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Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-fixes
[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/aio.h>
36 #include <linux/bit_spinlock.h>
37 #include <linux/xattr.h>
38 #include <linux/posix_acl.h>
39 #include <linux/falloc.h>
40 #include <linux/slab.h>
41 #include <linux/ratelimit.h>
42 #include <linux/mount.h>
43 #include <linux/btrfs.h>
44 #include <linux/blkdev.h>
45 #include <linux/posix_acl_xattr.h>
46 #include "compat.h"
47 #include "ctree.h"
48 #include "disk-io.h"
49 #include "transaction.h"
50 #include "btrfs_inode.h"
51 #include "print-tree.h"
52 #include "ordered-data.h"
53 #include "xattr.h"
54 #include "tree-log.h"
55 #include "volumes.h"
56 #include "compression.h"
57 #include "locking.h"
58 #include "free-space-cache.h"
59 #include "inode-map.h"
60 #include "backref.h"
61 #include "hash.h"
62
63 struct btrfs_iget_args {
64 u64 ino;
65 struct btrfs_root *root;
66 };
67
68 static const struct inode_operations btrfs_dir_inode_operations;
69 static const struct inode_operations btrfs_symlink_inode_operations;
70 static const struct inode_operations btrfs_dir_ro_inode_operations;
71 static const struct inode_operations btrfs_special_inode_operations;
72 static const struct inode_operations btrfs_file_inode_operations;
73 static const struct address_space_operations btrfs_aops;
74 static const struct address_space_operations btrfs_symlink_aops;
75 static const struct file_operations btrfs_dir_file_operations;
76 static struct extent_io_ops btrfs_extent_io_ops;
77
78 static struct kmem_cache *btrfs_inode_cachep;
79 static struct kmem_cache *btrfs_delalloc_work_cachep;
80 struct kmem_cache *btrfs_trans_handle_cachep;
81 struct kmem_cache *btrfs_transaction_cachep;
82 struct kmem_cache *btrfs_path_cachep;
83 struct kmem_cache *btrfs_free_space_cachep;
84
85 #define S_SHIFT 12
86 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
87 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
88 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
89 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
90 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
91 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
92 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
93 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
94 };
95
96 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
97 static int btrfs_truncate(struct inode *inode);
98 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
99 static noinline int cow_file_range(struct inode *inode,
100 struct page *locked_page,
101 u64 start, u64 end, int *page_started,
102 unsigned long *nr_written, int unlock);
103 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
104 u64 len, u64 orig_start,
105 u64 block_start, u64 block_len,
106 u64 orig_block_len, u64 ram_bytes,
107 int type);
108
109 static int btrfs_dirty_inode(struct inode *inode);
110
111 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
112 struct inode *inode, struct inode *dir,
113 const struct qstr *qstr)
114 {
115 int err;
116
117 err = btrfs_init_acl(trans, inode, dir);
118 if (!err)
119 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
120 return err;
121 }
122
123 /*
124 * this does all the hard work for inserting an inline extent into
125 * the btree. The caller should have done a btrfs_drop_extents so that
126 * no overlapping inline items exist in the btree
127 */
128 static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
129 struct btrfs_root *root, struct inode *inode,
130 u64 start, size_t size, size_t compressed_size,
131 int compress_type,
132 struct page **compressed_pages)
133 {
134 struct btrfs_key key;
135 struct btrfs_path *path;
136 struct extent_buffer *leaf;
137 struct page *page = NULL;
138 char *kaddr;
139 unsigned long ptr;
140 struct btrfs_file_extent_item *ei;
141 int err = 0;
142 int ret;
143 size_t cur_size = size;
144 size_t datasize;
145 unsigned long offset;
146
147 if (compressed_size && compressed_pages)
148 cur_size = compressed_size;
149
150 path = btrfs_alloc_path();
151 if (!path)
152 return -ENOMEM;
153
154 path->leave_spinning = 1;
155
156 key.objectid = btrfs_ino(inode);
157 key.offset = start;
158 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
159 datasize = btrfs_file_extent_calc_inline_size(cur_size);
160
161 inode_add_bytes(inode, size);
162 ret = btrfs_insert_empty_item(trans, root, path, &key,
163 datasize);
164 if (ret) {
165 err = ret;
166 goto fail;
167 }
168 leaf = path->nodes[0];
169 ei = btrfs_item_ptr(leaf, path->slots[0],
170 struct btrfs_file_extent_item);
171 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
172 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
173 btrfs_set_file_extent_encryption(leaf, ei, 0);
174 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
175 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
176 ptr = btrfs_file_extent_inline_start(ei);
177
178 if (compress_type != BTRFS_COMPRESS_NONE) {
179 struct page *cpage;
180 int i = 0;
181 while (compressed_size > 0) {
182 cpage = compressed_pages[i];
183 cur_size = min_t(unsigned long, compressed_size,
184 PAGE_CACHE_SIZE);
185
186 kaddr = kmap_atomic(cpage);
187 write_extent_buffer(leaf, kaddr, ptr, cur_size);
188 kunmap_atomic(kaddr);
189
190 i++;
191 ptr += cur_size;
192 compressed_size -= cur_size;
193 }
194 btrfs_set_file_extent_compression(leaf, ei,
195 compress_type);
196 } else {
197 page = find_get_page(inode->i_mapping,
198 start >> PAGE_CACHE_SHIFT);
199 btrfs_set_file_extent_compression(leaf, ei, 0);
200 kaddr = kmap_atomic(page);
201 offset = start & (PAGE_CACHE_SIZE - 1);
202 write_extent_buffer(leaf, kaddr + offset, ptr, size);
203 kunmap_atomic(kaddr);
204 page_cache_release(page);
205 }
206 btrfs_mark_buffer_dirty(leaf);
207 btrfs_free_path(path);
208
209 /*
210 * we're an inline extent, so nobody can
211 * extend the file past i_size without locking
212 * a page we already have locked.
213 *
214 * We must do any isize and inode updates
215 * before we unlock the pages. Otherwise we
216 * could end up racing with unlink.
217 */
218 BTRFS_I(inode)->disk_i_size = inode->i_size;
219 ret = btrfs_update_inode(trans, root, inode);
220
221 return ret;
222 fail:
223 btrfs_free_path(path);
224 return err;
225 }
226
227
228 /*
229 * conditionally insert an inline extent into the file. This
230 * does the checks required to make sure the data is small enough
231 * to fit as an inline extent.
232 */
233 static noinline int cow_file_range_inline(struct btrfs_trans_handle *trans,
234 struct btrfs_root *root,
235 struct inode *inode, u64 start, u64 end,
236 size_t compressed_size, int compress_type,
237 struct page **compressed_pages)
238 {
239 u64 isize = i_size_read(inode);
240 u64 actual_end = min(end + 1, isize);
241 u64 inline_len = actual_end - start;
242 u64 aligned_end = ALIGN(end, root->sectorsize);
243 u64 data_len = inline_len;
244 int ret;
245
246 if (compressed_size)
247 data_len = compressed_size;
248
249 if (start > 0 ||
250 actual_end >= PAGE_CACHE_SIZE ||
251 data_len >= BTRFS_MAX_INLINE_DATA_SIZE(root) ||
252 (!compressed_size &&
253 (actual_end & (root->sectorsize - 1)) == 0) ||
254 end + 1 < isize ||
255 data_len > root->fs_info->max_inline) {
256 return 1;
257 }
258
259 ret = btrfs_drop_extents(trans, root, inode, start, aligned_end, 1);
260 if (ret)
261 return ret;
262
263 if (isize > actual_end)
264 inline_len = min_t(u64, isize, actual_end);
265 ret = insert_inline_extent(trans, root, inode, start,
266 inline_len, compressed_size,
267 compress_type, compressed_pages);
268 if (ret && ret != -ENOSPC) {
269 btrfs_abort_transaction(trans, root, ret);
270 return ret;
271 } else if (ret == -ENOSPC) {
272 return 1;
273 }
274
275 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
276 btrfs_delalloc_release_metadata(inode, end + 1 - start);
277 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
278 return 0;
279 }
280
281 struct async_extent {
282 u64 start;
283 u64 ram_size;
284 u64 compressed_size;
285 struct page **pages;
286 unsigned long nr_pages;
287 int compress_type;
288 struct list_head list;
289 };
290
291 struct async_cow {
292 struct inode *inode;
293 struct btrfs_root *root;
294 struct page *locked_page;
295 u64 start;
296 u64 end;
297 struct list_head extents;
298 struct btrfs_work work;
299 };
300
301 static noinline int add_async_extent(struct async_cow *cow,
302 u64 start, u64 ram_size,
303 u64 compressed_size,
304 struct page **pages,
305 unsigned long nr_pages,
306 int compress_type)
307 {
308 struct async_extent *async_extent;
309
310 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
311 BUG_ON(!async_extent); /* -ENOMEM */
312 async_extent->start = start;
313 async_extent->ram_size = ram_size;
314 async_extent->compressed_size = compressed_size;
315 async_extent->pages = pages;
316 async_extent->nr_pages = nr_pages;
317 async_extent->compress_type = compress_type;
318 list_add_tail(&async_extent->list, &cow->extents);
319 return 0;
320 }
321
322 /*
323 * we create compressed extents in two phases. The first
324 * phase compresses a range of pages that have already been
325 * locked (both pages and state bits are locked).
326 *
327 * This is done inside an ordered work queue, and the compression
328 * is spread across many cpus. The actual IO submission is step
329 * two, and the ordered work queue takes care of making sure that
330 * happens in the same order things were put onto the queue by
331 * writepages and friends.
332 *
333 * If this code finds it can't get good compression, it puts an
334 * entry onto the work queue to write the uncompressed bytes. This
335 * makes sure that both compressed inodes and uncompressed inodes
336 * are written in the same order that the flusher thread sent them
337 * down.
338 */
339 static noinline int compress_file_range(struct inode *inode,
340 struct page *locked_page,
341 u64 start, u64 end,
342 struct async_cow *async_cow,
343 int *num_added)
344 {
345 struct btrfs_root *root = BTRFS_I(inode)->root;
346 struct btrfs_trans_handle *trans;
347 u64 num_bytes;
348 u64 blocksize = root->sectorsize;
349 u64 actual_end;
350 u64 isize = i_size_read(inode);
351 int ret = 0;
352 struct page **pages = NULL;
353 unsigned long nr_pages;
354 unsigned long nr_pages_ret = 0;
355 unsigned long total_compressed = 0;
356 unsigned long total_in = 0;
357 unsigned long max_compressed = 128 * 1024;
358 unsigned long max_uncompressed = 128 * 1024;
359 int i;
360 int will_compress;
361 int compress_type = root->fs_info->compress_type;
362 int redirty = 0;
363
364 /* if this is a small write inside eof, kick off a defrag */
365 if ((end - start + 1) < 16 * 1024 &&
366 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
367 btrfs_add_inode_defrag(NULL, inode);
368
369 actual_end = min_t(u64, isize, end + 1);
370 again:
371 will_compress = 0;
372 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
373 nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
374
375 /*
376 * we don't want to send crud past the end of i_size through
377 * compression, that's just a waste of CPU time. So, if the
378 * end of the file is before the start of our current
379 * requested range of bytes, we bail out to the uncompressed
380 * cleanup code that can deal with all of this.
381 *
382 * It isn't really the fastest way to fix things, but this is a
383 * very uncommon corner.
384 */
385 if (actual_end <= start)
386 goto cleanup_and_bail_uncompressed;
387
388 total_compressed = actual_end - start;
389
390 /* we want to make sure that amount of ram required to uncompress
391 * an extent is reasonable, so we limit the total size in ram
392 * of a compressed extent to 128k. This is a crucial number
393 * because it also controls how easily we can spread reads across
394 * cpus for decompression.
395 *
396 * We also want to make sure the amount of IO required to do
397 * a random read is reasonably small, so we limit the size of
398 * a compressed extent to 128k.
399 */
400 total_compressed = min(total_compressed, max_uncompressed);
401 num_bytes = ALIGN(end - start + 1, blocksize);
402 num_bytes = max(blocksize, num_bytes);
403 total_in = 0;
404 ret = 0;
405
406 /*
407 * we do compression for mount -o compress and when the
408 * inode has not been flagged as nocompress. This flag can
409 * change at any time if we discover bad compression ratios.
410 */
411 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) &&
412 (btrfs_test_opt(root, COMPRESS) ||
413 (BTRFS_I(inode)->force_compress) ||
414 (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))) {
415 WARN_ON(pages);
416 pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
417 if (!pages) {
418 /* just bail out to the uncompressed code */
419 goto cont;
420 }
421
422 if (BTRFS_I(inode)->force_compress)
423 compress_type = BTRFS_I(inode)->force_compress;
424
425 /*
426 * we need to call clear_page_dirty_for_io on each
427 * page in the range. Otherwise applications with the file
428 * mmap'd can wander in and change the page contents while
429 * we are compressing them.
430 *
431 * If the compression fails for any reason, we set the pages
432 * dirty again later on.
433 */
434 extent_range_clear_dirty_for_io(inode, start, end);
435 redirty = 1;
436 ret = btrfs_compress_pages(compress_type,
437 inode->i_mapping, start,
438 total_compressed, pages,
439 nr_pages, &nr_pages_ret,
440 &total_in,
441 &total_compressed,
442 max_compressed);
443
444 if (!ret) {
445 unsigned long offset = total_compressed &
446 (PAGE_CACHE_SIZE - 1);
447 struct page *page = pages[nr_pages_ret - 1];
448 char *kaddr;
449
450 /* zero the tail end of the last page, we might be
451 * sending it down to disk
452 */
453 if (offset) {
454 kaddr = kmap_atomic(page);
455 memset(kaddr + offset, 0,
456 PAGE_CACHE_SIZE - offset);
457 kunmap_atomic(kaddr);
458 }
459 will_compress = 1;
460 }
461 }
462 cont:
463 if (start == 0) {
464 trans = btrfs_join_transaction(root);
465 if (IS_ERR(trans)) {
466 ret = PTR_ERR(trans);
467 trans = NULL;
468 goto cleanup_and_out;
469 }
470 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
471
472 /* lets try to make an inline extent */
473 if (ret || total_in < (actual_end - start)) {
474 /* we didn't compress the entire range, try
475 * to make an uncompressed inline extent.
476 */
477 ret = cow_file_range_inline(trans, root, inode,
478 start, end, 0, 0, NULL);
479 } else {
480 /* try making a compressed inline extent */
481 ret = cow_file_range_inline(trans, root, inode,
482 start, end,
483 total_compressed,
484 compress_type, pages);
485 }
486 if (ret <= 0) {
487 /*
488 * inline extent creation worked or returned error,
489 * we don't need to create any more async work items.
490 * Unlock and free up our temp pages.
491 */
492 extent_clear_unlock_delalloc(inode,
493 &BTRFS_I(inode)->io_tree,
494 start, end, NULL,
495 EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
496 EXTENT_CLEAR_DELALLOC |
497 EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK);
498
499 btrfs_end_transaction(trans, root);
500 goto free_pages_out;
501 }
502 btrfs_end_transaction(trans, root);
503 }
504
505 if (will_compress) {
506 /*
507 * we aren't doing an inline extent round the compressed size
508 * up to a block size boundary so the allocator does sane
509 * things
510 */
511 total_compressed = ALIGN(total_compressed, blocksize);
512
513 /*
514 * one last check to make sure the compression is really a
515 * win, compare the page count read with the blocks on disk
516 */
517 total_in = ALIGN(total_in, PAGE_CACHE_SIZE);
518 if (total_compressed >= total_in) {
519 will_compress = 0;
520 } else {
521 num_bytes = total_in;
522 }
523 }
524 if (!will_compress && pages) {
525 /*
526 * the compression code ran but failed to make things smaller,
527 * free any pages it allocated and our page pointer array
528 */
529 for (i = 0; i < nr_pages_ret; i++) {
530 WARN_ON(pages[i]->mapping);
531 page_cache_release(pages[i]);
532 }
533 kfree(pages);
534 pages = NULL;
535 total_compressed = 0;
536 nr_pages_ret = 0;
537
538 /* flag the file so we don't compress in the future */
539 if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
540 !(BTRFS_I(inode)->force_compress)) {
541 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
542 }
543 }
544 if (will_compress) {
545 *num_added += 1;
546
547 /* the async work queues will take care of doing actual
548 * allocation on disk for these compressed pages,
549 * and will submit them to the elevator.
550 */
551 add_async_extent(async_cow, start, num_bytes,
552 total_compressed, pages, nr_pages_ret,
553 compress_type);
554
555 if (start + num_bytes < end) {
556 start += num_bytes;
557 pages = NULL;
558 cond_resched();
559 goto again;
560 }
561 } else {
562 cleanup_and_bail_uncompressed:
563 /*
564 * No compression, but we still need to write the pages in
565 * the file we've been given so far. redirty the locked
566 * page if it corresponds to our extent and set things up
567 * for the async work queue to run cow_file_range to do
568 * the normal delalloc dance
569 */
570 if (page_offset(locked_page) >= start &&
571 page_offset(locked_page) <= end) {
572 __set_page_dirty_nobuffers(locked_page);
573 /* unlocked later on in the async handlers */
574 }
575 if (redirty)
576 extent_range_redirty_for_io(inode, start, end);
577 add_async_extent(async_cow, start, end - start + 1,
578 0, NULL, 0, BTRFS_COMPRESS_NONE);
579 *num_added += 1;
580 }
581
582 out:
583 return ret;
584
585 free_pages_out:
586 for (i = 0; i < nr_pages_ret; i++) {
587 WARN_ON(pages[i]->mapping);
588 page_cache_release(pages[i]);
589 }
590 kfree(pages);
591
592 goto out;
593
594 cleanup_and_out:
595 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
596 start, end, NULL,
597 EXTENT_CLEAR_UNLOCK_PAGE |
598 EXTENT_CLEAR_DIRTY |
599 EXTENT_CLEAR_DELALLOC |
600 EXTENT_SET_WRITEBACK |
601 EXTENT_END_WRITEBACK);
602 if (!trans || IS_ERR(trans))
603 btrfs_error(root->fs_info, ret, "Failed to join transaction");
604 else
605 btrfs_abort_transaction(trans, root, ret);
606 goto free_pages_out;
607 }
608
609 /*
610 * phase two of compressed writeback. This is the ordered portion
611 * of the code, which only gets called in the order the work was
612 * queued. We walk all the async extents created by compress_file_range
613 * and send them down to the disk.
614 */
615 static noinline int submit_compressed_extents(struct inode *inode,
616 struct async_cow *async_cow)
617 {
618 struct async_extent *async_extent;
619 u64 alloc_hint = 0;
620 struct btrfs_trans_handle *trans;
621 struct btrfs_key ins;
622 struct extent_map *em;
623 struct btrfs_root *root = BTRFS_I(inode)->root;
624 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
625 struct extent_io_tree *io_tree;
626 int ret = 0;
627
628 if (list_empty(&async_cow->extents))
629 return 0;
630
631 again:
632 while (!list_empty(&async_cow->extents)) {
633 async_extent = list_entry(async_cow->extents.next,
634 struct async_extent, list);
635 list_del(&async_extent->list);
636
637 io_tree = &BTRFS_I(inode)->io_tree;
638
639 retry:
640 /* did the compression code fall back to uncompressed IO? */
641 if (!async_extent->pages) {
642 int page_started = 0;
643 unsigned long nr_written = 0;
644
645 lock_extent(io_tree, async_extent->start,
646 async_extent->start +
647 async_extent->ram_size - 1);
648
649 /* allocate blocks */
650 ret = cow_file_range(inode, async_cow->locked_page,
651 async_extent->start,
652 async_extent->start +
653 async_extent->ram_size - 1,
654 &page_started, &nr_written, 0);
655
656 /* JDM XXX */
657
658 /*
659 * if page_started, cow_file_range inserted an
660 * inline extent and took care of all the unlocking
661 * and IO for us. Otherwise, we need to submit
662 * all those pages down to the drive.
663 */
664 if (!page_started && !ret)
665 extent_write_locked_range(io_tree,
666 inode, async_extent->start,
667 async_extent->start +
668 async_extent->ram_size - 1,
669 btrfs_get_extent,
670 WB_SYNC_ALL);
671 else if (ret)
672 unlock_page(async_cow->locked_page);
673 kfree(async_extent);
674 cond_resched();
675 continue;
676 }
677
678 lock_extent(io_tree, async_extent->start,
679 async_extent->start + async_extent->ram_size - 1);
680
681 trans = btrfs_join_transaction(root);
682 if (IS_ERR(trans)) {
683 ret = PTR_ERR(trans);
684 } else {
685 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
686 ret = btrfs_reserve_extent(trans, root,
687 async_extent->compressed_size,
688 async_extent->compressed_size,
689 0, alloc_hint, &ins, 1);
690 if (ret && ret != -ENOSPC)
691 btrfs_abort_transaction(trans, root, ret);
692 btrfs_end_transaction(trans, root);
693 }
694
695 if (ret) {
696 int i;
697
698 for (i = 0; i < async_extent->nr_pages; i++) {
699 WARN_ON(async_extent->pages[i]->mapping);
700 page_cache_release(async_extent->pages[i]);
701 }
702 kfree(async_extent->pages);
703 async_extent->nr_pages = 0;
704 async_extent->pages = NULL;
705
706 if (ret == -ENOSPC) {
707 unlock_extent(io_tree, async_extent->start,
708 async_extent->start +
709 async_extent->ram_size - 1);
710 goto retry;
711 }
712 goto out_free;
713 }
714
715 /*
716 * here we're doing allocation and writeback of the
717 * compressed pages
718 */
719 btrfs_drop_extent_cache(inode, async_extent->start,
720 async_extent->start +
721 async_extent->ram_size - 1, 0);
722
723 em = alloc_extent_map();
724 if (!em) {
725 ret = -ENOMEM;
726 goto out_free_reserve;
727 }
728 em->start = async_extent->start;
729 em->len = async_extent->ram_size;
730 em->orig_start = em->start;
731 em->mod_start = em->start;
732 em->mod_len = em->len;
733
734 em->block_start = ins.objectid;
735 em->block_len = ins.offset;
736 em->orig_block_len = ins.offset;
737 em->ram_bytes = async_extent->ram_size;
738 em->bdev = root->fs_info->fs_devices->latest_bdev;
739 em->compress_type = async_extent->compress_type;
740 set_bit(EXTENT_FLAG_PINNED, &em->flags);
741 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
742 em->generation = -1;
743
744 while (1) {
745 write_lock(&em_tree->lock);
746 ret = add_extent_mapping(em_tree, em, 1);
747 write_unlock(&em_tree->lock);
748 if (ret != -EEXIST) {
749 free_extent_map(em);
750 break;
751 }
752 btrfs_drop_extent_cache(inode, async_extent->start,
753 async_extent->start +
754 async_extent->ram_size - 1, 0);
755 }
756
757 if (ret)
758 goto out_free_reserve;
759
760 ret = btrfs_add_ordered_extent_compress(inode,
761 async_extent->start,
762 ins.objectid,
763 async_extent->ram_size,
764 ins.offset,
765 BTRFS_ORDERED_COMPRESSED,
766 async_extent->compress_type);
767 if (ret)
768 goto out_free_reserve;
769
770 /*
771 * clear dirty, set writeback and unlock the pages.
772 */
773 extent_clear_unlock_delalloc(inode,
774 &BTRFS_I(inode)->io_tree,
775 async_extent->start,
776 async_extent->start +
777 async_extent->ram_size - 1,
778 NULL, EXTENT_CLEAR_UNLOCK_PAGE |
779 EXTENT_CLEAR_UNLOCK |
780 EXTENT_CLEAR_DELALLOC |
781 EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK);
782
783 ret = btrfs_submit_compressed_write(inode,
784 async_extent->start,
785 async_extent->ram_size,
786 ins.objectid,
787 ins.offset, async_extent->pages,
788 async_extent->nr_pages);
789 alloc_hint = ins.objectid + ins.offset;
790 kfree(async_extent);
791 if (ret)
792 goto out;
793 cond_resched();
794 }
795 ret = 0;
796 out:
797 return ret;
798 out_free_reserve:
799 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
800 out_free:
801 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
802 async_extent->start,
803 async_extent->start +
804 async_extent->ram_size - 1,
805 NULL, EXTENT_CLEAR_UNLOCK_PAGE |
806 EXTENT_CLEAR_UNLOCK |
807 EXTENT_CLEAR_DELALLOC |
808 EXTENT_CLEAR_DIRTY |
809 EXTENT_SET_WRITEBACK |
810 EXTENT_END_WRITEBACK);
811 kfree(async_extent);
812 goto again;
813 }
814
815 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
816 u64 num_bytes)
817 {
818 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
819 struct extent_map *em;
820 u64 alloc_hint = 0;
821
822 read_lock(&em_tree->lock);
823 em = search_extent_mapping(em_tree, start, num_bytes);
824 if (em) {
825 /*
826 * if block start isn't an actual block number then find the
827 * first block in this inode and use that as a hint. If that
828 * block is also bogus then just don't worry about it.
829 */
830 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
831 free_extent_map(em);
832 em = search_extent_mapping(em_tree, 0, 0);
833 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
834 alloc_hint = em->block_start;
835 if (em)
836 free_extent_map(em);
837 } else {
838 alloc_hint = em->block_start;
839 free_extent_map(em);
840 }
841 }
842 read_unlock(&em_tree->lock);
843
844 return alloc_hint;
845 }
846
847 /*
848 * when extent_io.c finds a delayed allocation range in the file,
849 * the call backs end up in this code. The basic idea is to
850 * allocate extents on disk for the range, and create ordered data structs
851 * in ram to track those extents.
852 *
853 * locked_page is the page that writepage had locked already. We use
854 * it to make sure we don't do extra locks or unlocks.
855 *
856 * *page_started is set to one if we unlock locked_page and do everything
857 * required to start IO on it. It may be clean and already done with
858 * IO when we return.
859 */
860 static noinline int __cow_file_range(struct btrfs_trans_handle *trans,
861 struct inode *inode,
862 struct btrfs_root *root,
863 struct page *locked_page,
864 u64 start, u64 end, int *page_started,
865 unsigned long *nr_written,
866 int unlock)
867 {
868 u64 alloc_hint = 0;
869 u64 num_bytes;
870 unsigned long ram_size;
871 u64 disk_num_bytes;
872 u64 cur_alloc_size;
873 u64 blocksize = root->sectorsize;
874 struct btrfs_key ins;
875 struct extent_map *em;
876 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
877 int ret = 0;
878
879 BUG_ON(btrfs_is_free_space_inode(inode));
880
881 num_bytes = ALIGN(end - start + 1, blocksize);
882 num_bytes = max(blocksize, num_bytes);
883 disk_num_bytes = num_bytes;
884
885 /* if this is a small write inside eof, kick off defrag */
886 if (num_bytes < 64 * 1024 &&
887 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
888 btrfs_add_inode_defrag(trans, inode);
889
890 if (start == 0) {
891 /* lets try to make an inline extent */
892 ret = cow_file_range_inline(trans, root, inode,
893 start, end, 0, 0, NULL);
894 if (ret == 0) {
895 extent_clear_unlock_delalloc(inode,
896 &BTRFS_I(inode)->io_tree,
897 start, end, NULL,
898 EXTENT_CLEAR_UNLOCK_PAGE |
899 EXTENT_CLEAR_UNLOCK |
900 EXTENT_CLEAR_DELALLOC |
901 EXTENT_CLEAR_DIRTY |
902 EXTENT_SET_WRITEBACK |
903 EXTENT_END_WRITEBACK);
904
905 *nr_written = *nr_written +
906 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
907 *page_started = 1;
908 goto out;
909 } else if (ret < 0) {
910 btrfs_abort_transaction(trans, root, ret);
911 goto out_unlock;
912 }
913 }
914
915 BUG_ON(disk_num_bytes >
916 btrfs_super_total_bytes(root->fs_info->super_copy));
917
918 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
919 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
920
921 while (disk_num_bytes > 0) {
922 unsigned long op;
923
924 cur_alloc_size = disk_num_bytes;
925 ret = btrfs_reserve_extent(trans, root, cur_alloc_size,
926 root->sectorsize, 0, alloc_hint,
927 &ins, 1);
928 if (ret < 0) {
929 btrfs_abort_transaction(trans, root, ret);
930 goto out_unlock;
931 }
932
933 em = alloc_extent_map();
934 if (!em) {
935 ret = -ENOMEM;
936 goto out_reserve;
937 }
938 em->start = start;
939 em->orig_start = em->start;
940 ram_size = ins.offset;
941 em->len = ins.offset;
942 em->mod_start = em->start;
943 em->mod_len = em->len;
944
945 em->block_start = ins.objectid;
946 em->block_len = ins.offset;
947 em->orig_block_len = ins.offset;
948 em->ram_bytes = ram_size;
949 em->bdev = root->fs_info->fs_devices->latest_bdev;
950 set_bit(EXTENT_FLAG_PINNED, &em->flags);
951 em->generation = -1;
952
953 while (1) {
954 write_lock(&em_tree->lock);
955 ret = add_extent_mapping(em_tree, em, 1);
956 write_unlock(&em_tree->lock);
957 if (ret != -EEXIST) {
958 free_extent_map(em);
959 break;
960 }
961 btrfs_drop_extent_cache(inode, start,
962 start + ram_size - 1, 0);
963 }
964 if (ret)
965 goto out_reserve;
966
967 cur_alloc_size = ins.offset;
968 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
969 ram_size, cur_alloc_size, 0);
970 if (ret)
971 goto out_reserve;
972
973 if (root->root_key.objectid ==
974 BTRFS_DATA_RELOC_TREE_OBJECTID) {
975 ret = btrfs_reloc_clone_csums(inode, start,
976 cur_alloc_size);
977 if (ret) {
978 btrfs_abort_transaction(trans, root, ret);
979 goto out_reserve;
980 }
981 }
982
983 if (disk_num_bytes < cur_alloc_size)
984 break;
985
986 /* we're not doing compressed IO, don't unlock the first
987 * page (which the caller expects to stay locked), don't
988 * clear any dirty bits and don't set any writeback bits
989 *
990 * Do set the Private2 bit so we know this page was properly
991 * setup for writepage
992 */
993 op = unlock ? EXTENT_CLEAR_UNLOCK_PAGE : 0;
994 op |= EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
995 EXTENT_SET_PRIVATE2;
996
997 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
998 start, start + ram_size - 1,
999 locked_page, op);
1000 disk_num_bytes -= cur_alloc_size;
1001 num_bytes -= cur_alloc_size;
1002 alloc_hint = ins.objectid + ins.offset;
1003 start += cur_alloc_size;
1004 }
1005 out:
1006 return ret;
1007
1008 out_reserve:
1009 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
1010 out_unlock:
1011 extent_clear_unlock_delalloc(inode,
1012 &BTRFS_I(inode)->io_tree,
1013 start, end, locked_page,
1014 EXTENT_CLEAR_UNLOCK_PAGE |
1015 EXTENT_CLEAR_UNLOCK |
1016 EXTENT_CLEAR_DELALLOC |
1017 EXTENT_CLEAR_DIRTY |
1018 EXTENT_SET_WRITEBACK |
1019 EXTENT_END_WRITEBACK);
1020
1021 goto out;
1022 }
1023
1024 static noinline int cow_file_range(struct inode *inode,
1025 struct page *locked_page,
1026 u64 start, u64 end, int *page_started,
1027 unsigned long *nr_written,
1028 int unlock)
1029 {
1030 struct btrfs_trans_handle *trans;
1031 struct btrfs_root *root = BTRFS_I(inode)->root;
1032 int ret;
1033
1034 trans = btrfs_join_transaction(root);
1035 if (IS_ERR(trans)) {
1036 extent_clear_unlock_delalloc(inode,
1037 &BTRFS_I(inode)->io_tree,
1038 start, end, locked_page,
1039 EXTENT_CLEAR_UNLOCK_PAGE |
1040 EXTENT_CLEAR_UNLOCK |
1041 EXTENT_CLEAR_DELALLOC |
1042 EXTENT_CLEAR_DIRTY |
1043 EXTENT_SET_WRITEBACK |
1044 EXTENT_END_WRITEBACK);
1045 return PTR_ERR(trans);
1046 }
1047 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1048
1049 ret = __cow_file_range(trans, inode, root, locked_page, start, end,
1050 page_started, nr_written, unlock);
1051
1052 btrfs_end_transaction(trans, root);
1053
1054 return ret;
1055 }
1056
1057 /*
1058 * work queue call back to started compression on a file and pages
1059 */
1060 static noinline void async_cow_start(struct btrfs_work *work)
1061 {
1062 struct async_cow *async_cow;
1063 int num_added = 0;
1064 async_cow = container_of(work, struct async_cow, work);
1065
1066 compress_file_range(async_cow->inode, async_cow->locked_page,
1067 async_cow->start, async_cow->end, async_cow,
1068 &num_added);
1069 if (num_added == 0) {
1070 btrfs_add_delayed_iput(async_cow->inode);
1071 async_cow->inode = NULL;
1072 }
1073 }
1074
1075 /*
1076 * work queue call back to submit previously compressed pages
1077 */
1078 static noinline void async_cow_submit(struct btrfs_work *work)
1079 {
1080 struct async_cow *async_cow;
1081 struct btrfs_root *root;
1082 unsigned long nr_pages;
1083
1084 async_cow = container_of(work, struct async_cow, work);
1085
1086 root = async_cow->root;
1087 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
1088 PAGE_CACHE_SHIFT;
1089
1090 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
1091 5 * 1024 * 1024 &&
1092 waitqueue_active(&root->fs_info->async_submit_wait))
1093 wake_up(&root->fs_info->async_submit_wait);
1094
1095 if (async_cow->inode)
1096 submit_compressed_extents(async_cow->inode, async_cow);
1097 }
1098
1099 static noinline void async_cow_free(struct btrfs_work *work)
1100 {
1101 struct async_cow *async_cow;
1102 async_cow = container_of(work, struct async_cow, work);
1103 if (async_cow->inode)
1104 btrfs_add_delayed_iput(async_cow->inode);
1105 kfree(async_cow);
1106 }
1107
1108 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1109 u64 start, u64 end, int *page_started,
1110 unsigned long *nr_written)
1111 {
1112 struct async_cow *async_cow;
1113 struct btrfs_root *root = BTRFS_I(inode)->root;
1114 unsigned long nr_pages;
1115 u64 cur_end;
1116 int limit = 10 * 1024 * 1024;
1117
1118 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1119 1, 0, NULL, GFP_NOFS);
1120 while (start < end) {
1121 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1122 BUG_ON(!async_cow); /* -ENOMEM */
1123 async_cow->inode = igrab(inode);
1124 async_cow->root = root;
1125 async_cow->locked_page = locked_page;
1126 async_cow->start = start;
1127
1128 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
1129 cur_end = end;
1130 else
1131 cur_end = min(end, start + 512 * 1024 - 1);
1132
1133 async_cow->end = cur_end;
1134 INIT_LIST_HEAD(&async_cow->extents);
1135
1136 async_cow->work.func = async_cow_start;
1137 async_cow->work.ordered_func = async_cow_submit;
1138 async_cow->work.ordered_free = async_cow_free;
1139 async_cow->work.flags = 0;
1140
1141 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
1142 PAGE_CACHE_SHIFT;
1143 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
1144
1145 btrfs_queue_worker(&root->fs_info->delalloc_workers,
1146 &async_cow->work);
1147
1148 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
1149 wait_event(root->fs_info->async_submit_wait,
1150 (atomic_read(&root->fs_info->async_delalloc_pages) <
1151 limit));
1152 }
1153
1154 while (atomic_read(&root->fs_info->async_submit_draining) &&
1155 atomic_read(&root->fs_info->async_delalloc_pages)) {
1156 wait_event(root->fs_info->async_submit_wait,
1157 (atomic_read(&root->fs_info->async_delalloc_pages) ==
1158 0));
1159 }
1160
1161 *nr_written += nr_pages;
1162 start = cur_end + 1;
1163 }
1164 *page_started = 1;
1165 return 0;
1166 }
1167
1168 static noinline int csum_exist_in_range(struct btrfs_root *root,
1169 u64 bytenr, u64 num_bytes)
1170 {
1171 int ret;
1172 struct btrfs_ordered_sum *sums;
1173 LIST_HEAD(list);
1174
1175 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1176 bytenr + num_bytes - 1, &list, 0);
1177 if (ret == 0 && list_empty(&list))
1178 return 0;
1179
1180 while (!list_empty(&list)) {
1181 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1182 list_del(&sums->list);
1183 kfree(sums);
1184 }
1185 return 1;
1186 }
1187
1188 /*
1189 * when nowcow writeback call back. This checks for snapshots or COW copies
1190 * of the extents that exist in the file, and COWs the file as required.
