Avoid beyond bounds copy while caching ACL
[zen-stable.git] / fs / btrfs / inode.c
blob892b34785ccc2fc2a8a1a2ded9d84a795c1eb1eb
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
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.
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.
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.
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 "compat.h"
43 #include "ctree.h"
44 #include "disk-io.h"
45 #include "transaction.h"
46 #include "btrfs_inode.h"
47 #include "ioctl.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"
58 struct btrfs_iget_args {
59 u64 ino;
60 struct btrfs_root *root;
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;
73 static struct kmem_cache *btrfs_inode_cachep;
74 struct kmem_cache *btrfs_trans_handle_cachep;
75 struct kmem_cache *btrfs_transaction_cachep;
76 struct kmem_cache *btrfs_path_cachep;
77 struct kmem_cache *btrfs_free_space_cachep;
79 #define S_SHIFT 12
80 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
81 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
82 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
83 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
84 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
85 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
86 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
87 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
90 static int btrfs_setsize(struct inode *inode, loff_t newsize);
91 static int btrfs_truncate(struct inode *inode);
92 static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end);
93 static noinline int cow_file_range(struct inode *inode,
94 struct page *locked_page,
95 u64 start, u64 end, int *page_started,
96 unsigned long *nr_written, int unlock);
97 static noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
98 struct btrfs_root *root, struct inode *inode);
100 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
101 struct inode *inode, struct inode *dir,
102 const struct qstr *qstr)
104 int err;
106 err = btrfs_init_acl(trans, inode, dir);
107 if (!err)
108 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
109 return err;
113 * this does all the hard work for inserting an inline extent into
114 * the btree. The caller should have done a btrfs_drop_extents so that
115 * no overlapping inline items exist in the btree
117 static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
118 struct btrfs_root *root, struct inode *inode,
119 u64 start, size_t size, size_t compressed_size,
120 int compress_type,
121 struct page **compressed_pages)
123 struct btrfs_key key;
124 struct btrfs_path *path;
125 struct extent_buffer *leaf;
126 struct page *page = NULL;
127 char *kaddr;
128 unsigned long ptr;
129 struct btrfs_file_extent_item *ei;
130 int err = 0;
131 int ret;
132 size_t cur_size = size;
133 size_t datasize;
134 unsigned long offset;
136 if (compressed_size && compressed_pages)
137 cur_size = compressed_size;
139 path = btrfs_alloc_path();
140 if (!path)
141 return -ENOMEM;
143 path->leave_spinning = 1;
145 key.objectid = btrfs_ino(inode);
146 key.offset = start;
147 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
148 datasize = btrfs_file_extent_calc_inline_size(cur_size);
150 inode_add_bytes(inode, size);
151 ret = btrfs_insert_empty_item(trans, root, path, &key,
152 datasize);
153 BUG_ON(ret);
154 if (ret) {
155 err = ret;
156 goto fail;
158 leaf = path->nodes[0];
159 ei = btrfs_item_ptr(leaf, path->slots[0],
160 struct btrfs_file_extent_item);
161 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
162 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
163 btrfs_set_file_extent_encryption(leaf, ei, 0);
164 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
165 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
166 ptr = btrfs_file_extent_inline_start(ei);
168 if (compress_type != BTRFS_COMPRESS_NONE) {
169 struct page *cpage;
170 int i = 0;
171 while (compressed_size > 0) {
172 cpage = compressed_pages[i];
173 cur_size = min_t(unsigned long, compressed_size,
174 PAGE_CACHE_SIZE);
176 kaddr = kmap_atomic(cpage, KM_USER0);
177 write_extent_buffer(leaf, kaddr, ptr, cur_size);
178 kunmap_atomic(kaddr, KM_USER0);
180 i++;
181 ptr += cur_size;
182 compressed_size -= cur_size;
184 btrfs_set_file_extent_compression(leaf, ei,
185 compress_type);
186 } else {
187 page = find_get_page(inode->i_mapping,
188 start >> PAGE_CACHE_SHIFT);
189 btrfs_set_file_extent_compression(leaf, ei, 0);
190 kaddr = kmap_atomic(page, KM_USER0);
191 offset = start & (PAGE_CACHE_SIZE - 1);
192 write_extent_buffer(leaf, kaddr + offset, ptr, size);
193 kunmap_atomic(kaddr, KM_USER0);
194 page_cache_release(page);
196 btrfs_mark_buffer_dirty(leaf);
197 btrfs_free_path(path);
200 * we're an inline extent, so nobody can
201 * extend the file past i_size without locking
202 * a page we already have locked.
204 * We must do any isize and inode updates
205 * before we unlock the pages. Otherwise we
206 * could end up racing with unlink.
208 BTRFS_I(inode)->disk_i_size = inode->i_size;
209 btrfs_update_inode(trans, root, inode);
211 return 0;
212 fail:
213 btrfs_free_path(path);
214 return err;
219 * conditionally insert an inline extent into the file. This
220 * does the checks required to make sure the data is small enough
221 * to fit as an inline extent.
223 static noinline int cow_file_range_inline(struct btrfs_trans_handle *trans,
224 struct btrfs_root *root,
225 struct inode *inode, u64 start, u64 end,
226 size_t compressed_size, int compress_type,
227 struct page **compressed_pages)
229 u64 isize = i_size_read(inode);
230 u64 actual_end = min(end + 1, isize);
231 u64 inline_len = actual_end - start;
232 u64 aligned_end = (end + root->sectorsize - 1) &
233 ~((u64)root->sectorsize - 1);
234 u64 hint_byte;
235 u64 data_len = inline_len;
236 int ret;
238 if (compressed_size)
239 data_len = compressed_size;
241 if (start > 0 ||
242 actual_end >= PAGE_CACHE_SIZE ||
243 data_len >= BTRFS_MAX_INLINE_DATA_SIZE(root) ||
244 (!compressed_size &&
245 (actual_end & (root->sectorsize - 1)) == 0) ||
246 end + 1 < isize ||
247 data_len > root->fs_info->max_inline) {
248 return 1;
251 ret = btrfs_drop_extents(trans, inode, start, aligned_end,
252 &hint_byte, 1);
253 BUG_ON(ret);
255 if (isize > actual_end)
256 inline_len = min_t(u64, isize, actual_end);
257 ret = insert_inline_extent(trans, root, inode, start,
258 inline_len, compressed_size,
259 compress_type, compressed_pages);
260 BUG_ON(ret);
261 btrfs_delalloc_release_metadata(inode, end + 1 - start);
262 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
263 return 0;
266 struct async_extent {
267 u64 start;
268 u64 ram_size;
269 u64 compressed_size;
270 struct page **pages;
271 unsigned long nr_pages;
272 int compress_type;
273 struct list_head list;
276 struct async_cow {
277 struct inode *inode;
278 struct btrfs_root *root;
279 struct page *locked_page;
280 u64 start;
281 u64 end;
282 struct list_head extents;
283 struct btrfs_work work;
286 static noinline int add_async_extent(struct async_cow *cow,
287 u64 start, u64 ram_size,
288 u64 compressed_size,
289 struct page **pages,
290 unsigned long nr_pages,
291 int compress_type)
293 struct async_extent *async_extent;
295 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
296 BUG_ON(!async_extent);
297 async_extent->start = start;
298 async_extent->ram_size = ram_size;
299 async_extent->compressed_size = compressed_size;
300 async_extent->pages = pages;
301 async_extent->nr_pages = nr_pages;
302 async_extent->compress_type = compress_type;
303 list_add_tail(&async_extent->list, &cow->extents);
304 return 0;
308 * we create compressed extents in two phases. The first
309 * phase compresses a range of pages that have already been
310 * locked (both pages and state bits are locked).
312 * This is done inside an ordered work queue, and the compression
313 * is spread across many cpus. The actual IO submission is step
314 * two, and the ordered work queue takes care of making sure that
315 * happens in the same order things were put onto the queue by
316 * writepages and friends.
318 * If this code finds it can't get good compression, it puts an
319 * entry onto the work queue to write the uncompressed bytes. This
320 * makes sure that both compressed inodes and uncompressed inodes
321 * are written in the same order that pdflush sent them down.
323 static noinline int compress_file_range(struct inode *inode,
324 struct page *locked_page,
325 u64 start, u64 end,
326 struct async_cow *async_cow,
327 int *num_added)
329 struct btrfs_root *root = BTRFS_I(inode)->root;
330 struct btrfs_trans_handle *trans;
331 u64 num_bytes;
332 u64 blocksize = root->sectorsize;
333 u64 actual_end;
334 u64 isize = i_size_read(inode);
335 int ret = 0;
336 struct page **pages = NULL;
337 unsigned long nr_pages;
338 unsigned long nr_pages_ret = 0;
339 unsigned long total_compressed = 0;
340 unsigned long total_in = 0;
341 unsigned long max_compressed = 128 * 1024;
342 unsigned long max_uncompressed = 128 * 1024;
343 int i;
344 int will_compress;
345 int compress_type = root->fs_info->compress_type;
347 /* if this is a small write inside eof, kick off a defragbot */
348 if (end <= BTRFS_I(inode)->disk_i_size && (end - start + 1) < 16 * 1024)
349 btrfs_add_inode_defrag(NULL, inode);
351 actual_end = min_t(u64, isize, end + 1);
352 again:
353 will_compress = 0;
354 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
355 nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
358 * we don't want to send crud past the end of i_size through
359 * compression, that's just a waste of CPU time. So, if the
360 * end of the file is before the start of our current
361 * requested range of bytes, we bail out to the uncompressed
362 * cleanup code that can deal with all of this.
364 * It isn't really the fastest way to fix things, but this is a
365 * very uncommon corner.
367 if (actual_end <= start)
368 goto cleanup_and_bail_uncompressed;
370 total_compressed = actual_end - start;
372 /* we want to make sure that amount of ram required to uncompress
373 * an extent is reasonable, so we limit the total size in ram
374 * of a compressed extent to 128k. This is a crucial number
375 * because it also controls how easily we can spread reads across
376 * cpus for decompression.
378 * We also want to make sure the amount of IO required to do
379 * a random read is reasonably small, so we limit the size of
380 * a compressed extent to 128k.
382 total_compressed = min(total_compressed, max_uncompressed);
383 num_bytes = (end - start + blocksize) & ~(blocksize - 1);
384 num_bytes = max(blocksize, num_bytes);
385 total_in = 0;
386 ret = 0;
389 * we do compression for mount -o compress and when the
390 * inode has not been flagged as nocompress. This flag can
391 * change at any time if we discover bad compression ratios.
393 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) &&
394 (btrfs_test_opt(root, COMPRESS) ||
395 (BTRFS_I(inode)->force_compress) ||
396 (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))) {
397 WARN_ON(pages);
398 pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
399 if (!pages) {
400 /* just bail out to the uncompressed code */
401 goto cont;
404 if (BTRFS_I(inode)->force_compress)
405 compress_type = BTRFS_I(inode)->force_compress;
407 ret = btrfs_compress_pages(compress_type,
408 inode->i_mapping, start,
409 total_compressed, pages,
410 nr_pages, &nr_pages_ret,
411 &total_in,
412 &total_compressed,
413 max_compressed);
415 if (!ret) {
416 unsigned long offset = total_compressed &
417 (PAGE_CACHE_SIZE - 1);
418 struct page *page = pages[nr_pages_ret - 1];
419 char *kaddr;
421 /* zero the tail end of the last page, we might be
422 * sending it down to disk
424 if (offset) {
425 kaddr = kmap_atomic(page, KM_USER0);
426 memset(kaddr + offset, 0,
427 PAGE_CACHE_SIZE - offset);
428 kunmap_atomic(kaddr, KM_USER0);
430 will_compress = 1;
433 cont:
434 if (start == 0) {
435 trans = btrfs_join_transaction(root);
436 BUG_ON(IS_ERR(trans));
437 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
439 /* lets try to make an inline extent */
440 if (ret || total_in < (actual_end - start)) {
441 /* we didn't compress the entire range, try
442 * to make an uncompressed inline extent.
444 ret = cow_file_range_inline(trans, root, inode,
445 start, end, 0, 0, NULL);
446 } else {
447 /* try making a compressed inline extent */
448 ret = cow_file_range_inline(trans, root, inode,
449 start, end,
450 total_compressed,
451 compress_type, pages);
453 if (ret == 0) {
455 * inline extent creation worked, we don't need
456 * to create any more async work items. Unlock
457 * and free up our temp pages.
459 extent_clear_unlock_delalloc(inode,
460 &BTRFS_I(inode)->io_tree,
461 start, end, NULL,
462 EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
463 EXTENT_CLEAR_DELALLOC |
464 EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK);
466 btrfs_end_transaction(trans, root);
467 goto free_pages_out;
469 btrfs_end_transaction(trans, root);
472 if (will_compress) {
474 * we aren't doing an inline extent round the compressed size
475 * up to a block size boundary so the allocator does sane
476 * things
478 total_compressed = (total_compressed + blocksize - 1) &
479 ~(blocksize - 1);
482 * one last check to make sure the compression is really a
483 * win, compare the page count read with the blocks on disk
485 total_in = (total_in + PAGE_CACHE_SIZE - 1) &
486 ~(PAGE_CACHE_SIZE - 1);
487 if (total_compressed >= total_in) {
488 will_compress = 0;
489 } else {
490 num_bytes = total_in;
493 if (!will_compress && pages) {
495 * the compression code ran but failed to make things smaller,
496 * free any pages it allocated and our page pointer array
498 for (i = 0; i < nr_pages_ret; i++) {
499 WARN_ON(pages[i]->mapping);
500 page_cache_release(pages[i]);
502 kfree(pages);
503 pages = NULL;
504 total_compressed = 0;
505 nr_pages_ret = 0;
507 /* flag the file so we don't compress in the future */
508 if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
509 !(BTRFS_I(inode)->force_compress)) {
510 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
513 if (will_compress) {
514 *num_added += 1;
516 /* the async work queues will take care of doing actual
517 * allocation on disk for these compressed pages,
518 * and will submit them to the elevator.
520 add_async_extent(async_cow, start, num_bytes,
521 total_compressed, pages, nr_pages_ret,
522 compress_type);
524 if (start + num_bytes < end) {
525 start += num_bytes;
526 pages = NULL;
527 cond_resched();
528 goto again;
530 } else {
531 cleanup_and_bail_uncompressed:
533 * No compression, but we still need to write the pages in
534 * the file we've been given so far. redirty the locked
535 * page if it corresponds to our extent and set things up
536 * for the async work queue to run cow_file_range to do
537 * the normal delalloc dance
539 if (page_offset(locked_page) >= start &&
540 page_offset(locked_page) <= end) {
541 __set_page_dirty_nobuffers(locked_page);
542 /* unlocked later on in the async handlers */
544 add_async_extent(async_cow, start, end - start + 1,
545 0, NULL, 0, BTRFS_COMPRESS_NONE);
546 *num_added += 1;
549 out:
550 return 0;
552 free_pages_out:
553 for (i = 0; i < nr_pages_ret; i++) {
554 WARN_ON(pages[i]->mapping);
555 page_cache_release(pages[i]);
557 kfree(pages);
559 goto out;
563 * phase two of compressed writeback. This is the ordered portion
564 * of the code, which only gets called in the order the work was
565 * queued. We walk all the async extents created by compress_file_range
566 * and send them down to the disk.
568 static noinline int submit_compressed_extents(struct inode *inode,
569 struct async_cow *async_cow)
571 struct async_extent *async_extent;
572 u64 alloc_hint = 0;
573 struct btrfs_trans_handle *trans;
574 struct btrfs_key ins;
575 struct extent_map *em;
576 struct btrfs_root *root = BTRFS_I(inode)->root;
577 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
578 struct extent_io_tree *io_tree;
579 int ret = 0;
581 if (list_empty(&async_cow->extents))
582 return 0;
585 while (!list_empty(&async_cow->extents)) {
586 async_extent = list_entry(async_cow->extents.next,
587 struct async_extent, list);
588 list_del(&async_extent->list);
590 io_tree = &BTRFS_I(inode)->io_tree;
592 retry:
593 /* did the compression code fall back to uncompressed IO? */
594 if (!async_extent->pages) {
595 int page_started = 0;
596 unsigned long nr_written = 0;
598 lock_extent(io_tree, async_extent->start,
599 async_extent->start +
600 async_extent->ram_size - 1, GFP_NOFS);
602 /* allocate blocks */
603 ret = cow_file_range(inode, async_cow->locked_page,
604 async_extent->start,
605 async_extent->start +
606 async_extent->ram_size - 1,
607 &page_started, &nr_written, 0);
610 * if page_started, cow_file_range inserted an
611 * inline extent and took care of all the unlocking
612 * and IO for us. Otherwise, we need to submit
613 * all those pages down to the drive.
615 if (!page_started && !ret)
616 extent_write_locked_range(io_tree,
617 inode, async_extent->start,
618 async_extent->start +
619 async_extent->ram_size - 1,
620 btrfs_get_extent,
621 WB_SYNC_ALL);
622 kfree(async_extent);
623 cond_resched();
624 continue;
627 lock_extent(io_tree, async_extent->start,
628 async_extent->start + async_extent->ram_size - 1,
629 GFP_NOFS);
631 trans = btrfs_join_transaction(root);
632 BUG_ON(IS_ERR(trans));
633 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
634 ret = btrfs_reserve_extent(trans, root,
635 async_extent->compressed_size,
636 async_extent->compressed_size,
637 0, alloc_hint,
638 (u64)-1, &ins, 1);
639 btrfs_end_transaction(trans, root);
641 if (ret) {
642 int i;
643 for (i = 0; i < async_extent->nr_pages; i++) {
644 WARN_ON(async_extent->pages[i]->mapping);
645 page_cache_release(async_extent->pages[i]);
647 kfree(async_extent->pages);
648 async_extent->nr_pages = 0;
649 async_extent->pages = NULL;
650 unlock_extent(io_tree, async_extent->start,
651 async_extent->start +
652 async_extent->ram_size - 1, GFP_NOFS);
653 goto retry;
657 * here we're doing allocation and writeback of the
658 * compressed pages
660 btrfs_drop_extent_cache(inode, async_extent->start,
661 async_extent->start +
662 async_extent->ram_size - 1, 0);
664 em = alloc_extent_map();
665 BUG_ON(!em);
666 em->start = async_extent->start;
667 em->len = async_extent->ram_size;
668 em->orig_start = em->start;
670 em->block_start = ins.objectid;
671 em->block_len = ins.offset;
672 em->bdev = root->fs_info->fs_devices->latest_bdev;
673 em->compress_type = async_extent->compress_type;
674 set_bit(EXTENT_FLAG_PINNED, &em->flags);
675 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
677 while (1) {
678 write_lock(&em_tree->lock);
679 ret = add_extent_mapping(em_tree, em);
680 write_unlock(&em_tree->lock);
681 if (ret != -EEXIST) {
682 free_extent_map(em);
683 break;
685 btrfs_drop_extent_cache(inode, async_extent->start,
686 async_extent->start +
687 async_extent->ram_size - 1, 0);
690 ret = btrfs_add_ordered_extent_compress(inode,
691 async_extent->start,
692 ins.objectid,
693 async_extent->ram_size,
694 ins.offset,
695 BTRFS_ORDERED_COMPRESSED,
696 async_extent->compress_type);
697 BUG_ON(ret);
700 * clear dirty, set writeback and unlock the pages.
702 extent_clear_unlock_delalloc(inode,
703 &BTRFS_I(inode)->io_tree,
704 async_extent->start,
705 async_extent->start +
706 async_extent->ram_size - 1,
707 NULL, EXTENT_CLEAR_UNLOCK_PAGE |
708 EXTENT_CLEAR_UNLOCK |
709 EXTENT_CLEAR_DELALLOC |
710 EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK);
712 ret = btrfs_submit_compressed_write(inode,
713 async_extent->start,
714 async_extent->ram_size,
715 ins.objectid,
716 ins.offset, async_extent->pages,
717 async_extent->nr_pages);
719 BUG_ON(ret);
720 alloc_hint = ins.objectid + ins.offset;
721 kfree(async_extent);
722 cond_resched();
725 return 0;
728 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
729 u64 num_bytes)
731 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
732 struct extent_map *em;
733 u64 alloc_hint = 0;
735 read_lock(&em_tree->lock);
736 em = search_extent_mapping(em_tree, start, num_bytes);
737 if (em) {
739 * if block start isn't an actual block number then find the
740 * first block in this inode and use that as a hint. If that
741 * block is also bogus then just don't worry about it.
743 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
744 free_extent_map(em);
745 em = search_extent_mapping(em_tree, 0, 0);
746 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
747 alloc_hint = em->block_start;
748 if (em)
749 free_extent_map(em);
750 } else {
751 alloc_hint = em->block_start;
752 free_extent_map(em);
755 read_unlock(&em_tree->lock);
757 return alloc_hint;
761 * when extent_io.c finds a delayed allocation range in the file,
762 * the call backs end up in this code. The basic idea is to
763 * allocate extents on disk for the range, and create ordered data structs
764 * in ram to track those extents.
766 * locked_page is the page that writepage had locked already. We use
767 * it to make sure we don't do extra locks or unlocks.
769 * *page_started is set to one if we unlock locked_page and do everything
770 * required to start IO on it. It may be clean and already done with
771 * IO when we return.
773 static noinline int cow_file_range(struct inode *inode,
774 struct page *locked_page,
775 u64 start, u64 end, int *page_started,
776 unsigned long *nr_written,
777 int unlock)
779 struct btrfs_root *root = BTRFS_I(inode)->root;
780 struct btrfs_trans_handle *trans;
781 u64 alloc_hint = 0;
782 u64 num_bytes;
783 unsigned long ram_size;
784 u64 disk_num_bytes;
785 u64 cur_alloc_size;
786 u64 blocksize = root->sectorsize;
787 struct btrfs_key ins;
788 struct extent_map *em;
789 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
790 int ret = 0;
792 BUG_ON(btrfs_is_free_space_inode(root, inode));
793 trans = btrfs_join_transaction(root);
794 BUG_ON(IS_ERR(trans));
795 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
797 num_bytes = (end - start + blocksize) & ~(blocksize - 1);
798 num_bytes = max(blocksize, num_bytes);
799 disk_num_bytes = num_bytes;
800 ret = 0;
802 /* if this is a small write inside eof, kick off defrag */
803 if (end <= BTRFS_I(inode)->disk_i_size && num_bytes < 64 * 1024)
804 btrfs_add_inode_defrag(trans, inode);
806 if (start == 0) {
807 /* lets try to make an inline extent */
808 ret = cow_file_range_inline(trans, root, inode,
809 start, end, 0, 0, NULL);
810 if (ret == 0) {
811 extent_clear_unlock_delalloc(inode,
812 &BTRFS_I(inode)->io_tree,
813 start, end, NULL,
814 EXTENT_CLEAR_UNLOCK_PAGE |
815 EXTENT_CLEAR_UNLOCK |
816 EXTENT_CLEAR_DELALLOC |
817 EXTENT_CLEAR_DIRTY |
818 EXTENT_SET_WRITEBACK |
819 EXTENT_END_WRITEBACK);
821 *nr_written = *nr_written +
822 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
823 *page_started = 1;
824 ret = 0;
825 goto out;
829 BUG_ON(disk_num_bytes >
830 btrfs_super_total_bytes(root->fs_info->super_copy));
832 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
833 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
835 while (disk_num_bytes > 0) {
836 unsigned long op;
838 cur_alloc_size = disk_num_bytes;
839 ret = btrfs_reserve_extent(trans, root, cur_alloc_size,
840 root->sectorsize, 0, alloc_hint,
841 (u64)-1, &ins, 1);
842 BUG_ON(ret);
844 em = alloc_extent_map();
845 BUG_ON(!em);
846 em->start = start;
847 em->orig_start = em->start;
848 ram_size = ins.offset;
849 em->len = ins.offset;
851 em->block_start = ins.objectid;
852 em->block_len = ins.offset;
853 em->bdev = root->fs_info->fs_devices->latest_bdev;
854 set_bit(EXTENT_FLAG_PINNED, &em->flags);
856 while (1) {
857 write_lock(&em_tree->lock);
858 ret = add_extent_mapping(em_tree, em);
859 write_unlock(&em_tree->lock);
860 if (ret != -EEXIST) {
861 free_extent_map(em);
862 break;
864 btrfs_drop_extent_cache(inode, start,
865 start + ram_size - 1, 0);
868 cur_alloc_size = ins.offset;
869 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
870 ram_size, cur_alloc_size, 0);
871 BUG_ON(ret);
873 if (root->root_key.objectid ==
874 BTRFS_DATA_RELOC_TREE_OBJECTID) {
875 ret = btrfs_reloc_clone_csums(inode, start,
876 cur_alloc_size);
877 BUG_ON(ret);
880 if (disk_num_bytes < cur_alloc_size)
881 break;
883 /* we're not doing compressed IO, don't unlock the first
884 * page (which the caller expects to stay locked), don't
885 * clear any dirty bits and don't set any writeback bits
887 * Do set the Private2 bit so we know this page was properly
888 * setup for writepage
890 op = unlock ? EXTENT_CLEAR_UNLOCK_PAGE : 0;
891 op |= EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
892 EXTENT_SET_PRIVATE2;
894 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
895 start, start + ram_size - 1,
896 locked_page, op);
897 disk_num_bytes -= cur_alloc_size;
898 num_bytes -= cur_alloc_size;
899 alloc_hint = ins.objectid + ins.offset;
900 start += cur_alloc_size;
902 out:
903 ret = 0;
904 btrfs_end_transaction(trans, root);
906 return ret;
910 * work queue call back to started compression on a file and pages
912 static noinline void async_cow_start(struct btrfs_work *work)
914 struct async_cow *async_cow;
915 int num_added = 0;
916 async_cow = container_of(work, struct async_cow, work);
918 compress_file_range(async_cow->inode, async_cow->locked_page,
919 async_cow->start, async_cow->end, async_cow,
920 &num_added);
921 if (num_added == 0)
922 async_cow->inode = NULL;
926 * work queue call back to submit previously compressed pages
928 static noinline void async_cow_submit(struct btrfs_work *work)
930 struct async_cow *async_cow;
931 struct btrfs_root *root;
932 unsigned long nr_pages;
934 async_cow = container_of(work, struct async_cow, work);
936 root = async_cow->root;
937 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
938 PAGE_CACHE_SHIFT;
940 atomic_sub(nr_pages, &root->fs_info->async_delalloc_pages);
942 if (atomic_read(&root->fs_info->async_delalloc_pages) <
943 5 * 1042 * 1024 &&
944 waitqueue_active(&root->fs_info->async_submit_wait))
945 wake_up(&root->fs_info->async_submit_wait);
947 if (async_cow->inode)
948 submit_compressed_extents(async_cow->inode, async_cow);
951 static noinline void async_cow_free(struct btrfs_work *work)
953 struct async_cow *async_cow;
954 async_cow = container_of(work, struct async_cow, work);
955 kfree(async_cow);
958 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
959 u64 start, u64 end, int *page_started,
960 unsigned long *nr_written)
962 struct async_cow *async_cow;
963 struct btrfs_root *root = BTRFS_I(inode)->root;
964 unsigned long nr_pages;
965 u64 cur_end;
966 int limit = 10 * 1024 * 1042;
968 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
969 1, 0, NULL, GFP_NOFS);
970 while (start < end) {
971 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
972 BUG_ON(!async_cow);
973 async_cow->inode = inode;
974 async_cow->root = root;
975 async_cow->locked_page = locked_page;
976 async_cow->start = start;
978 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
979 cur_end = end;
980 else
981 cur_end = min(end, start + 512 * 1024 - 1);
983 async_cow->end = cur_end;
984 INIT_LIST_HEAD(&async_cow->extents);
986 async_cow->work.func = async_cow_start;
987 async_cow->work.ordered_func = async_cow_submit;
988 async_cow->work.ordered_free = async_cow_free;
989 async_cow->work.flags = 0;
991 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
992 PAGE_CACHE_SHIFT;
993 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
995 btrfs_queue_worker(&root->fs_info->delalloc_workers,
996 &async_cow->work);
998 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
999 wait_event(root->fs_info->async_submit_wait,
1000 (atomic_read(&root->fs_info->async_delalloc_pages) <
1001 limit));
1004 while (atomic_read(&root->fs_info->async_submit_draining) &&
1005 atomic_read(&root->fs_info->async_delalloc_pages)) {
1006 wait_event(root->fs_info->async_submit_wait,
1007 (atomic_read(&root->fs_info->async_delalloc_pages) ==
1008 0));
1011 *nr_written += nr_pages;
1012 start = cur_end + 1;
1014 *page_started = 1;
1015 return 0;
1018 static noinline int csum_exist_in_range(struct btrfs_root *root,
1019 u64 bytenr, u64 num_bytes)
1021 int ret;
1022 struct btrfs_ordered_sum *sums;
1023 LIST_HEAD(list);
1025 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1026 bytenr + num_bytes - 1, &list, 0);
1027 if (ret == 0 && list_empty(&list))
1028 return 0;
1030 while (!list_empty(&list)) {
1031 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1032 list_del(&sums->list);
1033 kfree(sums);
1035 return 1;
1039 * when nowcow writeback call back. This checks for snapshots or COW copies
1040 * of the extents that exist in the file, and COWs the file as required.
