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-rw-r--r--fs/btrfs/inode.c5035
1 files changed, 5035 insertions, 0 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
new file mode 100644
index 000000000000..8adfe059ab41
--- /dev/null
+++ b/fs/btrfs/inode.c
@@ -0,0 +1,5035 @@
1/*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19#include <linux/kernel.h>
20#include <linux/bio.h>
21#include <linux/buffer_head.h>
22#include <linux/file.h>
23#include <linux/fs.h>
24#include <linux/pagemap.h>
25#include <linux/highmem.h>
26#include <linux/time.h>
27#include <linux/init.h>
28#include <linux/string.h>
29#include <linux/smp_lock.h>
30#include <linux/backing-dev.h>
31#include <linux/mpage.h>
32#include <linux/swap.h>
33#include <linux/writeback.h>
34#include <linux/statfs.h>
35#include <linux/compat.h>
36#include <linux/bit_spinlock.h>
37#include <linux/version.h>
38#include <linux/xattr.h>
39#include <linux/posix_acl.h>
40#include <linux/falloc.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 "ref-cache.h"
53#include "compression.h"
54
55struct btrfs_iget_args {
56 u64 ino;
57 struct btrfs_root *root;
58};
59
60static struct inode_operations btrfs_dir_inode_operations;
61static struct inode_operations btrfs_symlink_inode_operations;
62static struct inode_operations btrfs_dir_ro_inode_operations;
63static struct inode_operations btrfs_special_inode_operations;
64static struct inode_operations btrfs_file_inode_operations;
65static struct address_space_operations btrfs_aops;
66static struct address_space_operations btrfs_symlink_aops;
67static struct file_operations btrfs_dir_file_operations;
68static struct extent_io_ops btrfs_extent_io_ops;
69
70static struct kmem_cache *btrfs_inode_cachep;
71struct kmem_cache *btrfs_trans_handle_cachep;
72struct kmem_cache *btrfs_transaction_cachep;
73struct kmem_cache *btrfs_bit_radix_cachep;
74struct kmem_cache *btrfs_path_cachep;
75
76#define S_SHIFT 12
77static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
78 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
79 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
80 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
81 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
82 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
83 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
84 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
85};
86
87static void btrfs_truncate(struct inode *inode);
88static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end);
89static noinline int cow_file_range(struct inode *inode,
90 struct page *locked_page,
91 u64 start, u64 end, int *page_started,
92 unsigned long *nr_written, int unlock);
93
94/*
95 * a very lame attempt at stopping writes when the FS is 85% full. There
96 * are countless ways this is incorrect, but it is better than nothing.
97 */
98int btrfs_check_free_space(struct btrfs_root *root, u64 num_required,
99 int for_del)
100{
101 u64 total;
102 u64 used;
103 u64 thresh;
104 int ret = 0;
105
106 spin_lock(&root->fs_info->delalloc_lock);
107 total = btrfs_super_total_bytes(&root->fs_info->super_copy);
108 used = btrfs_super_bytes_used(&root->fs_info->super_copy);
109 if (for_del)
110 thresh = total * 90;
111 else
112 thresh = total * 85;
113
114 do_div(thresh, 100);
115
116 if (used + root->fs_info->delalloc_bytes + num_required > thresh)
117 ret = -ENOSPC;
118 spin_unlock(&root->fs_info->delalloc_lock);
119 return ret;
120}
121
122/*
123 * this does all the hard work for inserting an inline extent into
124 * the btree. The caller should have done a btrfs_drop_extents so that
125 * no overlapping inline items exist in the btree
126 */
127static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
128 struct btrfs_root *root, struct inode *inode,
129 u64 start, size_t size, size_t compressed_size,
130 struct page **compressed_pages)
131{
132 struct btrfs_key key;
133 struct btrfs_path *path;
134 struct extent_buffer *leaf;
135 struct page *page = NULL;
136 char *kaddr;
137 unsigned long ptr;
138 struct btrfs_file_extent_item *ei;
139 int err = 0;
140 int ret;
141 size_t cur_size = size;
142 size_t datasize;
143 unsigned long offset;
144 int use_compress = 0;
145
146 if (compressed_size && compressed_pages) {
147 use_compress = 1;
148 cur_size = compressed_size;
149 }
150
151 path = btrfs_alloc_path();
152 if (!path)
153 return -ENOMEM;
154
155 btrfs_set_trans_block_group(trans, inode);
156
157 key.objectid = inode->i_ino;
158 key.offset = start;
159 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
160 datasize = btrfs_file_extent_calc_inline_size(cur_size);
161
162 inode_add_bytes(inode, size);
163 ret = btrfs_insert_empty_item(trans, root, path, &key,
164 datasize);
165 BUG_ON(ret);
166 if (ret) {
167 err = ret;
168 goto fail;
169 }
170 leaf = path->nodes[0];
171 ei = btrfs_item_ptr(leaf, path->slots[0],
172 struct btrfs_file_extent_item);
173 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
174 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
175 btrfs_set_file_extent_encryption(leaf, ei, 0);
176 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
177 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
178 ptr = btrfs_file_extent_inline_start(ei);
179
180 if (use_compress) {
181 struct page *cpage;
182 int i = 0;
183 while (compressed_size > 0) {
184 cpage = compressed_pages[i];
185 cur_size = min_t(unsigned long, compressed_size,
186 PAGE_CACHE_SIZE);
187
188 kaddr = kmap(cpage);
189 write_extent_buffer(leaf, kaddr, ptr, cur_size);
190 kunmap(cpage);
191
192 i++;
193 ptr += cur_size;
194 compressed_size -= cur_size;
195 }
196 btrfs_set_file_extent_compression(leaf, ei,
197 BTRFS_COMPRESS_ZLIB);
198 } else {
199 page = find_get_page(inode->i_mapping,
200 start >> PAGE_CACHE_SHIFT);
201 btrfs_set_file_extent_compression(leaf, ei, 0);
202 kaddr = kmap_atomic(page, KM_USER0);
203 offset = start & (PAGE_CACHE_SIZE - 1);
204 write_extent_buffer(leaf, kaddr + offset, ptr, size);
205 kunmap_atomic(kaddr, KM_USER0);
206 page_cache_release(page);
207 }
208 btrfs_mark_buffer_dirty(leaf);
209 btrfs_free_path(path);
210
211 BTRFS_I(inode)->disk_i_size = inode->i_size;
212 btrfs_update_inode(trans, root, inode);
213 return 0;
214fail:
215 btrfs_free_path(path);
216 return err;
217}
218
219
220/*
221 * conditionally insert an inline extent into the file. This
222 * does the checks required to make sure the data is small enough
223 * to fit as an inline extent.
224 */
225static int cow_file_range_inline(struct btrfs_trans_handle *trans,
226 struct btrfs_root *root,
227 struct inode *inode, u64 start, u64 end,
228 size_t compressed_size,
229 struct page **compressed_pages)
230{
231 u64 isize = i_size_read(inode);
232 u64 actual_end = min(end + 1, isize);
233 u64 inline_len = actual_end - start;
234 u64 aligned_end = (end + root->sectorsize - 1) &
235 ~((u64)root->sectorsize - 1);
236 u64 hint_byte;
237 u64 data_len = inline_len;
238 int ret;
239
240 if (compressed_size)
241 data_len = compressed_size;
242
243 if (start > 0 ||
244 actual_end >= PAGE_CACHE_SIZE ||
245 data_len >= BTRFS_MAX_INLINE_DATA_SIZE(root) ||
246 (!compressed_size &&
247 (actual_end & (root->sectorsize - 1)) == 0) ||
248 end + 1 < isize ||
249 data_len > root->fs_info->max_inline) {
250 return 1;
251 }
252
253 ret = btrfs_drop_extents(trans, root, inode, start,
254 aligned_end, start, &hint_byte);
255 BUG_ON(ret);
256
257 if (isize > actual_end)
258 inline_len = min_t(u64, isize, actual_end);
259 ret = insert_inline_extent(trans, root, inode, start,
260 inline_len, compressed_size,
261 compressed_pages);
262 BUG_ON(ret);
263 btrfs_drop_extent_cache(inode, start, aligned_end, 0);
264 return 0;
265}
266
267struct async_extent {
268 u64 start;
269 u64 ram_size;
270 u64 compressed_size;
271 struct page **pages;
272 unsigned long nr_pages;
273 struct list_head list;
274};
275
276struct async_cow {
277 struct inode *inode;
278 struct btrfs_root *root;
279 struct page *locked_page;
280 u64 start;
281 u64 end;
282 struct list_head extents;
283 struct btrfs_work work;
284};
285
286static noinline int add_async_extent(struct async_cow *cow,
287 u64 start, u64 ram_size,
288 u64 compressed_size,
289 struct page **pages,
290 unsigned long nr_pages)
291{
292 struct async_extent *async_extent;
293
294 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
295 async_extent->start = start;
296 async_extent->ram_size = ram_size;
297 async_extent->compressed_size = compressed_size;
298 async_extent->pages = pages;
299 async_extent->nr_pages = nr_pages;
300 list_add_tail(&async_extent->list, &cow->extents);
301 return 0;
302}
303
304/*
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).
308 *
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.
314 *
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.
319 */
320static 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)
325{
326 struct btrfs_root *root = BTRFS_I(inode)->root;
327 struct btrfs_trans_handle *trans;
328 u64 num_bytes;
329 u64 orig_start;
330 u64 disk_num_bytes;
331 u64 blocksize = root->sectorsize;
332 u64 actual_end;
333 u64 isize = i_size_read(inode);
334 int ret = 0;
335 struct page **pages = NULL;
336 unsigned long nr_pages;
337 unsigned long nr_pages_ret = 0;
338 unsigned long total_compressed = 0;
339 unsigned long total_in = 0;
340 unsigned long max_compressed = 128 * 1024;
341 unsigned long max_uncompressed = 128 * 1024;
342 int i;
343 int will_compress;
344
345 orig_start = start;
346
347 actual_end = min_t(u64, isize, end + 1);
348again:
349 will_compress = 0;
350 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
351 nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
352
353 total_compressed = actual_end - start;
354
355 /* we want to make sure that amount of ram required to uncompress
356 * an extent is reasonable, so we limit the total size in ram
357 * of a compressed extent to 128k. This is a crucial number
358 * because it also controls how easily we can spread reads across
359 * cpus for decompression.
