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Merge tag 'kvm-3.11-2' of git://git.kernel.org/pub/scm/virt/kvm/kvm
[mirror_ubuntu-artful-kernel.git] / fs / btrfs / inode.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/kernel.h>
20 #include <linux/bio.h>
21 #include <linux/buffer_head.h>
22 #include <linux/file.h>
23 #include <linux/fs.h>
24 #include <linux/pagemap.h>
25 #include <linux/highmem.h>
26 #include <linux/time.h>
27 #include <linux/init.h>
28 #include <linux/string.h>
29 #include <linux/backing-dev.h>
30 #include <linux/mpage.h>
31 #include <linux/swap.h>
32 #include <linux/writeback.h>
33 #include <linux/statfs.h>
34 #include <linux/compat.h>
35 #include <linux/aio.h>
36 #include <linux/bit_spinlock.h>
37 #include <linux/xattr.h>
38 #include <linux/posix_acl.h>
39 #include <linux/falloc.h>
40 #include <linux/slab.h>
41 #include <linux/ratelimit.h>
42 #include <linux/mount.h>
43 #include <linux/btrfs.h>
44 #include <linux/blkdev.h>
45 #include <linux/posix_acl_xattr.h>
46 #include "compat.h"
47 #include "ctree.h"
48 #include "disk-io.h"
49 #include "transaction.h"
50 #include "btrfs_inode.h"
51 #include "print-tree.h"
52 #include "ordered-data.h"
53 #include "xattr.h"
54 #include "tree-log.h"
55 #include "volumes.h"
56 #include "compression.h"
57 #include "locking.h"
58 #include "free-space-cache.h"
59 #include "inode-map.h"
60 #include "backref.h"
61 #include "hash.h"
62
63 struct btrfs_iget_args {
64 u64 ino;
65 struct btrfs_root *root;
66 };
67
68 static const struct inode_operations btrfs_dir_inode_operations;
69 static const struct inode_operations btrfs_symlink_inode_operations;
70 static const struct inode_operations btrfs_dir_ro_inode_operations;
71 static const struct inode_operations btrfs_special_inode_operations;
72 static const struct inode_operations btrfs_file_inode_operations;
73 static const struct address_space_operations btrfs_aops;
74 static const struct address_space_operations btrfs_symlink_aops;
75 static const struct file_operations btrfs_dir_file_operations;
76 static struct extent_io_ops btrfs_extent_io_ops;
77
78 static struct kmem_cache *btrfs_inode_cachep;
79 static struct kmem_cache *btrfs_delalloc_work_cachep;
80 struct kmem_cache *btrfs_trans_handle_cachep;
81 struct kmem_cache *btrfs_transaction_cachep;
82 struct kmem_cache *btrfs_path_cachep;
83 struct kmem_cache *btrfs_free_space_cachep;
84
85 #define S_SHIFT 12
86 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
87 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
88 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
89 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
90 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
91 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
92 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
93 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
94 };
95
96 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
97 static int btrfs_truncate(struct inode *inode);
98 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
99 static noinline int cow_file_range(struct inode *inode,
100 struct page *locked_page,
101 u64 start, u64 end, int *page_started,
102 unsigned long *nr_written, int unlock);
103 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
104 u64 len, u64 orig_start,
105 u64 block_start, u64 block_len,
106 u64 orig_block_len, u64 ram_bytes,
107 int type);
108
109 static int btrfs_dirty_inode(struct inode *inode);
110
111 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
112 struct inode *inode, struct inode *dir,
113 const struct qstr *qstr)
114 {
115 int err;
116
117 err = btrfs_init_acl(trans, inode, dir);
118 if (!err)
119 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
120 return err;
121 }
122
123 /*
124 * this does all the hard work for inserting an inline extent into
125 * the btree. The caller should have done a btrfs_drop_extents so that
126 * no overlapping inline items exist in the btree
127 */
128 static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
129 struct btrfs_root *root, struct inode *inode,
130 u64 start, size_t size, size_t compressed_size,
131 int compress_type,
132 struct page **compressed_pages)
133 {
134 struct btrfs_key key;
135 struct btrfs_path *path;
136 struct extent_buffer *leaf;
137 struct page *page = NULL;
138 char *kaddr;
139 unsigned long ptr;
140 struct btrfs_file_extent_item *ei;
141 int err = 0;
142 int ret;
143 size_t cur_size = size;
144 size_t datasize;
145 unsigned long offset;
146
147 if (compressed_size && compressed_pages)
148 cur_size = compressed_size;
149
150 path = btrfs_alloc_path();
151 if (!path)
152 return -ENOMEM;
153
154 path->leave_spinning = 1;
155
156 key.objectid = btrfs_ino(inode);
157 key.offset = start;
158 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
159 datasize = btrfs_file_extent_calc_inline_size(cur_size);
160
161 inode_add_bytes(inode, size);
162 ret = btrfs_insert_empty_item(trans, root, path, &key,
163 datasize);
164 if (ret) {
165 err = ret;
166 goto fail;
167 }
168 leaf = path->nodes[0];
169 ei = btrfs_item_ptr(leaf, path->slots[0],
170 struct btrfs_file_extent_item);
171 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
172 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
173 btrfs_set_file_extent_encryption(leaf, ei, 0);
174 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
175 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
176 ptr = btrfs_file_extent_inline_start(ei);
177
178 if (compress_type != BTRFS_COMPRESS_NONE) {
179 struct page *cpage;
180 int i = 0;
181 while (compressed_size > 0) {
182 cpage = compressed_pages[i];
183 cur_size = min_t(unsigned long, compressed_size,
184 PAGE_CACHE_SIZE);
185
186 kaddr = kmap_atomic(cpage);
187 write_extent_buffer(leaf, kaddr, ptr, cur_size);
188 kunmap_atomic(kaddr);
189
190 i++;
191 ptr += cur_size;
192 compressed_size -= cur_size;
193 }
194 btrfs_set_file_extent_compression(leaf, ei,
195 compress_type);
196 } else {
197 page = find_get_page(inode->i_mapping,
198 start >> PAGE_CACHE_SHIFT);
199 btrfs_set_file_extent_compression(leaf, ei, 0);
200 kaddr = kmap_atomic(page);
201 offset = start & (PAGE_CACHE_SIZE - 1);
202 write_extent_buffer(leaf, kaddr + offset, ptr, size);
203 kunmap_atomic(kaddr);
204 page_cache_release(page);
205 }
206 btrfs_mark_buffer_dirty(leaf);
207 btrfs_free_path(path);
208
209 /*
210 * we're an inline extent, so nobody can
211 * extend the file past i_size without locking
212 * a page we already have locked.
213 *
214 * We must do any isize and inode updates
215 * before we unlock the pages. Otherwise we
216 * could end up racing with unlink.
217 */
218 BTRFS_I(inode)->disk_i_size = inode->i_size;
219 ret = btrfs_update_inode(trans, root, inode);
220
221 return ret;
222 fail:
223 btrfs_free_path(path);
224 return err;
225 }
226
227
228 /*
229 * conditionally insert an inline extent into the file. This
230 * does the checks required to make sure the data is small enough
231 * to fit as an inline extent.
232 */
233 static noinline int cow_file_range_inline(struct btrfs_trans_handle *trans,
234 struct btrfs_root *root,
235 struct inode *inode, u64 start, u64 end,
236 size_t compressed_size, int compress_type,
237 struct page **compressed_pages)
238 {
239 u64 isize = i_size_read(inode);
240 u64 actual_end = min(end + 1, isize);
241 u64 inline_len = actual_end - start;
242 u64 aligned_end = ALIGN(end, root->sectorsize);
243 u64 data_len = inline_len;
244 int ret;
245
246 if (compressed_size)
247 data_len = compressed_size;
248
249 if (start > 0 ||
250 actual_end >= PAGE_CACHE_SIZE ||
251 data_len >= BTRFS_MAX_INLINE_DATA_SIZE(root) ||
252 (!compressed_size &&
253 (actual_end & (root->sectorsize - 1)) == 0) ||
254 end + 1 < isize ||
255 data_len > root->fs_info->max_inline) {
256 return 1;
257 }
258
259 ret = btrfs_drop_extents(trans, root, inode, start, aligned_end, 1);
260 if (ret)
261 return ret;
262
263 if (isize > actual_end)
264 inline_len = min_t(u64, isize, actual_end);
265 ret = insert_inline_extent(trans, root, inode, start,
266 inline_len, compressed_size,
267 compress_type, compressed_pages);
268 if (ret && ret != -ENOSPC) {
269 btrfs_abort_transaction(trans, root, ret);
270 return ret;
271 } else if (ret == -ENOSPC) {
272 return 1;
273 }
274
275 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
276 btrfs_delalloc_release_metadata(inode, end + 1 - start);
277 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
278 return 0;
279 }
280
281 struct async_extent {
282 u64 start;
283 u64 ram_size;
284 u64 compressed_size;
285 struct page **pages;
286 unsigned long nr_pages;
287 int compress_type;
288 struct list_head list;
289 };
290
291 struct async_cow {
292 struct inode *inode;
293 struct btrfs_root *root;
294 struct page *locked_page;
295 u64 start;
296 u64 end;
297 struct list_head extents;
298 struct btrfs_work work;
299 };
300
301 static noinline int add_async_extent(struct async_cow *cow,
302 u64 start, u64 ram_size,
303 u64 compressed_size,
304 struct page **pages,
305 unsigned long nr_pages,
306 int compress_type)
307 {
308 struct async_extent *async_extent;
309
310 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
311 BUG_ON(!async_extent); /* -ENOMEM */
312 async_extent->start = start;
313 async_extent->ram_size = ram_size;
314 async_extent->compressed_size = compressed_size;
315 async_extent->pages = pages;
316 async_extent->nr_pages = nr_pages;
317 async_extent->compress_type = compress_type;
318 list_add_tail(&async_extent->list, &cow->extents);
319 return 0;
320 }
321
322 /*
323 * we create compressed extents in two phases. The first
324 * phase compresses a range of pages that have already been
325 * locked (both pages and state bits are locked).
326 *
327 * This is done inside an ordered work queue, and the compression
328 * is spread across many cpus. The actual IO submission is step
329 * two, and the ordered work queue takes care of making sure that
330 * happens in the same order things were put onto the queue by
331 * writepages and friends.
332 *
333 * If this code finds it can't get good compression, it puts an
334 * entry onto the work queue to write the uncompressed bytes. This
335 * makes sure that both compressed inodes and uncompressed inodes
336 * are written in the same order that the flusher thread sent them
337 * down.
338 */
339 static noinline int compress_file_range(struct inode *inode,
340 struct page *locked_page,
341 u64 start, u64 end,
342 struct async_cow *async_cow,
343 int *num_added)
344 {
345 struct btrfs_root *root = BTRFS_I(inode)->root;
346 struct btrfs_trans_handle *trans;
347 u64 num_bytes;
348 u64 blocksize = root->sectorsize;
349 u64 actual_end;
350 u64 isize = i_size_read(inode);
351 int ret = 0;
352 struct page **pages = NULL;
353 unsigned long nr_pages;
354 unsigned long nr_pages_ret = 0;
355 unsigned long total_compressed = 0;
356 unsigned long total_in = 0;
357 unsigned long max_compressed = 128 * 1024;
358 unsigned long max_uncompressed = 128 * 1024;
359 int i;
360 int will_compress;
361 int compress_type = root->fs_info->compress_type;
362 int redirty = 0;
363
364 /* if this is a small write inside eof, kick off a defrag */
365 if ((end - start + 1) < 16 * 1024 &&
366 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
367 btrfs_add_inode_defrag(NULL, inode);
368
369 actual_end = min_t(u64, isize, end + 1);
370 again:
371 will_compress = 0;
372 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
373 nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
374
375 /*
376 * we don't want to send crud past the end of i_size through
377 * compression, that's just a waste of CPU time. So, if the
378 * end of the file is before the start of our current
379 * requested range of bytes, we bail out to the uncompressed
380 * cleanup code that can deal with all of this.
381 *
382 * It isn't really the fastest way to fix things, but this is a
383 * very uncommon corner.
384 */
385 if (actual_end <= start)
386 goto cleanup_and_bail_uncompressed;
387
388 total_compressed = actual_end - start;
389
390 /* we want to make sure that amount of ram required to uncompress
391 * an extent is reasonable, so we limit the total size in ram
392 * of a compressed extent to 128k. This is a crucial number
393 * because it also controls how easily we can spread reads across
394 * cpus for decompression.
395 *
396 * We also want to make sure the amount of IO required to do
397 * a random read is reasonably small, so we limit the size of
398 * a compressed extent to 128k.
399 */
400 total_compressed = min(total_compressed, max_uncompressed);
401 num_bytes = ALIGN(end - start + 1, blocksize);
402 num_bytes = max(blocksize, num_bytes);
403 total_in = 0;
404 ret = 0;
405
406 /*
407 * we do compression for mount -o compress and when the
408 * inode has not been flagged as nocompress. This flag can
409 * change at any time if we discover bad compression ratios.
410 */
411 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) &&
412 (btrfs_test_opt(root, COMPRESS) ||
413 (BTRFS_I(inode)->force_compress) ||
414 (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))) {
415 WARN_ON(pages);
416 pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
417 if (!pages) {
418 /* just bail out to the uncompressed code */
419 goto cont;
420 }
421
422 if (BTRFS_I(inode)->force_compress)
423 compress_type = BTRFS_I(inode)->force_compress;
424
425 /*
426 * we need to call clear_page_dirty_for_io on each
427 * page in the range. Otherwise applications with the file
428 * mmap'd can wander in and change the page contents while
429 * we are compressing them.
430 *
431 * If the compression fails for any reason, we set the pages
432 * dirty again later on.
433 */
434 extent_range_clear_dirty_for_io(inode, start, end);
435 redirty = 1;
436 ret = btrfs_compress_pages(compress_type,
437 inode->i_mapping, start,
438 total_compressed, pages,
439 nr_pages, &nr_pages_ret,
440 &total_in,
441 &total_compressed,
442 max_compressed);
443
444 if (!ret) {
445 unsigned long offset = total_compressed &
446 (PAGE_CACHE_SIZE - 1);
447 struct page *page = pages[nr_pages_ret - 1];
448 char *kaddr;
449
450 /* zero the tail end of the last page, we might be
451 * sending it down to disk
452 */
453 if (offset) {
454 kaddr = kmap_atomic(page);
455 memset(kaddr + offset, 0,
456 PAGE_CACHE_SIZE - offset);
457 kunmap_atomic(kaddr);
458 }
459 will_compress = 1;
460 }
461 }
462 cont:
463 if (start == 0) {
464 trans = btrfs_join_transaction(root);
465 if (IS_ERR(trans)) {
466 ret = PTR_ERR(trans);
467 trans = NULL;
468 goto cleanup_and_out;
469 }
470 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
471
472 /* lets try to make an inline extent */
473 if (ret || total_in < (actual_end - start)) {
474 /* we didn't compress the entire range, try
475 * to make an uncompressed inline extent.
476 */
477 ret = cow_file_range_inline(trans, root, inode,
478 start, end, 0, 0, NULL);
479 } else {
480 /* try making a compressed inline extent */
481 ret = cow_file_range_inline(trans, root, inode,
482 start, end,
483 total_compressed,
484 compress_type, pages);
485 }
486 if (ret <= 0) {
487 /*
488 * inline extent creation worked or returned error,
489 * we don't need to create any more async work items.
490 * Unlock and free up our temp pages.
491 */
492 extent_clear_unlock_delalloc(inode,
493 &BTRFS_I(inode)->io_tree,
494 start, end, NULL,
495 EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
496 EXTENT_CLEAR_DELALLOC |
497 EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK);
498
499 btrfs_end_transaction(trans, root);
500 goto free_pages_out;
501 }
502 btrfs_end_transaction(trans, root);
503 }
504
505 if (will_compress) {
506 /*
507 * we aren't doing an inline extent round the compressed size
508 * up to a block size boundary so the allocator does sane
509 * things
510 */
511 total_compressed = ALIGN(total_compressed, blocksize);
512
513 /*
514 * one last check to make sure the compression is really a
515 * win, compare the page count read with the blocks on disk
516 */
517 total_in = ALIGN(total_in, PAGE_CACHE_SIZE);
518 if (total_compressed >= total_in) {
519 will_compress = 0;
520 } else {
521 num_bytes = total_in;
522 }
523 }
524 if (!will_compress && pages) {
525 /*
526 * the compression code ran but failed to make things smaller,
527 * free any pages it allocated and our page pointer array
528 */
529 for (i = 0; i < nr_pages_ret; i++) {
530 WARN_ON(pages[i]->mapping);
531 page_cache_release(pages[i]);
532 }
533 kfree(pages);
534 pages = NULL;
535 total_compressed = 0;
536 nr_pages_ret = 0;
537
538 /* flag the file so we don't compress in the future */
539 if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
540 !(BTRFS_I(inode)->force_compress)) {
541 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
542 }
543 }
544 if (will_compress) {
545 *num_added += 1;
546
547 /* the async work queues will take care of doing actual
548 * allocation on disk for these compressed pages,
549 * and will submit them to the elevator.
550 */
551 add_async_extent(async_cow, start, num_bytes,
552 total_compressed, pages, nr_pages_ret,
553 compress_type);
554
555 if (start + num_bytes < end) {
556 start += num_bytes;
557 pages = NULL;
558 cond_resched();
559 goto again;
560 }
561 } else {
562 cleanup_and_bail_uncompressed:
563 /*
564 * No compression, but we still need to write the pages in
565 * the file we've been given so far. redirty the locked
566 * page if it corresponds to our extent and set things up
567 * for the async work queue to run cow_file_range to do
568 * the normal delalloc dance
569 */
570 if (page_offset(locked_page) >= start &&
571 page_offset(locked_page) <= end) {
572 __set_page_dirty_nobuffers(locked_page);
573 /* unlocked later on in the async handlers */
574 }
575 if (redirty)
576 extent_range_redirty_for_io(inode, start, end);
577 add_async_extent(async_cow, start, end - start + 1,
578 0, NULL, 0, BTRFS_COMPRESS_NONE);
579 *num_added += 1;
580 }
581
582 out:
583 return ret;
584
585 free_pages_out:
586 for (i = 0; i < nr_pages_ret; i++) {
587 WARN_ON(pages[i]->mapping);
588 page_cache_release(pages[i]);
589 }
590 kfree(pages);
591
592 goto out;
593
594 cleanup_and_out:
595 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
596 start, end, NULL,
597 EXTENT_CLEAR_UNLOCK_PAGE |
598 EXTENT_CLEAR_DIRTY |
599 EXTENT_CLEAR_DELALLOC |
600 EXTENT_SET_WRITEBACK |
601 EXTENT_END_WRITEBACK);
602 if (!trans || IS_ERR(trans))
603 btrfs_error(root->fs_info, ret, "Failed to join transaction");
604 else
605 btrfs_abort_transaction(trans, root, ret);
606 goto free_pages_out;
607 }
608
609 /*
610 * phase two of compressed writeback. This is the ordered portion
611 * of the code, which only gets called in the order the work was
612 * queued. We walk all the async extents created by compress_file_range
613 * and send them down to the disk.
614 */
615 static noinline int submit_compressed_extents(struct inode *inode,
616 struct async_cow *async_cow)
617 {
618 struct async_extent *async_extent;
619 u64 alloc_hint = 0;
620 struct btrfs_trans_handle *trans;
621 struct btrfs_key ins;
622 struct extent_map *em;
623 struct btrfs_root *root = BTRFS_I(inode)->root;
624 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
625 struct extent_io_tree *io_tree;
626 int ret = 0;
627
628 if (list_empty(&async_cow->extents))
629 return 0;
630
631 again:
632 while (!list_empty(&async_cow->extents)) {
633 async_extent = list_entry(async_cow->extents.next,
634 struct async_extent, list);
635 list_del(&async_extent->list);
636
637 io_tree = &BTRFS_I(inode)->io_tree;
638
639 retry:
640 /* did the compression code fall back to uncompressed IO? */
641 if (!async_extent->pages) {
642 int page_started = 0;
643 unsigned long nr_written = 0;
644
645 lock_extent(io_tree, async_extent->start,
646 async_extent->start +
647 async_extent->ram_size - 1);
648
649 /* allocate blocks */
650 ret = cow_file_range(inode, async_cow->locked_page,
651 async_extent->start,
652 async_extent->start +
653 async_extent->ram_size - 1,
654 &page_started, &nr_written, 0);
655
656 /* JDM XXX */
657
658 /*
659 * if page_started, cow_file_range inserted an
660 * inline extent and took care of all the unlocking
661 * and IO for us. Otherwise, we need to submit
662 * all those pages down to the drive.
663 */
664 if (!page_started && !ret)
665 extent_write_locked_range(io_tree,
666 inode, async_extent->start,
667 async_extent->start +
668 async_extent->ram_size - 1,
669 btrfs_get_extent,
670 WB_SYNC_ALL);
671 else if (ret)
672 unlock_page(async_cow->locked_page);
673 kfree(async_extent);
674 cond_resched();
675 continue;
676 }
677
678 lock_extent(io_tree, async_extent->start,
679 async_extent->start + async_extent->ram_size - 1);
680
681 trans = btrfs_join_transaction(root);
682 if (IS_ERR(trans)) {
683 ret = PTR_ERR(trans);
684 } else {
685 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
686 ret = btrfs_reserve_extent(trans, root,
687 async_extent->compressed_size,
688 async_extent->compressed_size,
689 0, alloc_hint, &ins, 1);
690 if (ret && ret != -ENOSPC)
691 btrfs_abort_transaction(trans, root, ret);
692 btrfs_end_transaction(trans, root);
693 }
694
695 if (ret) {
696 int i;
697
698 for (i = 0; i < async_extent->nr_pages; i++) {
699 WARN_ON(async_extent->pages[i]->mapping);
700 page_cache_release(async_extent->pages[i]);
701 }
702 kfree(async_extent->pages);
703 async_extent->nr_pages = 0;
704 async_extent->pages = NULL;
705
706 if (ret == -ENOSPC) {
707 unlock_extent(io_tree, async_extent->start,
708 async_extent->start +
709 async_extent->ram_size - 1);
710 goto retry;
711 }
712 goto out_free;
713 }
714
715 /*
716 * here we're doing allocation and writeback of the
717 * compressed pages
718 */
719 btrfs_drop_extent_cache(inode, async_extent->start,
720 async_extent->start +
721 async_extent->ram_size - 1, 0);
722
723 em = alloc_extent_map();
724 if (!em) {
725 ret = -ENOMEM;
726 goto out_free_reserve;
727 }
728 em->start = async_extent->start;
729 em->len = async_extent->ram_size;
730 em->orig_start = em->start;
731 em->mod_start = em->start;
732 em->mod_len = em->len;
733
734 em->block_start = ins.objectid;
735 em->block_len = ins.offset;
736 em->orig_block_len = ins.offset;
737 em->ram_bytes = async_extent->ram_size;
738 em->bdev = root->fs_info->fs_devices->latest_bdev;
739 em->compress_type = async_extent->compress_type;
740 set_bit(EXTENT_FLAG_PINNED, &em->flags);
741 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
742 em->generation = -1;
743
744 while (1) {
745 write_lock(&em_tree->lock);
746 ret = add_extent_mapping(em_tree, em, 1);
747 write_unlock(&em_tree->lock);
748 if (ret != -EEXIST) {
749 free_extent_map(em);
750 break;
751 }
752 btrfs_drop_extent_cache(inode, async_extent->start,
753 async_extent->start +
754 async_extent->ram_size - 1, 0);
755 }
756
757 if (ret)
758 goto out_free_reserve;
759
760 ret = btrfs_add_ordered_extent_compress(inode,
761 async_extent->start,
762 ins.objectid,
763 async_extent->ram_size,
764 ins.offset,
765 BTRFS_ORDERED_COMPRESSED,
766 async_extent->compress_type);
767 if (ret)
768 goto out_free_reserve;
769
770 /*
771 * clear dirty, set writeback and unlock the pages.
772 */
773 extent_clear_unlock_delalloc(inode,
774 &BTRFS_I(inode)->io_tree,
775 async_extent->start,
776 async_extent->start +
777 async_extent->ram_size - 1,
778 NULL, EXTENT_CLEAR_UNLOCK_PAGE |
779 EXTENT_CLEAR_UNLOCK |
780 EXTENT_CLEAR_DELALLOC |
781 EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK);
782
783 ret = btrfs_submit_compressed_write(inode,
784 async_extent->start,
785 async_extent->ram_size,
786 ins.objectid,
787 ins.offset, async_extent->pages,
788 async_extent->nr_pages);
789 alloc_hint = ins.objectid + ins.offset;
790 kfree(async_extent);
791 if (ret)
792 goto out;
793 cond_resched();
794 }
795 ret = 0;
796 out:
797 return ret;
798 out_free_reserve:
799 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
800 out_free:
801 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
802 async_extent->start,
803 async_extent->start +
804 async_extent->ram_size - 1,
805 NULL, EXTENT_CLEAR_UNLOCK_PAGE |
806 EXTENT_CLEAR_UNLOCK |
807 EXTENT_CLEAR_DELALLOC |
808 EXTENT_CLEAR_DIRTY |
809 EXTENT_SET_WRITEBACK |
810 EXTENT_END_WRITEBACK);
811 kfree(async_extent);
812 goto again;
813 }
814
815 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
816 u64 num_bytes)
817 {
818 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
819 struct extent_map *em;
820 u64 alloc_hint = 0;
821
822 read_lock(&em_tree->lock);
823 em = search_extent_mapping(em_tree, start, num_bytes);
824 if (em) {
825 /*
826 * if block start isn't an actual block number then find the
827 * first block in this inode and use that as a hint. If that
828 * block is also bogus then just don't worry about it.
829 */
830 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
831 free_extent_map(em);
832 em = search_extent_mapping(em_tree, 0, 0);
833 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
834 alloc_hint = em->block_start;
835 if (em)
836 free_extent_map(em);
837 } else {
838 alloc_hint = em->block_start;
839 free_extent_map(em);
840 }
841 }
842 read_unlock(&em_tree->lock);
843
844 return alloc_hint;
845 }
846
847 /*
848 * when extent_io.c finds a delayed allocation range in the file,
849 * the call backs end up in this code. The basic idea is to
850 * allocate extents on disk for the range, and create ordered data structs
851 * in ram to track those extents.
852 *
853 * locked_page is the page that writepage had locked already. We use
854 * it to make sure we don't do extra locks or unlocks.
855 *
856 * *page_started is set to one if we unlock locked_page and do everything
857 * required to start IO on it. It may be clean and already done with
858 * IO when we return.
859 */
860 static noinline int __cow_file_range(struct btrfs_trans_handle *trans,
861 struct inode *inode,
862 struct btrfs_root *root,
863 struct page *locked_page,
864 u64 start, u64 end, int *page_started,
865 unsigned long *nr_written,
866 int unlock)
867 {
868 u64 alloc_hint = 0;
869 u64 num_bytes;
870 unsigned long ram_size;
871 u64 disk_num_bytes;
872 u64 cur_alloc_size;
873 u64 blocksize = root->sectorsize;
874 struct btrfs_key ins;
875 struct extent_map *em;
876 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
877 int ret = 0;
878
879 BUG_ON(btrfs_is_free_space_inode(inode));
880
881 num_bytes = ALIGN(end - start + 1, blocksize);
882 num_bytes = max(blocksize, num_bytes);
883 disk_num_bytes = num_bytes;
884
885 /* if this is a small write inside eof, kick off defrag */
886 if (num_bytes < 64 * 1024 &&
887 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
888 btrfs_add_inode_defrag(trans, inode);
889
890 if (start == 0) {
891 /* lets try to make an inline extent */
892 ret = cow_file_range_inline(trans, root, inode,
893 start, end, 0, 0, NULL);
894 if (ret == 0) {
895 extent_clear_unlock_delalloc(inode,
896 &BTRFS_I(inode)->io_tree,
897 start, end, NULL,
898 EXTENT_CLEAR_UNLOCK_PAGE |
899 EXTENT_CLEAR_UNLOCK |
900 EXTENT_CLEAR_DELALLOC |
901 EXTENT_CLEAR_DIRTY |
902 EXTENT_SET_WRITEBACK |
903 EXTENT_END_WRITEBACK);
904
905 *nr_written = *nr_written +
906 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
907 *page_started = 1;
908 goto out;
909 } else if (ret < 0) {
910 btrfs_abort_transaction(trans, root, ret);
911 goto out_unlock;
912 }
913 }
914
915 BUG_ON(disk_num_bytes >
916 btrfs_super_total_bytes(root->fs_info->super_copy));
917
918 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
919 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
920
921 while (disk_num_bytes > 0) {
922 unsigned long op;
923
924 cur_alloc_size = disk_num_bytes;
925 ret = btrfs_reserve_extent(trans, root, cur_alloc_size,
926 root->sectorsize, 0, alloc_hint,
927 &ins, 1);
928 if (ret < 0) {
929 btrfs_abort_transaction(trans, root, ret);
930 goto out_unlock;
931 }
932
933 em = alloc_extent_map();
934 if (!em) {
935 ret = -ENOMEM;
936 goto out_reserve;
937 }
938 em->start = start;
939 em->orig_start = em->start;
940 ram_size = ins.offset;
941 em->len = ins.offset;
942 em->mod_start = em->start;
943 em->mod_len = em->len;
944
945 em->block_start = ins.objectid;
946 em->block_len = ins.offset;
947 em->orig_block_len = ins.offset;
948 em->ram_bytes = ram_size;
949 em->bdev = root->fs_info->fs_devices->latest_bdev;
950 set_bit(EXTENT_FLAG_PINNED, &em->flags);
951 em->generation = -1;
952
953 while (1) {
954 write_lock(&em_tree->lock);
955 ret = add_extent_mapping(em_tree, em, 1);
956 write_unlock(&em_tree->lock);
957 if (ret != -EEXIST) {
958 free_extent_map(em);
959 break;
960 }
961 btrfs_drop_extent_cache(inode, start,
962 start + ram_size - 1, 0);
963 }
964 if (ret)
965 goto out_reserve;
966
967 cur_alloc_size = ins.offset;
968 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
969 ram_size, cur_alloc_size, 0);
970 if (ret)
971 goto out_reserve;
972
973 if (root->root_key.objectid ==
974 BTRFS_DATA_RELOC_TREE_OBJECTID) {
975 ret = btrfs_reloc_clone_csums(inode, start,
976 cur_alloc_size);
977 if (ret) {
978 btrfs_abort_transaction(trans, root, ret);
979 goto out_reserve;
980 }
981 }
982
983 if (disk_num_bytes < cur_alloc_size)
984 break;
985
986 /* we're not doing compressed IO, don't unlock the first
987 * page (which the caller expects to stay locked), don't
988 * clear any dirty bits and don't set any writeback bits
989 *
990 * Do set the Private2 bit so we know this page was properly
991 * setup for writepage
992 */
993 op = unlock ? EXTENT_CLEAR_UNLOCK_PAGE : 0;
994 op |= EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
995 EXTENT_SET_PRIVATE2;
996
997 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
998 start, start + ram_size - 1,
999 locked_page, op);
1000 disk_num_bytes -= cur_alloc_size;
1001 num_bytes -= cur_alloc_size;
1002 alloc_hint = ins.objectid + ins.offset;
1003 start += cur_alloc_size;
1004 }
1005 out:
1006 return ret;
1007
1008 out_reserve:
1009 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
1010 out_unlock:
1011 extent_clear_unlock_delalloc(inode,
1012 &BTRFS_I(inode)->io_tree,
1013 start, end, locked_page,
1014 EXTENT_CLEAR_UNLOCK_PAGE |
1015 EXTENT_CLEAR_UNLOCK |
1016 EXTENT_CLEAR_DELALLOC |
1017 EXTENT_CLEAR_DIRTY |
1018 EXTENT_SET_WRITEBACK |
1019 EXTENT_END_WRITEBACK);
1020
1021 goto out;
1022 }
1023
1024 static noinline int cow_file_range(struct inode *inode,
1025 struct page *locked_page,
1026 u64 start, u64 end, int *page_started,
1027 unsigned long *nr_written,
1028 int unlock)
1029 {
1030 struct btrfs_trans_handle *trans;
1031 struct btrfs_root *root = BTRFS_I(inode)->root;
1032 int ret;
1033
1034 trans = btrfs_join_transaction(root);
1035 if (IS_ERR(trans)) {
1036 extent_clear_unlock_delalloc(inode,
1037 &BTRFS_I(inode)->io_tree,
1038 start, end, locked_page,
1039 EXTENT_CLEAR_UNLOCK_PAGE |
1040 EXTENT_CLEAR_UNLOCK |
1041 EXTENT_CLEAR_DELALLOC |
1042 EXTENT_CLEAR_DIRTY |
1043 EXTENT_SET_WRITEBACK |
1044 EXTENT_END_WRITEBACK);
1045 return PTR_ERR(trans);
1046 }
1047 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1048
1049 ret = __cow_file_range(trans, inode, root, locked_page, start, end,
1050 page_started, nr_written, unlock);
1051
1052 btrfs_end_transaction(trans, root);
1053
1054 return ret;
1055 }
1056
1057 /*
1058 * work queue call back to started compression on a file and pages
1059 */
1060 static noinline void async_cow_start(struct btrfs_work *work)
1061 {
1062 struct async_cow *async_cow;
1063 int num_added = 0;
1064 async_cow = container_of(work, struct async_cow, work);
1065
1066 compress_file_range(async_cow->inode, async_cow->locked_page,
1067 async_cow->start, async_cow->end, async_cow,
1068 &num_added);
1069 if (num_added == 0) {
1070 btrfs_add_delayed_iput(async_cow->inode);
1071 async_cow->inode = NULL;
1072 }
1073 }
1074
1075 /*
1076 * work queue call back to submit previously compressed pages
1077 */
1078 static noinline void async_cow_submit(struct btrfs_work *work)
1079 {
1080 struct async_cow *async_cow;
1081 struct btrfs_root *root;
1082 unsigned long nr_pages;
1083
1084 async_cow = container_of(work, struct async_cow, work);
1085
1086 root = async_cow->root;
1087 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
1088 PAGE_CACHE_SHIFT;
1089
1090 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
1091 5 * 1024 * 1024 &&
1092 waitqueue_active(&root->fs_info->async_submit_wait))
1093 wake_up(&root->fs_info->async_submit_wait);
1094
1095 if (async_cow->inode)
1096 submit_compressed_extents(async_cow->inode, async_cow);
1097 }
1098
1099 static noinline void async_cow_free(struct btrfs_work *work)
1100 {
1101 struct async_cow *async_cow;
1102 async_cow = container_of(work, struct async_cow, work);
1103 if (async_cow->inode)
1104 btrfs_add_delayed_iput(async_cow->inode);
1105 kfree(async_cow);
1106 }
1107
1108 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1109 u64 start, u64 end, int *page_started,
1110 unsigned long *nr_written)
1111 {
1112 struct async_cow *async_cow;
1113 struct btrfs_root *root = BTRFS_I(inode)->root;
1114 unsigned long nr_pages;
1115 u64 cur_end;
1116 int limit = 10 * 1024 * 1024;
1117
1118 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1119 1, 0, NULL, GFP_NOFS);
1120 while (start < end) {
1121 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1122 BUG_ON(!async_cow); /* -ENOMEM */
1123 async_cow->inode = igrab(inode);
1124 async_cow->root = root;
1125 async_cow->locked_page = locked_page;
1126 async_cow->start = start;
1127
1128 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
1129 cur_end = end;
1130 else
1131 cur_end = min(end, start + 512 * 1024 - 1);
1132
1133 async_cow->end = cur_end;
1134 INIT_LIST_HEAD(&async_cow->extents);
1135
1136 async_cow->work.func = async_cow_start;
1137 async_cow->work.ordered_func = async_cow_submit;
1138 async_cow->work.ordered_free = async_cow_free;
1139 async_cow->work.flags = 0;
1140
1141 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
1142 PAGE_CACHE_SHIFT;
1143 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
1144
1145 btrfs_queue_worker(&root->fs_info->delalloc_workers,
1146 &async_cow->work);
1147
1148 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
1149 wait_event(root->fs_info->async_submit_wait,
1150 (atomic_read(&root->fs_info->async_delalloc_pages) <
1151 limit));
1152 }
1153
1154 while (atomic_read(&root->fs_info->async_submit_draining) &&
1155 atomic_read(&root->fs_info->async_delalloc_pages)) {
1156 wait_event(root->fs_info->async_submit_wait,
1157 (atomic_read(&root->fs_info->async_delalloc_pages) ==
1158 0));
1159 }
1160
1161 *nr_written += nr_pages;
1162 start = cur_end + 1;
1163 }
1164 *page_started = 1;
1165 return 0;
1166 }
1167
1168 static noinline int csum_exist_in_range(struct btrfs_root *root,
1169 u64 bytenr, u64 num_bytes)
1170 {
1171 int ret;
1172 struct btrfs_ordered_sum *sums;
1173 LIST_HEAD(list);
1174
1175 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1176 bytenr + num_bytes - 1, &list, 0);
1177 if (ret == 0 && list_empty(&list))
1178 return 0;
1179
1180 while (!list_empty(&list)) {
1181 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1182 list_del(&sums->list);
1183 kfree(sums);
1184 }
1185 return 1;
1186 }
1187
1188 /*
1189 * when nowcow writeback call back. This checks for snapshots or COW copies
1190 * of the extents that exist in the file, and COWs the file as required.
