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Btrfs: check if we can nocow if we don't have data space
[deliverable/linux.git] / fs / btrfs / inode.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/kernel.h>
20 #include <linux/bio.h>
21 #include <linux/buffer_head.h>
22 #include <linux/file.h>
23 #include <linux/fs.h>
24 #include <linux/pagemap.h>
25 #include <linux/highmem.h>
26 #include <linux/time.h>
27 #include <linux/init.h>
28 #include <linux/string.h>
29 #include <linux/backing-dev.h>
30 #include <linux/mpage.h>
31 #include <linux/swap.h>
32 #include <linux/writeback.h>
33 #include <linux/statfs.h>
34 #include <linux/compat.h>
35 #include <linux/bit_spinlock.h>
36 #include <linux/xattr.h>
37 #include <linux/posix_acl.h>
38 #include <linux/falloc.h>
39 #include <linux/slab.h>
40 #include <linux/ratelimit.h>
41 #include <linux/mount.h>
42 #include <linux/btrfs.h>
43 #include <linux/blkdev.h>
44 #include <linux/posix_acl_xattr.h>
45 #include "compat.h"
46 #include "ctree.h"
47 #include "disk-io.h"
48 #include "transaction.h"
49 #include "btrfs_inode.h"
50 #include "print-tree.h"
51 #include "ordered-data.h"
52 #include "xattr.h"
53 #include "tree-log.h"
54 #include "volumes.h"
55 #include "compression.h"
56 #include "locking.h"
57 #include "free-space-cache.h"
58 #include "inode-map.h"
59 #include "backref.h"
60 #include "hash.h"
61
62 struct btrfs_iget_args {
63 u64 ino;
64 struct btrfs_root *root;
65 };
66
67 static const struct inode_operations btrfs_dir_inode_operations;
68 static const struct inode_operations btrfs_symlink_inode_operations;
69 static const struct inode_operations btrfs_dir_ro_inode_operations;
70 static const struct inode_operations btrfs_special_inode_operations;
71 static const struct inode_operations btrfs_file_inode_operations;
72 static const struct address_space_operations btrfs_aops;
73 static const struct address_space_operations btrfs_symlink_aops;
74 static const struct file_operations btrfs_dir_file_operations;
75 static struct extent_io_ops btrfs_extent_io_ops;
76
77 static struct kmem_cache *btrfs_inode_cachep;
78 static struct kmem_cache *btrfs_delalloc_work_cachep;
79 struct kmem_cache *btrfs_trans_handle_cachep;
80 struct kmem_cache *btrfs_transaction_cachep;
81 struct kmem_cache *btrfs_path_cachep;
82 struct kmem_cache *btrfs_free_space_cachep;
83
84 #define S_SHIFT 12
85 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
86 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
87 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
88 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
89 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
90 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
91 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
92 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
93 };
94
95 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
96 static int btrfs_truncate(struct inode *inode);
97 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
98 static noinline int cow_file_range(struct inode *inode,
99 struct page *locked_page,
100 u64 start, u64 end, int *page_started,
101 unsigned long *nr_written, int unlock);
102 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
103 u64 len, u64 orig_start,
104 u64 block_start, u64 block_len,
105 u64 orig_block_len, u64 ram_bytes,
106 int type);
107
108 static int btrfs_dirty_inode(struct inode *inode);
109
110 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
111 struct inode *inode, struct inode *dir,
112 const struct qstr *qstr)
113 {
114 int err;
115
116 err = btrfs_init_acl(trans, inode, dir);
117 if (!err)
118 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
119 return err;
120 }
121
122 /*
123 * this does all the hard work for inserting an inline extent into
124 * the btree. The caller should have done a btrfs_drop_extents so that
125 * no overlapping inline items exist in the btree
126 */
127 static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
128 struct btrfs_root *root, struct inode *inode,
129 u64 start, size_t size, size_t compressed_size,
130 int compress_type,
131 struct page **compressed_pages)
132 {
133 struct btrfs_key key;
134 struct btrfs_path *path;
135 struct extent_buffer *leaf;
136 struct page *page = NULL;
137 char *kaddr;
138 unsigned long ptr;
139 struct btrfs_file_extent_item *ei;
140 int err = 0;
141 int ret;
142 size_t cur_size = size;
143 size_t datasize;
144 unsigned long offset;
145
146 if (compressed_size && compressed_pages)
147 cur_size = compressed_size;
148
149 path = btrfs_alloc_path();
150 if (!path)
151 return -ENOMEM;
152
153 path->leave_spinning = 1;
154
155 key.objectid = btrfs_ino(inode);
156 key.offset = start;
157 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
158 datasize = btrfs_file_extent_calc_inline_size(cur_size);
159
160 inode_add_bytes(inode, size);
161 ret = btrfs_insert_empty_item(trans, root, path, &key,
162 datasize);
163 if (ret) {
164 err = ret;
165 goto fail;
166 }
167 leaf = path->nodes[0];
168 ei = btrfs_item_ptr(leaf, path->slots[0],
169 struct btrfs_file_extent_item);
170 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
171 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
172 btrfs_set_file_extent_encryption(leaf, ei, 0);
173 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
174 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
175 ptr = btrfs_file_extent_inline_start(ei);
176
177 if (compress_type != BTRFS_COMPRESS_NONE) {
178 struct page *cpage;
179 int i = 0;
180 while (compressed_size > 0) {
181 cpage = compressed_pages[i];
182 cur_size = min_t(unsigned long, compressed_size,
183 PAGE_CACHE_SIZE);
184
185 kaddr = kmap_atomic(cpage);
186 write_extent_buffer(leaf, kaddr, ptr, cur_size);
187 kunmap_atomic(kaddr);
188
189 i++;
190 ptr += cur_size;
191 compressed_size -= cur_size;
192 }
193 btrfs_set_file_extent_compression(leaf, ei,
194 compress_type);
195 } else {
196 page = find_get_page(inode->i_mapping,
197 start >> PAGE_CACHE_SHIFT);
198 btrfs_set_file_extent_compression(leaf, ei, 0);
199 kaddr = kmap_atomic(page);
200 offset = start & (PAGE_CACHE_SIZE - 1);
201 write_extent_buffer(leaf, kaddr + offset, ptr, size);
202 kunmap_atomic(kaddr);
203 page_cache_release(page);
204 }
205 btrfs_mark_buffer_dirty(leaf);
206 btrfs_free_path(path);
207
208 /*
209 * we're an inline extent, so nobody can
210 * extend the file past i_size without locking
211 * a page we already have locked.
212 *
213 * We must do any isize and inode updates
214 * before we unlock the pages. Otherwise we
215 * could end up racing with unlink.
216 */
217 BTRFS_I(inode)->disk_i_size = inode->i_size;
218 ret = btrfs_update_inode(trans, root, inode);
219
220 return ret;
221 fail:
222 btrfs_free_path(path);
223 return err;
224 }
225
226
227 /*
228 * conditionally insert an inline extent into the file. This
229 * does the checks required to make sure the data is small enough
230 * to fit as an inline extent.
231 */
232 static noinline int cow_file_range_inline(struct btrfs_trans_handle *trans,
233 struct btrfs_root *root,
234 struct inode *inode, u64 start, u64 end,
235 size_t compressed_size, int compress_type,
236 struct page **compressed_pages)
237 {
238 u64 isize = i_size_read(inode);
239 u64 actual_end = min(end + 1, isize);
240 u64 inline_len = actual_end - start;
241 u64 aligned_end = ALIGN(end, root->sectorsize);
242 u64 data_len = inline_len;
243 int ret;
244
245 if (compressed_size)
246 data_len = compressed_size;
247
248 if (start > 0 ||
249 actual_end >= PAGE_CACHE_SIZE ||
250 data_len >= BTRFS_MAX_INLINE_DATA_SIZE(root) ||
251 (!compressed_size &&
252 (actual_end & (root->sectorsize - 1)) == 0) ||
253 end + 1 < isize ||
254 data_len > root->fs_info->max_inline) {
255 return 1;
256 }
257
258 ret = btrfs_drop_extents(trans, root, inode, start, aligned_end, 1);
259 if (ret)
260 return ret;
261
262 if (isize > actual_end)
263 inline_len = min_t(u64, isize, actual_end);
264 ret = insert_inline_extent(trans, root, inode, start,
265 inline_len, compressed_size,
266 compress_type, compressed_pages);
267 if (ret && ret != -ENOSPC) {
268 btrfs_abort_transaction(trans, root, ret);
269 return ret;
270 } else if (ret == -ENOSPC) {
271 return 1;
272 }
273
274 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
275 btrfs_delalloc_release_metadata(inode, end + 1 - start);
276 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
277 return 0;
278 }
279
280 struct async_extent {
281 u64 start;
282 u64 ram_size;
283 u64 compressed_size;
284 struct page **pages;
285 unsigned long nr_pages;
286 int compress_type;
287 struct list_head list;
288 };
289
290 struct async_cow {
291 struct inode *inode;
292 struct btrfs_root *root;
293 struct page *locked_page;
294 u64 start;
295 u64 end;
296 struct list_head extents;
297 struct btrfs_work work;
298 };
299
300 static noinline int add_async_extent(struct async_cow *cow,
301 u64 start, u64 ram_size,
302 u64 compressed_size,
303 struct page **pages,
304 unsigned long nr_pages,
305 int compress_type)
306 {
307 struct async_extent *async_extent;
308
309 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
310 BUG_ON(!async_extent); /* -ENOMEM */
311 async_extent->start = start;
312 async_extent->ram_size = ram_size;
313 async_extent->compressed_size = compressed_size;
314 async_extent->pages = pages;
315 async_extent->nr_pages = nr_pages;
316 async_extent->compress_type = compress_type;
317 list_add_tail(&async_extent->list, &cow->extents);
318 return 0;
319 }
320
321 /*
322 * we create compressed extents in two phases. The first
323 * phase compresses a range of pages that have already been
324 * locked (both pages and state bits are locked).
325 *
326 * This is done inside an ordered work queue, and the compression
327 * is spread across many cpus. The actual IO submission is step
328 * two, and the ordered work queue takes care of making sure that
329 * happens in the same order things were put onto the queue by
330 * writepages and friends.
331 *
332 * If this code finds it can't get good compression, it puts an
333 * entry onto the work queue to write the uncompressed bytes. This
334 * makes sure that both compressed inodes and uncompressed inodes
335 * are written in the same order that the flusher thread sent them
336 * down.
337 */
338 static noinline int compress_file_range(struct inode *inode,
339 struct page *locked_page,
340 u64 start, u64 end,
341 struct async_cow *async_cow,
342 int *num_added)
343 {
344 struct btrfs_root *root = BTRFS_I(inode)->root;
345 struct btrfs_trans_handle *trans;
346 u64 num_bytes;
347 u64 blocksize = root->sectorsize;
348 u64 actual_end;
349 u64 isize = i_size_read(inode);
350 int ret = 0;
351 struct page **pages = NULL;
352 unsigned long nr_pages;
353 unsigned long nr_pages_ret = 0;
354 unsigned long total_compressed = 0;
355 unsigned long total_in = 0;
356 unsigned long max_compressed = 128 * 1024;
357 unsigned long max_uncompressed = 128 * 1024;
358 int i;
359 int will_compress;
360 int compress_type = root->fs_info->compress_type;
361 int redirty = 0;
362
363 /* if this is a small write inside eof, kick off a defrag */
364 if ((end - start + 1) < 16 * 1024 &&
365 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
366 btrfs_add_inode_defrag(NULL, inode);
367
368 actual_end = min_t(u64, isize, end + 1);
369 again:
370 will_compress = 0;
371 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
372 nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
373
374 /*
375 * we don't want to send crud past the end of i_size through
376 * compression, that's just a waste of CPU time. So, if the
377 * end of the file is before the start of our current
378 * requested range of bytes, we bail out to the uncompressed
379 * cleanup code that can deal with all of this.
380 *
381 * It isn't really the fastest way to fix things, but this is a
382 * very uncommon corner.
383 */
384 if (actual_end <= start)
385 goto cleanup_and_bail_uncompressed;
386
387 total_compressed = actual_end - start;
388
389 /* we want to make sure that amount of ram required to uncompress
390 * an extent is reasonable, so we limit the total size in ram
391 * of a compressed extent to 128k. This is a crucial number
392 * because it also controls how easily we can spread reads across
393 * cpus for decompression.
394 *
395 * We also want to make sure the amount of IO required to do
396 * a random read is reasonably small, so we limit the size of
397 * a compressed extent to 128k.
398 */
399 total_compressed = min(total_compressed, max_uncompressed);
400 num_bytes = ALIGN(end - start + 1, blocksize);
401 num_bytes = max(blocksize, num_bytes);
402 total_in = 0;
403 ret = 0;
404
405 /*
406 * we do compression for mount -o compress and when the
407 * inode has not been flagged as nocompress. This flag can
408 * change at any time if we discover bad compression ratios.
409 */
410 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) &&
411 (btrfs_test_opt(root, COMPRESS) ||
412 (BTRFS_I(inode)->force_compress) ||
413 (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))) {
414 WARN_ON(pages);
415 pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
416 if (!pages) {
417 /* just bail out to the uncompressed code */
418 goto cont;
419 }
420
421 if (BTRFS_I(inode)->force_compress)
422 compress_type = BTRFS_I(inode)->force_compress;
423
424 /*
425 * we need to call clear_page_dirty_for_io on each
426 * page in the range. Otherwise applications with the file
427 * mmap'd can wander in and change the page contents while
428 * we are compressing them.
429 *
430 * If the compression fails for any reason, we set the pages
431 * dirty again later on.
432 */
433 extent_range_clear_dirty_for_io(inode, start, end);
434 redirty = 1;
435 ret = btrfs_compress_pages(compress_type,
436 inode->i_mapping, start,
437 total_compressed, pages,
438 nr_pages, &nr_pages_ret,
439 &total_in,
440 &total_compressed,
441 max_compressed);
442
443 if (!ret) {
444 unsigned long offset = total_compressed &
445 (PAGE_CACHE_SIZE - 1);
446 struct page *page = pages[nr_pages_ret - 1];
447 char *kaddr;
448
449 /* zero the tail end of the last page, we might be
450 * sending it down to disk
451 */
452 if (offset) {
453 kaddr = kmap_atomic(page);
454 memset(kaddr + offset, 0,
455 PAGE_CACHE_SIZE - offset);
456 kunmap_atomic(kaddr);
457 }
458 will_compress = 1;
459 }
460 }
461 cont:
462 if (start == 0) {
463 trans = btrfs_join_transaction(root);
464 if (IS_ERR(trans)) {
465 ret = PTR_ERR(trans);
466 trans = NULL;
467 goto cleanup_and_out;
468 }
469 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
470
471 /* lets try to make an inline extent */
472 if (ret || total_in < (actual_end - start)) {
473 /* we didn't compress the entire range, try
474 * to make an uncompressed inline extent.
475 */
476 ret = cow_file_range_inline(trans, root, inode,
477 start, end, 0, 0, NULL);
478 } else {
479 /* try making a compressed inline extent */
480 ret = cow_file_range_inline(trans, root, inode,
481 start, end,
482 total_compressed,
483 compress_type, pages);
484 }
485 if (ret <= 0) {
486 /*
487 * inline extent creation worked or returned error,
488 * we don't need to create any more async work items.
489 * Unlock and free up our temp pages.
490 */
491 extent_clear_unlock_delalloc(inode,
492 &BTRFS_I(inode)->io_tree,
493 start, end, NULL,
494 EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
495 EXTENT_CLEAR_DELALLOC |
496 EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK);
497
498 btrfs_end_transaction(trans, root);
499 goto free_pages_out;
500 }
501 btrfs_end_transaction(trans, root);
502 }
503
504 if (will_compress) {
505 /*
506 * we aren't doing an inline extent round the compressed size
507 * up to a block size boundary so the allocator does sane
508 * things
509 */
510 total_compressed = ALIGN(total_compressed, blocksize);
511
512 /*
513 * one last check to make sure the compression is really a
514 * win, compare the page count read with the blocks on disk
515 */
516 total_in = ALIGN(total_in, PAGE_CACHE_SIZE);
517 if (total_compressed >= total_in) {
518 will_compress = 0;
519 } else {
520 num_bytes = total_in;
521 }
522 }
523 if (!will_compress && pages) {
524 /*
525 * the compression code ran but failed to make things smaller,
526 * free any pages it allocated and our page pointer array
527 */
528 for (i = 0; i < nr_pages_ret; i++) {
529 WARN_ON(pages[i]->mapping);
530 page_cache_release(pages[i]);
531 }
532 kfree(pages);
533 pages = NULL;
534 total_compressed = 0;
535 nr_pages_ret = 0;
536
537 /* flag the file so we don't compress in the future */
538 if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
539 !(BTRFS_I(inode)->force_compress)) {
540 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
541 }
542 }
543 if (will_compress) {
544 *num_added += 1;
545
546 /* the async work queues will take care of doing actual
547 * allocation on disk for these compressed pages,
548 * and will submit them to the elevator.
549 */
550 add_async_extent(async_cow, start, num_bytes,
551 total_compressed, pages, nr_pages_ret,
552 compress_type);
553
554 if (start + num_bytes < end) {
555 start += num_bytes;
556 pages = NULL;
557 cond_resched();
558 goto again;
559 }
560 } else {
561 cleanup_and_bail_uncompressed:
562 /*
563 * No compression, but we still need to write the pages in
564 * the file we've been given so far. redirty the locked
565 * page if it corresponds to our extent and set things up
566 * for the async work queue to run cow_file_range to do
567 * the normal delalloc dance
568 */
569 if (page_offset(locked_page) >= start &&
570 page_offset(locked_page) <= end) {
571 __set_page_dirty_nobuffers(locked_page);
572 /* unlocked later on in the async handlers */
573 }
574 if (redirty)
575 extent_range_redirty_for_io(inode, start, end);
576 add_async_extent(async_cow, start, end - start + 1,
577 0, NULL, 0, BTRFS_COMPRESS_NONE);
578 *num_added += 1;
579 }
580
581 out:
582 return ret;
583
584 free_pages_out:
585 for (i = 0; i < nr_pages_ret; i++) {
586 WARN_ON(pages[i]->mapping);
587 page_cache_release(pages[i]);
588 }
589 kfree(pages);
590
591 goto out;
592
593 cleanup_and_out:
594 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
595 start, end, NULL,
596 EXTENT_CLEAR_UNLOCK_PAGE |
597 EXTENT_CLEAR_DIRTY |
598 EXTENT_CLEAR_DELALLOC |
599 EXTENT_SET_WRITEBACK |
600 EXTENT_END_WRITEBACK);
601 if (!trans || IS_ERR(trans))
602 btrfs_error(root->fs_info, ret, "Failed to join transaction");
603 else
604 btrfs_abort_transaction(trans, root, ret);
605 goto free_pages_out;
606 }
607
608 /*
609 * phase two of compressed writeback. This is the ordered portion
610 * of the code, which only gets called in the order the work was
611 * queued. We walk all the async extents created by compress_file_range
612 * and send them down to the disk.
613 */
614 static noinline int submit_compressed_extents(struct inode *inode,
615 struct async_cow *async_cow)
616 {
617 struct async_extent *async_extent;
618 u64 alloc_hint = 0;
619 struct btrfs_trans_handle *trans;
620 struct btrfs_key ins;
621 struct extent_map *em;
622 struct btrfs_root *root = BTRFS_I(inode)->root;
623 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
624 struct extent_io_tree *io_tree;
625 int ret = 0;
626
627 if (list_empty(&async_cow->extents))
628 return 0;
629
630 again:
631 while (!list_empty(&async_cow->extents)) {
632 async_extent = list_entry(async_cow->extents.next,
633 struct async_extent, list);
634 list_del(&async_extent->list);
635
636 io_tree = &BTRFS_I(inode)->io_tree;
637
638 retry:
639 /* did the compression code fall back to uncompressed IO? */
640 if (!async_extent->pages) {
641 int page_started = 0;
642 unsigned long nr_written = 0;
643
644 lock_extent(io_tree, async_extent->start,
645 async_extent->start +
646 async_extent->ram_size - 1);
647
648 /* allocate blocks */
649 ret = cow_file_range(inode, async_cow->locked_page,
650 async_extent->start,
651 async_extent->start +
652 async_extent->ram_size - 1,
653 &page_started, &nr_written, 0);
654
655 /* JDM XXX */
656
657 /*
658 * if page_started, cow_file_range inserted an
659 * inline extent and took care of all the unlocking
660 * and IO for us. Otherwise, we need to submit
661 * all those pages down to the drive.
662 */
663 if (!page_started && !ret)
664 extent_write_locked_range(io_tree,
665 inode, async_extent->start,
666 async_extent->start +
667 async_extent->ram_size - 1,
668 btrfs_get_extent,
669 WB_SYNC_ALL);
670 else if (ret)
671 unlock_page(async_cow->locked_page);
672 kfree(async_extent);
673 cond_resched();
674 continue;
675 }
676
677 lock_extent(io_tree, async_extent->start,
678 async_extent->start + async_extent->ram_size - 1);
679
680 trans = btrfs_join_transaction(root);
681 if (IS_ERR(trans)) {
682 ret = PTR_ERR(trans);
683 } else {
684 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
685 ret = btrfs_reserve_extent(trans, root,
686 async_extent->compressed_size,
687 async_extent->compressed_size,
688 0, alloc_hint, &ins, 1);
689 if (ret && ret != -ENOSPC)
690 btrfs_abort_transaction(trans, root, ret);
691 btrfs_end_transaction(trans, root);
692 }
693
694 if (ret) {
695 int i;
696
697 for (i = 0; i < async_extent->nr_pages; i++) {
698 WARN_ON(async_extent->pages[i]->mapping);
699 page_cache_release(async_extent->pages[i]);
700 }
701 kfree(async_extent->pages);
702 async_extent->nr_pages = 0;
703 async_extent->pages = NULL;
704
705 if (ret == -ENOSPC) {
706 unlock_extent(io_tree, async_extent->start,
707 async_extent->start +
708 async_extent->ram_size - 1);
709 goto retry;
710 }
711 goto out_free;
712 }
713
714 /*
715 * here we're doing allocation and writeback of the
716 * compressed pages
717 */
718 btrfs_drop_extent_cache(inode, async_extent->start,
719 async_extent->start +
720 async_extent->ram_size - 1, 0);
721
722 em = alloc_extent_map();
723 if (!em) {
724 ret = -ENOMEM;
725 goto out_free_reserve;
726 }
727 em->start = async_extent->start;
728 em->len = async_extent->ram_size;
729 em->orig_start = em->start;
730 em->mod_start = em->start;
731 em->mod_len = em->len;
732
733 em->block_start = ins.objectid;
734 em->block_len = ins.offset;
735 em->orig_block_len = ins.offset;
736 em->ram_bytes = async_extent->ram_size;
737 em->bdev = root->fs_info->fs_devices->latest_bdev;
738 em->compress_type = async_extent->compress_type;
739 set_bit(EXTENT_FLAG_PINNED, &em->flags);
740 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
741 em->generation = -1;
742
743 while (1) {
744 write_lock(&em_tree->lock);
745 ret = add_extent_mapping(em_tree, em, 1);
746 write_unlock(&em_tree->lock);
747 if (ret != -EEXIST) {
748 free_extent_map(em);
749 break;
750 }
751 btrfs_drop_extent_cache(inode, async_extent->start,
752 async_extent->start +
753 async_extent->ram_size - 1, 0);
754 }
755
756 if (ret)
757 goto out_free_reserve;
758
759 ret = btrfs_add_ordered_extent_compress(inode,
760 async_extent->start,
761 ins.objectid,
762 async_extent->ram_size,
763 ins.offset,
764 BTRFS_ORDERED_COMPRESSED,
765 async_extent->compress_type);
766 if (ret)
767 goto out_free_reserve;
768
769 /*
770 * clear dirty, set writeback and unlock the pages.
771 */
772 extent_clear_unlock_delalloc(inode,
773 &BTRFS_I(inode)->io_tree,
774 async_extent->start,
775 async_extent->start +
776 async_extent->ram_size - 1,
777 NULL, EXTENT_CLEAR_UNLOCK_PAGE |
778 EXTENT_CLEAR_UNLOCK |
779 EXTENT_CLEAR_DELALLOC |
780 EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK);
781
782 ret = btrfs_submit_compressed_write(inode,
783 async_extent->start,
784 async_extent->ram_size,
785 ins.objectid,
786 ins.offset, async_extent->pages,
787 async_extent->nr_pages);
788 alloc_hint = ins.objectid + ins.offset;
789 kfree(async_extent);
790 if (ret)
791 goto out;
792 cond_resched();
793 }
794 ret = 0;
795 out:
796 return ret;
797 out_free_reserve:
798 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
799 out_free:
800 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
801 async_extent->start,
802 async_extent->start +
803 async_extent->ram_size - 1,
804 NULL, EXTENT_CLEAR_UNLOCK_PAGE |
805 EXTENT_CLEAR_UNLOCK |
806 EXTENT_CLEAR_DELALLOC |
807 EXTENT_CLEAR_DIRTY |
808 EXTENT_SET_WRITEBACK |
809 EXTENT_END_WRITEBACK);
810 kfree(async_extent);
811 goto again;
812 }
813
814 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
815 u64 num_bytes)
816 {
817 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
818 struct extent_map *em;
819 u64 alloc_hint = 0;
820
821 read_lock(&em_tree->lock);
822 em = search_extent_mapping(em_tree, start, num_bytes);
823 if (em) {
824 /*
825 * if block start isn't an actual block number then find the
826 * first block in this inode and use that as a hint. If that
827 * block is also bogus then just don't worry about it.
828 */
829 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
830 free_extent_map(em);
831 em = search_extent_mapping(em_tree, 0, 0);
832 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
833 alloc_hint = em->block_start;
834 if (em)
835 free_extent_map(em);
836 } else {
837 alloc_hint = em->block_start;
838 free_extent_map(em);
839 }
840 }
841 read_unlock(&em_tree->lock);
842
843 return alloc_hint;
844 }
845
846 /*
847 * when extent_io.c finds a delayed allocation range in the file,
848 * the call backs end up in this code. The basic idea is to
849 * allocate extents on disk for the range, and create ordered data structs
850 * in ram to track those extents.
851 *
852 * locked_page is the page that writepage had locked already. We use
853 * it to make sure we don't do extra locks or unlocks.
854 *
855 * *page_started is set to one if we unlock locked_page and do everything
856 * required to start IO on it. It may be clean and already done with
857 * IO when we return.
858 */
859 static noinline int __cow_file_range(struct btrfs_trans_handle *trans,
860 struct inode *inode,
861 struct btrfs_root *root,
862 struct page *locked_page,
863 u64 start, u64 end, int *page_started,
864 unsigned long *nr_written,
865 int unlock)
866 {
867 u64 alloc_hint = 0;
868 u64 num_bytes;
869 unsigned long ram_size;
870 u64 disk_num_bytes;
871 u64 cur_alloc_size;
872 u64 blocksize = root->sectorsize;
873 struct btrfs_key ins;
874 struct extent_map *em;
875 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
876 int ret = 0;
877
878 BUG_ON(btrfs_is_free_space_inode(inode));
879
880 num_bytes = ALIGN(end - start + 1, blocksize);
881 num_bytes = max(blocksize, num_bytes);
882 disk_num_bytes = num_bytes;
883
884 /* if this is a small write inside eof, kick off defrag */
885 if (num_bytes < 64 * 1024 &&
886 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
887 btrfs_add_inode_defrag(trans, inode);
888
889 if (start == 0) {
890 /* lets try to make an inline extent */
891 ret = cow_file_range_inline(trans, root, inode,
892 start, end, 0, 0, NULL);
893 if (ret == 0) {
894 extent_clear_unlock_delalloc(inode,
895 &BTRFS_I(inode)->io_tree,
896 start, end, NULL,
897 EXTENT_CLEAR_UNLOCK_PAGE |
898 EXTENT_CLEAR_UNLOCK |
899 EXTENT_CLEAR_DELALLOC |
900 EXTENT_CLEAR_DIRTY |
901 EXTENT_SET_WRITEBACK |
902 EXTENT_END_WRITEBACK);
903
904 *nr_written = *nr_written +
905 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
906 *page_started = 1;
907 goto out;
908 } else if (ret < 0) {
909 btrfs_abort_transaction(trans, root, ret);
910 goto out_unlock;
911 }
912 }
913
914 BUG_ON(disk_num_bytes >
915 btrfs_super_total_bytes(root->fs_info->super_copy));
916
917 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
918 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
919
920 while (disk_num_bytes > 0) {
921 unsigned long op;
922
923 cur_alloc_size = disk_num_bytes;
924 ret = btrfs_reserve_extent(trans, root, cur_alloc_size,
925 root->sectorsize, 0, alloc_hint,
926 &ins, 1);
927 if (ret < 0) {
928 btrfs_abort_transaction(trans, root, ret);
929 goto out_unlock;
930 }
931
932 em = alloc_extent_map();
933 if (!em) {
934 ret = -ENOMEM;
935 goto out_reserve;
936 }
937 em->start = start;
938 em->orig_start = em->start;
939 ram_size = ins.offset;
940 em->len = ins.offset;
941 em->mod_start = em->start;
942 em->mod_len = em->len;
943
944 em->block_start = ins.objectid;
945 em->block_len = ins.offset;
946 em->orig_block_len = ins.offset;
947 em->ram_bytes = ram_size;
948 em->bdev = root->fs_info->fs_devices->latest_bdev;
949 set_bit(EXTENT_FLAG_PINNED, &em->flags);
950 em->generation = -1;
951
952 while (1) {
953 write_lock(&em_tree->lock);
954 ret = add_extent_mapping(em_tree, em, 1);
955 write_unlock(&em_tree->lock);
956 if (ret != -EEXIST) {
957 free_extent_map(em);
958 break;
959 }
960 btrfs_drop_extent_cache(inode, start,
961 start + ram_size - 1, 0);
962 }
963 if (ret)
964 goto out_reserve;
965
966 cur_alloc_size = ins.offset;
967 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
968 ram_size, cur_alloc_size, 0);
969 if (ret)
970 goto out_reserve;
971
972 if (root->root_key.objectid ==
973 BTRFS_DATA_RELOC_TREE_OBJECTID) {
974 ret = btrfs_reloc_clone_csums(inode, start,
975 cur_alloc_size);
976 if (ret) {
977 btrfs_abort_transaction(trans, root, ret);
978 goto out_reserve;
979 }
980 }
981
982 if (disk_num_bytes < cur_alloc_size)
983 break;
984
985 /* we're not doing compressed IO, don't unlock the first
986 * page (which the caller expects to stay locked), don't
987 * clear any dirty bits and don't set any writeback bits
988 *
989 * Do set the Private2 bit so we know this page was properly
990 * setup for writepage
991 */
992 op = unlock ? EXTENT_CLEAR_UNLOCK_PAGE : 0;
993 op |= EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
994 EXTENT_SET_PRIVATE2;
995
996 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
997 start, start + ram_size - 1,
998 locked_page, op);
999 disk_num_bytes -= cur_alloc_size;
1000 num_bytes -= cur_alloc_size;
1001 alloc_hint = ins.objectid + ins.offset;
1002 start += cur_alloc_size;
1003 }
1004 out:
1005 return ret;
1006
1007 out_reserve:
1008 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
1009 out_unlock:
1010 extent_clear_unlock_delalloc(inode,
1011 &BTRFS_I(inode)->io_tree,
1012 start, end, locked_page,
1013 EXTENT_CLEAR_UNLOCK_PAGE |
1014 EXTENT_CLEAR_UNLOCK |
1015 EXTENT_CLEAR_DELALLOC |
1016 EXTENT_CLEAR_DIRTY |
1017 EXTENT_SET_WRITEBACK |
1018 EXTENT_END_WRITEBACK);
1019
1020 goto out;
1021 }
1022
1023 static noinline int cow_file_range(struct inode *inode,
1024 struct page *locked_page,
1025 u64 start, u64 end, int *page_started,
1026 unsigned long *nr_written,
1027 int unlock)
1028 {
1029 struct btrfs_trans_handle *trans;
1030 struct btrfs_root *root = BTRFS_I(inode)->root;
1031 int ret;
1032
1033 trans = btrfs_join_transaction(root);
1034 if (IS_ERR(trans)) {
1035 extent_clear_unlock_delalloc(inode,
1036 &BTRFS_I(inode)->io_tree,
1037 start, end, locked_page,
1038 EXTENT_CLEAR_UNLOCK_PAGE |
1039 EXTENT_CLEAR_UNLOCK |
1040 EXTENT_CLEAR_DELALLOC |
1041 EXTENT_CLEAR_DIRTY |
1042 EXTENT_SET_WRITEBACK |
1043 EXTENT_END_WRITEBACK);
1044 return PTR_ERR(trans);
1045 }
1046 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1047
1048 ret = __cow_file_range(trans, inode, root, locked_page, start, end,
1049 page_started, nr_written, unlock);
1050
1051 btrfs_end_transaction(trans, root);
1052
1053 return ret;
1054 }
1055
1056 /*
1057 * work queue call back to started compression on a file and pages
1058 */
1059 static noinline void async_cow_start(struct btrfs_work *work)
1060 {
1061 struct async_cow *async_cow;
1062 int num_added = 0;
1063 async_cow = container_of(work, struct async_cow, work);
1064
1065 compress_file_range(async_cow->inode, async_cow->locked_page,
1066 async_cow->start, async_cow->end, async_cow,
1067 &num_added);
1068 if (num_added == 0) {
1069 btrfs_add_delayed_iput(async_cow->inode);
1070 async_cow->inode = NULL;
1071 }
1072 }
1073
1074 /*
1075 * work queue call back to submit previously compressed pages
1076 */
1077 static noinline void async_cow_submit(struct btrfs_work *work)
1078 {
1079 struct async_cow *async_cow;
1080 struct btrfs_root *root;
1081 unsigned long nr_pages;
1082
1083 async_cow = container_of(work, struct async_cow, work);
1084
1085 root = async_cow->root;
1086 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
1087 PAGE_CACHE_SHIFT;
1088
1089 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
1090 5 * 1024 * 1024 &&
1091 waitqueue_active(&root->fs_info->async_submit_wait))
1092 wake_up(&root->fs_info->async_submit_wait);
1093
1094 if (async_cow->inode)
1095 submit_compressed_extents(async_cow->inode, async_cow);
1096 }
1097
1098 static noinline void async_cow_free(struct btrfs_work *work)
1099 {
1100 struct async_cow *async_cow;
1101 async_cow = container_of(work, struct async_cow, work);
1102 if (async_cow->inode)
1103 btrfs_add_delayed_iput(async_cow->inode);
1104 kfree(async_cow);
1105 }
1106
1107 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1108 u64 start, u64 end, int *page_started,
1109 unsigned long *nr_written)
1110 {
1111 struct async_cow *async_cow;
1112 struct btrfs_root *root = BTRFS_I(inode)->root;
1113 unsigned long nr_pages;
1114 u64 cur_end;
1115 int limit = 10 * 1024 * 1024;
1116
1117 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1118 1, 0, NULL, GFP_NOFS);
1119 while (start < end) {
1120 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1121 BUG_ON(!async_cow); /* -ENOMEM */
1122 async_cow->inode = igrab(inode);
1123 async_cow->root = root;
1124 async_cow->locked_page = locked_page;
1125 async_cow->start = start;
1126
1127 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
1128 cur_end = end;
1129 else
1130 cur_end = min(end, start + 512 * 1024 - 1);
1131
1132 async_cow->end = cur_end;
1133 INIT_LIST_HEAD(&async_cow->extents);
1134
1135 async_cow->work.func = async_cow_start;
1136 async_cow->work.ordered_func = async_cow_submit;
1137 async_cow->work.ordered_free = async_cow_free;
1138 async_cow->work.flags = 0;
1139
1140 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
1141 PAGE_CACHE_SHIFT;
1142 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
1143
1144 btrfs_queue_worker(&root->fs_info->delalloc_workers,
1145 &async_cow->work);
1146
1147 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
1148 wait_event(root->fs_info->async_submit_wait,
1149 (atomic_read(&root->fs_info->async_delalloc_pages) <
1150 limit));
1151 }
1152
1153 while (atomic_read(&root->fs_info->async_submit_draining) &&
1154 atomic_read(&root->fs_info->async_delalloc_pages)) {
1155 wait_event(root->fs_info->async_submit_wait,
1156 (atomic_read(&root->fs_info->async_delalloc_pages) ==
1157 0));
1158 }
1159
1160 *nr_written += nr_pages;
1161 start = cur_end + 1;
1162 }
1163 *page_started = 1;
1164 return 0;
1165 }
1166
1167 static noinline int csum_exist_in_range(struct btrfs_root *root,
1168 u64 bytenr, u64 num_bytes)
1169 {
1170 int ret;
1171 struct btrfs_ordered_sum *sums;
1172 LIST_HEAD(list);
1173
1174 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1175 bytenr + num_bytes - 1, &list, 0);
1176 if (ret == 0 && list_empty(&list))
1177 return 0;
1178
1179 while (!list_empty(&list)) {
1180 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1181 list_del(&sums->list);
1182 kfree(sums);
1183 }
1184 return 1;
1185 }
1186
1187 /*
1188 * when nowcow writeback call back. This checks for snapshots or COW copies
1189 * of the extents that exist in the file, and COWs the file as required.