360 *
361 * We also want to make sure the amount of IO required to do
362 * a random read is reasonably small, so we limit the size of
363 * a compressed extent to 128k.
364 */
365 total_compressed = min(total_compressed, max_uncompressed);
366 num_bytes = (end - start + blocksize) & ~(blocksize - 1);
367 num_bytes = max(blocksize, num_bytes);
368 disk_num_bytes = num_bytes;
369 total_in = 0;
370 ret = 0;
371
372 /*
373 * we do compression for mount -o compress and when the
374 * inode has not been flagged as nocompress. This flag can
375 * change at any time if we discover bad compression ratios.
376 */
377 if (!btrfs_test_flag(inode, NOCOMPRESS) &&
378 btrfs_test_opt(root, COMPRESS)) {
379 WARN_ON(pages);
380 pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
381
382 ret = btrfs_zlib_compress_pages(inode->i_mapping, start,
383 total_compressed, pages,
384 nr_pages, &nr_pages_ret,
385 &total_in,
386 &total_compressed,
387 max_compressed);
388
389 if (!ret) {
390 unsigned long offset = total_compressed &
391 (PAGE_CACHE_SIZE - 1);
392 struct page *page = pages[nr_pages_ret - 1];
393 char *kaddr;
394
395 /* zero the tail end of the last page, we might be
396 * sending it down to disk
397 */
398 if (offset) {
399 kaddr = kmap_atomic(page, KM_USER0);
400 memset(kaddr + offset, 0,
401 PAGE_CACHE_SIZE - offset);
402 kunmap_atomic(kaddr, KM_USER0);
403 }
404 will_compress = 1;
405 }
406 }
407 if (start == 0) {
408 trans = btrfs_join_transaction(root, 1);
409 BUG_ON(!trans);
410 btrfs_set_trans_block_group(trans, inode);
411
412 /* lets try to make an inline extent */
413 if (ret || total_in < (actual_end - start)) {
414 /* we didn't compress the entire range, try
415 * to make an uncompressed inline extent.
416 */
417 ret = cow_file_range_inline(trans, root, inode,
418 start, end, 0, NULL);
419 } else {
420 /* try making a compressed inline extent */
421 ret = cow_file_range_inline(trans, root, inode,
422 start, end,
423 total_compressed, pages);
424 }
425 btrfs_end_transaction(trans, root);
426 if (ret == 0) {
427 /*
428 * inline extent creation worked, we don't need
429 * to create any more async work items. Unlock
430 * and free up our temp pages.
431 */
432 extent_clear_unlock_delalloc(inode,
433 &BTRFS_I(inode)->io_tree,
434 start, end, NULL, 1, 0,
435 0, 1, 1, 1);
436 ret = 0;
437 goto free_pages_out;
438 }
439 }
440
441 if (will_compress) {
442 /*
443 * we aren't doing an inline extent round the compressed size
444 * up to a block size boundary so the allocator does sane
445 * things
446 */
447 total_compressed = (total_compressed + blocksize - 1) &
448 ~(blocksize - 1);
449
450 /*
451 * one last check to make sure the compression is really a
452 * win, compare the page count read with the blocks on disk
453 */
454 total_in = (total_in + PAGE_CACHE_SIZE - 1) &
455 ~(PAGE_CACHE_SIZE - 1);
456 if (total_compressed >= total_in) {
457 will_compress = 0;
458 } else {
459 disk_num_bytes = total_compressed;
460 num_bytes = total_in;
461 }
462 }
463 if (!will_compress && pages) {
464 /*
465 * the compression code ran but failed to make things smaller,
466 * free any pages it allocated and our page pointer array
467 */
468 for (i = 0; i < nr_pages_ret; i++) {
469 WARN_ON(pages[i]->mapping);
470 page_cache_release(pages[i]);
471 }
472 kfree(pages);
473 pages = NULL;
474 total_compressed = 0;
475 nr_pages_ret = 0;
476
477 /* flag the file so we don't compress in the future */
478 btrfs_set_flag(inode, NOCOMPRESS);
479 }
480 if (will_compress) {
481 *num_added += 1;
482
483 /* the async work queues will take care of doing actual
484 * allocation on disk for these compressed pages,
485 * and will submit them to the elevator.
486 */
487 add_async_extent(async_cow, start, num_bytes,
488 total_compressed, pages, nr_pages_ret);
489
490 if (start + num_bytes < end && start + num_bytes < actual_end) {
491 start += num_bytes;
492 pages = NULL;
493 cond_resched();
494 goto again;
495 }
496 } else {
497 /*
498 * No compression, but we still need to write the pages in
499 * the file we've been given so far. redirty the locked
500 * page if it corresponds to our extent and set things up
501 * for the async work queue to run cow_file_range to do
502 * the normal delalloc dance
503 */
504 if (page_offset(locked_page) >= start &&
505 page_offset(locked_page) <= end) {
506 __set_page_dirty_nobuffers(locked_page);
507 /* unlocked later on in the async handlers */
508 }
509 add_async_extent(async_cow, start, end - start + 1, 0, NULL, 0);
510 *num_added += 1;
511 }
512
513out:
514 return 0;
515
516free_pages_out:
517 for (i = 0; i < nr_pages_ret; i++) {
518 WARN_ON(pages[i]->mapping);
519 page_cache_release(pages[i]);
520 }
521 kfree(pages);
522
523 goto out;
524}
525
526/*
527 * phase two of compressed writeback. This is the ordered portion
528 * of the code, which only gets called in the order the work was
529 * queued. We walk all the async extents created by compress_file_range
530 * and send them down to the disk.
531 */
532static noinline int submit_compressed_extents(struct inode *inode,
533 struct async_cow *async_cow)
534{
535 struct async_extent *async_extent;
536 u64 alloc_hint = 0;
537 struct btrfs_trans_handle *trans;
538 struct btrfs_key ins;
539 struct extent_map *em;
540 struct btrfs_root *root = BTRFS_I(inode)->root;
541 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
542 struct extent_io_tree *io_tree;
543 int ret;
544
545 if (list_empty(&async_cow->extents))
546 return 0;
547
548 trans = btrfs_join_transaction(root, 1);
549
550 while (!list_empty(&async_cow->extents)) {
551 async_extent = list_entry(async_cow->extents.next,
552 struct async_extent, list);
553 list_del(&async_extent->list);
554
555 io_tree = &BTRFS_I(inode)->io_tree;
556
557 /* did the compression code fall back to uncompressed IO? */
558 if (!async_extent->pages) {
559 int page_started = 0;
560 unsigned long nr_written = 0;
561
562 lock_extent(io_tree, async_extent->start,
563 async_extent->start +
564 async_extent->ram_size - 1, GFP_NOFS);
565
566 /* allocate blocks */
567 cow_file_range(inode, async_cow->locked_page,
568 async_extent->start,
569 async_extent->start +
570 async_extent->ram_size - 1,
571 &page_started, &nr_written, 0);
572
573 /*
574 * if page_started, cow_file_range inserted an
575 * inline extent and took care of all the unlocking
576 * and IO for us. Otherwise, we need to submit
577 * all those pages down to the drive.
578 */
579 if (!page_started)
580 extent_write_locked_range(io_tree,
581 inode, async_extent->start,
582 async_extent->start +
583 async_extent->ram_size - 1,
584 btrfs_get_extent,
585 WB_SYNC_ALL);
586 kfree(async_extent);
587 cond_resched();
588 continue;
589 }
590
591 lock_extent(io_tree, async_extent->start,
592 async_extent->start + async_extent->ram_size - 1,
593 GFP_NOFS);
594 /*
595 * here we're doing allocation and writeback of the
596 * compressed pages
597 */
598 btrfs_drop_extent_cache(inode, async_extent->start,
599 async_extent->start +
600 async_extent->ram_size - 1, 0);
601
602 ret = btrfs_reserve_extent(trans, root,
603 async_extent->compressed_size,
604 async_extent->compressed_size,
605 0, alloc_hint,
606 (u64)-1, &ins, 1);
607 BUG_ON(ret);
608 em = alloc_extent_map(GFP_NOFS);
609 em->start = async_extent->start;
610 em->len = async_extent->ram_size;
611 em->orig_start = em->start;
612
613 em->block_start = ins.objectid;
614 em->block_len = ins.offset;
615 em->bdev = root->fs_info->fs_devices->latest_bdev;
616 set_bit(EXTENT_FLAG_PINNED, &em->flags);
617 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
618
619 while (1) {
620 spin_lock(&em_tree->lock);
621 ret = add_extent_mapping(em_tree, em);
622 spin_unlock(&em_tree->lock);
623 if (ret != -EEXIST) {
624 free_extent_map(em);
625 break;
626 }
627 btrfs_drop_extent_cache(inode, async_extent->start,
628 async_extent->start +
629 async_extent->ram_size - 1, 0);
630 }
631
632 ret = btrfs_add_ordered_extent(inode, async_extent->start,
633 ins.objectid,
634 async_extent->ram_size,
635 ins.offset,
636 BTRFS_ORDERED_COMPRESSED);
637 BUG_ON(ret);
638
639 btrfs_end_transaction(trans, root);
640
641 /*
642 * clear dirty, set writeback and unlock the pages.
643 */
644 extent_clear_unlock_delalloc(inode,
645 &BTRFS_I(inode)->io_tree,
646 async_extent->start,
647 async_extent->start +
648 async_extent->ram_size - 1,
649 NULL, 1, 1, 0, 1, 1, 0);
650
651 ret = btrfs_submit_compressed_write(inode,
652 async_extent->start,
653 async_extent->ram_size,
654 ins.objectid,
655 ins.offset, async_extent->pages,
656 async_extent->nr_pages);
657
658 BUG_ON(ret);
659 trans = btrfs_join_transaction(root, 1);
660 alloc_hint = ins.objectid + ins.offset;
661 kfree(async_extent);
662 cond_resched();
663 }
664
665 btrfs_end_transaction(trans, root);
666 return 0;
667}
668
669/*
670 * when extent_io.c finds a delayed allocation range in the file,
671 * the call backs end up in this code. The basic idea is to
672 * allocate extents on disk for the range, and create ordered data structs
673 * in ram to track those extents.
