from underneath us */
8771 goto out_unlock;
8772 }
8773 wait_on_page_writeback(page);
8774
8775 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
8776 set_page_extent_mapped(page);
8777
8778 /*
8779 * we can't set the delalloc bits if there are pending ordered
8780 * extents. Drop our locks and wait for them to finish
8781 */
8782 ordered = btrfs_lookup_ordered_extent(inode, page_start);
8783 if (ordered) {
8784 unlock_extent_cached(io_tree, page_start, page_end,
8785 &cached_state, GFP_NOFS);
8786 unlock_page(page);
8787 btrfs_start_ordered_extent(inode, ordered, 1);
8788 btrfs_put_ordered_extent(ordered);
8789 goto again;
8790 }
8791
8792 /*
8793 * XXX - page_mkwrite gets called every time the page is dirtied, even
8794 * if it was already dirty, so for space accounting reasons we need to
8795 * clear any delalloc bits for the range we are fixing to save. There
8796 * is probably a better way to do this, but for now keep consistent with
8797 * prepare_pages in the normal write path.
8798 */
8799 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
8800 EXTENT_DIRTY | EXTENT_DELALLOC |
8801 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
8802 0, 0, &cached_state, GFP_NOFS);
8803
8804 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
8805 &cached_state);
8806 if (ret) {
8807 unlock_extent_cached(io_tree, page_start, page_end,
8808 &cached_state, GFP_NOFS);
8809 ret = VM_FAULT_SIGBUS;
8810 goto out_unlock;
8811 }
8812 ret = 0;
8813
8814 /* page is wholly or partially inside EOF */
8815 if (page_start + PAGE_CACHE_SIZE > size)
8816 zero_start = size & ~PAGE_CACHE_MASK;
8817 else
8818 zero_start = PAGE_CACHE_SIZE;
8819
8820 if (zero_start != PAGE_CACHE_SIZE) {
8821 kaddr = kmap(page);
8822 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
8823 flush_dcache_page(page);
8824 kunmap(page);
8825 }
8826 ClearPageChecked(page);
8827 set_page_dirty(page);
8828 SetPageUptodate(page);
8829
8830 BTRFS_I(inode)->last_trans = root->fs_info->generation;
8831 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
8832 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
8833
8834 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
8835
8836 out_unlock:
8837 if (!ret) {
8838 sb_end_pagefault(inode->i_sb);
8839 return VM_FAULT_LOCKED;
8840 }
8841 unlock_page(page);
8842 out:
8843 btrfs_delalloc_release_space(inode, page_start, PAGE_CACHE_SIZE);
8844 out_noreserve:
8845 sb_end_pagefault(inode->i_sb);
8846 return ret;
8847 }
8848
8849 static int btrfs_truncate(struct inode *inode)
8850 {
8851 struct btrfs_root *root = BTRFS_I(inode)->root;
8852 struct btrfs_block_rsv *rsv;
8853 int ret = 0;
8854 int err = 0;
8855 struct btrfs_trans_handle *trans;
8856 u64 mask = root->sectorsize - 1;
8857 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
8858
8859 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
8860 (u64)-1);
8861 if (ret)
8862 return ret;
8863
8864 /*
8865 * Yes ladies and gentelment, this is indeed ugly. The fact is we have
8866 * 3 things going on here
8867 *
8868 * 1) We need to reserve space for our orphan item and the space to
8869 * delete our orphan item. Lord knows we don't want to have a dangling
8870 * orphan item because we didn't reserve space to remove it.
8871 *
8872 * 2) We need to reserve space to update our inode.
8873 *
8874 * 3) We need to have something to cache all the space that is going to
8875 * be free'd up by the truncate operation, but also have some slack
8876 * space reserved in case it uses space during the truncate (thank you
8877 * very much snapshotting).
8878 *
8879 * And we need these to all be seperate. The fact is we can use alot of
8880 * space doing the truncate, and we have no earthly idea how much space
8881 * we will use, so we need the truncate reservation to be seperate so it
8882 * doesn't end up using space reserved for updating the inode or
8883 * removing the orphan item. We also need to be able to stop the
8884 * transaction and start a new one, which means we need to be able to
8885 * update the inode several times, and we have no idea of knowing how
8886 * many times that will be, so we can't just reserve 1 item for the
8887 * entirety of the opration, so that has to be done seperately as well.
8888 * Then there is the orphan item, which does indeed need to be held on
8889 * to for the whole operation, and we need nobody to touch this reserved
8890 * space except the orphan code.
8891 *
8892 * So that leaves us with
8893 *
8894 * 1) root->orphan_block_rsv - for the orphan deletion.
8895 * 2) rsv - for the truncate reservation, which we will steal from the
8896 * transaction reservation.
8897 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
8898 * updating the inode.
8899 */
8900 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
8901 if (!rsv)
8902 return -ENOMEM;
8903 rsv->size = min_size;
8904 rsv->failfast = 1;
8905
8906 /*
8907 * 1 for the truncate slack space
8908 * 1 for updating the inode.
8909 */
8910 trans = btrfs_start_transaction(root, 2);
8911 if (IS_ERR(trans)) {
8912 err = PTR_ERR(trans);
8913 goto out;
8914 }
8915
8916 /* Migrate the slack space for the truncate to our reserve */
8917 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
8918 min_size);
8919 BUG_ON(ret);
8920
8921 /*
8922 * So if we truncate and then write and fsync we normally would just
8923 * write the extents that changed, which is a problem if we need to
8924 * first truncate that entire inode. So set this flag so we write out
8925 * all of the extents in the inode to the sync log so we're completely
8926 * safe.