1190 *
1191 * If no cow copies or snapshots exist, we write directly to the existing
1192 * blocks on disk
1193 */
1194 static noinline int run_delalloc_nocow(struct inode *inode,
1195 struct page *locked_page,
1196 u64 start, u64 end, int *page_started, int force,
1197 unsigned long *nr_written)
1198 {
1199 struct btrfs_root *root = BTRFS_I(inode)->root;
1200 struct btrfs_trans_handle *trans;
1201 struct extent_buffer *leaf;
1202 struct btrfs_path *path;
1203 struct btrfs_file_extent_item *fi;
1204 struct btrfs_key found_key;
1205 u64 cow_start;
1206 u64 cur_offset;
1207 u64 extent_end;
1208 u64 extent_offset;
1209 u64 disk_bytenr;
1210 u64 num_bytes;
1211 u64 disk_num_bytes;
1212 u64 ram_bytes;
1213 int extent_type;
1214 int ret, err;
1215 int type;
1216 int nocow;
1217 int check_prev = 1;
1218 bool nolock;
1219 u64 ino = btrfs_ino(inode);
1220
1221 path = btrfs_alloc_path();
1222 if (!path) {
1223 extent_clear_unlock_delalloc(inode,
1224 &BTRFS_I(inode)->io_tree,
1225 start, end, locked_page,
1226 EXTENT_CLEAR_UNLOCK_PAGE |
1227 EXTENT_CLEAR_UNLOCK |
1228 EXTENT_CLEAR_DELALLOC |
1229 EXTENT_CLEAR_DIRTY |
1230 EXTENT_SET_WRITEBACK |
1231 EXTENT_END_WRITEBACK);
1232 return -ENOMEM;
1233 }
1234
1235 nolock = btrfs_is_free_space_inode(inode);
1236
1237 if (nolock)
1238 trans = btrfs_join_transaction_nolock(root);
1239 else
1240 trans = btrfs_join_transaction(root);
1241
1242 if (IS_ERR(trans)) {
1243 extent_clear_unlock_delalloc(inode,
1244 &BTRFS_I(inode)->io_tree,
1245 start, end, locked_page,
1246 EXTENT_CLEAR_UNLOCK_PAGE |
1247 EXTENT_CLEAR_UNLOCK |
1248 EXTENT_CLEAR_DELALLOC |
1249 EXTENT_CLEAR_DIRTY |
1250 EXTENT_SET_WRITEBACK |
1251 EXTENT_END_WRITEBACK);
1252 btrfs_free_path(path);
1253 return PTR_ERR(trans);
1254 }
1255
1256 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1257
1258 cow_start = (u64)-1;
1259 cur_offset = start;
1260 while (1) {
1261 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1262 cur_offset, 0);
1263 if (ret < 0) {
1264 btrfs_abort_transaction(trans, root, ret);
1265 goto error;
1266 }
1267 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1268 leaf = path->nodes[0];
1269 btrfs_item_key_to_cpu(leaf, &found_key,
1270 path->slots[0] - 1);
1271 if (found_key.objectid == ino &&
1272 found_key.type == BTRFS_EXTENT_DATA_KEY)
1273 path->slots[0]--;
1274 }
1275 check_prev = 0;
1276 next_slot:
1277 leaf = path->nodes[0];
1278 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1279 ret = btrfs_next_leaf(root, path);
1280 if (ret < 0) {
1281 btrfs_abort_transaction(trans, root, ret);
1282 goto error;
1283 }
1284 if (ret > 0)
1285 break;
1286 leaf = path->nodes[0];
1287 }
1288
1289 nocow = 0;
1290 disk_bytenr = 0;
1291 num_bytes = 0;
1292 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1293
1294 if (found_key.objectid > ino ||
1295 found_key.type > BTRFS_EXTENT_DATA_KEY ||
1296 found_key.offset > end)
1297 break;
1298
1299 if (found_key.offset > cur_offset) {
1300 extent_end = found_key.offset;
1301 extent_type = 0;
1302 goto out_check;
1303 }
1304
1305 fi = btrfs_item_ptr(leaf, path->slots[0],
1306 struct btrfs_file_extent_item);
1307 extent_type = btrfs_file_extent_type(leaf, fi);
1308
1309 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1310 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1311 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1312 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1313 extent_offset = btrfs_file_extent_offset(leaf, fi);
1314 extent_end = found_key.offset +
1315 btrfs_file_extent_num_bytes(leaf, fi);
1316 disk_num_bytes =
1317 btrfs_file_extent_disk_num_bytes(leaf, fi);
1318 if (extent_end <= start) {
1319 path->slots[0]++;
1320 goto next_slot;
1321 }
1322 if (disk_bytenr == 0)
1323 goto out_check;
1324 if (btrfs_file_extent_compression(leaf, fi) ||
1325 btrfs_file_extent_encryption(leaf, fi) ||
1326 btrfs_file_extent_other_encoding(leaf, fi))
1327 goto out_check;
1328 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1329 goto out_check;
1330 if (btrfs_extent_readonly(root, disk_bytenr))
1331 goto out_check;
1332 if (btrfs_cross_ref_exist(trans, root, ino,
1333 found_key.offset -
1334 extent_offset, disk_bytenr))
1335 goto out_check;
1336 disk_bytenr += extent_offset;
1337 disk_bytenr += cur_offset - found_key.offset;
1338 num_bytes = min(end + 1, extent_end) - cur_offset;
1339 /*
1340 * force cow if csum exists in the range.
1341 * this ensure that csum for a given extent are
1342 * either valid or do not exist.
1343 */
1344 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1345 goto out_check;
1346 nocow = 1;
1347 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1348 extent_end = found_key.offset +
1349 btrfs_file_extent_inline_len(leaf, fi);
1350 extent_end = ALIGN(extent_end, root->sectorsize);
1351 } else {
1352 BUG_ON(1);
1353 }
1354 out_check:
1355 if (extent_end <= start) {
1356 path->slots[0]++;
1357 goto next_slot;
1358 }
1359 if (!nocow) {
1360 if (cow_start == (u64)-1)
1361 cow_start = cur_offset;
1362 cur_offset = extent_end;
1363 if (cur_offset > end)
1364 break;
1365 path->slots[0]++;
1366 goto next_slot;
1367 }
1368
1369 btrfs_release_path(path);
1370 if (cow_start != (u64)-1) {
1371 ret = __cow_file_range(trans, inode, root, locked_page,
1372 cow_start, found_key.offset - 1,
1373 page_started, nr_written, 1);
1374 if (ret) {
1375 btrfs_abort_transaction(trans, root, ret);
1376 goto error;
1377 }
1378 cow_start = (u64)-1;
1379 }
1380
1381 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1382 struct extent_map *em;
1383 struct extent_map_tree *em_tree;
1384 em_tree = &BTRFS_I(inode)->extent_tree;
1385 em = alloc_extent_map();
1386 BUG_ON(!em); /* -ENOMEM */
1387 em->start = cur_offset;
1388 em->orig_start = found_key.offset - extent_offset;
1389 em->len = num_bytes;
1390 em->block_len = num_bytes;
1391 em->block_start = disk_bytenr;
1392 em->orig_block_len = disk_num_bytes;
1393 em->ram_bytes = ram_bytes;
1394 em->bdev = root->fs_info->fs_devices->latest_bdev;
1395 em->mod_start = em->start;
1396 em->mod_len = em->len;
1397 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1398 set_bit(EXTENT_FLAG_FILLING, &em->flags);
1399 em->generation = -1;
1400 while (1) {
1401 write_lock(&em_tree->lock);
1402 ret = add_extent_mapping(em_tree, em, 1);
1403 write_unlock(&em_tree->lock);
1404 if (ret != -EEXIST) {
1405 free_extent_map(em);
1406 break;
1407 }
1408 btrfs_drop_extent_cache(inode, em->start,
1409 em->start + em->len - 1, 0);
1410 }
1411 type = BTRFS_ORDERED_PREALLOC;
1412 } else {
1413 type = BTRFS_ORDERED_NOCOW;
1414 }
1415
1416 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1417 num_bytes, num_bytes, type);
1418 BUG_ON(ret); /* -ENOMEM */
1419
1420 if (root->root_key.objectid ==
1421 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1422 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1423 num_bytes);
1424 if (ret) {
1425 btrfs_abort_transaction(trans, root, ret);
1426 goto error;
1427 }
1428 }
1429
1430 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
1431 cur_offset, cur_offset + num_bytes - 1,
1432 locked_page, EXTENT_CLEAR_UNLOCK_PAGE |
1433 EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
1434 EXTENT_SET_PRIVATE2);
1435 cur_offset = extent_end;
1436 if (cur_offset > end)
1437 break;
1438 }
1439 btrfs_release_path(path);
1440
1441 if (cur_offset <= end && cow_start == (u64)-1) {
1442 cow_start = cur_offset;
1443 cur_offset = end;
1444 }
1445
1446 if (cow_start != (u64)-1) {
1447 ret = __cow_file_range(trans, inode, root, locked_page,
1448 cow_start, end,
1449 page_started, nr_written, 1);
1450 if (ret) {
1451 btrfs_abort_transaction(trans, root, ret);
1452 goto error;
1453 }
1454 }
1455
1456 error:
1457 err = btrfs_end_transaction(trans, root);
1458 if (!ret)
1459 ret = err;
1460
1461 if (ret && cur_offset < end)
1462 extent_clear_unlock_delalloc(inode,
1463 &BTRFS_I(inode)->io_tree,
1464 cur_offset, end, locked_page,
1465 EXTENT_CLEAR_UNLOCK_PAGE |
1466 EXTENT_CLEAR_UNLOCK |
1467 EXTENT_CLEAR_DELALLOC |
1468 EXTENT_CLEAR_DIRTY |
1469 EXTENT_SET_WRITEBACK |
1470 EXTENT_END_WRITEBACK);
1471
1472 btrfs_free_path(path);
1473 return ret;
1474 }
1475
1476 /*
1477 * extent_io.c call back to do delayed allocation processing
1478 */
1479 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1480 u64 start, u64 end, int *page_started,
1481 unsigned long *nr_written)
1482 {
1483 int ret;
1484 struct btrfs_root *root = BTRFS_I(inode)->root;
1485
1486 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) {
1487 ret = run_delalloc_nocow(inode, locked_page, start, end,
1488 page_started, 1, nr_written);
1489 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC) {
1490 ret = run_delalloc_nocow(inode, locked_page, start, end,
1491 page_started, 0, nr_written);
1492 } else if (!btrfs_test_opt(root, COMPRESS) &&
1493 !(BTRFS_I(inode)->force_compress) &&
1494 !(BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS)) {
1495 ret = cow_file_range(inode, locked_page, start, end,
1496 page_started, nr_written, 1);
1497 } else {
1498 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1499 &BTRFS_I(inode)->runtime_flags);
1500 ret = cow_file_range_async(inode, locked_page, start, end,
1501 page_started, nr_written);
1502 }
1503 return ret;
1504 }
1505
1506 static void btrfs_split_extent_hook(struct inode *inode,
1507 struct extent_state *orig, u64 split)
1508 {
1509 /* not delalloc, ignore it */
1510 if (!(orig->state & EXTENT_DELALLOC))
1511 return;
1512
1513 spin_lock(&BTRFS_I(inode)->lock);
1514 BTRFS_I(inode)->outstanding_extents++;
1515 spin_unlock(&BTRFS_I(inode)->lock);
1516 }
1517
1518 /*
1519 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1520 * extents so we can keep track of new extents that are just merged onto old
1521 * extents, such as when we are doing sequential writes, so we can properly
1522 * account for the metadata space we'll need.
1523 */
1524 static void btrfs_merge_extent_hook(struct inode *inode,
1525 struct extent_state *new,
1526 struct extent_state *other)
1527 {
1528 /* not delalloc, ignore it */
1529 if (!(other->state & EXTENT_DELALLOC))
1530 return;
1531
1532 spin_lock(&BTRFS_I(inode)->lock);
1533 BTRFS_I(inode)->outstanding_extents--;
1534 spin_unlock(&BTRFS_I(inode)->lock);
1535 }
1536
1537 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1538 struct inode *inode)
1539 {
1540 spin_lock(&root->delalloc_lock);
1541 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1542 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1543 &root->delalloc_inodes);
1544 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1545 &BTRFS_I(inode)->runtime_flags);
1546 root->nr_delalloc_inodes++;
1547 if (root->nr_delalloc_inodes == 1) {
1548 spin_lock(&root->fs_info->delalloc_root_lock);
1549 BUG_ON(!list_empty(&root->delalloc_root));
1550 list_add_tail(&root->delalloc_root,
1551 &root->fs_info->delalloc_roots);
1552 spin_unlock(&root->fs_info->delalloc_root_lock);
1553 }
1554 }
1555 spin_unlock(&root->delalloc_lock);
1556 }
1557
1558 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1559 struct inode *inode)
1560 {
1561 spin_lock(&root->delalloc_lock);
1562 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1563 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1564 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1565 &BTRFS_I(inode)->runtime_flags);
1566 root->nr_delalloc_inodes--;
1567 if (!root->nr_delalloc_inodes) {
1568 spin_lock(&root->fs_info->delalloc_root_lock);
1569 BUG_ON(list_empty(&root->delalloc_root));
1570 list_del_init(&root->delalloc_root);
1571 spin_unlock(&root->fs_info->delalloc_root_lock);
1572 }
1573 }
1574 spin_unlock(&root->delalloc_lock);
1575 }
1576
1577 /*
1578 * extent_io.c set_bit_hook, used to track delayed allocation
1579 * bytes in this file, and to maintain the list of inodes that
1580 * have pending delalloc work to be done.
1581 */
1582 static void btrfs_set_bit_hook(struct inode *inode,
1583 struct extent_state *state, unsigned long *bits)
1584 {
1585
1586 /*
1587 * set_bit and clear bit hooks normally require _irqsave/restore
1588 * but in this case, we are only testing for the DELALLOC
1589 * bit, which is only set or cleared with irqs on
1590 */
1591 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1592 struct btrfs_root *root = BTRFS_I(inode)->root;
1593 u64 len = state->end + 1 - state->start;
1594 bool do_list = !btrfs_is_free_space_inode(inode);
1595
1596 if (*bits & EXTENT_FIRST_DELALLOC) {
1597 *bits &= ~EXTENT_FIRST_DELALLOC;
1598 } else {
1599 spin_lock(&BTRFS_I(inode)->lock);
1600 BTRFS_I(inode)->outstanding_extents++;
1601 spin_unlock(&BTRFS_I(inode)->lock);
1602 }
1603
1604 __percpu_counter_add(&root->fs_info->delalloc_bytes, len,
1605 root->fs_info->delalloc_batch);
1606 spin_lock(&BTRFS_I(inode)->lock);
1607 BTRFS_I(inode)->delalloc_bytes += len;
1608 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1609 &BTRFS_I(inode)->runtime_flags))
1610 btrfs_add_delalloc_inodes(root, inode);
1611 spin_unlock(&BTRFS_I(inode)->lock);
1612 }
1613 }
1614
1615 /*
1616 * extent_io.c clear_bit_hook, see set_bit_hook for why
1617 */
1618 static void btrfs_clear_bit_hook(struct inode *inode,
1619 struct extent_state *state,
1620 unsigned long *bits)
1621 {
1622 /*
1623 * set_bit and clear bit hooks normally require _irqsave/restore
1624 * but in this case, we are only testing for the DELALLOC
1625 * bit, which is only set or cleared with irqs on
1626 */
1627 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1628 struct btrfs_root *root = BTRFS_I(inode)->root;
1629 u64 len = state->end + 1 - state->start;
1630 bool do_list = !btrfs_is_free_space_inode(inode);
1631
1632 if (*bits & EXTENT_FIRST_DELALLOC) {
1633 *bits &= ~EXTENT_FIRST_DELALLOC;
1634 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1635 spin_lock(&BTRFS_I(inode)->lock);
1636 BTRFS_I(inode)->outstanding_extents--;
1637 spin_unlock(&BTRFS_I(inode)->lock);
1638 }
1639
1640 if (*bits & EXTENT_DO_ACCOUNTING)
1641 btrfs_delalloc_release_metadata(inode, len);
1642
1643 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1644 && do_list && !(state->state & EXTENT_NORESERVE))
1645 btrfs_free_reserved_data_space(inode, len);
1646
1647 __percpu_counter_add(&root->fs_info->delalloc_bytes, -len,
1648 root->fs_info->delalloc_batch);
1649 spin_lock(&BTRFS_I(inode)->lock);
1650 BTRFS_I(inode)->delalloc_bytes -= len;
1651 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1652 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1653 &BTRFS_I(inode)->runtime_flags))
1654 btrfs_del_delalloc_inode(root, inode);
1655 spin_unlock(&BTRFS_I(inode)->lock);
1656 }
1657 }
1658
1659 /*
1660 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1661 * we don't create bios that span stripes or chunks
1662 */
1663 int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset,
1664 size_t size, struct bio *bio,
1665 unsigned long bio_flags)
1666 {
1667 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1668 u64 logical = (u64)bio->bi_sector << 9;
1669 u64 length = 0;
1670 u64 map_length;
1671 int ret;
1672
1673 if (bio_flags & EXTENT_BIO_COMPRESSED)
1674 return 0;
1675
1676 length = bio->bi_size;
1677 map_length = length;
1678 ret = btrfs_map_block(root->fs_info, rw, logical,
1679 &map_length, NULL, 0);
1680 /* Will always return 0 with map_multi == NULL */
1681 BUG_ON(ret < 0);
1682 if (map_length < length + size)
1683 return 1;
1684 return 0;
1685 }
1686
1687 /*
1688 * in order to insert checksums into the metadata in large chunks,
1689 * we wait until bio submission time. All the pages in the bio are
1690 * checksummed and sums are attached onto the ordered extent record.
1691 *
1692 * At IO completion time the cums attached on the ordered extent record
1693 * are inserted into the btree
1694 */
1695 static int __btrfs_submit_bio_start(struct inode *inode, int rw,
1696 struct bio *bio, int mirror_num,
1697 unsigned long bio_flags,
1698 u64 bio_offset)
1699 {
1700 struct btrfs_root *root = BTRFS_I(inode)->root;
1701 int ret = 0;
1702
1703 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1704 BUG_ON(ret); /* -ENOMEM */
1705 return 0;
1706 }
1707
1708 /*
1709 * in order to insert checksums into the metadata in large chunks,
1710 * we wait until bio submission time. All the pages in the bio are
1711 * checksummed and sums are attached onto the ordered extent record.
1712 *
1713 * At IO completion time the cums attached on the ordered extent record
1714 * are inserted into the btree
1715 */
1716 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1717 int mirror_num, unsigned long bio_flags,
1718 u64 bio_offset)
1719 {
1720 struct btrfs_root *root = BTRFS_I(inode)->root;
1721 int ret;
1722
1723 ret = btrfs_map_bio(root, rw, bio, mirror_num, 1);
1724 if (ret)
1725 bio_endio(bio, ret);
1726 return ret;
1727 }
1728
1729 /*
1730 * extent_io.c submission hook. This does the right thing for csum calculation
1731 * on write, or reading the csums from the tree before a read
1732 */
1733 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1734 int mirror_num, unsigned long bio_flags,
1735 u64 bio_offset)
1736 {
1737 struct btrfs_root *root = BTRFS_I(inode)->root;
1738 int ret = 0;
1739 int skip_sum;
1740 int metadata = 0;
1741 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1742
1743 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1744
1745 if (btrfs_is_free_space_inode(inode))
1746 metadata = 2;
1747
1748 if (!(rw & REQ_WRITE)) {
1749 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
1750 if (ret)
1751 goto out;
1752
1753 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1754 ret = btrfs_submit_compressed_read(inode, bio,
1755 mirror_num,
1756 bio_flags);
1757 goto out;
1758 } else if (!skip_sum) {
1759 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1760 if (ret)
1761 goto out;
1762 }
1763 goto mapit;
1764 } else if (async && !skip_sum) {
1765 /* csum items have already been cloned */
1766 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1767 goto mapit;
1768 /* we're doing a write, do the async checksumming */
1769 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1770 inode, rw, bio, mirror_num,
1771 bio_flags, bio_offset,
1772 __btrfs_submit_bio_start,
1773 __btrfs_submit_bio_done);
1774 goto out;
1775 } else if (!skip_sum) {
1776 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1777 if (ret)
1778 goto out;
1779 }
1780
1781 mapit:
1782 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
1783
1784 out:
1785 if (ret < 0)
1786 bio_endio(bio, ret);
1787 return ret;
1788 }
1789
1790 /*
1791 * given a list of ordered sums record them in the inode. This happens
1792 * at IO completion time based on sums calculated at bio submission time.
1793 */
1794 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1795 struct inode *inode, u64 file_offset,
1796 struct list_head *list)
1797 {
1798 struct btrfs_ordered_sum *sum;
1799
1800 list_for_each_entry(sum, list, list) {
1801 trans->adding_csums = 1;
1802 btrfs_csum_file_blocks(trans,
1803 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1804 trans->adding_csums = 0;
1805 }
1806 return 0;
1807 }
1808
1809 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1810 struct extent_state **cached_state)
1811 {
1812 WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0);
1813 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1814 cached_state, GFP_NOFS);
1815 }
1816
1817 /* see btrfs_writepage_start_hook for details on why this is required */
1818 struct btrfs_writepage_fixup {
1819 struct page *page;
1820 struct btrfs_work work;
1821 };
1822
1823 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1824 {
1825 struct btrfs_writepage_fixup *fixup;
1826 struct btrfs_ordered_extent *ordered;
1827 struct extent_state *cached_state = NULL;
1828 struct page *page;
1829 struct inode *inode;
1830 u64 page_start;
1831 u64 page_end;
1832 int ret;
1833
1834 fixup = container_of(work, struct btrfs_writepage_fixup, work);
1835 page = fixup->page;
1836 again:
1837 lock_page(page);
1838 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
1839 ClearPageChecked(page);
1840 goto out_page;
1841 }
1842
1843 inode = page->mapping->host;
1844 page_start = page_offset(page);
1845 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
1846
1847 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0,
1848 &cached_state);
1849
1850 /* already ordered? We're done */
1851 if (PagePrivate2(page))
1852 goto out;
1853
1854 ordered = btrfs_lookup_ordered_extent(inode, page_start);
1855 if (ordered) {
1856 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
1857 page_end, &cached_state, GFP_NOFS);
1858 unlock_page(page);
1859 btrfs_start_ordered_extent(inode, ordered, 1);
1860 btrfs_put_ordered_extent(ordered);
1861 goto again;
1862 }
1863
1864 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
1865 if (ret) {
1866 mapping_set_error(page->mapping, ret);
1867 end_extent_writepage(page, ret, page_start, page_end);
1868 ClearPageChecked(page);
1869 goto out;
1870 }
1871
1872 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
1873 ClearPageChecked(page);
1874 set_page_dirty(page);
1875 out:
1876 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
1877 &cached_state, GFP_NOFS);
1878 out_page:
1879 unlock_page(page);
1880 page_cache_release(page);
1881 kfree(fixup);
1882 }
1883
1884 /*
1885 * There are a few paths in the higher layers of the kernel that directly
1886 * set the page dirty bit without asking the filesystem if it is a
1887 * good idea. This causes problems because we want to make sure COW
1888 * properly happens and the data=ordered rules are followed.
1889 *
1890 * In our case any range that doesn't have the ORDERED bit set
1891 * hasn't been properly setup for IO. We kick off an async process
1892 * to fix it up. The async helper will wait for ordered extents, set
1893 * the delalloc bit and make it safe to write the page.
1894 */
1895 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
1896 {
1897 struct inode *inode = page->mapping->host;
1898 struct btrfs_writepage_fixup *fixup;
1899 struct btrfs_root *root = BTRFS_I(inode)->root;
1900
1901 /* this page is properly in the ordered list */
1902 if (TestClearPagePrivate2(page))
1903 return 0;
1904
1905 if (PageChecked(page))
1906 return -EAGAIN;
1907
1908 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
1909 if (!fixup)
1910 return -EAGAIN;
1911
1912 SetPageChecked(page);
1913 page_cache_get(page);
1914 fixup->work.func = btrfs_writepage_fixup_worker;
1915 fixup->page = page;
1916 btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work);
1917 return -EBUSY;
1918 }
1919
1920 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
1921 struct inode *inode, u64 file_pos,
1922 u64 disk_bytenr, u64 disk_num_bytes,
1923 u64 num_bytes, u64 ram_bytes,
1924 u8 compression, u8 encryption,
1925 u16 other_encoding, int extent_type)
1926 {
1927 struct btrfs_root *root = BTRFS_I(inode)->root;
1928 struct btrfs_file_extent_item *fi;
1929 struct btrfs_path *path;
1930 struct extent_buffer *leaf;
1931 struct btrfs_key ins;
1932 int ret;
1933
1934 path = btrfs_alloc_path();
1935 if (!path)
1936 return -ENOMEM;
1937
1938 path->leave_spinning = 1;
1939
1940 /*
1941 * we may be replacing one extent in the tree with another.
1942 * The new extent is pinned in the extent map, and we don't want
1943 * to drop it from the cache until it is completely in the btree.
1944 *
1945 * So, tell btrfs_drop_extents to leave this extent in the cache.
1946 * the caller is expected to unpin it and allow it to be merged
1947 * with the others.
1948 */
1949 ret = btrfs_drop_extents(trans, root, inode, file_pos,
1950 file_pos + num_bytes, 0);
1951 if (ret)
1952 goto out;
1953
1954 ins.objectid = btrfs_ino(inode);
1955 ins.offset = file_pos;
1956 ins.type = BTRFS_EXTENT_DATA_KEY;
1957 ret = btrfs_insert_empty_item(trans, root, path, &ins, sizeof(*fi));
1958 if (ret)
1959 goto out;
1960 leaf = path->nodes[0];
1961 fi = btrfs_item_ptr(leaf, path->slots[0],
1962 struct btrfs_file_extent_item);
1963 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1964 btrfs_set_file_extent_type(leaf, fi, extent_type);
1965 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
1966 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
1967 btrfs_set_file_extent_offset(leaf, fi, 0);
1968 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
1969 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
1970 btrfs_set_file_extent_compression(leaf, fi, compression);
1971 btrfs_set_file_extent_encryption(leaf, fi, encryption);
1972 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
1973
1974 btrfs_mark_buffer_dirty(leaf);
1975 btrfs_release_path(path);
1976
1977 inode_add_bytes(inode, num_bytes);
1978
1979 ins.objectid = disk_bytenr;
1980 ins.offset = disk_num_bytes;
1981 ins.type = BTRFS_EXTENT_ITEM_KEY;
1982 ret = btrfs_alloc_reserved_file_extent(trans, root,
1983 root->root_key.objectid,
1984 btrfs_ino(inode), file_pos, &ins);
1985 out:
1986 btrfs_free_path(path);
1987
1988 return ret;
1989 }
1990
1991 /* snapshot-aware defrag */
1992 struct sa_defrag_extent_backref {
1993 struct rb_node node;
1994 struct old_sa_defrag_extent *old;
1995 u64 root_id;
1996 u64 inum;
1997 u64 file_pos;
1998 u64 extent_offset;
1999 u64 num_bytes;
2000 u64 generation;
2001 };
2002
2003 struct old_sa_defrag_extent {
2004 struct list_head list;
2005 struct new_sa_defrag_extent *new;
2006
2007 u64 extent_offset;
2008 u64 bytenr;
2009 u64 offset;
2010 u64 len;
2011 int count;
2012 };
2013
2014 struct new_sa_defrag_extent {
2015 struct rb_root root;
2016 struct list_head head;
2017 struct btrfs_path *path;
2018 struct inode *inode;
2019 u64 file_pos;
2020 u64 len;
2021 u64 bytenr;
2022 u64 disk_len;
2023 u8 compress_type;
2024 };
2025
2026 static int backref_comp(struct sa_defrag_extent_backref *b1,
2027 struct sa_defrag_extent_backref *b2)
2028 {
2029 if (b1->root_id < b2->root_id)
2030 return -1;
2031 else if (b1->root_id > b2->root_id)
2032 return 1;
2033
2034 if (b1->inum < b2->inum)
2035 return -1;
2036 else if (b1->inum > b2->inum)
2037 return 1;
2038
2039 if (b1->file_pos < b2->file_pos)
2040 return -1;
2041 else if (b1->file_pos > b2->file_pos)
2042 return 1;
2043
2044 /*
2045 * [------------------------------] ===> (a range of space)
2046 * |<--->| |<---->| =============> (fs/file tree A)
2047 * |<---------------------------->| ===> (fs/file tree B)
2048 *
2049 * A range of space can refer to two file extents in one tree while
2050 * refer to only one file extent in another tree.
2051 *
2052 * So we may process a disk offset more than one time(two extents in A)
2053 * and locate at the same extent(one extent in B), then insert two same
2054 * backrefs(both refer to the extent in B).
2055 */
2056 return 0;
2057 }
2058
2059 static void backref_insert(struct rb_root *root,
2060 struct sa_defrag_extent_backref *backref)
2061 {
2062 struct rb_node **p = &root->rb_node;
2063 struct rb_node *parent = NULL;
2064 struct sa_defrag_extent_backref *entry;
2065 int ret;
2066
2067 while (*p) {
2068 parent = *p;
2069 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2070
2071 ret = backref_comp(backref, entry);
2072 if (ret < 0)
2073 p = &(*p)->rb_left;
2074 else
2075 p = &(*p)->rb_right;
2076 }
2077
2078 rb_link_node(&backref->node, parent, p);
2079 rb_insert_color(&backref->node, root);
2080 }
2081
2082 /*
2083 * Note the backref might has changed, and in this case we just return 0.
2084 */
2085 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2086 void *ctx)
2087 {
2088 struct btrfs_file_extent_item *extent;
2089 struct btrfs_fs_info *fs_info;
2090 struct old_sa_defrag_extent *old = ctx;
2091 struct new_sa_defrag_extent *new = old->new;
2092 struct btrfs_path *path = new->path;
2093 struct btrfs_key key;
2094 struct btrfs_root *root;
2095 struct sa_defrag_extent_backref *backref;
2096 struct extent_buffer *leaf;
2097 struct inode *inode = new->inode;
2098 int slot;
2099 int ret;
2100 u64 extent_offset;
2101 u64 num_bytes;
2102
2103 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2104 inum == btrfs_ino(inode))
2105 return 0;
2106
2107 key.objectid = root_id;
2108 key.type = BTRFS_ROOT_ITEM_KEY;
2109 key.offset = (u64)-1;
2110
2111 fs_info = BTRFS_I(inode)->root->fs_info;
2112 root = btrfs_read_fs_root_no_name(fs_info, &key);
2113 if (IS_ERR(root)) {
2114 if (PTR_ERR(root) == -ENOENT)
2115 return 0;
2116 WARN_ON(1);
2117 pr_debug("inum=%llu, offset=%llu, root_id=%llu\n",
2118 inum, offset, root_id);
2119 return PTR_ERR(root);
2120 }
2121
2122 key.objectid = inum;
2123 key.type = BTRFS_EXTENT_DATA_KEY;
2124 if (offset > (u64)-1 << 32)
2125 key.offset = 0;
2126 else
2127 key.offset = offset;
2128
2129 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2130 if (ret < 0) {
2131 WARN_ON(1);
2132 return ret;
2133 }
2134
2135 while (1) {
2136 cond_resched();
2137
2138 leaf = path->nodes[0];
2139 slot = path->slots[0];
2140
2141 if (slot >= btrfs_header_nritems(leaf)) {
2142 ret = btrfs_next_leaf(root, path);
2143 if (ret < 0) {
2144 goto out;
2145 } else if (ret > 0) {
2146 ret = 0;
2147 goto out;
2148 }
2149 continue;
2150 }
2151
2152 path->slots[0]++;
2153
2154 btrfs_item_key_to_cpu(leaf, &key, slot);
2155
2156 if (key.objectid > inum)
2157 goto out;
2158
2159 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2160 continue;
2161
2162 extent = btrfs_item_ptr(leaf, slot,
2163 struct btrfs_file_extent_item);
2164
2165 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2166 continue;
2167
2168 extent_offset = btrfs_file_extent_offset(leaf, extent);
2169 if (key.offset - extent_offset != offset)
2170 continue;
2171
2172 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2173 if (extent_offset >= old->extent_offset + old->offset +
2174 old->len || extent_offset + num_bytes <=
2175 old->extent_offset + old->offset)
2176 continue;
2177
2178 break;
2179 }
2180
2181 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2182 if (!backref) {
2183 ret = -ENOENT;
2184 goto out;
2185 }
2186
2187 backref->root_id = root_id;
2188 backref->inum = inum;
2189 backref->file_pos = offset + extent_offset;
2190 backref->num_bytes = num_bytes;
2191 backref->extent_offset = extent_offset;
2192 backref->generation = btrfs_file_extent_generation(leaf, extent);
2193 backref->old = old;
2194 backref_insert(&new->root, backref);
2195 old->count++;
2196 out:
2197 btrfs_release_path(path);
2198 WARN_ON(ret);
2199 return ret;
2200 }
2201
2202 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2203 struct new_sa_defrag_extent *new)
2204 {
2205 struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info;
2206 struct old_sa_defrag_extent *old, *tmp;
2207 int ret;
2208
2209 new->path = path;
2210
2211 list_for_each_entry_safe(old, tmp, &new->head, list) {
2212 ret = iterate_inodes_from_logical(old->bytenr, fs_info,
2213 path, record_one_backref,
2214 old);
2215 BUG_ON(ret < 0 && ret != -ENOENT);
2216
2217 /* no backref to be processed for this extent */
2218 if (!old->count) {
2219 list_del(&old->list);
2220 kfree(old);
2221 }
2222 }
2223
2224 if (list_empty(&new->head))
2225 return false;
2226
2227 return true;
2228 }
2229
2230 static int relink_is_mergable(struct extent_buffer *leaf,
2231 struct btrfs_file_extent_item *fi,
2232 u64 disk_bytenr)
2233 {
2234 if (btrfs_file_extent_disk_bytenr(leaf, fi) != disk_bytenr)
2235 return 0;
2236
2237 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2238 return 0;
2239
2240 if (btrfs_file_extent_compression(leaf, fi) ||
2241 btrfs_file_extent_encryption(leaf, fi) ||
2242 btrfs_file_extent_other_encoding(leaf, fi))
2243 return 0;
2244
2245 return 1;
2246 }
2247
2248 /*
2249 * Note the backref might has changed, and in this case we just return 0.