674 *
675 * locked_page is the page that writepage had locked already. We use
676 * it to make sure we don't do extra locks or unlocks.
677 *
678 * *page_started is set to one if we unlock locked_page and do everything
679 * required to start IO on it. It may be clean and already done with
680 * IO when we return.
681 */
682static noinline int cow_file_range(struct inode *inode,
683 struct page *locked_page,
684 u64 start, u64 end, int *page_started,
685 unsigned long *nr_written,
686 int unlock)
687{
688 struct btrfs_root *root = BTRFS_I(inode)->root;
689 struct btrfs_trans_handle *trans;
690 u64 alloc_hint = 0;
691 u64 num_bytes;
692 unsigned long ram_size;
693 u64 disk_num_bytes;
694 u64 cur_alloc_size;
695 u64 blocksize = root->sectorsize;
696 u64 actual_end;
697 u64 isize = i_size_read(inode);
698 struct btrfs_key ins;
699 struct extent_map *em;
700 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
701 int ret = 0;
702
703 trans = btrfs_join_transaction(root, 1);
704 BUG_ON(!trans);
705 btrfs_set_trans_block_group(trans, inode);
706
707 actual_end = min_t(u64, isize, end + 1);
708
709 num_bytes = (end - start + blocksize) & ~(blocksize - 1);
710 num_bytes = max(blocksize, num_bytes);
711 disk_num_bytes = num_bytes;
712 ret = 0;
713
714 if (start == 0) {
715 /* lets try to make an inline extent */
716 ret = cow_file_range_inline(trans, root, inode,
717 start, end, 0, NULL);
718 if (ret == 0) {
719 extent_clear_unlock_delalloc(inode,
720 &BTRFS_I(inode)->io_tree,
721 start, end, NULL, 1, 1,
722 1, 1, 1, 1);
723 *nr_written = *nr_written +
724 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
725 *page_started = 1;
726 ret = 0;
727 goto out;
728 }
729 }
730
731 BUG_ON(disk_num_bytes >
732 btrfs_super_total_bytes(&root->fs_info->super_copy));
733
734 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
735
736 while (disk_num_bytes > 0) {
737 cur_alloc_size = min(disk_num_bytes, root->fs_info->max_extent);
738 ret = btrfs_reserve_extent(trans, root, cur_alloc_size,
739 root->sectorsize, 0, alloc_hint,
740 (u64)-1, &ins, 1);
741 BUG_ON(ret);
742
743 em = alloc_extent_map(GFP_NOFS);
744 em->start = start;
745 em->orig_start = em->start;
746
747 ram_size = ins.offset;
748 em->len = ins.offset;
749
750 em->block_start = ins.objectid;
751 em->block_len = ins.offset;
752 em->bdev = root->fs_info->fs_devices->latest_bdev;
753 set_bit(EXTENT_FLAG_PINNED, &em->flags);
754
755 while (1) {
756 spin_lock(&em_tree->lock);
757 ret = add_extent_mapping(em_tree, em);
758 spin_unlock(&em_tree->lock);
759 if (ret != -EEXIST) {
760 free_extent_map(em);
761 break;
762 }
763 btrfs_drop_extent_cache(inode, start,
764 start + ram_size - 1, 0);
765 }
766
767 cur_alloc_size = ins.offset;
768 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
769 ram_size, cur_alloc_size, 0);
770 BUG_ON(ret);
771
772 if (root->root_key.objectid ==
773 BTRFS_DATA_RELOC_TREE_OBJECTID) {
774 ret = btrfs_reloc_clone_csums(inode, start,
775 cur_alloc_size);
776 BUG_ON(ret);
777 }
778
779 if (disk_num_bytes < cur_alloc_size)
780 break;
781
782 /* we're not doing compressed IO, don't unlock the first
783 * page (which the caller expects to stay locked), don't
784 * clear any dirty bits and don't set any writeback bits
785 */
786 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
787 start, start + ram_size - 1,
788 locked_page, unlock, 1,
789 1, 0, 0, 0);
790 disk_num_bytes -= cur_alloc_size;
791 num_bytes -= cur_alloc_size;
792 alloc_hint = ins.objectid + ins.offset;
793 start += cur_alloc_size;
794 }
795out:
796 ret = 0;
797 btrfs_end_transaction(trans, root);
798
799 return ret;
800}
801
802/*
803 * work queue call back to started compression on a file and pages
804 */
805static noinline void async_cow_start(struct btrfs_work *work)
806{
807 struct async_cow *async_cow;
808 int num_added = 0;
809 async_cow = container_of(work, struct async_cow, work);
810
811 compress_file_range(async_cow->inode, async_cow->locked_page,
812 async_cow->start, async_cow->end, async_cow,
813 &num_added);
814 if (num_added == 0)
815 async_cow->inode = NULL;
816}
817
818/*
819 * work queue call back to submit previously compressed pages
820 */
821static noinline void async_cow_submit(struct btrfs_work *work)
822{
823 struct async_cow *async_cow;
824 struct btrfs_root *root;
825 unsigned long nr_pages;
826
827 async_cow = container_of(work, struct async_cow, work);
828
829 root = async_cow->root;
830 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
831 PAGE_CACHE_SHIFT;
832
833 atomic_sub(nr_pages, &root->fs_info->async_delalloc_pages);
834
835 if (atomic_read(&root->fs_info->async_delalloc_pages) <
836 5 * 1042 * 1024 &&
837 waitqueue_active(&root->fs_info->async_submit_wait))
838 wake_up(&root->fs_info->async_submit_wait);
839
840 if (async_cow->inode)
841 submit_compressed_extents(async_cow->inode, async_cow);
842}
843
844static noinline void async_cow_free(struct btrfs_work *work)
845{
846 struct async_cow *async_cow;
847 async_cow = container_of(work, struct async_cow, work);
848 kfree(async_cow);
849}
850
851static int cow_file_range_async(struct inode *inode, struct page *locked_page,
852 u64 start, u64 end, int *page_started,
853 unsigned long *nr_written)
854{
855 struct async_cow *async_cow;
856 struct btrfs_root *root = BTRFS_I(inode)->root;
857 unsigned long nr_pages;
858 u64 cur_end;
859 int limit = 10 * 1024 * 1042;
860
861 if (!btrfs_test_opt(root, COMPRESS)) {
862 return cow_file_range(inode, locked_page, start, end,
863 page_started, nr_written, 1);
864 }
865
866 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED |
867 EXTENT_DELALLOC, 1, 0, GFP_NOFS);
868 while (start < end) {
869 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
870 async_cow->inode = inode;
871 async_cow->root = root;
872 async_cow->locked_page = locked_page;
873 async_cow->start = start;
874
875 if (btrfs_test_flag(inode, NOCOMPRESS))
876 cur_end = end;
877 else
878 cur_end = min(end, start + 512 * 1024 - 1);
879
880 async_cow->end = cur_end;
881 INIT_LIST_HEAD(&async_cow->extents);
882
883 async_cow->work.func = async_cow_start;
884 async_cow->work.ordered_func = async_cow_submit;
885 async_cow->work.ordered_free = async_cow_free;
886 async_cow->work.flags = 0;
887
888 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
889 PAGE_CACHE_SHIFT;
890 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
891
892 btrfs_queue_worker(&root->fs_info->delalloc_workers,
893 &async_cow->work);
894
895 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
896 wait_event(root->fs_info->async_submit_wait,
897 (atomic_read(&root->fs_info->async_delalloc_pages) <
898 limit));
899 }
900
901 while (atomic_read(&root->fs_info->async_submit_draining) &&
902 atomic_read(&root->fs_info->async_delalloc_pages)) {
903 wait_event(root->fs_info->async_submit_wait,
904 (atomic_read(&root->fs_info->async_delalloc_pages) ==
905 0));
906 }
907
908 *nr_written += nr_pages;
909 start = cur_end + 1;
910 }
911 *page_started = 1;
912 return 0;
913}
914
915static noinline int csum_exist_in_range(struct btrfs_root *root,
916 u64 bytenr, u64 num_bytes)
917{
918 int ret;
919 struct btrfs_ordered_sum *sums;
920 LIST_HEAD(list);
921
922 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
923 bytenr + num_bytes - 1, &list);
924 if (ret == 0 && list_empty(&list))
925 return 0;
926
927 while (!list_empty(&list)) {
928 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
929 list_del(&sums->list);
930 kfree(sums);
931 }
932 return 1;
933}
934
935/*
936 * when nowcow writeback call back. This checks for snapshots or COW copies
937 * of the extents that exist in the file, and COWs the file as required.