8927 */
8928 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
8929 trans->block_rsv = rsv;
8930
8931 while (1) {
8932 ret = btrfs_truncate_inode_items(trans, root, inode,
8933 inode->i_size,
8934 BTRFS_EXTENT_DATA_KEY);
8935 if (ret != -ENOSPC && ret != -EAGAIN) {
8936 err = ret;
8937 break;
8938 }
8939
8940 trans->block_rsv = &root->fs_info->trans_block_rsv;
8941 ret = btrfs_update_inode(trans, root, inode);
8942 if (ret) {
8943 err = ret;
8944 break;
8945 }
8946
8947 btrfs_end_transaction(trans, root);
8948 btrfs_btree_balance_dirty(root);
8949
8950 trans = btrfs_start_transaction(root, 2);
8951 if (IS_ERR(trans)) {
8952 ret = err = PTR_ERR(trans);
8953 trans = NULL;
8954 break;
8955 }
8956
8957 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
8958 rsv, min_size);
8959 BUG_ON(ret); /* shouldn't happen */
8960 trans->block_rsv = rsv;
8961 }
8962
8963 if (ret == 0 && inode->i_nlink > 0) {
8964 trans->block_rsv = root->orphan_block_rsv;
8965 ret = btrfs_orphan_del(trans, inode);
8966 if (ret)
8967 err = ret;
8968 }
8969
8970 if (trans) {
8971 trans->block_rsv = &root->fs_info->trans_block_rsv;
8972 ret = btrfs_update_inode(trans, root, inode);
8973 if (ret && !err)
8974 err = ret;
8975
8976 ret = btrfs_end_transaction(trans, root);
8977 btrfs_btree_balance_dirty(root);
8978 }
8979
8980 out:
8981 btrfs_free_block_rsv(root, rsv);
8982
8983 if (ret && !err)
8984 err = ret;
8985
8986 return err;
8987 }
8988
8989 /*
8990 * create a new subvolume directory/inode (helper for the ioctl).
8991 */
8992 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
8993 struct btrfs_root *new_root,
8994 struct btrfs_root *parent_root,
8995 u64 new_dirid)
8996 {
8997 struct inode *inode;
8998 int err;
8999 u64 index = 0;
9000
9001 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
9002 new_dirid, new_dirid,
9003 S_IFDIR | (~current_umask() & S_IRWXUGO),
9004 &index);
9005 if (IS_ERR(inode))
9006 return PTR_ERR(inode);
9007 inode->i_op = &btrfs_dir_inode_operations;
9008 inode->i_fop = &btrfs_dir_file_operations;
9009
9010 set_nlink(inode, 1);
9011 btrfs_i_size_write(inode, 0);
9012 unlock_new_inode(inode);
9013
9014 err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
9015 if (err)
9016 btrfs_err(new_root->fs_info,
9017 "error inheriting subvolume %llu properties: %d",
9018 new_root->root_key.objectid, err);
9019
9020 err = btrfs_update_inode(trans, new_root, inode);
9021
9022 iput(inode);
9023 return err;
9024 }
9025
9026 struct inode *btrfs_alloc_inode(struct super_block *sb)
9027 {
9028 struct btrfs_inode *ei;
9029 struct inode *inode;
9030
9031 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
9032 if (!ei)
9033 return NULL;
9034
9035 ei->root = NULL;
9036 ei->generation = 0;
9037 ei->last_trans = 0;
9038 ei->last_sub_trans = 0;
9039 ei->logged_trans = 0;
9040 ei->delalloc_bytes = 0;
9041 ei->defrag_bytes = 0;
9042 ei->disk_i_size = 0;
9043 ei->flags = 0;
9044 ei->csum_bytes = 0;
9045 ei->index_cnt = (u64)-1;
9046 ei->dir_index = 0;
9047 ei->last_unlink_trans = 0;
9048 ei->last_log_commit = 0;
9049
9050 spin_lock_init(&ei->lock);
9051 ei->outstanding_extents = 0;
9052 ei->reserved_extents = 0;
9053
9054 ei->runtime_flags = 0;
9055 ei->force_compress = BTRFS_COMPRESS_NONE;
9056
9057 ei->delayed_node = NULL;
9058
9059 ei->i_otime.tv_sec = 0;
9060 ei->i_otime.tv_nsec = 0;
9061
9062 inode = &ei->vfs_inode;
9063 extent_map_tree_init(&ei->extent_tree);
9064 extent_io_tree_init(&ei->io_tree, &inode->i_data);
9065 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
9066 ei->io_tree.track_uptodate = 1;
9067 ei->io_failure_tree.track_uptodate = 1;
9068 atomic_set(&ei->sync_writers, 0);
9069 mutex_init(&ei->log_mutex);
9070 mutex_init(&ei->delalloc_mutex);
9071 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
9072 INIT_LIST_HEAD(&ei->delalloc_inodes);
9073 RB_CLEAR_NODE(&ei->rb_node);
9074
9075 return inode;
9076 }
9077
9078 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
9079 void btrfs_test_destroy_inode(struct inode *inode)
9080 {
9081 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
9082 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9083 }
9084 #endif
9085
9086 static void btrfs_i_callback(struct rcu_head *head)
9087 {
9088 struct inode *inode = container_of(head, struct inode, i_rcu);
9089 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9090 }
9091
9092 void btrfs_destroy_inode(struct inode *inode)
9093 {
9094 struct btrfs_ordered_extent *ordered;
9095 struct btrfs_root *root = BTRFS_I(inode)->root;
9096
9097 WARN_ON(!hlist_empty(&inode->i_dentry));
9098 WARN_ON(inode->i_data.nrpages);
9099 WARN_ON(BTRFS_I(inode)->outstanding_extents);
9100 WARN_ON(BTRFS_I(inode)->reserved_extents);
9101 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
9102 WARN_ON(BTRFS_I(inode)->csum_bytes);
9103 WARN_ON(BTRFS_I(inode)->defrag_bytes);
9104
9105 /*
9106 * This can happen where we create an inode, but somebody else also
9107 * created the same inode and we need to destroy the one we already
9108 * created.