2250 */
2251 static noinline int relink_extent_backref(struct btrfs_path *path,
2252 struct sa_defrag_extent_backref *prev,
2253 struct sa_defrag_extent_backref *backref)
2254 {
2255 struct btrfs_file_extent_item *extent;
2256 struct btrfs_file_extent_item *item;
2257 struct btrfs_ordered_extent *ordered;
2258 struct btrfs_trans_handle *trans;
2259 struct btrfs_fs_info *fs_info;
2260 struct btrfs_root *root;
2261 struct btrfs_key key;
2262 struct extent_buffer *leaf;
2263 struct old_sa_defrag_extent *old = backref->old;
2264 struct new_sa_defrag_extent *new = old->new;
2265 struct inode *src_inode = new->inode;
2266 struct inode *inode;
2267 struct extent_state *cached = NULL;
2268 int ret = 0;
2269 u64 start;
2270 u64 len;
2271 u64 lock_start;
2272 u64 lock_end;
2273 bool merge = false;
2274 int index;
2275
2276 if (prev && prev->root_id == backref->root_id &&
2277 prev->inum == backref->inum &&
2278 prev->file_pos + prev->num_bytes == backref->file_pos)
2279 merge = true;
2280
2281 /* step 1: get root */
2282 key.objectid = backref->root_id;
2283 key.type = BTRFS_ROOT_ITEM_KEY;
2284 key.offset = (u64)-1;
2285
2286 fs_info = BTRFS_I(src_inode)->root->fs_info;
2287 index = srcu_read_lock(&fs_info->subvol_srcu);
2288
2289 root = btrfs_read_fs_root_no_name(fs_info, &key);
2290 if (IS_ERR(root)) {
2291 srcu_read_unlock(&fs_info->subvol_srcu, index);
2292 if (PTR_ERR(root) == -ENOENT)
2293 return 0;
2294 return PTR_ERR(root);
2295 }
2296
2297 /* step 2: get inode */
2298 key.objectid = backref->inum;
2299 key.type = BTRFS_INODE_ITEM_KEY;
2300 key.offset = 0;
2301
2302 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2303 if (IS_ERR(inode)) {
2304 srcu_read_unlock(&fs_info->subvol_srcu, index);
2305 return 0;
2306 }
2307
2308 srcu_read_unlock(&fs_info->subvol_srcu, index);
2309
2310 /* step 3: relink backref */
2311 lock_start = backref->file_pos;
2312 lock_end = backref->file_pos + backref->num_bytes - 1;
2313 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2314 0, &cached);
2315
2316 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2317 if (ordered) {
2318 btrfs_put_ordered_extent(ordered);
2319 goto out_unlock;
2320 }
2321
2322 trans = btrfs_join_transaction(root);
2323 if (IS_ERR(trans)) {
2324 ret = PTR_ERR(trans);
2325 goto out_unlock;
2326 }
2327
2328 key.objectid = backref->inum;
2329 key.type = BTRFS_EXTENT_DATA_KEY;
2330 key.offset = backref->file_pos;
2331
2332 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2333 if (ret < 0) {
2334 goto out_free_path;
2335 } else if (ret > 0) {
2336 ret = 0;
2337 goto out_free_path;
2338 }
2339
2340 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2341 struct btrfs_file_extent_item);
2342
2343 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2344 backref->generation)
2345 goto out_free_path;
2346
2347 btrfs_release_path(path);
2348
2349 start = backref->file_pos;
2350 if (backref->extent_offset < old->extent_offset + old->offset)
2351 start += old->extent_offset + old->offset -
2352 backref->extent_offset;
2353
2354 len = min(backref->extent_offset + backref->num_bytes,
2355 old->extent_offset + old->offset + old->len);
2356 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2357
2358 ret = btrfs_drop_extents(trans, root, inode, start,
2359 start + len, 1);
2360 if (ret)
2361 goto out_free_path;
2362 again:
2363 key.objectid = btrfs_ino(inode);
2364 key.type = BTRFS_EXTENT_DATA_KEY;
2365 key.offset = start;
2366
2367 path->leave_spinning = 1;
2368 if (merge) {
2369 struct btrfs_file_extent_item *fi;
2370 u64 extent_len;
2371 struct btrfs_key found_key;
2372
2373 ret = btrfs_search_slot(trans, root, &key, path, 1, 1);
2374 if (ret < 0)
2375 goto out_free_path;
2376
2377 path->slots[0]--;
2378 leaf = path->nodes[0];
2379 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2380
2381 fi = btrfs_item_ptr(leaf, path->slots[0],
2382 struct btrfs_file_extent_item);
2383 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2384
2385 if (relink_is_mergable(leaf, fi, new->bytenr) &&
2386 extent_len + found_key.offset == start) {
2387 btrfs_set_file_extent_num_bytes(leaf, fi,
2388 extent_len + len);
2389 btrfs_mark_buffer_dirty(leaf);
2390 inode_add_bytes(inode, len);
2391
2392 ret = 1;
2393 goto out_free_path;
2394 } else {
2395 merge = false;
2396 btrfs_release_path(path);
2397 goto again;
2398 }
2399 }
2400
2401 ret = btrfs_insert_empty_item(trans, root, path, &key,
2402 sizeof(*extent));
2403 if (ret) {
2404 btrfs_abort_transaction(trans, root, ret);
2405 goto out_free_path;
2406 }
2407
2408 leaf = path->nodes[0];
2409 item = btrfs_item_ptr(leaf, path->slots[0],
2410 struct btrfs_file_extent_item);
2411 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2412 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2413 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2414 btrfs_set_file_extent_num_bytes(leaf, item, len);
2415 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2416 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2417 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2418 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2419 btrfs_set_file_extent_encryption(leaf, item, 0);
2420 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2421
2422 btrfs_mark_buffer_dirty(leaf);
2423 inode_add_bytes(inode, len);
2424 btrfs_release_path(path);
2425
2426 ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
2427 new->disk_len, 0,
2428 backref->root_id, backref->inum,
2429 new->file_pos, 0); /* start - extent_offset */
2430 if (ret) {
2431 btrfs_abort_transaction(trans, root, ret);
2432 goto out_free_path;
2433 }
2434
2435 ret = 1;
2436 out_free_path:
2437 btrfs_release_path(path);
2438 path->leave_spinning = 0;
2439 btrfs_end_transaction(trans, root);
2440 out_unlock:
2441 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2442 &cached, GFP_NOFS);
2443 iput(inode);
2444 return ret;
2445 }
2446
2447 static void relink_file_extents(struct new_sa_defrag_extent *new)
2448 {
2449 struct btrfs_path *path;
2450 struct old_sa_defrag_extent *old, *tmp;
2451 struct sa_defrag_extent_backref *backref;
2452 struct sa_defrag_extent_backref *prev = NULL;
2453 struct inode *inode;
2454 struct btrfs_root *root;
2455 struct rb_node *node;
2456 int ret;
2457
2458 inode = new->inode;
2459 root = BTRFS_I(inode)->root;
2460
2461 path = btrfs_alloc_path();
2462 if (!path)
2463 return;
2464
2465 if (!record_extent_backrefs(path, new)) {
2466 btrfs_free_path(path);
2467 goto out;
2468 }
2469 btrfs_release_path(path);
2470
2471 while (1) {
2472 node = rb_first(&new->root);
2473 if (!node)
2474 break;
2475 rb_erase(node, &new->root);
2476
2477 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2478
2479 ret = relink_extent_backref(path, prev, backref);
2480 WARN_ON(ret < 0);
2481
2482 kfree(prev);
2483
2484 if (ret == 1)
2485 prev = backref;
2486 else
2487 prev = NULL;
2488 cond_resched();
2489 }
2490 kfree(prev);
2491
2492 btrfs_free_path(path);
2493
2494 list_for_each_entry_safe(old, tmp, &new->head, list) {
2495 list_del(&old->list);
2496 kfree(old);
2497 }
2498 out:
2499 atomic_dec(&root->fs_info->defrag_running);
2500 wake_up(&root->fs_info->transaction_wait);
2501
2502 kfree(new);
2503 }
2504
2505 static struct new_sa_defrag_extent *
2506 record_old_file_extents(struct inode *inode,
2507 struct btrfs_ordered_extent *ordered)
2508 {
2509 struct btrfs_root *root = BTRFS_I(inode)->root;
2510 struct btrfs_path *path;
2511 struct btrfs_key key;
2512 struct old_sa_defrag_extent *old, *tmp;
2513 struct new_sa_defrag_extent *new;
2514 int ret;
2515
2516 new = kmalloc(sizeof(*new), GFP_NOFS);
2517 if (!new)
2518 return NULL;
2519
2520 new->inode = inode;
2521 new->file_pos = ordered->file_offset;
2522 new->len = ordered->len;
2523 new->bytenr = ordered->start;
2524 new->disk_len = ordered->disk_len;
2525 new->compress_type = ordered->compress_type;
2526 new->root = RB_ROOT;
2527 INIT_LIST_HEAD(&new->head);
2528
2529 path = btrfs_alloc_path();
2530 if (!path)
2531 goto out_kfree;
2532
2533 key.objectid = btrfs_ino(inode);
2534 key.type = BTRFS_EXTENT_DATA_KEY;
2535 key.offset = new->file_pos;
2536
2537 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2538 if (ret < 0)
2539 goto out_free_path;
2540 if (ret > 0 && path->slots[0] > 0)
2541 path->slots[0]--;
2542
2543 /* find out all the old extents for the file range */
2544 while (1) {
2545 struct btrfs_file_extent_item *extent;
2546 struct extent_buffer *l;
2547 int slot;
2548 u64 num_bytes;
2549 u64 offset;
2550 u64 end;
2551 u64 disk_bytenr;
2552 u64 extent_offset;
2553
2554 l = path->nodes[0];
2555 slot = path->slots[0];
2556
2557 if (slot >= btrfs_header_nritems(l)) {
2558 ret = btrfs_next_leaf(root, path);
2559 if (ret < 0)
2560 goto out_free_list;
2561 else if (ret > 0)
2562 break;
2563 continue;
2564 }
2565
2566 btrfs_item_key_to_cpu(l, &key, slot);
2567
2568 if (key.objectid != btrfs_ino(inode))
2569 break;
2570 if (key.type != BTRFS_EXTENT_DATA_KEY)
2571 break;
2572 if (key.offset >= new->file_pos + new->len)
2573 break;
2574
2575 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2576
2577 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2578 if (key.offset + num_bytes < new->file_pos)
2579 goto next;
2580
2581 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2582 if (!disk_bytenr)
2583 goto next;
2584
2585 extent_offset = btrfs_file_extent_offset(l, extent);
2586
2587 old = kmalloc(sizeof(*old), GFP_NOFS);
2588 if (!old)
2589 goto out_free_list;
2590
2591 offset = max(new->file_pos, key.offset);
2592 end = min(new->file_pos + new->len, key.offset + num_bytes);
2593
2594 old->bytenr = disk_bytenr;
2595 old->extent_offset = extent_offset;
2596 old->offset = offset - key.offset;
2597 old->len = end - offset;
2598 old->new = new;
2599 old->count = 0;
2600 list_add_tail(&old->list, &new->head);
2601 next:
2602 path->slots[0]++;
2603 cond_resched();
2604 }
2605
2606 btrfs_free_path(path);
2607 atomic_inc(&root->fs_info->defrag_running);
2608
2609 return new;
2610
2611 out_free_list:
2612 list_for_each_entry_safe(old, tmp, &new->head, list) {
2613 list_del(&old->list);
2614 kfree(old);
2615 }
2616 out_free_path:
2617 btrfs_free_path(path);
2618 out_kfree:
2619 kfree(new);
2620 return NULL;
2621 }
2622
2623 /*
2624 * helper function for btrfs_finish_ordered_io, this
2625 * just reads in some of the csum leaves to prime them into ram
2626 * before we start the transaction. It limits the amount of btree
2627 * reads required while inside the transaction.
2628 */
2629 /* as ordered data IO finishes, this gets called so we can finish
2630 * an ordered extent if the range of bytes in the file it covers are
2631 * fully written.
2632 */
2633 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2634 {
2635 struct inode *inode = ordered_extent->inode;
2636 struct btrfs_root *root = BTRFS_I(inode)->root;
2637 struct btrfs_trans_handle *trans = NULL;
2638 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2639 struct extent_state *cached_state = NULL;
2640 struct new_sa_defrag_extent *new = NULL;
2641 int compress_type = 0;
2642 int ret;
2643 bool nolock;
2644
2645 nolock = btrfs_is_free_space_inode(inode);
2646
2647 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2648 ret = -EIO;
2649 goto out;
2650 }
2651
2652 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2653 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2654 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2655 if (nolock)
2656 trans = btrfs_join_transaction_nolock(root);
2657 else
2658 trans = btrfs_join_transaction(root);
2659 if (IS_ERR(trans)) {
2660 ret = PTR_ERR(trans);
2661 trans = NULL;
2662 goto out;
2663 }
2664 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2665 ret = btrfs_update_inode_fallback(trans, root, inode);
2666 if (ret) /* -ENOMEM or corruption */
2667 btrfs_abort_transaction(trans, root, ret);
2668 goto out;
2669 }
2670
2671 lock_extent_bits(io_tree, ordered_extent->file_offset,
2672 ordered_extent->file_offset + ordered_extent->len - 1,
2673 0, &cached_state);
2674
2675 ret = test_range_bit(io_tree, ordered_extent->file_offset,
2676 ordered_extent->file_offset + ordered_extent->len - 1,
2677 EXTENT_DEFRAG, 1, cached_state);
2678 if (ret) {
2679 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2680 if (last_snapshot >= BTRFS_I(inode)->generation)
2681 /* the inode is shared */
2682 new = record_old_file_extents(inode, ordered_extent);
2683
2684 clear_extent_bit(io_tree, ordered_extent->file_offset,
2685 ordered_extent->file_offset + ordered_extent->len - 1,
2686 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
2687 }
2688
2689 if (nolock)
2690 trans = btrfs_join_transaction_nolock(root);
2691 else
2692 trans = btrfs_join_transaction(root);
2693 if (IS_ERR(trans)) {
2694 ret = PTR_ERR(trans);
2695 trans = NULL;
2696 goto out_unlock;
2697 }
2698 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2699
2700 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
2701 compress_type = ordered_extent->compress_type;
2702 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
2703 BUG_ON(compress_type);
2704 ret = btrfs_mark_extent_written(trans, inode,
2705 ordered_extent->file_offset,
2706 ordered_extent->file_offset +
2707 ordered_extent->len);
2708 } else {
2709 BUG_ON(root == root->fs_info->tree_root);
2710 ret = insert_reserved_file_extent(trans, inode,
2711 ordered_extent->file_offset,
2712 ordered_extent->start,
2713 ordered_extent->disk_len,
2714 ordered_extent->len,
2715 ordered_extent->len,
2716 compress_type, 0, 0,
2717 BTRFS_FILE_EXTENT_REG);
2718 }
2719 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
2720 ordered_extent->file_offset, ordered_extent->len,
2721 trans->transid);
2722 if (ret < 0) {
2723 btrfs_abort_transaction(trans, root, ret);
2724 goto out_unlock;
2725 }
2726
2727 add_pending_csums(trans, inode, ordered_extent->file_offset,
2728 &ordered_extent->list);
2729
2730 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2731 ret = btrfs_update_inode_fallback(trans, root, inode);
2732 if (ret) { /* -ENOMEM or corruption */
2733 btrfs_abort_transaction(trans, root, ret);
2734 goto out_unlock;
2735 }
2736 ret = 0;
2737 out_unlock:
2738 unlock_extent_cached(io_tree, ordered_extent->file_offset,
2739 ordered_extent->file_offset +
2740 ordered_extent->len - 1, &cached_state, GFP_NOFS);
2741 out:
2742 if (root != root->fs_info->tree_root)
2743 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
2744 if (trans)
2745 btrfs_end_transaction(trans, root);
2746
2747 if (ret) {
2748 clear_extent_uptodate(io_tree, ordered_extent->file_offset,
2749 ordered_extent->file_offset +
2750 ordered_extent->len - 1, NULL, GFP_NOFS);
2751
2752 /*
2753 * If the ordered extent had an IOERR or something else went
2754 * wrong we need to return the space for this ordered extent
2755 * back to the allocator.
2756 */
2757 if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
2758 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
2759 btrfs_free_reserved_extent(root, ordered_extent->start,
2760 ordered_extent->disk_len);
2761 }
2762
2763
2764 /*
2765 * This needs to be done to make sure anybody waiting knows we are done
2766 * updating everything for this ordered extent.
2767 */
2768 btrfs_remove_ordered_extent(inode, ordered_extent);
2769
2770 /* for snapshot-aware defrag */
2771 if (new)
2772 relink_file_extents(new);
2773
2774 /* once for us */
2775 btrfs_put_ordered_extent(ordered_extent);
2776 /* once for the tree */
2777 btrfs_put_ordered_extent(ordered_extent);
2778
2779 return ret;
2780 }
2781
2782 static void finish_ordered_fn(struct btrfs_work *work)
2783 {
2784 struct btrfs_ordered_extent *ordered_extent;
2785 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
2786 btrfs_finish_ordered_io(ordered_extent);
2787 }
2788
2789 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
2790 struct extent_state *state, int uptodate)
2791 {
2792 struct inode *inode = page->mapping->host;
2793 struct btrfs_root *root = BTRFS_I(inode)->root;
2794 struct btrfs_ordered_extent *ordered_extent = NULL;
2795 struct btrfs_workers *workers;
2796
2797 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
2798
2799 ClearPagePrivate2(page);
2800 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
2801 end - start + 1, uptodate))
2802 return 0;
2803
2804 ordered_extent->work.func = finish_ordered_fn;
2805 ordered_extent->work.flags = 0;
2806
2807 if (btrfs_is_free_space_inode(inode))
2808 workers = &root->fs_info->endio_freespace_worker;
2809 else
2810 workers = &root->fs_info->endio_write_workers;
2811 btrfs_queue_worker(workers, &ordered_extent->work);
2812
2813 return 0;
2814 }
2815
2816 /*
2817 * when reads are done, we need to check csums to verify the data is correct
2818 * if there's a match, we allow the bio to finish. If not, the code in
2819 * extent_io.c will try to find good copies for us.
2820 */
2821 static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
2822 struct extent_state *state, int mirror)
2823 {
2824 size_t offset = start - page_offset(page);
2825 struct inode *inode = page->mapping->host;
2826 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2827 char *kaddr;
2828 u64 private = ~(u32)0;
2829 int ret;
2830 struct btrfs_root *root = BTRFS_I(inode)->root;
2831 u32 csum = ~(u32)0;
2832 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
2833 DEFAULT_RATELIMIT_BURST);
2834
2835 if (PageChecked(page)) {
2836 ClearPageChecked(page);
2837 goto good;
2838 }
2839
2840 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
2841 goto good;
2842
2843 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
2844 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
2845 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
2846 GFP_NOFS);
2847 return 0;
2848 }
2849
2850 if (state && state->start == start) {
2851 private = state->private;
2852 ret = 0;
2853 } else {
2854 ret = get_state_private(io_tree, start, &private);
2855 }
2856 kaddr = kmap_atomic(page);
2857 if (ret)
2858 goto zeroit;
2859
2860 csum = btrfs_csum_data(kaddr + offset, csum, end - start + 1);
2861 btrfs_csum_final(csum, (char *)&csum);
2862 if (csum != private)
2863 goto zeroit;
2864
2865 kunmap_atomic(kaddr);
2866 good:
2867 return 0;
2868
2869 zeroit:
2870 if (__ratelimit(&_rs))
2871 btrfs_info(root->fs_info, "csum failed ino %llu off %llu csum %u private %llu",
2872 (unsigned long long)btrfs_ino(page->mapping->host),
2873 (unsigned long long)start, csum,
2874 (unsigned long long)private);
2875 memset(kaddr + offset, 1, end - start + 1);
2876 flush_dcache_page(page);
2877 kunmap_atomic(kaddr);
2878 if (private == 0)
2879 return 0;
2880 return -EIO;
2881 }
2882
2883 struct delayed_iput {
2884 struct list_head list;
2885 struct inode *inode;
2886 };
2887
2888 /* JDM: If this is fs-wide, why can't we add a pointer to
2889 * btrfs_inode instead and avoid the allocation? */
2890 void btrfs_add_delayed_iput(struct inode *inode)
2891 {
2892 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2893 struct delayed_iput *delayed;
2894
2895 if (atomic_add_unless(&inode->i_count, -1, 1))
2896 return;
2897
2898 delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL);
2899 delayed->inode = inode;
2900
2901 spin_lock(&fs_info->delayed_iput_lock);
2902 list_add_tail(&delayed->list, &fs_info->delayed_iputs);
2903 spin_unlock(&fs_info->delayed_iput_lock);
2904 }
2905
2906 void btrfs_run_delayed_iputs(struct btrfs_root *root)
2907 {
2908 LIST_HEAD(list);
2909 struct btrfs_fs_info *fs_info = root->fs_info;
2910 struct delayed_iput *delayed;
2911 int empty;
2912
2913 spin_lock(&fs_info->delayed_iput_lock);
2914 empty = list_empty(&fs_info->delayed_iputs);
2915 spin_unlock(&fs_info->delayed_iput_lock);
2916 if (empty)
2917 return;
2918
2919 spin_lock(&fs_info->delayed_iput_lock);
2920 list_splice_init(&fs_info->delayed_iputs, &list);
2921 spin_unlock(&fs_info->delayed_iput_lock);
2922
2923 while (!list_empty(&list)) {
2924 delayed = list_entry(list.next, struct delayed_iput, list);
2925 list_del(&delayed->list);
2926 iput(delayed->inode);
2927 kfree(delayed);
2928 }
2929 }
2930
2931 /*
2932 * This is called in transaction commit time. If there are no orphan
2933 * files in the subvolume, it removes orphan item and frees block_rsv
2934 * structure.
2935 */
2936 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
2937 struct btrfs_root *root)
2938 {
2939 struct btrfs_block_rsv *block_rsv;
2940 int ret;
2941
2942 if (atomic_read(&root->orphan_inodes) ||
2943 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
2944 return;
2945
2946 spin_lock(&root->orphan_lock);
2947 if (atomic_read(&root->orphan_inodes)) {
2948 spin_unlock(&root->orphan_lock);
2949 return;
2950 }
2951
2952 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
2953 spin_unlock(&root->orphan_lock);
2954 return;
2955 }
2956
2957 block_rsv = root->orphan_block_rsv;
2958 root->orphan_block_rsv = NULL;
2959 spin_unlock(&root->orphan_lock);
2960
2961 if (root->orphan_item_inserted &&
2962 btrfs_root_refs(&root->root_item) > 0) {
2963 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
2964 root->root_key.objectid);
2965 BUG_ON(ret);
2966 root->orphan_item_inserted = 0;
2967 }
2968
2969 if (block_rsv) {
2970 WARN_ON(block_rsv->size > 0);
2971 btrfs_free_block_rsv(root, block_rsv);
2972 }
2973 }
2974
2975 /*
2976 * This creates an orphan entry for the given inode in case something goes
2977 * wrong in the middle of an unlink/truncate.
2978 *
2979 * NOTE: caller of this function should reserve 5 units of metadata for
2980 * this function.
2981 */
2982 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
2983 {
2984 struct btrfs_root *root = BTRFS_I(inode)->root;
2985 struct btrfs_block_rsv *block_rsv = NULL;
2986 int reserve = 0;
2987 int insert = 0;
2988 int ret;
2989
2990 if (!root->orphan_block_rsv) {
2991 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
2992 if (!block_rsv)
2993 return -ENOMEM;
2994 }
2995
2996 spin_lock(&root->orphan_lock);
2997 if (!root->orphan_block_rsv) {
2998 root->orphan_block_rsv = block_rsv;
2999 } else if (block_rsv) {
3000 btrfs_free_block_rsv(root, block_rsv);
3001 block_rsv = NULL;
3002 }
3003
3004 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3005 &BTRFS_I(inode)->runtime_flags)) {
3006 #if 0
3007 /*
3008 * For proper ENOSPC handling, we should do orphan
3009 * cleanup when mounting. But this introduces backward
3010 * compatibility issue.
3011 */
3012 if (!xchg(&root->orphan_item_inserted, 1))
3013 insert = 2;
3014 else
3015 insert = 1;
3016 #endif
3017 insert = 1;
3018 atomic_inc(&root->orphan_inodes);
3019 }
3020
3021 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3022 &BTRFS_I(inode)->runtime_flags))
3023 reserve = 1;
3024 spin_unlock(&root->orphan_lock);
3025
3026 /* grab metadata reservation from transaction handle */
3027 if (reserve) {
3028 ret = btrfs_orphan_reserve_metadata(trans, inode);
3029 BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */
3030 }
3031
3032 /* insert an orphan item to track this unlinked/truncated file */
3033 if (insert >= 1) {
3034 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3035 if (ret && ret != -EEXIST) {
3036 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3037 &BTRFS_I(inode)->runtime_flags);
3038 btrfs_abort_transaction(trans, root, ret);
3039 return ret;
3040 }
3041 ret = 0;
3042 }
3043
3044 /* insert an orphan item to track subvolume contains orphan files */
3045 if (insert >= 2) {
3046 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
3047 root->root_key.objectid);
3048 if (ret && ret != -EEXIST) {
3049 btrfs_abort_transaction(trans, root, ret);
3050 return ret;
3051 }
3052 }
3053 return 0;
3054 }
3055
3056 /*
3057 * We have done the truncate/delete so we can go ahead and remove the orphan
3058 * item for this particular inode.
3059 */
3060 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3061 struct inode *inode)
3062 {
3063 struct btrfs_root *root = BTRFS_I(inode)->root;
3064 int delete_item = 0;
3065 int release_rsv = 0;
3066 int ret = 0;
3067
3068 spin_lock(&root->orphan_lock);
3069 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3070 &BTRFS_I(inode)->runtime_flags))
3071 delete_item = 1;
3072
3073 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3074 &BTRFS_I(inode)->runtime_flags))
3075 release_rsv = 1;
3076 spin_unlock(&root->orphan_lock);
3077
3078 if (trans && delete_item) {
3079 ret = btrfs_del_orphan_item(trans, root, btrfs_ino(inode));
3080 BUG_ON(ret); /* -ENOMEM or corruption (JDM: Recheck) */
3081 }
3082
3083 if (release_rsv) {
3084 btrfs_orphan_release_metadata(inode);
3085 atomic_dec(&root->orphan_inodes);
3086 }
3087
3088 return 0;
3089 }
3090
3091 /*
3092 * this cleans up any orphans that may be left on the list from the last use
3093 * of this root.
3094 */
3095 int btrfs_orphan_cleanup(struct btrfs_root *root)
3096 {
3097 struct btrfs_path *path;
3098 struct extent_buffer *leaf;
3099 struct btrfs_key key, found_key;
3100 struct btrfs_trans_handle *trans;
3101 struct inode *inode;
3102 u64 last_objectid = 0;
3103 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3104
3105 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3106 return 0;
3107
3108 path = btrfs_alloc_path();
3109 if (!path) {
3110 ret = -ENOMEM;
3111 goto out;
3112 }
3113 path->reada = -1;
3114
3115 key.objectid = BTRFS_ORPHAN_OBJECTID;
3116 btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
3117 key.offset = (u64)-1;
3118
3119 while (1) {
3120 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3121 if (ret < 0)
3122 goto out;
3123
3124 /*
3125 * if ret == 0 means we found what we were searching for, which
3126 * is weird, but possible, so only screw with path if we didn't
3127 * find the key and see if we have stuff that matches
3128 */
3129 if (ret > 0) {
3130 ret = 0;
3131 if (path->slots[0] == 0)
3132 break;
3133 path->slots[0]--;
3134 }
3135
3136 /* pull out the item */
3137 leaf = path->nodes[0];
3138 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3139
3140 /* make sure the item matches what we want */
3141 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3142 break;
3143 if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY)
3144 break;
3145
3146 /* release the path since we're done with it */
3147 btrfs_release_path(path);
3148
3149 /*
3150 * this is where we are basically btrfs_lookup, without the
3151 * crossing root thing. we store the inode number in the
3152 * offset of the orphan item.
3153 */
3154
3155 if (found_key.offset == last_objectid) {
3156 btrfs_err(root->fs_info,
3157 "Error removing orphan entry, stopping orphan cleanup");
3158 ret = -EINVAL;
3159 goto out;
3160 }
3161
3162 last_objectid = found_key.offset;
3163
3164 found_key.objectid = found_key.offset;
3165 found_key.type = BTRFS_INODE_ITEM_KEY;
3166 found_key.offset = 0;
3167 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
3168 ret = PTR_RET(inode);
3169 if (ret && ret != -ESTALE)
3170 goto out;
3171
3172 if (ret == -ESTALE && root == root->fs_info->tree_root) {
3173 struct btrfs_root *dead_root;
3174 struct btrfs_fs_info *fs_info = root->fs_info;
3175 int is_dead_root = 0;
3176
3177 /*
3178 * this is an orphan in the tree root. Currently these
3179 * could come from 2 sources:
3180 * a) a snapshot deletion in progress
3181 * b) a free space cache inode
3182 * We need to distinguish those two, as the snapshot
3183 * orphan must not get deleted.
3184 * find_dead_roots already ran before us, so if this
3185 * is a snapshot deletion, we should find the root
3186 * in the dead_roots list
3187 */
3188 spin_lock(&fs_info->trans_lock);
3189 list_for_each_entry(dead_root, &fs_info->dead_roots,
3190 root_list) {
3191 if (dead_root->root_key.objectid ==
3192 found_key.objectid) {
3193 is_dead_root = 1;
3194 break;
3195 }
3196 }
3197 spin_unlock(&fs_info->trans_lock);
3198 if (is_dead_root) {
3199 /* prevent this orphan from being found again */
3200 key.offset = found_key.objectid - 1;
3201 continue;
3202 }
3203 }
3204 /*
3205 * Inode is already gone but the orphan item is still there,
3206 * kill the orphan item.
3207 */
3208 if (ret == -ESTALE) {
3209 trans = btrfs_start_transaction(root, 1);
3210 if (IS_ERR(trans)) {
3211 ret = PTR_ERR(trans);
3212 goto out;
3213 }
3214 btrfs_debug(root->fs_info, "auto deleting %Lu",
3215 found_key.objectid);
3216 ret = btrfs_del_orphan_item(trans, root,
3217 found_key.objectid);
3218 BUG_ON(ret); /* -ENOMEM or corruption (JDM: Recheck) */
3219 btrfs_end_transaction(trans, root);
3220 continue;
3221 }
3222
3223 /*
3224 * add this inode to the orphan list so btrfs_orphan_del does
3225 * the proper thing when we hit it
3226 */
3227 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3228 &BTRFS_I(inode)->runtime_flags);
3229 atomic_inc(&root->orphan_inodes);
3230
3231 /* if we have links, this was a truncate, lets do that */
3232 if (inode->i_nlink) {
3233 if (!S_ISREG(inode->i_mode)) {
3234 WARN_ON(1);
3235 iput(inode);
3236 continue;
3237 }
3238 nr_truncate++;
3239
3240 /* 1 for the orphan item deletion. */
3241 trans = btrfs_start_transaction(root, 1);
3242 if (IS_ERR(trans)) {
3243 iput(inode);
3244 ret = PTR_ERR(trans);
3245 goto out;
3246 }
3247 ret = btrfs_orphan_add(trans, inode);
3248 btrfs_end_transaction(trans, root);
3249 if (ret) {
3250 iput(inode);
3251 goto out;
3252 }
3253
3254 ret = btrfs_truncate(inode);
3255 if (ret)
3256 btrfs_orphan_del(NULL, inode);
3257 } else {
3258 nr_unlink++;
3259 }
3260
3261 /* this will do delete_inode and everything for us */
3262 iput(inode);
3263 if (ret)
3264 goto out;
3265 }
3266 /* release the path since we're done with it */
3267 btrfs_release_path(path);
3268
3269 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3270
3271 if (root->orphan_block_rsv)
3272 btrfs_block_rsv_release(root, root->orphan_block_rsv,
3273 (u64)-1);
3274
3275 if (root->orphan_block_rsv || root->orphan_item_inserted) {
3276 trans = btrfs_join_transaction(root);
3277 if (!IS_ERR(trans))
3278 btrfs_end_transaction(trans, root);
3279 }
3280
3281 if (nr_unlink)
3282 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink);
3283 if (nr_truncate)
3284 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate);
3285
3286 out:
3287 if (ret)
3288 btrfs_crit(root->fs_info,
3289 "could not do orphan cleanup %d", ret);
3290 btrfs_free_path(path);
3291 return ret;
3292 }
3293
3294 /*
3295 * very simple check to peek ahead in the leaf looking for xattrs. If we
3296 * don't find any xattrs, we know there can't be any acls.