938 *
939 * If no cow copies or snapshots exist, we write directly to the existing
940 * blocks on disk
941 */
942static int run_delalloc_nocow(struct inode *inode, struct page *locked_page,
943 u64 start, u64 end, int *page_started, int force,
944 unsigned long *nr_written)
945{
946 struct btrfs_root *root = BTRFS_I(inode)->root;
947 struct btrfs_trans_handle *trans;
948 struct extent_buffer *leaf;
949 struct btrfs_path *path;
950 struct btrfs_file_extent_item *fi;
951 struct btrfs_key found_key;
952 u64 cow_start;
953 u64 cur_offset;
954 u64 extent_end;
955 u64 disk_bytenr;
956 u64 num_bytes;
957 int extent_type;
958 int ret;
959 int type;
960 int nocow;
961 int check_prev = 1;
962
963 path = btrfs_alloc_path();
964 BUG_ON(!path);
965 trans = btrfs_join_transaction(root, 1);
966 BUG_ON(!trans);
967
968 cow_start = (u64)-1;
969 cur_offset = start;
970 while (1) {
971 ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
972 cur_offset, 0);
973 BUG_ON(ret < 0);
974 if (ret > 0 && path->slots[0] > 0 && check_prev) {
975 leaf = path->nodes[0];
976 btrfs_item_key_to_cpu(leaf, &found_key,
977 path->slots[0] - 1);
978 if (found_key.objectid == inode->i_ino &&
979 found_key.type == BTRFS_EXTENT_DATA_KEY)
980 path->slots[0]--;
981 }
982 check_prev = 0;
983next_slot:
984 leaf = path->nodes[0];
985 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
986 ret = btrfs_next_leaf(root, path);
987 if (ret < 0)
988 BUG_ON(1);
989 if (ret > 0)
990 break;
991 leaf = path->nodes[0];
992 }
993
994 nocow = 0;
995 disk_bytenr = 0;
996 num_bytes = 0;
997 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
998
999 if (found_key.objectid > inode->i_ino ||
1000 found_key.type > BTRFS_EXTENT_DATA_KEY ||
1001 found_key.offset > end)
1002 break;
1003
1004 if (found_key.offset > cur_offset) {
1005 extent_end = found_key.offset;
1006 goto out_check;
1007 }
1008
1009 fi = btrfs_item_ptr(leaf, path->slots[0],
1010 struct btrfs_file_extent_item);
1011 extent_type = btrfs_file_extent_type(leaf, fi);
1012
1013 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1014 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1015 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1016 extent_end = found_key.offset +
1017 btrfs_file_extent_num_bytes(leaf, fi);
1018 if (extent_end <= start) {
1019 path->slots[0]++;
1020 goto next_slot;
1021 }
1022 if (disk_bytenr == 0)
1023 goto out_check;
1024 if (btrfs_file_extent_compression(leaf, fi) ||
1025 btrfs_file_extent_encryption(leaf, fi) ||
1026 btrfs_file_extent_other_encoding(leaf, fi))
1027 goto out_check;
1028 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1029 goto out_check;
1030 if (btrfs_extent_readonly(root, disk_bytenr))
1031 goto out_check;
1032 if (btrfs_cross_ref_exist(trans, root, inode->i_ino,
1033 disk_bytenr))
1034 goto out_check;
1035 disk_bytenr += btrfs_file_extent_offset(leaf, fi);
1036 disk_bytenr += cur_offset - found_key.offset;
1037 num_bytes = min(end + 1, extent_end) - cur_offset;
1038 /*
1039 * force cow if csum exists in the range.
1040 * this ensure that csum for a given extent are
1041 * either valid or do not exist.
1042 */
1043 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1044 goto out_check;
1045 nocow = 1;
1046 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1047 extent_end = found_key.offset +
1048 btrfs_file_extent_inline_len(leaf, fi);
1049 extent_end = ALIGN(extent_end, root->sectorsize);
1050 } else {
1051 BUG_ON(1);
1052 }
1053out_check:
1054 if (extent_end <= start) {
1055 path->slots[0]++;
1056 goto next_slot;
1057 }
1058 if (!nocow) {
1059 if (cow_start == (u64)-1)
1060 cow_start = cur_offset;
1061 cur_offset = extent_end;
1062 if (cur_offset > end)
1063 break;
1064 path->slots[0]++;
1065 goto next_slot;
1066 }
1067
1068 btrfs_release_path(root, path);
1069 if (cow_start != (u64)-1) {
1070 ret = cow_file_range(inode, locked_page, cow_start,
1071 found_key.offset - 1, page_started,
1072 nr_written, 1);
1073 BUG_ON(ret);
1074 cow_start = (u64)-1;
1075 }
1076
1077 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1078 struct extent_map *em;
1079 struct extent_map_tree *em_tree;
1080 em_tree = &BTRFS_I(inode)->extent_tree;
1081 em = alloc_extent_map(GFP_NOFS);
1082 em->start = cur_offset;
1083 em->orig_start = em->start;
1084 em->len = num_bytes;
1085 em->block_len = num_bytes;
1086 em->block_start = disk_bytenr;
1087 em->bdev = root->fs_info->fs_devices->latest_bdev;
1088 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1089 while (1) {
1090 spin_lock(&em_tree->lock);
1091 ret = add_extent_mapping(em_tree, em);
1092 spin_unlock(&em_tree->lock);
1093 if (ret != -EEXIST) {
1094 free_extent_map(em);
1095 break;
1096 }
1097 btrfs_drop_extent_cache(inode, em->start,
1098 em->start + em->len - 1, 0);
1099 }
1100 type = BTRFS_ORDERED_PREALLOC;
1101 } else {
1102 type = BTRFS_ORDERED_NOCOW;
1103 }
1104
1105 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1106 num_bytes, num_bytes, type);
1107 BUG_ON(ret);
1108
1109 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
1110 cur_offset, cur_offset + num_bytes - 1,
1111 locked_page, 1, 1, 1, 0, 0, 0);
1112 cur_offset = extent_end;
1113 if (cur_offset > end)
1114 break;
1115 }
1116 btrfs_release_path(root, path);
1117
1118 if (cur_offset <= end && cow_start == (u64)-1)
1119 cow_start = cur_offset;
1120 if (cow_start != (u64)-1) {
1121 ret = cow_file_range(inode, locked_page, cow_start, end,
1122 page_started, nr_written, 1);
1123 BUG_ON(ret);
1124 }
1125
1126 ret = btrfs_end_transaction(trans, root);
1127 BUG_ON(ret);
1128 btrfs_free_path(path);
1129 return 0;
1130}
1131
1132/*
1133 * extent_io.c call back to do delayed allocation processing
1134 */
1135static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1136 u64 start, u64 end, int *page_started,
1137 unsigned long *nr_written)
1138{
1139 int ret;
1140
1141 if (btrfs_test_flag(inode, NODATACOW))
1142 ret = run_delalloc_nocow(inode, locked_page, start, end,
1143 page_started, 1, nr_written);
1144 else if (btrfs_test_flag(inode, PREALLOC))
1145 ret = run_delalloc_nocow(inode, locked_page, start, end,
1146 page_started, 0, nr_written);
1147 else
1148 ret = cow_file_range_async(inode, locked_page, start, end,
1149 page_started, nr_written);
1150
1151 return ret;
1152}
1153
1154/*
1155 * extent_io.c set_bit_hook, used to track delayed allocation
1156 * bytes in this file, and to maintain the list of inodes that
1157 * have pending delalloc work to be done.
1158 */
1159static int btrfs_set_bit_hook(struct inode *inode, u64 start, u64 end,
1160 unsigned long old, unsigned long bits)
1161{
1162 /*
1163 * set_bit and clear bit hooks normally require _irqsave/restore
1164 * but in this case, we are only testeing for the DELALLOC
1165 * bit, which is only set or cleared with irqs on
1166 */
1167 if (!(old & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) {
1168 struct btrfs_root *root = BTRFS_I(inode)->root;
1169 spin_lock(&root->fs_info->delalloc_lock);
1170 BTRFS_I(inode)->delalloc_bytes += end - start + 1;
1171 root->fs_info->delalloc_bytes += end - start + 1;
1172 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1173 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1174 &root->fs_info->delalloc_inodes);
1175 }
1176 spin_unlock(&root->fs_info->delalloc_lock);
1177 }
1178 return 0;
1179}
1180
1181/*
1182 * extent_io.c clear_bit_hook, see set_bit_hook for why
1183 */
1184static int btrfs_clear_bit_hook(struct inode *inode, u64 start, u64 end,
1185 unsigned long old, unsigned long bits)
1186{
1187 /*
1188 * set_bit and clear bit hooks normally require _irqsave/restore
1189 * but in this case, we are only testeing for the DELALLOC
1190 * bit, which is only set or cleared with irqs on
1191 */
1192 if ((old & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) {
1193 struct btrfs_root *root = BTRFS_I(inode)->root;
1194
1195 spin_lock(&root->fs_info->delalloc_lock);
1196 if (end - start + 1 > root->fs_info->delalloc_bytes) {
1197 printk(KERN_INFO "btrfs warning: delalloc account "
1198 "%llu %llu\n",
1199 (unsigned long long)end - start + 1,
1200 (unsigned long long)
1201 root->fs_info->delalloc_bytes);
1202 root->fs_info->delalloc_bytes = 0;
1203 BTRFS_I(inode)->delalloc_bytes = 0;
1204 } else {
1205 root->fs_info->delalloc_bytes -= end - start + 1;
1206 BTRFS_I(inode)->delalloc_bytes -= end - start + 1;
1207 }
1208 if (BTRFS_I(inode)->delalloc_bytes == 0 &&
1209 !list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1210 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1211 }
1212 spin_unlock(&root->fs_info->delalloc_lock);
1213 }
1214 return 0;
1215}
1216
1217/*
1218 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1219 * we don't create bios that span stripes or chunks
1220 */
1221int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
1222 size_t size, struct bio *bio,
1223 unsigned long bio_flags)
1224{
1225 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1226 struct btrfs_mapping_tree *map_tree;
1227 u64 logical = (u64)bio->bi_sector << 9;
1228 u64 length = 0;
1229 u64 map_length;
1230 int ret;
1231
1232 if (bio_flags & EXTENT_BIO_COMPRESSED)
1233 return 0;
1234
1235 length = bio->bi_size;
1236 map_tree = &root->fs_info->mapping_tree;
1237 map_length = length;
1238 ret = btrfs_map_block(map_tree, READ, logical,
1239 &map_length, NULL, 0);
1240
1241 if (map_length < length + size)
1242 return 1;
1243 return 0;
1244}
1245
1246/*
1247 * in order to insert checksums into the metadata in large chunks,
1248 * we wait until bio submission time. All the pages in the bio are
1249 * checksummed and sums are attached onto the ordered extent record.
1250 *
1251 * At IO completion time the cums attached on the ordered extent record
1252 * are inserted into the btree
1253 */
1254static int __btrfs_submit_bio_start(struct inode *inode, int rw,
1255 struct bio *bio, int mirror_num,
1256 unsigned long bio_flags)
1257{
1258 struct btrfs_root *root = BTRFS_I(inode)->root;
1259 int ret = 0;
1260
1261 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1262 BUG_ON(ret);
1263 return 0;
1264}
1265
1266/*
1267 * in order to insert checksums into the metadata in large chunks,
1268 * we wait until bio submission time. All the pages in the bio are
1269 * checksummed and sums are attached onto the ordered extent record.