1191 *
1192 * If no cow copies or snapshots exist, we write directly to the existing
1193 * blocks on disk
1194 */
1195 static noinline int run_delalloc_nocow(struct inode *inode,
1196 struct page *locked_page,
1197 u64 start, u64 end, int *page_started, int force,
1198 unsigned long *nr_written)
1199 {
1200 struct btrfs_root *root = BTRFS_I(inode)->root;
1201 struct btrfs_trans_handle *trans;
1202 struct extent_buffer *leaf;
1203 struct btrfs_path *path;
1204 struct btrfs_file_extent_item *fi;
1205 struct btrfs_key found_key;
1206 u64 cow_start;
1207 u64 cur_offset;
1208 u64 extent_end;
1209 u64 extent_offset;
1210 u64 disk_bytenr;
1211 u64 num_bytes;
1212 u64 disk_num_bytes;
1213 u64 ram_bytes;
1214 int extent_type;
1215 int ret, err;
1216 int type;
1217 int nocow;
1218 int check_prev = 1;
1219 bool nolock;
1220 u64 ino = btrfs_ino(inode);
1221
1222 path = btrfs_alloc_path();
1223 if (!path) {
1224 extent_clear_unlock_delalloc(inode,
1225 &BTRFS_I(inode)->io_tree,
1226 start, end, locked_page,
1227 EXTENT_CLEAR_UNLOCK_PAGE |
1228 EXTENT_CLEAR_UNLOCK |
1229 EXTENT_CLEAR_DELALLOC |
1230 EXTENT_CLEAR_DIRTY |
1231 EXTENT_SET_WRITEBACK |
1232 EXTENT_END_WRITEBACK);
1233 return -ENOMEM;
1234 }
1235
1236 nolock = btrfs_is_free_space_inode(inode);
1237
1238 if (nolock)
1239 trans = btrfs_join_transaction_nolock(root);
1240 else
1241 trans = btrfs_join_transaction(root);
1242
1243 if (IS_ERR(trans)) {
1244 extent_clear_unlock_delalloc(inode,
1245 &BTRFS_I(inode)->io_tree,
1246 start, end, locked_page,
1247 EXTENT_CLEAR_UNLOCK_PAGE |
1248 EXTENT_CLEAR_UNLOCK |
1249 EXTENT_CLEAR_DELALLOC |
1250 EXTENT_CLEAR_DIRTY |
1251 EXTENT_SET_WRITEBACK |
1252 EXTENT_END_WRITEBACK);
1253 btrfs_free_path(path);
1254 return PTR_ERR(trans);
1255 }
1256
1257 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1258
1259 cow_start = (u64)-1;
1260 cur_offset = start;
1261 while (1) {
1262 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1263 cur_offset, 0);
1264 if (ret < 0) {
1265 btrfs_abort_transaction(trans, root, ret);
1266 goto error;
1267 }
1268 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1269 leaf = path->nodes[0];
1270 btrfs_item_key_to_cpu(leaf, &found_key,
1271 path->slots[0] - 1);
1272 if (found_key.objectid == ino &&
1273 found_key.type == BTRFS_EXTENT_DATA_KEY)
1274 path->slots[0]--;
1275 }
1276 check_prev = 0;
1277 next_slot:
1278 leaf = path->nodes[0];
1279 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1280 ret = btrfs_next_leaf(root, path);
1281 if (ret < 0) {
1282 btrfs_abort_transaction(trans, root, ret);
1283 goto error;
1284 }
1285 if (ret > 0)
1286 break;
1287 leaf = path->nodes[0];
1288 }
1289
1290 nocow = 0;
1291 disk_bytenr = 0;
1292 num_bytes = 0;
1293 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1294
1295 if (found_key.objectid > ino ||
1296 found_key.type > BTRFS_EXTENT_DATA_KEY ||
1297 found_key.offset > end)
1298 break;
1299
1300 if (found_key.offset > cur_offset) {
1301 extent_end = found_key.offset;
1302 extent_type = 0;
1303 goto out_check;
1304 }
1305
1306 fi = btrfs_item_ptr(leaf, path->slots[0],
1307 struct btrfs_file_extent_item);
1308 extent_type = btrfs_file_extent_type(leaf, fi);
1309
1310 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1311 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1312 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1313 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1314 extent_offset = btrfs_file_extent_offset(leaf, fi);
1315 extent_end = found_key.offset +
1316 btrfs_file_extent_num_bytes(leaf, fi);
1317 disk_num_bytes =
1318 btrfs_file_extent_disk_num_bytes(leaf, fi);
1319 if (extent_end <= start) {
1320 path->slots[0]++;
1321 goto next_slot;
1322 }
1323 if (disk_bytenr == 0)
1324 goto out_check;
1325 if (btrfs_file_extent_compression(leaf, fi) ||
1326 btrfs_file_extent_encryption(leaf, fi) ||
1327 btrfs_file_extent_other_encoding(leaf, fi))
1328 goto out_check;
1329 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1330 goto out_check;
1331 if (btrfs_extent_readonly(root, disk_bytenr))
1332 goto out_check;
1333 if (btrfs_cross_ref_exist(trans, root, ino,
1334 found_key.offset -
1335 extent_offset, disk_bytenr))
1336 goto out_check;
1337 disk_bytenr += extent_offset;
1338 disk_bytenr += cur_offset - found_key.offset;
1339 num_bytes = min(end + 1, extent_end) - cur_offset;
1340 /*
1341 * force cow if csum exists in the range.
1342 * this ensure that csum for a given extent are
1343 * either valid or do not exist.
1344 */
1345 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1346 goto out_check;
1347 nocow = 1;
1348 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1349 extent_end = found_key.offset +
1350 btrfs_file_extent_inline_len(leaf, fi);
1351 extent_end = ALIGN(extent_end, root->sectorsize);
1352 } else {
1353 BUG_ON(1);
1354 }
1355 out_check:
1356 if (extent_end <= start) {
1357 path->slots[0]++;
1358 goto next_slot;
1359 }
1360 if (!nocow) {
1361 if (cow_start == (u64)-1)
1362 cow_start = cur_offset;
1363 cur_offset = extent_end;
1364 if (cur_offset > end)
1365 break;
1366 path->slots[0]++;
1367 goto next_slot;
1368 }
1369
1370 btrfs_release_path(path);
1371 if (cow_start != (u64)-1) {
1372 ret = __cow_file_range(trans, inode, root, locked_page,
1373 cow_start, found_key.offset - 1,
1374 page_started, nr_written, 1);
1375 if (ret) {
1376 btrfs_abort_transaction(trans, root, ret);
1377 goto error;
1378 }
1379 cow_start = (u64)-1;
1380 }
1381
1382 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1383 struct extent_map *em;
1384 struct extent_map_tree *em_tree;
1385 em_tree = &BTRFS_I(inode)->extent_tree;
1386 em = alloc_extent_map();
1387 BUG_ON(!em); /* -ENOMEM */
1388 em->start = cur_offset;
1389 em->orig_start = found_key.offset - extent_offset;
1390 em->len = num_bytes;
1391 em->block_len = num_bytes;
1392 em->block_start = disk_bytenr;
1393 em->orig_block_len = disk_num_bytes;
1394 em->ram_bytes = ram_bytes;
1395 em->bdev = root->fs_info->fs_devices->latest_bdev;
1396 em->mod_start = em->start;
1397 em->mod_len = em->len;
1398 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1399 set_bit(EXTENT_FLAG_FILLING, &em->flags);
1400 em->generation = -1;
1401 while (1) {
1402 write_lock(&em_tree->lock);
1403 ret = add_extent_mapping(em_tree, em, 1);
1404 write_unlock(&em_tree->lock);
1405 if (ret != -EEXIST) {
1406 free_extent_map(em);
1407 break;
1408 }
1409 btrfs_drop_extent_cache(inode, em->start,
1410 em->start + em->len - 1, 0);
1411 }
1412 type = BTRFS_ORDERED_PREALLOC;
1413 } else {
1414 type = BTRFS_ORDERED_NOCOW;
1415 }
1416
1417 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1418 num_bytes, num_bytes, type);
1419 BUG_ON(ret); /* -ENOMEM */
1420
1421 if (root->root_key.objectid ==
1422 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1423 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1424 num_bytes);
1425 if (ret) {
1426 btrfs_abort_transaction(trans, root, ret);
1427 goto error;
1428 }
1429 }
1430
1431 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
1432 cur_offset, cur_offset + num_bytes - 1,
1433 locked_page, EXTENT_CLEAR_UNLOCK_PAGE |
1434 EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
1435 EXTENT_SET_PRIVATE2);
1436 cur_offset = extent_end;
1437 if (cur_offset > end)
1438 break;
1439 }
1440 btrfs_release_path(path);
1441
1442 if (cur_offset <= end && cow_start == (u64)-1) {
1443 cow_start = cur_offset;
1444 cur_offset = end;
1445 }
1446
1447 if (cow_start != (u64)-1) {
1448 ret = __cow_file_range(trans, inode, root, locked_page,
1449 cow_start, end,
1450 page_started, nr_written, 1);
1451 if (ret) {
1452 btrfs_abort_transaction(trans, root, ret);
1453 goto error;
1454 }
1455 }
1456
1457 error:
1458 err = btrfs_end_transaction(trans, root);
1459 if (!ret)
1460 ret = err;
1461
1462 if (ret && cur_offset < end)
1463 extent_clear_unlock_delalloc(inode,
1464 &BTRFS_I(inode)->io_tree,
1465 cur_offset, end, locked_page,
1466 EXTENT_CLEAR_UNLOCK_PAGE |
1467 EXTENT_CLEAR_UNLOCK |
1468 EXTENT_CLEAR_DELALLOC |
1469 EXTENT_CLEAR_DIRTY |
1470 EXTENT_SET_WRITEBACK |
1471 EXTENT_END_WRITEBACK);
1472
1473 btrfs_free_path(path);
1474 return ret;
1475 }
1476
1477 /*
1478 * extent_io.c call back to do delayed allocation processing
1479 */
1480 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1481 u64 start, u64 end, int *page_started,
1482 unsigned long *nr_written)
1483 {
1484 int ret;
1485 struct btrfs_root *root = BTRFS_I(inode)->root;
1486
1487 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) {
1488 ret = run_delalloc_nocow(inode, locked_page, start, end,
1489 page_started, 1, nr_written);
1490 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC) {
1491 ret = run_delalloc_nocow(inode, locked_page, start, end,
1492 page_started, 0, nr_written);
1493 } else if (!btrfs_test_opt(root, COMPRESS) &&
1494 !(BTRFS_I(inode)->force_compress) &&
1495 !(BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS)) {
1496 ret = cow_file_range(inode, locked_page, start, end,
1497 page_started, nr_written, 1);
1498 } else {
1499 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1500 &BTRFS_I(inode)->runtime_flags);
1501 ret = cow_file_range_async(inode, locked_page, start, end,
1502 page_started, nr_written);
1503 }
1504 return ret;
1505 }
1506
1507 static void btrfs_split_extent_hook(struct inode *inode,
1508 struct extent_state *orig, u64 split)
1509 {
1510 /* not delalloc, ignore it */
1511 if (!(orig->state & EXTENT_DELALLOC))
1512 return;
1513
1514 spin_lock(&BTRFS_I(inode)->lock);
1515 BTRFS_I(inode)->outstanding_extents++;
1516 spin_unlock(&BTRFS_I(inode)->lock);
1517 }
1518
1519 /*
1520 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1521 * extents so we can keep track of new extents that are just merged onto old
1522 * extents, such as when we are doing sequential writes, so we can properly
1523 * account for the metadata space we'll need.
1524 */
1525 static void btrfs_merge_extent_hook(struct inode *inode,
1526 struct extent_state *new,
1527 struct extent_state *other)
1528 {
1529 /* not delalloc, ignore it */
1530 if (!(other->state & EXTENT_DELALLOC))
1531 return;
1532
1533 spin_lock(&BTRFS_I(inode)->lock);
1534 BTRFS_I(inode)->outstanding_extents--;
1535 spin_unlock(&BTRFS_I(inode)->lock);
1536 }
1537
1538 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1539 struct inode *inode)
1540 {
1541 spin_lock(&root->delalloc_lock);
1542 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1543 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1544 &root->delalloc_inodes);
1545 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1546 &BTRFS_I(inode)->runtime_flags);
1547 root->nr_delalloc_inodes++;
1548 if (root->nr_delalloc_inodes == 1) {
1549 spin_lock(&root->fs_info->delalloc_root_lock);
1550 BUG_ON(!list_empty(&root->delalloc_root));
1551 list_add_tail(&root->delalloc_root,
1552 &root->fs_info->delalloc_roots);
1553 spin_unlock(&root->fs_info->delalloc_root_lock);
1554 }
1555 }
1556 spin_unlock(&root->delalloc_lock);
1557 }
1558
1559 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1560 struct inode *inode)
1561 {
1562 spin_lock(&root->delalloc_lock);
1563 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1564 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1565 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1566 &BTRFS_I(inode)->runtime_flags);
1567 root->nr_delalloc_inodes--;
1568 if (!root->nr_delalloc_inodes) {
1569 spin_lock(&root->fs_info->delalloc_root_lock);
1570 BUG_ON(list_empty(&root->delalloc_root));
1571 list_del_init(&root->delalloc_root);
1572 spin_unlock(&root->fs_info->delalloc_root_lock);
1573 }
1574 }
1575 spin_unlock(&root->delalloc_lock);
1576 }
1577
1578 /*
1579 * extent_io.c set_bit_hook, used to track delayed allocation
1580 * bytes in this file, and to maintain the list of inodes that
1581 * have pending delalloc work to be done.
1582 */
1583 static void btrfs_set_bit_hook(struct inode *inode,
1584 struct extent_state *state, unsigned long *bits)
1585 {
1586
1587 /*
1588 * set_bit and clear bit hooks normally require _irqsave/restore
1589 * but in this case, we are only testing for the DELALLOC
1590 * bit, which is only set or cleared with irqs on
1591 */
1592 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1593 struct btrfs_root *root = BTRFS_I(inode)->root;
1594 u64 len = state->end + 1 - state->start;
1595 bool do_list = !btrfs_is_free_space_inode(inode);
1596
1597 if (*bits & EXTENT_FIRST_DELALLOC) {
1598 *bits &= ~EXTENT_FIRST_DELALLOC;
1599 } else {
1600 spin_lock(&BTRFS_I(inode)->lock);
1601 BTRFS_I(inode)->outstanding_extents++;
1602 spin_unlock(&BTRFS_I(inode)->lock);
1603 }
1604
1605 __percpu_counter_add(&root->fs_info->delalloc_bytes, len,
1606 root->fs_info->delalloc_batch);
1607 spin_lock(&BTRFS_I(inode)->lock);
1608 BTRFS_I(inode)->delalloc_bytes += len;
1609 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1610 &BTRFS_I(inode)->runtime_flags))
1611 btrfs_add_delalloc_inodes(root, inode);
1612 spin_unlock(&BTRFS_I(inode)->lock);
1613 }
1614 }
1615
1616 /*
1617 * extent_io.c clear_bit_hook, see set_bit_hook for why
1618 */
1619 static void btrfs_clear_bit_hook(struct inode *inode,
1620 struct extent_state *state,
1621 unsigned long *bits)
1622 {
1623 /*
1624 * set_bit and clear bit hooks normally require _irqsave/restore
1625 * but in this case, we are only testing for the DELALLOC
1626 * bit, which is only set or cleared with irqs on
1627 */
1628 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1629 struct btrfs_root *root = BTRFS_I(inode)->root;
1630 u64 len = state->end + 1 - state->start;
1631 bool do_list = !btrfs_is_free_space_inode(inode);
1632
1633 if (*bits & EXTENT_FIRST_DELALLOC) {
1634 *bits &= ~EXTENT_FIRST_DELALLOC;
1635 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1636 spin_lock(&BTRFS_I(inode)->lock);
1637 BTRFS_I(inode)->outstanding_extents--;
1638 spin_unlock(&BTRFS_I(inode)->lock);
1639 }
1640
1641 if (*bits & EXTENT_DO_ACCOUNTING)
1642 btrfs_delalloc_release_metadata(inode, len);
1643
1644 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1645 && do_list && !(state->state & EXTENT_NORESERVE))
1646 btrfs_free_reserved_data_space(inode, len);
1647
1648 __percpu_counter_add(&root->fs_info->delalloc_bytes, -len,
1649 root->fs_info->delalloc_batch);
1650 spin_lock(&BTRFS_I(inode)->lock);
1651 BTRFS_I(inode)->delalloc_bytes -= len;
1652 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1653 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1654 &BTRFS_I(inode)->runtime_flags))
1655 btrfs_del_delalloc_inode(root, inode);
1656 spin_unlock(&BTRFS_I(inode)->lock);
1657 }
1658 }
1659
1660 /*
1661 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1662 * we don't create bios that span stripes or chunks
1663 */
1664 int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset,
1665 size_t size, struct bio *bio,
1666 unsigned long bio_flags)
1667 {
1668 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1669 u64 logical = (u64)bio->bi_sector << 9;
1670 u64 length = 0;
1671 u64 map_length;
1672 int ret;
1673
1674 if (bio_flags & EXTENT_BIO_COMPRESSED)
1675 return 0;
1676
1677 length = bio->bi_size;
1678 map_length = length;
1679 ret = btrfs_map_block(root->fs_info, rw, logical,
1680 &map_length, NULL, 0);
1681 /* Will always return 0 with map_multi == NULL */
1682 BUG_ON(ret < 0);
1683 if (map_length < length + size)
1684 return 1;
1685 return 0;
1686 }
1687
1688 /*
1689 * in order to insert checksums into the metadata in large chunks,
1690 * we wait until bio submission time. All the pages in the bio are
1691 * checksummed and sums are attached onto the ordered extent record.
1692 *
1693 * At IO completion time the cums attached on the ordered extent record
1694 * are inserted into the btree
1695 */
1696 static int __btrfs_submit_bio_start(struct inode *inode, int rw,
1697 struct bio *bio, int mirror_num,
1698 unsigned long bio_flags,
1699 u64 bio_offset)
1700 {
1701 struct btrfs_root *root = BTRFS_I(inode)->root;
1702 int ret = 0;
1703
1704 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1705 BUG_ON(ret); /* -ENOMEM */
1706 return 0;
1707 }
1708
1709 /*
1710 * in order to insert checksums into the metadata in large chunks,
1711 * we wait until bio submission time. All the pages in the bio are
1712 * checksummed and sums are attached onto the ordered extent record.
1713 *
1714 * At IO completion time the cums attached on the ordered extent record
1715 * are inserted into the btree
1716 */
1717 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1718 int mirror_num, unsigned long bio_flags,
1719 u64 bio_offset)
1720 {
1721 struct btrfs_root *root = BTRFS_I(inode)->root;
1722 int ret;
1723
1724 ret = btrfs_map_bio(root, rw, bio, mirror_num, 1);
1725 if (ret)
1726 bio_endio(bio, ret);
1727 return ret;
1728 }
1729
1730 /*
1731 * extent_io.c submission hook. This does the right thing for csum calculation
1732 * on write, or reading the csums from the tree before a read
1733 */
1734 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1735 int mirror_num, unsigned long bio_flags,
1736 u64 bio_offset)
1737 {
1738 struct btrfs_root *root = BTRFS_I(inode)->root;
1739 int ret = 0;
1740 int skip_sum;
1741 int metadata = 0;
1742 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1743
1744 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1745
1746 if (btrfs_is_free_space_inode(inode))
1747 metadata = 2;
1748
1749 if (!(rw & REQ_WRITE)) {
1750 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
1751 if (ret)
1752 goto out;
1753
1754 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1755 ret = btrfs_submit_compressed_read(inode, bio,
1756 mirror_num,
1757 bio_flags);
1758 goto out;
1759 } else if (!skip_sum) {
1760 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1761 if (ret)
1762 goto out;
1763 }
1764 goto mapit;
1765 } else if (async && !skip_sum) {
1766 /* csum items have already been cloned */
1767 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1768 goto mapit;
1769 /* we're doing a write, do the async checksumming */
1770 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1771 inode, rw, bio, mirror_num,
1772 bio_flags, bio_offset,
1773 __btrfs_submit_bio_start,
1774 __btrfs_submit_bio_done);
1775 goto out;
1776 } else if (!skip_sum) {
1777 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1778 if (ret)
1779 goto out;
1780 }
1781
1782 mapit:
1783 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
1784
1785 out:
1786 if (ret < 0)
1787 bio_endio(bio, ret);
1788 return ret;
1789 }
1790
1791 /*
1792 * given a list of ordered sums record them in the inode. This happens
1793 * at IO completion time based on sums calculated at bio submission time.
1794 */
1795 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1796 struct inode *inode, u64 file_offset,
1797 struct list_head *list)
1798 {
1799 struct btrfs_ordered_sum *sum;
1800
1801 list_for_each_entry(sum, list, list) {
1802 trans->adding_csums = 1;
1803 btrfs_csum_file_blocks(trans,
1804 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1805 trans->adding_csums = 0;
1806 }
1807 return 0;
1808 }
1809
1810 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1811 struct extent_state **cached_state)
1812 {
1813 WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0);
1814 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1815 cached_state, GFP_NOFS);
1816 }
1817
1818 /* see btrfs_writepage_start_hook for details on why this is required */
1819 struct btrfs_writepage_fixup {
1820 struct page *page;
1821 struct btrfs_work work;
1822 };
1823
1824 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1825 {
1826 struct btrfs_writepage_fixup *fixup;
1827 struct btrfs_ordered_extent *ordered;
1828 struct extent_state *cached_state = NULL;
1829 struct page *page;
1830 struct inode *inode;
1831 u64 page_start;
1832 u64 page_end;
1833 int ret;
1834
1835 fixup = container_of(work, struct btrfs_writepage_fixup, work);
1836 page = fixup->page;
1837 again:
1838 lock_page(page);
1839 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
1840 ClearPageChecked(page);
1841 goto out_page;
1842 }
1843
1844 inode = page->mapping->host;
1845 page_start = page_offset(page);
1846 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
1847
1848 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0,
1849 &cached_state);
1850
1851 /* already ordered? We're done */
1852 if (PagePrivate2(page))
1853 goto out;
1854
1855 ordered = btrfs_lookup_ordered_extent(inode, page_start);
1856 if (ordered) {
1857 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
1858 page_end, &cached_state, GFP_NOFS);
1859 unlock_page(page);
1860 btrfs_start_ordered_extent(inode, ordered, 1);
1861 btrfs_put_ordered_extent(ordered);
1862 goto again;
1863 }
1864
1865 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
1866 if (ret) {
1867 mapping_set_error(page->mapping, ret);
1868 end_extent_writepage(page, ret, page_start, page_end);
1869 ClearPageChecked(page);
1870 goto out;
1871 }
1872
1873 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
1874 ClearPageChecked(page);
1875 set_page_dirty(page);
1876 out:
1877 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
1878 &cached_state, GFP_NOFS);
1879 out_page:
1880 unlock_page(page);
1881 page_cache_release(page);
1882 kfree(fixup);
1883 }
1884
1885 /*
1886 * There are a few paths in the higher layers of the kernel that directly
1887 * set the page dirty bit without asking the filesystem if it is a
1888 * good idea. This causes problems because we want to make sure COW
1889 * properly happens and the data=ordered rules are followed.
1890 *
1891 * In our case any range that doesn't have the ORDERED bit set
1892 * hasn't been properly setup for IO. We kick off an async process
1893 * to fix it up. The async helper will wait for ordered extents, set
1894 * the delalloc bit and make it safe to write the page.
1895 */
1896 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
1897 {
1898 struct inode *inode = page->mapping->host;
1899 struct btrfs_writepage_fixup *fixup;
1900 struct btrfs_root *root = BTRFS_I(inode)->root;
1901
1902 /* this page is properly in the ordered list */
1903 if (TestClearPagePrivate2(page))
1904 return 0;
1905
1906 if (PageChecked(page))
1907 return -EAGAIN;
1908
1909 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
1910 if (!fixup)
1911 return -EAGAIN;
1912
1913 SetPageChecked(page);
1914 page_cache_get(page);
1915 fixup->work.func = btrfs_writepage_fixup_worker;
1916 fixup->page = page;
1917 btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work);
1918 return -EBUSY;
1919 }
1920
1921 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
1922 struct inode *inode, u64 file_pos,
1923 u64 disk_bytenr, u64 disk_num_bytes,
1924 u64 num_bytes, u64 ram_bytes,
1925 u8 compression, u8 encryption,
1926 u16 other_encoding, int extent_type)
1927 {
1928 struct btrfs_root *root = BTRFS_I(inode)->root;
1929 struct btrfs_file_extent_item *fi;
1930 struct btrfs_path *path;
1931 struct extent_buffer *leaf;
1932 struct btrfs_key ins;
1933 int ret;
1934
1935 path = btrfs_alloc_path();
1936 if (!path)
1937 return -ENOMEM;
1938
1939 path->leave_spinning = 1;
1940
1941 /*
1942 * we may be replacing one extent in the tree with another.
1943 * The new extent is pinned in the extent map, and we don't want
1944 * to drop it from the cache until it is completely in the btree.
1945 *
1946 * So, tell btrfs_drop_extents to leave this extent in the cache.
1947 * the caller is expected to unpin it and allow it to be merged
1948 * with the others.
1949 */
1950 ret = btrfs_drop_extents(trans, root, inode, file_pos,
1951 file_pos + num_bytes, 0);
1952 if (ret)
1953 goto out;
1954
1955 ins.objectid = btrfs_ino(inode);
1956 ins.offset = file_pos;
1957 ins.type = BTRFS_EXTENT_DATA_KEY;
1958 ret = btrfs_insert_empty_item(trans, root, path, &ins, sizeof(*fi));
1959 if (ret)
1960 goto out;
1961 leaf = path->nodes[0];
1962 fi = btrfs_item_ptr(leaf, path->slots[0],
1963 struct btrfs_file_extent_item);
1964 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1965 btrfs_set_file_extent_type(leaf, fi, extent_type);
1966 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
1967 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
1968 btrfs_set_file_extent_offset(leaf, fi, 0);
1969 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
1970 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
1971 btrfs_set_file_extent_compression(leaf, fi, compression);
1972 btrfs_set_file_extent_encryption(leaf, fi, encryption);
1973 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
1974
1975 btrfs_mark_buffer_dirty(leaf);
1976 btrfs_release_path(path);
1977
1978 inode_add_bytes(inode, num_bytes);
1979
1980 ins.objectid = disk_bytenr;
1981 ins.offset = disk_num_bytes;
1982 ins.type = BTRFS_EXTENT_ITEM_KEY;
1983 ret = btrfs_alloc_reserved_file_extent(trans, root,
1984 root->root_key.objectid,
1985 btrfs_ino(inode), file_pos, &ins);
1986 out:
1987 btrfs_free_path(path);
1988
1989 return ret;
1990 }
1991
1992 /* snapshot-aware defrag */
1993 struct sa_defrag_extent_backref {
1994 struct rb_node node;
1995 struct old_sa_defrag_extent *old;
1996 u64 root_id;
1997 u64 inum;
1998 u64 file_pos;
1999 u64 extent_offset;
2000 u64 num_bytes;
2001 u64 generation;
2002 };
2003
2004 struct old_sa_defrag_extent {
2005 struct list_head list;
2006 struct new_sa_defrag_extent *new;
2007
2008 u64 extent_offset;
2009 u64 bytenr;
2010 u64 offset;
2011 u64 len;
2012 int count;
2013 };
2014
2015 struct new_sa_defrag_extent {
2016 struct rb_root root;
2017 struct list_head head;
2018 struct btrfs_path *path;
2019 struct inode *inode;
2020 u64 file_pos;
2021 u64 len;
2022 u64 bytenr;
2023 u64 disk_len;
2024 u8 compress_type;
2025 };
2026
2027 static int backref_comp(struct sa_defrag_extent_backref *b1,
2028 struct sa_defrag_extent_backref *b2)
2029 {
2030 if (b1->root_id < b2->root_id)
2031 return -1;
2032 else if (b1->root_id > b2->root_id)
2033 return 1;
2034
2035 if (b1->inum < b2->inum)
2036 return -1;
2037 else if (b1->inum > b2->inum)
2038 return 1;
2039
2040 if (b1->file_pos < b2->file_pos)
2041 return -1;
2042 else if (b1->file_pos > b2->file_pos)
2043 return 1;
2044
2045 /*
2046 * [------------------------------] ===> (a range of space)
2047 * |<--->| |<---->| =============> (fs/file tree A)
2048 * |<---------------------------->| ===> (fs/file tree B)
2049 *
2050 * A range of space can refer to two file extents in one tree while
2051 * refer to only one file extent in another tree.
2052 *
2053 * So we may process a disk offset more than one time(two extents in A)
2054 * and locate at the same extent(one extent in B), then insert two same
2055 * backrefs(both refer to the extent in B).
2056 */
2057 return 0;
2058 }
2059
2060 static void backref_insert(struct rb_root *root,
2061 struct sa_defrag_extent_backref *backref)
2062 {
2063 struct rb_node **p = &root->rb_node;
2064 struct rb_node *parent = NULL;
2065 struct sa_defrag_extent_backref *entry;
2066 int ret;
2067
2068 while (*p) {
2069 parent = *p;
2070 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2071
2072 ret = backref_comp(backref, entry);
2073 if (ret < 0)
2074 p = &(*p)->rb_left;
2075 else
2076 p = &(*p)->rb_right;
2077 }
2078
2079 rb_link_node(&backref->node, parent, p);
2080 rb_insert_color(&backref->node, root);
2081 }
2082
2083 /*
2084 * Note the backref might has changed, and in this case we just return 0.
2085 */
2086 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2087 void *ctx)
2088 {
2089 struct btrfs_file_extent_item *extent;
2090 struct btrfs_fs_info *fs_info;
2091 struct old_sa_defrag_extent *old = ctx;
2092 struct new_sa_defrag_extent *new = old->new;
2093 struct btrfs_path *path = new->path;
2094 struct btrfs_key key;
2095 struct btrfs_root *root;
2096 struct sa_defrag_extent_backref *backref;
2097 struct extent_buffer *leaf;
2098 struct inode *inode = new->inode;
2099 int slot;
2100 int ret;
2101 u64 extent_offset;
2102 u64 num_bytes;
2103
2104 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2105 inum == btrfs_ino(inode))
2106 return 0;
2107
2108 key.objectid = root_id;
2109 key.type = BTRFS_ROOT_ITEM_KEY;
2110 key.offset = (u64)-1;
2111
2112 fs_info = BTRFS_I(inode)->root->fs_info;
2113 root = btrfs_read_fs_root_no_name(fs_info, &key);
2114 if (IS_ERR(root)) {
2115 if (PTR_ERR(root) == -ENOENT)
2116 return 0;
2117 WARN_ON(1);
2118 pr_debug("inum=%llu, offset=%llu, root_id=%llu\n",
2119 inum, offset, root_id);
2120 return PTR_ERR(root);
2121 }
2122
2123 key.objectid = inum;
2124 key.type = BTRFS_EXTENT_DATA_KEY;
2125 if (offset > (u64)-1 << 32)
2126 key.offset = 0;
2127 else
2128 key.offset = offset;
2129
2130 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2131 if (ret < 0) {
2132 WARN_ON(1);
2133 return ret;
2134 }
2135
2136 while (1) {
2137 cond_resched();
2138
2139 leaf = path->nodes[0];
2140 slot = path->slots[0];
2141
2142 if (slot >= btrfs_header_nritems(leaf)) {
2143 ret = btrfs_next_leaf(root, path);
2144 if (ret < 0) {
2145 goto out;
2146 } else if (ret > 0) {
2147 ret = 0;
2148 goto out;
2149 }
2150 continue;
2151 }
2152
2153 path->slots[0]++;
2154
2155 btrfs_item_key_to_cpu(leaf, &key, slot);
2156
2157 if (key.objectid > inum)
2158 goto out;
2159
2160 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2161 continue;
2162
2163 extent = btrfs_item_ptr(leaf, slot,
2164 struct btrfs_file_extent_item);
2165
2166 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2167 continue;
2168
2169 extent_offset = btrfs_file_extent_offset(leaf, extent);
2170 if (key.offset - extent_offset != offset)
2171 continue;
2172
2173 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2174 if (extent_offset >= old->extent_offset + old->offset +
2175 old->len || extent_offset + num_bytes <=
2176 old->extent_offset + old->offset)
2177 continue;
2178
2179 break;
2180 }
2181
2182 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2183 if (!backref) {
2184 ret = -ENOENT;
2185 goto out;
2186 }
2187
2188 backref->root_id = root_id;
2189 backref->inum = inum;
2190 backref->file_pos = offset + extent_offset;
2191 backref->num_bytes = num_bytes;
2192 backref->extent_offset = extent_offset;
2193 backref->generation = btrfs_file_extent_generation(leaf, extent);
2194 backref->old = old;
2195 backref_insert(&new->root, backref);
2196 old->count++;
2197 out:
2198 btrfs_release_path(path);
2199 WARN_ON(ret);
2200 return ret;
2201 }
2202
2203 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2204 struct new_sa_defrag_extent *new)
2205 {
2206 struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info;
2207 struct old_sa_defrag_extent *old, *tmp;
2208 int ret;
2209
2210 new->path = path;
2211
2212 list_for_each_entry_safe(old, tmp, &new->head, list) {
2213 ret = iterate_inodes_from_logical(old->bytenr, fs_info,
2214 path, record_one_backref,
2215 old);
2216 BUG_ON(ret < 0 && ret != -ENOENT);
2217
2218 /* no backref to be processed for this extent */
2219 if (!old->count) {
2220 list_del(&old->list);
2221 kfree(old);
2222 }
2223 }
2224
2225 if (list_empty(&new->head))
2226 return false;
2227
2228 return true;
2229 }
2230
2231 static int relink_is_mergable(struct extent_buffer *leaf,
2232 struct btrfs_file_extent_item *fi,
2233 u64 disk_bytenr)
2234 {
2235 if (btrfs_file_extent_disk_bytenr(leaf, fi) != disk_bytenr)
2236 return 0;
2237
2238 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2239 return 0;
2240
2241 if (btrfs_file_extent_compression(leaf, fi) ||
2242 btrfs_file_extent_encryption(leaf, fi) ||
2243 btrfs_file_extent_other_encoding(leaf, fi))
2244 return 0;
2245
2246 return 1;
2247 }
2248
2249 /*
2250 * Note the backref might has changed, and in this case we just return 0.