3297 *
3298 * slot is the slot the inode is in, objectid is the objectid of the inode
3299 */
3300 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3301 int slot, u64 objectid)
3302 {
3303 u32 nritems = btrfs_header_nritems(leaf);
3304 struct btrfs_key found_key;
3305 static u64 xattr_access = 0;
3306 static u64 xattr_default = 0;
3307 int scanned = 0;
3308
3309 if (!xattr_access) {
3310 xattr_access = btrfs_name_hash(POSIX_ACL_XATTR_ACCESS,
3311 strlen(POSIX_ACL_XATTR_ACCESS));
3312 xattr_default = btrfs_name_hash(POSIX_ACL_XATTR_DEFAULT,
3313 strlen(POSIX_ACL_XATTR_DEFAULT));
3314 }
3315
3316 slot++;
3317 while (slot < nritems) {
3318 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3319
3320 /* we found a different objectid, there must not be acls */
3321 if (found_key.objectid != objectid)
3322 return 0;
3323
3324 /* we found an xattr, assume we've got an acl */
3325 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3326 if (found_key.offset == xattr_access ||
3327 found_key.offset == xattr_default)
3328 return 1;
3329 }
3330
3331 /*
3332 * we found a key greater than an xattr key, there can't
3333 * be any acls later on
3334 */
3335 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3336 return 0;
3337
3338 slot++;
3339 scanned++;
3340
3341 /*
3342 * it goes inode, inode backrefs, xattrs, extents,
3343 * so if there are a ton of hard links to an inode there can
3344 * be a lot of backrefs. Don't waste time searching too hard,
3345 * this is just an optimization
3346 */
3347 if (scanned >= 8)
3348 break;
3349 }
3350 /* we hit the end of the leaf before we found an xattr or
3351 * something larger than an xattr. We have to assume the inode
3352 * has acls
3353 */
3354 return 1;
3355 }
3356
3357 /*
3358 * read an inode from the btree into the in-memory inode
3359 */
3360 static void btrfs_read_locked_inode(struct inode *inode)
3361 {
3362 struct btrfs_path *path;
3363 struct extent_buffer *leaf;
3364 struct btrfs_inode_item *inode_item;
3365 struct btrfs_timespec *tspec;
3366 struct btrfs_root *root = BTRFS_I(inode)->root;
3367 struct btrfs_key location;
3368 int maybe_acls;
3369 u32 rdev;
3370 int ret;
3371 bool filled = false;
3372
3373 ret = btrfs_fill_inode(inode, &rdev);
3374 if (!ret)
3375 filled = true;
3376
3377 path = btrfs_alloc_path();
3378 if (!path)
3379 goto make_bad;
3380
3381 path->leave_spinning = 1;
3382 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3383
3384 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3385 if (ret)
3386 goto make_bad;
3387
3388 leaf = path->nodes[0];
3389
3390 if (filled)
3391 goto cache_acl;
3392
3393 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3394 struct btrfs_inode_item);
3395 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3396 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3397 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3398 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3399 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
3400
3401 tspec = btrfs_inode_atime(inode_item);
3402 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3403 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3404
3405 tspec = btrfs_inode_mtime(inode_item);
3406 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3407 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3408
3409 tspec = btrfs_inode_ctime(inode_item);
3410 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3411 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3412
3413 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3414 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3415 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3416
3417 /*
3418 * If we were modified in the current generation and evicted from memory
3419 * and then re-read we need to do a full sync since we don't have any
3420 * idea about which extents were modified before we were evicted from
3421 * cache.
3422 */
3423 if (BTRFS_I(inode)->last_trans == root->fs_info->generation)
3424 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3425 &BTRFS_I(inode)->runtime_flags);
3426
3427 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
3428 inode->i_generation = BTRFS_I(inode)->generation;
3429 inode->i_rdev = 0;
3430 rdev = btrfs_inode_rdev(leaf, inode_item);
3431
3432 BTRFS_I(inode)->index_cnt = (u64)-1;
3433 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3434 cache_acl:
3435 /*
3436 * try to precache a NULL acl entry for files that don't have
3437 * any xattrs or acls
3438 */
3439 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3440 btrfs_ino(inode));
3441 if (!maybe_acls)
3442 cache_no_acl(inode);
3443
3444 btrfs_free_path(path);
3445
3446 switch (inode->i_mode & S_IFMT) {
3447 case S_IFREG:
3448 inode->i_mapping->a_ops = &btrfs_aops;
3449 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3450 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3451 inode->i_fop = &btrfs_file_operations;
3452 inode->i_op = &btrfs_file_inode_operations;
3453 break;
3454 case S_IFDIR:
3455 inode->i_fop = &btrfs_dir_file_operations;
3456 if (root == root->fs_info->tree_root)
3457 inode->i_op = &btrfs_dir_ro_inode_operations;
3458 else
3459 inode->i_op = &btrfs_dir_inode_operations;
3460 break;
3461 case S_IFLNK:
3462 inode->i_op = &btrfs_symlink_inode_operations;
3463 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3464 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3465 break;
3466 default:
3467 inode->i_op = &btrfs_special_inode_operations;
3468 init_special_inode(inode, inode->i_mode, rdev);
3469 break;
3470 }
3471
3472 btrfs_update_iflags(inode);
3473 return;
3474
3475 make_bad:
3476 btrfs_free_path(path);
3477 make_bad_inode(inode);
3478 }
3479
3480 /*
3481 * given a leaf and an inode, copy the inode fields into the leaf
3482 */
3483 static void fill_inode_item(struct btrfs_trans_handle *trans,
3484 struct extent_buffer *leaf,
3485 struct btrfs_inode_item *item,
3486 struct inode *inode)
3487 {
3488 struct btrfs_map_token token;
3489
3490 btrfs_init_map_token(&token);
3491
3492 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3493 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3494 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3495 &token);
3496 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3497 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3498
3499 btrfs_set_token_timespec_sec(leaf, btrfs_inode_atime(item),
3500 inode->i_atime.tv_sec, &token);
3501 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_atime(item),
3502 inode->i_atime.tv_nsec, &token);
3503
3504 btrfs_set_token_timespec_sec(leaf, btrfs_inode_mtime(item),
3505 inode->i_mtime.tv_sec, &token);
3506 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_mtime(item),
3507 inode->i_mtime.tv_nsec, &token);
3508
3509 btrfs_set_token_timespec_sec(leaf, btrfs_inode_ctime(item),
3510 inode->i_ctime.tv_sec, &token);
3511 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_ctime(item),
3512 inode->i_ctime.tv_nsec, &token);
3513
3514 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3515 &token);
3516 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3517 &token);
3518 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3519 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3520 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3521 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3522 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3523 }
3524
3525 /*
3526 * copy everything in the in-memory inode into the btree.
3527 */
3528 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3529 struct btrfs_root *root, struct inode *inode)
3530 {
3531 struct btrfs_inode_item *inode_item;
3532 struct btrfs_path *path;
3533 struct extent_buffer *leaf;
3534 int ret;
3535
3536 path = btrfs_alloc_path();
3537 if (!path)
3538 return -ENOMEM;
3539
3540 path->leave_spinning = 1;
3541 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3542 1);
3543 if (ret) {
3544 if (ret > 0)
3545 ret = -ENOENT;
3546 goto failed;
3547 }
3548
3549 btrfs_unlock_up_safe(path, 1);
3550 leaf = path->nodes[0];
3551 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3552 struct btrfs_inode_item);
3553
3554 fill_inode_item(trans, leaf, inode_item, inode);
3555 btrfs_mark_buffer_dirty(leaf);
3556 btrfs_set_inode_last_trans(trans, inode);
3557 ret = 0;
3558 failed:
3559 btrfs_free_path(path);
3560 return ret;
3561 }
3562
3563 /*
3564 * copy everything in the in-memory inode into the btree.
3565 */
3566 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3567 struct btrfs_root *root, struct inode *inode)
3568 {
3569 int ret;
3570
3571 /*
3572 * If the inode is a free space inode, we can deadlock during commit
3573 * if we put it into the delayed code.
3574 *
3575 * The data relocation inode should also be directly updated
3576 * without delay
3577 */
3578 if (!btrfs_is_free_space_inode(inode)
3579 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID) {
3580 btrfs_update_root_times(trans, root);
3581
3582 ret = btrfs_delayed_update_inode(trans, root, inode);
3583 if (!ret)
3584 btrfs_set_inode_last_trans(trans, inode);
3585 return ret;
3586 }
3587
3588 return btrfs_update_inode_item(trans, root, inode);
3589 }
3590
3591 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
3592 struct btrfs_root *root,
3593 struct inode *inode)
3594 {
3595 int ret;
3596
3597 ret = btrfs_update_inode(trans, root, inode);
3598 if (ret == -ENOSPC)
3599 return btrfs_update_inode_item(trans, root, inode);
3600 return ret;
3601 }
3602
3603 /*
3604 * unlink helper that gets used here in inode.c and in the tree logging
3605 * recovery code. It remove a link in a directory with a given name, and
3606 * also drops the back refs in the inode to the directory
3607 */
3608 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3609 struct btrfs_root *root,
3610 struct inode *dir, struct inode *inode,
3611 const char *name, int name_len)
3612 {
3613 struct btrfs_path *path;
3614 int ret = 0;
3615 struct extent_buffer *leaf;
3616 struct btrfs_dir_item *di;
3617 struct btrfs_key key;
3618 u64 index;
3619 u64 ino = btrfs_ino(inode);
3620 u64 dir_ino = btrfs_ino(dir);
3621
3622 path = btrfs_alloc_path();
3623 if (!path) {
3624 ret = -ENOMEM;
3625 goto out;
3626 }
3627
3628 path->leave_spinning = 1;
3629 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3630 name, name_len, -1);
3631 if (IS_ERR(di)) {
3632 ret = PTR_ERR(di);
3633 goto err;
3634 }
3635 if (!di) {
3636 ret = -ENOENT;
3637 goto err;
3638 }
3639 leaf = path->nodes[0];
3640 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3641 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3642 if (ret)
3643 goto err;
3644 btrfs_release_path(path);
3645
3646 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
3647 dir_ino, &index);
3648 if (ret) {
3649 btrfs_info(root->fs_info,
3650 "failed to delete reference to %.*s, inode %llu parent %llu",
3651 name_len, name,
3652 (unsigned long long)ino, (unsigned long long)dir_ino);
3653 btrfs_abort_transaction(trans, root, ret);
3654 goto err;
3655 }
3656
3657 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3658 if (ret) {
3659 btrfs_abort_transaction(trans, root, ret);
3660 goto err;
3661 }
3662
3663 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
3664 inode, dir_ino);
3665 if (ret != 0 && ret != -ENOENT) {
3666 btrfs_abort_transaction(trans, root, ret);
3667 goto err;
3668 }
3669
3670 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
3671 dir, index);
3672 if (ret == -ENOENT)
3673 ret = 0;
3674 else if (ret)
3675 btrfs_abort_transaction(trans, root, ret);
3676 err:
3677 btrfs_free_path(path);
3678 if (ret)
3679 goto out;
3680
3681 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3682 inode_inc_iversion(inode);
3683 inode_inc_iversion(dir);
3684 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3685 ret = btrfs_update_inode(trans, root, dir);
3686 out:
3687 return ret;
3688 }
3689
3690 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3691 struct btrfs_root *root,
3692 struct inode *dir, struct inode *inode,
3693 const char *name, int name_len)
3694 {
3695 int ret;
3696 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
3697 if (!ret) {
3698 btrfs_drop_nlink(inode);
3699 ret = btrfs_update_inode(trans, root, inode);
3700 }
3701 return ret;
3702 }
3703
3704 /*
3705 * helper to start transaction for unlink and rmdir.
3706 *
3707 * unlink and rmdir are special in btrfs, they do not always free space, so
3708 * if we cannot make our reservations the normal way try and see if there is
3709 * plenty of slack room in the global reserve to migrate, otherwise we cannot
3710 * allow the unlink to occur.
3711 */
3712 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
3713 {
3714 struct btrfs_trans_handle *trans;
3715 struct btrfs_root *root = BTRFS_I(dir)->root;
3716 int ret;
3717
3718 /*
3719 * 1 for the possible orphan item
3720 * 1 for the dir item
3721 * 1 for the dir index
3722 * 1 for the inode ref
3723 * 1 for the inode
3724 */
3725 trans = btrfs_start_transaction(root, 5);
3726 if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
3727 return trans;
3728
3729 if (PTR_ERR(trans) == -ENOSPC) {
3730 u64 num_bytes = btrfs_calc_trans_metadata_size(root, 5);
3731
3732 trans = btrfs_start_transaction(root, 0);
3733 if (IS_ERR(trans))
3734 return trans;
3735 ret = btrfs_cond_migrate_bytes(root->fs_info,
3736 &root->fs_info->trans_block_rsv,
3737 num_bytes, 5);
3738 if (ret) {
3739 btrfs_end_transaction(trans, root);
3740 return ERR_PTR(ret);
3741 }
3742 trans->block_rsv = &root->fs_info->trans_block_rsv;
3743 trans->bytes_reserved = num_bytes;
3744 }
3745 return trans;
3746 }
3747
3748 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
3749 {
3750 struct btrfs_root *root = BTRFS_I(dir)->root;
3751 struct btrfs_trans_handle *trans;
3752 struct inode *inode = dentry->d_inode;
3753 int ret;
3754
3755 trans = __unlink_start_trans(dir);
3756 if (IS_ERR(trans))
3757 return PTR_ERR(trans);
3758
3759 btrfs_record_unlink_dir(trans, dir, dentry->d_inode, 0);
3760
3761 ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
3762 dentry->d_name.name, dentry->d_name.len);
3763 if (ret)
3764 goto out;
3765
3766 if (inode->i_nlink == 0) {
3767 ret = btrfs_orphan_add(trans, inode);
3768 if (ret)
3769 goto out;
3770 }
3771
3772 out:
3773 btrfs_end_transaction(trans, root);
3774 btrfs_btree_balance_dirty(root);
3775 return ret;
3776 }
3777
3778 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
3779 struct btrfs_root *root,
3780 struct inode *dir, u64 objectid,
3781 const char *name, int name_len)
3782 {
3783 struct btrfs_path *path;
3784 struct extent_buffer *leaf;
3785 struct btrfs_dir_item *di;
3786 struct btrfs_key key;
3787 u64 index;
3788 int ret;
3789 u64 dir_ino = btrfs_ino(dir);
3790
3791 path = btrfs_alloc_path();
3792 if (!path)
3793 return -ENOMEM;
3794
3795 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3796 name, name_len, -1);
3797 if (IS_ERR_OR_NULL(di)) {
3798 if (!di)
3799 ret = -ENOENT;
3800 else
3801 ret = PTR_ERR(di);
3802 goto out;
3803 }
3804
3805 leaf = path->nodes[0];
3806 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3807 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
3808 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3809 if (ret) {
3810 btrfs_abort_transaction(trans, root, ret);
3811 goto out;
3812 }
3813 btrfs_release_path(path);
3814
3815 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
3816 objectid, root->root_key.objectid,
3817 dir_ino, &index, name, name_len);
3818 if (ret < 0) {
3819 if (ret != -ENOENT) {
3820 btrfs_abort_transaction(trans, root, ret);
3821 goto out;
3822 }
3823 di = btrfs_search_dir_index_item(root, path, dir_ino,
3824 name, name_len);
3825 if (IS_ERR_OR_NULL(di)) {
3826 if (!di)
3827 ret = -ENOENT;
3828 else
3829 ret = PTR_ERR(di);
3830 btrfs_abort_transaction(trans, root, ret);
3831 goto out;
3832 }
3833
3834 leaf = path->nodes[0];
3835 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3836 btrfs_release_path(path);
3837 index = key.offset;
3838 }
3839 btrfs_release_path(path);
3840
3841 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3842 if (ret) {
3843 btrfs_abort_transaction(trans, root, ret);
3844 goto out;
3845 }
3846
3847 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3848 inode_inc_iversion(dir);
3849 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3850 ret = btrfs_update_inode_fallback(trans, root, dir);
3851 if (ret)
3852 btrfs_abort_transaction(trans, root, ret);
3853 out:
3854 btrfs_free_path(path);
3855 return ret;
3856 }
3857
3858 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
3859 {
3860 struct inode *inode = dentry->d_inode;
3861 int err = 0;
3862 struct btrfs_root *root = BTRFS_I(dir)->root;
3863 struct btrfs_trans_handle *trans;
3864
3865 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
3866 return -ENOTEMPTY;
3867 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
3868 return -EPERM;
3869
3870 trans = __unlink_start_trans(dir);
3871 if (IS_ERR(trans))
3872 return PTR_ERR(trans);
3873
3874 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
3875 err = btrfs_unlink_subvol(trans, root, dir,
3876 BTRFS_I(inode)->location.objectid,
3877 dentry->d_name.name,
3878 dentry->d_name.len);
3879 goto out;
3880 }
3881
3882 err = btrfs_orphan_add(trans, inode);
3883 if (err)
3884 goto out;
3885
3886 /* now the directory is empty */
3887 err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
3888 dentry->d_name.name, dentry->d_name.len);
3889 if (!err)
3890 btrfs_i_size_write(inode, 0);
3891 out:
3892 btrfs_end_transaction(trans, root);
3893 btrfs_btree_balance_dirty(root);
3894
3895 return err;
3896 }
3897
3898 /*
3899 * this can truncate away extent items, csum items and directory items.
3900 * It starts at a high offset and removes keys until it can't find
3901 * any higher than new_size
3902 *
3903 * csum items that cross the new i_size are truncated to the new size
3904 * as well.
3905 *
3906 * min_type is the minimum key type to truncate down to. If set to 0, this
3907 * will kill all the items on this inode, including the INODE_ITEM_KEY.
3908 */
3909 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
3910 struct btrfs_root *root,
3911 struct inode *inode,
3912 u64 new_size, u32 min_type)
3913 {
3914 struct btrfs_path *path;
3915 struct extent_buffer *leaf;
3916 struct btrfs_file_extent_item *fi;
3917 struct btrfs_key key;
3918 struct btrfs_key found_key;
3919 u64 extent_start = 0;
3920 u64 extent_num_bytes = 0;
3921 u64 extent_offset = 0;
3922 u64 item_end = 0;
3923 u32 found_type = (u8)-1;
3924 int found_extent;
3925 int del_item;
3926 int pending_del_nr = 0;
3927 int pending_del_slot = 0;
3928 int extent_type = -1;
3929 int ret;
3930 int err = 0;
3931 u64 ino = btrfs_ino(inode);
3932
3933 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
3934
3935 path = btrfs_alloc_path();
3936 if (!path)
3937 return -ENOMEM;
3938 path->reada = -1;
3939
3940 /*
3941 * We want to drop from the next block forward in case this new size is
3942 * not block aligned since we will be keeping the last block of the
3943 * extent just the way it is.
3944 */
3945 if (root->ref_cows || root == root->fs_info->tree_root)
3946 btrfs_drop_extent_cache(inode, ALIGN(new_size,
3947 root->sectorsize), (u64)-1, 0);
3948
3949 /*
3950 * This function is also used to drop the items in the log tree before
3951 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
3952 * it is used to drop the loged items. So we shouldn't kill the delayed
3953 * items.
3954 */
3955 if (min_type == 0 && root == BTRFS_I(inode)->root)
3956 btrfs_kill_delayed_inode_items(inode);
3957
3958 key.objectid = ino;
3959 key.offset = (u64)-1;
3960 key.type = (u8)-1;
3961
3962 search_again:
3963 path->leave_spinning = 1;
3964 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
3965 if (ret < 0) {
3966 err = ret;
3967 goto out;
3968 }
3969
3970 if (ret > 0) {
3971 /* there are no items in the tree for us to truncate, we're
3972 * done
3973 */
3974 if (path->slots[0] == 0)
3975 goto out;
3976 path->slots[0]--;
3977 }
3978
3979 while (1) {
3980 fi = NULL;
3981 leaf = path->nodes[0];
3982 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3983 found_type = btrfs_key_type(&found_key);
3984
3985 if (found_key.objectid != ino)
3986 break;
3987
3988 if (found_type < min_type)
3989 break;
3990
3991 item_end = found_key.offset;
3992 if (found_type == BTRFS_EXTENT_DATA_KEY) {
3993 fi = btrfs_item_ptr(leaf, path->slots[0],
3994 struct btrfs_file_extent_item);
3995 extent_type = btrfs_file_extent_type(leaf, fi);
3996 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
3997 item_end +=
3998 btrfs_file_extent_num_bytes(leaf, fi);
3999 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4000 item_end += btrfs_file_extent_inline_len(leaf,
4001 fi);
4002 }
4003 item_end--;
4004 }
4005 if (found_type > min_type) {
4006 del_item = 1;
4007 } else {
4008 if (item_end < new_size)
4009 break;
4010 if (found_key.offset >= new_size)
4011 del_item = 1;
4012 else
4013 del_item = 0;
4014 }
4015 found_extent = 0;
4016 /* FIXME, shrink the extent if the ref count is only 1 */
4017 if (found_type != BTRFS_EXTENT_DATA_KEY)
4018 goto delete;
4019
4020 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4021 u64 num_dec;
4022 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4023 if (!del_item) {
4024 u64 orig_num_bytes =
4025 btrfs_file_extent_num_bytes(leaf, fi);
4026 extent_num_bytes = ALIGN(new_size -
4027 found_key.offset,
4028 root->sectorsize);
4029 btrfs_set_file_extent_num_bytes(leaf, fi,
4030 extent_num_bytes);
4031 num_dec = (orig_num_bytes -
4032 extent_num_bytes);
4033 if (root->ref_cows && extent_start != 0)
4034 inode_sub_bytes(inode, num_dec);
4035 btrfs_mark_buffer_dirty(leaf);
4036 } else {
4037 extent_num_bytes =
4038 btrfs_file_extent_disk_num_bytes(leaf,
4039 fi);
4040 extent_offset = found_key.offset -
4041 btrfs_file_extent_offset(leaf, fi);
4042
4043 /* FIXME blocksize != 4096 */
4044 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4045 if (extent_start != 0) {
4046 found_extent = 1;
4047 if (root->ref_cows)
4048 inode_sub_bytes(inode, num_dec);
4049 }
4050 }
4051 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4052 /*
4053 * we can't truncate inline items that have had
4054 * special encodings
4055 */
4056 if (!del_item &&
4057 btrfs_file_extent_compression(leaf, fi) == 0 &&
4058 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4059 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
4060 u32 size = new_size - found_key.offset;
4061
4062 if (root->ref_cows) {
4063 inode_sub_bytes(inode, item_end + 1 -
4064 new_size);
4065 }
4066 size =
4067 btrfs_file_extent_calc_inline_size(size);
4068 btrfs_truncate_item(root, path, size, 1);
4069 } else if (root->ref_cows) {
4070 inode_sub_bytes(inode, item_end + 1 -
4071 found_key.offset);
4072 }
4073 }
4074 delete:
4075 if (del_item) {
4076 if (!pending_del_nr) {
4077 /* no pending yet, add ourselves */
4078 pending_del_slot = path->slots[0];
4079 pending_del_nr = 1;
4080 } else if (pending_del_nr &&
4081 path->slots[0] + 1 == pending_del_slot) {
4082 /* hop on the pending chunk */
4083 pending_del_nr++;
4084 pending_del_slot = path->slots[0];
4085 } else {
4086 BUG();
4087 }
4088 } else {
4089 break;
4090 }
4091 if (found_extent && (root->ref_cows ||
4092 root == root->fs_info->tree_root)) {
4093 btrfs_set_path_blocking(path);
4094 ret = btrfs_free_extent(trans, root, extent_start,
4095 extent_num_bytes, 0,
4096 btrfs_header_owner(leaf),
4097 ino, extent_offset, 0);
4098 BUG_ON(ret);
4099 }
4100
4101 if (found_type == BTRFS_INODE_ITEM_KEY)
4102 break;
4103
4104 if (path->slots[0] == 0 ||
4105 path->slots[0] != pending_del_slot) {
4106 if (pending_del_nr) {
4107 ret = btrfs_del_items(trans, root, path,
4108 pending_del_slot,
4109 pending_del_nr);
4110 if (ret) {
4111 btrfs_abort_transaction(trans,
4112 root, ret);
4113 goto error;
4114 }
4115 pending_del_nr = 0;
4116 }
4117 btrfs_release_path(path);
4118 goto search_again;
4119 } else {
4120 path->slots[0]--;
4121 }
4122 }
4123 out:
4124 if (pending_del_nr) {
4125 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4126 pending_del_nr);
4127 if (ret)
4128 btrfs_abort_transaction(trans, root, ret);
4129 }
4130 error:
4131 btrfs_free_path(path);
4132 return err;
4133 }
4134
4135 /*
4136 * btrfs_truncate_page - read, zero a chunk and write a page
4137 * @inode - inode that we're zeroing
4138 * @from - the offset to start zeroing
4139 * @len - the length to zero, 0 to zero the entire range respective to the
4140 * offset
4141 * @front - zero up to the offset instead of from the offset on
4142 *
4143 * This will find the page for the "from" offset and cow the page and zero the
4144 * part we want to zero. This is used with truncate and hole punching.
4145 */
4146 int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len,
4147 int front)
4148 {
4149 struct address_space *mapping = inode->i_mapping;
4150 struct btrfs_root *root = BTRFS_I(inode)->root;
4151 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4152 struct btrfs_ordered_extent *ordered;
4153 struct extent_state *cached_state = NULL;
4154 char *kaddr;
4155 u32 blocksize = root->sectorsize;
4156 pgoff_t index = from >> PAGE_CACHE_SHIFT;
4157 unsigned offset = from & (PAGE_CACHE_SIZE-1);
4158 struct page *page;
4159 gfp_t mask = btrfs_alloc_write_mask(mapping);
4160 int ret = 0;
4161 u64 page_start;
4162 u64 page_end;
4163
4164 if ((offset & (blocksize - 1)) == 0 &&
4165 (!len || ((len & (blocksize - 1)) == 0)))
4166 goto out;
4167 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
4168 if (ret)
4169 goto out;
4170
4171 again:
4172 page = find_or_create_page(mapping, index, mask);
4173 if (!page) {
4174 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
4175 ret = -ENOMEM;
4176 goto out;
4177 }
4178
4179 page_start = page_offset(page);
4180 page_end = page_start + PAGE_CACHE_SIZE - 1;
4181
4182 if (!PageUptodate(page)) {
4183 ret = btrfs_readpage(NULL, page);
4184 lock_page(page);
4185 if (page->mapping != mapping) {
4186 unlock_page(page);
4187 page_cache_release(page);
4188 goto again;
4189 }
4190 if (!PageUptodate(page)) {
4191 ret = -EIO;
4192 goto out_unlock;
4193 }
4194 }
4195 wait_on_page_writeback(page);
4196
4197 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
4198 set_page_extent_mapped(page);
4199
4200 ordered = btrfs_lookup_ordered_extent(inode, page_start);
4201 if (ordered) {
4202 unlock_extent_cached(io_tree, page_start, page_end,
4203 &cached_state, GFP_NOFS);
4204 unlock_page(page);
4205 page_cache_release(page);
4206 btrfs_start_ordered_extent(inode, ordered, 1);
4207 btrfs_put_ordered_extent(ordered);
4208 goto again;
4209 }
4210
4211 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
4212 EXTENT_DIRTY | EXTENT_DELALLOC |
4213 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4214 0, 0, &cached_state, GFP_NOFS);
4215
4216 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
4217 &cached_state);
4218 if (ret) {
4219 unlock_extent_cached(io_tree, page_start, page_end,
4220 &cached_state, GFP_NOFS);
4221 goto out_unlock;
4222 }
4223
4224 if (offset != PAGE_CACHE_SIZE) {
4225 if (!len)
4226 len = PAGE_CACHE_SIZE - offset;
4227 kaddr = kmap(page);
4228 if (front)
4229 memset(kaddr, 0, offset);
4230 else
4231 memset(kaddr + offset, 0, len);
4232 flush_dcache_page(page);
4233 kunmap(page);
4234 }
4235 ClearPageChecked(page);
4236 set_page_dirty(page);
4237 unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
4238 GFP_NOFS);
4239
4240 out_unlock:
4241 if (ret)
4242 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
4243 unlock_page(page);
4244 page_cache_release(page);
4245 out:
4246 return ret;
4247 }
4248
4249 /*
4250 * This function puts in dummy file extents for the area we're creating a hole
4251 * for. So if we are truncating this file to a larger size we need to insert
4252 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4253 * the range between oldsize and size
4254 */
4255 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4256 {
4257 struct btrfs_trans_handle *trans;
4258 struct btrfs_root *root = BTRFS_I(inode)->root;
4259 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4260 struct extent_map *em = NULL;
4261 struct extent_state *cached_state = NULL;
4262 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4263 u64 hole_start = ALIGN(oldsize, root->sectorsize);
4264 u64 block_end = ALIGN(size, root->sectorsize);
4265 u64 last_byte;
4266 u64 cur_offset;
4267 u64 hole_size;
4268 int err = 0;
4269
4270 /*
4271 * If our size started in the middle of a page we need to zero out the
4272 * rest of the page before we expand the i_size, otherwise we could
4273 * expose stale data.
4274 */
4275 err = btrfs_truncate_page(inode, oldsize, 0, 0);
4276 if (err)
4277 return err;
4278
4279 if (size <= hole_start)
4280 return 0;
4281
4282 while (1) {
4283 struct btrfs_ordered_extent *ordered;
4284 btrfs_wait_ordered_range(inode, hole_start,
4285 block_end - hole_start);
4286 lock_extent_bits(io_tree, hole_start, block_end - 1, 0,
4287 &cached_state);
4288 ordered = btrfs_lookup_ordered_extent(inode, hole_start);
4289 if (!ordered)
4290 break;
4291 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4292 &cached_state, GFP_NOFS);
4293 btrfs_put_ordered_extent(ordered);
4294 }
4295
4296 cur_offset = hole_start;
4297 while (1) {
4298 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
4299 block_end - cur_offset, 0);
4300 if (IS_ERR(em)) {
4301 err = PTR_ERR(em);
4302 em = NULL;
4303 break;
4304 }
4305 last_byte = min(extent_map_end(em), block_end);
4306 last_byte = ALIGN(last_byte , root->sectorsize);
4307 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4308 struct extent_map *hole_em;
4309 hole_size = last_byte - cur_offset;
4310
4311 trans = btrfs_start_transaction(root, 3);
4312 if (IS_ERR(trans)) {
4313 err = PTR_ERR(trans);
4314 break;
4315 }
4316
4317 err = btrfs_drop_extents(trans, root, inode,
4318 cur_offset,
4319 cur_offset + hole_size, 1);
4320 if (err) {
4321 btrfs_abort_transaction(trans, root, err);
4322 btrfs_end_transaction(trans, root);
4323 break;
4324 }
4325
4326 err = btrfs_insert_file_extent(trans, root,
4327 btrfs_ino(inode), cur_offset, 0,
4328 0, hole_size, 0, hole_size,
4329 0, 0, 0);
4330 if (err) {
4331 btrfs_abort_transaction(trans, root, err);
4332 btrfs_end_transaction(trans, root);
4333 break;
4334 }
4335
4336 btrfs_drop_extent_cache(inode, cur_offset,
4337 cur_offset + hole_size - 1, 0);
4338 hole_em = alloc_extent_map();
4339 if (!hole_em) {
4340 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4341 &BTRFS_I(inode)->runtime_flags);
4342 goto next;
4343 }
4344 hole_em->start = cur_offset;
4345 hole_em->len = hole_size;
4346 hole_em->orig_start = cur_offset;
4347
4348 hole_em->block_start = EXTENT_MAP_HOLE;
4349 hole_em->block_len = 0;
4350 hole_em->orig_block_len = 0;
4351 hole_em->ram_bytes = hole_size;
4352 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
4353 hole_em->compress_type = BTRFS_COMPRESS_NONE;
4354 hole_em->generation = trans->transid;
4355
4356 while (1) {
4357 write_lock(&em_tree->lock);
4358 err = add_extent_mapping(em_tree, hole_em, 1);
4359 write_unlock(&em_tree->lock);
4360 if (err != -EEXIST)
4361 break;
4362 btrfs_drop_extent_cache(inode, cur_offset,
4363 cur_offset +
4364 hole_size - 1, 0);
4365 }
4366 free_extent_map(hole_em);
4367 next:
4368 btrfs_update_inode(trans, root, inode);
4369 btrfs_end_transaction(trans, root);
4370 }
4371 free_extent_map(em);
4372 em = NULL;
4373 cur_offset = last_byte;
4374 if (cur_offset >= block_end)
4375 break;
4376 }
4377
4378 free_extent_map(em);
4379 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
4380 GFP_NOFS);
4381 return err;
4382 }
4383
4384 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
4385 {
4386 struct btrfs_root *root = BTRFS_I(inode)->root;
4387 struct btrfs_trans_handle *trans;
4388 loff_t oldsize = i_size_read(inode);
4389 loff_t newsize = attr->ia_size;
4390 int mask = attr->ia_valid;
4391 int ret;
4392
4393 if (newsize == oldsize)
4394 return 0;
4395
4396 /*
4397 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
4398 * special case where we need to update the times despite not having
4399 * these flags set. For all other operations the VFS set these flags
4400 * explicitly if it wants a timestamp update.
4401 */
4402 if (newsize != oldsize && (!(mask & (ATTR_CTIME | ATTR_MTIME))))
4403 inode->i_ctime = inode->i_mtime = current_fs_time(inode->i_sb);
4404
4405 if (newsize > oldsize) {
4406 truncate_pagecache(inode, oldsize, newsize);
4407 ret = btrfs_cont_expand(inode, oldsize, newsize);
4408 if (ret)
4409 return ret;
4410
4411 trans = btrfs_start_transaction(root, 1);
4412 if (IS_ERR(trans))
4413 return PTR_ERR(trans);
4414
4415 i_size_write(inode, newsize);
4416 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
4417 ret = btrfs_update_inode(trans, root, inode);
4418 btrfs_end_transaction(trans, root);
4419 } else {
4420
4421 /*
4422 * We're truncating a file that used to have good data down to
4423 * zero. Make sure it gets into the ordered flush list so that
4424 * any new writes get down to disk quickly.
4425 */
4426 if (newsize == 0)
4427 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
4428 &BTRFS_I(inode)->runtime_flags);
4429
4430 /*
4431 * 1 for the orphan item we're going to add
4432 * 1 for the orphan item deletion.
4433 */
4434 trans = btrfs_start_transaction(root, 2);
4435 if (IS_ERR(trans))
4436 return PTR_ERR(trans);
4437
4438 /*
4439 * We need to do this in case we fail at _any_ point during the
4440 * actual truncate. Once we do the truncate_setsize we could
4441 * invalidate pages which forces any outstanding ordered io to
4442 * be instantly completed which will give us extents that need
4443 * to be truncated. If we fail to get an orphan inode down we
4444 * could have left over extents that were never meant to live,
4445 * so we need to garuntee from this point on that everything
4446 * will be consistent.