1270 *
1271 * At IO completion time the cums attached on the ordered extent record
1272 * are inserted into the btree
1273 */
1274static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1275 int mirror_num, unsigned long bio_flags)
1276{
1277 struct btrfs_root *root = BTRFS_I(inode)->root;
1278 return btrfs_map_bio(root, rw, bio, mirror_num, 1);
1279}
1280
1281/*
1282 * extent_io.c submission hook. This does the right thing for csum calculation
1283 * on write, or reading the csums from the tree before a read
1284 */
1285static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1286 int mirror_num, unsigned long bio_flags)
1287{
1288 struct btrfs_root *root = BTRFS_I(inode)->root;
1289 int ret = 0;
1290 int skip_sum;
1291
1292 skip_sum = btrfs_test_flag(inode, NODATASUM);
1293
1294 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
1295 BUG_ON(ret);
1296
1297 if (!(rw & (1 << BIO_RW))) {
1298 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1299 return btrfs_submit_compressed_read(inode, bio,
1300 mirror_num, bio_flags);
1301 } else if (!skip_sum)
1302 btrfs_lookup_bio_sums(root, inode, bio, NULL);
1303 goto mapit;
1304 } else if (!skip_sum) {
1305 /* csum items have already been cloned */
1306 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1307 goto mapit;
1308 /* we're doing a write, do the async checksumming */
1309 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1310 inode, rw, bio, mirror_num,
1311 bio_flags, __btrfs_submit_bio_start,
1312 __btrfs_submit_bio_done);
1313 }
1314
1315mapit:
1316 return btrfs_map_bio(root, rw, bio, mirror_num, 0);
1317}
1318
1319/*
1320 * given a list of ordered sums record them in the inode. This happens
1321 * at IO completion time based on sums calculated at bio submission time.
1322 */
1323static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1324 struct inode *inode, u64 file_offset,
1325 struct list_head *list)
1326{
1327 struct list_head *cur;
1328 struct btrfs_ordered_sum *sum;
1329
1330 btrfs_set_trans_block_group(trans, inode);
1331 list_for_each(cur, list) {
1332 sum = list_entry(cur, struct btrfs_ordered_sum, list);
1333 btrfs_csum_file_blocks(trans,
1334 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1335 }
1336 return 0;
1337}
1338
1339int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end)
1340{
1341 if ((end & (PAGE_CACHE_SIZE - 1)) == 0)
1342 WARN_ON(1);
1343 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1344 GFP_NOFS);
1345}
1346
1347/* see btrfs_writepage_start_hook for details on why this is required */
1348struct btrfs_writepage_fixup {
1349 struct page *page;
1350 struct btrfs_work work;
1351};
1352
1353static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1354{
1355 struct btrfs_writepage_fixup *fixup;
1356 struct btrfs_ordered_extent *ordered;
1357 struct page *page;
1358 struct inode *inode;
1359 u64 page_start;
1360 u64 page_end;
1361
1362 fixup = container_of(work, struct btrfs_writepage_fixup, work);
1363 page = fixup->page;
1364again:
1365 lock_page(page);
1366 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
1367 ClearPageChecked(page);
1368 goto out_page;
1369 }
1370
1371 inode = page->mapping->host;
1372 page_start = page_offset(page);
1373 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
1374
1375 lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end, GFP_NOFS);
1376
1377 /* already ordered? We're done */
1378 if (test_range_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
1379 EXTENT_ORDERED, 0)) {
1380 goto out;
1381 }
1382
1383 ordered = btrfs_lookup_ordered_extent(inode, page_start);
1384 if (ordered) {
1385 unlock_extent(&BTRFS_I(inode)->io_tree, page_start,
1386 page_end, GFP_NOFS);
1387 unlock_page(page);
1388 btrfs_start_ordered_extent(inode, ordered, 1);
1389 goto again;
1390 }
1391
1392 btrfs_set_extent_delalloc(inode, page_start, page_end);
1393 ClearPageChecked(page);
1394out:
1395 unlock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end, GFP_NOFS);
1396out_page:
1397 unlock_page(page);
1398 page_cache_release(page);
1399}
1400
1401/*
1402 * There are a few paths in the higher layers of the kernel that directly
1403 * set the page dirty bit without asking the filesystem if it is a
1404 * good idea. This causes problems because we want to make sure COW
1405 * properly happens and the data=ordered rules are followed.
1406 *
1407 * In our case any range that doesn't have the ORDERED bit set
1408 * hasn't been properly setup for IO. We kick off an async process
1409 * to fix it up. The async helper will wait for ordered extents, set
1410 * the delalloc bit and make it safe to write the page.
1411 */
1412static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
1413{
1414 struct inode *inode = page->mapping->host;
1415 struct btrfs_writepage_fixup *fixup;
1416 struct btrfs_root *root = BTRFS_I(inode)->root;
1417 int ret;
1418
1419 ret = test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
1420 EXTENT_ORDERED, 0);
1421 if (ret)
1422 return 0;
1423
1424 if (PageChecked(page))
1425 return -EAGAIN;
1426
1427 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
1428 if (!fixup)
1429 return -EAGAIN;
1430
1431 SetPageChecked(page);
1432 page_cache_get(page);
1433 fixup->work.func = btrfs_writepage_fixup_worker;
1434 fixup->page = page;
1435 btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work);
1436 return -EAGAIN;
1437}
1438
1439static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
1440 struct inode *inode, u64 file_pos,
1441 u64 disk_bytenr, u64 disk_num_bytes,
1442 u64 num_bytes, u64 ram_bytes,
1443 u8 compression, u8 encryption,
1444 u16 other_encoding, int extent_type)
1445{
1446 struct btrfs_root *root = BTRFS_I(inode)->root;
1447 struct btrfs_file_extent_item *fi;
1448 struct btrfs_path *path;
1449 struct extent_buffer *leaf;
1450 struct btrfs_key ins;
1451 u64 hint;
1452 int ret;
1453
1454 path = btrfs_alloc_path();
1455 BUG_ON(!path);
1456
1457 ret = btrfs_drop_extents(trans, root, inode, file_pos,
1458 file_pos + num_bytes, file_pos, &hint);
1459 BUG_ON(ret);
1460
1461 ins.objectid = inode->i_ino;
1462 ins.offset = file_pos;
1463 ins.type = BTRFS_EXTENT_DATA_KEY;
1464 ret = btrfs_insert_empty_item(trans, root, path, &ins, sizeof(*fi));
1465 BUG_ON(ret);
1466 leaf = path->nodes[0];
1467 fi = btrfs_item_ptr(leaf, path->slots[0],
1468 struct btrfs_file_extent_item);
1469 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1470 btrfs_set_file_extent_type(leaf, fi, extent_type);
1471 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
1472 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
1473 btrfs_set_file_extent_offset(leaf, fi, 0);
1474 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
1475 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
1476 btrfs_set_file_extent_compression(leaf, fi, compression);
1477 btrfs_set_file_extent_encryption(leaf, fi, encryption);
1478 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
1479 btrfs_mark_buffer_dirty(leaf);
1480
1481 inode_add_bytes(inode, num_bytes);
1482 btrfs_drop_extent_cache(inode, file_pos, file_pos + num_bytes - 1, 0);
1483
1484 ins.objectid = disk_bytenr;
1485 ins.offset = disk_num_bytes;
1486 ins.type = BTRFS_EXTENT_ITEM_KEY;
1487 ret = btrfs_alloc_reserved_extent(trans, root, leaf->start,
1488 root->root_key.objectid,
1489 trans->transid, inode->i_ino, &ins);
1490 BUG_ON(ret);
1491
1492 btrfs_free_path(path);
1493 return 0;
1494}
1495
1496/* as ordered data IO finishes, this gets called so we can finish
1497 * an ordered extent if the range of bytes in the file it covers are
1498 * fully written.
1499 */
1500static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
1501{
1502 struct btrfs_root *root = BTRFS_I(inode)->root;
1503 struct btrfs_trans_handle *trans;
1504 struct btrfs_ordered_extent *ordered_extent;
1505 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1506 int compressed = 0;
1507 int ret;
1508
1509 ret = btrfs_dec_test_ordered_pending(inode, start, end - start + 1);
1510 if (!ret)
1511 return 0;
1512
1513 trans = btrfs_join_transaction(root, 1);
1514
1515 ordered_extent = btrfs_lookup_ordered_extent(inode, start);
1516 BUG_ON(!ordered_extent);
1517 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags))
1518 goto nocow;
1519
1520 lock_extent(io_tree, ordered_extent->file_offset,
1521 ordered_extent->file_offset + ordered_extent->len - 1,
1522 GFP_NOFS);
1523
1524 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
1525 compressed = 1;
1526 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
1527 BUG_ON(compressed);
1528 ret = btrfs_mark_extent_written(trans, root, inode,
1529 ordered_extent->file_offset,
1530 ordered_extent->file_offset +
1531 ordered_extent->len);
1532 BUG_ON(ret);
1533 } else {
1534 ret = insert_reserved_file_extent(trans, inode,
1535 ordered_extent->file_offset,
1536 ordered_extent->start,
1537 ordered_extent->disk_len,
1538 ordered_extent->len,
1539 ordered_extent->len,
1540 compressed, 0, 0,
1541 BTRFS_FILE_EXTENT_REG);
1542 BUG_ON(ret);
1543 }
1544 unlock_extent(io_tree, ordered_extent->file_offset,
1545 ordered_extent->file_offset + ordered_extent->len - 1,
1546 GFP_NOFS);
1547nocow:
1548 add_pending_csums(trans, inode, ordered_extent->file_offset,
1549 &ordered_extent->list);
1550
1551 mutex_lock(&BTRFS_I(inode)->extent_mutex);
1552 btrfs_ordered_update_i_size(inode, ordered_extent);
1553 btrfs_update_inode(trans, root, inode);
1554 btrfs_remove_ordered_extent(inode, ordered_extent);
1555 mutex_unlock(&BTRFS_I(inode)->extent_mutex);
1556
1557 /* once for us */
1558 btrfs_put_ordered_extent(ordered_extent);
1559 /* once for the tree */
1560 btrfs_put_ordered_extent(ordered_extent);
1561
1562 btrfs_end_transaction(trans, root);
1563 return 0;
1564}
1565
1566static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
1567 struct extent_state *state, int uptodate)
1568{
1569 return btrfs_finish_ordered_io(page->mapping->host, start, end);
1570}
1571
1572/*
1573 * When IO fails, either with EIO or csum verification fails, we
1574 * try other mirrors that might have a good copy of the data. This
1575 * io_failure_record is used to record state as we go through all the
1576 * mirrors. If another mirror has good data, the page is set up to date
1577 * and things continue. If a good mirror can't be found, the original
1578 * bio end_io callback is called to indicate things have failed.