2251 */
2252 static noinline int relink_extent_backref(struct btrfs_path *path,
2253 struct sa_defrag_extent_backref *prev,
2254 struct sa_defrag_extent_backref *backref)
2255 {
2256 struct btrfs_file_extent_item *extent;
2257 struct btrfs_file_extent_item *item;
2258 struct btrfs_ordered_extent *ordered;
2259 struct btrfs_trans_handle *trans;
2260 struct btrfs_fs_info *fs_info;
2261 struct btrfs_root *root;
2262 struct btrfs_key key;
2263 struct extent_buffer *leaf;
2264 struct old_sa_defrag_extent *old = backref->old;
2265 struct new_sa_defrag_extent *new = old->new;
2266 struct inode *src_inode = new->inode;
2267 struct inode *inode;
2268 struct extent_state *cached = NULL;
2269 int ret = 0;
2270 u64 start;
2271 u64 len;
2272 u64 lock_start;
2273 u64 lock_end;
2274 bool merge = false;
2275 int index;
2276
2277 if (prev && prev->root_id == backref->root_id &&
2278 prev->inum == backref->inum &&
2279 prev->file_pos + prev->num_bytes == backref->file_pos)
2280 merge = true;
2281
2282 /* step 1: get root */
2283 key.objectid = backref->root_id;
2284 key.type = BTRFS_ROOT_ITEM_KEY;
2285 key.offset = (u64)-1;
2286
2287 fs_info = BTRFS_I(src_inode)->root->fs_info;
2288 index = srcu_read_lock(&fs_info->subvol_srcu);
2289
2290 root = btrfs_read_fs_root_no_name(fs_info, &key);
2291 if (IS_ERR(root)) {
2292 srcu_read_unlock(&fs_info->subvol_srcu, index);
2293 if (PTR_ERR(root) == -ENOENT)
2294 return 0;
2295 return PTR_ERR(root);
2296 }
2297
2298 /* step 2: get inode */
2299 key.objectid = backref->inum;
2300 key.type = BTRFS_INODE_ITEM_KEY;
2301 key.offset = 0;
2302
2303 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2304 if (IS_ERR(inode)) {
2305 srcu_read_unlock(&fs_info->subvol_srcu, index);
2306 return 0;
2307 }
2308
2309 srcu_read_unlock(&fs_info->subvol_srcu, index);
2310
2311 /* step 3: relink backref */
2312 lock_start = backref->file_pos;
2313 lock_end = backref->file_pos + backref->num_bytes - 1;
2314 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2315 0, &cached);
2316
2317 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2318 if (ordered) {
2319 btrfs_put_ordered_extent(ordered);
2320 goto out_unlock;
2321 }
2322
2323 trans = btrfs_join_transaction(root);
2324 if (IS_ERR(trans)) {
2325 ret = PTR_ERR(trans);
2326 goto out_unlock;
2327 }
2328
2329 key.objectid = backref->inum;
2330 key.type = BTRFS_EXTENT_DATA_KEY;
2331 key.offset = backref->file_pos;
2332
2333 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2334 if (ret < 0) {
2335 goto out_free_path;
2336 } else if (ret > 0) {
2337 ret = 0;
2338 goto out_free_path;
2339 }
2340
2341 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2342 struct btrfs_file_extent_item);
2343
2344 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2345 backref->generation)
2346 goto out_free_path;
2347
2348 btrfs_release_path(path);
2349
2350 start = backref->file_pos;
2351 if (backref->extent_offset < old->extent_offset + old->offset)
2352 start += old->extent_offset + old->offset -
2353 backref->extent_offset;
2354
2355 len = min(backref->extent_offset + backref->num_bytes,
2356 old->extent_offset + old->offset + old->len);
2357 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2358
2359 ret = btrfs_drop_extents(trans, root, inode, start,
2360 start + len, 1);
2361 if (ret)
2362 goto out_free_path;
2363 again:
2364 key.objectid = btrfs_ino(inode);
2365 key.type = BTRFS_EXTENT_DATA_KEY;
2366 key.offset = start;
2367
2368 path->leave_spinning = 1;
2369 if (merge) {
2370 struct btrfs_file_extent_item *fi;
2371 u64 extent_len;
2372 struct btrfs_key found_key;
2373
2374 ret = btrfs_search_slot(trans, root, &key, path, 1, 1);
2375 if (ret < 0)
2376 goto out_free_path;
2377
2378 path->slots[0]--;
2379 leaf = path->nodes[0];
2380 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2381
2382 fi = btrfs_item_ptr(leaf, path->slots[0],
2383 struct btrfs_file_extent_item);
2384 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2385
2386 if (relink_is_mergable(leaf, fi, new->bytenr) &&
2387 extent_len + found_key.offset == start) {
2388 btrfs_set_file_extent_num_bytes(leaf, fi,
2389 extent_len + len);
2390 btrfs_mark_buffer_dirty(leaf);
2391 inode_add_bytes(inode, len);
2392
2393 ret = 1;
2394 goto out_free_path;
2395 } else {
2396 merge = false;
2397 btrfs_release_path(path);
2398 goto again;
2399 }
2400 }
2401
2402 ret = btrfs_insert_empty_item(trans, root, path, &key,
2403 sizeof(*extent));
2404 if (ret) {
2405 btrfs_abort_transaction(trans, root, ret);
2406 goto out_free_path;
2407 }
2408
2409 leaf = path->nodes[0];
2410 item = btrfs_item_ptr(leaf, path->slots[0],
2411 struct btrfs_file_extent_item);
2412 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2413 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2414 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2415 btrfs_set_file_extent_num_bytes(leaf, item, len);
2416 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2417 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2418 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2419 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2420 btrfs_set_file_extent_encryption(leaf, item, 0);
2421 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2422
2423 btrfs_mark_buffer_dirty(leaf);
2424 inode_add_bytes(inode, len);
2425 btrfs_release_path(path);
2426
2427 ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
2428 new->disk_len, 0,
2429 backref->root_id, backref->inum,
2430 new->file_pos, 0); /* start - extent_offset */
2431 if (ret) {
2432 btrfs_abort_transaction(trans, root, ret);
2433 goto out_free_path;
2434 }
2435
2436 ret = 1;
2437 out_free_path:
2438 btrfs_release_path(path);
2439 path->leave_spinning = 0;
2440 btrfs_end_transaction(trans, root);
2441 out_unlock:
2442 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2443 &cached, GFP_NOFS);
2444 iput(inode);
2445 return ret;
2446 }
2447
2448 static void relink_file_extents(struct new_sa_defrag_extent *new)
2449 {
2450 struct btrfs_path *path;
2451 struct old_sa_defrag_extent *old, *tmp;
2452 struct sa_defrag_extent_backref *backref;
2453 struct sa_defrag_extent_backref *prev = NULL;
2454 struct inode *inode;
2455 struct btrfs_root *root;
2456 struct rb_node *node;
2457 int ret;
2458
2459 inode = new->inode;
2460 root = BTRFS_I(inode)->root;
2461
2462 path = btrfs_alloc_path();
2463 if (!path)
2464 return;
2465
2466 if (!record_extent_backrefs(path, new)) {
2467 btrfs_free_path(path);
2468 goto out;
2469 }
2470 btrfs_release_path(path);
2471
2472 while (1) {
2473 node = rb_first(&new->root);
2474 if (!node)
2475 break;
2476 rb_erase(node, &new->root);
2477
2478 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2479
2480 ret = relink_extent_backref(path, prev, backref);
2481 WARN_ON(ret < 0);
2482
2483 kfree(prev);
2484
2485 if (ret == 1)
2486 prev = backref;
2487 else
2488 prev = NULL;
2489 cond_resched();
2490 }
2491 kfree(prev);
2492
2493 btrfs_free_path(path);
2494
2495 list_for_each_entry_safe(old, tmp, &new->head, list) {
2496 list_del(&old->list);
2497 kfree(old);
2498 }
2499 out:
2500 atomic_dec(&root->fs_info->defrag_running);
2501 wake_up(&root->fs_info->transaction_wait);
2502
2503 kfree(new);
2504 }
2505
2506 static struct new_sa_defrag_extent *
2507 record_old_file_extents(struct inode *inode,
2508 struct btrfs_ordered_extent *ordered)
2509 {
2510 struct btrfs_root *root = BTRFS_I(inode)->root;
2511 struct btrfs_path *path;
2512 struct btrfs_key key;
2513 struct old_sa_defrag_extent *old, *tmp;
2514 struct new_sa_defrag_extent *new;
2515 int ret;
2516
2517 new = kmalloc(sizeof(*new), GFP_NOFS);
2518 if (!new)
2519 return NULL;
2520
2521 new->inode = inode;
2522 new->file_pos = ordered->file_offset;
2523 new->len = ordered->len;
2524 new->bytenr = ordered->start;
2525 new->disk_len = ordered->disk_len;
2526 new->compress_type = ordered->compress_type;
2527 new->root = RB_ROOT;
2528 INIT_LIST_HEAD(&new->head);
2529
2530 path = btrfs_alloc_path();
2531 if (!path)
2532 goto out_kfree;
2533
2534 key.objectid = btrfs_ino(inode);
2535 key.type = BTRFS_EXTENT_DATA_KEY;
2536 key.offset = new->file_pos;
2537
2538 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2539 if (ret < 0)
2540 goto out_free_path;
2541 if (ret > 0 && path->slots[0] > 0)
2542 path->slots[0]--;
2543
2544 /* find out all the old extents for the file range */
2545 while (1) {
2546 struct btrfs_file_extent_item *extent;
2547 struct extent_buffer *l;
2548 int slot;
2549 u64 num_bytes;
2550 u64 offset;
2551 u64 end;
2552 u64 disk_bytenr;
2553 u64 extent_offset;
2554
2555 l = path->nodes[0];
2556 slot = path->slots[0];
2557
2558 if (slot >= btrfs_header_nritems(l)) {
2559 ret = btrfs_next_leaf(root, path);
2560 if (ret < 0)
2561 goto out_free_list;
2562 else if (ret > 0)
2563 break;
2564 continue;
2565 }
2566
2567 btrfs_item_key_to_cpu(l, &key, slot);
2568
2569 if (key.objectid != btrfs_ino(inode))
2570 break;
2571 if (key.type != BTRFS_EXTENT_DATA_KEY)
2572 break;
2573 if (key.offset >= new->file_pos + new->len)
2574 break;
2575
2576 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2577
2578 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2579 if (key.offset + num_bytes < new->file_pos)
2580 goto next;
2581
2582 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2583 if (!disk_bytenr)
2584 goto next;
2585
2586 extent_offset = btrfs_file_extent_offset(l, extent);
2587
2588 old = kmalloc(sizeof(*old), GFP_NOFS);
2589 if (!old)
2590 goto out_free_list;
2591
2592 offset = max(new->file_pos, key.offset);
2593 end = min(new->file_pos + new->len, key.offset + num_bytes);
2594
2595 old->bytenr = disk_bytenr;
2596 old->extent_offset = extent_offset;
2597 old->offset = offset - key.offset;
2598 old->len = end - offset;
2599 old->new = new;
2600 old->count = 0;
2601 list_add_tail(&old->list, &new->head);
2602 next:
2603 path->slots[0]++;
2604 cond_resched();
2605 }
2606
2607 btrfs_free_path(path);
2608 atomic_inc(&root->fs_info->defrag_running);
2609
2610 return new;
2611
2612 out_free_list:
2613 list_for_each_entry_safe(old, tmp, &new->head, list) {
2614 list_del(&old->list);
2615 kfree(old);
2616 }
2617 out_free_path:
2618 btrfs_free_path(path);
2619 out_kfree:
2620 kfree(new);
2621 return NULL;
2622 }
2623
2624 /*
2625 * helper function for btrfs_finish_ordered_io, this
2626 * just reads in some of the csum leaves to prime them into ram
2627 * before we start the transaction. It limits the amount of btree
2628 * reads required while inside the transaction.
2629 */
2630 /* as ordered data IO finishes, this gets called so we can finish
2631 * an ordered extent if the range of bytes in the file it covers are
2632 * fully written.
2633 */
2634 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2635 {
2636 struct inode *inode = ordered_extent->inode;
2637 struct btrfs_root *root = BTRFS_I(inode)->root;
2638 struct btrfs_trans_handle *trans = NULL;
2639 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2640 struct extent_state *cached_state = NULL;
2641 struct new_sa_defrag_extent *new = NULL;
2642 int compress_type = 0;
2643 int ret;
2644 bool nolock;
2645
2646 nolock = btrfs_is_free_space_inode(inode);
2647
2648 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2649 ret = -EIO;
2650 goto out;
2651 }
2652
2653 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2654 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2655 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2656 if (nolock)
2657 trans = btrfs_join_transaction_nolock(root);
2658 else
2659 trans = btrfs_join_transaction(root);
2660 if (IS_ERR(trans)) {
2661 ret = PTR_ERR(trans);
2662 trans = NULL;
2663 goto out;
2664 }
2665 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2666 ret = btrfs_update_inode_fallback(trans, root, inode);
2667 if (ret) /* -ENOMEM or corruption */
2668 btrfs_abort_transaction(trans, root, ret);
2669 goto out;
2670 }
2671
2672 lock_extent_bits(io_tree, ordered_extent->file_offset,
2673 ordered_extent->file_offset + ordered_extent->len - 1,
2674 0, &cached_state);
2675
2676 ret = test_range_bit(io_tree, ordered_extent->file_offset,
2677 ordered_extent->file_offset + ordered_extent->len - 1,
2678 EXTENT_DEFRAG, 1, cached_state);
2679 if (ret) {
2680 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2681 if (last_snapshot >= BTRFS_I(inode)->generation)
2682 /* the inode is shared */
2683 new = record_old_file_extents(inode, ordered_extent);
2684
2685 clear_extent_bit(io_tree, ordered_extent->file_offset,
2686 ordered_extent->file_offset + ordered_extent->len - 1,
2687 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
2688 }
2689
2690 if (nolock)
2691 trans = btrfs_join_transaction_nolock(root);
2692 else
2693 trans = btrfs_join_transaction(root);
2694 if (IS_ERR(trans)) {
2695 ret = PTR_ERR(trans);
2696 trans = NULL;
2697 goto out_unlock;
2698 }
2699 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2700
2701 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
2702 compress_type = ordered_extent->compress_type;
2703 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
2704 BUG_ON(compress_type);
2705 ret = btrfs_mark_extent_written(trans, inode,
2706 ordered_extent->file_offset,
2707 ordered_extent->file_offset +
2708 ordered_extent->len);
2709 } else {
2710 BUG_ON(root == root->fs_info->tree_root);
2711 ret = insert_reserved_file_extent(trans, inode,
2712 ordered_extent->file_offset,
2713 ordered_extent->start,
2714 ordered_extent->disk_len,
2715 ordered_extent->len,
2716 ordered_extent->len,
2717 compress_type, 0, 0,
2718 BTRFS_FILE_EXTENT_REG);
2719 }
2720 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
2721 ordered_extent->file_offset, ordered_extent->len,
2722 trans->transid);
2723 if (ret < 0) {
2724 btrfs_abort_transaction(trans, root, ret);
2725 goto out_unlock;
2726 }
2727
2728 add_pending_csums(trans, inode, ordered_extent->file_offset,
2729 &ordered_extent->list);
2730
2731 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2732 ret = btrfs_update_inode_fallback(trans, root, inode);
2733 if (ret) { /* -ENOMEM or corruption */
2734 btrfs_abort_transaction(trans, root, ret);
2735 goto out_unlock;
2736 }
2737 ret = 0;
2738 out_unlock:
2739 unlock_extent_cached(io_tree, ordered_extent->file_offset,
2740 ordered_extent->file_offset +
2741 ordered_extent->len - 1, &cached_state, GFP_NOFS);
2742 out:
2743 if (root != root->fs_info->tree_root)
2744 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
2745 if (trans)
2746 btrfs_end_transaction(trans, root);
2747
2748 if (ret) {
2749 clear_extent_uptodate(io_tree, ordered_extent->file_offset,
2750 ordered_extent->file_offset +
2751 ordered_extent->len - 1, NULL, GFP_NOFS);
2752
2753 /*
2754 * If the ordered extent had an IOERR or something else went
2755 * wrong we need to return the space for this ordered extent
2756 * back to the allocator.
2757 */
2758 if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
2759 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
2760 btrfs_free_reserved_extent(root, ordered_extent->start,
2761 ordered_extent->disk_len);
2762 }
2763
2764
2765 /*
2766 * This needs to be done to make sure anybody waiting knows we are done
2767 * updating everything for this ordered extent.
2768 */
2769 btrfs_remove_ordered_extent(inode, ordered_extent);
2770
2771 /* for snapshot-aware defrag */
2772 if (new)
2773 relink_file_extents(new);
2774
2775 /* once for us */
2776 btrfs_put_ordered_extent(ordered_extent);
2777 /* once for the tree */
2778 btrfs_put_ordered_extent(ordered_extent);
2779
2780 return ret;
2781 }
2782
2783 static void finish_ordered_fn(struct btrfs_work *work)
2784 {
2785 struct btrfs_ordered_extent *ordered_extent;
2786 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
2787 btrfs_finish_ordered_io(ordered_extent);
2788 }
2789
2790 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
2791 struct extent_state *state, int uptodate)
2792 {
2793 struct inode *inode = page->mapping->host;
2794 struct btrfs_root *root = BTRFS_I(inode)->root;
2795 struct btrfs_ordered_extent *ordered_extent = NULL;
2796 struct btrfs_workers *workers;
2797
2798 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
2799
2800 ClearPagePrivate2(page);
2801 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
2802 end - start + 1, uptodate))
2803 return 0;
2804
2805 ordered_extent->work.func = finish_ordered_fn;
2806 ordered_extent->work.flags = 0;
2807
2808 if (btrfs_is_free_space_inode(inode))
2809 workers = &root->fs_info->endio_freespace_worker;
2810 else
2811 workers = &root->fs_info->endio_write_workers;
2812 btrfs_queue_worker(workers, &ordered_extent->work);
2813
2814 return 0;
2815 }
2816
2817 /*
2818 * when reads are done, we need to check csums to verify the data is correct
2819 * if there's a match, we allow the bio to finish. If not, the code in
2820 * extent_io.c will try to find good copies for us.
2821 */
2822 static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
2823 struct extent_state *state, int mirror)
2824 {
2825 size_t offset = start - page_offset(page);
2826 struct inode *inode = page->mapping->host;
2827 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2828 char *kaddr;
2829 u64 private = ~(u32)0;
2830 int ret;
2831 struct btrfs_root *root = BTRFS_I(inode)->root;
2832 u32 csum = ~(u32)0;
2833 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
2834 DEFAULT_RATELIMIT_BURST);
2835
2836 if (PageChecked(page)) {
2837 ClearPageChecked(page);
2838 goto good;
2839 }
2840
2841 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
2842 goto good;
2843
2844 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
2845 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
2846 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
2847 GFP_NOFS);
2848 return 0;
2849 }
2850
2851 if (state && state->start == start) {
2852 private = state->private;
2853 ret = 0;
2854 } else {
2855 ret = get_state_private(io_tree, start, &private);
2856 }
2857 kaddr = kmap_atomic(page);
2858 if (ret)
2859 goto zeroit;
2860
2861 csum = btrfs_csum_data(kaddr + offset, csum, end - start + 1);
2862 btrfs_csum_final(csum, (char *)&csum);
2863 if (csum != private)
2864 goto zeroit;
2865
2866 kunmap_atomic(kaddr);
2867 good:
2868 return 0;
2869
2870 zeroit:
2871 if (__ratelimit(&_rs))
2872 btrfs_info(root->fs_info, "csum failed ino %llu off %llu csum %u private %llu",
2873 (unsigned long long)btrfs_ino(page->mapping->host),
2874 (unsigned long long)start, csum,
2875 (unsigned long long)private);
2876 memset(kaddr + offset, 1, end - start + 1);
2877 flush_dcache_page(page);
2878 kunmap_atomic(kaddr);
2879 if (private == 0)
2880 return 0;
2881 return -EIO;
2882 }
2883
2884 struct delayed_iput {
2885 struct list_head list;
2886 struct inode *inode;
2887 };
2888
2889 /* JDM: If this is fs-wide, why can't we add a pointer to
2890 * btrfs_inode instead and avoid the allocation? */
2891 void btrfs_add_delayed_iput(struct inode *inode)
2892 {
2893 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2894 struct delayed_iput *delayed;
2895
2896 if (atomic_add_unless(&inode->i_count, -1, 1))
2897 return;
2898
2899 delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL);
2900 delayed->inode = inode;
2901
2902 spin_lock(&fs_info->delayed_iput_lock);
2903 list_add_tail(&delayed->list, &fs_info->delayed_iputs);
2904 spin_unlock(&fs_info->delayed_iput_lock);
2905 }
2906
2907 void btrfs_run_delayed_iputs(struct btrfs_root *root)
2908 {
2909 LIST_HEAD(list);
2910 struct btrfs_fs_info *fs_info = root->fs_info;
2911 struct delayed_iput *delayed;
2912 int empty;
2913
2914 spin_lock(&fs_info->delayed_iput_lock);
2915 empty = list_empty(&fs_info->delayed_iputs);
2916 spin_unlock(&fs_info->delayed_iput_lock);
2917 if (empty)
2918 return;
2919
2920 spin_lock(&fs_info->delayed_iput_lock);
2921 list_splice_init(&fs_info->delayed_iputs, &list);
2922 spin_unlock(&fs_info->delayed_iput_lock);
2923
2924 while (!list_empty(&list)) {
2925 delayed = list_entry(list.next, struct delayed_iput, list);
2926 list_del(&delayed->list);
2927 iput(delayed->inode);
2928 kfree(delayed);
2929 }
2930 }
2931
2932 /*
2933 * This is called in transaction commit time. If there are no orphan
2934 * files in the subvolume, it removes orphan item and frees block_rsv
2935 * structure.
2936 */
2937 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
2938 struct btrfs_root *root)
2939 {
2940 struct btrfs_block_rsv *block_rsv;
2941 int ret;
2942
2943 if (atomic_read(&root->orphan_inodes) ||
2944 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
2945 return;
2946
2947 spin_lock(&root->orphan_lock);
2948 if (atomic_read(&root->orphan_inodes)) {
2949 spin_unlock(&root->orphan_lock);
2950 return;
2951 }
2952
2953 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
2954 spin_unlock(&root->orphan_lock);
2955 return;
2956 }
2957
2958 block_rsv = root->orphan_block_rsv;
2959 root->orphan_block_rsv = NULL;
2960 spin_unlock(&root->orphan_lock);
2961
2962 if (root->orphan_item_inserted &&
2963 btrfs_root_refs(&root->root_item) > 0) {
2964 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
2965 root->root_key.objectid);
2966 BUG_ON(ret);
2967 root->orphan_item_inserted = 0;
2968 }
2969
2970 if (block_rsv) {
2971 WARN_ON(block_rsv->size > 0);
2972 btrfs_free_block_rsv(root, block_rsv);
2973 }
2974 }
2975
2976 /*
2977 * This creates an orphan entry for the given inode in case something goes
2978 * wrong in the middle of an unlink/truncate.
2979 *
2980 * NOTE: caller of this function should reserve 5 units of metadata for
2981 * this function.
2982 */
2983 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
2984 {
2985 struct btrfs_root *root = BTRFS_I(inode)->root;
2986 struct btrfs_block_rsv *block_rsv = NULL;
2987 int reserve = 0;
2988 int insert = 0;
2989 int ret;
2990
2991 if (!root->orphan_block_rsv) {
2992 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
2993 if (!block_rsv)
2994 return -ENOMEM;
2995 }
2996
2997 spin_lock(&root->orphan_lock);
2998 if (!root->orphan_block_rsv) {
2999 root->orphan_block_rsv = block_rsv;
3000 } else if (block_rsv) {
3001 btrfs_free_block_rsv(root, block_rsv);
3002 block_rsv = NULL;
3003 }
3004
3005 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3006 &BTRFS_I(inode)->runtime_flags)) {
3007 #if 0
3008 /*
3009 * For proper ENOSPC handling, we should do orphan
3010 * cleanup when mounting. But this introduces backward
3011 * compatibility issue.
3012 */
3013 if (!xchg(&root->orphan_item_inserted, 1))
3014 insert = 2;
3015 else
3016 insert = 1;
3017 #endif
3018 insert = 1;
3019 atomic_inc(&root->orphan_inodes);
3020 }
3021
3022 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3023 &BTRFS_I(inode)->runtime_flags))
3024 reserve = 1;
3025 spin_unlock(&root->orphan_lock);
3026
3027 /* grab metadata reservation from transaction handle */
3028 if (reserve) {
3029 ret = btrfs_orphan_reserve_metadata(trans, inode);
3030 BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */
3031 }
3032
3033 /* insert an orphan item to track this unlinked/truncated file */
3034 if (insert >= 1) {
3035 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3036 if (ret && ret != -EEXIST) {
3037 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3038 &BTRFS_I(inode)->runtime_flags);
3039 btrfs_abort_transaction(trans, root, ret);
3040 return ret;
3041 }
3042 ret = 0;
3043 }
3044
3045 /* insert an orphan item to track subvolume contains orphan files */
3046 if (insert >= 2) {
3047 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
3048 root->root_key.objectid);
3049 if (ret && ret != -EEXIST) {
3050 btrfs_abort_transaction(trans, root, ret);
3051 return ret;
3052 }
3053 }
3054 return 0;
3055 }
3056
3057 /*
3058 * We have done the truncate/delete so we can go ahead and remove the orphan
3059 * item for this particular inode.
3060 */
3061 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3062 struct inode *inode)
3063 {
3064 struct btrfs_root *root = BTRFS_I(inode)->root;
3065 int delete_item = 0;
3066 int release_rsv = 0;
3067 int ret = 0;
3068
3069 spin_lock(&root->orphan_lock);
3070 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3071 &BTRFS_I(inode)->runtime_flags))
3072 delete_item = 1;
3073
3074 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3075 &BTRFS_I(inode)->runtime_flags))
3076 release_rsv = 1;
3077 spin_unlock(&root->orphan_lock);
3078
3079 if (trans && delete_item) {
3080 ret = btrfs_del_orphan_item(trans, root, btrfs_ino(inode));
3081 BUG_ON(ret); /* -ENOMEM or corruption (JDM: Recheck) */
3082 }
3083
3084 if (release_rsv) {
3085 btrfs_orphan_release_metadata(inode);
3086 atomic_dec(&root->orphan_inodes);
3087 }
3088
3089 return 0;
3090 }
3091
3092 /*
3093 * this cleans up any orphans that may be left on the list from the last use
3094 * of this root.
3095 */
3096 int btrfs_orphan_cleanup(struct btrfs_root *root)
3097 {
3098 struct btrfs_path *path;
3099 struct extent_buffer *leaf;
3100 struct btrfs_key key, found_key;
3101 struct btrfs_trans_handle *trans;
3102 struct inode *inode;
3103 u64 last_objectid = 0;
3104 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3105
3106 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3107 return 0;
3108
3109 path = btrfs_alloc_path();
3110 if (!path) {
3111 ret = -ENOMEM;
3112 goto out;
3113 }
3114 path->reada = -1;
3115
3116 key.objectid = BTRFS_ORPHAN_OBJECTID;
3117 btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
3118 key.offset = (u64)-1;
3119
3120 while (1) {
3121 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3122 if (ret < 0)
3123 goto out;
3124
3125 /*
3126 * if ret == 0 means we found what we were searching for, which
3127 * is weird, but possible, so only screw with path if we didn't
3128 * find the key and see if we have stuff that matches
3129 */
3130 if (ret > 0) {
3131 ret = 0;
3132 if (path->slots[0] == 0)
3133 break;
3134 path->slots[0]--;
3135 }
3136
3137 /* pull out the item */
3138 leaf = path->nodes[0];
3139 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3140
3141 /* make sure the item matches what we want */
3142 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3143 break;
3144 if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY)
3145 break;
3146
3147 /* release the path since we're done with it */
3148 btrfs_release_path(path);
3149
3150 /*
3151 * this is where we are basically btrfs_lookup, without the
3152 * crossing root thing. we store the inode number in the
3153 * offset of the orphan item.
3154 */
3155
3156 if (found_key.offset == last_objectid) {
3157 btrfs_err(root->fs_info,
3158 "Error removing orphan entry, stopping orphan cleanup");
3159 ret = -EINVAL;
3160 goto out;
3161 }
3162
3163 last_objectid = found_key.offset;
3164
3165 found_key.objectid = found_key.offset;
3166 found_key.type = BTRFS_INODE_ITEM_KEY;
3167 found_key.offset = 0;
3168 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
3169 ret = PTR_RET(inode);
3170 if (ret && ret != -ESTALE)
3171 goto out;
3172
3173 if (ret == -ESTALE && root == root->fs_info->tree_root) {
3174 struct btrfs_root *dead_root;
3175 struct btrfs_fs_info *fs_info = root->fs_info;
3176 int is_dead_root = 0;
3177
3178 /*
3179 * this is an orphan in the tree root. Currently these
3180 * could come from 2 sources:
3181 * a) a snapshot deletion in progress
3182 * b) a free space cache inode
3183 * We need to distinguish those two, as the snapshot
3184 * orphan must not get deleted.
3185 * find_dead_roots already ran before us, so if this
3186 * is a snapshot deletion, we should find the root
3187 * in the dead_roots list
3188 */
3189 spin_lock(&fs_info->trans_lock);
3190 list_for_each_entry(dead_root, &fs_info->dead_roots,
3191 root_list) {
3192 if (dead_root->root_key.objectid ==
3193 found_key.objectid) {
3194 is_dead_root = 1;
3195 break;
3196 }
3197 }
3198 spin_unlock(&fs_info->trans_lock);
3199 if (is_dead_root) {
3200 /* prevent this orphan from being found again */
3201 key.offset = found_key.objectid - 1;
3202 continue;
3203 }
3204 }
3205 /*
3206 * Inode is already gone but the orphan item is still there,
3207 * kill the orphan item.
3208 */
3209 if (ret == -ESTALE) {
3210 trans = btrfs_start_transaction(root, 1);
3211 if (IS_ERR(trans)) {
3212 ret = PTR_ERR(trans);
3213 goto out;
3214 }
3215 btrfs_debug(root->fs_info, "auto deleting %Lu",
3216 found_key.objectid);
3217 ret = btrfs_del_orphan_item(trans, root,
3218 found_key.objectid);
3219 BUG_ON(ret); /* -ENOMEM or corruption (JDM: Recheck) */
3220 btrfs_end_transaction(trans, root);
3221 continue;
3222 }
3223
3224 /*
3225 * add this inode to the orphan list so btrfs_orphan_del does
3226 * the proper thing when we hit it
3227 */
3228 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3229 &BTRFS_I(inode)->runtime_flags);
3230 atomic_inc(&root->orphan_inodes);
3231
3232 /* if we have links, this was a truncate, lets do that */
3233 if (inode->i_nlink) {
3234 if (!S_ISREG(inode->i_mode)) {
3235 WARN_ON(1);
3236 iput(inode);
3237 continue;
3238 }
3239 nr_truncate++;
3240
3241 /* 1 for the orphan item deletion. */
3242 trans = btrfs_start_transaction(root, 1);
3243 if (IS_ERR(trans)) {
3244 iput(inode);
3245 ret = PTR_ERR(trans);
3246 goto out;
3247 }
3248 ret = btrfs_orphan_add(trans, inode);
3249 btrfs_end_transaction(trans, root);
3250 if (ret) {
3251 iput(inode);
3252 goto out;
3253 }
3254
3255 ret = btrfs_truncate(inode);
3256 if (ret)
3257 btrfs_orphan_del(NULL, inode);
3258 } else {
3259 nr_unlink++;
3260 }
3261
3262 /* this will do delete_inode and everything for us */
3263 iput(inode);
3264 if (ret)
3265 goto out;
3266 }
3267 /* release the path since we're done with it */
3268 btrfs_release_path(path);
3269
3270 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3271
3272 if (root->orphan_block_rsv)
3273 btrfs_block_rsv_release(root, root->orphan_block_rsv,
3274 (u64)-1);
3275
3276 if (root->orphan_block_rsv || root->orphan_item_inserted) {
3277 trans = btrfs_join_transaction(root);
3278 if (!IS_ERR(trans))
3279 btrfs_end_transaction(trans, root);
3280 }
3281
3282 if (nr_unlink)
3283 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink);
3284 if (nr_truncate)
3285 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate);
3286
3287 out:
3288 if (ret)
3289 btrfs_crit(root->fs_info,
3290 "could not do orphan cleanup %d", ret);
3291 btrfs_free_path(path);
3292 return ret;
3293 }
3294
3295 /*
3296 * very simple check to peek ahead in the leaf looking for xattrs. If we
3297 * don't find any xattrs, we know there can't be any acls.