9109 */
9110 if (!root)
9111 goto free;
9112
9113 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
9114 &BTRFS_I(inode)->runtime_flags)) {
9115 btrfs_info(root->fs_info, "inode %llu still on the orphan list",
9116 btrfs_ino(inode));
9117 atomic_dec(&root->orphan_inodes);
9118 }
9119
9120 while (1) {
9121 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
9122 if (!ordered)
9123 break;
9124 else {
9125 btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup",
9126 ordered->file_offset, ordered->len);
9127 btrfs_remove_ordered_extent(inode, ordered);
9128 btrfs_put_ordered_extent(ordered);
9129 btrfs_put_ordered_extent(ordered);
9130 }
9131 }
9132 btrfs_qgroup_check_reserved_leak(inode);
9133 inode_tree_del(inode);
9134 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
9135 free:
9136 call_rcu(&inode->i_rcu, btrfs_i_callback);
9137 }
9138
9139 int btrfs_drop_inode(struct inode *inode)
9140 {
9141 struct btrfs_root *root = BTRFS_I(inode)->root;
9142
9143 if (root == NULL)
9144 return 1;
9145
9146 /* the snap/subvol tree is on deleting */
9147 if (btrfs_root_refs(&root->root_item) == 0)
9148 return 1;
9149 else
9150 return generic_drop_inode(inode);
9151 }
9152
9153 static void init_once(void *foo)
9154 {
9155 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
9156
9157 inode_init_once(&ei->vfs_inode);
9158 }
9159
9160 void btrfs_destroy_cachep(void)
9161 {
9162 /*
9163 * Make sure all delayed rcu free inodes are flushed before we
9164 * destroy cache.
9165 */
9166 rcu_barrier();
9167 if (btrfs_inode_cachep)
9168 kmem_cache_destroy(btrfs_inode_cachep);
9169 if (btrfs_trans_handle_cachep)
9170 kmem_cache_destroy(btrfs_trans_handle_cachep);
9171 if (btrfs_transaction_cachep)
9172 kmem_cache_destroy(btrfs_transaction_cachep);
9173 if (btrfs_path_cachep)
9174 kmem_cache_destroy(btrfs_path_cachep);
9175 if (btrfs_free_space_cachep)
9176 kmem_cache_destroy(btrfs_free_space_cachep);
9177 if (btrfs_delalloc_work_cachep)
9178 kmem_cache_destroy(btrfs_delalloc_work_cachep);
9179 }
9180
9181 int btrfs_init_cachep(void)
9182 {
9183 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
9184 sizeof(struct btrfs_inode), 0,
9185 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once);
9186 if (!btrfs_inode_cachep)
9187 goto fail;
9188
9189 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
9190 sizeof(struct btrfs_trans_handle), 0,
9191 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
9192 if (!btrfs_trans_handle_cachep)
9193 goto fail;
9194
9195 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
9196 sizeof(struct btrfs_transaction), 0,
9197 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
9198 if (!btrfs_transaction_cachep)
9199 goto fail;
9200
9201 btrfs_path_cachep = kmem_cache_create("btrfs_path",
9202 sizeof(struct btrfs_path), 0,
9203 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
9204 if (!btrfs_path_cachep)
9205 goto fail;
9206
9207 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
9208 sizeof(struct btrfs_free_space), 0,
9209 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
9210 if (!btrfs_free_space_cachep)
9211 goto fail;
9212
9213 btrfs_delalloc_work_cachep = kmem_cache_create("btrfs_delalloc_work",
9214 sizeof(struct btrfs_delalloc_work), 0,
9215 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
9216 NULL);
9217 if (!btrfs_delalloc_work_cachep)
9218 goto fail;
9219
9220 return 0;
9221 fail:
9222 btrfs_destroy_cachep();
9223 return -ENOMEM;
9224 }
9225
9226 static int btrfs_getattr(struct vfsmount *mnt,
9227 struct dentry *dentry, struct kstat *stat)
9228 {
9229 u64 delalloc_bytes;
9230 struct inode *inode = d_inode(dentry);
9231 u32 blocksize = inode->i_sb->s_blocksize;
9232
9233 generic_fillattr(inode, stat);
9234 stat->dev = BTRFS_I(inode)->root->anon_dev;
9235 stat->blksize = PAGE_CACHE_SIZE;
9236
9237 spin_lock(&BTRFS_I(inode)->lock);
9238 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;
9239 spin_unlock(&BTRFS_I(inode)->lock);
9240 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
9241 ALIGN(delalloc_bytes, blocksize)) >> 9;
9242 return 0;
9243 }
9244
9245 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
9246 struct inode *new_dir, struct dentry *new_dentry)
9247 {
9248 struct btrfs_trans_handle *trans;
9249 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9250 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9251 struct inode *new_inode = d_inode(new_dentry);
9252 struct inode *old_inode = d_inode(old_dentry);
9253 struct timespec ctime = CURRENT_TIME;
9254 u64 index = 0;
9255 u64 root_objectid;
9256 int ret;
9257 u64 old_ino = btrfs_ino(old_inode);
9258
9259 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
9260 return -EPERM;
9261
9262 /* we only allow rename subvolume link between subvolumes */
9263 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9264 return -EXDEV;
9265
9266 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
9267 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
9268 return -ENOTEMPTY;
9269
9270 if (S_ISDIR(old_inode->i_mode) && new_inode &&
9271 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
9272 return -ENOTEMPTY;
9273
9274
9275 /* check for collisions, even if the name isn't there */
9276 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
9277 new_dentry->d_name.name,
9278 new_dentry->d_name.len);
9279
9280 if (ret) {
9281 if (ret == -EEXIST) {
9282 /* we shouldn't get
9283 * eexist without a new_inode */
9284 if (WARN_ON(!new_inode)) {
9285 return ret;
9286 }
9287 } else {
9288 /* maybe -EOVERFLOW */
9289 return ret;
9290 }
9291 }
9292 ret = 0;
9293
9294 /*
9295 * we're using rename to replace one file with another. Start IO on it
9296 * now so we don't add too much work to the end of the transaction
9297 */
9298 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
9299 filemap_flush(old_inode->i_mapping);
9300
9301 /* close the racy window with snapshot create/destroy ioctl */
9302 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9303 down_read(&root->fs_info->subvol_sem);
9304 /*
9305 * We want to reserve the absolute worst case amount of items. So if
9306 * both inodes are subvols and we need to unlink them then that would
9307 * require 4 item modifications, but if they are both normal inodes it
9308 * would require 5 item modifications, so we'll assume their normal
9309 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
9310 * should cover the worst case number of items we'll modify.
