Merge branch 'btrfs-3.0' into for-linus
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / btrfs / inode.c
blob377e9bb0974fce95dc6e01f7c7dc52cc64f44e3d
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 "compat.h"
42 #include "ctree.h"
43 #include "disk-io.h"
44 #include "transaction.h"
45 #include "btrfs_inode.h"
46 #include "ioctl.h"
47 #include "print-tree.h"
48 #include "volumes.h"
49 #include "ordered-data.h"
50 #include "xattr.h"
51 #include "tree-log.h"
52 #include "compression.h"
53 #include "locking.h"
54 #include "free-space-cache.h"
55 #include "inode-map.h"
57 struct btrfs_iget_args {
58 u64 ino;
59 struct btrfs_root *root;
62 static const struct inode_operations btrfs_dir_inode_operations;
63 static const struct inode_operations btrfs_symlink_inode_operations;
64 static const struct inode_operations btrfs_dir_ro_inode_operations;
65 static const struct inode_operations btrfs_special_inode_operations;
66 static const struct inode_operations btrfs_file_inode_operations;
67 static const struct address_space_operations btrfs_aops;
68 static const struct address_space_operations btrfs_symlink_aops;
69 static const struct file_operations btrfs_dir_file_operations;
70 static struct extent_io_ops btrfs_extent_io_ops;
72 static struct kmem_cache *btrfs_inode_cachep;
73 struct kmem_cache *btrfs_trans_handle_cachep;
74 struct kmem_cache *btrfs_transaction_cachep;
75 struct kmem_cache *btrfs_path_cachep;
76 struct kmem_cache *btrfs_free_space_cachep;
78 #define S_SHIFT 12
79 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
80 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
81 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
82 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
83 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
84 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
85 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
86 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
89 static int btrfs_setsize(struct inode *inode, loff_t newsize);
90 static int btrfs_truncate(struct inode *inode);
91 static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end);
92 static noinline int cow_file_range(struct inode *inode,
93 struct page *locked_page,
94 u64 start, u64 end, int *page_started,
95 unsigned long *nr_written, int unlock);
97 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
98 struct inode *inode, struct inode *dir,
99 const struct qstr *qstr)
101 int err;
103 err = btrfs_init_acl(trans, inode, dir);
104 if (!err)
105 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
106 return err;
110 * this does all the hard work for inserting an inline extent into
111 * the btree. The caller should have done a btrfs_drop_extents so that
112 * no overlapping inline items exist in the btree
114 static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
115 struct btrfs_root *root, struct inode *inode,
116 u64 start, size_t size, size_t compressed_size,
117 int compress_type,
118 struct page **compressed_pages)
120 struct btrfs_key key;
121 struct btrfs_path *path;
122 struct extent_buffer *leaf;
123 struct page *page = NULL;
124 char *kaddr;
125 unsigned long ptr;
126 struct btrfs_file_extent_item *ei;
127 int err = 0;
128 int ret;
129 size_t cur_size = size;
130 size_t datasize;
131 unsigned long offset;
133 if (compressed_size && compressed_pages)
134 cur_size = compressed_size;
136 path = btrfs_alloc_path();
137 if (!path)
138 return -ENOMEM;
140 path->leave_spinning = 1;
142 key.objectid = btrfs_ino(inode);
143 key.offset = start;
144 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
145 datasize = btrfs_file_extent_calc_inline_size(cur_size);
147 inode_add_bytes(inode, size);
148 ret = btrfs_insert_empty_item(trans, root, path, &key,
149 datasize);
150 BUG_ON(ret);
151 if (ret) {
152 err = ret;
153 goto fail;
155 leaf = path->nodes[0];
156 ei = btrfs_item_ptr(leaf, path->slots[0],
157 struct btrfs_file_extent_item);
158 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
159 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
160 btrfs_set_file_extent_encryption(leaf, ei, 0);
161 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
162 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
163 ptr = btrfs_file_extent_inline_start(ei);
165 if (compress_type != BTRFS_COMPRESS_NONE) {
166 struct page *cpage;
167 int i = 0;
168 while (compressed_size > 0) {
169 cpage = compressed_pages[i];
170 cur_size = min_t(unsigned long, compressed_size,
171 PAGE_CACHE_SIZE);
173 kaddr = kmap_atomic(cpage, KM_USER0);
174 write_extent_buffer(leaf, kaddr, ptr, cur_size);
175 kunmap_atomic(kaddr, KM_USER0);
177 i++;
178 ptr += cur_size;
179 compressed_size -= cur_size;
181 btrfs_set_file_extent_compression(leaf, ei,
182 compress_type);
183 } else {
184 page = find_get_page(inode->i_mapping,
185 start >> PAGE_CACHE_SHIFT);
186 btrfs_set_file_extent_compression(leaf, ei, 0);
187 kaddr = kmap_atomic(page, KM_USER0);
188 offset = start & (PAGE_CACHE_SIZE - 1);
189 write_extent_buffer(leaf, kaddr + offset, ptr, size);
190 kunmap_atomic(kaddr, KM_USER0);
191 page_cache_release(page);
193 btrfs_mark_buffer_dirty(leaf);
194 btrfs_free_path(path);
197 * we're an inline extent, so nobody can
198 * extend the file past i_size without locking
199 * a page we already have locked.
201 * We must do any isize and inode updates
202 * before we unlock the pages. Otherwise we
203 * could end up racing with unlink.
205 BTRFS_I(inode)->disk_i_size = inode->i_size;
206 btrfs_update_inode(trans, root, inode);
208 return 0;
209 fail:
210 btrfs_free_path(path);
211 return err;
216 * conditionally insert an inline extent into the file. This
217 * does the checks required to make sure the data is small enough
218 * to fit as an inline extent.
220 static noinline int cow_file_range_inline(struct btrfs_trans_handle *trans,
221 struct btrfs_root *root,
222 struct inode *inode, u64 start, u64 end,
223 size_t compressed_size, int compress_type,
224 struct page **compressed_pages)
226 u64 isize = i_size_read(inode);
227 u64 actual_end = min(end + 1, isize);
228 u64 inline_len = actual_end - start;
229 u64 aligned_end = (end + root->sectorsize - 1) &
230 ~((u64)root->sectorsize - 1);
231 u64 hint_byte;
232 u64 data_len = inline_len;
233 int ret;
235 if (compressed_size)
236 data_len = compressed_size;
238 if (start > 0 ||
239 actual_end >= PAGE_CACHE_SIZE ||
240 data_len >= BTRFS_MAX_INLINE_DATA_SIZE(root) ||
241 (!compressed_size &&
242 (actual_end & (root->sectorsize - 1)) == 0) ||
243 end + 1 < isize ||
244 data_len > root->fs_info->max_inline) {
245 return 1;
248 ret = btrfs_drop_extents(trans, inode, start, aligned_end,
249 &hint_byte, 1);
250 BUG_ON(ret);
252 if (isize > actual_end)
253 inline_len = min_t(u64, isize, actual_end);
254 ret = insert_inline_extent(trans, root, inode, start,
255 inline_len, compressed_size,
256 compress_type, compressed_pages);
257 BUG_ON(ret);
258 btrfs_delalloc_release_metadata(inode, end + 1 - start);
259 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
260 return 0;
263 struct async_extent {
264 u64 start;
265 u64 ram_size;
266 u64 compressed_size;
267 struct page **pages;
268 unsigned long nr_pages;
269 int compress_type;
270 struct list_head list;
273 struct async_cow {
274 struct inode *inode;
275 struct btrfs_root *root;
276 struct page *locked_page;
277 u64 start;
278 u64 end;
279 struct list_head extents;
280 struct btrfs_work work;
283 static noinline int add_async_extent(struct async_cow *cow,
284 u64 start, u64 ram_size,
285 u64 compressed_size,
286 struct page **pages,
287 unsigned long nr_pages,
288 int compress_type)
290 struct async_extent *async_extent;
292 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
293 BUG_ON(!async_extent);
294 async_extent->start = start;
295 async_extent->ram_size = ram_size;
296 async_extent->compressed_size = compressed_size;
297 async_extent->pages = pages;
298 async_extent->nr_pages = nr_pages;
299 async_extent->compress_type = compress_type;
300 list_add_tail(&async_extent->list, &cow->extents);
301 return 0;
305 * we create compressed extents in two phases. The first
306 * phase compresses a range of pages that have already been
307 * locked (both pages and state bits are locked).
309 * This is done inside an ordered work queue, and the compression
310 * is spread across many cpus. The actual IO submission is step
311 * two, and the ordered work queue takes care of making sure that
312 * happens in the same order things were put onto the queue by
313 * writepages and friends.
315 * If this code finds it can't get good compression, it puts an
316 * entry onto the work queue to write the uncompressed bytes. This
317 * makes sure that both compressed inodes and uncompressed inodes
318 * are written in the same order that pdflush sent them down.
320 static noinline int compress_file_range(struct inode *inode,
321 struct page *locked_page,
322 u64 start, u64 end,
323 struct async_cow *async_cow,
324 int *num_added)
326 struct btrfs_root *root = BTRFS_I(inode)->root;
327 struct btrfs_trans_handle *trans;
328 u64 num_bytes;
329 u64 blocksize = root->sectorsize;
330 u64 actual_end;
331 u64 isize = i_size_read(inode);
332 int ret = 0;
333 struct page **pages = NULL;
334 unsigned long nr_pages;
335 unsigned long nr_pages_ret = 0;
336 unsigned long total_compressed = 0;
337 unsigned long total_in = 0;
338 unsigned long max_compressed = 128 * 1024;
339 unsigned long max_uncompressed = 128 * 1024;
340 int i;
341 int will_compress;
342 int compress_type = root->fs_info->compress_type;
344 /* if this is a small write inside eof, kick off a defragbot */
345 if (end <= BTRFS_I(inode)->disk_i_size && (end - start + 1) < 16 * 1024)
346 btrfs_add_inode_defrag(NULL, inode);
348 actual_end = min_t(u64, isize, end + 1);
349 again:
350 will_compress = 0;
351 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
352 nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
355 * we don't want to send crud past the end of i_size through
356 * compression, that's just a waste of CPU time. So, if the
357 * end of the file is before the start of our current
358 * requested range of bytes, we bail out to the uncompressed
359 * cleanup code that can deal with all of this.
361 * It isn't really the fastest way to fix things, but this is a
362 * very uncommon corner.
364 if (actual_end <= start)
365 goto cleanup_and_bail_uncompressed;
367 total_compressed = actual_end - start;
369 /* we want to make sure that amount of ram required to uncompress
370 * an extent is reasonable, so we limit the total size in ram
371 * of a compressed extent to 128k. This is a crucial number
372 * because it also controls how easily we can spread reads across
373 * cpus for decompression.
375 * We also want to make sure the amount of IO required to do
376 * a random read is reasonably small, so we limit the size of
377 * a compressed extent to 128k.
379 total_compressed = min(total_compressed, max_uncompressed);
380 num_bytes = (end - start + blocksize) & ~(blocksize - 1);
381 num_bytes = max(blocksize, num_bytes);
382 total_in = 0;
383 ret = 0;
386 * we do compression for mount -o compress and when the
387 * inode has not been flagged as nocompress. This flag can
388 * change at any time if we discover bad compression ratios.
390 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) &&
391 (btrfs_test_opt(root, COMPRESS) ||
392 (BTRFS_I(inode)->force_compress) ||
393 (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))) {
394 WARN_ON(pages);
395 pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
396 BUG_ON(!pages);
398 if (BTRFS_I(inode)->force_compress)
399 compress_type = BTRFS_I(inode)->force_compress;
401 ret = btrfs_compress_pages(compress_type,
402 inode->i_mapping, start,
403 total_compressed, pages,
404 nr_pages, &nr_pages_ret,
405 &total_in,
406 &total_compressed,
407 max_compressed);
409 if (!ret) {
410 unsigned long offset = total_compressed &
411 (PAGE_CACHE_SIZE - 1);
412 struct page *page = pages[nr_pages_ret - 1];
413 char *kaddr;
415 /* zero the tail end of the last page, we might be
416 * sending it down to disk
418 if (offset) {
419 kaddr = kmap_atomic(page, KM_USER0);
420 memset(kaddr + offset, 0,
421 PAGE_CACHE_SIZE - offset);
422 kunmap_atomic(kaddr, KM_USER0);
424 will_compress = 1;
427 if (start == 0) {
428 trans = btrfs_join_transaction(root);
429 BUG_ON(IS_ERR(trans));
430 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
432 /* lets try to make an inline extent */
433 if (ret || total_in < (actual_end - start)) {
434 /* we didn't compress the entire range, try
435 * to make an uncompressed inline extent.
437 ret = cow_file_range_inline(trans, root, inode,
438 start, end, 0, 0, NULL);
439 } else {
440 /* try making a compressed inline extent */
441 ret = cow_file_range_inline(trans, root, inode,
442 start, end,
443 total_compressed,
444 compress_type, pages);
446 if (ret == 0) {
448 * inline extent creation worked, we don't need
449 * to create any more async work items. Unlock
450 * and free up our temp pages.
452 extent_clear_unlock_delalloc(inode,
453 &BTRFS_I(inode)->io_tree,
454 start, end, NULL,
455 EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
456 EXTENT_CLEAR_DELALLOC |
457 EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK);
459 btrfs_end_transaction(trans, root);
460 goto free_pages_out;
462 btrfs_end_transaction(trans, root);
465 if (will_compress) {
467 * we aren't doing an inline extent round the compressed size
468 * up to a block size boundary so the allocator does sane
469 * things
471 total_compressed = (total_compressed + blocksize - 1) &
472 ~(blocksize - 1);
475 * one last check to make sure the compression is really a
476 * win, compare the page count read with the blocks on disk
478 total_in = (total_in + PAGE_CACHE_SIZE - 1) &
479 ~(PAGE_CACHE_SIZE - 1);
480 if (total_compressed >= total_in) {
481 will_compress = 0;
482 } else {
483 num_bytes = total_in;
486 if (!will_compress && pages) {
488 * the compression code ran but failed to make things smaller,
489 * free any pages it allocated and our page pointer array
491 for (i = 0; i < nr_pages_ret; i++) {
492 WARN_ON(pages[i]->mapping);
493 page_cache_release(pages[i]);
495 kfree(pages);
496 pages = NULL;
497 total_compressed = 0;
498 nr_pages_ret = 0;
500 /* flag the file so we don't compress in the future */
501 if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
502 !(BTRFS_I(inode)->force_compress)) {
503 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
506 if (will_compress) {
507 *num_added += 1;
509 /* the async work queues will take care of doing actual
510 * allocation on disk for these compressed pages,
511 * and will submit them to the elevator.
513 add_async_extent(async_cow, start, num_bytes,
514 total_compressed, pages, nr_pages_ret,
515 compress_type);
517 if (start + num_bytes < end) {
518 start += num_bytes;
519 pages = NULL;
520 cond_resched();
521 goto again;
523 } else {
524 cleanup_and_bail_uncompressed:
526 * No compression, but we still need to write the pages in
527 * the file we've been given so far. redirty the locked
528 * page if it corresponds to our extent and set things up
529 * for the async work queue to run cow_file_range to do
530 * the normal delalloc dance
532 if (page_offset(locked_page) >= start &&
533 page_offset(locked_page) <= end) {
534 __set_page_dirty_nobuffers(locked_page);
535 /* unlocked later on in the async handlers */
537 add_async_extent(async_cow, start, end - start + 1,
538 0, NULL, 0, BTRFS_COMPRESS_NONE);
539 *num_added += 1;
542 out:
543 return 0;
545 free_pages_out:
546 for (i = 0; i < nr_pages_ret; i++) {
547 WARN_ON(pages[i]->mapping);
548 page_cache_release(pages[i]);
550 kfree(pages);
552 goto out;
556 * phase two of compressed writeback. This is the ordered portion
557 * of the code, which only gets called in the order the work was
558 * queued. We walk all the async extents created by compress_file_range
559 * and send them down to the disk.
561 static noinline int submit_compressed_extents(struct inode *inode,
562 struct async_cow *async_cow)
564 struct async_extent *async_extent;
565 u64 alloc_hint = 0;
566 struct btrfs_trans_handle *trans;
567 struct btrfs_key ins;
568 struct extent_map *em;
569 struct btrfs_root *root = BTRFS_I(inode)->root;
570 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
571 struct extent_io_tree *io_tree;
572 int ret = 0;
574 if (list_empty(&async_cow->extents))
575 return 0;
578 while (!list_empty(&async_cow->extents)) {
579 async_extent = list_entry(async_cow->extents.next,
580 struct async_extent, list);
581 list_del(&async_extent->list);
583 io_tree = &BTRFS_I(inode)->io_tree;
585 retry:
586 /* did the compression code fall back to uncompressed IO? */
587 if (!async_extent->pages) {
588 int page_started = 0;
589 unsigned long nr_written = 0;
591 lock_extent(io_tree, async_extent->start,
592 async_extent->start +
593 async_extent->ram_size - 1, GFP_NOFS);
595 /* allocate blocks */
596 ret = cow_file_range(inode, async_cow->locked_page,
597 async_extent->start,
598 async_extent->start +
599 async_extent->ram_size - 1,
600 &page_started, &nr_written, 0);
603 * if page_started, cow_file_range inserted an
604 * inline extent and took care of all the unlocking
605 * and IO for us. Otherwise, we need to submit
606 * all those pages down to the drive.
608 if (!page_started && !ret)
609 extent_write_locked_range(io_tree,
610 inode, async_extent->start,
611 async_extent->start +
612 async_extent->ram_size - 1,
613 btrfs_get_extent,
614 WB_SYNC_ALL);
615 kfree(async_extent);
616 cond_resched();
617 continue;
620 lock_extent(io_tree, async_extent->start,
621 async_extent->start + async_extent->ram_size - 1,
622 GFP_NOFS);
624 trans = btrfs_join_transaction(root);
625 BUG_ON(IS_ERR(trans));
626 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
627 ret = btrfs_reserve_extent(trans, root,
628 async_extent->compressed_size,
629 async_extent->compressed_size,
630 0, alloc_hint,
631 (u64)-1, &ins, 1);
632 btrfs_end_transaction(trans, root);
634 if (ret) {
635 int i;
636 for (i = 0; i < async_extent->nr_pages; i++) {
637 WARN_ON(async_extent->pages[i]->mapping);
638 page_cache_release(async_extent->pages[i]);
640 kfree(async_extent->pages);
641 async_extent->nr_pages = 0;
642 async_extent->pages = NULL;
643 unlock_extent(io_tree, async_extent->start,
644 async_extent->start +
645 async_extent->ram_size - 1, GFP_NOFS);
646 goto retry;
650 * here we're doing allocation and writeback of the
651 * compressed pages
653 btrfs_drop_extent_cache(inode, async_extent->start,
654 async_extent->start +
655 async_extent->ram_size - 1, 0);
657 em = alloc_extent_map();
658 BUG_ON(!em);
659 em->start = async_extent->start;
660 em->len = async_extent->ram_size;
661 em->orig_start = em->start;
663 em->block_start = ins.objectid;
664 em->block_len = ins.offset;
665 em->bdev = root->fs_info->fs_devices->latest_bdev;
666 em->compress_type = async_extent->compress_type;
667 set_bit(EXTENT_FLAG_PINNED, &em->flags);
668 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
670 while (1) {
671 write_lock(&em_tree->lock);
672 ret = add_extent_mapping(em_tree, em);
673 write_unlock(&em_tree->lock);
674 if (ret != -EEXIST) {
675 free_extent_map(em);
676 break;
678 btrfs_drop_extent_cache(inode, async_extent->start,
679 async_extent->start +
680 async_extent->ram_size - 1, 0);
683 ret = btrfs_add_ordered_extent_compress(inode,
684 async_extent->start,
685 ins.objectid,
686 async_extent->ram_size,
687 ins.offset,
688 BTRFS_ORDERED_COMPRESSED,
689 async_extent->compress_type);
690 BUG_ON(ret);
693 * clear dirty, set writeback and unlock the pages.
695 extent_clear_unlock_delalloc(inode,
696 &BTRFS_I(inode)->io_tree,
697 async_extent->start,
698 async_extent->start +
699 async_extent->ram_size - 1,
700 NULL, EXTENT_CLEAR_UNLOCK_PAGE |
701 EXTENT_CLEAR_UNLOCK |
702 EXTENT_CLEAR_DELALLOC |
703 EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK);
705 ret = btrfs_submit_compressed_write(inode,
706 async_extent->start,
707 async_extent->ram_size,
708 ins.objectid,
709 ins.offset, async_extent->pages,
710 async_extent->nr_pages);
712 BUG_ON(ret);
713 alloc_hint = ins.objectid + ins.offset;
714 kfree(async_extent);
715 cond_resched();
718 return 0;
721 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
722 u64 num_bytes)
724 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
725 struct extent_map *em;
726 u64 alloc_hint = 0;
728 read_lock(&em_tree->lock);
729 em = search_extent_mapping(em_tree, start, num_bytes);
730 if (em) {
732 * if block start isn't an actual block number then find the
733 * first block in this inode and use that as a hint. If that
734 * block is also bogus then just don't worry about it.
736 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
737 free_extent_map(em);
738 em = search_extent_mapping(em_tree, 0, 0);
739 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
740 alloc_hint = em->block_start;
741 if (em)
742 free_extent_map(em);
743 } else {
744 alloc_hint = em->block_start;
745 free_extent_map(em);
748 read_unlock(&em_tree->lock);
750 return alloc_hint;
754 * when extent_io.c finds a delayed allocation range in the file,
755 * the call backs end up in this code. The basic idea is to
756 * allocate extents on disk for the range, and create ordered data structs
757 * in ram to track those extents.
759 * locked_page is the page that writepage had locked already. We use
760 * it to make sure we don't do extra locks or unlocks.
762 * *page_started is set to one if we unlock locked_page and do everything
763 * required to start IO on it. It may be clean and already done with
764 * IO when we return.
766 static noinline int cow_file_range(struct inode *inode,
767 struct page *locked_page,
768 u64 start, u64 end, int *page_started,
769 unsigned long *nr_written,
770 int unlock)
772 struct btrfs_root *root = BTRFS_I(inode)->root;
773 struct btrfs_trans_handle *trans;
774 u64 alloc_hint = 0;
775 u64 num_bytes;
776 unsigned long ram_size;
777 u64 disk_num_bytes;
778 u64 cur_alloc_size;
779 u64 blocksize = root->sectorsize;
780 struct btrfs_key ins;
781 struct extent_map *em;
782 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
783 int ret = 0;
785 BUG_ON(btrfs_is_free_space_inode(root, inode));
786 trans = btrfs_join_transaction(root);
787 BUG_ON(IS_ERR(trans));
788 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
790 num_bytes = (end - start + blocksize) & ~(blocksize - 1);
791 num_bytes = max(blocksize, num_bytes);
792 disk_num_bytes = num_bytes;
793 ret = 0;
795 /* if this is a small write inside eof, kick off defrag */
796 if (end <= BTRFS_I(inode)->disk_i_size && num_bytes < 64 * 1024)
797 btrfs_add_inode_defrag(trans, inode);
799 if (start == 0) {
800 /* lets try to make an inline extent */
801 ret = cow_file_range_inline(trans, root, inode,
802 start, end, 0, 0, NULL);
803 if (ret == 0) {
804 extent_clear_unlock_delalloc(inode,
805 &BTRFS_I(inode)->io_tree,
806 start, end, NULL,
807 EXTENT_CLEAR_UNLOCK_PAGE |
808 EXTENT_CLEAR_UNLOCK |
809 EXTENT_CLEAR_DELALLOC |
810 EXTENT_CLEAR_DIRTY |
811 EXTENT_SET_WRITEBACK |
812 EXTENT_END_WRITEBACK);
814 *nr_written = *nr_written +
815 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
816 *page_started = 1;
817 ret = 0;
818 goto out;
822 BUG_ON(disk_num_bytes >
823 btrfs_super_total_bytes(&root->fs_info->super_copy));
825 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
826 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
828 while (disk_num_bytes > 0) {
829 unsigned long op;
831 cur_alloc_size = disk_num_bytes;
832 ret = btrfs_reserve_extent(trans, root, cur_alloc_size,
833 root->sectorsize, 0, alloc_hint,
834 (u64)-1, &ins, 1);
835 BUG_ON(ret);
837 em = alloc_extent_map();
838 BUG_ON(!em);
839 em->start = start;
840 em->orig_start = em->start;
841 ram_size = ins.offset;
842 em->len = ins.offset;
844 em->block_start = ins.objectid;
845 em->block_len = ins.offset;
846 em->bdev = root->fs_info->fs_devices->latest_bdev;
847 set_bit(EXTENT_FLAG_PINNED, &em->flags);
849 while (1) {
850 write_lock(&em_tree->lock);
851 ret = add_extent_mapping(em_tree, em);
852 write_unlock(&em_tree->lock);
853 if (ret != -EEXIST) {
854 free_extent_map(em);
855 break;
857 btrfs_drop_extent_cache(inode, start,
858 start + ram_size - 1, 0);
861 cur_alloc_size = ins.offset;
862 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
863 ram_size, cur_alloc_size, 0);
864 BUG_ON(ret);
866 if (root->root_key.objectid ==
867 BTRFS_DATA_RELOC_TREE_OBJECTID) {
868 ret = btrfs_reloc_clone_csums(inode, start,
869 cur_alloc_size);
870 BUG_ON(ret);
873 if (disk_num_bytes < cur_alloc_size)
874 break;
876 /* we're not doing compressed IO, don't unlock the first
877 * page (which the caller expects to stay locked), don't
878 * clear any dirty bits and don't set any writeback bits
880 * Do set the Private2 bit so we know this page was properly
881 * setup for writepage
883 op = unlock ? EXTENT_CLEAR_UNLOCK_PAGE : 0;
884 op |= EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
885 EXTENT_SET_PRIVATE2;
887 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
888 start, start + ram_size - 1,
889 locked_page, op);
890 disk_num_bytes -= cur_alloc_size;
891 num_bytes -= cur_alloc_size;
892 alloc_hint = ins.objectid + ins.offset;
893 start += cur_alloc_size;
895 out:
896 ret = 0;
897 btrfs_end_transaction(trans, root);
899 return ret;
903 * work queue call back to started compression on a file and pages
905 static noinline void async_cow_start(struct btrfs_work *work)
907 struct async_cow *async_cow;
908 int num_added = 0;
909 async_cow = container_of(work, struct async_cow, work);
911 compress_file_range(async_cow->inode, async_cow->locked_page,
912 async_cow->start, async_cow->end, async_cow,
913 &num_added);
914 if (num_added == 0)
915 async_cow->inode = NULL;
919 * work queue call back to submit previously compressed pages
921 static noinline void async_cow_submit(struct btrfs_work *work)
923 struct async_cow *async_cow;
924 struct btrfs_root *root;
925 unsigned long nr_pages;
927 async_cow = container_of(work, struct async_cow, work);
929 root = async_cow->root;
930 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
931 PAGE_CACHE_SHIFT;
933 atomic_sub(nr_pages, &root->fs_info->async_delalloc_pages);
935 if (atomic_read(&root->fs_info->async_delalloc_pages) <
936 5 * 1042 * 1024 &&
937 waitqueue_active(&root->fs_info->async_submit_wait))
938 wake_up(&root->fs_info->async_submit_wait);
940 if (async_cow->inode)
941 submit_compressed_extents(async_cow->inode, async_cow);
944 static noinline void async_cow_free(struct btrfs_work *work)
946 struct async_cow *async_cow;
947 async_cow = container_of(work, struct async_cow, work);
948 kfree(async_cow);
951 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
952 u64 start, u64 end, int *page_started,
953 unsigned long *nr_written)
955 struct async_cow *async_cow;
956 struct btrfs_root *root = BTRFS_I(inode)->root;
957 unsigned long nr_pages;
958 u64 cur_end;
959 int limit = 10 * 1024 * 1042;
961 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
962 1, 0, NULL, GFP_NOFS);
963 while (start < end) {
964 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
965 BUG_ON(!async_cow);
966 async_cow->inode = inode;
967 async_cow->root = root;
968 async_cow->locked_page = locked_page;
969 async_cow->start = start;
971 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
972 cur_end = end;
973 else
974 cur_end = min(end, start + 512 * 1024 - 1);
976 async_cow->end = cur_end;
977 INIT_LIST_HEAD(&async_cow->extents);
979 async_cow->work.func = async_cow_start;
980 async_cow->work.ordered_func = async_cow_submit;
981 async_cow->work.ordered_free = async_cow_free;
982 async_cow->work.flags = 0;
984 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
985 PAGE_CACHE_SHIFT;
986 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
988 btrfs_queue_worker(&root->fs_info->delalloc_workers,
989 &async_cow->work);
991 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
992 wait_event(root->fs_info->async_submit_wait,
993 (atomic_read(&root->fs_info->async_delalloc_pages) <
994 limit));
997 while (atomic_read(&root->fs_info->async_submit_draining) &&
998 atomic_read(&root->fs_info->async_delalloc_pages)) {
999 wait_event(root->fs_info->async_submit_wait,
1000 (atomic_read(&root->fs_info->async_delalloc_pages) ==
1001 0));
1004 *nr_written += nr_pages;
1005 start = cur_end + 1;
1007 *page_started = 1;
1008 return 0;
1011 static noinline int csum_exist_in_range(struct btrfs_root *root,
1012 u64 bytenr, u64 num_bytes)
1014 int ret;
1015 struct btrfs_ordered_sum *sums;
1016 LIST_HEAD(list);
1018 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1019 bytenr + num_bytes - 1, &list, 0);
1020 if (ret == 0 && list_empty(&list))
1021 return 0;
1023 while (!list_empty(&list)) {
1024 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1025 list_del(&sums->list);
1026 kfree(sums);
1028 return 1;
1032 * when nowcow writeback call back. This checks for snapshots or COW copies
1033 * of the extents that exist in the file, and COWs the file as required.