1042 * If no cow copies or snapshots exist, we write directly to the existing
1043 * blocks on disk
1045 static noinline int run_delalloc_nocow(struct inode *inode,
1046 struct page *locked_page,
1047 u64 start, u64 end, int *page_started, int force,
1048 unsigned long *nr_written)
1050 struct btrfs_root *root = BTRFS_I(inode)->root;
1051 struct btrfs_trans_handle *trans;
1052 struct extent_buffer *leaf;
1053 struct btrfs_path *path;
1054 struct btrfs_file_extent_item *fi;
1055 struct btrfs_key found_key;
1056 u64 cow_start;
1057 u64 cur_offset;
1058 u64 extent_end;
1059 u64 extent_offset;
1060 u64 disk_bytenr;
1061 u64 num_bytes;
1062 int extent_type;
1063 int ret;
1064 int type;
1065 int nocow;
1066 int check_prev = 1;
1067 bool nolock;
1068 u64 ino = btrfs_ino(inode);
1070 path = btrfs_alloc_path();
1071 if (!path)
1072 return -ENOMEM;
1074 nolock = btrfs_is_free_space_inode(root, inode);
1076 if (nolock)
1077 trans = btrfs_join_transaction_nolock(root);
1078 else
1079 trans = btrfs_join_transaction(root);
1081 BUG_ON(IS_ERR(trans));
1082 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1084 cow_start = (u64)-1;
1085 cur_offset = start;
1086 while (1) {
1087 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1088 cur_offset, 0);
1089 BUG_ON(ret < 0);
1090 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1091 leaf = path->nodes[0];
1092 btrfs_item_key_to_cpu(leaf, &found_key,
1093 path->slots[0] - 1);
1094 if (found_key.objectid == ino &&
1095 found_key.type == BTRFS_EXTENT_DATA_KEY)
1096 path->slots[0]--;
1098 check_prev = 0;
1099 next_slot:
1100 leaf = path->nodes[0];
1101 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1102 ret = btrfs_next_leaf(root, path);
1103 if (ret < 0)
1104 BUG_ON(1);
1105 if (ret > 0)
1106 break;
1107 leaf = path->nodes[0];
1110 nocow = 0;
1111 disk_bytenr = 0;
1112 num_bytes = 0;
1113 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1115 if (found_key.objectid > ino ||
1116 found_key.type > BTRFS_EXTENT_DATA_KEY ||
1117 found_key.offset > end)
1118 break;
1120 if (found_key.offset > cur_offset) {
1121 extent_end = found_key.offset;
1122 extent_type = 0;
1123 goto out_check;
1126 fi = btrfs_item_ptr(leaf, path->slots[0],
1127 struct btrfs_file_extent_item);
1128 extent_type = btrfs_file_extent_type(leaf, fi);
1130 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1131 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1132 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1133 extent_offset = btrfs_file_extent_offset(leaf, fi);
1134 extent_end = found_key.offset +
1135 btrfs_file_extent_num_bytes(leaf, fi);
1136 if (extent_end <= start) {
1137 path->slots[0]++;
1138 goto next_slot;
1140 if (disk_bytenr == 0)
1141 goto out_check;
1142 if (btrfs_file_extent_compression(leaf, fi) ||
1143 btrfs_file_extent_encryption(leaf, fi) ||
1144 btrfs_file_extent_other_encoding(leaf, fi))
1145 goto out_check;
1146 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1147 goto out_check;
1148 if (btrfs_extent_readonly(root, disk_bytenr))
1149 goto out_check;
1150 if (btrfs_cross_ref_exist(trans, root, ino,
1151 found_key.offset -
1152 extent_offset, disk_bytenr))
1153 goto out_check;
1154 disk_bytenr += extent_offset;
1155 disk_bytenr += cur_offset - found_key.offset;
1156 num_bytes = min(end + 1, extent_end) - cur_offset;
1158 * force cow if csum exists in the range.
1159 * this ensure that csum for a given extent are
1160 * either valid or do not exist.
1162 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1163 goto out_check;
1164 nocow = 1;
1165 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1166 extent_end = found_key.offset +
1167 btrfs_file_extent_inline_len(leaf, fi);
1168 extent_end = ALIGN(extent_end, root->sectorsize);
1169 } else {
1170 BUG_ON(1);
1172 out_check:
1173 if (extent_end <= start) {
1174 path->slots[0]++;
1175 goto next_slot;
1177 if (!nocow) {
1178 if (cow_start == (u64)-1)
1179 cow_start = cur_offset;
1180 cur_offset = extent_end;
1181 if (cur_offset > end)
1182 break;
1183 path->slots[0]++;
1184 goto next_slot;
1187 btrfs_release_path(path);
1188 if (cow_start != (u64)-1) {
1189 ret = cow_file_range(inode, locked_page, cow_start,
1190 found_key.offset - 1, page_started,
1191 nr_written, 1);
1192 BUG_ON(ret);
1193 cow_start = (u64)-1;
1196 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1197 struct extent_map *em;
1198 struct extent_map_tree *em_tree;
1199 em_tree = &BTRFS_I(inode)->extent_tree;
1200 em = alloc_extent_map();
1201 BUG_ON(!em);
1202 em->start = cur_offset;
1203 em->orig_start = em->start;
1204 em->len = num_bytes;
1205 em->block_len = num_bytes;
1206 em->block_start = disk_bytenr;
1207 em->bdev = root->fs_info->fs_devices->latest_bdev;
1208 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1209 while (1) {
1210 write_lock(&em_tree->lock);
1211 ret = add_extent_mapping(em_tree, em);
1212 write_unlock(&em_tree->lock);
1213 if (ret != -EEXIST) {
1214 free_extent_map(em);
1215 break;
1217 btrfs_drop_extent_cache(inode, em->start,
1218 em->start + em->len - 1, 0);
1220 type = BTRFS_ORDERED_PREALLOC;
1221 } else {
1222 type = BTRFS_ORDERED_NOCOW;
1225 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1226 num_bytes, num_bytes, type);
1227 BUG_ON(ret);
1229 if (root->root_key.objectid ==
1230 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1231 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1232 num_bytes);
1233 BUG_ON(ret);
1236 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
1237 cur_offset, cur_offset + num_bytes - 1,
1238 locked_page, EXTENT_CLEAR_UNLOCK_PAGE |
1239 EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
1240 EXTENT_SET_PRIVATE2);
1241 cur_offset = extent_end;
1242 if (cur_offset > end)
1243 break;
1245 btrfs_release_path(path);
1247 if (cur_offset <= end && cow_start == (u64)-1)
1248 cow_start = cur_offset;
1249 if (cow_start != (u64)-1) {
1250 ret = cow_file_range(inode, locked_page, cow_start, end,
1251 page_started, nr_written, 1);
1252 BUG_ON(ret);
1255 if (nolock) {
1256 ret = btrfs_end_transaction_nolock(trans, root);
1257 BUG_ON(ret);
1258 } else {
1259 ret = btrfs_end_transaction(trans, root);
1260 BUG_ON(ret);
1262 btrfs_free_path(path);
1263 return 0;
1267 * extent_io.c call back to do delayed allocation processing
1269 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1270 u64 start, u64 end, int *page_started,
1271 unsigned long *nr_written)
1273 int ret;
1274 struct btrfs_root *root = BTRFS_I(inode)->root;
1276 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW)
1277 ret = run_delalloc_nocow(inode, locked_page, start, end,
1278 page_started, 1, nr_written);
1279 else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC)
1280 ret = run_delalloc_nocow(inode, locked_page, start, end,
1281 page_started, 0, nr_written);
1282 else if (!btrfs_test_opt(root, COMPRESS) &&
1283 !(BTRFS_I(inode)->force_compress) &&
1284 !(BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))
1285 ret = cow_file_range(inode, locked_page, start, end,
1286 page_started, nr_written, 1);
1287 else
1288 ret = cow_file_range_async(inode, locked_page, start, end,
1289 page_started, nr_written);
1290 return ret;
1293 static void btrfs_split_extent_hook(struct inode *inode,
1294 struct extent_state *orig, u64 split)
1296 /* not delalloc, ignore it */
1297 if (!(orig->state & EXTENT_DELALLOC))
1298 return;
1300 spin_lock(&BTRFS_I(inode)->lock);
1301 BTRFS_I(inode)->outstanding_extents++;
1302 spin_unlock(&BTRFS_I(inode)->lock);
1306 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1307 * extents so we can keep track of new extents that are just merged onto old
1308 * extents, such as when we are doing sequential writes, so we can properly
1309 * account for the metadata space we'll need.
1311 static void btrfs_merge_extent_hook(struct inode *inode,
1312 struct extent_state *new,
1313 struct extent_state *other)
1315 /* not delalloc, ignore it */
1316 if (!(other->state & EXTENT_DELALLOC))
1317 return;
1319 spin_lock(&BTRFS_I(inode)->lock);
1320 BTRFS_I(inode)->outstanding_extents--;
1321 spin_unlock(&BTRFS_I(inode)->lock);
1325 * extent_io.c set_bit_hook, used to track delayed allocation
1326 * bytes in this file, and to maintain the list of inodes that
1327 * have pending delalloc work to be done.
1329 static void btrfs_set_bit_hook(struct inode *inode,
1330 struct extent_state *state, int *bits)
1334 * set_bit and clear bit hooks normally require _irqsave/restore
1335 * but in this case, we are only testing for the DELALLOC
1336 * bit, which is only set or cleared with irqs on
1338 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1339 struct btrfs_root *root = BTRFS_I(inode)->root;
1340 u64 len = state->end + 1 - state->start;
1341 bool do_list = !btrfs_is_free_space_inode(root, inode);
1343 if (*bits & EXTENT_FIRST_DELALLOC) {
1344 *bits &= ~EXTENT_FIRST_DELALLOC;
1345 } else {
1346 spin_lock(&BTRFS_I(inode)->lock);
1347 BTRFS_I(inode)->outstanding_extents++;
1348 spin_unlock(&BTRFS_I(inode)->lock);
1351 spin_lock(&root->fs_info->delalloc_lock);
1352 BTRFS_I(inode)->delalloc_bytes += len;
1353 root->fs_info->delalloc_bytes += len;
1354 if (do_list && list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1355 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1356 &root->fs_info->delalloc_inodes);
1358 spin_unlock(&root->fs_info->delalloc_lock);
1363 * extent_io.c clear_bit_hook, see set_bit_hook for why
1365 static void btrfs_clear_bit_hook(struct inode *inode,
1366 struct extent_state *state, int *bits)
1369 * set_bit and clear bit hooks normally require _irqsave/restore
1370 * but in this case, we are only testing for the DELALLOC
1371 * bit, which is only set or cleared with irqs on
1373 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1374 struct btrfs_root *root = BTRFS_I(inode)->root;
1375 u64 len = state->end + 1 - state->start;
1376 bool do_list = !btrfs_is_free_space_inode(root, inode);
1378 if (*bits & EXTENT_FIRST_DELALLOC) {
1379 *bits &= ~EXTENT_FIRST_DELALLOC;
1380 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1381 spin_lock(&BTRFS_I(inode)->lock);
1382 BTRFS_I(inode)->outstanding_extents--;
1383 spin_unlock(&BTRFS_I(inode)->lock);
1386 if (*bits & EXTENT_DO_ACCOUNTING)
1387 btrfs_delalloc_release_metadata(inode, len);
1389 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1390 && do_list)
1391 btrfs_free_reserved_data_space(inode, len);
1393 spin_lock(&root->fs_info->delalloc_lock);
1394 root->fs_info->delalloc_bytes -= len;
1395 BTRFS_I(inode)->delalloc_bytes -= len;
1397 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1398 !list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1399 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1401 spin_unlock(&root->fs_info->delalloc_lock);
1406 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1407 * we don't create bios that span stripes or chunks
1409 int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
1410 size_t size, struct bio *bio,
1411 unsigned long bio_flags)
1413 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1414 struct btrfs_mapping_tree *map_tree;
1415 u64 logical = (u64)bio->bi_sector << 9;
1416 u64 length = 0;
1417 u64 map_length;
1418 int ret;
1420 if (bio_flags & EXTENT_BIO_COMPRESSED)
1421 return 0;
1423 length = bio->bi_size;
1424 map_tree = &root->fs_info->mapping_tree;
1425 map_length = length;
1426 ret = btrfs_map_block(map_tree, READ, logical,
1427 &map_length, NULL, 0);
1429 if (map_length < length + size)
1430 return 1;
1431 return ret;
1435 * in order to insert checksums into the metadata in large chunks,
1436 * we wait until bio submission time. All the pages in the bio are
1437 * checksummed and sums are attached onto the ordered extent record.
1439 * At IO completion time the cums attached on the ordered extent record
1440 * are inserted into the btree
1442 static int __btrfs_submit_bio_start(struct inode *inode, int rw,
1443 struct bio *bio, int mirror_num,
1444 unsigned long bio_flags,
1445 u64 bio_offset)
1447 struct btrfs_root *root = BTRFS_I(inode)->root;
1448 int ret = 0;
1450 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1451 BUG_ON(ret);
1452 return 0;
1456 * in order to insert checksums into the metadata in large chunks,
1457 * we wait until bio submission time. All the pages in the bio are
1458 * checksummed and sums are attached onto the ordered extent record.
1460 * At IO completion time the cums attached on the ordered extent record
1461 * are inserted into the btree
1463 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1464 int mirror_num, unsigned long bio_flags,
1465 u64 bio_offset)
1467 struct btrfs_root *root = BTRFS_I(inode)->root;
1468 return btrfs_map_bio(root, rw, bio, mirror_num, 1);
1472 * extent_io.c submission hook. This does the right thing for csum calculation
1473 * on write, or reading the csums from the tree before a read
1475 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1476 int mirror_num, unsigned long bio_flags,
1477 u64 bio_offset)
1479 struct btrfs_root *root = BTRFS_I(inode)->root;
1480 int ret = 0;
1481 int skip_sum;
1483 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1485 if (btrfs_is_free_space_inode(root, inode))
1486 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 2);
1487 else
1488 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
1489 BUG_ON(ret);
1491 if (!(rw & REQ_WRITE)) {
1492 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1493 return btrfs_submit_compressed_read(inode, bio,
1494 mirror_num, bio_flags);
1495 } else if (!skip_sum) {
1496 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1497 if (ret)
1498 return ret;
1500 goto mapit;
1501 } else if (!skip_sum) {
1502 /* csum items have already been cloned */
1503 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1504 goto mapit;
1505 /* we're doing a write, do the async checksumming */
1506 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1507 inode, rw, bio, mirror_num,
1508 bio_flags, bio_offset,
1509 __btrfs_submit_bio_start,
1510 __btrfs_submit_bio_done);
1513 mapit:
1514 return btrfs_map_bio(root, rw, bio, mirror_num, 0);
1518 * given a list of ordered sums record them in the inode. This happens
1519 * at IO completion time based on sums calculated at bio submission time.
1521 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1522 struct inode *inode, u64 file_offset,
1523 struct list_head *list)
1525 struct btrfs_ordered_sum *sum;
1527 list_for_each_entry(sum, list, list) {
1528 btrfs_csum_file_blocks(trans,
1529 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1531 return 0;
1534 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1535 struct extent_state **cached_state)
1537 if ((end & (PAGE_CACHE_SIZE - 1)) == 0)
1538 WARN_ON(1);
1539 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1540 cached_state, GFP_NOFS);
1543 /* see btrfs_writepage_start_hook for details on why this is required */
1544 struct btrfs_writepage_fixup {
1545 struct page *page;
1546 struct btrfs_work work;
1549 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1551 struct btrfs_writepage_fixup *fixup;
1552 struct btrfs_ordered_extent *ordered;
1553 struct extent_state *cached_state = NULL;
1554 struct page *page;
1555 struct inode *inode;
1556 u64 page_start;
1557 u64 page_end;
1558 int ret;
1560 fixup = container_of(work, struct btrfs_writepage_fixup, work);
1561 page = fixup->page;
1562 again:
1563 lock_page(page);
1564 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
1565 ClearPageChecked(page);
1566 goto out_page;
1569 inode = page->mapping->host;
1570 page_start = page_offset(page);
1571 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
1573 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0,
1574 &cached_state, GFP_NOFS);
1576 /* already ordered? We're done */
1577 if (PagePrivate2(page))
1578 goto out;
1580 ordered = btrfs_lookup_ordered_extent(inode, page_start);
1581 if (ordered) {
1582 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
1583 page_end, &cached_state, GFP_NOFS);
1584 unlock_page(page);
1585 btrfs_start_ordered_extent(inode, ordered, 1);
1586 btrfs_put_ordered_extent(ordered);
1587 goto again;
1590 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
1591 if (ret) {
1592 mapping_set_error(page->mapping, ret);
1593 end_extent_writepage(page, ret, page_start, page_end);
1594 ClearPageChecked(page);
1595 goto out;
1598 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
1599 ClearPageChecked(page);
1600 set_page_dirty(page);
1601 out:
1602 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
1603 &cached_state, GFP_NOFS);
1604 out_page:
1605 unlock_page(page);
1606 page_cache_release(page);
1607 kfree(fixup);
1611 * There are a few paths in the higher layers of the kernel that directly
1612 * set the page dirty bit without asking the filesystem if it is a
1613 * good idea. This causes problems because we want to make sure COW
1614 * properly happens and the data=ordered rules are followed.
1616 * In our case any range that doesn't have the ORDERED bit set
1617 * hasn't been properly setup for IO. We kick off an async process
1618 * to fix it up. The async helper will wait for ordered extents, set
1619 * the delalloc bit and make it safe to write the page.
1621 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
1623 struct inode *inode = page->mapping->host;
1624 struct btrfs_writepage_fixup *fixup;
1625 struct btrfs_root *root = BTRFS_I(inode)->root;
1627 /* this page is properly in the ordered list */
1628 if (TestClearPagePrivate2(page))
1629 return 0;
1631 if (PageChecked(page))
1632 return -EAGAIN;
1634 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
1635 if (!fixup)
1636 return -EAGAIN;
1638 SetPageChecked(page);
1639 page_cache_get(page);
1640 fixup->work.func = btrfs_writepage_fixup_worker;
1641 fixup->page = page;
1642 btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work);
1643 return -EBUSY;
1646 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
1647 struct inode *inode, u64 file_pos,
1648 u64 disk_bytenr, u64 disk_num_bytes,
1649 u64 num_bytes, u64 ram_bytes,
1650 u8 compression, u8 encryption,
1651 u16 other_encoding, int extent_type)
1653 struct btrfs_root *root = BTRFS_I(inode)->root;
1654 struct btrfs_file_extent_item *fi;
1655 struct btrfs_path *path;
1656 struct extent_buffer *leaf;
1657 struct btrfs_key ins;
1658 u64 hint;
1659 int ret;
1661 path = btrfs_alloc_path();
1662 if (!path)
1663 return -ENOMEM;
1665 path->leave_spinning = 1;
1668 * we may be replacing one extent in the tree with another.
1669 * The new extent is pinned in the extent map, and we don't want
1670 * to drop it from the cache until it is completely in the btree.
1672 * So, tell btrfs_drop_extents to leave this extent in the cache.
1673 * the caller is expected to unpin it and allow it to be merged
1674 * with the others.
1676 ret = btrfs_drop_extents(trans, inode, file_pos, file_pos + num_bytes,
1677 &hint, 0);
1678 BUG_ON(ret);
1680 ins.objectid = btrfs_ino(inode);
1681 ins.offset = file_pos;
1682 ins.type = BTRFS_EXTENT_DATA_KEY;
1683 ret = btrfs_insert_empty_item(trans, root, path, &ins, sizeof(*fi));
1684 BUG_ON(ret);
1685 leaf = path->nodes[0];
1686 fi = btrfs_item_ptr(leaf, path->slots[0],
1687 struct btrfs_file_extent_item);
1688 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1689 btrfs_set_file_extent_type(leaf, fi, extent_type);
1690 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
1691 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
1692 btrfs_set_file_extent_offset(leaf, fi, 0);
1693 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
1694 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
1695 btrfs_set_file_extent_compression(leaf, fi, compression);
1696 btrfs_set_file_extent_encryption(leaf, fi, encryption);
1697 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
1699 btrfs_unlock_up_safe(path, 1);
1700 btrfs_set_lock_blocking(leaf);
1702 btrfs_mark_buffer_dirty(leaf);
1704 inode_add_bytes(inode, num_bytes);
1706 ins.objectid = disk_bytenr;
1707 ins.offset = disk_num_bytes;
1708 ins.type = BTRFS_EXTENT_ITEM_KEY;
1709 ret = btrfs_alloc_reserved_file_extent(trans, root,
1710 root->root_key.objectid,
1711 btrfs_ino(inode), file_pos, &ins);
1712 BUG_ON(ret);
1713 btrfs_free_path(path);
1715 return 0;
1719 * helper function for btrfs_finish_ordered_io, this
1720 * just reads in some of the csum leaves to prime them into ram
1721 * before we start the transaction. It limits the amount of btree
1722 * reads required while inside the transaction.
1724 /* as ordered data IO finishes, this gets called so we can finish
1725 * an ordered extent if the range of bytes in the file it covers are
1726 * fully written.
1728 static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
1730 struct btrfs_root *root = BTRFS_I(inode)->root;
1731 struct btrfs_trans_handle *trans = NULL;
1732 struct btrfs_ordered_extent *ordered_extent = NULL;
1733 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1734 struct extent_state *cached_state = NULL;
1735 int compress_type = 0;
1736 int ret;
1737 bool nolock;
1739 ret = btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
1740 end - start + 1);
1741 if (!ret)
1742 return 0;
1743 BUG_ON(!ordered_extent);
1745 nolock = btrfs_is_free_space_inode(root, inode);
1747 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
1748 BUG_ON(!list_empty(&ordered_extent->list));
1749 ret = btrfs_ordered_update_i_size(inode, 0, ordered_extent);
1750 if (!ret) {
1751 if (nolock)
1752 trans = btrfs_join_transaction_nolock(root);
1753 else
1754 trans = btrfs_join_transaction(root);
1755 BUG_ON(IS_ERR(trans));
1756 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1757 ret = btrfs_update_inode_fallback(trans, root, inode);
1758 BUG_ON(ret);
1760 goto out;
1763 lock_extent_bits(io_tree, ordered_extent->file_offset,
1764 ordered_extent->file_offset + ordered_extent->len - 1,
1765 0, &cached_state, GFP_NOFS);
1767 if (nolock)
1768 trans = btrfs_join_transaction_nolock(root);
1769 else
1770 trans = btrfs_join_transaction(root);
1771 BUG_ON(IS_ERR(trans));
1772 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1774 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
1775 compress_type = ordered_extent->compress_type;
1776 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
1777 BUG_ON(compress_type);
1778 ret = btrfs_mark_extent_written(trans, inode,
1779 ordered_extent->file_offset,
1780 ordered_extent->file_offset +
1781 ordered_extent->len);
1782 BUG_ON(ret);
1783 } else {
1784 BUG_ON(root == root->fs_info->tree_root);
1785 ret = insert_reserved_file_extent(trans, inode,
1786 ordered_extent->file_offset,
1787 ordered_extent->start,
1788 ordered_extent->disk_len,
1789 ordered_extent->len,
1790 ordered_extent->len,
1791 compress_type, 0, 0,
1792 BTRFS_FILE_EXTENT_REG);
1793 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
1794 ordered_extent->file_offset,
1795 ordered_extent->len);
1796 BUG_ON(ret);
1798 unlock_extent_cached(io_tree, ordered_extent->file_offset,
1799 ordered_extent->file_offset +
1800 ordered_extent->len - 1, &cached_state, GFP_NOFS);
1802 add_pending_csums(trans, inode, ordered_extent->file_offset,
1803 &ordered_extent->list);
1805 ret = btrfs_ordered_update_i_size(inode, 0, ordered_extent);
1806 if (!ret || !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
1807 ret = btrfs_update_inode_fallback(trans, root, inode);
1808 BUG_ON(ret);
1810 ret = 0;
1811 out:
1812 if (root != root->fs_info->tree_root)
1813 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
1814 if (trans) {
1815 if (nolock)
1816 btrfs_end_transaction_nolock(trans, root);
1817 else
1818 btrfs_end_transaction(trans, root);
1821 /* once for us */
1822 btrfs_put_ordered_extent(ordered_extent);
1823 /* once for the tree */
1824 btrfs_put_ordered_extent(ordered_extent);
1826 return 0;
1829 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
1830 struct extent_state *state, int uptodate)
1832 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
1834 ClearPagePrivate2(page);
1835 return btrfs_finish_ordered_io(page->mapping->host, start, end);
1839 * when reads are done, we need to check csums to verify the data is correct
1840 * if there's a match, we allow the bio to finish. If not, the code in
1841 * extent_io.c will try to find good copies for us.
1843 static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
1844 struct extent_state *state)
1846 size_t offset = start - ((u64)page->index << PAGE_CACHE_SHIFT);
1847 struct inode *inode = page->mapping->host;
1848 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1849 char *kaddr;
1850 u64 private = ~(u32)0;
1851 int ret;
1852 struct btrfs_root *root = BTRFS_I(inode)->root;
1853 u32 csum = ~(u32)0;
1855 if (PageChecked(page)) {
1856 ClearPageChecked(page);
1857 goto good;
1860 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
1861 goto good;
1863 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
1864 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
1865 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
1866 GFP_NOFS);
1867 return 0;
1870 if (state && state->start == start) {
1871 private = state->private;
1872 ret = 0;
1873 } else {
1874 ret = get_state_private(io_tree, start, &private);
1876 kaddr = kmap_atomic(page, KM_USER0);
1877 if (ret)
1878 goto zeroit;
1880 csum = btrfs_csum_data(root, kaddr + offset, csum, end - start + 1);
1881 btrfs_csum_final(csum, (char *)&csum);
1882 if (csum != private)
1883 goto zeroit;
1885 kunmap_atomic(kaddr, KM_USER0);
1886 good:
1887 return 0;
1889 zeroit:
1890 printk_ratelimited(KERN_INFO "btrfs csum failed ino %llu off %llu csum %u "
1891 "private %llu\n",
1892 (unsigned long long)btrfs_ino(page->mapping->host),
1893 (unsigned long long)start, csum,
1894 (unsigned long long)private);
1895 memset(kaddr + offset, 1, end - start + 1);
1896 flush_dcache_page(page);
1897 kunmap_atomic(kaddr, KM_USER0);
1898 if (private == 0)
1899 return 0;
1900 return -EIO;
1903 struct delayed_iput {
1904 struct list_head list;
1905 struct inode *inode;
1908 void btrfs_add_delayed_iput(struct inode *inode)
1910 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
1911 struct delayed_iput *delayed;
1913 if (atomic_add_unless(&inode->i_count, -1, 1))
1914 return;
1916 delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL);
1917 delayed->inode = inode;
1919 spin_lock(&fs_info->delayed_iput_lock);
1920 list_add_tail(&delayed->list, &fs_info->delayed_iputs);
1921 spin_unlock(&fs_info->delayed_iput_lock);
1924 void btrfs_run_delayed_iputs(struct btrfs_root *root)
1926 LIST_HEAD(list);
1927 struct btrfs_fs_info *fs_info = root->fs_info;
1928 struct delayed_iput *delayed;
1929 int empty;
1931 spin_lock(&fs_info->delayed_iput_lock);
1932 empty = list_empty(&fs_info->delayed_iputs);
1933 spin_unlock(&fs_info->delayed_iput_lock);
1934 if (empty)
1935 return;
1937 down_read(&root->fs_info->cleanup_work_sem);
1938 spin_lock(&fs_info->delayed_iput_lock);
1939 list_splice_init(&fs_info->delayed_iputs, &list);
1940 spin_unlock(&fs_info->delayed_iput_lock);
1942 while (!list_empty(&list)) {
1943 delayed = list_entry(list.next, struct delayed_iput, list);
1944 list_del(&delayed->list);
1945 iput(delayed->inode);
1946 kfree(delayed);
1948 up_read(&root->fs_info->cleanup_work_sem);
1951 enum btrfs_orphan_cleanup_state {
1952 ORPHAN_CLEANUP_STARTED = 1,
1953 ORPHAN_CLEANUP_DONE = 2,
1957 * This is called in transaction commit time. If there are no orphan
1958 * files in the subvolume, it removes orphan item and frees block_rsv
1959 * structure.