9311 */
9312 trans = btrfs_start_transaction(root, 11);
9313 if (IS_ERR(trans)) {
9314 ret = PTR_ERR(trans);
9315 goto out_notrans;
9316 }
9317
9318 if (dest != root)
9319 btrfs_record_root_in_trans(trans, dest);
9320
9321 ret = btrfs_set_inode_index(new_dir, &index);
9322 if (ret)
9323 goto out_fail;
9324
9325 BTRFS_I(old_inode)->dir_index = 0ULL;
9326 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9327 /* force full log commit if subvolume involved. */
9328 btrfs_set_log_full_commit(root->fs_info, trans);
9329 } else {
9330 ret = btrfs_insert_inode_ref(trans, dest,
9331 new_dentry->d_name.name,
9332 new_dentry->d_name.len,
9333 old_ino,
9334 btrfs_ino(new_dir), index);
9335 if (ret)
9336 goto out_fail;
9337 /*
9338 * this is an ugly little race, but the rename is required
9339 * to make sure that if we crash, the inode is either at the
9340 * old name or the new one. pinning the log transaction lets
9341 * us make sure we don't allow a log commit to come in after
9342 * we unlink the name but before we add the new name back in.
9343 */
9344 btrfs_pin_log_trans(root);
9345 }
9346
9347 inode_inc_iversion(old_dir);
9348 inode_inc_iversion(new_dir);
9349 inode_inc_iversion(old_inode);
9350 old_dir->i_ctime = old_dir->i_mtime = ctime;
9351 new_dir->i_ctime = new_dir->i_mtime = ctime;
9352 old_inode->i_ctime = ctime;
9353
9354 if (old_dentry->d_parent != new_dentry->d_parent)
9355 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
9356
9357 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9358 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9359 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
9360 old_dentry->d_name.name,
9361 old_dentry->d_name.len);
9362 } else {
9363 ret = __btrfs_unlink_inode(trans, root, old_dir,
9364 d_inode(old_dentry),
9365 old_dentry->d_name.name,
9366 old_dentry->d_name.len);
9367 if (!ret)
9368 ret = btrfs_update_inode(trans, root, old_inode);
9369 }
9370 if (ret) {
9371 btrfs_abort_transaction(trans, root, ret);
9372 goto out_fail;
9373 }
9374
9375 if (new_inode) {
9376 inode_inc_iversion(new_inode);
9377 new_inode->i_ctime = CURRENT_TIME;
9378 if (unlikely(btrfs_ino(new_inode) ==
9379 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
9380 root_objectid = BTRFS_I(new_inode)->location.objectid;
9381 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9382 root_objectid,
9383 new_dentry->d_name.name,
9384 new_dentry->d_name.len);
9385 BUG_ON(new_inode->i_nlink == 0);
9386 } else {
9387 ret = btrfs_unlink_inode(trans, dest, new_dir,
9388 d_inode(new_dentry),
9389 new_dentry->d_name.name,
9390 new_dentry->d_name.len);
9391 }
9392 if (!ret && new_inode->i_nlink == 0)
9393 ret = btrfs_orphan_add(trans, d_inode(new_dentry));
9394 if (ret) {
9395 btrfs_abort_transaction(trans, root, ret);
9396 goto out_fail;
9397 }
9398 }
9399
9400 ret = btrfs_add_link(trans, new_dir, old_inode,
9401 new_dentry->d_name.name,
9402 new_dentry->d_name.len, 0, index);
9403 if (ret) {
9404 btrfs_abort_transaction(trans, root, ret);
9405 goto out_fail;
9406 }
9407
9408 if (old_inode->i_nlink == 1)
9409 BTRFS_I(old_inode)->dir_index = index;
9410
9411 if (old_ino != BTRFS_FIRST_FREE_OBJECTID) {
9412 struct dentry *parent = new_dentry->d_parent;
9413 btrfs_log_new_name(trans, old_inode, old_dir, parent);
9414 btrfs_end_log_trans(root);
9415 }
9416 out_fail:
9417 btrfs_end_transaction(trans, root);
9418 out_notrans:
9419 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9420 up_read(&root->fs_info->subvol_sem);
9421
9422 return ret;
9423 }
9424
9425 static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
9426 struct inode *new_dir, struct dentry *new_dentry,
9427 unsigned int flags)
9428 {
9429 if (flags & ~RENAME_NOREPLACE)
9430 return -EINVAL;
9431
9432 return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry);
9433 }
9434
9435 static void btrfs_run_delalloc_work(struct btrfs_work *work)
9436 {
9437 struct btrfs_delalloc_work *delalloc_work;
9438 struct inode *inode;
9439
9440 delalloc_work = container_of(work, struct btrfs_delalloc_work,
9441 work);
9442 inode = delalloc_work->inode;
9443 if (delalloc_work->wait) {
9444 btrfs_wait_ordered_range(inode, 0, (u64)-1);
9445 } else {
9446 filemap_flush(inode->i_mapping);
9447 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
9448 &BTRFS_I(inode)->runtime_flags))
9449 filemap_flush(inode->i_mapping);
9450 }
9451
9452 if (delalloc_work->delay_iput)
9453 btrfs_add_delayed_iput(inode);
9454 else
9455 iput(inode);
9456 complete(&delalloc_work->completion);
9457 }
9458
9459 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
9460 int wait, int delay_iput)
9461 {
9462 struct btrfs_delalloc_work *work;
9463
9464 work = kmem_cache_zalloc(btrfs_delalloc_work_cachep, GFP_NOFS);
9465 if (!work)
9466 return NULL;
9467
9468 init_completion(&work->completion);
9469 INIT_LIST_HEAD(&work->list);
9470 work->inode = inode;
9471 work->wait = wait;
9472 work->delay_iput = delay_iput;
9473 WARN_ON_ONCE(!inode);
9474 btrfs_init_work(&work->work, btrfs_flush_delalloc_helper,
9475 btrfs_run_delalloc_work, NULL, NULL);
9476
9477 return work;
9478 }
9479
9480 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
9481 {
9482 wait_for_completion(&work->completion);
9483 kmem_cache_free(btrfs_delalloc_work_cachep, work);
9484 }
9485
9486 /*
9487 * some fairly slow code that needs optimization. This walks the list
9488 * of all the inodes with pending delalloc and forces them to disk.