1035 * If no cow copies or snapshots exist, we write directly to the existing
1036 * blocks on disk
1038 static noinline int run_delalloc_nocow(struct inode *inode,
1039 struct page *locked_page,
1040 u64 start, u64 end, int *page_started, int force,
1041 unsigned long *nr_written)
1043 struct btrfs_root *root = BTRFS_I(inode)->root;
1044 struct btrfs_trans_handle *trans;
1045 struct extent_buffer *leaf;
1046 struct btrfs_path *path;
1047 struct btrfs_file_extent_item *fi;
1048 struct btrfs_key found_key;
1049 u64 cow_start;
1050 u64 cur_offset;
1051 u64 extent_end;
1052 u64 extent_offset;
1053 u64 disk_bytenr;
1054 u64 num_bytes;
1055 int extent_type;
1056 int ret;
1057 int type;
1058 int nocow;
1059 int check_prev = 1;
1060 bool nolock;
1061 u64 ino = btrfs_ino(inode);
1063 path = btrfs_alloc_path();
1064 if (!path)
1065 return -ENOMEM;
1067 nolock = btrfs_is_free_space_inode(root, inode);
1069 if (nolock)
1070 trans = btrfs_join_transaction_nolock(root);
1071 else
1072 trans = btrfs_join_transaction(root);
1074 BUG_ON(IS_ERR(trans));
1075 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1077 cow_start = (u64)-1;
1078 cur_offset = start;
1079 while (1) {
1080 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1081 cur_offset, 0);
1082 BUG_ON(ret < 0);
1083 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1084 leaf = path->nodes[0];
1085 btrfs_item_key_to_cpu(leaf, &found_key,
1086 path->slots[0] - 1);
1087 if (found_key.objectid == ino &&
1088 found_key.type == BTRFS_EXTENT_DATA_KEY)
1089 path->slots[0]--;
1091 check_prev = 0;
1092 next_slot:
1093 leaf = path->nodes[0];
1094 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1095 ret = btrfs_next_leaf(root, path);
1096 if (ret < 0)
1097 BUG_ON(1);
1098 if (ret > 0)
1099 break;
1100 leaf = path->nodes[0];
1103 nocow = 0;
1104 disk_bytenr = 0;
1105 num_bytes = 0;
1106 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1108 if (found_key.objectid > ino ||
1109 found_key.type > BTRFS_EXTENT_DATA_KEY ||
1110 found_key.offset > end)
1111 break;
1113 if (found_key.offset > cur_offset) {
1114 extent_end = found_key.offset;
1115 extent_type = 0;
1116 goto out_check;
1119 fi = btrfs_item_ptr(leaf, path->slots[0],
1120 struct btrfs_file_extent_item);
1121 extent_type = btrfs_file_extent_type(leaf, fi);
1123 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1124 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1125 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1126 extent_offset = btrfs_file_extent_offset(leaf, fi);
1127 extent_end = found_key.offset +
1128 btrfs_file_extent_num_bytes(leaf, fi);
1129 if (extent_end <= start) {
1130 path->slots[0]++;
1131 goto next_slot;
1133 if (disk_bytenr == 0)
1134 goto out_check;
1135 if (btrfs_file_extent_compression(leaf, fi) ||
1136 btrfs_file_extent_encryption(leaf, fi) ||
1137 btrfs_file_extent_other_encoding(leaf, fi))
1138 goto out_check;
1139 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1140 goto out_check;
1141 if (btrfs_extent_readonly(root, disk_bytenr))
1142 goto out_check;
1143 if (btrfs_cross_ref_exist(trans, root, ino,
1144 found_key.offset -
1145 extent_offset, disk_bytenr))
1146 goto out_check;
1147 disk_bytenr += extent_offset;
1148 disk_bytenr += cur_offset - found_key.offset;
1149 num_bytes = min(end + 1, extent_end) - cur_offset;
1151 * force cow if csum exists in the range.
1152 * this ensure that csum for a given extent are
1153 * either valid or do not exist.
1155 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1156 goto out_check;
1157 nocow = 1;
1158 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1159 extent_end = found_key.offset +
1160 btrfs_file_extent_inline_len(leaf, fi);
1161 extent_end = ALIGN(extent_end, root->sectorsize);
1162 } else {
1163 BUG_ON(1);
1165 out_check:
1166 if (extent_end <= start) {
1167 path->slots[0]++;
1168 goto next_slot;
1170 if (!nocow) {
1171 if (cow_start == (u64)-1)
1172 cow_start = cur_offset;
1173 cur_offset = extent_end;
1174 if (cur_offset > end)
1175 break;
1176 path->slots[0]++;
1177 goto next_slot;
1180 btrfs_release_path(path);
1181 if (cow_start != (u64)-1) {
1182 ret = cow_file_range(inode, locked_page, cow_start,
1183 found_key.offset - 1, page_started,
1184 nr_written, 1);
1185 BUG_ON(ret);
1186 cow_start = (u64)-1;
1189 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1190 struct extent_map *em;
1191 struct extent_map_tree *em_tree;
1192 em_tree = &BTRFS_I(inode)->extent_tree;
1193 em = alloc_extent_map();
1194 BUG_ON(!em);
1195 em->start = cur_offset;
1196 em->orig_start = em->start;
1197 em->len = num_bytes;
1198 em->block_len = num_bytes;
1199 em->block_start = disk_bytenr;
1200 em->bdev = root->fs_info->fs_devices->latest_bdev;
1201 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1202 while (1) {
1203 write_lock(&em_tree->lock);
1204 ret = add_extent_mapping(em_tree, em);
1205 write_unlock(&em_tree->lock);
1206 if (ret != -EEXIST) {
1207 free_extent_map(em);
1208 break;
1210 btrfs_drop_extent_cache(inode, em->start,
1211 em->start + em->len - 1, 0);
1213 type = BTRFS_ORDERED_PREALLOC;
1214 } else {
1215 type = BTRFS_ORDERED_NOCOW;
1218 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1219 num_bytes, num_bytes, type);
1220 BUG_ON(ret);
1222 if (root->root_key.objectid ==
1223 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1224 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1225 num_bytes);
1226 BUG_ON(ret);
1229 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
1230 cur_offset, cur_offset + num_bytes - 1,
1231 locked_page, EXTENT_CLEAR_UNLOCK_PAGE |
1232 EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
1233 EXTENT_SET_PRIVATE2);
1234 cur_offset = extent_end;
1235 if (cur_offset > end)
1236 break;
1238 btrfs_release_path(path);
1240 if (cur_offset <= end && cow_start == (u64)-1)
1241 cow_start = cur_offset;
1242 if (cow_start != (u64)-1) {
1243 ret = cow_file_range(inode, locked_page, cow_start, end,
1244 page_started, nr_written, 1);
1245 BUG_ON(ret);
1248 if (nolock) {
1249 ret = btrfs_end_transaction_nolock(trans, root);
1250 BUG_ON(ret);
1251 } else {
1252 ret = btrfs_end_transaction(trans, root);
1253 BUG_ON(ret);
1255 btrfs_free_path(path);
1256 return 0;
1260 * extent_io.c call back to do delayed allocation processing
1262 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1263 u64 start, u64 end, int *page_started,
1264 unsigned long *nr_written)
1266 int ret;
1267 struct btrfs_root *root = BTRFS_I(inode)->root;
1269 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW)
1270 ret = run_delalloc_nocow(inode, locked_page, start, end,
1271 page_started, 1, nr_written);
1272 else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC)
1273 ret = run_delalloc_nocow(inode, locked_page, start, end,
1274 page_started, 0, nr_written);
1275 else if (!btrfs_test_opt(root, COMPRESS) &&
1276 !(BTRFS_I(inode)->force_compress) &&
1277 !(BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))
1278 ret = cow_file_range(inode, locked_page, start, end,
1279 page_started, nr_written, 1);
1280 else
1281 ret = cow_file_range_async(inode, locked_page, start, end,
1282 page_started, nr_written);
1283 return ret;
1286 static void btrfs_split_extent_hook(struct inode *inode,
1287 struct extent_state *orig, u64 split)
1289 /* not delalloc, ignore it */
1290 if (!(orig->state & EXTENT_DELALLOC))
1291 return;
1293 spin_lock(&BTRFS_I(inode)->lock);
1294 BTRFS_I(inode)->outstanding_extents++;
1295 spin_unlock(&BTRFS_I(inode)->lock);
1299 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1300 * extents so we can keep track of new extents that are just merged onto old
1301 * extents, such as when we are doing sequential writes, so we can properly
1302 * account for the metadata space we'll need.
1304 static void btrfs_merge_extent_hook(struct inode *inode,
1305 struct extent_state *new,
1306 struct extent_state *other)
1308 /* not delalloc, ignore it */
1309 if (!(other->state & EXTENT_DELALLOC))
1310 return;
1312 spin_lock(&BTRFS_I(inode)->lock);
1313 BTRFS_I(inode)->outstanding_extents--;
1314 spin_unlock(&BTRFS_I(inode)->lock);
1318 * extent_io.c set_bit_hook, used to track delayed allocation
1319 * bytes in this file, and to maintain the list of inodes that
1320 * have pending delalloc work to be done.
1322 static void btrfs_set_bit_hook(struct inode *inode,
1323 struct extent_state *state, int *bits)
1327 * set_bit and clear bit hooks normally require _irqsave/restore
1328 * but in this case, we are only testing for the DELALLOC
1329 * bit, which is only set or cleared with irqs on
1331 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1332 struct btrfs_root *root = BTRFS_I(inode)->root;
1333 u64 len = state->end + 1 - state->start;
1334 bool do_list = !btrfs_is_free_space_inode(root, inode);
1336 if (*bits & EXTENT_FIRST_DELALLOC) {
1337 *bits &= ~EXTENT_FIRST_DELALLOC;
1338 } else {
1339 spin_lock(&BTRFS_I(inode)->lock);
1340 BTRFS_I(inode)->outstanding_extents++;
1341 spin_unlock(&BTRFS_I(inode)->lock);
1344 spin_lock(&root->fs_info->delalloc_lock);
1345 BTRFS_I(inode)->delalloc_bytes += len;
1346 root->fs_info->delalloc_bytes += len;
1347 if (do_list && list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1348 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1349 &root->fs_info->delalloc_inodes);
1351 spin_unlock(&root->fs_info->delalloc_lock);
1356 * extent_io.c clear_bit_hook, see set_bit_hook for why
1358 static void btrfs_clear_bit_hook(struct inode *inode,
1359 struct extent_state *state, int *bits)
1362 * set_bit and clear bit hooks normally require _irqsave/restore
1363 * but in this case, we are only testing for the DELALLOC
1364 * bit, which is only set or cleared with irqs on
1366 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1367 struct btrfs_root *root = BTRFS_I(inode)->root;
1368 u64 len = state->end + 1 - state->start;
1369 bool do_list = !btrfs_is_free_space_inode(root, inode);
1371 if (*bits & EXTENT_FIRST_DELALLOC) {
1372 *bits &= ~EXTENT_FIRST_DELALLOC;
1373 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1374 spin_lock(&BTRFS_I(inode)->lock);
1375 BTRFS_I(inode)->outstanding_extents--;
1376 spin_unlock(&BTRFS_I(inode)->lock);
1379 if (*bits & EXTENT_DO_ACCOUNTING)
1380 btrfs_delalloc_release_metadata(inode, len);
1382 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1383 && do_list)
1384 btrfs_free_reserved_data_space(inode, len);
1386 spin_lock(&root->fs_info->delalloc_lock);
1387 root->fs_info->delalloc_bytes -= len;
1388 BTRFS_I(inode)->delalloc_bytes -= len;
1390 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1391 !list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1392 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1394 spin_unlock(&root->fs_info->delalloc_lock);
1399 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1400 * we don't create bios that span stripes or chunks
1402 int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
1403 size_t size, struct bio *bio,
1404 unsigned long bio_flags)
1406 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1407 struct btrfs_mapping_tree *map_tree;
1408 u64 logical = (u64)bio->bi_sector << 9;
1409 u64 length = 0;
1410 u64 map_length;
1411 int ret;
1413 if (bio_flags & EXTENT_BIO_COMPRESSED)
1414 return 0;
1416 length = bio->bi_size;
1417 map_tree = &root->fs_info->mapping_tree;
1418 map_length = length;
1419 ret = btrfs_map_block(map_tree, READ, logical,
1420 &map_length, NULL, 0);
1422 if (map_length < length + size)
1423 return 1;
1424 return ret;
1428 * in order to insert checksums into the metadata in large chunks,
1429 * we wait until bio submission time. All the pages in the bio are
1430 * checksummed and sums are attached onto the ordered extent record.
1432 * At IO completion time the cums attached on the ordered extent record
1433 * are inserted into the btree
1435 static int __btrfs_submit_bio_start(struct inode *inode, int rw,
1436 struct bio *bio, int mirror_num,
1437 unsigned long bio_flags,
1438 u64 bio_offset)
1440 struct btrfs_root *root = BTRFS_I(inode)->root;
1441 int ret = 0;
1443 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1444 BUG_ON(ret);
1445 return 0;
1449 * in order to insert checksums into the metadata in large chunks,
1450 * we wait until bio submission time. All the pages in the bio are
1451 * checksummed and sums are attached onto the ordered extent record.
1453 * At IO completion time the cums attached on the ordered extent record
1454 * are inserted into the btree
1456 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1457 int mirror_num, unsigned long bio_flags,
1458 u64 bio_offset)
1460 struct btrfs_root *root = BTRFS_I(inode)->root;
1461 return btrfs_map_bio(root, rw, bio, mirror_num, 1);
1465 * extent_io.c submission hook. This does the right thing for csum calculation
1466 * on write, or reading the csums from the tree before a read
1468 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1469 int mirror_num, unsigned long bio_flags,
1470 u64 bio_offset)
1472 struct btrfs_root *root = BTRFS_I(inode)->root;
1473 int ret = 0;
1474 int skip_sum;
1476 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1478 if (btrfs_is_free_space_inode(root, inode))
1479 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 2);
1480 else
1481 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
1482 BUG_ON(ret);
1484 if (!(rw & REQ_WRITE)) {
1485 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1486 return btrfs_submit_compressed_read(inode, bio,
1487 mirror_num, bio_flags);
1488 } else if (!skip_sum) {
1489 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1490 if (ret)
1491 return ret;
1493 goto mapit;
1494 } else if (!skip_sum) {
1495 /* csum items have already been cloned */
1496 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1497 goto mapit;
1498 /* we're doing a write, do the async checksumming */
1499 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1500 inode, rw, bio, mirror_num,
1501 bio_flags, bio_offset,
1502 __btrfs_submit_bio_start,
1503 __btrfs_submit_bio_done);
1506 mapit:
1507 return btrfs_map_bio(root, rw, bio, mirror_num, 0);
1511 * given a list of ordered sums record them in the inode. This happens
1512 * at IO completion time based on sums calculated at bio submission time.
1514 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1515 struct inode *inode, u64 file_offset,
1516 struct list_head *list)
1518 struct btrfs_ordered_sum *sum;
1520 list_for_each_entry(sum, list, list) {
1521 btrfs_csum_file_blocks(trans,
1522 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1524 return 0;
1527 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1528 struct extent_state **cached_state)
1530 if ((end & (PAGE_CACHE_SIZE - 1)) == 0)
1531 WARN_ON(1);
1532 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1533 cached_state, GFP_NOFS);
1536 /* see btrfs_writepage_start_hook for details on why this is required */
1537 struct btrfs_writepage_fixup {
1538 struct page *page;
1539 struct btrfs_work work;
1542 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1544 struct btrfs_writepage_fixup *fixup;
1545 struct btrfs_ordered_extent *ordered;
1546 struct extent_state *cached_state = NULL;
1547 struct page *page;
1548 struct inode *inode;
1549 u64 page_start;
1550 u64 page_end;
1552 fixup = container_of(work, struct btrfs_writepage_fixup, work);
1553 page = fixup->page;
1554 again:
1555 lock_page(page);
1556 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
1557 ClearPageChecked(page);
1558 goto out_page;
1561 inode = page->mapping->host;
1562 page_start = page_offset(page);
1563 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
1565 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0,
1566 &cached_state, GFP_NOFS);
1568 /* already ordered? We're done */
1569 if (PagePrivate2(page))
1570 goto out;
1572 ordered = btrfs_lookup_ordered_extent(inode, page_start);
1573 if (ordered) {
1574 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
1575 page_end, &cached_state, GFP_NOFS);
1576 unlock_page(page);
1577 btrfs_start_ordered_extent(inode, ordered, 1);
1578 goto again;
1581 BUG();
1582 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
1583 ClearPageChecked(page);
1584 out:
1585 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
1586 &cached_state, GFP_NOFS);
1587 out_page:
1588 unlock_page(page);
1589 page_cache_release(page);
1590 kfree(fixup);
1594 * There are a few paths in the higher layers of the kernel that directly
1595 * set the page dirty bit without asking the filesystem if it is a
1596 * good idea. This causes problems because we want to make sure COW
1597 * properly happens and the data=ordered rules are followed.
1599 * In our case any range that doesn't have the ORDERED bit set
1600 * hasn't been properly setup for IO. We kick off an async process
1601 * to fix it up. The async helper will wait for ordered extents, set
1602 * the delalloc bit and make it safe to write the page.
1604 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
1606 struct inode *inode = page->mapping->host;
1607 struct btrfs_writepage_fixup *fixup;
1608 struct btrfs_root *root = BTRFS_I(inode)->root;
1610 /* this page is properly in the ordered list */
1611 if (TestClearPagePrivate2(page))
1612 return 0;
1614 if (PageChecked(page))
1615 return -EAGAIN;
1617 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
1618 if (!fixup)
1619 return -EAGAIN;
1621 SetPageChecked(page);
1622 page_cache_get(page);
1623 fixup->work.func = btrfs_writepage_fixup_worker;
1624 fixup->page = page;
1625 btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work);
1626 return -EAGAIN;
1629 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
1630 struct inode *inode, u64 file_pos,
1631 u64 disk_bytenr, u64 disk_num_bytes,
1632 u64 num_bytes, u64 ram_bytes,
1633 u8 compression, u8 encryption,
1634 u16 other_encoding, int extent_type)
1636 struct btrfs_root *root = BTRFS_I(inode)->root;
1637 struct btrfs_file_extent_item *fi;
1638 struct btrfs_path *path;
1639 struct extent_buffer *leaf;
1640 struct btrfs_key ins;
1641 u64 hint;
1642 int ret;
1644 path = btrfs_alloc_path();
1645 if (!path)
1646 return -ENOMEM;
1648 path->leave_spinning = 1;
1651 * we may be replacing one extent in the tree with another.
1652 * The new extent is pinned in the extent map, and we don't want
1653 * to drop it from the cache until it is completely in the btree.
1655 * So, tell btrfs_drop_extents to leave this extent in the cache.
1656 * the caller is expected to unpin it and allow it to be merged
1657 * with the others.
1659 ret = btrfs_drop_extents(trans, inode, file_pos, file_pos + num_bytes,
1660 &hint, 0);
1661 BUG_ON(ret);
1663 ins.objectid = btrfs_ino(inode);
1664 ins.offset = file_pos;
1665 ins.type = BTRFS_EXTENT_DATA_KEY;
1666 ret = btrfs_insert_empty_item(trans, root, path, &ins, sizeof(*fi));
1667 BUG_ON(ret);
1668 leaf = path->nodes[0];
1669 fi = btrfs_item_ptr(leaf, path->slots[0],
1670 struct btrfs_file_extent_item);
1671 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1672 btrfs_set_file_extent_type(leaf, fi, extent_type);
1673 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
1674 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
1675 btrfs_set_file_extent_offset(leaf, fi, 0);
1676 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
1677 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
1678 btrfs_set_file_extent_compression(leaf, fi, compression);
1679 btrfs_set_file_extent_encryption(leaf, fi, encryption);
1680 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
1682 btrfs_unlock_up_safe(path, 1);
1683 btrfs_set_lock_blocking(leaf);
1685 btrfs_mark_buffer_dirty(leaf);
1687 inode_add_bytes(inode, num_bytes);
1689 ins.objectid = disk_bytenr;
1690 ins.offset = disk_num_bytes;
1691 ins.type = BTRFS_EXTENT_ITEM_KEY;
1692 ret = btrfs_alloc_reserved_file_extent(trans, root,
1693 root->root_key.objectid,
1694 btrfs_ino(inode), file_pos, &ins);
1695 BUG_ON(ret);
1696 btrfs_free_path(path);
1698 return 0;
1702 * helper function for btrfs_finish_ordered_io, this
1703 * just reads in some of the csum leaves to prime them into ram
1704 * before we start the transaction. It limits the amount of btree
1705 * reads required while inside the transaction.
1707 /* as ordered data IO finishes, this gets called so we can finish
1708 * an ordered extent if the range of bytes in the file it covers are
1709 * fully written.
1711 static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
1713 struct btrfs_root *root = BTRFS_I(inode)->root;
1714 struct btrfs_trans_handle *trans = NULL;
1715 struct btrfs_ordered_extent *ordered_extent = NULL;
1716 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1717 struct extent_state *cached_state = NULL;
1718 int compress_type = 0;
1719 int ret;
1720 bool nolock;
1722 ret = btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
1723 end - start + 1);
1724 if (!ret)
1725 return 0;
1726 BUG_ON(!ordered_extent);
1728 nolock = btrfs_is_free_space_inode(root, inode);
1730 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
1731 BUG_ON(!list_empty(&ordered_extent->list));
1732 ret = btrfs_ordered_update_i_size(inode, 0, ordered_extent);
1733 if (!ret) {
1734 if (nolock)
1735 trans = btrfs_join_transaction_nolock(root);
1736 else
1737 trans = btrfs_join_transaction(root);
1738 BUG_ON(IS_ERR(trans));
1739 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1740 ret = btrfs_update_inode(trans, root, inode);
1741 BUG_ON(ret);
1743 goto out;
1746 lock_extent_bits(io_tree, ordered_extent->file_offset,
1747 ordered_extent->file_offset + ordered_extent->len - 1,
1748 0, &cached_state, GFP_NOFS);
1750 if (nolock)
1751 trans = btrfs_join_transaction_nolock(root);
1752 else
1753 trans = btrfs_join_transaction(root);
1754 BUG_ON(IS_ERR(trans));
1755 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1757 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
1758 compress_type = ordered_extent->compress_type;
1759 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
1760 BUG_ON(compress_type);
1761 ret = btrfs_mark_extent_written(trans, inode,
1762 ordered_extent->file_offset,
1763 ordered_extent->file_offset +
1764 ordered_extent->len);
1765 BUG_ON(ret);
1766 } else {
1767 BUG_ON(root == root->fs_info->tree_root);
1768 ret = insert_reserved_file_extent(trans, inode,
1769 ordered_extent->file_offset,
1770 ordered_extent->start,
1771 ordered_extent->disk_len,
1772 ordered_extent->len,
1773 ordered_extent->len,
1774 compress_type, 0, 0,
1775 BTRFS_FILE_EXTENT_REG);
1776 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
1777 ordered_extent->file_offset,
1778 ordered_extent->len);
1779 BUG_ON(ret);
1781 unlock_extent_cached(io_tree, ordered_extent->file_offset,
1782 ordered_extent->file_offset +
1783 ordered_extent->len - 1, &cached_state, GFP_NOFS);
1785 add_pending_csums(trans, inode, ordered_extent->file_offset,
1786 &ordered_extent->list);
1788 ret = btrfs_ordered_update_i_size(inode, 0, ordered_extent);
1789 if (!ret || !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
1790 ret = btrfs_update_inode(trans, root, inode);
1791 BUG_ON(ret);
1793 ret = 0;
1794 out:
1795 if (nolock) {
1796 if (trans)
1797 btrfs_end_transaction_nolock(trans, root);
1798 } else {
1799 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
1800 if (trans)
1801 btrfs_end_transaction(trans, root);
1804 /* once for us */
1805 btrfs_put_ordered_extent(ordered_extent);
1806 /* once for the tree */
1807 btrfs_put_ordered_extent(ordered_extent);
1809 return 0;
1812 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
1813 struct extent_state *state, int uptodate)
1815 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
1817 ClearPagePrivate2(page);
1818 return btrfs_finish_ordered_io(page->mapping->host, start, end);
1822 * When IO fails, either with EIO or csum verification fails, we
1823 * try other mirrors that might have a good copy of the data. This
1824 * io_failure_record is used to record state as we go through all the
1825 * mirrors. If another mirror has good data, the page is set up to date
1826 * and things continue. If a good mirror can't be found, the original
1827 * bio end_io callback is called to indicate things have failed.