3298 *
3299 * slot is the slot the inode is in, objectid is the objectid of the inode
3300 */
3301 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3302 int slot, u64 objectid)
3303 {
3304 u32 nritems = btrfs_header_nritems(leaf);
3305 struct btrfs_key found_key;
3306 static u64 xattr_access = 0;
3307 static u64 xattr_default = 0;
3308 int scanned = 0;
3309
3310 if (!xattr_access) {
3311 xattr_access = btrfs_name_hash(POSIX_ACL_XATTR_ACCESS,
3312 strlen(POSIX_ACL_XATTR_ACCESS));
3313 xattr_default = btrfs_name_hash(POSIX_ACL_XATTR_DEFAULT,
3314 strlen(POSIX_ACL_XATTR_DEFAULT));
3315 }
3316
3317 slot++;
3318 while (slot < nritems) {
3319 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3320
3321 /* we found a different objectid, there must not be acls */
3322 if (found_key.objectid != objectid)
3323 return 0;
3324
3325 /* we found an xattr, assume we've got an acl */
3326 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3327 if (found_key.offset == xattr_access ||
3328 found_key.offset == xattr_default)
3329 return 1;
3330 }
3331
3332 /*
3333 * we found a key greater than an xattr key, there can't
3334 * be any acls later on
3335 */
3336 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3337 return 0;
3338
3339 slot++;
3340 scanned++;
3341
3342 /*
3343 * it goes inode, inode backrefs, xattrs, extents,
3344 * so if there are a ton of hard links to an inode there can
3345 * be a lot of backrefs. Don't waste time searching too hard,
3346 * this is just an optimization
3347 */
3348 if (scanned >= 8)
3349 break;
3350 }
3351 /* we hit the end of the leaf before we found an xattr or
3352 * something larger than an xattr. We have to assume the inode
3353 * has acls
3354 */
3355 return 1;
3356 }
3357
3358 /*
3359 * read an inode from the btree into the in-memory inode
3360 */
3361 static void btrfs_read_locked_inode(struct inode *inode)
3362 {
3363 struct btrfs_path *path;
3364 struct extent_buffer *leaf;
3365 struct btrfs_inode_item *inode_item;
3366 struct btrfs_timespec *tspec;
3367 struct btrfs_root *root = BTRFS_I(inode)->root;
3368 struct btrfs_key location;
3369 int maybe_acls;
3370 u32 rdev;
3371 int ret;
3372 bool filled = false;
3373
3374 ret = btrfs_fill_inode(inode, &rdev);
3375 if (!ret)
3376 filled = true;
3377
3378 path = btrfs_alloc_path();
3379 if (!path)
3380 goto make_bad;
3381
3382 path->leave_spinning = 1;
3383 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3384
3385 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3386 if (ret)
3387 goto make_bad;
3388
3389 leaf = path->nodes[0];
3390
3391 if (filled)
3392 goto cache_acl;
3393
3394 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3395 struct btrfs_inode_item);
3396 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3397 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3398 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3399 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3400 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
3401
3402 tspec = btrfs_inode_atime(inode_item);
3403 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3404 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3405
3406 tspec = btrfs_inode_mtime(inode_item);
3407 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3408 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3409
3410 tspec = btrfs_inode_ctime(inode_item);
3411 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3412 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3413
3414 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3415 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3416 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3417
3418 /*
3419 * If we were modified in the current generation and evicted from memory
3420 * and then re-read we need to do a full sync since we don't have any
3421 * idea about which extents were modified before we were evicted from
3422 * cache.
3423 */
3424 if (BTRFS_I(inode)->last_trans == root->fs_info->generation)
3425 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3426 &BTRFS_I(inode)->runtime_flags);
3427
3428 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
3429 inode->i_generation = BTRFS_I(inode)->generation;
3430 inode->i_rdev = 0;
3431 rdev = btrfs_inode_rdev(leaf, inode_item);
3432
3433 BTRFS_I(inode)->index_cnt = (u64)-1;
3434 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3435 cache_acl:
3436 /*
3437 * try to precache a NULL acl entry for files that don't have
3438 * any xattrs or acls
3439 */
3440 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3441 btrfs_ino(inode));
3442 if (!maybe_acls)
3443 cache_no_acl(inode);
3444
3445 btrfs_free_path(path);
3446
3447 switch (inode->i_mode & S_IFMT) {
3448 case S_IFREG:
3449 inode->i_mapping->a_ops = &btrfs_aops;
3450 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3451 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3452 inode->i_fop = &btrfs_file_operations;
3453 inode->i_op = &btrfs_file_inode_operations;
3454 break;
3455 case S_IFDIR:
3456 inode->i_fop = &btrfs_dir_file_operations;
3457 if (root == root->fs_info->tree_root)
3458 inode->i_op = &btrfs_dir_ro_inode_operations;
3459 else
3460 inode->i_op = &btrfs_dir_inode_operations;
3461 break;
3462 case S_IFLNK:
3463 inode->i_op = &btrfs_symlink_inode_operations;
3464 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3465 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3466 break;
3467 default:
3468 inode->i_op = &btrfs_special_inode_operations;
3469 init_special_inode(inode, inode->i_mode, rdev);
3470 break;
3471 }
3472
3473 btrfs_update_iflags(inode);
3474 return;
3475
3476 make_bad:
3477 btrfs_free_path(path);
3478 make_bad_inode(inode);
3479 }
3480
3481 /*
3482 * given a leaf and an inode, copy the inode fields into the leaf
3483 */
3484 static void fill_inode_item(struct btrfs_trans_handle *trans,
3485 struct extent_buffer *leaf,
3486 struct btrfs_inode_item *item,
3487 struct inode *inode)
3488 {
3489 struct btrfs_map_token token;
3490
3491 btrfs_init_map_token(&token);
3492
3493 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3494 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3495 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3496 &token);
3497 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3498 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3499
3500 btrfs_set_token_timespec_sec(leaf, btrfs_inode_atime(item),
3501 inode->i_atime.tv_sec, &token);
3502 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_atime(item),
3503 inode->i_atime.tv_nsec, &token);
3504
3505 btrfs_set_token_timespec_sec(leaf, btrfs_inode_mtime(item),
3506 inode->i_mtime.tv_sec, &token);
3507 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_mtime(item),
3508 inode->i_mtime.tv_nsec, &token);
3509
3510 btrfs_set_token_timespec_sec(leaf, btrfs_inode_ctime(item),
3511 inode->i_ctime.tv_sec, &token);
3512 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_ctime(item),
3513 inode->i_ctime.tv_nsec, &token);
3514
3515 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3516 &token);
3517 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3518 &token);
3519 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3520 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3521 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3522 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3523 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3524 }
3525
3526 /*
3527 * copy everything in the in-memory inode into the btree.
3528 */
3529 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3530 struct btrfs_root *root, struct inode *inode)
3531 {
3532 struct btrfs_inode_item *inode_item;
3533 struct btrfs_path *path;
3534 struct extent_buffer *leaf;
3535 int ret;
3536
3537 path = btrfs_alloc_path();
3538 if (!path)
3539 return -ENOMEM;
3540
3541 path->leave_spinning = 1;
3542 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3543 1);
3544 if (ret) {
3545 if (ret > 0)
3546 ret = -ENOENT;
3547 goto failed;
3548 }
3549
3550 btrfs_unlock_up_safe(path, 1);
3551 leaf = path->nodes[0];
3552 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3553 struct btrfs_inode_item);
3554
3555 fill_inode_item(trans, leaf, inode_item, inode);
3556 btrfs_mark_buffer_dirty(leaf);
3557 btrfs_set_inode_last_trans(trans, inode);
3558 ret = 0;
3559 failed:
3560 btrfs_free_path(path);
3561 return ret;
3562 }
3563
3564 /*
3565 * copy everything in the in-memory inode into the btree.
3566 */
3567 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3568 struct btrfs_root *root, struct inode *inode)
3569 {
3570 int ret;
3571
3572 /*
3573 * If the inode is a free space inode, we can deadlock during commit
3574 * if we put it into the delayed code.
3575 *
3576 * The data relocation inode should also be directly updated
3577 * without delay
3578 */
3579 if (!btrfs_is_free_space_inode(inode)
3580 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID) {
3581 btrfs_update_root_times(trans, root);
3582
3583 ret = btrfs_delayed_update_inode(trans, root, inode);
3584 if (!ret)
3585 btrfs_set_inode_last_trans(trans, inode);
3586 return ret;
3587 }
3588
3589 return btrfs_update_inode_item(trans, root, inode);
3590 }
3591
3592 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
3593 struct btrfs_root *root,
3594 struct inode *inode)
3595 {
3596 int ret;
3597
3598 ret = btrfs_update_inode(trans, root, inode);
3599 if (ret == -ENOSPC)
3600 return btrfs_update_inode_item(trans, root, inode);
3601 return ret;
3602 }
3603
3604 /*
3605 * unlink helper that gets used here in inode.c and in the tree logging
3606 * recovery code. It remove a link in a directory with a given name, and
3607 * also drops the back refs in the inode to the directory
3608 */
3609 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3610 struct btrfs_root *root,
3611 struct inode *dir, struct inode *inode,
3612 const char *name, int name_len)
3613 {
3614 struct btrfs_path *path;
3615 int ret = 0;
3616 struct extent_buffer *leaf;
3617 struct btrfs_dir_item *di;
3618 struct btrfs_key key;
3619 u64 index;
3620 u64 ino = btrfs_ino(inode);
3621 u64 dir_ino = btrfs_ino(dir);
3622
3623 path = btrfs_alloc_path();
3624 if (!path) {
3625 ret = -ENOMEM;
3626 goto out;
3627 }
3628
3629 path->leave_spinning = 1;
3630 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3631 name, name_len, -1);
3632 if (IS_ERR(di)) {
3633 ret = PTR_ERR(di);
3634 goto err;
3635 }
3636 if (!di) {
3637 ret = -ENOENT;
3638 goto err;
3639 }
3640 leaf = path->nodes[0];
3641 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3642 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3643 if (ret)
3644 goto err;
3645 btrfs_release_path(path);
3646
3647 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
3648 dir_ino, &index);
3649 if (ret) {
3650 btrfs_info(root->fs_info,
3651 "failed to delete reference to %.*s, inode %llu parent %llu",
3652 name_len, name,
3653 (unsigned long long)ino, (unsigned long long)dir_ino);
3654 btrfs_abort_transaction(trans, root, ret);
3655 goto err;
3656 }
3657
3658 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3659 if (ret) {
3660 btrfs_abort_transaction(trans, root, ret);
3661 goto err;
3662 }
3663
3664 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
3665 inode, dir_ino);
3666 if (ret != 0 && ret != -ENOENT) {
3667 btrfs_abort_transaction(trans, root, ret);
3668 goto err;
3669 }
3670
3671 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
3672 dir, index);
3673 if (ret == -ENOENT)
3674 ret = 0;
3675 else if (ret)
3676 btrfs_abort_transaction(trans, root, ret);
3677 err:
3678 btrfs_free_path(path);
3679 if (ret)
3680 goto out;
3681
3682 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3683 inode_inc_iversion(inode);
3684 inode_inc_iversion(dir);
3685 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3686 ret = btrfs_update_inode(trans, root, dir);
3687 out:
3688 return ret;
3689 }
3690
3691 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3692 struct btrfs_root *root,
3693 struct inode *dir, struct inode *inode,
3694 const char *name, int name_len)
3695 {
3696 int ret;
3697 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
3698 if (!ret) {
3699 btrfs_drop_nlink(inode);
3700 ret = btrfs_update_inode(trans, root, inode);
3701 }
3702 return ret;
3703 }
3704
3705 /*
3706 * helper to start transaction for unlink and rmdir.
3707 *
3708 * unlink and rmdir are special in btrfs, they do not always free space, so
3709 * if we cannot make our reservations the normal way try and see if there is
3710 * plenty of slack room in the global reserve to migrate, otherwise we cannot
3711 * allow the unlink to occur.
3712 */
3713 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
3714 {
3715 struct btrfs_trans_handle *trans;
3716 struct btrfs_root *root = BTRFS_I(dir)->root;
3717 int ret;
3718
3719 /*
3720 * 1 for the possible orphan item
3721 * 1 for the dir item
3722 * 1 for the dir index
3723 * 1 for the inode ref
3724 * 1 for the inode
3725 */
3726 trans = btrfs_start_transaction(root, 5);
3727 if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
3728 return trans;
3729
3730 if (PTR_ERR(trans) == -ENOSPC) {
3731 u64 num_bytes = btrfs_calc_trans_metadata_size(root, 5);
3732
3733 trans = btrfs_start_transaction(root, 0);
3734 if (IS_ERR(trans))
3735 return trans;
3736 ret = btrfs_cond_migrate_bytes(root->fs_info,
3737 &root->fs_info->trans_block_rsv,
3738 num_bytes, 5);
3739 if (ret) {
3740 btrfs_end_transaction(trans, root);
3741 return ERR_PTR(ret);
3742 }
3743 trans->block_rsv = &root->fs_info->trans_block_rsv;
3744 trans->bytes_reserved = num_bytes;
3745 }
3746 return trans;
3747 }
3748
3749 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
3750 {
3751 struct btrfs_root *root = BTRFS_I(dir)->root;
3752 struct btrfs_trans_handle *trans;
3753 struct inode *inode = dentry->d_inode;
3754 int ret;
3755
3756 trans = __unlink_start_trans(dir);
3757 if (IS_ERR(trans))
3758 return PTR_ERR(trans);
3759
3760 btrfs_record_unlink_dir(trans, dir, dentry->d_inode, 0);
3761
3762 ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
3763 dentry->d_name.name, dentry->d_name.len);
3764 if (ret)
3765 goto out;
3766
3767 if (inode->i_nlink == 0) {
3768 ret = btrfs_orphan_add(trans, inode);
3769 if (ret)
3770 goto out;
3771 }
3772
3773 out:
3774 btrfs_end_transaction(trans, root);
3775 btrfs_btree_balance_dirty(root);
3776 return ret;
3777 }
3778
3779 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
3780 struct btrfs_root *root,
3781 struct inode *dir, u64 objectid,
3782 const char *name, int name_len)
3783 {
3784 struct btrfs_path *path;
3785 struct extent_buffer *leaf;
3786 struct btrfs_dir_item *di;
3787 struct btrfs_key key;
3788 u64 index;
3789 int ret;
3790 u64 dir_ino = btrfs_ino(dir);
3791
3792 path = btrfs_alloc_path();
3793 if (!path)
3794 return -ENOMEM;
3795
3796 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3797 name, name_len, -1);
3798 if (IS_ERR_OR_NULL(di)) {
3799 if (!di)
3800 ret = -ENOENT;
3801 else
3802 ret = PTR_ERR(di);
3803 goto out;
3804 }
3805
3806 leaf = path->nodes[0];
3807 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3808 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
3809 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3810 if (ret) {
3811 btrfs_abort_transaction(trans, root, ret);
3812 goto out;
3813 }
3814 btrfs_release_path(path);
3815
3816 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
3817 objectid, root->root_key.objectid,
3818 dir_ino, &index, name, name_len);
3819 if (ret < 0) {
3820 if (ret != -ENOENT) {
3821 btrfs_abort_transaction(trans, root, ret);
3822 goto out;
3823 }
3824 di = btrfs_search_dir_index_item(root, path, dir_ino,
3825 name, name_len);
3826 if (IS_ERR_OR_NULL(di)) {
3827 if (!di)
3828 ret = -ENOENT;
3829 else
3830 ret = PTR_ERR(di);
3831 btrfs_abort_transaction(trans, root, ret);
3832 goto out;
3833 }
3834
3835 leaf = path->nodes[0];
3836 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3837 btrfs_release_path(path);
3838 index = key.offset;
3839 }
3840 btrfs_release_path(path);
3841
3842 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3843 if (ret) {
3844 btrfs_abort_transaction(trans, root, ret);
3845 goto out;
3846 }
3847
3848 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3849 inode_inc_iversion(dir);
3850 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3851 ret = btrfs_update_inode_fallback(trans, root, dir);
3852 if (ret)
3853 btrfs_abort_transaction(trans, root, ret);
3854 out:
3855 btrfs_free_path(path);
3856 return ret;
3857 }
3858
3859 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
3860 {
3861 struct inode *inode = dentry->d_inode;
3862 int err = 0;
3863 struct btrfs_root *root = BTRFS_I(dir)->root;
3864 struct btrfs_trans_handle *trans;
3865
3866 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
3867 return -ENOTEMPTY;
3868 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
3869 return -EPERM;
3870
3871 trans = __unlink_start_trans(dir);
3872 if (IS_ERR(trans))
3873 return PTR_ERR(trans);
3874
3875 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
3876 err = btrfs_unlink_subvol(trans, root, dir,
3877 BTRFS_I(inode)->location.objectid,
3878 dentry->d_name.name,
3879 dentry->d_name.len);
3880 goto out;
3881 }
3882
3883 err = btrfs_orphan_add(trans, inode);
3884 if (err)
3885 goto out;
3886
3887 /* now the directory is empty */
3888 err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
3889 dentry->d_name.name, dentry->d_name.len);
3890 if (!err)
3891 btrfs_i_size_write(inode, 0);
3892 out:
3893 btrfs_end_transaction(trans, root);
3894 btrfs_btree_balance_dirty(root);
3895
3896 return err;
3897 }
3898
3899 /*
3900 * this can truncate away extent items, csum items and directory items.
3901 * It starts at a high offset and removes keys until it can't find
3902 * any higher than new_size
3903 *
3904 * csum items that cross the new i_size are truncated to the new size
3905 * as well.
3906 *
3907 * min_type is the minimum key type to truncate down to. If set to 0, this
3908 * will kill all the items on this inode, including the INODE_ITEM_KEY.
3909 */
3910 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
3911 struct btrfs_root *root,
3912 struct inode *inode,
3913 u64 new_size, u32 min_type)
3914 {
3915 struct btrfs_path *path;
3916 struct extent_buffer *leaf;
3917 struct btrfs_file_extent_item *fi;
3918 struct btrfs_key key;
3919 struct btrfs_key found_key;
3920 u64 extent_start = 0;
3921 u64 extent_num_bytes = 0;
3922 u64 extent_offset = 0;
3923 u64 item_end = 0;
3924 u32 found_type = (u8)-1;
3925 int found_extent;
3926 int del_item;
3927 int pending_del_nr = 0;
3928 int pending_del_slot = 0;
3929 int extent_type = -1;
3930 int ret;
3931 int err = 0;
3932 u64 ino = btrfs_ino(inode);
3933
3934 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
3935
3936 path = btrfs_alloc_path();
3937 if (!path)
3938 return -ENOMEM;
3939 path->reada = -1;
3940
3941 /*
3942 * We want to drop from the next block forward in case this new size is
3943 * not block aligned since we will be keeping the last block of the
3944 * extent just the way it is.
3945 */
3946 if (root->ref_cows || root == root->fs_info->tree_root)
3947 btrfs_drop_extent_cache(inode, ALIGN(new_size,
3948 root->sectorsize), (u64)-1, 0);
3949
3950 /*
3951 * This function is also used to drop the items in the log tree before
3952 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
3953 * it is used to drop the loged items. So we shouldn't kill the delayed
3954 * items.
3955 */
3956 if (min_type == 0 && root == BTRFS_I(inode)->root)
3957 btrfs_kill_delayed_inode_items(inode);
3958
3959 key.objectid = ino;
3960 key.offset = (u64)-1;
3961 key.type = (u8)-1;
3962
3963 search_again:
3964 path->leave_spinning = 1;
3965 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
3966 if (ret < 0) {
3967 err = ret;
3968 goto out;
3969 }
3970
3971 if (ret > 0) {
3972 /* there are no items in the tree for us to truncate, we're
3973 * done
3974 */
3975 if (path->slots[0] == 0)
3976 goto out;
3977 path->slots[0]--;
3978 }
3979
3980 while (1) {
3981 fi = NULL;
3982 leaf = path->nodes[0];
3983 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3984 found_type = btrfs_key_type(&found_key);
3985
3986 if (found_key.objectid != ino)
3987 break;
3988
3989 if (found_type < min_type)
3990 break;
3991
3992 item_end = found_key.offset;
3993 if (found_type == BTRFS_EXTENT_DATA_KEY) {
3994 fi = btrfs_item_ptr(leaf, path->slots[0],
3995 struct btrfs_file_extent_item);
3996 extent_type = btrfs_file_extent_type(leaf, fi);
3997 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
3998 item_end +=
3999 btrfs_file_extent_num_bytes(leaf, fi);
4000 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4001 item_end += btrfs_file_extent_inline_len(leaf,
4002 fi);
4003 }
4004 item_end--;
4005 }
4006 if (found_type > min_type) {
4007 del_item = 1;
4008 } else {
4009 if (item_end < new_size)
4010 break;
4011 if (found_key.offset >= new_size)
4012 del_item = 1;
4013 else
4014 del_item = 0;
4015 }
4016 found_extent = 0;
4017 /* FIXME, shrink the extent if the ref count is only 1 */
4018 if (found_type != BTRFS_EXTENT_DATA_KEY)
4019 goto delete;
4020
4021 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4022 u64 num_dec;
4023 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4024 if (!del_item) {
4025 u64 orig_num_bytes =
4026 btrfs_file_extent_num_bytes(leaf, fi);
4027 extent_num_bytes = ALIGN(new_size -
4028 found_key.offset,
4029 root->sectorsize);
4030 btrfs_set_file_extent_num_bytes(leaf, fi,
4031 extent_num_bytes);
4032 num_dec = (orig_num_bytes -
4033 extent_num_bytes);
4034 if (root->ref_cows && extent_start != 0)
4035 inode_sub_bytes(inode, num_dec);
4036 btrfs_mark_buffer_dirty(leaf);
4037 } else {
4038 extent_num_bytes =
4039 btrfs_file_extent_disk_num_bytes(leaf,
4040 fi);
4041 extent_offset = found_key.offset -
4042 btrfs_file_extent_offset(leaf, fi);
4043
4044 /* FIXME blocksize != 4096 */
4045 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4046 if (extent_start != 0) {
4047 found_extent = 1;
4048 if (root->ref_cows)
4049 inode_sub_bytes(inode, num_dec);
4050 }
4051 }
4052 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4053 /*
4054 * we can't truncate inline items that have had
4055 * special encodings
4056 */
4057 if (!del_item &&
4058 btrfs_file_extent_compression(leaf, fi) == 0 &&
4059 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4060 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
4061 u32 size = new_size - found_key.offset;
4062
4063 if (root->ref_cows) {
4064 inode_sub_bytes(inode, item_end + 1 -
4065 new_size);
4066 }
4067 size =
4068 btrfs_file_extent_calc_inline_size(size);
4069 btrfs_truncate_item(root, path, size, 1);
4070 } else if (root->ref_cows) {
4071 inode_sub_bytes(inode, item_end + 1 -
4072 found_key.offset);
4073 }
4074 }
4075 delete:
4076 if (del_item) {
4077 if (!pending_del_nr) {
4078 /* no pending yet, add ourselves */
4079 pending_del_slot = path->slots[0];
4080 pending_del_nr = 1;
4081 } else if (pending_del_nr &&
4082 path->slots[0] + 1 == pending_del_slot) {
4083 /* hop on the pending chunk */
4084 pending_del_nr++;
4085 pending_del_slot = path->slots[0];
4086 } else {
4087 BUG();
4088 }
4089 } else {
4090 break;
4091 }
4092 if (found_extent && (root->ref_cows ||
4093 root == root->fs_info->tree_root)) {
4094 btrfs_set_path_blocking(path);
4095 ret = btrfs_free_extent(trans, root, extent_start,
4096 extent_num_bytes, 0,
4097 btrfs_header_owner(leaf),
4098 ino, extent_offset, 0);
4099 BUG_ON(ret);
4100 }
4101
4102 if (found_type == BTRFS_INODE_ITEM_KEY)
4103 break;
4104
4105 if (path->slots[0] == 0 ||
4106 path->slots[0] != pending_del_slot) {
4107 if (pending_del_nr) {
4108 ret = btrfs_del_items(trans, root, path,
4109 pending_del_slot,
4110 pending_del_nr);
4111 if (ret) {
4112 btrfs_abort_transaction(trans,
4113 root, ret);
4114 goto error;
4115 }
4116 pending_del_nr = 0;
4117 }
4118 btrfs_release_path(path);
4119 goto search_again;
4120 } else {
4121 path->slots[0]--;
4122 }
4123 }
4124 out:
4125 if (pending_del_nr) {
4126 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4127 pending_del_nr);
4128 if (ret)
4129 btrfs_abort_transaction(trans, root, ret);
4130 }
4131 error:
4132 btrfs_free_path(path);
4133 return err;
4134 }
4135
4136 /*
4137 * btrfs_truncate_page - read, zero a chunk and write a page
4138 * @inode - inode that we're zeroing
4139 * @from - the offset to start zeroing
4140 * @len - the length to zero, 0 to zero the entire range respective to the
4141 * offset
4142 * @front - zero up to the offset instead of from the offset on
4143 *
4144 * This will find the page for the "from" offset and cow the page and zero the
4145 * part we want to zero. This is used with truncate and hole punching.
4146 */
4147 int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len,
4148 int front)
4149 {
4150 struct address_space *mapping = inode->i_mapping;
4151 struct btrfs_root *root = BTRFS_I(inode)->root;
4152 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4153 struct btrfs_ordered_extent *ordered;
4154 struct extent_state *cached_state = NULL;
4155 char *kaddr;
4156 u32 blocksize = root->sectorsize;
4157 pgoff_t index = from >> PAGE_CACHE_SHIFT;
4158 unsigned offset = from & (PAGE_CACHE_SIZE-1);
4159 struct page *page;
4160 gfp_t mask = btrfs_alloc_write_mask(mapping);
4161 int ret = 0;
4162 u64 page_start;
4163 u64 page_end;
4164
4165 if ((offset & (blocksize - 1)) == 0 &&
4166 (!len || ((len & (blocksize - 1)) == 0)))
4167 goto out;
4168 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
4169 if (ret)
4170 goto out;
4171
4172 again:
4173 page = find_or_create_page(mapping, index, mask);
4174 if (!page) {
4175 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
4176 ret = -ENOMEM;
4177 goto out;
4178 }
4179
4180 page_start = page_offset(page);
4181 page_end = page_start + PAGE_CACHE_SIZE - 1;
4182
4183 if (!PageUptodate(page)) {
4184 ret = btrfs_readpage(NULL, page);
4185 lock_page(page);
4186 if (page->mapping != mapping) {
4187 unlock_page(page);
4188 page_cache_release(page);
4189 goto again;
4190 }
4191 if (!PageUptodate(page)) {
4192 ret = -EIO;
4193 goto out_unlock;
4194 }
4195 }
4196 wait_on_page_writeback(page);
4197
4198 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
4199 set_page_extent_mapped(page);
4200
4201 ordered = btrfs_lookup_ordered_extent(inode, page_start);
4202 if (ordered) {
4203 unlock_extent_cached(io_tree, page_start, page_end,
4204 &cached_state, GFP_NOFS);
4205 unlock_page(page);
4206 page_cache_release(page);
4207 btrfs_start_ordered_extent(inode, ordered, 1);
4208 btrfs_put_ordered_extent(ordered);
4209 goto again;
4210 }
4211
4212 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
4213 EXTENT_DIRTY | EXTENT_DELALLOC |
4214 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4215 0, 0, &cached_state, GFP_NOFS);
4216
4217 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
4218 &cached_state);
4219 if (ret) {
4220 unlock_extent_cached(io_tree, page_start, page_end,
4221 &cached_state, GFP_NOFS);
4222 goto out_unlock;
4223 }
4224
4225 if (offset != PAGE_CACHE_SIZE) {
4226 if (!len)
4227 len = PAGE_CACHE_SIZE - offset;
4228 kaddr = kmap(page);
4229 if (front)
4230 memset(kaddr, 0, offset);
4231 else
4232 memset(kaddr + offset, 0, len);
4233 flush_dcache_page(page);
4234 kunmap(page);
4235 }
4236 ClearPageChecked(page);
4237 set_page_dirty(page);
4238 unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
4239 GFP_NOFS);
4240
4241 out_unlock:
4242 if (ret)
4243 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
4244 unlock_page(page);
4245 page_cache_release(page);
4246 out:
4247 return ret;
4248 }
4249
4250 /*
4251 * This function puts in dummy file extents for the area we're creating a hole
4252 * for. So if we are truncating this file to a larger size we need to insert
4253 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4254 * the range between oldsize and size
4255 */
4256 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4257 {
4258 struct btrfs_trans_handle *trans;
4259 struct btrfs_root *root = BTRFS_I(inode)->root;
4260 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4261 struct extent_map *em = NULL;
4262 struct extent_state *cached_state = NULL;
4263 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4264 u64 hole_start = ALIGN(oldsize, root->sectorsize);
4265 u64 block_end = ALIGN(size, root->sectorsize);
4266 u64 last_byte;
4267 u64 cur_offset;
4268 u64 hole_size;
4269 int err = 0;
4270
4271 /*
4272 * If our size started in the middle of a page we need to zero out the
4273 * rest of the page before we expand the i_size, otherwise we could
4274 * expose stale data.
4275 */
4276 err = btrfs_truncate_page(inode, oldsize, 0, 0);
4277 if (err)
4278 return err;
4279
4280 if (size <= hole_start)
4281 return 0;
4282
4283 while (1) {
4284 struct btrfs_ordered_extent *ordered;
4285 btrfs_wait_ordered_range(inode, hole_start,
4286 block_end - hole_start);
4287 lock_extent_bits(io_tree, hole_start, block_end - 1, 0,
4288 &cached_state);
4289 ordered = btrfs_lookup_ordered_extent(inode, hole_start);
4290 if (!ordered)
4291 break;
4292 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4293 &cached_state, GFP_NOFS);
4294 btrfs_put_ordered_extent(ordered);
4295 }
4296
4297 cur_offset = hole_start;
4298 while (1) {
4299 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
4300 block_end - cur_offset, 0);
4301 if (IS_ERR(em)) {
4302 err = PTR_ERR(em);
4303 em = NULL;
4304 break;
4305 }
4306 last_byte = min(extent_map_end(em), block_end);
4307 last_byte = ALIGN(last_byte , root->sectorsize);
4308 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4309 struct extent_map *hole_em;
4310 hole_size = last_byte - cur_offset;
4311
4312 trans = btrfs_start_transaction(root, 3);
4313 if (IS_ERR(trans)) {
4314 err = PTR_ERR(trans);
4315 break;
4316 }
4317
4318 err = btrfs_drop_extents(trans, root, inode,
4319 cur_offset,
4320 cur_offset + hole_size, 1);
4321 if (err) {
4322 btrfs_abort_transaction(trans, root, err);
4323 btrfs_end_transaction(trans, root);
4324 break;
4325 }
4326
4327 err = btrfs_insert_file_extent(trans, root,
4328 btrfs_ino(inode), cur_offset, 0,
4329 0, hole_size, 0, hole_size,
4330 0, 0, 0);
4331 if (err) {
4332 btrfs_abort_transaction(trans, root, err);
4333 btrfs_end_transaction(trans, root);
4334 break;
4335 }
4336
4337 btrfs_drop_extent_cache(inode, cur_offset,
4338 cur_offset + hole_size - 1, 0);
4339 hole_em = alloc_extent_map();
4340 if (!hole_em) {
4341 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4342 &BTRFS_I(inode)->runtime_flags);
4343 goto next;
4344 }
4345 hole_em->start = cur_offset;
4346 hole_em->len = hole_size;
4347 hole_em->orig_start = cur_offset;
4348
4349 hole_em->block_start = EXTENT_MAP_HOLE;
4350 hole_em->block_len = 0;
4351 hole_em->orig_block_len = 0;
4352 hole_em->ram_bytes = hole_size;
4353 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
4354 hole_em->compress_type = BTRFS_COMPRESS_NONE;
4355 hole_em->generation = trans->transid;
4356
4357 while (1) {
4358 write_lock(&em_tree->lock);
4359 err = add_extent_mapping(em_tree, hole_em, 1);
4360 write_unlock(&em_tree->lock);
4361 if (err != -EEXIST)
4362 break;
4363 btrfs_drop_extent_cache(inode, cur_offset,
4364 cur_offset +
4365 hole_size - 1, 0);
4366 }
4367 free_extent_map(hole_em);
4368 next:
4369 btrfs_update_inode(trans, root, inode);
4370 btrfs_end_transaction(trans, root);
4371 }
4372 free_extent_map(em);
4373 em = NULL;
4374 cur_offset = last_byte;
4375 if (cur_offset >= block_end)
4376 break;
4377 }
4378
4379 free_extent_map(em);
4380 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
4381 GFP_NOFS);
4382 return err;
4383 }
4384
4385 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
4386 {
4387 struct btrfs_root *root = BTRFS_I(inode)->root;
4388 struct btrfs_trans_handle *trans;
4389 loff_t oldsize = i_size_read(inode);
4390 loff_t newsize = attr->ia_size;
4391 int mask = attr->ia_valid;
4392 int ret;
4393
4394 if (newsize == oldsize)
4395 return 0;
4396
4397 /*
4398 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
4399 * special case where we need to update the times despite not having
4400 * these flags set. For all other operations the VFS set these flags
4401 * explicitly if it wants a timestamp update.
4402 */
4403 if (newsize != oldsize && (!(mask & (ATTR_CTIME | ATTR_MTIME))))
4404 inode->i_ctime = inode->i_mtime = current_fs_time(inode->i_sb);
4405
4406 if (newsize > oldsize) {
4407 truncate_pagecache(inode, oldsize, newsize);
4408 ret = btrfs_cont_expand(inode, oldsize, newsize);
4409 if (ret)
4410 return ret;
4411
4412 trans = btrfs_start_transaction(root, 1);
4413 if (IS_ERR(trans))
4414 return PTR_ERR(trans);
4415
4416 i_size_write(inode, newsize);
4417 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
4418 ret = btrfs_update_inode(trans, root, inode);
4419 btrfs_end_transaction(trans, root);
4420 } else {
4421
4422 /*
4423 * We're truncating a file that used to have good data down to
4424 * zero. Make sure it gets into the ordered flush list so that
4425 * any new writes get down to disk quickly.
4426 */
4427 if (newsize == 0)
4428 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
4429 &BTRFS_I(inode)->runtime_flags);
4430
4431 /*
4432 * 1 for the orphan item we're going to add
4433 * 1 for the orphan item deletion.
4434 */
4435 trans = btrfs_start_transaction(root, 2);
4436 if (IS_ERR(trans))
4437 return PTR_ERR(trans);
4438
4439 /*
4440 * We need to do this in case we fail at _any_ point during the
4441 * actual truncate. Once we do the truncate_setsize we could
4442 * invalidate pages which forces any outstanding ordered io to
4443 * be instantly completed which will give us extents that need
4444 * to be truncated. If we fail to get an orphan inode down we
4445 * could have left over extents that were never meant to live,
4446 * so we need to garuntee from this point on that everything
4447 * will be consistent.