1191 *
1192 * If no cow copies or snapshots exist, we write directly to the existing
1193 * blocks on disk
1194 */
1195 static noinline int run_delalloc_nocow(struct inode *inode,
1196 struct page *locked_page,
1197 u64 start, u64 end, int *page_started, int force,
1198 unsigned long *nr_written)
1199 {
1200 struct btrfs_root *root = BTRFS_I(inode)->root;
1201 struct btrfs_trans_handle *trans;
1202 struct extent_buffer *leaf;
1203 struct btrfs_path *path;
1204 struct btrfs_file_extent_item *fi;
1205 struct btrfs_key found_key;
1206 u64 cow_start;
1207 u64 cur_offset;
1208 u64 extent_end;
1209 u64 extent_offset;
1210 u64 disk_bytenr;
1211 u64 num_bytes;
1212 u64 disk_num_bytes;
1213 u64 ram_bytes;
1214 int extent_type;
1215 int ret, err;
1216 int type;
1217 int nocow;
1218 int check_prev = 1;
1219 bool nolock;
1220 u64 ino = btrfs_ino(inode);
1221
1222 path = btrfs_alloc_path();
1223 if (!path) {
1224 extent_clear_unlock_delalloc(inode,
1225 &BTRFS_I(inode)->io_tree,
1226 start, end, locked_page,
1227 EXTENT_CLEAR_UNLOCK_PAGE |
1228 EXTENT_CLEAR_UNLOCK |
1229 EXTENT_CLEAR_DELALLOC |
1230 EXTENT_CLEAR_DIRTY |
1231 EXTENT_SET_WRITEBACK |
1232 EXTENT_END_WRITEBACK);
1233 return -ENOMEM;
1234 }
1235
1236 nolock = btrfs_is_free_space_inode(inode);
1237
1238 if (nolock)
1239 trans = btrfs_join_transaction_nolock(root);
1240 else
1241 trans = btrfs_join_transaction(root);
1242
1243 if (IS_ERR(trans)) {
1244 extent_clear_unlock_delalloc(inode,
1245 &BTRFS_I(inode)->io_tree,
1246 start, end, locked_page,
1247 EXTENT_CLEAR_UNLOCK_PAGE |
1248 EXTENT_CLEAR_UNLOCK |
1249 EXTENT_CLEAR_DELALLOC |
1250 EXTENT_CLEAR_DIRTY |
1251 EXTENT_SET_WRITEBACK |
1252 EXTENT_END_WRITEBACK);
1253 btrfs_free_path(path);
1254 return PTR_ERR(trans);
1255 }
1256
1257 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1258
1259 cow_start = (u64)-1;
1260 cur_offset = start;
1261 while (1) {
1262 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1263 cur_offset, 0);
1264 if (ret < 0) {
1265 btrfs_abort_transaction(trans, root, ret);
1266 goto error;
1267 }
1268 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1269 leaf = path->nodes[0];
1270 btrfs_item_key_to_cpu(leaf, &found_key,
1271 path->slots[0] - 1);
1272 if (found_key.objectid == ino &&
1273 found_key.type == BTRFS_EXTENT_DATA_KEY)
1274 path->slots[0]--;
1275 }
1276 check_prev = 0;
1277 next_slot:
1278 leaf = path->nodes[0];
1279 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1280 ret = btrfs_next_leaf(root, path);
1281 if (ret < 0) {
1282 btrfs_abort_transaction(trans, root, ret);
1283 goto error;
1284 }
1285 if (ret > 0)
1286 break;
1287 leaf = path->nodes[0];
1288 }
1289
1290 nocow = 0;
1291 disk_bytenr = 0;
1292 num_bytes = 0;
1293 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1294
1295 if (found_key.objectid > ino ||
1296 found_key.type > BTRFS_EXTENT_DATA_KEY ||
1297 found_key.offset > end)
1298 break;
1299
1300 if (found_key.offset > cur_offset) {
1301 extent_end = found_key.offset;
1302 extent_type = 0;
1303 goto out_check;
1304 }
1305
1306 fi = btrfs_item_ptr(leaf, path->slots[0],
1307 struct btrfs_file_extent_item);
1308 extent_type = btrfs_file_extent_type(leaf, fi);
1309
1310 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1311 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1312 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1313 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1314 extent_offset = btrfs_file_extent_offset(leaf, fi);
1315 extent_end = found_key.offset +
1316 btrfs_file_extent_num_bytes(leaf, fi);
1317 disk_num_bytes =
1318 btrfs_file_extent_disk_num_bytes(leaf, fi);
1319 if (extent_end <= start) {
1320 path->slots[0]++;
1321 goto next_slot;
1322 }
1323 if (disk_bytenr == 0)
1324 goto out_check;
1325 if (btrfs_file_extent_compression(leaf, fi) ||
1326 btrfs_file_extent_encryption(leaf, fi) ||
1327 btrfs_file_extent_other_encoding(leaf, fi))
1328 goto out_check;
1329 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1330 goto out_check;
1331 if (btrfs_extent_readonly(root, disk_bytenr))
1332 goto out_check;
1333 if (btrfs_cross_ref_exist(trans, root, ino,
1334 found_key.offset -
1335 extent_offset, disk_bytenr))
1336 goto out_check;
1337 disk_bytenr += extent_offset;
1338 disk_bytenr += cur_offset - found_key.offset;
1339 num_bytes = min(end + 1, extent_end) - cur_offset;
1340 /*
1341 * force cow if csum exists in the range.
1342 * this ensure that csum for a given extent are
1343 * either valid or do not exist.
1344 */
1345 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1346 goto out_check;
1347 nocow = 1;
1348 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1349 extent_end = found_key.offset +
1350 btrfs_file_extent_inline_len(leaf, fi);
1351 extent_end = ALIGN(extent_end, root->sectorsize);
1352 } else {
1353 BUG_ON(1);
1354 }
1355 out_check:
1356 if (extent_end <= start) {
1357 path->slots[0]++;
1358 goto next_slot;
1359 }
1360 if (!nocow) {
1361 if (cow_start == (u64)-1)
1362 cow_start = cur_offset;
1363 cur_offset = extent_end;
1364 if (cur_offset > end)
1365 break;
1366 path->slots[0]++;
1367 goto next_slot;
1368 }
1369
1370 btrfs_release_path(path);
1371 if (cow_start != (u64)-1) {
1372 ret = __cow_file_range(trans, inode, root, locked_page,
1373 cow_start, found_key.offset - 1,
1374 page_started, nr_written, 1);
1375 if (ret) {
1376 btrfs_abort_transaction(trans, root, ret);
1377 goto error;
1378 }
1379 cow_start = (u64)-1;
1380 }
1381
1382 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1383 struct extent_map *em;
1384 struct extent_map_tree *em_tree;
1385 em_tree = &BTRFS_I(inode)->extent_tree;
1386 em = alloc_extent_map();
1387 BUG_ON(!em); /* -ENOMEM */
1388 em->start = cur_offset;
1389 em->orig_start = found_key.offset - extent_offset;
1390 em->len = num_bytes;
1391 em->block_len = num_bytes;
1392 em->block_start = disk_bytenr;
1393 em->orig_block_len = disk_num_bytes;
1394 em->ram_bytes = ram_bytes;
1395 em->bdev = root->fs_info->fs_devices->latest_bdev;
1396 em->mod_start = em->start;
1397 em->mod_len = em->len;
1398 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1399 set_bit(EXTENT_FLAG_FILLING, &em->flags);
1400 em->generation = -1;
1401 while (1) {
1402 write_lock(&em_tree->lock);
1403 ret = add_extent_mapping(em_tree, em, 1);
1404 write_unlock(&em_tree->lock);
1405 if (ret != -EEXIST) {
1406 free_extent_map(em);
1407 break;
1408 }
1409 btrfs_drop_extent_cache(inode, em->start,
1410 em->start + em->len - 1, 0);
1411 }
1412 type = BTRFS_ORDERED_PREALLOC;
1413 } else {
1414 type = BTRFS_ORDERED_NOCOW;
1415 }
1416
1417 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1418 num_bytes, num_bytes, type);
1419 BUG_ON(ret); /* -ENOMEM */
1420
1421 if (root->root_key.objectid ==
1422 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1423 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1424 num_bytes);
1425 if (ret) {
1426 btrfs_abort_transaction(trans, root, ret);
1427 goto error;
1428 }
1429 }
1430
1431 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
1432 cur_offset, cur_offset + num_bytes - 1,
1433 locked_page, EXTENT_CLEAR_UNLOCK_PAGE |
1434 EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
1435 EXTENT_SET_PRIVATE2);
1436 cur_offset = extent_end;
1437 if (cur_offset > end)
1438 break;
1439 }
1440 btrfs_release_path(path);
1441
1442 if (cur_offset <= end && cow_start == (u64)-1) {
1443 cow_start = cur_offset;
1444 cur_offset = end;
1445 }
1446
1447 if (cow_start != (u64)-1) {
1448 ret = __cow_file_range(trans, inode, root, locked_page,
1449 cow_start, end,
1450 page_started, nr_written, 1);
1451 if (ret) {
1452 btrfs_abort_transaction(trans, root, ret);
1453 goto error;
1454 }
1455 }
1456
1457 error:
1458 err = btrfs_end_transaction(trans, root);
1459 if (!ret)
1460 ret = err;
1461
1462 if (ret && cur_offset < end)
1463 extent_clear_unlock_delalloc(inode,
1464 &BTRFS_I(inode)->io_tree,
1465 cur_offset, end, locked_page,
1466 EXTENT_CLEAR_UNLOCK_PAGE |
1467 EXTENT_CLEAR_UNLOCK |
1468 EXTENT_CLEAR_DELALLOC |
1469 EXTENT_CLEAR_DIRTY |
1470 EXTENT_SET_WRITEBACK |
1471 EXTENT_END_WRITEBACK);
1472
1473 btrfs_free_path(path);
1474 return ret;
1475 }
1476
1477 /*
1478 * extent_io.c call back to do delayed allocation processing
1479 */
1480 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1481 u64 start, u64 end, int *page_started,
1482 unsigned long *nr_written)
1483 {
1484 int ret;
1485 struct btrfs_root *root = BTRFS_I(inode)->root;
1486
1487 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) {
1488 ret = run_delalloc_nocow(inode, locked_page, start, end,
1489 page_started, 1, nr_written);
1490 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC) {
1491 ret = run_delalloc_nocow(inode, locked_page, start, end,
1492 page_started, 0, nr_written);
1493 } else if (!btrfs_test_opt(root, COMPRESS) &&
1494 !(BTRFS_I(inode)->force_compress) &&
1495 !(BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS)) {
1496 ret = cow_file_range(inode, locked_page, start, end,
1497 page_started, nr_written, 1);
1498 } else {
1499 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1500 &BTRFS_I(inode)->runtime_flags);
1501 ret = cow_file_range_async(inode, locked_page, start, end,
1502 page_started, nr_written);
1503 }
1504 return ret;
1505 }
1506
1507 static void btrfs_split_extent_hook(struct inode *inode,
1508 struct extent_state *orig, u64 split)
1509 {
1510 /* not delalloc, ignore it */
1511 if (!(orig->state & EXTENT_DELALLOC))
1512 return;
1513
1514 spin_lock(&BTRFS_I(inode)->lock);
1515 BTRFS_I(inode)->outstanding_extents++;
1516 spin_unlock(&BTRFS_I(inode)->lock);
1517 }
1518
1519 /*
1520 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1521 * extents so we can keep track of new extents that are just merged onto old
1522 * extents, such as when we are doing sequential writes, so we can properly
1523 * account for the metadata space we'll need.
1524 */
1525 static void btrfs_merge_extent_hook(struct inode *inode,
1526 struct extent_state *new,
1527 struct extent_state *other)
1528 {
1529 /* not delalloc, ignore it */
1530 if (!(other->state & EXTENT_DELALLOC))
1531 return;
1532
1533 spin_lock(&BTRFS_I(inode)->lock);
1534 BTRFS_I(inode)->outstanding_extents--;
1535 spin_unlock(&BTRFS_I(inode)->lock);
1536 }
1537
1538 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1539 struct inode *inode)
1540 {
1541 spin_lock(&root->delalloc_lock);
1542 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1543 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1544 &root->delalloc_inodes);
1545 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1546 &BTRFS_I(inode)->runtime_flags);
1547 root->nr_delalloc_inodes++;
1548 if (root->nr_delalloc_inodes == 1) {
1549 spin_lock(&root->fs_info->delalloc_root_lock);
1550 BUG_ON(!list_empty(&root->delalloc_root));
1551 list_add_tail(&root->delalloc_root,
1552 &root->fs_info->delalloc_roots);
1553 spin_unlock(&root->fs_info->delalloc_root_lock);
1554 }
1555 }
1556 spin_unlock(&root->delalloc_lock);
1557 }
1558
1559 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1560 struct inode *inode)
1561 {
1562 spin_lock(&root->delalloc_lock);
1563 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1564 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1565 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1566 &BTRFS_I(inode)->runtime_flags);
1567 root->nr_delalloc_inodes--;
1568 if (!root->nr_delalloc_inodes) {
1569 spin_lock(&root->fs_info->delalloc_root_lock);
1570 BUG_ON(list_empty(&root->delalloc_root));
1571 list_del_init(&root->delalloc_root);
1572 spin_unlock(&root->fs_info->delalloc_root_lock);
1573 }
1574 }
1575 spin_unlock(&root->delalloc_lock);
1576 }
1577
1578 /*
1579 * extent_io.c set_bit_hook, used to track delayed allocation
1580 * bytes in this file, and to maintain the list of inodes that
1581 * have pending delalloc work to be done.
1582 */
1583 static void btrfs_set_bit_hook(struct inode *inode,
1584 struct extent_state *state, unsigned long *bits)
1585 {
1586
1587 /*
1588 * set_bit and clear bit hooks normally require _irqsave/restore
1589 * but in this case, we are only testing for the DELALLOC
1590 * bit, which is only set or cleared with irqs on
1591 */
1592 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1593 struct btrfs_root *root = BTRFS_I(inode)->root;
1594 u64 len = state->end + 1 - state->start;
1595 bool do_list = !btrfs_is_free_space_inode(inode);
1596
1597 if (*bits & EXTENT_FIRST_DELALLOC) {
1598 *bits &= ~EXTENT_FIRST_DELALLOC;
1599 } else {
1600 spin_lock(&BTRFS_I(inode)->lock);
1601 BTRFS_I(inode)->outstanding_extents++;
1602 spin_unlock(&BTRFS_I(inode)->lock);
1603 }
1604
1605 __percpu_counter_add(&root->fs_info->delalloc_bytes, len,
1606 root->fs_info->delalloc_batch);
1607 spin_lock(&BTRFS_I(inode)->lock);
1608 BTRFS_I(inode)->delalloc_bytes += len;
1609 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1610 &BTRFS_I(inode)->runtime_flags))
1611 btrfs_add_delalloc_inodes(root, inode);
1612 spin_unlock(&BTRFS_I(inode)->lock);
1613 }
1614 }
1615
1616 /*
1617 * extent_io.c clear_bit_hook, see set_bit_hook for why
1618 */
1619 static void btrfs_clear_bit_hook(struct inode *inode,
1620 struct extent_state *state,
1621 unsigned long *bits)
1622 {
1623 /*
1624 * set_bit and clear bit hooks normally require _irqsave/restore
1625 * but in this case, we are only testing for the DELALLOC
1626 * bit, which is only set or cleared with irqs on
1627 */
1628 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1629 struct btrfs_root *root = BTRFS_I(inode)->root;
1630 u64 len = state->end + 1 - state->start;
1631 bool do_list = !btrfs_is_free_space_inode(inode);
1632
1633 if (*bits & EXTENT_FIRST_DELALLOC) {
1634 *bits &= ~EXTENT_FIRST_DELALLOC;
1635 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1636 spin_lock(&BTRFS_I(inode)->lock);
1637 BTRFS_I(inode)->outstanding_extents--;
1638 spin_unlock(&BTRFS_I(inode)->lock);
1639 }
1640
1641 if (*bits & EXTENT_DO_ACCOUNTING)
1642 btrfs_delalloc_release_metadata(inode, len);
1643
1644 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1645 && do_list && !(state->state & EXTENT_NORESERVE))
1646 btrfs_free_reserved_data_space(inode, len);
1647
1648 __percpu_counter_add(&root->fs_info->delalloc_bytes, -len,
1649 root->fs_info->delalloc_batch);
1650 spin_lock(&BTRFS_I(inode)->lock);
1651 BTRFS_I(inode)->delalloc_bytes -= len;
1652 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1653 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1654 &BTRFS_I(inode)->runtime_flags))
1655 btrfs_del_delalloc_inode(root, inode);
1656 spin_unlock(&BTRFS_I(inode)->lock);
1657 }
1658 }
1659
1660 /*
1661 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1662 * we don't create bios that span stripes or chunks
1663 */
1664 int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset,
1665 size_t size, struct bio *bio,
1666 unsigned long bio_flags)
1667 {
1668 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1669 u64 logical = (u64)bio->bi_sector << 9;
1670 u64 length = 0;
1671 u64 map_length;
1672 int ret;
1673
1674 if (bio_flags & EXTENT_BIO_COMPRESSED)
1675 return 0;
1676
1677 length = bio->bi_size;
1678 map_length = length;
1679 ret = btrfs_map_block(root->fs_info, rw, logical,
1680 &map_length, NULL, 0);
1681 /* Will always return 0 with map_multi == NULL */
1682 BUG_ON(ret < 0);
1683 if (map_length < length + size)
1684 return 1;
1685 return 0;
1686 }
1687
1688 /*
1689 * in order to insert checksums into the metadata in large chunks,
1690 * we wait until bio submission time. All the pages in the bio are
1691 * checksummed and sums are attached onto the ordered extent record.
1692 *
1693 * At IO completion time the cums attached on the ordered extent record
1694 * are inserted into the btree
1695 */
1696 static int __btrfs_submit_bio_start(struct inode *inode, int rw,
1697 struct bio *bio, int mirror_num,
1698 unsigned long bio_flags,
1699 u64 bio_offset)
1700 {
1701 struct btrfs_root *root = BTRFS_I(inode)->root;
1702 int ret = 0;
1703
1704 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1705 BUG_ON(ret); /* -ENOMEM */
1706 return 0;
1707 }
1708
1709 /*
1710 * in order to insert checksums into the metadata in large chunks,
1711 * we wait until bio submission time. All the pages in the bio are
1712 * checksummed and sums are attached onto the ordered extent record.
1713 *
1714 * At IO completion time the cums attached on the ordered extent record
1715 * are inserted into the btree
1716 */
1717 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1718 int mirror_num, unsigned long bio_flags,
1719 u64 bio_offset)
1720 {
1721 struct btrfs_root *root = BTRFS_I(inode)->root;
1722 int ret;
1723
1724 ret = btrfs_map_bio(root, rw, bio, mirror_num, 1);
1725 if (ret)
1726 bio_endio(bio, ret);
1727 return ret;
1728 }
1729
1730 /*
1731 * extent_io.c submission hook. This does the right thing for csum calculation
1732 * on write, or reading the csums from the tree before a read
1733 */
1734 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1735 int mirror_num, unsigned long bio_flags,
1736 u64 bio_offset)
1737 {
1738 struct btrfs_root *root = BTRFS_I(inode)->root;
1739 int ret = 0;
1740 int skip_sum;
1741 int metadata = 0;
1742 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1743
1744 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1745
1746 if (btrfs_is_free_space_inode(inode))
1747 metadata = 2;
1748
1749 if (!(rw & REQ_WRITE)) {
1750 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
1751 if (ret)
1752 goto out;
1753
1754 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1755 ret = btrfs_submit_compressed_read(inode, bio,
1756 mirror_num,
1757 bio_flags);
1758 goto out;
1759 } else if (!skip_sum) {
1760 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1761 if (ret)
1762 goto out;
1763 }
1764 goto mapit;
1765 } else if (async && !skip_sum) {
1766 /* csum items have already been cloned */
1767 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1768 goto mapit;
1769 /* we're doing a write, do the async checksumming */
1770 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1771 inode, rw, bio, mirror_num,
1772 bio_flags, bio_offset,
1773 __btrfs_submit_bio_start,
1774 __btrfs_submit_bio_done);
1775 goto out;
1776 } else if (!skip_sum) {
1777 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1778 if (ret)
1779 goto out;
1780 }
1781
1782 mapit:
1783 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
1784
1785 out:
1786 if (ret < 0)
1787 bio_endio(bio, ret);
1788 return ret;
1789 }
1790
1791 /*
1792 * given a list of ordered sums record them in the inode. This happens
1793 * at IO completion time based on sums calculated at bio submission time.
1794 */
1795 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1796 struct inode *inode, u64 file_offset,
1797 struct list_head *list)
1798 {
1799 struct btrfs_ordered_sum *sum;
1800
1801 list_for_each_entry(sum, list, list) {
1802 trans->adding_csums = 1;
1803 btrfs_csum_file_blocks(trans,
1804 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1805 trans->adding_csums = 0;
1806 }
1807 return 0;
1808 }
1809
1810 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1811 struct extent_state **cached_state)
1812 {
1813 WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0);
1814 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1815 cached_state, GFP_NOFS);
1816 }
1817
1818 /* see btrfs_writepage_start_hook for details on why this is required */
1819 struct btrfs_writepage_fixup {
1820 struct page *page;
1821 struct btrfs_work work;
1822 };
1823
1824 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1825 {
1826 struct btrfs_writepage_fixup *fixup;
1827 struct btrfs_ordered_extent *ordered;
1828 struct extent_state *cached_state = NULL;
1829 struct page *page;
1830 struct inode *inode;
1831 u64 page_start;
1832 u64 page_end;
1833 int ret;
1834
1835 fixup = container_of(work, struct btrfs_writepage_fixup, work);
1836 page = fixup->page;
1837 again:
1838 lock_page(page);
1839 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
1840 ClearPageChecked(page);
1841 goto out_page;
1842 }
1843
1844 inode = page->mapping->host;
1845 page_start = page_offset(page);
1846 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
1847
1848 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0,
1849 &cached_state);
1850
1851 /* already ordered? We're done */
1852 if (PagePrivate2(page))
1853 goto out;
1854
1855 ordered = btrfs_lookup_ordered_extent(inode, page_start);
1856 if (ordered) {
1857 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
1858 page_end, &cached_state, GFP_NOFS);
1859 unlock_page(page);
1860 btrfs_start_ordered_extent(inode, ordered, 1);
1861 btrfs_put_ordered_extent(ordered);
1862 goto again;
1863 }
1864
1865 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
1866 if (ret) {
1867 mapping_set_error(page->mapping, ret);
1868 end_extent_writepage(page, ret, page_start, page_end);
1869 ClearPageChecked(page);
1870 goto out;
1871 }
1872
1873 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
1874 ClearPageChecked(page);
1875 set_page_dirty(page);
1876 out:
1877 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
1878 &cached_state, GFP_NOFS);
1879 out_page:
1880 unlock_page(page);
1881 page_cache_release(page);
1882 kfree(fixup);
1883 }
1884
1885 /*
1886 * There are a few paths in the higher layers of the kernel that directly
1887 * set the page dirty bit without asking the filesystem if it is a
1888 * good idea. This causes problems because we want to make sure COW
1889 * properly happens and the data=ordered rules are followed.
1890 *
1891 * In our case any range that doesn't have the ORDERED bit set
1892 * hasn't been properly setup for IO. We kick off an async process
1893 * to fix it up. The async helper will wait for ordered extents, set
1894 * the delalloc bit and make it safe to write the page.
1895 */
1896 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
1897 {
1898 struct inode *inode = page->mapping->host;
1899 struct btrfs_writepage_fixup *fixup;
1900 struct btrfs_root *root = BTRFS_I(inode)->root;
1901
1902 /* this page is properly in the ordered list */
1903 if (TestClearPagePrivate2(page))
1904 return 0;
1905
1906 if (PageChecked(page))
1907 return -EAGAIN;
1908
1909 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
1910 if (!fixup)
1911 return -EAGAIN;
1912
1913 SetPageChecked(page);
1914 page_cache_get(page);
1915 fixup->work.func = btrfs_writepage_fixup_worker;
1916 fixup->page = page;
1917 btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work);
1918 return -EBUSY;
1919 }
1920
1921 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
1922 struct inode *inode, u64 file_pos,
1923 u64 disk_bytenr, u64 disk_num_bytes,
1924 u64 num_bytes, u64 ram_bytes,
1925 u8 compression, u8 encryption,
1926 u16 other_encoding, int extent_type)
1927 {
1928 struct btrfs_root *root = BTRFS_I(inode)->root;
1929 struct btrfs_file_extent_item *fi;
1930 struct btrfs_path *path;
1931 struct extent_buffer *leaf;
1932 struct btrfs_key ins;
1933 int ret;
1934
1935 path = btrfs_alloc_path();
1936 if (!path)
1937 return -ENOMEM;
1938
1939 path->leave_spinning = 1;
1940
1941 /*
1942 * we may be replacing one extent in the tree with another.
1943 * The new extent is pinned in the extent map, and we don't want
1944 * to drop it from the cache until it is completely in the btree.
1945 *
1946 * So, tell btrfs_drop_extents to leave this extent in the cache.
1947 * the caller is expected to unpin it and allow it to be merged
1948 * with the others.
1949 */
1950 ret = btrfs_drop_extents(trans, root, inode, file_pos,
1951 file_pos + num_bytes, 0);
1952 if (ret)
1953 goto out;
1954
1955 ins.objectid = btrfs_ino(inode);
1956 ins.offset = file_pos;
1957 ins.type = BTRFS_EXTENT_DATA_KEY;
1958 ret = btrfs_insert_empty_item(trans, root, path, &ins, sizeof(*fi));
1959 if (ret)
1960 goto out;
1961 leaf = path->nodes[0];
1962 fi = btrfs_item_ptr(leaf, path->slots[0],
1963 struct btrfs_file_extent_item);
1964 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1965 btrfs_set_file_extent_type(leaf, fi, extent_type);
1966 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
1967 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
1968 btrfs_set_file_extent_offset(leaf, fi, 0);
1969 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
1970 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
1971 btrfs_set_file_extent_compression(leaf, fi, compression);
1972 btrfs_set_file_extent_encryption(leaf, fi, encryption);
1973 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
1974
1975 btrfs_mark_buffer_dirty(leaf);
1976 btrfs_release_path(path);
1977
1978 inode_add_bytes(inode, num_bytes);
1979
1980 ins.objectid = disk_bytenr;
1981 ins.offset = disk_num_bytes;
1982 ins.type = BTRFS_EXTENT_ITEM_KEY;
1983 ret = btrfs_alloc_reserved_file_extent(trans, root,
1984 root->root_key.objectid,
1985 btrfs_ino(inode), file_pos, &ins);
1986 out:
1987 btrfs_free_path(path);
1988
1989 return ret;
1990 }
1991
1992 /* snapshot-aware defrag */
1993 struct sa_defrag_extent_backref {
1994 struct rb_node node;
1995 struct old_sa_defrag_extent *old;
1996 u64 root_id;
1997 u64 inum;
1998 u64 file_pos;
1999 u64 extent_offset;
2000 u64 num_bytes;
2001 u64 generation;
2002 };
2003
2004 struct old_sa_defrag_extent {
2005 struct list_head list;
2006 struct new_sa_defrag_extent *new;
2007
2008 u64 extent_offset;
2009 u64 bytenr;
2010 u64 offset;
2011 u64 len;
2012 int count;
2013 };
2014
2015 struct new_sa_defrag_extent {
2016 struct rb_root root;
2017 struct list_head head;
2018 struct btrfs_path *path;
2019 struct inode *inode;
2020 u64 file_pos;
2021 u64 len;
2022 u64 bytenr;
2023 u64 disk_len;
2024 u8 compress_type;
2025 };
2026
2027 static int backref_comp(struct sa_defrag_extent_backref *b1,
2028 struct sa_defrag_extent_backref *b2)
2029 {
2030 if (b1->root_id < b2->root_id)
2031 return -1;
2032 else if (b1->root_id > b2->root_id)
2033 return 1;
2034
2035 if (b1->inum < b2->inum)
2036 return -1;
2037 else if (b1->inum > b2->inum)
2038 return 1;
2039
2040 if (b1->file_pos < b2->file_pos)
2041 return -1;
2042 else if (b1->file_pos > b2->file_pos)
2043 return 1;
2044
2045 /*
2046 * [------------------------------] ===> (a range of space)
2047 * |<--->| |<---->| =============> (fs/file tree A)
2048 * |<---------------------------->| ===> (fs/file tree B)
2049 *
2050 * A range of space can refer to two file extents in one tree while
2051 * refer to only one file extent in another tree.
2052 *
2053 * So we may process a disk offset more than one time(two extents in A)
2054 * and locate at the same extent(one extent in B), then insert two same
2055 * backrefs(both refer to the extent in B).
2056 */
2057 return 0;
2058 }
2059
2060 static void backref_insert(struct rb_root *root,
2061 struct sa_defrag_extent_backref *backref)
2062 {
2063 struct rb_node **p = &root->rb_node;
2064 struct rb_node *parent = NULL;
2065 struct sa_defrag_extent_backref *entry;
2066 int ret;
2067
2068 while (*p) {
2069 parent = *p;
2070 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2071
2072 ret = backref_comp(backref, entry);
2073 if (ret < 0)
2074 p = &(*p)->rb_left;
2075 else
2076 p = &(*p)->rb_right;
2077 }
2078
2079 rb_link_node(&backref->node, parent, p);
2080 rb_insert_color(&backref->node, root);
2081 }
2082
2083 /*
2084 * Note the backref might has changed, and in this case we just return 0.
2085 */
2086 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2087 void *ctx)
2088 {
2089 struct btrfs_file_extent_item *extent;
2090 struct btrfs_fs_info *fs_info;
2091 struct old_sa_defrag_extent *old = ctx;
2092 struct new_sa_defrag_extent *new = old->new;
2093 struct btrfs_path *path = new->path;
2094 struct btrfs_key key;
2095 struct btrfs_root *root;
2096 struct sa_defrag_extent_backref *backref;
2097 struct extent_buffer *leaf;
2098 struct inode *inode = new->inode;
2099 int slot;
2100 int ret;
2101 u64 extent_offset;
2102 u64 num_bytes;
2103
2104 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2105 inum == btrfs_ino(inode))
2106 return 0;
2107
2108 key.objectid = root_id;
2109 key.type = BTRFS_ROOT_ITEM_KEY;
2110 key.offset = (u64)-1;
2111
2112 fs_info = BTRFS_I(inode)->root->fs_info;
2113 root = btrfs_read_fs_root_no_name(fs_info, &key);
2114 if (IS_ERR(root)) {
2115 if (PTR_ERR(root) == -ENOENT)
2116 return 0;
2117 WARN_ON(1);
2118 pr_debug("inum=%llu, offset=%llu, root_id=%llu\n",
2119 inum, offset, root_id);
2120 return PTR_ERR(root);
2121 }
2122
2123 key.objectid = inum;
2124 key.type = BTRFS_EXTENT_DATA_KEY;
2125 if (offset > (u64)-1 << 32)
2126 key.offset = 0;
2127 else
2128 key.offset = offset;
2129
2130 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2131 if (ret < 0) {
2132 WARN_ON(1);
2133 return ret;
2134 }
2135
2136 while (1) {
2137 cond_resched();
2138
2139 leaf = path->nodes[0];
2140 slot = path->slots[0];
2141
2142 if (slot >= btrfs_header_nritems(leaf)) {
2143 ret = btrfs_next_leaf(root, path);
2144 if (ret < 0) {
2145 goto out;
2146 } else if (ret > 0) {
2147 ret = 0;
2148 goto out;
2149 }
2150 continue;
2151 }
2152
2153 path->slots[0]++;
2154
2155 btrfs_item_key_to_cpu(leaf, &key, slot);
2156
2157 if (key.objectid > inum)
2158 goto out;
2159
2160 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2161 continue;
2162
2163 extent = btrfs_item_ptr(leaf, slot,
2164 struct btrfs_file_extent_item);
2165
2166 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2167 continue;
2168
2169 /*
2170 * 'offset' refers to the exact key.offset,
2171 * NOT the 'offset' field in btrfs_extent_data_ref, ie.
2172 * (key.offset - extent_offset).