1829 struct io_failure_record {
1830 struct page *page;
1831 u64 start;
1832 u64 len;
1833 u64 logical;
1834 unsigned long bio_flags;
1835 int last_mirror;
1838 static int btrfs_io_failed_hook(struct bio *failed_bio,
1839 struct page *page, u64 start, u64 end,
1840 struct extent_state *state)
1842 struct io_failure_record *failrec = NULL;
1843 u64 private;
1844 struct extent_map *em;
1845 struct inode *inode = page->mapping->host;
1846 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
1847 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1848 struct bio *bio;
1849 int num_copies;
1850 int ret;
1851 int rw;
1852 u64 logical;
1854 ret = get_state_private(failure_tree, start, &private);
1855 if (ret) {
1856 failrec = kmalloc(sizeof(*failrec), GFP_NOFS);
1857 if (!failrec)
1858 return -ENOMEM;
1859 failrec->start = start;
1860 failrec->len = end - start + 1;
1861 failrec->last_mirror = 0;
1862 failrec->bio_flags = 0;
1864 read_lock(&em_tree->lock);
1865 em = lookup_extent_mapping(em_tree, start, failrec->len);
1866 if (em->start > start || em->start + em->len < start) {
1867 free_extent_map(em);
1868 em = NULL;
1870 read_unlock(&em_tree->lock);
1872 if (IS_ERR_OR_NULL(em)) {
1873 kfree(failrec);
1874 return -EIO;
1876 logical = start - em->start;
1877 logical = em->block_start + logical;
1878 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
1879 logical = em->block_start;
1880 failrec->bio_flags = EXTENT_BIO_COMPRESSED;
1881 extent_set_compress_type(&failrec->bio_flags,
1882 em->compress_type);
1884 failrec->logical = logical;
1885 free_extent_map(em);
1886 set_extent_bits(failure_tree, start, end, EXTENT_LOCKED |
1887 EXTENT_DIRTY, GFP_NOFS);
1888 set_state_private(failure_tree, start,
1889 (u64)(unsigned long)failrec);
1890 } else {
1891 failrec = (struct io_failure_record *)(unsigned long)private;
1893 num_copies = btrfs_num_copies(
1894 &BTRFS_I(inode)->root->fs_info->mapping_tree,
1895 failrec->logical, failrec->len);
1896 failrec->last_mirror++;
1897 if (!state) {
1898 spin_lock(&BTRFS_I(inode)->io_tree.lock);
1899 state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree,
1900 failrec->start,
1901 EXTENT_LOCKED);
1902 if (state && state->start != failrec->start)
1903 state = NULL;
1904 spin_unlock(&BTRFS_I(inode)->io_tree.lock);
1906 if (!state || failrec->last_mirror > num_copies) {
1907 set_state_private(failure_tree, failrec->start, 0);
1908 clear_extent_bits(failure_tree, failrec->start,
1909 failrec->start + failrec->len - 1,
1910 EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
1911 kfree(failrec);
1912 return -EIO;
1914 bio = bio_alloc(GFP_NOFS, 1);
1915 bio->bi_private = state;
1916 bio->bi_end_io = failed_bio->bi_end_io;
1917 bio->bi_sector = failrec->logical >> 9;
1918 bio->bi_bdev = failed_bio->bi_bdev;
1919 bio->bi_size = 0;
1921 bio_add_page(bio, page, failrec->len, start - page_offset(page));
1922 if (failed_bio->bi_rw & REQ_WRITE)
1923 rw = WRITE;
1924 else
1925 rw = READ;
1927 ret = BTRFS_I(inode)->io_tree.ops->submit_bio_hook(inode, rw, bio,
1928 failrec->last_mirror,
1929 failrec->bio_flags, 0);
1930 return ret;
1934 * each time an IO finishes, we do a fast check in the IO failure tree
1935 * to see if we need to process or clean up an io_failure_record
1937 static int btrfs_clean_io_failures(struct inode *inode, u64 start)
1939 u64 private;
1940 u64 private_failure;
1941 struct io_failure_record *failure;
1942 int ret;
1944 private = 0;
1945 if (count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private,
1946 (u64)-1, 1, EXTENT_DIRTY, 0)) {
1947 ret = get_state_private(&BTRFS_I(inode)->io_failure_tree,
1948 start, &private_failure);
1949 if (ret == 0) {
1950 failure = (struct io_failure_record *)(unsigned long)
1951 private_failure;
1952 set_state_private(&BTRFS_I(inode)->io_failure_tree,
1953 failure->start, 0);
1954 clear_extent_bits(&BTRFS_I(inode)->io_failure_tree,
1955 failure->start,
1956 failure->start + failure->len - 1,
1957 EXTENT_DIRTY | EXTENT_LOCKED,
1958 GFP_NOFS);
1959 kfree(failure);
1962 return 0;
1966 * when reads are done, we need to check csums to verify the data is correct
1967 * if there's a match, we allow the bio to finish. If not, we go through
1968 * the io_failure_record routines to find good copies
1970 static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
1971 struct extent_state *state)
1973 size_t offset = start - ((u64)page->index << PAGE_CACHE_SHIFT);
1974 struct inode *inode = page->mapping->host;
1975 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1976 char *kaddr;
1977 u64 private = ~(u32)0;
1978 int ret;
1979 struct btrfs_root *root = BTRFS_I(inode)->root;
1980 u32 csum = ~(u32)0;
1982 if (PageChecked(page)) {
1983 ClearPageChecked(page);
1984 goto good;
1987 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
1988 goto good;
1990 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
1991 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
1992 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
1993 GFP_NOFS);
1994 return 0;
1997 if (state && state->start == start) {
1998 private = state->private;
1999 ret = 0;
2000 } else {
2001 ret = get_state_private(io_tree, start, &private);
2003 kaddr = kmap_atomic(page, KM_USER0);
2004 if (ret)
2005 goto zeroit;
2007 csum = btrfs_csum_data(root, kaddr + offset, csum, end - start + 1);
2008 btrfs_csum_final(csum, (char *)&csum);
2009 if (csum != private)
2010 goto zeroit;
2012 kunmap_atomic(kaddr, KM_USER0);
2013 good:
2014 /* if the io failure tree for this inode is non-empty,
2015 * check to see if we've recovered from a failed IO
2017 btrfs_clean_io_failures(inode, start);
2018 return 0;
2020 zeroit:
2021 printk_ratelimited(KERN_INFO "btrfs csum failed ino %llu off %llu csum %u "
2022 "private %llu\n",
2023 (unsigned long long)btrfs_ino(page->mapping->host),
2024 (unsigned long long)start, csum,
2025 (unsigned long long)private);
2026 memset(kaddr + offset, 1, end - start + 1);
2027 flush_dcache_page(page);
2028 kunmap_atomic(kaddr, KM_USER0);
2029 if (private == 0)
2030 return 0;
2031 return -EIO;
2034 struct delayed_iput {
2035 struct list_head list;
2036 struct inode *inode;
2039 void btrfs_add_delayed_iput(struct inode *inode)
2041 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2042 struct delayed_iput *delayed;
2044 if (atomic_add_unless(&inode->i_count, -1, 1))
2045 return;
2047 delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL);
2048 delayed->inode = inode;
2050 spin_lock(&fs_info->delayed_iput_lock);
2051 list_add_tail(&delayed->list, &fs_info->delayed_iputs);
2052 spin_unlock(&fs_info->delayed_iput_lock);
2055 void btrfs_run_delayed_iputs(struct btrfs_root *root)
2057 LIST_HEAD(list);
2058 struct btrfs_fs_info *fs_info = root->fs_info;
2059 struct delayed_iput *delayed;
2060 int empty;
2062 spin_lock(&fs_info->delayed_iput_lock);
2063 empty = list_empty(&fs_info->delayed_iputs);
2064 spin_unlock(&fs_info->delayed_iput_lock);
2065 if (empty)
2066 return;
2068 down_read(&root->fs_info->cleanup_work_sem);
2069 spin_lock(&fs_info->delayed_iput_lock);
2070 list_splice_init(&fs_info->delayed_iputs, &list);
2071 spin_unlock(&fs_info->delayed_iput_lock);
2073 while (!list_empty(&list)) {
2074 delayed = list_entry(list.next, struct delayed_iput, list);
2075 list_del(&delayed->list);
2076 iput(delayed->inode);
2077 kfree(delayed);
2079 up_read(&root->fs_info->cleanup_work_sem);
2083 * calculate extra metadata reservation when snapshotting a subvolume
2084 * contains orphan files.
2086 void btrfs_orphan_pre_snapshot(struct btrfs_trans_handle *trans,
2087 struct btrfs_pending_snapshot *pending,
2088 u64 *bytes_to_reserve)
2090 struct btrfs_root *root;
2091 struct btrfs_block_rsv *block_rsv;
2092 u64 num_bytes;
2093 int index;
2095 root = pending->root;
2096 if (!root->orphan_block_rsv || list_empty(&root->orphan_list))
2097 return;
2099 block_rsv = root->orphan_block_rsv;
2101 /* orphan block reservation for the snapshot */
2102 num_bytes = block_rsv->size;
2105 * after the snapshot is created, COWing tree blocks may use more
2106 * space than it frees. So we should make sure there is enough
2107 * reserved space.
2109 index = trans->transid & 0x1;
2110 if (block_rsv->reserved + block_rsv->freed[index] < block_rsv->size) {
2111 num_bytes += block_rsv->size -
2112 (block_rsv->reserved + block_rsv->freed[index]);
2115 *bytes_to_reserve += num_bytes;
2118 void btrfs_orphan_post_snapshot(struct btrfs_trans_handle *trans,
2119 struct btrfs_pending_snapshot *pending)
2121 struct btrfs_root *root = pending->root;
2122 struct btrfs_root *snap = pending->snap;
2123 struct btrfs_block_rsv *block_rsv;
2124 u64 num_bytes;
2125 int index;
2126 int ret;
2128 if (!root->orphan_block_rsv || list_empty(&root->orphan_list))
2129 return;
2131 /* refill source subvolume's orphan block reservation */
2132 block_rsv = root->orphan_block_rsv;
2133 index = trans->transid & 0x1;
2134 if (block_rsv->reserved + block_rsv->freed[index] < block_rsv->size) {
2135 num_bytes = block_rsv->size -
2136 (block_rsv->reserved + block_rsv->freed[index]);
2137 ret = btrfs_block_rsv_migrate(&pending->block_rsv,
2138 root->orphan_block_rsv,
2139 num_bytes);
2140 BUG_ON(ret);
2143 /* setup orphan block reservation for the snapshot */
2144 block_rsv = btrfs_alloc_block_rsv(snap);
2145 BUG_ON(!block_rsv);
2147 btrfs_add_durable_block_rsv(root->fs_info, block_rsv);
2148 snap->orphan_block_rsv = block_rsv;
2150 num_bytes = root->orphan_block_rsv->size;
2151 ret = btrfs_block_rsv_migrate(&pending->block_rsv,
2152 block_rsv, num_bytes);
2153 BUG_ON(ret);
2155 #if 0
2156 /* insert orphan item for the snapshot */
2157 WARN_ON(!root->orphan_item_inserted);
2158 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
2159 snap->root_key.objectid);
2160 BUG_ON(ret);
2161 snap->orphan_item_inserted = 1;
2162 #endif
2165 enum btrfs_orphan_cleanup_state {
2166 ORPHAN_CLEANUP_STARTED = 1,
2167 ORPHAN_CLEANUP_DONE = 2,
2171 * This is called in transaction commmit time. If there are no orphan
2172 * files in the subvolume, it removes orphan item and frees block_rsv
2173 * structure.
2175 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
2176 struct btrfs_root *root)
2178 int ret;
2180 if (!list_empty(&root->orphan_list) ||
2181 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
2182 return;
2184 if (root->orphan_item_inserted &&
2185 btrfs_root_refs(&root->root_item) > 0) {
2186 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
2187 root->root_key.objectid);
2188 BUG_ON(ret);
2189 root->orphan_item_inserted = 0;
2192 if (root->orphan_block_rsv) {
2193 WARN_ON(root->orphan_block_rsv->size > 0);
2194 btrfs_free_block_rsv(root, root->orphan_block_rsv);
2195 root->orphan_block_rsv = NULL;
2200 * This creates an orphan entry for the given inode in case something goes
2201 * wrong in the middle of an unlink/truncate.
2203 * NOTE: caller of this function should reserve 5 units of metadata for
2204 * this function.
2206 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
2208 struct btrfs_root *root = BTRFS_I(inode)->root;
2209 struct btrfs_block_rsv *block_rsv = NULL;
2210 int reserve = 0;
2211 int insert = 0;
2212 int ret;
2214 if (!root->orphan_block_rsv) {
2215 block_rsv = btrfs_alloc_block_rsv(root);
2216 if (!block_rsv)
2217 return -ENOMEM;
2220 spin_lock(&root->orphan_lock);
2221 if (!root->orphan_block_rsv) {
2222 root->orphan_block_rsv = block_rsv;
2223 } else if (block_rsv) {
2224 btrfs_free_block_rsv(root, block_rsv);
2225 block_rsv = NULL;
2228 if (list_empty(&BTRFS_I(inode)->i_orphan)) {
2229 list_add(&BTRFS_I(inode)->i_orphan, &root->orphan_list);
2230 #if 0
2232 * For proper ENOSPC handling, we should do orphan
2233 * cleanup when mounting. But this introduces backward
2234 * compatibility issue.
2236 if (!xchg(&root->orphan_item_inserted, 1))
2237 insert = 2;
2238 else
2239 insert = 1;
2240 #endif
2241 insert = 1;
2244 if (!BTRFS_I(inode)->orphan_meta_reserved) {
2245 BTRFS_I(inode)->orphan_meta_reserved = 1;
2246 reserve = 1;
2248 spin_unlock(&root->orphan_lock);
2250 if (block_rsv)
2251 btrfs_add_durable_block_rsv(root->fs_info, block_rsv);
2253 /* grab metadata reservation from transaction handle */
2254 if (reserve) {
2255 ret = btrfs_orphan_reserve_metadata(trans, inode);
2256 BUG_ON(ret);
2259 /* insert an orphan item to track this unlinked/truncated file */
2260 if (insert >= 1) {
2261 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
2262 BUG_ON(ret);
2265 /* insert an orphan item to track subvolume contains orphan files */
2266 if (insert >= 2) {
2267 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
2268 root->root_key.objectid);
2269 BUG_ON(ret);
2271 return 0;
2275 * We have done the truncate/delete so we can go ahead and remove the orphan
2276 * item for this particular inode.
2278 int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode)
2280 struct btrfs_root *root = BTRFS_I(inode)->root;
2281 int delete_item = 0;
2282 int release_rsv = 0;
2283 int ret = 0;
2285 spin_lock(&root->orphan_lock);
2286 if (!list_empty(&BTRFS_I(inode)->i_orphan)) {
2287 list_del_init(&BTRFS_I(inode)->i_orphan);
2288 delete_item = 1;
2291 if (BTRFS_I(inode)->orphan_meta_reserved) {
2292 BTRFS_I(inode)->orphan_meta_reserved = 0;
2293 release_rsv = 1;
2295 spin_unlock(&root->orphan_lock);
2297 if (trans && delete_item) {
2298 ret = btrfs_del_orphan_item(trans, root, btrfs_ino(inode));
2299 BUG_ON(ret);
2302 if (release_rsv)
2303 btrfs_orphan_release_metadata(inode);
2305 return 0;
2309 * this cleans up any orphans that may be left on the list from the last use
2310 * of this root.
2312 int btrfs_orphan_cleanup(struct btrfs_root *root)
2314 struct btrfs_path *path;
2315 struct extent_buffer *leaf;
2316 struct btrfs_key key, found_key;
2317 struct btrfs_trans_handle *trans;
2318 struct inode *inode;
2319 int ret = 0, nr_unlink = 0, nr_truncate = 0;
2321 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
2322 return 0;
2324 path = btrfs_alloc_path();
2325 if (!path) {
2326 ret = -ENOMEM;
2327 goto out;
2329 path->reada = -1;
2331 key.objectid = BTRFS_ORPHAN_OBJECTID;
2332 btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
2333 key.offset = (u64)-1;
2335 while (1) {
2336 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2337 if (ret < 0)
2338 goto out;
2341 * if ret == 0 means we found what we were searching for, which
2342 * is weird, but possible, so only screw with path if we didn't
2343 * find the key and see if we have stuff that matches
2345 if (ret > 0) {
2346 ret = 0;
2347 if (path->slots[0] == 0)
2348 break;
2349 path->slots[0]--;
2352 /* pull out the item */
2353 leaf = path->nodes[0];
2354 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2356 /* make sure the item matches what we want */
2357 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
2358 break;
2359 if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY)
2360 break;
2362 /* release the path since we're done with it */
2363 btrfs_release_path(path);
2366 * this is where we are basically btrfs_lookup, without the
2367 * crossing root thing. we store the inode number in the
2368 * offset of the orphan item.
2370 found_key.objectid = found_key.offset;
2371 found_key.type = BTRFS_INODE_ITEM_KEY;
2372 found_key.offset = 0;
2373 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
2374 if (IS_ERR(inode)) {
2375 ret = PTR_ERR(inode);
2376 goto out;
2380 * add this inode to the orphan list so btrfs_orphan_del does
2381 * the proper thing when we hit it
2383 spin_lock(&root->orphan_lock);
2384 list_add(&BTRFS_I(inode)->i_orphan, &root->orphan_list);
2385 spin_unlock(&root->orphan_lock);
2388 * if this is a bad inode, means we actually succeeded in
2389 * removing the inode, but not the orphan record, which means
2390 * we need to manually delete the orphan since iput will just
2391 * do a destroy_inode
2393 if (is_bad_inode(inode)) {
2394 trans = btrfs_start_transaction(root, 0);
2395 if (IS_ERR(trans)) {
2396 ret = PTR_ERR(trans);
2397 goto out;
2399 btrfs_orphan_del(trans, inode);
2400 btrfs_end_transaction(trans, root);
2401 iput(inode);
2402 continue;
2405 /* if we have links, this was a truncate, lets do that */
2406 if (inode->i_nlink) {
2407 if (!S_ISREG(inode->i_mode)) {
2408 WARN_ON(1);
2409 iput(inode);
2410 continue;
2412 nr_truncate++;
2413 ret = btrfs_truncate(inode);
2414 } else {
2415 nr_unlink++;
2418 /* this will do delete_inode and everything for us */
2419 iput(inode);
2420 if (ret)
2421 goto out;
2423 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
2425 if (root->orphan_block_rsv)
2426 btrfs_block_rsv_release(root, root->orphan_block_rsv,
2427 (u64)-1);
2429 if (root->orphan_block_rsv || root->orphan_item_inserted) {
2430 trans = btrfs_join_transaction(root);
2431 if (!IS_ERR(trans))
2432 btrfs_end_transaction(trans, root);
2435 if (nr_unlink)
2436 printk(KERN_INFO "btrfs: unlinked %d orphans\n", nr_unlink);
2437 if (nr_truncate)
2438 printk(KERN_INFO "btrfs: truncated %d orphans\n", nr_truncate);
2440 out:
2441 if (ret)
2442 printk(KERN_CRIT "btrfs: could not do orphan cleanup %d\n", ret);
2443 btrfs_free_path(path);
2444 return ret;
2448 * very simple check to peek ahead in the leaf looking for xattrs. If we
2449 * don't find any xattrs, we know there can't be any acls.
2451 * slot is the slot the inode is in, objectid is the objectid of the inode
2453 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
2454 int slot, u64 objectid)
2456 u32 nritems = btrfs_header_nritems(leaf);
2457 struct btrfs_key found_key;
2458 int scanned = 0;
2460 slot++;
2461 while (slot < nritems) {
2462 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2464 /* we found a different objectid, there must not be acls */
2465 if (found_key.objectid != objectid)
2466 return 0;
2468 /* we found an xattr, assume we've got an acl */
2469 if (found_key.type == BTRFS_XATTR_ITEM_KEY)
2470 return 1;
2473 * we found a key greater than an xattr key, there can't
2474 * be any acls later on
2476 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
2477 return 0;
2479 slot++;
2480 scanned++;
2483 * it goes inode, inode backrefs, xattrs, extents,
2484 * so if there are a ton of hard links to an inode there can
2485 * be a lot of backrefs. Don't waste time searching too hard,
2486 * this is just an optimization
2488 if (scanned >= 8)
2489 break;
2491 /* we hit the end of the leaf before we found an xattr or
2492 * something larger than an xattr. We have to assume the inode
2493 * has acls
2495 return 1;
2499 * read an inode from the btree into the in-memory inode
2501 static void btrfs_read_locked_inode(struct inode *inode)
2503 struct btrfs_path *path;
2504 struct extent_buffer *leaf;
2505 struct btrfs_inode_item *inode_item;
2506 struct btrfs_timespec *tspec;
2507 struct btrfs_root *root = BTRFS_I(inode)->root;
2508 struct btrfs_key location;
2509 int maybe_acls;
2510 u32 rdev;
2511 int ret;
2512 bool filled = false;
2514 ret = btrfs_fill_inode(inode, &rdev);
2515 if (!ret)
2516 filled = true;
2518 path = btrfs_alloc_path();
2519 if (!path)
2520 goto make_bad;
2522 path->leave_spinning = 1;
2523 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
2525 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
2526 if (ret)
2527 goto make_bad;
2529 leaf = path->nodes[0];
2531 if (filled)
2532 goto cache_acl;
2534 inode_item = btrfs_item_ptr(leaf, path->slots[0],
2535 struct btrfs_inode_item);
2536 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
2537 inode->i_nlink = btrfs_inode_nlink(leaf, inode_item);
2538 inode->i_uid = btrfs_inode_uid(leaf, inode_item);
2539 inode->i_gid = btrfs_inode_gid(leaf, inode_item);
2540 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
2542 tspec = btrfs_inode_atime(inode_item);
2543 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
2544 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
2546 tspec = btrfs_inode_mtime(inode_item);
2547 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
2548 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
2550 tspec = btrfs_inode_ctime(inode_item);
2551 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
2552 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
2554 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
2555 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
2556 BTRFS_I(inode)->sequence = btrfs_inode_sequence(leaf, inode_item);
2557 inode->i_generation = BTRFS_I(inode)->generation;
2558 inode->i_rdev = 0;
2559 rdev = btrfs_inode_rdev(leaf, inode_item);
2561 BTRFS_I(inode)->index_cnt = (u64)-1;
2562 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
2563 cache_acl:
2565 * try to precache a NULL acl entry for files that don't have
2566 * any xattrs or acls
2568 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
2569 btrfs_ino(inode));
2570 if (!maybe_acls)
2571 cache_no_acl(inode);
2573 btrfs_free_path(path);
2575 switch (inode->i_mode & S_IFMT) {
2576 case S_IFREG:
2577 inode->i_mapping->a_ops = &btrfs_aops;
2578 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
2579 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
2580 inode->i_fop = &btrfs_file_operations;
2581 inode->i_op = &btrfs_file_inode_operations;
2582 break;
2583 case S_IFDIR:
2584 inode->i_fop = &btrfs_dir_file_operations;
2585 if (root == root->fs_info->tree_root)
2586 inode->i_op = &btrfs_dir_ro_inode_operations;
2587 else
2588 inode->i_op = &btrfs_dir_inode_operations;
2589 break;
2590 case S_IFLNK:
2591 inode->i_op = &btrfs_symlink_inode_operations;
2592 inode->i_mapping->a_ops = &btrfs_symlink_aops;
2593 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
2594 break;
2595 default:
2596 inode->i_op = &btrfs_special_inode_operations;
2597 init_special_inode(inode, inode->i_mode, rdev);
2598 break;
2601 btrfs_update_iflags(inode);
2602 return;
2604 make_bad:
2605 btrfs_free_path(path);
2606 make_bad_inode(inode);
2610 * given a leaf and an inode, copy the inode fields into the leaf
2612 static void fill_inode_item(struct btrfs_trans_handle *trans,
2613 struct extent_buffer *leaf,
2614 struct btrfs_inode_item *item,
2615 struct inode *inode)
2617 btrfs_set_inode_uid(leaf, item, inode->i_uid);
2618 btrfs_set_inode_gid(leaf, item, inode->i_gid);
2619 btrfs_set_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size);
2620 btrfs_set_inode_mode(leaf, item, inode->i_mode);
2621 btrfs_set_inode_nlink(leaf, item, inode->i_nlink);
2623 btrfs_set_timespec_sec(leaf, btrfs_inode_atime(item),
2624 inode->i_atime.tv_sec);
2625 btrfs_set_timespec_nsec(leaf, btrfs_inode_atime(item),
2626 inode->i_atime.tv_nsec);
2628 btrfs_set_timespec_sec(leaf, btrfs_inode_mtime(item),
2629 inode->i_mtime.tv_sec);
2630 btrfs_set_timespec_nsec(leaf, btrfs_inode_mtime(item),
2631 inode->i_mtime.tv_nsec);
2633 btrfs_set_timespec_sec(leaf, btrfs_inode_ctime(item),
2634 inode->i_ctime.tv_sec);
2635 btrfs_set_timespec_nsec(leaf, btrfs_inode_ctime(item),
2636 inode->i_ctime.tv_nsec);
2638 btrfs_set_inode_nbytes(leaf, item, inode_get_bytes(inode));
2639 btrfs_set_inode_generation(leaf, item, BTRFS_I(inode)->generation);
2640 btrfs_set_inode_sequence(leaf, item, BTRFS_I(inode)->sequence);
2641 btrfs_set_inode_transid(leaf, item, trans->transid);
2642 btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
2643 btrfs_set_inode_flags(leaf, item, BTRFS_I(inode)->flags);
2644 btrfs_set_inode_block_group(leaf, item, 0);
2648 * copy everything in the in-memory inode into the btree.
2650 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
2651 struct btrfs_root *root, struct inode *inode)
2653 struct btrfs_inode_item *inode_item;
2654 struct btrfs_path *path;
2655 struct extent_buffer *leaf;
2656 int ret;
2659 * If the inode is a free space inode, we can deadlock during commit
2660 * if we put it into the delayed code.
2662 * The data relocation inode should also be directly updated
2663 * without delay
2665 if (!btrfs_is_free_space_inode(root, inode)
2666 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID) {
2667 ret = btrfs_delayed_update_inode(trans, root, inode);
2668 if (!ret)
2669 btrfs_set_inode_last_trans(trans, inode);
2670 return ret;
2673 path = btrfs_alloc_path();
2674 if (!path)
2675 return -ENOMEM;
2677 path->leave_spinning = 1;
2678 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
2680 if (ret) {
2681 if (ret > 0)
2682 ret = -ENOENT;
2683 goto failed;
2686 btrfs_unlock_up_safe(path, 1);
2687 leaf = path->nodes[0];
2688 inode_item = btrfs_item_ptr(leaf, path->slots[0],
2689 struct btrfs_inode_item);
2691 fill_inode_item(trans, leaf, inode_item, inode);
2692 btrfs_mark_buffer_dirty(leaf);
2693 btrfs_set_inode_last_trans(trans, inode);
2694 ret = 0;
2695 failed:
2696 btrfs_free_path(path);
2697 return ret;
2701 * unlink helper that gets used here in inode.c and in the tree logging
2702 * recovery code. It remove a link in a directory with a given name, and
2703 * also drops the back refs in the inode to the directory
2705 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
2706 struct btrfs_root *root,
2707 struct inode *dir, struct inode *inode,
2708 const char *name, int name_len)
2710 struct btrfs_path *path;
2711 int ret = 0;
2712 struct extent_buffer *leaf;
2713 struct btrfs_dir_item *di;
2714 struct btrfs_key key;
2715 u64 index;
2716 u64 ino = btrfs_ino(inode);
2717 u64 dir_ino = btrfs_ino(dir);
2719 path = btrfs_alloc_path();
2720 if (!path) {
2721 ret = -ENOMEM;
2722 goto out;
2725 path->leave_spinning = 1;
2726 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
2727 name, name_len, -1);
2728 if (IS_ERR(di)) {
2729 ret = PTR_ERR(di);
2730 goto err;
2732 if (!di) {
2733 ret = -ENOENT;
2734 goto err;
2736 leaf = path->nodes[0];
2737 btrfs_dir_item_key_to_cpu(leaf, di, &key);
2738 ret = btrfs_delete_one_dir_name(trans, root, path, di);
2739 if (ret)
2740 goto err;
2741 btrfs_release_path(path);
2743 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
2744 dir_ino, &index);
2745 if (ret) {
2746 printk(KERN_INFO "btrfs failed to delete reference to %.*s, "
2747 "inode %llu parent %llu\n", name_len, name,
2748 (unsigned long long)ino, (unsigned long long)dir_ino);
2749 goto err;
2752 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
2753 if (ret)
2754 goto err;
2756 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
2757 inode, dir_ino);
2758 BUG_ON(ret != 0 && ret != -ENOENT);
2760 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
2761 dir, index);
2762 if (ret == -ENOENT)
2763 ret = 0;
2764 err:
2765 btrfs_free_path(path);
2766 if (ret)
2767 goto out;
2769 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
2770 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
2771 btrfs_update_inode(trans, root, dir);
2772 out:
2773 return ret;
2776 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
2777 struct btrfs_root *root,
2778 struct inode *dir, struct inode *inode,
2779 const char *name, int name_len)
2781 int ret;
2782 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
2783 if (!ret) {
2784 btrfs_drop_nlink(inode);
2785 ret = btrfs_update_inode(trans, root, inode);
2787 return ret;
2791 /* helper to check if there is any shared block in the path */
2792 static int check_path_shared(struct btrfs_root *root,
2793 struct btrfs_path *path)
2795 struct extent_buffer *eb;
2796 int level;
2797 u64 refs = 1;
2799 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
2800 int ret;
2802 if (!path->nodes[level])
2803 break;
2804 eb = path->nodes[level];
2805 if (!btrfs_block_can_be_shared(root, eb))
2806 continue;
2807 ret = btrfs_lookup_extent_info(NULL, root, eb->start, eb->len,
2808 &refs, NULL);
2809 if (refs > 1)
2810 return 1;
2812 return 0;
2816 * helper to start transaction for unlink and rmdir.
2818 * unlink and rmdir are special in btrfs, they do not always free space.
2819 * so in enospc case, we should make sure they will free space before
2820 * allowing them to use the global metadata reservation.