1961 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
1962 struct btrfs_root *root)
1964 struct btrfs_block_rsv *block_rsv;
1965 int ret;
1967 if (!list_empty(&root->orphan_list) ||
1968 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
1969 return;
1971 spin_lock(&root->orphan_lock);
1972 if (!list_empty(&root->orphan_list)) {
1973 spin_unlock(&root->orphan_lock);
1974 return;
1977 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
1978 spin_unlock(&root->orphan_lock);
1979 return;
1982 block_rsv = root->orphan_block_rsv;
1983 root->orphan_block_rsv = NULL;
1984 spin_unlock(&root->orphan_lock);
1986 if (root->orphan_item_inserted &&
1987 btrfs_root_refs(&root->root_item) > 0) {
1988 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
1989 root->root_key.objectid);
1990 BUG_ON(ret);
1991 root->orphan_item_inserted = 0;
1994 if (block_rsv) {
1995 WARN_ON(block_rsv->size > 0);
1996 btrfs_free_block_rsv(root, block_rsv);
2001 * This creates an orphan entry for the given inode in case something goes
2002 * wrong in the middle of an unlink/truncate.
2004 * NOTE: caller of this function should reserve 5 units of metadata for
2005 * this function.
2007 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
2009 struct btrfs_root *root = BTRFS_I(inode)->root;
2010 struct btrfs_block_rsv *block_rsv = NULL;
2011 int reserve = 0;
2012 int insert = 0;
2013 int ret;
2015 if (!root->orphan_block_rsv) {
2016 block_rsv = btrfs_alloc_block_rsv(root);
2017 if (!block_rsv)
2018 return -ENOMEM;
2021 spin_lock(&root->orphan_lock);
2022 if (!root->orphan_block_rsv) {
2023 root->orphan_block_rsv = block_rsv;
2024 } else if (block_rsv) {
2025 btrfs_free_block_rsv(root, block_rsv);
2026 block_rsv = NULL;
2029 if (list_empty(&BTRFS_I(inode)->i_orphan)) {
2030 list_add(&BTRFS_I(inode)->i_orphan, &root->orphan_list);
2031 #if 0
2033 * For proper ENOSPC handling, we should do orphan
2034 * cleanup when mounting. But this introduces backward
2035 * compatibility issue.
2037 if (!xchg(&root->orphan_item_inserted, 1))
2038 insert = 2;
2039 else
2040 insert = 1;
2041 #endif
2042 insert = 1;
2045 if (!BTRFS_I(inode)->orphan_meta_reserved) {
2046 BTRFS_I(inode)->orphan_meta_reserved = 1;
2047 reserve = 1;
2049 spin_unlock(&root->orphan_lock);
2051 /* grab metadata reservation from transaction handle */
2052 if (reserve) {
2053 ret = btrfs_orphan_reserve_metadata(trans, inode);
2054 BUG_ON(ret);
2057 /* insert an orphan item to track this unlinked/truncated file */
2058 if (insert >= 1) {
2059 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
2060 BUG_ON(ret && ret != -EEXIST);
2063 /* insert an orphan item to track subvolume contains orphan files */
2064 if (insert >= 2) {
2065 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
2066 root->root_key.objectid);
2067 BUG_ON(ret);
2069 return 0;
2073 * We have done the truncate/delete so we can go ahead and remove the orphan
2074 * item for this particular inode.
2076 int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode)
2078 struct btrfs_root *root = BTRFS_I(inode)->root;
2079 int delete_item = 0;
2080 int release_rsv = 0;
2081 int ret = 0;
2083 spin_lock(&root->orphan_lock);
2084 if (!list_empty(&BTRFS_I(inode)->i_orphan)) {
2085 list_del_init(&BTRFS_I(inode)->i_orphan);
2086 delete_item = 1;
2089 if (BTRFS_I(inode)->orphan_meta_reserved) {
2090 BTRFS_I(inode)->orphan_meta_reserved = 0;
2091 release_rsv = 1;
2093 spin_unlock(&root->orphan_lock);
2095 if (trans && delete_item) {
2096 ret = btrfs_del_orphan_item(trans, root, btrfs_ino(inode));
2097 BUG_ON(ret);
2100 if (release_rsv)
2101 btrfs_orphan_release_metadata(inode);
2103 return 0;
2107 * this cleans up any orphans that may be left on the list from the last use
2108 * of this root.
2110 int btrfs_orphan_cleanup(struct btrfs_root *root)
2112 struct btrfs_path *path;
2113 struct extent_buffer *leaf;
2114 struct btrfs_key key, found_key;
2115 struct btrfs_trans_handle *trans;
2116 struct inode *inode;
2117 u64 last_objectid = 0;
2118 int ret = 0, nr_unlink = 0, nr_truncate = 0;
2120 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
2121 return 0;
2123 path = btrfs_alloc_path();
2124 if (!path) {
2125 ret = -ENOMEM;
2126 goto out;
2128 path->reada = -1;
2130 key.objectid = BTRFS_ORPHAN_OBJECTID;
2131 btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
2132 key.offset = (u64)-1;
2134 while (1) {
2135 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2136 if (ret < 0)
2137 goto out;
2140 * if ret == 0 means we found what we were searching for, which
2141 * is weird, but possible, so only screw with path if we didn't
2142 * find the key and see if we have stuff that matches
2144 if (ret > 0) {
2145 ret = 0;
2146 if (path->slots[0] == 0)
2147 break;
2148 path->slots[0]--;
2151 /* pull out the item */
2152 leaf = path->nodes[0];
2153 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2155 /* make sure the item matches what we want */
2156 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
2157 break;
2158 if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY)
2159 break;
2161 /* release the path since we're done with it */
2162 btrfs_release_path(path);
2165 * this is where we are basically btrfs_lookup, without the
2166 * crossing root thing. we store the inode number in the
2167 * offset of the orphan item.
2170 if (found_key.offset == last_objectid) {
2171 printk(KERN_ERR "btrfs: Error removing orphan entry, "
2172 "stopping orphan cleanup\n");
2173 ret = -EINVAL;
2174 goto out;
2177 last_objectid = found_key.offset;
2179 found_key.objectid = found_key.offset;
2180 found_key.type = BTRFS_INODE_ITEM_KEY;
2181 found_key.offset = 0;
2182 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
2183 ret = PTR_RET(inode);
2184 if (ret && ret != -ESTALE)
2185 goto out;
2187 if (ret == -ESTALE && root == root->fs_info->tree_root) {
2188 struct btrfs_root *dead_root;
2189 struct btrfs_fs_info *fs_info = root->fs_info;
2190 int is_dead_root = 0;
2193 * this is an orphan in the tree root. Currently these
2194 * could come from 2 sources:
2195 * a) a snapshot deletion in progress
2196 * b) a free space cache inode
2197 * We need to distinguish those two, as the snapshot
2198 * orphan must not get deleted.
2199 * find_dead_roots already ran before us, so if this
2200 * is a snapshot deletion, we should find the root
2201 * in the dead_roots list
2203 spin_lock(&fs_info->trans_lock);
2204 list_for_each_entry(dead_root, &fs_info->dead_roots,
2205 root_list) {
2206 if (dead_root->root_key.objectid ==
2207 found_key.objectid) {
2208 is_dead_root = 1;
2209 break;
2212 spin_unlock(&fs_info->trans_lock);
2213 if (is_dead_root) {
2214 /* prevent this orphan from being found again */
2215 key.offset = found_key.objectid - 1;
2216 continue;
2220 * Inode is already gone but the orphan item is still there,
2221 * kill the orphan item.
2223 if (ret == -ESTALE) {
2224 trans = btrfs_start_transaction(root, 1);
2225 if (IS_ERR(trans)) {
2226 ret = PTR_ERR(trans);
2227 goto out;
2229 ret = btrfs_del_orphan_item(trans, root,
2230 found_key.objectid);
2231 BUG_ON(ret);
2232 btrfs_end_transaction(trans, root);
2233 continue;
2237 * add this inode to the orphan list so btrfs_orphan_del does
2238 * the proper thing when we hit it
2240 spin_lock(&root->orphan_lock);
2241 list_add(&BTRFS_I(inode)->i_orphan, &root->orphan_list);
2242 spin_unlock(&root->orphan_lock);
2244 /* if we have links, this was a truncate, lets do that */
2245 if (inode->i_nlink) {
2246 if (!S_ISREG(inode->i_mode)) {
2247 WARN_ON(1);
2248 iput(inode);
2249 continue;
2251 nr_truncate++;
2252 ret = btrfs_truncate(inode);
2253 } else {
2254 nr_unlink++;
2257 /* this will do delete_inode and everything for us */
2258 iput(inode);
2259 if (ret)
2260 goto out;
2262 /* release the path since we're done with it */
2263 btrfs_release_path(path);
2265 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
2267 if (root->orphan_block_rsv)
2268 btrfs_block_rsv_release(root, root->orphan_block_rsv,
2269 (u64)-1);
2271 if (root->orphan_block_rsv || root->orphan_item_inserted) {
2272 trans = btrfs_join_transaction(root);
2273 if (!IS_ERR(trans))
2274 btrfs_end_transaction(trans, root);
2277 if (nr_unlink)
2278 printk(KERN_INFO "btrfs: unlinked %d orphans\n", nr_unlink);
2279 if (nr_truncate)
2280 printk(KERN_INFO "btrfs: truncated %d orphans\n", nr_truncate);
2282 out:
2283 if (ret)
2284 printk(KERN_CRIT "btrfs: could not do orphan cleanup %d\n", ret);
2285 btrfs_free_path(path);
2286 return ret;
2290 * very simple check to peek ahead in the leaf looking for xattrs. If we
2291 * don't find any xattrs, we know there can't be any acls.
2293 * slot is the slot the inode is in, objectid is the objectid of the inode
2295 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
2296 int slot, u64 objectid)
2298 u32 nritems = btrfs_header_nritems(leaf);
2299 struct btrfs_key found_key;
2300 int scanned = 0;
2302 slot++;
2303 while (slot < nritems) {
2304 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2306 /* we found a different objectid, there must not be acls */
2307 if (found_key.objectid != objectid)
2308 return 0;
2310 /* we found an xattr, assume we've got an acl */
2311 if (found_key.type == BTRFS_XATTR_ITEM_KEY)
2312 return 1;
2315 * we found a key greater than an xattr key, there can't
2316 * be any acls later on
2318 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
2319 return 0;
2321 slot++;
2322 scanned++;
2325 * it goes inode, inode backrefs, xattrs, extents,
2326 * so if there are a ton of hard links to an inode there can
2327 * be a lot of backrefs. Don't waste time searching too hard,
2328 * this is just an optimization
2330 if (scanned >= 8)
2331 break;
2333 /* we hit the end of the leaf before we found an xattr or
2334 * something larger than an xattr. We have to assume the inode
2335 * has acls
2337 return 1;
2341 * read an inode from the btree into the in-memory inode
2343 static void btrfs_read_locked_inode(struct inode *inode)
2345 struct btrfs_path *path;
2346 struct extent_buffer *leaf;
2347 struct btrfs_inode_item *inode_item;
2348 struct btrfs_timespec *tspec;
2349 struct btrfs_root *root = BTRFS_I(inode)->root;
2350 struct btrfs_key location;
2351 int maybe_acls;
2352 u32 rdev;
2353 int ret;
2354 bool filled = false;
2356 ret = btrfs_fill_inode(inode, &rdev);
2357 if (!ret)
2358 filled = true;
2360 path = btrfs_alloc_path();
2361 if (!path)
2362 goto make_bad;
2364 path->leave_spinning = 1;
2365 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
2367 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
2368 if (ret)
2369 goto make_bad;
2371 leaf = path->nodes[0];
2373 if (filled)
2374 goto cache_acl;
2376 inode_item = btrfs_item_ptr(leaf, path->slots[0],
2377 struct btrfs_inode_item);
2378 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
2379 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
2380 inode->i_uid = btrfs_inode_uid(leaf, inode_item);
2381 inode->i_gid = btrfs_inode_gid(leaf, inode_item);
2382 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
2384 tspec = btrfs_inode_atime(inode_item);
2385 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
2386 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
2388 tspec = btrfs_inode_mtime(inode_item);
2389 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
2390 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
2392 tspec = btrfs_inode_ctime(inode_item);
2393 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
2394 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
2396 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
2397 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
2398 BTRFS_I(inode)->sequence = btrfs_inode_sequence(leaf, inode_item);
2399 inode->i_generation = BTRFS_I(inode)->generation;
2400 inode->i_rdev = 0;
2401 rdev = btrfs_inode_rdev(leaf, inode_item);
2403 BTRFS_I(inode)->index_cnt = (u64)-1;
2404 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
2405 cache_acl:
2407 * try to precache a NULL acl entry for files that don't have
2408 * any xattrs or acls
2410 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
2411 btrfs_ino(inode));
2412 if (!maybe_acls)
2413 cache_no_acl(inode);
2415 btrfs_free_path(path);
2417 switch (inode->i_mode & S_IFMT) {
2418 case S_IFREG:
2419 inode->i_mapping->a_ops = &btrfs_aops;
2420 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
2421 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
2422 inode->i_fop = &btrfs_file_operations;
2423 inode->i_op = &btrfs_file_inode_operations;
2424 break;
2425 case S_IFDIR:
2426 inode->i_fop = &btrfs_dir_file_operations;
2427 if (root == root->fs_info->tree_root)
2428 inode->i_op = &btrfs_dir_ro_inode_operations;
2429 else
2430 inode->i_op = &btrfs_dir_inode_operations;
2431 break;
2432 case S_IFLNK:
2433 inode->i_op = &btrfs_symlink_inode_operations;
2434 inode->i_mapping->a_ops = &btrfs_symlink_aops;
2435 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
2436 break;
2437 default:
2438 inode->i_op = &btrfs_special_inode_operations;
2439 init_special_inode(inode, inode->i_mode, rdev);
2440 break;
2443 btrfs_update_iflags(inode);
2444 return;
2446 make_bad:
2447 btrfs_free_path(path);
2448 make_bad_inode(inode);
2452 * given a leaf and an inode, copy the inode fields into the leaf
2454 static void fill_inode_item(struct btrfs_trans_handle *trans,
2455 struct extent_buffer *leaf,
2456 struct btrfs_inode_item *item,
2457 struct inode *inode)
2459 btrfs_set_inode_uid(leaf, item, inode->i_uid);
2460 btrfs_set_inode_gid(leaf, item, inode->i_gid);
2461 btrfs_set_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size);
2462 btrfs_set_inode_mode(leaf, item, inode->i_mode);
2463 btrfs_set_inode_nlink(leaf, item, inode->i_nlink);
2465 btrfs_set_timespec_sec(leaf, btrfs_inode_atime(item),
2466 inode->i_atime.tv_sec);
2467 btrfs_set_timespec_nsec(leaf, btrfs_inode_atime(item),
2468 inode->i_atime.tv_nsec);
2470 btrfs_set_timespec_sec(leaf, btrfs_inode_mtime(item),
2471 inode->i_mtime.tv_sec);
2472 btrfs_set_timespec_nsec(leaf, btrfs_inode_mtime(item),
2473 inode->i_mtime.tv_nsec);
2475 btrfs_set_timespec_sec(leaf, btrfs_inode_ctime(item),
2476 inode->i_ctime.tv_sec);
2477 btrfs_set_timespec_nsec(leaf, btrfs_inode_ctime(item),
2478 inode->i_ctime.tv_nsec);
2480 btrfs_set_inode_nbytes(leaf, item, inode_get_bytes(inode));
2481 btrfs_set_inode_generation(leaf, item, BTRFS_I(inode)->generation);
2482 btrfs_set_inode_sequence(leaf, item, BTRFS_I(inode)->sequence);
2483 btrfs_set_inode_transid(leaf, item, trans->transid);
2484 btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
2485 btrfs_set_inode_flags(leaf, item, BTRFS_I(inode)->flags);
2486 btrfs_set_inode_block_group(leaf, item, 0);
2490 * copy everything in the in-memory inode into the btree.
2492 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
2493 struct btrfs_root *root, struct inode *inode)
2495 struct btrfs_inode_item *inode_item;
2496 struct btrfs_path *path;
2497 struct extent_buffer *leaf;
2498 int ret;
2500 path = btrfs_alloc_path();
2501 if (!path)
2502 return -ENOMEM;
2504 path->leave_spinning = 1;
2505 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
2507 if (ret) {
2508 if (ret > 0)
2509 ret = -ENOENT;
2510 goto failed;
2513 btrfs_unlock_up_safe(path, 1);
2514 leaf = path->nodes[0];
2515 inode_item = btrfs_item_ptr(leaf, path->slots[0],
2516 struct btrfs_inode_item);
2518 fill_inode_item(trans, leaf, inode_item, inode);
2519 btrfs_mark_buffer_dirty(leaf);
2520 btrfs_set_inode_last_trans(trans, inode);
2521 ret = 0;
2522 failed:
2523 btrfs_free_path(path);
2524 return ret;
2528 * copy everything in the in-memory inode into the btree.
2530 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
2531 struct btrfs_root *root, struct inode *inode)
2533 int ret;
2536 * If the inode is a free space inode, we can deadlock during commit
2537 * if we put it into the delayed code.
2539 * The data relocation inode should also be directly updated
2540 * without delay
2542 if (!btrfs_is_free_space_inode(root, inode)
2543 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID) {
2544 ret = btrfs_delayed_update_inode(trans, root, inode);
2545 if (!ret)
2546 btrfs_set_inode_last_trans(trans, inode);
2547 return ret;
2550 return btrfs_update_inode_item(trans, root, inode);
2553 static noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
2554 struct btrfs_root *root, struct inode *inode)
2556 int ret;
2558 ret = btrfs_update_inode(trans, root, inode);
2559 if (ret == -ENOSPC)
2560 return btrfs_update_inode_item(trans, root, inode);
2561 return ret;
2565 * unlink helper that gets used here in inode.c and in the tree logging
2566 * recovery code. It remove a link in a directory with a given name, and
2567 * also drops the back refs in the inode to the directory
2569 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
2570 struct btrfs_root *root,
2571 struct inode *dir, struct inode *inode,
2572 const char *name, int name_len)
2574 struct btrfs_path *path;
2575 int ret = 0;
2576 struct extent_buffer *leaf;
2577 struct btrfs_dir_item *di;
2578 struct btrfs_key key;
2579 u64 index;
2580 u64 ino = btrfs_ino(inode);
2581 u64 dir_ino = btrfs_ino(dir);
2583 path = btrfs_alloc_path();
2584 if (!path) {
2585 ret = -ENOMEM;
2586 goto out;
2589 path->leave_spinning = 1;
2590 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
2591 name, name_len, -1);
2592 if (IS_ERR(di)) {
2593 ret = PTR_ERR(di);
2594 goto err;
2596 if (!di) {
2597 ret = -ENOENT;
2598 goto err;
2600 leaf = path->nodes[0];
2601 btrfs_dir_item_key_to_cpu(leaf, di, &key);
2602 ret = btrfs_delete_one_dir_name(trans, root, path, di);
2603 if (ret)
2604 goto err;
2605 btrfs_release_path(path);
2607 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
2608 dir_ino, &index);
2609 if (ret) {
2610 printk(KERN_INFO "btrfs failed to delete reference to %.*s, "
2611 "inode %llu parent %llu\n", name_len, name,
2612 (unsigned long long)ino, (unsigned long long)dir_ino);
2613 goto err;
2616 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
2617 if (ret)
2618 goto err;
2620 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
2621 inode, dir_ino);
2622 BUG_ON(ret != 0 && ret != -ENOENT);
2624 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
2625 dir, index);
2626 if (ret == -ENOENT)
2627 ret = 0;
2628 err:
2629 btrfs_free_path(path);
2630 if (ret)
2631 goto out;
2633 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
2634 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
2635 btrfs_update_inode(trans, root, dir);
2636 out:
2637 return ret;
2640 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
2641 struct btrfs_root *root,
2642 struct inode *dir, struct inode *inode,
2643 const char *name, int name_len)
2645 int ret;
2646 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
2647 if (!ret) {
2648 btrfs_drop_nlink(inode);
2649 ret = btrfs_update_inode(trans, root, inode);
2651 return ret;
2655 /* helper to check if there is any shared block in the path */
2656 static int check_path_shared(struct btrfs_root *root,
2657 struct btrfs_path *path)
2659 struct extent_buffer *eb;
2660 int level;
2661 u64 refs = 1;
2663 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
2664 int ret;
2666 if (!path->nodes[level])
2667 break;
2668 eb = path->nodes[level];
2669 if (!btrfs_block_can_be_shared(root, eb))
2670 continue;
2671 ret = btrfs_lookup_extent_info(NULL, root, eb->start, eb->len,
2672 &refs, NULL);
2673 if (refs > 1)
2674 return 1;
2676 return 0;
2680 * helper to start transaction for unlink and rmdir.
2682 * unlink and rmdir are special in btrfs, they do not always free space.
2683 * so in enospc case, we should make sure they will free space before
2684 * allowing them to use the global metadata reservation.
2686 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir,
2687 struct dentry *dentry)
2689 struct btrfs_trans_handle *trans;
2690 struct btrfs_root *root = BTRFS_I(dir)->root;
2691 struct btrfs_path *path;
2692 struct btrfs_inode_ref *ref;
2693 struct btrfs_dir_item *di;
2694 struct inode *inode = dentry->d_inode;
2695 u64 index;
2696 int check_link = 1;
2697 int err = -ENOSPC;
2698 int ret;
2699 u64 ino = btrfs_ino(inode);
2700 u64 dir_ino = btrfs_ino(dir);
2703 * 1 for the possible orphan item
2704 * 1 for the dir item
2705 * 1 for the dir index
2706 * 1 for the inode ref
2707 * 1 for the inode ref in the tree log
2708 * 2 for the dir entries in the log
2709 * 1 for the inode
2711 trans = btrfs_start_transaction(root, 8);
2712 if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
2713 return trans;
2715 if (ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
2716 return ERR_PTR(-ENOSPC);
2718 /* check if there is someone else holds reference */
2719 if (S_ISDIR(inode->i_mode) && atomic_read(&inode->i_count) > 1)
2720 return ERR_PTR(-ENOSPC);
2722 if (atomic_read(&inode->i_count) > 2)
2723 return ERR_PTR(-ENOSPC);
2725 if (xchg(&root->fs_info->enospc_unlink, 1))
2726 return ERR_PTR(-ENOSPC);
2728 path = btrfs_alloc_path();
2729 if (!path) {
2730 root->fs_info->enospc_unlink = 0;
2731 return ERR_PTR(-ENOMEM);
2734 /* 1 for the orphan item */
2735 trans = btrfs_start_transaction(root, 1);
2736 if (IS_ERR(trans)) {
2737 btrfs_free_path(path);
2738 root->fs_info->enospc_unlink = 0;
2739 return trans;
2742 path->skip_locking = 1;
2743 path->search_commit_root = 1;
2745 ret = btrfs_lookup_inode(trans, root, path,
2746 &BTRFS_I(dir)->location, 0);
2747 if (ret < 0) {
2748 err = ret;
2749 goto out;
2751 if (ret == 0) {
2752 if (check_path_shared(root, path))
2753 goto out;
2754 } else {
2755 check_link = 0;
2757 btrfs_release_path(path);
2759 ret = btrfs_lookup_inode(trans, root, path,
2760 &BTRFS_I(inode)->location, 0);
2761 if (ret < 0) {
2762 err = ret;
2763 goto out;
2765 if (ret == 0) {
2766 if (check_path_shared(root, path))
2767 goto out;
2768 } else {
2769 check_link = 0;
2771 btrfs_release_path(path);
2773 if (ret == 0 && S_ISREG(inode->i_mode)) {
2774 ret = btrfs_lookup_file_extent(trans, root, path,
2775 ino, (u64)-1, 0);
2776 if (ret < 0) {
2777 err = ret;
2778 goto out;
2780 BUG_ON(ret == 0);
2781 if (check_path_shared(root, path))
2782 goto out;
2783 btrfs_release_path(path);
2786 if (!check_link) {
2787 err = 0;
2788 goto out;
2791 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
2792 dentry->d_name.name, dentry->d_name.len, 0);
2793 if (IS_ERR(di)) {
2794 err = PTR_ERR(di);
2795 goto out;
2797 if (di) {
2798 if (check_path_shared(root, path))
2799 goto out;
2800 } else {
2801 err = 0;
2802 goto out;
2804 btrfs_release_path(path);
2806 ref = btrfs_lookup_inode_ref(trans, root, path,
2807 dentry->d_name.name, dentry->d_name.len,
2808 ino, dir_ino, 0);
2809 if (IS_ERR(ref)) {
2810 err = PTR_ERR(ref);
2811 goto out;
2813 BUG_ON(!ref);
2814 if (check_path_shared(root, path))
2815 goto out;
2816 index = btrfs_inode_ref_index(path->nodes[0], ref);
2817 btrfs_release_path(path);
2820 * This is a commit root search, if we can lookup inode item and other
2821 * relative items in the commit root, it means the transaction of
2822 * dir/file creation has been committed, and the dir index item that we
2823 * delay to insert has also been inserted into the commit root. So
2824 * we needn't worry about the delayed insertion of the dir index item
2825 * here.