2173 */
2174 if (key.offset != offset)
2175 continue;
2176
2177 extent_offset = btrfs_file_extent_offset(leaf, extent);
2178 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2179
2180 if (extent_offset >= old->extent_offset + old->offset +
2181 old->len || extent_offset + num_bytes <=
2182 old->extent_offset + old->offset)
2183 continue;
2184
2185 ret = 0;
2186 break;
2187 }
2188
2189 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2190 if (!backref) {
2191 ret = -ENOENT;
2192 goto out;
2193 }
2194
2195 backref->root_id = root_id;
2196 backref->inum = inum;
2197 backref->file_pos = offset;
2198 backref->num_bytes = num_bytes;
2199 backref->extent_offset = extent_offset;
2200 backref->generation = btrfs_file_extent_generation(leaf, extent);
2201 backref->old = old;
2202 backref_insert(&new->root, backref);
2203 old->count++;
2204 out:
2205 btrfs_release_path(path);
2206 WARN_ON(ret);
2207 return ret;
2208 }
2209
2210 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2211 struct new_sa_defrag_extent *new)
2212 {
2213 struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info;
2214 struct old_sa_defrag_extent *old, *tmp;
2215 int ret;
2216
2217 new->path = path;
2218
2219 list_for_each_entry_safe(old, tmp, &new->head, list) {
2220 ret = iterate_inodes_from_logical(old->bytenr +
2221 old->extent_offset, fs_info,
2222 path, record_one_backref,
2223 old);
2224 BUG_ON(ret < 0 && ret != -ENOENT);
2225
2226 /* no backref to be processed for this extent */
2227 if (!old->count) {
2228 list_del(&old->list);
2229 kfree(old);
2230 }
2231 }
2232
2233 if (list_empty(&new->head))
2234 return false;
2235
2236 return true;
2237 }
2238
2239 static int relink_is_mergable(struct extent_buffer *leaf,
2240 struct btrfs_file_extent_item *fi,
2241 u64 disk_bytenr)
2242 {
2243 if (btrfs_file_extent_disk_bytenr(leaf, fi) != disk_bytenr)
2244 return 0;
2245
2246 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2247 return 0;
2248
2249 if (btrfs_file_extent_compression(leaf, fi) ||
2250 btrfs_file_extent_encryption(leaf, fi) ||
2251 btrfs_file_extent_other_encoding(leaf, fi))
2252 return 0;
2253
2254 return 1;
2255 }
2256
2257 /*
2258 * Note the backref might has changed, and in this case we just return 0.
2259 */
2260 static noinline int relink_extent_backref(struct btrfs_path *path,
2261 struct sa_defrag_extent_backref *prev,
2262 struct sa_defrag_extent_backref *backref)
2263 {
2264 struct btrfs_file_extent_item *extent;
2265 struct btrfs_file_extent_item *item;
2266 struct btrfs_ordered_extent *ordered;
2267 struct btrfs_trans_handle *trans;
2268 struct btrfs_fs_info *fs_info;
2269 struct btrfs_root *root;
2270 struct btrfs_key key;
2271 struct extent_buffer *leaf;
2272 struct old_sa_defrag_extent *old = backref->old;
2273 struct new_sa_defrag_extent *new = old->new;
2274 struct inode *src_inode = new->inode;
2275 struct inode *inode;
2276 struct extent_state *cached = NULL;
2277 int ret = 0;
2278 u64 start;
2279 u64 len;
2280 u64 lock_start;
2281 u64 lock_end;
2282 bool merge = false;
2283 int index;
2284
2285 if (prev && prev->root_id == backref->root_id &&
2286 prev->inum == backref->inum &&
2287 prev->file_pos + prev->num_bytes == backref->file_pos)
2288 merge = true;
2289
2290 /* step 1: get root */
2291 key.objectid = backref->root_id;
2292 key.type = BTRFS_ROOT_ITEM_KEY;
2293 key.offset = (u64)-1;
2294
2295 fs_info = BTRFS_I(src_inode)->root->fs_info;
2296 index = srcu_read_lock(&fs_info->subvol_srcu);
2297
2298 root = btrfs_read_fs_root_no_name(fs_info, &key);
2299 if (IS_ERR(root)) {
2300 srcu_read_unlock(&fs_info->subvol_srcu, index);
2301 if (PTR_ERR(root) == -ENOENT)
2302 return 0;
2303 return PTR_ERR(root);
2304 }
2305
2306 /* step 2: get inode */
2307 key.objectid = backref->inum;
2308 key.type = BTRFS_INODE_ITEM_KEY;
2309 key.offset = 0;
2310
2311 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2312 if (IS_ERR(inode)) {
2313 srcu_read_unlock(&fs_info->subvol_srcu, index);
2314 return 0;
2315 }
2316
2317 srcu_read_unlock(&fs_info->subvol_srcu, index);
2318
2319 /* step 3: relink backref */
2320 lock_start = backref->file_pos;
2321 lock_end = backref->file_pos + backref->num_bytes - 1;
2322 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2323 0, &cached);
2324
2325 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2326 if (ordered) {
2327 btrfs_put_ordered_extent(ordered);
2328 goto out_unlock;
2329 }
2330
2331 trans = btrfs_join_transaction(root);
2332 if (IS_ERR(trans)) {
2333 ret = PTR_ERR(trans);
2334 goto out_unlock;
2335 }
2336
2337 key.objectid = backref->inum;
2338 key.type = BTRFS_EXTENT_DATA_KEY;
2339 key.offset = backref->file_pos;
2340
2341 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2342 if (ret < 0) {
2343 goto out_free_path;
2344 } else if (ret > 0) {
2345 ret = 0;
2346 goto out_free_path;
2347 }
2348
2349 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2350 struct btrfs_file_extent_item);
2351
2352 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2353 backref->generation)
2354 goto out_free_path;
2355
2356 btrfs_release_path(path);
2357
2358 start = backref->file_pos;
2359 if (backref->extent_offset < old->extent_offset + old->offset)
2360 start += old->extent_offset + old->offset -
2361 backref->extent_offset;
2362
2363 len = min(backref->extent_offset + backref->num_bytes,
2364 old->extent_offset + old->offset + old->len);
2365 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2366
2367 ret = btrfs_drop_extents(trans, root, inode, start,
2368 start + len, 1);
2369 if (ret)
2370 goto out_free_path;
2371 again:
2372 key.objectid = btrfs_ino(inode);
2373 key.type = BTRFS_EXTENT_DATA_KEY;
2374 key.offset = start;
2375
2376 path->leave_spinning = 1;
2377 if (merge) {
2378 struct btrfs_file_extent_item *fi;
2379 u64 extent_len;
2380 struct btrfs_key found_key;
2381
2382 ret = btrfs_search_slot(trans, root, &key, path, 1, 1);
2383 if (ret < 0)
2384 goto out_free_path;
2385
2386 path->slots[0]--;
2387 leaf = path->nodes[0];
2388 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2389
2390 fi = btrfs_item_ptr(leaf, path->slots[0],
2391 struct btrfs_file_extent_item);
2392 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2393
2394 if (relink_is_mergable(leaf, fi, new->bytenr) &&
2395 extent_len + found_key.offset == start) {
2396 btrfs_set_file_extent_num_bytes(leaf, fi,
2397 extent_len + len);
2398 btrfs_mark_buffer_dirty(leaf);
2399 inode_add_bytes(inode, len);
2400
2401 ret = 1;
2402 goto out_free_path;
2403 } else {
2404 merge = false;
2405 btrfs_release_path(path);
2406 goto again;
2407 }
2408 }
2409
2410 ret = btrfs_insert_empty_item(trans, root, path, &key,
2411 sizeof(*extent));
2412 if (ret) {
2413 btrfs_abort_transaction(trans, root, ret);
2414 goto out_free_path;
2415 }
2416
2417 leaf = path->nodes[0];
2418 item = btrfs_item_ptr(leaf, path->slots[0],
2419 struct btrfs_file_extent_item);
2420 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2421 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2422 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2423 btrfs_set_file_extent_num_bytes(leaf, item, len);
2424 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2425 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2426 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2427 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2428 btrfs_set_file_extent_encryption(leaf, item, 0);
2429 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2430
2431 btrfs_mark_buffer_dirty(leaf);
2432 inode_add_bytes(inode, len);
2433 btrfs_release_path(path);
2434
2435 ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
2436 new->disk_len, 0,
2437 backref->root_id, backref->inum,
2438 new->file_pos, 0); /* start - extent_offset */
2439 if (ret) {
2440 btrfs_abort_transaction(trans, root, ret);
2441 goto out_free_path;
2442 }
2443
2444 ret = 1;
2445 out_free_path:
2446 btrfs_release_path(path);
2447 path->leave_spinning = 0;
2448 btrfs_end_transaction(trans, root);
2449 out_unlock:
2450 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2451 &cached, GFP_NOFS);
2452 iput(inode);
2453 return ret;
2454 }
2455
2456 static void relink_file_extents(struct new_sa_defrag_extent *new)
2457 {
2458 struct btrfs_path *path;
2459 struct old_sa_defrag_extent *old, *tmp;
2460 struct sa_defrag_extent_backref *backref;
2461 struct sa_defrag_extent_backref *prev = NULL;
2462 struct inode *inode;
2463 struct btrfs_root *root;
2464 struct rb_node *node;
2465 int ret;
2466
2467 inode = new->inode;
2468 root = BTRFS_I(inode)->root;
2469
2470 path = btrfs_alloc_path();
2471 if (!path)
2472 return;
2473
2474 if (!record_extent_backrefs(path, new)) {
2475 btrfs_free_path(path);
2476 goto out;
2477 }
2478 btrfs_release_path(path);
2479
2480 while (1) {
2481 node = rb_first(&new->root);
2482 if (!node)
2483 break;
2484 rb_erase(node, &new->root);
2485
2486 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2487
2488 ret = relink_extent_backref(path, prev, backref);
2489 WARN_ON(ret < 0);
2490
2491 kfree(prev);
2492
2493 if (ret == 1)
2494 prev = backref;
2495 else
2496 prev = NULL;
2497 cond_resched();
2498 }
2499 kfree(prev);
2500
2501 btrfs_free_path(path);
2502
2503 list_for_each_entry_safe(old, tmp, &new->head, list) {
2504 list_del(&old->list);
2505 kfree(old);
2506 }
2507 out:
2508 atomic_dec(&root->fs_info->defrag_running);
2509 wake_up(&root->fs_info->transaction_wait);
2510
2511 kfree(new);
2512 }
2513
2514 static struct new_sa_defrag_extent *
2515 record_old_file_extents(struct inode *inode,
2516 struct btrfs_ordered_extent *ordered)
2517 {
2518 struct btrfs_root *root = BTRFS_I(inode)->root;
2519 struct btrfs_path *path;
2520 struct btrfs_key key;
2521 struct old_sa_defrag_extent *old, *tmp;
2522 struct new_sa_defrag_extent *new;
2523 int ret;
2524
2525 new = kmalloc(sizeof(*new), GFP_NOFS);
2526 if (!new)
2527 return NULL;
2528
2529 new->inode = inode;
2530 new->file_pos = ordered->file_offset;
2531 new->len = ordered->len;
2532 new->bytenr = ordered->start;
2533 new->disk_len = ordered->disk_len;
2534 new->compress_type = ordered->compress_type;
2535 new->root = RB_ROOT;
2536 INIT_LIST_HEAD(&new->head);
2537
2538 path = btrfs_alloc_path();
2539 if (!path)
2540 goto out_kfree;
2541
2542 key.objectid = btrfs_ino(inode);
2543 key.type = BTRFS_EXTENT_DATA_KEY;
2544 key.offset = new->file_pos;
2545
2546 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2547 if (ret < 0)
2548 goto out_free_path;
2549 if (ret > 0 && path->slots[0] > 0)
2550 path->slots[0]--;
2551
2552 /* find out all the old extents for the file range */
2553 while (1) {
2554 struct btrfs_file_extent_item *extent;
2555 struct extent_buffer *l;
2556 int slot;
2557 u64 num_bytes;
2558 u64 offset;
2559 u64 end;
2560 u64 disk_bytenr;
2561 u64 extent_offset;
2562
2563 l = path->nodes[0];
2564 slot = path->slots[0];
2565
2566 if (slot >= btrfs_header_nritems(l)) {
2567 ret = btrfs_next_leaf(root, path);
2568 if (ret < 0)
2569 goto out_free_list;
2570 else if (ret > 0)
2571 break;
2572 continue;
2573 }
2574
2575 btrfs_item_key_to_cpu(l, &key, slot);
2576
2577 if (key.objectid != btrfs_ino(inode))
2578 break;
2579 if (key.type != BTRFS_EXTENT_DATA_KEY)
2580 break;
2581 if (key.offset >= new->file_pos + new->len)
2582 break;
2583
2584 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2585
2586 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2587 if (key.offset + num_bytes < new->file_pos)
2588 goto next;
2589
2590 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2591 if (!disk_bytenr)
2592 goto next;
2593
2594 extent_offset = btrfs_file_extent_offset(l, extent);
2595
2596 old = kmalloc(sizeof(*old), GFP_NOFS);
2597 if (!old)
2598 goto out_free_list;
2599
2600 offset = max(new->file_pos, key.offset);
2601 end = min(new->file_pos + new->len, key.offset + num_bytes);
2602
2603 old->bytenr = disk_bytenr;
2604 old->extent_offset = extent_offset;
2605 old->offset = offset - key.offset;
2606 old->len = end - offset;
2607 old->new = new;
2608 old->count = 0;
2609 list_add_tail(&old->list, &new->head);
2610 next:
2611 path->slots[0]++;
2612 cond_resched();
2613 }
2614
2615 btrfs_free_path(path);
2616 atomic_inc(&root->fs_info->defrag_running);
2617
2618 return new;
2619
2620 out_free_list:
2621 list_for_each_entry_safe(old, tmp, &new->head, list) {
2622 list_del(&old->list);
2623 kfree(old);
2624 }
2625 out_free_path:
2626 btrfs_free_path(path);
2627 out_kfree:
2628 kfree(new);
2629 return NULL;
2630 }
2631
2632 /*
2633 * helper function for btrfs_finish_ordered_io, this
2634 * just reads in some of the csum leaves to prime them into ram
2635 * before we start the transaction. It limits the amount of btree
2636 * reads required while inside the transaction.
2637 */
2638 /* as ordered data IO finishes, this gets called so we can finish
2639 * an ordered extent if the range of bytes in the file it covers are
2640 * fully written.
2641 */
2642 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2643 {
2644 struct inode *inode = ordered_extent->inode;
2645 struct btrfs_root *root = BTRFS_I(inode)->root;
2646 struct btrfs_trans_handle *trans = NULL;
2647 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2648 struct extent_state *cached_state = NULL;
2649 struct new_sa_defrag_extent *new = NULL;
2650 int compress_type = 0;
2651 int ret;
2652 bool nolock;
2653
2654 nolock = btrfs_is_free_space_inode(inode);
2655
2656 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2657 ret = -EIO;
2658 goto out;
2659 }
2660
2661 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2662 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2663 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2664 if (nolock)
2665 trans = btrfs_join_transaction_nolock(root);
2666 else
2667 trans = btrfs_join_transaction(root);
2668 if (IS_ERR(trans)) {
2669 ret = PTR_ERR(trans);
2670 trans = NULL;
2671 goto out;
2672 }
2673 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2674 ret = btrfs_update_inode_fallback(trans, root, inode);
2675 if (ret) /* -ENOMEM or corruption */
2676 btrfs_abort_transaction(trans, root, ret);
2677 goto out;
2678 }
2679
2680 lock_extent_bits(io_tree, ordered_extent->file_offset,
2681 ordered_extent->file_offset + ordered_extent->len - 1,
2682 0, &cached_state);
2683
2684 ret = test_range_bit(io_tree, ordered_extent->file_offset,
2685 ordered_extent->file_offset + ordered_extent->len - 1,
2686 EXTENT_DEFRAG, 1, cached_state);
2687 if (ret) {
2688 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2689 if (last_snapshot >= BTRFS_I(inode)->generation)
2690 /* the inode is shared */
2691 new = record_old_file_extents(inode, ordered_extent);
2692
2693 clear_extent_bit(io_tree, ordered_extent->file_offset,
2694 ordered_extent->file_offset + ordered_extent->len - 1,
2695 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
2696 }
2697
2698 if (nolock)
2699 trans = btrfs_join_transaction_nolock(root);
2700 else
2701 trans = btrfs_join_transaction(root);
2702 if (IS_ERR(trans)) {
2703 ret = PTR_ERR(trans);
2704 trans = NULL;
2705 goto out_unlock;
2706 }
2707 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2708
2709 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
2710 compress_type = ordered_extent->compress_type;
2711 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
2712 BUG_ON(compress_type);
2713 ret = btrfs_mark_extent_written(trans, inode,
2714 ordered_extent->file_offset,
2715 ordered_extent->file_offset +
2716 ordered_extent->len);
2717 } else {
2718 BUG_ON(root == root->fs_info->tree_root);
2719 ret = insert_reserved_file_extent(trans, inode,
2720 ordered_extent->file_offset,
2721 ordered_extent->start,
2722 ordered_extent->disk_len,
2723 ordered_extent->len,
2724 ordered_extent->len,
2725 compress_type, 0, 0,
2726 BTRFS_FILE_EXTENT_REG);
2727 }
2728 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
2729 ordered_extent->file_offset, ordered_extent->len,
2730 trans->transid);
2731 if (ret < 0) {
2732 btrfs_abort_transaction(trans, root, ret);
2733 goto out_unlock;
2734 }
2735
2736 add_pending_csums(trans, inode, ordered_extent->file_offset,
2737 &ordered_extent->list);
2738
2739 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2740 ret = btrfs_update_inode_fallback(trans, root, inode);
2741 if (ret) { /* -ENOMEM or corruption */
2742 btrfs_abort_transaction(trans, root, ret);
2743 goto out_unlock;
2744 }
2745 ret = 0;
2746 out_unlock:
2747 unlock_extent_cached(io_tree, ordered_extent->file_offset,
2748 ordered_extent->file_offset +
2749 ordered_extent->len - 1, &cached_state, GFP_NOFS);
2750 out:
2751 if (root != root->fs_info->tree_root)
2752 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
2753 if (trans)
2754 btrfs_end_transaction(trans, root);
2755
2756 if (ret) {
2757 clear_extent_uptodate(io_tree, ordered_extent->file_offset,
2758 ordered_extent->file_offset +
2759 ordered_extent->len - 1, NULL, GFP_NOFS);
2760
2761 /*
2762 * If the ordered extent had an IOERR or something else went
2763 * wrong we need to return the space for this ordered extent
2764 * back to the allocator.
2765 */
2766 if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
2767 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
2768 btrfs_free_reserved_extent(root, ordered_extent->start,
2769 ordered_extent->disk_len);
2770 }
2771
2772
2773 /*
2774 * This needs to be done to make sure anybody waiting knows we are done
2775 * updating everything for this ordered extent.
2776 */
2777 btrfs_remove_ordered_extent(inode, ordered_extent);
2778
2779 /* for snapshot-aware defrag */
2780 if (new)
2781 relink_file_extents(new);
2782
2783 /* once for us */
2784 btrfs_put_ordered_extent(ordered_extent);
2785 /* once for the tree */
2786 btrfs_put_ordered_extent(ordered_extent);
2787
2788 return ret;
2789 }
2790
2791 static void finish_ordered_fn(struct btrfs_work *work)
2792 {
2793 struct btrfs_ordered_extent *ordered_extent;
2794 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
2795 btrfs_finish_ordered_io(ordered_extent);
2796 }
2797
2798 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
2799 struct extent_state *state, int uptodate)
2800 {
2801 struct inode *inode = page->mapping->host;
2802 struct btrfs_root *root = BTRFS_I(inode)->root;
2803 struct btrfs_ordered_extent *ordered_extent = NULL;
2804 struct btrfs_workers *workers;
2805
2806 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
2807
2808 ClearPagePrivate2(page);
2809 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
2810 end - start + 1, uptodate))
2811 return 0;
2812
2813 ordered_extent->work.func = finish_ordered_fn;
2814 ordered_extent->work.flags = 0;
2815
2816 if (btrfs_is_free_space_inode(inode))
2817 workers = &root->fs_info->endio_freespace_worker;
2818 else
2819 workers = &root->fs_info->endio_write_workers;
2820 btrfs_queue_worker(workers, &ordered_extent->work);
2821
2822 return 0;
2823 }
2824
2825 /*
2826 * when reads are done, we need to check csums to verify the data is correct
2827 * if there's a match, we allow the bio to finish. If not, the code in
2828 * extent_io.c will try to find good copies for us.
2829 */
2830 static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
2831 struct extent_state *state, int mirror)
2832 {
2833 size_t offset = start - page_offset(page);
2834 struct inode *inode = page->mapping->host;
2835 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2836 char *kaddr;
2837 u64 private = ~(u32)0;
2838 int ret;
2839 struct btrfs_root *root = BTRFS_I(inode)->root;
2840 u32 csum = ~(u32)0;
2841 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
2842 DEFAULT_RATELIMIT_BURST);
2843
2844 if (PageChecked(page)) {
2845 ClearPageChecked(page);
2846 goto good;
2847 }
2848
2849 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
2850 goto good;
2851
2852 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
2853 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
2854 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
2855 GFP_NOFS);
2856 return 0;
2857 }
2858
2859 if (state && state->start == start) {
2860 private = state->private;
2861 ret = 0;
2862 } else {
2863 ret = get_state_private(io_tree, start, &private);
2864 }
2865 kaddr = kmap_atomic(page);
2866 if (ret)
2867 goto zeroit;
2868
2869 csum = btrfs_csum_data(kaddr + offset, csum, end - start + 1);
2870 btrfs_csum_final(csum, (char *)&csum);
2871 if (csum != private)
2872 goto zeroit;
2873
2874 kunmap_atomic(kaddr);
2875 good:
2876 return 0;
2877
2878 zeroit:
2879 if (__ratelimit(&_rs))
2880 btrfs_info(root->fs_info, "csum failed ino %llu off %llu csum %u private %llu",
2881 (unsigned long long)btrfs_ino(page->mapping->host),
2882 (unsigned long long)start, csum,
2883 (unsigned long long)private);
2884 memset(kaddr + offset, 1, end - start + 1);
2885 flush_dcache_page(page);
2886 kunmap_atomic(kaddr);
2887 if (private == 0)
2888 return 0;
2889 return -EIO;
2890 }
2891
2892 struct delayed_iput {
2893 struct list_head list;
2894 struct inode *inode;
2895 };
2896
2897 /* JDM: If this is fs-wide, why can't we add a pointer to
2898 * btrfs_inode instead and avoid the allocation? */
2899 void btrfs_add_delayed_iput(struct inode *inode)
2900 {
2901 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2902 struct delayed_iput *delayed;
2903
2904 if (atomic_add_unless(&inode->i_count, -1, 1))
2905 return;
2906
2907 delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL);
2908 delayed->inode = inode;
2909
2910 spin_lock(&fs_info->delayed_iput_lock);
2911 list_add_tail(&delayed->list, &fs_info->delayed_iputs);
2912 spin_unlock(&fs_info->delayed_iput_lock);
2913 }
2914
2915 void btrfs_run_delayed_iputs(struct btrfs_root *root)
2916 {
2917 LIST_HEAD(list);
2918 struct btrfs_fs_info *fs_info = root->fs_info;
2919 struct delayed_iput *delayed;
2920 int empty;
2921
2922 spin_lock(&fs_info->delayed_iput_lock);
2923 empty = list_empty(&fs_info->delayed_iputs);
2924 spin_unlock(&fs_info->delayed_iput_lock);
2925 if (empty)
2926 return;
2927
2928 spin_lock(&fs_info->delayed_iput_lock);
2929 list_splice_init(&fs_info->delayed_iputs, &list);
2930 spin_unlock(&fs_info->delayed_iput_lock);
2931
2932 while (!list_empty(&list)) {
2933 delayed = list_entry(list.next, struct delayed_iput, list);
2934 list_del(&delayed->list);
2935 iput(delayed->inode);
2936 kfree(delayed);
2937 }
2938 }
2939
2940 /*
2941 * This is called in transaction commit time. If there are no orphan
2942 * files in the subvolume, it removes orphan item and frees block_rsv
2943 * structure.
2944 */
2945 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
2946 struct btrfs_root *root)
2947 {
2948 struct btrfs_block_rsv *block_rsv;
2949 int ret;
2950
2951 if (atomic_read(&root->orphan_inodes) ||
2952 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
2953 return;
2954
2955 spin_lock(&root->orphan_lock);
2956 if (atomic_read(&root->orphan_inodes)) {
2957 spin_unlock(&root->orphan_lock);
2958 return;
2959 }
2960
2961 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
2962 spin_unlock(&root->orphan_lock);
2963 return;
2964 }
2965
2966 block_rsv = root->orphan_block_rsv;
2967 root->orphan_block_rsv = NULL;
2968 spin_unlock(&root->orphan_lock);
2969
2970 if (root->orphan_item_inserted &&
2971 btrfs_root_refs(&root->root_item) > 0) {
2972 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
2973 root->root_key.objectid);
2974 BUG_ON(ret);
2975 root->orphan_item_inserted = 0;
2976 }
2977
2978 if (block_rsv) {
2979 WARN_ON(block_rsv->size > 0);
2980 btrfs_free_block_rsv(root, block_rsv);
2981 }
2982 }
2983
2984 /*
2985 * This creates an orphan entry for the given inode in case something goes
2986 * wrong in the middle of an unlink/truncate.
2987 *
2988 * NOTE: caller of this function should reserve 5 units of metadata for
2989 * this function.
2990 */
2991 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
2992 {
2993 struct btrfs_root *root = BTRFS_I(inode)->root;
2994 struct btrfs_block_rsv *block_rsv = NULL;
2995 int reserve = 0;
2996 int insert = 0;
2997 int ret;
2998
2999 if (!root->orphan_block_rsv) {
3000 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
3001 if (!block_rsv)
3002 return -ENOMEM;
3003 }
3004
3005 spin_lock(&root->orphan_lock);
3006 if (!root->orphan_block_rsv) {
3007 root->orphan_block_rsv = block_rsv;
3008 } else if (block_rsv) {
3009 btrfs_free_block_rsv(root, block_rsv);
3010 block_rsv = NULL;
3011 }
3012
3013 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3014 &BTRFS_I(inode)->runtime_flags)) {
3015 #if 0
3016 /*
3017 * For proper ENOSPC handling, we should do orphan
3018 * cleanup when mounting. But this introduces backward
3019 * compatibility issue.
3020 */
3021 if (!xchg(&root->orphan_item_inserted, 1))
3022 insert = 2;
3023 else
3024 insert = 1;
3025 #endif
3026 insert = 1;
3027 atomic_inc(&root->orphan_inodes);
3028 }
3029
3030 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3031 &BTRFS_I(inode)->runtime_flags))
3032 reserve = 1;
3033 spin_unlock(&root->orphan_lock);
3034
3035 /* grab metadata reservation from transaction handle */
3036 if (reserve) {
3037 ret = btrfs_orphan_reserve_metadata(trans, inode);
3038 BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */
3039 }
3040
3041 /* insert an orphan item to track this unlinked/truncated file */
3042 if (insert >= 1) {
3043 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3044 if (ret && ret != -EEXIST) {
3045 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3046 &BTRFS_I(inode)->runtime_flags);
3047 btrfs_abort_transaction(trans, root, ret);
3048 return ret;
3049 }
3050 ret = 0;
3051 }
3052
3053 /* insert an orphan item to track subvolume contains orphan files */
3054 if (insert >= 2) {
3055 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
3056 root->root_key.objectid);
3057 if (ret && ret != -EEXIST) {
3058 btrfs_abort_transaction(trans, root, ret);
3059 return ret;
3060 }
3061 }
3062 return 0;
3063 }
3064
3065 /*
3066 * We have done the truncate/delete so we can go ahead and remove the orphan
3067 * item for this particular inode.
3068 */
3069 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3070 struct inode *inode)
3071 {
3072 struct btrfs_root *root = BTRFS_I(inode)->root;
3073 int delete_item = 0;
3074 int release_rsv = 0;
3075 int ret = 0;
3076
3077 spin_lock(&root->orphan_lock);
3078 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3079 &BTRFS_I(inode)->runtime_flags))
3080 delete_item = 1;
3081
3082 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3083 &BTRFS_I(inode)->runtime_flags))
3084 release_rsv = 1;
3085 spin_unlock(&root->orphan_lock);
3086
3087 if (trans && delete_item) {
3088 ret = btrfs_del_orphan_item(trans, root, btrfs_ino(inode));
3089 BUG_ON(ret); /* -ENOMEM or corruption (JDM: Recheck) */
3090 }
3091
3092 if (release_rsv) {
3093 btrfs_orphan_release_metadata(inode);
3094 atomic_dec(&root->orphan_inodes);
3095 }
3096
3097 return 0;
3098 }
3099
3100 /*
3101 * this cleans up any orphans that may be left on the list from the last use
3102 * of this root.
3103 */
3104 int btrfs_orphan_cleanup(struct btrfs_root *root)
3105 {
3106 struct btrfs_path *path;
3107 struct extent_buffer *leaf;
3108 struct btrfs_key key, found_key;
3109 struct btrfs_trans_handle *trans;
3110 struct inode *inode;
3111 u64 last_objectid = 0;
3112 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3113
3114 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3115 return 0;
3116
3117 path = btrfs_alloc_path();
3118 if (!path) {
3119 ret = -ENOMEM;
3120 goto out;
3121 }
3122 path->reada = -1;
3123
3124 key.objectid = BTRFS_ORPHAN_OBJECTID;
3125 btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
3126 key.offset = (u64)-1;
3127
3128 while (1) {
3129 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3130 if (ret < 0)
3131 goto out;
3132
3133 /*
3134 * if ret == 0 means we found what we were searching for, which
3135 * is weird, but possible, so only screw with path if we didn't
3136 * find the key and see if we have stuff that matches
3137 */
3138 if (ret > 0) {
3139 ret = 0;
3140 if (path->slots[0] == 0)
3141 break;
3142 path->slots[0]--;
3143 }
3144
3145 /* pull out the item */
3146 leaf = path->nodes[0];
3147 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3148
3149 /* make sure the item matches what we want */
3150 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3151 break;
3152 if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY)
3153 break;
3154
3155 /* release the path since we're done with it */
3156 btrfs_release_path(path);
3157
3158 /*
3159 * this is where we are basically btrfs_lookup, without the
3160 * crossing root thing. we store the inode number in the
3161 * offset of the orphan item.
3162 */
3163
3164 if (found_key.offset == last_objectid) {
3165 btrfs_err(root->fs_info,
3166 "Error removing orphan entry, stopping orphan cleanup");
3167 ret = -EINVAL;
3168 goto out;
3169 }
3170
3171 last_objectid = found_key.offset;
3172
3173 found_key.objectid = found_key.offset;
3174 found_key.type = BTRFS_INODE_ITEM_KEY;
3175 found_key.offset = 0;
3176 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
3177 ret = PTR_RET(inode);
3178 if (ret && ret != -ESTALE)
3179 goto out;
3180
3181 if (ret == -ESTALE && root == root->fs_info->tree_root) {
3182 struct btrfs_root *dead_root;
3183 struct btrfs_fs_info *fs_info = root->fs_info;
3184 int is_dead_root = 0;
3185
3186 /*
3187 * this is an orphan in the tree root. Currently these
3188 * could come from 2 sources:
3189 * a) a snapshot deletion in progress
3190 * b) a free space cache inode
3191 * We need to distinguish those two, as the snapshot
3192 * orphan must not get deleted.
3193 * find_dead_roots already ran before us, so if this
3194 * is a snapshot deletion, we should find the root
3195 * in the dead_roots list
3196 */
3197 spin_lock(&fs_info->trans_lock);
3198 list_for_each_entry(dead_root, &fs_info->dead_roots,
3199 root_list) {
3200 if (dead_root->root_key.objectid ==
3201 found_key.objectid) {
3202 is_dead_root = 1;
3203 break;
3204 }
3205 }
3206 spin_unlock(&fs_info->trans_lock);
3207 if (is_dead_root) {
3208 /* prevent this orphan from being found again */
3209 key.offset = found_key.objectid - 1;
3210 continue;
3211 }
3212 }
3213 /*
3214 * Inode is already gone but the orphan item is still there,
3215 * kill the orphan item.
3216 */
3217 if (ret == -ESTALE) {
3218 trans = btrfs_start_transaction(root, 1);
3219 if (IS_ERR(trans)) {
3220 ret = PTR_ERR(trans);
3221 goto out;
3222 }
3223 btrfs_debug(root->fs_info, "auto deleting %Lu",
3224 found_key.objectid);
3225 ret = btrfs_del_orphan_item(trans, root,
3226 found_key.objectid);
3227 BUG_ON(ret); /* -ENOMEM or corruption (JDM: Recheck) */
3228 btrfs_end_transaction(trans, root);
3229 continue;
3230 }
3231
3232 /*
3233 * add this inode to the orphan list so btrfs_orphan_del does
3234 * the proper thing when we hit it
3235 */
3236 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3237 &BTRFS_I(inode)->runtime_flags);
3238 atomic_inc(&root->orphan_inodes);
3239
3240 /* if we have links, this was a truncate, lets do that */
3241 if (inode->i_nlink) {
3242 if (!S_ISREG(inode->i_mode)) {
3243 WARN_ON(1);
3244 iput(inode);
3245 continue;
3246 }
3247 nr_truncate++;
3248
3249 /* 1 for the orphan item deletion. */
3250 trans = btrfs_start_transaction(root, 1);
3251 if (IS_ERR(trans)) {
3252 iput(inode);
3253 ret = PTR_ERR(trans);
3254 goto out;
3255 }
3256 ret = btrfs_orphan_add(trans, inode);
3257 btrfs_end_transaction(trans, root);
3258 if (ret) {
3259 iput(inode);
3260 goto out;
3261 }
3262
3263 ret = btrfs_truncate(inode);
3264 if (ret)
3265 btrfs_orphan_del(NULL, inode);
3266 } else {
3267 nr_unlink++;
3268 }
3269
3270 /* this will do delete_inode and everything for us */
3271 iput(inode);
3272 if (ret)
3273 goto out;
3274 }
3275 /* release the path since we're done with it */
3276 btrfs_release_path(path);
3277
3278 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3279
3280 if (root->orphan_block_rsv)
3281 btrfs_block_rsv_release(root, root->orphan_block_rsv,
3282 (u64)-1);
3283
3284 if (root->orphan_block_rsv || root->orphan_item_inserted) {
3285 trans = btrfs_join_transaction(root);
3286 if (!IS_ERR(trans))
3287 btrfs_end_transaction(trans, root);
3288 }
3289
3290 if (nr_unlink)
3291 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink);
3292 if (nr_truncate)
3293 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate);
3294
3295 out:
3296 if (ret)
3297 btrfs_crit(root->fs_info,
3298 "could not do orphan cleanup %d", ret);
3299 btrfs_free_path(path);
3300 return ret;
3301 }
3302
3303 /*
3304 * very simple check to peek ahead in the leaf looking for xattrs. If we
3305 * don't find any xattrs, we know there can't be any acls.