9489 */
9490 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput,
9491 int nr)
9492 {
9493 struct btrfs_inode *binode;
9494 struct inode *inode;
9495 struct btrfs_delalloc_work *work, *next;
9496 struct list_head works;
9497 struct list_head splice;
9498 int ret = 0;
9499
9500 INIT_LIST_HEAD(&works);
9501 INIT_LIST_HEAD(&splice);
9502
9503 mutex_lock(&root->delalloc_mutex);
9504 spin_lock(&root->delalloc_lock);
9505 list_splice_init(&root->delalloc_inodes, &splice);
9506 while (!list_empty(&splice)) {
9507 binode = list_entry(splice.next, struct btrfs_inode,
9508 delalloc_inodes);
9509
9510 list_move_tail(&binode->delalloc_inodes,
9511 &root->delalloc_inodes);
9512 inode = igrab(&binode->vfs_inode);
9513 if (!inode) {
9514 cond_resched_lock(&root->delalloc_lock);
9515 continue;
9516 }
9517 spin_unlock(&root->delalloc_lock);
9518
9519 work = btrfs_alloc_delalloc_work(inode, 0, delay_iput);
9520 if (!work) {
9521 if (delay_iput)
9522 btrfs_add_delayed_iput(inode);
9523 else
9524 iput(inode);
9525 ret = -ENOMEM;
9526 goto out;
9527 }
9528 list_add_tail(&work->list, &works);
9529 btrfs_queue_work(root->fs_info->flush_workers,
9530 &work->work);
9531 ret++;
9532 if (nr != -1 && ret >= nr)
9533 goto out;
9534 cond_resched();
9535 spin_lock(&root->delalloc_lock);
9536 }
9537 spin_unlock(&root->delalloc_lock);
9538
9539 out:
9540 list_for_each_entry_safe(work, next, &works, list) {
9541 list_del_init(&work->list);
9542 btrfs_wait_and_free_delalloc_work(work);
9543 }
9544
9545 if (!list_empty_careful(&splice)) {
9546 spin_lock(&root->delalloc_lock);
9547 list_splice_tail(&splice, &root->delalloc_inodes);
9548 spin_unlock(&root->delalloc_lock);
9549 }
9550 mutex_unlock(&root->delalloc_mutex);
9551 return ret;
9552 }
9553
9554 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
9555 {
9556 int ret;
9557
9558 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
9559 return -EROFS;
9560
9561 ret = __start_delalloc_inodes(root, delay_iput, -1);
9562 if (ret > 0)
9563 ret = 0;
9564 /*
9565 * the filemap_flush will queue IO into the worker threads, but
9566 * we have to make sure the IO is actually started and that
9567 * ordered extents get created before we return
9568 */
9569 atomic_inc(&root->fs_info->async_submit_draining);
9570 while (atomic_read(&root->fs_info->nr_async_submits) ||
9571 atomic_read(&root->fs_info->async_delalloc_pages)) {
9572 wait_event(root->fs_info->async_submit_wait,
9573 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
9574 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
9575 }
9576 atomic_dec(&root->fs_info->async_submit_draining);
9577 return ret;
9578 }
9579
9580 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput,
9581 int nr)
9582 {
9583 struct btrfs_root *root;
9584 struct list_head splice;
9585 int ret;
9586
9587 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
9588 return -EROFS;
9589
9590 INIT_LIST_HEAD(&splice);
9591
9592 mutex_lock(&fs_info->delalloc_root_mutex);
9593 spin_lock(&fs_info->delalloc_root_lock);
9594 list_splice_init(&fs_info->delalloc_roots, &splice);
9595 while (!list_empty(&splice) && nr) {
9596 root = list_first_entry(&splice, struct btrfs_root,
9597 delalloc_root);
9598 root = btrfs_grab_fs_root(root);
9599 BUG_ON(!root);
9600 list_move_tail(&root->delalloc_root,
9601 &fs_info->delalloc_roots);
9602 spin_unlock(&fs_info->delalloc_root_lock);
9603
9604 ret = __start_delalloc_inodes(root, delay_iput, nr);
9605 btrfs_put_fs_root(root);
9606 if (ret < 0)
9607 goto out;
9608
9609 if (nr != -1) {
9610 nr -= ret;
9611 WARN_ON(nr < 0);
9612 }
9613 spin_lock(&fs_info->delalloc_root_lock);
9614 }
9615 spin_unlock(&fs_info->delalloc_root_lock);
9616
9617 ret = 0;
9618 atomic_inc(&fs_info->async_submit_draining);
9619 while (atomic_read(&fs_info->nr_async_submits) ||
9620 atomic_read(&fs_info->async_delalloc_pages)) {
9621 wait_event(fs_info->async_submit_wait,
9622 (atomic_read(&fs_info->nr_async_submits) == 0 &&
9623 atomic_read(&fs_info->async_delalloc_pages) == 0));
9624 }
9625 atomic_dec(&fs_info->async_submit_draining);
9626 out:
9627 if (!list_empty_careful(&splice)) {
9628 spin_lock(&fs_info->delalloc_root_lock);
9629 list_splice_tail(&splice, &fs_info->delalloc_roots);
9630 spin_unlock(&fs_info->delalloc_root_lock);
9631 }
9632 mutex_unlock(&fs_info->delalloc_root_mutex);
9633 return ret;
9634 }
9635
9636 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
9637 const char *symname)
9638 {
9639 struct btrfs_trans_handle *trans;
9640 struct btrfs_root *root = BTRFS_I(dir)->root;
9641 struct btrfs_path *path;
9642 struct btrfs_key key;
9643 struct inode *inode = NULL;
9644 int err;
9645 int drop_inode = 0;
9646 u64 objectid;
9647 u64 index = 0;
9648 int name_len;
9649 int datasize;
9650 unsigned long ptr;
9651 struct btrfs_file_extent_item *ei;
9652 struct extent_buffer *leaf;
9653
9654 name_len = strlen(symname);
9655 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
9656 return -ENAMETOOLONG;
9657
9658 /*
9659 * 2 items for inode item and ref
9660 * 2 items for dir items
9661 * 1 item for xattr if selinux is on
9662 */
9663 trans = btrfs_start_transaction(root, 5);
9664 if (IS_ERR(trans))
9665 return PTR_ERR(trans);
9666
9667 err = btrfs_find_free_ino(root, &objectid);
9668 if (err)
9669 goto out_unlock;
9670
9671 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
9672 dentry->d_name.len, btrfs_ino(dir), objectid,
9673 S_IFLNK|S_IRWXUGO, &index);
9674 if (IS_ERR(inode)) {
9675 err = PTR_ERR(inode);
9676 goto out_unlock;
9677 }
9678
9679 /*
9680 * If the active LSM wants to access the inode during
9681 * d_instantiate it needs these. Smack checks to see
9682 * if the filesystem supports xattrs by looking at the
9683 * ops vector.