1579 */
1580struct io_failure_record {
1581 struct page *page;
1582 u64 start;
1583 u64 len;
1584 u64 logical;
1585 unsigned long bio_flags;
1586 int last_mirror;
1587};
1588
1589static int btrfs_io_failed_hook(struct bio *failed_bio,
1590 struct page *page, u64 start, u64 end,
1591 struct extent_state *state)
1592{
1593 struct io_failure_record *failrec = NULL;
1594 u64 private;
1595 struct extent_map *em;
1596 struct inode *inode = page->mapping->host;
1597 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
1598 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1599 struct bio *bio;
1600 int num_copies;
1601 int ret;
1602 int rw;
1603 u64 logical;
1604
1605 ret = get_state_private(failure_tree, start, &private);
1606 if (ret) {
1607 failrec = kmalloc(sizeof(*failrec), GFP_NOFS);
1608 if (!failrec)
1609 return -ENOMEM;
1610 failrec->start = start;
1611 failrec->len = end - start + 1;
1612 failrec->last_mirror = 0;
1613 failrec->bio_flags = 0;
1614
1615 spin_lock(&em_tree->lock);
1616 em = lookup_extent_mapping(em_tree, start, failrec->len);
1617 if (em->start > start || em->start + em->len < start) {
1618 free_extent_map(em);
1619 em = NULL;
1620 }
1621 spin_unlock(&em_tree->lock);
1622
1623 if (!em || IS_ERR(em)) {
1624 kfree(failrec);
1625 return -EIO;
1626 }
1627 logical = start - em->start;
1628 logical = em->block_start + logical;
1629 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
1630 logical = em->block_start;
1631 failrec->bio_flags = EXTENT_BIO_COMPRESSED;
1632 }
1633 failrec->logical = logical;
1634 free_extent_map(em);
1635 set_extent_bits(failure_tree, start, end, EXTENT_LOCKED |
1636 EXTENT_DIRTY, GFP_NOFS);
1637 set_state_private(failure_tree, start,
1638 (u64)(unsigned long)failrec);
1639 } else {
1640 failrec = (struct io_failure_record *)(unsigned long)private;
1641 }
1642 num_copies = btrfs_num_copies(
1643 &BTRFS_I(inode)->root->fs_info->mapping_tree,
1644 failrec->logical, failrec->len);
1645 failrec->last_mirror++;
1646 if (!state) {
1647 spin_lock(&BTRFS_I(inode)->io_tree.lock);
1648 state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree,
1649 failrec->start,
1650 EXTENT_LOCKED);
1651 if (state && state->start != failrec->start)
1652 state = NULL;
1653 spin_unlock(&BTRFS_I(inode)->io_tree.lock);
1654 }
1655 if (!state || failrec->last_mirror > num_copies) {
1656 set_state_private(failure_tree, failrec->start, 0);
1657 clear_extent_bits(failure_tree, failrec->start,
1658 failrec->start + failrec->len - 1,
1659 EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
1660 kfree(failrec);
1661 return -EIO;
1662 }
1663 bio = bio_alloc(GFP_NOFS, 1);
1664 bio->bi_private = state;
1665 bio->bi_end_io = failed_bio->bi_end_io;
1666 bio->bi_sector = failrec->logical >> 9;
1667 bio->bi_bdev = failed_bio->bi_bdev;
1668 bio->bi_size = 0;
1669
1670 bio_add_page(bio, page, failrec->len, start - page_offset(page));
1671 if (failed_bio->bi_rw & (1 << BIO_RW))
1672 rw = WRITE;
1673 else
1674 rw = READ;
1675
1676 BTRFS_I(inode)->io_tree.ops->submit_bio_hook(inode, rw, bio,
1677 failrec->last_mirror,
1678 failrec->bio_flags);
1679 return 0;
1680}
1681
1682/*
1683 * each time an IO finishes, we do a fast check in the IO failure tree
1684 * to see if we need to process or clean up an io_failure_record
1685 */
1686static int btrfs_clean_io_failures(struct inode *inode, u64 start)
1687{
1688 u64 private;
1689 u64 private_failure;
1690 struct io_failure_record *failure;
1691 int ret;
1692
1693 private = 0;
1694 if (count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private,
1695 (u64)-1, 1, EXTENT_DIRTY)) {
1696 ret = get_state_private(&BTRFS_I(inode)->io_failure_tree,
1697 start, &private_failure);
1698 if (ret == 0) {
1699 failure = (struct io_failure_record *)(unsigned long)
1700 private_failure;
1701 set_state_private(&BTRFS_I(inode)->io_failure_tree,
1702 failure->start, 0);
1703 clear_extent_bits(&BTRFS_I(inode)->io_failure_tree,
1704 failure->start,
1705 failure->start + failure->len - 1,
1706 EXTENT_DIRTY | EXTENT_LOCKED,
1707 GFP_NOFS);
1708 kfree(failure);
1709 }
1710 }
1711 return 0;
1712}
1713
1714/*
1715 * when reads are done, we need to check csums to verify the data is correct
1716 * if there's a match, we allow the bio to finish. If not, we go through
1717 * the io_failure_record routines to find good copies
1718 */
1719static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
1720 struct extent_state *state)
1721{
1722 size_t offset = start - ((u64)page->index << PAGE_CACHE_SHIFT);
1723 struct inode *inode = page->mapping->host;
1724 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1725 char *kaddr;
1726 u64 private = ~(u32)0;
1727 int ret;
1728 struct btrfs_root *root = BTRFS_I(inode)->root;
1729 u32 csum = ~(u32)0;
1730
1731 if (PageChecked(page)) {
1732 ClearPageChecked(page);
1733 goto good;
1734 }
1735 if (btrfs_test_flag(inode, NODATASUM))
1736 return 0;
1737
1738 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
1739 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1)) {
1740 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
1741 GFP_NOFS);
1742 return 0;
1743 }
1744
1745 if (state && state->start == start) {
1746 private = state->private;
1747 ret = 0;
1748 } else {
1749 ret = get_state_private(io_tree, start, &private);
1750 }
1751 kaddr = kmap_atomic(page, KM_USER0);
1752 if (ret)
1753 goto zeroit;
1754
1755 csum = btrfs_csum_data(root, kaddr + offset, csum, end - start + 1);
1756 btrfs_csum_final(csum, (char *)&csum);
1757 if (csum != private)
1758 goto zeroit;
1759
1760 kunmap_atomic(kaddr, KM_USER0);
1761good:
1762 /* if the io failure tree for this inode is non-empty,
1763 * check to see if we've recovered from a failed IO
1764 */
1765 btrfs_clean_io_failures(inode, start);
1766 return 0;
1767
1768zeroit:
1769 printk(KERN_INFO "btrfs csum failed ino %lu off %llu csum %u "
1770 "private %llu\n", page->mapping->host->i_ino,
1771 (unsigned long long)start, csum,
1772 (unsigned long long)private);
1773 memset(kaddr + offset, 1, end - start + 1);
1774 flush_dcache_page(page);
1775 kunmap_atomic(kaddr, KM_USER0);
1776 if (private == 0)
1777 return 0;
1778 return -EIO;
1779}
1780
1781/*
1782 * This creates an orphan entry for the given inode in case something goes
1783 * wrong in the middle of an unlink/truncate.
1784 */
1785int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
1786{
1787 struct btrfs_root *root = BTRFS_I(inode)->root;
1788 int ret = 0;
1789
1790 spin_lock(&root->list_lock);
1791
1792 /* already on the orphan list, we're good */
1793 if (!list_empty(&BTRFS_I(inode)->i_orphan)) {
1794 spin_unlock(&root->list_lock);
1795 return 0;
1796 }
1797
1798 list_add(&BTRFS_I(inode)->i_orphan, &root->orphan_list);
1799
1800 spin_unlock(&root->list_lock);
1801
1802 /*
1803 * insert an orphan item to track this unlinked/truncated file
1804 */
1805 ret = btrfs_insert_orphan_item(trans, root, inode->i_ino);
1806
1807 return ret;
1808}
1809
1810/*
1811 * We have done the truncate/delete so we can go ahead and remove the orphan
1812 * item for this particular inode.
1813 */
1814int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode)
1815{
1816 struct btrfs_root *root = BTRFS_I(inode)->root;
1817 int ret = 0;
1818
1819 spin_lock(&root->list_lock);
1820
1821 if (list_empty(&BTRFS_I(inode)->i_orphan)) {
1822 spin_unlock(&root->list_lock);
1823 return 0;
1824 }
1825
1826 list_del_init(&BTRFS_I(inode)->i_orphan);
1827 if (!trans) {
1828 spin_unlock(&root->list_lock);
1829 return 0;
1830 }
1831
1832 spin_unlock(&root->list_lock);
1833
1834 ret = btrfs_del_orphan_item(trans, root, inode->i_ino);
1835
1836 return ret;
1837}
1838
1839/*
1840 * this cleans up any orphans that may be left on the list from the last use
1841 * of this root.