3306 *
3307 * slot is the slot the inode is in, objectid is the objectid of the inode
3308 */
3309 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3310 int slot, u64 objectid)
3311 {
3312 u32 nritems = btrfs_header_nritems(leaf);
3313 struct btrfs_key found_key;
3314 static u64 xattr_access = 0;
3315 static u64 xattr_default = 0;
3316 int scanned = 0;
3317
3318 if (!xattr_access) {
3319 xattr_access = btrfs_name_hash(POSIX_ACL_XATTR_ACCESS,
3320 strlen(POSIX_ACL_XATTR_ACCESS));
3321 xattr_default = btrfs_name_hash(POSIX_ACL_XATTR_DEFAULT,
3322 strlen(POSIX_ACL_XATTR_DEFAULT));
3323 }
3324
3325 slot++;
3326 while (slot < nritems) {
3327 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3328
3329 /* we found a different objectid, there must not be acls */
3330 if (found_key.objectid != objectid)
3331 return 0;
3332
3333 /* we found an xattr, assume we've got an acl */
3334 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3335 if (found_key.offset == xattr_access ||
3336 found_key.offset == xattr_default)
3337 return 1;
3338 }
3339
3340 /*
3341 * we found a key greater than an xattr key, there can't
3342 * be any acls later on
3343 */
3344 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3345 return 0;
3346
3347 slot++;
3348 scanned++;
3349
3350 /*
3351 * it goes inode, inode backrefs, xattrs, extents,
3352 * so if there are a ton of hard links to an inode there can
3353 * be a lot of backrefs. Don't waste time searching too hard,
3354 * this is just an optimization
3355 */
3356 if (scanned >= 8)
3357 break;
3358 }
3359 /* we hit the end of the leaf before we found an xattr or
3360 * something larger than an xattr. We have to assume the inode
3361 * has acls
3362 */
3363 return 1;
3364 }
3365
3366 /*
3367 * read an inode from the btree into the in-memory inode
3368 */
3369 static void btrfs_read_locked_inode(struct inode *inode)
3370 {
3371 struct btrfs_path *path;
3372 struct extent_buffer *leaf;
3373 struct btrfs_inode_item *inode_item;
3374 struct btrfs_timespec *tspec;
3375 struct btrfs_root *root = BTRFS_I(inode)->root;
3376 struct btrfs_key location;
3377 int maybe_acls;
3378 u32 rdev;
3379 int ret;
3380 bool filled = false;
3381
3382 ret = btrfs_fill_inode(inode, &rdev);
3383 if (!ret)
3384 filled = true;
3385
3386 path = btrfs_alloc_path();
3387 if (!path)
3388 goto make_bad;
3389
3390 path->leave_spinning = 1;
3391 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3392
3393 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3394 if (ret)
3395 goto make_bad;
3396
3397 leaf = path->nodes[0];
3398
3399 if (filled)
3400 goto cache_acl;
3401
3402 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3403 struct btrfs_inode_item);
3404 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3405 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3406 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3407 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3408 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
3409
3410 tspec = btrfs_inode_atime(inode_item);
3411 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3412 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3413
3414 tspec = btrfs_inode_mtime(inode_item);
3415 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3416 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3417
3418 tspec = btrfs_inode_ctime(inode_item);
3419 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3420 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3421
3422 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3423 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3424 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3425
3426 /*
3427 * If we were modified in the current generation and evicted from memory
3428 * and then re-read we need to do a full sync since we don't have any
3429 * idea about which extents were modified before we were evicted from
3430 * cache.
3431 */
3432 if (BTRFS_I(inode)->last_trans == root->fs_info->generation)
3433 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3434 &BTRFS_I(inode)->runtime_flags);
3435
3436 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
3437 inode->i_generation = BTRFS_I(inode)->generation;
3438 inode->i_rdev = 0;
3439 rdev = btrfs_inode_rdev(leaf, inode_item);
3440
3441 BTRFS_I(inode)->index_cnt = (u64)-1;
3442 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3443 cache_acl:
3444 /*
3445 * try to precache a NULL acl entry for files that don't have
3446 * any xattrs or acls
3447 */
3448 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3449 btrfs_ino(inode));
3450 if (!maybe_acls)
3451 cache_no_acl(inode);
3452
3453 btrfs_free_path(path);
3454
3455 switch (inode->i_mode & S_IFMT) {
3456 case S_IFREG:
3457 inode->i_mapping->a_ops = &btrfs_aops;
3458 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3459 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3460 inode->i_fop = &btrfs_file_operations;
3461 inode->i_op = &btrfs_file_inode_operations;
3462 break;
3463 case S_IFDIR:
3464 inode->i_fop = &btrfs_dir_file_operations;
3465 if (root == root->fs_info->tree_root)
3466 inode->i_op = &btrfs_dir_ro_inode_operations;
3467 else
3468 inode->i_op = &btrfs_dir_inode_operations;
3469 break;
3470 case S_IFLNK:
3471 inode->i_op = &btrfs_symlink_inode_operations;
3472 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3473 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3474 break;
3475 default:
3476 inode->i_op = &btrfs_special_inode_operations;
3477 init_special_inode(inode, inode->i_mode, rdev);
3478 break;
3479 }
3480
3481 btrfs_update_iflags(inode);
3482 return;
3483
3484 make_bad:
3485 btrfs_free_path(path);
3486 make_bad_inode(inode);
3487 }
3488
3489 /*
3490 * given a leaf and an inode, copy the inode fields into the leaf
3491 */
3492 static void fill_inode_item(struct btrfs_trans_handle *trans,
3493 struct extent_buffer *leaf,
3494 struct btrfs_inode_item *item,
3495 struct inode *inode)
3496 {
3497 struct btrfs_map_token token;
3498
3499 btrfs_init_map_token(&token);
3500
3501 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3502 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3503 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3504 &token);
3505 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3506 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3507
3508 btrfs_set_token_timespec_sec(leaf, btrfs_inode_atime(item),
3509 inode->i_atime.tv_sec, &token);
3510 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_atime(item),
3511 inode->i_atime.tv_nsec, &token);
3512
3513 btrfs_set_token_timespec_sec(leaf, btrfs_inode_mtime(item),
3514 inode->i_mtime.tv_sec, &token);
3515 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_mtime(item),
3516 inode->i_mtime.tv_nsec, &token);
3517
3518 btrfs_set_token_timespec_sec(leaf, btrfs_inode_ctime(item),
3519 inode->i_ctime.tv_sec, &token);
3520 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_ctime(item),
3521 inode->i_ctime.tv_nsec, &token);
3522
3523 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3524 &token);
3525 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3526 &token);
3527 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3528 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3529 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3530 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3531 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3532 }
3533
3534 /*
3535 * copy everything in the in-memory inode into the btree.
3536 */
3537 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3538 struct btrfs_root *root, struct inode *inode)
3539 {
3540 struct btrfs_inode_item *inode_item;
3541 struct btrfs_path *path;
3542 struct extent_buffer *leaf;
3543 int ret;
3544
3545 path = btrfs_alloc_path();
3546 if (!path)
3547 return -ENOMEM;
3548
3549 path->leave_spinning = 1;
3550 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3551 1);
3552 if (ret) {
3553 if (ret > 0)
3554 ret = -ENOENT;
3555 goto failed;
3556 }
3557
3558 btrfs_unlock_up_safe(path, 1);
3559 leaf = path->nodes[0];
3560 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3561 struct btrfs_inode_item);
3562
3563 fill_inode_item(trans, leaf, inode_item, inode);
3564 btrfs_mark_buffer_dirty(leaf);
3565 btrfs_set_inode_last_trans(trans, inode);
3566 ret = 0;
3567 failed:
3568 btrfs_free_path(path);
3569 return ret;
3570 }
3571
3572 /*
3573 * copy everything in the in-memory inode into the btree.
3574 */
3575 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3576 struct btrfs_root *root, struct inode *inode)
3577 {
3578 int ret;
3579
3580 /*
3581 * If the inode is a free space inode, we can deadlock during commit
3582 * if we put it into the delayed code.
3583 *
3584 * The data relocation inode should also be directly updated
3585 * without delay
3586 */
3587 if (!btrfs_is_free_space_inode(inode)
3588 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID) {
3589 btrfs_update_root_times(trans, root);
3590
3591 ret = btrfs_delayed_update_inode(trans, root, inode);
3592 if (!ret)
3593 btrfs_set_inode_last_trans(trans, inode);
3594 return ret;
3595 }
3596
3597 return btrfs_update_inode_item(trans, root, inode);
3598 }
3599
3600 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
3601 struct btrfs_root *root,
3602 struct inode *inode)
3603 {
3604 int ret;
3605
3606 ret = btrfs_update_inode(trans, root, inode);
3607 if (ret == -ENOSPC)
3608 return btrfs_update_inode_item(trans, root, inode);
3609 return ret;
3610 }
3611
3612 /*
3613 * unlink helper that gets used here in inode.c and in the tree logging
3614 * recovery code. It remove a link in a directory with a given name, and
3615 * also drops the back refs in the inode to the directory
3616 */
3617 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3618 struct btrfs_root *root,
3619 struct inode *dir, struct inode *inode,
3620 const char *name, int name_len)
3621 {
3622 struct btrfs_path *path;
3623 int ret = 0;
3624 struct extent_buffer *leaf;
3625 struct btrfs_dir_item *di;
3626 struct btrfs_key key;
3627 u64 index;
3628 u64 ino = btrfs_ino(inode);
3629 u64 dir_ino = btrfs_ino(dir);
3630
3631 path = btrfs_alloc_path();
3632 if (!path) {
3633 ret = -ENOMEM;
3634 goto out;
3635 }
3636
3637 path->leave_spinning = 1;
3638 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3639 name, name_len, -1);
3640 if (IS_ERR(di)) {
3641 ret = PTR_ERR(di);
3642 goto err;
3643 }
3644 if (!di) {
3645 ret = -ENOENT;
3646 goto err;
3647 }
3648 leaf = path->nodes[0];
3649 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3650 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3651 if (ret)
3652 goto err;
3653 btrfs_release_path(path);
3654
3655 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
3656 dir_ino, &index);
3657 if (ret) {
3658 btrfs_info(root->fs_info,
3659 "failed to delete reference to %.*s, inode %llu parent %llu",
3660 name_len, name,
3661 (unsigned long long)ino, (unsigned long long)dir_ino);
3662 btrfs_abort_transaction(trans, root, ret);
3663 goto err;
3664 }
3665
3666 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3667 if (ret) {
3668 btrfs_abort_transaction(trans, root, ret);
3669 goto err;
3670 }
3671
3672 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
3673 inode, dir_ino);
3674 if (ret != 0 && ret != -ENOENT) {
3675 btrfs_abort_transaction(trans, root, ret);
3676 goto err;
3677 }
3678
3679 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
3680 dir, index);
3681 if (ret == -ENOENT)
3682 ret = 0;
3683 else if (ret)
3684 btrfs_abort_transaction(trans, root, ret);
3685 err:
3686 btrfs_free_path(path);
3687 if (ret)
3688 goto out;
3689
3690 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3691 inode_inc_iversion(inode);
3692 inode_inc_iversion(dir);
3693 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3694 ret = btrfs_update_inode(trans, root, dir);
3695 out:
3696 return ret;
3697 }
3698
3699 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3700 struct btrfs_root *root,
3701 struct inode *dir, struct inode *inode,
3702 const char *name, int name_len)
3703 {
3704 int ret;
3705 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
3706 if (!ret) {
3707 btrfs_drop_nlink(inode);
3708 ret = btrfs_update_inode(trans, root, inode);
3709 }
3710 return ret;
3711 }
3712
3713 /*
3714 * helper to start transaction for unlink and rmdir.
3715 *
3716 * unlink and rmdir are special in btrfs, they do not always free space, so
3717 * if we cannot make our reservations the normal way try and see if there is
3718 * plenty of slack room in the global reserve to migrate, otherwise we cannot
3719 * allow the unlink to occur.
3720 */
3721 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
3722 {
3723 struct btrfs_trans_handle *trans;
3724 struct btrfs_root *root = BTRFS_I(dir)->root;
3725 int ret;
3726
3727 /*
3728 * 1 for the possible orphan item
3729 * 1 for the dir item
3730 * 1 for the dir index
3731 * 1 for the inode ref
3732 * 1 for the inode
3733 */
3734 trans = btrfs_start_transaction(root, 5);
3735 if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
3736 return trans;
3737
3738 if (PTR_ERR(trans) == -ENOSPC) {
3739 u64 num_bytes = btrfs_calc_trans_metadata_size(root, 5);
3740
3741 trans = btrfs_start_transaction(root, 0);
3742 if (IS_ERR(trans))
3743 return trans;
3744 ret = btrfs_cond_migrate_bytes(root->fs_info,
3745 &root->fs_info->trans_block_rsv,
3746 num_bytes, 5);
3747 if (ret) {
3748 btrfs_end_transaction(trans, root);
3749 return ERR_PTR(ret);
3750 }
3751 trans->block_rsv = &root->fs_info->trans_block_rsv;
3752 trans->bytes_reserved = num_bytes;
3753 }
3754 return trans;
3755 }
3756
3757 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
3758 {
3759 struct btrfs_root *root = BTRFS_I(dir)->root;
3760 struct btrfs_trans_handle *trans;
3761 struct inode *inode = dentry->d_inode;
3762 int ret;
3763
3764 trans = __unlink_start_trans(dir);
3765 if (IS_ERR(trans))
3766 return PTR_ERR(trans);
3767
3768 btrfs_record_unlink_dir(trans, dir, dentry->d_inode, 0);
3769
3770 ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
3771 dentry->d_name.name, dentry->d_name.len);
3772 if (ret)
3773 goto out;
3774
3775 if (inode->i_nlink == 0) {
3776 ret = btrfs_orphan_add(trans, inode);
3777 if (ret)
3778 goto out;
3779 }
3780
3781 out:
3782 btrfs_end_transaction(trans, root);
3783 btrfs_btree_balance_dirty(root);
3784 return ret;
3785 }
3786
3787 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
3788 struct btrfs_root *root,
3789 struct inode *dir, u64 objectid,
3790 const char *name, int name_len)
3791 {
3792 struct btrfs_path *path;
3793 struct extent_buffer *leaf;
3794 struct btrfs_dir_item *di;
3795 struct btrfs_key key;
3796 u64 index;
3797 int ret;
3798 u64 dir_ino = btrfs_ino(dir);
3799
3800 path = btrfs_alloc_path();
3801 if (!path)
3802 return -ENOMEM;
3803
3804 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3805 name, name_len, -1);
3806 if (IS_ERR_OR_NULL(di)) {
3807 if (!di)
3808 ret = -ENOENT;
3809 else
3810 ret = PTR_ERR(di);
3811 goto out;
3812 }
3813
3814 leaf = path->nodes[0];
3815 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3816 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
3817 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3818 if (ret) {
3819 btrfs_abort_transaction(trans, root, ret);
3820 goto out;
3821 }
3822 btrfs_release_path(path);
3823
3824 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
3825 objectid, root->root_key.objectid,
3826 dir_ino, &index, name, name_len);
3827 if (ret < 0) {
3828 if (ret != -ENOENT) {
3829 btrfs_abort_transaction(trans, root, ret);
3830 goto out;
3831 }
3832 di = btrfs_search_dir_index_item(root, path, dir_ino,
3833 name, name_len);
3834 if (IS_ERR_OR_NULL(di)) {
3835 if (!di)
3836 ret = -ENOENT;
3837 else
3838 ret = PTR_ERR(di);
3839 btrfs_abort_transaction(trans, root, ret);
3840 goto out;
3841 }
3842
3843 leaf = path->nodes[0];
3844 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3845 btrfs_release_path(path);
3846 index = key.offset;
3847 }
3848 btrfs_release_path(path);
3849
3850 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3851 if (ret) {
3852 btrfs_abort_transaction(trans, root, ret);
3853 goto out;
3854 }
3855
3856 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3857 inode_inc_iversion(dir);
3858 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3859 ret = btrfs_update_inode_fallback(trans, root, dir);
3860 if (ret)
3861 btrfs_abort_transaction(trans, root, ret);
3862 out:
3863 btrfs_free_path(path);
3864 return ret;
3865 }
3866
3867 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
3868 {
3869 struct inode *inode = dentry->d_inode;
3870 int err = 0;
3871 struct btrfs_root *root = BTRFS_I(dir)->root;
3872 struct btrfs_trans_handle *trans;
3873
3874 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
3875 return -ENOTEMPTY;
3876 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
3877 return -EPERM;
3878
3879 trans = __unlink_start_trans(dir);
3880 if (IS_ERR(trans))
3881 return PTR_ERR(trans);
3882
3883 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
3884 err = btrfs_unlink_subvol(trans, root, dir,
3885 BTRFS_I(inode)->location.objectid,
3886 dentry->d_name.name,
3887 dentry->d_name.len);
3888 goto out;
3889 }
3890
3891 err = btrfs_orphan_add(trans, inode);
3892 if (err)
3893 goto out;
3894
3895 /* now the directory is empty */
3896 err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
3897 dentry->d_name.name, dentry->d_name.len);
3898 if (!err)
3899 btrfs_i_size_write(inode, 0);
3900 out:
3901 btrfs_end_transaction(trans, root);
3902 btrfs_btree_balance_dirty(root);
3903
3904 return err;
3905 }
3906
3907 /*
3908 * this can truncate away extent items, csum items and directory items.
3909 * It starts at a high offset and removes keys until it can't find
3910 * any higher than new_size
3911 *
3912 * csum items that cross the new i_size are truncated to the new size
3913 * as well.
3914 *
3915 * min_type is the minimum key type to truncate down to. If set to 0, this
3916 * will kill all the items on this inode, including the INODE_ITEM_KEY.
3917 */
3918 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
3919 struct btrfs_root *root,
3920 struct inode *inode,
3921 u64 new_size, u32 min_type)
3922 {
3923 struct btrfs_path *path;
3924 struct extent_buffer *leaf;
3925 struct btrfs_file_extent_item *fi;
3926 struct btrfs_key key;
3927 struct btrfs_key found_key;
3928 u64 extent_start = 0;
3929 u64 extent_num_bytes = 0;
3930 u64 extent_offset = 0;
3931 u64 item_end = 0;
3932 u32 found_type = (u8)-1;
3933 int found_extent;
3934 int del_item;
3935 int pending_del_nr = 0;
3936 int pending_del_slot = 0;
3937 int extent_type = -1;
3938 int ret;
3939 int err = 0;
3940 u64 ino = btrfs_ino(inode);
3941
3942 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
3943
3944 path = btrfs_alloc_path();
3945 if (!path)
3946 return -ENOMEM;
3947 path->reada = -1;
3948
3949 /*
3950 * We want to drop from the next block forward in case this new size is
3951 * not block aligned since we will be keeping the last block of the
3952 * extent just the way it is.
3953 */
3954 if (root->ref_cows || root == root->fs_info->tree_root)
3955 btrfs_drop_extent_cache(inode, ALIGN(new_size,
3956 root->sectorsize), (u64)-1, 0);
3957
3958 /*
3959 * This function is also used to drop the items in the log tree before
3960 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
3961 * it is used to drop the loged items. So we shouldn't kill the delayed
3962 * items.
3963 */
3964 if (min_type == 0 && root == BTRFS_I(inode)->root)
3965 btrfs_kill_delayed_inode_items(inode);
3966
3967 key.objectid = ino;
3968 key.offset = (u64)-1;
3969 key.type = (u8)-1;
3970
3971 search_again:
3972 path->leave_spinning = 1;
3973 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
3974 if (ret < 0) {
3975 err = ret;
3976 goto out;
3977 }
3978
3979 if (ret > 0) {
3980 /* there are no items in the tree for us to truncate, we're
3981 * done
3982 */
3983 if (path->slots[0] == 0)
3984 goto out;
3985 path->slots[0]--;
3986 }
3987
3988 while (1) {
3989 fi = NULL;
3990 leaf = path->nodes[0];
3991 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3992 found_type = btrfs_key_type(&found_key);
3993
3994 if (found_key.objectid != ino)
3995 break;
3996
3997 if (found_type < min_type)
3998 break;
3999
4000 item_end = found_key.offset;
4001 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4002 fi = btrfs_item_ptr(leaf, path->slots[0],
4003 struct btrfs_file_extent_item);
4004 extent_type = btrfs_file_extent_type(leaf, fi);
4005 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4006 item_end +=
4007 btrfs_file_extent_num_bytes(leaf, fi);
4008 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4009 item_end += btrfs_file_extent_inline_len(leaf,
4010 fi);
4011 }
4012 item_end--;
4013 }
4014 if (found_type > min_type) {
4015 del_item = 1;
4016 } else {
4017 if (item_end < new_size)
4018 break;
4019 if (found_key.offset >= new_size)
4020 del_item = 1;
4021 else
4022 del_item = 0;
4023 }
4024 found_extent = 0;
4025 /* FIXME, shrink the extent if the ref count is only 1 */
4026 if (found_type != BTRFS_EXTENT_DATA_KEY)
4027 goto delete;
4028
4029 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4030 u64 num_dec;
4031 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4032 if (!del_item) {
4033 u64 orig_num_bytes =
4034 btrfs_file_extent_num_bytes(leaf, fi);
4035 extent_num_bytes = ALIGN(new_size -
4036 found_key.offset,
4037 root->sectorsize);
4038 btrfs_set_file_extent_num_bytes(leaf, fi,
4039 extent_num_bytes);
4040 num_dec = (orig_num_bytes -
4041 extent_num_bytes);
4042 if (root->ref_cows && extent_start != 0)
4043 inode_sub_bytes(inode, num_dec);
4044 btrfs_mark_buffer_dirty(leaf);
4045 } else {
4046 extent_num_bytes =
4047 btrfs_file_extent_disk_num_bytes(leaf,
4048 fi);
4049 extent_offset = found_key.offset -
4050 btrfs_file_extent_offset(leaf, fi);
4051
4052 /* FIXME blocksize != 4096 */
4053 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4054 if (extent_start != 0) {
4055 found_extent = 1;
4056 if (root->ref_cows)
4057 inode_sub_bytes(inode, num_dec);
4058 }
4059 }
4060 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4061 /*
4062 * we can't truncate inline items that have had
4063 * special encodings
4064 */
4065 if (!del_item &&
4066 btrfs_file_extent_compression(leaf, fi) == 0 &&
4067 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4068 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
4069 u32 size = new_size - found_key.offset;
4070
4071 if (root->ref_cows) {
4072 inode_sub_bytes(inode, item_end + 1 -
4073 new_size);
4074 }
4075 size =
4076 btrfs_file_extent_calc_inline_size(size);
4077 btrfs_truncate_item(root, path, size, 1);
4078 } else if (root->ref_cows) {
4079 inode_sub_bytes(inode, item_end + 1 -
4080 found_key.offset);
4081 }
4082 }
4083 delete:
4084 if (del_item) {
4085 if (!pending_del_nr) {
4086 /* no pending yet, add ourselves */
4087 pending_del_slot = path->slots[0];
4088 pending_del_nr = 1;
4089 } else if (pending_del_nr &&
4090 path->slots[0] + 1 == pending_del_slot) {
4091 /* hop on the pending chunk */
4092 pending_del_nr++;
4093 pending_del_slot = path->slots[0];
4094 } else {
4095 BUG();
4096 }
4097 } else {
4098 break;
4099 }
4100 if (found_extent && (root->ref_cows ||
4101 root == root->fs_info->tree_root)) {
4102 btrfs_set_path_blocking(path);
4103 ret = btrfs_free_extent(trans, root, extent_start,
4104 extent_num_bytes, 0,
4105 btrfs_header_owner(leaf),
4106 ino, extent_offset, 0);
4107 BUG_ON(ret);
4108 }
4109
4110 if (found_type == BTRFS_INODE_ITEM_KEY)
4111 break;
4112
4113 if (path->slots[0] == 0 ||
4114 path->slots[0] != pending_del_slot) {
4115 if (pending_del_nr) {
4116 ret = btrfs_del_items(trans, root, path,
4117 pending_del_slot,
4118 pending_del_nr);
4119 if (ret) {
4120 btrfs_abort_transaction(trans,
4121 root, ret);
4122 goto error;
4123 }
4124 pending_del_nr = 0;
4125 }
4126 btrfs_release_path(path);
4127 goto search_again;
4128 } else {
4129 path->slots[0]--;
4130 }
4131 }
4132 out:
4133 if (pending_del_nr) {
4134 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4135 pending_del_nr);
4136 if (ret)
4137 btrfs_abort_transaction(trans, root, ret);
4138 }
4139 error:
4140 btrfs_free_path(path);
4141 return err;
4142 }
4143
4144 /*
4145 * btrfs_truncate_page - read, zero a chunk and write a page
4146 * @inode - inode that we're zeroing
4147 * @from - the offset to start zeroing
4148 * @len - the length to zero, 0 to zero the entire range respective to the
4149 * offset
4150 * @front - zero up to the offset instead of from the offset on
4151 *
4152 * This will find the page for the "from" offset and cow the page and zero the
4153 * part we want to zero. This is used with truncate and hole punching.
4154 */
4155 int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len,
4156 int front)
4157 {
4158 struct address_space *mapping = inode->i_mapping;
4159 struct btrfs_root *root = BTRFS_I(inode)->root;
4160 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4161 struct btrfs_ordered_extent *ordered;
4162 struct extent_state *cached_state = NULL;
4163 char *kaddr;
4164 u32 blocksize = root->sectorsize;
4165 pgoff_t index = from >> PAGE_CACHE_SHIFT;
4166 unsigned offset = from & (PAGE_CACHE_SIZE-1);
4167 struct page *page;
4168 gfp_t mask = btrfs_alloc_write_mask(mapping);
4169 int ret = 0;
4170 u64 page_start;
4171 u64 page_end;
4172
4173 if ((offset & (blocksize - 1)) == 0 &&
4174 (!len || ((len & (blocksize - 1)) == 0)))
4175 goto out;
4176 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
4177 if (ret)
4178 goto out;
4179
4180 again:
4181 page = find_or_create_page(mapping, index, mask);
4182 if (!page) {
4183 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
4184 ret = -ENOMEM;
4185 goto out;
4186 }
4187
4188 page_start = page_offset(page);
4189 page_end = page_start + PAGE_CACHE_SIZE - 1;
4190
4191 if (!PageUptodate(page)) {
4192 ret = btrfs_readpage(NULL, page);
4193 lock_page(page);
4194 if (page->mapping != mapping) {
4195 unlock_page(page);
4196 page_cache_release(page);
4197 goto again;
4198 }
4199 if (!PageUptodate(page)) {
4200 ret = -EIO;
4201 goto out_unlock;
4202 }
4203 }
4204 wait_on_page_writeback(page);
4205
4206 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
4207 set_page_extent_mapped(page);
4208
4209 ordered = btrfs_lookup_ordered_extent(inode, page_start);
4210 if (ordered) {
4211 unlock_extent_cached(io_tree, page_start, page_end,
4212 &cached_state, GFP_NOFS);
4213 unlock_page(page);
4214 page_cache_release(page);
4215 btrfs_start_ordered_extent(inode, ordered, 1);
4216 btrfs_put_ordered_extent(ordered);
4217 goto again;
4218 }
4219
4220 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
4221 EXTENT_DIRTY | EXTENT_DELALLOC |
4222 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4223 0, 0, &cached_state, GFP_NOFS);
4224
4225 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
4226 &cached_state);
4227 if (ret) {
4228 unlock_extent_cached(io_tree, page_start, page_end,
4229 &cached_state, GFP_NOFS);
4230 goto out_unlock;
4231 }
4232
4233 if (offset != PAGE_CACHE_SIZE) {
4234 if (!len)
4235 len = PAGE_CACHE_SIZE - offset;
4236 kaddr = kmap(page);
4237 if (front)
4238 memset(kaddr, 0, offset);
4239 else
4240 memset(kaddr + offset, 0, len);
4241 flush_dcache_page(page);
4242 kunmap(page);
4243 }
4244 ClearPageChecked(page);
4245 set_page_dirty(page);
4246 unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
4247 GFP_NOFS);
4248
4249 out_unlock:
4250 if (ret)
4251 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
4252 unlock_page(page);
4253 page_cache_release(page);
4254 out:
4255 return ret;
4256 }
4257
4258 /*
4259 * This function puts in dummy file extents for the area we're creating a hole
4260 * for. So if we are truncating this file to a larger size we need to insert
4261 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4262 * the range between oldsize and size
4263 */
4264 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4265 {
4266 struct btrfs_trans_handle *trans;
4267 struct btrfs_root *root = BTRFS_I(inode)->root;
4268 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4269 struct extent_map *em = NULL;
4270 struct extent_state *cached_state = NULL;
4271 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4272 u64 hole_start = ALIGN(oldsize, root->sectorsize);
4273 u64 block_end = ALIGN(size, root->sectorsize);
4274 u64 last_byte;
4275 u64 cur_offset;
4276 u64 hole_size;
4277 int err = 0;
4278
4279 /*
4280 * If our size started in the middle of a page we need to zero out the
4281 * rest of the page before we expand the i_size, otherwise we could
4282 * expose stale data.
4283 */
4284 err = btrfs_truncate_page(inode, oldsize, 0, 0);
4285 if (err)
4286 return err;
4287
4288 if (size <= hole_start)
4289 return 0;
4290
4291 while (1) {
4292 struct btrfs_ordered_extent *ordered;
4293 btrfs_wait_ordered_range(inode, hole_start,
4294 block_end - hole_start);
4295 lock_extent_bits(io_tree, hole_start, block_end - 1, 0,
4296 &cached_state);
4297 ordered = btrfs_lookup_ordered_extent(inode, hole_start);
4298 if (!ordered)
4299 break;
4300 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4301 &cached_state, GFP_NOFS);
4302 btrfs_put_ordered_extent(ordered);
4303 }
4304
4305 cur_offset = hole_start;
4306 while (1) {
4307 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
4308 block_end - cur_offset, 0);
4309 if (IS_ERR(em)) {
4310 err = PTR_ERR(em);
4311 em = NULL;
4312 break;
4313 }
4314 last_byte = min(extent_map_end(em), block_end);
4315 last_byte = ALIGN(last_byte , root->sectorsize);
4316 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4317 struct extent_map *hole_em;
4318 hole_size = last_byte - cur_offset;
4319
4320 trans = btrfs_start_transaction(root, 3);
4321 if (IS_ERR(trans)) {
4322 err = PTR_ERR(trans);
4323 break;
4324 }
4325
4326 err = btrfs_drop_extents(trans, root, inode,
4327 cur_offset,
4328 cur_offset + hole_size, 1);
4329 if (err) {
4330 btrfs_abort_transaction(trans, root, err);
4331 btrfs_end_transaction(trans, root);
4332 break;
4333 }
4334
4335 err = btrfs_insert_file_extent(trans, root,
4336 btrfs_ino(inode), cur_offset, 0,
4337 0, hole_size, 0, hole_size,
4338 0, 0, 0);
4339 if (err) {
4340 btrfs_abort_transaction(trans, root, err);
4341 btrfs_end_transaction(trans, root);
4342 break;
4343 }
4344
4345 btrfs_drop_extent_cache(inode, cur_offset,
4346 cur_offset + hole_size - 1, 0);
4347 hole_em = alloc_extent_map();
4348 if (!hole_em) {
4349 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4350 &BTRFS_I(inode)->runtime_flags);
4351 goto next;
4352 }
4353 hole_em->start = cur_offset;
4354 hole_em->len = hole_size;
4355 hole_em->orig_start = cur_offset;
4356
4357 hole_em->block_start = EXTENT_MAP_HOLE;
4358 hole_em->block_len = 0;
4359 hole_em->orig_block_len = 0;
4360 hole_em->ram_bytes = hole_size;
4361 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
4362 hole_em->compress_type = BTRFS_COMPRESS_NONE;
4363 hole_em->generation = trans->transid;
4364
4365 while (1) {
4366 write_lock(&em_tree->lock);
4367 err = add_extent_mapping(em_tree, hole_em, 1);
4368 write_unlock(&em_tree->lock);
4369 if (err != -EEXIST)
4370 break;
4371 btrfs_drop_extent_cache(inode, cur_offset,
4372 cur_offset +
4373 hole_size - 1, 0);
4374 }
4375 free_extent_map(hole_em);
4376 next:
4377 btrfs_update_inode(trans, root, inode);
4378 btrfs_end_transaction(trans, root);
4379 }
4380 free_extent_map(em);
4381 em = NULL;
4382 cur_offset = last_byte;
4383 if (cur_offset >= block_end)
4384 break;
4385 }
4386
4387 free_extent_map(em);
4388 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
4389 GFP_NOFS);
4390 return err;
4391 }
4392
4393 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
4394 {
4395 struct btrfs_root *root = BTRFS_I(inode)->root;
4396 struct btrfs_trans_handle *trans;
4397 loff_t oldsize = i_size_read(inode);
4398 loff_t newsize = attr->ia_size;
4399 int mask = attr->ia_valid;
4400 int ret;
4401
4402 /*
4403 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
4404 * special case where we need to update the times despite not having
4405 * these flags set. For all other operations the VFS set these flags
4406 * explicitly if it wants a timestamp update.
4407 */
4408 if (newsize != oldsize && (!(mask & (ATTR_CTIME | ATTR_MTIME))))
4409 inode->i_ctime = inode->i_mtime = current_fs_time(inode->i_sb);
4410
4411 if (newsize > oldsize) {
4412 truncate_pagecache(inode, oldsize, newsize);
4413 ret = btrfs_cont_expand(inode, oldsize, newsize);
4414 if (ret)
4415 return ret;
4416
4417 trans = btrfs_start_transaction(root, 1);
4418 if (IS_ERR(trans))
4419 return PTR_ERR(trans);
4420
4421 i_size_write(inode, newsize);
4422 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
4423 ret = btrfs_update_inode(trans, root, inode);
4424 btrfs_end_transaction(trans, root);
4425 } else {
4426
4427 /*
4428 * We're truncating a file that used to have good data down to
4429 * zero. Make sure it gets into the ordered flush list so that
4430 * any new writes get down to disk quickly.
4431 */
4432 if (newsize == 0)
4433 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
4434 &BTRFS_I(inode)->runtime_flags);
4435
4436 /*
4437 * 1 for the orphan item we're going to add
4438 * 1 for the orphan item deletion.
4439 */
4440 trans = btrfs_start_transaction(root, 2);
4441 if (IS_ERR(trans))
4442 return PTR_ERR(trans);
4443
4444 /*
4445 * We need to do this in case we fail at _any_ point during the
4446 * actual truncate. Once we do the truncate_setsize we could
4447 * invalidate pages which forces any outstanding ordered io to
4448 * be instantly completed which will give us extents that need
4449 * to be truncated. If we fail to get an orphan inode down we
4450 * could have left over extents that were never meant to live,
4451 * so we need to garuntee from this point on that everything
4452 * will be consistent.