2827 di = btrfs_lookup_dir_index_item(trans, root, path, dir_ino, index,
2828 dentry->d_name.name, dentry->d_name.len, 0);
2829 if (IS_ERR(di)) {
2830 err = PTR_ERR(di);
2831 goto out;
2833 BUG_ON(ret == -ENOENT);
2834 if (check_path_shared(root, path))
2835 goto out;
2837 err = 0;
2838 out:
2839 btrfs_free_path(path);
2840 /* Migrate the orphan reservation over */
2841 if (!err)
2842 err = btrfs_block_rsv_migrate(trans->block_rsv,
2843 &root->fs_info->global_block_rsv,
2844 trans->bytes_reserved);
2846 if (err) {
2847 btrfs_end_transaction(trans, root);
2848 root->fs_info->enospc_unlink = 0;
2849 return ERR_PTR(err);
2852 trans->block_rsv = &root->fs_info->global_block_rsv;
2853 return trans;
2856 static void __unlink_end_trans(struct btrfs_trans_handle *trans,
2857 struct btrfs_root *root)
2859 if (trans->block_rsv == &root->fs_info->global_block_rsv) {
2860 btrfs_block_rsv_release(root, trans->block_rsv,
2861 trans->bytes_reserved);
2862 trans->block_rsv = &root->fs_info->trans_block_rsv;
2863 BUG_ON(!root->fs_info->enospc_unlink);
2864 root->fs_info->enospc_unlink = 0;
2866 btrfs_end_transaction(trans, root);
2869 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
2871 struct btrfs_root *root = BTRFS_I(dir)->root;
2872 struct btrfs_trans_handle *trans;
2873 struct inode *inode = dentry->d_inode;
2874 int ret;
2875 unsigned long nr = 0;
2877 trans = __unlink_start_trans(dir, dentry);
2878 if (IS_ERR(trans))
2879 return PTR_ERR(trans);
2881 btrfs_record_unlink_dir(trans, dir, dentry->d_inode, 0);
2883 ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
2884 dentry->d_name.name, dentry->d_name.len);
2885 if (ret)
2886 goto out;
2888 if (inode->i_nlink == 0) {
2889 ret = btrfs_orphan_add(trans, inode);
2890 if (ret)
2891 goto out;
2894 out:
2895 nr = trans->blocks_used;
2896 __unlink_end_trans(trans, root);
2897 btrfs_btree_balance_dirty(root, nr);
2898 return ret;
2901 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
2902 struct btrfs_root *root,
2903 struct inode *dir, u64 objectid,
2904 const char *name, int name_len)
2906 struct btrfs_path *path;
2907 struct extent_buffer *leaf;
2908 struct btrfs_dir_item *di;
2909 struct btrfs_key key;
2910 u64 index;
2911 int ret;
2912 u64 dir_ino = btrfs_ino(dir);
2914 path = btrfs_alloc_path();
2915 if (!path)
2916 return -ENOMEM;
2918 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
2919 name, name_len, -1);
2920 BUG_ON(IS_ERR_OR_NULL(di));
2922 leaf = path->nodes[0];
2923 btrfs_dir_item_key_to_cpu(leaf, di, &key);
2924 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
2925 ret = btrfs_delete_one_dir_name(trans, root, path, di);
2926 BUG_ON(ret);
2927 btrfs_release_path(path);
2929 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
2930 objectid, root->root_key.objectid,
2931 dir_ino, &index, name, name_len);
2932 if (ret < 0) {
2933 BUG_ON(ret != -ENOENT);
2934 di = btrfs_search_dir_index_item(root, path, dir_ino,
2935 name, name_len);
2936 BUG_ON(IS_ERR_OR_NULL(di));
2938 leaf = path->nodes[0];
2939 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2940 btrfs_release_path(path);
2941 index = key.offset;
2943 btrfs_release_path(path);
2945 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
2946 BUG_ON(ret);
2948 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
2949 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
2950 ret = btrfs_update_inode(trans, root, dir);
2951 BUG_ON(ret);
2953 btrfs_free_path(path);
2954 return 0;
2957 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
2959 struct inode *inode = dentry->d_inode;
2960 int err = 0;
2961 struct btrfs_root *root = BTRFS_I(dir)->root;
2962 struct btrfs_trans_handle *trans;
2963 unsigned long nr = 0;
2965 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE ||
2966 btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
2967 return -ENOTEMPTY;
2969 trans = __unlink_start_trans(dir, dentry);
2970 if (IS_ERR(trans))
2971 return PTR_ERR(trans);
2973 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
2974 err = btrfs_unlink_subvol(trans, root, dir,
2975 BTRFS_I(inode)->location.objectid,
2976 dentry->d_name.name,
2977 dentry->d_name.len);
2978 goto out;
2981 err = btrfs_orphan_add(trans, inode);
2982 if (err)
2983 goto out;
2985 /* now the directory is empty */
2986 err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
2987 dentry->d_name.name, dentry->d_name.len);
2988 if (!err)
2989 btrfs_i_size_write(inode, 0);
2990 out:
2991 nr = trans->blocks_used;
2992 __unlink_end_trans(trans, root);
2993 btrfs_btree_balance_dirty(root, nr);
2995 return err;
2999 * this can truncate away extent items, csum items and directory items.
3000 * It starts at a high offset and removes keys until it can't find
3001 * any higher than new_size
3003 * csum items that cross the new i_size are truncated to the new size
3004 * as well.
3006 * min_type is the minimum key type to truncate down to. If set to 0, this
3007 * will kill all the items on this inode, including the INODE_ITEM_KEY.
3009 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
3010 struct btrfs_root *root,
3011 struct inode *inode,
3012 u64 new_size, u32 min_type)
3014 struct btrfs_path *path;
3015 struct extent_buffer *leaf;
3016 struct btrfs_file_extent_item *fi;
3017 struct btrfs_key key;
3018 struct btrfs_key found_key;
3019 u64 extent_start = 0;
3020 u64 extent_num_bytes = 0;
3021 u64 extent_offset = 0;
3022 u64 item_end = 0;
3023 u64 mask = root->sectorsize - 1;
3024 u32 found_type = (u8)-1;
3025 int found_extent;
3026 int del_item;
3027 int pending_del_nr = 0;
3028 int pending_del_slot = 0;
3029 int extent_type = -1;
3030 int ret;
3031 int err = 0;
3032 u64 ino = btrfs_ino(inode);
3034 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
3036 path = btrfs_alloc_path();
3037 if (!path)
3038 return -ENOMEM;
3039 path->reada = -1;
3041 if (root->ref_cows || root == root->fs_info->tree_root)
3042 btrfs_drop_extent_cache(inode, new_size & (~mask), (u64)-1, 0);
3045 * This function is also used to drop the items in the log tree before
3046 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
3047 * it is used to drop the loged items. So we shouldn't kill the delayed
3048 * items.
3050 if (min_type == 0 && root == BTRFS_I(inode)->root)
3051 btrfs_kill_delayed_inode_items(inode);
3053 key.objectid = ino;
3054 key.offset = (u64)-1;
3055 key.type = (u8)-1;
3057 search_again:
3058 path->leave_spinning = 1;
3059 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
3060 if (ret < 0) {
3061 err = ret;
3062 goto out;
3065 if (ret > 0) {
3066 /* there are no items in the tree for us to truncate, we're
3067 * done
3069 if (path->slots[0] == 0)
3070 goto out;
3071 path->slots[0]--;
3074 while (1) {
3075 fi = NULL;
3076 leaf = path->nodes[0];
3077 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3078 found_type = btrfs_key_type(&found_key);
3080 if (found_key.objectid != ino)
3081 break;
3083 if (found_type < min_type)
3084 break;
3086 item_end = found_key.offset;
3087 if (found_type == BTRFS_EXTENT_DATA_KEY) {
3088 fi = btrfs_item_ptr(leaf, path->slots[0],
3089 struct btrfs_file_extent_item);
3090 extent_type = btrfs_file_extent_type(leaf, fi);
3091 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
3092 item_end +=
3093 btrfs_file_extent_num_bytes(leaf, fi);
3094 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
3095 item_end += btrfs_file_extent_inline_len(leaf,
3096 fi);
3098 item_end--;
3100 if (found_type > min_type) {
3101 del_item = 1;
3102 } else {
3103 if (item_end < new_size)
3104 break;
3105 if (found_key.offset >= new_size)
3106 del_item = 1;
3107 else
3108 del_item = 0;
3110 found_extent = 0;
3111 /* FIXME, shrink the extent if the ref count is only 1 */
3112 if (found_type != BTRFS_EXTENT_DATA_KEY)
3113 goto delete;
3115 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
3116 u64 num_dec;
3117 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
3118 if (!del_item) {
3119 u64 orig_num_bytes =
3120 btrfs_file_extent_num_bytes(leaf, fi);
3121 extent_num_bytes = new_size -
3122 found_key.offset + root->sectorsize - 1;
3123 extent_num_bytes = extent_num_bytes &
3124 ~((u64)root->sectorsize - 1);
3125 btrfs_set_file_extent_num_bytes(leaf, fi,
3126 extent_num_bytes);
3127 num_dec = (orig_num_bytes -
3128 extent_num_bytes);
3129 if (root->ref_cows && extent_start != 0)
3130 inode_sub_bytes(inode, num_dec);
3131 btrfs_mark_buffer_dirty(leaf);
3132 } else {
3133 extent_num_bytes =
3134 btrfs_file_extent_disk_num_bytes(leaf,
3135 fi);
3136 extent_offset = found_key.offset -
3137 btrfs_file_extent_offset(leaf, fi);
3139 /* FIXME blocksize != 4096 */
3140 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
3141 if (extent_start != 0) {
3142 found_extent = 1;
3143 if (root->ref_cows)
3144 inode_sub_bytes(inode, num_dec);
3147 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
3149 * we can't truncate inline items that have had
3150 * special encodings
3152 if (!del_item &&
3153 btrfs_file_extent_compression(leaf, fi) == 0 &&
3154 btrfs_file_extent_encryption(leaf, fi) == 0 &&
3155 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
3156 u32 size = new_size - found_key.offset;
3158 if (root->ref_cows) {
3159 inode_sub_bytes(inode, item_end + 1 -
3160 new_size);
3162 size =
3163 btrfs_file_extent_calc_inline_size(size);
3164 ret = btrfs_truncate_item(trans, root, path,
3165 size, 1);
3166 } else if (root->ref_cows) {
3167 inode_sub_bytes(inode, item_end + 1 -
3168 found_key.offset);
3171 delete:
3172 if (del_item) {
3173 if (!pending_del_nr) {
3174 /* no pending yet, add ourselves */
3175 pending_del_slot = path->slots[0];
3176 pending_del_nr = 1;
3177 } else if (pending_del_nr &&
3178 path->slots[0] + 1 == pending_del_slot) {
3179 /* hop on the pending chunk */
3180 pending_del_nr++;
3181 pending_del_slot = path->slots[0];
3182 } else {
3183 BUG();
3185 } else {
3186 break;
3188 if (found_extent && (root->ref_cows ||
3189 root == root->fs_info->tree_root)) {
3190 btrfs_set_path_blocking(path);
3191 ret = btrfs_free_extent(trans, root, extent_start,
3192 extent_num_bytes, 0,
3193 btrfs_header_owner(leaf),
3194 ino, extent_offset, 0);
3195 BUG_ON(ret);
3198 if (found_type == BTRFS_INODE_ITEM_KEY)
3199 break;
3201 if (path->slots[0] == 0 ||
3202 path->slots[0] != pending_del_slot) {
3203 if (root->ref_cows &&
3204 BTRFS_I(inode)->location.objectid !=
3205 BTRFS_FREE_INO_OBJECTID) {
3206 err = -EAGAIN;
3207 goto out;
3209 if (pending_del_nr) {
3210 ret = btrfs_del_items(trans, root, path,
3211 pending_del_slot,
3212 pending_del_nr);
3213 BUG_ON(ret);
3214 pending_del_nr = 0;
3216 btrfs_release_path(path);
3217 goto search_again;
3218 } else {
3219 path->slots[0]--;
3222 out:
3223 if (pending_del_nr) {
3224 ret = btrfs_del_items(trans, root, path, pending_del_slot,
3225 pending_del_nr);
3226 BUG_ON(ret);
3228 btrfs_free_path(path);
3229 return err;
3233 * taken from block_truncate_page, but does cow as it zeros out
3234 * any bytes left in the last page in the file.
3236 static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
3238 struct inode *inode = mapping->host;
3239 struct btrfs_root *root = BTRFS_I(inode)->root;
3240 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3241 struct btrfs_ordered_extent *ordered;
3242 struct extent_state *cached_state = NULL;
3243 char *kaddr;
3244 u32 blocksize = root->sectorsize;
3245 pgoff_t index = from >> PAGE_CACHE_SHIFT;
3246 unsigned offset = from & (PAGE_CACHE_SIZE-1);
3247 struct page *page;
3248 gfp_t mask = btrfs_alloc_write_mask(mapping);
3249 int ret = 0;
3250 u64 page_start;
3251 u64 page_end;
3253 if ((offset & (blocksize - 1)) == 0)
3254 goto out;
3255 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
3256 if (ret)
3257 goto out;
3259 ret = -ENOMEM;
3260 again:
3261 page = find_or_create_page(mapping, index, mask);
3262 if (!page) {
3263 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
3264 goto out;
3267 page_start = page_offset(page);
3268 page_end = page_start + PAGE_CACHE_SIZE - 1;
3270 if (!PageUptodate(page)) {
3271 ret = btrfs_readpage(NULL, page);
3272 lock_page(page);
3273 if (page->mapping != mapping) {
3274 unlock_page(page);
3275 page_cache_release(page);
3276 goto again;
3278 if (!PageUptodate(page)) {
3279 ret = -EIO;
3280 goto out_unlock;
3283 wait_on_page_writeback(page);
3285 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state,
3286 GFP_NOFS);
3287 set_page_extent_mapped(page);
3289 ordered = btrfs_lookup_ordered_extent(inode, page_start);
3290 if (ordered) {
3291 unlock_extent_cached(io_tree, page_start, page_end,
3292 &cached_state, GFP_NOFS);
3293 unlock_page(page);
3294 page_cache_release(page);
3295 btrfs_start_ordered_extent(inode, ordered, 1);
3296 btrfs_put_ordered_extent(ordered);
3297 goto again;
3300 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
3301 EXTENT_DIRTY | EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING,
3302 0, 0, &cached_state, GFP_NOFS);
3304 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
3305 &cached_state);
3306 if (ret) {
3307 unlock_extent_cached(io_tree, page_start, page_end,
3308 &cached_state, GFP_NOFS);
3309 goto out_unlock;
3312 ret = 0;
3313 if (offset != PAGE_CACHE_SIZE) {
3314 kaddr = kmap(page);
3315 memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
3316 flush_dcache_page(page);
3317 kunmap(page);
3319 ClearPageChecked(page);
3320 set_page_dirty(page);
3321 unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
3322 GFP_NOFS);
3324 out_unlock:
3325 if (ret)
3326 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
3327 unlock_page(page);
3328 page_cache_release(page);
3329 out:
3330 return ret;
3334 * This function puts in dummy file extents for the area we're creating a hole
3335 * for. So if we are truncating this file to a larger size we need to insert
3336 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
3337 * the range between oldsize and size
3339 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
3341 struct btrfs_trans_handle *trans;
3342 struct btrfs_root *root = BTRFS_I(inode)->root;
3343 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3344 struct extent_map *em = NULL;
3345 struct extent_state *cached_state = NULL;
3346 u64 mask = root->sectorsize - 1;
3347 u64 hole_start = (oldsize + mask) & ~mask;
3348 u64 block_end = (size + mask) & ~mask;
3349 u64 last_byte;
3350 u64 cur_offset;
3351 u64 hole_size;
3352 int err = 0;
3354 if (size <= hole_start)
3355 return 0;
3357 while (1) {
3358 struct btrfs_ordered_extent *ordered;
3359 btrfs_wait_ordered_range(inode, hole_start,
3360 block_end - hole_start);
3361 lock_extent_bits(io_tree, hole_start, block_end - 1, 0,
3362 &cached_state, GFP_NOFS);
3363 ordered = btrfs_lookup_ordered_extent(inode, hole_start);
3364 if (!ordered)
3365 break;
3366 unlock_extent_cached(io_tree, hole_start, block_end - 1,
3367 &cached_state, GFP_NOFS);
3368 btrfs_put_ordered_extent(ordered);
3371 cur_offset = hole_start;
3372 while (1) {
3373 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
3374 block_end - cur_offset, 0);
3375 BUG_ON(IS_ERR_OR_NULL(em));
3376 last_byte = min(extent_map_end(em), block_end);
3377 last_byte = (last_byte + mask) & ~mask;
3378 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
3379 u64 hint_byte = 0;
3380 hole_size = last_byte - cur_offset;
3382 trans = btrfs_start_transaction(root, 3);
3383 if (IS_ERR(trans)) {
3384 err = PTR_ERR(trans);
3385 break;
3388 err = btrfs_drop_extents(trans, inode, cur_offset,
3389 cur_offset + hole_size,
3390 &hint_byte, 1);
3391 if (err) {
3392 btrfs_update_inode(trans, root, inode);
3393 btrfs_end_transaction(trans, root);
3394 break;
3397 err = btrfs_insert_file_extent(trans, root,
3398 btrfs_ino(inode), cur_offset, 0,
3399 0, hole_size, 0, hole_size,
3400 0, 0, 0);
3401 if (err) {
3402 btrfs_update_inode(trans, root, inode);
3403 btrfs_end_transaction(trans, root);
3404 break;
3407 btrfs_drop_extent_cache(inode, hole_start,
3408 last_byte - 1, 0);
3410 btrfs_update_inode(trans, root, inode);
3411 btrfs_end_transaction(trans, root);
3413 free_extent_map(em);
3414 em = NULL;
3415 cur_offset = last_byte;
3416 if (cur_offset >= block_end)
3417 break;
3420 free_extent_map(em);
3421 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
3422 GFP_NOFS);
3423 return err;
3426 static int btrfs_setsize(struct inode *inode, loff_t newsize)
3428 struct btrfs_root *root = BTRFS_I(inode)->root;
3429 struct btrfs_trans_handle *trans;
3430 loff_t oldsize = i_size_read(inode);
3431 int ret;
3433 if (newsize == oldsize)
3434 return 0;
3436 if (newsize > oldsize) {
3437 truncate_pagecache(inode, oldsize, newsize);
3438 ret = btrfs_cont_expand(inode, oldsize, newsize);
3439 if (ret)
3440 return ret;
3442 trans = btrfs_start_transaction(root, 1);
3443 if (IS_ERR(trans))
3444 return PTR_ERR(trans);
3446 i_size_write(inode, newsize);
3447 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
3448 ret = btrfs_update_inode(trans, root, inode);
3449 btrfs_end_transaction(trans, root);
3450 } else {
3453 * We're truncating a file that used to have good data down to
3454 * zero. Make sure it gets into the ordered flush list so that
3455 * any new writes get down to disk quickly.
3457 if (newsize == 0)
3458 BTRFS_I(inode)->ordered_data_close = 1;
3460 /* we don't support swapfiles, so vmtruncate shouldn't fail */
3461 truncate_setsize(inode, newsize);
3462 ret = btrfs_truncate(inode);
3465 return ret;
3468 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
3470 struct inode *inode = dentry->d_inode;
3471 struct btrfs_root *root = BTRFS_I(inode)->root;
3472 int err;
3474 if (btrfs_root_readonly(root))
3475 return -EROFS;
3477 err = inode_change_ok(inode, attr);
3478 if (err)
3479 return err;
3481 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
3482 err = btrfs_setsize(inode, attr->ia_size);
3483 if (err)
3484 return err;
3487 if (attr->ia_valid) {
3488 setattr_copy(inode, attr);
3489 err = btrfs_dirty_inode(inode);
3491 if (!err && attr->ia_valid & ATTR_MODE)
3492 err = btrfs_acl_chmod(inode);
3495 return err;
3498 void btrfs_evict_inode(struct inode *inode)
3500 struct btrfs_trans_handle *trans;
3501 struct btrfs_root *root = BTRFS_I(inode)->root;
3502 struct btrfs_block_rsv *rsv, *global_rsv;
3503 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
3504 unsigned long nr;
3505 int ret;
3507 trace_btrfs_inode_evict(inode);
3509 truncate_inode_pages(&inode->i_data, 0);
3510 if (inode->i_nlink && (btrfs_root_refs(&root->root_item) != 0 ||
3511 btrfs_is_free_space_inode(root, inode)))
3512 goto no_delete;
3514 if (is_bad_inode(inode)) {
3515 btrfs_orphan_del(NULL, inode);
3516 goto no_delete;
3518 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
3519 btrfs_wait_ordered_range(inode, 0, (u64)-1);
3521 if (root->fs_info->log_root_recovering) {
3522 BUG_ON(!list_empty(&BTRFS_I(inode)->i_orphan));
3523 goto no_delete;
3526 if (inode->i_nlink > 0) {
3527 BUG_ON(btrfs_root_refs(&root->root_item) != 0);
3528 goto no_delete;
3531 rsv = btrfs_alloc_block_rsv(root);
3532 if (!rsv) {
3533 btrfs_orphan_del(NULL, inode);
3534 goto no_delete;
3536 rsv->size = min_size;
3537 global_rsv = &root->fs_info->global_block_rsv;
3539 btrfs_i_size_write(inode, 0);
3542 * This is a bit simpler than btrfs_truncate since
3544 * 1) We've already reserved our space for our orphan item in the
3545 * unlink.
3546 * 2) We're going to delete the inode item, so we don't need to update
3547 * it at all.
3549 * So we just need to reserve some slack space in case we add bytes when
3550 * doing the truncate.
3552 while (1) {
3553 ret = btrfs_block_rsv_refill_noflush(root, rsv, min_size);
3556 * Try and steal from the global reserve since we will
3557 * likely not use this space anyway, we want to try as
3558 * hard as possible to get this to work.
3560 if (ret)
3561 ret = btrfs_block_rsv_migrate(global_rsv, rsv, min_size);
3563 if (ret) {
3564 printk(KERN_WARNING "Could not get space for a "
3565 "delete, will truncate on mount %d\n", ret);
3566 btrfs_orphan_del(NULL, inode);
3567 btrfs_free_block_rsv(root, rsv);
3568 goto no_delete;
3571 trans = btrfs_start_transaction(root, 0);
3572 if (IS_ERR(trans)) {
3573 btrfs_orphan_del(NULL, inode);
3574 btrfs_free_block_rsv(root, rsv);
3575 goto no_delete;
3578 trans->block_rsv = rsv;
3580 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
3581 if (ret != -EAGAIN)
3582 break;
3584 nr = trans->blocks_used;
3585 btrfs_end_transaction(trans, root);
3586 trans = NULL;
3587 btrfs_btree_balance_dirty(root, nr);
3590 btrfs_free_block_rsv(root, rsv);
3592 if (ret == 0) {
3593 trans->block_rsv = root->orphan_block_rsv;
3594 ret = btrfs_orphan_del(trans, inode);
3595 BUG_ON(ret);
3598 trans->block_rsv = &root->fs_info->trans_block_rsv;
3599 if (!(root == root->fs_info->tree_root ||
3600 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
3601 btrfs_return_ino(root, btrfs_ino(inode));
3603 nr = trans->blocks_used;
3604 btrfs_end_transaction(trans, root);
3605 btrfs_btree_balance_dirty(root, nr);
3606 no_delete:
3607 end_writeback(inode);
3608 return;
3612 * this returns the key found in the dir entry in the location pointer.
3613 * If no dir entries were found, location->objectid is 0.
3615 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
3616 struct btrfs_key *location)
3618 const char *name = dentry->d_name.name;
3619 int namelen = dentry->d_name.len;
3620 struct btrfs_dir_item *di;
3621 struct btrfs_path *path;
3622 struct btrfs_root *root = BTRFS_I(dir)->root;
3623 int ret = 0;
3625 path = btrfs_alloc_path();
3626 if (!path)
3627 return -ENOMEM;
3629 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
3630 namelen, 0);
3631 if (IS_ERR(di))
3632 ret = PTR_ERR(di);
3634 if (IS_ERR_OR_NULL(di))
3635 goto out_err;
3637 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
3638 out:
3639 btrfs_free_path(path);
3640 return ret;
3641 out_err:
3642 location->objectid = 0;
3643 goto out;
3647 * when we hit a tree root in a directory, the btrfs part of the inode
3648 * needs to be changed to reflect the root directory of the tree root. This
3649 * is kind of like crossing a mount point.
3651 static int fixup_tree_root_location(struct btrfs_root *root,
3652 struct inode *dir,
3653 struct dentry *dentry,
3654 struct btrfs_key *location,
3655 struct btrfs_root **sub_root)
3657 struct btrfs_path *path;
3658 struct btrfs_root *new_root;
3659 struct btrfs_root_ref *ref;
3660 struct extent_buffer *leaf;
3661 int ret;
3662 int err = 0;
3664 path = btrfs_alloc_path();
3665 if (!path) {
3666 err = -ENOMEM;
3667 goto out;
3670 err = -ENOENT;
3671 ret = btrfs_find_root_ref(root->fs_info->tree_root, path,
3672 BTRFS_I(dir)->root->root_key.objectid,
3673 location->objectid);
3674 if (ret) {
3675 if (ret < 0)
3676 err = ret;
3677 goto out;
3680 leaf = path->nodes[0];
3681 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
3682 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
3683 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
3684 goto out;
3686 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
3687 (unsigned long)(ref + 1),
3688 dentry->d_name.len);
3689 if (ret)
3690 goto out;
3692 btrfs_release_path(path);
3694 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
3695 if (IS_ERR(new_root)) {
3696 err = PTR_ERR(new_root);
3697 goto out;
3700 if (btrfs_root_refs(&new_root->root_item) == 0) {
3701 err = -ENOENT;
3702 goto out;
3705 *sub_root = new_root;
3706 location->objectid = btrfs_root_dirid(&new_root->root_item);
3707 location->type = BTRFS_INODE_ITEM_KEY;
3708 location->offset = 0;
3709 err = 0;
3710 out:
3711 btrfs_free_path(path);
3712 return err;
3715 static void inode_tree_add(struct inode *inode)
3717 struct btrfs_root *root = BTRFS_I(inode)->root;
3718 struct btrfs_inode *entry;
3719 struct rb_node **p;
3720 struct rb_node *parent;
3721 u64 ino = btrfs_ino(inode);
3722 again:
3723 p = &root->inode_tree.rb_node;
3724 parent = NULL;
3726 if (inode_unhashed(inode))
3727 return;
3729 spin_lock(&root->inode_lock);
3730 while (*p) {
3731 parent = *p;
3732 entry = rb_entry(parent, struct btrfs_inode, rb_node);
3734 if (ino < btrfs_ino(&entry->vfs_inode))
3735 p = &parent->rb_left;
3736 else if (ino > btrfs_ino(&entry->vfs_inode))
3737 p = &parent->rb_right;
3738 else {
3739 WARN_ON(!(entry->vfs_inode.i_state &
3740 (I_WILL_FREE | I_FREEING)));
3741 rb_erase(parent, &root->inode_tree);
3742 RB_CLEAR_NODE(parent);
3743 spin_unlock(&root->inode_lock);
3744 goto again;
3747 rb_link_node(&BTRFS_I(inode)->rb_node, parent, p);
3748 rb_insert_color(&BTRFS_I(inode)->rb_node, &root->inode_tree);
3749 spin_unlock(&root->inode_lock);
3752 static void inode_tree_del(struct inode *inode)
3754 struct btrfs_root *root = BTRFS_I(inode)->root;
3755 int empty = 0;
3757 spin_lock(&root->inode_lock);
3758 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
3759 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
3760 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
3761 empty = RB_EMPTY_ROOT(&root->inode_tree);
3763 spin_unlock(&root->inode_lock);
3766 * Free space cache has inodes in the tree root, but the tree root has a
3767 * root_refs of 0, so this could end up dropping the tree root as a
3768 * snapshot, so we need the extra !root->fs_info->tree_root check to
3769 * make sure we don't drop it.
3771 if (empty && btrfs_root_refs(&root->root_item) == 0 &&
3772 root != root->fs_info->tree_root) {
3773 synchronize_srcu(&root->fs_info->subvol_srcu);
3774 spin_lock(&root->inode_lock);
3775 empty = RB_EMPTY_ROOT(&root->inode_tree);
3776 spin_unlock(&root->inode_lock);
3777 if (empty)
3778 btrfs_add_dead_root(root);
3782 int btrfs_invalidate_inodes(struct btrfs_root *root)
3784 struct rb_node *node;
3785 struct rb_node *prev;
3786 struct btrfs_inode *entry;
3787 struct inode *inode;
3788 u64 objectid = 0;
3790 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
3792 spin_lock(&root->inode_lock);
3793 again:
3794 node = root->inode_tree.rb_node;
3795 prev = NULL;
3796 while (node) {
3797 prev = node;
3798 entry = rb_entry(node, struct btrfs_inode, rb_node);
3800 if (objectid < btrfs_ino(&entry->vfs_inode))
3801 node = node->rb_left;
3802 else if (objectid > btrfs_ino(&entry->vfs_inode))
3803 node = node->rb_right;
3804 else
3805 break;
3807 if (!node) {
3808 while (prev) {
3809 entry = rb_entry(prev, struct btrfs_inode, rb_node);
3810 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
3811 node = prev;
3812 break;
3814 prev = rb_next(prev);
3817 while (node) {
3818 entry = rb_entry(node, struct btrfs_inode, rb_node);
3819 objectid = btrfs_ino(&entry->vfs_inode) + 1;
3820 inode = igrab(&entry->vfs_inode);
3821 if (inode) {
3822 spin_unlock(&root->inode_lock);
3823 if (atomic_read(&inode->i_count) > 1)
3824 d_prune_aliases(inode);
3826 * btrfs_drop_inode will have it removed from
3827 * the inode cache when its usage count
3828 * hits zero.