4448 */
4449 ret = btrfs_orphan_add(trans, inode);
4450 btrfs_end_transaction(trans, root);
4451 if (ret)
4452 return ret;
4453
4454 /* we don't support swapfiles, so vmtruncate shouldn't fail */
4455 truncate_setsize(inode, newsize);
4456
4457 /* Disable nonlocked read DIO to avoid the end less truncate */
4458 btrfs_inode_block_unlocked_dio(inode);
4459 inode_dio_wait(inode);
4460 btrfs_inode_resume_unlocked_dio(inode);
4461
4462 ret = btrfs_truncate(inode);
4463 if (ret && inode->i_nlink)
4464 btrfs_orphan_del(NULL, inode);
4465 }
4466
4467 return ret;
4468 }
4469
4470 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
4471 {
4472 struct inode *inode = dentry->d_inode;
4473 struct btrfs_root *root = BTRFS_I(inode)->root;
4474 int err;
4475
4476 if (btrfs_root_readonly(root))
4477 return -EROFS;
4478
4479 err = inode_change_ok(inode, attr);
4480 if (err)
4481 return err;
4482
4483 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
4484 err = btrfs_setsize(inode, attr);
4485 if (err)
4486 return err;
4487 }
4488
4489 if (attr->ia_valid) {
4490 setattr_copy(inode, attr);
4491 inode_inc_iversion(inode);
4492 err = btrfs_dirty_inode(inode);
4493
4494 if (!err && attr->ia_valid & ATTR_MODE)
4495 err = btrfs_acl_chmod(inode);
4496 }
4497
4498 return err;
4499 }
4500
4501 void btrfs_evict_inode(struct inode *inode)
4502 {
4503 struct btrfs_trans_handle *trans;
4504 struct btrfs_root *root = BTRFS_I(inode)->root;
4505 struct btrfs_block_rsv *rsv, *global_rsv;
4506 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
4507 int ret;
4508
4509 trace_btrfs_inode_evict(inode);
4510
4511 truncate_inode_pages(&inode->i_data, 0);
4512 if (inode->i_nlink && (btrfs_root_refs(&root->root_item) != 0 ||
4513 btrfs_is_free_space_inode(inode)))
4514 goto no_delete;
4515
4516 if (is_bad_inode(inode)) {
4517 btrfs_orphan_del(NULL, inode);
4518 goto no_delete;
4519 }
4520 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
4521 btrfs_wait_ordered_range(inode, 0, (u64)-1);
4522
4523 if (root->fs_info->log_root_recovering) {
4524 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
4525 &BTRFS_I(inode)->runtime_flags));
4526 goto no_delete;
4527 }
4528
4529 if (inode->i_nlink > 0) {
4530 BUG_ON(btrfs_root_refs(&root->root_item) != 0);
4531 goto no_delete;
4532 }
4533
4534 ret = btrfs_commit_inode_delayed_inode(inode);
4535 if (ret) {
4536 btrfs_orphan_del(NULL, inode);
4537 goto no_delete;
4538 }
4539
4540 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
4541 if (!rsv) {
4542 btrfs_orphan_del(NULL, inode);
4543 goto no_delete;
4544 }
4545 rsv->size = min_size;
4546 rsv->failfast = 1;
4547 global_rsv = &root->fs_info->global_block_rsv;
4548
4549 btrfs_i_size_write(inode, 0);
4550
4551 /*
4552 * This is a bit simpler than btrfs_truncate since we've already
4553 * reserved our space for our orphan item in the unlink, so we just
4554 * need to reserve some slack space in case we add bytes and update
4555 * inode item when doing the truncate.
4556 */
4557 while (1) {
4558 ret = btrfs_block_rsv_refill(root, rsv, min_size,
4559 BTRFS_RESERVE_FLUSH_LIMIT);
4560
4561 /*
4562 * Try and steal from the global reserve since we will
4563 * likely not use this space anyway, we want to try as
4564 * hard as possible to get this to work.
4565 */
4566 if (ret)
4567 ret = btrfs_block_rsv_migrate(global_rsv, rsv, min_size);
4568
4569 if (ret) {
4570 btrfs_warn(root->fs_info,
4571 "Could not get space for a delete, will truncate on mount %d",
4572 ret);
4573 btrfs_orphan_del(NULL, inode);
4574 btrfs_free_block_rsv(root, rsv);
4575 goto no_delete;
4576 }
4577
4578 trans = btrfs_join_transaction(root);
4579 if (IS_ERR(trans)) {
4580 btrfs_orphan_del(NULL, inode);
4581 btrfs_free_block_rsv(root, rsv);
4582 goto no_delete;
4583 }
4584
4585 trans->block_rsv = rsv;
4586
4587 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
4588 if (ret != -ENOSPC)
4589 break;
4590
4591 trans->block_rsv = &root->fs_info->trans_block_rsv;
4592 btrfs_end_transaction(trans, root);
4593 trans = NULL;
4594 btrfs_btree_balance_dirty(root);
4595 }
4596
4597 btrfs_free_block_rsv(root, rsv);
4598
4599 if (ret == 0) {
4600 trans->block_rsv = root->orphan_block_rsv;
4601 ret = btrfs_orphan_del(trans, inode);
4602 BUG_ON(ret);
4603 }
4604
4605 trans->block_rsv = &root->fs_info->trans_block_rsv;
4606 if (!(root == root->fs_info->tree_root ||
4607 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
4608 btrfs_return_ino(root, btrfs_ino(inode));
4609
4610 btrfs_end_transaction(trans, root);
4611 btrfs_btree_balance_dirty(root);
4612 no_delete:
4613 btrfs_remove_delayed_node(inode);
4614 clear_inode(inode);
4615 return;
4616 }
4617
4618 /*
4619 * this returns the key found in the dir entry in the location pointer.
4620 * If no dir entries were found, location->objectid is 0.
4621 */
4622 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
4623 struct btrfs_key *location)
4624 {
4625 const char *name = dentry->d_name.name;
4626 int namelen = dentry->d_name.len;
4627 struct btrfs_dir_item *di;
4628 struct btrfs_path *path;
4629 struct btrfs_root *root = BTRFS_I(dir)->root;
4630 int ret = 0;
4631
4632 path = btrfs_alloc_path();
4633 if (!path)
4634 return -ENOMEM;
4635
4636 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
4637 namelen, 0);
4638 if (IS_ERR(di))
4639 ret = PTR_ERR(di);
4640
4641 if (IS_ERR_OR_NULL(di))
4642 goto out_err;
4643
4644 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
4645 out:
4646 btrfs_free_path(path);
4647 return ret;
4648 out_err:
4649 location->objectid = 0;
4650 goto out;
4651 }
4652
4653 /*
4654 * when we hit a tree root in a directory, the btrfs part of the inode
4655 * needs to be changed to reflect the root directory of the tree root. This
4656 * is kind of like crossing a mount point.
4657 */
4658 static int fixup_tree_root_location(struct btrfs_root *root,
4659 struct inode *dir,
4660 struct dentry *dentry,
4661 struct btrfs_key *location,
4662 struct btrfs_root **sub_root)
4663 {
4664 struct btrfs_path *path;
4665 struct btrfs_root *new_root;
4666 struct btrfs_root_ref *ref;
4667 struct extent_buffer *leaf;
4668 int ret;
4669 int err = 0;
4670
4671 path = btrfs_alloc_path();
4672 if (!path) {
4673 err = -ENOMEM;
4674 goto out;
4675 }
4676
4677 err = -ENOENT;
4678 ret = btrfs_find_root_ref(root->fs_info->tree_root, path,
4679 BTRFS_I(dir)->root->root_key.objectid,
4680 location->objectid);
4681 if (ret) {
4682 if (ret < 0)
4683 err = ret;
4684 goto out;
4685 }
4686
4687 leaf = path->nodes[0];
4688 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
4689 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
4690 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
4691 goto out;
4692
4693 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
4694 (unsigned long)(ref + 1),
4695 dentry->d_name.len);
4696 if (ret)
4697 goto out;
4698
4699 btrfs_release_path(path);
4700
4701 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
4702 if (IS_ERR(new_root)) {
4703 err = PTR_ERR(new_root);
4704 goto out;
4705 }
4706
4707 *sub_root = new_root;
4708 location->objectid = btrfs_root_dirid(&new_root->root_item);
4709 location->type = BTRFS_INODE_ITEM_KEY;
4710 location->offset = 0;
4711 err = 0;
4712 out:
4713 btrfs_free_path(path);
4714 return err;
4715 }
4716
4717 static void inode_tree_add(struct inode *inode)
4718 {
4719 struct btrfs_root *root = BTRFS_I(inode)->root;
4720 struct btrfs_inode *entry;
4721 struct rb_node **p;
4722 struct rb_node *parent;
4723 u64 ino = btrfs_ino(inode);
4724
4725 if (inode_unhashed(inode))
4726 return;
4727 again:
4728 parent = NULL;
4729 spin_lock(&root->inode_lock);
4730 p = &root->inode_tree.rb_node;
4731 while (*p) {
4732 parent = *p;
4733 entry = rb_entry(parent, struct btrfs_inode, rb_node);
4734
4735 if (ino < btrfs_ino(&entry->vfs_inode))
4736 p = &parent->rb_left;
4737 else if (ino > btrfs_ino(&entry->vfs_inode))
4738 p = &parent->rb_right;
4739 else {
4740 WARN_ON(!(entry->vfs_inode.i_state &
4741 (I_WILL_FREE | I_FREEING)));
4742 rb_erase(parent, &root->inode_tree);
4743 RB_CLEAR_NODE(parent);
4744 spin_unlock(&root->inode_lock);
4745 goto again;
4746 }
4747 }
4748 rb_link_node(&BTRFS_I(inode)->rb_node, parent, p);
4749 rb_insert_color(&BTRFS_I(inode)->rb_node, &root->inode_tree);
4750 spin_unlock(&root->inode_lock);
4751 }
4752
4753 static void inode_tree_del(struct inode *inode)
4754 {
4755 struct btrfs_root *root = BTRFS_I(inode)->root;
4756 int empty = 0;
4757
4758 spin_lock(&root->inode_lock);
4759 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
4760 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
4761 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
4762 empty = RB_EMPTY_ROOT(&root->inode_tree);
4763 }
4764 spin_unlock(&root->inode_lock);
4765
4766 /*
4767 * Free space cache has inodes in the tree root, but the tree root has a
4768 * root_refs of 0, so this could end up dropping the tree root as a
4769 * snapshot, so we need the extra !root->fs_info->tree_root check to
4770 * make sure we don't drop it.
4771 */
4772 if (empty && btrfs_root_refs(&root->root_item) == 0 &&
4773 root != root->fs_info->tree_root) {
4774 synchronize_srcu(&root->fs_info->subvol_srcu);
4775 spin_lock(&root->inode_lock);
4776 empty = RB_EMPTY_ROOT(&root->inode_tree);
4777 spin_unlock(&root->inode_lock);
4778 if (empty)
4779 btrfs_add_dead_root(root);
4780 }
4781 }
4782
4783 void btrfs_invalidate_inodes(struct btrfs_root *root)
4784 {
4785 struct rb_node *node;
4786 struct rb_node *prev;
4787 struct btrfs_inode *entry;
4788 struct inode *inode;
4789 u64 objectid = 0;
4790
4791 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
4792
4793 spin_lock(&root->inode_lock);
4794 again:
4795 node = root->inode_tree.rb_node;
4796 prev = NULL;
4797 while (node) {
4798 prev = node;
4799 entry = rb_entry(node, struct btrfs_inode, rb_node);
4800
4801 if (objectid < btrfs_ino(&entry->vfs_inode))
4802 node = node->rb_left;
4803 else if (objectid > btrfs_ino(&entry->vfs_inode))
4804 node = node->rb_right;
4805 else
4806 break;
4807 }
4808 if (!node) {
4809 while (prev) {
4810 entry = rb_entry(prev, struct btrfs_inode, rb_node);
4811 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
4812 node = prev;
4813 break;
4814 }
4815 prev = rb_next(prev);
4816 }
4817 }
4818 while (node) {
4819 entry = rb_entry(node, struct btrfs_inode, rb_node);
4820 objectid = btrfs_ino(&entry->vfs_inode) + 1;
4821 inode = igrab(&entry->vfs_inode);
4822 if (inode) {
4823 spin_unlock(&root->inode_lock);
4824 if (atomic_read(&inode->i_count) > 1)
4825 d_prune_aliases(inode);
4826 /*
4827 * btrfs_drop_inode will have it removed from
4828 * the inode cache when its usage count
4829 * hits zero.
4830 */
4831 iput(inode);
4832 cond_resched();
4833 spin_lock(&root->inode_lock);
4834 goto again;
4835 }
4836
4837 if (cond_resched_lock(&root->inode_lock))
4838 goto again;
4839
4840 node = rb_next(node);
4841 }
4842 spin_unlock(&root->inode_lock);
4843 }
4844
4845 static int btrfs_init_locked_inode(struct inode *inode, void *p)
4846 {
4847 struct btrfs_iget_args *args = p;
4848 inode->i_ino = args->ino;
4849 BTRFS_I(inode)->root = args->root;
4850 return 0;
4851 }
4852
4853 static int btrfs_find_actor(struct inode *inode, void *opaque)
4854 {
4855 struct btrfs_iget_args *args = opaque;
4856 return args->ino == btrfs_ino(inode) &&
4857 args->root == BTRFS_I(inode)->root;
4858 }
4859
4860 static struct inode *btrfs_iget_locked(struct super_block *s,
4861 u64 objectid,
4862 struct btrfs_root *root)
4863 {
4864 struct inode *inode;
4865 struct btrfs_iget_args args;
4866 args.ino = objectid;
4867 args.root = root;
4868
4869 inode = iget5_locked(s, objectid, btrfs_find_actor,
4870 btrfs_init_locked_inode,
4871 (void *)&args);
4872 return inode;
4873 }
4874
4875 /* Get an inode object given its location and corresponding root.
4876 * Returns in *is_new if the inode was read from disk
4877 */
4878 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
4879 struct btrfs_root *root, int *new)
4880 {
4881 struct inode *inode;
4882
4883 inode = btrfs_iget_locked(s, location->objectid, root);
4884 if (!inode)
4885 return ERR_PTR(-ENOMEM);
4886
4887 if (inode->i_state & I_NEW) {
4888 BTRFS_I(inode)->root = root;
4889 memcpy(&BTRFS_I(inode)->location, location, sizeof(*location));
4890 btrfs_read_locked_inode(inode);
4891 if (!is_bad_inode(inode)) {
4892 inode_tree_add(inode);
4893 unlock_new_inode(inode);
4894 if (new)
4895 *new = 1;
4896 } else {
4897 unlock_new_inode(inode);
4898 iput(inode);
4899 inode = ERR_PTR(-ESTALE);
4900 }
4901 }
4902
4903 return inode;
4904 }
4905
4906 static struct inode *new_simple_dir(struct super_block *s,
4907 struct btrfs_key *key,
4908 struct btrfs_root *root)
4909 {
4910 struct inode *inode = new_inode(s);
4911
4912 if (!inode)
4913 return ERR_PTR(-ENOMEM);
4914
4915 BTRFS_I(inode)->root = root;
4916 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
4917 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
4918
4919 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
4920 inode->i_op = &btrfs_dir_ro_inode_operations;
4921 inode->i_fop = &simple_dir_operations;
4922 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
4923 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
4924
4925 return inode;
4926 }
4927
4928 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
4929 {
4930 struct inode *inode;
4931 struct btrfs_root *root = BTRFS_I(dir)->root;
4932 struct btrfs_root *sub_root = root;
4933 struct btrfs_key location;
4934 int index;
4935 int ret = 0;
4936
4937 if (dentry->d_name.len > BTRFS_NAME_LEN)
4938 return ERR_PTR(-ENAMETOOLONG);
4939
4940 ret = btrfs_inode_by_name(dir, dentry, &location);
4941 if (ret < 0)
4942 return ERR_PTR(ret);
4943
4944 if (location.objectid == 0)
4945 return NULL;
4946
4947 if (location.type == BTRFS_INODE_ITEM_KEY) {
4948 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
4949 return inode;
4950 }
4951
4952 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
4953
4954 index = srcu_read_lock(&root->fs_info->subvol_srcu);
4955 ret = fixup_tree_root_location(root, dir, dentry,
4956 &location, &sub_root);
4957 if (ret < 0) {
4958 if (ret != -ENOENT)
4959 inode = ERR_PTR(ret);
4960 else
4961 inode = new_simple_dir(dir->i_sb, &location, sub_root);
4962 } else {
4963 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
4964 }
4965 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
4966
4967 if (!IS_ERR(inode) && root != sub_root) {
4968 down_read(&root->fs_info->cleanup_work_sem);
4969 if (!(inode->i_sb->s_flags & MS_RDONLY))
4970 ret = btrfs_orphan_cleanup(sub_root);
4971 up_read(&root->fs_info->cleanup_work_sem);
4972 if (ret) {
4973 iput(inode);
4974 inode = ERR_PTR(ret);
4975 }
4976 }
4977
4978 return inode;
4979 }
4980
4981 static int btrfs_dentry_delete(const struct dentry *dentry)
4982 {
4983 struct btrfs_root *root;
4984 struct inode *inode = dentry->d_inode;
4985
4986 if (!inode && !IS_ROOT(dentry))
4987 inode = dentry->d_parent->d_inode;
4988
4989 if (inode) {
4990 root = BTRFS_I(inode)->root;
4991 if (btrfs_root_refs(&root->root_item) == 0)
4992 return 1;
4993
4994 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
4995 return 1;
4996 }
4997 return 0;
4998 }
4999
5000 static void btrfs_dentry_release(struct dentry *dentry)
5001 {
5002 if (dentry->d_fsdata)
5003 kfree(dentry->d_fsdata);
5004 }
5005
5006 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5007 unsigned int flags)
5008 {
5009 struct dentry *ret;
5010
5011 ret = d_splice_alias(btrfs_lookup_dentry(dir, dentry), dentry);
5012 return ret;
5013 }
5014
5015 unsigned char btrfs_filetype_table[] = {
5016 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5017 };
5018
5019 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
5020 {
5021 struct inode *inode = file_inode(file);
5022 struct btrfs_root *root = BTRFS_I(inode)->root;
5023 struct btrfs_item *item;
5024 struct btrfs_dir_item *di;
5025 struct btrfs_key key;
5026 struct btrfs_key found_key;
5027 struct btrfs_path *path;
5028 struct list_head ins_list;
5029 struct list_head del_list;
5030 int ret;
5031 struct extent_buffer *leaf;
5032 int slot;
5033 unsigned char d_type;
5034 int over = 0;
5035 u32 di_cur;
5036 u32 di_total;
5037 u32 di_len;
5038 int key_type = BTRFS_DIR_INDEX_KEY;
5039 char tmp_name[32];
5040 char *name_ptr;
5041 int name_len;
5042 int is_curr = 0; /* ctx->pos points to the current index? */
5043
5044 /* FIXME, use a real flag for deciding about the key type */
5045 if (root->fs_info->tree_root == root)
5046 key_type = BTRFS_DIR_ITEM_KEY;
5047
5048 if (!dir_emit_dots(file, ctx))
5049 return 0;
5050
5051 path = btrfs_alloc_path();
5052 if (!path)
5053 return -ENOMEM;
5054
5055 path->reada = 1;
5056
5057 if (key_type == BTRFS_DIR_INDEX_KEY) {
5058 INIT_LIST_HEAD(&ins_list);
5059 INIT_LIST_HEAD(&del_list);
5060 btrfs_get_delayed_items(inode, &ins_list, &del_list);
5061 }
5062
5063 btrfs_set_key_type(&key, key_type);
5064 key.offset = ctx->pos;
5065 key.objectid = btrfs_ino(inode);
5066
5067 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5068 if (ret < 0)
5069 goto err;
5070
5071 while (1) {
5072 leaf = path->nodes[0];
5073 slot = path->slots[0];
5074 if (slot >= btrfs_header_nritems(leaf)) {
5075 ret = btrfs_next_leaf(root, path);
5076 if (ret < 0)
5077 goto err;
5078 else if (ret > 0)
5079 break;
5080 continue;
5081 }
5082
5083 item = btrfs_item_nr(leaf, slot);
5084 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5085
5086 if (found_key.objectid != key.objectid)
5087 break;
5088 if (btrfs_key_type(&found_key) != key_type)
5089 break;
5090 if (found_key.offset < ctx->pos)
5091 goto next;
5092 if (key_type == BTRFS_DIR_INDEX_KEY &&
5093 btrfs_should_delete_dir_index(&del_list,
5094 found_key.offset))
5095 goto next;
5096
5097 ctx->pos = found_key.offset;
5098 is_curr = 1;
5099
5100 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5101 di_cur = 0;
5102 di_total = btrfs_item_size(leaf, item);
5103
5104 while (di_cur < di_total) {
5105 struct btrfs_key location;
5106
5107 if (verify_dir_item(root, leaf, di))
5108 break;
5109
5110 name_len = btrfs_dir_name_len(leaf, di);
5111 if (name_len <= sizeof(tmp_name)) {
5112 name_ptr = tmp_name;
5113 } else {
5114 name_ptr = kmalloc(name_len, GFP_NOFS);
5115 if (!name_ptr) {
5116 ret = -ENOMEM;
5117 goto err;
5118 }
5119 }
5120 read_extent_buffer(leaf, name_ptr,
5121 (unsigned long)(di + 1), name_len);
5122
5123 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
5124 btrfs_dir_item_key_to_cpu(leaf, di, &location);
5125
5126
5127 /* is this a reference to our own snapshot? If so
5128 * skip it.
5129 *
5130 * In contrast to old kernels, we insert the snapshot's
5131 * dir item and dir index after it has been created, so
5132 * we won't find a reference to our own snapshot. We
5133 * still keep the following code for backward
5134 * compatibility.
5135 */
5136 if (location.type == BTRFS_ROOT_ITEM_KEY &&
5137 location.objectid == root->root_key.objectid) {
5138 over = 0;
5139 goto skip;
5140 }
5141 over = !dir_emit(ctx, name_ptr, name_len,
5142 location.objectid, d_type);
5143
5144 skip:
5145 if (name_ptr != tmp_name)
5146 kfree(name_ptr);
5147
5148 if (over)
5149 goto nopos;
5150 di_len = btrfs_dir_name_len(leaf, di) +
5151 btrfs_dir_data_len(leaf, di) + sizeof(*di);
5152 di_cur += di_len;
5153 di = (struct btrfs_dir_item *)((char *)di + di_len);
5154 }
5155 next:
5156 path->slots[0]++;
5157 }
5158
5159 if (key_type == BTRFS_DIR_INDEX_KEY) {
5160 if (is_curr)
5161 ctx->pos++;
5162 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
5163 if (ret)
5164 goto nopos;
5165 }
5166
5167 /* Reached end of directory/root. Bump pos past the last item. */
5168 if (key_type == BTRFS_DIR_INDEX_KEY)
5169 /*
5170 * 32-bit glibc will use getdents64, but then strtol -
5171 * so the last number we can serve is this.
5172 */
5173 ctx->pos = 0x7fffffff;
5174 else
5175 ctx->pos++;
5176 nopos:
5177 ret = 0;
5178 err:
5179 if (key_type == BTRFS_DIR_INDEX_KEY)
5180 btrfs_put_delayed_items(&ins_list, &del_list);
5181 btrfs_free_path(path);
5182 return ret;
5183 }
5184
5185 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
5186 {
5187 struct btrfs_root *root = BTRFS_I(inode)->root;
5188 struct btrfs_trans_handle *trans;
5189 int ret = 0;
5190 bool nolock = false;
5191
5192 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5193 return 0;
5194
5195 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
5196 nolock = true;
5197
5198 if (wbc->sync_mode == WB_SYNC_ALL) {
5199 if (nolock)
5200 trans = btrfs_join_transaction_nolock(root);
5201 else
5202 trans = btrfs_join_transaction(root);
5203 if (IS_ERR(trans))
5204 return PTR_ERR(trans);
5205 ret = btrfs_commit_transaction(trans, root);
5206 }
5207 return ret;
5208 }
5209
5210 /*
5211 * This is somewhat expensive, updating the tree every time the
5212 * inode changes. But, it is most likely to find the inode in cache.
5213 * FIXME, needs more benchmarking...there are no reasons other than performance
5214 * to keep or drop this code.
5215 */
5216 static int btrfs_dirty_inode(struct inode *inode)
5217 {
5218 struct btrfs_root *root = BTRFS_I(inode)->root;
5219 struct btrfs_trans_handle *trans;
5220 int ret;
5221
5222 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5223 return 0;
5224
5225 trans = btrfs_join_transaction(root);
5226 if (IS_ERR(trans))
5227 return PTR_ERR(trans);
5228
5229 ret = btrfs_update_inode(trans, root, inode);
5230 if (ret && ret == -ENOSPC) {
5231 /* whoops, lets try again with the full transaction */
5232 btrfs_end_transaction(trans, root);
5233 trans = btrfs_start_transaction(root, 1);
5234 if (IS_ERR(trans))
5235 return PTR_ERR(trans);
5236
5237 ret = btrfs_update_inode(trans, root, inode);
5238 }
5239 btrfs_end_transaction(trans, root);
5240 if (BTRFS_I(inode)->delayed_node)
5241 btrfs_balance_delayed_items(root);
5242
5243 return ret;
5244 }
5245
5246 /*
5247 * This is a copy of file_update_time. We need this so we can return error on
5248 * ENOSPC for updating the inode in the case of file write and mmap writes.
5249 */
5250 static int btrfs_update_time(struct inode *inode, struct timespec *now,
5251 int flags)
5252 {
5253 struct btrfs_root *root = BTRFS_I(inode)->root;
5254
5255 if (btrfs_root_readonly(root))
5256 return -EROFS;
5257
5258 if (flags & S_VERSION)
5259 inode_inc_iversion(inode);
5260 if (flags & S_CTIME)
5261 inode->i_ctime = *now;
5262 if (flags & S_MTIME)
5263 inode->i_mtime = *now;
5264 if (flags & S_ATIME)
5265 inode->i_atime = *now;
5266 return btrfs_dirty_inode(inode);
5267 }
5268
5269 /*
5270 * find the highest existing sequence number in a directory
5271 * and then set the in-memory index_cnt variable to reflect
5272 * free sequence numbers
5273 */
5274 static int btrfs_set_inode_index_count(struct inode *inode)
5275 {
5276 struct btrfs_root *root = BTRFS_I(inode)->root;
5277 struct btrfs_key key, found_key;
5278 struct btrfs_path *path;
5279 struct extent_buffer *leaf;
5280 int ret;
5281
5282 key.objectid = btrfs_ino(inode);
5283 btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
5284 key.offset = (u64)-1;
5285
5286 path = btrfs_alloc_path();
5287 if (!path)
5288 return -ENOMEM;
5289
5290 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5291 if (ret < 0)
5292 goto out;
5293 /* FIXME: we should be able to handle this */
5294 if (ret == 0)
5295 goto out;
5296 ret = 0;
5297
5298 /*
5299 * MAGIC NUMBER EXPLANATION:
5300 * since we search a directory based on f_pos we have to start at 2
5301 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
5302 * else has to start at 2
5303 */
5304 if (path->slots[0] == 0) {
5305 BTRFS_I(inode)->index_cnt = 2;
5306 goto out;
5307 }
5308
5309 path->slots[0]--;
5310
5311 leaf = path->nodes[0];
5312 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5313
5314 if (found_key.objectid != btrfs_ino(inode) ||
5315 btrfs_key_type(&found_key) != BTRFS_DIR_INDEX_KEY) {
5316 BTRFS_I(inode)->index_cnt = 2;
5317 goto out;
5318 }
5319
5320 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
5321 out:
5322 btrfs_free_path(path);
5323 return ret;
5324 }
5325
5326 /*
5327 * helper to find a free sequence number in a given directory. This current
5328 * code is very simple, later versions will do smarter things in the btree
5329 */
5330 int btrfs_set_inode_index(struct inode *dir, u64 *index)
5331 {
5332 int ret = 0;
5333
5334 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
5335 ret = btrfs_inode_delayed_dir_index_count(dir);
5336 if (ret) {
5337 ret = btrfs_set_inode_index_count(dir);
5338 if (ret)
5339 return ret;
5340 }
5341 }
5342
5343 *index = BTRFS_I(dir)->index_cnt;
5344 BTRFS_I(dir)->index_cnt++;
5345
5346 return ret;
5347 }
5348
5349 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
5350 struct btrfs_root *root,
5351 struct inode *dir,
5352 const char *name, int name_len,
5353 u64 ref_objectid, u64 objectid,
5354 umode_t mode, u64 *index)
5355 {
5356 struct inode *inode;
5357 struct btrfs_inode_item *inode_item;
5358 struct btrfs_key *location;
5359 struct btrfs_path *path;
5360 struct btrfs_inode_ref *ref;
5361 struct btrfs_key key[2];
5362 u32 sizes[2];
5363 unsigned long ptr;
5364 int ret;
5365 int owner;
5366
5367 path = btrfs_alloc_path();
5368 if (!path)
5369 return ERR_PTR(-ENOMEM);
5370
5371 inode = new_inode(root->fs_info->sb);
5372 if (!inode) {
5373 btrfs_free_path(path);
5374 return ERR_PTR(-ENOMEM);
5375 }
5376
5377 /*
5378 * we have to initialize this early, so we can reclaim the inode
5379 * number if we fail afterwards in this function.
5380 */
5381 inode->i_ino = objectid;
5382
5383 if (dir) {
5384 trace_btrfs_inode_request(dir);
5385
5386 ret = btrfs_set_inode_index(dir, index);
5387 if (ret) {
5388 btrfs_free_path(path);
5389 iput(inode);
5390 return ERR_PTR(ret);
5391 }
5392 }
5393 /*
5394 * index_cnt is ignored for everything but a dir,
5395 * btrfs_get_inode_index_count has an explanation for the magic
5396 * number
5397 */
5398 BTRFS_I(inode)->index_cnt = 2;
5399 BTRFS_I(inode)->root = root;
5400 BTRFS_I(inode)->generation = trans->transid;
5401 inode->i_generation = BTRFS_I(inode)->generation;
5402
5403 /*
5404 * We could have gotten an inode number from somebody who was fsynced
5405 * and then removed in this same transaction, so let's just set full
5406 * sync since it will be a full sync anyway and this will blow away the
5407 * old info in the log.
5408 */
5409 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
5410
5411 if (S_ISDIR(mode))
5412 owner = 0;
5413 else
5414 owner = 1;
5415
5416 key[0].objectid = objectid;
5417 btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
5418 key[0].offset = 0;
5419
5420 /*
5421 * Start new inodes with an inode_ref. This is slightly more
5422 * efficient for small numbers of hard links since they will
5423 * be packed into one item. Extended refs will kick in if we
5424 * add more hard links than can fit in the ref item.
5425 */
5426 key[1].objectid = objectid;
5427 btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
5428 key[1].offset = ref_objectid;
5429
5430 sizes[0] = sizeof(struct btrfs_inode_item);
5431 sizes[1] = name_len + sizeof(*ref);
5432
5433 path->leave_spinning = 1;
5434 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
5435 if (ret != 0)
5436 goto fail;
5437
5438 inode_init_owner(inode, dir, mode);
5439 inode_set_bytes(inode, 0);
5440 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
5441 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
5442 struct btrfs_inode_item);
5443 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
5444 sizeof(*inode_item));
5445 fill_inode_item(trans, path->nodes[0], inode_item, inode);
5446
5447 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
5448 struct btrfs_inode_ref);
5449 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
5450 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
5451 ptr = (unsigned long)(ref + 1);
5452 write_extent_buffer(path->nodes[0], name, ptr, name_len);
5453
5454 btrfs_mark_buffer_dirty(path->nodes[0]);
5455 btrfs_free_path(path);
5456
5457 location = &BTRFS_I(inode)->location;
5458 location->objectid = objectid;
5459 location->offset = 0;
5460 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
5461
5462 btrfs_inherit_iflags(inode, dir);
5463
5464 if (S_ISREG(mode)) {
5465 if (btrfs_test_opt(root, NODATASUM))
5466 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
5467 if (btrfs_test_opt(root, NODATACOW))
5468 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
5469 BTRFS_INODE_NODATASUM;
5470 }
5471
5472 insert_inode_hash(inode);
5473 inode_tree_add(inode);
5474
5475 trace_btrfs_inode_new(inode);
5476 btrfs_set_inode_last_trans(trans, inode);
5477
5478 btrfs_update_root_times(trans, root);
5479
5480 return inode;
5481 fail:
5482 if (dir)
5483 BTRFS_I(dir)->index_cnt--;
5484 btrfs_free_path(path);
5485 iput(inode);
5486 return ERR_PTR(ret);
5487 }
5488
5489 static inline u8 btrfs_inode_type(struct inode *inode)
5490 {
5491 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
5492 }
5493
5494 /*
5495 * utility function to add 'inode' into 'parent_inode' with
5496 * a give name and a given sequence number.
5497 * if 'add_backref' is true, also insert a backref from the
5498 * inode to the parent directory.
5499 */
5500 int btrfs_add_link(struct btrfs_trans_handle *trans,
5501 struct inode *parent_inode, struct inode *inode,
5502 const char *name, int name_len, int add_backref, u64 index)
5503 {
5504 int ret = 0;
5505 struct btrfs_key key;
5506 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
5507 u64 ino = btrfs_ino(inode);
5508 u64 parent_ino = btrfs_ino(parent_inode);
5509
5510 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5511 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
5512 } else {
5513 key.objectid = ino;
5514 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
5515 key.offset = 0;
5516 }
5517
5518 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5519 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
5520 key.objectid, root->root_key.objectid,
5521 parent_ino, index, name, name_len);
5522 } else if (add_backref) {
5523 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
5524 parent_ino, index);
5525 }
5526
5527 /* Nothing to clean up yet */
5528 if (ret)
5529 return ret;
5530
5531 ret = btrfs_insert_dir_item(trans, root, name, name_len,
5532 parent_inode, &key,
5533 btrfs_inode_type(inode), index);
5534 if (ret == -EEXIST || ret == -EOVERFLOW)
5535 goto fail_dir_item;
5536 else if (ret) {
5537 btrfs_abort_transaction(trans, root, ret);
5538 return ret;
5539 }
5540
5541 btrfs_i_size_write(parent_inode, parent_inode->i_size +
5542 name_len * 2);
5543 inode_inc_iversion(parent_inode);
5544 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
5545 ret = btrfs_update_inode(trans, root, parent_inode);
5546 if (ret)
5547 btrfs_abort_transaction(trans, root, ret);
5548 return ret;
5549
5550 fail_dir_item:
5551 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5552 u64 local_index;
5553 int err;
5554 err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
5555 key.objectid, root->root_key.objectid,
5556 parent_ino, &local_index, name, name_len);
5557
5558 } else if (add_backref) {
5559 u64 local_index;
5560 int err;
5561
5562 err = btrfs_del_inode_ref(trans, root, name, name_len,
5563 ino, parent_ino, &local_index);
5564 }
5565 return ret;
5566 }
5567
5568 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
5569 struct inode *dir, struct dentry *dentry,
5570 struct inode *inode, int backref, u64 index)
5571 {
5572 int err = btrfs_add_link(trans, dir, inode,
5573 dentry->d_name.name, dentry->d_name.len,
5574 backref, index);
5575 if (err > 0)
5576 err = -EEXIST;
5577 return err;
5578 }
5579
5580 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
5581 umode_t mode, dev_t rdev)
5582 {
5583 struct btrfs_trans_handle *trans;
5584 struct btrfs_root *root = BTRFS_I(dir)->root;
5585 struct inode *inode = NULL;
5586 int err;
5587 int drop_inode = 0;
5588 u64 objectid;
5589 u64 index = 0;
5590
5591 if (!new_valid_dev(rdev))
5592 return -EINVAL;
5593
5594 /*
5595 * 2 for inode item and ref
5596 * 2 for dir items
5597 * 1 for xattr if selinux is on
5598 */
5599 trans = btrfs_start_transaction(root, 5);
5600 if (IS_ERR(trans))
5601 return PTR_ERR(trans);
5602
5603 err = btrfs_find_free_ino(root, &objectid);
5604 if (err)
5605 goto out_unlock;
5606
5607 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5608 dentry->d_name.len, btrfs_ino(dir), objectid,
5609 mode, &index);
5610 if (IS_ERR(inode)) {
5611 err = PTR_ERR(inode);
5612 goto out_unlock;
5613 }
5614
5615 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5616 if (err) {
5617 drop_inode = 1;
5618 goto out_unlock;
5619 }
5620
5621 /*
5622 * If the active LSM wants to access the inode during
5623 * d_instantiate it needs these. Smack checks to see
5624 * if the filesystem supports xattrs by looking at the
5625 * ops vector.