9684 */
9685 inode->i_fop = &btrfs_file_operations;
9686 inode->i_op = &btrfs_file_inode_operations;
9687 inode->i_mapping->a_ops = &btrfs_aops;
9688 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
9689
9690 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
9691 if (err)
9692 goto out_unlock_inode;
9693
9694 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
9695 if (err)
9696 goto out_unlock_inode;
9697
9698 path = btrfs_alloc_path();
9699 if (!path) {
9700 err = -ENOMEM;
9701 goto out_unlock_inode;
9702 }
9703 key.objectid = btrfs_ino(inode);
9704 key.offset = 0;
9705 key.type = BTRFS_EXTENT_DATA_KEY;
9706 datasize = btrfs_file_extent_calc_inline_size(name_len);
9707 err = btrfs_insert_empty_item(trans, root, path, &key,
9708 datasize);
9709 if (err) {
9710 btrfs_free_path(path);
9711 goto out_unlock_inode;
9712 }
9713 leaf = path->nodes[0];
9714 ei = btrfs_item_ptr(leaf, path->slots[0],
9715 struct btrfs_file_extent_item);
9716 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
9717 btrfs_set_file_extent_type(leaf, ei,
9718 BTRFS_FILE_EXTENT_INLINE);
9719 btrfs_set_file_extent_encryption(leaf, ei, 0);
9720 btrfs_set_file_extent_compression(leaf, ei, 0);
9721 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
9722 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
9723
9724 ptr = btrfs_file_extent_inline_start(ei);
9725 write_extent_buffer(leaf, symname, ptr, name_len);
9726 btrfs_mark_buffer_dirty(leaf);
9727 btrfs_free_path(path);
9728
9729 inode->i_op = &btrfs_symlink_inode_operations;
9730 inode->i_mapping->a_ops = &btrfs_symlink_aops;
9731 inode_set_bytes(inode, name_len);
9732 btrfs_i_size_write(inode, name_len);
9733 err = btrfs_update_inode(trans, root, inode);
9734 if (err) {
9735 drop_inode = 1;
9736 goto out_unlock_inode;
9737 }
9738
9739 unlock_new_inode(inode);
9740 d_instantiate(dentry, inode);
9741
9742 out_unlock:
9743 btrfs_end_transaction(trans, root);
9744 if (drop_inode) {
9745 inode_dec_link_count(inode);
9746 iput(inode);
9747 }
9748 btrfs_btree_balance_dirty(root);
9749 return err;
9750
9751 out_unlock_inode:
9752 drop_inode = 1;
9753 unlock_new_inode(inode);
9754 goto out_unlock;
9755 }
9756
9757 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
9758 u64 start, u64 num_bytes, u64 min_size,
9759 loff_t actual_len, u64 *alloc_hint,
9760 struct btrfs_trans_handle *trans)
9761 {
9762 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
9763 struct extent_map *em;
9764 struct btrfs_root *root = BTRFS_I(inode)->root;
9765 struct btrfs_key ins;
9766 u64 cur_offset = start;
9767 u64 i_size;
9768 u64 cur_bytes;
9769 u64 last_alloc = (u64)-1;
9770 int ret = 0;
9771 bool own_trans = true;
9772
9773 if (trans)
9774 own_trans = false;
9775 while (num_bytes > 0) {
9776 if (own_trans) {
9777 trans = btrfs_start_transaction(root, 3);
9778 if (IS_ERR(trans)) {
9779 ret = PTR_ERR(trans);
9780 break;
9781 }
9782 }
9783
9784 cur_bytes = min(num_bytes, 256ULL * 1024 * 1024);
9785 cur_bytes = max(cur_bytes, min_size);
9786 /*
9787 * If we are severely fragmented we could end up with really
9788 * small allocations, so if the allocator is returning small
9789 * chunks lets make its job easier by only searching for those
9790 * sized chunks.