4453 */
4454 ret = btrfs_orphan_add(trans, inode);
4455 btrfs_end_transaction(trans, root);
4456 if (ret)
4457 return ret;
4458
4459 /* we don't support swapfiles, so vmtruncate shouldn't fail */
4460 truncate_setsize(inode, newsize);
4461
4462 /* Disable nonlocked read DIO to avoid the end less truncate */
4463 btrfs_inode_block_unlocked_dio(inode);
4464 inode_dio_wait(inode);
4465 btrfs_inode_resume_unlocked_dio(inode);
4466
4467 ret = btrfs_truncate(inode);
4468 if (ret && inode->i_nlink)
4469 btrfs_orphan_del(NULL, inode);
4470 }
4471
4472 return ret;
4473 }
4474
4475 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
4476 {
4477 struct inode *inode = dentry->d_inode;
4478 struct btrfs_root *root = BTRFS_I(inode)->root;
4479 int err;
4480
4481 if (btrfs_root_readonly(root))
4482 return -EROFS;
4483
4484 err = inode_change_ok(inode, attr);
4485 if (err)
4486 return err;
4487
4488 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
4489 err = btrfs_setsize(inode, attr);
4490 if (err)
4491 return err;
4492 }
4493
4494 if (attr->ia_valid) {
4495 setattr_copy(inode, attr);
4496 inode_inc_iversion(inode);
4497 err = btrfs_dirty_inode(inode);
4498
4499 if (!err && attr->ia_valid & ATTR_MODE)
4500 err = btrfs_acl_chmod(inode);
4501 }
4502
4503 return err;
4504 }
4505
4506 void btrfs_evict_inode(struct inode *inode)
4507 {
4508 struct btrfs_trans_handle *trans;
4509 struct btrfs_root *root = BTRFS_I(inode)->root;
4510 struct btrfs_block_rsv *rsv, *global_rsv;
4511 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
4512 int ret;
4513
4514 trace_btrfs_inode_evict(inode);
4515
4516 truncate_inode_pages(&inode->i_data, 0);
4517 if (inode->i_nlink && (btrfs_root_refs(&root->root_item) != 0 ||
4518 btrfs_is_free_space_inode(inode)))
4519 goto no_delete;
4520
4521 if (is_bad_inode(inode)) {
4522 btrfs_orphan_del(NULL, inode);
4523 goto no_delete;
4524 }
4525 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
4526 btrfs_wait_ordered_range(inode, 0, (u64)-1);
4527
4528 if (root->fs_info->log_root_recovering) {
4529 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
4530 &BTRFS_I(inode)->runtime_flags));
4531 goto no_delete;
4532 }
4533
4534 if (inode->i_nlink > 0) {
4535 BUG_ON(btrfs_root_refs(&root->root_item) != 0);
4536 goto no_delete;
4537 }
4538
4539 ret = btrfs_commit_inode_delayed_inode(inode);
4540 if (ret) {
4541 btrfs_orphan_del(NULL, inode);
4542 goto no_delete;
4543 }
4544
4545 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
4546 if (!rsv) {
4547 btrfs_orphan_del(NULL, inode);
4548 goto no_delete;
4549 }
4550 rsv->size = min_size;
4551 rsv->failfast = 1;
4552 global_rsv = &root->fs_info->global_block_rsv;
4553
4554 btrfs_i_size_write(inode, 0);
4555
4556 /*
4557 * This is a bit simpler than btrfs_truncate since we've already
4558 * reserved our space for our orphan item in the unlink, so we just
4559 * need to reserve some slack space in case we add bytes and update
4560 * inode item when doing the truncate.
4561 */
4562 while (1) {
4563 ret = btrfs_block_rsv_refill(root, rsv, min_size,
4564 BTRFS_RESERVE_FLUSH_LIMIT);
4565
4566 /*
4567 * Try and steal from the global reserve since we will
4568 * likely not use this space anyway, we want to try as
4569 * hard as possible to get this to work.
4570 */
4571 if (ret)
4572 ret = btrfs_block_rsv_migrate(global_rsv, rsv, min_size);
4573
4574 if (ret) {
4575 btrfs_warn(root->fs_info,
4576 "Could not get space for a delete, will truncate on mount %d",
4577 ret);
4578 btrfs_orphan_del(NULL, inode);
4579 btrfs_free_block_rsv(root, rsv);
4580 goto no_delete;
4581 }
4582
4583 trans = btrfs_join_transaction(root);
4584 if (IS_ERR(trans)) {
4585 btrfs_orphan_del(NULL, inode);
4586 btrfs_free_block_rsv(root, rsv);
4587 goto no_delete;
4588 }
4589
4590 trans->block_rsv = rsv;
4591
4592 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
4593 if (ret != -ENOSPC)
4594 break;
4595
4596 trans->block_rsv = &root->fs_info->trans_block_rsv;
4597 btrfs_end_transaction(trans, root);
4598 trans = NULL;
4599 btrfs_btree_balance_dirty(root);
4600 }
4601
4602 btrfs_free_block_rsv(root, rsv);
4603
4604 if (ret == 0) {
4605 trans->block_rsv = root->orphan_block_rsv;
4606 ret = btrfs_orphan_del(trans, inode);
4607 BUG_ON(ret);
4608 }
4609
4610 trans->block_rsv = &root->fs_info->trans_block_rsv;
4611 if (!(root == root->fs_info->tree_root ||
4612 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
4613 btrfs_return_ino(root, btrfs_ino(inode));
4614
4615 btrfs_end_transaction(trans, root);
4616 btrfs_btree_balance_dirty(root);
4617 no_delete:
4618 btrfs_remove_delayed_node(inode);
4619 clear_inode(inode);
4620 return;
4621 }
4622
4623 /*
4624 * this returns the key found in the dir entry in the location pointer.
4625 * If no dir entries were found, location->objectid is 0.
4626 */
4627 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
4628 struct btrfs_key *location)
4629 {
4630 const char *name = dentry->d_name.name;
4631 int namelen = dentry->d_name.len;
4632 struct btrfs_dir_item *di;
4633 struct btrfs_path *path;
4634 struct btrfs_root *root = BTRFS_I(dir)->root;
4635 int ret = 0;
4636
4637 path = btrfs_alloc_path();
4638 if (!path)
4639 return -ENOMEM;
4640
4641 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
4642 namelen, 0);
4643 if (IS_ERR(di))
4644 ret = PTR_ERR(di);
4645
4646 if (IS_ERR_OR_NULL(di))
4647 goto out_err;
4648
4649 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
4650 out:
4651 btrfs_free_path(path);
4652 return ret;
4653 out_err:
4654 location->objectid = 0;
4655 goto out;
4656 }
4657
4658 /*
4659 * when we hit a tree root in a directory, the btrfs part of the inode
4660 * needs to be changed to reflect the root directory of the tree root. This
4661 * is kind of like crossing a mount point.
4662 */
4663 static int fixup_tree_root_location(struct btrfs_root *root,
4664 struct inode *dir,
4665 struct dentry *dentry,
4666 struct btrfs_key *location,
4667 struct btrfs_root **sub_root)
4668 {
4669 struct btrfs_path *path;
4670 struct btrfs_root *new_root;
4671 struct btrfs_root_ref *ref;
4672 struct extent_buffer *leaf;
4673 int ret;
4674 int err = 0;
4675
4676 path = btrfs_alloc_path();
4677 if (!path) {
4678 err = -ENOMEM;
4679 goto out;
4680 }
4681
4682 err = -ENOENT;
4683 ret = btrfs_find_root_ref(root->fs_info->tree_root, path,
4684 BTRFS_I(dir)->root->root_key.objectid,
4685 location->objectid);
4686 if (ret) {
4687 if (ret < 0)
4688 err = ret;
4689 goto out;
4690 }
4691
4692 leaf = path->nodes[0];
4693 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
4694 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
4695 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
4696 goto out;
4697
4698 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
4699 (unsigned long)(ref + 1),
4700 dentry->d_name.len);
4701 if (ret)
4702 goto out;
4703
4704 btrfs_release_path(path);
4705
4706 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
4707 if (IS_ERR(new_root)) {
4708 err = PTR_ERR(new_root);
4709 goto out;
4710 }
4711
4712 *sub_root = new_root;
4713 location->objectid = btrfs_root_dirid(&new_root->root_item);
4714 location->type = BTRFS_INODE_ITEM_KEY;
4715 location->offset = 0;
4716 err = 0;
4717 out:
4718 btrfs_free_path(path);
4719 return err;
4720 }
4721
4722 static void inode_tree_add(struct inode *inode)
4723 {
4724 struct btrfs_root *root = BTRFS_I(inode)->root;
4725 struct btrfs_inode *entry;
4726 struct rb_node **p;
4727 struct rb_node *parent;
4728 u64 ino = btrfs_ino(inode);
4729
4730 if (inode_unhashed(inode))
4731 return;
4732 again:
4733 parent = NULL;
4734 spin_lock(&root->inode_lock);
4735 p = &root->inode_tree.rb_node;
4736 while (*p) {
4737 parent = *p;
4738 entry = rb_entry(parent, struct btrfs_inode, rb_node);
4739
4740 if (ino < btrfs_ino(&entry->vfs_inode))
4741 p = &parent->rb_left;
4742 else if (ino > btrfs_ino(&entry->vfs_inode))
4743 p = &parent->rb_right;
4744 else {
4745 WARN_ON(!(entry->vfs_inode.i_state &
4746 (I_WILL_FREE | I_FREEING)));
4747 rb_erase(parent, &root->inode_tree);
4748 RB_CLEAR_NODE(parent);
4749 spin_unlock(&root->inode_lock);
4750 goto again;
4751 }
4752 }
4753 rb_link_node(&BTRFS_I(inode)->rb_node, parent, p);
4754 rb_insert_color(&BTRFS_I(inode)->rb_node, &root->inode_tree);
4755 spin_unlock(&root->inode_lock);
4756 }
4757
4758 static void inode_tree_del(struct inode *inode)
4759 {
4760 struct btrfs_root *root = BTRFS_I(inode)->root;
4761 int empty = 0;
4762
4763 spin_lock(&root->inode_lock);
4764 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
4765 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
4766 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
4767 empty = RB_EMPTY_ROOT(&root->inode_tree);
4768 }
4769 spin_unlock(&root->inode_lock);
4770
4771 /*
4772 * Free space cache has inodes in the tree root, but the tree root has a
4773 * root_refs of 0, so this could end up dropping the tree root as a
4774 * snapshot, so we need the extra !root->fs_info->tree_root check to
4775 * make sure we don't drop it.
4776 */
4777 if (empty && btrfs_root_refs(&root->root_item) == 0 &&
4778 root != root->fs_info->tree_root) {
4779 synchronize_srcu(&root->fs_info->subvol_srcu);
4780 spin_lock(&root->inode_lock);
4781 empty = RB_EMPTY_ROOT(&root->inode_tree);
4782 spin_unlock(&root->inode_lock);
4783 if (empty)
4784 btrfs_add_dead_root(root);
4785 }
4786 }
4787
4788 void btrfs_invalidate_inodes(struct btrfs_root *root)
4789 {
4790 struct rb_node *node;
4791 struct rb_node *prev;
4792 struct btrfs_inode *entry;
4793 struct inode *inode;
4794 u64 objectid = 0;
4795
4796 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
4797
4798 spin_lock(&root->inode_lock);
4799 again:
4800 node = root->inode_tree.rb_node;
4801 prev = NULL;
4802 while (node) {
4803 prev = node;
4804 entry = rb_entry(node, struct btrfs_inode, rb_node);
4805
4806 if (objectid < btrfs_ino(&entry->vfs_inode))
4807 node = node->rb_left;
4808 else if (objectid > btrfs_ino(&entry->vfs_inode))
4809 node = node->rb_right;
4810 else
4811 break;
4812 }
4813 if (!node) {
4814 while (prev) {
4815 entry = rb_entry(prev, struct btrfs_inode, rb_node);
4816 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
4817 node = prev;
4818 break;
4819 }
4820 prev = rb_next(prev);
4821 }
4822 }
4823 while (node) {
4824 entry = rb_entry(node, struct btrfs_inode, rb_node);
4825 objectid = btrfs_ino(&entry->vfs_inode) + 1;
4826 inode = igrab(&entry->vfs_inode);
4827 if (inode) {
4828 spin_unlock(&root->inode_lock);
4829 if (atomic_read(&inode->i_count) > 1)
4830 d_prune_aliases(inode);
4831 /*
4832 * btrfs_drop_inode will have it removed from
4833 * the inode cache when its usage count
4834 * hits zero.
4835 */
4836 iput(inode);
4837 cond_resched();
4838 spin_lock(&root->inode_lock);
4839 goto again;
4840 }
4841
4842 if (cond_resched_lock(&root->inode_lock))
4843 goto again;
4844
4845 node = rb_next(node);
4846 }
4847 spin_unlock(&root->inode_lock);
4848 }
4849
4850 static int btrfs_init_locked_inode(struct inode *inode, void *p)
4851 {
4852 struct btrfs_iget_args *args = p;
4853 inode->i_ino = args->ino;
4854 BTRFS_I(inode)->root = args->root;
4855 return 0;
4856 }
4857
4858 static int btrfs_find_actor(struct inode *inode, void *opaque)
4859 {
4860 struct btrfs_iget_args *args = opaque;
4861 return args->ino == btrfs_ino(inode) &&
4862 args->root == BTRFS_I(inode)->root;
4863 }
4864
4865 static struct inode *btrfs_iget_locked(struct super_block *s,
4866 u64 objectid,
4867 struct btrfs_root *root)
4868 {
4869 struct inode *inode;
4870 struct btrfs_iget_args args;
4871 args.ino = objectid;
4872 args.root = root;
4873
4874 inode = iget5_locked(s, objectid, btrfs_find_actor,
4875 btrfs_init_locked_inode,
4876 (void *)&args);
4877 return inode;
4878 }
4879
4880 /* Get an inode object given its location and corresponding root.
4881 * Returns in *is_new if the inode was read from disk
4882 */
4883 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
4884 struct btrfs_root *root, int *new)
4885 {
4886 struct inode *inode;
4887
4888 inode = btrfs_iget_locked(s, location->objectid, root);
4889 if (!inode)
4890 return ERR_PTR(-ENOMEM);
4891
4892 if (inode->i_state & I_NEW) {
4893 BTRFS_I(inode)->root = root;
4894 memcpy(&BTRFS_I(inode)->location, location, sizeof(*location));
4895 btrfs_read_locked_inode(inode);
4896 if (!is_bad_inode(inode)) {
4897 inode_tree_add(inode);
4898 unlock_new_inode(inode);
4899 if (new)
4900 *new = 1;
4901 } else {
4902 unlock_new_inode(inode);
4903 iput(inode);
4904 inode = ERR_PTR(-ESTALE);
4905 }
4906 }
4907
4908 return inode;
4909 }
4910
4911 static struct inode *new_simple_dir(struct super_block *s,
4912 struct btrfs_key *key,
4913 struct btrfs_root *root)
4914 {
4915 struct inode *inode = new_inode(s);
4916
4917 if (!inode)
4918 return ERR_PTR(-ENOMEM);
4919
4920 BTRFS_I(inode)->root = root;
4921 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
4922 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
4923
4924 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
4925 inode->i_op = &btrfs_dir_ro_inode_operations;
4926 inode->i_fop = &simple_dir_operations;
4927 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
4928 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
4929
4930 return inode;
4931 }
4932
4933 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
4934 {
4935 struct inode *inode;
4936 struct btrfs_root *root = BTRFS_I(dir)->root;
4937 struct btrfs_root *sub_root = root;
4938 struct btrfs_key location;
4939 int index;
4940 int ret = 0;
4941
4942 if (dentry->d_name.len > BTRFS_NAME_LEN)
4943 return ERR_PTR(-ENAMETOOLONG);
4944
4945 ret = btrfs_inode_by_name(dir, dentry, &location);
4946 if (ret < 0)
4947 return ERR_PTR(ret);
4948
4949 if (location.objectid == 0)
4950 return NULL;
4951
4952 if (location.type == BTRFS_INODE_ITEM_KEY) {
4953 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
4954 return inode;
4955 }
4956
4957 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
4958
4959 index = srcu_read_lock(&root->fs_info->subvol_srcu);
4960 ret = fixup_tree_root_location(root, dir, dentry,
4961 &location, &sub_root);
4962 if (ret < 0) {
4963 if (ret != -ENOENT)
4964 inode = ERR_PTR(ret);
4965 else
4966 inode = new_simple_dir(dir->i_sb, &location, sub_root);
4967 } else {
4968 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
4969 }
4970 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
4971
4972 if (!IS_ERR(inode) && root != sub_root) {
4973 down_read(&root->fs_info->cleanup_work_sem);
4974 if (!(inode->i_sb->s_flags & MS_RDONLY))
4975 ret = btrfs_orphan_cleanup(sub_root);
4976 up_read(&root->fs_info->cleanup_work_sem);
4977 if (ret) {
4978 iput(inode);
4979 inode = ERR_PTR(ret);
4980 }
4981 }
4982
4983 return inode;
4984 }
4985
4986 static int btrfs_dentry_delete(const struct dentry *dentry)
4987 {
4988 struct btrfs_root *root;
4989 struct inode *inode = dentry->d_inode;
4990
4991 if (!inode && !IS_ROOT(dentry))
4992 inode = dentry->d_parent->d_inode;
4993
4994 if (inode) {
4995 root = BTRFS_I(inode)->root;
4996 if (btrfs_root_refs(&root->root_item) == 0)
4997 return 1;
4998
4999 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5000 return 1;
5001 }
5002 return 0;
5003 }
5004
5005 static void btrfs_dentry_release(struct dentry *dentry)
5006 {
5007 if (dentry->d_fsdata)
5008 kfree(dentry->d_fsdata);
5009 }
5010
5011 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5012 unsigned int flags)
5013 {
5014 struct dentry *ret;
5015
5016 ret = d_splice_alias(btrfs_lookup_dentry(dir, dentry), dentry);
5017 return ret;
5018 }
5019
5020 unsigned char btrfs_filetype_table[] = {
5021 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5022 };
5023
5024 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
5025 {
5026 struct inode *inode = file_inode(file);
5027 struct btrfs_root *root = BTRFS_I(inode)->root;
5028 struct btrfs_item *item;
5029 struct btrfs_dir_item *di;
5030 struct btrfs_key key;
5031 struct btrfs_key found_key;
5032 struct btrfs_path *path;
5033 struct list_head ins_list;
5034 struct list_head del_list;
5035 int ret;
5036 struct extent_buffer *leaf;
5037 int slot;
5038 unsigned char d_type;
5039 int over = 0;
5040 u32 di_cur;
5041 u32 di_total;
5042 u32 di_len;
5043 int key_type = BTRFS_DIR_INDEX_KEY;
5044 char tmp_name[32];
5045 char *name_ptr;
5046 int name_len;
5047 int is_curr = 0; /* ctx->pos points to the current index? */
5048
5049 /* FIXME, use a real flag for deciding about the key type */
5050 if (root->fs_info->tree_root == root)
5051 key_type = BTRFS_DIR_ITEM_KEY;
5052
5053 if (!dir_emit_dots(file, ctx))
5054 return 0;
5055
5056 path = btrfs_alloc_path();
5057 if (!path)
5058 return -ENOMEM;
5059
5060 path->reada = 1;
5061
5062 if (key_type == BTRFS_DIR_INDEX_KEY) {
5063 INIT_LIST_HEAD(&ins_list);
5064 INIT_LIST_HEAD(&del_list);
5065 btrfs_get_delayed_items(inode, &ins_list, &del_list);
5066 }
5067
5068 btrfs_set_key_type(&key, key_type);
5069 key.offset = ctx->pos;
5070 key.objectid = btrfs_ino(inode);
5071
5072 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5073 if (ret < 0)
5074 goto err;
5075
5076 while (1) {
5077 leaf = path->nodes[0];
5078 slot = path->slots[0];
5079 if (slot >= btrfs_header_nritems(leaf)) {
5080 ret = btrfs_next_leaf(root, path);
5081 if (ret < 0)
5082 goto err;
5083 else if (ret > 0)
5084 break;
5085 continue;
5086 }
5087
5088 item = btrfs_item_nr(leaf, slot);
5089 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5090
5091 if (found_key.objectid != key.objectid)
5092 break;
5093 if (btrfs_key_type(&found_key) != key_type)
5094 break;
5095 if (found_key.offset < ctx->pos)
5096 goto next;
5097 if (key_type == BTRFS_DIR_INDEX_KEY &&
5098 btrfs_should_delete_dir_index(&del_list,
5099 found_key.offset))
5100 goto next;
5101
5102 ctx->pos = found_key.offset;
5103 is_curr = 1;
5104
5105 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5106 di_cur = 0;
5107 di_total = btrfs_item_size(leaf, item);
5108
5109 while (di_cur < di_total) {
5110 struct btrfs_key location;
5111
5112 if (verify_dir_item(root, leaf, di))
5113 break;
5114
5115 name_len = btrfs_dir_name_len(leaf, di);
5116 if (name_len <= sizeof(tmp_name)) {
5117 name_ptr = tmp_name;
5118 } else {
5119 name_ptr = kmalloc(name_len, GFP_NOFS);
5120 if (!name_ptr) {
5121 ret = -ENOMEM;
5122 goto err;
5123 }
5124 }
5125 read_extent_buffer(leaf, name_ptr,
5126 (unsigned long)(di + 1), name_len);
5127
5128 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
5129 btrfs_dir_item_key_to_cpu(leaf, di, &location);
5130
5131
5132 /* is this a reference to our own snapshot? If so
5133 * skip it.
5134 *
5135 * In contrast to old kernels, we insert the snapshot's
5136 * dir item and dir index after it has been created, so
5137 * we won't find a reference to our own snapshot. We
5138 * still keep the following code for backward
5139 * compatibility.
5140 */
5141 if (location.type == BTRFS_ROOT_ITEM_KEY &&
5142 location.objectid == root->root_key.objectid) {
5143 over = 0;
5144 goto skip;
5145 }
5146 over = !dir_emit(ctx, name_ptr, name_len,
5147 location.objectid, d_type);
5148
5149 skip:
5150 if (name_ptr != tmp_name)
5151 kfree(name_ptr);
5152
5153 if (over)
5154 goto nopos;
5155 di_len = btrfs_dir_name_len(leaf, di) +
5156 btrfs_dir_data_len(leaf, di) + sizeof(*di);
5157 di_cur += di_len;
5158 di = (struct btrfs_dir_item *)((char *)di + di_len);
5159 }
5160 next:
5161 path->slots[0]++;
5162 }
5163
5164 if (key_type == BTRFS_DIR_INDEX_KEY) {
5165 if (is_curr)
5166 ctx->pos++;
5167 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
5168 if (ret)
5169 goto nopos;
5170 }
5171
5172 /* Reached end of directory/root. Bump pos past the last item. */
5173 ctx->pos++;
5174
5175 /*
5176 * Stop new entries from being returned after we return the last
5177 * entry.
5178 *
5179 * New directory entries are assigned a strictly increasing
5180 * offset. This means that new entries created during readdir
5181 * are *guaranteed* to be seen in the future by that readdir.
5182 * This has broken buggy programs which operate on names as
5183 * they're returned by readdir. Until we re-use freed offsets
5184 * we have this hack to stop new entries from being returned
5185 * under the assumption that they'll never reach this huge
5186 * offset.
5187 *
5188 * This is being careful not to overflow 32bit loff_t unless the
5189 * last entry requires it because doing so has broken 32bit apps
5190 * in the past.
5191 */
5192 if (key_type == BTRFS_DIR_INDEX_KEY) {
5193 if (ctx->pos >= INT_MAX)
5194 ctx->pos = LLONG_MAX;
5195 else
5196 ctx->pos = INT_MAX;
5197 }
5198 nopos:
5199 ret = 0;
5200 err:
5201 if (key_type == BTRFS_DIR_INDEX_KEY)
5202 btrfs_put_delayed_items(&ins_list, &del_list);
5203 btrfs_free_path(path);
5204 return ret;
5205 }
5206
5207 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
5208 {
5209 struct btrfs_root *root = BTRFS_I(inode)->root;
5210 struct btrfs_trans_handle *trans;
5211 int ret = 0;
5212 bool nolock = false;
5213
5214 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5215 return 0;
5216
5217 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
5218 nolock = true;
5219
5220 if (wbc->sync_mode == WB_SYNC_ALL) {
5221 if (nolock)
5222 trans = btrfs_join_transaction_nolock(root);
5223 else
5224 trans = btrfs_join_transaction(root);
5225 if (IS_ERR(trans))
5226 return PTR_ERR(trans);
5227 ret = btrfs_commit_transaction(trans, root);
5228 }
5229 return ret;
5230 }
5231
5232 /*
5233 * This is somewhat expensive, updating the tree every time the
5234 * inode changes. But, it is most likely to find the inode in cache.
5235 * FIXME, needs more benchmarking...there are no reasons other than performance
5236 * to keep or drop this code.
5237 */
5238 static int btrfs_dirty_inode(struct inode *inode)
5239 {
5240 struct btrfs_root *root = BTRFS_I(inode)->root;
5241 struct btrfs_trans_handle *trans;
5242 int ret;
5243
5244 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5245 return 0;
5246
5247 trans = btrfs_join_transaction(root);
5248 if (IS_ERR(trans))
5249 return PTR_ERR(trans);
5250
5251 ret = btrfs_update_inode(trans, root, inode);
5252 if (ret && ret == -ENOSPC) {
5253 /* whoops, lets try again with the full transaction */
5254 btrfs_end_transaction(trans, root);
5255 trans = btrfs_start_transaction(root, 1);
5256 if (IS_ERR(trans))
5257 return PTR_ERR(trans);
5258
5259 ret = btrfs_update_inode(trans, root, inode);
5260 }
5261 btrfs_end_transaction(trans, root);
5262 if (BTRFS_I(inode)->delayed_node)
5263 btrfs_balance_delayed_items(root);
5264
5265 return ret;
5266 }
5267
5268 /*
5269 * This is a copy of file_update_time. We need this so we can return error on
5270 * ENOSPC for updating the inode in the case of file write and mmap writes.
5271 */
5272 static int btrfs_update_time(struct inode *inode, struct timespec *now,
5273 int flags)
5274 {
5275 struct btrfs_root *root = BTRFS_I(inode)->root;
5276
5277 if (btrfs_root_readonly(root))
5278 return -EROFS;
5279
5280 if (flags & S_VERSION)
5281 inode_inc_iversion(inode);
5282 if (flags & S_CTIME)
5283 inode->i_ctime = *now;
5284 if (flags & S_MTIME)
5285 inode->i_mtime = *now;
5286 if (flags & S_ATIME)
5287 inode->i_atime = *now;
5288 return btrfs_dirty_inode(inode);
5289 }
5290
5291 /*
5292 * find the highest existing sequence number in a directory
5293 * and then set the in-memory index_cnt variable to reflect
5294 * free sequence numbers
5295 */
5296 static int btrfs_set_inode_index_count(struct inode *inode)
5297 {
5298 struct btrfs_root *root = BTRFS_I(inode)->root;
5299 struct btrfs_key key, found_key;
5300 struct btrfs_path *path;
5301 struct extent_buffer *leaf;
5302 int ret;
5303
5304 key.objectid = btrfs_ino(inode);
5305 btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
5306 key.offset = (u64)-1;
5307
5308 path = btrfs_alloc_path();
5309 if (!path)
5310 return -ENOMEM;
5311
5312 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5313 if (ret < 0)
5314 goto out;
5315 /* FIXME: we should be able to handle this */
5316 if (ret == 0)
5317 goto out;
5318 ret = 0;
5319
5320 /*
5321 * MAGIC NUMBER EXPLANATION:
5322 * since we search a directory based on f_pos we have to start at 2
5323 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
5324 * else has to start at 2
5325 */
5326 if (path->slots[0] == 0) {
5327 BTRFS_I(inode)->index_cnt = 2;
5328 goto out;
5329 }
5330
5331 path->slots[0]--;
5332
5333 leaf = path->nodes[0];
5334 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5335
5336 if (found_key.objectid != btrfs_ino(inode) ||
5337 btrfs_key_type(&found_key) != BTRFS_DIR_INDEX_KEY) {
5338 BTRFS_I(inode)->index_cnt = 2;
5339 goto out;
5340 }
5341
5342 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
5343 out:
5344 btrfs_free_path(path);
5345 return ret;
5346 }
5347
5348 /*
5349 * helper to find a free sequence number in a given directory. This current
5350 * code is very simple, later versions will do smarter things in the btree
5351 */
5352 int btrfs_set_inode_index(struct inode *dir, u64 *index)
5353 {
5354 int ret = 0;
5355
5356 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
5357 ret = btrfs_inode_delayed_dir_index_count(dir);
5358 if (ret) {
5359 ret = btrfs_set_inode_index_count(dir);
5360 if (ret)
5361 return ret;
5362 }
5363 }
5364
5365 *index = BTRFS_I(dir)->index_cnt;
5366 BTRFS_I(dir)->index_cnt++;
5367
5368 return ret;
5369 }
5370
5371 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
5372 struct btrfs_root *root,
5373 struct inode *dir,
5374 const char *name, int name_len,
5375 u64 ref_objectid, u64 objectid,
5376 umode_t mode, u64 *index)
5377 {
5378 struct inode *inode;
5379 struct btrfs_inode_item *inode_item;
5380 struct btrfs_key *location;
5381 struct btrfs_path *path;
5382 struct btrfs_inode_ref *ref;
5383 struct btrfs_key key[2];
5384 u32 sizes[2];
5385 unsigned long ptr;
5386 int ret;
5387 int owner;
5388
5389 path = btrfs_alloc_path();
5390 if (!path)
5391 return ERR_PTR(-ENOMEM);
5392
5393 inode = new_inode(root->fs_info->sb);
5394 if (!inode) {
5395 btrfs_free_path(path);
5396 return ERR_PTR(-ENOMEM);
5397 }
5398
5399 /*
5400 * we have to initialize this early, so we can reclaim the inode
5401 * number if we fail afterwards in this function.
5402 */
5403 inode->i_ino = objectid;
5404
5405 if (dir) {
5406 trace_btrfs_inode_request(dir);
5407
5408 ret = btrfs_set_inode_index(dir, index);
5409 if (ret) {
5410 btrfs_free_path(path);
5411 iput(inode);
5412 return ERR_PTR(ret);
5413 }
5414 }
5415 /*
5416 * index_cnt is ignored for everything but a dir,
5417 * btrfs_get_inode_index_count has an explanation for the magic
5418 * number
5419 */
5420 BTRFS_I(inode)->index_cnt = 2;
5421 BTRFS_I(inode)->root = root;
5422 BTRFS_I(inode)->generation = trans->transid;
5423 inode->i_generation = BTRFS_I(inode)->generation;
5424
5425 /*
5426 * We could have gotten an inode number from somebody who was fsynced
5427 * and then removed in this same transaction, so let's just set full
5428 * sync since it will be a full sync anyway and this will blow away the
5429 * old info in the log.
5430 */
5431 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
5432
5433 if (S_ISDIR(mode))
5434 owner = 0;
5435 else
5436 owner = 1;
5437
5438 key[0].objectid = objectid;
5439 btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
5440 key[0].offset = 0;
5441
5442 /*
5443 * Start new inodes with an inode_ref. This is slightly more
5444 * efficient for small numbers of hard links since they will
5445 * be packed into one item. Extended refs will kick in if we
5446 * add more hard links than can fit in the ref item.
5447 */
5448 key[1].objectid = objectid;
5449 btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
5450 key[1].offset = ref_objectid;
5451
5452 sizes[0] = sizeof(struct btrfs_inode_item);
5453 sizes[1] = name_len + sizeof(*ref);
5454
5455 path->leave_spinning = 1;
5456 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
5457 if (ret != 0)
5458 goto fail;
5459
5460 inode_init_owner(inode, dir, mode);
5461 inode_set_bytes(inode, 0);
5462 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
5463 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
5464 struct btrfs_inode_item);
5465 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
5466 sizeof(*inode_item));
5467 fill_inode_item(trans, path->nodes[0], inode_item, inode);
5468
5469 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
5470 struct btrfs_inode_ref);
5471 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
5472 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
5473 ptr = (unsigned long)(ref + 1);
5474 write_extent_buffer(path->nodes[0], name, ptr, name_len);
5475
5476 btrfs_mark_buffer_dirty(path->nodes[0]);
5477 btrfs_free_path(path);
5478
5479 location = &BTRFS_I(inode)->location;
5480 location->objectid = objectid;
5481 location->offset = 0;
5482 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
5483
5484 btrfs_inherit_iflags(inode, dir);
5485
5486 if (S_ISREG(mode)) {
5487 if (btrfs_test_opt(root, NODATASUM))
5488 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
5489 if (btrfs_test_opt(root, NODATACOW))
5490 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
5491 BTRFS_INODE_NODATASUM;
5492 }
5493
5494 insert_inode_hash(inode);
5495 inode_tree_add(inode);
5496
5497 trace_btrfs_inode_new(inode);
5498 btrfs_set_inode_last_trans(trans, inode);
5499
5500 btrfs_update_root_times(trans, root);
5501
5502 return inode;
5503 fail:
5504 if (dir)
5505 BTRFS_I(dir)->index_cnt--;
5506 btrfs_free_path(path);
5507 iput(inode);
5508 return ERR_PTR(ret);
5509 }
5510
5511 static inline u8 btrfs_inode_type(struct inode *inode)
5512 {
5513 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
5514 }
5515
5516 /*
5517 * utility function to add 'inode' into 'parent_inode' with
5518 * a give name and a given sequence number.
5519 * if 'add_backref' is true, also insert a backref from the
5520 * inode to the parent directory.
5521 */
5522 int btrfs_add_link(struct btrfs_trans_handle *trans,
5523 struct inode *parent_inode, struct inode *inode,
5524 const char *name, int name_len, int add_backref, u64 index)
5525 {
5526 int ret = 0;
5527 struct btrfs_key key;
5528 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
5529 u64 ino = btrfs_ino(inode);
5530 u64 parent_ino = btrfs_ino(parent_inode);
5531
5532 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5533 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
5534 } else {
5535 key.objectid = ino;
5536 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
5537 key.offset = 0;
5538 }
5539
5540 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5541 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
5542 key.objectid, root->root_key.objectid,
5543 parent_ino, index, name, name_len);
5544 } else if (add_backref) {
5545 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
5546 parent_ino, index);
5547 }
5548
5549 /* Nothing to clean up yet */
5550 if (ret)
5551 return ret;
5552
5553 ret = btrfs_insert_dir_item(trans, root, name, name_len,
5554 parent_inode, &key,
5555 btrfs_inode_type(inode), index);
5556 if (ret == -EEXIST || ret == -EOVERFLOW)
5557 goto fail_dir_item;
5558 else if (ret) {
5559 btrfs_abort_transaction(trans, root, ret);
5560 return ret;
5561 }
5562
5563 btrfs_i_size_write(parent_inode, parent_inode->i_size +
5564 name_len * 2);
5565 inode_inc_iversion(parent_inode);
5566 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
5567 ret = btrfs_update_inode(trans, root, parent_inode);
5568 if (ret)
5569 btrfs_abort_transaction(trans, root, ret);
5570 return ret;
5571
5572 fail_dir_item:
5573 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5574 u64 local_index;
5575 int err;
5576 err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
5577 key.objectid, root->root_key.objectid,
5578 parent_ino, &local_index, name, name_len);
5579
5580 } else if (add_backref) {
5581 u64 local_index;
5582 int err;
5583
5584 err = btrfs_del_inode_ref(trans, root, name, name_len,
5585 ino, parent_ino, &local_index);
5586 }
5587 return ret;
5588 }
5589
5590 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
5591 struct inode *dir, struct dentry *dentry,
5592 struct inode *inode, int backref, u64 index)
5593 {
5594 int err = btrfs_add_link(trans, dir, inode,
5595 dentry->d_name.name, dentry->d_name.len,
5596 backref, index);
5597 if (err > 0)
5598 err = -EEXIST;
5599 return err;
5600 }
5601
5602 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
5603 umode_t mode, dev_t rdev)
5604 {
5605 struct btrfs_trans_handle *trans;
5606 struct btrfs_root *root = BTRFS_I(dir)->root;
5607 struct inode *inode = NULL;
5608 int err;
5609 int drop_inode = 0;
5610 u64 objectid;
5611 u64 index = 0;
5612
5613 if (!new_valid_dev(rdev))
5614 return -EINVAL;
5615
5616 /*
5617 * 2 for inode item and ref
5618 * 2 for dir items
5619 * 1 for xattr if selinux is on
5620 */
5621 trans = btrfs_start_transaction(root, 5);
5622 if (IS_ERR(trans))
5623 return PTR_ERR(trans);
5624
5625 err = btrfs_find_free_ino(root, &objectid);
5626 if (err)
5627 goto out_unlock;
5628
5629 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5630 dentry->d_name.len, btrfs_ino(dir), objectid,
5631 mode, &index);
5632 if (IS_ERR(inode)) {
5633 err = PTR_ERR(inode);
5634 goto out_unlock;
5635 }
5636
5637 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5638 if (err) {
5639 drop_inode = 1;
5640 goto out_unlock;
5641 }
5642
5643 /*
5644 * If the active LSM wants to access the inode during
5645 * d_instantiate it needs these. Smack checks to see
5646 * if the filesystem supports xattrs by looking at the
5647 * ops vector.