3830 iput(inode);
3831 cond_resched();
3832 spin_lock(&root->inode_lock);
3833 goto again;
3836 if (cond_resched_lock(&root->inode_lock))
3837 goto again;
3839 node = rb_next(node);
3841 spin_unlock(&root->inode_lock);
3842 return 0;
3845 static int btrfs_init_locked_inode(struct inode *inode, void *p)
3847 struct btrfs_iget_args *args = p;
3848 inode->i_ino = args->ino;
3849 BTRFS_I(inode)->root = args->root;
3850 btrfs_set_inode_space_info(args->root, inode);
3851 return 0;
3854 static int btrfs_find_actor(struct inode *inode, void *opaque)
3856 struct btrfs_iget_args *args = opaque;
3857 return args->ino == btrfs_ino(inode) &&
3858 args->root == BTRFS_I(inode)->root;
3861 static struct inode *btrfs_iget_locked(struct super_block *s,
3862 u64 objectid,
3863 struct btrfs_root *root)
3865 struct inode *inode;
3866 struct btrfs_iget_args args;
3867 args.ino = objectid;
3868 args.root = root;
3870 inode = iget5_locked(s, objectid, btrfs_find_actor,
3871 btrfs_init_locked_inode,
3872 (void *)&args);
3873 return inode;
3876 /* Get an inode object given its location and corresponding root.
3877 * Returns in *is_new if the inode was read from disk
3879 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
3880 struct btrfs_root *root, int *new)
3882 struct inode *inode;
3884 inode = btrfs_iget_locked(s, location->objectid, root);
3885 if (!inode)
3886 return ERR_PTR(-ENOMEM);
3888 if (inode->i_state & I_NEW) {
3889 BTRFS_I(inode)->root = root;
3890 memcpy(&BTRFS_I(inode)->location, location, sizeof(*location));
3891 btrfs_read_locked_inode(inode);
3892 if (!is_bad_inode(inode)) {
3893 inode_tree_add(inode);
3894 unlock_new_inode(inode);
3895 if (new)
3896 *new = 1;
3897 } else {
3898 unlock_new_inode(inode);
3899 iput(inode);
3900 inode = ERR_PTR(-ESTALE);
3904 return inode;
3907 static struct inode *new_simple_dir(struct super_block *s,
3908 struct btrfs_key *key,
3909 struct btrfs_root *root)
3911 struct inode *inode = new_inode(s);
3913 if (!inode)
3914 return ERR_PTR(-ENOMEM);
3916 BTRFS_I(inode)->root = root;
3917 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
3918 BTRFS_I(inode)->dummy_inode = 1;
3920 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
3921 inode->i_op = &simple_dir_inode_operations;
3922 inode->i_fop = &simple_dir_operations;
3923 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
3924 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
3926 return inode;
3929 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
3931 struct inode *inode;
3932 struct btrfs_root *root = BTRFS_I(dir)->root;
3933 struct btrfs_root *sub_root = root;
3934 struct btrfs_key location;
3935 int index;
3936 int ret = 0;
3938 if (dentry->d_name.len > BTRFS_NAME_LEN)
3939 return ERR_PTR(-ENAMETOOLONG);
3941 if (unlikely(d_need_lookup(dentry))) {
3942 memcpy(&location, dentry->d_fsdata, sizeof(struct btrfs_key));
3943 kfree(dentry->d_fsdata);
3944 dentry->d_fsdata = NULL;
3945 /* This thing is hashed, drop it for now */
3946 d_drop(dentry);
3947 } else {
3948 ret = btrfs_inode_by_name(dir, dentry, &location);
3951 if (ret < 0)
3952 return ERR_PTR(ret);
3954 if (location.objectid == 0)
3955 return NULL;
3957 if (location.type == BTRFS_INODE_ITEM_KEY) {
3958 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
3959 return inode;
3962 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
3964 index = srcu_read_lock(&root->fs_info->subvol_srcu);
3965 ret = fixup_tree_root_location(root, dir, dentry,
3966 &location, &sub_root);
3967 if (ret < 0) {
3968 if (ret != -ENOENT)
3969 inode = ERR_PTR(ret);
3970 else
3971 inode = new_simple_dir(dir->i_sb, &location, sub_root);
3972 } else {
3973 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
3975 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
3977 if (!IS_ERR(inode) && root != sub_root) {
3978 down_read(&root->fs_info->cleanup_work_sem);
3979 if (!(inode->i_sb->s_flags & MS_RDONLY))
3980 ret = btrfs_orphan_cleanup(sub_root);
3981 up_read(&root->fs_info->cleanup_work_sem);
3982 if (ret)
3983 inode = ERR_PTR(ret);
3986 return inode;
3989 static int btrfs_dentry_delete(const struct dentry *dentry)
3991 struct btrfs_root *root;
3993 if (!dentry->d_inode && !IS_ROOT(dentry))
3994 dentry = dentry->d_parent;
3996 if (dentry->d_inode) {
3997 root = BTRFS_I(dentry->d_inode)->root;
3998 if (btrfs_root_refs(&root->root_item) == 0)
3999 return 1;
4001 return 0;
4004 static void btrfs_dentry_release(struct dentry *dentry)
4006 if (dentry->d_fsdata)
4007 kfree(dentry->d_fsdata);
4010 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
4011 struct nameidata *nd)
4013 struct dentry *ret;
4015 ret = d_splice_alias(btrfs_lookup_dentry(dir, dentry), dentry);
4016 if (unlikely(d_need_lookup(dentry))) {
4017 spin_lock(&dentry->d_lock);
4018 dentry->d_flags &= ~DCACHE_NEED_LOOKUP;
4019 spin_unlock(&dentry->d_lock);
4021 return ret;
4024 unsigned char btrfs_filetype_table[] = {
4025 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
4028 static int btrfs_real_readdir(struct file *filp, void *dirent,
4029 filldir_t filldir)
4031 struct inode *inode = filp->f_dentry->d_inode;
4032 struct btrfs_root *root = BTRFS_I(inode)->root;
4033 struct btrfs_item *item;
4034 struct btrfs_dir_item *di;
4035 struct btrfs_key key;
4036 struct btrfs_key found_key;
4037 struct btrfs_path *path;
4038 struct list_head ins_list;
4039 struct list_head del_list;
4040 struct qstr q;
4041 int ret;
4042 struct extent_buffer *leaf;
4043 int slot;
4044 unsigned char d_type;
4045 int over = 0;
4046 u32 di_cur;
4047 u32 di_total;
4048 u32 di_len;
4049 int key_type = BTRFS_DIR_INDEX_KEY;
4050 char tmp_name[32];
4051 char *name_ptr;
4052 int name_len;
4053 int is_curr = 0; /* filp->f_pos points to the current index? */
4055 /* FIXME, use a real flag for deciding about the key type */
4056 if (root->fs_info->tree_root == root)
4057 key_type = BTRFS_DIR_ITEM_KEY;
4059 /* special case for "." */
4060 if (filp->f_pos == 0) {
4061 over = filldir(dirent, ".", 1,
4062 filp->f_pos, btrfs_ino(inode), DT_DIR);
4063 if (over)
4064 return 0;
4065 filp->f_pos = 1;
4067 /* special case for .., just use the back ref */
4068 if (filp->f_pos == 1) {
4069 u64 pino = parent_ino(filp->f_path.dentry);
4070 over = filldir(dirent, "..", 2,
4071 filp->f_pos, pino, DT_DIR);
4072 if (over)
4073 return 0;
4074 filp->f_pos = 2;
4076 path = btrfs_alloc_path();
4077 if (!path)
4078 return -ENOMEM;
4080 path->reada = 1;
4082 if (key_type == BTRFS_DIR_INDEX_KEY) {
4083 INIT_LIST_HEAD(&ins_list);
4084 INIT_LIST_HEAD(&del_list);
4085 btrfs_get_delayed_items(inode, &ins_list, &del_list);
4088 btrfs_set_key_type(&key, key_type);
4089 key.offset = filp->f_pos;
4090 key.objectid = btrfs_ino(inode);
4092 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4093 if (ret < 0)
4094 goto err;
4096 while (1) {
4097 leaf = path->nodes[0];
4098 slot = path->slots[0];
4099 if (slot >= btrfs_header_nritems(leaf)) {
4100 ret = btrfs_next_leaf(root, path);
4101 if (ret < 0)
4102 goto err;
4103 else if (ret > 0)
4104 break;
4105 continue;
4108 item = btrfs_item_nr(leaf, slot);
4109 btrfs_item_key_to_cpu(leaf, &found_key, slot);
4111 if (found_key.objectid != key.objectid)
4112 break;
4113 if (btrfs_key_type(&found_key) != key_type)
4114 break;
4115 if (found_key.offset < filp->f_pos)
4116 goto next;
4117 if (key_type == BTRFS_DIR_INDEX_KEY &&
4118 btrfs_should_delete_dir_index(&del_list,
4119 found_key.offset))
4120 goto next;
4122 filp->f_pos = found_key.offset;
4123 is_curr = 1;
4125 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
4126 di_cur = 0;
4127 di_total = btrfs_item_size(leaf, item);
4129 while (di_cur < di_total) {
4130 struct btrfs_key location;
4131 struct dentry *tmp;
4133 if (verify_dir_item(root, leaf, di))
4134 break;
4136 name_len = btrfs_dir_name_len(leaf, di);
4137 if (name_len <= sizeof(tmp_name)) {
4138 name_ptr = tmp_name;
4139 } else {
4140 name_ptr = kmalloc(name_len, GFP_NOFS);
4141 if (!name_ptr) {
4142 ret = -ENOMEM;
4143 goto err;
4146 read_extent_buffer(leaf, name_ptr,
4147 (unsigned long)(di + 1), name_len);
4149 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
4150 btrfs_dir_item_key_to_cpu(leaf, di, &location);
4152 q.name = name_ptr;
4153 q.len = name_len;
4154 q.hash = full_name_hash(q.name, q.len);
4155 tmp = d_lookup(filp->f_dentry, &q);
4156 if (!tmp) {
4157 struct btrfs_key *newkey;
4159 newkey = kzalloc(sizeof(struct btrfs_key),
4160 GFP_NOFS);
4161 if (!newkey)
4162 goto no_dentry;
4163 tmp = d_alloc(filp->f_dentry, &q);
4164 if (!tmp) {
4165 kfree(newkey);
4166 dput(tmp);
4167 goto no_dentry;
4169 memcpy(newkey, &location,
4170 sizeof(struct btrfs_key));
4171 tmp->d_fsdata = newkey;
4172 tmp->d_flags |= DCACHE_NEED_LOOKUP;
4173 d_rehash(tmp);
4174 dput(tmp);
4175 } else {
4176 dput(tmp);
4178 no_dentry:
4179 /* is this a reference to our own snapshot? If so
4180 * skip it
4182 if (location.type == BTRFS_ROOT_ITEM_KEY &&
4183 location.objectid == root->root_key.objectid) {
4184 over = 0;
4185 goto skip;
4187 over = filldir(dirent, name_ptr, name_len,
4188 found_key.offset, location.objectid,
4189 d_type);
4191 skip:
4192 if (name_ptr != tmp_name)
4193 kfree(name_ptr);
4195 if (over)
4196 goto nopos;
4197 di_len = btrfs_dir_name_len(leaf, di) +
4198 btrfs_dir_data_len(leaf, di) + sizeof(*di);
4199 di_cur += di_len;
4200 di = (struct btrfs_dir_item *)((char *)di + di_len);
4202 next:
4203 path->slots[0]++;
4206 if (key_type == BTRFS_DIR_INDEX_KEY) {
4207 if (is_curr)
4208 filp->f_pos++;
4209 ret = btrfs_readdir_delayed_dir_index(filp, dirent, filldir,
4210 &ins_list);
4211 if (ret)
4212 goto nopos;
4215 /* Reached end of directory/root. Bump pos past the last item. */
4216 if (key_type == BTRFS_DIR_INDEX_KEY)
4218 * 32-bit glibc will use getdents64, but then strtol -
4219 * so the last number we can serve is this.
4221 filp->f_pos = 0x7fffffff;
4222 else
4223 filp->f_pos++;
4224 nopos:
4225 ret = 0;
4226 err:
4227 if (key_type == BTRFS_DIR_INDEX_KEY)
4228 btrfs_put_delayed_items(&ins_list, &del_list);
4229 btrfs_free_path(path);
4230 return ret;
4233 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
4235 struct btrfs_root *root = BTRFS_I(inode)->root;
4236 struct btrfs_trans_handle *trans;
4237 int ret = 0;
4238 bool nolock = false;
4240 if (BTRFS_I(inode)->dummy_inode)
4241 return 0;
4243 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(root, inode))
4244 nolock = true;
4246 if (wbc->sync_mode == WB_SYNC_ALL) {
4247 if (nolock)
4248 trans = btrfs_join_transaction_nolock(root);
4249 else
4250 trans = btrfs_join_transaction(root);
4251 if (IS_ERR(trans))
4252 return PTR_ERR(trans);
4253 if (nolock)
4254 ret = btrfs_end_transaction_nolock(trans, root);
4255 else
4256 ret = btrfs_commit_transaction(trans, root);
4258 return ret;
4262 * This is somewhat expensive, updating the tree every time the
4263 * inode changes. But, it is most likely to find the inode in cache.
4264 * FIXME, needs more benchmarking...there are no reasons other than performance
4265 * to keep or drop this code.
4267 int btrfs_dirty_inode(struct inode *inode)
4269 struct btrfs_root *root = BTRFS_I(inode)->root;
4270 struct btrfs_trans_handle *trans;
4271 int ret;
4273 if (BTRFS_I(inode)->dummy_inode)
4274 return 0;
4276 trans = btrfs_join_transaction(root);
4277 if (IS_ERR(trans))
4278 return PTR_ERR(trans);
4280 ret = btrfs_update_inode(trans, root, inode);
4281 if (ret && ret == -ENOSPC) {
4282 /* whoops, lets try again with the full transaction */
4283 btrfs_end_transaction(trans, root);
4284 trans = btrfs_start_transaction(root, 1);
4285 if (IS_ERR(trans))
4286 return PTR_ERR(trans);
4288 ret = btrfs_update_inode(trans, root, inode);
4290 btrfs_end_transaction(trans, root);
4291 if (BTRFS_I(inode)->delayed_node)
4292 btrfs_balance_delayed_items(root);
4294 return ret;
4298 * This is a copy of file_update_time. We need this so we can return error on
4299 * ENOSPC for updating the inode in the case of file write and mmap writes.
4301 int btrfs_update_time(struct file *file)
4303 struct inode *inode = file->f_path.dentry->d_inode;
4304 struct timespec now;
4305 int ret;
4306 enum { S_MTIME = 1, S_CTIME = 2, S_VERSION = 4 } sync_it = 0;
4308 /* First try to exhaust all avenues to not sync */
4309 if (IS_NOCMTIME(inode))
4310 return 0;
4312 now = current_fs_time(inode->i_sb);
4313 if (!timespec_equal(&inode->i_mtime, &now))
4314 sync_it = S_MTIME;
4316 if (!timespec_equal(&inode->i_ctime, &now))
4317 sync_it |= S_CTIME;
4319 if (IS_I_VERSION(inode))
4320 sync_it |= S_VERSION;
4322 if (!sync_it)
4323 return 0;
4325 /* Finally allowed to write? Takes lock. */
4326 if (mnt_want_write_file(file))
4327 return 0;
4329 /* Only change inode inside the lock region */
4330 if (sync_it & S_VERSION)
4331 inode_inc_iversion(inode);
4332 if (sync_it & S_CTIME)
4333 inode->i_ctime = now;
4334 if (sync_it & S_MTIME)
4335 inode->i_mtime = now;
4336 ret = btrfs_dirty_inode(inode);
4337 if (!ret)
4338 mark_inode_dirty_sync(inode);
4339 mnt_drop_write(file->f_path.mnt);
4340 return ret;
4344 * find the highest existing sequence number in a directory
4345 * and then set the in-memory index_cnt variable to reflect
4346 * free sequence numbers
4348 static int btrfs_set_inode_index_count(struct inode *inode)
4350 struct btrfs_root *root = BTRFS_I(inode)->root;
4351 struct btrfs_key key, found_key;
4352 struct btrfs_path *path;
4353 struct extent_buffer *leaf;
4354 int ret;
4356 key.objectid = btrfs_ino(inode);
4357 btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
4358 key.offset = (u64)-1;
4360 path = btrfs_alloc_path();
4361 if (!path)
4362 return -ENOMEM;
4364 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4365 if (ret < 0)
4366 goto out;
4367 /* FIXME: we should be able to handle this */
4368 if (ret == 0)
4369 goto out;
4370 ret = 0;
4373 * MAGIC NUMBER EXPLANATION:
4374 * since we search a directory based on f_pos we have to start at 2
4375 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
4376 * else has to start at 2
4378 if (path->slots[0] == 0) {
4379 BTRFS_I(inode)->index_cnt = 2;
4380 goto out;
4383 path->slots[0]--;
4385 leaf = path->nodes[0];
4386 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4388 if (found_key.objectid != btrfs_ino(inode) ||
4389 btrfs_key_type(&found_key) != BTRFS_DIR_INDEX_KEY) {
4390 BTRFS_I(inode)->index_cnt = 2;
4391 goto out;
4394 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
4395 out:
4396 btrfs_free_path(path);
4397 return ret;
4401 * helper to find a free sequence number in a given directory. This current
4402 * code is very simple, later versions will do smarter things in the btree
4404 int btrfs_set_inode_index(struct inode *dir, u64 *index)
4406 int ret = 0;
4408 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
4409 ret = btrfs_inode_delayed_dir_index_count(dir);
4410 if (ret) {
4411 ret = btrfs_set_inode_index_count(dir);
4412 if (ret)
4413 return ret;
4417 *index = BTRFS_I(dir)->index_cnt;
4418 BTRFS_I(dir)->index_cnt++;
4420 return ret;
4423 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
4424 struct btrfs_root *root,
4425 struct inode *dir,
4426 const char *name, int name_len,
4427 u64 ref_objectid, u64 objectid,
4428 umode_t mode, u64 *index)
4430 struct inode *inode;
4431 struct btrfs_inode_item *inode_item;
4432 struct btrfs_key *location;
4433 struct btrfs_path *path;
4434 struct btrfs_inode_ref *ref;
4435 struct btrfs_key key[2];
4436 u32 sizes[2];
4437 unsigned long ptr;
4438 int ret;
4439 int owner;
4441 path = btrfs_alloc_path();
4442 if (!path)
4443 return ERR_PTR(-ENOMEM);
4445 inode = new_inode(root->fs_info->sb);
4446 if (!inode) {
4447 btrfs_free_path(path);
4448 return ERR_PTR(-ENOMEM);
4452 * we have to initialize this early, so we can reclaim the inode
4453 * number if we fail afterwards in this function.
4455 inode->i_ino = objectid;
4457 if (dir) {
4458 trace_btrfs_inode_request(dir);
4460 ret = btrfs_set_inode_index(dir, index);
4461 if (ret) {
4462 btrfs_free_path(path);
4463 iput(inode);
4464 return ERR_PTR(ret);
4468 * index_cnt is ignored for everything but a dir,
4469 * btrfs_get_inode_index_count has an explanation for the magic
4470 * number
4472 BTRFS_I(inode)->index_cnt = 2;
4473 BTRFS_I(inode)->root = root;
4474 BTRFS_I(inode)->generation = trans->transid;
4475 inode->i_generation = BTRFS_I(inode)->generation;
4476 btrfs_set_inode_space_info(root, inode);
4478 if (S_ISDIR(mode))
4479 owner = 0;
4480 else
4481 owner = 1;
4483 key[0].objectid = objectid;
4484 btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
4485 key[0].offset = 0;
4487 key[1].objectid = objectid;
4488 btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
4489 key[1].offset = ref_objectid;
4491 sizes[0] = sizeof(struct btrfs_inode_item);
4492 sizes[1] = name_len + sizeof(*ref);
4494 path->leave_spinning = 1;
4495 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
4496 if (ret != 0)
4497 goto fail;
4499 inode_init_owner(inode, dir, mode);
4500 inode_set_bytes(inode, 0);
4501 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
4502 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
4503 struct btrfs_inode_item);
4504 fill_inode_item(trans, path->nodes[0], inode_item, inode);
4506 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
4507 struct btrfs_inode_ref);
4508 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
4509 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
4510 ptr = (unsigned long)(ref + 1);
4511 write_extent_buffer(path->nodes[0], name, ptr, name_len);
4513 btrfs_mark_buffer_dirty(path->nodes[0]);
4514 btrfs_free_path(path);
4516 location = &BTRFS_I(inode)->location;
4517 location->objectid = objectid;
4518 location->offset = 0;
4519 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
4521 btrfs_inherit_iflags(inode, dir);
4523 if (S_ISREG(mode)) {
4524 if (btrfs_test_opt(root, NODATASUM))
4525 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
4526 if (btrfs_test_opt(root, NODATACOW) ||
4527 (BTRFS_I(dir)->flags & BTRFS_INODE_NODATACOW))
4528 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
4531 insert_inode_hash(inode);
4532 inode_tree_add(inode);
4534 trace_btrfs_inode_new(inode);
4535 btrfs_set_inode_last_trans(trans, inode);
4537 return inode;
4538 fail:
4539 if (dir)
4540 BTRFS_I(dir)->index_cnt--;
4541 btrfs_free_path(path);
4542 iput(inode);
4543 return ERR_PTR(ret);
4546 static inline u8 btrfs_inode_type(struct inode *inode)
4548 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
4552 * utility function to add 'inode' into 'parent_inode' with
4553 * a give name and a given sequence number.
4554 * if 'add_backref' is true, also insert a backref from the
4555 * inode to the parent directory.
4557 int btrfs_add_link(struct btrfs_trans_handle *trans,
4558 struct inode *parent_inode, struct inode *inode,
4559 const char *name, int name_len, int add_backref, u64 index)
4561 int ret = 0;
4562 struct btrfs_key key;
4563 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
4564 u64 ino = btrfs_ino(inode);
4565 u64 parent_ino = btrfs_ino(parent_inode);
4567 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
4568 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
4569 } else {
4570 key.objectid = ino;
4571 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
4572 key.offset = 0;
4575 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
4576 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
4577 key.objectid, root->root_key.objectid,
4578 parent_ino, index, name, name_len);
4579 } else if (add_backref) {
4580 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
4581 parent_ino, index);
4584 if (ret == 0) {
4585 ret = btrfs_insert_dir_item(trans, root, name, name_len,
4586 parent_inode, &key,
4587 btrfs_inode_type(inode), index);
4588 if (ret)
4589 goto fail_dir_item;
4591 btrfs_i_size_write(parent_inode, parent_inode->i_size +
4592 name_len * 2);
4593 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
4594 ret = btrfs_update_inode(trans, root, parent_inode);
4596 return ret;
4598 fail_dir_item:
4599 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
4600 u64 local_index;
4601 int err;
4602 err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
4603 key.objectid, root->root_key.objectid,
4604 parent_ino, &local_index, name, name_len);
4606 } else if (add_backref) {
4607 u64 local_index;
4608 int err;
4610 err = btrfs_del_inode_ref(trans, root, name, name_len,
4611 ino, parent_ino, &local_index);
4613 return ret;
4616 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
4617 struct inode *dir, struct dentry *dentry,
4618 struct inode *inode, int backref, u64 index)
4620 int err = btrfs_add_link(trans, dir, inode,
4621 dentry->d_name.name, dentry->d_name.len,
4622 backref, index);
4623 if (err > 0)
4624 err = -EEXIST;
4625 return err;
4628 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
4629 umode_t mode, dev_t rdev)
4631 struct btrfs_trans_handle *trans;
4632 struct btrfs_root *root = BTRFS_I(dir)->root;
4633 struct inode *inode = NULL;
4634 int err;
4635 int drop_inode = 0;
4636 u64 objectid;
4637 unsigned long nr = 0;
4638 u64 index = 0;
4640 if (!new_valid_dev(rdev))
4641 return -EINVAL;
4644 * 2 for inode item and ref
4645 * 2 for dir items
4646 * 1 for xattr if selinux is on
4648 trans = btrfs_start_transaction(root, 5);
4649 if (IS_ERR(trans))
4650 return PTR_ERR(trans);
4652 err = btrfs_find_free_ino(root, &objectid);
4653 if (err)
4654 goto out_unlock;
4656 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
4657 dentry->d_name.len, btrfs_ino(dir), objectid,
4658 mode, &index);
4659 if (IS_ERR(inode)) {
4660 err = PTR_ERR(inode);
4661 goto out_unlock;
4664 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
4665 if (err) {
4666 drop_inode = 1;
4667 goto out_unlock;
4671 * If the active LSM wants to access the inode during
4672 * d_instantiate it needs these. Smack checks to see
4673 * if the filesystem supports xattrs by looking at the
4674 * ops vector.
4677 inode->i_op = &btrfs_special_inode_operations;
4678 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
4679 if (err)
4680 drop_inode = 1;
4681 else {
4682 init_special_inode(inode, inode->i_mode, rdev);
4683 btrfs_update_inode(trans, root, inode);
4684 d_instantiate(dentry, inode);
4686 out_unlock:
4687 nr = trans->blocks_used;
4688 btrfs_end_transaction(trans, root);
4689 btrfs_btree_balance_dirty(root, nr);
4690 if (drop_inode) {
4691 inode_dec_link_count(inode);
4692 iput(inode);
4694 return err;
4697 static int btrfs_create(struct inode *dir, struct dentry *dentry,
4698 umode_t mode, struct nameidata *nd)
4700 struct btrfs_trans_handle *trans;
4701 struct btrfs_root *root = BTRFS_I(dir)->root;
4702 struct inode *inode = NULL;
4703 int drop_inode = 0;
4704 int err;
4705 unsigned long nr = 0;
4706 u64 objectid;
4707 u64 index = 0;
4710 * 2 for inode item and ref
4711 * 2 for dir items
4712 * 1 for xattr if selinux is on
4714 trans = btrfs_start_transaction(root, 5);
4715 if (IS_ERR(trans))
4716 return PTR_ERR(trans);
4718 err = btrfs_find_free_ino(root, &objectid);
4719 if (err)
4720 goto out_unlock;
4722 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
4723 dentry->d_name.len, btrfs_ino(dir), objectid,
4724 mode, &index);
4725 if (IS_ERR(inode)) {
4726 err = PTR_ERR(inode);
4727 goto out_unlock;
4730 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
4731 if (err) {
4732 drop_inode = 1;
4733 goto out_unlock;
4737 * If the active LSM wants to access the inode during
4738 * d_instantiate it needs these. Smack checks to see
4739 * if the filesystem supports xattrs by looking at the
4740 * ops vector.