9791 */
9792 cur_bytes = min(cur_bytes, last_alloc);
9793 ret = btrfs_reserve_extent(root, cur_bytes, min_size, 0,
9794 *alloc_hint, &ins, 1, 0);
9795 if (ret) {
9796 if (own_trans)
9797 btrfs_end_transaction(trans, root);
9798 break;
9799 }
9800
9801 last_alloc = ins.offset;
9802 ret = insert_reserved_file_extent(trans, inode,
9803 cur_offset, ins.objectid,
9804 ins.offset, ins.offset,
9805 ins.offset, 0, 0, 0,
9806 BTRFS_FILE_EXTENT_PREALLOC);
9807 if (ret) {
9808 btrfs_free_reserved_extent(root, ins.objectid,
9809 ins.offset, 0);
9810 btrfs_abort_transaction(trans, root, ret);
9811 if (own_trans)
9812 btrfs_end_transaction(trans, root);
9813 break;
9814 }
9815
9816 btrfs_drop_extent_cache(inode, cur_offset,
9817 cur_offset + ins.offset -1, 0);
9818
9819 em = alloc_extent_map();
9820 if (!em) {
9821 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
9822 &BTRFS_I(inode)->runtime_flags);
9823 goto next;
9824 }
9825
9826 em->start = cur_offset;
9827 em->orig_start = cur_offset;
9828 em->len = ins.offset;
9829 em->block_start = ins.objectid;
9830 em->block_len = ins.offset;
9831 em->orig_block_len = ins.offset;
9832 em->ram_bytes = ins.offset;
9833 em->bdev = root->fs_info->fs_devices->latest_bdev;
9834 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
9835 em->generation = trans->transid;
9836
9837 while (1) {
9838 write_lock(&em_tree->lock);
9839 ret = add_extent_mapping(em_tree, em, 1);
9840 write_unlock(&em_tree->lock);
9841 if (ret != -EEXIST)
9842 break;
9843 btrfs_drop_extent_cache(inode, cur_offset,
9844 cur_offset + ins.offset - 1,
9845 0);
9846 }
9847 free_extent_map(em);
9848 next:
9849 num_bytes -= ins.offset;
9850 cur_offset += ins.offset;
9851 *alloc_hint = ins.objectid + ins.offset;
9852
9853 inode_inc_iversion(inode);
9854 inode->i_ctime = CURRENT_TIME;
9855 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
9856 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
9857 (actual_len > inode->i_size) &&
9858 (cur_offset > inode->i_size)) {
9859 if (cur_offset > actual_len)
9860 i_size = actual_len;
9861 else
9862 i_size = cur_offset;
9863 i_size_write(inode, i_size);
9864 btrfs_ordered_update_i_size(inode, i_size, NULL);
9865 }
9866
9867 ret = btrfs_update_inode(trans, root, inode);
9868
9869 if (ret) {
9870 btrfs_abort_transaction(trans, root, ret);
9871 if (own_trans)
9872 btrfs_end_transaction(trans, root);
9873 break;
9874 }
9875
9876 if (own_trans)
9877 btrfs_end_transaction(trans, root);
9878 }
9879 return ret;
9880 }
9881
9882 int btrfs_prealloc_file_range(struct inode *inode, int mode,
9883 u64 start, u64 num_bytes, u64 min_size,
9884 loff_t actual_len, u64 *alloc_hint)
9885 {
9886 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
9887 min_size, actual_len, alloc_hint,
9888 NULL);
9889 }
9890
9891 int btrfs_prealloc_file_range_trans(struct inode *inode,
9892 struct btrfs_trans_handle *trans, int mode,
9893 u64 start, u64 num_bytes, u64 min_size,
9894 loff_t actual_len, u64 *alloc_hint)
9895 {
9896 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
9897 min_size, actual_len, alloc_hint, trans);
9898 }
9899
9900 static int btrfs_set_page_dirty(struct page *page)
9901 {
9902 return __set_page_dirty_nobuffers(page);
9903 }
9904
9905 static int btrfs_permission(struct inode *inode, int mask)
9906 {
9907 struct btrfs_root *root = BTRFS_I(inode)->root;
9908 umode_t mode = inode->i_mode;
9909
9910 if (mask & MAY_WRITE &&
9911 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
9912 if (btrfs_root_readonly(root))
9913 return -EROFS;
9914 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
9915 return -EACCES;
9916 }
9917 return generic_permission(inode, mask);
9918 }
9919
9920 static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
9921 {
9922 struct btrfs_trans_handle *trans;
9923 struct btrfs_root *root = BTRFS_I(dir)->root;
9924 struct inode *inode = NULL;
9925 u64 objectid;
9926 u64 index;
9927 int ret = 0;
9928
9929 /*
9930 * 5 units required for adding orphan entry
9931 */
9932 trans = btrfs_start_transaction(root, 5);
9933 if (IS_ERR(trans))
9934 return PTR_ERR(trans);
9935
9936 ret = btrfs_find_free_ino(root, &objectid);
9937 if (ret)
9938 goto out;
9939
9940 inode = btrfs_new_inode(trans, root, dir, NULL, 0,
9941 btrfs_ino(dir), objectid, mode, &index);
9942 if (IS_ERR(inode)) {
9943 ret = PTR_ERR(inode);
9944 inode = NULL;
9945 goto out;
9946 }
9947
9948 inode->i_fop = &btrfs_file_operations;
9949 inode->i_op = &btrfs_file_inode_operations;
9950
9951 inode->i_mapping->a_ops = &btrfs_aops;
9952 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
9953
9954 ret = btrfs_init_inode_security(trans, inode, dir, NULL);
9955 if (ret)
9956 goto out_inode;
9957
9958 ret = btrfs_update_inode(trans, root, inode);
9959 if (ret)
9960 goto out_inode;
9961 ret = btrfs_orphan_add(trans, inode);
9962 if (ret)
9963 goto out_inode;
9964
9965 /*
9966 * We set number of links to 0 in btrfs_new_inode(), and here we set
9967 * it to 1 because d_tmpfile() will issue a warning if the count is 0,
9968 * through:
9969 *
9970 * d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
9971 */
9972 set_nlink(inode, 1);
9973 unlock_new_inode(inode);
9974 d_tmpfile(dentry, inode);
9975 mark_inode_dirty(inode);
9976
9977 out:
9978 btrfs_end_transaction(trans, root);
9979 if (ret)
9980 iput(inode);
9981 btrfs_balance_delayed_items(root);
9982 btrfs_btree_balance_dirty(root);