2822 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir,
2823 struct dentry *dentry)
2825 struct btrfs_trans_handle *trans;
2826 struct btrfs_root *root = BTRFS_I(dir)->root;
2827 struct btrfs_path *path;
2828 struct btrfs_inode_ref *ref;
2829 struct btrfs_dir_item *di;
2830 struct inode *inode = dentry->d_inode;
2831 u64 index;
2832 int check_link = 1;
2833 int err = -ENOSPC;
2834 int ret;
2835 u64 ino = btrfs_ino(inode);
2836 u64 dir_ino = btrfs_ino(dir);
2838 trans = btrfs_start_transaction(root, 10);
2839 if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
2840 return trans;
2842 if (ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
2843 return ERR_PTR(-ENOSPC);
2845 /* check if there is someone else holds reference */
2846 if (S_ISDIR(inode->i_mode) && atomic_read(&inode->i_count) > 1)
2847 return ERR_PTR(-ENOSPC);
2849 if (atomic_read(&inode->i_count) > 2)
2850 return ERR_PTR(-ENOSPC);
2852 if (xchg(&root->fs_info->enospc_unlink, 1))
2853 return ERR_PTR(-ENOSPC);
2855 path = btrfs_alloc_path();
2856 if (!path) {
2857 root->fs_info->enospc_unlink = 0;
2858 return ERR_PTR(-ENOMEM);
2861 trans = btrfs_start_transaction(root, 0);
2862 if (IS_ERR(trans)) {
2863 btrfs_free_path(path);
2864 root->fs_info->enospc_unlink = 0;
2865 return trans;
2868 path->skip_locking = 1;
2869 path->search_commit_root = 1;
2871 ret = btrfs_lookup_inode(trans, root, path,
2872 &BTRFS_I(dir)->location, 0);
2873 if (ret < 0) {
2874 err = ret;
2875 goto out;
2877 if (ret == 0) {
2878 if (check_path_shared(root, path))
2879 goto out;
2880 } else {
2881 check_link = 0;
2883 btrfs_release_path(path);
2885 ret = btrfs_lookup_inode(trans, root, path,
2886 &BTRFS_I(inode)->location, 0);
2887 if (ret < 0) {
2888 err = ret;
2889 goto out;
2891 if (ret == 0) {
2892 if (check_path_shared(root, path))
2893 goto out;
2894 } else {
2895 check_link = 0;
2897 btrfs_release_path(path);
2899 if (ret == 0 && S_ISREG(inode->i_mode)) {
2900 ret = btrfs_lookup_file_extent(trans, root, path,
2901 ino, (u64)-1, 0);
2902 if (ret < 0) {
2903 err = ret;
2904 goto out;
2906 BUG_ON(ret == 0);
2907 if (check_path_shared(root, path))
2908 goto out;
2909 btrfs_release_path(path);
2912 if (!check_link) {
2913 err = 0;
2914 goto out;
2917 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
2918 dentry->d_name.name, dentry->d_name.len, 0);
2919 if (IS_ERR(di)) {
2920 err = PTR_ERR(di);
2921 goto out;
2923 if (di) {
2924 if (check_path_shared(root, path))
2925 goto out;
2926 } else {
2927 err = 0;
2928 goto out;
2930 btrfs_release_path(path);
2932 ref = btrfs_lookup_inode_ref(trans, root, path,
2933 dentry->d_name.name, dentry->d_name.len,
2934 ino, dir_ino, 0);
2935 if (IS_ERR(ref)) {
2936 err = PTR_ERR(ref);
2937 goto out;
2939 BUG_ON(!ref);
2940 if (check_path_shared(root, path))
2941 goto out;
2942 index = btrfs_inode_ref_index(path->nodes[0], ref);
2943 btrfs_release_path(path);
2946 * This is a commit root search, if we can lookup inode item and other
2947 * relative items in the commit root, it means the transaction of
2948 * dir/file creation has been committed, and the dir index item that we
2949 * delay to insert has also been inserted into the commit root. So
2950 * we needn't worry about the delayed insertion of the dir index item
2951 * here.
2953 di = btrfs_lookup_dir_index_item(trans, root, path, dir_ino, index,
2954 dentry->d_name.name, dentry->d_name.len, 0);
2955 if (IS_ERR(di)) {
2956 err = PTR_ERR(di);
2957 goto out;
2959 BUG_ON(ret == -ENOENT);
2960 if (check_path_shared(root, path))
2961 goto out;
2963 err = 0;
2964 out:
2965 btrfs_free_path(path);
2966 if (err) {
2967 btrfs_end_transaction(trans, root);
2968 root->fs_info->enospc_unlink = 0;
2969 return ERR_PTR(err);
2972 trans->block_rsv = &root->fs_info->global_block_rsv;
2973 return trans;
2976 static void __unlink_end_trans(struct btrfs_trans_handle *trans,
2977 struct btrfs_root *root)
2979 if (trans->block_rsv == &root->fs_info->global_block_rsv) {
2980 BUG_ON(!root->fs_info->enospc_unlink);
2981 root->fs_info->enospc_unlink = 0;
2983 btrfs_end_transaction_throttle(trans, root);
2986 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
2988 struct btrfs_root *root = BTRFS_I(dir)->root;
2989 struct btrfs_trans_handle *trans;
2990 struct inode *inode = dentry->d_inode;
2991 int ret;
2992 unsigned long nr = 0;
2994 trans = __unlink_start_trans(dir, dentry);
2995 if (IS_ERR(trans))
2996 return PTR_ERR(trans);
2998 btrfs_record_unlink_dir(trans, dir, dentry->d_inode, 0);
3000 ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
3001 dentry->d_name.name, dentry->d_name.len);
3002 if (ret)
3003 goto out;
3005 if (inode->i_nlink == 0) {
3006 ret = btrfs_orphan_add(trans, inode);
3007 if (ret)
3008 goto out;
3011 out:
3012 nr = trans->blocks_used;
3013 __unlink_end_trans(trans, root);
3014 btrfs_btree_balance_dirty(root, nr);
3015 return ret;
3018 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
3019 struct btrfs_root *root,
3020 struct inode *dir, u64 objectid,
3021 const char *name, int name_len)
3023 struct btrfs_path *path;
3024 struct extent_buffer *leaf;
3025 struct btrfs_dir_item *di;
3026 struct btrfs_key key;
3027 u64 index;
3028 int ret;
3029 u64 dir_ino = btrfs_ino(dir);
3031 path = btrfs_alloc_path();
3032 if (!path)
3033 return -ENOMEM;
3035 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3036 name, name_len, -1);
3037 BUG_ON(IS_ERR_OR_NULL(di));
3039 leaf = path->nodes[0];
3040 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3041 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
3042 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3043 BUG_ON(ret);
3044 btrfs_release_path(path);
3046 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
3047 objectid, root->root_key.objectid,
3048 dir_ino, &index, name, name_len);
3049 if (ret < 0) {
3050 BUG_ON(ret != -ENOENT);
3051 di = btrfs_search_dir_index_item(root, path, dir_ino,
3052 name, name_len);
3053 BUG_ON(IS_ERR_OR_NULL(di));
3055 leaf = path->nodes[0];
3056 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3057 btrfs_release_path(path);
3058 index = key.offset;
3060 btrfs_release_path(path);
3062 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3063 BUG_ON(ret);
3065 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3066 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3067 ret = btrfs_update_inode(trans, root, dir);
3068 BUG_ON(ret);
3070 btrfs_free_path(path);
3071 return 0;
3074 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
3076 struct inode *inode = dentry->d_inode;
3077 int err = 0;
3078 struct btrfs_root *root = BTRFS_I(dir)->root;
3079 struct btrfs_trans_handle *trans;
3080 unsigned long nr = 0;
3082 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE ||
3083 btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
3084 return -ENOTEMPTY;
3086 trans = __unlink_start_trans(dir, dentry);
3087 if (IS_ERR(trans))
3088 return PTR_ERR(trans);
3090 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
3091 err = btrfs_unlink_subvol(trans, root, dir,
3092 BTRFS_I(inode)->location.objectid,
3093 dentry->d_name.name,
3094 dentry->d_name.len);
3095 goto out;
3098 err = btrfs_orphan_add(trans, inode);
3099 if (err)
3100 goto out;
3102 /* now the directory is empty */
3103 err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
3104 dentry->d_name.name, dentry->d_name.len);
3105 if (!err)
3106 btrfs_i_size_write(inode, 0);
3107 out:
3108 nr = trans->blocks_used;
3109 __unlink_end_trans(trans, root);
3110 btrfs_btree_balance_dirty(root, nr);
3112 return err;
3116 * this can truncate away extent items, csum items and directory items.
3117 * It starts at a high offset and removes keys until it can't find
3118 * any higher than new_size
3120 * csum items that cross the new i_size are truncated to the new size
3121 * as well.
3123 * min_type is the minimum key type to truncate down to. If set to 0, this
3124 * will kill all the items on this inode, including the INODE_ITEM_KEY.
3126 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
3127 struct btrfs_root *root,
3128 struct inode *inode,
3129 u64 new_size, u32 min_type)
3131 struct btrfs_path *path;
3132 struct extent_buffer *leaf;
3133 struct btrfs_file_extent_item *fi;
3134 struct btrfs_key key;
3135 struct btrfs_key found_key;
3136 u64 extent_start = 0;
3137 u64 extent_num_bytes = 0;
3138 u64 extent_offset = 0;
3139 u64 item_end = 0;
3140 u64 mask = root->sectorsize - 1;
3141 u32 found_type = (u8)-1;
3142 int found_extent;
3143 int del_item;
3144 int pending_del_nr = 0;
3145 int pending_del_slot = 0;
3146 int extent_type = -1;
3147 int encoding;
3148 int ret;
3149 int err = 0;
3150 u64 ino = btrfs_ino(inode);
3152 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
3154 path = btrfs_alloc_path();
3155 if (!path)
3156 return -ENOMEM;
3157 path->reada = -1;
3159 if (root->ref_cows || root == root->fs_info->tree_root)
3160 btrfs_drop_extent_cache(inode, new_size & (~mask), (u64)-1, 0);
3163 * This function is also used to drop the items in the log tree before
3164 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
3165 * it is used to drop the loged items. So we shouldn't kill the delayed
3166 * items.
3168 if (min_type == 0 && root == BTRFS_I(inode)->root)
3169 btrfs_kill_delayed_inode_items(inode);
3171 key.objectid = ino;
3172 key.offset = (u64)-1;
3173 key.type = (u8)-1;
3175 search_again:
3176 path->leave_spinning = 1;
3177 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
3178 if (ret < 0) {
3179 err = ret;
3180 goto out;
3183 if (ret > 0) {
3184 /* there are no items in the tree for us to truncate, we're
3185 * done
3187 if (path->slots[0] == 0)
3188 goto out;
3189 path->slots[0]--;
3192 while (1) {
3193 fi = NULL;
3194 leaf = path->nodes[0];
3195 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3196 found_type = btrfs_key_type(&found_key);
3197 encoding = 0;
3199 if (found_key.objectid != ino)
3200 break;
3202 if (found_type < min_type)
3203 break;
3205 item_end = found_key.offset;
3206 if (found_type == BTRFS_EXTENT_DATA_KEY) {
3207 fi = btrfs_item_ptr(leaf, path->slots[0],
3208 struct btrfs_file_extent_item);
3209 extent_type = btrfs_file_extent_type(leaf, fi);
3210 encoding = btrfs_file_extent_compression(leaf, fi);
3211 encoding |= btrfs_file_extent_encryption(leaf, fi);
3212 encoding |= btrfs_file_extent_other_encoding(leaf, fi);
3214 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
3215 item_end +=
3216 btrfs_file_extent_num_bytes(leaf, fi);
3217 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
3218 item_end += btrfs_file_extent_inline_len(leaf,
3219 fi);
3221 item_end--;
3223 if (found_type > min_type) {
3224 del_item = 1;
3225 } else {
3226 if (item_end < new_size)
3227 break;
3228 if (found_key.offset >= new_size)
3229 del_item = 1;
3230 else
3231 del_item = 0;
3233 found_extent = 0;
3234 /* FIXME, shrink the extent if the ref count is only 1 */
3235 if (found_type != BTRFS_EXTENT_DATA_KEY)
3236 goto delete;
3238 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
3239 u64 num_dec;
3240 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
3241 if (!del_item && !encoding) {
3242 u64 orig_num_bytes =
3243 btrfs_file_extent_num_bytes(leaf, fi);
3244 extent_num_bytes = new_size -
3245 found_key.offset + root->sectorsize - 1;
3246 extent_num_bytes = extent_num_bytes &
3247 ~((u64)root->sectorsize - 1);
3248 btrfs_set_file_extent_num_bytes(leaf, fi,
3249 extent_num_bytes);
3250 num_dec = (orig_num_bytes -
3251 extent_num_bytes);
3252 if (root->ref_cows && extent_start != 0)
3253 inode_sub_bytes(inode, num_dec);
3254 btrfs_mark_buffer_dirty(leaf);
3255 } else {
3256 extent_num_bytes =
3257 btrfs_file_extent_disk_num_bytes(leaf,
3258 fi);
3259 extent_offset = found_key.offset -
3260 btrfs_file_extent_offset(leaf, fi);
3262 /* FIXME blocksize != 4096 */
3263 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
3264 if (extent_start != 0) {
3265 found_extent = 1;
3266 if (root->ref_cows)
3267 inode_sub_bytes(inode, num_dec);
3270 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
3272 * we can't truncate inline items that have had
3273 * special encodings
3275 if (!del_item &&
3276 btrfs_file_extent_compression(leaf, fi) == 0 &&
3277 btrfs_file_extent_encryption(leaf, fi) == 0 &&
3278 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
3279 u32 size = new_size - found_key.offset;
3281 if (root->ref_cows) {
3282 inode_sub_bytes(inode, item_end + 1 -
3283 new_size);
3285 size =
3286 btrfs_file_extent_calc_inline_size(size);
3287 ret = btrfs_truncate_item(trans, root, path,
3288 size, 1);
3289 } else if (root->ref_cows) {
3290 inode_sub_bytes(inode, item_end + 1 -
3291 found_key.offset);
3294 delete:
3295 if (del_item) {
3296 if (!pending_del_nr) {
3297 /* no pending yet, add ourselves */
3298 pending_del_slot = path->slots[0];
3299 pending_del_nr = 1;
3300 } else if (pending_del_nr &&
3301 path->slots[0] + 1 == pending_del_slot) {
3302 /* hop on the pending chunk */
3303 pending_del_nr++;
3304 pending_del_slot = path->slots[0];
3305 } else {
3306 BUG();
3308 } else {
3309 break;
3311 if (found_extent && (root->ref_cows ||
3312 root == root->fs_info->tree_root)) {
3313 btrfs_set_path_blocking(path);
3314 ret = btrfs_free_extent(trans, root, extent_start,
3315 extent_num_bytes, 0,
3316 btrfs_header_owner(leaf),
3317 ino, extent_offset);
3318 BUG_ON(ret);
3321 if (found_type == BTRFS_INODE_ITEM_KEY)
3322 break;
3324 if (path->slots[0] == 0 ||
3325 path->slots[0] != pending_del_slot) {
3326 if (root->ref_cows &&
3327 BTRFS_I(inode)->location.objectid !=
3328 BTRFS_FREE_INO_OBJECTID) {
3329 err = -EAGAIN;
3330 goto out;
3332 if (pending_del_nr) {
3333 ret = btrfs_del_items(trans, root, path,
3334 pending_del_slot,
3335 pending_del_nr);
3336 BUG_ON(ret);
3337 pending_del_nr = 0;
3339 btrfs_release_path(path);
3340 goto search_again;
3341 } else {
3342 path->slots[0]--;
3345 out:
3346 if (pending_del_nr) {
3347 ret = btrfs_del_items(trans, root, path, pending_del_slot,
3348 pending_del_nr);
3349 BUG_ON(ret);
3351 btrfs_free_path(path);
3352 return err;
3356 * taken from block_truncate_page, but does cow as it zeros out
3357 * any bytes left in the last page in the file.
3359 static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
3361 struct inode *inode = mapping->host;
3362 struct btrfs_root *root = BTRFS_I(inode)->root;
3363 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3364 struct btrfs_ordered_extent *ordered;
3365 struct extent_state *cached_state = NULL;
3366 char *kaddr;
3367 u32 blocksize = root->sectorsize;
3368 pgoff_t index = from >> PAGE_CACHE_SHIFT;
3369 unsigned offset = from & (PAGE_CACHE_SIZE-1);
3370 struct page *page;
3371 int ret = 0;
3372 u64 page_start;
3373 u64 page_end;
3375 if ((offset & (blocksize - 1)) == 0)
3376 goto out;
3377 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
3378 if (ret)
3379 goto out;
3381 ret = -ENOMEM;
3382 again:
3383 page = find_or_create_page(mapping, index, GFP_NOFS);
3384 if (!page) {
3385 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
3386 goto out;
3389 page_start = page_offset(page);
3390 page_end = page_start + PAGE_CACHE_SIZE - 1;
3392 if (!PageUptodate(page)) {
3393 ret = btrfs_readpage(NULL, page);
3394 lock_page(page);
3395 if (page->mapping != mapping) {
3396 unlock_page(page);
3397 page_cache_release(page);
3398 goto again;
3400 if (!PageUptodate(page)) {
3401 ret = -EIO;
3402 goto out_unlock;
3405 wait_on_page_writeback(page);
3407 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state,
3408 GFP_NOFS);
3409 set_page_extent_mapped(page);
3411 ordered = btrfs_lookup_ordered_extent(inode, page_start);
3412 if (ordered) {
3413 unlock_extent_cached(io_tree, page_start, page_end,
3414 &cached_state, GFP_NOFS);
3415 unlock_page(page);
3416 page_cache_release(page);
3417 btrfs_start_ordered_extent(inode, ordered, 1);
3418 btrfs_put_ordered_extent(ordered);
3419 goto again;
3422 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
3423 EXTENT_DIRTY | EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING,
3424 0, 0, &cached_state, GFP_NOFS);
3426 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
3427 &cached_state);
3428 if (ret) {
3429 unlock_extent_cached(io_tree, page_start, page_end,
3430 &cached_state, GFP_NOFS);
3431 goto out_unlock;
3434 ret = 0;
3435 if (offset != PAGE_CACHE_SIZE) {
3436 kaddr = kmap(page);
3437 memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
3438 flush_dcache_page(page);
3439 kunmap(page);
3441 ClearPageChecked(page);
3442 set_page_dirty(page);
3443 unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
3444 GFP_NOFS);
3446 out_unlock:
3447 if (ret)
3448 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
3449 unlock_page(page);
3450 page_cache_release(page);
3451 out:
3452 return ret;
3456 * This function puts in dummy file extents for the area we're creating a hole
3457 * for. So if we are truncating this file to a larger size we need to insert
3458 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
3459 * the range between oldsize and size
3461 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
3463 struct btrfs_trans_handle *trans;
3464 struct btrfs_root *root = BTRFS_I(inode)->root;
3465 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3466 struct extent_map *em = NULL;
3467 struct extent_state *cached_state = NULL;
3468 u64 mask = root->sectorsize - 1;
3469 u64 hole_start = (oldsize + mask) & ~mask;
3470 u64 block_end = (size + mask) & ~mask;
3471 u64 last_byte;
3472 u64 cur_offset;
3473 u64 hole_size;
3474 int err = 0;
3476 if (size <= hole_start)
3477 return 0;
3479 while (1) {
3480 struct btrfs_ordered_extent *ordered;
3481 btrfs_wait_ordered_range(inode, hole_start,
3482 block_end - hole_start);
3483 lock_extent_bits(io_tree, hole_start, block_end - 1, 0,
3484 &cached_state, GFP_NOFS);
3485 ordered = btrfs_lookup_ordered_extent(inode, hole_start);
3486 if (!ordered)
3487 break;
3488 unlock_extent_cached(io_tree, hole_start, block_end - 1,
3489 &cached_state, GFP_NOFS);
3490 btrfs_put_ordered_extent(ordered);
3493 cur_offset = hole_start;
3494 while (1) {
3495 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
3496 block_end - cur_offset, 0);
3497 BUG_ON(IS_ERR_OR_NULL(em));
3498 last_byte = min(extent_map_end(em), block_end);
3499 last_byte = (last_byte + mask) & ~mask;
3500 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
3501 u64 hint_byte = 0;
3502 hole_size = last_byte - cur_offset;
3504 trans = btrfs_start_transaction(root, 2);
3505 if (IS_ERR(trans)) {
3506 err = PTR_ERR(trans);
3507 break;
3510 err = btrfs_drop_extents(trans, inode, cur_offset,
3511 cur_offset + hole_size,
3512 &hint_byte, 1);
3513 if (err) {
3514 btrfs_end_transaction(trans, root);
3515 break;
3518 err = btrfs_insert_file_extent(trans, root,
3519 btrfs_ino(inode), cur_offset, 0,
3520 0, hole_size, 0, hole_size,
3521 0, 0, 0);
3522 if (err) {
3523 btrfs_end_transaction(trans, root);
3524 break;
3527 btrfs_drop_extent_cache(inode, hole_start,
3528 last_byte - 1, 0);
3530 btrfs_end_transaction(trans, root);
3532 free_extent_map(em);
3533 em = NULL;
3534 cur_offset = last_byte;
3535 if (cur_offset >= block_end)
3536 break;
3539 free_extent_map(em);
3540 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
3541 GFP_NOFS);
3542 return err;
3545 static int btrfs_setsize(struct inode *inode, loff_t newsize)
3547 loff_t oldsize = i_size_read(inode);
3548 int ret;
3550 if (newsize == oldsize)
3551 return 0;
3553 if (newsize > oldsize) {
3554 i_size_write(inode, newsize);
3555 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
3556 truncate_pagecache(inode, oldsize, newsize);
3557 ret = btrfs_cont_expand(inode, oldsize, newsize);
3558 if (ret) {
3559 btrfs_setsize(inode, oldsize);
3560 return ret;
3563 mark_inode_dirty(inode);
3564 } else {
3567 * We're truncating a file that used to have good data down to
3568 * zero. Make sure it gets into the ordered flush list so that
3569 * any new writes get down to disk quickly.
3571 if (newsize == 0)
3572 BTRFS_I(inode)->ordered_data_close = 1;
3574 /* we don't support swapfiles, so vmtruncate shouldn't fail */
3575 truncate_setsize(inode, newsize);
3576 ret = btrfs_truncate(inode);
3579 return ret;
3582 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
3584 struct inode *inode = dentry->d_inode;
3585 struct btrfs_root *root = BTRFS_I(inode)->root;
3586 int err;
3588 if (btrfs_root_readonly(root))
3589 return -EROFS;
3591 err = inode_change_ok(inode, attr);
3592 if (err)
3593 return err;
3595 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
3596 err = btrfs_setsize(inode, attr->ia_size);
3597 if (err)
3598 return err;
3601 if (attr->ia_valid) {
3602 setattr_copy(inode, attr);
3603 mark_inode_dirty(inode);
3605 if (attr->ia_valid & ATTR_MODE)
3606 err = btrfs_acl_chmod(inode);
3609 return err;
3612 void btrfs_evict_inode(struct inode *inode)
3614 struct btrfs_trans_handle *trans;
3615 struct btrfs_root *root = BTRFS_I(inode)->root;
3616 unsigned long nr;
3617 int ret;
3619 trace_btrfs_inode_evict(inode);
3621 truncate_inode_pages(&inode->i_data, 0);
3622 if (inode->i_nlink && (btrfs_root_refs(&root->root_item) != 0 ||
3623 btrfs_is_free_space_inode(root, inode)))
3624 goto no_delete;
3626 if (is_bad_inode(inode)) {
3627 btrfs_orphan_del(NULL, inode);
3628 goto no_delete;
3630 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
3631 btrfs_wait_ordered_range(inode, 0, (u64)-1);
3633 if (root->fs_info->log_root_recovering) {
3634 BUG_ON(!list_empty(&BTRFS_I(inode)->i_orphan));
3635 goto no_delete;
3638 if (inode->i_nlink > 0) {
3639 BUG_ON(btrfs_root_refs(&root->root_item) != 0);
3640 goto no_delete;
3643 btrfs_i_size_write(inode, 0);
3645 while (1) {
3646 trans = btrfs_join_transaction(root);
3647 BUG_ON(IS_ERR(trans));
3648 trans->block_rsv = root->orphan_block_rsv;
3650 ret = btrfs_block_rsv_check(trans, root,
3651 root->orphan_block_rsv, 0, 5);
3652 if (ret) {
3653 BUG_ON(ret != -EAGAIN);
3654 ret = btrfs_commit_transaction(trans, root);
3655 BUG_ON(ret);
3656 continue;
3659 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
3660 if (ret != -EAGAIN)
3661 break;
3663 nr = trans->blocks_used;
3664 btrfs_end_transaction(trans, root);
3665 trans = NULL;
3666 btrfs_btree_balance_dirty(root, nr);
3670 if (ret == 0) {
3671 ret = btrfs_orphan_del(trans, inode);
3672 BUG_ON(ret);
3675 if (!(root == root->fs_info->tree_root ||
3676 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
3677 btrfs_return_ino(root, btrfs_ino(inode));
3679 nr = trans->blocks_used;
3680 btrfs_end_transaction(trans, root);
3681 btrfs_btree_balance_dirty(root, nr);
3682 no_delete:
3683 end_writeback(inode);
3684 return;
3688 * this returns the key found in the dir entry in the location pointer.
3689 * If no dir entries were found, location->objectid is 0.
3691 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
3692 struct btrfs_key *location)
3694 const char *name = dentry->d_name.name;
3695 int namelen = dentry->d_name.len;
3696 struct btrfs_dir_item *di;
3697 struct btrfs_path *path;
3698 struct btrfs_root *root = BTRFS_I(dir)->root;
3699 int ret = 0;
3701 path = btrfs_alloc_path();
3702 if (!path)
3703 return -ENOMEM;
3705 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
3706 namelen, 0);
3707 if (IS_ERR(di))
3708 ret = PTR_ERR(di);
3710 if (IS_ERR_OR_NULL(di))
3711 goto out_err;
3713 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
3714 out:
3715 btrfs_free_path(path);
3716 return ret;
3717 out_err:
3718 location->objectid = 0;
3719 goto out;
3723 * when we hit a tree root in a directory, the btrfs part of the inode
3724 * needs to be changed to reflect the root directory of the tree root. This
3725 * is kind of like crossing a mount point.
3727 static int fixup_tree_root_location(struct btrfs_root *root,
3728 struct inode *dir,
3729 struct dentry *dentry,
3730 struct btrfs_key *location,
3731 struct btrfs_root **sub_root)
3733 struct btrfs_path *path;
3734 struct btrfs_root *new_root;
3735 struct btrfs_root_ref *ref;
3736 struct extent_buffer *leaf;
3737 int ret;
3738 int err = 0;
3740 path = btrfs_alloc_path();
3741 if (!path) {
3742 err = -ENOMEM;
3743 goto out;
3746 err = -ENOENT;
3747 ret = btrfs_find_root_ref(root->fs_info->tree_root, path,
3748 BTRFS_I(dir)->root->root_key.objectid,
3749 location->objectid);
3750 if (ret) {
3751 if (ret < 0)
3752 err = ret;
3753 goto out;
3756 leaf = path->nodes[0];
3757 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
3758 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
3759 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
3760 goto out;
3762 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
3763 (unsigned long)(ref + 1),
3764 dentry->d_name.len);
3765 if (ret)
3766 goto out;
3768 btrfs_release_path(path);
3770 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
3771 if (IS_ERR(new_root)) {
3772 err = PTR_ERR(new_root);
3773 goto out;
3776 if (btrfs_root_refs(&new_root->root_item) == 0) {
3777 err = -ENOENT;
3778 goto out;
3781 *sub_root = new_root;
3782 location->objectid = btrfs_root_dirid(&new_root->root_item);
3783 location->type = BTRFS_INODE_ITEM_KEY;
3784 location->offset = 0;
3785 err = 0;
3786 out:
3787 btrfs_free_path(path);
3788 return err;
3791 static void inode_tree_add(struct inode *inode)
3793 struct btrfs_root *root = BTRFS_I(inode)->root;
3794 struct btrfs_inode *entry;
3795 struct rb_node **p;
3796 struct rb_node *parent;
3797 u64 ino = btrfs_ino(inode);
3798 again:
3799 p = &root->inode_tree.rb_node;
3800 parent = NULL;
3802 if (inode_unhashed(inode))
3803 return;
3805 spin_lock(&root->inode_lock);
3806 while (*p) {
3807 parent = *p;
3808 entry = rb_entry(parent, struct btrfs_inode, rb_node);
3810 if (ino < btrfs_ino(&entry->vfs_inode))
3811 p = &parent->rb_left;
3812 else if (ino > btrfs_ino(&entry->vfs_inode))
3813 p = &parent->rb_right;
3814 else {
3815 WARN_ON(!(entry->vfs_inode.i_state &
3816 (I_WILL_FREE | I_FREEING)));
3817 rb_erase(parent, &root->inode_tree);
3818 RB_CLEAR_NODE(parent);
3819 spin_unlock(&root->inode_lock);
3820 goto again;
3823 rb_link_node(&BTRFS_I(inode)->rb_node, parent, p);
3824 rb_insert_color(&BTRFS_I(inode)->rb_node, &root->inode_tree);
3825 spin_unlock(&root->inode_lock);
3828 static void inode_tree_del(struct inode *inode)
3830 struct btrfs_root *root = BTRFS_I(inode)->root;
3831 int empty = 0;
3833 spin_lock(&root->inode_lock);
3834 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
3835 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
3836 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
3837 empty = RB_EMPTY_ROOT(&root->inode_tree);
3839 spin_unlock(&root->inode_lock);
3842 * Free space cache has inodes in the tree root, but the tree root has a
3843 * root_refs of 0, so this could end up dropping the tree root as a
3844 * snapshot, so we need the extra !root->fs_info->tree_root check to
3845 * make sure we don't drop it.