5648 */
5649
5650 inode->i_op = &btrfs_special_inode_operations;
5651 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
5652 if (err)
5653 drop_inode = 1;
5654 else {
5655 init_special_inode(inode, inode->i_mode, rdev);
5656 btrfs_update_inode(trans, root, inode);
5657 d_instantiate(dentry, inode);
5658 }
5659 out_unlock:
5660 btrfs_end_transaction(trans, root);
5661 btrfs_btree_balance_dirty(root);
5662 if (drop_inode) {
5663 inode_dec_link_count(inode);
5664 iput(inode);
5665 }
5666 return err;
5667 }
5668
5669 static int btrfs_create(struct inode *dir, struct dentry *dentry,
5670 umode_t mode, bool excl)
5671 {
5672 struct btrfs_trans_handle *trans;
5673 struct btrfs_root *root = BTRFS_I(dir)->root;
5674 struct inode *inode = NULL;
5675 int drop_inode_on_err = 0;
5676 int err;
5677 u64 objectid;
5678 u64 index = 0;
5679
5680 /*
5681 * 2 for inode item and ref
5682 * 2 for dir items
5683 * 1 for xattr if selinux is on
5684 */
5685 trans = btrfs_start_transaction(root, 5);
5686 if (IS_ERR(trans))
5687 return PTR_ERR(trans);
5688
5689 err = btrfs_find_free_ino(root, &objectid);
5690 if (err)
5691 goto out_unlock;
5692
5693 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5694 dentry->d_name.len, btrfs_ino(dir), objectid,
5695 mode, &index);
5696 if (IS_ERR(inode)) {
5697 err = PTR_ERR(inode);
5698 goto out_unlock;
5699 }
5700 drop_inode_on_err = 1;
5701
5702 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5703 if (err)
5704 goto out_unlock;
5705
5706 err = btrfs_update_inode(trans, root, inode);
5707 if (err)
5708 goto out_unlock;
5709
5710 /*
5711 * If the active LSM wants to access the inode during
5712 * d_instantiate it needs these. Smack checks to see
5713 * if the filesystem supports xattrs by looking at the
5714 * ops vector.
5715 */
5716 inode->i_fop = &btrfs_file_operations;
5717 inode->i_op = &btrfs_file_inode_operations;
5718
5719 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
5720 if (err)
5721 goto out_unlock;
5722
5723 inode->i_mapping->a_ops = &btrfs_aops;
5724 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
5725 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
5726 d_instantiate(dentry, inode);
5727
5728 out_unlock:
5729 btrfs_end_transaction(trans, root);
5730 if (err && drop_inode_on_err) {
5731 inode_dec_link_count(inode);
5732 iput(inode);
5733 }
5734 btrfs_btree_balance_dirty(root);
5735 return err;
5736 }
5737
5738 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
5739 struct dentry *dentry)
5740 {
5741 struct btrfs_trans_handle *trans;
5742 struct btrfs_root *root = BTRFS_I(dir)->root;
5743 struct inode *inode = old_dentry->d_inode;
5744 u64 index;
5745 int err;
5746 int drop_inode = 0;
5747
5748 /* do not allow sys_link's with other subvols of the same device */
5749 if (root->objectid != BTRFS_I(inode)->root->objectid)
5750 return -EXDEV;
5751
5752 if (inode->i_nlink >= BTRFS_LINK_MAX)
5753 return -EMLINK;
5754
5755 err = btrfs_set_inode_index(dir, &index);
5756 if (err)
5757 goto fail;
5758
5759 /*
5760 * 2 items for inode and inode ref
5761 * 2 items for dir items
5762 * 1 item for parent inode
5763 */
5764 trans = btrfs_start_transaction(root, 5);
5765 if (IS_ERR(trans)) {
5766 err = PTR_ERR(trans);
5767 goto fail;
5768 }
5769
5770 btrfs_inc_nlink(inode);
5771 inode_inc_iversion(inode);
5772 inode->i_ctime = CURRENT_TIME;
5773 ihold(inode);
5774 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
5775
5776 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
5777
5778 if (err) {
5779 drop_inode = 1;
5780 } else {
5781 struct dentry *parent = dentry->d_parent;
5782 err = btrfs_update_inode(trans, root, inode);
5783 if (err)
5784 goto fail;
5785 d_instantiate(dentry, inode);
5786 btrfs_log_new_name(trans, inode, NULL, parent);
5787 }
5788
5789 btrfs_end_transaction(trans, root);
5790 fail:
5791 if (drop_inode) {
5792 inode_dec_link_count(inode);
5793 iput(inode);
5794 }
5795 btrfs_btree_balance_dirty(root);
5796 return err;
5797 }
5798
5799 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
5800 {
5801 struct inode *inode = NULL;
5802 struct btrfs_trans_handle *trans;
5803 struct btrfs_root *root = BTRFS_I(dir)->root;
5804 int err = 0;
5805 int drop_on_err = 0;
5806 u64 objectid = 0;
5807 u64 index = 0;
5808
5809 /*
5810 * 2 items for inode and ref
5811 * 2 items for dir items
5812 * 1 for xattr if selinux is on
5813 */
5814 trans = btrfs_start_transaction(root, 5);
5815 if (IS_ERR(trans))
5816 return PTR_ERR(trans);
5817
5818 err = btrfs_find_free_ino(root, &objectid);
5819 if (err)
5820 goto out_fail;
5821
5822 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5823 dentry->d_name.len, btrfs_ino(dir), objectid,
5824 S_IFDIR | mode, &index);
5825 if (IS_ERR(inode)) {
5826 err = PTR_ERR(inode);
5827 goto out_fail;
5828 }
5829
5830 drop_on_err = 1;
5831
5832 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5833 if (err)
5834 goto out_fail;
5835
5836 inode->i_op = &btrfs_dir_inode_operations;
5837 inode->i_fop = &btrfs_dir_file_operations;
5838
5839 btrfs_i_size_write(inode, 0);
5840 err = btrfs_update_inode(trans, root, inode);
5841 if (err)
5842 goto out_fail;
5843
5844 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
5845 dentry->d_name.len, 0, index);
5846 if (err)
5847 goto out_fail;
5848
5849 d_instantiate(dentry, inode);
5850 drop_on_err = 0;
5851
5852 out_fail:
5853 btrfs_end_transaction(trans, root);
5854 if (drop_on_err)
5855 iput(inode);
5856 btrfs_btree_balance_dirty(root);
5857 return err;
5858 }
5859
5860 /* helper for btfs_get_extent. Given an existing extent in the tree,
5861 * and an extent that you want to insert, deal with overlap and insert
5862 * the new extent into the tree.
5863 */
5864 static int merge_extent_mapping(struct extent_map_tree *em_tree,
5865 struct extent_map *existing,
5866 struct extent_map *em,
5867 u64 map_start, u64 map_len)
5868 {
5869 u64 start_diff;
5870
5871 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
5872 start_diff = map_start - em->start;
5873 em->start = map_start;
5874 em->len = map_len;
5875 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
5876 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
5877 em->block_start += start_diff;
5878 em->block_len -= start_diff;
5879 }
5880 return add_extent_mapping(em_tree, em, 0);
5881 }
5882
5883 static noinline int uncompress_inline(struct btrfs_path *path,
5884 struct inode *inode, struct page *page,
5885 size_t pg_offset, u64 extent_offset,
5886 struct btrfs_file_extent_item *item)
5887 {
5888 int ret;
5889 struct extent_buffer *leaf = path->nodes[0];
5890 char *tmp;
5891 size_t max_size;
5892 unsigned long inline_size;
5893 unsigned long ptr;
5894 int compress_type;
5895
5896 WARN_ON(pg_offset != 0);
5897 compress_type = btrfs_file_extent_compression(leaf, item);
5898 max_size = btrfs_file_extent_ram_bytes(leaf, item);
5899 inline_size = btrfs_file_extent_inline_item_len(leaf,
5900 btrfs_item_nr(leaf, path->slots[0]));
5901 tmp = kmalloc(inline_size, GFP_NOFS);
5902 if (!tmp)
5903 return -ENOMEM;
5904 ptr = btrfs_file_extent_inline_start(item);
5905
5906 read_extent_buffer(leaf, tmp, ptr, inline_size);
5907
5908 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
5909 ret = btrfs_decompress(compress_type, tmp, page,
5910 extent_offset, inline_size, max_size);
5911 if (ret) {
5912 char *kaddr = kmap_atomic(page);
5913 unsigned long copy_size = min_t(u64,
5914 PAGE_CACHE_SIZE - pg_offset,
5915 max_size - extent_offset);
5916 memset(kaddr + pg_offset, 0, copy_size);
5917 kunmap_atomic(kaddr);
5918 }
5919 kfree(tmp);
5920 return 0;
5921 }
5922
5923 /*
5924 * a bit scary, this does extent mapping from logical file offset to the disk.
5925 * the ugly parts come from merging extents from the disk with the in-ram
5926 * representation. This gets more complex because of the data=ordered code,
5927 * where the in-ram extents might be locked pending data=ordered completion.
5928 *
5929 * This also copies inline extents directly into the page.
5930 */
5931
5932 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
5933 size_t pg_offset, u64 start, u64 len,
5934 int create)
5935 {
5936 int ret;
5937 int err = 0;
5938 u64 bytenr;
5939 u64 extent_start = 0;
5940 u64 extent_end = 0;
5941 u64 objectid = btrfs_ino(inode);
5942 u32 found_type;
5943 struct btrfs_path *path = NULL;
5944 struct btrfs_root *root = BTRFS_I(inode)->root;
5945 struct btrfs_file_extent_item *item;
5946 struct extent_buffer *leaf;
5947 struct btrfs_key found_key;
5948 struct extent_map *em = NULL;
5949 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
5950 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5951 struct btrfs_trans_handle *trans = NULL;
5952 int compress_type;
5953
5954 again:
5955 read_lock(&em_tree->lock);
5956 em = lookup_extent_mapping(em_tree, start, len);
5957 if (em)
5958 em->bdev = root->fs_info->fs_devices->latest_bdev;
5959 read_unlock(&em_tree->lock);
5960
5961 if (em) {
5962 if (em->start > start || em->start + em->len <= start)
5963 free_extent_map(em);
5964 else if (em->block_start == EXTENT_MAP_INLINE && page)
5965 free_extent_map(em);
5966 else
5967 goto out;
5968 }
5969 em = alloc_extent_map();
5970 if (!em) {
5971 err = -ENOMEM;
5972 goto out;
5973 }
5974 em->bdev = root->fs_info->fs_devices->latest_bdev;
5975 em->start = EXTENT_MAP_HOLE;
5976 em->orig_start = EXTENT_MAP_HOLE;
5977 em->len = (u64)-1;
5978 em->block_len = (u64)-1;
5979
5980 if (!path) {
5981 path = btrfs_alloc_path();
5982 if (!path) {
5983 err = -ENOMEM;
5984 goto out;
5985 }
5986 /*
5987 * Chances are we'll be called again, so go ahead and do
5988 * readahead
5989 */
5990 path->reada = 1;
5991 }
5992
5993 ret = btrfs_lookup_file_extent(trans, root, path,
5994 objectid, start, trans != NULL);
5995 if (ret < 0) {
5996 err = ret;
5997 goto out;
5998 }
5999
6000 if (ret != 0) {
6001 if (path->slots[0] == 0)
6002 goto not_found;
6003 path->slots[0]--;
6004 }
6005
6006 leaf = path->nodes[0];
6007 item = btrfs_item_ptr(leaf, path->slots[0],
6008 struct btrfs_file_extent_item);
6009 /* are we inside the extent that was found? */
6010 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6011 found_type = btrfs_key_type(&found_key);
6012 if (found_key.objectid != objectid ||
6013 found_type != BTRFS_EXTENT_DATA_KEY) {
6014 goto not_found;
6015 }
6016
6017 found_type = btrfs_file_extent_type(leaf, item);
6018 extent_start = found_key.offset;
6019 compress_type = btrfs_file_extent_compression(leaf, item);
6020 if (found_type == BTRFS_FILE_EXTENT_REG ||
6021 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6022 extent_end = extent_start +
6023 btrfs_file_extent_num_bytes(leaf, item);
6024 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6025 size_t size;
6026 size = btrfs_file_extent_inline_len(leaf, item);
6027 extent_end = ALIGN(extent_start + size, root->sectorsize);
6028 }
6029
6030 if (start >= extent_end) {
6031 path->slots[0]++;
6032 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
6033 ret = btrfs_next_leaf(root, path);
6034 if (ret < 0) {
6035 err = ret;
6036 goto out;
6037 }
6038 if (ret > 0)
6039 goto not_found;
6040 leaf = path->nodes[0];
6041 }
6042 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6043 if (found_key.objectid != objectid ||
6044 found_key.type != BTRFS_EXTENT_DATA_KEY)
6045 goto not_found;
6046 if (start + len <= found_key.offset)
6047 goto not_found;
6048 em->start = start;
6049 em->orig_start = start;
6050 em->len = found_key.offset - start;
6051 goto not_found_em;
6052 }
6053
6054 em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, item);
6055 if (found_type == BTRFS_FILE_EXTENT_REG ||
6056 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6057 em->start = extent_start;
6058 em->len = extent_end - extent_start;
6059 em->orig_start = extent_start -
6060 btrfs_file_extent_offset(leaf, item);
6061 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf,
6062 item);
6063 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
6064 if (bytenr == 0) {
6065 em->block_start = EXTENT_MAP_HOLE;
6066 goto insert;
6067 }
6068 if (compress_type != BTRFS_COMPRESS_NONE) {
6069 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
6070 em->compress_type = compress_type;
6071 em->block_start = bytenr;
6072 em->block_len = em->orig_block_len;
6073 } else {
6074 bytenr += btrfs_file_extent_offset(leaf, item);
6075 em->block_start = bytenr;
6076 em->block_len = em->len;
6077 if (found_type == BTRFS_FILE_EXTENT_PREALLOC)
6078 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
6079 }
6080 goto insert;
6081 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6082 unsigned long ptr;
6083 char *map;
6084 size_t size;
6085 size_t extent_offset;
6086 size_t copy_size;
6087
6088 em->block_start = EXTENT_MAP_INLINE;
6089 if (!page || create) {
6090 em->start = extent_start;
6091 em->len = extent_end - extent_start;
6092 goto out;
6093 }
6094
6095 size = btrfs_file_extent_inline_len(leaf, item);
6096 extent_offset = page_offset(page) + pg_offset - extent_start;
6097 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
6098 size - extent_offset);
6099 em->start = extent_start + extent_offset;
6100 em->len = ALIGN(copy_size, root->sectorsize);
6101 em->orig_block_len = em->len;
6102 em->orig_start = em->start;
6103 if (compress_type) {
6104 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
6105 em->compress_type = compress_type;
6106 }
6107 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
6108 if (create == 0 && !PageUptodate(page)) {
6109 if (btrfs_file_extent_compression(leaf, item) !=
6110 BTRFS_COMPRESS_NONE) {
6111 ret = uncompress_inline(path, inode, page,
6112 pg_offset,
6113 extent_offset, item);
6114 BUG_ON(ret); /* -ENOMEM */
6115 } else {
6116 map = kmap(page);
6117 read_extent_buffer(leaf, map + pg_offset, ptr,
6118 copy_size);
6119 if (pg_offset + copy_size < PAGE_CACHE_SIZE) {
6120 memset(map + pg_offset + copy_size, 0,
6121 PAGE_CACHE_SIZE - pg_offset -
6122 copy_size);
6123 }
6124 kunmap(page);
6125 }
6126 flush_dcache_page(page);
6127 } else if (create && PageUptodate(page)) {
6128 BUG();
6129 if (!trans) {
6130 kunmap(page);
6131 free_extent_map(em);
6132 em = NULL;
6133
6134 btrfs_release_path(path);
6135 trans = btrfs_join_transaction(root);
6136
6137 if (IS_ERR(trans))
6138 return ERR_CAST(trans);
6139 goto again;
6140 }
6141 map = kmap(page);
6142 write_extent_buffer(leaf, map + pg_offset, ptr,
6143 copy_size);
6144 kunmap(page);
6145 btrfs_mark_buffer_dirty(leaf);
6146 }
6147 set_extent_uptodate(io_tree, em->start,
6148 extent_map_end(em) - 1, NULL, GFP_NOFS);
6149 goto insert;
6150 } else {
6151 WARN(1, KERN_ERR "btrfs unknown found_type %d\n", found_type);
6152 }
6153 not_found:
6154 em->start = start;
6155 em->orig_start = start;
6156 em->len = len;
6157 not_found_em:
6158 em->block_start = EXTENT_MAP_HOLE;
6159 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
6160 insert:
6161 btrfs_release_path(path);
6162 if (em->start > start || extent_map_end(em) <= start) {
6163 btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]",
6164 (unsigned long long)em->start,
6165 (unsigned long long)em->len,
6166 (unsigned long long)start,
6167 (unsigned long long)len);
6168 err = -EIO;
6169 goto out;
6170 }
6171
6172 err = 0;
6173 write_lock(&em_tree->lock);
6174 ret = add_extent_mapping(em_tree, em, 0);
6175 /* it is possible that someone inserted the extent into the tree
6176 * while we had the lock dropped. It is also possible that
6177 * an overlapping map exists in the tree
6178 */
6179 if (ret == -EEXIST) {
6180 struct extent_map *existing;
6181
6182 ret = 0;
6183
6184 existing = lookup_extent_mapping(em_tree, start, len);
6185 if (existing && (existing->start > start ||
6186 existing->start + existing->len <= start)) {
6187 free_extent_map(existing);
6188 existing = NULL;
6189 }
6190 if (!existing) {
6191 existing = lookup_extent_mapping(em_tree, em->start,
6192 em->len);
6193 if (existing) {
6194 err = merge_extent_mapping(em_tree, existing,
6195 em, start,
6196 root->sectorsize);
6197 free_extent_map(existing);
6198 if (err) {
6199 free_extent_map(em);
6200 em = NULL;
6201 }
6202 } else {
6203 err = -EIO;
6204 free_extent_map(em);
6205 em = NULL;
6206 }
6207 } else {
6208 free_extent_map(em);
6209 em = existing;
6210 err = 0;
6211 }
6212 }
6213 write_unlock(&em_tree->lock);
6214 out:
6215
6216 if (em)
6217 trace_btrfs_get_extent(root, em);
6218
6219 if (path)
6220 btrfs_free_path(path);
6221 if (trans) {
6222 ret = btrfs_end_transaction(trans, root);
6223 if (!err)
6224 err = ret;
6225 }
6226 if (err) {
6227 free_extent_map(em);
6228 return ERR_PTR(err);
6229 }
6230 BUG_ON(!em); /* Error is always set */
6231 return em;
6232 }
6233
6234 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
6235 size_t pg_offset, u64 start, u64 len,
6236 int create)
6237 {
6238 struct extent_map *em;
6239 struct extent_map *hole_em = NULL;
6240 u64 range_start = start;
6241 u64 end;
6242 u64 found;
6243 u64 found_end;
6244 int err = 0;
6245
6246 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
6247 if (IS_ERR(em))
6248 return em;
6249 if (em) {
6250 /*
6251 * if our em maps to
6252 * - a hole or
6253 * - a pre-alloc extent,
6254 * there might actually be delalloc bytes behind it.
6255 */
6256 if (em->block_start != EXTENT_MAP_HOLE &&
6257 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6258 return em;
6259 else
6260 hole_em = em;
6261 }
6262
6263 /* check to see if we've wrapped (len == -1 or similar) */
6264 end = start + len;
6265 if (end < start)
6266 end = (u64)-1;
6267 else
6268 end -= 1;
6269
6270 em = NULL;
6271
6272 /* ok, we didn't find anything, lets look for delalloc */
6273 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
6274 end, len, EXTENT_DELALLOC, 1);
6275 found_end = range_start + found;
6276 if (found_end < range_start)
6277 found_end = (u64)-1;
6278
6279 /*
6280 * we didn't find anything useful, return
6281 * the original results from get_extent()
6282 */
6283 if (range_start > end || found_end <= start) {
6284 em = hole_em;
6285 hole_em = NULL;
6286 goto out;
6287 }
6288
6289 /* adjust the range_start to make sure it doesn't
6290 * go backwards from the start they passed in
6291 */
6292 range_start = max(start,range_start);
6293 found = found_end - range_start;
6294
6295 if (found > 0) {
6296 u64 hole_start = start;
6297 u64 hole_len = len;
6298
6299 em = alloc_extent_map();
6300 if (!em) {
6301 err = -ENOMEM;
6302 goto out;
6303 }
6304 /*
6305 * when btrfs_get_extent can't find anything it
6306 * returns one huge hole
6307 *
6308 * make sure what it found really fits our range, and
6309 * adjust to make sure it is based on the start from
6310 * the caller
6311 */
6312 if (hole_em) {
6313 u64 calc_end = extent_map_end(hole_em);
6314
6315 if (calc_end <= start || (hole_em->start > end)) {
6316 free_extent_map(hole_em);
6317 hole_em = NULL;
6318 } else {
6319 hole_start = max(hole_em->start, start);
6320 hole_len = calc_end - hole_start;
6321 }
6322 }
6323 em->bdev = NULL;
6324 if (hole_em && range_start > hole_start) {
6325 /* our hole starts before our delalloc, so we
6326 * have to return just the parts of the hole
6327 * that go until the delalloc starts
6328 */
6329 em->len = min(hole_len,
6330 range_start - hole_start);
6331 em->start = hole_start;
6332 em->orig_start = hole_start;
6333 /*
6334 * don't adjust block start at all,
6335 * it is fixed at EXTENT_MAP_HOLE
6336 */
6337 em->block_start = hole_em->block_start;
6338 em->block_len = hole_len;
6339 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
6340 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
6341 } else {
6342 em->start = range_start;
6343 em->len = found;
6344 em->orig_start = range_start;
6345 em->block_start = EXTENT_MAP_DELALLOC;
6346 em->block_len = found;
6347 }
6348 } else if (hole_em) {
6349 return hole_em;
6350 }
6351 out:
6352
6353 free_extent_map(hole_em);
6354 if (err) {
6355 free_extent_map(em);
6356 return ERR_PTR(err);
6357 }
6358 return em;
6359 }
6360
6361 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
6362 u64 start, u64 len)
6363 {
6364 struct btrfs_root *root = BTRFS_I(inode)->root;
6365 struct btrfs_trans_handle *trans;
6366 struct extent_map *em;
6367 struct btrfs_key ins;
6368 u64 alloc_hint;
6369 int ret;
6370
6371 trans = btrfs_join_transaction(root);
6372 if (IS_ERR(trans))
6373 return ERR_CAST(trans);
6374
6375 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
6376
6377 alloc_hint = get_extent_allocation_hint(inode, start, len);
6378 ret = btrfs_reserve_extent(trans, root, len, root->sectorsize, 0,
6379 alloc_hint, &ins, 1);
6380 if (ret) {
6381 em = ERR_PTR(ret);
6382 goto out;
6383 }
6384
6385 em = create_pinned_em(inode, start, ins.offset, start, ins.objectid,
6386 ins.offset, ins.offset, ins.offset, 0);
6387 if (IS_ERR(em))
6388 goto out;
6389
6390 ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
6391 ins.offset, ins.offset, 0);
6392 if (ret) {
6393 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
6394 em = ERR_PTR(ret);
6395 }
6396 out:
6397 btrfs_end_transaction(trans, root);
6398 return em;
6399 }
6400
6401 /*
6402 * returns 1 when the nocow is safe, < 1 on error, 0 if the
6403 * block must be cow'd
6404 */
6405 noinline int can_nocow_extent(struct btrfs_trans_handle *trans,
6406 struct inode *inode, u64 offset, u64 *len,
6407 u64 *orig_start, u64 *orig_block_len,
6408 u64 *ram_bytes)
6409 {
6410 struct btrfs_path *path;
6411 int ret;
6412 struct extent_buffer *leaf;
6413 struct btrfs_root *root = BTRFS_I(inode)->root;
6414 struct btrfs_file_extent_item *fi;
6415 struct btrfs_key key;
6416 u64 disk_bytenr;
6417 u64 backref_offset;
6418 u64 extent_end;
6419 u64 num_bytes;
6420 int slot;
6421 int found_type;
6422 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
6423 path = btrfs_alloc_path();
6424 if (!path)
6425 return -ENOMEM;
6426
6427 ret = btrfs_lookup_file_extent(trans, root, path, btrfs_ino(inode),
6428 offset, 0);
6429 if (ret < 0)
6430 goto out;
6431
6432 slot = path->slots[0];
6433 if (ret == 1) {
6434 if (slot == 0) {
6435 /* can't find the item, must cow */
6436 ret = 0;
6437 goto out;
6438 }
6439 slot--;
6440 }
6441 ret = 0;
6442 leaf = path->nodes[0];
6443 btrfs_item_key_to_cpu(leaf, &key, slot);
6444 if (key.objectid != btrfs_ino(inode) ||
6445 key.type != BTRFS_EXTENT_DATA_KEY) {
6446 /* not our file or wrong item type, must cow */
6447 goto out;
6448 }
6449
6450 if (key.offset > offset) {
6451 /* Wrong offset, must cow */
6452 goto out;
6453 }
6454
6455 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
6456 found_type = btrfs_file_extent_type(leaf, fi);
6457 if (found_type != BTRFS_FILE_EXTENT_REG &&
6458 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
6459 /* not a regular extent, must cow */
6460 goto out;
6461 }
6462
6463 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
6464 goto out;
6465
6466 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
6467 if (disk_bytenr == 0)
6468 goto out;
6469
6470 if (btrfs_file_extent_compression(leaf, fi) ||
6471 btrfs_file_extent_encryption(leaf, fi) ||
6472 btrfs_file_extent_other_encoding(leaf, fi))
6473 goto out;
6474
6475 backref_offset = btrfs_file_extent_offset(leaf, fi);
6476
6477 if (orig_start) {
6478 *orig_start = key.offset - backref_offset;
6479 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
6480 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
6481 }
6482
6483 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
6484
6485 if (btrfs_extent_readonly(root, disk_bytenr))
6486 goto out;
6487
6488 /*
6489 * look for other files referencing this extent, if we
6490 * find any we must cow
6491 */
6492 if (btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
6493 key.offset - backref_offset, disk_bytenr))
6494 goto out;
6495
6496 /*
6497 * adjust disk_bytenr and num_bytes to cover just the bytes
6498 * in this extent we are about to write. If there
6499 * are any csums in that range we have to cow in order
6500 * to keep the csums correct
6501 */
6502 disk_bytenr += backref_offset;
6503 disk_bytenr += offset - key.offset;
6504 num_bytes = min(offset + *len, extent_end) - offset;
6505 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
6506 goto out;
6507 /*
6508 * all of the above have passed, it is safe to overwrite this extent
6509 * without cow
6510 */
6511 *len = num_bytes;
6512 ret = 1;
6513 out:
6514 btrfs_free_path(path);
6515 return ret;
6516 }
6517
6518 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
6519 struct extent_state **cached_state, int writing)
6520 {
6521 struct btrfs_ordered_extent *ordered;
6522 int ret = 0;
6523
6524 while (1) {
6525 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6526 0, cached_state);
6527 /*
6528 * We're concerned with the entire range that we're going to be
6529 * doing DIO to, so we need to make sure theres no ordered
6530 * extents in this range.
6531 */
6532 ordered = btrfs_lookup_ordered_range(inode, lockstart,
6533 lockend - lockstart + 1);
6534
6535 /*
6536 * We need to make sure there are no buffered pages in this
6537 * range either, we could have raced between the invalidate in
6538 * generic_file_direct_write and locking the extent. The
6539 * invalidate needs to happen so that reads after a write do not
6540 * get stale data.
6541 */
6542 if (!ordered && (!writing ||
6543 !test_range_bit(&BTRFS_I(inode)->io_tree,
6544 lockstart, lockend, EXTENT_UPTODATE, 0,
6545 *cached_state)))
6546 break;
6547
6548 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6549 cached_state, GFP_NOFS);
6550
6551 if (ordered) {
6552 btrfs_start_ordered_extent(inode, ordered, 1);
6553 btrfs_put_ordered_extent(ordered);
6554 } else {
6555 /* Screw you mmap */
6556 ret = filemap_write_and_wait_range(inode->i_mapping,
6557 lockstart,
6558 lockend);
6559 if (ret)
6560 break;
6561
6562 /*
6563 * If we found a page that couldn't be invalidated just
6564 * fall back to buffered.
6565 */
6566 ret = invalidate_inode_pages2_range(inode->i_mapping,
6567 lockstart >> PAGE_CACHE_SHIFT,
6568 lockend >> PAGE_CACHE_SHIFT);
6569 if (ret)
6570 break;
6571 }
6572
6573 cond_resched();
6574 }
6575
6576 return ret;
6577 }
6578
6579 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
6580 u64 len, u64 orig_start,
6581 u64 block_start, u64 block_len,
6582 u64 orig_block_len, u64 ram_bytes,
6583 int type)
6584 {
6585 struct extent_map_tree *em_tree;
6586 struct extent_map *em;
6587 struct btrfs_root *root = BTRFS_I(inode)->root;
6588 int ret;
6589
6590 em_tree = &BTRFS_I(inode)->extent_tree;
6591 em = alloc_extent_map();
6592 if (!em)
6593 return ERR_PTR(-ENOMEM);
6594
6595 em->start = start;
6596 em->orig_start = orig_start;
6597 em->mod_start = start;
6598 em->mod_len = len;
6599 em->len = len;
6600 em->block_len = block_len;
6601 em->block_start = block_start;
6602 em->bdev = root->fs_info->fs_devices->latest_bdev;
6603 em->orig_block_len = orig_block_len;
6604 em->ram_bytes = ram_bytes;
6605 em->generation = -1;
6606 set_bit(EXTENT_FLAG_PINNED, &em->flags);
6607 if (type == BTRFS_ORDERED_PREALLOC)
6608 set_bit(EXTENT_FLAG_FILLING, &em->flags);
6609
6610 do {
6611 btrfs_drop_extent_cache(inode, em->start,
6612 em->start + em->len - 1, 0);
6613 write_lock(&em_tree->lock);
6614 ret = add_extent_mapping(em_tree, em, 1);
6615 write_unlock(&em_tree->lock);
6616 } while (ret == -EEXIST);
6617
6618 if (ret) {
6619 free_extent_map(em);
6620 return ERR_PTR(ret);
6621 }
6622
6623 return em;
6624 }
6625
6626
6627 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
6628 struct buffer_head *bh_result, int create)
6629 {
6630 struct extent_map *em;
6631 struct btrfs_root *root = BTRFS_I(inode)->root;
6632 struct extent_state *cached_state = NULL;
6633 u64 start = iblock << inode->i_blkbits;
6634 u64 lockstart, lockend;
6635 u64 len = bh_result->b_size;
6636 struct btrfs_trans_handle *trans;
6637 int unlock_bits = EXTENT_LOCKED;
6638 int ret = 0;
6639
6640 if (create)
6641 unlock_bits |= EXTENT_DELALLOC | EXTENT_DIRTY;
6642 else
6643 len = min_t(u64, len, root->sectorsize);
6644
6645 lockstart = start;
6646 lockend = start + len - 1;
6647
6648 /*
6649 * If this errors out it's because we couldn't invalidate pagecache for
6650 * this range and we need to fallback to buffered.
6651 */
6652 if (lock_extent_direct(inode, lockstart, lockend, &cached_state, create))
6653 return -ENOTBLK;
6654
6655 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
6656 if (IS_ERR(em)) {
6657 ret = PTR_ERR(em);
6658 goto unlock_err;
6659 }
6660
6661 /*
6662 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
6663 * io. INLINE is special, and we could probably kludge it in here, but
6664 * it's still buffered so for safety lets just fall back to the generic
6665 * buffered path.
6666 *
6667 * For COMPRESSED we _have_ to read the entire extent in so we can
6668 * decompress it, so there will be buffering required no matter what we
6669 * do, so go ahead and fallback to buffered.
6670 *
6671 * We return -ENOTBLK because thats what makes DIO go ahead and go back
6672 * to buffered IO. Don't blame me, this is the price we pay for using
6673 * the generic code.
6674 */
6675 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
6676 em->block_start == EXTENT_MAP_INLINE) {
6677 free_extent_map(em);
6678 ret = -ENOTBLK;
6679 goto unlock_err;
6680 }
6681
6682 /* Just a good old fashioned hole, return */
6683 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
6684 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
6685 free_extent_map(em);
6686 goto unlock_err;
6687 }
6688
6689 /*
6690 * We don't allocate a new extent in the following cases
6691 *
6692 * 1) The inode is marked as NODATACOW. In this case we'll just use the
6693 * existing extent.
6694 * 2) The extent is marked as PREALLOC. We're good to go here and can
6695 * just use the extent.