5626 */
5627
5628 inode->i_op = &btrfs_special_inode_operations;
5629 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
5630 if (err)
5631 drop_inode = 1;
5632 else {
5633 init_special_inode(inode, inode->i_mode, rdev);
5634 btrfs_update_inode(trans, root, inode);
5635 d_instantiate(dentry, inode);
5636 }
5637 out_unlock:
5638 btrfs_end_transaction(trans, root);
5639 btrfs_btree_balance_dirty(root);
5640 if (drop_inode) {
5641 inode_dec_link_count(inode);
5642 iput(inode);
5643 }
5644 return err;
5645 }
5646
5647 static int btrfs_create(struct inode *dir, struct dentry *dentry,
5648 umode_t mode, bool excl)
5649 {
5650 struct btrfs_trans_handle *trans;
5651 struct btrfs_root *root = BTRFS_I(dir)->root;
5652 struct inode *inode = NULL;
5653 int drop_inode_on_err = 0;
5654 int err;
5655 u64 objectid;
5656 u64 index = 0;
5657
5658 /*
5659 * 2 for inode item and ref
5660 * 2 for dir items
5661 * 1 for xattr if selinux is on
5662 */
5663 trans = btrfs_start_transaction(root, 5);
5664 if (IS_ERR(trans))
5665 return PTR_ERR(trans);
5666
5667 err = btrfs_find_free_ino(root, &objectid);
5668 if (err)
5669 goto out_unlock;
5670
5671 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5672 dentry->d_name.len, btrfs_ino(dir), objectid,
5673 mode, &index);
5674 if (IS_ERR(inode)) {
5675 err = PTR_ERR(inode);
5676 goto out_unlock;
5677 }
5678 drop_inode_on_err = 1;
5679
5680 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5681 if (err)
5682 goto out_unlock;
5683
5684 err = btrfs_update_inode(trans, root, inode);
5685 if (err)
5686 goto out_unlock;
5687
5688 /*
5689 * If the active LSM wants to access the inode during
5690 * d_instantiate it needs these. Smack checks to see
5691 * if the filesystem supports xattrs by looking at the
5692 * ops vector.
5693 */
5694 inode->i_fop = &btrfs_file_operations;
5695 inode->i_op = &btrfs_file_inode_operations;
5696
5697 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
5698 if (err)
5699 goto out_unlock;
5700
5701 inode->i_mapping->a_ops = &btrfs_aops;
5702 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
5703 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
5704 d_instantiate(dentry, inode);
5705
5706 out_unlock:
5707 btrfs_end_transaction(trans, root);
5708 if (err && drop_inode_on_err) {
5709 inode_dec_link_count(inode);
5710 iput(inode);
5711 }
5712 btrfs_btree_balance_dirty(root);
5713 return err;
5714 }
5715
5716 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
5717 struct dentry *dentry)
5718 {
5719 struct btrfs_trans_handle *trans;
5720 struct btrfs_root *root = BTRFS_I(dir)->root;
5721 struct inode *inode = old_dentry->d_inode;
5722 u64 index;
5723 int err;
5724 int drop_inode = 0;
5725
5726 /* do not allow sys_link's with other subvols of the same device */
5727 if (root->objectid != BTRFS_I(inode)->root->objectid)
5728 return -EXDEV;
5729
5730 if (inode->i_nlink >= BTRFS_LINK_MAX)
5731 return -EMLINK;
5732
5733 err = btrfs_set_inode_index(dir, &index);
5734 if (err)
5735 goto fail;
5736
5737 /*
5738 * 2 items for inode and inode ref
5739 * 2 items for dir items
5740 * 1 item for parent inode
5741 */
5742 trans = btrfs_start_transaction(root, 5);
5743 if (IS_ERR(trans)) {
5744 err = PTR_ERR(trans);
5745 goto fail;
5746 }
5747
5748 btrfs_inc_nlink(inode);
5749 inode_inc_iversion(inode);
5750 inode->i_ctime = CURRENT_TIME;
5751 ihold(inode);
5752 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
5753
5754 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
5755
5756 if (err) {
5757 drop_inode = 1;
5758 } else {
5759 struct dentry *parent = dentry->d_parent;
5760 err = btrfs_update_inode(trans, root, inode);
5761 if (err)
5762 goto fail;
5763 d_instantiate(dentry, inode);
5764 btrfs_log_new_name(trans, inode, NULL, parent);
5765 }
5766
5767 btrfs_end_transaction(trans, root);
5768 fail:
5769 if (drop_inode) {
5770 inode_dec_link_count(inode);
5771 iput(inode);
5772 }
5773 btrfs_btree_balance_dirty(root);
5774 return err;
5775 }
5776
5777 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
5778 {
5779 struct inode *inode = NULL;
5780 struct btrfs_trans_handle *trans;
5781 struct btrfs_root *root = BTRFS_I(dir)->root;
5782 int err = 0;
5783 int drop_on_err = 0;
5784 u64 objectid = 0;
5785 u64 index = 0;
5786
5787 /*
5788 * 2 items for inode and ref
5789 * 2 items for dir items
5790 * 1 for xattr if selinux is on
5791 */
5792 trans = btrfs_start_transaction(root, 5);
5793 if (IS_ERR(trans))
5794 return PTR_ERR(trans);
5795
5796 err = btrfs_find_free_ino(root, &objectid);
5797 if (err)
5798 goto out_fail;
5799
5800 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5801 dentry->d_name.len, btrfs_ino(dir), objectid,
5802 S_IFDIR | mode, &index);
5803 if (IS_ERR(inode)) {
5804 err = PTR_ERR(inode);
5805 goto out_fail;
5806 }
5807
5808 drop_on_err = 1;
5809
5810 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5811 if (err)
5812 goto out_fail;
5813
5814 inode->i_op = &btrfs_dir_inode_operations;
5815 inode->i_fop = &btrfs_dir_file_operations;
5816
5817 btrfs_i_size_write(inode, 0);
5818 err = btrfs_update_inode(trans, root, inode);
5819 if (err)
5820 goto out_fail;
5821
5822 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
5823 dentry->d_name.len, 0, index);
5824 if (err)
5825 goto out_fail;
5826
5827 d_instantiate(dentry, inode);
5828 drop_on_err = 0;
5829
5830 out_fail:
5831 btrfs_end_transaction(trans, root);
5832 if (drop_on_err)
5833 iput(inode);
5834 btrfs_btree_balance_dirty(root);
5835 return err;
5836 }
5837
5838 /* helper for btfs_get_extent. Given an existing extent in the tree,
5839 * and an extent that you want to insert, deal with overlap and insert
5840 * the new extent into the tree.
5841 */
5842 static int merge_extent_mapping(struct extent_map_tree *em_tree,
5843 struct extent_map *existing,
5844 struct extent_map *em,
5845 u64 map_start, u64 map_len)
5846 {
5847 u64 start_diff;
5848
5849 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
5850 start_diff = map_start - em->start;
5851 em->start = map_start;
5852 em->len = map_len;
5853 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
5854 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
5855 em->block_start += start_diff;
5856 em->block_len -= start_diff;
5857 }
5858 return add_extent_mapping(em_tree, em, 0);
5859 }
5860
5861 static noinline int uncompress_inline(struct btrfs_path *path,
5862 struct inode *inode, struct page *page,
5863 size_t pg_offset, u64 extent_offset,
5864 struct btrfs_file_extent_item *item)
5865 {
5866 int ret;
5867 struct extent_buffer *leaf = path->nodes[0];
5868 char *tmp;
5869 size_t max_size;
5870 unsigned long inline_size;
5871 unsigned long ptr;
5872 int compress_type;
5873
5874 WARN_ON(pg_offset != 0);
5875 compress_type = btrfs_file_extent_compression(leaf, item);
5876 max_size = btrfs_file_extent_ram_bytes(leaf, item);
5877 inline_size = btrfs_file_extent_inline_item_len(leaf,
5878 btrfs_item_nr(leaf, path->slots[0]));
5879 tmp = kmalloc(inline_size, GFP_NOFS);
5880 if (!tmp)
5881 return -ENOMEM;
5882 ptr = btrfs_file_extent_inline_start(item);
5883
5884 read_extent_buffer(leaf, tmp, ptr, inline_size);
5885
5886 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
5887 ret = btrfs_decompress(compress_type, tmp, page,
5888 extent_offset, inline_size, max_size);
5889 if (ret) {
5890 char *kaddr = kmap_atomic(page);
5891 unsigned long copy_size = min_t(u64,
5892 PAGE_CACHE_SIZE - pg_offset,
5893 max_size - extent_offset);
5894 memset(kaddr + pg_offset, 0, copy_size);
5895 kunmap_atomic(kaddr);
5896 }
5897 kfree(tmp);
5898 return 0;
5899 }
5900
5901 /*
5902 * a bit scary, this does extent mapping from logical file offset to the disk.
5903 * the ugly parts come from merging extents from the disk with the in-ram
5904 * representation. This gets more complex because of the data=ordered code,
5905 * where the in-ram extents might be locked pending data=ordered completion.
5906 *
5907 * This also copies inline extents directly into the page.
5908 */
5909
5910 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
5911 size_t pg_offset, u64 start, u64 len,
5912 int create)
5913 {
5914 int ret;
5915 int err = 0;
5916 u64 bytenr;
5917 u64 extent_start = 0;
5918 u64 extent_end = 0;
5919 u64 objectid = btrfs_ino(inode);
5920 u32 found_type;
5921 struct btrfs_path *path = NULL;
5922 struct btrfs_root *root = BTRFS_I(inode)->root;
5923 struct btrfs_file_extent_item *item;
5924 struct extent_buffer *leaf;
5925 struct btrfs_key found_key;
5926 struct extent_map *em = NULL;
5927 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
5928 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5929 struct btrfs_trans_handle *trans = NULL;
5930 int compress_type;
5931
5932 again:
5933 read_lock(&em_tree->lock);
5934 em = lookup_extent_mapping(em_tree, start, len);
5935 if (em)
5936 em->bdev = root->fs_info->fs_devices->latest_bdev;
5937 read_unlock(&em_tree->lock);
5938
5939 if (em) {
5940 if (em->start > start || em->start + em->len <= start)
5941 free_extent_map(em);
5942 else if (em->block_start == EXTENT_MAP_INLINE && page)
5943 free_extent_map(em);
5944 else
5945 goto out;
5946 }
5947 em = alloc_extent_map();
5948 if (!em) {
5949 err = -ENOMEM;
5950 goto out;
5951 }
5952 em->bdev = root->fs_info->fs_devices->latest_bdev;
5953 em->start = EXTENT_MAP_HOLE;
5954 em->orig_start = EXTENT_MAP_HOLE;
5955 em->len = (u64)-1;
5956 em->block_len = (u64)-1;
5957
5958 if (!path) {
5959 path = btrfs_alloc_path();
5960 if (!path) {
5961 err = -ENOMEM;
5962 goto out;
5963 }
5964 /*
5965 * Chances are we'll be called again, so go ahead and do
5966 * readahead
5967 */
5968 path->reada = 1;
5969 }
5970
5971 ret = btrfs_lookup_file_extent(trans, root, path,
5972 objectid, start, trans != NULL);
5973 if (ret < 0) {
5974 err = ret;
5975 goto out;
5976 }
5977
5978 if (ret != 0) {
5979 if (path->slots[0] == 0)
5980 goto not_found;
5981 path->slots[0]--;
5982 }
5983
5984 leaf = path->nodes[0];
5985 item = btrfs_item_ptr(leaf, path->slots[0],
5986 struct btrfs_file_extent_item);
5987 /* are we inside the extent that was found? */
5988 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5989 found_type = btrfs_key_type(&found_key);
5990 if (found_key.objectid != objectid ||
5991 found_type != BTRFS_EXTENT_DATA_KEY) {
5992 goto not_found;
5993 }
5994
5995 found_type = btrfs_file_extent_type(leaf, item);
5996 extent_start = found_key.offset;
5997 compress_type = btrfs_file_extent_compression(leaf, item);
5998 if (found_type == BTRFS_FILE_EXTENT_REG ||
5999 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6000 extent_end = extent_start +
6001 btrfs_file_extent_num_bytes(leaf, item);
6002 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6003 size_t size;
6004 size = btrfs_file_extent_inline_len(leaf, item);
6005 extent_end = ALIGN(extent_start + size, root->sectorsize);
6006 }
6007
6008 if (start >= extent_end) {
6009 path->slots[0]++;
6010 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
6011 ret = btrfs_next_leaf(root, path);
6012 if (ret < 0) {
6013 err = ret;
6014 goto out;
6015 }
6016 if (ret > 0)
6017 goto not_found;
6018 leaf = path->nodes[0];
6019 }
6020 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6021 if (found_key.objectid != objectid ||
6022 found_key.type != BTRFS_EXTENT_DATA_KEY)
6023 goto not_found;
6024 if (start + len <= found_key.offset)
6025 goto not_found;
6026 em->start = start;
6027 em->orig_start = start;
6028 em->len = found_key.offset - start;
6029 goto not_found_em;
6030 }
6031
6032 em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, item);
6033 if (found_type == BTRFS_FILE_EXTENT_REG ||
6034 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6035 em->start = extent_start;
6036 em->len = extent_end - extent_start;
6037 em->orig_start = extent_start -
6038 btrfs_file_extent_offset(leaf, item);
6039 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf,
6040 item);
6041 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
6042 if (bytenr == 0) {
6043 em->block_start = EXTENT_MAP_HOLE;
6044 goto insert;
6045 }
6046 if (compress_type != BTRFS_COMPRESS_NONE) {
6047 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
6048 em->compress_type = compress_type;
6049 em->block_start = bytenr;
6050 em->block_len = em->orig_block_len;
6051 } else {
6052 bytenr += btrfs_file_extent_offset(leaf, item);
6053 em->block_start = bytenr;
6054 em->block_len = em->len;
6055 if (found_type == BTRFS_FILE_EXTENT_PREALLOC)
6056 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
6057 }
6058 goto insert;
6059 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6060 unsigned long ptr;
6061 char *map;
6062 size_t size;
6063 size_t extent_offset;
6064 size_t copy_size;
6065
6066 em->block_start = EXTENT_MAP_INLINE;
6067 if (!page || create) {
6068 em->start = extent_start;
6069 em->len = extent_end - extent_start;
6070 goto out;
6071 }
6072
6073 size = btrfs_file_extent_inline_len(leaf, item);
6074 extent_offset = page_offset(page) + pg_offset - extent_start;
6075 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
6076 size - extent_offset);
6077 em->start = extent_start + extent_offset;
6078 em->len = ALIGN(copy_size, root->sectorsize);
6079 em->orig_block_len = em->len;
6080 em->orig_start = em->start;
6081 if (compress_type) {
6082 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
6083 em->compress_type = compress_type;
6084 }
6085 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
6086 if (create == 0 && !PageUptodate(page)) {
6087 if (btrfs_file_extent_compression(leaf, item) !=
6088 BTRFS_COMPRESS_NONE) {
6089 ret = uncompress_inline(path, inode, page,
6090 pg_offset,
6091 extent_offset, item);
6092 BUG_ON(ret); /* -ENOMEM */
6093 } else {
6094 map = kmap(page);
6095 read_extent_buffer(leaf, map + pg_offset, ptr,
6096 copy_size);
6097 if (pg_offset + copy_size < PAGE_CACHE_SIZE) {
6098 memset(map + pg_offset + copy_size, 0,
6099 PAGE_CACHE_SIZE - pg_offset -
6100 copy_size);
6101 }
6102 kunmap(page);
6103 }
6104 flush_dcache_page(page);
6105 } else if (create && PageUptodate(page)) {
6106 BUG();
6107 if (!trans) {
6108 kunmap(page);
6109 free_extent_map(em);
6110 em = NULL;
6111
6112 btrfs_release_path(path);
6113 trans = btrfs_join_transaction(root);
6114
6115 if (IS_ERR(trans))
6116 return ERR_CAST(trans);
6117 goto again;
6118 }
6119 map = kmap(page);
6120 write_extent_buffer(leaf, map + pg_offset, ptr,
6121 copy_size);
6122 kunmap(page);
6123 btrfs_mark_buffer_dirty(leaf);
6124 }
6125 set_extent_uptodate(io_tree, em->start,
6126 extent_map_end(em) - 1, NULL, GFP_NOFS);
6127 goto insert;
6128 } else {
6129 WARN(1, KERN_ERR "btrfs unknown found_type %d\n", found_type);
6130 }
6131 not_found:
6132 em->start = start;
6133 em->orig_start = start;
6134 em->len = len;
6135 not_found_em:
6136 em->block_start = EXTENT_MAP_HOLE;
6137 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
6138 insert:
6139 btrfs_release_path(path);
6140 if (em->start > start || extent_map_end(em) <= start) {
6141 btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]",
6142 (unsigned long long)em->start,
6143 (unsigned long long)em->len,
6144 (unsigned long long)start,
6145 (unsigned long long)len);
6146 err = -EIO;
6147 goto out;
6148 }
6149
6150 err = 0;
6151 write_lock(&em_tree->lock);
6152 ret = add_extent_mapping(em_tree, em, 0);
6153 /* it is possible that someone inserted the extent into the tree
6154 * while we had the lock dropped. It is also possible that
6155 * an overlapping map exists in the tree
6156 */
6157 if (ret == -EEXIST) {
6158 struct extent_map *existing;
6159
6160 ret = 0;
6161
6162 existing = lookup_extent_mapping(em_tree, start, len);
6163 if (existing && (existing->start > start ||
6164 existing->start + existing->len <= start)) {
6165 free_extent_map(existing);
6166 existing = NULL;
6167 }
6168 if (!existing) {
6169 existing = lookup_extent_mapping(em_tree, em->start,
6170 em->len);
6171 if (existing) {
6172 err = merge_extent_mapping(em_tree, existing,
6173 em, start,
6174 root->sectorsize);
6175 free_extent_map(existing);
6176 if (err) {
6177 free_extent_map(em);
6178 em = NULL;
6179 }
6180 } else {
6181 err = -EIO;
6182 free_extent_map(em);
6183 em = NULL;
6184 }
6185 } else {
6186 free_extent_map(em);
6187 em = existing;
6188 err = 0;
6189 }
6190 }
6191 write_unlock(&em_tree->lock);
6192 out:
6193
6194 if (em)
6195 trace_btrfs_get_extent(root, em);
6196
6197 if (path)
6198 btrfs_free_path(path);
6199 if (trans) {
6200 ret = btrfs_end_transaction(trans, root);
6201 if (!err)
6202 err = ret;
6203 }
6204 if (err) {
6205 free_extent_map(em);
6206 return ERR_PTR(err);
6207 }
6208 BUG_ON(!em); /* Error is always set */
6209 return em;
6210 }
6211
6212 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
6213 size_t pg_offset, u64 start, u64 len,
6214 int create)
6215 {
6216 struct extent_map *em;
6217 struct extent_map *hole_em = NULL;
6218 u64 range_start = start;
6219 u64 end;
6220 u64 found;
6221 u64 found_end;
6222 int err = 0;
6223
6224 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
6225 if (IS_ERR(em))
6226 return em;
6227 if (em) {
6228 /*
6229 * if our em maps to
6230 * - a hole or
6231 * - a pre-alloc extent,
6232 * there might actually be delalloc bytes behind it.
6233 */
6234 if (em->block_start != EXTENT_MAP_HOLE &&
6235 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6236 return em;
6237 else
6238 hole_em = em;
6239 }
6240
6241 /* check to see if we've wrapped (len == -1 or similar) */
6242 end = start + len;
6243 if (end < start)
6244 end = (u64)-1;
6245 else
6246 end -= 1;
6247
6248 em = NULL;
6249
6250 /* ok, we didn't find anything, lets look for delalloc */
6251 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
6252 end, len, EXTENT_DELALLOC, 1);
6253 found_end = range_start + found;
6254 if (found_end < range_start)
6255 found_end = (u64)-1;
6256
6257 /*
6258 * we didn't find anything useful, return
6259 * the original results from get_extent()
6260 */
6261 if (range_start > end || found_end <= start) {
6262 em = hole_em;
6263 hole_em = NULL;
6264 goto out;
6265 }
6266
6267 /* adjust the range_start to make sure it doesn't
6268 * go backwards from the start they passed in
6269 */
6270 range_start = max(start,range_start);
6271 found = found_end - range_start;
6272
6273 if (found > 0) {
6274 u64 hole_start = start;
6275 u64 hole_len = len;
6276
6277 em = alloc_extent_map();
6278 if (!em) {
6279 err = -ENOMEM;
6280 goto out;
6281 }
6282 /*
6283 * when btrfs_get_extent can't find anything it
6284 * returns one huge hole
6285 *
6286 * make sure what it found really fits our range, and
6287 * adjust to make sure it is based on the start from
6288 * the caller
6289 */
6290 if (hole_em) {
6291 u64 calc_end = extent_map_end(hole_em);
6292
6293 if (calc_end <= start || (hole_em->start > end)) {
6294 free_extent_map(hole_em);
6295 hole_em = NULL;
6296 } else {
6297 hole_start = max(hole_em->start, start);
6298 hole_len = calc_end - hole_start;
6299 }
6300 }
6301 em->bdev = NULL;
6302 if (hole_em && range_start > hole_start) {
6303 /* our hole starts before our delalloc, so we
6304 * have to return just the parts of the hole
6305 * that go until the delalloc starts
6306 */
6307 em->len = min(hole_len,
6308 range_start - hole_start);
6309 em->start = hole_start;
6310 em->orig_start = hole_start;
6311 /*
6312 * don't adjust block start at all,
6313 * it is fixed at EXTENT_MAP_HOLE
6314 */
6315 em->block_start = hole_em->block_start;
6316 em->block_len = hole_len;
6317 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
6318 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
6319 } else {
6320 em->start = range_start;
6321 em->len = found;
6322 em->orig_start = range_start;
6323 em->block_start = EXTENT_MAP_DELALLOC;
6324 em->block_len = found;
6325 }
6326 } else if (hole_em) {
6327 return hole_em;
6328 }
6329 out:
6330
6331 free_extent_map(hole_em);
6332 if (err) {
6333 free_extent_map(em);
6334 return ERR_PTR(err);
6335 }
6336 return em;
6337 }
6338
6339 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
6340 u64 start, u64 len)
6341 {
6342 struct btrfs_root *root = BTRFS_I(inode)->root;
6343 struct btrfs_trans_handle *trans;
6344 struct extent_map *em;
6345 struct btrfs_key ins;
6346 u64 alloc_hint;
6347 int ret;
6348
6349 trans = btrfs_join_transaction(root);
6350 if (IS_ERR(trans))
6351 return ERR_CAST(trans);
6352
6353 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
6354
6355 alloc_hint = get_extent_allocation_hint(inode, start, len);
6356 ret = btrfs_reserve_extent(trans, root, len, root->sectorsize, 0,
6357 alloc_hint, &ins, 1);
6358 if (ret) {
6359 em = ERR_PTR(ret);
6360 goto out;
6361 }
6362
6363 em = create_pinned_em(inode, start, ins.offset, start, ins.objectid,
6364 ins.offset, ins.offset, ins.offset, 0);
6365 if (IS_ERR(em))
6366 goto out;
6367
6368 ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
6369 ins.offset, ins.offset, 0);
6370 if (ret) {
6371 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
6372 em = ERR_PTR(ret);
6373 }
6374 out:
6375 btrfs_end_transaction(trans, root);
6376 return em;
6377 }
6378
6379 /*
6380 * returns 1 when the nocow is safe, < 1 on error, 0 if the
6381 * block must be cow'd
6382 */
6383 noinline int can_nocow_extent(struct btrfs_trans_handle *trans,
6384 struct inode *inode, u64 offset, u64 *len,
6385 u64 *orig_start, u64 *orig_block_len,
6386 u64 *ram_bytes)
6387 {
6388 struct btrfs_path *path;
6389 int ret;
6390 struct extent_buffer *leaf;
6391 struct btrfs_root *root = BTRFS_I(inode)->root;
6392 struct btrfs_file_extent_item *fi;
6393 struct btrfs_key key;
6394 u64 disk_bytenr;
6395 u64 backref_offset;
6396 u64 extent_end;
6397 u64 num_bytes;
6398 int slot;
6399 int found_type;
6400 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
6401 path = btrfs_alloc_path();
6402 if (!path)
6403 return -ENOMEM;
6404
6405 ret = btrfs_lookup_file_extent(trans, root, path, btrfs_ino(inode),
6406 offset, 0);
6407 if (ret < 0)
6408 goto out;
6409
6410 slot = path->slots[0];
6411 if (ret == 1) {
6412 if (slot == 0) {
6413 /* can't find the item, must cow */
6414 ret = 0;
6415 goto out;
6416 }
6417 slot--;
6418 }
6419 ret = 0;
6420 leaf = path->nodes[0];
6421 btrfs_item_key_to_cpu(leaf, &key, slot);
6422 if (key.objectid != btrfs_ino(inode) ||
6423 key.type != BTRFS_EXTENT_DATA_KEY) {
6424 /* not our file or wrong item type, must cow */
6425 goto out;
6426 }
6427
6428 if (key.offset > offset) {
6429 /* Wrong offset, must cow */
6430 goto out;
6431 }
6432
6433 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
6434 found_type = btrfs_file_extent_type(leaf, fi);
6435 if (found_type != BTRFS_FILE_EXTENT_REG &&
6436 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
6437 /* not a regular extent, must cow */
6438 goto out;
6439 }
6440
6441 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
6442 goto out;
6443
6444 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
6445 if (disk_bytenr == 0)
6446 goto out;
6447
6448 if (btrfs_file_extent_compression(leaf, fi) ||
6449 btrfs_file_extent_encryption(leaf, fi) ||
6450 btrfs_file_extent_other_encoding(leaf, fi))
6451 goto out;
6452
6453 backref_offset = btrfs_file_extent_offset(leaf, fi);
6454
6455 if (orig_start) {
6456 *orig_start = key.offset - backref_offset;
6457 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
6458 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
6459 }
6460
6461 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
6462
6463 if (btrfs_extent_readonly(root, disk_bytenr))
6464 goto out;
6465
6466 /*
6467 * look for other files referencing this extent, if we
6468 * find any we must cow
6469 */
6470 if (btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
6471 key.offset - backref_offset, disk_bytenr))
6472 goto out;
6473
6474 /*
6475 * adjust disk_bytenr and num_bytes to cover just the bytes
6476 * in this extent we are about to write. If there
6477 * are any csums in that range we have to cow in order
6478 * to keep the csums correct
6479 */
6480 disk_bytenr += backref_offset;
6481 disk_bytenr += offset - key.offset;
6482 num_bytes = min(offset + *len, extent_end) - offset;
6483 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
6484 goto out;
6485 /*
6486 * all of the above have passed, it is safe to overwrite this extent
6487 * without cow
6488 */
6489 *len = num_bytes;
6490 ret = 1;
6491 out:
6492 btrfs_free_path(path);
6493 return ret;
6494 }
6495
6496 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
6497 struct extent_state **cached_state, int writing)
6498 {
6499 struct btrfs_ordered_extent *ordered;
6500 int ret = 0;
6501
6502 while (1) {
6503 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6504 0, cached_state);
6505 /*
6506 * We're concerned with the entire range that we're going to be
6507 * doing DIO to, so we need to make sure theres no ordered
6508 * extents in this range.
6509 */
6510 ordered = btrfs_lookup_ordered_range(inode, lockstart,
6511 lockend - lockstart + 1);
6512
6513 /*
6514 * We need to make sure there are no buffered pages in this
6515 * range either, we could have raced between the invalidate in
6516 * generic_file_direct_write and locking the extent. The
6517 * invalidate needs to happen so that reads after a write do not
6518 * get stale data.
6519 */
6520 if (!ordered && (!writing ||
6521 !test_range_bit(&BTRFS_I(inode)->io_tree,
6522 lockstart, lockend, EXTENT_UPTODATE, 0,
6523 *cached_state)))
6524 break;
6525
6526 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6527 cached_state, GFP_NOFS);
6528
6529 if (ordered) {
6530 btrfs_start_ordered_extent(inode, ordered, 1);
6531 btrfs_put_ordered_extent(ordered);
6532 } else {
6533 /* Screw you mmap */
6534 ret = filemap_write_and_wait_range(inode->i_mapping,
6535 lockstart,
6536 lockend);
6537 if (ret)
6538 break;
6539
6540 /*
6541 * If we found a page that couldn't be invalidated just
6542 * fall back to buffered.
6543 */
6544 ret = invalidate_inode_pages2_range(inode->i_mapping,
6545 lockstart >> PAGE_CACHE_SHIFT,
6546 lockend >> PAGE_CACHE_SHIFT);
6547 if (ret)
6548 break;
6549 }
6550
6551 cond_resched();
6552 }
6553
6554 return ret;
6555 }
6556
6557 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
6558 u64 len, u64 orig_start,
6559 u64 block_start, u64 block_len,
6560 u64 orig_block_len, u64 ram_bytes,
6561 int type)
6562 {
6563 struct extent_map_tree *em_tree;
6564 struct extent_map *em;
6565 struct btrfs_root *root = BTRFS_I(inode)->root;
6566 int ret;
6567
6568 em_tree = &BTRFS_I(inode)->extent_tree;
6569 em = alloc_extent_map();
6570 if (!em)
6571 return ERR_PTR(-ENOMEM);
6572
6573 em->start = start;
6574 em->orig_start = orig_start;
6575 em->mod_start = start;
6576 em->mod_len = len;
6577 em->len = len;
6578 em->block_len = block_len;
6579 em->block_start = block_start;
6580 em->bdev = root->fs_info->fs_devices->latest_bdev;
6581 em->orig_block_len = orig_block_len;
6582 em->ram_bytes = ram_bytes;
6583 em->generation = -1;
6584 set_bit(EXTENT_FLAG_PINNED, &em->flags);
6585 if (type == BTRFS_ORDERED_PREALLOC)
6586 set_bit(EXTENT_FLAG_FILLING, &em->flags);
6587
6588 do {
6589 btrfs_drop_extent_cache(inode, em->start,
6590 em->start + em->len - 1, 0);
6591 write_lock(&em_tree->lock);
6592 ret = add_extent_mapping(em_tree, em, 1);
6593 write_unlock(&em_tree->lock);
6594 } while (ret == -EEXIST);
6595
6596 if (ret) {
6597 free_extent_map(em);
6598 return ERR_PTR(ret);
6599 }
6600
6601 return em;
6602 }
6603
6604
6605 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
6606 struct buffer_head *bh_result, int create)
6607 {
6608 struct extent_map *em;
6609 struct btrfs_root *root = BTRFS_I(inode)->root;
6610 struct extent_state *cached_state = NULL;
6611 u64 start = iblock << inode->i_blkbits;
6612 u64 lockstart, lockend;
6613 u64 len = bh_result->b_size;
6614 struct btrfs_trans_handle *trans;
6615 int unlock_bits = EXTENT_LOCKED;
6616 int ret = 0;
6617
6618 if (create)
6619 unlock_bits |= EXTENT_DELALLOC | EXTENT_DIRTY;
6620 else
6621 len = min_t(u64, len, root->sectorsize);
6622
6623 lockstart = start;
6624 lockend = start + len - 1;
6625
6626 /*
6627 * If this errors out it's because we couldn't invalidate pagecache for
6628 * this range and we need to fallback to buffered.
6629 */
6630 if (lock_extent_direct(inode, lockstart, lockend, &cached_state, create))
6631 return -ENOTBLK;
6632
6633 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
6634 if (IS_ERR(em)) {
6635 ret = PTR_ERR(em);
6636 goto unlock_err;
6637 }
6638
6639 /*
6640 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
6641 * io. INLINE is special, and we could probably kludge it in here, but
6642 * it's still buffered so for safety lets just fall back to the generic
6643 * buffered path.
6644 *
6645 * For COMPRESSED we _have_ to read the entire extent in so we can
6646 * decompress it, so there will be buffering required no matter what we
6647 * do, so go ahead and fallback to buffered.
6648 *
6649 * We return -ENOTBLK because thats what makes DIO go ahead and go back
6650 * to buffered IO. Don't blame me, this is the price we pay for using
6651 * the generic code.
6652 */
6653 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
6654 em->block_start == EXTENT_MAP_INLINE) {
6655 free_extent_map(em);
6656 ret = -ENOTBLK;
6657 goto unlock_err;
6658 }
6659
6660 /* Just a good old fashioned hole, return */
6661 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
6662 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
6663 free_extent_map(em);
6664 goto unlock_err;
6665 }
6666
6667 /*
6668 * We don't allocate a new extent in the following cases
6669 *
6670 * 1) The inode is marked as NODATACOW. In this case we'll just use the
6671 * existing extent.
6672 * 2) The extent is marked as PREALLOC. We're good to go here and can
6673 * just use the extent.