3847 if (empty && btrfs_root_refs(&root->root_item) == 0 &&
3848 root != root->fs_info->tree_root) {
3849 synchronize_srcu(&root->fs_info->subvol_srcu);
3850 spin_lock(&root->inode_lock);
3851 empty = RB_EMPTY_ROOT(&root->inode_tree);
3852 spin_unlock(&root->inode_lock);
3853 if (empty)
3854 btrfs_add_dead_root(root);
3858 int btrfs_invalidate_inodes(struct btrfs_root *root)
3860 struct rb_node *node;
3861 struct rb_node *prev;
3862 struct btrfs_inode *entry;
3863 struct inode *inode;
3864 u64 objectid = 0;
3866 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
3868 spin_lock(&root->inode_lock);
3869 again:
3870 node = root->inode_tree.rb_node;
3871 prev = NULL;
3872 while (node) {
3873 prev = node;
3874 entry = rb_entry(node, struct btrfs_inode, rb_node);
3876 if (objectid < btrfs_ino(&entry->vfs_inode))
3877 node = node->rb_left;
3878 else if (objectid > btrfs_ino(&entry->vfs_inode))
3879 node = node->rb_right;
3880 else
3881 break;
3883 if (!node) {
3884 while (prev) {
3885 entry = rb_entry(prev, struct btrfs_inode, rb_node);
3886 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
3887 node = prev;
3888 break;
3890 prev = rb_next(prev);
3893 while (node) {
3894 entry = rb_entry(node, struct btrfs_inode, rb_node);
3895 objectid = btrfs_ino(&entry->vfs_inode) + 1;
3896 inode = igrab(&entry->vfs_inode);
3897 if (inode) {
3898 spin_unlock(&root->inode_lock);
3899 if (atomic_read(&inode->i_count) > 1)
3900 d_prune_aliases(inode);
3902 * btrfs_drop_inode will have it removed from
3903 * the inode cache when its usage count
3904 * hits zero.
3906 iput(inode);
3907 cond_resched();
3908 spin_lock(&root->inode_lock);
3909 goto again;
3912 if (cond_resched_lock(&root->inode_lock))
3913 goto again;
3915 node = rb_next(node);
3917 spin_unlock(&root->inode_lock);
3918 return 0;
3921 static int btrfs_init_locked_inode(struct inode *inode, void *p)
3923 struct btrfs_iget_args *args = p;
3924 inode->i_ino = args->ino;
3925 BTRFS_I(inode)->root = args->root;
3926 btrfs_set_inode_space_info(args->root, inode);
3927 return 0;
3930 static int btrfs_find_actor(struct inode *inode, void *opaque)
3932 struct btrfs_iget_args *args = opaque;
3933 return args->ino == btrfs_ino(inode) &&
3934 args->root == BTRFS_I(inode)->root;
3937 static struct inode *btrfs_iget_locked(struct super_block *s,
3938 u64 objectid,
3939 struct btrfs_root *root)
3941 struct inode *inode;
3942 struct btrfs_iget_args args;
3943 args.ino = objectid;
3944 args.root = root;
3946 inode = iget5_locked(s, objectid, btrfs_find_actor,
3947 btrfs_init_locked_inode,
3948 (void *)&args);
3949 return inode;
3952 /* Get an inode object given its location and corresponding root.
3953 * Returns in *is_new if the inode was read from disk
3955 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
3956 struct btrfs_root *root, int *new)
3958 struct inode *inode;
3960 inode = btrfs_iget_locked(s, location->objectid, root);
3961 if (!inode)
3962 return ERR_PTR(-ENOMEM);
3964 if (inode->i_state & I_NEW) {
3965 BTRFS_I(inode)->root = root;
3966 memcpy(&BTRFS_I(inode)->location, location, sizeof(*location));
3967 btrfs_read_locked_inode(inode);
3968 if (!is_bad_inode(inode)) {
3969 inode_tree_add(inode);
3970 unlock_new_inode(inode);
3971 if (new)
3972 *new = 1;
3973 } else {
3974 unlock_new_inode(inode);
3975 iput(inode);
3976 inode = ERR_PTR(-ESTALE);
3980 return inode;
3983 static struct inode *new_simple_dir(struct super_block *s,
3984 struct btrfs_key *key,
3985 struct btrfs_root *root)
3987 struct inode *inode = new_inode(s);
3989 if (!inode)
3990 return ERR_PTR(-ENOMEM);
3992 BTRFS_I(inode)->root = root;
3993 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
3994 BTRFS_I(inode)->dummy_inode = 1;
3996 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
3997 inode->i_op = &simple_dir_inode_operations;
3998 inode->i_fop = &simple_dir_operations;
3999 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
4000 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
4002 return inode;
4005 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
4007 struct inode *inode;
4008 struct btrfs_root *root = BTRFS_I(dir)->root;
4009 struct btrfs_root *sub_root = root;
4010 struct btrfs_key location;
4011 int index;
4012 int ret = 0;
4014 if (dentry->d_name.len > BTRFS_NAME_LEN)
4015 return ERR_PTR(-ENAMETOOLONG);
4017 if (unlikely(d_need_lookup(dentry))) {
4018 memcpy(&location, dentry->d_fsdata, sizeof(struct btrfs_key));
4019 kfree(dentry->d_fsdata);
4020 dentry->d_fsdata = NULL;
4021 d_clear_need_lookup(dentry);
4022 } else {
4023 ret = btrfs_inode_by_name(dir, dentry, &location);
4026 if (ret < 0)
4027 return ERR_PTR(ret);
4029 if (location.objectid == 0)
4030 return NULL;
4032 if (location.type == BTRFS_INODE_ITEM_KEY) {
4033 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
4034 return inode;
4037 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
4039 index = srcu_read_lock(&root->fs_info->subvol_srcu);
4040 ret = fixup_tree_root_location(root, dir, dentry,
4041 &location, &sub_root);
4042 if (ret < 0) {
4043 if (ret != -ENOENT)
4044 inode = ERR_PTR(ret);
4045 else
4046 inode = new_simple_dir(dir->i_sb, &location, sub_root);
4047 } else {
4048 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
4050 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
4052 if (!IS_ERR(inode) && root != sub_root) {
4053 down_read(&root->fs_info->cleanup_work_sem);
4054 if (!(inode->i_sb->s_flags & MS_RDONLY))
4055 ret = btrfs_orphan_cleanup(sub_root);
4056 up_read(&root->fs_info->cleanup_work_sem);
4057 if (ret)
4058 inode = ERR_PTR(ret);
4061 return inode;
4064 static int btrfs_dentry_delete(const struct dentry *dentry)
4066 struct btrfs_root *root;
4068 if (!dentry->d_inode && !IS_ROOT(dentry))
4069 dentry = dentry->d_parent;
4071 if (dentry->d_inode) {
4072 root = BTRFS_I(dentry->d_inode)->root;
4073 if (btrfs_root_refs(&root->root_item) == 0)
4074 return 1;
4076 return 0;
4079 static void btrfs_dentry_release(struct dentry *dentry)
4081 if (dentry->d_fsdata)
4082 kfree(dentry->d_fsdata);
4085 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
4086 struct nameidata *nd)
4088 return d_splice_alias(btrfs_lookup_dentry(dir, dentry), dentry);
4091 unsigned char btrfs_filetype_table[] = {
4092 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
4095 static int btrfs_real_readdir(struct file *filp, void *dirent,
4096 filldir_t filldir)
4098 struct inode *inode = filp->f_dentry->d_inode;
4099 struct btrfs_root *root = BTRFS_I(inode)->root;
4100 struct btrfs_item *item;
4101 struct btrfs_dir_item *di;
4102 struct btrfs_key key;
4103 struct btrfs_key found_key;
4104 struct btrfs_path *path;
4105 struct list_head ins_list;
4106 struct list_head del_list;
4107 struct qstr q;
4108 int ret;
4109 struct extent_buffer *leaf;
4110 int slot;
4111 unsigned char d_type;
4112 int over = 0;
4113 u32 di_cur;
4114 u32 di_total;
4115 u32 di_len;
4116 int key_type = BTRFS_DIR_INDEX_KEY;
4117 char tmp_name[32];
4118 char *name_ptr;
4119 int name_len;
4120 int is_curr = 0; /* filp->f_pos points to the current index? */
4122 /* FIXME, use a real flag for deciding about the key type */
4123 if (root->fs_info->tree_root == root)
4124 key_type = BTRFS_DIR_ITEM_KEY;
4126 /* special case for "." */
4127 if (filp->f_pos == 0) {
4128 over = filldir(dirent, ".", 1,
4129 filp->f_pos, btrfs_ino(inode), DT_DIR);
4130 if (over)
4131 return 0;
4132 filp->f_pos = 1;
4134 /* special case for .., just use the back ref */
4135 if (filp->f_pos == 1) {
4136 u64 pino = parent_ino(filp->f_path.dentry);
4137 over = filldir(dirent, "..", 2,
4138 filp->f_pos, pino, DT_DIR);
4139 if (over)
4140 return 0;
4141 filp->f_pos = 2;
4143 path = btrfs_alloc_path();
4144 if (!path)
4145 return -ENOMEM;
4147 path->reada = 1;
4149 if (key_type == BTRFS_DIR_INDEX_KEY) {
4150 INIT_LIST_HEAD(&ins_list);
4151 INIT_LIST_HEAD(&del_list);
4152 btrfs_get_delayed_items(inode, &ins_list, &del_list);
4155 btrfs_set_key_type(&key, key_type);
4156 key.offset = filp->f_pos;
4157 key.objectid = btrfs_ino(inode);
4159 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4160 if (ret < 0)
4161 goto err;
4163 while (1) {
4164 leaf = path->nodes[0];
4165 slot = path->slots[0];
4166 if (slot >= btrfs_header_nritems(leaf)) {
4167 ret = btrfs_next_leaf(root, path);
4168 if (ret < 0)
4169 goto err;
4170 else if (ret > 0)
4171 break;
4172 continue;
4175 item = btrfs_item_nr(leaf, slot);
4176 btrfs_item_key_to_cpu(leaf, &found_key, slot);
4178 if (found_key.objectid != key.objectid)
4179 break;
4180 if (btrfs_key_type(&found_key) != key_type)
4181 break;
4182 if (found_key.offset < filp->f_pos)
4183 goto next;
4184 if (key_type == BTRFS_DIR_INDEX_KEY &&
4185 btrfs_should_delete_dir_index(&del_list,
4186 found_key.offset))
4187 goto next;
4189 filp->f_pos = found_key.offset;
4190 is_curr = 1;
4192 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
4193 di_cur = 0;
4194 di_total = btrfs_item_size(leaf, item);
4196 while (di_cur < di_total) {
4197 struct btrfs_key location;
4198 struct dentry *tmp;
4200 if (verify_dir_item(root, leaf, di))
4201 break;
4203 name_len = btrfs_dir_name_len(leaf, di);
4204 if (name_len <= sizeof(tmp_name)) {
4205 name_ptr = tmp_name;
4206 } else {
4207 name_ptr = kmalloc(name_len, GFP_NOFS);
4208 if (!name_ptr) {
4209 ret = -ENOMEM;
4210 goto err;
4213 read_extent_buffer(leaf, name_ptr,
4214 (unsigned long)(di + 1), name_len);
4216 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
4217 btrfs_dir_item_key_to_cpu(leaf, di, &location);
4219 q.name = name_ptr;
4220 q.len = name_len;
4221 q.hash = full_name_hash(q.name, q.len);
4222 tmp = d_lookup(filp->f_dentry, &q);
4223 if (!tmp) {
4224 struct btrfs_key *newkey;
4226 newkey = kzalloc(sizeof(struct btrfs_key),
4227 GFP_NOFS);
4228 if (!newkey)
4229 goto no_dentry;
4230 tmp = d_alloc(filp->f_dentry, &q);
4231 if (!tmp) {
4232 kfree(newkey);
4233 dput(tmp);
4234 goto no_dentry;
4236 memcpy(newkey, &location,
4237 sizeof(struct btrfs_key));
4238 tmp->d_fsdata = newkey;
4239 tmp->d_flags |= DCACHE_NEED_LOOKUP;
4240 d_rehash(tmp);
4241 dput(tmp);
4242 } else {
4243 dput(tmp);
4245 no_dentry:
4246 /* is this a reference to our own snapshot? If so
4247 * skip it
4249 if (location.type == BTRFS_ROOT_ITEM_KEY &&
4250 location.objectid == root->root_key.objectid) {
4251 over = 0;
4252 goto skip;
4254 over = filldir(dirent, name_ptr, name_len,
4255 found_key.offset, location.objectid,
4256 d_type);
4258 skip:
4259 if (name_ptr != tmp_name)
4260 kfree(name_ptr);
4262 if (over)
4263 goto nopos;
4264 di_len = btrfs_dir_name_len(leaf, di) +
4265 btrfs_dir_data_len(leaf, di) + sizeof(*di);
4266 di_cur += di_len;
4267 di = (struct btrfs_dir_item *)((char *)di + di_len);
4269 next:
4270 path->slots[0]++;
4273 if (key_type == BTRFS_DIR_INDEX_KEY) {
4274 if (is_curr)
4275 filp->f_pos++;
4276 ret = btrfs_readdir_delayed_dir_index(filp, dirent, filldir,
4277 &ins_list);
4278 if (ret)
4279 goto nopos;
4282 /* Reached end of directory/root. Bump pos past the last item. */
4283 if (key_type == BTRFS_DIR_INDEX_KEY)
4285 * 32-bit glibc will use getdents64, but then strtol -
4286 * so the last number we can serve is this.
4288 filp->f_pos = 0x7fffffff;
4289 else
4290 filp->f_pos++;
4291 nopos:
4292 ret = 0;
4293 err:
4294 if (key_type == BTRFS_DIR_INDEX_KEY)
4295 btrfs_put_delayed_items(&ins_list, &del_list);
4296 btrfs_free_path(path);
4297 return ret;
4300 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
4302 struct btrfs_root *root = BTRFS_I(inode)->root;
4303 struct btrfs_trans_handle *trans;
4304 int ret = 0;
4305 bool nolock = false;
4307 if (BTRFS_I(inode)->dummy_inode)
4308 return 0;
4310 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(root, inode))
4311 nolock = true;
4313 if (wbc->sync_mode == WB_SYNC_ALL) {
4314 if (nolock)
4315 trans = btrfs_join_transaction_nolock(root);
4316 else
4317 trans = btrfs_join_transaction(root);
4318 if (IS_ERR(trans))
4319 return PTR_ERR(trans);
4320 if (nolock)
4321 ret = btrfs_end_transaction_nolock(trans, root);
4322 else
4323 ret = btrfs_commit_transaction(trans, root);
4325 return ret;
4329 * This is somewhat expensive, updating the tree every time the
4330 * inode changes. But, it is most likely to find the inode in cache.
4331 * FIXME, needs more benchmarking...there are no reasons other than performance
4332 * to keep or drop this code.
4334 void btrfs_dirty_inode(struct inode *inode, int flags)
4336 struct btrfs_root *root = BTRFS_I(inode)->root;
4337 struct btrfs_trans_handle *trans;
4338 int ret;
4340 if (BTRFS_I(inode)->dummy_inode)
4341 return;
4343 trans = btrfs_join_transaction(root);
4344 BUG_ON(IS_ERR(trans));
4346 ret = btrfs_update_inode(trans, root, inode);
4347 if (ret && ret == -ENOSPC) {
4348 /* whoops, lets try again with the full transaction */
4349 btrfs_end_transaction(trans, root);
4350 trans = btrfs_start_transaction(root, 1);
4351 if (IS_ERR(trans)) {
4352 printk_ratelimited(KERN_ERR "btrfs: fail to "
4353 "dirty inode %llu error %ld\n",
4354 (unsigned long long)btrfs_ino(inode),
4355 PTR_ERR(trans));
4356 return;
4359 ret = btrfs_update_inode(trans, root, inode);
4360 if (ret) {
4361 printk_ratelimited(KERN_ERR "btrfs: fail to "
4362 "dirty inode %llu error %d\n",
4363 (unsigned long long)btrfs_ino(inode),
4364 ret);
4367 btrfs_end_transaction(trans, root);
4368 if (BTRFS_I(inode)->delayed_node)
4369 btrfs_balance_delayed_items(root);
4373 * find the highest existing sequence number in a directory
4374 * and then set the in-memory index_cnt variable to reflect
4375 * free sequence numbers
4377 static int btrfs_set_inode_index_count(struct inode *inode)
4379 struct btrfs_root *root = BTRFS_I(inode)->root;
4380 struct btrfs_key key, found_key;
4381 struct btrfs_path *path;
4382 struct extent_buffer *leaf;
4383 int ret;
4385 key.objectid = btrfs_ino(inode);
4386 btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
4387 key.offset = (u64)-1;
4389 path = btrfs_alloc_path();
4390 if (!path)
4391 return -ENOMEM;
4393 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4394 if (ret < 0)
4395 goto out;
4396 /* FIXME: we should be able to handle this */
4397 if (ret == 0)
4398 goto out;
4399 ret = 0;
4402 * MAGIC NUMBER EXPLANATION:
4403 * since we search a directory based on f_pos we have to start at 2
4404 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
4405 * else has to start at 2
4407 if (path->slots[0] == 0) {
4408 BTRFS_I(inode)->index_cnt = 2;
4409 goto out;
4412 path->slots[0]--;
4414 leaf = path->nodes[0];
4415 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4417 if (found_key.objectid != btrfs_ino(inode) ||
4418 btrfs_key_type(&found_key) != BTRFS_DIR_INDEX_KEY) {
4419 BTRFS_I(inode)->index_cnt = 2;
4420 goto out;
4423 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
4424 out:
4425 btrfs_free_path(path);
4426 return ret;
4430 * helper to find a free sequence number in a given directory. This current
4431 * code is very simple, later versions will do smarter things in the btree
4433 int btrfs_set_inode_index(struct inode *dir, u64 *index)
4435 int ret = 0;
4437 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
4438 ret = btrfs_inode_delayed_dir_index_count(dir);
4439 if (ret) {
4440 ret = btrfs_set_inode_index_count(dir);
4441 if (ret)
4442 return ret;
4446 *index = BTRFS_I(dir)->index_cnt;
4447 BTRFS_I(dir)->index_cnt++;
4449 return ret;
4452 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
4453 struct btrfs_root *root,
4454 struct inode *dir,
4455 const char *name, int name_len,
4456 u64 ref_objectid, u64 objectid, int mode,
4457 u64 *index)
4459 struct inode *inode;
4460 struct btrfs_inode_item *inode_item;
4461 struct btrfs_key *location;
4462 struct btrfs_path *path;
4463 struct btrfs_inode_ref *ref;
4464 struct btrfs_key key[2];
4465 u32 sizes[2];
4466 unsigned long ptr;
4467 int ret;
4468 int owner;
4470 path = btrfs_alloc_path();
4471 if (!path)
4472 return ERR_PTR(-ENOMEM);
4474 inode = new_inode(root->fs_info->sb);
4475 if (!inode) {
4476 btrfs_free_path(path);
4477 return ERR_PTR(-ENOMEM);
4481 * we have to initialize this early, so we can reclaim the inode
4482 * number if we fail afterwards in this function.
4484 inode->i_ino = objectid;
4486 if (dir) {
4487 trace_btrfs_inode_request(dir);
4489 ret = btrfs_set_inode_index(dir, index);
4490 if (ret) {
4491 btrfs_free_path(path);
4492 iput(inode);
4493 return ERR_PTR(ret);
4497 * index_cnt is ignored for everything but a dir,
4498 * btrfs_get_inode_index_count has an explanation for the magic
4499 * number
4501 BTRFS_I(inode)->index_cnt = 2;
4502 BTRFS_I(inode)->root = root;
4503 BTRFS_I(inode)->generation = trans->transid;
4504 inode->i_generation = BTRFS_I(inode)->generation;
4505 btrfs_set_inode_space_info(root, inode);
4507 if (S_ISDIR(mode))
4508 owner = 0;
4509 else
4510 owner = 1;
4512 key[0].objectid = objectid;
4513 btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
4514 key[0].offset = 0;
4516 key[1].objectid = objectid;
4517 btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
4518 key[1].offset = ref_objectid;
4520 sizes[0] = sizeof(struct btrfs_inode_item);
4521 sizes[1] = name_len + sizeof(*ref);
4523 path->leave_spinning = 1;
4524 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
4525 if (ret != 0)
4526 goto fail;
4528 inode_init_owner(inode, dir, mode);
4529 inode_set_bytes(inode, 0);
4530 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
4531 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
4532 struct btrfs_inode_item);
4533 fill_inode_item(trans, path->nodes[0], inode_item, inode);
4535 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
4536 struct btrfs_inode_ref);
4537 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
4538 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
4539 ptr = (unsigned long)(ref + 1);
4540 write_extent_buffer(path->nodes[0], name, ptr, name_len);
4542 btrfs_mark_buffer_dirty(path->nodes[0]);
4543 btrfs_free_path(path);
4545 location = &BTRFS_I(inode)->location;
4546 location->objectid = objectid;
4547 location->offset = 0;
4548 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
4550 btrfs_inherit_iflags(inode, dir);
4552 if (S_ISREG(mode)) {
4553 if (btrfs_test_opt(root, NODATASUM))
4554 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
4555 if (btrfs_test_opt(root, NODATACOW) ||
4556 (BTRFS_I(dir)->flags & BTRFS_INODE_NODATACOW))
4557 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
4560 insert_inode_hash(inode);
4561 inode_tree_add(inode);
4563 trace_btrfs_inode_new(inode);
4564 btrfs_set_inode_last_trans(trans, inode);
4566 return inode;
4567 fail:
4568 if (dir)
4569 BTRFS_I(dir)->index_cnt--;
4570 btrfs_free_path(path);
4571 iput(inode);
4572 return ERR_PTR(ret);
4575 static inline u8 btrfs_inode_type(struct inode *inode)
4577 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
4581 * utility function to add 'inode' into 'parent_inode' with
4582 * a give name and a given sequence number.
4583 * if 'add_backref' is true, also insert a backref from the
4584 * inode to the parent directory.
4586 int btrfs_add_link(struct btrfs_trans_handle *trans,
4587 struct inode *parent_inode, struct inode *inode,
4588 const char *name, int name_len, int add_backref, u64 index)
4590 int ret = 0;
4591 struct btrfs_key key;
4592 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
4593 u64 ino = btrfs_ino(inode);
4594 u64 parent_ino = btrfs_ino(parent_inode);
4596 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
4597 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
4598 } else {
4599 key.objectid = ino;
4600 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
4601 key.offset = 0;
4604 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
4605 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
4606 key.objectid, root->root_key.objectid,
4607 parent_ino, index, name, name_len);
4608 } else if (add_backref) {
4609 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
4610 parent_ino, index);
4613 if (ret == 0) {
4614 ret = btrfs_insert_dir_item(trans, root, name, name_len,
4615 parent_inode, &key,
4616 btrfs_inode_type(inode), index);
4617 BUG_ON(ret);
4619 btrfs_i_size_write(parent_inode, parent_inode->i_size +
4620 name_len * 2);
4621 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
4622 ret = btrfs_update_inode(trans, root, parent_inode);
4624 return ret;
4627 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
4628 struct inode *dir, struct dentry *dentry,
4629 struct inode *inode, int backref, u64 index)
4631 int err = btrfs_add_link(trans, dir, inode,
4632 dentry->d_name.name, dentry->d_name.len,
4633 backref, index);
4634 if (!err) {
4635 d_instantiate(dentry, inode);
4636 return 0;
4638 if (err > 0)
4639 err = -EEXIST;
4640 return err;
4643 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
4644 int mode, dev_t rdev)
4646 struct btrfs_trans_handle *trans;
4647 struct btrfs_root *root = BTRFS_I(dir)->root;
4648 struct inode *inode = NULL;
4649 int err;
4650 int drop_inode = 0;
4651 u64 objectid;
4652 unsigned long nr = 0;
4653 u64 index = 0;
4655 if (!new_valid_dev(rdev))
4656 return -EINVAL;
4659 * 2 for inode item and ref
4660 * 2 for dir items
4661 * 1 for xattr if selinux is on
4663 trans = btrfs_start_transaction(root, 5);
4664 if (IS_ERR(trans))
4665 return PTR_ERR(trans);
4667 err = btrfs_find_free_ino(root, &objectid);
4668 if (err)
4669 goto out_unlock;
4671 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
4672 dentry->d_name.len, btrfs_ino(dir), objectid,
4673 mode, &index);
4674 if (IS_ERR(inode)) {
4675 err = PTR_ERR(inode);
4676 goto out_unlock;
4679 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
4680 if (err) {
4681 drop_inode = 1;
4682 goto out_unlock;
4685 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
4686 if (err)
4687 drop_inode = 1;
4688 else {
4689 inode->i_op = &btrfs_special_inode_operations;
4690 init_special_inode(inode, inode->i_mode, rdev);
4691 btrfs_update_inode(trans, root, inode);
4693 out_unlock:
4694 nr = trans->blocks_used;
4695 btrfs_end_transaction_throttle(trans, root);
4696 btrfs_btree_balance_dirty(root, nr);
4697 if (drop_inode) {
4698 inode_dec_link_count(inode);
4699 iput(inode);
4701 return err;
4704 static int btrfs_create(struct inode *dir, struct dentry *dentry,
4705 int mode, struct nameidata *nd)
4707 struct btrfs_trans_handle *trans;
4708 struct btrfs_root *root = BTRFS_I(dir)->root;
4709 struct inode *inode = NULL;
4710 int drop_inode = 0;
4711 int err;
4712 unsigned long nr = 0;
4713 u64 objectid;
4714 u64 index = 0;
4717 * 2 for inode item and ref
4718 * 2 for dir items
4719 * 1 for xattr if selinux is on
4721 trans = btrfs_start_transaction(root, 5);
4722 if (IS_ERR(trans))
4723 return PTR_ERR(trans);
4725 err = btrfs_find_free_ino(root, &objectid);
4726 if (err)
4727 goto out_unlock;
4729 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
4730 dentry->d_name.len, btrfs_ino(dir), objectid,
4731 mode, &index);
4732 if (IS_ERR(inode)) {
4733 err = PTR_ERR(inode);
4734 goto out_unlock;
4737 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
4738 if (err) {
4739 drop_inode = 1;
4740 goto out_unlock;
4743 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
4744 if (err)
4745 drop_inode = 1;
4746 else {
4747 inode->i_mapping->a_ops = &btrfs_aops;
4748 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
4749 inode->i_fop = &btrfs_file_operations;
4750 inode->i_op = &btrfs_file_inode_operations;
4751 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
4753 out_unlock:
4754 nr = trans->blocks_used;
4755 btrfs_end_transaction_throttle(trans, root);
4756 if (drop_inode) {
4757 inode_dec_link_count(inode);
4758 iput(inode);
4760 btrfs_btree_balance_dirty(root, nr);
4761 return err;
4764 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
4765 struct dentry *dentry)
4767 struct btrfs_trans_handle *trans;
4768 struct btrfs_root *root = BTRFS_I(dir)->root;
4769 struct inode *inode = old_dentry->d_inode;
4770 u64 index;
4771 unsigned long nr = 0;
4772 int err;
4773 int drop_inode = 0;
4775 /* do not allow sys_link's with other subvols of the same device */
4776 if (root->objectid != BTRFS_I(inode)->root->objectid)
4777 return -EXDEV;
4779 if (inode->i_nlink == ~0U)
4780 return -EMLINK;
4782 err = btrfs_set_inode_index(dir, &index);
4783 if (err)
4784 goto fail;
4787 * 2 items for inode and inode ref
4788 * 2 items for dir items
4789 * 1 item for parent inode
4791 trans = btrfs_start_transaction(root, 5);
4792 if (IS_ERR(trans)) {
4793 err = PTR_ERR(trans);
4794 goto fail;
4797 btrfs_inc_nlink(inode);
4798 inode->i_ctime = CURRENT_TIME;
4799 ihold(inode);
4801 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
4803 if (err) {
4804 drop_inode = 1;
4805 } else {
4806 struct dentry *parent = dentry->d_parent;
4807 err = btrfs_update_inode(trans, root, inode);
4808 BUG_ON(err);
4809 btrfs_log_new_name(trans, inode, NULL, parent);
4812 nr = trans->blocks_used;
4813 btrfs_end_transaction_throttle(trans, root);
4814 fail:
4815 if (drop_inode) {
4816 inode_dec_link_count(inode);
4817 iput(inode);
4819 btrfs_btree_balance_dirty(root, nr);
4820 return err;
4823 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
4825 struct inode *inode = NULL;
4826 struct btrfs_trans_handle *trans;
4827 struct btrfs_root *root = BTRFS_I(dir)->root;
4828 int err = 0;
4829 int drop_on_err = 0;
4830 u64 objectid = 0;
4831 u64 index = 0;
4832 unsigned long nr = 1;
4835 * 2 items for inode and ref
4836 * 2 items for dir items
4837 * 1 for xattr if selinux is on
4839 trans = btrfs_start_transaction(root, 5);
4840 if (IS_ERR(trans))
4841 return PTR_ERR(trans);
4843 err = btrfs_find_free_ino(root, &objectid);
4844 if (err)
4845 goto out_fail;
4847 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
4848 dentry->d_name.len, btrfs_ino(dir), objectid,
4849 S_IFDIR | mode, &index);
4850 if (IS_ERR(inode)) {
4851 err = PTR_ERR(inode);
4852 goto out_fail;
4855 drop_on_err = 1;
4857 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
4858 if (err)
4859 goto out_fail;
4861 inode->i_op = &btrfs_dir_inode_operations;
4862 inode->i_fop = &btrfs_dir_file_operations;
4864 btrfs_i_size_write(inode, 0);
4865 err = btrfs_update_inode(trans, root, inode);
4866 if (err)
4867 goto out_fail;
4869 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
4870 dentry->d_name.len, 0, index);
4871 if (err)
4872 goto out_fail;
4874 d_instantiate(dentry, inode);
4875 drop_on_err = 0;
4877 out_fail:
4878 nr = trans->blocks_used;
4879 btrfs_end_transaction_throttle(trans, root);
4880 if (drop_on_err)
4881 iput(inode);
4882 btrfs_btree_balance_dirty(root, nr);
4883 return err;
4886 /* helper for btfs_get_extent. Given an existing extent in the tree,
4887 * and an extent that you want to insert, deal with overlap and insert
4888 * the new extent into the tree.