4447 */
4448 ret = btrfs_orphan_add(trans, inode);
4449 btrfs_end_transaction(trans, root);
4450 if (ret)
4451 return ret;
4452
4453 /* we don't support swapfiles, so vmtruncate shouldn't fail */
4454 truncate_setsize(inode, newsize);
4455
4456 /* Disable nonlocked read DIO to avoid the end less truncate */
4457 btrfs_inode_block_unlocked_dio(inode);
4458 inode_dio_wait(inode);
4459 btrfs_inode_resume_unlocked_dio(inode);
4460
4461 ret = btrfs_truncate(inode);
4462 if (ret && inode->i_nlink)
4463 btrfs_orphan_del(NULL, inode);
4464 }
4465
4466 return ret;
4467 }
4468
4469 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
4470 {
4471 struct inode *inode = dentry->d_inode;
4472 struct btrfs_root *root = BTRFS_I(inode)->root;
4473 int err;
4474
4475 if (btrfs_root_readonly(root))
4476 return -EROFS;
4477
4478 err = inode_change_ok(inode, attr);
4479 if (err)
4480 return err;
4481
4482 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
4483 err = btrfs_setsize(inode, attr);
4484 if (err)
4485 return err;
4486 }
4487
4488 if (attr->ia_valid) {
4489 setattr_copy(inode, attr);
4490 inode_inc_iversion(inode);
4491 err = btrfs_dirty_inode(inode);
4492
4493 if (!err && attr->ia_valid & ATTR_MODE)
4494 err = btrfs_acl_chmod(inode);
4495 }
4496
4497 return err;
4498 }
4499
4500 void btrfs_evict_inode(struct inode *inode)
4501 {
4502 struct btrfs_trans_handle *trans;
4503 struct btrfs_root *root = BTRFS_I(inode)->root;
4504 struct btrfs_block_rsv *rsv, *global_rsv;
4505 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
4506 int ret;
4507
4508 trace_btrfs_inode_evict(inode);
4509
4510 truncate_inode_pages(&inode->i_data, 0);
4511 if (inode->i_nlink && (btrfs_root_refs(&root->root_item) != 0 ||
4512 btrfs_is_free_space_inode(inode)))
4513 goto no_delete;
4514
4515 if (is_bad_inode(inode)) {
4516 btrfs_orphan_del(NULL, inode);
4517 goto no_delete;
4518 }
4519 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
4520 btrfs_wait_ordered_range(inode, 0, (u64)-1);
4521
4522 if (root->fs_info->log_root_recovering) {
4523 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
4524 &BTRFS_I(inode)->runtime_flags));
4525 goto no_delete;
4526 }
4527
4528 if (inode->i_nlink > 0) {
4529 BUG_ON(btrfs_root_refs(&root->root_item) != 0);
4530 goto no_delete;
4531 }
4532
4533 ret = btrfs_commit_inode_delayed_inode(inode);
4534 if (ret) {
4535 btrfs_orphan_del(NULL, inode);
4536 goto no_delete;
4537 }
4538
4539 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
4540 if (!rsv) {
4541 btrfs_orphan_del(NULL, inode);
4542 goto no_delete;
4543 }
4544 rsv->size = min_size;
4545 rsv->failfast = 1;
4546 global_rsv = &root->fs_info->global_block_rsv;
4547
4548 btrfs_i_size_write(inode, 0);
4549
4550 /*
4551 * This is a bit simpler than btrfs_truncate since we've already
4552 * reserved our space for our orphan item in the unlink, so we just
4553 * need to reserve some slack space in case we add bytes and update
4554 * inode item when doing the truncate.
4555 */
4556 while (1) {
4557 ret = btrfs_block_rsv_refill(root, rsv, min_size,
4558 BTRFS_RESERVE_FLUSH_LIMIT);
4559
4560 /*
4561 * Try and steal from the global reserve since we will
4562 * likely not use this space anyway, we want to try as
4563 * hard as possible to get this to work.
4564 */
4565 if (ret)
4566 ret = btrfs_block_rsv_migrate(global_rsv, rsv, min_size);
4567
4568 if (ret) {
4569 btrfs_warn(root->fs_info,
4570 "Could not get space for a delete, will truncate on mount %d",
4571 ret);
4572 btrfs_orphan_del(NULL, inode);
4573 btrfs_free_block_rsv(root, rsv);
4574 goto no_delete;
4575 }
4576
4577 trans = btrfs_join_transaction(root);
4578 if (IS_ERR(trans)) {
4579 btrfs_orphan_del(NULL, inode);
4580 btrfs_free_block_rsv(root, rsv);
4581 goto no_delete;
4582 }
4583
4584 trans->block_rsv = rsv;
4585
4586 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
4587 if (ret != -ENOSPC)
4588 break;
4589
4590 trans->block_rsv = &root->fs_info->trans_block_rsv;
4591 btrfs_end_transaction(trans, root);
4592 trans = NULL;
4593 btrfs_btree_balance_dirty(root);
4594 }
4595
4596 btrfs_free_block_rsv(root, rsv);
4597
4598 if (ret == 0) {
4599 trans->block_rsv = root->orphan_block_rsv;
4600 ret = btrfs_orphan_del(trans, inode);
4601 BUG_ON(ret);
4602 }
4603
4604 trans->block_rsv = &root->fs_info->trans_block_rsv;
4605 if (!(root == root->fs_info->tree_root ||
4606 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
4607 btrfs_return_ino(root, btrfs_ino(inode));
4608
4609 btrfs_end_transaction(trans, root);
4610 btrfs_btree_balance_dirty(root);
4611 no_delete:
4612 btrfs_remove_delayed_node(inode);
4613 clear_inode(inode);
4614 return;
4615 }
4616
4617 /*
4618 * this returns the key found in the dir entry in the location pointer.
4619 * If no dir entries were found, location->objectid is 0.
4620 */
4621 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
4622 struct btrfs_key *location)
4623 {
4624 const char *name = dentry->d_name.name;
4625 int namelen = dentry->d_name.len;
4626 struct btrfs_dir_item *di;
4627 struct btrfs_path *path;
4628 struct btrfs_root *root = BTRFS_I(dir)->root;
4629 int ret = 0;
4630
4631 path = btrfs_alloc_path();
4632 if (!path)
4633 return -ENOMEM;
4634
4635 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
4636 namelen, 0);
4637 if (IS_ERR(di))
4638 ret = PTR_ERR(di);
4639
4640 if (IS_ERR_OR_NULL(di))
4641 goto out_err;
4642
4643 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
4644 out:
4645 btrfs_free_path(path);
4646 return ret;
4647 out_err:
4648 location->objectid = 0;
4649 goto out;
4650 }
4651
4652 /*
4653 * when we hit a tree root in a directory, the btrfs part of the inode
4654 * needs to be changed to reflect the root directory of the tree root. This
4655 * is kind of like crossing a mount point.
4656 */
4657 static int fixup_tree_root_location(struct btrfs_root *root,
4658 struct inode *dir,
4659 struct dentry *dentry,
4660 struct btrfs_key *location,
4661 struct btrfs_root **sub_root)
4662 {
4663 struct btrfs_path *path;
4664 struct btrfs_root *new_root;
4665 struct btrfs_root_ref *ref;
4666 struct extent_buffer *leaf;
4667 int ret;
4668 int err = 0;
4669
4670 path = btrfs_alloc_path();
4671 if (!path) {
4672 err = -ENOMEM;
4673 goto out;
4674 }
4675
4676 err = -ENOENT;
4677 ret = btrfs_find_root_ref(root->fs_info->tree_root, path,
4678 BTRFS_I(dir)->root->root_key.objectid,
4679 location->objectid);
4680 if (ret) {
4681 if (ret < 0)
4682 err = ret;
4683 goto out;
4684 }
4685
4686 leaf = path->nodes[0];
4687 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
4688 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
4689 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
4690 goto out;
4691
4692 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
4693 (unsigned long)(ref + 1),
4694 dentry->d_name.len);
4695 if (ret)
4696 goto out;
4697
4698 btrfs_release_path(path);
4699
4700 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
4701 if (IS_ERR(new_root)) {
4702 err = PTR_ERR(new_root);
4703 goto out;
4704 }
4705
4706 *sub_root = new_root;
4707 location->objectid = btrfs_root_dirid(&new_root->root_item);
4708 location->type = BTRFS_INODE_ITEM_KEY;
4709 location->offset = 0;
4710 err = 0;
4711 out:
4712 btrfs_free_path(path);
4713 return err;
4714 }
4715
4716 static void inode_tree_add(struct inode *inode)
4717 {
4718 struct btrfs_root *root = BTRFS_I(inode)->root;
4719 struct btrfs_inode *entry;
4720 struct rb_node **p;
4721 struct rb_node *parent;
4722 u64 ino = btrfs_ino(inode);
4723
4724 if (inode_unhashed(inode))
4725 return;
4726 again:
4727 parent = NULL;
4728 spin_lock(&root->inode_lock);
4729 p = &root->inode_tree.rb_node;
4730 while (*p) {
4731 parent = *p;
4732 entry = rb_entry(parent, struct btrfs_inode, rb_node);
4733
4734 if (ino < btrfs_ino(&entry->vfs_inode))
4735 p = &parent->rb_left;
4736 else if (ino > btrfs_ino(&entry->vfs_inode))
4737 p = &parent->rb_right;
4738 else {
4739 WARN_ON(!(entry->vfs_inode.i_state &
4740 (I_WILL_FREE | I_FREEING)));
4741 rb_erase(parent, &root->inode_tree);
4742 RB_CLEAR_NODE(parent);
4743 spin_unlock(&root->inode_lock);
4744 goto again;
4745 }
4746 }
4747 rb_link_node(&BTRFS_I(inode)->rb_node, parent, p);
4748 rb_insert_color(&BTRFS_I(inode)->rb_node, &root->inode_tree);
4749 spin_unlock(&root->inode_lock);
4750 }
4751
4752 static void inode_tree_del(struct inode *inode)
4753 {
4754 struct btrfs_root *root = BTRFS_I(inode)->root;
4755 int empty = 0;
4756
4757 spin_lock(&root->inode_lock);
4758 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
4759 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
4760 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
4761 empty = RB_EMPTY_ROOT(&root->inode_tree);
4762 }
4763 spin_unlock(&root->inode_lock);
4764
4765 /*
4766 * Free space cache has inodes in the tree root, but the tree root has a
4767 * root_refs of 0, so this could end up dropping the tree root as a
4768 * snapshot, so we need the extra !root->fs_info->tree_root check to
4769 * make sure we don't drop it.
4770 */
4771 if (empty && btrfs_root_refs(&root->root_item) == 0 &&
4772 root != root->fs_info->tree_root) {
4773 synchronize_srcu(&root->fs_info->subvol_srcu);
4774 spin_lock(&root->inode_lock);
4775 empty = RB_EMPTY_ROOT(&root->inode_tree);
4776 spin_unlock(&root->inode_lock);
4777 if (empty)
4778 btrfs_add_dead_root(root);
4779 }
4780 }
4781
4782 void btrfs_invalidate_inodes(struct btrfs_root *root)
4783 {
4784 struct rb_node *node;
4785 struct rb_node *prev;
4786 struct btrfs_inode *entry;
4787 struct inode *inode;
4788 u64 objectid = 0;
4789
4790 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
4791
4792 spin_lock(&root->inode_lock);
4793 again:
4794 node = root->inode_tree.rb_node;
4795 prev = NULL;
4796 while (node) {
4797 prev = node;
4798 entry = rb_entry(node, struct btrfs_inode, rb_node);
4799
4800 if (objectid < btrfs_ino(&entry->vfs_inode))
4801 node = node->rb_left;
4802 else if (objectid > btrfs_ino(&entry->vfs_inode))
4803 node = node->rb_right;
4804 else
4805 break;
4806 }
4807 if (!node) {
4808 while (prev) {
4809 entry = rb_entry(prev, struct btrfs_inode, rb_node);
4810 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
4811 node = prev;
4812 break;
4813 }
4814 prev = rb_next(prev);
4815 }
4816 }
4817 while (node) {
4818 entry = rb_entry(node, struct btrfs_inode, rb_node);
4819 objectid = btrfs_ino(&entry->vfs_inode) + 1;
4820 inode = igrab(&entry->vfs_inode);
4821 if (inode) {
4822 spin_unlock(&root->inode_lock);
4823 if (atomic_read(&inode->i_count) > 1)
4824 d_prune_aliases(inode);
4825 /*
4826 * btrfs_drop_inode will have it removed from
4827 * the inode cache when its usage count
4828 * hits zero.
4829 */
4830 iput(inode);
4831 cond_resched();
4832 spin_lock(&root->inode_lock);
4833 goto again;
4834 }
4835
4836 if (cond_resched_lock(&root->inode_lock))
4837 goto again;
4838
4839 node = rb_next(node);
4840 }
4841 spin_unlock(&root->inode_lock);
4842 }
4843
4844 static int btrfs_init_locked_inode(struct inode *inode, void *p)
4845 {
4846 struct btrfs_iget_args *args = p;
4847 inode->i_ino = args->ino;
4848 BTRFS_I(inode)->root = args->root;
4849 return 0;
4850 }
4851
4852 static int btrfs_find_actor(struct inode *inode, void *opaque)
4853 {
4854 struct btrfs_iget_args *args = opaque;
4855 return args->ino == btrfs_ino(inode) &&
4856 args->root == BTRFS_I(inode)->root;
4857 }
4858
4859 static struct inode *btrfs_iget_locked(struct super_block *s,
4860 u64 objectid,
4861 struct btrfs_root *root)
4862 {
4863 struct inode *inode;
4864 struct btrfs_iget_args args;
4865 args.ino = objectid;
4866 args.root = root;
4867
4868 inode = iget5_locked(s, objectid, btrfs_find_actor,
4869 btrfs_init_locked_inode,
4870 (void *)&args);
4871 return inode;
4872 }
4873
4874 /* Get an inode object given its location and corresponding root.
4875 * Returns in *is_new if the inode was read from disk
4876 */
4877 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
4878 struct btrfs_root *root, int *new)
4879 {
4880 struct inode *inode;
4881
4882 inode = btrfs_iget_locked(s, location->objectid, root);
4883 if (!inode)
4884 return ERR_PTR(-ENOMEM);
4885
4886 if (inode->i_state & I_NEW) {
4887 BTRFS_I(inode)->root = root;
4888 memcpy(&BTRFS_I(inode)->location, location, sizeof(*location));
4889 btrfs_read_locked_inode(inode);
4890 if (!is_bad_inode(inode)) {
4891 inode_tree_add(inode);
4892 unlock_new_inode(inode);
4893 if (new)
4894 *new = 1;
4895 } else {
4896 unlock_new_inode(inode);
4897 iput(inode);
4898 inode = ERR_PTR(-ESTALE);
4899 }
4900 }
4901
4902 return inode;
4903 }
4904
4905 static struct inode *new_simple_dir(struct super_block *s,
4906 struct btrfs_key *key,
4907 struct btrfs_root *root)
4908 {
4909 struct inode *inode = new_inode(s);
4910
4911 if (!inode)
4912 return ERR_PTR(-ENOMEM);
4913
4914 BTRFS_I(inode)->root = root;
4915 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
4916 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
4917
4918 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
4919 inode->i_op = &btrfs_dir_ro_inode_operations;
4920 inode->i_fop = &simple_dir_operations;
4921 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
4922 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
4923
4924 return inode;
4925 }
4926
4927 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
4928 {
4929 struct inode *inode;
4930 struct btrfs_root *root = BTRFS_I(dir)->root;
4931 struct btrfs_root *sub_root = root;
4932 struct btrfs_key location;
4933 int index;
4934 int ret = 0;
4935
4936 if (dentry->d_name.len > BTRFS_NAME_LEN)
4937 return ERR_PTR(-ENAMETOOLONG);
4938
4939 ret = btrfs_inode_by_name(dir, dentry, &location);
4940 if (ret < 0)
4941 return ERR_PTR(ret);
4942
4943 if (location.objectid == 0)
4944 return NULL;
4945
4946 if (location.type == BTRFS_INODE_ITEM_KEY) {
4947 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
4948 return inode;
4949 }
4950
4951 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
4952
4953 index = srcu_read_lock(&root->fs_info->subvol_srcu);
4954 ret = fixup_tree_root_location(root, dir, dentry,
4955 &location, &sub_root);
4956 if (ret < 0) {
4957 if (ret != -ENOENT)
4958 inode = ERR_PTR(ret);
4959 else
4960 inode = new_simple_dir(dir->i_sb, &location, sub_root);
4961 } else {
4962 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
4963 }
4964 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
4965
4966 if (!IS_ERR(inode) && root != sub_root) {
4967 down_read(&root->fs_info->cleanup_work_sem);
4968 if (!(inode->i_sb->s_flags & MS_RDONLY))
4969 ret = btrfs_orphan_cleanup(sub_root);
4970 up_read(&root->fs_info->cleanup_work_sem);
4971 if (ret) {
4972 iput(inode);
4973 inode = ERR_PTR(ret);
4974 }
4975 }
4976
4977 return inode;
4978 }
4979
4980 static int btrfs_dentry_delete(const struct dentry *dentry)
4981 {
4982 struct btrfs_root *root;
4983 struct inode *inode = dentry->d_inode;
4984
4985 if (!inode && !IS_ROOT(dentry))
4986 inode = dentry->d_parent->d_inode;
4987
4988 if (inode) {
4989 root = BTRFS_I(inode)->root;
4990 if (btrfs_root_refs(&root->root_item) == 0)
4991 return 1;
4992
4993 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
4994 return 1;
4995 }
4996 return 0;
4997 }
4998
4999 static void btrfs_dentry_release(struct dentry *dentry)
5000 {
5001 if (dentry->d_fsdata)
5002 kfree(dentry->d_fsdata);
5003 }
5004
5005 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5006 unsigned int flags)
5007 {
5008 struct dentry *ret;
5009
5010 ret = d_splice_alias(btrfs_lookup_dentry(dir, dentry), dentry);
5011 return ret;
5012 }
5013
5014 unsigned char btrfs_filetype_table[] = {
5015 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5016 };
5017
5018 static int btrfs_real_readdir(struct file *filp, void *dirent,
5019 filldir_t filldir)
5020 {
5021 struct inode *inode = file_inode(filp);
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; /* filp->f_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 /* special case for "." */
5049 if (filp->f_pos == 0) {
5050 over = filldir(dirent, ".", 1,
5051 filp->f_pos, btrfs_ino(inode), DT_DIR);
5052 if (over)
5053 return 0;
5054 filp->f_pos = 1;
5055 }
5056 /* special case for .., just use the back ref */
5057 if (filp->f_pos == 1) {
5058 u64 pino = parent_ino(filp->f_path.dentry);
5059 over = filldir(dirent, "..", 2,
5060 filp->f_pos, pino, DT_DIR);
5061 if (over)
5062 return 0;
5063 filp->f_pos = 2;
5064 }
5065 path = btrfs_alloc_path();
5066 if (!path)
5067 return -ENOMEM;
5068
5069 path->reada = 1;
5070
5071 if (key_type == BTRFS_DIR_INDEX_KEY) {
5072 INIT_LIST_HEAD(&ins_list);
5073 INIT_LIST_HEAD(&del_list);
5074 btrfs_get_delayed_items(inode, &ins_list, &del_list);
5075 }
5076
5077 btrfs_set_key_type(&key, key_type);
5078 key.offset = filp->f_pos;
5079 key.objectid = btrfs_ino(inode);
5080
5081 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5082 if (ret < 0)
5083 goto err;
5084
5085 while (1) {
5086 leaf = path->nodes[0];
5087 slot = path->slots[0];
5088 if (slot >= btrfs_header_nritems(leaf)) {
5089 ret = btrfs_next_leaf(root, path);
5090 if (ret < 0)
5091 goto err;
5092 else if (ret > 0)
5093 break;
5094 continue;
5095 }
5096
5097 item = btrfs_item_nr(leaf, slot);
5098 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5099
5100 if (found_key.objectid != key.objectid)
5101 break;
5102 if (btrfs_key_type(&found_key) != key_type)
5103 break;
5104 if (found_key.offset < filp->f_pos)
5105 goto next;
5106 if (key_type == BTRFS_DIR_INDEX_KEY &&
5107 btrfs_should_delete_dir_index(&del_list,
5108 found_key.offset))
5109 goto next;
5110
5111 filp->f_pos = found_key.offset;
5112 is_curr = 1;
5113
5114 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5115 di_cur = 0;
5116 di_total = btrfs_item_size(leaf, item);
5117
5118 while (di_cur < di_total) {
5119 struct btrfs_key location;
5120
5121 if (verify_dir_item(root, leaf, di))
5122 break;
5123
5124 name_len = btrfs_dir_name_len(leaf, di);
5125 if (name_len <= sizeof(tmp_name)) {
5126 name_ptr = tmp_name;
5127 } else {
5128 name_ptr = kmalloc(name_len, GFP_NOFS);
5129 if (!name_ptr) {
5130 ret = -ENOMEM;
5131 goto err;
5132 }
5133 }
5134 read_extent_buffer(leaf, name_ptr,
5135 (unsigned long)(di + 1), name_len);
5136
5137 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
5138 btrfs_dir_item_key_to_cpu(leaf, di, &location);
5139
5140
5141 /* is this a reference to our own snapshot? If so
5142 * skip it.
5143 *
5144 * In contrast to old kernels, we insert the snapshot's
5145 * dir item and dir index after it has been created, so
5146 * we won't find a reference to our own snapshot. We
5147 * still keep the following code for backward
5148 * compatibility.
5149 */
5150 if (location.type == BTRFS_ROOT_ITEM_KEY &&
5151 location.objectid == root->root_key.objectid) {
5152 over = 0;
5153 goto skip;
5154 }
5155 over = filldir(dirent, name_ptr, name_len,
5156 found_key.offset, location.objectid,
5157 d_type);
5158
5159 skip:
5160 if (name_ptr != tmp_name)
5161 kfree(name_ptr);
5162
5163 if (over)
5164 goto nopos;
5165 di_len = btrfs_dir_name_len(leaf, di) +
5166 btrfs_dir_data_len(leaf, di) + sizeof(*di);
5167 di_cur += di_len;
5168 di = (struct btrfs_dir_item *)((char *)di + di_len);
5169 }
5170 next:
5171 path->slots[0]++;
5172 }
5173
5174 if (key_type == BTRFS_DIR_INDEX_KEY) {
5175 if (is_curr)
5176 filp->f_pos++;
5177 ret = btrfs_readdir_delayed_dir_index(filp, dirent, filldir,
5178 &ins_list);
5179 if (ret)
5180 goto nopos;
5181 }
5182
5183 /* Reached end of directory/root. Bump pos past the last item. */
5184 if (key_type == BTRFS_DIR_INDEX_KEY)
5185 /*
5186 * 32-bit glibc will use getdents64, but then strtol -
5187 * so the last number we can serve is this.
5188 */
5189 filp->f_pos = 0x7fffffff;
5190 else
5191 filp->f_pos++;
5192 nopos:
5193 ret = 0;
5194 err:
5195 if (key_type == BTRFS_DIR_INDEX_KEY)
5196 btrfs_put_delayed_items(&ins_list, &del_list);
5197 btrfs_free_path(path);
5198 return ret;
5199 }
5200
5201 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
5202 {
5203 struct btrfs_root *root = BTRFS_I(inode)->root;
5204 struct btrfs_trans_handle *trans;
5205 int ret = 0;
5206 bool nolock = false;
5207
5208 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5209 return 0;
5210
5211 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
5212 nolock = true;
5213
5214 if (wbc->sync_mode == WB_SYNC_ALL) {
5215 if (nolock)
5216 trans = btrfs_join_transaction_nolock(root);
5217 else
5218 trans = btrfs_join_transaction(root);
5219 if (IS_ERR(trans))
5220 return PTR_ERR(trans);
5221 ret = btrfs_commit_transaction(trans, root);
5222 }
5223 return ret;
5224 }
5225
5226 /*
5227 * This is somewhat expensive, updating the tree every time the
5228 * inode changes. But, it is most likely to find the inode in cache.
5229 * FIXME, needs more benchmarking...there are no reasons other than performance
5230 * to keep or drop this code.
5231 */
5232 static int btrfs_dirty_inode(struct inode *inode)
5233 {
5234 struct btrfs_root *root = BTRFS_I(inode)->root;
5235 struct btrfs_trans_handle *trans;
5236 int ret;
5237
5238 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5239 return 0;
5240
5241 trans = btrfs_join_transaction(root);
5242 if (IS_ERR(trans))
5243 return PTR_ERR(trans);
5244
5245 ret = btrfs_update_inode(trans, root, inode);
5246 if (ret && ret == -ENOSPC) {
5247 /* whoops, lets try again with the full transaction */
5248 btrfs_end_transaction(trans, root);
5249 trans = btrfs_start_transaction(root, 1);
5250 if (IS_ERR(trans))
5251 return PTR_ERR(trans);
5252
5253 ret = btrfs_update_inode(trans, root, inode);
5254 }
5255 btrfs_end_transaction(trans, root);
5256 if (BTRFS_I(inode)->delayed_node)
5257 btrfs_balance_delayed_items(root);
5258
5259 return ret;
5260 }
5261
5262 /*
5263 * This is a copy of file_update_time. We need this so we can return error on
5264 * ENOSPC for updating the inode in the case of file write and mmap writes.
5265 */
5266 static int btrfs_update_time(struct inode *inode, struct timespec *now,
5267 int flags)
5268 {
5269 struct btrfs_root *root = BTRFS_I(inode)->root;
5270
5271 if (btrfs_root_readonly(root))
5272 return -EROFS;
5273
5274 if (flags & S_VERSION)
5275 inode_inc_iversion(inode);
5276 if (flags & S_CTIME)
5277 inode->i_ctime = *now;
5278 if (flags & S_MTIME)
5279 inode->i_mtime = *now;
5280 if (flags & S_ATIME)
5281 inode->i_atime = *now;
5282 return btrfs_dirty_inode(inode);
5283 }
5284
5285 /*
5286 * find the highest existing sequence number in a directory
5287 * and then set the in-memory index_cnt variable to reflect
5288 * free sequence numbers
5289 */
5290 static int btrfs_set_inode_index_count(struct inode *inode)
5291 {
5292 struct btrfs_root *root = BTRFS_I(inode)->root;
5293 struct btrfs_key key, found_key;
5294 struct btrfs_path *path;
5295 struct extent_buffer *leaf;
5296 int ret;
5297
5298 key.objectid = btrfs_ino(inode);
5299 btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
5300 key.offset = (u64)-1;
5301
5302 path = btrfs_alloc_path();
5303 if (!path)
5304 return -ENOMEM;
5305
5306 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5307 if (ret < 0)
5308 goto out;
5309 /* FIXME: we should be able to handle this */
5310 if (ret == 0)
5311 goto out;
5312 ret = 0;
5313
5314 /*
5315 * MAGIC NUMBER EXPLANATION:
5316 * since we search a directory based on f_pos we have to start at 2
5317 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
5318 * else has to start at 2
5319 */
5320 if (path->slots[0] == 0) {
5321 BTRFS_I(inode)->index_cnt = 2;
5322 goto out;
5323 }
5324
5325 path->slots[0]--;
5326
5327 leaf = path->nodes[0];
5328 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5329
5330 if (found_key.objectid != btrfs_ino(inode) ||
5331 btrfs_key_type(&found_key) != BTRFS_DIR_INDEX_KEY) {
5332 BTRFS_I(inode)->index_cnt = 2;
5333 goto out;
5334 }
5335
5336 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
5337 out:
5338 btrfs_free_path(path);
5339 return ret;
5340 }
5341
5342 /*
5343 * helper to find a free sequence number in a given directory. This current
5344 * code is very simple, later versions will do smarter things in the btree
5345 */
5346 int btrfs_set_inode_index(struct inode *dir, u64 *index)
5347 {
5348 int ret = 0;
5349
5350 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
5351 ret = btrfs_inode_delayed_dir_index_count(dir);
5352 if (ret) {
5353 ret = btrfs_set_inode_index_count(dir);
5354 if (ret)
5355 return ret;
5356 }
5357 }
5358
5359 *index = BTRFS_I(dir)->index_cnt;
5360 BTRFS_I(dir)->index_cnt++;
5361
5362 return ret;
5363 }
5364
5365 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
5366 struct btrfs_root *root,
5367 struct inode *dir,
5368 const char *name, int name_len,
5369 u64 ref_objectid, u64 objectid,
5370 umode_t mode, u64 *index)
5371 {
5372 struct inode *inode;
5373 struct btrfs_inode_item *inode_item;
5374 struct btrfs_key *location;
5375 struct btrfs_path *path;
5376 struct btrfs_inode_ref *ref;
5377 struct btrfs_key key[2];
5378 u32 sizes[2];
5379 unsigned long ptr;
5380 int ret;
5381 int owner;
5382
5383 path = btrfs_alloc_path();
5384 if (!path)
5385 return ERR_PTR(-ENOMEM);
5386
5387 inode = new_inode(root->fs_info->sb);
5388 if (!inode) {
5389 btrfs_free_path(path);
5390 return ERR_PTR(-ENOMEM);
5391 }
5392
5393 /*
5394 * we have to initialize this early, so we can reclaim the inode
5395 * number if we fail afterwards in this function.
5396 */
5397 inode->i_ino = objectid;
5398
5399 if (dir) {
5400 trace_btrfs_inode_request(dir);
5401
5402 ret = btrfs_set_inode_index(dir, index);
5403 if (ret) {
5404 btrfs_free_path(path);
5405 iput(inode);
5406 return ERR_PTR(ret);
5407 }
5408 }
5409 /*
5410 * index_cnt is ignored for everything but a dir,
5411 * btrfs_get_inode_index_count has an explanation for the magic
5412 * number
5413 */
5414 BTRFS_I(inode)->index_cnt = 2;
5415 BTRFS_I(inode)->root = root;
5416 BTRFS_I(inode)->generation = trans->transid;
5417 inode->i_generation = BTRFS_I(inode)->generation;
5418
5419 /*
5420 * We could have gotten an inode number from somebody who was fsynced
5421 * and then removed in this same transaction, so let's just set full
5422 * sync since it will be a full sync anyway and this will blow away the
5423 * old info in the log.
5424 */
5425 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
5426
5427 if (S_ISDIR(mode))
5428 owner = 0;
5429 else
5430 owner = 1;
5431
5432 key[0].objectid = objectid;
5433 btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
5434 key[0].offset = 0;
5435
5436 /*
5437 * Start new inodes with an inode_ref. This is slightly more
5438 * efficient for small numbers of hard links since they will
5439 * be packed into one item. Extended refs will kick in if we
5440 * add more hard links than can fit in the ref item.
5441 */
5442 key[1].objectid = objectid;
5443 btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
5444 key[1].offset = ref_objectid;
5445
5446 sizes[0] = sizeof(struct btrfs_inode_item);
5447 sizes[1] = name_len + sizeof(*ref);
5448
5449 path->leave_spinning = 1;
5450 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
5451 if (ret != 0)
5452 goto fail;
5453
5454 inode_init_owner(inode, dir, mode);
5455 inode_set_bytes(inode, 0);
5456 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
5457 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
5458 struct btrfs_inode_item);
5459 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
5460 sizeof(*inode_item));
5461 fill_inode_item(trans, path->nodes[0], inode_item, inode);
5462
5463 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
5464 struct btrfs_inode_ref);
5465 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
5466 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
5467 ptr = (unsigned long)(ref + 1);
5468 write_extent_buffer(path->nodes[0], name, ptr, name_len);
5469
5470 btrfs_mark_buffer_dirty(path->nodes[0]);
5471 btrfs_free_path(path);
5472
5473 location = &BTRFS_I(inode)->location;
5474 location->objectid = objectid;
5475 location->offset = 0;
5476 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
5477
5478 btrfs_inherit_iflags(inode, dir);
5479
5480 if (S_ISREG(mode)) {
5481 if (btrfs_test_opt(root, NODATASUM))
5482 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
5483 if (btrfs_test_opt(root, NODATACOW))
5484 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
5485 BTRFS_INODE_NODATASUM;
5486 }
5487
5488 insert_inode_hash(inode);
5489 inode_tree_add(inode);
5490
5491 trace_btrfs_inode_new(inode);
5492 btrfs_set_inode_last_trans(trans, inode);
5493
5494 btrfs_update_root_times(trans, root);
5495
5496 return inode;
5497 fail:
5498 if (dir)
5499 BTRFS_I(dir)->index_cnt--;
5500 btrfs_free_path(path);
5501 iput(inode);
5502 return ERR_PTR(ret);
5503 }
5504
5505 static inline u8 btrfs_inode_type(struct inode *inode)
5506 {
5507 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
5508 }
5509
5510 /*
5511 * utility function to add 'inode' into 'parent_inode' with
5512 * a give name and a given sequence number.
5513 * if 'add_backref' is true, also insert a backref from the
5514 * inode to the parent directory.
5515 */
5516 int btrfs_add_link(struct btrfs_trans_handle *trans,
5517 struct inode *parent_inode, struct inode *inode,
5518 const char *name, int name_len, int add_backref, u64 index)
5519 {
5520 int ret = 0;
5521 struct btrfs_key key;
5522 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
5523 u64 ino = btrfs_ino(inode);
5524 u64 parent_ino = btrfs_ino(parent_inode);
5525
5526 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5527 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
5528 } else {
5529 key.objectid = ino;
5530 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
5531 key.offset = 0;
5532 }
5533
5534 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5535 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
5536 key.objectid, root->root_key.objectid,
5537 parent_ino, index, name, name_len);
5538 } else if (add_backref) {
5539 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
5540 parent_ino, index);
5541 }
5542
5543 /* Nothing to clean up yet */
5544 if (ret)
5545 return ret;
5546
5547 ret = btrfs_insert_dir_item(trans, root, name, name_len,
5548 parent_inode, &key,
5549 btrfs_inode_type(inode), index);
5550 if (ret == -EEXIST || ret == -EOVERFLOW)
5551 goto fail_dir_item;
5552 else if (ret) {
5553 btrfs_abort_transaction(trans, root, ret);
5554 return ret;
5555 }
5556
5557 btrfs_i_size_write(parent_inode, parent_inode->i_size +
5558 name_len * 2);
5559 inode_inc_iversion(parent_inode);
5560 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
5561 ret = btrfs_update_inode(trans, root, parent_inode);
5562 if (ret)
5563 btrfs_abort_transaction(trans, root, ret);
5564 return ret;
5565
5566 fail_dir_item:
5567 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5568 u64 local_index;
5569 int err;
5570 err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
5571 key.objectid, root->root_key.objectid,
5572 parent_ino, &local_index, name, name_len);
5573
5574 } else if (add_backref) {
5575 u64 local_index;
5576 int err;
5577
5578 err = btrfs_del_inode_ref(trans, root, name, name_len,
5579 ino, parent_ino, &local_index);
5580 }
5581 return ret;
5582 }
5583
5584 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
5585 struct inode *dir, struct dentry *dentry,
5586 struct inode *inode, int backref, u64 index)
5587 {
5588 int err = btrfs_add_link(trans, dir, inode,
5589 dentry->d_name.name, dentry->d_name.len,
5590 backref, index);
5591 if (err > 0)
5592 err = -EEXIST;
5593 return err;
5594 }
5595
5596 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
5597 umode_t mode, dev_t rdev)
5598 {
5599 struct btrfs_trans_handle *trans;
5600 struct btrfs_root *root = BTRFS_I(dir)->root;
5601 struct inode *inode = NULL;
5602 int err;
5603 int drop_inode = 0;
5604 u64 objectid;
5605 u64 index = 0;
5606
5607 if (!new_valid_dev(rdev))
5608 return -EINVAL;
5609
5610 /*
5611 * 2 for inode item and ref
5612 * 2 for dir items
5613 * 1 for xattr if selinux is on
5614 */
5615 trans = btrfs_start_transaction(root, 5);
5616 if (IS_ERR(trans))
5617 return PTR_ERR(trans);
5618
5619 err = btrfs_find_free_ino(root, &objectid);
5620 if (err)
5621 goto out_unlock;
5622
5623 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5624 dentry->d_name.len, btrfs_ino(dir), objectid,
5625 mode, &index);
5626 if (IS_ERR(inode)) {
5627 err = PTR_ERR(inode);
5628 goto out_unlock;
5629 }
5630
5631 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5632 if (err) {
5633 drop_inode = 1;
5634 goto out_unlock;
5635 }
5636
5637 /*
5638 * If the active LSM wants to access the inode during
5639 * d_instantiate it needs these. Smack checks to see
5640 * if the filesystem supports xattrs by looking at the
5641 * ops vector.