1842 */
1843void btrfs_orphan_cleanup(struct btrfs_root *root)
1844{
1845 struct btrfs_path *path;
1846 struct extent_buffer *leaf;
1847 struct btrfs_item *item;
1848 struct btrfs_key key, found_key;
1849 struct btrfs_trans_handle *trans;
1850 struct inode *inode;
1851 int ret = 0, nr_unlink = 0, nr_truncate = 0;
1852
1853 path = btrfs_alloc_path();
1854 if (!path)
1855 return;
1856 path->reada = -1;
1857
1858 key.objectid = BTRFS_ORPHAN_OBJECTID;
1859 btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
1860 key.offset = (u64)-1;
1861
1862
1863 while (1) {
1864 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1865 if (ret < 0) {
1866 printk(KERN_ERR "Error searching slot for orphan: %d"
1867 "\n", ret);
1868 break;
1869 }
1870
1871 /*
1872 * if ret == 0 means we found what we were searching for, which
1873 * is weird, but possible, so only screw with path if we didnt
1874 * find the key and see if we have stuff that matches
1875 */
1876 if (ret > 0) {
1877 if (path->slots[0] == 0)
1878 break;
1879 path->slots[0]--;
1880 }
1881
1882 /* pull out the item */
1883 leaf = path->nodes[0];
1884 item = btrfs_item_nr(leaf, path->slots[0]);
1885 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1886
1887 /* make sure the item matches what we want */
1888 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
1889 break;
1890 if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY)
1891 break;
1892
1893 /* release the path since we're done with it */
1894 btrfs_release_path(root, path);
1895
1896 /*
1897 * this is where we are basically btrfs_lookup, without the
1898 * crossing root thing. we store the inode number in the
1899 * offset of the orphan item.
1900 */
1901 inode = btrfs_iget_locked(root->fs_info->sb,
1902 found_key.offset, root);
1903 if (!inode)
1904 break;
1905
1906 if (inode->i_state & I_NEW) {
1907 BTRFS_I(inode)->root = root;
1908
1909 /* have to set the location manually */
1910 BTRFS_I(inode)->location.objectid = inode->i_ino;
1911 BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
1912 BTRFS_I(inode)->location.offset = 0;
1913
1914 btrfs_read_locked_inode(inode);
1915 unlock_new_inode(inode);
1916 }
1917
1918 /*
1919 * add this inode to the orphan list so btrfs_orphan_del does
1920 * the proper thing when we hit it
1921 */
1922 spin_lock(&root->list_lock);
1923 list_add(&BTRFS_I(inode)->i_orphan, &root->orphan_list);
1924 spin_unlock(&root->list_lock);
1925
1926 /*
1927 * if this is a bad inode, means we actually succeeded in
1928 * removing the inode, but not the orphan record, which means
1929 * we need to manually delete the orphan since iput will just
1930 * do a destroy_inode
1931 */
1932 if (is_bad_inode(inode)) {
1933 trans = btrfs_start_transaction(root, 1);
1934 btrfs_orphan_del(trans, inode);
1935 btrfs_end_transaction(trans, root);
1936 iput(inode);
1937 continue;
1938 }
1939
1940 /* if we have links, this was a truncate, lets do that */
1941 if (inode->i_nlink) {
1942 nr_truncate++;
1943 btrfs_truncate(inode);
1944 } else {
1945 nr_unlink++;
1946 }
1947
1948 /* this will do delete_inode and everything for us */
1949 iput(inode);
1950 }
1951
1952 if (nr_unlink)
1953 printk(KERN_INFO "btrfs: unlinked %d orphans\n", nr_unlink);
1954 if (nr_truncate)
1955 printk(KERN_INFO "btrfs: truncated %d orphans\n", nr_truncate);
1956
1957 btrfs_free_path(path);
1958}
1959
1960/*
1961 * read an inode from the btree into the in-memory inode
1962 */
1963void btrfs_read_locked_inode(struct inode *inode)
1964{
1965 struct btrfs_path *path;
1966 struct extent_buffer *leaf;
1967 struct btrfs_inode_item *inode_item;
1968 struct btrfs_timespec *tspec;
1969 struct btrfs_root *root = BTRFS_I(inode)->root;
1970 struct btrfs_key location;
1971 u64 alloc_group_block;
1972 u32 rdev;
1973 int ret;
1974
1975 path = btrfs_alloc_path();
1976 BUG_ON(!path);
1977 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
1978
1979 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
1980 if (ret)
1981 goto make_bad;
1982
1983 leaf = path->nodes[0];
1984 inode_item = btrfs_item_ptr(leaf, path->slots[0],
1985 struct btrfs_inode_item);
1986
1987 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
1988 inode->i_nlink = btrfs_inode_nlink(leaf, inode_item);
1989 inode->i_uid = btrfs_inode_uid(leaf, inode_item);
1990 inode->i_gid = btrfs_inode_gid(leaf, inode_item);
1991 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
1992
1993 tspec = btrfs_inode_atime(inode_item);
1994 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
1995 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
1996
1997 tspec = btrfs_inode_mtime(inode_item);
1998 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
1999 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
2000
2001 tspec = btrfs_inode_ctime(inode_item);
2002 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
2003 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
2004
2005 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
2006 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
2007 BTRFS_I(inode)->sequence = btrfs_inode_sequence(leaf, inode_item);
2008 inode->i_generation = BTRFS_I(inode)->generation;
2009 inode->i_rdev = 0;
2010 rdev = btrfs_inode_rdev(leaf, inode_item);
2011
2012 BTRFS_I(inode)->index_cnt = (u64)-1;
2013 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
2014
2015 alloc_group_block = btrfs_inode_block_group(leaf, inode_item);
2016 BTRFS_I(inode)->block_group = btrfs_find_block_group(root, 0,
2017 alloc_group_block, 0);
2018 btrfs_free_path(path);
2019 inode_item = NULL;
2020
2021 switch (inode->i_mode & S_IFMT) {
2022 case S_IFREG:
2023 inode->i_mapping->a_ops = &btrfs_aops;
2024 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
2025 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
2026 inode->i_fop = &btrfs_file_operations;
2027 inode->i_op = &btrfs_file_inode_operations;
2028 break;
2029 case S_IFDIR:
2030 inode->i_fop = &btrfs_dir_file_operations;
2031 if (root == root->fs_info->tree_root)
2032 inode->i_op = &btrfs_dir_ro_inode_operations;
2033 else
2034 inode->i_op = &btrfs_dir_inode_operations;
2035 break;
2036 case S_IFLNK:
2037 inode->i_op = &btrfs_symlink_inode_operations;
2038 inode->i_mapping->a_ops = &btrfs_symlink_aops;
2039 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
2040 break;
2041 default:
2042 init_special_inode(inode, inode->i_mode, rdev);
2043 break;
2044 }
2045 return;
2046
2047make_bad:
2048 btrfs_free_path(path);
2049 make_bad_inode(inode);
2050}
2051
2052/*
2053 * given a leaf and an inode, copy the inode fields into the leaf
2054 */
2055static void fill_inode_item(struct btrfs_trans_handle *trans,
2056 struct extent_buffer *leaf,
2057 struct btrfs_inode_item *item,
2058 struct inode *inode)
2059{
2060 btrfs_set_inode_uid(leaf, item, inode->i_uid);
2061 btrfs_set_inode_gid(leaf, item, inode->i_gid);
2062 btrfs_set_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size);
2063 btrfs_set_inode_mode(leaf, item, inode->i_mode);
2064 btrfs_set_inode_nlink(leaf, item, inode->i_nlink);
2065
2066 btrfs_set_timespec_sec(leaf, btrfs_inode_atime(item),
2067 inode->i_atime.tv_sec);
2068 btrfs_set_timespec_nsec(leaf, btrfs_inode_atime(item),
2069 inode->i_atime.tv_nsec);
2070
2071 btrfs_set_timespec_sec(leaf, btrfs_inode_mtime(item),
2072 inode->i_mtime.tv_sec);
2073 btrfs_set_timespec_nsec(leaf, btrfs_inode_mtime(item),
2074 inode->i_mtime.tv_nsec);
2075
2076 btrfs_set_timespec_sec(leaf, btrfs_inode_ctime(item),
2077 inode->i_ctime.tv_sec);
2078 btrfs_set_timespec_nsec(leaf, btrfs_inode_ctime(item),
2079 inode->i_ctime.tv_nsec);
2080
2081 btrfs_set_inode_nbytes(leaf, item, inode_get_bytes(inode));
2082 btrfs_set_inode_generation(leaf, item, BTRFS_I(inode)->generation);
2083 btrfs_set_inode_sequence(leaf, item, BTRFS_I(inode)->sequence);
2084 btrfs_set_inode_transid(leaf, item, trans->transid);
2085 btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
2086 btrfs_set_inode_flags(leaf, item, BTRFS_I(inode)->flags);
2087 btrfs_set_inode_block_group(leaf, item, BTRFS_I(inode)->block_group);
2088}
2089
2090/*
2091 * copy everything in the in-memory inode into the btree.