4890 static int merge_extent_mapping(struct extent_map_tree *em_tree,
4891 struct extent_map *existing,
4892 struct extent_map *em,
4893 u64 map_start, u64 map_len)
4895 u64 start_diff;
4897 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
4898 start_diff = map_start - em->start;
4899 em->start = map_start;
4900 em->len = map_len;
4901 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
4902 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
4903 em->block_start += start_diff;
4904 em->block_len -= start_diff;
4906 return add_extent_mapping(em_tree, em);
4909 static noinline int uncompress_inline(struct btrfs_path *path,
4910 struct inode *inode, struct page *page,
4911 size_t pg_offset, u64 extent_offset,
4912 struct btrfs_file_extent_item *item)
4914 int ret;
4915 struct extent_buffer *leaf = path->nodes[0];
4916 char *tmp;
4917 size_t max_size;
4918 unsigned long inline_size;
4919 unsigned long ptr;
4920 int compress_type;
4922 WARN_ON(pg_offset != 0);
4923 compress_type = btrfs_file_extent_compression(leaf, item);
4924 max_size = btrfs_file_extent_ram_bytes(leaf, item);
4925 inline_size = btrfs_file_extent_inline_item_len(leaf,
4926 btrfs_item_nr(leaf, path->slots[0]));
4927 tmp = kmalloc(inline_size, GFP_NOFS);
4928 if (!tmp)
4929 return -ENOMEM;
4930 ptr = btrfs_file_extent_inline_start(item);
4932 read_extent_buffer(leaf, tmp, ptr, inline_size);
4934 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
4935 ret = btrfs_decompress(compress_type, tmp, page,
4936 extent_offset, inline_size, max_size);
4937 if (ret) {
4938 char *kaddr = kmap_atomic(page, KM_USER0);
4939 unsigned long copy_size = min_t(u64,
4940 PAGE_CACHE_SIZE - pg_offset,
4941 max_size - extent_offset);
4942 memset(kaddr + pg_offset, 0, copy_size);
4943 kunmap_atomic(kaddr, KM_USER0);
4945 kfree(tmp);
4946 return 0;
4950 * a bit scary, this does extent mapping from logical file offset to the disk.
4951 * the ugly parts come from merging extents from the disk with the in-ram
4952 * representation. This gets more complex because of the data=ordered code,
4953 * where the in-ram extents might be locked pending data=ordered completion.
4955 * This also copies inline extents directly into the page.
4958 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
4959 size_t pg_offset, u64 start, u64 len,
4960 int create)
4962 int ret;
4963 int err = 0;
4964 u64 bytenr;
4965 u64 extent_start = 0;
4966 u64 extent_end = 0;
4967 u64 objectid = btrfs_ino(inode);
4968 u32 found_type;
4969 struct btrfs_path *path = NULL;
4970 struct btrfs_root *root = BTRFS_I(inode)->root;
4971 struct btrfs_file_extent_item *item;
4972 struct extent_buffer *leaf;
4973 struct btrfs_key found_key;
4974 struct extent_map *em = NULL;
4975 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4976 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4977 struct btrfs_trans_handle *trans = NULL;
4978 int compress_type;
4980 again:
4981 read_lock(&em_tree->lock);
4982 em = lookup_extent_mapping(em_tree, start, len);
4983 if (em)
4984 em->bdev = root->fs_info->fs_devices->latest_bdev;
4985 read_unlock(&em_tree->lock);
4987 if (em) {
4988 if (em->start > start || em->start + em->len <= start)
4989 free_extent_map(em);
4990 else if (em->block_start == EXTENT_MAP_INLINE && page)
4991 free_extent_map(em);
4992 else
4993 goto out;
4995 em = alloc_extent_map();
4996 if (!em) {
4997 err = -ENOMEM;
4998 goto out;
5000 em->bdev = root->fs_info->fs_devices->latest_bdev;
5001 em->start = EXTENT_MAP_HOLE;
5002 em->orig_start = EXTENT_MAP_HOLE;
5003 em->len = (u64)-1;
5004 em->block_len = (u64)-1;
5006 if (!path) {
5007 path = btrfs_alloc_path();
5008 if (!path) {
5009 err = -ENOMEM;
5010 goto out;
5013 * Chances are we'll be called again, so go ahead and do
5014 * readahead
5016 path->reada = 1;
5019 ret = btrfs_lookup_file_extent(trans, root, path,
5020 objectid, start, trans != NULL);
5021 if (ret < 0) {
5022 err = ret;
5023 goto out;
5026 if (ret != 0) {
5027 if (path->slots[0] == 0)
5028 goto not_found;
5029 path->slots[0]--;
5032 leaf = path->nodes[0];
5033 item = btrfs_item_ptr(leaf, path->slots[0],
5034 struct btrfs_file_extent_item);
5035 /* are we inside the extent that was found? */
5036 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5037 found_type = btrfs_key_type(&found_key);
5038 if (found_key.objectid != objectid ||
5039 found_type != BTRFS_EXTENT_DATA_KEY) {
5040 goto not_found;
5043 found_type = btrfs_file_extent_type(leaf, item);
5044 extent_start = found_key.offset;
5045 compress_type = btrfs_file_extent_compression(leaf, item);
5046 if (found_type == BTRFS_FILE_EXTENT_REG ||
5047 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
5048 extent_end = extent_start +
5049 btrfs_file_extent_num_bytes(leaf, item);
5050 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
5051 size_t size;
5052 size = btrfs_file_extent_inline_len(leaf, item);
5053 extent_end = (extent_start + size + root->sectorsize - 1) &
5054 ~((u64)root->sectorsize - 1);
5057 if (start >= extent_end) {
5058 path->slots[0]++;
5059 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
5060 ret = btrfs_next_leaf(root, path);
5061 if (ret < 0) {
5062 err = ret;
5063 goto out;
5065 if (ret > 0)
5066 goto not_found;
5067 leaf = path->nodes[0];
5069 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5070 if (found_key.objectid != objectid ||
5071 found_key.type != BTRFS_EXTENT_DATA_KEY)
5072 goto not_found;
5073 if (start + len <= found_key.offset)
5074 goto not_found;
5075 em->start = start;
5076 em->len = found_key.offset - start;
5077 goto not_found_em;
5080 if (found_type == BTRFS_FILE_EXTENT_REG ||
5081 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
5082 em->start = extent_start;
5083 em->len = extent_end - extent_start;
5084 em->orig_start = extent_start -
5085 btrfs_file_extent_offset(leaf, item);
5086 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
5087 if (bytenr == 0) {
5088 em->block_start = EXTENT_MAP_HOLE;
5089 goto insert;
5091 if (compress_type != BTRFS_COMPRESS_NONE) {
5092 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
5093 em->compress_type = compress_type;
5094 em->block_start = bytenr;
5095 em->block_len = btrfs_file_extent_disk_num_bytes(leaf,
5096 item);
5097 } else {
5098 bytenr += btrfs_file_extent_offset(leaf, item);
5099 em->block_start = bytenr;
5100 em->block_len = em->len;
5101 if (found_type == BTRFS_FILE_EXTENT_PREALLOC)
5102 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
5104 goto insert;
5105 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
5106 unsigned long ptr;
5107 char *map;
5108 size_t size;
5109 size_t extent_offset;
5110 size_t copy_size;
5112 em->block_start = EXTENT_MAP_INLINE;
5113 if (!page || create) {
5114 em->start = extent_start;
5115 em->len = extent_end - extent_start;
5116 goto out;
5119 size = btrfs_file_extent_inline_len(leaf, item);
5120 extent_offset = page_offset(page) + pg_offset - extent_start;
5121 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
5122 size - extent_offset);
5123 em->start = extent_start + extent_offset;
5124 em->len = (copy_size + root->sectorsize - 1) &
5125 ~((u64)root->sectorsize - 1);
5126 em->orig_start = EXTENT_MAP_INLINE;
5127 if (compress_type) {
5128 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
5129 em->compress_type = compress_type;
5131 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
5132 if (create == 0 && !PageUptodate(page)) {
5133 if (btrfs_file_extent_compression(leaf, item) !=
5134 BTRFS_COMPRESS_NONE) {
5135 ret = uncompress_inline(path, inode, page,
5136 pg_offset,
5137 extent_offset, item);
5138 BUG_ON(ret);
5139 } else {
5140 map = kmap(page);
5141 read_extent_buffer(leaf, map + pg_offset, ptr,
5142 copy_size);
5143 if (pg_offset + copy_size < PAGE_CACHE_SIZE) {
5144 memset(map + pg_offset + copy_size, 0,
5145 PAGE_CACHE_SIZE - pg_offset -
5146 copy_size);
5148 kunmap(page);
5150 flush_dcache_page(page);
5151 } else if (create && PageUptodate(page)) {
5152 WARN_ON(1);
5153 if (!trans) {
5154 kunmap(page);
5155 free_extent_map(em);
5156 em = NULL;
5158 btrfs_release_path(path);
5159 trans = btrfs_join_transaction(root);
5161 if (IS_ERR(trans))
5162 return ERR_CAST(trans);
5163 goto again;
5165 map = kmap(page);
5166 write_extent_buffer(leaf, map + pg_offset, ptr,
5167 copy_size);
5168 kunmap(page);
5169 btrfs_mark_buffer_dirty(leaf);
5171 set_extent_uptodate(io_tree, em->start,
5172 extent_map_end(em) - 1, NULL, GFP_NOFS);
5173 goto insert;
5174 } else {
5175 printk(KERN_ERR "btrfs unknown found_type %d\n", found_type);
5176 WARN_ON(1);
5178 not_found:
5179 em->start = start;
5180 em->len = len;
5181 not_found_em:
5182 em->block_start = EXTENT_MAP_HOLE;
5183 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
5184 insert:
5185 btrfs_release_path(path);
5186 if (em->start > start || extent_map_end(em) <= start) {
5187 printk(KERN_ERR "Btrfs: bad extent! em: [%llu %llu] passed "
5188 "[%llu %llu]\n", (unsigned long long)em->start,
5189 (unsigned long long)em->len,
5190 (unsigned long long)start,
5191 (unsigned long long)len);
5192 err = -EIO;
5193 goto out;
5196 err = 0;
5197 write_lock(&em_tree->lock);
5198 ret = add_extent_mapping(em_tree, em);
5199 /* it is possible that someone inserted the extent into the tree
5200 * while we had the lock dropped. It is also possible that
5201 * an overlapping map exists in the tree
5203 if (ret == -EEXIST) {
5204 struct extent_map *existing;
5206 ret = 0;
5208 existing = lookup_extent_mapping(em_tree, start, len);
5209 if (existing && (existing->start > start ||
5210 existing->start + existing->len <= start)) {
5211 free_extent_map(existing);
5212 existing = NULL;
5214 if (!existing) {
5215 existing = lookup_extent_mapping(em_tree, em->start,
5216 em->len);
5217 if (existing) {
5218 err = merge_extent_mapping(em_tree, existing,
5219 em, start,
5220 root->sectorsize);
5221 free_extent_map(existing);
5222 if (err) {
5223 free_extent_map(em);
5224 em = NULL;
5226 } else {
5227 err = -EIO;
5228 free_extent_map(em);
5229 em = NULL;
5231 } else {
5232 free_extent_map(em);
5233 em = existing;
5234 err = 0;
5237 write_unlock(&em_tree->lock);
5238 out:
5240 trace_btrfs_get_extent(root, em);
5242 if (path)
5243 btrfs_free_path(path);
5244 if (trans) {
5245 ret = btrfs_end_transaction(trans, root);
5246 if (!err)
5247 err = ret;
5249 if (err) {
5250 free_extent_map(em);
5251 return ERR_PTR(err);
5253 return em;
5256 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
5257 size_t pg_offset, u64 start, u64 len,
5258 int create)
5260 struct extent_map *em;
5261 struct extent_map *hole_em = NULL;
5262 u64 range_start = start;
5263 u64 end;
5264 u64 found;
5265 u64 found_end;
5266 int err = 0;
5268 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
5269 if (IS_ERR(em))
5270 return em;
5271 if (em) {
5273 * if our em maps to a hole, there might
5274 * actually be delalloc bytes behind it
5276 if (em->block_start != EXTENT_MAP_HOLE)
5277 return em;
5278 else
5279 hole_em = em;
5282 /* check to see if we've wrapped (len == -1 or similar) */
5283 end = start + len;
5284 if (end < start)
5285 end = (u64)-1;
5286 else
5287 end -= 1;
5289 em = NULL;
5291 /* ok, we didn't find anything, lets look for delalloc */
5292 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
5293 end, len, EXTENT_DELALLOC, 1);
5294 found_end = range_start + found;
5295 if (found_end < range_start)
5296 found_end = (u64)-1;
5299 * we didn't find anything useful, return
5300 * the original results from get_extent()
5302 if (range_start > end || found_end <= start) {
5303 em = hole_em;
5304 hole_em = NULL;
5305 goto out;
5308 /* adjust the range_start to make sure it doesn't
5309 * go backwards from the start they passed in
5311 range_start = max(start,range_start);
5312 found = found_end - range_start;
5314 if (found > 0) {
5315 u64 hole_start = start;
5316 u64 hole_len = len;
5318 em = alloc_extent_map();
5319 if (!em) {
5320 err = -ENOMEM;
5321 goto out;
5324 * when btrfs_get_extent can't find anything it
5325 * returns one huge hole
5327 * make sure what it found really fits our range, and
5328 * adjust to make sure it is based on the start from
5329 * the caller
5331 if (hole_em) {
5332 u64 calc_end = extent_map_end(hole_em);
5334 if (calc_end <= start || (hole_em->start > end)) {
5335 free_extent_map(hole_em);
5336 hole_em = NULL;
5337 } else {
5338 hole_start = max(hole_em->start, start);
5339 hole_len = calc_end - hole_start;
5342 em->bdev = NULL;
5343 if (hole_em && range_start > hole_start) {
5344 /* our hole starts before our delalloc, so we
5345 * have to return just the parts of the hole
5346 * that go until the delalloc starts
5348 em->len = min(hole_len,
5349 range_start - hole_start);
5350 em->start = hole_start;
5351 em->orig_start = hole_start;
5353 * don't adjust block start at all,
5354 * it is fixed at EXTENT_MAP_HOLE
5356 em->block_start = hole_em->block_start;
5357 em->block_len = hole_len;
5358 } else {
5359 em->start = range_start;
5360 em->len = found;
5361 em->orig_start = range_start;
5362 em->block_start = EXTENT_MAP_DELALLOC;
5363 em->block_len = found;
5365 } else if (hole_em) {
5366 return hole_em;
5368 out:
5370 free_extent_map(hole_em);
5371 if (err) {
5372 free_extent_map(em);
5373 return ERR_PTR(err);
5375 return em;
5378 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
5379 struct extent_map *em,
5380 u64 start, u64 len)
5382 struct btrfs_root *root = BTRFS_I(inode)->root;
5383 struct btrfs_trans_handle *trans;
5384 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
5385 struct btrfs_key ins;
5386 u64 alloc_hint;
5387 int ret;
5388 bool insert = false;
5391 * Ok if the extent map we looked up is a hole and is for the exact
5392 * range we want, there is no reason to allocate a new one, however if
5393 * it is not right then we need to free this one and drop the cache for
5394 * our range.
5396 if (em->block_start != EXTENT_MAP_HOLE || em->start != start ||
5397 em->len != len) {
5398 free_extent_map(em);
5399 em = NULL;
5400 insert = true;
5401 btrfs_drop_extent_cache(inode, start, start + len - 1, 0);
5404 trans = btrfs_join_transaction(root);
5405 if (IS_ERR(trans))
5406 return ERR_CAST(trans);
5408 if (start <= BTRFS_I(inode)->disk_i_size && len < 64 * 1024)
5409 btrfs_add_inode_defrag(trans, inode);
5411 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
5413 alloc_hint = get_extent_allocation_hint(inode, start, len);
5414 ret = btrfs_reserve_extent(trans, root, len, root->sectorsize, 0,
5415 alloc_hint, (u64)-1, &ins, 1);
5416 if (ret) {
5417 em = ERR_PTR(ret);
5418 goto out;
5421 if (!em) {
5422 em = alloc_extent_map();
5423 if (!em) {
5424 em = ERR_PTR(-ENOMEM);
5425 goto out;
5429 em->start = start;
5430 em->orig_start = em->start;
5431 em->len = ins.offset;
5433 em->block_start = ins.objectid;
5434 em->block_len = ins.offset;
5435 em->bdev = root->fs_info->fs_devices->latest_bdev;
5438 * We need to do this because if we're using the original em we searched
5439 * for, we could have EXTENT_FLAG_VACANCY set, and we don't want that.
5441 em->flags = 0;
5442 set_bit(EXTENT_FLAG_PINNED, &em->flags);
5444 while (insert) {
5445 write_lock(&em_tree->lock);
5446 ret = add_extent_mapping(em_tree, em);
5447 write_unlock(&em_tree->lock);
5448 if (ret != -EEXIST)
5449 break;
5450 btrfs_drop_extent_cache(inode, start, start + em->len - 1, 0);
5453 ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
5454 ins.offset, ins.offset, 0);
5455 if (ret) {
5456 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
5457 em = ERR_PTR(ret);
5459 out:
5460 btrfs_end_transaction(trans, root);
5461 return em;
5465 * returns 1 when the nocow is safe, < 1 on error, 0 if the
5466 * block must be cow'd
5468 static noinline int can_nocow_odirect(struct btrfs_trans_handle *trans,
5469 struct inode *inode, u64 offset, u64 len)
5471 struct btrfs_path *path;
5472 int ret;
5473 struct extent_buffer *leaf;
5474 struct btrfs_root *root = BTRFS_I(inode)->root;
5475 struct btrfs_file_extent_item *fi;
5476 struct btrfs_key key;
5477 u64 disk_bytenr;
5478 u64 backref_offset;
5479 u64 extent_end;
5480 u64 num_bytes;
5481 int slot;
5482 int found_type;
5484 path = btrfs_alloc_path();
5485 if (!path)
5486 return -ENOMEM;
5488 ret = btrfs_lookup_file_extent(trans, root, path, btrfs_ino(inode),
5489 offset, 0);
5490 if (ret < 0)
5491 goto out;
5493 slot = path->slots[0];
5494 if (ret == 1) {
5495 if (slot == 0) {
5496 /* can't find the item, must cow */
5497 ret = 0;
5498 goto out;
5500 slot--;
5502 ret = 0;
5503 leaf = path->nodes[0];
5504 btrfs_item_key_to_cpu(leaf, &key, slot);
5505 if (key.objectid != btrfs_ino(inode) ||
5506 key.type != BTRFS_EXTENT_DATA_KEY) {
5507 /* not our file or wrong item type, must cow */
5508 goto out;
5511 if (key.offset > offset) {
5512 /* Wrong offset, must cow */
5513 goto out;
5516 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
5517 found_type = btrfs_file_extent_type(leaf, fi);
5518 if (found_type != BTRFS_FILE_EXTENT_REG &&
5519 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
5520 /* not a regular extent, must cow */
5521 goto out;
5523 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
5524 backref_offset = btrfs_file_extent_offset(leaf, fi);
5526 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
5527 if (extent_end < offset + len) {
5528 /* extent doesn't include our full range, must cow */
5529 goto out;
5532 if (btrfs_extent_readonly(root, disk_bytenr))
5533 goto out;
5536 * look for other files referencing this extent, if we
5537 * find any we must cow
5539 if (btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
5540 key.offset - backref_offset, disk_bytenr))
5541 goto out;
5544 * adjust disk_bytenr and num_bytes to cover just the bytes
5545 * in this extent we are about to write. If there
5546 * are any csums in that range we have to cow in order
5547 * to keep the csums correct
5549 disk_bytenr += backref_offset;
5550 disk_bytenr += offset - key.offset;
5551 num_bytes = min(offset + len, extent_end) - offset;
5552 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
5553 goto out;
5555 * all of the above have passed, it is safe to overwrite this extent
5556 * without cow
5558 ret = 1;
5559 out:
5560 btrfs_free_path(path);
5561 return ret;
5564 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
5565 struct buffer_head *bh_result, int create)
5567 struct extent_map *em;
5568 struct btrfs_root *root = BTRFS_I(inode)->root;
5569 u64 start = iblock << inode->i_blkbits;
5570 u64 len = bh_result->b_size;
5571 struct btrfs_trans_handle *trans;
5573 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
5574 if (IS_ERR(em))
5575 return PTR_ERR(em);
5578 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
5579 * io. INLINE is special, and we could probably kludge it in here, but
5580 * it's still buffered so for safety lets just fall back to the generic
5581 * buffered path.
5583 * For COMPRESSED we _have_ to read the entire extent in so we can
5584 * decompress it, so there will be buffering required no matter what we
5585 * do, so go ahead and fallback to buffered.
5587 * We return -ENOTBLK because thats what makes DIO go ahead and go back
5588 * to buffered IO. Don't blame me, this is the price we pay for using
5589 * the generic code.
5591 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
5592 em->block_start == EXTENT_MAP_INLINE) {
5593 free_extent_map(em);
5594 return -ENOTBLK;
5597 /* Just a good old fashioned hole, return */
5598 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
5599 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
5600 free_extent_map(em);
5601 /* DIO will do one hole at a time, so just unlock a sector */
5602 unlock_extent(&BTRFS_I(inode)->io_tree, start,
5603 start + root->sectorsize - 1, GFP_NOFS);
5604 return 0;
5608 * We don't allocate a new extent in the following cases
5610 * 1) The inode is marked as NODATACOW. In this case we'll just use the
5611 * existing extent.
5612 * 2) The extent is marked as PREALLOC. We're good to go here and can
5613 * just use the extent.