4742 inode->i_fop = &btrfs_file_operations;
4743 inode->i_op = &btrfs_file_inode_operations;
4745 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
4746 if (err)
4747 drop_inode = 1;
4748 else {
4749 inode->i_mapping->a_ops = &btrfs_aops;
4750 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
4751 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
4752 d_instantiate(dentry, inode);
4754 out_unlock:
4755 nr = trans->blocks_used;
4756 btrfs_end_transaction(trans, root);
4757 if (drop_inode) {
4758 inode_dec_link_count(inode);
4759 iput(inode);
4761 btrfs_btree_balance_dirty(root, nr);
4762 return err;
4765 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
4766 struct dentry *dentry)
4768 struct btrfs_trans_handle *trans;
4769 struct btrfs_root *root = BTRFS_I(dir)->root;
4770 struct inode *inode = old_dentry->d_inode;
4771 u64 index;
4772 unsigned long nr = 0;
4773 int err;
4774 int drop_inode = 0;
4776 /* do not allow sys_link's with other subvols of the same device */
4777 if (root->objectid != BTRFS_I(inode)->root->objectid)
4778 return -EXDEV;
4780 if (inode->i_nlink == ~0U)
4781 return -EMLINK;
4783 err = btrfs_set_inode_index(dir, &index);
4784 if (err)
4785 goto fail;
4788 * 2 items for inode and inode ref
4789 * 2 items for dir items
4790 * 1 item for parent inode
4792 trans = btrfs_start_transaction(root, 5);
4793 if (IS_ERR(trans)) {
4794 err = PTR_ERR(trans);
4795 goto fail;
4798 btrfs_inc_nlink(inode);
4799 inode->i_ctime = CURRENT_TIME;
4800 ihold(inode);
4802 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
4804 if (err) {
4805 drop_inode = 1;
4806 } else {
4807 struct dentry *parent = dentry->d_parent;
4808 err = btrfs_update_inode(trans, root, inode);
4809 BUG_ON(err);
4810 d_instantiate(dentry, inode);
4811 btrfs_log_new_name(trans, inode, NULL, parent);
4814 nr = trans->blocks_used;
4815 btrfs_end_transaction(trans, root);
4816 fail:
4817 if (drop_inode) {
4818 inode_dec_link_count(inode);
4819 iput(inode);
4821 btrfs_btree_balance_dirty(root, nr);
4822 return err;
4825 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
4827 struct inode *inode = NULL;
4828 struct btrfs_trans_handle *trans;
4829 struct btrfs_root *root = BTRFS_I(dir)->root;
4830 int err = 0;
4831 int drop_on_err = 0;
4832 u64 objectid = 0;
4833 u64 index = 0;
4834 unsigned long nr = 1;
4837 * 2 items for inode and ref
4838 * 2 items for dir items
4839 * 1 for xattr if selinux is on
4841 trans = btrfs_start_transaction(root, 5);
4842 if (IS_ERR(trans))
4843 return PTR_ERR(trans);
4845 err = btrfs_find_free_ino(root, &objectid);
4846 if (err)
4847 goto out_fail;
4849 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
4850 dentry->d_name.len, btrfs_ino(dir), objectid,
4851 S_IFDIR | mode, &index);
4852 if (IS_ERR(inode)) {
4853 err = PTR_ERR(inode);
4854 goto out_fail;
4857 drop_on_err = 1;
4859 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
4860 if (err)
4861 goto out_fail;
4863 inode->i_op = &btrfs_dir_inode_operations;
4864 inode->i_fop = &btrfs_dir_file_operations;
4866 btrfs_i_size_write(inode, 0);
4867 err = btrfs_update_inode(trans, root, inode);
4868 if (err)
4869 goto out_fail;
4871 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
4872 dentry->d_name.len, 0, index);
4873 if (err)
4874 goto out_fail;
4876 d_instantiate(dentry, inode);
4877 drop_on_err = 0;
4879 out_fail:
4880 nr = trans->blocks_used;
4881 btrfs_end_transaction(trans, root);
4882 if (drop_on_err)
4883 iput(inode);
4884 btrfs_btree_balance_dirty(root, nr);
4885 return err;
4888 /* helper for btfs_get_extent. Given an existing extent in the tree,
4889 * and an extent that you want to insert, deal with overlap and insert
4890 * the new extent into the tree.
4892 static int merge_extent_mapping(struct extent_map_tree *em_tree,
4893 struct extent_map *existing,
4894 struct extent_map *em,
4895 u64 map_start, u64 map_len)
4897 u64 start_diff;
4899 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
4900 start_diff = map_start - em->start;
4901 em->start = map_start;
4902 em->len = map_len;
4903 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
4904 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
4905 em->block_start += start_diff;
4906 em->block_len -= start_diff;
4908 return add_extent_mapping(em_tree, em);
4911 static noinline int uncompress_inline(struct btrfs_path *path,
4912 struct inode *inode, struct page *page,
4913 size_t pg_offset, u64 extent_offset,
4914 struct btrfs_file_extent_item *item)
4916 int ret;
4917 struct extent_buffer *leaf = path->nodes[0];
4918 char *tmp;
4919 size_t max_size;
4920 unsigned long inline_size;
4921 unsigned long ptr;
4922 int compress_type;
4924 WARN_ON(pg_offset != 0);
4925 compress_type = btrfs_file_extent_compression(leaf, item);
4926 max_size = btrfs_file_extent_ram_bytes(leaf, item);
4927 inline_size = btrfs_file_extent_inline_item_len(leaf,
4928 btrfs_item_nr(leaf, path->slots[0]));
4929 tmp = kmalloc(inline_size, GFP_NOFS);
4930 if (!tmp)
4931 return -ENOMEM;
4932 ptr = btrfs_file_extent_inline_start(item);
4934 read_extent_buffer(leaf, tmp, ptr, inline_size);
4936 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
4937 ret = btrfs_decompress(compress_type, tmp, page,
4938 extent_offset, inline_size, max_size);
4939 if (ret) {
4940 char *kaddr = kmap_atomic(page, KM_USER0);
4941 unsigned long copy_size = min_t(u64,
4942 PAGE_CACHE_SIZE - pg_offset,
4943 max_size - extent_offset);
4944 memset(kaddr + pg_offset, 0, copy_size);
4945 kunmap_atomic(kaddr, KM_USER0);
4947 kfree(tmp);
4948 return 0;
4952 * a bit scary, this does extent mapping from logical file offset to the disk.
4953 * the ugly parts come from merging extents from the disk with the in-ram
4954 * representation. This gets more complex because of the data=ordered code,
4955 * where the in-ram extents might be locked pending data=ordered completion.
4957 * This also copies inline extents directly into the page.
4960 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
4961 size_t pg_offset, u64 start, u64 len,
4962 int create)
4964 int ret;
4965 int err = 0;
4966 u64 bytenr;
4967 u64 extent_start = 0;
4968 u64 extent_end = 0;
4969 u64 objectid = btrfs_ino(inode);
4970 u32 found_type;
4971 struct btrfs_path *path = NULL;
4972 struct btrfs_root *root = BTRFS_I(inode)->root;
4973 struct btrfs_file_extent_item *item;
4974 struct extent_buffer *leaf;
4975 struct btrfs_key found_key;
4976 struct extent_map *em = NULL;
4977 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4978 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4979 struct btrfs_trans_handle *trans = NULL;
4980 int compress_type;
4982 again:
4983 read_lock(&em_tree->lock);
4984 em = lookup_extent_mapping(em_tree, start, len);
4985 if (em)
4986 em->bdev = root->fs_info->fs_devices->latest_bdev;
4987 read_unlock(&em_tree->lock);
4989 if (em) {
4990 if (em->start > start || em->start + em->len <= start)
4991 free_extent_map(em);
4992 else if (em->block_start == EXTENT_MAP_INLINE && page)
4993 free_extent_map(em);
4994 else
4995 goto out;
4997 em = alloc_extent_map();
4998 if (!em) {
4999 err = -ENOMEM;
5000 goto out;
5002 em->bdev = root->fs_info->fs_devices->latest_bdev;
5003 em->start = EXTENT_MAP_HOLE;
5004 em->orig_start = EXTENT_MAP_HOLE;
5005 em->len = (u64)-1;
5006 em->block_len = (u64)-1;
5008 if (!path) {
5009 path = btrfs_alloc_path();
5010 if (!path) {
5011 err = -ENOMEM;
5012 goto out;
5015 * Chances are we'll be called again, so go ahead and do
5016 * readahead
5018 path->reada = 1;
5021 ret = btrfs_lookup_file_extent(trans, root, path,
5022 objectid, start, trans != NULL);
5023 if (ret < 0) {
5024 err = ret;
5025 goto out;
5028 if (ret != 0) {
5029 if (path->slots[0] == 0)
5030 goto not_found;
5031 path->slots[0]--;
5034 leaf = path->nodes[0];
5035 item = btrfs_item_ptr(leaf, path->slots[0],
5036 struct btrfs_file_extent_item);
5037 /* are we inside the extent that was found? */
5038 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5039 found_type = btrfs_key_type(&found_key);
5040 if (found_key.objectid != objectid ||
5041 found_type != BTRFS_EXTENT_DATA_KEY) {
5042 goto not_found;
5045 found_type = btrfs_file_extent_type(leaf, item);
5046 extent_start = found_key.offset;
5047 compress_type = btrfs_file_extent_compression(leaf, item);
5048 if (found_type == BTRFS_FILE_EXTENT_REG ||
5049 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
5050 extent_end = extent_start +
5051 btrfs_file_extent_num_bytes(leaf, item);
5052 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
5053 size_t size;
5054 size = btrfs_file_extent_inline_len(leaf, item);
5055 extent_end = (extent_start + size + root->sectorsize - 1) &
5056 ~((u64)root->sectorsize - 1);
5059 if (start >= extent_end) {
5060 path->slots[0]++;
5061 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
5062 ret = btrfs_next_leaf(root, path);
5063 if (ret < 0) {
5064 err = ret;
5065 goto out;
5067 if (ret > 0)
5068 goto not_found;
5069 leaf = path->nodes[0];
5071 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5072 if (found_key.objectid != objectid ||
5073 found_key.type != BTRFS_EXTENT_DATA_KEY)
5074 goto not_found;
5075 if (start + len <= found_key.offset)
5076 goto not_found;
5077 em->start = start;
5078 em->len = found_key.offset - start;
5079 goto not_found_em;
5082 if (found_type == BTRFS_FILE_EXTENT_REG ||
5083 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
5084 em->start = extent_start;
5085 em->len = extent_end - extent_start;
5086 em->orig_start = extent_start -
5087 btrfs_file_extent_offset(leaf, item);
5088 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
5089 if (bytenr == 0) {
5090 em->block_start = EXTENT_MAP_HOLE;
5091 goto insert;
5093 if (compress_type != BTRFS_COMPRESS_NONE) {
5094 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
5095 em->compress_type = compress_type;
5096 em->block_start = bytenr;
5097 em->block_len = btrfs_file_extent_disk_num_bytes(leaf,
5098 item);
5099 } else {
5100 bytenr += btrfs_file_extent_offset(leaf, item);
5101 em->block_start = bytenr;
5102 em->block_len = em->len;
5103 if (found_type == BTRFS_FILE_EXTENT_PREALLOC)
5104 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
5106 goto insert;
5107 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
5108 unsigned long ptr;
5109 char *map;
5110 size_t size;
5111 size_t extent_offset;
5112 size_t copy_size;
5114 em->block_start = EXTENT_MAP_INLINE;
5115 if (!page || create) {
5116 em->start = extent_start;
5117 em->len = extent_end - extent_start;
5118 goto out;
5121 size = btrfs_file_extent_inline_len(leaf, item);
5122 extent_offset = page_offset(page) + pg_offset - extent_start;
5123 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
5124 size - extent_offset);
5125 em->start = extent_start + extent_offset;
5126 em->len = (copy_size + root->sectorsize - 1) &
5127 ~((u64)root->sectorsize - 1);
5128 em->orig_start = EXTENT_MAP_INLINE;
5129 if (compress_type) {
5130 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
5131 em->compress_type = compress_type;
5133 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
5134 if (create == 0 && !PageUptodate(page)) {
5135 if (btrfs_file_extent_compression(leaf, item) !=
5136 BTRFS_COMPRESS_NONE) {
5137 ret = uncompress_inline(path, inode, page,
5138 pg_offset,
5139 extent_offset, item);
5140 BUG_ON(ret);
5141 } else {
5142 map = kmap(page);
5143 read_extent_buffer(leaf, map + pg_offset, ptr,
5144 copy_size);
5145 if (pg_offset + copy_size < PAGE_CACHE_SIZE) {
5146 memset(map + pg_offset + copy_size, 0,
5147 PAGE_CACHE_SIZE - pg_offset -
5148 copy_size);
5150 kunmap(page);
5152 flush_dcache_page(page);
5153 } else if (create && PageUptodate(page)) {
5154 BUG();
5155 if (!trans) {
5156 kunmap(page);
5157 free_extent_map(em);
5158 em = NULL;
5160 btrfs_release_path(path);
5161 trans = btrfs_join_transaction(root);
5163 if (IS_ERR(trans))
5164 return ERR_CAST(trans);
5165 goto again;
5167 map = kmap(page);
5168 write_extent_buffer(leaf, map + pg_offset, ptr,
5169 copy_size);
5170 kunmap(page);
5171 btrfs_mark_buffer_dirty(leaf);
5173 set_extent_uptodate(io_tree, em->start,
5174 extent_map_end(em) - 1, NULL, GFP_NOFS);
5175 goto insert;
5176 } else {
5177 printk(KERN_ERR "btrfs unknown found_type %d\n", found_type);
5178 WARN_ON(1);
5180 not_found:
5181 em->start = start;
5182 em->len = len;
5183 not_found_em:
5184 em->block_start = EXTENT_MAP_HOLE;
5185 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
5186 insert:
5187 btrfs_release_path(path);
5188 if (em->start > start || extent_map_end(em) <= start) {
5189 printk(KERN_ERR "Btrfs: bad extent! em: [%llu %llu] passed "
5190 "[%llu %llu]\n", (unsigned long long)em->start,
5191 (unsigned long long)em->len,
5192 (unsigned long long)start,
5193 (unsigned long long)len);
5194 err = -EIO;
5195 goto out;
5198 err = 0;
5199 write_lock(&em_tree->lock);
5200 ret = add_extent_mapping(em_tree, em);
5201 /* it is possible that someone inserted the extent into the tree
5202 * while we had the lock dropped. It is also possible that
5203 * an overlapping map exists in the tree
5205 if (ret == -EEXIST) {
5206 struct extent_map *existing;
5208 ret = 0;
5210 existing = lookup_extent_mapping(em_tree, start, len);
5211 if (existing && (existing->start > start ||
5212 existing->start + existing->len <= start)) {
5213 free_extent_map(existing);
5214 existing = NULL;
5216 if (!existing) {
5217 existing = lookup_extent_mapping(em_tree, em->start,
5218 em->len);
5219 if (existing) {
5220 err = merge_extent_mapping(em_tree, existing,
5221 em, start,
5222 root->sectorsize);
5223 free_extent_map(existing);
5224 if (err) {
5225 free_extent_map(em);
5226 em = NULL;
5228 } else {
5229 err = -EIO;
5230 free_extent_map(em);
5231 em = NULL;
5233 } else {
5234 free_extent_map(em);
5235 em = existing;
5236 err = 0;
5239 write_unlock(&em_tree->lock);
5240 out:
5242 trace_btrfs_get_extent(root, em);
5244 if (path)
5245 btrfs_free_path(path);
5246 if (trans) {
5247 ret = btrfs_end_transaction(trans, root);
5248 if (!err)
5249 err = ret;
5251 if (err) {
5252 free_extent_map(em);
5253 return ERR_PTR(err);
5255 return em;
5258 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
5259 size_t pg_offset, u64 start, u64 len,
5260 int create)
5262 struct extent_map *em;
5263 struct extent_map *hole_em = NULL;
5264 u64 range_start = start;
5265 u64 end;
5266 u64 found;
5267 u64 found_end;
5268 int err = 0;
5270 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
5271 if (IS_ERR(em))
5272 return em;
5273 if (em) {
5275 * if our em maps to a hole, there might
5276 * actually be delalloc bytes behind it
5278 if (em->block_start != EXTENT_MAP_HOLE)
5279 return em;
5280 else
5281 hole_em = em;
5284 /* check to see if we've wrapped (len == -1 or similar) */
5285 end = start + len;
5286 if (end < start)
5287 end = (u64)-1;
5288 else
5289 end -= 1;
5291 em = NULL;
5293 /* ok, we didn't find anything, lets look for delalloc */
5294 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
5295 end, len, EXTENT_DELALLOC, 1);
5296 found_end = range_start + found;
5297 if (found_end < range_start)
5298 found_end = (u64)-1;
5301 * we didn't find anything useful, return
5302 * the original results from get_extent()
5304 if (range_start > end || found_end <= start) {
5305 em = hole_em;
5306 hole_em = NULL;
5307 goto out;
5310 /* adjust the range_start to make sure it doesn't
5311 * go backwards from the start they passed in
5313 range_start = max(start,range_start);
5314 found = found_end - range_start;
5316 if (found > 0) {
5317 u64 hole_start = start;
5318 u64 hole_len = len;
5320 em = alloc_extent_map();
5321 if (!em) {
5322 err = -ENOMEM;
5323 goto out;
5326 * when btrfs_get_extent can't find anything it
5327 * returns one huge hole
5329 * make sure what it found really fits our range, and
5330 * adjust to make sure it is based on the start from
5331 * the caller
5333 if (hole_em) {
5334 u64 calc_end = extent_map_end(hole_em);
5336 if (calc_end <= start || (hole_em->start > end)) {
5337 free_extent_map(hole_em);
5338 hole_em = NULL;
5339 } else {
5340 hole_start = max(hole_em->start, start);
5341 hole_len = calc_end - hole_start;
5344 em->bdev = NULL;
5345 if (hole_em && range_start > hole_start) {
5346 /* our hole starts before our delalloc, so we
5347 * have to return just the parts of the hole
5348 * that go until the delalloc starts
5350 em->len = min(hole_len,
5351 range_start - hole_start);
5352 em->start = hole_start;
5353 em->orig_start = hole_start;
5355 * don't adjust block start at all,
5356 * it is fixed at EXTENT_MAP_HOLE
5358 em->block_start = hole_em->block_start;
5359 em->block_len = hole_len;
5360 } else {
5361 em->start = range_start;
5362 em->len = found;
5363 em->orig_start = range_start;
5364 em->block_start = EXTENT_MAP_DELALLOC;
5365 em->block_len = found;
5367 } else if (hole_em) {
5368 return hole_em;
5370 out:
5372 free_extent_map(hole_em);
5373 if (err) {
5374 free_extent_map(em);
5375 return ERR_PTR(err);
5377 return em;
5380 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
5381 struct extent_map *em,
5382 u64 start, u64 len)
5384 struct btrfs_root *root = BTRFS_I(inode)->root;
5385 struct btrfs_trans_handle *trans;
5386 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
5387 struct btrfs_key ins;
5388 u64 alloc_hint;
5389 int ret;
5390 bool insert = false;
5393 * Ok if the extent map we looked up is a hole and is for the exact
5394 * range we want, there is no reason to allocate a new one, however if
5395 * it is not right then we need to free this one and drop the cache for
5396 * our range.
5398 if (em->block_start != EXTENT_MAP_HOLE || em->start != start ||
5399 em->len != len) {
5400 free_extent_map(em);
5401 em = NULL;
5402 insert = true;
5403 btrfs_drop_extent_cache(inode, start, start + len - 1, 0);
5406 trans = btrfs_join_transaction(root);
5407 if (IS_ERR(trans))
5408 return ERR_CAST(trans);
5410 if (start <= BTRFS_I(inode)->disk_i_size && len < 64 * 1024)
5411 btrfs_add_inode_defrag(trans, inode);
5413 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
5415 alloc_hint = get_extent_allocation_hint(inode, start, len);
5416 ret = btrfs_reserve_extent(trans, root, len, root->sectorsize, 0,
5417 alloc_hint, (u64)-1, &ins, 1);
5418 if (ret) {
5419 em = ERR_PTR(ret);
5420 goto out;
5423 if (!em) {
5424 em = alloc_extent_map();
5425 if (!em) {
5426 em = ERR_PTR(-ENOMEM);
5427 goto out;
5431 em->start = start;
5432 em->orig_start = em->start;
5433 em->len = ins.offset;
5435 em->block_start = ins.objectid;
5436 em->block_len = ins.offset;
5437 em->bdev = root->fs_info->fs_devices->latest_bdev;
5440 * We need to do this because if we're using the original em we searched
5441 * for, we could have EXTENT_FLAG_VACANCY set, and we don't want that.
5443 em->flags = 0;
5444 set_bit(EXTENT_FLAG_PINNED, &em->flags);
5446 while (insert) {
5447 write_lock(&em_tree->lock);
5448 ret = add_extent_mapping(em_tree, em);
5449 write_unlock(&em_tree->lock);
5450 if (ret != -EEXIST)
5451 break;
5452 btrfs_drop_extent_cache(inode, start, start + em->len - 1, 0);
5455 ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
5456 ins.offset, ins.offset, 0);
5457 if (ret) {
5458 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
5459 em = ERR_PTR(ret);
5461 out:
5462 btrfs_end_transaction(trans, root);
5463 return em;
5467 * returns 1 when the nocow is safe, < 1 on error, 0 if the
5468 * block must be cow'd
5470 static noinline int can_nocow_odirect(struct btrfs_trans_handle *trans,
5471 struct inode *inode, u64 offset, u64 len)
5473 struct btrfs_path *path;
5474 int ret;
5475 struct extent_buffer *leaf;
5476 struct btrfs_root *root = BTRFS_I(inode)->root;
5477 struct btrfs_file_extent_item *fi;
5478 struct btrfs_key key;
5479 u64 disk_bytenr;
5480 u64 backref_offset;
5481 u64 extent_end;
5482 u64 num_bytes;
5483 int slot;
5484 int found_type;
5486 path = btrfs_alloc_path();
5487 if (!path)
5488 return -ENOMEM;
5490 ret = btrfs_lookup_file_extent(trans, root, path, btrfs_ino(inode),
5491 offset, 0);
5492 if (ret < 0)
5493 goto out;
5495 slot = path->slots[0];
5496 if (ret == 1) {
5497 if (slot == 0) {
5498 /* can't find the item, must cow */
5499 ret = 0;
5500 goto out;
5502 slot--;
5504 ret = 0;
5505 leaf = path->nodes[0];
5506 btrfs_item_key_to_cpu(leaf, &key, slot);
5507 if (key.objectid != btrfs_ino(inode) ||
5508 key.type != BTRFS_EXTENT_DATA_KEY) {
5509 /* not our file or wrong item type, must cow */
5510 goto out;
5513 if (key.offset > offset) {
5514 /* Wrong offset, must cow */
5515 goto out;
5518 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
5519 found_type = btrfs_file_extent_type(leaf, fi);
5520 if (found_type != BTRFS_FILE_EXTENT_REG &&
5521 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
5522 /* not a regular extent, must cow */
5523 goto out;
5525 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
5526 backref_offset = btrfs_file_extent_offset(leaf, fi);
5528 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
5529 if (extent_end < offset + len) {
5530 /* extent doesn't include our full range, must cow */
5531 goto out;
5534 if (btrfs_extent_readonly(root, disk_bytenr))
5535 goto out;
5538 * look for other files referencing this extent, if we
5539 * find any we must cow
5541 if (btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
5542 key.offset - backref_offset, disk_bytenr))
5543 goto out;
5546 * adjust disk_bytenr and num_bytes to cover just the bytes
5547 * in this extent we are about to write. If there
5548 * are any csums in that range we have to cow in order
5549 * to keep the csums correct
5551 disk_bytenr += backref_offset;
5552 disk_bytenr += offset - key.offset;
5553 num_bytes = min(offset + len, extent_end) - offset;
5554 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
5555 goto out;
5557 * all of the above have passed, it is safe to overwrite this extent
5558 * without cow
5560 ret = 1;
5561 out:
5562 btrfs_free_path(path);
5563 return ret;
5566 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
5567 struct buffer_head *bh_result, int create)
5569 struct extent_map *em;
5570 struct btrfs_root *root = BTRFS_I(inode)->root;
5571 u64 start = iblock << inode->i_blkbits;
5572 u64 len = bh_result->b_size;
5573 struct btrfs_trans_handle *trans;
5575 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
5576 if (IS_ERR(em))
5577 return PTR_ERR(em);
5580 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
5581 * io. INLINE is special, and we could probably kludge it in here, but
5582 * it's still buffered so for safety lets just fall back to the generic
5583 * buffered path.
5585 * For COMPRESSED we _have_ to read the entire extent in so we can
5586 * decompress it, so there will be buffering required no matter what we
5587 * do, so go ahead and fallback to buffered.
5589 * We return -ENOTBLK because thats what makes DIO go ahead and go back
5590 * to buffered IO. Don't blame me, this is the price we pay for using
5591 * the generic code.
5593 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
5594 em->block_start == EXTENT_MAP_INLINE) {
5595 free_extent_map(em);
5596 return -ENOTBLK;
5599 /* Just a good old fashioned hole, return */
5600 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
5601 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
5602 free_extent_map(em);
5603 /* DIO will do one hole at a time, so just unlock a sector */
5604 unlock_extent(&BTRFS_I(inode)->io_tree, start,
5605 start + root->sectorsize - 1, GFP_NOFS);
5606 return 0;
5610 * We don't allocate a new extent in the following cases
5612 * 1) The inode is marked as NODATACOW. In this case we'll just use the
5613 * existing extent.
5614 * 2) The extent is marked as PREALLOC. We're good to go here and can
5615 * just use the extent.
5618 if (!create) {
5619 len = em->len - (start - em->start);
5620 goto map;
5623 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
5624 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
5625 em->block_start != EXTENT_MAP_HOLE)) {
5626 int type;
5627 int ret;
5628 u64 block_start;
5630 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
5631 type = BTRFS_ORDERED_PREALLOC;
5632 else
5633 type = BTRFS_ORDERED_NOCOW;
5634 len = min(len, em->len - (start - em->start));
5635 block_start = em->block_start + (start - em->start);
5638 * we're not going to log anything, but we do need
5639 * to make sure the current transaction stays open
5640 * while we look for nocow cross refs
5642 trans = btrfs_join_transaction(root);
5643 if (IS_ERR(trans))
5644 goto must_cow;
5646 if (can_nocow_odirect(trans, inode, start, len) == 1) {
5647 ret = btrfs_add_ordered_extent_dio(inode, start,
5648 block_start, len, len, type);
5649 btrfs_end_transaction(trans, root);
5650 if (ret) {
5651 free_extent_map(em);
5652 return ret;
5654 goto unlock;
5656 btrfs_end_transaction(trans, root);
5658 must_cow:
5660 * this will cow the extent, reset the len in case we changed
5661 * it above
5663 len = bh_result->b_size;
5664 em = btrfs_new_extent_direct(inode, em, start, len);
5665 if (IS_ERR(em))
5666 return PTR_ERR(em);
5667 len = min(len, em->len - (start - em->start));
5668 unlock:
5669 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, start + len - 1,
5670 EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DIRTY, 1,
5671 0, NULL, GFP_NOFS);
5672 map:
5673 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
5674 inode->i_blkbits;
5675 bh_result->b_size = len;
5676 bh_result->b_bdev = em->bdev;
5677 set_buffer_mapped(bh_result);
5678 if (create && !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
5679 set_buffer_new(bh_result);
5681 free_extent_map(em);
5683 return 0;
5686 struct btrfs_dio_private {
5687 struct inode *inode;
5688 u64 logical_offset;
5689 u64 disk_bytenr;
5690 u64 bytes;
5691 u32 *csums;
5692 void *private;
5694 /* number of bios pending for this dio */
5695 atomic_t pending_bios;
5697 /* IO errors */
5698 int errors;
5700 struct bio *orig_bio;
5703 static void btrfs_endio_direct_read(struct bio *bio, int err)
5705 struct btrfs_dio_private *dip = bio->bi_private;
5706 struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
5707 struct bio_vec *bvec = bio->bi_io_vec;
5708 struct inode *inode = dip->inode;
5709 struct btrfs_root *root = BTRFS_I(inode)->root;
5710 u64 start;
5711 u32 *private = dip->csums;
5713 start = dip->logical_offset;
5714 do {
5715 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
5716 struct page *page = bvec->bv_page;
5717 char *kaddr;
5718 u32 csum = ~(u32)0;
5719 unsigned long flags;
5721 local_irq_save(flags);
5722 kaddr = kmap_atomic(page, KM_IRQ0);
5723 csum = btrfs_csum_data(root, kaddr + bvec->bv_offset,
5724 csum, bvec->bv_len);
5725 btrfs_csum_final(csum, (char *)&csum);
5726 kunmap_atomic(kaddr, KM_IRQ0);
5727 local_irq_restore(flags);
5729 flush_dcache_page(bvec->bv_page);
5730 if (csum != *private) {
5731 printk(KERN_ERR "btrfs csum failed ino %llu off"
5732 " %llu csum %u private %u\n",
5733 (unsigned long long)btrfs_ino(inode),
5734 (unsigned long long)start,
5735 csum, *private);
5736 err = -EIO;
5740 start += bvec->bv_len;
5741 private++;
5742 bvec++;
5743 } while (bvec <= bvec_end);
5745 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
5746 dip->logical_offset + dip->bytes - 1, GFP_NOFS);
5747 bio->bi_private = dip->private;
5749 kfree(dip->csums);
5750 kfree(dip);
5752 /* If we had a csum failure make sure to clear the uptodate flag */
5753 if (err)
5754 clear_bit(BIO_UPTODATE, &bio->bi_flags);
5755 dio_end_io(bio, err);
5758 static void btrfs_endio_direct_write(struct bio *bio, int err)
5760 struct btrfs_dio_private *dip = bio->bi_private;
5761 struct inode *inode = dip->inode;
5762 struct btrfs_root *root = BTRFS_I(inode)->root;
5763 struct btrfs_trans_handle *trans;
5764 struct btrfs_ordered_extent *ordered = NULL;
5765 struct extent_state *cached_state = NULL;
5766 u64 ordered_offset = dip->logical_offset;
5767 u64 ordered_bytes = dip->bytes;
5768 int ret;
5770 if (err)
5771 goto out_done;
5772 again:
5773 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
5774 &ordered_offset,
5775 ordered_bytes);
5776 if (!ret)
5777 goto out_test;
5779 BUG_ON(!ordered);
5781 trans = btrfs_join_transaction(root);
5782 if (IS_ERR(trans)) {
5783 err = -ENOMEM;
5784 goto out;
5786 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
5788 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags)) {
5789 ret = btrfs_ordered_update_i_size(inode, 0, ordered);
5790 if (!ret)
5791 err = btrfs_update_inode_fallback(trans, root, inode);
5792 goto out;
5795 lock_extent_bits(&BTRFS_I(inode)->io_tree, ordered->file_offset,
5796 ordered->file_offset + ordered->len - 1, 0,
5797 &cached_state, GFP_NOFS);
5799 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags)) {
5800 ret = btrfs_mark_extent_written(trans, inode,
5801 ordered->file_offset,
5802 ordered->file_offset +
5803 ordered->len);
5804 if (ret) {
5805 err = ret;
5806 goto out_unlock;
5808 } else {
5809 ret = insert_reserved_file_extent(trans, inode,
5810 ordered->file_offset,
5811 ordered->start,
5812 ordered->disk_len,
5813 ordered->len,
5814 ordered->len,
5815 0, 0, 0,
5816 BTRFS_FILE_EXTENT_REG);
5817 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
5818 ordered->file_offset, ordered->len);
5819 if (ret) {
5820 err = ret;
5821 WARN_ON(1);
5822 goto out_unlock;
5826 add_pending_csums(trans, inode, ordered->file_offset, &ordered->list);
5827 ret = btrfs_ordered_update_i_size(inode, 0, ordered);
5828 if (!ret || !test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags))
5829 btrfs_update_inode_fallback(trans, root, inode);
5830 ret = 0;
5831 out_unlock:
5832 unlock_extent_cached(&BTRFS_I(inode)->io_tree, ordered->file_offset,
5833 ordered->file_offset + ordered->len - 1,
5834 &cached_state, GFP_NOFS);
5835 out:
5836 btrfs_delalloc_release_metadata(inode, ordered->len);
5837 btrfs_end_transaction(trans, root);
5838 ordered_offset = ordered->file_offset + ordered->len;
5839 btrfs_put_ordered_extent(ordered);
5840 btrfs_put_ordered_extent(ordered);
5842 out_test:
5844 * our bio might span multiple ordered extents. If we haven't
5845 * completed the accounting for the whole dio, go back and try again
5847 if (ordered_offset < dip->logical_offset + dip->bytes) {
5848 ordered_bytes = dip->logical_offset + dip->bytes -
5849 ordered_offset;
5850 goto again;
5852 out_done:
5853 bio->bi_private = dip->private;
5855 kfree(dip->csums);
5856 kfree(dip);
5858 /* If we had an error make sure to clear the uptodate flag */
5859 if (err)
5860 clear_bit(BIO_UPTODATE, &bio->bi_flags);
5861 dio_end_io(bio, err);
5864 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
5865 struct bio *bio, int mirror_num,
5866 unsigned long bio_flags, u64 offset)
5868 int ret;
5869 struct btrfs_root *root = BTRFS_I(inode)->root;
5870 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
5871 BUG_ON(ret);
5872 return 0;
5875 static void btrfs_end_dio_bio(struct bio *bio, int err)
5877 struct btrfs_dio_private *dip = bio->bi_private;
5879 if (err) {
5880 printk(KERN_ERR "btrfs direct IO failed ino %llu rw %lu "
5881 "sector %#Lx len %u err no %d\n",
5882 (unsigned long long)btrfs_ino(dip->inode), bio->bi_rw,
5883 (unsigned long long)bio->bi_sector, bio->bi_size, err);
5884 dip->errors = 1;
5887 * before atomic variable goto zero, we must make sure
5888 * dip->errors is perceived to be set.