6674 *
6675 */
6676 if (!create) {
6677 len = min(len, em->len - (start - em->start));
6678 lockstart = start + len;
6679 goto unlock;
6680 }
6681
6682 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
6683 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
6684 em->block_start != EXTENT_MAP_HOLE)) {
6685 int type;
6686 int ret;
6687 u64 block_start, orig_start, orig_block_len, ram_bytes;
6688
6689 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6690 type = BTRFS_ORDERED_PREALLOC;
6691 else
6692 type = BTRFS_ORDERED_NOCOW;
6693 len = min(len, em->len - (start - em->start));
6694 block_start = em->block_start + (start - em->start);
6695
6696 /*
6697 * we're not going to log anything, but we do need
6698 * to make sure the current transaction stays open
6699 * while we look for nocow cross refs
6700 */
6701 trans = btrfs_join_transaction(root);
6702 if (IS_ERR(trans))
6703 goto must_cow;
6704
6705 if (can_nocow_extent(trans, inode, start, &len, &orig_start,
6706 &orig_block_len, &ram_bytes) == 1) {
6707 if (type == BTRFS_ORDERED_PREALLOC) {
6708 free_extent_map(em);
6709 em = create_pinned_em(inode, start, len,
6710 orig_start,
6711 block_start, len,
6712 orig_block_len,
6713 ram_bytes, type);
6714 if (IS_ERR(em)) {
6715 btrfs_end_transaction(trans, root);
6716 goto unlock_err;
6717 }
6718 }
6719
6720 ret = btrfs_add_ordered_extent_dio(inode, start,
6721 block_start, len, len, type);
6722 btrfs_end_transaction(trans, root);
6723 if (ret) {
6724 free_extent_map(em);
6725 goto unlock_err;
6726 }
6727 goto unlock;
6728 }
6729 btrfs_end_transaction(trans, root);
6730 }
6731 must_cow:
6732 /*
6733 * this will cow the extent, reset the len in case we changed
6734 * it above
6735 */
6736 len = bh_result->b_size;
6737 free_extent_map(em);
6738 em = btrfs_new_extent_direct(inode, start, len);
6739 if (IS_ERR(em)) {
6740 ret = PTR_ERR(em);
6741 goto unlock_err;
6742 }
6743 len = min(len, em->len - (start - em->start));
6744 unlock:
6745 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
6746 inode->i_blkbits;
6747 bh_result->b_size = len;
6748 bh_result->b_bdev = em->bdev;
6749 set_buffer_mapped(bh_result);
6750 if (create) {
6751 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6752 set_buffer_new(bh_result);
6753
6754 /*
6755 * Need to update the i_size under the extent lock so buffered
6756 * readers will get the updated i_size when we unlock.
6757 */
6758 if (start + len > i_size_read(inode))
6759 i_size_write(inode, start + len);
6760
6761 spin_lock(&BTRFS_I(inode)->lock);
6762 BTRFS_I(inode)->outstanding_extents++;
6763 spin_unlock(&BTRFS_I(inode)->lock);
6764
6765 ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
6766 lockstart + len - 1, EXTENT_DELALLOC, NULL,
6767 &cached_state, GFP_NOFS);
6768 BUG_ON(ret);
6769 }
6770
6771 /*
6772 * In the case of write we need to clear and unlock the entire range,
6773 * in the case of read we need to unlock only the end area that we
6774 * aren't using if there is any left over space.
6775 */
6776 if (lockstart < lockend) {
6777 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
6778 lockend, unlock_bits, 1, 0,
6779 &cached_state, GFP_NOFS);
6780 } else {
6781 free_extent_state(cached_state);
6782 }
6783
6784 free_extent_map(em);
6785
6786 return 0;
6787
6788 unlock_err:
6789 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6790 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
6791 return ret;
6792 }
6793
6794 struct btrfs_dio_private {
6795 struct inode *inode;
6796 u64 logical_offset;
6797 u64 disk_bytenr;
6798 u64 bytes;
6799 void *private;
6800
6801 /* number of bios pending for this dio */
6802 atomic_t pending_bios;
6803
6804 /* IO errors */
6805 int errors;
6806
6807 /* orig_bio is our btrfs_io_bio */
6808 struct bio *orig_bio;
6809
6810 /* dio_bio came from fs/direct-io.c */
6811 struct bio *dio_bio;
6812 };
6813
6814 static void btrfs_endio_direct_read(struct bio *bio, int err)
6815 {
6816 struct btrfs_dio_private *dip = bio->bi_private;
6817 struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
6818 struct bio_vec *bvec = bio->bi_io_vec;
6819 struct inode *inode = dip->inode;
6820 struct btrfs_root *root = BTRFS_I(inode)->root;
6821 struct bio *dio_bio;
6822 u64 start;
6823
6824 start = dip->logical_offset;
6825 do {
6826 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
6827 struct page *page = bvec->bv_page;
6828 char *kaddr;
6829 u32 csum = ~(u32)0;
6830 u64 private = ~(u32)0;
6831 unsigned long flags;
6832
6833 if (get_state_private(&BTRFS_I(inode)->io_tree,
6834 start, &private))
6835 goto failed;
6836 local_irq_save(flags);
6837 kaddr = kmap_atomic(page);
6838 csum = btrfs_csum_data(kaddr + bvec->bv_offset,
6839 csum, bvec->bv_len);
6840 btrfs_csum_final(csum, (char *)&csum);
6841 kunmap_atomic(kaddr);
6842 local_irq_restore(flags);
6843
6844 flush_dcache_page(bvec->bv_page);
6845 if (csum != private) {
6846 failed:
6847 btrfs_err(root->fs_info, "csum failed ino %llu off %llu csum %u private %u",
6848 (unsigned long long)btrfs_ino(inode),
6849 (unsigned long long)start,
6850 csum, (unsigned)private);
6851 err = -EIO;
6852 }
6853 }
6854
6855 start += bvec->bv_len;
6856 bvec++;
6857 } while (bvec <= bvec_end);
6858
6859 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
6860 dip->logical_offset + dip->bytes - 1);
6861 dio_bio = dip->dio_bio;
6862
6863 kfree(dip);
6864
6865 /* If we had a csum failure make sure to clear the uptodate flag */
6866 if (err)
6867 clear_bit(BIO_UPTODATE, &dio_bio->bi_flags);
6868 dio_end_io(dio_bio, err);
6869 bio_put(bio);
6870 }
6871
6872 static void btrfs_endio_direct_write(struct bio *bio, int err)
6873 {
6874 struct btrfs_dio_private *dip = bio->bi_private;
6875 struct inode *inode = dip->inode;
6876 struct btrfs_root *root = BTRFS_I(inode)->root;
6877 struct btrfs_ordered_extent *ordered = NULL;
6878 u64 ordered_offset = dip->logical_offset;
6879 u64 ordered_bytes = dip->bytes;
6880 struct bio *dio_bio;
6881 int ret;
6882
6883 if (err)
6884 goto out_done;
6885 again:
6886 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
6887 &ordered_offset,
6888 ordered_bytes, !err);
6889 if (!ret)
6890 goto out_test;
6891
6892 ordered->work.func = finish_ordered_fn;
6893 ordered->work.flags = 0;
6894 btrfs_queue_worker(&root->fs_info->endio_write_workers,
6895 &ordered->work);
6896 out_test:
6897 /*
6898 * our bio might span multiple ordered extents. If we haven't
6899 * completed the accounting for the whole dio, go back and try again
6900 */
6901 if (ordered_offset < dip->logical_offset + dip->bytes) {
6902 ordered_bytes = dip->logical_offset + dip->bytes -
6903 ordered_offset;
6904 ordered = NULL;
6905 goto again;
6906 }
6907 out_done:
6908 dio_bio = dip->dio_bio;
6909
6910 kfree(dip);
6911
6912 /* If we had an error make sure to clear the uptodate flag */
6913 if (err)
6914 clear_bit(BIO_UPTODATE, &dio_bio->bi_flags);
6915 dio_end_io(dio_bio, err);
6916 bio_put(bio);
6917 }
6918
6919 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
6920 struct bio *bio, int mirror_num,
6921 unsigned long bio_flags, u64 offset)
6922 {
6923 int ret;
6924 struct btrfs_root *root = BTRFS_I(inode)->root;
6925 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
6926 BUG_ON(ret); /* -ENOMEM */
6927 return 0;
6928 }
6929
6930 static void btrfs_end_dio_bio(struct bio *bio, int err)
6931 {
6932 struct btrfs_dio_private *dip = bio->bi_private;
6933
6934 if (err) {
6935 printk(KERN_ERR "btrfs direct IO failed ino %llu rw %lu "
6936 "sector %#Lx len %u err no %d\n",
6937 (unsigned long long)btrfs_ino(dip->inode), bio->bi_rw,
6938 (unsigned long long)bio->bi_sector, bio->bi_size, err);
6939 dip->errors = 1;
6940
6941 /*
6942 * before atomic variable goto zero, we must make sure
6943 * dip->errors is perceived to be set.
6944 */
6945 smp_mb__before_atomic_dec();
6946 }
6947
6948 /* if there are more bios still pending for this dio, just exit */
6949 if (!atomic_dec_and_test(&dip->pending_bios))
6950 goto out;
6951
6952 if (dip->errors) {
6953 bio_io_error(dip->orig_bio);
6954 } else {
6955 set_bit(BIO_UPTODATE, &dip->dio_bio->bi_flags);
6956 bio_endio(dip->orig_bio, 0);
6957 }
6958 out:
6959 bio_put(bio);
6960 }
6961
6962 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
6963 u64 first_sector, gfp_t gfp_flags)
6964 {
6965 int nr_vecs = bio_get_nr_vecs(bdev);
6966 return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags);
6967 }
6968
6969 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
6970 int rw, u64 file_offset, int skip_sum,
6971 int async_submit)
6972 {
6973 int write = rw & REQ_WRITE;
6974 struct btrfs_root *root = BTRFS_I(inode)->root;
6975 int ret;
6976
6977 if (async_submit)
6978 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
6979
6980 bio_get(bio);
6981
6982 if (!write) {
6983 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
6984 if (ret)
6985 goto err;
6986 }
6987
6988 if (skip_sum)
6989 goto map;
6990
6991 if (write && async_submit) {
6992 ret = btrfs_wq_submit_bio(root->fs_info,
6993 inode, rw, bio, 0, 0,
6994 file_offset,
6995 __btrfs_submit_bio_start_direct_io,
6996 __btrfs_submit_bio_done);
6997 goto err;
6998 } else if (write) {
6999 /*
7000 * If we aren't doing async submit, calculate the csum of the
7001 * bio now.
7002 */
7003 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
7004 if (ret)
7005 goto err;
7006 } else if (!skip_sum) {
7007 ret = btrfs_lookup_bio_sums_dio(root, inode, bio, file_offset);
7008 if (ret)
7009 goto err;
7010 }
7011
7012 map:
7013 ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
7014 err:
7015 bio_put(bio);
7016 return ret;
7017 }
7018
7019 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
7020 int skip_sum)
7021 {
7022 struct inode *inode = dip->inode;
7023 struct btrfs_root *root = BTRFS_I(inode)->root;
7024 struct bio *bio;
7025 struct bio *orig_bio = dip->orig_bio;
7026 struct bio_vec *bvec = orig_bio->bi_io_vec;
7027 u64 start_sector = orig_bio->bi_sector;
7028 u64 file_offset = dip->logical_offset;
7029 u64 submit_len = 0;
7030 u64 map_length;
7031 int nr_pages = 0;
7032 int ret = 0;
7033 int async_submit = 0;
7034
7035 map_length = orig_bio->bi_size;
7036 ret = btrfs_map_block(root->fs_info, rw, start_sector << 9,
7037 &map_length, NULL, 0);
7038 if (ret) {
7039 bio_put(orig_bio);
7040 return -EIO;
7041 }
7042 if (map_length >= orig_bio->bi_size) {
7043 bio = orig_bio;
7044 goto submit;
7045 }
7046
7047 /* async crcs make it difficult to collect full stripe writes. */
7048 if (btrfs_get_alloc_profile(root, 1) &
7049 (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6))
7050 async_submit = 0;
7051 else
7052 async_submit = 1;
7053
7054 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
7055 if (!bio)
7056 return -ENOMEM;
7057 bio->bi_private = dip;
7058 bio->bi_end_io = btrfs_end_dio_bio;
7059 atomic_inc(&dip->pending_bios);
7060
7061 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
7062 if (unlikely(map_length < submit_len + bvec->bv_len ||
7063 bio_add_page(bio, bvec->bv_page, bvec->bv_len,
7064 bvec->bv_offset) < bvec->bv_len)) {
7065 /*
7066 * inc the count before we submit the bio so
7067 * we know the end IO handler won't happen before
7068 * we inc the count. Otherwise, the dip might get freed
7069 * before we're done setting it up
7070 */
7071 atomic_inc(&dip->pending_bios);
7072 ret = __btrfs_submit_dio_bio(bio, inode, rw,
7073 file_offset, skip_sum,
7074 async_submit);
7075 if (ret) {
7076 bio_put(bio);
7077 atomic_dec(&dip->pending_bios);
7078 goto out_err;
7079 }
7080
7081 start_sector += submit_len >> 9;
7082 file_offset += submit_len;
7083
7084 submit_len = 0;
7085 nr_pages = 0;
7086
7087 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
7088 start_sector, GFP_NOFS);
7089 if (!bio)
7090 goto out_err;
7091 bio->bi_private = dip;
7092 bio->bi_end_io = btrfs_end_dio_bio;
7093
7094 map_length = orig_bio->bi_size;
7095 ret = btrfs_map_block(root->fs_info, rw,
7096 start_sector << 9,
7097 &map_length, NULL, 0);
7098 if (ret) {
7099 bio_put(bio);
7100 goto out_err;
7101 }
7102 } else {
7103 submit_len += bvec->bv_len;
7104 nr_pages ++;
7105 bvec++;
7106 }
7107 }
7108
7109 submit:
7110 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
7111 async_submit);
7112 if (!ret)
7113 return 0;
7114
7115 bio_put(bio);
7116 out_err:
7117 dip->errors = 1;
7118 /*
7119 * before atomic variable goto zero, we must
7120 * make sure dip->errors is perceived to be set.
7121 */
7122 smp_mb__before_atomic_dec();
7123 if (atomic_dec_and_test(&dip->pending_bios))
7124 bio_io_error(dip->orig_bio);
7125
7126 /* bio_end_io() will handle error, so we needn't return it */
7127 return 0;
7128 }
7129
7130 static void btrfs_submit_direct(int rw, struct bio *dio_bio,
7131 struct inode *inode, loff_t file_offset)
7132 {
7133 struct btrfs_root *root = BTRFS_I(inode)->root;
7134 struct btrfs_dio_private *dip;
7135 struct bio *io_bio;
7136 int skip_sum;
7137 int write = rw & REQ_WRITE;
7138 int ret = 0;
7139
7140 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
7141
7142 io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS);
7143
7144 if (!io_bio) {
7145 ret = -ENOMEM;
7146 goto free_ordered;
7147 }
7148
7149 dip = kmalloc(sizeof(*dip), GFP_NOFS);
7150 if (!dip) {
7151 ret = -ENOMEM;
7152 goto free_io_bio;
7153 }
7154
7155 dip->private = dio_bio->bi_private;
7156 dip->inode = inode;
7157 dip->logical_offset = file_offset;
7158 dip->bytes = dio_bio->bi_size;
7159 dip->disk_bytenr = (u64)dio_bio->bi_sector << 9;
7160 io_bio->bi_private = dip;
7161 dip->errors = 0;
7162 dip->orig_bio = io_bio;
7163 dip->dio_bio = dio_bio;
7164 atomic_set(&dip->pending_bios, 0);
7165
7166 if (write)
7167 io_bio->bi_end_io = btrfs_endio_direct_write;
7168 else
7169 io_bio->bi_end_io = btrfs_endio_direct_read;
7170
7171 ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
7172 if (!ret)
7173 return;
7174
7175 free_io_bio:
7176 bio_put(io_bio);
7177
7178 free_ordered:
7179 /*
7180 * If this is a write, we need to clean up the reserved space and kill
7181 * the ordered extent.
7182 */
7183 if (write) {
7184 struct btrfs_ordered_extent *ordered;
7185 ordered = btrfs_lookup_ordered_extent(inode, file_offset);
7186 if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) &&
7187 !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
7188 btrfs_free_reserved_extent(root, ordered->start,
7189 ordered->disk_len);
7190 btrfs_put_ordered_extent(ordered);
7191 btrfs_put_ordered_extent(ordered);
7192 }
7193 bio_endio(dio_bio, ret);
7194 }
7195
7196 static ssize_t check_direct_IO(struct btrfs_root *root, int rw, struct kiocb *iocb,
7197 const struct iovec *iov, loff_t offset,
7198 unsigned long nr_segs)
7199 {
7200 int seg;
7201 int i;
7202 size_t size;
7203 unsigned long addr;
7204 unsigned blocksize_mask = root->sectorsize - 1;
7205 ssize_t retval = -EINVAL;
7206 loff_t end = offset;
7207
7208 if (offset & blocksize_mask)
7209 goto out;
7210
7211 /* Check the memory alignment. Blocks cannot straddle pages */
7212 for (seg = 0; seg < nr_segs; seg++) {
7213 addr = (unsigned long)iov[seg].iov_base;
7214 size = iov[seg].iov_len;
7215 end += size;
7216 if ((addr & blocksize_mask) || (size & blocksize_mask))
7217 goto out;
7218
7219 /* If this is a write we don't need to check anymore */
7220 if (rw & WRITE)
7221 continue;
7222
7223 /*
7224 * Check to make sure we don't have duplicate iov_base's in this
7225 * iovec, if so return EINVAL, otherwise we'll get csum errors
7226 * when reading back.
7227 */
7228 for (i = seg + 1; i < nr_segs; i++) {
7229 if (iov[seg].iov_base == iov[i].iov_base)
7230 goto out;
7231 }
7232 }
7233 retval = 0;
7234 out:
7235 return retval;
7236 }
7237
7238 static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
7239 const struct iovec *iov, loff_t offset,
7240 unsigned long nr_segs)
7241 {
7242 struct file *file = iocb->ki_filp;
7243 struct inode *inode = file->f_mapping->host;
7244 size_t count = 0;
7245 int flags = 0;
7246 bool wakeup = true;
7247 bool relock = false;
7248 ssize_t ret;
7249
7250 if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iov,
7251 offset, nr_segs))
7252 return 0;
7253
7254 atomic_inc(&inode->i_dio_count);
7255 smp_mb__after_atomic_inc();
7256
7257 /*
7258 * The generic stuff only does filemap_write_and_wait_range, which isn't
7259 * enough if we've written compressed pages to this area, so we need to
7260 * call btrfs_wait_ordered_range to make absolutely sure that any
7261 * outstanding dirty pages are on disk.
7262 */
7263 count = iov_length(iov, nr_segs);
7264 btrfs_wait_ordered_range(inode, offset, count);
7265
7266 if (rw & WRITE) {
7267 /*
7268 * If the write DIO is beyond the EOF, we need update
7269 * the isize, but it is protected by i_mutex. So we can
7270 * not unlock the i_mutex at this case.
7271 */
7272 if (offset + count <= inode->i_size) {
7273 mutex_unlock(&inode->i_mutex);
7274 relock = true;
7275 }
7276 ret = btrfs_delalloc_reserve_space(inode, count);
7277 if (ret)
7278 goto out;
7279 } else if (unlikely(test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
7280 &BTRFS_I(inode)->runtime_flags))) {
7281 inode_dio_done(inode);
7282 flags = DIO_LOCKING | DIO_SKIP_HOLES;
7283 wakeup = false;
7284 }
7285
7286 ret = __blockdev_direct_IO(rw, iocb, inode,
7287 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
7288 iov, offset, nr_segs, btrfs_get_blocks_direct, NULL,
7289 btrfs_submit_direct, flags);
7290 if (rw & WRITE) {
7291 if (ret < 0 && ret != -EIOCBQUEUED)
7292 btrfs_delalloc_release_space(inode, count);
7293 else if (ret >= 0 && (size_t)ret < count)
7294 btrfs_delalloc_release_space(inode,
7295 count - (size_t)ret);
7296 else
7297 btrfs_delalloc_release_metadata(inode, 0);
7298 }
7299 out:
7300 if (wakeup)
7301 inode_dio_done(inode);
7302 if (relock)
7303 mutex_lock(&inode->i_mutex);
7304
7305 return ret;
7306 }
7307
7308 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
7309
7310 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
7311 __u64 start, __u64 len)
7312 {
7313 int ret;
7314
7315 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
7316 if (ret)
7317 return ret;
7318
7319 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
7320 }
7321
7322 int btrfs_readpage(struct file *file, struct page *page)
7323 {
7324 struct extent_io_tree *tree;
7325 tree = &BTRFS_I(page->mapping->host)->io_tree;
7326 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
7327 }
7328
7329 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
7330 {
7331 struct extent_io_tree *tree;
7332
7333
7334 if (current->flags & PF_MEMALLOC) {
7335 redirty_page_for_writepage(wbc, page);
7336 unlock_page(page);
7337 return 0;
7338 }
7339 tree = &BTRFS_I(page->mapping->host)->io_tree;
7340 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
7341 }
7342
7343 static int btrfs_writepages(struct address_space *mapping,
7344 struct writeback_control *wbc)
7345 {
7346 struct extent_io_tree *tree;
7347
7348 tree = &BTRFS_I(mapping->host)->io_tree;
7349 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
7350 }
7351
7352 static int
7353 btrfs_readpages(struct file *file, struct address_space *mapping,
7354 struct list_head *pages, unsigned nr_pages)
7355 {
7356 struct extent_io_tree *tree;
7357 tree = &BTRFS_I(mapping->host)->io_tree;
7358 return extent_readpages(tree, mapping, pages, nr_pages,
7359 btrfs_get_extent);
7360 }
7361 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
7362 {
7363 struct extent_io_tree *tree;
7364 struct extent_map_tree *map;
7365 int ret;
7366
7367 tree = &BTRFS_I(page->mapping->host)->io_tree;
7368 map = &BTRFS_I(page->mapping->host)->extent_tree;
7369 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
7370 if (ret == 1) {
7371 ClearPagePrivate(page);
7372 set_page_private(page, 0);
7373 page_cache_release(page);
7374 }
7375 return ret;
7376 }
7377
7378 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
7379 {
7380 if (PageWriteback(page) || PageDirty(page))
7381 return 0;
7382 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
7383 }
7384
7385 static void btrfs_invalidatepage(struct page *page, unsigned int offset,
7386 unsigned int length)
7387 {
7388 struct inode *inode = page->mapping->host;
7389 struct extent_io_tree *tree;
7390 struct btrfs_ordered_extent *ordered;
7391 struct extent_state *cached_state = NULL;
7392 u64 page_start = page_offset(page);
7393 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
7394
7395 /*
7396 * we have the page locked, so new writeback can't start,
7397 * and the dirty bit won't be cleared while we are here.
7398 *
7399 * Wait for IO on this page so that we can safely clear
7400 * the PagePrivate2 bit and do ordered accounting
7401 */
7402 wait_on_page_writeback(page);
7403
7404 tree = &BTRFS_I(inode)->io_tree;
7405 if (offset) {
7406 btrfs_releasepage(page, GFP_NOFS);
7407 return;
7408 }
7409 lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
7410 ordered = btrfs_lookup_ordered_extent(inode, page_offset(page));
7411 if (ordered) {
7412 /*
7413 * IO on this page will never be started, so we need
7414 * to account for any ordered extents now
7415 */
7416 clear_extent_bit(tree, page_start, page_end,
7417 EXTENT_DIRTY | EXTENT_DELALLOC |
7418 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
7419 EXTENT_DEFRAG, 1, 0, &cached_state, GFP_NOFS);
7420 /*
7421 * whoever cleared the private bit is responsible
7422 * for the finish_ordered_io
7423 */
7424 if (TestClearPagePrivate2(page) &&
7425 btrfs_dec_test_ordered_pending(inode, &ordered, page_start,
7426 PAGE_CACHE_SIZE, 1)) {
7427 btrfs_finish_ordered_io(ordered);
7428 }
7429 btrfs_put_ordered_extent(ordered);
7430 cached_state = NULL;
7431 lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
7432 }
7433 clear_extent_bit(tree, page_start, page_end,
7434 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
7435 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1,
7436 &cached_state, GFP_NOFS);
7437 __btrfs_releasepage(page, GFP_NOFS);
7438
7439 ClearPageChecked(page);
7440 if (PagePrivate(page)) {
7441 ClearPagePrivate(page);
7442 set_page_private(page, 0);
7443 page_cache_release(page);
7444 }
7445 }
7446
7447 /*
7448 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
7449 * called from a page fault handler when a page is first dirtied. Hence we must
7450 * be careful to check for EOF conditions here. We set the page up correctly
7451 * for a written page which means we get ENOSPC checking when writing into
7452 * holes and correct delalloc and unwritten extent mapping on filesystems that
7453 * support these features.
7454 *
7455 * We are not allowed to take the i_mutex here so we have to play games to
7456 * protect against truncate races as the page could now be beyond EOF. Because
7457 * vmtruncate() writes the inode size before removing pages, once we have the
7458 * page lock we can determine safely if the page is beyond EOF. If it is not
7459 * beyond EOF, then the page is guaranteed safe against truncation until we
7460 * unlock the page.
7461 */
7462 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
7463 {
7464 struct page *page = vmf->page;
7465 struct inode *inode = file_inode(vma->vm_file);
7466 struct btrfs_root *root = BTRFS_I(inode)->root;
7467 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7468 struct btrfs_ordered_extent *ordered;
7469 struct extent_state *cached_state = NULL;
7470 char *kaddr;
7471 unsigned long zero_start;
7472 loff_t size;
7473 int ret;
7474 int reserved = 0;
7475 u64 page_start;
7476 u64 page_end;
7477
7478 sb_start_pagefault(inode->i_sb);
7479 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
7480 if (!ret) {
7481 ret = file_update_time(vma->vm_file);
7482 reserved = 1;
7483 }
7484 if (ret) {
7485 if (ret == -ENOMEM)
7486 ret = VM_FAULT_OOM;
7487 else /* -ENOSPC, -EIO, etc */
7488 ret = VM_FAULT_SIGBUS;
7489 if (reserved)
7490 goto out;
7491 goto out_noreserve;
7492 }
7493
7494 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
7495 again:
7496 lock_page(page);
7497 size = i_size_read(inode);
7498 page_start = page_offset(page);
7499 page_end = page_start + PAGE_CACHE_SIZE - 1;
7500
7501 if ((page->mapping != inode->i_mapping) ||
7502 (page_start >= size)) {
7503 /* page got truncated out from underneath us */
7504 goto out_unlock;
7505 }
7506 wait_on_page_writeback(page);
7507
7508 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
7509 set_page_extent_mapped(page);
7510
7511 /*
7512 * we can't set the delalloc bits if there are pending ordered
7513 * extents. Drop our locks and wait for them to finish
7514 */
7515 ordered = btrfs_lookup_ordered_extent(inode, page_start);
7516 if (ordered) {
7517 unlock_extent_cached(io_tree, page_start, page_end,
7518 &cached_state, GFP_NOFS);
7519 unlock_page(page);
7520 btrfs_start_ordered_extent(inode, ordered, 1);
7521 btrfs_put_ordered_extent(ordered);
7522 goto again;
7523 }
7524
7525 /*
7526 * XXX - page_mkwrite gets called every time the page is dirtied, even
7527 * if it was already dirty, so for space accounting reasons we need to
7528 * clear any delalloc bits for the range we are fixing to save. There
7529 * is probably a better way to do this, but for now keep consistent with
7530 * prepare_pages in the normal write path.
7531 */
7532 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
7533 EXTENT_DIRTY | EXTENT_DELALLOC |
7534 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
7535 0, 0, &cached_state, GFP_NOFS);
7536
7537 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
7538 &cached_state);
7539 if (ret) {
7540 unlock_extent_cached(io_tree, page_start, page_end,
7541 &cached_state, GFP_NOFS);
7542 ret = VM_FAULT_SIGBUS;
7543 goto out_unlock;
7544 }
7545 ret = 0;
7546
7547 /* page is wholly or partially inside EOF */
7548 if (page_start + PAGE_CACHE_SIZE > size)
7549 zero_start = size & ~PAGE_CACHE_MASK;
7550 else
7551 zero_start = PAGE_CACHE_SIZE;
7552
7553 if (zero_start != PAGE_CACHE_SIZE) {
7554 kaddr = kmap(page);
7555 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
7556 flush_dcache_page(page);
7557 kunmap(page);
7558 }
7559 ClearPageChecked(page);
7560 set_page_dirty(page);
7561 SetPageUptodate(page);
7562
7563 BTRFS_I(inode)->last_trans = root->fs_info->generation;
7564 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
7565 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
7566
7567 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
7568
7569 out_unlock:
7570 if (!ret) {
7571 sb_end_pagefault(inode->i_sb);
7572 return VM_FAULT_LOCKED;
7573 }
7574 unlock_page(page);
7575 out:
7576 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
7577 out_noreserve:
7578 sb_end_pagefault(inode->i_sb);
7579 return ret;
7580 }
7581
7582 static int btrfs_truncate(struct inode *inode)
7583 {
7584 struct btrfs_root *root = BTRFS_I(inode)->root;
7585 struct btrfs_block_rsv *rsv;
7586 int ret = 0;
7587 int err = 0;
7588 struct btrfs_trans_handle *trans;
7589 u64 mask = root->sectorsize - 1;
7590 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
7591
7592 btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
7593 btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
7594
7595 /*
7596 * Yes ladies and gentelment, this is indeed ugly. The fact is we have
7597 * 3 things going on here
7598 *
7599 * 1) We need to reserve space for our orphan item and the space to
7600 * delete our orphan item. Lord knows we don't want to have a dangling
7601 * orphan item because we didn't reserve space to remove it.
7602 *
7603 * 2) We need to reserve space to update our inode.
7604 *
7605 * 3) We need to have something to cache all the space that is going to
7606 * be free'd up by the truncate operation, but also have some slack
7607 * space reserved in case it uses space during the truncate (thank you
7608 * very much snapshotting).
7609 *
7610 * And we need these to all be seperate. The fact is we can use alot of
7611 * space doing the truncate, and we have no earthly idea how much space
7612 * we will use, so we need the truncate reservation to be seperate so it
7613 * doesn't end up using space reserved for updating the inode or
7614 * removing the orphan item. We also need to be able to stop the
7615 * transaction and start a new one, which means we need to be able to
7616 * update the inode several times, and we have no idea of knowing how
7617 * many times that will be, so we can't just reserve 1 item for the
7618 * entirety of the opration, so that has to be done seperately as well.
7619 * Then there is the orphan item, which does indeed need to be held on
7620 * to for the whole operation, and we need nobody to touch this reserved
7621 * space except the orphan code.
7622 *
7623 * So that leaves us with
7624 *
7625 * 1) root->orphan_block_rsv - for the orphan deletion.
7626 * 2) rsv - for the truncate reservation, which we will steal from the
7627 * transaction reservation.
7628 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
7629 * updating the inode.
7630 */
7631 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
7632 if (!rsv)
7633 return -ENOMEM;
7634 rsv->size = min_size;
7635 rsv->failfast = 1;
7636
7637 /*
7638 * 1 for the truncate slack space
7639 * 1 for updating the inode.
7640 */
7641 trans = btrfs_start_transaction(root, 2);
7642 if (IS_ERR(trans)) {
7643 err = PTR_ERR(trans);
7644 goto out;
7645 }
7646
7647 /* Migrate the slack space for the truncate to our reserve */
7648 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
7649 min_size);
7650 BUG_ON(ret);
7651
7652 /*
7653 * setattr is responsible for setting the ordered_data_close flag,
7654 * but that is only tested during the last file release. That
7655 * could happen well after the next commit, leaving a great big
7656 * window where new writes may get lost if someone chooses to write
7657 * to this file after truncating to zero
7658 *
7659 * The inode doesn't have any dirty data here, and so if we commit
7660 * this is a noop. If someone immediately starts writing to the inode
7661 * it is very likely we'll catch some of their writes in this
7662 * transaction, and the commit will find this file on the ordered
7663 * data list with good things to send down.
7664 *
7665 * This is a best effort solution, there is still a window where
7666 * using truncate to replace the contents of the file will
7667 * end up with a zero length file after a crash.
7668 */
7669 if (inode->i_size == 0 && test_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
7670 &BTRFS_I(inode)->runtime_flags))
7671 btrfs_add_ordered_operation(trans, root, inode);
7672
7673 /*
7674 * So if we truncate and then write and fsync we normally would just
7675 * write the extents that changed, which is a problem if we need to
7676 * first truncate that entire inode. So set this flag so we write out
7677 * all of the extents in the inode to the sync log so we're completely
7678 * safe.
7679 */
7680 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
7681 trans->block_rsv = rsv;
7682
7683 while (1) {
7684 ret = btrfs_truncate_inode_items(trans, root, inode,
7685 inode->i_size,
7686 BTRFS_EXTENT_DATA_KEY);
7687 if (ret != -ENOSPC) {
7688 err = ret;
7689 break;
7690 }
7691
7692 trans->block_rsv = &root->fs_info->trans_block_rsv;
7693 ret = btrfs_update_inode(trans, root, inode);
7694 if (ret) {
7695 err = ret;
7696 break;
7697 }
7698
7699 btrfs_end_transaction(trans, root);
7700 btrfs_btree_balance_dirty(root);
7701
7702 trans = btrfs_start_transaction(root, 2);
7703 if (IS_ERR(trans)) {
7704 ret = err = PTR_ERR(trans);
7705 trans = NULL;
7706 break;
7707 }
7708
7709 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
7710 rsv, min_size);
7711 BUG_ON(ret); /* shouldn't happen */
7712 trans->block_rsv = rsv;
7713 }
7714
7715 if (ret == 0 && inode->i_nlink > 0) {
7716 trans->block_rsv = root->orphan_block_rsv;
7717 ret = btrfs_orphan_del(trans, inode);
7718 if (ret)
7719 err = ret;
7720 }
7721
7722 if (trans) {
7723 trans->block_rsv = &root->fs_info->trans_block_rsv;
7724 ret = btrfs_update_inode(trans, root, inode);
7725 if (ret && !err)
7726 err = ret;
7727
7728 ret = btrfs_end_transaction(trans, root);
7729 btrfs_btree_balance_dirty(root);
7730 }
7731
7732 out:
7733 btrfs_free_block_rsv(root, rsv);
7734
7735 if (ret && !err)
7736 err = ret;
7737
7738 return err;
7739 }
7740
7741 /*
7742 * create a new subvolume directory/inode (helper for the ioctl).