5642 */
5643
5644 inode->i_op = &btrfs_special_inode_operations;
5645 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
5646 if (err)
5647 drop_inode = 1;
5648 else {
5649 init_special_inode(inode, inode->i_mode, rdev);
5650 btrfs_update_inode(trans, root, inode);
5651 d_instantiate(dentry, inode);
5652 }
5653 out_unlock:
5654 btrfs_end_transaction(trans, root);
5655 btrfs_btree_balance_dirty(root);
5656 if (drop_inode) {
5657 inode_dec_link_count(inode);
5658 iput(inode);
5659 }
5660 return err;
5661 }
5662
5663 static int btrfs_create(struct inode *dir, struct dentry *dentry,
5664 umode_t mode, bool excl)
5665 {
5666 struct btrfs_trans_handle *trans;
5667 struct btrfs_root *root = BTRFS_I(dir)->root;
5668 struct inode *inode = NULL;
5669 int drop_inode_on_err = 0;
5670 int err;
5671 u64 objectid;
5672 u64 index = 0;
5673
5674 /*
5675 * 2 for inode item and ref
5676 * 2 for dir items
5677 * 1 for xattr if selinux is on
5678 */
5679 trans = btrfs_start_transaction(root, 5);
5680 if (IS_ERR(trans))
5681 return PTR_ERR(trans);
5682
5683 err = btrfs_find_free_ino(root, &objectid);
5684 if (err)
5685 goto out_unlock;
5686
5687 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5688 dentry->d_name.len, btrfs_ino(dir), objectid,
5689 mode, &index);
5690 if (IS_ERR(inode)) {
5691 err = PTR_ERR(inode);
5692 goto out_unlock;
5693 }
5694 drop_inode_on_err = 1;
5695
5696 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5697 if (err)
5698 goto out_unlock;
5699
5700 err = btrfs_update_inode(trans, root, inode);
5701 if (err)
5702 goto out_unlock;
5703
5704 /*
5705 * If the active LSM wants to access the inode during
5706 * d_instantiate it needs these. Smack checks to see
5707 * if the filesystem supports xattrs by looking at the
5708 * ops vector.
5709 */
5710 inode->i_fop = &btrfs_file_operations;
5711 inode->i_op = &btrfs_file_inode_operations;
5712
5713 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
5714 if (err)
5715 goto out_unlock;
5716
5717 inode->i_mapping->a_ops = &btrfs_aops;
5718 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
5719 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
5720 d_instantiate(dentry, inode);
5721
5722 out_unlock:
5723 btrfs_end_transaction(trans, root);
5724 if (err && drop_inode_on_err) {
5725 inode_dec_link_count(inode);
5726 iput(inode);
5727 }
5728 btrfs_btree_balance_dirty(root);
5729 return err;
5730 }
5731
5732 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
5733 struct dentry *dentry)
5734 {
5735 struct btrfs_trans_handle *trans;
5736 struct btrfs_root *root = BTRFS_I(dir)->root;
5737 struct inode *inode = old_dentry->d_inode;
5738 u64 index;
5739 int err;
5740 int drop_inode = 0;
5741
5742 /* do not allow sys_link's with other subvols of the same device */
5743 if (root->objectid != BTRFS_I(inode)->root->objectid)
5744 return -EXDEV;
5745
5746 if (inode->i_nlink >= BTRFS_LINK_MAX)
5747 return -EMLINK;
5748
5749 err = btrfs_set_inode_index(dir, &index);
5750 if (err)
5751 goto fail;
5752
5753 /*
5754 * 2 items for inode and inode ref
5755 * 2 items for dir items
5756 * 1 item for parent inode
5757 */
5758 trans = btrfs_start_transaction(root, 5);
5759 if (IS_ERR(trans)) {
5760 err = PTR_ERR(trans);
5761 goto fail;
5762 }
5763
5764 btrfs_inc_nlink(inode);
5765 inode_inc_iversion(inode);
5766 inode->i_ctime = CURRENT_TIME;
5767 ihold(inode);
5768 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
5769
5770 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
5771
5772 if (err) {
5773 drop_inode = 1;
5774 } else {
5775 struct dentry *parent = dentry->d_parent;
5776 err = btrfs_update_inode(trans, root, inode);
5777 if (err)
5778 goto fail;
5779 d_instantiate(dentry, inode);
5780 btrfs_log_new_name(trans, inode, NULL, parent);
5781 }
5782
5783 btrfs_end_transaction(trans, root);
5784 fail:
5785 if (drop_inode) {
5786 inode_dec_link_count(inode);
5787 iput(inode);
5788 }
5789 btrfs_btree_balance_dirty(root);
5790 return err;
5791 }
5792
5793 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
5794 {
5795 struct inode *inode = NULL;
5796 struct btrfs_trans_handle *trans;
5797 struct btrfs_root *root = BTRFS_I(dir)->root;
5798 int err = 0;
5799 int drop_on_err = 0;
5800 u64 objectid = 0;
5801 u64 index = 0;
5802
5803 /*
5804 * 2 items for inode and ref
5805 * 2 items for dir items
5806 * 1 for xattr if selinux is on
5807 */
5808 trans = btrfs_start_transaction(root, 5);
5809 if (IS_ERR(trans))
5810 return PTR_ERR(trans);
5811
5812 err = btrfs_find_free_ino(root, &objectid);
5813 if (err)
5814 goto out_fail;
5815
5816 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5817 dentry->d_name.len, btrfs_ino(dir), objectid,
5818 S_IFDIR | mode, &index);
5819 if (IS_ERR(inode)) {
5820 err = PTR_ERR(inode);
5821 goto out_fail;
5822 }
5823
5824 drop_on_err = 1;
5825
5826 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5827 if (err)
5828 goto out_fail;
5829
5830 inode->i_op = &btrfs_dir_inode_operations;
5831 inode->i_fop = &btrfs_dir_file_operations;
5832
5833 btrfs_i_size_write(inode, 0);
5834 err = btrfs_update_inode(trans, root, inode);
5835 if (err)
5836 goto out_fail;
5837
5838 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
5839 dentry->d_name.len, 0, index);
5840 if (err)
5841 goto out_fail;
5842
5843 d_instantiate(dentry, inode);
5844 drop_on_err = 0;
5845
5846 out_fail:
5847 btrfs_end_transaction(trans, root);
5848 if (drop_on_err)
5849 iput(inode);
5850 btrfs_btree_balance_dirty(root);
5851 return err;
5852 }
5853
5854 /* helper for btfs_get_extent. Given an existing extent in the tree,
5855 * and an extent that you want to insert, deal with overlap and insert
5856 * the new extent into the tree.
5857 */
5858 static int merge_extent_mapping(struct extent_map_tree *em_tree,
5859 struct extent_map *existing,
5860 struct extent_map *em,
5861 u64 map_start, u64 map_len)
5862 {
5863 u64 start_diff;
5864
5865 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
5866 start_diff = map_start - em->start;
5867 em->start = map_start;
5868 em->len = map_len;
5869 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
5870 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
5871 em->block_start += start_diff;
5872 em->block_len -= start_diff;
5873 }
5874 return add_extent_mapping(em_tree, em, 0);
5875 }
5876
5877 static noinline int uncompress_inline(struct btrfs_path *path,
5878 struct inode *inode, struct page *page,
5879 size_t pg_offset, u64 extent_offset,
5880 struct btrfs_file_extent_item *item)
5881 {
5882 int ret;
5883 struct extent_buffer *leaf = path->nodes[0];
5884 char *tmp;
5885 size_t max_size;
5886 unsigned long inline_size;
5887 unsigned long ptr;
5888 int compress_type;
5889
5890 WARN_ON(pg_offset != 0);
5891 compress_type = btrfs_file_extent_compression(leaf, item);
5892 max_size = btrfs_file_extent_ram_bytes(leaf, item);
5893 inline_size = btrfs_file_extent_inline_item_len(leaf,
5894 btrfs_item_nr(leaf, path->slots[0]));
5895 tmp = kmalloc(inline_size, GFP_NOFS);
5896 if (!tmp)
5897 return -ENOMEM;
5898 ptr = btrfs_file_extent_inline_start(item);
5899
5900 read_extent_buffer(leaf, tmp, ptr, inline_size);
5901
5902 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
5903 ret = btrfs_decompress(compress_type, tmp, page,
5904 extent_offset, inline_size, max_size);
5905 if (ret) {
5906 char *kaddr = kmap_atomic(page);
5907 unsigned long copy_size = min_t(u64,
5908 PAGE_CACHE_SIZE - pg_offset,
5909 max_size - extent_offset);
5910 memset(kaddr + pg_offset, 0, copy_size);
5911 kunmap_atomic(kaddr);
5912 }
5913 kfree(tmp);
5914 return 0;
5915 }
5916
5917 /*
5918 * a bit scary, this does extent mapping from logical file offset to the disk.
5919 * the ugly parts come from merging extents from the disk with the in-ram
5920 * representation. This gets more complex because of the data=ordered code,
5921 * where the in-ram extents might be locked pending data=ordered completion.
5922 *
5923 * This also copies inline extents directly into the page.
5924 */
5925
5926 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
5927 size_t pg_offset, u64 start, u64 len,
5928 int create)
5929 {
5930 int ret;
5931 int err = 0;
5932 u64 bytenr;
5933 u64 extent_start = 0;
5934 u64 extent_end = 0;
5935 u64 objectid = btrfs_ino(inode);
5936 u32 found_type;
5937 struct btrfs_path *path = NULL;
5938 struct btrfs_root *root = BTRFS_I(inode)->root;
5939 struct btrfs_file_extent_item *item;
5940 struct extent_buffer *leaf;
5941 struct btrfs_key found_key;
5942 struct extent_map *em = NULL;
5943 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
5944 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5945 struct btrfs_trans_handle *trans = NULL;
5946 int compress_type;
5947
5948 again:
5949 read_lock(&em_tree->lock);
5950 em = lookup_extent_mapping(em_tree, start, len);
5951 if (em)
5952 em->bdev = root->fs_info->fs_devices->latest_bdev;
5953 read_unlock(&em_tree->lock);
5954
5955 if (em) {
5956 if (em->start > start || em->start + em->len <= start)
5957 free_extent_map(em);
5958 else if (em->block_start == EXTENT_MAP_INLINE && page)
5959 free_extent_map(em);
5960 else
5961 goto out;
5962 }
5963 em = alloc_extent_map();
5964 if (!em) {
5965 err = -ENOMEM;
5966 goto out;
5967 }
5968 em->bdev = root->fs_info->fs_devices->latest_bdev;
5969 em->start = EXTENT_MAP_HOLE;
5970 em->orig_start = EXTENT_MAP_HOLE;
5971 em->len = (u64)-1;
5972 em->block_len = (u64)-1;
5973
5974 if (!path) {
5975 path = btrfs_alloc_path();
5976 if (!path) {
5977 err = -ENOMEM;
5978 goto out;
5979 }
5980 /*
5981 * Chances are we'll be called again, so go ahead and do
5982 * readahead
5983 */
5984 path->reada = 1;
5985 }
5986
5987 ret = btrfs_lookup_file_extent(trans, root, path,
5988 objectid, start, trans != NULL);
5989 if (ret < 0) {
5990 err = ret;
5991 goto out;
5992 }
5993
5994 if (ret != 0) {
5995 if (path->slots[0] == 0)
5996 goto not_found;
5997 path->slots[0]--;
5998 }
5999
6000 leaf = path->nodes[0];
6001 item = btrfs_item_ptr(leaf, path->slots[0],
6002 struct btrfs_file_extent_item);
6003 /* are we inside the extent that was found? */
6004 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6005 found_type = btrfs_key_type(&found_key);
6006 if (found_key.objectid != objectid ||
6007 found_type != BTRFS_EXTENT_DATA_KEY) {
6008 goto not_found;
6009 }
6010
6011 found_type = btrfs_file_extent_type(leaf, item);
6012 extent_start = found_key.offset;
6013 compress_type = btrfs_file_extent_compression(leaf, item);
6014 if (found_type == BTRFS_FILE_EXTENT_REG ||
6015 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6016 extent_end = extent_start +
6017 btrfs_file_extent_num_bytes(leaf, item);
6018 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6019 size_t size;
6020 size = btrfs_file_extent_inline_len(leaf, item);
6021 extent_end = ALIGN(extent_start + size, root->sectorsize);
6022 }
6023
6024 if (start >= extent_end) {
6025 path->slots[0]++;
6026 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
6027 ret = btrfs_next_leaf(root, path);
6028 if (ret < 0) {
6029 err = ret;
6030 goto out;
6031 }
6032 if (ret > 0)
6033 goto not_found;
6034 leaf = path->nodes[0];
6035 }
6036 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6037 if (found_key.objectid != objectid ||
6038 found_key.type != BTRFS_EXTENT_DATA_KEY)
6039 goto not_found;
6040 if (start + len <= found_key.offset)
6041 goto not_found;
6042 em->start = start;
6043 em->orig_start = start;
6044 em->len = found_key.offset - start;
6045 goto not_found_em;
6046 }
6047
6048 em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, item);
6049 if (found_type == BTRFS_FILE_EXTENT_REG ||
6050 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6051 em->start = extent_start;
6052 em->len = extent_end - extent_start;
6053 em->orig_start = extent_start -
6054 btrfs_file_extent_offset(leaf, item);
6055 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf,
6056 item);
6057 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
6058 if (bytenr == 0) {
6059 em->block_start = EXTENT_MAP_HOLE;
6060 goto insert;
6061 }
6062 if (compress_type != BTRFS_COMPRESS_NONE) {
6063 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
6064 em->compress_type = compress_type;
6065 em->block_start = bytenr;
6066 em->block_len = em->orig_block_len;
6067 } else {
6068 bytenr += btrfs_file_extent_offset(leaf, item);
6069 em->block_start = bytenr;
6070 em->block_len = em->len;
6071 if (found_type == BTRFS_FILE_EXTENT_PREALLOC)
6072 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
6073 }
6074 goto insert;
6075 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6076 unsigned long ptr;
6077 char *map;
6078 size_t size;
6079 size_t extent_offset;
6080 size_t copy_size;
6081
6082 em->block_start = EXTENT_MAP_INLINE;
6083 if (!page || create) {
6084 em->start = extent_start;
6085 em->len = extent_end - extent_start;
6086 goto out;
6087 }
6088
6089 size = btrfs_file_extent_inline_len(leaf, item);
6090 extent_offset = page_offset(page) + pg_offset - extent_start;
6091 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
6092 size - extent_offset);
6093 em->start = extent_start + extent_offset;
6094 em->len = ALIGN(copy_size, root->sectorsize);
6095 em->orig_block_len = em->len;
6096 em->orig_start = em->start;
6097 if (compress_type) {
6098 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
6099 em->compress_type = compress_type;
6100 }
6101 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
6102 if (create == 0 && !PageUptodate(page)) {
6103 if (btrfs_file_extent_compression(leaf, item) !=
6104 BTRFS_COMPRESS_NONE) {
6105 ret = uncompress_inline(path, inode, page,
6106 pg_offset,
6107 extent_offset, item);
6108 BUG_ON(ret); /* -ENOMEM */
6109 } else {
6110 map = kmap(page);
6111 read_extent_buffer(leaf, map + pg_offset, ptr,
6112 copy_size);
6113 if (pg_offset + copy_size < PAGE_CACHE_SIZE) {
6114 memset(map + pg_offset + copy_size, 0,
6115 PAGE_CACHE_SIZE - pg_offset -
6116 copy_size);
6117 }
6118 kunmap(page);
6119 }
6120 flush_dcache_page(page);
6121 } else if (create && PageUptodate(page)) {
6122 BUG();
6123 if (!trans) {
6124 kunmap(page);
6125 free_extent_map(em);
6126 em = NULL;
6127
6128 btrfs_release_path(path);
6129 trans = btrfs_join_transaction(root);
6130
6131 if (IS_ERR(trans))
6132 return ERR_CAST(trans);
6133 goto again;
6134 }
6135 map = kmap(page);
6136 write_extent_buffer(leaf, map + pg_offset, ptr,
6137 copy_size);
6138 kunmap(page);
6139 btrfs_mark_buffer_dirty(leaf);
6140 }
6141 set_extent_uptodate(io_tree, em->start,
6142 extent_map_end(em) - 1, NULL, GFP_NOFS);
6143 goto insert;
6144 } else {
6145 WARN(1, KERN_ERR "btrfs unknown found_type %d\n", found_type);
6146 }
6147 not_found:
6148 em->start = start;
6149 em->orig_start = start;
6150 em->len = len;
6151 not_found_em:
6152 em->block_start = EXTENT_MAP_HOLE;
6153 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
6154 insert:
6155 btrfs_release_path(path);
6156 if (em->start > start || extent_map_end(em) <= start) {
6157 btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]",
6158 (unsigned long long)em->start,
6159 (unsigned long long)em->len,
6160 (unsigned long long)start,
6161 (unsigned long long)len);
6162 err = -EIO;
6163 goto out;
6164 }
6165
6166 err = 0;
6167 write_lock(&em_tree->lock);
6168 ret = add_extent_mapping(em_tree, em, 0);
6169 /* it is possible that someone inserted the extent into the tree
6170 * while we had the lock dropped. It is also possible that
6171 * an overlapping map exists in the tree
6172 */
6173 if (ret == -EEXIST) {
6174 struct extent_map *existing;
6175
6176 ret = 0;
6177
6178 existing = lookup_extent_mapping(em_tree, start, len);
6179 if (existing && (existing->start > start ||
6180 existing->start + existing->len <= start)) {
6181 free_extent_map(existing);
6182 existing = NULL;
6183 }
6184 if (!existing) {
6185 existing = lookup_extent_mapping(em_tree, em->start,
6186 em->len);
6187 if (existing) {
6188 err = merge_extent_mapping(em_tree, existing,
6189 em, start,
6190 root->sectorsize);
6191 free_extent_map(existing);
6192 if (err) {
6193 free_extent_map(em);
6194 em = NULL;
6195 }
6196 } else {
6197 err = -EIO;
6198 free_extent_map(em);
6199 em = NULL;
6200 }
6201 } else {
6202 free_extent_map(em);
6203 em = existing;
6204 err = 0;
6205 }
6206 }
6207 write_unlock(&em_tree->lock);
6208 out:
6209
6210 if (em)
6211 trace_btrfs_get_extent(root, em);
6212
6213 if (path)
6214 btrfs_free_path(path);
6215 if (trans) {
6216 ret = btrfs_end_transaction(trans, root);
6217 if (!err)
6218 err = ret;
6219 }
6220 if (err) {
6221 free_extent_map(em);
6222 return ERR_PTR(err);
6223 }
6224 BUG_ON(!em); /* Error is always set */
6225 return em;
6226 }
6227
6228 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
6229 size_t pg_offset, u64 start, u64 len,
6230 int create)
6231 {
6232 struct extent_map *em;
6233 struct extent_map *hole_em = NULL;
6234 u64 range_start = start;
6235 u64 end;
6236 u64 found;
6237 u64 found_end;
6238 int err = 0;
6239
6240 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
6241 if (IS_ERR(em))
6242 return em;
6243 if (em) {
6244 /*
6245 * if our em maps to
6246 * - a hole or
6247 * - a pre-alloc extent,
6248 * there might actually be delalloc bytes behind it.
6249 */
6250 if (em->block_start != EXTENT_MAP_HOLE &&
6251 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6252 return em;
6253 else
6254 hole_em = em;
6255 }
6256
6257 /* check to see if we've wrapped (len == -1 or similar) */
6258 end = start + len;
6259 if (end < start)
6260 end = (u64)-1;
6261 else
6262 end -= 1;
6263
6264 em = NULL;
6265
6266 /* ok, we didn't find anything, lets look for delalloc */
6267 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
6268 end, len, EXTENT_DELALLOC, 1);
6269 found_end = range_start + found;
6270 if (found_end < range_start)
6271 found_end = (u64)-1;
6272
6273 /*
6274 * we didn't find anything useful, return
6275 * the original results from get_extent()
6276 */
6277 if (range_start > end || found_end <= start) {
6278 em = hole_em;
6279 hole_em = NULL;
6280 goto out;
6281 }
6282
6283 /* adjust the range_start to make sure it doesn't
6284 * go backwards from the start they passed in
6285 */
6286 range_start = max(start,range_start);
6287 found = found_end - range_start;
6288
6289 if (found > 0) {
6290 u64 hole_start = start;
6291 u64 hole_len = len;
6292
6293 em = alloc_extent_map();
6294 if (!em) {
6295 err = -ENOMEM;
6296 goto out;
6297 }
6298 /*
6299 * when btrfs_get_extent can't find anything it
6300 * returns one huge hole
6301 *
6302 * make sure what it found really fits our range, and
6303 * adjust to make sure it is based on the start from
6304 * the caller
6305 */
6306 if (hole_em) {
6307 u64 calc_end = extent_map_end(hole_em);
6308
6309 if (calc_end <= start || (hole_em->start > end)) {
6310 free_extent_map(hole_em);
6311 hole_em = NULL;
6312 } else {
6313 hole_start = max(hole_em->start, start);
6314 hole_len = calc_end - hole_start;
6315 }
6316 }
6317 em->bdev = NULL;
6318 if (hole_em && range_start > hole_start) {
6319 /* our hole starts before our delalloc, so we
6320 * have to return just the parts of the hole
6321 * that go until the delalloc starts
6322 */
6323 em->len = min(hole_len,
6324 range_start - hole_start);
6325 em->start = hole_start;
6326 em->orig_start = hole_start;
6327 /*
6328 * don't adjust block start at all,
6329 * it is fixed at EXTENT_MAP_HOLE
6330 */
6331 em->block_start = hole_em->block_start;
6332 em->block_len = hole_len;
6333 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
6334 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
6335 } else {
6336 em->start = range_start;
6337 em->len = found;
6338 em->orig_start = range_start;
6339 em->block_start = EXTENT_MAP_DELALLOC;
6340 em->block_len = found;
6341 }
6342 } else if (hole_em) {
6343 return hole_em;
6344 }
6345 out:
6346
6347 free_extent_map(hole_em);
6348 if (err) {
6349 free_extent_map(em);
6350 return ERR_PTR(err);
6351 }
6352 return em;
6353 }
6354
6355 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
6356 u64 start, u64 len)
6357 {
6358 struct btrfs_root *root = BTRFS_I(inode)->root;
6359 struct btrfs_trans_handle *trans;
6360 struct extent_map *em;
6361 struct btrfs_key ins;
6362 u64 alloc_hint;
6363 int ret;
6364
6365 trans = btrfs_join_transaction(root);
6366 if (IS_ERR(trans))
6367 return ERR_CAST(trans);
6368
6369 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
6370
6371 alloc_hint = get_extent_allocation_hint(inode, start, len);
6372 ret = btrfs_reserve_extent(trans, root, len, root->sectorsize, 0,
6373 alloc_hint, &ins, 1);
6374 if (ret) {
6375 em = ERR_PTR(ret);
6376 goto out;
6377 }
6378
6379 em = create_pinned_em(inode, start, ins.offset, start, ins.objectid,
6380 ins.offset, ins.offset, ins.offset, 0);
6381 if (IS_ERR(em))
6382 goto out;
6383
6384 ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
6385 ins.offset, ins.offset, 0);
6386 if (ret) {
6387 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
6388 em = ERR_PTR(ret);
6389 }
6390 out:
6391 btrfs_end_transaction(trans, root);
6392 return em;
6393 }
6394
6395 /*
6396 * returns 1 when the nocow is safe, < 1 on error, 0 if the
6397 * block must be cow'd
6398 */
6399 noinline int can_nocow_extent(struct btrfs_trans_handle *trans,
6400 struct inode *inode, u64 offset, u64 *len,
6401 u64 *orig_start, u64 *orig_block_len,
6402 u64 *ram_bytes)
6403 {
6404 struct btrfs_path *path;
6405 int ret;
6406 struct extent_buffer *leaf;
6407 struct btrfs_root *root = BTRFS_I(inode)->root;
6408 struct btrfs_file_extent_item *fi;
6409 struct btrfs_key key;
6410 u64 disk_bytenr;
6411 u64 backref_offset;
6412 u64 extent_end;
6413 u64 num_bytes;
6414 int slot;
6415 int found_type;
6416 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
6417 path = btrfs_alloc_path();
6418 if (!path)
6419 return -ENOMEM;
6420
6421 ret = btrfs_lookup_file_extent(trans, root, path, btrfs_ino(inode),
6422 offset, 0);
6423 if (ret < 0)
6424 goto out;
6425
6426 slot = path->slots[0];
6427 if (ret == 1) {
6428 if (slot == 0) {
6429 /* can't find the item, must cow */
6430 ret = 0;
6431 goto out;
6432 }
6433 slot--;
6434 }
6435 ret = 0;
6436 leaf = path->nodes[0];
6437 btrfs_item_key_to_cpu(leaf, &key, slot);
6438 if (key.objectid != btrfs_ino(inode) ||
6439 key.type != BTRFS_EXTENT_DATA_KEY) {
6440 /* not our file or wrong item type, must cow */
6441 goto out;
6442 }
6443
6444 if (key.offset > offset) {
6445 /* Wrong offset, must cow */
6446 goto out;
6447 }
6448
6449 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
6450 found_type = btrfs_file_extent_type(leaf, fi);
6451 if (found_type != BTRFS_FILE_EXTENT_REG &&
6452 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
6453 /* not a regular extent, must cow */
6454 goto out;
6455 }
6456
6457 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
6458 goto out;
6459
6460 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
6461 if (disk_bytenr == 0)
6462 goto out;
6463
6464 if (btrfs_file_extent_compression(leaf, fi) ||
6465 btrfs_file_extent_encryption(leaf, fi) ||
6466 btrfs_file_extent_other_encoding(leaf, fi))
6467 goto out;
6468
6469 backref_offset = btrfs_file_extent_offset(leaf, fi);
6470
6471 if (orig_start) {
6472 *orig_start = key.offset - backref_offset;
6473 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
6474 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
6475 }
6476
6477 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
6478
6479 if (btrfs_extent_readonly(root, disk_bytenr))
6480 goto out;
6481
6482 /*
6483 * look for other files referencing this extent, if we
6484 * find any we must cow
6485 */
6486 if (btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
6487 key.offset - backref_offset, disk_bytenr))
6488 goto out;
6489
6490 /*
6491 * adjust disk_bytenr and num_bytes to cover just the bytes
6492 * in this extent we are about to write. If there
6493 * are any csums in that range we have to cow in order
6494 * to keep the csums correct
6495 */
6496 disk_bytenr += backref_offset;
6497 disk_bytenr += offset - key.offset;
6498 num_bytes = min(offset + *len, extent_end) - offset;
6499 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
6500 goto out;
6501 /*
6502 * all of the above have passed, it is safe to overwrite this extent
6503 * without cow
6504 */
6505 *len = num_bytes;
6506 ret = 1;
6507 out:
6508 btrfs_free_path(path);
6509 return ret;
6510 }
6511
6512 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
6513 struct extent_state **cached_state, int writing)
6514 {
6515 struct btrfs_ordered_extent *ordered;
6516 int ret = 0;
6517
6518 while (1) {
6519 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6520 0, cached_state);
6521 /*
6522 * We're concerned with the entire range that we're going to be
6523 * doing DIO to, so we need to make sure theres no ordered
6524 * extents in this range.
6525 */
6526 ordered = btrfs_lookup_ordered_range(inode, lockstart,
6527 lockend - lockstart + 1);
6528
6529 /*
6530 * We need to make sure there are no buffered pages in this
6531 * range either, we could have raced between the invalidate in
6532 * generic_file_direct_write and locking the extent. The
6533 * invalidate needs to happen so that reads after a write do not
6534 * get stale data.
6535 */
6536 if (!ordered && (!writing ||
6537 !test_range_bit(&BTRFS_I(inode)->io_tree,
6538 lockstart, lockend, EXTENT_UPTODATE, 0,
6539 *cached_state)))
6540 break;
6541
6542 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6543 cached_state, GFP_NOFS);
6544
6545 if (ordered) {
6546 btrfs_start_ordered_extent(inode, ordered, 1);
6547 btrfs_put_ordered_extent(ordered);
6548 } else {
6549 /* Screw you mmap */
6550 ret = filemap_write_and_wait_range(inode->i_mapping,
6551 lockstart,
6552 lockend);
6553 if (ret)
6554 break;
6555
6556 /*
6557 * If we found a page that couldn't be invalidated just
6558 * fall back to buffered.
6559 */
6560 ret = invalidate_inode_pages2_range(inode->i_mapping,
6561 lockstart >> PAGE_CACHE_SHIFT,
6562 lockend >> PAGE_CACHE_SHIFT);
6563 if (ret)
6564 break;
6565 }
6566
6567 cond_resched();
6568 }
6569
6570 return ret;
6571 }
6572
6573 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
6574 u64 len, u64 orig_start,
6575 u64 block_start, u64 block_len,
6576 u64 orig_block_len, u64 ram_bytes,
6577 int type)
6578 {
6579 struct extent_map_tree *em_tree;
6580 struct extent_map *em;
6581 struct btrfs_root *root = BTRFS_I(inode)->root;
6582 int ret;
6583
6584 em_tree = &BTRFS_I(inode)->extent_tree;
6585 em = alloc_extent_map();
6586 if (!em)
6587 return ERR_PTR(-ENOMEM);
6588
6589 em->start = start;
6590 em->orig_start = orig_start;
6591 em->mod_start = start;
6592 em->mod_len = len;
6593 em->len = len;
6594 em->block_len = block_len;
6595 em->block_start = block_start;
6596 em->bdev = root->fs_info->fs_devices->latest_bdev;
6597 em->orig_block_len = orig_block_len;
6598 em->ram_bytes = ram_bytes;
6599 em->generation = -1;
6600 set_bit(EXTENT_FLAG_PINNED, &em->flags);
6601 if (type == BTRFS_ORDERED_PREALLOC)
6602 set_bit(EXTENT_FLAG_FILLING, &em->flags);
6603
6604 do {
6605 btrfs_drop_extent_cache(inode, em->start,
6606 em->start + em->len - 1, 0);
6607 write_lock(&em_tree->lock);
6608 ret = add_extent_mapping(em_tree, em, 1);
6609 write_unlock(&em_tree->lock);
6610 } while (ret == -EEXIST);
6611
6612 if (ret) {
6613 free_extent_map(em);
6614 return ERR_PTR(ret);
6615 }
6616
6617 return em;
6618 }
6619
6620
6621 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
6622 struct buffer_head *bh_result, int create)
6623 {
6624 struct extent_map *em;
6625 struct btrfs_root *root = BTRFS_I(inode)->root;
6626 struct extent_state *cached_state = NULL;
6627 u64 start = iblock << inode->i_blkbits;
6628 u64 lockstart, lockend;
6629 u64 len = bh_result->b_size;
6630 struct btrfs_trans_handle *trans;
6631 int unlock_bits = EXTENT_LOCKED;
6632 int ret = 0;
6633
6634 if (create)
6635 unlock_bits |= EXTENT_DELALLOC | EXTENT_DIRTY;
6636 else
6637 len = min_t(u64, len, root->sectorsize);
6638
6639 lockstart = start;
6640 lockend = start + len - 1;
6641
6642 /*
6643 * If this errors out it's because we couldn't invalidate pagecache for
6644 * this range and we need to fallback to buffered.
6645 */
6646 if (lock_extent_direct(inode, lockstart, lockend, &cached_state, create))
6647 return -ENOTBLK;
6648
6649 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
6650 if (IS_ERR(em)) {
6651 ret = PTR_ERR(em);
6652 goto unlock_err;
6653 }
6654
6655 /*
6656 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
6657 * io. INLINE is special, and we could probably kludge it in here, but
6658 * it's still buffered so for safety lets just fall back to the generic
6659 * buffered path.
6660 *
6661 * For COMPRESSED we _have_ to read the entire extent in so we can
6662 * decompress it, so there will be buffering required no matter what we
6663 * do, so go ahead and fallback to buffered.
6664 *
6665 * We return -ENOTBLK because thats what makes DIO go ahead and go back
6666 * to buffered IO. Don't blame me, this is the price we pay for using
6667 * the generic code.
6668 */
6669 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
6670 em->block_start == EXTENT_MAP_INLINE) {
6671 free_extent_map(em);
6672 ret = -ENOTBLK;
6673 goto unlock_err;
6674 }
6675
6676 /* Just a good old fashioned hole, return */
6677 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
6678 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
6679 free_extent_map(em);
6680 goto unlock_err;
6681 }
6682
6683 /*
6684 * We don't allocate a new extent in the following cases
6685 *
6686 * 1) The inode is marked as NODATACOW. In this case we'll just use the
6687 * existing extent.
6688 * 2) The extent is marked as PREALLOC. We're good to go here and can
6689 * just use the extent.