5616 if (!create) {
5617 len = em->len - (start - em->start);
5618 goto map;
5621 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
5622 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
5623 em->block_start != EXTENT_MAP_HOLE)) {
5624 int type;
5625 int ret;
5626 u64 block_start;
5628 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
5629 type = BTRFS_ORDERED_PREALLOC;
5630 else
5631 type = BTRFS_ORDERED_NOCOW;
5632 len = min(len, em->len - (start - em->start));
5633 block_start = em->block_start + (start - em->start);
5636 * we're not going to log anything, but we do need
5637 * to make sure the current transaction stays open
5638 * while we look for nocow cross refs
5640 trans = btrfs_join_transaction(root);
5641 if (IS_ERR(trans))
5642 goto must_cow;
5644 if (can_nocow_odirect(trans, inode, start, len) == 1) {
5645 ret = btrfs_add_ordered_extent_dio(inode, start,
5646 block_start, len, len, type);
5647 btrfs_end_transaction(trans, root);
5648 if (ret) {
5649 free_extent_map(em);
5650 return ret;
5652 goto unlock;
5654 btrfs_end_transaction(trans, root);
5656 must_cow:
5658 * this will cow the extent, reset the len in case we changed
5659 * it above
5661 len = bh_result->b_size;
5662 em = btrfs_new_extent_direct(inode, em, start, len);
5663 if (IS_ERR(em))
5664 return PTR_ERR(em);
5665 len = min(len, em->len - (start - em->start));
5666 unlock:
5667 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, start + len - 1,
5668 EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DIRTY, 1,
5669 0, NULL, GFP_NOFS);
5670 map:
5671 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
5672 inode->i_blkbits;
5673 bh_result->b_size = len;
5674 bh_result->b_bdev = em->bdev;
5675 set_buffer_mapped(bh_result);
5676 if (create && !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
5677 set_buffer_new(bh_result);
5679 free_extent_map(em);
5681 return 0;
5684 struct btrfs_dio_private {
5685 struct inode *inode;
5686 u64 logical_offset;
5687 u64 disk_bytenr;
5688 u64 bytes;
5689 u32 *csums;
5690 void *private;
5692 /* number of bios pending for this dio */
5693 atomic_t pending_bios;
5695 /* IO errors */
5696 int errors;
5698 struct bio *orig_bio;
5701 static void btrfs_endio_direct_read(struct bio *bio, int err)
5703 struct btrfs_dio_private *dip = bio->bi_private;
5704 struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
5705 struct bio_vec *bvec = bio->bi_io_vec;
5706 struct inode *inode = dip->inode;
5707 struct btrfs_root *root = BTRFS_I(inode)->root;
5708 u64 start;
5709 u32 *private = dip->csums;
5711 start = dip->logical_offset;
5712 do {
5713 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
5714 struct page *page = bvec->bv_page;
5715 char *kaddr;
5716 u32 csum = ~(u32)0;
5717 unsigned long flags;
5719 local_irq_save(flags);
5720 kaddr = kmap_atomic(page, KM_IRQ0);
5721 csum = btrfs_csum_data(root, kaddr + bvec->bv_offset,
5722 csum, bvec->bv_len);
5723 btrfs_csum_final(csum, (char *)&csum);
5724 kunmap_atomic(kaddr, KM_IRQ0);
5725 local_irq_restore(flags);
5727 flush_dcache_page(bvec->bv_page);
5728 if (csum != *private) {
5729 printk(KERN_ERR "btrfs csum failed ino %llu off"
5730 " %llu csum %u private %u\n",
5731 (unsigned long long)btrfs_ino(inode),
5732 (unsigned long long)start,
5733 csum, *private);
5734 err = -EIO;
5738 start += bvec->bv_len;
5739 private++;
5740 bvec++;
5741 } while (bvec <= bvec_end);
5743 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
5744 dip->logical_offset + dip->bytes - 1, GFP_NOFS);
5745 bio->bi_private = dip->private;
5747 kfree(dip->csums);
5748 kfree(dip);
5750 /* If we had a csum failure make sure to clear the uptodate flag */
5751 if (err)
5752 clear_bit(BIO_UPTODATE, &bio->bi_flags);
5753 dio_end_io(bio, err);
5756 static void btrfs_endio_direct_write(struct bio *bio, int err)
5758 struct btrfs_dio_private *dip = bio->bi_private;
5759 struct inode *inode = dip->inode;
5760 struct btrfs_root *root = BTRFS_I(inode)->root;
5761 struct btrfs_trans_handle *trans;
5762 struct btrfs_ordered_extent *ordered = NULL;
5763 struct extent_state *cached_state = NULL;
5764 u64 ordered_offset = dip->logical_offset;
5765 u64 ordered_bytes = dip->bytes;
5766 int ret;
5768 if (err)
5769 goto out_done;
5770 again:
5771 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
5772 &ordered_offset,
5773 ordered_bytes);
5774 if (!ret)
5775 goto out_test;
5777 BUG_ON(!ordered);
5779 trans = btrfs_join_transaction(root);
5780 if (IS_ERR(trans)) {
5781 err = -ENOMEM;
5782 goto out;
5784 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
5786 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags)) {
5787 ret = btrfs_ordered_update_i_size(inode, 0, ordered);
5788 if (!ret)
5789 ret = btrfs_update_inode(trans, root, inode);
5790 err = ret;
5791 goto out;
5794 lock_extent_bits(&BTRFS_I(inode)->io_tree, ordered->file_offset,
5795 ordered->file_offset + ordered->len - 1, 0,
5796 &cached_state, GFP_NOFS);
5798 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags)) {
5799 ret = btrfs_mark_extent_written(trans, inode,
5800 ordered->file_offset,
5801 ordered->file_offset +
5802 ordered->len);
5803 if (ret) {
5804 err = ret;
5805 goto out_unlock;
5807 } else {
5808 ret = insert_reserved_file_extent(trans, inode,
5809 ordered->file_offset,
5810 ordered->start,
5811 ordered->disk_len,
5812 ordered->len,
5813 ordered->len,
5814 0, 0, 0,
5815 BTRFS_FILE_EXTENT_REG);
5816 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
5817 ordered->file_offset, ordered->len);
5818 if (ret) {
5819 err = ret;
5820 WARN_ON(1);
5821 goto out_unlock;
5825 add_pending_csums(trans, inode, ordered->file_offset, &ordered->list);
5826 ret = btrfs_ordered_update_i_size(inode, 0, ordered);
5827 if (!ret || !test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags))
5828 btrfs_update_inode(trans, root, inode);
5829 ret = 0;
5830 out_unlock:
5831 unlock_extent_cached(&BTRFS_I(inode)->io_tree, ordered->file_offset,
5832 ordered->file_offset + ordered->len - 1,
5833 &cached_state, GFP_NOFS);
5834 out:
5835 btrfs_delalloc_release_metadata(inode, ordered->len);
5836 btrfs_end_transaction(trans, root);
5837 ordered_offset = ordered->file_offset + ordered->len;
5838 btrfs_put_ordered_extent(ordered);
5839 btrfs_put_ordered_extent(ordered);
5841 out_test:
5843 * our bio might span multiple ordered extents. If we haven't
5844 * completed the accounting for the whole dio, go back and try again
5846 if (ordered_offset < dip->logical_offset + dip->bytes) {
5847 ordered_bytes = dip->logical_offset + dip->bytes -
5848 ordered_offset;
5849 goto again;
5851 out_done:
5852 bio->bi_private = dip->private;
5854 kfree(dip->csums);
5855 kfree(dip);
5857 /* If we had an error make sure to clear the uptodate flag */
5858 if (err)
5859 clear_bit(BIO_UPTODATE, &bio->bi_flags);
5860 dio_end_io(bio, err);
5863 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
5864 struct bio *bio, int mirror_num,
5865 unsigned long bio_flags, u64 offset)
5867 int ret;
5868 struct btrfs_root *root = BTRFS_I(inode)->root;
5869 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
5870 BUG_ON(ret);
5871 return 0;
5874 static void btrfs_end_dio_bio(struct bio *bio, int err)
5876 struct btrfs_dio_private *dip = bio->bi_private;
5878 if (err) {
5879 printk(KERN_ERR "btrfs direct IO failed ino %llu rw %lu "
5880 "sector %#Lx len %u err no %d\n",
5881 (unsigned long long)btrfs_ino(dip->inode), bio->bi_rw,
5882 (unsigned long long)bio->bi_sector, bio->bi_size, err);
5883 dip->errors = 1;
5886 * before atomic variable goto zero, we must make sure
5887 * dip->errors is perceived to be set.
5889 smp_mb__before_atomic_dec();
5892 /* if there are more bios still pending for this dio, just exit */
5893 if (!atomic_dec_and_test(&dip->pending_bios))
5894 goto out;
5896 if (dip->errors)
5897 bio_io_error(dip->orig_bio);
5898 else {
5899 set_bit(BIO_UPTODATE, &dip->orig_bio->bi_flags);
5900 bio_endio(dip->orig_bio, 0);
5902 out:
5903 bio_put(bio);
5906 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
5907 u64 first_sector, gfp_t gfp_flags)
5909 int nr_vecs = bio_get_nr_vecs(bdev);
5910 return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags);
5913 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
5914 int rw, u64 file_offset, int skip_sum,
5915 u32 *csums, int async_submit)
5917 int write = rw & REQ_WRITE;
5918 struct btrfs_root *root = BTRFS_I(inode)->root;
5919 int ret;
5921 bio_get(bio);
5922 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
5923 if (ret)
5924 goto err;
5926 if (skip_sum)
5927 goto map;
5929 if (write && async_submit) {
5930 ret = btrfs_wq_submit_bio(root->fs_info,
5931 inode, rw, bio, 0, 0,
5932 file_offset,
5933 __btrfs_submit_bio_start_direct_io,
5934 __btrfs_submit_bio_done);
5935 goto err;
5936 } else if (write) {
5938 * If we aren't doing async submit, calculate the csum of the
5939 * bio now.
5941 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
5942 if (ret)
5943 goto err;
5944 } else if (!skip_sum) {
5945 ret = btrfs_lookup_bio_sums_dio(root, inode, bio,
5946 file_offset, csums);
5947 if (ret)
5948 goto err;
5951 map:
5952 ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
5953 err:
5954 bio_put(bio);
5955 return ret;
5958 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
5959 int skip_sum)
5961 struct inode *inode = dip->inode;
5962 struct btrfs_root *root = BTRFS_I(inode)->root;
5963 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
5964 struct bio *bio;
5965 struct bio *orig_bio = dip->orig_bio;
5966 struct bio_vec *bvec = orig_bio->bi_io_vec;
5967 u64 start_sector = orig_bio->bi_sector;
5968 u64 file_offset = dip->logical_offset;
5969 u64 submit_len = 0;
5970 u64 map_length;
5971 int nr_pages = 0;
5972 u32 *csums = dip->csums;
5973 int ret = 0;
5974 int async_submit = 0;
5975 int write = rw & REQ_WRITE;
5977 map_length = orig_bio->bi_size;
5978 ret = btrfs_map_block(map_tree, READ, start_sector << 9,
5979 &map_length, NULL, 0);
5980 if (ret) {
5981 bio_put(orig_bio);
5982 return -EIO;
5985 if (map_length >= orig_bio->bi_size) {
5986 bio = orig_bio;
5987 goto submit;
5990 async_submit = 1;
5991 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
5992 if (!bio)
5993 return -ENOMEM;
5994 bio->bi_private = dip;
5995 bio->bi_end_io = btrfs_end_dio_bio;
5996 atomic_inc(&dip->pending_bios);
5998 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
5999 if (unlikely(map_length < submit_len + bvec->bv_len ||
6000 bio_add_page(bio, bvec->bv_page, bvec->bv_len,
6001 bvec->bv_offset) < bvec->bv_len)) {
6003 * inc the count before we submit the bio so
6004 * we know the end IO handler won't happen before
6005 * we inc the count. Otherwise, the dip might get freed
6006 * before we're done setting it up
6008 atomic_inc(&dip->pending_bios);
6009 ret = __btrfs_submit_dio_bio(bio, inode, rw,
6010 file_offset, skip_sum,
6011 csums, async_submit);
6012 if (ret) {
6013 bio_put(bio);
6014 atomic_dec(&dip->pending_bios);
6015 goto out_err;
6018 /* Write's use the ordered csums */
6019 if (!write && !skip_sum)
6020 csums = csums + nr_pages;
6021 start_sector += submit_len >> 9;
6022 file_offset += submit_len;
6024 submit_len = 0;
6025 nr_pages = 0;
6027 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
6028 start_sector, GFP_NOFS);
6029 if (!bio)
6030 goto out_err;
6031 bio->bi_private = dip;
6032 bio->bi_end_io = btrfs_end_dio_bio;
6034 map_length = orig_bio->bi_size;
6035 ret = btrfs_map_block(map_tree, READ, start_sector << 9,
6036 &map_length, NULL, 0);
6037 if (ret) {
6038 bio_put(bio);
6039 goto out_err;
6041 } else {
6042 submit_len += bvec->bv_len;
6043 nr_pages ++;
6044 bvec++;
6048 submit:
6049 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
6050 csums, async_submit);
6051 if (!ret)
6052 return 0;
6054 bio_put(bio);
6055 out_err:
6056 dip->errors = 1;
6058 * before atomic variable goto zero, we must
6059 * make sure dip->errors is perceived to be set.
6061 smp_mb__before_atomic_dec();
6062 if (atomic_dec_and_test(&dip->pending_bios))
6063 bio_io_error(dip->orig_bio);
6065 /* bio_end_io() will handle error, so we needn't return it */
6066 return 0;
6069 static void btrfs_submit_direct(int rw, struct bio *bio, struct inode *inode,
6070 loff_t file_offset)
6072 struct btrfs_root *root = BTRFS_I(inode)->root;
6073 struct btrfs_dio_private *dip;
6074 struct bio_vec *bvec = bio->bi_io_vec;
6075 int skip_sum;
6076 int write = rw & REQ_WRITE;
6077 int ret = 0;
6079 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
6081 dip = kmalloc(sizeof(*dip), GFP_NOFS);
6082 if (!dip) {
6083 ret = -ENOMEM;
6084 goto free_ordered;
6086 dip->csums = NULL;
6088 /* Write's use the ordered csum stuff, so we don't need dip->csums */
6089 if (!write && !skip_sum) {
6090 dip->csums = kmalloc(sizeof(u32) * bio->bi_vcnt, GFP_NOFS);
6091 if (!dip->csums) {
6092 kfree(dip);
6093 ret = -ENOMEM;
6094 goto free_ordered;
6098 dip->private = bio->bi_private;
6099 dip->inode = inode;
6100 dip->logical_offset = file_offset;
6102 dip->bytes = 0;
6103 do {
6104 dip->bytes += bvec->bv_len;
6105 bvec++;
6106 } while (bvec <= (bio->bi_io_vec + bio->bi_vcnt - 1));
6108 dip->disk_bytenr = (u64)bio->bi_sector << 9;
6109 bio->bi_private = dip;
6110 dip->errors = 0;
6111 dip->orig_bio = bio;
6112 atomic_set(&dip->pending_bios, 0);
6114 if (write)
6115 bio->bi_end_io = btrfs_endio_direct_write;
6116 else
6117 bio->bi_end_io = btrfs_endio_direct_read;
6119 ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
6120 if (!ret)
6121 return;
6122 free_ordered:
6124 * If this is a write, we need to clean up the reserved space and kill
6125 * the ordered extent.
6127 if (write) {
6128 struct btrfs_ordered_extent *ordered;
6129 ordered = btrfs_lookup_ordered_extent(inode, file_offset);
6130 if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) &&
6131 !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
6132 btrfs_free_reserved_extent(root, ordered->start,
6133 ordered->disk_len);
6134 btrfs_put_ordered_extent(ordered);
6135 btrfs_put_ordered_extent(ordered);
6137 bio_endio(bio, ret);
6140 static ssize_t check_direct_IO(struct btrfs_root *root, int rw, struct kiocb *iocb,
6141 const struct iovec *iov, loff_t offset,
6142 unsigned long nr_segs)
6144 int seg;
6145 int i;
6146 size_t size;
6147 unsigned long addr;
6148 unsigned blocksize_mask = root->sectorsize - 1;
6149 ssize_t retval = -EINVAL;
6150 loff_t end = offset;
6152 if (offset & blocksize_mask)
6153 goto out;
6155 /* Check the memory alignment. Blocks cannot straddle pages */
6156 for (seg = 0; seg < nr_segs; seg++) {
6157 addr = (unsigned long)iov[seg].iov_base;
6158 size = iov[seg].iov_len;
6159 end += size;
6160 if ((addr & blocksize_mask) || (size & blocksize_mask))
6161 goto out;
6163 /* If this is a write we don't need to check anymore */
6164 if (rw & WRITE)
6165 continue;
6168 * Check to make sure we don't have duplicate iov_base's in this
6169 * iovec, if so return EINVAL, otherwise we'll get csum errors
6170 * when reading back.
6172 for (i = seg + 1; i < nr_segs; i++) {
6173 if (iov[seg].iov_base == iov[i].iov_base)
6174 goto out;
6177 retval = 0;
6178 out:
6179 return retval;
6181 static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
6182 const struct iovec *iov, loff_t offset,
6183 unsigned long nr_segs)
6185 struct file *file = iocb->ki_filp;
6186 struct inode *inode = file->f_mapping->host;
6187 struct btrfs_ordered_extent *ordered;
6188 struct extent_state *cached_state = NULL;
6189 u64 lockstart, lockend;
6190 ssize_t ret;
6191 int writing = rw & WRITE;
6192 int write_bits = 0;
6193 size_t count = iov_length(iov, nr_segs);
6195 if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iov,
6196 offset, nr_segs)) {
6197 return 0;
6200 lockstart = offset;
6201 lockend = offset + count - 1;
6203 if (writing) {
6204 ret = btrfs_delalloc_reserve_space(inode, count);
6205 if (ret)
6206 goto out;
6209 while (1) {
6210 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6211 0, &cached_state, GFP_NOFS);
6213 * We're concerned with the entire range that we're going to be
6214 * doing DIO to, so we need to make sure theres no ordered
6215 * extents in this range.
6217 ordered = btrfs_lookup_ordered_range(inode, lockstart,
6218 lockend - lockstart + 1);
6219 if (!ordered)
6220 break;
6221 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6222 &cached_state, GFP_NOFS);
6223 btrfs_start_ordered_extent(inode, ordered, 1);
6224 btrfs_put_ordered_extent(ordered);
6225 cond_resched();
6229 * we don't use btrfs_set_extent_delalloc because we don't want
6230 * the dirty or uptodate bits
6232 if (writing) {
6233 write_bits = EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING;
6234 ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6235 EXTENT_DELALLOC, 0, NULL, &cached_state,
6236 GFP_NOFS);
6237 if (ret) {
6238 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
6239 lockend, EXTENT_LOCKED | write_bits,
6240 1, 0, &cached_state, GFP_NOFS);
6241 goto out;
6245 free_extent_state(cached_state);
6246 cached_state = NULL;
6248 ret = __blockdev_direct_IO(rw, iocb, inode,
6249 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
6250 iov, offset, nr_segs, btrfs_get_blocks_direct, NULL,
6251 btrfs_submit_direct, 0);
6253 if (ret < 0 && ret != -EIOCBQUEUED) {
6254 clear_extent_bit(&BTRFS_I(inode)->io_tree, offset,
6255 offset + iov_length(iov, nr_segs) - 1,
6256 EXTENT_LOCKED | write_bits, 1, 0,
6257 &cached_state, GFP_NOFS);
6258 } else if (ret >= 0 && ret < iov_length(iov, nr_segs)) {
6260 * We're falling back to buffered, unlock the section we didn't
6261 * do IO on.
6263 clear_extent_bit(&BTRFS_I(inode)->io_tree, offset + ret,
6264 offset + iov_length(iov, nr_segs) - 1,
6265 EXTENT_LOCKED | write_bits, 1, 0,
6266 &cached_state, GFP_NOFS);
6268 out:
6269 free_extent_state(cached_state);
6270 return ret;
6273 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
6274 __u64 start, __u64 len)
6276 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
6279 int btrfs_readpage(struct file *file, struct page *page)
6281 struct extent_io_tree *tree;
6282 tree = &BTRFS_I(page->mapping->host)->io_tree;
6283 return extent_read_full_page(tree, page, btrfs_get_extent);
6286 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
6288 struct extent_io_tree *tree;
6291 if (current->flags & PF_MEMALLOC) {
6292 redirty_page_for_writepage(wbc, page);
6293 unlock_page(page);
6294 return 0;
6296 tree = &BTRFS_I(page->mapping->host)->io_tree;
6297 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
6300 int btrfs_writepages(struct address_space *mapping,
6301 struct writeback_control *wbc)
6303 struct extent_io_tree *tree;
6305 tree = &BTRFS_I(mapping->host)->io_tree;
6306 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
6309 static int
6310 btrfs_readpages(struct file *file, struct address_space *mapping,
6311 struct list_head *pages, unsigned nr_pages)
6313 struct extent_io_tree *tree;
6314 tree = &BTRFS_I(mapping->host)->io_tree;
6315 return extent_readpages(tree, mapping, pages, nr_pages,
6316 btrfs_get_extent);
6318 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
6320 struct extent_io_tree *tree;
6321 struct extent_map_tree *map;
6322 int ret;
6324 tree = &BTRFS_I(page->mapping->host)->io_tree;
6325 map = &BTRFS_I(page->mapping->host)->extent_tree;
6326 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
6327 if (ret == 1) {
6328 ClearPagePrivate(page);
6329 set_page_private(page, 0);
6330 page_cache_release(page);
6332 return ret;
6335 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
6337 if (PageWriteback(page) || PageDirty(page))
6338 return 0;
6339 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
6342 static void btrfs_invalidatepage(struct page *page, unsigned long offset)
6344 struct extent_io_tree *tree;
6345 struct btrfs_ordered_extent *ordered;
6346 struct extent_state *cached_state = NULL;
6347 u64 page_start = page_offset(page);
6348 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
6352 * we have the page locked, so new writeback can't start,
6353 * and the dirty bit won't be cleared while we are here.
6355 * Wait for IO on this page so that we can safely clear
6356 * the PagePrivate2 bit and do ordered accounting
6358 wait_on_page_writeback(page);
6360 tree = &BTRFS_I(page->mapping->host)->io_tree;
6361 if (offset) {
6362 btrfs_releasepage(page, GFP_NOFS);
6363 return;
6365 lock_extent_bits(tree, page_start, page_end, 0, &cached_state,
6366 GFP_NOFS);
6367 ordered = btrfs_lookup_ordered_extent(page->mapping->host,
6368 page_offset(page));
6369 if (ordered) {
6371 * IO on this page will never be started, so we need
6372 * to account for any ordered extents now
6374 clear_extent_bit(tree, page_start, page_end,
6375 EXTENT_DIRTY | EXTENT_DELALLOC |
6376 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING, 1, 0,
6377 &cached_state, GFP_NOFS);
6379 * whoever cleared the private bit is responsible
6380 * for the finish_ordered_io
6382 if (TestClearPagePrivate2(page)) {
6383 btrfs_finish_ordered_io(page->mapping->host,
6384 page_start, page_end);
6386 btrfs_put_ordered_extent(ordered);
6387 cached_state = NULL;
6388 lock_extent_bits(tree, page_start, page_end, 0, &cached_state,
6389 GFP_NOFS);
6391 clear_extent_bit(tree, page_start, page_end,
6392 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
6393 EXTENT_DO_ACCOUNTING, 1, 1, &cached_state, GFP_NOFS);
6394 __btrfs_releasepage(page, GFP_NOFS);
6396 ClearPageChecked(page);
6397 if (PagePrivate(page)) {
6398 ClearPagePrivate(page);
6399 set_page_private(page, 0);
6400 page_cache_release(page);
6405 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
6406 * called from a page fault handler when a page is first dirtied. Hence we must
6407 * be careful to check for EOF conditions here. We set the page up correctly
6408 * for a written page which means we get ENOSPC checking when writing into
6409 * holes and correct delalloc and unwritten extent mapping on filesystems that
6410 * support these features.
6412 * We are not allowed to take the i_mutex here so we have to play games to
6413 * protect against truncate races as the page could now be beyond EOF. Because
6414 * vmtruncate() writes the inode size before removing pages, once we have the
6415 * page lock we can determine safely if the page is beyond EOF. If it is not
6416 * beyond EOF, then the page is guaranteed safe against truncation until we
6417 * unlock the page.
6419 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
6421 struct page *page = vmf->page;
6422 struct inode *inode = fdentry(vma->vm_file)->d_inode;
6423 struct btrfs_root *root = BTRFS_I(inode)->root;
6424 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6425 struct btrfs_ordered_extent *ordered;
6426 struct extent_state *cached_state = NULL;
6427 char *kaddr;
6428 unsigned long zero_start;
6429 loff_t size;
6430 int ret;
6431 u64 page_start;
6432 u64 page_end;
6434 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
6435 if (ret) {
6436 if (ret == -ENOMEM)
6437 ret = VM_FAULT_OOM;
6438 else /* -ENOSPC, -EIO, etc */
6439 ret = VM_FAULT_SIGBUS;
6440 goto out;
6443 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
6444 again:
6445 lock_page(page);
6446 size = i_size_read(inode);
6447 page_start = page_offset(page);
6448 page_end = page_start + PAGE_CACHE_SIZE - 1;
6450 if ((page->mapping != inode->i_mapping) ||
6451 (page_start >= size)) {
6452 /* page got truncated out from underneath us */
6453 goto out_unlock;
6455 wait_on_page_writeback(page);
6457 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state,
6458 GFP_NOFS);
6459 set_page_extent_mapped(page);
6462 * we can't set the delalloc bits if there are pending ordered
6463 * extents. Drop our locks and wait for them to finish
6465 ordered = btrfs_lookup_ordered_extent(inode, page_start);
6466 if (ordered) {
6467 unlock_extent_cached(io_tree, page_start, page_end,
6468 &cached_state, GFP_NOFS);
6469 unlock_page(page);
6470 btrfs_start_ordered_extent(inode, ordered, 1);
6471 btrfs_put_ordered_extent(ordered);
6472 goto again;
6476 * XXX - page_mkwrite gets called every time the page is dirtied, even
6477 * if it was already dirty, so for space accounting reasons we need to
6478 * clear any delalloc bits for the range we are fixing to save. There
6479 * is probably a better way to do this, but for now keep consistent with
6480 * prepare_pages in the normal write path.
6482 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
6483 EXTENT_DIRTY | EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING,
6484 0, 0, &cached_state, GFP_NOFS);
6486 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
6487 &cached_state);
6488 if (ret) {
6489 unlock_extent_cached(io_tree, page_start, page_end,
6490 &cached_state, GFP_NOFS);
6491 ret = VM_FAULT_SIGBUS;
6492 goto out_unlock;
6494 ret = 0;
6496 /* page is wholly or partially inside EOF */
6497 if (page_start + PAGE_CACHE_SIZE > size)
6498 zero_start = size & ~PAGE_CACHE_MASK;
6499 else
6500 zero_start = PAGE_CACHE_SIZE;
6502 if (zero_start != PAGE_CACHE_SIZE) {
6503 kaddr = kmap(page);
6504 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
6505 flush_dcache_page(page);
6506 kunmap(page);
6508 ClearPageChecked(page);
6509 set_page_dirty(page);
6510 SetPageUptodate(page);
6512 BTRFS_I(inode)->last_trans = root->fs_info->generation;
6513 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
6515 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
6517 out_unlock:
6518 if (!ret)
6519 return VM_FAULT_LOCKED;
6520 unlock_page(page);
6521 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
6522 out:
6523 return ret;
6526 static int btrfs_truncate(struct inode *inode)
6528 struct btrfs_root *root = BTRFS_I(inode)->root;
6529 struct btrfs_block_rsv *rsv;
6530 int ret;
6531 int err = 0;
6532 struct btrfs_trans_handle *trans;
6533 unsigned long nr;
6534 u64 mask = root->sectorsize - 1;
6536 ret = btrfs_truncate_page(inode->i_mapping, inode->i_size);
6537 if (ret)
6538 return ret;
6540 btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
6541 btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
6544 * Yes ladies and gentelment, this is indeed ugly. The fact is we have
6545 * 3 things going on here
6547 * 1) We need to reserve space for our orphan item and the space to
6548 * delete our orphan item. Lord knows we don't want to have a dangling
6549 * orphan item because we didn't reserve space to remove it.
6551 * 2) We need to reserve space to update our inode.
6553 * 3) We need to have something to cache all the space that is going to
6554 * be free'd up by the truncate operation, but also have some slack
6555 * space reserved in case it uses space during the truncate (thank you
6556 * very much snapshotting).
6558 * And we need these to all be seperate. The fact is we can use alot of
6559 * space doing the truncate, and we have no earthly idea how much space
6560 * we will use, so we need the truncate reservation to be seperate so it
6561 * doesn't end up using space reserved for updating the inode or
6562 * removing the orphan item. We also need to be able to stop the
6563 * transaction and start a new one, which means we need to be able to
6564 * update the inode several times, and we have no idea of knowing how
6565 * many times that will be, so we can't just reserve 1 item for the
6566 * entirety of the opration, so that has to be done seperately as well.
6567 * Then there is the orphan item, which does indeed need to be held on
6568 * to for the whole operation, and we need nobody to touch this reserved
6569 * space except the orphan code.
6571 * So that leaves us with
6573 * 1) root->orphan_block_rsv - for the orphan deletion.
6574 * 2) rsv - for the truncate reservation, which we will steal from the
6575 * transaction reservation.
6576 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
6577 * updating the inode.
6579 rsv = btrfs_alloc_block_rsv(root);
6580 if (!rsv)
6581 return -ENOMEM;
6582 btrfs_add_durable_block_rsv(root->fs_info, rsv);
6584 trans = btrfs_start_transaction(root, 4);
6585 if (IS_ERR(trans)) {
6586 err = PTR_ERR(trans);
6587 goto out;
6591 * Reserve space for the truncate process. Truncate should be adding
6592 * space, but if there are snapshots it may end up using space.
6594 ret = btrfs_truncate_reserve_metadata(trans, root, rsv);
6595 BUG_ON(ret);
6597 ret = btrfs_orphan_add(trans, inode);
6598 if (ret) {
6599 btrfs_end_transaction(trans, root);
6600 goto out;
6603 nr = trans->blocks_used;
6604 btrfs_end_transaction(trans, root);
6605 btrfs_btree_balance_dirty(root, nr);
6608 * Ok so we've already migrated our bytes over for the truncate, so here
6609 * just reserve the one slot we need for updating the inode.
6611 trans = btrfs_start_transaction(root, 1);
6612 if (IS_ERR(trans)) {
6613 err = PTR_ERR(trans);
6614 goto out;
6616 trans->block_rsv = rsv;
6619 * setattr is responsible for setting the ordered_data_close flag,
6620 * but that is only tested during the last file release. That
6621 * could happen well after the next commit, leaving a great big
6622 * window where new writes may get lost if someone chooses to write
6623 * to this file after truncating to zero
6625 * The inode doesn't have any dirty data here, and so if we commit
6626 * this is a noop. If someone immediately starts writing to the inode
6627 * it is very likely we'll catch some of their writes in this
6628 * transaction, and the commit will find this file on the ordered
6629 * data list with good things to send down.
6631 * This is a best effort solution, there is still a window where
6632 * using truncate to replace the contents of the file will
6633 * end up with a zero length file after a crash.