6696 *
6697 */
6698 if (!create) {
6699 len = min(len, em->len - (start - em->start));
6700 lockstart = start + len;
6701 goto unlock;
6702 }
6703
6704 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
6705 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
6706 em->block_start != EXTENT_MAP_HOLE)) {
6707 int type;
6708 int ret;
6709 u64 block_start, orig_start, orig_block_len, ram_bytes;
6710
6711 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6712 type = BTRFS_ORDERED_PREALLOC;
6713 else
6714 type = BTRFS_ORDERED_NOCOW;
6715 len = min(len, em->len - (start - em->start));
6716 block_start = em->block_start + (start - em->start);
6717
6718 /*
6719 * we're not going to log anything, but we do need
6720 * to make sure the current transaction stays open
6721 * while we look for nocow cross refs
6722 */
6723 trans = btrfs_join_transaction(root);
6724 if (IS_ERR(trans))
6725 goto must_cow;
6726
6727 if (can_nocow_extent(trans, inode, start, &len, &orig_start,
6728 &orig_block_len, &ram_bytes) == 1) {
6729 if (type == BTRFS_ORDERED_PREALLOC) {
6730 free_extent_map(em);
6731 em = create_pinned_em(inode, start, len,
6732 orig_start,
6733 block_start, len,
6734 orig_block_len,
6735 ram_bytes, type);
6736 if (IS_ERR(em)) {
6737 btrfs_end_transaction(trans, root);
6738 goto unlock_err;
6739 }
6740 }
6741
6742 ret = btrfs_add_ordered_extent_dio(inode, start,
6743 block_start, len, len, type);
6744 btrfs_end_transaction(trans, root);
6745 if (ret) {
6746 free_extent_map(em);
6747 goto unlock_err;
6748 }
6749 goto unlock;
6750 }
6751 btrfs_end_transaction(trans, root);
6752 }
6753 must_cow:
6754 /*
6755 * this will cow the extent, reset the len in case we changed
6756 * it above
6757 */
6758 len = bh_result->b_size;
6759 free_extent_map(em);
6760 em = btrfs_new_extent_direct(inode, start, len);
6761 if (IS_ERR(em)) {
6762 ret = PTR_ERR(em);
6763 goto unlock_err;
6764 }
6765 len = min(len, em->len - (start - em->start));
6766 unlock:
6767 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
6768 inode->i_blkbits;
6769 bh_result->b_size = len;
6770 bh_result->b_bdev = em->bdev;
6771 set_buffer_mapped(bh_result);
6772 if (create) {
6773 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6774 set_buffer_new(bh_result);
6775
6776 /*
6777 * Need to update the i_size under the extent lock so buffered
6778 * readers will get the updated i_size when we unlock.
6779 */
6780 if (start + len > i_size_read(inode))
6781 i_size_write(inode, start + len);
6782
6783 spin_lock(&BTRFS_I(inode)->lock);
6784 BTRFS_I(inode)->outstanding_extents++;
6785 spin_unlock(&BTRFS_I(inode)->lock);
6786
6787 ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
6788 lockstart + len - 1, EXTENT_DELALLOC, NULL,
6789 &cached_state, GFP_NOFS);
6790 BUG_ON(ret);
6791 }
6792
6793 /*
6794 * In the case of write we need to clear and unlock the entire range,
6795 * in the case of read we need to unlock only the end area that we
6796 * aren't using if there is any left over space.
6797 */
6798 if (lockstart < lockend) {
6799 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
6800 lockend, unlock_bits, 1, 0,
6801 &cached_state, GFP_NOFS);
6802 } else {
6803 free_extent_state(cached_state);
6804 }
6805
6806 free_extent_map(em);
6807
6808 return 0;
6809
6810 unlock_err:
6811 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6812 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
6813 return ret;
6814 }
6815
6816 struct btrfs_dio_private {
6817 struct inode *inode;
6818 u64 logical_offset;
6819 u64 disk_bytenr;
6820 u64 bytes;
6821 void *private;
6822
6823 /* number of bios pending for this dio */
6824 atomic_t pending_bios;
6825
6826 /* IO errors */
6827 int errors;
6828
6829 /* orig_bio is our btrfs_io_bio */
6830 struct bio *orig_bio;
6831
6832 /* dio_bio came from fs/direct-io.c */
6833 struct bio *dio_bio;
6834 };
6835
6836 static void btrfs_endio_direct_read(struct bio *bio, int err)
6837 {
6838 struct btrfs_dio_private *dip = bio->bi_private;
6839 struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
6840 struct bio_vec *bvec = bio->bi_io_vec;
6841 struct inode *inode = dip->inode;
6842 struct btrfs_root *root = BTRFS_I(inode)->root;
6843 struct bio *dio_bio;
6844 u64 start;
6845
6846 start = dip->logical_offset;
6847 do {
6848 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
6849 struct page *page = bvec->bv_page;
6850 char *kaddr;
6851 u32 csum = ~(u32)0;
6852 u64 private = ~(u32)0;
6853 unsigned long flags;
6854
6855 if (get_state_private(&BTRFS_I(inode)->io_tree,
6856 start, &private))
6857 goto failed;
6858 local_irq_save(flags);
6859 kaddr = kmap_atomic(page);
6860 csum = btrfs_csum_data(kaddr + bvec->bv_offset,
6861 csum, bvec->bv_len);
6862 btrfs_csum_final(csum, (char *)&csum);
6863 kunmap_atomic(kaddr);
6864 local_irq_restore(flags);
6865
6866 flush_dcache_page(bvec->bv_page);
6867 if (csum != private) {
6868 failed:
6869 btrfs_err(root->fs_info, "csum failed ino %llu off %llu csum %u private %u",
6870 (unsigned long long)btrfs_ino(inode),
6871 (unsigned long long)start,
6872 csum, (unsigned)private);
6873 err = -EIO;
6874 }
6875 }
6876
6877 start += bvec->bv_len;
6878 bvec++;
6879 } while (bvec <= bvec_end);
6880
6881 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
6882 dip->logical_offset + dip->bytes - 1);
6883 dio_bio = dip->dio_bio;
6884
6885 kfree(dip);
6886
6887 /* If we had a csum failure make sure to clear the uptodate flag */
6888 if (err)
6889 clear_bit(BIO_UPTODATE, &dio_bio->bi_flags);
6890 dio_end_io(dio_bio, err);
6891 bio_put(bio);
6892 }
6893
6894 static void btrfs_endio_direct_write(struct bio *bio, int err)
6895 {
6896 struct btrfs_dio_private *dip = bio->bi_private;
6897 struct inode *inode = dip->inode;
6898 struct btrfs_root *root = BTRFS_I(inode)->root;
6899 struct btrfs_ordered_extent *ordered = NULL;
6900 u64 ordered_offset = dip->logical_offset;
6901 u64 ordered_bytes = dip->bytes;
6902 struct bio *dio_bio;
6903 int ret;
6904
6905 if (err)
6906 goto out_done;
6907 again:
6908 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
6909 &ordered_offset,
6910 ordered_bytes, !err);
6911 if (!ret)
6912 goto out_test;
6913
6914 ordered->work.func = finish_ordered_fn;
6915 ordered->work.flags = 0;
6916 btrfs_queue_worker(&root->fs_info->endio_write_workers,
6917 &ordered->work);
6918 out_test:
6919 /*
6920 * our bio might span multiple ordered extents. If we haven't
6921 * completed the accounting for the whole dio, go back and try again
6922 */
6923 if (ordered_offset < dip->logical_offset + dip->bytes) {
6924 ordered_bytes = dip->logical_offset + dip->bytes -
6925 ordered_offset;
6926 ordered = NULL;
6927 goto again;
6928 }
6929 out_done:
6930 dio_bio = dip->dio_bio;
6931
6932 kfree(dip);
6933
6934 /* If we had an error make sure to clear the uptodate flag */
6935 if (err)
6936 clear_bit(BIO_UPTODATE, &dio_bio->bi_flags);
6937 dio_end_io(dio_bio, err);
6938 bio_put(bio);
6939 }
6940
6941 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
6942 struct bio *bio, int mirror_num,
6943 unsigned long bio_flags, u64 offset)
6944 {
6945 int ret;
6946 struct btrfs_root *root = BTRFS_I(inode)->root;
6947 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
6948 BUG_ON(ret); /* -ENOMEM */
6949 return 0;
6950 }
6951
6952 static void btrfs_end_dio_bio(struct bio *bio, int err)
6953 {
6954 struct btrfs_dio_private *dip = bio->bi_private;
6955
6956 if (err) {
6957 printk(KERN_ERR "btrfs direct IO failed ino %llu rw %lu "
6958 "sector %#Lx len %u err no %d\n",
6959 (unsigned long long)btrfs_ino(dip->inode), bio->bi_rw,
6960 (unsigned long long)bio->bi_sector, bio->bi_size, err);
6961 dip->errors = 1;
6962
6963 /*
6964 * before atomic variable goto zero, we must make sure
6965 * dip->errors is perceived to be set.
6966 */
6967 smp_mb__before_atomic_dec();
6968 }
6969
6970 /* if there are more bios still pending for this dio, just exit */
6971 if (!atomic_dec_and_test(&dip->pending_bios))
6972 goto out;
6973
6974 if (dip->errors) {
6975 bio_io_error(dip->orig_bio);
6976 } else {
6977 set_bit(BIO_UPTODATE, &dip->dio_bio->bi_flags);
6978 bio_endio(dip->orig_bio, 0);
6979 }
6980 out:
6981 bio_put(bio);
6982 }
6983
6984 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
6985 u64 first_sector, gfp_t gfp_flags)
6986 {
6987 int nr_vecs = bio_get_nr_vecs(bdev);
6988 return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags);
6989 }
6990
6991 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
6992 int rw, u64 file_offset, int skip_sum,
6993 int async_submit)
6994 {
6995 int write = rw & REQ_WRITE;
6996 struct btrfs_root *root = BTRFS_I(inode)->root;
6997 int ret;
6998
6999 if (async_submit)
7000 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
7001
7002 bio_get(bio);
7003
7004 if (!write) {
7005 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
7006 if (ret)
7007 goto err;
7008 }
7009
7010 if (skip_sum)
7011 goto map;
7012
7013 if (write && async_submit) {
7014 ret = btrfs_wq_submit_bio(root->fs_info,
7015 inode, rw, bio, 0, 0,
7016 file_offset,
7017 __btrfs_submit_bio_start_direct_io,
7018 __btrfs_submit_bio_done);
7019 goto err;
7020 } else if (write) {
7021 /*
7022 * If we aren't doing async submit, calculate the csum of the
7023 * bio now.
7024 */
7025 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
7026 if (ret)
7027 goto err;
7028 } else if (!skip_sum) {
7029 ret = btrfs_lookup_bio_sums_dio(root, inode, bio, file_offset);
7030 if (ret)
7031 goto err;
7032 }
7033
7034 map:
7035 ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
7036 err:
7037 bio_put(bio);
7038 return ret;
7039 }
7040
7041 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
7042 int skip_sum)
7043 {
7044 struct inode *inode = dip->inode;
7045 struct btrfs_root *root = BTRFS_I(inode)->root;
7046 struct bio *bio;
7047 struct bio *orig_bio = dip->orig_bio;
7048 struct bio_vec *bvec = orig_bio->bi_io_vec;
7049 u64 start_sector = orig_bio->bi_sector;
7050 u64 file_offset = dip->logical_offset;
7051 u64 submit_len = 0;
7052 u64 map_length;
7053 int nr_pages = 0;
7054 int ret = 0;
7055 int async_submit = 0;
7056
7057 map_length = orig_bio->bi_size;
7058 ret = btrfs_map_block(root->fs_info, rw, start_sector << 9,
7059 &map_length, NULL, 0);
7060 if (ret) {
7061 bio_put(orig_bio);
7062 return -EIO;
7063 }
7064 if (map_length >= orig_bio->bi_size) {
7065 bio = orig_bio;
7066 goto submit;
7067 }
7068
7069 /* async crcs make it difficult to collect full stripe writes. */
7070 if (btrfs_get_alloc_profile(root, 1) &
7071 (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6))
7072 async_submit = 0;
7073 else
7074 async_submit = 1;
7075
7076 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
7077 if (!bio)
7078 return -ENOMEM;
7079 bio->bi_private = dip;
7080 bio->bi_end_io = btrfs_end_dio_bio;
7081 atomic_inc(&dip->pending_bios);
7082
7083 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
7084 if (unlikely(map_length < submit_len + bvec->bv_len ||
7085 bio_add_page(bio, bvec->bv_page, bvec->bv_len,
7086 bvec->bv_offset) < bvec->bv_len)) {
7087 /*
7088 * inc the count before we submit the bio so
7089 * we know the end IO handler won't happen before
7090 * we inc the count. Otherwise, the dip might get freed
7091 * before we're done setting it up
7092 */
7093 atomic_inc(&dip->pending_bios);
7094 ret = __btrfs_submit_dio_bio(bio, inode, rw,
7095 file_offset, skip_sum,
7096 async_submit);
7097 if (ret) {
7098 bio_put(bio);
7099 atomic_dec(&dip->pending_bios);
7100 goto out_err;
7101 }
7102
7103 start_sector += submit_len >> 9;
7104 file_offset += submit_len;
7105
7106 submit_len = 0;
7107 nr_pages = 0;
7108
7109 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
7110 start_sector, GFP_NOFS);
7111 if (!bio)
7112 goto out_err;
7113 bio->bi_private = dip;
7114 bio->bi_end_io = btrfs_end_dio_bio;
7115
7116 map_length = orig_bio->bi_size;
7117 ret = btrfs_map_block(root->fs_info, rw,
7118 start_sector << 9,
7119 &map_length, NULL, 0);
7120 if (ret) {
7121 bio_put(bio);
7122 goto out_err;
7123 }
7124 } else {
7125 submit_len += bvec->bv_len;
7126 nr_pages ++;
7127 bvec++;
7128 }
7129 }
7130
7131 submit:
7132 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
7133 async_submit);
7134 if (!ret)
7135 return 0;
7136
7137 bio_put(bio);
7138 out_err:
7139 dip->errors = 1;
7140 /*
7141 * before atomic variable goto zero, we must
7142 * make sure dip->errors is perceived to be set.
7143 */
7144 smp_mb__before_atomic_dec();
7145 if (atomic_dec_and_test(&dip->pending_bios))
7146 bio_io_error(dip->orig_bio);
7147
7148 /* bio_end_io() will handle error, so we needn't return it */
7149 return 0;
7150 }
7151
7152 static void btrfs_submit_direct(int rw, struct bio *dio_bio,
7153 struct inode *inode, loff_t file_offset)
7154 {
7155 struct btrfs_root *root = BTRFS_I(inode)->root;
7156 struct btrfs_dio_private *dip;
7157 struct bio *io_bio;
7158 int skip_sum;
7159 int write = rw & REQ_WRITE;
7160 int ret = 0;
7161
7162 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
7163
7164 io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS);
7165
7166 if (!io_bio) {
7167 ret = -ENOMEM;
7168 goto free_ordered;
7169 }
7170
7171 dip = kmalloc(sizeof(*dip), GFP_NOFS);
7172 if (!dip) {
7173 ret = -ENOMEM;
7174 goto free_io_bio;
7175 }
7176
7177 dip->private = dio_bio->bi_private;
7178 dip->inode = inode;
7179 dip->logical_offset = file_offset;
7180 dip->bytes = dio_bio->bi_size;
7181 dip->disk_bytenr = (u64)dio_bio->bi_sector << 9;
7182 io_bio->bi_private = dip;
7183 dip->errors = 0;
7184 dip->orig_bio = io_bio;
7185 dip->dio_bio = dio_bio;
7186 atomic_set(&dip->pending_bios, 0);
7187
7188 if (write)
7189 io_bio->bi_end_io = btrfs_endio_direct_write;
7190 else
7191 io_bio->bi_end_io = btrfs_endio_direct_read;
7192
7193 ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
7194 if (!ret)
7195 return;
7196
7197 free_io_bio:
7198 bio_put(io_bio);
7199
7200 free_ordered:
7201 /*
7202 * If this is a write, we need to clean up the reserved space and kill
7203 * the ordered extent.
7204 */
7205 if (write) {
7206 struct btrfs_ordered_extent *ordered;
7207 ordered = btrfs_lookup_ordered_extent(inode, file_offset);
7208 if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) &&
7209 !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
7210 btrfs_free_reserved_extent(root, ordered->start,
7211 ordered->disk_len);
7212 btrfs_put_ordered_extent(ordered);
7213 btrfs_put_ordered_extent(ordered);
7214 }
7215 bio_endio(dio_bio, ret);
7216 }
7217
7218 static ssize_t check_direct_IO(struct btrfs_root *root, int rw, struct kiocb *iocb,
7219 const struct iovec *iov, loff_t offset,
7220 unsigned long nr_segs)
7221 {
7222 int seg;
7223 int i;
7224 size_t size;
7225 unsigned long addr;
7226 unsigned blocksize_mask = root->sectorsize - 1;
7227 ssize_t retval = -EINVAL;
7228 loff_t end = offset;
7229
7230 if (offset & blocksize_mask)
7231 goto out;
7232
7233 /* Check the memory alignment. Blocks cannot straddle pages */
7234 for (seg = 0; seg < nr_segs; seg++) {
7235 addr = (unsigned long)iov[seg].iov_base;
7236 size = iov[seg].iov_len;
7237 end += size;
7238 if ((addr & blocksize_mask) || (size & blocksize_mask))
7239 goto out;
7240
7241 /* If this is a write we don't need to check anymore */
7242 if (rw & WRITE)
7243 continue;
7244
7245 /*
7246 * Check to make sure we don't have duplicate iov_base's in this
7247 * iovec, if so return EINVAL, otherwise we'll get csum errors
7248 * when reading back.
7249 */
7250 for (i = seg + 1; i < nr_segs; i++) {
7251 if (iov[seg].iov_base == iov[i].iov_base)
7252 goto out;
7253 }
7254 }
7255 retval = 0;
7256 out:
7257 return retval;
7258 }
7259
7260 static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
7261 const struct iovec *iov, loff_t offset,
7262 unsigned long nr_segs)
7263 {
7264 struct file *file = iocb->ki_filp;
7265 struct inode *inode = file->f_mapping->host;
7266 size_t count = 0;
7267 int flags = 0;
7268 bool wakeup = true;
7269 bool relock = false;
7270 ssize_t ret;
7271
7272 if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iov,
7273 offset, nr_segs))
7274 return 0;
7275
7276 atomic_inc(&inode->i_dio_count);
7277 smp_mb__after_atomic_inc();
7278
7279 /*
7280 * The generic stuff only does filemap_write_and_wait_range, which isn't
7281 * enough if we've written compressed pages to this area, so we need to
7282 * call btrfs_wait_ordered_range to make absolutely sure that any
7283 * outstanding dirty pages are on disk.
7284 */
7285 count = iov_length(iov, nr_segs);
7286 btrfs_wait_ordered_range(inode, offset, count);
7287
7288 if (rw & WRITE) {
7289 /*
7290 * If the write DIO is beyond the EOF, we need update
7291 * the isize, but it is protected by i_mutex. So we can
7292 * not unlock the i_mutex at this case.
7293 */
7294 if (offset + count <= inode->i_size) {
7295 mutex_unlock(&inode->i_mutex);
7296 relock = true;
7297 }
7298 ret = btrfs_delalloc_reserve_space(inode, count);
7299 if (ret)
7300 goto out;
7301 } else if (unlikely(test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
7302 &BTRFS_I(inode)->runtime_flags))) {
7303 inode_dio_done(inode);
7304 flags = DIO_LOCKING | DIO_SKIP_HOLES;
7305 wakeup = false;
7306 }
7307
7308 ret = __blockdev_direct_IO(rw, iocb, inode,
7309 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
7310 iov, offset, nr_segs, btrfs_get_blocks_direct, NULL,
7311 btrfs_submit_direct, flags);
7312 if (rw & WRITE) {
7313 if (ret < 0 && ret != -EIOCBQUEUED)
7314 btrfs_delalloc_release_space(inode, count);
7315 else if (ret >= 0 && (size_t)ret < count)
7316 btrfs_delalloc_release_space(inode,
7317 count - (size_t)ret);
7318 else
7319 btrfs_delalloc_release_metadata(inode, 0);
7320 }
7321 out:
7322 if (wakeup)
7323 inode_dio_done(inode);
7324 if (relock)
7325 mutex_lock(&inode->i_mutex);
7326
7327 return ret;
7328 }
7329
7330 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
7331
7332 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
7333 __u64 start, __u64 len)
7334 {
7335 int ret;
7336
7337 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
7338 if (ret)
7339 return ret;
7340
7341 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
7342 }
7343
7344 int btrfs_readpage(struct file *file, struct page *page)
7345 {
7346 struct extent_io_tree *tree;
7347 tree = &BTRFS_I(page->mapping->host)->io_tree;
7348 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
7349 }
7350
7351 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
7352 {
7353 struct extent_io_tree *tree;
7354
7355
7356 if (current->flags & PF_MEMALLOC) {
7357 redirty_page_for_writepage(wbc, page);
7358 unlock_page(page);
7359 return 0;
7360 }
7361 tree = &BTRFS_I(page->mapping->host)->io_tree;
7362 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
7363 }
7364
7365 static int btrfs_writepages(struct address_space *mapping,
7366 struct writeback_control *wbc)
7367 {
7368 struct extent_io_tree *tree;
7369
7370 tree = &BTRFS_I(mapping->host)->io_tree;
7371 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
7372 }
7373
7374 static int
7375 btrfs_readpages(struct file *file, struct address_space *mapping,
7376 struct list_head *pages, unsigned nr_pages)
7377 {
7378 struct extent_io_tree *tree;
7379 tree = &BTRFS_I(mapping->host)->io_tree;
7380 return extent_readpages(tree, mapping, pages, nr_pages,
7381 btrfs_get_extent);
7382 }
7383 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
7384 {
7385 struct extent_io_tree *tree;
7386 struct extent_map_tree *map;
7387 int ret;
7388
7389 tree = &BTRFS_I(page->mapping->host)->io_tree;
7390 map = &BTRFS_I(page->mapping->host)->extent_tree;
7391 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
7392 if (ret == 1) {
7393 ClearPagePrivate(page);
7394 set_page_private(page, 0);
7395 page_cache_release(page);
7396 }
7397 return ret;
7398 }
7399
7400 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
7401 {
7402 if (PageWriteback(page) || PageDirty(page))
7403 return 0;
7404 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
7405 }
7406
7407 static void btrfs_invalidatepage(struct page *page, unsigned int offset,
7408 unsigned int length)
7409 {
7410 struct inode *inode = page->mapping->host;
7411 struct extent_io_tree *tree;
7412 struct btrfs_ordered_extent *ordered;
7413 struct extent_state *cached_state = NULL;
7414 u64 page_start = page_offset(page);
7415 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
7416
7417 /*
7418 * we have the page locked, so new writeback can't start,
7419 * and the dirty bit won't be cleared while we are here.
7420 *
7421 * Wait for IO on this page so that we can safely clear
7422 * the PagePrivate2 bit and do ordered accounting
7423 */
7424 wait_on_page_writeback(page);
7425
7426 tree = &BTRFS_I(inode)->io_tree;
7427 if (offset) {
7428 btrfs_releasepage(page, GFP_NOFS);
7429 return;
7430 }
7431 lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
7432 ordered = btrfs_lookup_ordered_extent(inode, page_offset(page));
7433 if (ordered) {
7434 /*
7435 * IO on this page will never be started, so we need
7436 * to account for any ordered extents now
7437 */
7438 clear_extent_bit(tree, page_start, page_end,
7439 EXTENT_DIRTY | EXTENT_DELALLOC |
7440 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
7441 EXTENT_DEFRAG, 1, 0, &cached_state, GFP_NOFS);
7442 /*
7443 * whoever cleared the private bit is responsible
7444 * for the finish_ordered_io
7445 */
7446 if (TestClearPagePrivate2(page) &&
7447 btrfs_dec_test_ordered_pending(inode, &ordered, page_start,
7448 PAGE_CACHE_SIZE, 1)) {
7449 btrfs_finish_ordered_io(ordered);
7450 }
7451 btrfs_put_ordered_extent(ordered);
7452 cached_state = NULL;
7453 lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
7454 }
7455 clear_extent_bit(tree, page_start, page_end,
7456 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
7457 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1,
7458 &cached_state, GFP_NOFS);
7459 __btrfs_releasepage(page, GFP_NOFS);
7460
7461 ClearPageChecked(page);
7462 if (PagePrivate(page)) {
7463 ClearPagePrivate(page);
7464 set_page_private(page, 0);
7465 page_cache_release(page);
7466 }
7467 }
7468
7469 /*
7470 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
7471 * called from a page fault handler when a page is first dirtied. Hence we must
7472 * be careful to check for EOF conditions here. We set the page up correctly
7473 * for a written page which means we get ENOSPC checking when writing into
7474 * holes and correct delalloc and unwritten extent mapping on filesystems that
7475 * support these features.
7476 *
7477 * We are not allowed to take the i_mutex here so we have to play games to
7478 * protect against truncate races as the page could now be beyond EOF. Because
7479 * vmtruncate() writes the inode size before removing pages, once we have the
7480 * page lock we can determine safely if the page is beyond EOF. If it is not
7481 * beyond EOF, then the page is guaranteed safe against truncation until we
7482 * unlock the page.
7483 */
7484 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
7485 {
7486 struct page *page = vmf->page;
7487 struct inode *inode = file_inode(vma->vm_file);
7488 struct btrfs_root *root = BTRFS_I(inode)->root;
7489 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7490 struct btrfs_ordered_extent *ordered;
7491 struct extent_state *cached_state = NULL;
7492 char *kaddr;
7493 unsigned long zero_start;
7494 loff_t size;
7495 int ret;
7496 int reserved = 0;
7497 u64 page_start;
7498 u64 page_end;
7499
7500 sb_start_pagefault(inode->i_sb);
7501 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
7502 if (!ret) {
7503 ret = file_update_time(vma->vm_file);
7504 reserved = 1;
7505 }
7506 if (ret) {
7507 if (ret == -ENOMEM)
7508 ret = VM_FAULT_OOM;
7509 else /* -ENOSPC, -EIO, etc */
7510 ret = VM_FAULT_SIGBUS;
7511 if (reserved)
7512 goto out;
7513 goto out_noreserve;
7514 }
7515
7516 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
7517 again:
7518 lock_page(page);
7519 size = i_size_read(inode);
7520 page_start = page_offset(page);
7521 page_end = page_start + PAGE_CACHE_SIZE - 1;
7522
7523 if ((page->mapping != inode->i_mapping) ||
7524 (page_start >= size)) {
7525 /* page got truncated out from underneath us */
7526 goto out_unlock;
7527 }
7528 wait_on_page_writeback(page);
7529
7530 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
7531 set_page_extent_mapped(page);
7532
7533 /*
7534 * we can't set the delalloc bits if there are pending ordered
7535 * extents. Drop our locks and wait for them to finish
7536 */
7537 ordered = btrfs_lookup_ordered_extent(inode, page_start);
7538 if (ordered) {
7539 unlock_extent_cached(io_tree, page_start, page_end,
7540 &cached_state, GFP_NOFS);
7541 unlock_page(page);
7542 btrfs_start_ordered_extent(inode, ordered, 1);
7543 btrfs_put_ordered_extent(ordered);
7544 goto again;
7545 }
7546
7547 /*
7548 * XXX - page_mkwrite gets called every time the page is dirtied, even
7549 * if it was already dirty, so for space accounting reasons we need to
7550 * clear any delalloc bits for the range we are fixing to save. There
7551 * is probably a better way to do this, but for now keep consistent with
7552 * prepare_pages in the normal write path.
7553 */
7554 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
7555 EXTENT_DIRTY | EXTENT_DELALLOC |
7556 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
7557 0, 0, &cached_state, GFP_NOFS);
7558
7559 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
7560 &cached_state);
7561 if (ret) {
7562 unlock_extent_cached(io_tree, page_start, page_end,
7563 &cached_state, GFP_NOFS);
7564 ret = VM_FAULT_SIGBUS;
7565 goto out_unlock;
7566 }
7567 ret = 0;
7568
7569 /* page is wholly or partially inside EOF */
7570 if (page_start + PAGE_CACHE_SIZE > size)
7571 zero_start = size & ~PAGE_CACHE_MASK;
7572 else
7573 zero_start = PAGE_CACHE_SIZE;
7574
7575 if (zero_start != PAGE_CACHE_SIZE) {
7576 kaddr = kmap(page);
7577 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
7578 flush_dcache_page(page);
7579 kunmap(page);
7580 }
7581 ClearPageChecked(page);
7582 set_page_dirty(page);
7583 SetPageUptodate(page);
7584
7585 BTRFS_I(inode)->last_trans = root->fs_info->generation;
7586 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
7587 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
7588
7589 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
7590
7591 out_unlock:
7592 if (!ret) {
7593 sb_end_pagefault(inode->i_sb);
7594 return VM_FAULT_LOCKED;
7595 }
7596 unlock_page(page);
7597 out:
7598 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
7599 out_noreserve:
7600 sb_end_pagefault(inode->i_sb);
7601 return ret;
7602 }
7603
7604 static int btrfs_truncate(struct inode *inode)
7605 {
7606 struct btrfs_root *root = BTRFS_I(inode)->root;
7607 struct btrfs_block_rsv *rsv;
7608 int ret = 0;
7609 int err = 0;
7610 struct btrfs_trans_handle *trans;
7611 u64 mask = root->sectorsize - 1;
7612 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
7613
7614 btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
7615 btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
7616
7617 /*
7618 * Yes ladies and gentelment, this is indeed ugly. The fact is we have
7619 * 3 things going on here
7620 *
7621 * 1) We need to reserve space for our orphan item and the space to
7622 * delete our orphan item. Lord knows we don't want to have a dangling
7623 * orphan item because we didn't reserve space to remove it.
7624 *
7625 * 2) We need to reserve space to update our inode.
7626 *
7627 * 3) We need to have something to cache all the space that is going to
7628 * be free'd up by the truncate operation, but also have some slack
7629 * space reserved in case it uses space during the truncate (thank you
7630 * very much snapshotting).
7631 *
7632 * And we need these to all be seperate. The fact is we can use alot of
7633 * space doing the truncate, and we have no earthly idea how much space
7634 * we will use, so we need the truncate reservation to be seperate so it
7635 * doesn't end up using space reserved for updating the inode or
7636 * removing the orphan item. We also need to be able to stop the
7637 * transaction and start a new one, which means we need to be able to
7638 * update the inode several times, and we have no idea of knowing how
7639 * many times that will be, so we can't just reserve 1 item for the
7640 * entirety of the opration, so that has to be done seperately as well.
7641 * Then there is the orphan item, which does indeed need to be held on
7642 * to for the whole operation, and we need nobody to touch this reserved
7643 * space except the orphan code.
7644 *
7645 * So that leaves us with
7646 *
7647 * 1) root->orphan_block_rsv - for the orphan deletion.
7648 * 2) rsv - for the truncate reservation, which we will steal from the
7649 * transaction reservation.
7650 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
7651 * updating the inode.
7652 */
7653 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
7654 if (!rsv)
7655 return -ENOMEM;
7656 rsv->size = min_size;
7657 rsv->failfast = 1;
7658
7659 /*
7660 * 1 for the truncate slack space
7661 * 1 for updating the inode.
7662 */
7663 trans = btrfs_start_transaction(root, 2);
7664 if (IS_ERR(trans)) {
7665 err = PTR_ERR(trans);
7666 goto out;
7667 }
7668
7669 /* Migrate the slack space for the truncate to our reserve */
7670 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
7671 min_size);
7672 BUG_ON(ret);
7673
7674 /*
7675 * setattr is responsible for setting the ordered_data_close flag,
7676 * but that is only tested during the last file release. That
7677 * could happen well after the next commit, leaving a great big
7678 * window where new writes may get lost if someone chooses to write
7679 * to this file after truncating to zero
7680 *
7681 * The inode doesn't have any dirty data here, and so if we commit
7682 * this is a noop. If someone immediately starts writing to the inode
7683 * it is very likely we'll catch some of their writes in this
7684 * transaction, and the commit will find this file on the ordered
7685 * data list with good things to send down.
7686 *
7687 * This is a best effort solution, there is still a window where
7688 * using truncate to replace the contents of the file will
7689 * end up with a zero length file after a crash.
7690 */
7691 if (inode->i_size == 0 && test_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
7692 &BTRFS_I(inode)->runtime_flags))
7693 btrfs_add_ordered_operation(trans, root, inode);
7694
7695 /*
7696 * So if we truncate and then write and fsync we normally would just
7697 * write the extents that changed, which is a problem if we need to
7698 * first truncate that entire inode. So set this flag so we write out
7699 * all of the extents in the inode to the sync log so we're completely
7700 * safe.
7701 */
7702 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
7703 trans->block_rsv = rsv;
7704
7705 while (1) {
7706 ret = btrfs_truncate_inode_items(trans, root, inode,
7707 inode->i_size,
7708 BTRFS_EXTENT_DATA_KEY);
7709 if (ret != -ENOSPC) {
7710 err = ret;
7711 break;
7712 }
7713
7714 trans->block_rsv = &root->fs_info->trans_block_rsv;
7715 ret = btrfs_update_inode(trans, root, inode);
7716 if (ret) {
7717 err = ret;
7718 break;
7719 }
7720
7721 btrfs_end_transaction(trans, root);
7722 btrfs_btree_balance_dirty(root);
7723
7724 trans = btrfs_start_transaction(root, 2);
7725 if (IS_ERR(trans)) {
7726 ret = err = PTR_ERR(trans);
7727 trans = NULL;
7728 break;
7729 }
7730
7731 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
7732 rsv, min_size);
7733 BUG_ON(ret); /* shouldn't happen */
7734 trans->block_rsv = rsv;
7735 }
7736
7737 if (ret == 0 && inode->i_nlink > 0) {
7738 trans->block_rsv = root->orphan_block_rsv;
7739 ret = btrfs_orphan_del(trans, inode);
7740 if (ret)
7741 err = ret;
7742 }
7743
7744 if (trans) {
7745 trans->block_rsv = &root->fs_info->trans_block_rsv;
7746 ret = btrfs_update_inode(trans, root, inode);
7747 if (ret && !err)
7748 err = ret;
7749
7750 ret = btrfs_end_transaction(trans, root);
7751 btrfs_btree_balance_dirty(root);
7752 }
7753
7754 out:
7755 btrfs_free_block_rsv(root, rsv);
7756
7757 if (ret && !err)
7758 err = ret;
7759
7760 return err;
7761 }
7762
7763 /*
7764 * create a new subvolume directory/inode (helper for the ioctl).