5890 smp_mb__before_atomic_dec();
5893 /* if there are more bios still pending for this dio, just exit */
5894 if (!atomic_dec_and_test(&dip->pending_bios))
5895 goto out;
5897 if (dip->errors)
5898 bio_io_error(dip->orig_bio);
5899 else {
5900 set_bit(BIO_UPTODATE, &dip->orig_bio->bi_flags);
5901 bio_endio(dip->orig_bio, 0);
5903 out:
5904 bio_put(bio);
5907 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
5908 u64 first_sector, gfp_t gfp_flags)
5910 int nr_vecs = bio_get_nr_vecs(bdev);
5911 return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags);
5914 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
5915 int rw, u64 file_offset, int skip_sum,
5916 u32 *csums, int async_submit)
5918 int write = rw & REQ_WRITE;
5919 struct btrfs_root *root = BTRFS_I(inode)->root;
5920 int ret;
5922 bio_get(bio);
5923 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
5924 if (ret)
5925 goto err;
5927 if (skip_sum)
5928 goto map;
5930 if (write && async_submit) {
5931 ret = btrfs_wq_submit_bio(root->fs_info,
5932 inode, rw, bio, 0, 0,
5933 file_offset,
5934 __btrfs_submit_bio_start_direct_io,
5935 __btrfs_submit_bio_done);
5936 goto err;
5937 } else if (write) {
5939 * If we aren't doing async submit, calculate the csum of the
5940 * bio now.
5942 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
5943 if (ret)
5944 goto err;
5945 } else if (!skip_sum) {
5946 ret = btrfs_lookup_bio_sums_dio(root, inode, bio,
5947 file_offset, csums);
5948 if (ret)
5949 goto err;
5952 map:
5953 ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
5954 err:
5955 bio_put(bio);
5956 return ret;
5959 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
5960 int skip_sum)
5962 struct inode *inode = dip->inode;
5963 struct btrfs_root *root = BTRFS_I(inode)->root;
5964 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
5965 struct bio *bio;
5966 struct bio *orig_bio = dip->orig_bio;
5967 struct bio_vec *bvec = orig_bio->bi_io_vec;
5968 u64 start_sector = orig_bio->bi_sector;
5969 u64 file_offset = dip->logical_offset;
5970 u64 submit_len = 0;
5971 u64 map_length;
5972 int nr_pages = 0;
5973 u32 *csums = dip->csums;
5974 int ret = 0;
5975 int async_submit = 0;
5976 int write = rw & REQ_WRITE;
5978 map_length = orig_bio->bi_size;
5979 ret = btrfs_map_block(map_tree, READ, start_sector << 9,
5980 &map_length, NULL, 0);
5981 if (ret) {
5982 bio_put(orig_bio);
5983 return -EIO;
5986 if (map_length >= orig_bio->bi_size) {
5987 bio = orig_bio;
5988 goto submit;
5991 async_submit = 1;
5992 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
5993 if (!bio)
5994 return -ENOMEM;
5995 bio->bi_private = dip;
5996 bio->bi_end_io = btrfs_end_dio_bio;
5997 atomic_inc(&dip->pending_bios);
5999 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
6000 if (unlikely(map_length < submit_len + bvec->bv_len ||
6001 bio_add_page(bio, bvec->bv_page, bvec->bv_len,
6002 bvec->bv_offset) < bvec->bv_len)) {
6004 * inc the count before we submit the bio so
6005 * we know the end IO handler won't happen before
6006 * we inc the count. Otherwise, the dip might get freed
6007 * before we're done setting it up
6009 atomic_inc(&dip->pending_bios);
6010 ret = __btrfs_submit_dio_bio(bio, inode, rw,
6011 file_offset, skip_sum,
6012 csums, async_submit);
6013 if (ret) {
6014 bio_put(bio);
6015 atomic_dec(&dip->pending_bios);
6016 goto out_err;
6019 /* Write's use the ordered csums */
6020 if (!write && !skip_sum)
6021 csums = csums + nr_pages;
6022 start_sector += submit_len >> 9;
6023 file_offset += submit_len;
6025 submit_len = 0;
6026 nr_pages = 0;
6028 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
6029 start_sector, GFP_NOFS);
6030 if (!bio)
6031 goto out_err;
6032 bio->bi_private = dip;
6033 bio->bi_end_io = btrfs_end_dio_bio;
6035 map_length = orig_bio->bi_size;
6036 ret = btrfs_map_block(map_tree, READ, start_sector << 9,
6037 &map_length, NULL, 0);
6038 if (ret) {
6039 bio_put(bio);
6040 goto out_err;
6042 } else {
6043 submit_len += bvec->bv_len;
6044 nr_pages ++;
6045 bvec++;
6049 submit:
6050 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
6051 csums, async_submit);
6052 if (!ret)
6053 return 0;
6055 bio_put(bio);
6056 out_err:
6057 dip->errors = 1;
6059 * before atomic variable goto zero, we must
6060 * make sure dip->errors is perceived to be set.
6062 smp_mb__before_atomic_dec();
6063 if (atomic_dec_and_test(&dip->pending_bios))
6064 bio_io_error(dip->orig_bio);
6066 /* bio_end_io() will handle error, so we needn't return it */
6067 return 0;
6070 static void btrfs_submit_direct(int rw, struct bio *bio, struct inode *inode,
6071 loff_t file_offset)
6073 struct btrfs_root *root = BTRFS_I(inode)->root;
6074 struct btrfs_dio_private *dip;
6075 struct bio_vec *bvec = bio->bi_io_vec;
6076 int skip_sum;
6077 int write = rw & REQ_WRITE;
6078 int ret = 0;
6080 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
6082 dip = kmalloc(sizeof(*dip), GFP_NOFS);
6083 if (!dip) {
6084 ret = -ENOMEM;
6085 goto free_ordered;
6087 dip->csums = NULL;
6089 /* Write's use the ordered csum stuff, so we don't need dip->csums */
6090 if (!write && !skip_sum) {
6091 dip->csums = kmalloc(sizeof(u32) * bio->bi_vcnt, GFP_NOFS);
6092 if (!dip->csums) {
6093 kfree(dip);
6094 ret = -ENOMEM;
6095 goto free_ordered;
6099 dip->private = bio->bi_private;
6100 dip->inode = inode;
6101 dip->logical_offset = file_offset;
6103 dip->bytes = 0;
6104 do {
6105 dip->bytes += bvec->bv_len;
6106 bvec++;
6107 } while (bvec <= (bio->bi_io_vec + bio->bi_vcnt - 1));
6109 dip->disk_bytenr = (u64)bio->bi_sector << 9;
6110 bio->bi_private = dip;
6111 dip->errors = 0;
6112 dip->orig_bio = bio;
6113 atomic_set(&dip->pending_bios, 0);
6115 if (write)
6116 bio->bi_end_io = btrfs_endio_direct_write;
6117 else
6118 bio->bi_end_io = btrfs_endio_direct_read;
6120 ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
6121 if (!ret)
6122 return;
6123 free_ordered:
6125 * If this is a write, we need to clean up the reserved space and kill
6126 * the ordered extent.
6128 if (write) {
6129 struct btrfs_ordered_extent *ordered;
6130 ordered = btrfs_lookup_ordered_extent(inode, file_offset);
6131 if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) &&
6132 !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
6133 btrfs_free_reserved_extent(root, ordered->start,
6134 ordered->disk_len);
6135 btrfs_put_ordered_extent(ordered);
6136 btrfs_put_ordered_extent(ordered);
6138 bio_endio(bio, ret);
6141 static ssize_t check_direct_IO(struct btrfs_root *root, int rw, struct kiocb *iocb,
6142 const struct iovec *iov, loff_t offset,
6143 unsigned long nr_segs)
6145 int seg;
6146 int i;
6147 size_t size;
6148 unsigned long addr;
6149 unsigned blocksize_mask = root->sectorsize - 1;
6150 ssize_t retval = -EINVAL;
6151 loff_t end = offset;
6153 if (offset & blocksize_mask)
6154 goto out;
6156 /* Check the memory alignment. Blocks cannot straddle pages */
6157 for (seg = 0; seg < nr_segs; seg++) {
6158 addr = (unsigned long)iov[seg].iov_base;
6159 size = iov[seg].iov_len;
6160 end += size;
6161 if ((addr & blocksize_mask) || (size & blocksize_mask))
6162 goto out;
6164 /* If this is a write we don't need to check anymore */
6165 if (rw & WRITE)
6166 continue;
6169 * Check to make sure we don't have duplicate iov_base's in this
6170 * iovec, if so return EINVAL, otherwise we'll get csum errors
6171 * when reading back.
6173 for (i = seg + 1; i < nr_segs; i++) {
6174 if (iov[seg].iov_base == iov[i].iov_base)
6175 goto out;
6178 retval = 0;
6179 out:
6180 return retval;
6182 static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
6183 const struct iovec *iov, loff_t offset,
6184 unsigned long nr_segs)
6186 struct file *file = iocb->ki_filp;
6187 struct inode *inode = file->f_mapping->host;
6188 struct btrfs_ordered_extent *ordered;
6189 struct extent_state *cached_state = NULL;
6190 u64 lockstart, lockend;
6191 ssize_t ret;
6192 int writing = rw & WRITE;
6193 int write_bits = 0;
6194 size_t count = iov_length(iov, nr_segs);
6196 if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iov,
6197 offset, nr_segs)) {
6198 return 0;
6201 lockstart = offset;
6202 lockend = offset + count - 1;
6204 if (writing) {
6205 ret = btrfs_delalloc_reserve_space(inode, count);
6206 if (ret)
6207 goto out;
6210 while (1) {
6211 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6212 0, &cached_state, GFP_NOFS);
6214 * We're concerned with the entire range that we're going to be
6215 * doing DIO to, so we need to make sure theres no ordered
6216 * extents in this range.
6218 ordered = btrfs_lookup_ordered_range(inode, lockstart,
6219 lockend - lockstart + 1);
6220 if (!ordered)
6221 break;
6222 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6223 &cached_state, GFP_NOFS);
6224 btrfs_start_ordered_extent(inode, ordered, 1);
6225 btrfs_put_ordered_extent(ordered);
6226 cond_resched();
6230 * we don't use btrfs_set_extent_delalloc because we don't want
6231 * the dirty or uptodate bits
6233 if (writing) {
6234 write_bits = EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING;
6235 ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6236 EXTENT_DELALLOC, 0, NULL, &cached_state,
6237 GFP_NOFS);
6238 if (ret) {
6239 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
6240 lockend, EXTENT_LOCKED | write_bits,
6241 1, 0, &cached_state, GFP_NOFS);
6242 goto out;
6246 free_extent_state(cached_state);
6247 cached_state = NULL;
6249 ret = __blockdev_direct_IO(rw, iocb, inode,
6250 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
6251 iov, offset, nr_segs, btrfs_get_blocks_direct, NULL,
6252 btrfs_submit_direct, 0);
6254 if (ret < 0 && ret != -EIOCBQUEUED) {
6255 clear_extent_bit(&BTRFS_I(inode)->io_tree, offset,
6256 offset + iov_length(iov, nr_segs) - 1,
6257 EXTENT_LOCKED | write_bits, 1, 0,
6258 &cached_state, GFP_NOFS);
6259 } else if (ret >= 0 && ret < iov_length(iov, nr_segs)) {
6261 * We're falling back to buffered, unlock the section we didn't
6262 * do IO on.
6264 clear_extent_bit(&BTRFS_I(inode)->io_tree, offset + ret,
6265 offset + iov_length(iov, nr_segs) - 1,
6266 EXTENT_LOCKED | write_bits, 1, 0,
6267 &cached_state, GFP_NOFS);
6269 out:
6270 free_extent_state(cached_state);
6271 return ret;
6274 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
6275 __u64 start, __u64 len)
6277 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
6280 int btrfs_readpage(struct file *file, struct page *page)
6282 struct extent_io_tree *tree;
6283 tree = &BTRFS_I(page->mapping->host)->io_tree;
6284 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
6287 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
6289 struct extent_io_tree *tree;
6292 if (current->flags & PF_MEMALLOC) {
6293 redirty_page_for_writepage(wbc, page);
6294 unlock_page(page);
6295 return 0;
6297 tree = &BTRFS_I(page->mapping->host)->io_tree;
6298 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
6301 int btrfs_writepages(struct address_space *mapping,
6302 struct writeback_control *wbc)
6304 struct extent_io_tree *tree;
6306 tree = &BTRFS_I(mapping->host)->io_tree;
6307 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
6310 static int
6311 btrfs_readpages(struct file *file, struct address_space *mapping,
6312 struct list_head *pages, unsigned nr_pages)
6314 struct extent_io_tree *tree;
6315 tree = &BTRFS_I(mapping->host)->io_tree;
6316 return extent_readpages(tree, mapping, pages, nr_pages,
6317 btrfs_get_extent);
6319 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
6321 struct extent_io_tree *tree;
6322 struct extent_map_tree *map;
6323 int ret;
6325 tree = &BTRFS_I(page->mapping->host)->io_tree;
6326 map = &BTRFS_I(page->mapping->host)->extent_tree;
6327 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
6328 if (ret == 1) {
6329 ClearPagePrivate(page);
6330 set_page_private(page, 0);
6331 page_cache_release(page);
6333 return ret;
6336 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
6338 if (PageWriteback(page) || PageDirty(page))
6339 return 0;
6340 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
6343 static void btrfs_invalidatepage(struct page *page, unsigned long offset)
6345 struct extent_io_tree *tree;
6346 struct btrfs_ordered_extent *ordered;
6347 struct extent_state *cached_state = NULL;
6348 u64 page_start = page_offset(page);
6349 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
6353 * we have the page locked, so new writeback can't start,
6354 * and the dirty bit won't be cleared while we are here.
6356 * Wait for IO on this page so that we can safely clear
6357 * the PagePrivate2 bit and do ordered accounting
6359 wait_on_page_writeback(page);
6361 tree = &BTRFS_I(page->mapping->host)->io_tree;
6362 if (offset) {
6363 btrfs_releasepage(page, GFP_NOFS);
6364 return;
6366 lock_extent_bits(tree, page_start, page_end, 0, &cached_state,
6367 GFP_NOFS);
6368 ordered = btrfs_lookup_ordered_extent(page->mapping->host,
6369 page_offset(page));
6370 if (ordered) {
6372 * IO on this page will never be started, so we need
6373 * to account for any ordered extents now
6375 clear_extent_bit(tree, page_start, page_end,
6376 EXTENT_DIRTY | EXTENT_DELALLOC |
6377 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING, 1, 0,
6378 &cached_state, GFP_NOFS);
6380 * whoever cleared the private bit is responsible
6381 * for the finish_ordered_io
6383 if (TestClearPagePrivate2(page)) {
6384 btrfs_finish_ordered_io(page->mapping->host,
6385 page_start, page_end);
6387 btrfs_put_ordered_extent(ordered);
6388 cached_state = NULL;
6389 lock_extent_bits(tree, page_start, page_end, 0, &cached_state,
6390 GFP_NOFS);
6392 clear_extent_bit(tree, page_start, page_end,
6393 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
6394 EXTENT_DO_ACCOUNTING, 1, 1, &cached_state, GFP_NOFS);
6395 __btrfs_releasepage(page, GFP_NOFS);
6397 ClearPageChecked(page);
6398 if (PagePrivate(page)) {
6399 ClearPagePrivate(page);
6400 set_page_private(page, 0);
6401 page_cache_release(page);
6406 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
6407 * called from a page fault handler when a page is first dirtied. Hence we must
6408 * be careful to check for EOF conditions here. We set the page up correctly
6409 * for a written page which means we get ENOSPC checking when writing into
6410 * holes and correct delalloc and unwritten extent mapping on filesystems that
6411 * support these features.
6413 * We are not allowed to take the i_mutex here so we have to play games to
6414 * protect against truncate races as the page could now be beyond EOF. Because
6415 * vmtruncate() writes the inode size before removing pages, once we have the
6416 * page lock we can determine safely if the page is beyond EOF. If it is not
6417 * beyond EOF, then the page is guaranteed safe against truncation until we
6418 * unlock the page.
6420 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
6422 struct page *page = vmf->page;
6423 struct inode *inode = fdentry(vma->vm_file)->d_inode;
6424 struct btrfs_root *root = BTRFS_I(inode)->root;
6425 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6426 struct btrfs_ordered_extent *ordered;
6427 struct extent_state *cached_state = NULL;
6428 char *kaddr;
6429 unsigned long zero_start;
6430 loff_t size;
6431 int ret;
6432 int reserved = 0;
6433 u64 page_start;
6434 u64 page_end;
6436 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
6437 if (!ret) {
6438 ret = btrfs_update_time(vma->vm_file);
6439 reserved = 1;
6441 if (ret) {
6442 if (ret == -ENOMEM)
6443 ret = VM_FAULT_OOM;
6444 else /* -ENOSPC, -EIO, etc */
6445 ret = VM_FAULT_SIGBUS;
6446 if (reserved)
6447 goto out;
6448 goto out_noreserve;
6451 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
6452 again:
6453 lock_page(page);
6454 size = i_size_read(inode);
6455 page_start = page_offset(page);
6456 page_end = page_start + PAGE_CACHE_SIZE - 1;
6458 if ((page->mapping != inode->i_mapping) ||
6459 (page_start >= size)) {
6460 /* page got truncated out from underneath us */
6461 goto out_unlock;
6463 wait_on_page_writeback(page);
6465 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state,
6466 GFP_NOFS);
6467 set_page_extent_mapped(page);
6470 * we can't set the delalloc bits if there are pending ordered
6471 * extents. Drop our locks and wait for them to finish
6473 ordered = btrfs_lookup_ordered_extent(inode, page_start);
6474 if (ordered) {
6475 unlock_extent_cached(io_tree, page_start, page_end,
6476 &cached_state, GFP_NOFS);
6477 unlock_page(page);
6478 btrfs_start_ordered_extent(inode, ordered, 1);
6479 btrfs_put_ordered_extent(ordered);
6480 goto again;
6484 * XXX - page_mkwrite gets called every time the page is dirtied, even
6485 * if it was already dirty, so for space accounting reasons we need to
6486 * clear any delalloc bits for the range we are fixing to save. There
6487 * is probably a better way to do this, but for now keep consistent with
6488 * prepare_pages in the normal write path.
6490 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
6491 EXTENT_DIRTY | EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING,
6492 0, 0, &cached_state, GFP_NOFS);
6494 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
6495 &cached_state);
6496 if (ret) {
6497 unlock_extent_cached(io_tree, page_start, page_end,
6498 &cached_state, GFP_NOFS);
6499 ret = VM_FAULT_SIGBUS;
6500 goto out_unlock;
6502 ret = 0;
6504 /* page is wholly or partially inside EOF */
6505 if (page_start + PAGE_CACHE_SIZE > size)
6506 zero_start = size & ~PAGE_CACHE_MASK;
6507 else
6508 zero_start = PAGE_CACHE_SIZE;
6510 if (zero_start != PAGE_CACHE_SIZE) {
6511 kaddr = kmap(page);
6512 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
6513 flush_dcache_page(page);
6514 kunmap(page);
6516 ClearPageChecked(page);
6517 set_page_dirty(page);
6518 SetPageUptodate(page);
6520 BTRFS_I(inode)->last_trans = root->fs_info->generation;
6521 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
6523 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
6525 out_unlock:
6526 if (!ret)
6527 return VM_FAULT_LOCKED;
6528 unlock_page(page);
6529 out:
6530 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
6531 out_noreserve:
6532 return ret;
6535 static int btrfs_truncate(struct inode *inode)
6537 struct btrfs_root *root = BTRFS_I(inode)->root;
6538 struct btrfs_block_rsv *rsv;
6539 int ret;
6540 int err = 0;
6541 struct btrfs_trans_handle *trans;
6542 unsigned long nr;
6543 u64 mask = root->sectorsize - 1;
6544 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
6546 ret = btrfs_truncate_page(inode->i_mapping, inode->i_size);
6547 if (ret)
6548 return ret;
6550 btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
6551 btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
6554 * Yes ladies and gentelment, this is indeed ugly. The fact is we have
6555 * 3 things going on here
6557 * 1) We need to reserve space for our orphan item and the space to
6558 * delete our orphan item. Lord knows we don't want to have a dangling
6559 * orphan item because we didn't reserve space to remove it.
6561 * 2) We need to reserve space to update our inode.
6563 * 3) We need to have something to cache all the space that is going to
6564 * be free'd up by the truncate operation, but also have some slack
6565 * space reserved in case it uses space during the truncate (thank you
6566 * very much snapshotting).
6568 * And we need these to all be seperate. The fact is we can use alot of
6569 * space doing the truncate, and we have no earthly idea how much space
6570 * we will use, so we need the truncate reservation to be seperate so it
6571 * doesn't end up using space reserved for updating the inode or
6572 * removing the orphan item. We also need to be able to stop the
6573 * transaction and start a new one, which means we need to be able to
6574 * update the inode several times, and we have no idea of knowing how
6575 * many times that will be, so we can't just reserve 1 item for the
6576 * entirety of the opration, so that has to be done seperately as well.
6577 * Then there is the orphan item, which does indeed need to be held on
6578 * to for the whole operation, and we need nobody to touch this reserved
6579 * space except the orphan code.
6581 * So that leaves us with
6583 * 1) root->orphan_block_rsv - for the orphan deletion.
6584 * 2) rsv - for the truncate reservation, which we will steal from the
6585 * transaction reservation.
6586 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
6587 * updating the inode.
6589 rsv = btrfs_alloc_block_rsv(root);
6590 if (!rsv)
6591 return -ENOMEM;
6592 rsv->size = min_size;
6595 * 1 for the truncate slack space
6596 * 1 for the orphan item we're going to add
6597 * 1 for the orphan item deletion
6598 * 1 for updating the inode.
6600 trans = btrfs_start_transaction(root, 4);
6601 if (IS_ERR(trans)) {
6602 err = PTR_ERR(trans);
6603 goto out;
6606 /* Migrate the slack space for the truncate to our reserve */
6607 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
6608 min_size);
6609 BUG_ON(ret);
6611 ret = btrfs_orphan_add(trans, inode);
6612 if (ret) {
6613 btrfs_end_transaction(trans, root);
6614 goto out;
6618 * setattr is responsible for setting the ordered_data_close flag,
6619 * but that is only tested during the last file release. That
6620 * could happen well after the next commit, leaving a great big
6621 * window where new writes may get lost if someone chooses to write
6622 * to this file after truncating to zero
6624 * The inode doesn't have any dirty data here, and so if we commit
6625 * this is a noop. If someone immediately starts writing to the inode
6626 * it is very likely we'll catch some of their writes in this
6627 * transaction, and the commit will find this file on the ordered
6628 * data list with good things to send down.
6630 * This is a best effort solution, there is still a window where
6631 * using truncate to replace the contents of the file will
6632 * end up with a zero length file after a crash.
6634 if (inode->i_size == 0 && BTRFS_I(inode)->ordered_data_close)
6635 btrfs_add_ordered_operation(trans, root, inode);
6637 while (1) {
6638 ret = btrfs_block_rsv_refill(root, rsv, min_size);
6639 if (ret) {
6641 * This can only happen with the original transaction we
6642 * started above, every other time we shouldn't have a
6643 * transaction started yet.
6645 if (ret == -EAGAIN)
6646 goto end_trans;
6647 err = ret;
6648 break;
6651 if (!trans) {
6652 /* Just need the 1 for updating the inode */
6653 trans = btrfs_start_transaction(root, 1);
6654 if (IS_ERR(trans)) {
6655 ret = err = PTR_ERR(trans);
6656 trans = NULL;
6657 break;
6661 trans->block_rsv = rsv;
6663 ret = btrfs_truncate_inode_items(trans, root, inode,
6664 inode->i_size,
6665 BTRFS_EXTENT_DATA_KEY);
6666 if (ret != -EAGAIN) {
6667 err = ret;
6668 break;
6671 trans->block_rsv = &root->fs_info->trans_block_rsv;
6672 ret = btrfs_update_inode(trans, root, inode);
6673 if (ret) {
6674 err = ret;
6675 break;
6677 end_trans:
6678 nr = trans->blocks_used;
6679 btrfs_end_transaction(trans, root);
6680 trans = NULL;
6681 btrfs_btree_balance_dirty(root, nr);
6684 if (ret == 0 && inode->i_nlink > 0) {
6685 trans->block_rsv = root->orphan_block_rsv;
6686 ret = btrfs_orphan_del(trans, inode);
6687 if (ret)
6688 err = ret;
6689 } else if (ret && inode->i_nlink > 0) {
6691 * Failed to do the truncate, remove us from the in memory
6692 * orphan list.