9983 return ret;
9984
9985 out_inode:
9986 unlock_new_inode(inode);
9987 goto out;
9988
9989 }
9990
9991 /* Inspired by filemap_check_errors() */
9992 int btrfs_inode_check_errors(struct inode *inode)
9993 {
9994 int ret = 0;
9995
9996 if (test_bit(AS_ENOSPC, &inode->i_mapping->flags) &&
9997 test_and_clear_bit(AS_ENOSPC, &inode->i_mapping->flags))
9998 ret = -ENOSPC;
9999 if (test_bit(AS_EIO, &inode->i_mapping->flags) &&
10000 test_and_clear_bit(AS_EIO, &inode->i_mapping->flags))
10001 ret = -EIO;
10002
10003 return ret;
10004 }
10005
10006 static const struct inode_operations btrfs_dir_inode_operations = {
10007 .getattr = btrfs_getattr,
10008 .lookup = btrfs_lookup,
10009 .create = btrfs_create,
10010 .unlink = btrfs_unlink,
10011 .link = btrfs_link,
10012 .mkdir = btrfs_mkdir,
10013 .rmdir = btrfs_rmdir,
10014 .rename2 = btrfs_rename2,
10015 .symlink = btrfs_symlink,
10016 .setattr = btrfs_setattr,
10017 .mknod = btrfs_mknod,
10018 .setxattr = btrfs_setxattr,
10019 .getxattr = btrfs_getxattr,
10020 .listxattr = btrfs_listxattr,
10021 .removexattr = btrfs_removexattr,
10022 .permission = btrfs_permission,
10023 .get_acl = btrfs_get_acl,
10024 .set_acl = btrfs_set_acl,
10025 .update_time = btrfs_update_time,
10026 .tmpfile = btrfs_tmpfile,
10027 };
10028 static const struct inode_operations btrfs_dir_ro_inode_operations = {
10029 .lookup = btrfs_lookup,
10030 .permission = btrfs_permission,
10031 .get_acl = btrfs_get_acl,
10032 .set_acl = btrfs_set_acl,
10033 .update_time = btrfs_update_time,
10034 };
10035
10036 static const struct file_operations btrfs_dir_file_operations = {
10037 .llseek = generic_file_llseek,
10038 .read = generic_read_dir,
10039 .iterate = btrfs_real_readdir,
10040 .unlocked_ioctl = btrfs_ioctl,
10041 #ifdef CONFIG_COMPAT
10042 .compat_ioctl = btrfs_ioctl,
10043 #endif
10044 .release = btrfs_release_file,
10045 .fsync = btrfs_sync_file,
10046 };
10047
10048 static struct extent_io_ops btrfs_extent_io_ops = {
10049 .fill_delalloc = run_delalloc_range,
10050 .submit_bio_hook = btrfs_submit_bio_hook,
10051 .merge_bio_hook = btrfs_merge_bio_hook,
10052 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
10053 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
10054 .writepage_start_hook = btrfs_writepage_start_hook,
10055 .set_bit_hook = btrfs_set_bit_hook,
10056 .clear_bit_hook = btrfs_clear_bit_hook,
10057 .merge_extent_hook = btrfs_merge_extent_hook,
10058 .split_extent_hook = btrfs_split_extent_hook,
10059 };
10060
10061 /*
10062 * btrfs doesn't support the bmap operation because swapfiles
10063 * use bmap to make a mapping of extents in the file. They assume
10064 * these extents won't change over the life of the file and they
10065 * use the bmap result to do IO directly to the drive.
10066 *
10067 * the btrfs bmap call would return logical addresses that aren't
10068 * suitable for IO and they also will change frequently as COW
10069 * operations happen. So, swapfile + btrfs == corruption.
10070 *
10071 * For now we're avoiding this by dropping bmap.
10072 */
10073 static const struct address_space_operations btrfs_aops = {
10074 .readpage = btrfs_readpage,
10075 .writepage = btrfs_writepage,
10076 .writepages = btrfs_writepages,
10077 .readpages = btrfs_readpages,
10078 .direct_IO = btrfs_direct_IO,
10079 .invalidatepage = btrfs_invalidatepage,
10080 .releasepage = btrfs_releasepage,
10081 .set_page_dirty = btrfs_set_page_dirty,
10082 .error_remove_page = generic_error_remove_page,
10083 };
10084
10085 static const struct address_space_operations btrfs_symlink_aops = {
10086 .readpage = btrfs_readpage,
10087 .writepage = btrfs_writepage,
10088 .invalidatepage = btrfs_invalidatepage,
10089 .releasepage = btrfs_releasepage,
10090 };
10091
10092 static const struct inode_operations btrfs_file_inode_operations = {
10093 .getattr = btrfs_getattr,
10094 .setattr = btrfs_setattr,
10095 .setxattr = btrfs_setxattr,
10096 .getxattr = btrfs_getxattr,
10097 .listxattr = btrfs_listxattr,
10098 .removexattr = btrfs_removexattr,
10099 .permission = btrfs_permission,
10100 .fiemap = btrfs_fiemap,
10101 .get_acl = btrfs_get_acl,
10102 .set_acl = btrfs_set_acl,
10103 .update_time = btrfs_update_time,
10104 };
10105 static const struct inode_operations btrfs_special_inode_operations = {
10106 .getattr = btrfs_getattr,
10107 .setattr = btrfs_setattr,
10108 .permission = btrfs_permission,
10109 .setxattr = btrfs_setxattr,
10110 .getxattr = btrfs_getxattr,
10111 .listxattr = btrfs_listxattr,
10112 .removexattr = btrfs_removexattr,
10113 .get_acl = btrfs_get_acl,
10114 .set_acl = btrfs_set_acl,
10115 .update_time = btrfs_update_time,
10116 };
10117 static const struct inode_operations btrfs_symlink_inode_operations = {
10118 .readlink = generic_readlink,
10119 .follow_link = page_follow_link_light,
10120 .put_link = page_put_link,
10121 .getattr = btrfs_getattr,
10122 .setattr = btrfs_setattr,
10123 .permission = btrfs_permission,
10124 .setxattr = btrfs_setxattr,
10125 .getxattr = btrfs_getxattr,
10126 .listxattr = btrfs_listxattr,
10127 .removexattr = btrfs_removexattr,
10128 .update_time = btrfs_update_time,
10129 };
10130
10131 const struct dentry_operations btrfs_dentry_operations = {
10132 .d_delete = btrfs_dentry_delete,
10133 .d_release = btrfs_dentry_release,
10134 };
Linux kernel - Deliverables
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