6690 *
6691 */
6692 if (!create) {
6693 len = min(len, em->len - (start - em->start));
6694 lockstart = start + len;
6695 goto unlock;
6696 }
6697
6698 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
6699 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
6700 em->block_start != EXTENT_MAP_HOLE)) {
6701 int type;
6702 int ret;
6703 u64 block_start, orig_start, orig_block_len, ram_bytes;
6704
6705 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6706 type = BTRFS_ORDERED_PREALLOC;
6707 else
6708 type = BTRFS_ORDERED_NOCOW;
6709 len = min(len, em->len - (start - em->start));
6710 block_start = em->block_start + (start - em->start);
6711
6712 /*
6713 * we're not going to log anything, but we do need
6714 * to make sure the current transaction stays open
6715 * while we look for nocow cross refs
6716 */
6717 trans = btrfs_join_transaction(root);
6718 if (IS_ERR(trans))
6719 goto must_cow;
6720
6721 if (can_nocow_extent(trans, inode, start, &len, &orig_start,
6722 &orig_block_len, &ram_bytes) == 1) {
6723 if (type == BTRFS_ORDERED_PREALLOC) {
6724 free_extent_map(em);
6725 em = create_pinned_em(inode, start, len,
6726 orig_start,
6727 block_start, len,
6728 orig_block_len,
6729 ram_bytes, type);
6730 if (IS_ERR(em)) {
6731 btrfs_end_transaction(trans, root);
6732 goto unlock_err;
6733 }
6734 }
6735
6736 ret = btrfs_add_ordered_extent_dio(inode, start,
6737 block_start, len, len, type);
6738 btrfs_end_transaction(trans, root);
6739 if (ret) {
6740 free_extent_map(em);
6741 goto unlock_err;
6742 }
6743 goto unlock;
6744 }
6745 btrfs_end_transaction(trans, root);
6746 }
6747 must_cow:
6748 /*
6749 * this will cow the extent, reset the len in case we changed
6750 * it above
6751 */
6752 len = bh_result->b_size;
6753 free_extent_map(em);
6754 em = btrfs_new_extent_direct(inode, start, len);
6755 if (IS_ERR(em)) {
6756 ret = PTR_ERR(em);
6757 goto unlock_err;
6758 }
6759 len = min(len, em->len - (start - em->start));
6760 unlock:
6761 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
6762 inode->i_blkbits;
6763 bh_result->b_size = len;
6764 bh_result->b_bdev = em->bdev;
6765 set_buffer_mapped(bh_result);
6766 if (create) {
6767 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6768 set_buffer_new(bh_result);
6769
6770 /*
6771 * Need to update the i_size under the extent lock so buffered
6772 * readers will get the updated i_size when we unlock.
6773 */
6774 if (start + len > i_size_read(inode))
6775 i_size_write(inode, start + len);
6776
6777 spin_lock(&BTRFS_I(inode)->lock);
6778 BTRFS_I(inode)->outstanding_extents++;
6779 spin_unlock(&BTRFS_I(inode)->lock);
6780
6781 ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
6782 lockstart + len - 1, EXTENT_DELALLOC, NULL,
6783 &cached_state, GFP_NOFS);
6784 BUG_ON(ret);
6785 }
6786
6787 /*
6788 * In the case of write we need to clear and unlock the entire range,
6789 * in the case of read we need to unlock only the end area that we
6790 * aren't using if there is any left over space.
6791 */
6792 if (lockstart < lockend) {
6793 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
6794 lockend, unlock_bits, 1, 0,
6795 &cached_state, GFP_NOFS);
6796 } else {
6797 free_extent_state(cached_state);
6798 }
6799
6800 free_extent_map(em);
6801
6802 return 0;
6803
6804 unlock_err:
6805 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6806 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
6807 return ret;
6808 }
6809
6810 struct btrfs_dio_private {
6811 struct inode *inode;
6812 u64 logical_offset;
6813 u64 disk_bytenr;
6814 u64 bytes;
6815 void *private;
6816
6817 /* number of bios pending for this dio */
6818 atomic_t pending_bios;
6819
6820 /* IO errors */
6821 int errors;
6822
6823 /* orig_bio is our btrfs_io_bio */
6824 struct bio *orig_bio;
6825
6826 /* dio_bio came from fs/direct-io.c */
6827 struct bio *dio_bio;
6828 };
6829
6830 static void btrfs_endio_direct_read(struct bio *bio, int err)
6831 {
6832 struct btrfs_dio_private *dip = bio->bi_private;
6833 struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
6834 struct bio_vec *bvec = bio->bi_io_vec;
6835 struct inode *inode = dip->inode;
6836 struct btrfs_root *root = BTRFS_I(inode)->root;
6837 struct bio *dio_bio;
6838 u64 start;
6839
6840 start = dip->logical_offset;
6841 do {
6842 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
6843 struct page *page = bvec->bv_page;
6844 char *kaddr;
6845 u32 csum = ~(u32)0;
6846 u64 private = ~(u32)0;
6847 unsigned long flags;
6848
6849 if (get_state_private(&BTRFS_I(inode)->io_tree,
6850 start, &private))
6851 goto failed;
6852 local_irq_save(flags);
6853 kaddr = kmap_atomic(page);
6854 csum = btrfs_csum_data(kaddr + bvec->bv_offset,
6855 csum, bvec->bv_len);
6856 btrfs_csum_final(csum, (char *)&csum);
6857 kunmap_atomic(kaddr);
6858 local_irq_restore(flags);
6859
6860 flush_dcache_page(bvec->bv_page);
6861 if (csum != private) {
6862 failed:
6863 btrfs_err(root->fs_info, "csum failed ino %llu off %llu csum %u private %u",
6864 (unsigned long long)btrfs_ino(inode),
6865 (unsigned long long)start,
6866 csum, (unsigned)private);
6867 err = -EIO;
6868 }
6869 }
6870
6871 start += bvec->bv_len;
6872 bvec++;
6873 } while (bvec <= bvec_end);
6874
6875 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
6876 dip->logical_offset + dip->bytes - 1);
6877 dio_bio = dip->dio_bio;
6878
6879 kfree(dip);
6880
6881 /* If we had a csum failure make sure to clear the uptodate flag */
6882 if (err)
6883 clear_bit(BIO_UPTODATE, &dio_bio->bi_flags);
6884 dio_end_io(dio_bio, err);
6885 bio_put(bio);
6886 }
6887
6888 static void btrfs_endio_direct_write(struct bio *bio, int err)
6889 {
6890 struct btrfs_dio_private *dip = bio->bi_private;
6891 struct inode *inode = dip->inode;
6892 struct btrfs_root *root = BTRFS_I(inode)->root;
6893 struct btrfs_ordered_extent *ordered = NULL;
6894 u64 ordered_offset = dip->logical_offset;
6895 u64 ordered_bytes = dip->bytes;
6896 struct bio *dio_bio;
6897 int ret;
6898
6899 if (err)
6900 goto out_done;
6901 again:
6902 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
6903 &ordered_offset,
6904 ordered_bytes, !err);
6905 if (!ret)
6906 goto out_test;
6907
6908 ordered->work.func = finish_ordered_fn;
6909 ordered->work.flags = 0;
6910 btrfs_queue_worker(&root->fs_info->endio_write_workers,
6911 &ordered->work);
6912 out_test:
6913 /*
6914 * our bio might span multiple ordered extents. If we haven't
6915 * completed the accounting for the whole dio, go back and try again
6916 */
6917 if (ordered_offset < dip->logical_offset + dip->bytes) {
6918 ordered_bytes = dip->logical_offset + dip->bytes -
6919 ordered_offset;
6920 ordered = NULL;
6921 goto again;
6922 }
6923 out_done:
6924 dio_bio = dip->dio_bio;
6925
6926 kfree(dip);
6927
6928 /* If we had an error make sure to clear the uptodate flag */
6929 if (err)
6930 clear_bit(BIO_UPTODATE, &dio_bio->bi_flags);
6931 dio_end_io(dio_bio, err);
6932 bio_put(bio);
6933 }
6934
6935 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
6936 struct bio *bio, int mirror_num,
6937 unsigned long bio_flags, u64 offset)
6938 {
6939 int ret;
6940 struct btrfs_root *root = BTRFS_I(inode)->root;
6941 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
6942 BUG_ON(ret); /* -ENOMEM */
6943 return 0;
6944 }
6945
6946 static void btrfs_end_dio_bio(struct bio *bio, int err)
6947 {
6948 struct btrfs_dio_private *dip = bio->bi_private;
6949
6950 if (err) {
6951 printk(KERN_ERR "btrfs direct IO failed ino %llu rw %lu "
6952 "sector %#Lx len %u err no %d\n",
6953 (unsigned long long)btrfs_ino(dip->inode), bio->bi_rw,
6954 (unsigned long long)bio->bi_sector, bio->bi_size, err);
6955 dip->errors = 1;
6956
6957 /*
6958 * before atomic variable goto zero, we must make sure
6959 * dip->errors is perceived to be set.
6960 */
6961 smp_mb__before_atomic_dec();
6962 }
6963
6964 /* if there are more bios still pending for this dio, just exit */
6965 if (!atomic_dec_and_test(&dip->pending_bios))
6966 goto out;
6967
6968 if (dip->errors) {
6969 bio_io_error(dip->orig_bio);
6970 } else {
6971 set_bit(BIO_UPTODATE, &dip->dio_bio->bi_flags);
6972 bio_endio(dip->orig_bio, 0);
6973 }
6974 out:
6975 bio_put(bio);
6976 }
6977
6978 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
6979 u64 first_sector, gfp_t gfp_flags)
6980 {
6981 int nr_vecs = bio_get_nr_vecs(bdev);
6982 return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags);
6983 }
6984
6985 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
6986 int rw, u64 file_offset, int skip_sum,
6987 int async_submit)
6988 {
6989 int write = rw & REQ_WRITE;
6990 struct btrfs_root *root = BTRFS_I(inode)->root;
6991 int ret;
6992
6993 if (async_submit)
6994 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
6995
6996 bio_get(bio);
6997
6998 if (!write) {
6999 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
7000 if (ret)
7001 goto err;
7002 }
7003
7004 if (skip_sum)
7005 goto map;
7006
7007 if (write && async_submit) {
7008 ret = btrfs_wq_submit_bio(root->fs_info,
7009 inode, rw, bio, 0, 0,
7010 file_offset,
7011 __btrfs_submit_bio_start_direct_io,
7012 __btrfs_submit_bio_done);
7013 goto err;
7014 } else if (write) {
7015 /*
7016 * If we aren't doing async submit, calculate the csum of the
7017 * bio now.
7018 */
7019 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
7020 if (ret)
7021 goto err;
7022 } else if (!skip_sum) {
7023 ret = btrfs_lookup_bio_sums_dio(root, inode, bio, file_offset);
7024 if (ret)
7025 goto err;
7026 }
7027
7028 map:
7029 ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
7030 err:
7031 bio_put(bio);
7032 return ret;
7033 }
7034
7035 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
7036 int skip_sum)
7037 {
7038 struct inode *inode = dip->inode;
7039 struct btrfs_root *root = BTRFS_I(inode)->root;
7040 struct bio *bio;
7041 struct bio *orig_bio = dip->orig_bio;
7042 struct bio_vec *bvec = orig_bio->bi_io_vec;
7043 u64 start_sector = orig_bio->bi_sector;
7044 u64 file_offset = dip->logical_offset;
7045 u64 submit_len = 0;
7046 u64 map_length;
7047 int nr_pages = 0;
7048 int ret = 0;
7049 int async_submit = 0;
7050
7051 map_length = orig_bio->bi_size;
7052 ret = btrfs_map_block(root->fs_info, rw, start_sector << 9,
7053 &map_length, NULL, 0);
7054 if (ret) {
7055 bio_put(orig_bio);
7056 return -EIO;
7057 }
7058 if (map_length >= orig_bio->bi_size) {
7059 bio = orig_bio;
7060 goto submit;
7061 }
7062
7063 /* async crcs make it difficult to collect full stripe writes. */
7064 if (btrfs_get_alloc_profile(root, 1) &
7065 (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6))
7066 async_submit = 0;
7067 else
7068 async_submit = 1;
7069
7070 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
7071 if (!bio)
7072 return -ENOMEM;
7073 bio->bi_private = dip;
7074 bio->bi_end_io = btrfs_end_dio_bio;
7075 atomic_inc(&dip->pending_bios);
7076
7077 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
7078 if (unlikely(map_length < submit_len + bvec->bv_len ||
7079 bio_add_page(bio, bvec->bv_page, bvec->bv_len,
7080 bvec->bv_offset) < bvec->bv_len)) {
7081 /*
7082 * inc the count before we submit the bio so
7083 * we know the end IO handler won't happen before
7084 * we inc the count. Otherwise, the dip might get freed
7085 * before we're done setting it up
7086 */
7087 atomic_inc(&dip->pending_bios);
7088 ret = __btrfs_submit_dio_bio(bio, inode, rw,
7089 file_offset, skip_sum,
7090 async_submit);
7091 if (ret) {
7092 bio_put(bio);
7093 atomic_dec(&dip->pending_bios);
7094 goto out_err;
7095 }
7096
7097 start_sector += submit_len >> 9;
7098 file_offset += submit_len;
7099
7100 submit_len = 0;
7101 nr_pages = 0;
7102
7103 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
7104 start_sector, GFP_NOFS);
7105 if (!bio)
7106 goto out_err;
7107 bio->bi_private = dip;
7108 bio->bi_end_io = btrfs_end_dio_bio;
7109
7110 map_length = orig_bio->bi_size;
7111 ret = btrfs_map_block(root->fs_info, rw,
7112 start_sector << 9,
7113 &map_length, NULL, 0);
7114 if (ret) {
7115 bio_put(bio);
7116 goto out_err;
7117 }
7118 } else {
7119 submit_len += bvec->bv_len;
7120 nr_pages ++;
7121 bvec++;
7122 }
7123 }
7124
7125 submit:
7126 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
7127 async_submit);
7128 if (!ret)
7129 return 0;
7130
7131 bio_put(bio);
7132 out_err:
7133 dip->errors = 1;
7134 /*
7135 * before atomic variable goto zero, we must
7136 * make sure dip->errors is perceived to be set.
7137 */
7138 smp_mb__before_atomic_dec();
7139 if (atomic_dec_and_test(&dip->pending_bios))
7140 bio_io_error(dip->orig_bio);
7141
7142 /* bio_end_io() will handle error, so we needn't return it */
7143 return 0;
7144 }
7145
7146 static void btrfs_submit_direct(int rw, struct bio *dio_bio,
7147 struct inode *inode, loff_t file_offset)
7148 {
7149 struct btrfs_root *root = BTRFS_I(inode)->root;
7150 struct btrfs_dio_private *dip;
7151 struct bio_vec *bvec = dio_bio->bi_io_vec;
7152 struct bio *io_bio;
7153 int skip_sum;
7154 int write = rw & REQ_WRITE;
7155 int ret = 0;
7156
7157 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
7158
7159 io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS);
7160
7161 if (!io_bio) {
7162 ret = -ENOMEM;
7163 goto free_ordered;
7164 }
7165
7166 dip = kmalloc(sizeof(*dip), GFP_NOFS);
7167 if (!dip) {
7168 ret = -ENOMEM;
7169 goto free_io_bio;
7170 }
7171
7172 dip->private = dio_bio->bi_private;
7173 io_bio->bi_private = dio_bio->bi_private;
7174 dip->inode = inode;
7175 dip->logical_offset = file_offset;
7176
7177 dip->bytes = 0;
7178 do {
7179 dip->bytes += bvec->bv_len;
7180 bvec++;
7181 } while (bvec <= (dio_bio->bi_io_vec + dio_bio->bi_vcnt - 1));
7182
7183 dip->disk_bytenr = (u64)dio_bio->bi_sector << 9;
7184 io_bio->bi_private = dip;
7185 dip->errors = 0;
7186 dip->orig_bio = io_bio;
7187 dip->dio_bio = dio_bio;
7188 atomic_set(&dip->pending_bios, 0);
7189
7190 if (write)
7191 io_bio->bi_end_io = btrfs_endio_direct_write;
7192 else
7193 io_bio->bi_end_io = btrfs_endio_direct_read;
7194
7195 ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
7196 if (!ret)
7197 return;
7198
7199 free_io_bio:
7200 bio_put(io_bio);
7201
7202 free_ordered:
7203 /*
7204 * If this is a write, we need to clean up the reserved space and kill
7205 * the ordered extent.
7206 */
7207 if (write) {
7208 struct btrfs_ordered_extent *ordered;
7209 ordered = btrfs_lookup_ordered_extent(inode, file_offset);
7210 if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) &&
7211 !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
7212 btrfs_free_reserved_extent(root, ordered->start,
7213 ordered->disk_len);
7214 btrfs_put_ordered_extent(ordered);
7215 btrfs_put_ordered_extent(ordered);
7216 }
7217 bio_endio(dio_bio, ret);
7218 }
7219
7220 static ssize_t check_direct_IO(struct btrfs_root *root, int rw, struct kiocb *iocb,
7221 const struct iovec *iov, loff_t offset,
7222 unsigned long nr_segs)
7223 {
7224 int seg;
7225 int i;
7226 size_t size;
7227 unsigned long addr;
7228 unsigned blocksize_mask = root->sectorsize - 1;
7229 ssize_t retval = -EINVAL;
7230 loff_t end = offset;
7231
7232 if (offset & blocksize_mask)
7233 goto out;
7234
7235 /* Check the memory alignment. Blocks cannot straddle pages */
7236 for (seg = 0; seg < nr_segs; seg++) {
7237 addr = (unsigned long)iov[seg].iov_base;
7238 size = iov[seg].iov_len;
7239 end += size;
7240 if ((addr & blocksize_mask) || (size & blocksize_mask))
7241 goto out;
7242
7243 /* If this is a write we don't need to check anymore */
7244 if (rw & WRITE)
7245 continue;
7246
7247 /*
7248 * Check to make sure we don't have duplicate iov_base's in this
7249 * iovec, if so return EINVAL, otherwise we'll get csum errors
7250 * when reading back.
7251 */
7252 for (i = seg + 1; i < nr_segs; i++) {
7253 if (iov[seg].iov_base == iov[i].iov_base)
7254 goto out;
7255 }
7256 }
7257 retval = 0;
7258 out:
7259 return retval;
7260 }
7261
7262 static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
7263 const struct iovec *iov, loff_t offset,
7264 unsigned long nr_segs)
7265 {
7266 struct file *file = iocb->ki_filp;
7267 struct inode *inode = file->f_mapping->host;
7268 size_t count = 0;
7269 int flags = 0;
7270 bool wakeup = true;
7271 bool relock = false;
7272 ssize_t ret;
7273
7274 if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iov,
7275 offset, nr_segs))
7276 return 0;
7277
7278 atomic_inc(&inode->i_dio_count);
7279 smp_mb__after_atomic_inc();
7280
7281 if (rw & WRITE) {
7282 count = iov_length(iov, nr_segs);
7283 /*
7284 * If the write DIO is beyond the EOF, we need update
7285 * the isize, but it is protected by i_mutex. So we can
7286 * not unlock the i_mutex at this case.
7287 */
7288 if (offset + count <= inode->i_size) {
7289 mutex_unlock(&inode->i_mutex);
7290 relock = true;
7291 }
7292 ret = btrfs_delalloc_reserve_space(inode, count);
7293 if (ret)
7294 goto out;
7295 } else if (unlikely(test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
7296 &BTRFS_I(inode)->runtime_flags))) {
7297 inode_dio_done(inode);
7298 flags = DIO_LOCKING | DIO_SKIP_HOLES;
7299 wakeup = false;
7300 }
7301
7302 ret = __blockdev_direct_IO(rw, iocb, inode,
7303 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
7304 iov, offset, nr_segs, btrfs_get_blocks_direct, NULL,
7305 btrfs_submit_direct, flags);
7306 if (rw & WRITE) {
7307 if (ret < 0 && ret != -EIOCBQUEUED)
7308 btrfs_delalloc_release_space(inode, count);
7309 else if (ret >= 0 && (size_t)ret < count)
7310 btrfs_delalloc_release_space(inode,
7311 count - (size_t)ret);
7312 else
7313 btrfs_delalloc_release_metadata(inode, 0);
7314 }
7315 out:
7316 if (wakeup)
7317 inode_dio_done(inode);
7318 if (relock)
7319 mutex_lock(&inode->i_mutex);
7320
7321 return ret;
7322 }
7323
7324 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
7325
7326 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
7327 __u64 start, __u64 len)
7328 {
7329 int ret;
7330
7331 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
7332 if (ret)
7333 return ret;
7334
7335 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
7336 }
7337
7338 int btrfs_readpage(struct file *file, struct page *page)
7339 {
7340 struct extent_io_tree *tree;
7341 tree = &BTRFS_I(page->mapping->host)->io_tree;
7342 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
7343 }
7344
7345 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
7346 {
7347 struct extent_io_tree *tree;
7348
7349
7350 if (current->flags & PF_MEMALLOC) {
7351 redirty_page_for_writepage(wbc, page);
7352 unlock_page(page);
7353 return 0;
7354 }
7355 tree = &BTRFS_I(page->mapping->host)->io_tree;
7356 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
7357 }
7358
7359 static int btrfs_writepages(struct address_space *mapping,
7360 struct writeback_control *wbc)
7361 {
7362 struct extent_io_tree *tree;
7363
7364 tree = &BTRFS_I(mapping->host)->io_tree;
7365 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
7366 }
7367
7368 static int
7369 btrfs_readpages(struct file *file, struct address_space *mapping,
7370 struct list_head *pages, unsigned nr_pages)
7371 {
7372 struct extent_io_tree *tree;
7373 tree = &BTRFS_I(mapping->host)->io_tree;
7374 return extent_readpages(tree, mapping, pages, nr_pages,
7375 btrfs_get_extent);
7376 }
7377 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
7378 {
7379 struct extent_io_tree *tree;
7380 struct extent_map_tree *map;
7381 int ret;
7382
7383 tree = &BTRFS_I(page->mapping->host)->io_tree;
7384 map = &BTRFS_I(page->mapping->host)->extent_tree;
7385 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
7386 if (ret == 1) {
7387 ClearPagePrivate(page);
7388 set_page_private(page, 0);
7389 page_cache_release(page);
7390 }
7391 return ret;
7392 }
7393
7394 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
7395 {
7396 if (PageWriteback(page) || PageDirty(page))
7397 return 0;
7398 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
7399 }
7400
7401 static void btrfs_invalidatepage(struct page *page, unsigned long offset)
7402 {
7403 struct inode *inode = page->mapping->host;
7404 struct extent_io_tree *tree;
7405 struct btrfs_ordered_extent *ordered;
7406 struct extent_state *cached_state = NULL;
7407 u64 page_start = page_offset(page);
7408 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
7409
7410 /*
7411 * we have the page locked, so new writeback can't start,
7412 * and the dirty bit won't be cleared while we are here.
7413 *
7414 * Wait for IO on this page so that we can safely clear
7415 * the PagePrivate2 bit and do ordered accounting
7416 */
7417 wait_on_page_writeback(page);
7418
7419 tree = &BTRFS_I(inode)->io_tree;
7420 if (offset) {
7421 btrfs_releasepage(page, GFP_NOFS);
7422 return;
7423 }
7424 lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
7425 ordered = btrfs_lookup_ordered_extent(inode, page_offset(page));
7426 if (ordered) {
7427 /*
7428 * IO on this page will never be started, so we need
7429 * to account for any ordered extents now
7430 */
7431 clear_extent_bit(tree, page_start, page_end,
7432 EXTENT_DIRTY | EXTENT_DELALLOC |
7433 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
7434 EXTENT_DEFRAG, 1, 0, &cached_state, GFP_NOFS);
7435 /*
7436 * whoever cleared the private bit is responsible
7437 * for the finish_ordered_io
7438 */
7439 if (TestClearPagePrivate2(page) &&
7440 btrfs_dec_test_ordered_pending(inode, &ordered, page_start,
7441 PAGE_CACHE_SIZE, 1)) {
7442 btrfs_finish_ordered_io(ordered);
7443 }
7444 btrfs_put_ordered_extent(ordered);
7445 cached_state = NULL;
7446 lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
7447 }
7448 clear_extent_bit(tree, page_start, page_end,
7449 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
7450 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1,
7451 &cached_state, GFP_NOFS);
7452 __btrfs_releasepage(page, GFP_NOFS);
7453
7454 ClearPageChecked(page);
7455 if (PagePrivate(page)) {
7456 ClearPagePrivate(page);
7457 set_page_private(page, 0);
7458 page_cache_release(page);
7459 }
7460 }
7461
7462 /*
7463 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
7464 * called from a page fault handler when a page is first dirtied. Hence we must
7465 * be careful to check for EOF conditions here. We set the page up correctly
7466 * for a written page which means we get ENOSPC checking when writing into
7467 * holes and correct delalloc and unwritten extent mapping on filesystems that
7468 * support these features.
7469 *
7470 * We are not allowed to take the i_mutex here so we have to play games to
7471 * protect against truncate races as the page could now be beyond EOF. Because
7472 * vmtruncate() writes the inode size before removing pages, once we have the
7473 * page lock we can determine safely if the page is beyond EOF. If it is not
7474 * beyond EOF, then the page is guaranteed safe against truncation until we
7475 * unlock the page.
7476 */
7477 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
7478 {
7479 struct page *page = vmf->page;
7480 struct inode *inode = file_inode(vma->vm_file);
7481 struct btrfs_root *root = BTRFS_I(inode)->root;
7482 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7483 struct btrfs_ordered_extent *ordered;
7484 struct extent_state *cached_state = NULL;
7485 char *kaddr;
7486 unsigned long zero_start;
7487 loff_t size;
7488 int ret;
7489 int reserved = 0;
7490 u64 page_start;
7491 u64 page_end;
7492
7493 sb_start_pagefault(inode->i_sb);
7494 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
7495 if (!ret) {
7496 ret = file_update_time(vma->vm_file);
7497 reserved = 1;
7498 }
7499 if (ret) {
7500 if (ret == -ENOMEM)
7501 ret = VM_FAULT_OOM;
7502 else /* -ENOSPC, -EIO, etc */
7503 ret = VM_FAULT_SIGBUS;
7504 if (reserved)
7505 goto out;
7506 goto out_noreserve;
7507 }
7508
7509 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
7510 again:
7511 lock_page(page);
7512 size = i_size_read(inode);
7513 page_start = page_offset(page);
7514 page_end = page_start + PAGE_CACHE_SIZE - 1;
7515
7516 if ((page->mapping != inode->i_mapping) ||
7517 (page_start >= size)) {
7518 /* page got truncated out from underneath us */
7519 goto out_unlock;
7520 }
7521 wait_on_page_writeback(page);
7522
7523 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
7524 set_page_extent_mapped(page);
7525
7526 /*
7527 * we can't set the delalloc bits if there are pending ordered
7528 * extents. Drop our locks and wait for them to finish
7529 */
7530 ordered = btrfs_lookup_ordered_extent(inode, page_start);
7531 if (ordered) {
7532 unlock_extent_cached(io_tree, page_start, page_end,
7533 &cached_state, GFP_NOFS);
7534 unlock_page(page);
7535 btrfs_start_ordered_extent(inode, ordered, 1);
7536 btrfs_put_ordered_extent(ordered);
7537 goto again;
7538 }
7539
7540 /*
7541 * XXX - page_mkwrite gets called every time the page is dirtied, even
7542 * if it was already dirty, so for space accounting reasons we need to
7543 * clear any delalloc bits for the range we are fixing to save. There
7544 * is probably a better way to do this, but for now keep consistent with
7545 * prepare_pages in the normal write path.
7546 */
7547 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
7548 EXTENT_DIRTY | EXTENT_DELALLOC |
7549 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
7550 0, 0, &cached_state, GFP_NOFS);
7551
7552 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
7553 &cached_state);
7554 if (ret) {
7555 unlock_extent_cached(io_tree, page_start, page_end,
7556 &cached_state, GFP_NOFS);
7557 ret = VM_FAULT_SIGBUS;
7558 goto out_unlock;
7559 }
7560 ret = 0;
7561
7562 /* page is wholly or partially inside EOF */
7563 if (page_start + PAGE_CACHE_SIZE > size)
7564 zero_start = size & ~PAGE_CACHE_MASK;
7565 else
7566 zero_start = PAGE_CACHE_SIZE;
7567
7568 if (zero_start != PAGE_CACHE_SIZE) {
7569 kaddr = kmap(page);
7570 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
7571 flush_dcache_page(page);
7572 kunmap(page);
7573 }
7574 ClearPageChecked(page);
7575 set_page_dirty(page);
7576 SetPageUptodate(page);
7577
7578 BTRFS_I(inode)->last_trans = root->fs_info->generation;
7579 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
7580 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
7581
7582 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
7583
7584 out_unlock:
7585 if (!ret) {
7586 sb_end_pagefault(inode->i_sb);
7587 return VM_FAULT_LOCKED;
7588 }
7589 unlock_page(page);
7590 out:
7591 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
7592 out_noreserve:
7593 sb_end_pagefault(inode->i_sb);
7594 return ret;
7595 }
7596
7597 static int btrfs_truncate(struct inode *inode)
7598 {
7599 struct btrfs_root *root = BTRFS_I(inode)->root;
7600 struct btrfs_block_rsv *rsv;
7601 int ret = 0;
7602 int err = 0;
7603 struct btrfs_trans_handle *trans;
7604 u64 mask = root->sectorsize - 1;
7605 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
7606
7607 btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
7608 btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
7609
7610 /*
7611 * Yes ladies and gentelment, this is indeed ugly. The fact is we have
7612 * 3 things going on here
7613 *
7614 * 1) We need to reserve space for our orphan item and the space to
7615 * delete our orphan item. Lord knows we don't want to have a dangling
7616 * orphan item because we didn't reserve space to remove it.
7617 *
7618 * 2) We need to reserve space to update our inode.
7619 *
7620 * 3) We need to have something to cache all the space that is going to
7621 * be free'd up by the truncate operation, but also have some slack
7622 * space reserved in case it uses space during the truncate (thank you
7623 * very much snapshotting).
7624 *
7625 * And we need these to all be seperate. The fact is we can use alot of
7626 * space doing the truncate, and we have no earthly idea how much space
7627 * we will use, so we need the truncate reservation to be seperate so it
7628 * doesn't end up using space reserved for updating the inode or
7629 * removing the orphan item. We also need to be able to stop the
7630 * transaction and start a new one, which means we need to be able to
7631 * update the inode several times, and we have no idea of knowing how
7632 * many times that will be, so we can't just reserve 1 item for the
7633 * entirety of the opration, so that has to be done seperately as well.
7634 * Then there is the orphan item, which does indeed need to be held on
7635 * to for the whole operation, and we need nobody to touch this reserved
7636 * space except the orphan code.
7637 *
7638 * So that leaves us with
7639 *
7640 * 1) root->orphan_block_rsv - for the orphan deletion.
7641 * 2) rsv - for the truncate reservation, which we will steal from the
7642 * transaction reservation.
7643 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
7644 * updating the inode.
7645 */
7646 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
7647 if (!rsv)
7648 return -ENOMEM;
7649 rsv->size = min_size;
7650 rsv->failfast = 1;
7651
7652 /*
7653 * 1 for the truncate slack space
7654 * 1 for updating the inode.
7655 */
7656 trans = btrfs_start_transaction(root, 2);
7657 if (IS_ERR(trans)) {
7658 err = PTR_ERR(trans);
7659 goto out;
7660 }
7661
7662 /* Migrate the slack space for the truncate to our reserve */
7663 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
7664 min_size);
7665 BUG_ON(ret);
7666
7667 /*
7668 * setattr is responsible for setting the ordered_data_close flag,
7669 * but that is only tested during the last file release. That
7670 * could happen well after the next commit, leaving a great big
7671 * window where new writes may get lost if someone chooses to write
7672 * to this file after truncating to zero
7673 *
7674 * The inode doesn't have any dirty data here, and so if we commit
7675 * this is a noop. If someone immediately starts writing to the inode
7676 * it is very likely we'll catch some of their writes in this
7677 * transaction, and the commit will find this file on the ordered
7678 * data list with good things to send down.
7679 *
7680 * This is a best effort solution, there is still a window where
7681 * using truncate to replace the contents of the file will
7682 * end up with a zero length file after a crash.
7683 */
7684 if (inode->i_size == 0 && test_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
7685 &BTRFS_I(inode)->runtime_flags))
7686 btrfs_add_ordered_operation(trans, root, inode);
7687
7688 /*
7689 * So if we truncate and then write and fsync we normally would just
7690 * write the extents that changed, which is a problem if we need to
7691 * first truncate that entire inode. So set this flag so we write out
7692 * all of the extents in the inode to the sync log so we're completely
7693 * safe.
7694 */
7695 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
7696 trans->block_rsv = rsv;
7697
7698 while (1) {
7699 ret = btrfs_truncate_inode_items(trans, root, inode,
7700 inode->i_size,
7701 BTRFS_EXTENT_DATA_KEY);
7702 if (ret != -ENOSPC) {
7703 err = ret;
7704 break;
7705 }
7706
7707 trans->block_rsv = &root->fs_info->trans_block_rsv;
7708 ret = btrfs_update_inode(trans, root, inode);
7709 if (ret) {
7710 err = ret;
7711 break;
7712 }
7713
7714 btrfs_end_transaction(trans, root);
7715 btrfs_btree_balance_dirty(root);
7716
7717 trans = btrfs_start_transaction(root, 2);
7718 if (IS_ERR(trans)) {
7719 ret = err = PTR_ERR(trans);
7720 trans = NULL;
7721 break;
7722 }
7723
7724 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
7725 rsv, min_size);
7726 BUG_ON(ret); /* shouldn't happen */
7727 trans->block_rsv = rsv;
7728 }
7729
7730 if (ret == 0 && inode->i_nlink > 0) {
7731 trans->block_rsv = root->orphan_block_rsv;
7732 ret = btrfs_orphan_del(trans, inode);
7733 if (ret)
7734 err = ret;
7735 }
7736
7737 if (trans) {
7738 trans->block_rsv = &root->fs_info->trans_block_rsv;
7739 ret = btrfs_update_inode(trans, root, inode);
7740 if (ret && !err)
7741 err = ret;
7742
7743 ret = btrfs_end_transaction(trans, root);
7744 btrfs_btree_balance_dirty(root);
7745 }
7746
7747 out:
7748 btrfs_free_block_rsv(root, rsv);
7749
7750 if (ret && !err)
7751 err = ret;
7752
7753 return err;
7754 }
7755
7756 /*
7757 * create a new subvolume directory/inode (helper for the ioctl).