7765 */
7766 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
7767 struct btrfs_root *new_root, u64 new_dirid)
7768 {
7769 struct inode *inode;
7770 int err;
7771 u64 index = 0;
7772
7773 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
7774 new_dirid, new_dirid,
7775 S_IFDIR | (~current_umask() & S_IRWXUGO),
7776 &index);
7777 if (IS_ERR(inode))
7778 return PTR_ERR(inode);
7779 inode->i_op = &btrfs_dir_inode_operations;
7780 inode->i_fop = &btrfs_dir_file_operations;
7781
7782 set_nlink(inode, 1);
7783 btrfs_i_size_write(inode, 0);
7784
7785 err = btrfs_update_inode(trans, new_root, inode);
7786
7787 iput(inode);
7788 return err;
7789 }
7790
7791 struct inode *btrfs_alloc_inode(struct super_block *sb)
7792 {
7793 struct btrfs_inode *ei;
7794 struct inode *inode;
7795
7796 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
7797 if (!ei)
7798 return NULL;
7799
7800 ei->root = NULL;
7801 ei->generation = 0;
7802 ei->last_trans = 0;
7803 ei->last_sub_trans = 0;
7804 ei->logged_trans = 0;
7805 ei->delalloc_bytes = 0;
7806 ei->disk_i_size = 0;
7807 ei->flags = 0;
7808 ei->csum_bytes = 0;
7809 ei->index_cnt = (u64)-1;
7810 ei->last_unlink_trans = 0;
7811 ei->last_log_commit = 0;
7812
7813 spin_lock_init(&ei->lock);
7814 ei->outstanding_extents = 0;
7815 ei->reserved_extents = 0;
7816
7817 ei->runtime_flags = 0;
7818 ei->force_compress = BTRFS_COMPRESS_NONE;
7819
7820 ei->delayed_node = NULL;
7821
7822 inode = &ei->vfs_inode;
7823 extent_map_tree_init(&ei->extent_tree);
7824 extent_io_tree_init(&ei->io_tree, &inode->i_data);
7825 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
7826 ei->io_tree.track_uptodate = 1;
7827 ei->io_failure_tree.track_uptodate = 1;
7828 atomic_set(&ei->sync_writers, 0);
7829 mutex_init(&ei->log_mutex);
7830 mutex_init(&ei->delalloc_mutex);
7831 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
7832 INIT_LIST_HEAD(&ei->delalloc_inodes);
7833 INIT_LIST_HEAD(&ei->ordered_operations);
7834 RB_CLEAR_NODE(&ei->rb_node);
7835
7836 return inode;
7837 }
7838
7839 static void btrfs_i_callback(struct rcu_head *head)
7840 {
7841 struct inode *inode = container_of(head, struct inode, i_rcu);
7842 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
7843 }
7844
7845 void btrfs_destroy_inode(struct inode *inode)
7846 {
7847 struct btrfs_ordered_extent *ordered;
7848 struct btrfs_root *root = BTRFS_I(inode)->root;
7849
7850 WARN_ON(!hlist_empty(&inode->i_dentry));
7851 WARN_ON(inode->i_data.nrpages);
7852 WARN_ON(BTRFS_I(inode)->outstanding_extents);
7853 WARN_ON(BTRFS_I(inode)->reserved_extents);
7854 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
7855 WARN_ON(BTRFS_I(inode)->csum_bytes);
7856
7857 /*
7858 * This can happen where we create an inode, but somebody else also
7859 * created the same inode and we need to destroy the one we already
7860 * created.
7861 */
7862 if (!root)
7863 goto free;
7864
7865 /*
7866 * Make sure we're properly removed from the ordered operation
7867 * lists.
7868 */
7869 smp_mb();
7870 if (!list_empty(&BTRFS_I(inode)->ordered_operations)) {
7871 spin_lock(&root->fs_info->ordered_root_lock);
7872 list_del_init(&BTRFS_I(inode)->ordered_operations);
7873 spin_unlock(&root->fs_info->ordered_root_lock);
7874 }
7875
7876 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
7877 &BTRFS_I(inode)->runtime_flags)) {
7878 btrfs_info(root->fs_info, "inode %llu still on the orphan list",
7879 (unsigned long long)btrfs_ino(inode));
7880 atomic_dec(&root->orphan_inodes);
7881 }
7882
7883 while (1) {
7884 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
7885 if (!ordered)
7886 break;
7887 else {
7888 btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup",
7889 (unsigned long long)ordered->file_offset,
7890 (unsigned long long)ordered->len);
7891 btrfs_remove_ordered_extent(inode, ordered);
7892 btrfs_put_ordered_extent(ordered);
7893 btrfs_put_ordered_extent(ordered);
7894 }
7895 }
7896 inode_tree_del(inode);
7897 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
7898 free:
7899 call_rcu(&inode->i_rcu, btrfs_i_callback);
7900 }
7901
7902 int btrfs_drop_inode(struct inode *inode)
7903 {
7904 struct btrfs_root *root = BTRFS_I(inode)->root;
7905
7906 if (root == NULL)
7907 return 1;
7908
7909 /* the snap/subvol tree is on deleting */
7910 if (btrfs_root_refs(&root->root_item) == 0 &&
7911 root != root->fs_info->tree_root)
7912 return 1;
7913 else
7914 return generic_drop_inode(inode);
7915 }
7916
7917 static void init_once(void *foo)
7918 {
7919 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
7920
7921 inode_init_once(&ei->vfs_inode);
7922 }
7923
7924 void btrfs_destroy_cachep(void)
7925 {
7926 /*
7927 * Make sure all delayed rcu free inodes are flushed before we
7928 * destroy cache.
7929 */
7930 rcu_barrier();
7931 if (btrfs_inode_cachep)
7932 kmem_cache_destroy(btrfs_inode_cachep);
7933 if (btrfs_trans_handle_cachep)
7934 kmem_cache_destroy(btrfs_trans_handle_cachep);
7935 if (btrfs_transaction_cachep)
7936 kmem_cache_destroy(btrfs_transaction_cachep);
7937 if (btrfs_path_cachep)
7938 kmem_cache_destroy(btrfs_path_cachep);
7939 if (btrfs_free_space_cachep)
7940 kmem_cache_destroy(btrfs_free_space_cachep);
7941 if (btrfs_delalloc_work_cachep)
7942 kmem_cache_destroy(btrfs_delalloc_work_cachep);
7943 }
7944
7945 int btrfs_init_cachep(void)
7946 {
7947 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
7948 sizeof(struct btrfs_inode), 0,
7949 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once);
7950 if (!btrfs_inode_cachep)
7951 goto fail;
7952
7953 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
7954 sizeof(struct btrfs_trans_handle), 0,
7955 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
7956 if (!btrfs_trans_handle_cachep)
7957 goto fail;
7958
7959 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
7960 sizeof(struct btrfs_transaction), 0,
7961 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
7962 if (!btrfs_transaction_cachep)
7963 goto fail;
7964
7965 btrfs_path_cachep = kmem_cache_create("btrfs_path",
7966 sizeof(struct btrfs_path), 0,
7967 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
7968 if (!btrfs_path_cachep)
7969 goto fail;
7970
7971 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
7972 sizeof(struct btrfs_free_space), 0,
7973 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
7974 if (!btrfs_free_space_cachep)
7975 goto fail;
7976
7977 btrfs_delalloc_work_cachep = kmem_cache_create("btrfs_delalloc_work",
7978 sizeof(struct btrfs_delalloc_work), 0,
7979 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
7980 NULL);
7981 if (!btrfs_delalloc_work_cachep)
7982 goto fail;
7983
7984 return 0;
7985 fail:
7986 btrfs_destroy_cachep();
7987 return -ENOMEM;
7988 }
7989
7990 static int btrfs_getattr(struct vfsmount *mnt,
7991 struct dentry *dentry, struct kstat *stat)
7992 {
7993 u64 delalloc_bytes;
7994 struct inode *inode = dentry->d_inode;
7995 u32 blocksize = inode->i_sb->s_blocksize;
7996
7997 generic_fillattr(inode, stat);
7998 stat->dev = BTRFS_I(inode)->root->anon_dev;
7999 stat->blksize = PAGE_CACHE_SIZE;
8000
8001 spin_lock(&BTRFS_I(inode)->lock);
8002 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;
8003 spin_unlock(&BTRFS_I(inode)->lock);
8004 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
8005 ALIGN(delalloc_bytes, blocksize)) >> 9;
8006 return 0;
8007 }
8008
8009 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
8010 struct inode *new_dir, struct dentry *new_dentry)
8011 {
8012 struct btrfs_trans_handle *trans;
8013 struct btrfs_root *root = BTRFS_I(old_dir)->root;
8014 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
8015 struct inode *new_inode = new_dentry->d_inode;
8016 struct inode *old_inode = old_dentry->d_inode;
8017 struct timespec ctime = CURRENT_TIME;
8018 u64 index = 0;
8019 u64 root_objectid;
8020 int ret;
8021 u64 old_ino = btrfs_ino(old_inode);
8022
8023 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
8024 return -EPERM;
8025
8026 /* we only allow rename subvolume link between subvolumes */
8027 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
8028 return -EXDEV;
8029
8030 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
8031 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
8032 return -ENOTEMPTY;
8033
8034 if (S_ISDIR(old_inode->i_mode) && new_inode &&
8035 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
8036 return -ENOTEMPTY;
8037
8038
8039 /* check for collisions, even if the name isn't there */
8040 ret = btrfs_check_dir_item_collision(root, new_dir->i_ino,
8041 new_dentry->d_name.name,
8042 new_dentry->d_name.len);
8043
8044 if (ret) {
8045 if (ret == -EEXIST) {
8046 /* we shouldn't get
8047 * eexist without a new_inode */
8048 if (!new_inode) {
8049 WARN_ON(1);
8050 return ret;
8051 }
8052 } else {
8053 /* maybe -EOVERFLOW */
8054 return ret;
8055 }
8056 }
8057 ret = 0;
8058
8059 /*
8060 * we're using rename to replace one file with another.
8061 * and the replacement file is large. Start IO on it now so
8062 * we don't add too much work to the end of the transaction
8063 */
8064 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size &&
8065 old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
8066 filemap_flush(old_inode->i_mapping);
8067
8068 /* close the racy window with snapshot create/destroy ioctl */
8069 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
8070 down_read(&root->fs_info->subvol_sem);
8071 /*
8072 * We want to reserve the absolute worst case amount of items. So if
8073 * both inodes are subvols and we need to unlink them then that would
8074 * require 4 item modifications, but if they are both normal inodes it
8075 * would require 5 item modifications, so we'll assume their normal
8076 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
8077 * should cover the worst case number of items we'll modify.
8078 */
8079 trans = btrfs_start_transaction(root, 11);
8080 if (IS_ERR(trans)) {
8081 ret = PTR_ERR(trans);
8082 goto out_notrans;
8083 }
8084
8085 if (dest != root)
8086 btrfs_record_root_in_trans(trans, dest);
8087
8088 ret = btrfs_set_inode_index(new_dir, &index);
8089 if (ret)
8090 goto out_fail;
8091
8092 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
8093 /* force full log commit if subvolume involved. */
8094 root->fs_info->last_trans_log_full_commit = trans->transid;
8095 } else {
8096 ret = btrfs_insert_inode_ref(trans, dest,
8097 new_dentry->d_name.name,
8098 new_dentry->d_name.len,
8099 old_ino,
8100 btrfs_ino(new_dir), index);
8101 if (ret)
8102 goto out_fail;
8103 /*
8104 * this is an ugly little race, but the rename is required
8105 * to make sure that if we crash, the inode is either at the
8106 * old name or the new one. pinning the log transaction lets
8107 * us make sure we don't allow a log commit to come in after
8108 * we unlink the name but before we add the new name back in.
8109 */
8110 btrfs_pin_log_trans(root);
8111 }
8112 /*
8113 * make sure the inode gets flushed if it is replacing
8114 * something.
8115 */
8116 if (new_inode && new_inode->i_size && S_ISREG(old_inode->i_mode))
8117 btrfs_add_ordered_operation(trans, root, old_inode);
8118
8119 inode_inc_iversion(old_dir);
8120 inode_inc_iversion(new_dir);
8121 inode_inc_iversion(old_inode);
8122 old_dir->i_ctime = old_dir->i_mtime = ctime;
8123 new_dir->i_ctime = new_dir->i_mtime = ctime;
8124 old_inode->i_ctime = ctime;
8125
8126 if (old_dentry->d_parent != new_dentry->d_parent)
8127 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
8128
8129 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
8130 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
8131 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
8132 old_dentry->d_name.name,
8133 old_dentry->d_name.len);
8134 } else {
8135 ret = __btrfs_unlink_inode(trans, root, old_dir,
8136 old_dentry->d_inode,
8137 old_dentry->d_name.name,
8138 old_dentry->d_name.len);
8139 if (!ret)
8140 ret = btrfs_update_inode(trans, root, old_inode);
8141 }
8142 if (ret) {
8143 btrfs_abort_transaction(trans, root, ret);
8144 goto out_fail;
8145 }
8146
8147 if (new_inode) {
8148 inode_inc_iversion(new_inode);
8149 new_inode->i_ctime = CURRENT_TIME;
8150 if (unlikely(btrfs_ino(new_inode) ==
8151 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
8152 root_objectid = BTRFS_I(new_inode)->location.objectid;
8153 ret = btrfs_unlink_subvol(trans, dest, new_dir,
8154 root_objectid,
8155 new_dentry->d_name.name,
8156 new_dentry->d_name.len);
8157 BUG_ON(new_inode->i_nlink == 0);
8158 } else {
8159 ret = btrfs_unlink_inode(trans, dest, new_dir,
8160 new_dentry->d_inode,
8161 new_dentry->d_name.name,
8162 new_dentry->d_name.len);
8163 }
8164 if (!ret && new_inode->i_nlink == 0) {
8165 ret = btrfs_orphan_add(trans, new_dentry->d_inode);
8166 BUG_ON(ret);
8167 }
8168 if (ret) {
8169 btrfs_abort_transaction(trans, root, ret);
8170 goto out_fail;
8171 }
8172 }
8173
8174 ret = btrfs_add_link(trans, new_dir, old_inode,
8175 new_dentry->d_name.name,
8176 new_dentry->d_name.len, 0, index);
8177 if (ret) {
8178 btrfs_abort_transaction(trans, root, ret);
8179 goto out_fail;
8180 }
8181
8182 if (old_ino != BTRFS_FIRST_FREE_OBJECTID) {
8183 struct dentry *parent = new_dentry->d_parent;
8184 btrfs_log_new_name(trans, old_inode, old_dir, parent);
8185 btrfs_end_log_trans(root);
8186 }
8187 out_fail:
8188 btrfs_end_transaction(trans, root);
8189 out_notrans:
8190 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
8191 up_read(&root->fs_info->subvol_sem);
8192
8193 return ret;
8194 }
8195
8196 static void btrfs_run_delalloc_work(struct btrfs_work *work)
8197 {
8198 struct btrfs_delalloc_work *delalloc_work;
8199
8200 delalloc_work = container_of(work, struct btrfs_delalloc_work,
8201 work);
8202 if (delalloc_work->wait)
8203 btrfs_wait_ordered_range(delalloc_work->inode, 0, (u64)-1);
8204 else
8205 filemap_flush(delalloc_work->inode->i_mapping);
8206
8207 if (delalloc_work->delay_iput)
8208 btrfs_add_delayed_iput(delalloc_work->inode);
8209 else
8210 iput(delalloc_work->inode);
8211 complete(&delalloc_work->completion);
8212 }
8213
8214 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
8215 int wait, int delay_iput)
8216 {
8217 struct btrfs_delalloc_work *work;
8218
8219 work = kmem_cache_zalloc(btrfs_delalloc_work_cachep, GFP_NOFS);
8220 if (!work)
8221 return NULL;
8222
8223 init_completion(&work->completion);
8224 INIT_LIST_HEAD(&work->list);
8225 work->inode = inode;
8226 work->wait = wait;
8227 work->delay_iput = delay_iput;
8228 work->work.func = btrfs_run_delalloc_work;
8229
8230 return work;
8231 }
8232
8233 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
8234 {
8235 wait_for_completion(&work->completion);
8236 kmem_cache_free(btrfs_delalloc_work_cachep, work);
8237 }
8238
8239 /*
8240 * some fairly slow code that needs optimization. This walks the list
8241 * of all the inodes with pending delalloc and forces them to disk.
8242 */
8243 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
8244 {
8245 struct btrfs_inode *binode;
8246 struct inode *inode;
8247 struct btrfs_delalloc_work *work, *next;
8248 struct list_head works;
8249 struct list_head splice;
8250 int ret = 0;
8251
8252 INIT_LIST_HEAD(&works);
8253 INIT_LIST_HEAD(&splice);
8254
8255 spin_lock(&root->delalloc_lock);
8256 list_splice_init(&root->delalloc_inodes, &splice);
8257 while (!list_empty(&splice)) {
8258 binode = list_entry(splice.next, struct btrfs_inode,
8259 delalloc_inodes);
8260
8261 list_move_tail(&binode->delalloc_inodes,
8262 &root->delalloc_inodes);
8263 inode = igrab(&binode->vfs_inode);
8264 if (!inode) {
8265 cond_resched_lock(&root->delalloc_lock);
8266 continue;
8267 }
8268 spin_unlock(&root->delalloc_lock);
8269
8270 work = btrfs_alloc_delalloc_work(inode, 0, delay_iput);
8271 if (unlikely(!work)) {
8272 ret = -ENOMEM;
8273 goto out;
8274 }
8275 list_add_tail(&work->list, &works);
8276 btrfs_queue_worker(&root->fs_info->flush_workers,
8277 &work->work);
8278
8279 cond_resched();
8280 spin_lock(&root->delalloc_lock);
8281 }
8282 spin_unlock(&root->delalloc_lock);
8283
8284 list_for_each_entry_safe(work, next, &works, list) {
8285 list_del_init(&work->list);
8286 btrfs_wait_and_free_delalloc_work(work);
8287 }
8288 return 0;
8289 out:
8290 list_for_each_entry_safe(work, next, &works, list) {
8291 list_del_init(&work->list);
8292 btrfs_wait_and_free_delalloc_work(work);
8293 }
8294
8295 if (!list_empty_careful(&splice)) {
8296 spin_lock(&root->delalloc_lock);
8297 list_splice_tail(&splice, &root->delalloc_inodes);
8298 spin_unlock(&root->delalloc_lock);
8299 }
8300 return ret;
8301 }
8302
8303 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
8304 {
8305 int ret;
8306
8307 if (root->fs_info->sb->s_flags & MS_RDONLY)
8308 return -EROFS;
8309
8310 ret = __start_delalloc_inodes(root, delay_iput);
8311 /*
8312 * the filemap_flush will queue IO into the worker threads, but
8313 * we have to make sure the IO is actually started and that
8314 * ordered extents get created before we return
8315 */
8316 atomic_inc(&root->fs_info->async_submit_draining);
8317 while (atomic_read(&root->fs_info->nr_async_submits) ||
8318 atomic_read(&root->fs_info->async_delalloc_pages)) {
8319 wait_event(root->fs_info->async_submit_wait,
8320 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
8321 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
8322 }
8323 atomic_dec(&root->fs_info->async_submit_draining);
8324 return ret;
8325 }
8326
8327 int btrfs_start_all_delalloc_inodes(struct btrfs_fs_info *fs_info,
8328 int delay_iput)
8329 {
8330 struct btrfs_root *root;
8331 struct list_head splice;
8332 int ret;
8333
8334 if (fs_info->sb->s_flags & MS_RDONLY)
8335 return -EROFS;
8336
8337 INIT_LIST_HEAD(&splice);
8338
8339 spin_lock(&fs_info->delalloc_root_lock);
8340 list_splice_init(&fs_info->delalloc_roots, &splice);
8341 while (!list_empty(&splice)) {
8342 root = list_first_entry(&splice, struct btrfs_root,
8343 delalloc_root);
8344 root = btrfs_grab_fs_root(root);
8345 BUG_ON(!root);
8346 list_move_tail(&root->delalloc_root,
8347 &fs_info->delalloc_roots);
8348 spin_unlock(&fs_info->delalloc_root_lock);
8349
8350 ret = __start_delalloc_inodes(root, delay_iput);
8351 btrfs_put_fs_root(root);
8352 if (ret)
8353 goto out;
8354
8355 spin_lock(&fs_info->delalloc_root_lock);
8356 }
8357 spin_unlock(&fs_info->delalloc_root_lock);
8358
8359 atomic_inc(&fs_info->async_submit_draining);
8360 while (atomic_read(&fs_info->nr_async_submits) ||
8361 atomic_read(&fs_info->async_delalloc_pages)) {
8362 wait_event(fs_info->async_submit_wait,
8363 (atomic_read(&fs_info->nr_async_submits) == 0 &&
8364 atomic_read(&fs_info->async_delalloc_pages) == 0));
8365 }
8366 atomic_dec(&fs_info->async_submit_draining);
8367 return 0;
8368 out:
8369 if (!list_empty_careful(&splice)) {
8370 spin_lock(&fs_info->delalloc_root_lock);
8371 list_splice_tail(&splice, &fs_info->delalloc_roots);
8372 spin_unlock(&fs_info->delalloc_root_lock);
8373 }
8374 return ret;
8375 }
8376
8377 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
8378 const char *symname)
8379 {
8380 struct btrfs_trans_handle *trans;
8381 struct btrfs_root *root = BTRFS_I(dir)->root;
8382 struct btrfs_path *path;
8383 struct btrfs_key key;
8384 struct inode *inode = NULL;
8385 int err;
8386 int drop_inode = 0;
8387 u64 objectid;
8388 u64 index = 0 ;
8389 int name_len;
8390 int datasize;
8391 unsigned long ptr;
8392 struct btrfs_file_extent_item *ei;
8393 struct extent_buffer *leaf;
8394
8395 name_len = strlen(symname) + 1;
8396 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
8397 return -ENAMETOOLONG;
8398
8399 /*
8400 * 2 items for inode item and ref
8401 * 2 items for dir items
8402 * 1 item for xattr if selinux is on
8403 */
8404 trans = btrfs_start_transaction(root, 5);
8405 if (IS_ERR(trans))
8406 return PTR_ERR(trans);
8407
8408 err = btrfs_find_free_ino(root, &objectid);
8409 if (err)
8410 goto out_unlock;
8411
8412 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
8413 dentry->d_name.len, btrfs_ino(dir), objectid,
8414 S_IFLNK|S_IRWXUGO, &index);
8415 if (IS_ERR(inode)) {
8416 err = PTR_ERR(inode);
8417 goto out_unlock;
8418 }
8419
8420 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
8421 if (err) {
8422 drop_inode = 1;
8423 goto out_unlock;
8424 }
8425
8426 /*
8427 * If the active LSM wants to access the inode during
8428 * d_instantiate it needs these. Smack checks to see
8429 * if the filesystem supports xattrs by looking at the
8430 * ops vector.
8431 */
8432 inode->i_fop = &btrfs_file_operations;
8433 inode->i_op = &btrfs_file_inode_operations;
8434
8435 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
8436 if (err)
8437 drop_inode = 1;
8438 else {
8439 inode->i_mapping->a_ops = &btrfs_aops;
8440 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
8441 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
8442 }
8443 if (drop_inode)
8444 goto out_unlock;
8445
8446 path = btrfs_alloc_path();
8447 if (!path) {
8448 err = -ENOMEM;
8449 drop_inode = 1;
8450 goto out_unlock;
8451 }
8452 key.objectid = btrfs_ino(inode);
8453 key.offset = 0;
8454 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
8455 datasize = btrfs_file_extent_calc_inline_size(name_len);
8456 err = btrfs_insert_empty_item(trans, root, path, &key,
8457 datasize);
8458 if (err) {
8459 drop_inode = 1;
8460 btrfs_free_path(path);
8461 goto out_unlock;
8462 }
8463 leaf = path->nodes[0];
8464 ei = btrfs_item_ptr(leaf, path->slots[0],
8465 struct btrfs_file_extent_item);
8466 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
8467 btrfs_set_file_extent_type(leaf, ei,
8468 BTRFS_FILE_EXTENT_INLINE);
8469 btrfs_set_file_extent_encryption(leaf, ei, 0);
8470 btrfs_set_file_extent_compression(leaf, ei, 0);
8471 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
8472 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
8473
8474 ptr = btrfs_file_extent_inline_start(ei);
8475 write_extent_buffer(leaf, symname, ptr, name_len);
8476 btrfs_mark_buffer_dirty(leaf);
8477 btrfs_free_path(path);
8478
8479 inode->i_op = &btrfs_symlink_inode_operations;
8480 inode->i_mapping->a_ops = &btrfs_symlink_aops;
8481 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
8482 inode_set_bytes(inode, name_len);
8483 btrfs_i_size_write(inode, name_len - 1);
8484 err = btrfs_update_inode(trans, root, inode);
8485 if (err)
8486 drop_inode = 1;
8487
8488 out_unlock:
8489 if (!err)
8490 d_instantiate(dentry, inode);
8491 btrfs_end_transaction(trans, root);
8492 if (drop_inode) {
8493 inode_dec_link_count(inode);
8494 iput(inode);
8495 }
8496 btrfs_btree_balance_dirty(root);
8497 return err;
8498 }
8499
8500 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
8501 u64 start, u64 num_bytes, u64 min_size,
8502 loff_t actual_len, u64 *alloc_hint,
8503 struct btrfs_trans_handle *trans)
8504 {
8505 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
8506 struct extent_map *em;
8507 struct btrfs_root *root = BTRFS_I(inode)->root;
8508 struct btrfs_key ins;
8509 u64 cur_offset = start;
8510 u64 i_size;
8511 u64 cur_bytes;
8512 int ret = 0;
8513 bool own_trans = true;
8514
8515 if (trans)
8516 own_trans = false;
8517 while (num_bytes > 0) {
8518 if (own_trans) {
8519 trans = btrfs_start_transaction(root, 3);
8520 if (IS_ERR(trans)) {
8521 ret = PTR_ERR(trans);
8522 break;
8523 }
8524 }
8525
8526 cur_bytes = min(num_bytes, 256ULL * 1024 * 1024);
8527 cur_bytes = max(cur_bytes, min_size);
8528 ret = btrfs_reserve_extent(trans, root, cur_bytes,
8529 min_size, 0, *alloc_hint, &ins, 1);
8530 if (ret) {
8531 if (own_trans)
8532 btrfs_end_transaction(trans, root);
8533 break;
8534 }
8535
8536 ret = insert_reserved_file_extent(trans, inode,
8537 cur_offset, ins.objectid,
8538 ins.offset, ins.offset,
8539 ins.offset, 0, 0, 0,
8540 BTRFS_FILE_EXTENT_PREALLOC);
8541 if (ret) {
8542 btrfs_abort_transaction(trans, root, ret);
8543 if (own_trans)
8544 btrfs_end_transaction(trans, root);
8545 break;
8546 }
8547 btrfs_drop_extent_cache(inode, cur_offset,
8548 cur_offset + ins.offset -1, 0);
8549
8550 em = alloc_extent_map();
8551 if (!em) {
8552 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
8553 &BTRFS_I(inode)->runtime_flags);
8554 goto next;
8555 }
8556
8557 em->start = cur_offset;
8558 em->orig_start = cur_offset;
8559 em->len = ins.offset;
8560 em->block_start = ins.objectid;
8561 em->block_len = ins.offset;
8562 em->orig_block_len = ins.offset;
8563 em->ram_bytes = ins.offset;
8564 em->bdev = root->fs_info->fs_devices->latest_bdev;
8565 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
8566 em->generation = trans->transid;
8567
8568 while (1) {
8569 write_lock(&em_tree->lock);
8570 ret = add_extent_mapping(em_tree, em, 1);
8571 write_unlock(&em_tree->lock);
8572 if (ret != -EEXIST)
8573 break;
8574 btrfs_drop_extent_cache(inode, cur_offset,
8575 cur_offset + ins.offset - 1,
8576 0);
8577 }
8578 free_extent_map(em);
8579 next:
8580 num_bytes -= ins.offset;
8581 cur_offset += ins.offset;
8582 *alloc_hint = ins.objectid + ins.offset;
8583
8584 inode_inc_iversion(inode);
8585 inode->i_ctime = CURRENT_TIME;
8586 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
8587 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
8588 (actual_len > inode->i_size) &&
8589 (cur_offset > inode->i_size)) {
8590 if (cur_offset > actual_len)
8591 i_size = actual_len;
8592 else
8593 i_size = cur_offset;
8594 i_size_write(inode, i_size);
8595 btrfs_ordered_update_i_size(inode, i_size, NULL);
8596 }
8597
8598 ret = btrfs_update_inode(trans, root, inode);
8599
8600 if (ret) {
8601 btrfs_abort_transaction(trans, root, ret);
8602 if (own_trans)
8603 btrfs_end_transaction(trans, root);
8604 break;
8605 }
8606
8607 if (own_trans)
8608 btrfs_end_transaction(trans, root);
8609 }
8610 return ret;
8611 }
8612
8613 int btrfs_prealloc_file_range(struct inode *inode, int mode,
8614 u64 start, u64 num_bytes, u64 min_size,
8615 loff_t actual_len, u64 *alloc_hint)
8616 {
8617 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
8618 min_size, actual_len, alloc_hint,
8619 NULL);
8620 }
8621
8622 int btrfs_prealloc_file_range_trans(struct inode *inode,
8623 struct btrfs_trans_handle *trans, int mode,
8624 u64 start, u64 num_bytes, u64 min_size,
8625 loff_t actual_len, u64 *alloc_hint)
8626 {
8627 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
8628 min_size, actual_len, alloc_hint, trans);
8629 }
8630
8631 static int btrfs_set_page_dirty(struct page *page)
8632 {
8633 return __set_page_dirty_nobuffers(page);
8634 }
8635
8636 static int btrfs_permission(struct inode *inode, int mask)
8637 {
8638 struct btrfs_root *root = BTRFS_I(inode)->root;
8639 umode_t mode = inode->i_mode;
8640
8641 if (mask & MAY_WRITE &&
8642 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
8643 if (btrfs_root_readonly(root))
8644 return -EROFS;
8645 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
8646 return -EACCES;
8647 }
8648 return generic_permission(inode, mask);
8649 }
8650
8651 static const struct inode_operations btrfs_dir_inode_operations = {
8652 .getattr = btrfs_getattr,
8653 .lookup = btrfs_lookup,
8654 .create = btrfs_create,
8655 .unlink = btrfs_unlink,
8656 .link = btrfs_link,
8657 .mkdir = btrfs_mkdir,
8658 .rmdir = btrfs_rmdir,
8659 .rename = btrfs_rename,
8660 .symlink = btrfs_symlink,
8661 .setattr = btrfs_setattr,
8662 .mknod = btrfs_mknod,
8663 .setxattr = btrfs_setxattr,
8664 .getxattr = btrfs_getxattr,
8665 .listxattr = btrfs_listxattr,
8666 .removexattr = btrfs_removexattr,
8667 .permission = btrfs_permission,
8668 .get_acl = btrfs_get_acl,
8669 };
8670 static const struct inode_operations btrfs_dir_ro_inode_operations = {
8671 .lookup = btrfs_lookup,
8672 .permission = btrfs_permission,
8673 .get_acl = btrfs_get_acl,
8674 };
8675
8676 static const struct file_operations btrfs_dir_file_operations = {
8677 .llseek = generic_file_llseek,
8678 .read = generic_read_dir,
8679 .iterate = btrfs_real_readdir,
8680 .unlocked_ioctl = btrfs_ioctl,
8681 #ifdef CONFIG_COMPAT
8682 .compat_ioctl = btrfs_ioctl,
8683 #endif
8684 .release = btrfs_release_file,
8685 .fsync = btrfs_sync_file,
8686 };
8687
8688 static struct extent_io_ops btrfs_extent_io_ops = {
8689 .fill_delalloc = run_delalloc_range,
8690 .submit_bio_hook = btrfs_submit_bio_hook,
8691 .merge_bio_hook = btrfs_merge_bio_hook,
8692 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
8693 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
8694 .writepage_start_hook = btrfs_writepage_start_hook,
8695 .set_bit_hook = btrfs_set_bit_hook,
8696 .clear_bit_hook = btrfs_clear_bit_hook,
8697 .merge_extent_hook = btrfs_merge_extent_hook,
8698 .split_extent_hook = btrfs_split_extent_hook,
8699 };
8700
8701 /*
8702 * btrfs doesn't support the bmap operation because swapfiles
8703 * use bmap to make a mapping of extents in the file. They assume
8704 * these extents won't change over the life of the file and they
8705 * use the bmap result to do IO directly to the drive.
8706 *
8707 * the btrfs bmap call would return logical addresses that aren't
8708 * suitable for IO and they also will change frequently as COW
8709 * operations happen. So, swapfile + btrfs == corruption.
8710 *
8711 * For now we're avoiding this by dropping bmap.
8712 */
8713 static const struct address_space_operations btrfs_aops = {
8714 .readpage = btrfs_readpage,
8715 .writepage = btrfs_writepage,
8716 .writepages = btrfs_writepages,
8717 .readpages = btrfs_readpages,
8718 .direct_IO = btrfs_direct_IO,
8719 .invalidatepage = btrfs_invalidatepage,
8720 .releasepage = btrfs_releasepage,
8721 .set_page_dirty = btrfs_set_page_dirty,
8722 .error_remove_page = generic_error_remove_page,
8723 };
8724
8725 static const struct address_space_operations btrfs_symlink_aops = {
8726 .readpage = btrfs_readpage,
8727 .writepage = btrfs_writepage,
8728 .invalidatepage = btrfs_invalidatepage,
8729 .releasepage = btrfs_releasepage,
8730 };
8731
8732 static const struct inode_operations btrfs_file_inode_operations = {
8733 .getattr = btrfs_getattr,
8734 .setattr = btrfs_setattr,
8735 .setxattr = btrfs_setxattr,
8736 .getxattr = btrfs_getxattr,
8737 .listxattr = btrfs_listxattr,
8738 .removexattr = btrfs_removexattr,
8739 .permission = btrfs_permission,
8740 .fiemap = btrfs_fiemap,
8741 .get_acl = btrfs_get_acl,
8742 .update_time = btrfs_update_time,
8743 };
8744 static const struct inode_operations btrfs_special_inode_operations = {
8745 .getattr = btrfs_getattr,
8746 .setattr = btrfs_setattr,
8747 .permission = btrfs_permission,
8748 .setxattr = btrfs_setxattr,
8749 .getxattr = btrfs_getxattr,
8750 .listxattr = btrfs_listxattr,
8751 .removexattr = btrfs_removexattr,
8752 .get_acl = btrfs_get_acl,
8753 .update_time = btrfs_update_time,
8754 };
8755 static const struct inode_operations btrfs_symlink_inode_operations = {
8756 .readlink = generic_readlink,
8757 .follow_link = page_follow_link_light,
8758 .put_link = page_put_link,
8759 .getattr = btrfs_getattr,
8760 .setattr = btrfs_setattr,
8761 .permission = btrfs_permission,
8762 .setxattr = btrfs_setxattr,
8763 .getxattr = btrfs_getxattr,
8764 .listxattr = btrfs_listxattr,
8765 .removexattr = btrfs_removexattr,
8766 .get_acl = btrfs_get_acl,
8767 .update_time = btrfs_update_time,
8768 };
8769
8770 const struct dentry_operations btrfs_dentry_operations = {
8771 .d_delete = btrfs_dentry_delete,
8772 .d_release = btrfs_dentry_release,
8773 };
Linux kernel - Deliverables
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