6635 if (inode->i_size == 0 && BTRFS_I(inode)->ordered_data_close)
6636 btrfs_add_ordered_operation(trans, root, inode);
6638 while (1) {
6639 if (!trans) {
6640 trans = btrfs_start_transaction(root, 3);
6641 if (IS_ERR(trans)) {
6642 err = PTR_ERR(trans);
6643 goto out;
6646 ret = btrfs_truncate_reserve_metadata(trans, root,
6647 rsv);
6648 BUG_ON(ret);
6650 trans->block_rsv = rsv;
6653 ret = btrfs_truncate_inode_items(trans, root, inode,
6654 inode->i_size,
6655 BTRFS_EXTENT_DATA_KEY);
6656 if (ret != -EAGAIN) {
6657 err = ret;
6658 break;
6661 trans->block_rsv = &root->fs_info->trans_block_rsv;
6662 ret = btrfs_update_inode(trans, root, inode);
6663 if (ret) {
6664 err = ret;
6665 break;
6668 nr = trans->blocks_used;
6669 btrfs_end_transaction(trans, root);
6670 trans = NULL;
6671 btrfs_btree_balance_dirty(root, nr);
6674 if (ret == 0 && inode->i_nlink > 0) {
6675 trans->block_rsv = root->orphan_block_rsv;
6676 ret = btrfs_orphan_del(trans, inode);
6677 if (ret)
6678 err = ret;
6679 } else if (ret && inode->i_nlink > 0) {
6681 * Failed to do the truncate, remove us from the in memory
6682 * orphan list.
6684 ret = btrfs_orphan_del(NULL, inode);
6687 trans->block_rsv = &root->fs_info->trans_block_rsv;
6688 ret = btrfs_update_inode(trans, root, inode);
6689 if (ret && !err)
6690 err = ret;
6692 nr = trans->blocks_used;
6693 ret = btrfs_end_transaction_throttle(trans, root);
6694 btrfs_btree_balance_dirty(root, nr);
6696 out:
6697 btrfs_free_block_rsv(root, rsv);
6699 if (ret && !err)
6700 err = ret;
6702 return err;
6706 * create a new subvolume directory/inode (helper for the ioctl).
6708 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
6709 struct btrfs_root *new_root, u64 new_dirid)
6711 struct inode *inode;
6712 int err;
6713 u64 index = 0;
6715 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2, new_dirid,
6716 new_dirid, S_IFDIR | 0700, &index);
6717 if (IS_ERR(inode))
6718 return PTR_ERR(inode);
6719 inode->i_op = &btrfs_dir_inode_operations;
6720 inode->i_fop = &btrfs_dir_file_operations;
6722 inode->i_nlink = 1;
6723 btrfs_i_size_write(inode, 0);
6725 err = btrfs_update_inode(trans, new_root, inode);
6726 BUG_ON(err);
6728 iput(inode);
6729 return 0;
6732 struct inode *btrfs_alloc_inode(struct super_block *sb)
6734 struct btrfs_inode *ei;
6735 struct inode *inode;
6737 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
6738 if (!ei)
6739 return NULL;
6741 ei->root = NULL;
6742 ei->space_info = NULL;
6743 ei->generation = 0;
6744 ei->sequence = 0;
6745 ei->last_trans = 0;
6746 ei->last_sub_trans = 0;
6747 ei->logged_trans = 0;
6748 ei->delalloc_bytes = 0;
6749 ei->reserved_bytes = 0;
6750 ei->disk_i_size = 0;
6751 ei->flags = 0;
6752 ei->index_cnt = (u64)-1;
6753 ei->last_unlink_trans = 0;
6755 spin_lock_init(&ei->lock);
6756 ei->outstanding_extents = 0;
6757 ei->reserved_extents = 0;
6759 ei->ordered_data_close = 0;
6760 ei->orphan_meta_reserved = 0;
6761 ei->dummy_inode = 0;
6762 ei->in_defrag = 0;
6763 ei->force_compress = BTRFS_COMPRESS_NONE;
6765 ei->delayed_node = NULL;
6767 inode = &ei->vfs_inode;
6768 extent_map_tree_init(&ei->extent_tree);
6769 extent_io_tree_init(&ei->io_tree, &inode->i_data);
6770 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
6771 mutex_init(&ei->log_mutex);
6772 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
6773 INIT_LIST_HEAD(&ei->i_orphan);
6774 INIT_LIST_HEAD(&ei->delalloc_inodes);
6775 INIT_LIST_HEAD(&ei->ordered_operations);
6776 RB_CLEAR_NODE(&ei->rb_node);
6778 return inode;
6781 static void btrfs_i_callback(struct rcu_head *head)
6783 struct inode *inode = container_of(head, struct inode, i_rcu);
6784 INIT_LIST_HEAD(&inode->i_dentry);
6785 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
6788 void btrfs_destroy_inode(struct inode *inode)
6790 struct btrfs_ordered_extent *ordered;
6791 struct btrfs_root *root = BTRFS_I(inode)->root;
6793 WARN_ON(!list_empty(&inode->i_dentry));
6794 WARN_ON(inode->i_data.nrpages);
6795 WARN_ON(BTRFS_I(inode)->outstanding_extents);
6796 WARN_ON(BTRFS_I(inode)->reserved_extents);
6799 * This can happen where we create an inode, but somebody else also
6800 * created the same inode and we need to destroy the one we already
6801 * created.
6803 if (!root)
6804 goto free;
6807 * Make sure we're properly removed from the ordered operation
6808 * lists.
6810 smp_mb();
6811 if (!list_empty(&BTRFS_I(inode)->ordered_operations)) {
6812 spin_lock(&root->fs_info->ordered_extent_lock);
6813 list_del_init(&BTRFS_I(inode)->ordered_operations);
6814 spin_unlock(&root->fs_info->ordered_extent_lock);
6817 spin_lock(&root->orphan_lock);
6818 if (!list_empty(&BTRFS_I(inode)->i_orphan)) {
6819 printk(KERN_INFO "BTRFS: inode %llu still on the orphan list\n",
6820 (unsigned long long)btrfs_ino(inode));
6821 list_del_init(&BTRFS_I(inode)->i_orphan);
6823 spin_unlock(&root->orphan_lock);
6825 while (1) {
6826 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
6827 if (!ordered)
6828 break;
6829 else {
6830 printk(KERN_ERR "btrfs found ordered "
6831 "extent %llu %llu on inode cleanup\n",
6832 (unsigned long long)ordered->file_offset,
6833 (unsigned long long)ordered->len);
6834 btrfs_remove_ordered_extent(inode, ordered);
6835 btrfs_put_ordered_extent(ordered);
6836 btrfs_put_ordered_extent(ordered);
6839 inode_tree_del(inode);
6840 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
6841 free:
6842 btrfs_remove_delayed_node(inode);
6843 call_rcu(&inode->i_rcu, btrfs_i_callback);
6846 int btrfs_drop_inode(struct inode *inode)
6848 struct btrfs_root *root = BTRFS_I(inode)->root;
6850 if (btrfs_root_refs(&root->root_item) == 0 &&
6851 !btrfs_is_free_space_inode(root, inode))
6852 return 1;
6853 else
6854 return generic_drop_inode(inode);
6857 static void init_once(void *foo)
6859 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
6861 inode_init_once(&ei->vfs_inode);
6864 void btrfs_destroy_cachep(void)
6866 if (btrfs_inode_cachep)
6867 kmem_cache_destroy(btrfs_inode_cachep);
6868 if (btrfs_trans_handle_cachep)
6869 kmem_cache_destroy(btrfs_trans_handle_cachep);
6870 if (btrfs_transaction_cachep)
6871 kmem_cache_destroy(btrfs_transaction_cachep);
6872 if (btrfs_path_cachep)
6873 kmem_cache_destroy(btrfs_path_cachep);
6874 if (btrfs_free_space_cachep)
6875 kmem_cache_destroy(btrfs_free_space_cachep);
6878 int btrfs_init_cachep(void)
6880 btrfs_inode_cachep = kmem_cache_create("btrfs_inode_cache",
6881 sizeof(struct btrfs_inode), 0,
6882 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once);
6883 if (!btrfs_inode_cachep)
6884 goto fail;
6886 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle_cache",
6887 sizeof(struct btrfs_trans_handle), 0,
6888 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
6889 if (!btrfs_trans_handle_cachep)
6890 goto fail;
6892 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction_cache",
6893 sizeof(struct btrfs_transaction), 0,
6894 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
6895 if (!btrfs_transaction_cachep)
6896 goto fail;
6898 btrfs_path_cachep = kmem_cache_create("btrfs_path_cache",
6899 sizeof(struct btrfs_path), 0,
6900 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
6901 if (!btrfs_path_cachep)
6902 goto fail;
6904 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space_cache",
6905 sizeof(struct btrfs_free_space), 0,
6906 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
6907 if (!btrfs_free_space_cachep)
6908 goto fail;
6910 return 0;
6911 fail:
6912 btrfs_destroy_cachep();
6913 return -ENOMEM;
6916 static int btrfs_getattr(struct vfsmount *mnt,
6917 struct dentry *dentry, struct kstat *stat)
6919 struct inode *inode = dentry->d_inode;
6920 generic_fillattr(inode, stat);
6921 stat->dev = BTRFS_I(inode)->root->anon_dev;
6922 stat->blksize = PAGE_CACHE_SIZE;
6923 stat->blocks = (inode_get_bytes(inode) +
6924 BTRFS_I(inode)->delalloc_bytes) >> 9;
6925 return 0;
6929 * If a file is moved, it will inherit the cow and compression flags of the new
6930 * directory.
6932 static void fixup_inode_flags(struct inode *dir, struct inode *inode)
6934 struct btrfs_inode *b_dir = BTRFS_I(dir);
6935 struct btrfs_inode *b_inode = BTRFS_I(inode);
6937 if (b_dir->flags & BTRFS_INODE_NODATACOW)
6938 b_inode->flags |= BTRFS_INODE_NODATACOW;
6939 else
6940 b_inode->flags &= ~BTRFS_INODE_NODATACOW;
6942 if (b_dir->flags & BTRFS_INODE_COMPRESS)
6943 b_inode->flags |= BTRFS_INODE_COMPRESS;
6944 else
6945 b_inode->flags &= ~BTRFS_INODE_COMPRESS;
6948 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
6949 struct inode *new_dir, struct dentry *new_dentry)
6951 struct btrfs_trans_handle *trans;
6952 struct btrfs_root *root = BTRFS_I(old_dir)->root;
6953 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
6954 struct inode *new_inode = new_dentry->d_inode;
6955 struct inode *old_inode = old_dentry->d_inode;
6956 struct timespec ctime = CURRENT_TIME;
6957 u64 index = 0;
6958 u64 root_objectid;
6959 int ret;
6960 u64 old_ino = btrfs_ino(old_inode);
6962 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
6963 return -EPERM;
6965 /* we only allow rename subvolume link between subvolumes */
6966 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
6967 return -EXDEV;
6969 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
6970 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
6971 return -ENOTEMPTY;
6973 if (S_ISDIR(old_inode->i_mode) && new_inode &&
6974 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
6975 return -ENOTEMPTY;
6977 * we're using rename to replace one file with another.
6978 * and the replacement file is large. Start IO on it now so
6979 * we don't add too much work to the end of the transaction
6981 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size &&
6982 old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
6983 filemap_flush(old_inode->i_mapping);
6985 /* close the racy window with snapshot create/destroy ioctl */
6986 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
6987 down_read(&root->fs_info->subvol_sem);
6989 * We want to reserve the absolute worst case amount of items. So if
6990 * both inodes are subvols and we need to unlink them then that would
6991 * require 4 item modifications, but if they are both normal inodes it
6992 * would require 5 item modifications, so we'll assume their normal
6993 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
6994 * should cover the worst case number of items we'll modify.
6996 trans = btrfs_start_transaction(root, 20);
6997 if (IS_ERR(trans)) {
6998 ret = PTR_ERR(trans);
6999 goto out_notrans;
7002 if (dest != root)
7003 btrfs_record_root_in_trans(trans, dest);
7005 ret = btrfs_set_inode_index(new_dir, &index);
7006 if (ret)
7007 goto out_fail;
7009 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
7010 /* force full log commit if subvolume involved. */
7011 root->fs_info->last_trans_log_full_commit = trans->transid;
7012 } else {
7013 ret = btrfs_insert_inode_ref(trans, dest,
7014 new_dentry->d_name.name,
7015 new_dentry->d_name.len,
7016 old_ino,
7017 btrfs_ino(new_dir), index);
7018 if (ret)
7019 goto out_fail;
7021 * this is an ugly little race, but the rename is required
7022 * to make sure that if we crash, the inode is either at the
7023 * old name or the new one. pinning the log transaction lets
7024 * us make sure we don't allow a log commit to come in after
7025 * we unlink the name but before we add the new name back in.
7027 btrfs_pin_log_trans(root);
7030 * make sure the inode gets flushed if it is replacing
7031 * something.
7033 if (new_inode && new_inode->i_size && S_ISREG(old_inode->i_mode))
7034 btrfs_add_ordered_operation(trans, root, old_inode);
7036 old_dir->i_ctime = old_dir->i_mtime = ctime;
7037 new_dir->i_ctime = new_dir->i_mtime = ctime;
7038 old_inode->i_ctime = ctime;
7040 if (old_dentry->d_parent != new_dentry->d_parent)
7041 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
7043 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
7044 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
7045 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
7046 old_dentry->d_name.name,
7047 old_dentry->d_name.len);
7048 } else {
7049 ret = __btrfs_unlink_inode(trans, root, old_dir,
7050 old_dentry->d_inode,
7051 old_dentry->d_name.name,
7052 old_dentry->d_name.len);
7053 if (!ret)
7054 ret = btrfs_update_inode(trans, root, old_inode);
7056 BUG_ON(ret);
7058 if (new_inode) {
7059 new_inode->i_ctime = CURRENT_TIME;
7060 if (unlikely(btrfs_ino(new_inode) ==
7061 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
7062 root_objectid = BTRFS_I(new_inode)->location.objectid;
7063 ret = btrfs_unlink_subvol(trans, dest, new_dir,
7064 root_objectid,
7065 new_dentry->d_name.name,
7066 new_dentry->d_name.len);
7067 BUG_ON(new_inode->i_nlink == 0);
7068 } else {
7069 ret = btrfs_unlink_inode(trans, dest, new_dir,
7070 new_dentry->d_inode,
7071 new_dentry->d_name.name,
7072 new_dentry->d_name.len);
7074 BUG_ON(ret);
7075 if (new_inode->i_nlink == 0) {
7076 ret = btrfs_orphan_add(trans, new_dentry->d_inode);
7077 BUG_ON(ret);
7081 fixup_inode_flags(new_dir, old_inode);
7083 ret = btrfs_add_link(trans, new_dir, old_inode,
7084 new_dentry->d_name.name,
7085 new_dentry->d_name.len, 0, index);
7086 BUG_ON(ret);
7088 if (old_ino != BTRFS_FIRST_FREE_OBJECTID) {
7089 struct dentry *parent = new_dentry->d_parent;
7090 btrfs_log_new_name(trans, old_inode, old_dir, parent);
7091 btrfs_end_log_trans(root);
7093 out_fail:
7094 btrfs_end_transaction_throttle(trans, root);
7095 out_notrans:
7096 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
7097 up_read(&root->fs_info->subvol_sem);
7099 return ret;
7103 * some fairly slow code that needs optimization. This walks the list
7104 * of all the inodes with pending delalloc and forces them to disk.
7106 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
7108 struct list_head *head = &root->fs_info->delalloc_inodes;
7109 struct btrfs_inode *binode;
7110 struct inode *inode;
7112 if (root->fs_info->sb->s_flags & MS_RDONLY)
7113 return -EROFS;
7115 spin_lock(&root->fs_info->delalloc_lock);
7116 while (!list_empty(head)) {
7117 binode = list_entry(head->next, struct btrfs_inode,
7118 delalloc_inodes);
7119 inode = igrab(&binode->vfs_inode);
7120 if (!inode)
7121 list_del_init(&binode->delalloc_inodes);
7122 spin_unlock(&root->fs_info->delalloc_lock);
7123 if (inode) {
7124 filemap_flush(inode->i_mapping);
7125 if (delay_iput)
7126 btrfs_add_delayed_iput(inode);
7127 else
7128 iput(inode);
7130 cond_resched();
7131 spin_lock(&root->fs_info->delalloc_lock);
7133 spin_unlock(&root->fs_info->delalloc_lock);
7135 /* the filemap_flush will queue IO into the worker threads, but
7136 * we have to make sure the IO is actually started and that
7137 * ordered extents get created before we return
7139 atomic_inc(&root->fs_info->async_submit_draining);
7140 while (atomic_read(&root->fs_info->nr_async_submits) ||
7141 atomic_read(&root->fs_info->async_delalloc_pages)) {
7142 wait_event(root->fs_info->async_submit_wait,
7143 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
7144 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
7146 atomic_dec(&root->fs_info->async_submit_draining);
7147 return 0;
7150 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
7151 const char *symname)
7153 struct btrfs_trans_handle *trans;
7154 struct btrfs_root *root = BTRFS_I(dir)->root;
7155 struct btrfs_path *path;
7156 struct btrfs_key key;
7157 struct inode *inode = NULL;
7158 int err;
7159 int drop_inode = 0;
7160 u64 objectid;
7161 u64 index = 0 ;
7162 int name_len;
7163 int datasize;
7164 unsigned long ptr;
7165 struct btrfs_file_extent_item *ei;
7166 struct extent_buffer *leaf;
7167 unsigned long nr = 0;
7169 name_len = strlen(symname) + 1;
7170 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
7171 return -ENAMETOOLONG;
7174 * 2 items for inode item and ref
7175 * 2 items for dir items
7176 * 1 item for xattr if selinux is on
7178 trans = btrfs_start_transaction(root, 5);
7179 if (IS_ERR(trans))
7180 return PTR_ERR(trans);
7182 err = btrfs_find_free_ino(root, &objectid);
7183 if (err)
7184 goto out_unlock;
7186 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
7187 dentry->d_name.len, btrfs_ino(dir), objectid,
7188 S_IFLNK|S_IRWXUGO, &index);
7189 if (IS_ERR(inode)) {
7190 err = PTR_ERR(inode);
7191 goto out_unlock;
7194 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
7195 if (err) {
7196 drop_inode = 1;
7197 goto out_unlock;
7200 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
7201 if (err)
7202 drop_inode = 1;
7203 else {
7204 inode->i_mapping->a_ops = &btrfs_aops;
7205 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
7206 inode->i_fop = &btrfs_file_operations;
7207 inode->i_op = &btrfs_file_inode_operations;
7208 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
7210 if (drop_inode)
7211 goto out_unlock;
7213 path = btrfs_alloc_path();
7214 if (!path) {
7215 err = -ENOMEM;
7216 drop_inode = 1;
7217 goto out_unlock;
7219 key.objectid = btrfs_ino(inode);
7220 key.offset = 0;
7221 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
7222 datasize = btrfs_file_extent_calc_inline_size(name_len);
7223 err = btrfs_insert_empty_item(trans, root, path, &key,
7224 datasize);
7225 if (err) {
7226 drop_inode = 1;
7227 btrfs_free_path(path);
7228 goto out_unlock;
7230 leaf = path->nodes[0];
7231 ei = btrfs_item_ptr(leaf, path->slots[0],
7232 struct btrfs_file_extent_item);
7233 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
7234 btrfs_set_file_extent_type(leaf, ei,
7235 BTRFS_FILE_EXTENT_INLINE);
7236 btrfs_set_file_extent_encryption(leaf, ei, 0);
7237 btrfs_set_file_extent_compression(leaf, ei, 0);
7238 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
7239 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
7241 ptr = btrfs_file_extent_inline_start(ei);
7242 write_extent_buffer(leaf, symname, ptr, name_len);
7243 btrfs_mark_buffer_dirty(leaf);
7244 btrfs_free_path(path);
7246 inode->i_op = &btrfs_symlink_inode_operations;
7247 inode->i_mapping->a_ops = &btrfs_symlink_aops;
7248 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
7249 inode_set_bytes(inode, name_len);
7250 btrfs_i_size_write(inode, name_len - 1);
7251 err = btrfs_update_inode(trans, root, inode);
7252 if (err)
7253 drop_inode = 1;
7255 out_unlock:
7256 nr = trans->blocks_used;
7257 btrfs_end_transaction_throttle(trans, root);
7258 if (drop_inode) {
7259 inode_dec_link_count(inode);
7260 iput(inode);
7262 btrfs_btree_balance_dirty(root, nr);
7263 return err;
7266 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
7267 u64 start, u64 num_bytes, u64 min_size,
7268 loff_t actual_len, u64 *alloc_hint,
7269 struct btrfs_trans_handle *trans)
7271 struct btrfs_root *root = BTRFS_I(inode)->root;
7272 struct btrfs_key ins;
7273 u64 cur_offset = start;
7274 u64 i_size;
7275 int ret = 0;
7276 bool own_trans = true;
7278 if (trans)
7279 own_trans = false;
7280 while (num_bytes > 0) {
7281 if (own_trans) {
7282 trans = btrfs_start_transaction(root, 3);
7283 if (IS_ERR(trans)) {
7284 ret = PTR_ERR(trans);
7285 break;
7289 ret = btrfs_reserve_extent(trans, root, num_bytes, min_size,
7290 0, *alloc_hint, (u64)-1, &ins, 1);
7291 if (ret) {
7292 if (own_trans)
7293 btrfs_end_transaction(trans, root);
7294 break;
7297 ret = insert_reserved_file_extent(trans, inode,
7298 cur_offset, ins.objectid,
7299 ins.offset, ins.offset,
7300 ins.offset, 0, 0, 0,
7301 BTRFS_FILE_EXTENT_PREALLOC);
7302 BUG_ON(ret);
7303 btrfs_drop_extent_cache(inode, cur_offset,
7304 cur_offset + ins.offset -1, 0);
7306 num_bytes -= ins.offset;
7307 cur_offset += ins.offset;
7308 *alloc_hint = ins.objectid + ins.offset;
7310 inode->i_ctime = CURRENT_TIME;
7311 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
7312 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
7313 (actual_len > inode->i_size) &&
7314 (cur_offset > inode->i_size)) {
7315 if (cur_offset > actual_len)
7316 i_size = actual_len;
7317 else
7318 i_size = cur_offset;
7319 i_size_write(inode, i_size);
7320 btrfs_ordered_update_i_size(inode, i_size, NULL);
7323 ret = btrfs_update_inode(trans, root, inode);
7324 BUG_ON(ret);
7326 if (own_trans)
7327 btrfs_end_transaction(trans, root);
7329 return ret;
7332 int btrfs_prealloc_file_range(struct inode *inode, int mode,
7333 u64 start, u64 num_bytes, u64 min_size,
7334 loff_t actual_len, u64 *alloc_hint)
7336 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
7337 min_size, actual_len, alloc_hint,
7338 NULL);
7341 int btrfs_prealloc_file_range_trans(struct inode *inode,
7342 struct btrfs_trans_handle *trans, int mode,
7343 u64 start, u64 num_bytes, u64 min_size,
7344 loff_t actual_len, u64 *alloc_hint)
7346 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
7347 min_size, actual_len, alloc_hint, trans);
7350 static int btrfs_set_page_dirty(struct page *page)
7352 return __set_page_dirty_nobuffers(page);
7355 static int btrfs_permission(struct inode *inode, int mask)
7357 struct btrfs_root *root = BTRFS_I(inode)->root;
7358 umode_t mode = inode->i_mode;
7360 if (mask & MAY_WRITE &&
7361 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
7362 if (btrfs_root_readonly(root))
7363 return -EROFS;
7364 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
7365 return -EACCES;
7367 return generic_permission(inode, mask);
7370 static const struct inode_operations btrfs_dir_inode_operations = {
7371 .getattr = btrfs_getattr,
7372 .lookup = btrfs_lookup,
7373 .create = btrfs_create,
7374 .unlink = btrfs_unlink,
7375 .link = btrfs_link,
7376 .mkdir = btrfs_mkdir,
7377 .rmdir = btrfs_rmdir,
7378 .rename = btrfs_rename,
7379 .symlink = btrfs_symlink,
7380 .setattr = btrfs_setattr,
7381 .mknod = btrfs_mknod,
7382 .setxattr = btrfs_setxattr,
7383 .getxattr = btrfs_getxattr,
7384 .listxattr = btrfs_listxattr,
7385 .removexattr = btrfs_removexattr,
7386 .permission = btrfs_permission,
7387 .get_acl = btrfs_get_acl,
7389 static const struct inode_operations btrfs_dir_ro_inode_operations = {
7390 .lookup = btrfs_lookup,
7391 .permission = btrfs_permission,
7392 .get_acl = btrfs_get_acl,
7395 static const struct file_operations btrfs_dir_file_operations = {
7396 .llseek = generic_file_llseek,
7397 .read = generic_read_dir,
7398 .readdir = btrfs_real_readdir,
7399 .unlocked_ioctl = btrfs_ioctl,
7400 #ifdef CONFIG_COMPAT
7401 .compat_ioctl = btrfs_ioctl,
7402 #endif
7403 .release = btrfs_release_file,
7404 .fsync = btrfs_sync_file,
7407 static struct extent_io_ops btrfs_extent_io_ops = {
7408 .fill_delalloc = run_delalloc_range,
7409 .submit_bio_hook = btrfs_submit_bio_hook,
7410 .merge_bio_hook = btrfs_merge_bio_hook,
7411 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
7412 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
7413 .writepage_start_hook = btrfs_writepage_start_hook,
7414 .readpage_io_failed_hook = btrfs_io_failed_hook,
7415 .set_bit_hook = btrfs_set_bit_hook,
7416 .clear_bit_hook = btrfs_clear_bit_hook,
7417 .merge_extent_hook = btrfs_merge_extent_hook,
7418 .split_extent_hook = btrfs_split_extent_hook,
7422 * btrfs doesn't support the bmap operation because swapfiles
7423 * use bmap to make a mapping of extents in the file. They assume
7424 * these extents won't change over the life of the file and they
7425 * use the bmap result to do IO directly to the drive.
7427 * the btrfs bmap call would return logical addresses that aren't
7428 * suitable for IO and they also will change frequently as COW
7429 * operations happen. So, swapfile + btrfs == corruption.
7431 * For now we're avoiding this by dropping bmap.
7433 static const struct address_space_operations btrfs_aops = {
7434 .readpage = btrfs_readpage,
7435 .writepage = btrfs_writepage,
7436 .writepages = btrfs_writepages,
7437 .readpages = btrfs_readpages,
7438 .direct_IO = btrfs_direct_IO,
7439 .invalidatepage = btrfs_invalidatepage,
7440 .releasepage = btrfs_releasepage,
7441 .set_page_dirty = btrfs_set_page_dirty,
7442 .error_remove_page = generic_error_remove_page,
7445 static const struct address_space_operations btrfs_symlink_aops = {
7446 .readpage = btrfs_readpage,
7447 .writepage = btrfs_writepage,
7448 .invalidatepage = btrfs_invalidatepage,
7449 .releasepage = btrfs_releasepage,
7452 static const struct inode_operations btrfs_file_inode_operations = {
7453 .getattr = btrfs_getattr,
7454 .setattr = btrfs_setattr,
7455 .setxattr = btrfs_setxattr,
7456 .getxattr = btrfs_getxattr,
7457 .listxattr = btrfs_listxattr,
7458 .removexattr = btrfs_removexattr,
7459 .permission = btrfs_permission,
7460 .fiemap = btrfs_fiemap,
7461 .get_acl = btrfs_get_acl,
7463 static const struct inode_operations btrfs_special_inode_operations = {
7464 .getattr = btrfs_getattr,
7465 .setattr = btrfs_setattr,
7466 .permission = btrfs_permission,
7467 .setxattr = btrfs_setxattr,
7468 .getxattr = btrfs_getxattr,
7469 .listxattr = btrfs_listxattr,
7470 .removexattr = btrfs_removexattr,
7471 .get_acl = btrfs_get_acl,
7473 static const struct inode_operations btrfs_symlink_inode_operations = {
7474 .readlink = generic_readlink,
7475 .follow_link = page_follow_link_light,
7476 .put_link = page_put_link,
7477 .getattr = btrfs_getattr,
7478 .permission = btrfs_permission,
7479 .setxattr = btrfs_setxattr,
7480 .getxattr = btrfs_getxattr,
7481 .listxattr = btrfs_listxattr,
7482 .removexattr = btrfs_removexattr,
7483 .get_acl = btrfs_get_acl,
7486 const struct dentry_operations btrfs_dentry_operations = {
7487 .d_delete = btrfs_dentry_delete,
7488 .d_release = btrfs_dentry_release,