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