6694 ret = btrfs_orphan_del(NULL, inode);
6697 if (trans) {
6698 trans->block_rsv = &root->fs_info->trans_block_rsv;
6699 ret = btrfs_update_inode(trans, root, inode);
6700 if (ret && !err)
6701 err = ret;
6703 nr = trans->blocks_used;
6704 ret = btrfs_end_transaction(trans, root);
6705 btrfs_btree_balance_dirty(root, nr);
6708 out:
6709 btrfs_free_block_rsv(root, rsv);
6711 if (ret && !err)
6712 err = ret;
6714 return err;
6718 * create a new subvolume directory/inode (helper for the ioctl).
6720 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
6721 struct btrfs_root *new_root, u64 new_dirid)
6723 struct inode *inode;
6724 int err;
6725 u64 index = 0;
6727 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
6728 new_dirid, new_dirid,
6729 S_IFDIR | (~current_umask() & S_IRWXUGO),
6730 &index);
6731 if (IS_ERR(inode))
6732 return PTR_ERR(inode);
6733 inode->i_op = &btrfs_dir_inode_operations;
6734 inode->i_fop = &btrfs_dir_file_operations;
6736 set_nlink(inode, 1);
6737 btrfs_i_size_write(inode, 0);
6739 err = btrfs_update_inode(trans, new_root, inode);
6740 BUG_ON(err);
6742 iput(inode);
6743 return 0;
6746 struct inode *btrfs_alloc_inode(struct super_block *sb)
6748 struct btrfs_inode *ei;
6749 struct inode *inode;
6751 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
6752 if (!ei)
6753 return NULL;
6755 ei->root = NULL;
6756 ei->space_info = NULL;
6757 ei->generation = 0;
6758 ei->sequence = 0;
6759 ei->last_trans = 0;
6760 ei->last_sub_trans = 0;
6761 ei->logged_trans = 0;
6762 ei->delalloc_bytes = 0;
6763 ei->disk_i_size = 0;
6764 ei->flags = 0;
6765 ei->csum_bytes = 0;
6766 ei->index_cnt = (u64)-1;
6767 ei->last_unlink_trans = 0;
6769 spin_lock_init(&ei->lock);
6770 ei->outstanding_extents = 0;
6771 ei->reserved_extents = 0;
6773 ei->ordered_data_close = 0;
6774 ei->orphan_meta_reserved = 0;
6775 ei->dummy_inode = 0;
6776 ei->in_defrag = 0;
6777 ei->delalloc_meta_reserved = 0;
6778 ei->force_compress = BTRFS_COMPRESS_NONE;
6780 ei->delayed_node = NULL;
6782 inode = &ei->vfs_inode;
6783 extent_map_tree_init(&ei->extent_tree);
6784 extent_io_tree_init(&ei->io_tree, &inode->i_data);
6785 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
6786 mutex_init(&ei->log_mutex);
6787 mutex_init(&ei->delalloc_mutex);
6788 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
6789 INIT_LIST_HEAD(&ei->i_orphan);
6790 INIT_LIST_HEAD(&ei->delalloc_inodes);
6791 INIT_LIST_HEAD(&ei->ordered_operations);
6792 RB_CLEAR_NODE(&ei->rb_node);
6794 return inode;
6797 static void btrfs_i_callback(struct rcu_head *head)
6799 struct inode *inode = container_of(head, struct inode, i_rcu);
6800 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
6803 void btrfs_destroy_inode(struct inode *inode)
6805 struct btrfs_ordered_extent *ordered;
6806 struct btrfs_root *root = BTRFS_I(inode)->root;
6808 WARN_ON(!list_empty(&inode->i_dentry));
6809 WARN_ON(inode->i_data.nrpages);
6810 WARN_ON(BTRFS_I(inode)->outstanding_extents);
6811 WARN_ON(BTRFS_I(inode)->reserved_extents);
6812 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
6813 WARN_ON(BTRFS_I(inode)->csum_bytes);
6816 * This can happen where we create an inode, but somebody else also
6817 * created the same inode and we need to destroy the one we already
6818 * created.
6820 if (!root)
6821 goto free;
6824 * Make sure we're properly removed from the ordered operation
6825 * lists.
6827 smp_mb();
6828 if (!list_empty(&BTRFS_I(inode)->ordered_operations)) {
6829 spin_lock(&root->fs_info->ordered_extent_lock);
6830 list_del_init(&BTRFS_I(inode)->ordered_operations);
6831 spin_unlock(&root->fs_info->ordered_extent_lock);
6834 spin_lock(&root->orphan_lock);
6835 if (!list_empty(&BTRFS_I(inode)->i_orphan)) {
6836 printk(KERN_INFO "BTRFS: inode %llu still on the orphan list\n",
6837 (unsigned long long)btrfs_ino(inode));
6838 list_del_init(&BTRFS_I(inode)->i_orphan);
6840 spin_unlock(&root->orphan_lock);
6842 while (1) {
6843 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
6844 if (!ordered)
6845 break;
6846 else {
6847 printk(KERN_ERR "btrfs found ordered "
6848 "extent %llu %llu on inode cleanup\n",
6849 (unsigned long long)ordered->file_offset,
6850 (unsigned long long)ordered->len);
6851 btrfs_remove_ordered_extent(inode, ordered);
6852 btrfs_put_ordered_extent(ordered);
6853 btrfs_put_ordered_extent(ordered);
6856 inode_tree_del(inode);
6857 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
6858 free:
6859 btrfs_remove_delayed_node(inode);
6860 call_rcu(&inode->i_rcu, btrfs_i_callback);
6863 int btrfs_drop_inode(struct inode *inode)
6865 struct btrfs_root *root = BTRFS_I(inode)->root;
6867 if (btrfs_root_refs(&root->root_item) == 0 &&
6868 !btrfs_is_free_space_inode(root, inode))
6869 return 1;
6870 else
6871 return generic_drop_inode(inode);
6874 static void init_once(void *foo)
6876 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
6878 inode_init_once(&ei->vfs_inode);
6881 void btrfs_destroy_cachep(void)
6883 if (btrfs_inode_cachep)
6884 kmem_cache_destroy(btrfs_inode_cachep);
6885 if (btrfs_trans_handle_cachep)
6886 kmem_cache_destroy(btrfs_trans_handle_cachep);
6887 if (btrfs_transaction_cachep)
6888 kmem_cache_destroy(btrfs_transaction_cachep);
6889 if (btrfs_path_cachep)
6890 kmem_cache_destroy(btrfs_path_cachep);
6891 if (btrfs_free_space_cachep)
6892 kmem_cache_destroy(btrfs_free_space_cachep);
6895 int btrfs_init_cachep(void)
6897 btrfs_inode_cachep = kmem_cache_create("btrfs_inode_cache",
6898 sizeof(struct btrfs_inode), 0,
6899 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once);
6900 if (!btrfs_inode_cachep)
6901 goto fail;
6903 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle_cache",
6904 sizeof(struct btrfs_trans_handle), 0,
6905 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
6906 if (!btrfs_trans_handle_cachep)
6907 goto fail;
6909 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction_cache",
6910 sizeof(struct btrfs_transaction), 0,
6911 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
6912 if (!btrfs_transaction_cachep)
6913 goto fail;
6915 btrfs_path_cachep = kmem_cache_create("btrfs_path_cache",
6916 sizeof(struct btrfs_path), 0,
6917 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
6918 if (!btrfs_path_cachep)
6919 goto fail;
6921 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space_cache",
6922 sizeof(struct btrfs_free_space), 0,
6923 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
6924 if (!btrfs_free_space_cachep)
6925 goto fail;
6927 return 0;
6928 fail:
6929 btrfs_destroy_cachep();
6930 return -ENOMEM;
6933 static int btrfs_getattr(struct vfsmount *mnt,
6934 struct dentry *dentry, struct kstat *stat)
6936 struct inode *inode = dentry->d_inode;
6937 u32 blocksize = inode->i_sb->s_blocksize;
6939 generic_fillattr(inode, stat);
6940 stat->dev = BTRFS_I(inode)->root->anon_dev;
6941 stat->blksize = PAGE_CACHE_SIZE;
6942 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
6943 ALIGN(BTRFS_I(inode)->delalloc_bytes, blocksize)) >> 9;
6944 return 0;
6948 * If a file is moved, it will inherit the cow and compression flags of the new
6949 * directory.
6951 static void fixup_inode_flags(struct inode *dir, struct inode *inode)
6953 struct btrfs_inode *b_dir = BTRFS_I(dir);
6954 struct btrfs_inode *b_inode = BTRFS_I(inode);
6956 if (b_dir->flags & BTRFS_INODE_NODATACOW)
6957 b_inode->flags |= BTRFS_INODE_NODATACOW;
6958 else
6959 b_inode->flags &= ~BTRFS_INODE_NODATACOW;
6961 if (b_dir->flags & BTRFS_INODE_COMPRESS)
6962 b_inode->flags |= BTRFS_INODE_COMPRESS;
6963 else
6964 b_inode->flags &= ~BTRFS_INODE_COMPRESS;
6967 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
6968 struct inode *new_dir, struct dentry *new_dentry)
6970 struct btrfs_trans_handle *trans;
6971 struct btrfs_root *root = BTRFS_I(old_dir)->root;
6972 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
6973 struct inode *new_inode = new_dentry->d_inode;
6974 struct inode *old_inode = old_dentry->d_inode;
6975 struct timespec ctime = CURRENT_TIME;
6976 u64 index = 0;
6977 u64 root_objectid;
6978 int ret;
6979 u64 old_ino = btrfs_ino(old_inode);
6981 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
6982 return -EPERM;
6984 /* we only allow rename subvolume link between subvolumes */
6985 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
6986 return -EXDEV;
6988 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
6989 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
6990 return -ENOTEMPTY;
6992 if (S_ISDIR(old_inode->i_mode) && new_inode &&
6993 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
6994 return -ENOTEMPTY;
6996 * we're using rename to replace one file with another.
6997 * and the replacement file is large. Start IO on it now so
6998 * we don't add too much work to the end of the transaction
7000 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size &&
7001 old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
7002 filemap_flush(old_inode->i_mapping);
7004 /* close the racy window with snapshot create/destroy ioctl */
7005 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
7006 down_read(&root->fs_info->subvol_sem);
7008 * We want to reserve the absolute worst case amount of items. So if
7009 * both inodes are subvols and we need to unlink them then that would
7010 * require 4 item modifications, but if they are both normal inodes it
7011 * would require 5 item modifications, so we'll assume their normal
7012 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
7013 * should cover the worst case number of items we'll modify.
7015 trans = btrfs_start_transaction(root, 20);
7016 if (IS_ERR(trans)) {
7017 ret = PTR_ERR(trans);
7018 goto out_notrans;
7021 if (dest != root)
7022 btrfs_record_root_in_trans(trans, dest);
7024 ret = btrfs_set_inode_index(new_dir, &index);
7025 if (ret)
7026 goto out_fail;
7028 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
7029 /* force full log commit if subvolume involved. */
7030 root->fs_info->last_trans_log_full_commit = trans->transid;
7031 } else {
7032 ret = btrfs_insert_inode_ref(trans, dest,
7033 new_dentry->d_name.name,
7034 new_dentry->d_name.len,
7035 old_ino,
7036 btrfs_ino(new_dir), index);
7037 if (ret)
7038 goto out_fail;
7040 * this is an ugly little race, but the rename is required
7041 * to make sure that if we crash, the inode is either at the
7042 * old name or the new one. pinning the log transaction lets
7043 * us make sure we don't allow a log commit to come in after
7044 * we unlink the name but before we add the new name back in.
7046 btrfs_pin_log_trans(root);
7049 * make sure the inode gets flushed if it is replacing
7050 * something.
7052 if (new_inode && new_inode->i_size && S_ISREG(old_inode->i_mode))
7053 btrfs_add_ordered_operation(trans, root, old_inode);
7055 old_dir->i_ctime = old_dir->i_mtime = ctime;
7056 new_dir->i_ctime = new_dir->i_mtime = ctime;
7057 old_inode->i_ctime = ctime;
7059 if (old_dentry->d_parent != new_dentry->d_parent)
7060 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
7062 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
7063 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
7064 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
7065 old_dentry->d_name.name,
7066 old_dentry->d_name.len);
7067 } else {
7068 ret = __btrfs_unlink_inode(trans, root, old_dir,
7069 old_dentry->d_inode,
7070 old_dentry->d_name.name,
7071 old_dentry->d_name.len);
7072 if (!ret)
7073 ret = btrfs_update_inode(trans, root, old_inode);
7075 BUG_ON(ret);
7077 if (new_inode) {
7078 new_inode->i_ctime = CURRENT_TIME;
7079 if (unlikely(btrfs_ino(new_inode) ==
7080 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
7081 root_objectid = BTRFS_I(new_inode)->location.objectid;
7082 ret = btrfs_unlink_subvol(trans, dest, new_dir,
7083 root_objectid,
7084 new_dentry->d_name.name,
7085 new_dentry->d_name.len);
7086 BUG_ON(new_inode->i_nlink == 0);
7087 } else {
7088 ret = btrfs_unlink_inode(trans, dest, new_dir,
7089 new_dentry->d_inode,
7090 new_dentry->d_name.name,
7091 new_dentry->d_name.len);
7093 BUG_ON(ret);
7094 if (new_inode->i_nlink == 0) {
7095 ret = btrfs_orphan_add(trans, new_dentry->d_inode);
7096 BUG_ON(ret);
7100 fixup_inode_flags(new_dir, old_inode);
7102 ret = btrfs_add_link(trans, new_dir, old_inode,
7103 new_dentry->d_name.name,
7104 new_dentry->d_name.len, 0, index);
7105 BUG_ON(ret);
7107 if (old_ino != BTRFS_FIRST_FREE_OBJECTID) {
7108 struct dentry *parent = new_dentry->d_parent;
7109 btrfs_log_new_name(trans, old_inode, old_dir, parent);
7110 btrfs_end_log_trans(root);
7112 out_fail:
7113 btrfs_end_transaction(trans, root);
7114 out_notrans:
7115 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
7116 up_read(&root->fs_info->subvol_sem);
7118 return ret;
7122 * some fairly slow code that needs optimization. This walks the list
7123 * of all the inodes with pending delalloc and forces them to disk.
7125 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
7127 struct list_head *head = &root->fs_info->delalloc_inodes;
7128 struct btrfs_inode *binode;
7129 struct inode *inode;
7131 if (root->fs_info->sb->s_flags & MS_RDONLY)
7132 return -EROFS;
7134 spin_lock(&root->fs_info->delalloc_lock);
7135 while (!list_empty(head)) {
7136 binode = list_entry(head->next, struct btrfs_inode,
7137 delalloc_inodes);
7138 inode = igrab(&binode->vfs_inode);
7139 if (!inode)
7140 list_del_init(&binode->delalloc_inodes);
7141 spin_unlock(&root->fs_info->delalloc_lock);
7142 if (inode) {
7143 filemap_flush(inode->i_mapping);
7144 if (delay_iput)
7145 btrfs_add_delayed_iput(inode);
7146 else
7147 iput(inode);
7149 cond_resched();
7150 spin_lock(&root->fs_info->delalloc_lock);
7152 spin_unlock(&root->fs_info->delalloc_lock);
7154 /* the filemap_flush will queue IO into the worker threads, but
7155 * we have to make sure the IO is actually started and that
7156 * ordered extents get created before we return
7158 atomic_inc(&root->fs_info->async_submit_draining);
7159 while (atomic_read(&root->fs_info->nr_async_submits) ||
7160 atomic_read(&root->fs_info->async_delalloc_pages)) {
7161 wait_event(root->fs_info->async_submit_wait,
7162 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
7163 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
7165 atomic_dec(&root->fs_info->async_submit_draining);
7166 return 0;
7169 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
7170 const char *symname)
7172 struct btrfs_trans_handle *trans;
7173 struct btrfs_root *root = BTRFS_I(dir)->root;
7174 struct btrfs_path *path;
7175 struct btrfs_key key;
7176 struct inode *inode = NULL;
7177 int err;
7178 int drop_inode = 0;
7179 u64 objectid;
7180 u64 index = 0 ;
7181 int name_len;
7182 int datasize;
7183 unsigned long ptr;
7184 struct btrfs_file_extent_item *ei;
7185 struct extent_buffer *leaf;
7186 unsigned long nr = 0;
7188 name_len = strlen(symname) + 1;
7189 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
7190 return -ENAMETOOLONG;
7193 * 2 items for inode item and ref
7194 * 2 items for dir items
7195 * 1 item for xattr if selinux is on
7197 trans = btrfs_start_transaction(root, 5);
7198 if (IS_ERR(trans))
7199 return PTR_ERR(trans);
7201 err = btrfs_find_free_ino(root, &objectid);
7202 if (err)
7203 goto out_unlock;
7205 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
7206 dentry->d_name.len, btrfs_ino(dir), objectid,
7207 S_IFLNK|S_IRWXUGO, &index);
7208 if (IS_ERR(inode)) {
7209 err = PTR_ERR(inode);
7210 goto out_unlock;
7213 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
7214 if (err) {
7215 drop_inode = 1;
7216 goto out_unlock;
7220 * If the active LSM wants to access the inode during
7221 * d_instantiate it needs these. Smack checks to see
7222 * if the filesystem supports xattrs by looking at the
7223 * ops vector.
7225 inode->i_fop = &btrfs_file_operations;
7226 inode->i_op = &btrfs_file_inode_operations;
7228 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
7229 if (err)
7230 drop_inode = 1;
7231 else {
7232 inode->i_mapping->a_ops = &btrfs_aops;
7233 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
7234 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
7236 if (drop_inode)
7237 goto out_unlock;
7239 path = btrfs_alloc_path();
7240 if (!path) {
7241 err = -ENOMEM;
7242 drop_inode = 1;
7243 goto out_unlock;
7245 key.objectid = btrfs_ino(inode);
7246 key.offset = 0;
7247 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
7248 datasize = btrfs_file_extent_calc_inline_size(name_len);
7249 err = btrfs_insert_empty_item(trans, root, path, &key,
7250 datasize);
7251 if (err) {
7252 drop_inode = 1;
7253 btrfs_free_path(path);
7254 goto out_unlock;
7256 leaf = path->nodes[0];
7257 ei = btrfs_item_ptr(leaf, path->slots[0],
7258 struct btrfs_file_extent_item);
7259 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
7260 btrfs_set_file_extent_type(leaf, ei,
7261 BTRFS_FILE_EXTENT_INLINE);
7262 btrfs_set_file_extent_encryption(leaf, ei, 0);
7263 btrfs_set_file_extent_compression(leaf, ei, 0);
7264 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
7265 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
7267 ptr = btrfs_file_extent_inline_start(ei);
7268 write_extent_buffer(leaf, symname, ptr, name_len);
7269 btrfs_mark_buffer_dirty(leaf);
7270 btrfs_free_path(path);
7272 inode->i_op = &btrfs_symlink_inode_operations;
7273 inode->i_mapping->a_ops = &btrfs_symlink_aops;
7274 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
7275 inode_set_bytes(inode, name_len);
7276 btrfs_i_size_write(inode, name_len - 1);
7277 err = btrfs_update_inode(trans, root, inode);
7278 if (err)
7279 drop_inode = 1;
7281 out_unlock:
7282 if (!err)
7283 d_instantiate(dentry, inode);
7284 nr = trans->blocks_used;
7285 btrfs_end_transaction(trans, root);
7286 if (drop_inode) {
7287 inode_dec_link_count(inode);
7288 iput(inode);
7290 btrfs_btree_balance_dirty(root, nr);
7291 return err;
7294 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
7295 u64 start, u64 num_bytes, u64 min_size,
7296 loff_t actual_len, u64 *alloc_hint,
7297 struct btrfs_trans_handle *trans)
7299 struct btrfs_root *root = BTRFS_I(inode)->root;
7300 struct btrfs_key ins;
7301 u64 cur_offset = start;
7302 u64 i_size;
7303 int ret = 0;
7304 bool own_trans = true;
7306 if (trans)
7307 own_trans = false;
7308 while (num_bytes > 0) {
7309 if (own_trans) {
7310 trans = btrfs_start_transaction(root, 3);
7311 if (IS_ERR(trans)) {
7312 ret = PTR_ERR(trans);
7313 break;
7317 ret = btrfs_reserve_extent(trans, root, num_bytes, min_size,
7318 0, *alloc_hint, (u64)-1, &ins, 1);
7319 if (ret) {
7320 if (own_trans)
7321 btrfs_end_transaction(trans, root);
7322 break;
7325 ret = insert_reserved_file_extent(trans, inode,
7326 cur_offset, ins.objectid,
7327 ins.offset, ins.offset,
7328 ins.offset, 0, 0, 0,
7329 BTRFS_FILE_EXTENT_PREALLOC);
7330 BUG_ON(ret);
7331 btrfs_drop_extent_cache(inode, cur_offset,
7332 cur_offset + ins.offset -1, 0);
7334 num_bytes -= ins.offset;
7335 cur_offset += ins.offset;
7336 *alloc_hint = ins.objectid + ins.offset;
7338 inode->i_ctime = CURRENT_TIME;
7339 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
7340 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
7341 (actual_len > inode->i_size) &&
7342 (cur_offset > inode->i_size)) {
7343 if (cur_offset > actual_len)
7344 i_size = actual_len;
7345 else
7346 i_size = cur_offset;
7347 i_size_write(inode, i_size);
7348 btrfs_ordered_update_i_size(inode, i_size, NULL);
7351 ret = btrfs_update_inode(trans, root, inode);
7352 BUG_ON(ret);
7354 if (own_trans)
7355 btrfs_end_transaction(trans, root);
7357 return ret;
7360 int btrfs_prealloc_file_range(struct inode *inode, int mode,
7361 u64 start, u64 num_bytes, u64 min_size,
7362 loff_t actual_len, u64 *alloc_hint)
7364 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
7365 min_size, actual_len, alloc_hint,
7366 NULL);
7369 int btrfs_prealloc_file_range_trans(struct inode *inode,
7370 struct btrfs_trans_handle *trans, int mode,
7371 u64 start, u64 num_bytes, u64 min_size,
7372 loff_t actual_len, u64 *alloc_hint)
7374 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
7375 min_size, actual_len, alloc_hint, trans);
7378 static int btrfs_set_page_dirty(struct page *page)
7380 return __set_page_dirty_nobuffers(page);
7383 static int btrfs_permission(struct inode *inode, int mask)
7385 struct btrfs_root *root = BTRFS_I(inode)->root;
7386 umode_t mode = inode->i_mode;
7388 if (mask & MAY_WRITE &&
7389 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
7390 if (btrfs_root_readonly(root))
7391 return -EROFS;
7392 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
7393 return -EACCES;
7395 return generic_permission(inode, mask);
7398 static const struct inode_operations btrfs_dir_inode_operations = {
7399 .getattr = btrfs_getattr,
7400 .lookup = btrfs_lookup,
7401 .create = btrfs_create,
7402 .unlink = btrfs_unlink,
7403 .link = btrfs_link,
7404 .mkdir = btrfs_mkdir,
7405 .rmdir = btrfs_rmdir,
7406 .rename = btrfs_rename,
7407 .symlink = btrfs_symlink,
7408 .setattr = btrfs_setattr,
7409 .mknod = btrfs_mknod,
7410 .setxattr = btrfs_setxattr,
7411 .getxattr = btrfs_getxattr,
7412 .listxattr = btrfs_listxattr,
7413 .removexattr = btrfs_removexattr,
7414 .permission = btrfs_permission,
7415 .get_acl = btrfs_get_acl,
7417 static const struct inode_operations btrfs_dir_ro_inode_operations = {
7418 .lookup = btrfs_lookup,
7419 .permission = btrfs_permission,
7420 .get_acl = btrfs_get_acl,
7423 static const struct file_operations btrfs_dir_file_operations = {
7424 .llseek = generic_file_llseek,
7425 .read = generic_read_dir,
7426 .readdir = btrfs_real_readdir,
7427 .unlocked_ioctl = btrfs_ioctl,
7428 #ifdef CONFIG_COMPAT
7429 .compat_ioctl = btrfs_ioctl,
7430 #endif
7431 .release = btrfs_release_file,
7432 .fsync = btrfs_sync_file,
7435 static struct extent_io_ops btrfs_extent_io_ops = {
7436 .fill_delalloc = run_delalloc_range,
7437 .submit_bio_hook = btrfs_submit_bio_hook,
7438 .merge_bio_hook = btrfs_merge_bio_hook,
7439 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
7440 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
7441 .writepage_start_hook = btrfs_writepage_start_hook,
7442 .set_bit_hook = btrfs_set_bit_hook,
7443 .clear_bit_hook = btrfs_clear_bit_hook,
7444 .merge_extent_hook = btrfs_merge_extent_hook,
7445 .split_extent_hook = btrfs_split_extent_hook,
7449 * btrfs doesn't support the bmap operation because swapfiles
7450 * use bmap to make a mapping of extents in the file. They assume
7451 * these extents won't change over the life of the file and they
7452 * use the bmap result to do IO directly to the drive.
7454 * the btrfs bmap call would return logical addresses that aren't
7455 * suitable for IO and they also will change frequently as COW
7456 * operations happen. So, swapfile + btrfs == corruption.
7458 * For now we're avoiding this by dropping bmap.
7460 static const struct address_space_operations btrfs_aops = {
7461 .readpage = btrfs_readpage,
7462 .writepage = btrfs_writepage,
7463 .writepages = btrfs_writepages,
7464 .readpages = btrfs_readpages,
7465 .direct_IO = btrfs_direct_IO,
7466 .invalidatepage = btrfs_invalidatepage,
7467 .releasepage = btrfs_releasepage,
7468 .set_page_dirty = btrfs_set_page_dirty,
7469 .error_remove_page = generic_error_remove_page,
7472 static const struct address_space_operations btrfs_symlink_aops = {
7473 .readpage = btrfs_readpage,
7474 .writepage = btrfs_writepage,
7475 .invalidatepage = btrfs_invalidatepage,
7476 .releasepage = btrfs_releasepage,
7479 static const struct inode_operations btrfs_file_inode_operations = {
7480 .getattr = btrfs_getattr,
7481 .setattr = btrfs_setattr,
7482 .setxattr = btrfs_setxattr,
7483 .getxattr = btrfs_getxattr,
7484 .listxattr = btrfs_listxattr,
7485 .removexattr = btrfs_removexattr,
7486 .permission = btrfs_permission,
7487 .fiemap = btrfs_fiemap,
7488 .get_acl = btrfs_get_acl,
7490 static const struct inode_operations btrfs_special_inode_operations = {
7491 .getattr = btrfs_getattr,
7492 .setattr = btrfs_setattr,
7493 .permission = btrfs_permission,
7494 .setxattr = btrfs_setxattr,
7495 .getxattr = btrfs_getxattr,
7496 .listxattr = btrfs_listxattr,
7497 .removexattr = btrfs_removexattr,
7498 .get_acl = btrfs_get_acl,
7500 static const struct inode_operations btrfs_symlink_inode_operations = {
7501 .readlink = generic_readlink,
7502 .follow_link = page_follow_link_light,
7503 .put_link = page_put_link,
7504 .getattr = btrfs_getattr,
7505 .setattr = btrfs_setattr,
7506 .permission = btrfs_permission,
7507 .setxattr = btrfs_setxattr,
7508 .getxattr = btrfs_getxattr,
7509 .listxattr = btrfs_listxattr,
7510 .removexattr = btrfs_removexattr,
7511 .get_acl = btrfs_get_acl,
7514 const struct dentry_operations btrfs_dentry_operations = {
7515 .d_delete = btrfs_dentry_delete,
7516 .d_release = btrfs_dentry_release,