7743 */
7744 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
7745 struct btrfs_root *new_root, u64 new_dirid)
7746 {
7747 struct inode *inode;
7748 int err;
7749 u64 index = 0;
7750
7751 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
7752 new_dirid, new_dirid,
7753 S_IFDIR | (~current_umask() & S_IRWXUGO),
7754 &index);
7755 if (IS_ERR(inode))
7756 return PTR_ERR(inode);
7757 inode->i_op = &btrfs_dir_inode_operations;
7758 inode->i_fop = &btrfs_dir_file_operations;
7759
7760 set_nlink(inode, 1);
7761 btrfs_i_size_write(inode, 0);
7762
7763 err = btrfs_update_inode(trans, new_root, inode);
7764
7765 iput(inode);
7766 return err;
7767 }
7768
7769 struct inode *btrfs_alloc_inode(struct super_block *sb)
7770 {
7771 struct btrfs_inode *ei;
7772 struct inode *inode;
7773
7774 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
7775 if (!ei)
7776 return NULL;
7777
7778 ei->root = NULL;
7779 ei->generation = 0;
7780 ei->last_trans = 0;
7781 ei->last_sub_trans = 0;
7782 ei->logged_trans = 0;
7783 ei->delalloc_bytes = 0;
7784 ei->disk_i_size = 0;
7785 ei->flags = 0;
7786 ei->csum_bytes = 0;
7787 ei->index_cnt = (u64)-1;
7788 ei->last_unlink_trans = 0;
7789 ei->last_log_commit = 0;
7790
7791 spin_lock_init(&ei->lock);
7792 ei->outstanding_extents = 0;
7793 ei->reserved_extents = 0;
7794
7795 ei->runtime_flags = 0;
7796 ei->force_compress = BTRFS_COMPRESS_NONE;
7797
7798 ei->delayed_node = NULL;
7799
7800 inode = &ei->vfs_inode;
7801 extent_map_tree_init(&ei->extent_tree);
7802 extent_io_tree_init(&ei->io_tree, &inode->i_data);
7803 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
7804 ei->io_tree.track_uptodate = 1;
7805 ei->io_failure_tree.track_uptodate = 1;
7806 atomic_set(&ei->sync_writers, 0);
7807 mutex_init(&ei->log_mutex);
7808 mutex_init(&ei->delalloc_mutex);
7809 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
7810 INIT_LIST_HEAD(&ei->delalloc_inodes);
7811 INIT_LIST_HEAD(&ei->ordered_operations);
7812 RB_CLEAR_NODE(&ei->rb_node);
7813
7814 return inode;
7815 }
7816
7817 static void btrfs_i_callback(struct rcu_head *head)
7818 {
7819 struct inode *inode = container_of(head, struct inode, i_rcu);
7820 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
7821 }
7822
7823 void btrfs_destroy_inode(struct inode *inode)
7824 {
7825 struct btrfs_ordered_extent *ordered;
7826 struct btrfs_root *root = BTRFS_I(inode)->root;
7827
7828 WARN_ON(!hlist_empty(&inode->i_dentry));
7829 WARN_ON(inode->i_data.nrpages);
7830 WARN_ON(BTRFS_I(inode)->outstanding_extents);
7831 WARN_ON(BTRFS_I(inode)->reserved_extents);
7832 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
7833 WARN_ON(BTRFS_I(inode)->csum_bytes);
7834
7835 /*
7836 * This can happen where we create an inode, but somebody else also
7837 * created the same inode and we need to destroy the one we already
7838 * created.
7839 */
7840 if (!root)
7841 goto free;
7842
7843 /*
7844 * Make sure we're properly removed from the ordered operation
7845 * lists.
7846 */
7847 smp_mb();
7848 if (!list_empty(&BTRFS_I(inode)->ordered_operations)) {
7849 spin_lock(&root->fs_info->ordered_root_lock);
7850 list_del_init(&BTRFS_I(inode)->ordered_operations);
7851 spin_unlock(&root->fs_info->ordered_root_lock);
7852 }
7853
7854 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
7855 &BTRFS_I(inode)->runtime_flags)) {
7856 btrfs_info(root->fs_info, "inode %llu still on the orphan list",
7857 (unsigned long long)btrfs_ino(inode));
7858 atomic_dec(&root->orphan_inodes);
7859 }
7860
7861 while (1) {
7862 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
7863 if (!ordered)
7864 break;
7865 else {
7866 btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup",
7867 (unsigned long long)ordered->file_offset,
7868 (unsigned long long)ordered->len);
7869 btrfs_remove_ordered_extent(inode, ordered);
7870 btrfs_put_ordered_extent(ordered);
7871 btrfs_put_ordered_extent(ordered);
7872 }
7873 }
7874 inode_tree_del(inode);
7875 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
7876 free:
7877 call_rcu(&inode->i_rcu, btrfs_i_callback);
7878 }
7879
7880 int btrfs_drop_inode(struct inode *inode)
7881 {
7882 struct btrfs_root *root = BTRFS_I(inode)->root;
7883
7884 if (root == NULL)
7885 return 1;
7886
7887 /* the snap/subvol tree is on deleting */
7888 if (btrfs_root_refs(&root->root_item) == 0 &&
7889 root != root->fs_info->tree_root)
7890 return 1;
7891 else
7892 return generic_drop_inode(inode);
7893 }
7894
7895 static void init_once(void *foo)
7896 {
7897 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
7898
7899 inode_init_once(&ei->vfs_inode);
7900 }
7901
7902 void btrfs_destroy_cachep(void)
7903 {
7904 /*
7905 * Make sure all delayed rcu free inodes are flushed before we
7906 * destroy cache.
7907 */
7908 rcu_barrier();
7909 if (btrfs_inode_cachep)
7910 kmem_cache_destroy(btrfs_inode_cachep);
7911 if (btrfs_trans_handle_cachep)
7912 kmem_cache_destroy(btrfs_trans_handle_cachep);
7913 if (btrfs_transaction_cachep)
7914 kmem_cache_destroy(btrfs_transaction_cachep);
7915 if (btrfs_path_cachep)
7916 kmem_cache_destroy(btrfs_path_cachep);
7917 if (btrfs_free_space_cachep)
7918 kmem_cache_destroy(btrfs_free_space_cachep);
7919 if (btrfs_delalloc_work_cachep)
7920 kmem_cache_destroy(btrfs_delalloc_work_cachep);
7921 }
7922
7923 int btrfs_init_cachep(void)
7924 {
7925 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
7926 sizeof(struct btrfs_inode), 0,
7927 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once);
7928 if (!btrfs_inode_cachep)
7929 goto fail;
7930
7931 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
7932 sizeof(struct btrfs_trans_handle), 0,
7933 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
7934 if (!btrfs_trans_handle_cachep)
7935 goto fail;
7936
7937 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
7938 sizeof(struct btrfs_transaction), 0,
7939 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
7940 if (!btrfs_transaction_cachep)
7941 goto fail;
7942
7943 btrfs_path_cachep = kmem_cache_create("btrfs_path",
7944 sizeof(struct btrfs_path), 0,
7945 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
7946 if (!btrfs_path_cachep)
7947 goto fail;
7948
7949 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
7950 sizeof(struct btrfs_free_space), 0,
7951 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
7952 if (!btrfs_free_space_cachep)
7953 goto fail;
7954
7955 btrfs_delalloc_work_cachep = kmem_cache_create("btrfs_delalloc_work",
7956 sizeof(struct btrfs_delalloc_work), 0,
7957 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
7958 NULL);
7959 if (!btrfs_delalloc_work_cachep)
7960 goto fail;
7961
7962 return 0;
7963 fail:
7964 btrfs_destroy_cachep();
7965 return -ENOMEM;
7966 }
7967
7968 static int btrfs_getattr(struct vfsmount *mnt,
7969 struct dentry *dentry, struct kstat *stat)
7970 {
7971 u64 delalloc_bytes;
7972 struct inode *inode = dentry->d_inode;
7973 u32 blocksize = inode->i_sb->s_blocksize;
7974
7975 generic_fillattr(inode, stat);
7976 stat->dev = BTRFS_I(inode)->root->anon_dev;
7977 stat->blksize = PAGE_CACHE_SIZE;
7978
7979 spin_lock(&BTRFS_I(inode)->lock);
7980 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;
7981 spin_unlock(&BTRFS_I(inode)->lock);
7982 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
7983 ALIGN(delalloc_bytes, blocksize)) >> 9;
7984 return 0;
7985 }
7986
7987 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
7988 struct inode *new_dir, struct dentry *new_dentry)
7989 {
7990 struct btrfs_trans_handle *trans;
7991 struct btrfs_root *root = BTRFS_I(old_dir)->root;
7992 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
7993 struct inode *new_inode = new_dentry->d_inode;
7994 struct inode *old_inode = old_dentry->d_inode;
7995 struct timespec ctime = CURRENT_TIME;
7996 u64 index = 0;
7997 u64 root_objectid;
7998 int ret;
7999 u64 old_ino = btrfs_ino(old_inode);
8000
8001 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
8002 return -EPERM;
8003
8004 /* we only allow rename subvolume link between subvolumes */
8005 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
8006 return -EXDEV;
8007
8008 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
8009 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
8010 return -ENOTEMPTY;
8011
8012 if (S_ISDIR(old_inode->i_mode) && new_inode &&
8013 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
8014 return -ENOTEMPTY;
8015
8016
8017 /* check for collisions, even if the name isn't there */
8018 ret = btrfs_check_dir_item_collision(root, new_dir->i_ino,
8019 new_dentry->d_name.name,
8020 new_dentry->d_name.len);
8021
8022 if (ret) {
8023 if (ret == -EEXIST) {
8024 /* we shouldn't get
8025 * eexist without a new_inode */
8026 if (!new_inode) {
8027 WARN_ON(1);
8028 return ret;
8029 }
8030 } else {
8031 /* maybe -EOVERFLOW */
8032 return ret;
8033 }
8034 }
8035 ret = 0;
8036
8037 /*
8038 * we're using rename to replace one file with another.
8039 * and the replacement file is large. Start IO on it now so
8040 * we don't add too much work to the end of the transaction
8041 */
8042 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size &&
8043 old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
8044 filemap_flush(old_inode->i_mapping);
8045
8046 /* close the racy window with snapshot create/destroy ioctl */
8047 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
8048 down_read(&root->fs_info->subvol_sem);
8049 /*
8050 * We want to reserve the absolute worst case amount of items. So if
8051 * both inodes are subvols and we need to unlink them then that would
8052 * require 4 item modifications, but if they are both normal inodes it
8053 * would require 5 item modifications, so we'll assume their normal
8054 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
8055 * should cover the worst case number of items we'll modify.
8056 */
8057 trans = btrfs_start_transaction(root, 11);
8058 if (IS_ERR(trans)) {
8059 ret = PTR_ERR(trans);
8060 goto out_notrans;
8061 }
8062
8063 if (dest != root)
8064 btrfs_record_root_in_trans(trans, dest);
8065
8066 ret = btrfs_set_inode_index(new_dir, &index);
8067 if (ret)
8068 goto out_fail;
8069
8070 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
8071 /* force full log commit if subvolume involved. */
8072 root->fs_info->last_trans_log_full_commit = trans->transid;
8073 } else {
8074 ret = btrfs_insert_inode_ref(trans, dest,
8075 new_dentry->d_name.name,
8076 new_dentry->d_name.len,
8077 old_ino,
8078 btrfs_ino(new_dir), index);
8079 if (ret)
8080 goto out_fail;
8081 /*
8082 * this is an ugly little race, but the rename is required
8083 * to make sure that if we crash, the inode is either at the
8084 * old name or the new one. pinning the log transaction lets
8085 * us make sure we don't allow a log commit to come in after
8086 * we unlink the name but before we add the new name back in.
8087 */
8088 btrfs_pin_log_trans(root);
8089 }
8090 /*
8091 * make sure the inode gets flushed if it is replacing
8092 * something.
8093 */
8094 if (new_inode && new_inode->i_size && S_ISREG(old_inode->i_mode))
8095 btrfs_add_ordered_operation(trans, root, old_inode);
8096
8097 inode_inc_iversion(old_dir);
8098 inode_inc_iversion(new_dir);
8099 inode_inc_iversion(old_inode);
8100 old_dir->i_ctime = old_dir->i_mtime = ctime;
8101 new_dir->i_ctime = new_dir->i_mtime = ctime;
8102 old_inode->i_ctime = ctime;
8103
8104 if (old_dentry->d_parent != new_dentry->d_parent)
8105 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
8106
8107 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
8108 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
8109 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
8110 old_dentry->d_name.name,
8111 old_dentry->d_name.len);
8112 } else {
8113 ret = __btrfs_unlink_inode(trans, root, old_dir,
8114 old_dentry->d_inode,
8115 old_dentry->d_name.name,
8116 old_dentry->d_name.len);
8117 if (!ret)
8118 ret = btrfs_update_inode(trans, root, old_inode);
8119 }
8120 if (ret) {
8121 btrfs_abort_transaction(trans, root, ret);
8122 goto out_fail;
8123 }
8124
8125 if (new_inode) {
8126 inode_inc_iversion(new_inode);
8127 new_inode->i_ctime = CURRENT_TIME;
8128 if (unlikely(btrfs_ino(new_inode) ==
8129 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
8130 root_objectid = BTRFS_I(new_inode)->location.objectid;
8131 ret = btrfs_unlink_subvol(trans, dest, new_dir,
8132 root_objectid,
8133 new_dentry->d_name.name,
8134 new_dentry->d_name.len);
8135 BUG_ON(new_inode->i_nlink == 0);
8136 } else {
8137 ret = btrfs_unlink_inode(trans, dest, new_dir,
8138 new_dentry->d_inode,
8139 new_dentry->d_name.name,
8140 new_dentry->d_name.len);
8141 }
8142 if (!ret && new_inode->i_nlink == 0) {
8143 ret = btrfs_orphan_add(trans, new_dentry->d_inode);
8144 BUG_ON(ret);
8145 }
8146 if (ret) {
8147 btrfs_abort_transaction(trans, root, ret);
8148 goto out_fail;
8149 }
8150 }
8151
8152 ret = btrfs_add_link(trans, new_dir, old_inode,
8153 new_dentry->d_name.name,
8154 new_dentry->d_name.len, 0, index);
8155 if (ret) {
8156 btrfs_abort_transaction(trans, root, ret);
8157 goto out_fail;
8158 }
8159
8160 if (old_ino != BTRFS_FIRST_FREE_OBJECTID) {
8161 struct dentry *parent = new_dentry->d_parent;
8162 btrfs_log_new_name(trans, old_inode, old_dir, parent);
8163 btrfs_end_log_trans(root);
8164 }
8165 out_fail:
8166 btrfs_end_transaction(trans, root);
8167 out_notrans:
8168 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
8169 up_read(&root->fs_info->subvol_sem);
8170
8171 return ret;
8172 }
8173
8174 static void btrfs_run_delalloc_work(struct btrfs_work *work)
8175 {
8176 struct btrfs_delalloc_work *delalloc_work;
8177
8178 delalloc_work = container_of(work, struct btrfs_delalloc_work,
8179 work);
8180 if (delalloc_work->wait)
8181 btrfs_wait_ordered_range(delalloc_work->inode, 0, (u64)-1);
8182 else
8183 filemap_flush(delalloc_work->inode->i_mapping);
8184
8185 if (delalloc_work->delay_iput)
8186 btrfs_add_delayed_iput(delalloc_work->inode);
8187 else
8188 iput(delalloc_work->inode);
8189 complete(&delalloc_work->completion);
8190 }
8191
8192 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
8193 int wait, int delay_iput)
8194 {
8195 struct btrfs_delalloc_work *work;
8196
8197 work = kmem_cache_zalloc(btrfs_delalloc_work_cachep, GFP_NOFS);
8198 if (!work)
8199 return NULL;
8200
8201 init_completion(&work->completion);
8202 INIT_LIST_HEAD(&work->list);
8203 work->inode = inode;
8204 work->wait = wait;
8205 work->delay_iput = delay_iput;
8206 work->work.func = btrfs_run_delalloc_work;
8207
8208 return work;
8209 }
8210
8211 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
8212 {
8213 wait_for_completion(&work->completion);
8214 kmem_cache_free(btrfs_delalloc_work_cachep, work);
8215 }
8216
8217 /*
8218 * some fairly slow code that needs optimization. This walks the list
8219 * of all the inodes with pending delalloc and forces them to disk.
8220 */
8221 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
8222 {
8223 struct btrfs_inode *binode;
8224 struct inode *inode;
8225 struct btrfs_delalloc_work *work, *next;
8226 struct list_head works;
8227 struct list_head splice;
8228 int ret = 0;
8229
8230 INIT_LIST_HEAD(&works);
8231 INIT_LIST_HEAD(&splice);
8232
8233 spin_lock(&root->delalloc_lock);
8234 list_splice_init(&root->delalloc_inodes, &splice);
8235 while (!list_empty(&splice)) {
8236 binode = list_entry(splice.next, struct btrfs_inode,
8237 delalloc_inodes);
8238
8239 list_move_tail(&binode->delalloc_inodes,
8240 &root->delalloc_inodes);
8241 inode = igrab(&binode->vfs_inode);
8242 if (!inode) {
8243 cond_resched_lock(&root->delalloc_lock);
8244 continue;
8245 }
8246 spin_unlock(&root->delalloc_lock);
8247
8248 work = btrfs_alloc_delalloc_work(inode, 0, delay_iput);
8249 if (unlikely(!work)) {
8250 ret = -ENOMEM;
8251 goto out;
8252 }
8253 list_add_tail(&work->list, &works);
8254 btrfs_queue_worker(&root->fs_info->flush_workers,
8255 &work->work);
8256
8257 cond_resched();
8258 spin_lock(&root->delalloc_lock);
8259 }
8260 spin_unlock(&root->delalloc_lock);
8261
8262 list_for_each_entry_safe(work, next, &works, list) {
8263 list_del_init(&work->list);
8264 btrfs_wait_and_free_delalloc_work(work);
8265 }
8266 return 0;
8267 out:
8268 list_for_each_entry_safe(work, next, &works, list) {
8269 list_del_init(&work->list);
8270 btrfs_wait_and_free_delalloc_work(work);
8271 }
8272
8273 if (!list_empty_careful(&splice)) {
8274 spin_lock(&root->delalloc_lock);
8275 list_splice_tail(&splice, &root->delalloc_inodes);
8276 spin_unlock(&root->delalloc_lock);
8277 }
8278 return ret;
8279 }
8280
8281 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
8282 {
8283 int ret;
8284
8285 if (root->fs_info->sb->s_flags & MS_RDONLY)
8286 return -EROFS;
8287
8288 ret = __start_delalloc_inodes(root, delay_iput);
8289 /*
8290 * the filemap_flush will queue IO into the worker threads, but
8291 * we have to make sure the IO is actually started and that
8292 * ordered extents get created before we return
8293 */
8294 atomic_inc(&root->fs_info->async_submit_draining);
8295 while (atomic_read(&root->fs_info->nr_async_submits) ||
8296 atomic_read(&root->fs_info->async_delalloc_pages)) {
8297 wait_event(root->fs_info->async_submit_wait,
8298 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
8299 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
8300 }
8301 atomic_dec(&root->fs_info->async_submit_draining);
8302 return ret;
8303 }
8304
8305 int btrfs_start_all_delalloc_inodes(struct btrfs_fs_info *fs_info,
8306 int delay_iput)
8307 {
8308 struct btrfs_root *root;
8309 struct list_head splice;
8310 int ret;
8311
8312 if (fs_info->sb->s_flags & MS_RDONLY)
8313 return -EROFS;
8314
8315 INIT_LIST_HEAD(&splice);
8316
8317 spin_lock(&fs_info->delalloc_root_lock);
8318 list_splice_init(&fs_info->delalloc_roots, &splice);
8319 while (!list_empty(&splice)) {
8320 root = list_first_entry(&splice, struct btrfs_root,
8321 delalloc_root);
8322 root = btrfs_grab_fs_root(root);
8323 BUG_ON(!root);
8324 list_move_tail(&root->delalloc_root,
8325 &fs_info->delalloc_roots);
8326 spin_unlock(&fs_info->delalloc_root_lock);
8327
8328 ret = __start_delalloc_inodes(root, delay_iput);
8329 btrfs_put_fs_root(root);
8330 if (ret)
8331 goto out;
8332
8333 spin_lock(&fs_info->delalloc_root_lock);
8334 }
8335 spin_unlock(&fs_info->delalloc_root_lock);
8336
8337 atomic_inc(&fs_info->async_submit_draining);
8338 while (atomic_read(&fs_info->nr_async_submits) ||
8339 atomic_read(&fs_info->async_delalloc_pages)) {
8340 wait_event(fs_info->async_submit_wait,
8341 (atomic_read(&fs_info->nr_async_submits) == 0 &&
8342 atomic_read(&fs_info->async_delalloc_pages) == 0));
8343 }
8344 atomic_dec(&fs_info->async_submit_draining);
8345 return 0;
8346 out:
8347 if (!list_empty_careful(&splice)) {
8348 spin_lock(&fs_info->delalloc_root_lock);
8349 list_splice_tail(&splice, &fs_info->delalloc_roots);
8350 spin_unlock(&fs_info->delalloc_root_lock);
8351 }
8352 return ret;
8353 }
8354
8355 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
8356 const char *symname)
8357 {
8358 struct btrfs_trans_handle *trans;
8359 struct btrfs_root *root = BTRFS_I(dir)->root;
8360 struct btrfs_path *path;
8361 struct btrfs_key key;
8362 struct inode *inode = NULL;
8363 int err;
8364 int drop_inode = 0;
8365 u64 objectid;
8366 u64 index = 0 ;
8367 int name_len;
8368 int datasize;
8369 unsigned long ptr;
8370 struct btrfs_file_extent_item *ei;
8371 struct extent_buffer *leaf;
8372
8373 name_len = strlen(symname) + 1;
8374 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
8375 return -ENAMETOOLONG;
8376
8377 /*
8378 * 2 items for inode item and ref
8379 * 2 items for dir items
8380 * 1 item for xattr if selinux is on
8381 */
8382 trans = btrfs_start_transaction(root, 5);
8383 if (IS_ERR(trans))
8384 return PTR_ERR(trans);
8385
8386 err = btrfs_find_free_ino(root, &objectid);
8387 if (err)
8388 goto out_unlock;
8389
8390 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
8391 dentry->d_name.len, btrfs_ino(dir), objectid,
8392 S_IFLNK|S_IRWXUGO, &index);
8393 if (IS_ERR(inode)) {
8394 err = PTR_ERR(inode);
8395 goto out_unlock;
8396 }
8397
8398 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
8399 if (err) {
8400 drop_inode = 1;
8401 goto out_unlock;
8402 }
8403
8404 /*
8405 * If the active LSM wants to access the inode during
8406 * d_instantiate it needs these. Smack checks to see
8407 * if the filesystem supports xattrs by looking at the
8408 * ops vector.
8409 */
8410 inode->i_fop = &btrfs_file_operations;
8411 inode->i_op = &btrfs_file_inode_operations;
8412
8413 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
8414 if (err)
8415 drop_inode = 1;
8416 else {
8417 inode->i_mapping->a_ops = &btrfs_aops;
8418 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
8419 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
8420 }
8421 if (drop_inode)
8422 goto out_unlock;
8423
8424 path = btrfs_alloc_path();
8425 if (!path) {
8426 err = -ENOMEM;
8427 drop_inode = 1;
8428 goto out_unlock;
8429 }
8430 key.objectid = btrfs_ino(inode);
8431 key.offset = 0;
8432 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
8433 datasize = btrfs_file_extent_calc_inline_size(name_len);
8434 err = btrfs_insert_empty_item(trans, root, path, &key,
8435 datasize);
8436 if (err) {
8437 drop_inode = 1;
8438 btrfs_free_path(path);
8439 goto out_unlock;
8440 }
8441 leaf = path->nodes[0];
8442 ei = btrfs_item_ptr(leaf, path->slots[0],
8443 struct btrfs_file_extent_item);
8444 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
8445 btrfs_set_file_extent_type(leaf, ei,
8446 BTRFS_FILE_EXTENT_INLINE);
8447 btrfs_set_file_extent_encryption(leaf, ei, 0);
8448 btrfs_set_file_extent_compression(leaf, ei, 0);
8449 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
8450 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
8451
8452 ptr = btrfs_file_extent_inline_start(ei);
8453 write_extent_buffer(leaf, symname, ptr, name_len);
8454 btrfs_mark_buffer_dirty(leaf);
8455 btrfs_free_path(path);
8456
8457 inode->i_op = &btrfs_symlink_inode_operations;
8458 inode->i_mapping->a_ops = &btrfs_symlink_aops;
8459 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
8460 inode_set_bytes(inode, name_len);
8461 btrfs_i_size_write(inode, name_len - 1);
8462 err = btrfs_update_inode(trans, root, inode);
8463 if (err)
8464 drop_inode = 1;
8465
8466 out_unlock:
8467 if (!err)
8468 d_instantiate(dentry, inode);
8469 btrfs_end_transaction(trans, root);
8470 if (drop_inode) {
8471 inode_dec_link_count(inode);
8472 iput(inode);
8473 }
8474 btrfs_btree_balance_dirty(root);
8475 return err;
8476 }
8477
8478 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
8479 u64 start, u64 num_bytes, u64 min_size,
8480 loff_t actual_len, u64 *alloc_hint,
8481 struct btrfs_trans_handle *trans)
8482 {
8483 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
8484 struct extent_map *em;
8485 struct btrfs_root *root = BTRFS_I(inode)->root;
8486 struct btrfs_key ins;
8487 u64 cur_offset = start;
8488 u64 i_size;
8489 u64 cur_bytes;
8490 int ret = 0;
8491 bool own_trans = true;
8492
8493 if (trans)
8494 own_trans = false;
8495 while (num_bytes > 0) {
8496 if (own_trans) {
8497 trans = btrfs_start_transaction(root, 3);
8498 if (IS_ERR(trans)) {
8499 ret = PTR_ERR(trans);
8500 break;
8501 }
8502 }
8503
8504 cur_bytes = min(num_bytes, 256ULL * 1024 * 1024);
8505 cur_bytes = max(cur_bytes, min_size);
8506 ret = btrfs_reserve_extent(trans, root, cur_bytes,
8507 min_size, 0, *alloc_hint, &ins, 1);
8508 if (ret) {
8509 if (own_trans)
8510 btrfs_end_transaction(trans, root);
8511 break;
8512 }
8513
8514 ret = insert_reserved_file_extent(trans, inode,
8515 cur_offset, ins.objectid,
8516 ins.offset, ins.offset,
8517 ins.offset, 0, 0, 0,
8518 BTRFS_FILE_EXTENT_PREALLOC);
8519 if (ret) {
8520 btrfs_abort_transaction(trans, root, ret);
8521 if (own_trans)
8522 btrfs_end_transaction(trans, root);
8523 break;
8524 }
8525 btrfs_drop_extent_cache(inode, cur_offset,
8526 cur_offset + ins.offset -1, 0);
8527
8528 em = alloc_extent_map();
8529 if (!em) {
8530 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
8531 &BTRFS_I(inode)->runtime_flags);
8532 goto next;
8533 }
8534
8535 em->start = cur_offset;
8536 em->orig_start = cur_offset;
8537 em->len = ins.offset;
8538 em->block_start = ins.objectid;
8539 em->block_len = ins.offset;
8540 em->orig_block_len = ins.offset;
8541 em->ram_bytes = ins.offset;
8542 em->bdev = root->fs_info->fs_devices->latest_bdev;
8543 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
8544 em->generation = trans->transid;
8545
8546 while (1) {
8547 write_lock(&em_tree->lock);
8548 ret = add_extent_mapping(em_tree, em, 1);
8549 write_unlock(&em_tree->lock);
8550 if (ret != -EEXIST)
8551 break;
8552 btrfs_drop_extent_cache(inode, cur_offset,
8553 cur_offset + ins.offset - 1,
8554 0);
8555 }
8556 free_extent_map(em);
8557 next:
8558 num_bytes -= ins.offset;
8559 cur_offset += ins.offset;
8560 *alloc_hint = ins.objectid + ins.offset;
8561
8562 inode_inc_iversion(inode);
8563 inode->i_ctime = CURRENT_TIME;
8564 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
8565 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
8566 (actual_len > inode->i_size) &&
8567 (cur_offset > inode->i_size)) {
8568 if (cur_offset > actual_len)
8569 i_size = actual_len;
8570 else
8571 i_size = cur_offset;
8572 i_size_write(inode, i_size);
8573 btrfs_ordered_update_i_size(inode, i_size, NULL);
8574 }
8575
8576 ret = btrfs_update_inode(trans, root, inode);
8577
8578 if (ret) {
8579 btrfs_abort_transaction(trans, root, ret);
8580 if (own_trans)
8581 btrfs_end_transaction(trans, root);
8582 break;
8583 }
8584
8585 if (own_trans)
8586 btrfs_end_transaction(trans, root);
8587 }
8588 return ret;
8589 }
8590
8591 int btrfs_prealloc_file_range(struct inode *inode, int mode,
8592 u64 start, u64 num_bytes, u64 min_size,
8593 loff_t actual_len, u64 *alloc_hint)
8594 {
8595 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
8596 min_size, actual_len, alloc_hint,
8597 NULL);
8598 }
8599
8600 int btrfs_prealloc_file_range_trans(struct inode *inode,
8601 struct btrfs_trans_handle *trans, int mode,
8602 u64 start, u64 num_bytes, u64 min_size,
8603 loff_t actual_len, u64 *alloc_hint)
8604 {
8605 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
8606 min_size, actual_len, alloc_hint, trans);
8607 }
8608
8609 static int btrfs_set_page_dirty(struct page *page)
8610 {
8611 return __set_page_dirty_nobuffers(page);
8612 }
8613
8614 static int btrfs_permission(struct inode *inode, int mask)
8615 {
8616 struct btrfs_root *root = BTRFS_I(inode)->root;
8617 umode_t mode = inode->i_mode;
8618
8619 if (mask & MAY_WRITE &&
8620 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
8621 if (btrfs_root_readonly(root))
8622 return -EROFS;
8623 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
8624 return -EACCES;
8625 }
8626 return generic_permission(inode, mask);
8627 }
8628
8629 static const struct inode_operations btrfs_dir_inode_operations = {
8630 .getattr = btrfs_getattr,
8631 .lookup = btrfs_lookup,
8632 .create = btrfs_create,
8633 .unlink = btrfs_unlink,
8634 .link = btrfs_link,
8635 .mkdir = btrfs_mkdir,
8636 .rmdir = btrfs_rmdir,
8637 .rename = btrfs_rename,
8638 .symlink = btrfs_symlink,
8639 .setattr = btrfs_setattr,
8640 .mknod = btrfs_mknod,
8641 .setxattr = btrfs_setxattr,
8642 .getxattr = btrfs_getxattr,
8643 .listxattr = btrfs_listxattr,
8644 .removexattr = btrfs_removexattr,
8645 .permission = btrfs_permission,
8646 .get_acl = btrfs_get_acl,
8647 };
8648 static const struct inode_operations btrfs_dir_ro_inode_operations = {
8649 .lookup = btrfs_lookup,
8650 .permission = btrfs_permission,
8651 .get_acl = btrfs_get_acl,
8652 };
8653
8654 static const struct file_operations btrfs_dir_file_operations = {
8655 .llseek = generic_file_llseek,
8656 .read = generic_read_dir,
8657 .iterate = btrfs_real_readdir,
8658 .unlocked_ioctl = btrfs_ioctl,
8659 #ifdef CONFIG_COMPAT
8660 .compat_ioctl = btrfs_ioctl,
8661 #endif
8662 .release = btrfs_release_file,
8663 .fsync = btrfs_sync_file,
8664 };
8665
8666 static struct extent_io_ops btrfs_extent_io_ops = {
8667 .fill_delalloc = run_delalloc_range,
8668 .submit_bio_hook = btrfs_submit_bio_hook,
8669 .merge_bio_hook = btrfs_merge_bio_hook,
8670 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
8671 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
8672 .writepage_start_hook = btrfs_writepage_start_hook,
8673 .set_bit_hook = btrfs_set_bit_hook,
8674 .clear_bit_hook = btrfs_clear_bit_hook,
8675 .merge_extent_hook = btrfs_merge_extent_hook,
8676 .split_extent_hook = btrfs_split_extent_hook,
8677 };
8678
8679 /*
8680 * btrfs doesn't support the bmap operation because swapfiles
8681 * use bmap to make a mapping of extents in the file. They assume
8682 * these extents won't change over the life of the file and they
8683 * use the bmap result to do IO directly to the drive.
8684 *
8685 * the btrfs bmap call would return logical addresses that aren't
8686 * suitable for IO and they also will change frequently as COW
8687 * operations happen. So, swapfile + btrfs == corruption.
8688 *
8689 * For now we're avoiding this by dropping bmap.
8690 */
8691 static const struct address_space_operations btrfs_aops = {
8692 .readpage = btrfs_readpage,
8693 .writepage = btrfs_writepage,
8694 .writepages = btrfs_writepages,
8695 .readpages = btrfs_readpages,
8696 .direct_IO = btrfs_direct_IO,
8697 .invalidatepage = btrfs_invalidatepage,
8698 .releasepage = btrfs_releasepage,
8699 .set_page_dirty = btrfs_set_page_dirty,
8700 .error_remove_page = generic_error_remove_page,
8701 };
8702
8703 static const struct address_space_operations btrfs_symlink_aops = {
8704 .readpage = btrfs_readpage,
8705 .writepage = btrfs_writepage,
8706 .invalidatepage = btrfs_invalidatepage,
8707 .releasepage = btrfs_releasepage,
8708 };
8709
8710 static const struct inode_operations btrfs_file_inode_operations = {
8711 .getattr = btrfs_getattr,
8712 .setattr = btrfs_setattr,
8713 .setxattr = btrfs_setxattr,
8714 .getxattr = btrfs_getxattr,
8715 .listxattr = btrfs_listxattr,
8716 .removexattr = btrfs_removexattr,
8717 .permission = btrfs_permission,
8718 .fiemap = btrfs_fiemap,
8719 .get_acl = btrfs_get_acl,
8720 .update_time = btrfs_update_time,
8721 };
8722 static const struct inode_operations btrfs_special_inode_operations = {
8723 .getattr = btrfs_getattr,
8724 .setattr = btrfs_setattr,
8725 .permission = btrfs_permission,
8726 .setxattr = btrfs_setxattr,
8727 .getxattr = btrfs_getxattr,
8728 .listxattr = btrfs_listxattr,
8729 .removexattr = btrfs_removexattr,
8730 .get_acl = btrfs_get_acl,
8731 .update_time = btrfs_update_time,
8732 };
8733 static const struct inode_operations btrfs_symlink_inode_operations = {
8734 .readlink = generic_readlink,
8735 .follow_link = page_follow_link_light,
8736 .put_link = page_put_link,
8737 .getattr = btrfs_getattr,
8738 .setattr = btrfs_setattr,
8739 .permission = btrfs_permission,
8740 .setxattr = btrfs_setxattr,
8741 .getxattr = btrfs_getxattr,
8742 .listxattr = btrfs_listxattr,
8743 .removexattr = btrfs_removexattr,
8744 .get_acl = btrfs_get_acl,
8745 .update_time = btrfs_update_time,
8746 };
8747
8748 const struct dentry_operations btrfs_dentry_operations = {
8749 .d_delete = btrfs_dentry_delete,
8750 .d_release = btrfs_dentry_release,
8751 };
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