7758 */
7759 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
7760 struct btrfs_root *new_root, u64 new_dirid)
7761 {
7762 struct inode *inode;
7763 int err;
7764 u64 index = 0;
7765
7766 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
7767 new_dirid, new_dirid,
7768 S_IFDIR | (~current_umask() & S_IRWXUGO),
7769 &index);
7770 if (IS_ERR(inode))
7771 return PTR_ERR(inode);
7772 inode->i_op = &btrfs_dir_inode_operations;
7773 inode->i_fop = &btrfs_dir_file_operations;
7774
7775 set_nlink(inode, 1);
7776 btrfs_i_size_write(inode, 0);
7777
7778 err = btrfs_update_inode(trans, new_root, inode);
7779
7780 iput(inode);
7781 return err;
7782 }
7783
7784 struct inode *btrfs_alloc_inode(struct super_block *sb)
7785 {
7786 struct btrfs_inode *ei;
7787 struct inode *inode;
7788
7789 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
7790 if (!ei)
7791 return NULL;
7792
7793 ei->root = NULL;
7794 ei->generation = 0;
7795 ei->last_trans = 0;
7796 ei->last_sub_trans = 0;
7797 ei->logged_trans = 0;
7798 ei->delalloc_bytes = 0;
7799 ei->disk_i_size = 0;
7800 ei->flags = 0;
7801 ei->csum_bytes = 0;
7802 ei->index_cnt = (u64)-1;
7803 ei->last_unlink_trans = 0;
7804 ei->last_log_commit = 0;
7805
7806 spin_lock_init(&ei->lock);
7807 ei->outstanding_extents = 0;
7808 ei->reserved_extents = 0;
7809
7810 ei->runtime_flags = 0;
7811 ei->force_compress = BTRFS_COMPRESS_NONE;
7812
7813 ei->delayed_node = NULL;
7814
7815 inode = &ei->vfs_inode;
7816 extent_map_tree_init(&ei->extent_tree);
7817 extent_io_tree_init(&ei->io_tree, &inode->i_data);
7818 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
7819 ei->io_tree.track_uptodate = 1;
7820 ei->io_failure_tree.track_uptodate = 1;
7821 atomic_set(&ei->sync_writers, 0);
7822 mutex_init(&ei->log_mutex);
7823 mutex_init(&ei->delalloc_mutex);
7824 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
7825 INIT_LIST_HEAD(&ei->delalloc_inodes);
7826 INIT_LIST_HEAD(&ei->ordered_operations);
7827 RB_CLEAR_NODE(&ei->rb_node);
7828
7829 return inode;
7830 }
7831
7832 static void btrfs_i_callback(struct rcu_head *head)
7833 {
7834 struct inode *inode = container_of(head, struct inode, i_rcu);
7835 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
7836 }
7837
7838 void btrfs_destroy_inode(struct inode *inode)
7839 {
7840 struct btrfs_ordered_extent *ordered;
7841 struct btrfs_root *root = BTRFS_I(inode)->root;
7842
7843 WARN_ON(!hlist_empty(&inode->i_dentry));
7844 WARN_ON(inode->i_data.nrpages);
7845 WARN_ON(BTRFS_I(inode)->outstanding_extents);
7846 WARN_ON(BTRFS_I(inode)->reserved_extents);
7847 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
7848 WARN_ON(BTRFS_I(inode)->csum_bytes);
7849
7850 /*
7851 * This can happen where we create an inode, but somebody else also
7852 * created the same inode and we need to destroy the one we already
7853 * created.
7854 */
7855 if (!root)
7856 goto free;
7857
7858 /*
7859 * Make sure we're properly removed from the ordered operation
7860 * lists.
7861 */
7862 smp_mb();
7863 if (!list_empty(&BTRFS_I(inode)->ordered_operations)) {
7864 spin_lock(&root->fs_info->ordered_root_lock);
7865 list_del_init(&BTRFS_I(inode)->ordered_operations);
7866 spin_unlock(&root->fs_info->ordered_root_lock);
7867 }
7868
7869 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
7870 &BTRFS_I(inode)->runtime_flags)) {
7871 btrfs_info(root->fs_info, "inode %llu still on the orphan list",
7872 (unsigned long long)btrfs_ino(inode));
7873 atomic_dec(&root->orphan_inodes);
7874 }
7875
7876 while (1) {
7877 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
7878 if (!ordered)
7879 break;
7880 else {
7881 btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup",
7882 (unsigned long long)ordered->file_offset,
7883 (unsigned long long)ordered->len);
7884 btrfs_remove_ordered_extent(inode, ordered);
7885 btrfs_put_ordered_extent(ordered);
7886 btrfs_put_ordered_extent(ordered);
7887 }
7888 }
7889 inode_tree_del(inode);
7890 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
7891 free:
7892 call_rcu(&inode->i_rcu, btrfs_i_callback);
7893 }
7894
7895 int btrfs_drop_inode(struct inode *inode)
7896 {
7897 struct btrfs_root *root = BTRFS_I(inode)->root;
7898
7899 if (root == NULL)
7900 return 1;
7901
7902 /* the snap/subvol tree is on deleting */
7903 if (btrfs_root_refs(&root->root_item) == 0 &&
7904 root != root->fs_info->tree_root)
7905 return 1;
7906 else
7907 return generic_drop_inode(inode);
7908 }
7909
7910 static void init_once(void *foo)
7911 {
7912 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
7913
7914 inode_init_once(&ei->vfs_inode);
7915 }
7916
7917 void btrfs_destroy_cachep(void)
7918 {
7919 /*
7920 * Make sure all delayed rcu free inodes are flushed before we
7921 * destroy cache.
7922 */
7923 rcu_barrier();
7924 if (btrfs_inode_cachep)
7925 kmem_cache_destroy(btrfs_inode_cachep);
7926 if (btrfs_trans_handle_cachep)
7927 kmem_cache_destroy(btrfs_trans_handle_cachep);
7928 if (btrfs_transaction_cachep)
7929 kmem_cache_destroy(btrfs_transaction_cachep);
7930 if (btrfs_path_cachep)
7931 kmem_cache_destroy(btrfs_path_cachep);
7932 if (btrfs_free_space_cachep)
7933 kmem_cache_destroy(btrfs_free_space_cachep);
7934 if (btrfs_delalloc_work_cachep)
7935 kmem_cache_destroy(btrfs_delalloc_work_cachep);
7936 }
7937
7938 int btrfs_init_cachep(void)
7939 {
7940 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
7941 sizeof(struct btrfs_inode), 0,
7942 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once);
7943 if (!btrfs_inode_cachep)
7944 goto fail;
7945
7946 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
7947 sizeof(struct btrfs_trans_handle), 0,
7948 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
7949 if (!btrfs_trans_handle_cachep)
7950 goto fail;
7951
7952 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
7953 sizeof(struct btrfs_transaction), 0,
7954 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
7955 if (!btrfs_transaction_cachep)
7956 goto fail;
7957
7958 btrfs_path_cachep = kmem_cache_create("btrfs_path",
7959 sizeof(struct btrfs_path), 0,
7960 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
7961 if (!btrfs_path_cachep)
7962 goto fail;
7963
7964 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
7965 sizeof(struct btrfs_free_space), 0,
7966 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
7967 if (!btrfs_free_space_cachep)
7968 goto fail;
7969
7970 btrfs_delalloc_work_cachep = kmem_cache_create("btrfs_delalloc_work",
7971 sizeof(struct btrfs_delalloc_work), 0,
7972 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
7973 NULL);
7974 if (!btrfs_delalloc_work_cachep)
7975 goto fail;
7976
7977 return 0;
7978 fail:
7979 btrfs_destroy_cachep();
7980 return -ENOMEM;
7981 }
7982
7983 static int btrfs_getattr(struct vfsmount *mnt,
7984 struct dentry *dentry, struct kstat *stat)
7985 {
7986 u64 delalloc_bytes;
7987 struct inode *inode = dentry->d_inode;
7988 u32 blocksize = inode->i_sb->s_blocksize;
7989
7990 generic_fillattr(inode, stat);
7991 stat->dev = BTRFS_I(inode)->root->anon_dev;
7992 stat->blksize = PAGE_CACHE_SIZE;
7993
7994 spin_lock(&BTRFS_I(inode)->lock);
7995 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;
7996 spin_unlock(&BTRFS_I(inode)->lock);
7997 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
7998 ALIGN(delalloc_bytes, blocksize)) >> 9;
7999 return 0;
8000 }
8001
8002 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
8003 struct inode *new_dir, struct dentry *new_dentry)
8004 {
8005 struct btrfs_trans_handle *trans;
8006 struct btrfs_root *root = BTRFS_I(old_dir)->root;
8007 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
8008 struct inode *new_inode = new_dentry->d_inode;
8009 struct inode *old_inode = old_dentry->d_inode;
8010 struct timespec ctime = CURRENT_TIME;
8011 u64 index = 0;
8012 u64 root_objectid;
8013 int ret;
8014 u64 old_ino = btrfs_ino(old_inode);
8015
8016 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
8017 return -EPERM;
8018
8019 /* we only allow rename subvolume link between subvolumes */
8020 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
8021 return -EXDEV;
8022
8023 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
8024 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
8025 return -ENOTEMPTY;
8026
8027 if (S_ISDIR(old_inode->i_mode) && new_inode &&
8028 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
8029 return -ENOTEMPTY;
8030
8031
8032 /* check for collisions, even if the name isn't there */
8033 ret = btrfs_check_dir_item_collision(root, new_dir->i_ino,
8034 new_dentry->d_name.name,
8035 new_dentry->d_name.len);
8036
8037 if (ret) {
8038 if (ret == -EEXIST) {
8039 /* we shouldn't get
8040 * eexist without a new_inode */
8041 if (!new_inode) {
8042 WARN_ON(1);
8043 return ret;
8044 }
8045 } else {
8046 /* maybe -EOVERFLOW */
8047 return ret;
8048 }
8049 }
8050 ret = 0;
8051
8052 /*
8053 * we're using rename to replace one file with another.
8054 * and the replacement file is large. Start IO on it now so
8055 * we don't add too much work to the end of the transaction
8056 */
8057 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size &&
8058 old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
8059 filemap_flush(old_inode->i_mapping);
8060
8061 /* close the racy window with snapshot create/destroy ioctl */
8062 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
8063 down_read(&root->fs_info->subvol_sem);
8064 /*
8065 * We want to reserve the absolute worst case amount of items. So if
8066 * both inodes are subvols and we need to unlink them then that would
8067 * require 4 item modifications, but if they are both normal inodes it
8068 * would require 5 item modifications, so we'll assume their normal
8069 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
8070 * should cover the worst case number of items we'll modify.
8071 */
8072 trans = btrfs_start_transaction(root, 11);
8073 if (IS_ERR(trans)) {
8074 ret = PTR_ERR(trans);
8075 goto out_notrans;
8076 }
8077
8078 if (dest != root)
8079 btrfs_record_root_in_trans(trans, dest);
8080
8081 ret = btrfs_set_inode_index(new_dir, &index);
8082 if (ret)
8083 goto out_fail;
8084
8085 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
8086 /* force full log commit if subvolume involved. */
8087 root->fs_info->last_trans_log_full_commit = trans->transid;
8088 } else {
8089 ret = btrfs_insert_inode_ref(trans, dest,
8090 new_dentry->d_name.name,
8091 new_dentry->d_name.len,
8092 old_ino,
8093 btrfs_ino(new_dir), index);
8094 if (ret)
8095 goto out_fail;
8096 /*
8097 * this is an ugly little race, but the rename is required
8098 * to make sure that if we crash, the inode is either at the
8099 * old name or the new one. pinning the log transaction lets
8100 * us make sure we don't allow a log commit to come in after
8101 * we unlink the name but before we add the new name back in.
8102 */
8103 btrfs_pin_log_trans(root);
8104 }
8105 /*
8106 * make sure the inode gets flushed if it is replacing
8107 * something.
8108 */
8109 if (new_inode && new_inode->i_size && S_ISREG(old_inode->i_mode))
8110 btrfs_add_ordered_operation(trans, root, old_inode);
8111
8112 inode_inc_iversion(old_dir);
8113 inode_inc_iversion(new_dir);
8114 inode_inc_iversion(old_inode);
8115 old_dir->i_ctime = old_dir->i_mtime = ctime;
8116 new_dir->i_ctime = new_dir->i_mtime = ctime;
8117 old_inode->i_ctime = ctime;
8118
8119 if (old_dentry->d_parent != new_dentry->d_parent)
8120 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
8121
8122 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
8123 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
8124 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
8125 old_dentry->d_name.name,
8126 old_dentry->d_name.len);
8127 } else {
8128 ret = __btrfs_unlink_inode(trans, root, old_dir,
8129 old_dentry->d_inode,
8130 old_dentry->d_name.name,
8131 old_dentry->d_name.len);
8132 if (!ret)
8133 ret = btrfs_update_inode(trans, root, old_inode);
8134 }
8135 if (ret) {
8136 btrfs_abort_transaction(trans, root, ret);
8137 goto out_fail;
8138 }
8139
8140 if (new_inode) {
8141 inode_inc_iversion(new_inode);
8142 new_inode->i_ctime = CURRENT_TIME;
8143 if (unlikely(btrfs_ino(new_inode) ==
8144 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
8145 root_objectid = BTRFS_I(new_inode)->location.objectid;
8146 ret = btrfs_unlink_subvol(trans, dest, new_dir,
8147 root_objectid,
8148 new_dentry->d_name.name,
8149 new_dentry->d_name.len);
8150 BUG_ON(new_inode->i_nlink == 0);
8151 } else {
8152 ret = btrfs_unlink_inode(trans, dest, new_dir,
8153 new_dentry->d_inode,
8154 new_dentry->d_name.name,
8155 new_dentry->d_name.len);
8156 }
8157 if (!ret && new_inode->i_nlink == 0) {
8158 ret = btrfs_orphan_add(trans, new_dentry->d_inode);
8159 BUG_ON(ret);
8160 }
8161 if (ret) {
8162 btrfs_abort_transaction(trans, root, ret);
8163 goto out_fail;
8164 }
8165 }
8166
8167 ret = btrfs_add_link(trans, new_dir, old_inode,
8168 new_dentry->d_name.name,
8169 new_dentry->d_name.len, 0, index);
8170 if (ret) {
8171 btrfs_abort_transaction(trans, root, ret);
8172 goto out_fail;
8173 }
8174
8175 if (old_ino != BTRFS_FIRST_FREE_OBJECTID) {
8176 struct dentry *parent = new_dentry->d_parent;
8177 btrfs_log_new_name(trans, old_inode, old_dir, parent);
8178 btrfs_end_log_trans(root);
8179 }
8180 out_fail:
8181 btrfs_end_transaction(trans, root);
8182 out_notrans:
8183 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
8184 up_read(&root->fs_info->subvol_sem);
8185
8186 return ret;
8187 }
8188
8189 static void btrfs_run_delalloc_work(struct btrfs_work *work)
8190 {
8191 struct btrfs_delalloc_work *delalloc_work;
8192
8193 delalloc_work = container_of(work, struct btrfs_delalloc_work,
8194 work);
8195 if (delalloc_work->wait)
8196 btrfs_wait_ordered_range(delalloc_work->inode, 0, (u64)-1);
8197 else
8198 filemap_flush(delalloc_work->inode->i_mapping);
8199
8200 if (delalloc_work->delay_iput)
8201 btrfs_add_delayed_iput(delalloc_work->inode);
8202 else
8203 iput(delalloc_work->inode);
8204 complete(&delalloc_work->completion);
8205 }
8206
8207 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
8208 int wait, int delay_iput)
8209 {
8210 struct btrfs_delalloc_work *work;
8211
8212 work = kmem_cache_zalloc(btrfs_delalloc_work_cachep, GFP_NOFS);
8213 if (!work)
8214 return NULL;
8215
8216 init_completion(&work->completion);
8217 INIT_LIST_HEAD(&work->list);
8218 work->inode = inode;
8219 work->wait = wait;
8220 work->delay_iput = delay_iput;
8221 work->work.func = btrfs_run_delalloc_work;
8222
8223 return work;
8224 }
8225
8226 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
8227 {
8228 wait_for_completion(&work->completion);
8229 kmem_cache_free(btrfs_delalloc_work_cachep, work);
8230 }
8231
8232 /*
8233 * some fairly slow code that needs optimization. This walks the list
8234 * of all the inodes with pending delalloc and forces them to disk.
8235 */
8236 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
8237 {
8238 struct btrfs_inode *binode;
8239 struct inode *inode;
8240 struct btrfs_delalloc_work *work, *next;
8241 struct list_head works;
8242 struct list_head splice;
8243 int ret = 0;
8244
8245 INIT_LIST_HEAD(&works);
8246 INIT_LIST_HEAD(&splice);
8247
8248 spin_lock(&root->delalloc_lock);
8249 list_splice_init(&root->delalloc_inodes, &splice);
8250 while (!list_empty(&splice)) {
8251 binode = list_entry(splice.next, struct btrfs_inode,
8252 delalloc_inodes);
8253
8254 list_move_tail(&binode->delalloc_inodes,
8255 &root->delalloc_inodes);
8256 inode = igrab(&binode->vfs_inode);
8257 if (!inode) {
8258 cond_resched_lock(&root->delalloc_lock);
8259 continue;
8260 }
8261 spin_unlock(&root->delalloc_lock);
8262
8263 work = btrfs_alloc_delalloc_work(inode, 0, delay_iput);
8264 if (unlikely(!work)) {
8265 ret = -ENOMEM;
8266 goto out;
8267 }
8268 list_add_tail(&work->list, &works);
8269 btrfs_queue_worker(&root->fs_info->flush_workers,
8270 &work->work);
8271
8272 cond_resched();
8273 spin_lock(&root->delalloc_lock);
8274 }
8275 spin_unlock(&root->delalloc_lock);
8276
8277 list_for_each_entry_safe(work, next, &works, list) {
8278 list_del_init(&work->list);
8279 btrfs_wait_and_free_delalloc_work(work);
8280 }
8281 return 0;
8282 out:
8283 list_for_each_entry_safe(work, next, &works, list) {
8284 list_del_init(&work->list);
8285 btrfs_wait_and_free_delalloc_work(work);
8286 }
8287
8288 if (!list_empty_careful(&splice)) {
8289 spin_lock(&root->delalloc_lock);
8290 list_splice_tail(&splice, &root->delalloc_inodes);
8291 spin_unlock(&root->delalloc_lock);
8292 }
8293 return ret;
8294 }
8295
8296 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
8297 {
8298 int ret;
8299
8300 if (root->fs_info->sb->s_flags & MS_RDONLY)
8301 return -EROFS;
8302
8303 ret = __start_delalloc_inodes(root, delay_iput);
8304 /*
8305 * the filemap_flush will queue IO into the worker threads, but
8306 * we have to make sure the IO is actually started and that
8307 * ordered extents get created before we return
8308 */
8309 atomic_inc(&root->fs_info->async_submit_draining);
8310 while (atomic_read(&root->fs_info->nr_async_submits) ||
8311 atomic_read(&root->fs_info->async_delalloc_pages)) {
8312 wait_event(root->fs_info->async_submit_wait,
8313 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
8314 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
8315 }
8316 atomic_dec(&root->fs_info->async_submit_draining);
8317 return ret;
8318 }
8319
8320 int btrfs_start_all_delalloc_inodes(struct btrfs_fs_info *fs_info,
8321 int delay_iput)
8322 {
8323 struct btrfs_root *root;
8324 struct list_head splice;
8325 int ret;
8326
8327 if (fs_info->sb->s_flags & MS_RDONLY)
8328 return -EROFS;
8329
8330 INIT_LIST_HEAD(&splice);
8331
8332 spin_lock(&fs_info->delalloc_root_lock);
8333 list_splice_init(&fs_info->delalloc_roots, &splice);
8334 while (!list_empty(&splice)) {
8335 root = list_first_entry(&splice, struct btrfs_root,
8336 delalloc_root);
8337 root = btrfs_grab_fs_root(root);
8338 BUG_ON(!root);
8339 list_move_tail(&root->delalloc_root,
8340 &fs_info->delalloc_roots);
8341 spin_unlock(&fs_info->delalloc_root_lock);
8342
8343 ret = __start_delalloc_inodes(root, delay_iput);
8344 btrfs_put_fs_root(root);
8345 if (ret)
8346 goto out;
8347
8348 spin_lock(&fs_info->delalloc_root_lock);
8349 }
8350 spin_unlock(&fs_info->delalloc_root_lock);
8351
8352 atomic_inc(&fs_info->async_submit_draining);
8353 while (atomic_read(&fs_info->nr_async_submits) ||
8354 atomic_read(&fs_info->async_delalloc_pages)) {
8355 wait_event(fs_info->async_submit_wait,
8356 (atomic_read(&fs_info->nr_async_submits) == 0 &&
8357 atomic_read(&fs_info->async_delalloc_pages) == 0));
8358 }
8359 atomic_dec(&fs_info->async_submit_draining);
8360 return 0;
8361 out:
8362 if (!list_empty_careful(&splice)) {
8363 spin_lock(&fs_info->delalloc_root_lock);
8364 list_splice_tail(&splice, &fs_info->delalloc_roots);
8365 spin_unlock(&fs_info->delalloc_root_lock);
8366 }
8367 return ret;
8368 }
8369
8370 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
8371 const char *symname)
8372 {
8373 struct btrfs_trans_handle *trans;
8374 struct btrfs_root *root = BTRFS_I(dir)->root;
8375 struct btrfs_path *path;
8376 struct btrfs_key key;
8377 struct inode *inode = NULL;
8378 int err;
8379 int drop_inode = 0;
8380 u64 objectid;
8381 u64 index = 0 ;
8382 int name_len;
8383 int datasize;
8384 unsigned long ptr;
8385 struct btrfs_file_extent_item *ei;
8386 struct extent_buffer *leaf;
8387
8388 name_len = strlen(symname) + 1;
8389 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
8390 return -ENAMETOOLONG;
8391
8392 /*
8393 * 2 items for inode item and ref
8394 * 2 items for dir items
8395 * 1 item for xattr if selinux is on
8396 */
8397 trans = btrfs_start_transaction(root, 5);
8398 if (IS_ERR(trans))
8399 return PTR_ERR(trans);
8400
8401 err = btrfs_find_free_ino(root, &objectid);
8402 if (err)
8403 goto out_unlock;
8404
8405 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
8406 dentry->d_name.len, btrfs_ino(dir), objectid,
8407 S_IFLNK|S_IRWXUGO, &index);
8408 if (IS_ERR(inode)) {
8409 err = PTR_ERR(inode);
8410 goto out_unlock;
8411 }
8412
8413 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
8414 if (err) {
8415 drop_inode = 1;
8416 goto out_unlock;
8417 }
8418
8419 /*
8420 * If the active LSM wants to access the inode during
8421 * d_instantiate it needs these. Smack checks to see
8422 * if the filesystem supports xattrs by looking at the
8423 * ops vector.
8424 */
8425 inode->i_fop = &btrfs_file_operations;
8426 inode->i_op = &btrfs_file_inode_operations;
8427
8428 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
8429 if (err)
8430 drop_inode = 1;
8431 else {
8432 inode->i_mapping->a_ops = &btrfs_aops;
8433 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
8434 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
8435 }
8436 if (drop_inode)
8437 goto out_unlock;
8438
8439 path = btrfs_alloc_path();
8440 if (!path) {
8441 err = -ENOMEM;
8442 drop_inode = 1;
8443 goto out_unlock;
8444 }
8445 key.objectid = btrfs_ino(inode);
8446 key.offset = 0;
8447 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
8448 datasize = btrfs_file_extent_calc_inline_size(name_len);
8449 err = btrfs_insert_empty_item(trans, root, path, &key,
8450 datasize);
8451 if (err) {
8452 drop_inode = 1;
8453 btrfs_free_path(path);
8454 goto out_unlock;
8455 }
8456 leaf = path->nodes[0];
8457 ei = btrfs_item_ptr(leaf, path->slots[0],
8458 struct btrfs_file_extent_item);
8459 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
8460 btrfs_set_file_extent_type(leaf, ei,
8461 BTRFS_FILE_EXTENT_INLINE);
8462 btrfs_set_file_extent_encryption(leaf, ei, 0);
8463 btrfs_set_file_extent_compression(leaf, ei, 0);
8464 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
8465 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
8466
8467 ptr = btrfs_file_extent_inline_start(ei);
8468 write_extent_buffer(leaf, symname, ptr, name_len);
8469 btrfs_mark_buffer_dirty(leaf);
8470 btrfs_free_path(path);
8471
8472 inode->i_op = &btrfs_symlink_inode_operations;
8473 inode->i_mapping->a_ops = &btrfs_symlink_aops;
8474 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
8475 inode_set_bytes(inode, name_len);
8476 btrfs_i_size_write(inode, name_len - 1);
8477 err = btrfs_update_inode(trans, root, inode);
8478 if (err)
8479 drop_inode = 1;
8480
8481 out_unlock:
8482 if (!err)
8483 d_instantiate(dentry, inode);
8484 btrfs_end_transaction(trans, root);
8485 if (drop_inode) {
8486 inode_dec_link_count(inode);
8487 iput(inode);
8488 }
8489 btrfs_btree_balance_dirty(root);
8490 return err;
8491 }
8492
8493 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
8494 u64 start, u64 num_bytes, u64 min_size,
8495 loff_t actual_len, u64 *alloc_hint,
8496 struct btrfs_trans_handle *trans)
8497 {
8498 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
8499 struct extent_map *em;
8500 struct btrfs_root *root = BTRFS_I(inode)->root;
8501 struct btrfs_key ins;
8502 u64 cur_offset = start;
8503 u64 i_size;
8504 u64 cur_bytes;
8505 int ret = 0;
8506 bool own_trans = true;
8507
8508 if (trans)
8509 own_trans = false;
8510 while (num_bytes > 0) {
8511 if (own_trans) {
8512 trans = btrfs_start_transaction(root, 3);
8513 if (IS_ERR(trans)) {
8514 ret = PTR_ERR(trans);
8515 break;
8516 }
8517 }
8518
8519 cur_bytes = min(num_bytes, 256ULL * 1024 * 1024);
8520 cur_bytes = max(cur_bytes, min_size);
8521 ret = btrfs_reserve_extent(trans, root, cur_bytes,
8522 min_size, 0, *alloc_hint, &ins, 1);
8523 if (ret) {
8524 if (own_trans)
8525 btrfs_end_transaction(trans, root);
8526 break;
8527 }
8528
8529 ret = insert_reserved_file_extent(trans, inode,
8530 cur_offset, ins.objectid,
8531 ins.offset, ins.offset,
8532 ins.offset, 0, 0, 0,
8533 BTRFS_FILE_EXTENT_PREALLOC);
8534 if (ret) {
8535 btrfs_abort_transaction(trans, root, ret);
8536 if (own_trans)
8537 btrfs_end_transaction(trans, root);
8538 break;
8539 }
8540 btrfs_drop_extent_cache(inode, cur_offset,
8541 cur_offset + ins.offset -1, 0);
8542
8543 em = alloc_extent_map();
8544 if (!em) {
8545 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
8546 &BTRFS_I(inode)->runtime_flags);
8547 goto next;
8548 }
8549
8550 em->start = cur_offset;
8551 em->orig_start = cur_offset;
8552 em->len = ins.offset;
8553 em->block_start = ins.objectid;
8554 em->block_len = ins.offset;
8555 em->orig_block_len = ins.offset;
8556 em->ram_bytes = ins.offset;
8557 em->bdev = root->fs_info->fs_devices->latest_bdev;
8558 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
8559 em->generation = trans->transid;
8560
8561 while (1) {
8562 write_lock(&em_tree->lock);
8563 ret = add_extent_mapping(em_tree, em, 1);
8564 write_unlock(&em_tree->lock);
8565 if (ret != -EEXIST)
8566 break;
8567 btrfs_drop_extent_cache(inode, cur_offset,
8568 cur_offset + ins.offset - 1,
8569 0);
8570 }
8571 free_extent_map(em);
8572 next:
8573 num_bytes -= ins.offset;
8574 cur_offset += ins.offset;
8575 *alloc_hint = ins.objectid + ins.offset;
8576
8577 inode_inc_iversion(inode);
8578 inode->i_ctime = CURRENT_TIME;
8579 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
8580 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
8581 (actual_len > inode->i_size) &&
8582 (cur_offset > inode->i_size)) {
8583 if (cur_offset > actual_len)
8584 i_size = actual_len;
8585 else
8586 i_size = cur_offset;
8587 i_size_write(inode, i_size);
8588 btrfs_ordered_update_i_size(inode, i_size, NULL);
8589 }
8590
8591 ret = btrfs_update_inode(trans, root, inode);
8592
8593 if (ret) {
8594 btrfs_abort_transaction(trans, root, ret);
8595 if (own_trans)
8596 btrfs_end_transaction(trans, root);
8597 break;
8598 }
8599
8600 if (own_trans)
8601 btrfs_end_transaction(trans, root);
8602 }
8603 return ret;
8604 }
8605
8606 int btrfs_prealloc_file_range(struct inode *inode, int mode,
8607 u64 start, u64 num_bytes, u64 min_size,
8608 loff_t actual_len, u64 *alloc_hint)
8609 {
8610 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
8611 min_size, actual_len, alloc_hint,
8612 NULL);
8613 }
8614
8615 int btrfs_prealloc_file_range_trans(struct inode *inode,
8616 struct btrfs_trans_handle *trans, int mode,
8617 u64 start, u64 num_bytes, u64 min_size,
8618 loff_t actual_len, u64 *alloc_hint)
8619 {
8620 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
8621 min_size, actual_len, alloc_hint, trans);
8622 }
8623
8624 static int btrfs_set_page_dirty(struct page *page)
8625 {
8626 return __set_page_dirty_nobuffers(page);
8627 }
8628
8629 static int btrfs_permission(struct inode *inode, int mask)
8630 {
8631 struct btrfs_root *root = BTRFS_I(inode)->root;
8632 umode_t mode = inode->i_mode;
8633
8634 if (mask & MAY_WRITE &&
8635 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
8636 if (btrfs_root_readonly(root))
8637 return -EROFS;
8638 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
8639 return -EACCES;
8640 }
8641 return generic_permission(inode, mask);
8642 }
8643
8644 static const struct inode_operations btrfs_dir_inode_operations = {
8645 .getattr = btrfs_getattr,
8646 .lookup = btrfs_lookup,
8647 .create = btrfs_create,
8648 .unlink = btrfs_unlink,
8649 .link = btrfs_link,
8650 .mkdir = btrfs_mkdir,
8651 .rmdir = btrfs_rmdir,
8652 .rename = btrfs_rename,
8653 .symlink = btrfs_symlink,
8654 .setattr = btrfs_setattr,
8655 .mknod = btrfs_mknod,
8656 .setxattr = btrfs_setxattr,
8657 .getxattr = btrfs_getxattr,
8658 .listxattr = btrfs_listxattr,
8659 .removexattr = btrfs_removexattr,
8660 .permission = btrfs_permission,
8661 .get_acl = btrfs_get_acl,
8662 };
8663 static const struct inode_operations btrfs_dir_ro_inode_operations = {
8664 .lookup = btrfs_lookup,
8665 .permission = btrfs_permission,
8666 .get_acl = btrfs_get_acl,
8667 };
8668
8669 static const struct file_operations btrfs_dir_file_operations = {
8670 .llseek = generic_file_llseek,
8671 .read = generic_read_dir,
8672 .readdir = btrfs_real_readdir,
8673 .unlocked_ioctl = btrfs_ioctl,
8674 #ifdef CONFIG_COMPAT
8675 .compat_ioctl = btrfs_ioctl,
8676 #endif
8677 .release = btrfs_release_file,
8678 .fsync = btrfs_sync_file,
8679 };
8680
8681 static struct extent_io_ops btrfs_extent_io_ops = {
8682 .fill_delalloc = run_delalloc_range,
8683 .submit_bio_hook = btrfs_submit_bio_hook,
8684 .merge_bio_hook = btrfs_merge_bio_hook,
8685 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
8686 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
8687 .writepage_start_hook = btrfs_writepage_start_hook,
8688 .set_bit_hook = btrfs_set_bit_hook,
8689 .clear_bit_hook = btrfs_clear_bit_hook,
8690 .merge_extent_hook = btrfs_merge_extent_hook,
8691 .split_extent_hook = btrfs_split_extent_hook,
8692 };
8693
8694 /*
8695 * btrfs doesn't support the bmap operation because swapfiles
8696 * use bmap to make a mapping of extents in the file. They assume
8697 * these extents won't change over the life of the file and they
8698 * use the bmap result to do IO directly to the drive.
8699 *
8700 * the btrfs bmap call would return logical addresses that aren't
8701 * suitable for IO and they also will change frequently as COW
8702 * operations happen. So, swapfile + btrfs == corruption.
8703 *
8704 * For now we're avoiding this by dropping bmap.
8705 */
8706 static const struct address_space_operations btrfs_aops = {
8707 .readpage = btrfs_readpage,
8708 .writepage = btrfs_writepage,
8709 .writepages = btrfs_writepages,
8710 .readpages = btrfs_readpages,
8711 .direct_IO = btrfs_direct_IO,
8712 .invalidatepage = btrfs_invalidatepage,
8713 .releasepage = btrfs_releasepage,
8714 .set_page_dirty = btrfs_set_page_dirty,
8715 .error_remove_page = generic_error_remove_page,
8716 };
8717
8718 static const struct address_space_operations btrfs_symlink_aops = {
8719 .readpage = btrfs_readpage,
8720 .writepage = btrfs_writepage,
8721 .invalidatepage = btrfs_invalidatepage,
8722 .releasepage = btrfs_releasepage,
8723 };
8724
8725 static const struct inode_operations btrfs_file_inode_operations = {
8726 .getattr = btrfs_getattr,
8727 .setattr = btrfs_setattr,
8728 .setxattr = btrfs_setxattr,
8729 .getxattr = btrfs_getxattr,
8730 .listxattr = btrfs_listxattr,
8731 .removexattr = btrfs_removexattr,
8732 .permission = btrfs_permission,
8733 .fiemap = btrfs_fiemap,
8734 .get_acl = btrfs_get_acl,
8735 .update_time = btrfs_update_time,
8736 };
8737 static const struct inode_operations btrfs_special_inode_operations = {
8738 .getattr = btrfs_getattr,
8739 .setattr = btrfs_setattr,
8740 .permission = btrfs_permission,
8741 .setxattr = btrfs_setxattr,
8742 .getxattr = btrfs_getxattr,
8743 .listxattr = btrfs_listxattr,
8744 .removexattr = btrfs_removexattr,
8745 .get_acl = btrfs_get_acl,
8746 .update_time = btrfs_update_time,
8747 };
8748 static const struct inode_operations btrfs_symlink_inode_operations = {
8749 .readlink = generic_readlink,
8750 .follow_link = page_follow_link_light,
8751 .put_link = page_put_link,
8752 .getattr = btrfs_getattr,
8753 .setattr = btrfs_setattr,
8754 .permission = btrfs_permission,
8755 .setxattr = btrfs_setxattr,
8756 .getxattr = btrfs_getxattr,
8757 .listxattr = btrfs_listxattr,
8758 .removexattr = btrfs_removexattr,
8759 .get_acl = btrfs_get_acl,
8760 .update_time = btrfs_update_time,
8761 };
8762
8763 const struct dentry_operations btrfs_dentry_operations = {
8764 .d_delete = btrfs_dentry_delete,
8765 .d_release = btrfs_dentry_release,
8766 };
Linux kernel - Deliverables
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