2092 */
2093noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
2094 struct btrfs_root *root, struct inode *inode)
2095{
2096 struct btrfs_inode_item *inode_item;
2097 struct btrfs_path *path;
2098 struct extent_buffer *leaf;
2099 int ret;
2100
2101 path = btrfs_alloc_path();
2102 BUG_ON(!path);
2103 ret = btrfs_lookup_inode(trans, root, path,
2104 &BTRFS_I(inode)->location, 1);
2105 if (ret) {
2106 if (ret > 0)
2107 ret = -ENOENT;
2108 goto failed;
2109 }
2110
2111 leaf = path->nodes[0];
2112 inode_item = btrfs_item_ptr(leaf, path->slots[0],
2113 struct btrfs_inode_item);
2114
2115 fill_inode_item(trans, leaf, inode_item, inode);
2116 btrfs_mark_buffer_dirty(leaf);
2117 btrfs_set_inode_last_trans(trans, inode);
2118 ret = 0;
2119failed:
2120 btrfs_free_path(path);
2121 return ret;
2122}
2123
2124
2125/*
2126 * unlink helper that gets used here in inode.c and in the tree logging
2127 * recovery code. It remove a link in a directory with a given name, and
2128 * also drops the back refs in the inode to the directory
2129 */
2130int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
2131 struct btrfs_root *root,
2132 struct inode *dir, struct inode *inode,
2133 const char *name, int name_len)
2134{
2135 struct btrfs_path *path;
2136 int ret = 0;
2137 struct extent_buffer *leaf;
2138 struct btrfs_dir_item *di;
2139 struct btrfs_key key;
2140 u64 index;
2141
2142 path = btrfs_alloc_path();
2143 if (!path) {
2144 ret = -ENOMEM;
2145 goto err;
2146 }
2147
2148 di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
2149 name, name_len, -1);
2150 if (IS_ERR(di)) {
2151 ret = PTR_ERR(di);
2152 goto err;
2153 }
2154 if (!di) {
2155 ret = -ENOENT;
2156 goto err;
2157 }
2158 leaf = path->nodes[0];
2159 btrfs_dir_item_key_to_cpu(leaf, di, &key);
2160 ret = btrfs_delete_one_dir_name(trans, root, path, di);
2161 if (ret)
2162 goto err;
2163 btrfs_release_path(root, path);
2164
2165 ret = btrfs_del_inode_ref(trans, root, name, name_len,
2166 inode->i_ino,
2167 dir->i_ino, &index);
2168 if (ret) {
2169 printk(KERN_INFO "btrfs failed to delete reference to %.*s, "
2170 "inode %lu parent %lu\n", name_len, name,
2171 inode->i_ino, dir->i_ino);
2172 goto err;
2173 }
2174
2175 di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
2176 index, name, name_len, -1);
2177 if (IS_ERR(di)) {
2178 ret = PTR_ERR(di);
2179 goto err;
2180 }
2181 if (!di) {
2182 ret = -ENOENT;
2183 goto err;
2184 }
2185 ret = btrfs_delete_one_dir_name(trans, root, path, di);
2186 btrfs_release_path(root, path);
2187
2188 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
2189 inode, dir->i_ino);
2190 BUG_ON(ret != 0 && ret != -ENOENT);
2191 if (ret != -ENOENT)
2192 BTRFS_I(dir)->log_dirty_trans = trans->transid;
2193
2194 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
2195 dir, index);
2196 BUG_ON(ret);
2197err:
2198 btrfs_free_path(path);
2199 if (ret)
2200 goto out;
2201
2202 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
2203 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
2204 btrfs_update_inode(trans, root, dir);
2205 btrfs_drop_nlink(inode);
2206 ret = btrfs_update_inode(trans, root, inode);
2207 dir->i_sb->s_dirt = 1;
2208out:
2209 return ret;
2210}
2211
2212static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
2213{
2214 struct btrfs_root *root;
2215 struct btrfs_trans_handle *trans;
2216 struct inode *inode = dentry->d_inode;
2217 int ret;
2218 unsigned long nr = 0;
2219
2220 root = BTRFS_I(dir)->root;
2221
2222 ret = btrfs_check_free_space(root, 1, 1);
2223 if (ret)
2224 goto fail;
2225
2226 trans = btrfs_start_transaction(root, 1);
2227
2228 btrfs_set_trans_block_group(trans, dir);
2229 ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
2230 dentry->d_name.name, dentry->d_name.len);
2231
2232 if (inode->i_nlink == 0)
2233 ret = btrfs_orphan_add(trans, inode);
2234
2235 nr = trans->blocks_used;
2236
2237 btrfs_end_transaction_throttle(trans, root);
2238fail:
2239 btrfs_btree_balance_dirty(root, nr);
2240 return ret;
2241}
2242
2243static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
2244{
2245 struct inode *inode = dentry->d_inode;
2246 int err = 0;
2247 int ret;
2248 struct btrfs_root *root = BTRFS_I(dir)->root;
2249 struct btrfs_trans_handle *trans;
2250 unsigned long nr = 0;
2251
2252 /*
2253 * the FIRST_FREE_OBJECTID check makes sure we don't try to rmdir
2254 * the root of a subvolume or snapshot
2255 */
2256 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE ||
2257 inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) {
2258 return -ENOTEMPTY;
2259 }
2260
2261 ret = btrfs_check_free_space(root, 1, 1);
2262 if (ret)
2263 goto fail;
2264
2265 trans = btrfs_start_transaction(root, 1);
2266 btrfs_set_trans_block_group(trans, dir);
2267
2268 err = btrfs_orphan_add(trans, inode);
2269 if (err)
2270 goto fail_trans;
2271
2272 /* now the directory is empty */
2273 err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
2274 dentry->d_name.name, dentry->d_name.len);
2275 if (!err)
2276 btrfs_i_size_write(inode, 0);
2277
2278fail_trans:
2279 nr = trans->blocks_used;
2280 ret = btrfs_end_transaction_throttle(trans, root);
2281fail:
2282 btrfs_btree_balance_dirty(root, nr);
2283
2284 if (ret && !err)
2285 err = ret;
2286 return err;
2287}
2288
2289#if 0
2290/*
2291 * when truncating bytes in a file, it is possible to avoid reading
2292 * the leaves that contain only checksum items. This can be the
2293 * majority of the IO required to delete a large file, but it must
2294 * be done carefully.
2295 *
2296 * The keys in the level just above the leaves are checked to make sure
2297 * the lowest key in a given leaf is a csum key, and starts at an offset
2298 * after the new size.
2299 *
2300 * Then the key for the next leaf is checked to make sure it also has
2301 * a checksum item for the same file. If it does, we know our target leaf
2302 * contains only checksum items, and it can be safely freed without reading
2303 * it.
2304 *
2305 * This is just an optimization targeted at large files. It may do
2306 * nothing. It will return 0 unless things went badly.
2307 */
2308static noinline int drop_csum_leaves(struct btrfs_trans_handle *trans,
2309 struct btrfs_root *root,
2310 struct btrfs_path *path,
2311 struct inode *inode, u64 new_size)
2312{
2313 struct btrfs_key key;
2314 int ret;
2315 int nritems;
2316 struct btrfs_key found_key;
2317 struct btrfs_key other_key;
2318 struct btrfs_leaf_ref *ref;
2319 u64 leaf_gen;
2320 u64 leaf_start;
2321
2322 path->lowest_level = 1;
2323 key.objectid = inode->i_ino;
2324 key.type = BTRFS_CSUM_ITEM_KEY;
2325 key.offset = new_size;
2326again:
2327 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2328 if (ret < 0)
2329 goto out;
2330
2331 if (path->nodes[1] == NULL) {
2332 ret = 0;
2333 goto out;
2334 }
2335 ret = 0;
2336 btrfs_node_key_to_cpu(path->nodes[1], &found_key, path->slots[1]);
2337 nritems = btrfs_header_nritems(path->nodes[1]);
2338
2339 if (!nritems)
2340 goto out;
2341
2342 if (path->slots[1] >= nritems)
2343 goto next_node;
2344
2345 /* did we find a key greater than anything we want to delete? */
2346 if (found_key.objectid > inode->i_ino ||
2347 (found_key.objectid == inode->i_ino && found_key.type > key.type))
2348 goto out;
2349
2350 /* we check the next key in the node to make sure the leave contains
2351 * only checksum items. This comparison doesn't work if our
2352 * leaf is the last one in the node
2353 */
2354 if (path->slots[1] + 1 >= nritems) {
2355next_node:
2356 /* search forward from the last key in the node, this
2357 * will bring us into the next node in the tree
2358 */
2359 btrfs_node_key_to_cpu(path->nodes[1], &found_key, nritems - 1);
2360
2361 /* unlikely, but we inc below, so check to be safe */
2362 if (found_key.offset == (u64)-1)
2363 goto out;
2364
2365 /* search_forward needs a path with locks held, do the
2366 * search again for the original key. It is possible
2367 * this will race with a balance and return a path that
2368 * we could modify, but this drop is just an optimization
2369 * and is allowed to miss some leaves.
2370 */
2371 btrfs_release_path(root, path);
2372 found_key.offset++;
2373
2374 /* setup a max key for search_forward */
2375 other_key.offset = (u64)-1;
2376 other_key.type = key.type;
2377 other_key.objectid = key.objectid;
2378
2379 path->keep_locks = 1;
2380 ret = btrfs_search_forward(root, &found_key, &other_key,
2381 path, 0, 0);
2382 path->keep_locks = 0;
2383 if (ret || found_key.objectid != key.objectid ||
2384 found_key.type != key.type) {
2385 ret = 0;
2386 goto out;
2387 }
2388
2389 key.offset = found_key.offset;
2390 btrfs_release_path(root, path);
2391 cond_resched();
2392 goto again;
2393 }
2394
2395 /* we know there's one more slot after us in the tree,
2396 * read that key so we can verify it is also a checksum item
2397 */
2398 btrfs_node_key_to_cpu(path->nodes[1], &other_key, path->slots[1] + 1);
2399
2400 if (found_key.objectid < inode->i_ino)
2401 goto next_key;
2402
2403 if (found_key.type != key.type || found_key.offset < new_size)
2404 goto next_key;
2405
2406 /*
2407 * if the key for the next leaf isn't a csum key from this objectid,
2408 * we can't be sure there aren't good items inside this leaf.
2409 * Bail out
2410 */
2411 if (other_key.objectid != inode->i_ino || other_key.type != key.type)
2412 goto out;
2413
2414 leaf_start = btrfs_node_blockptr(path->nodes[1], path->slots[1]);
2415 leaf_gen = btrfs_node_ptr_generation(path->nodes[1], path->slots[1]);
2416 /*
2417 * it is safe to delete this leaf, it contains only
2418 * csum items from this inode at an offset >= new_size
2419 */
2420 ret = btrfs_del_leaf(trans, root, path, leaf_start);
2421 BUG_ON(ret);
2422
2423 if (root->ref_cows && leaf_gen < trans->transid) {
2424 ref = btrfs_alloc_leaf_ref(root, 0);
2425 if (ref) {
2426 ref->root_gen = root->root_key.offset;
2427 ref->bytenr = leaf_start;
2428 ref->owner = 0;
2429 ref->generation = leaf_gen;
2430 ref->nritems = 0;
2431
2432 ret = btrfs_add_leaf_ref(root, ref, 0);
2433 WARN_ON(ret);
2434 btrfs_free_leaf_ref(root, ref);
2435 } else {
2436 WARN_ON(1);
2437 }
2438 }
2439next_key:
2440 btrfs_release_path(root, path);
2441
2442 if (other_key.objectid == inode->i_ino &&
2443 other_key.type == key.type && other_key.offset > key.offset) {
2444 key.offset = other_key.offset;
2445 cond_resched();
2446 goto again;
2447 }
2448 ret = 0;
2449out:
2450 /* fixup any changes we've made to the path */
2451 path->lowest_level = 0;
2452 path->keep_locks = 0;
2453 btrfs_release_path(root, path);
2454 return ret;
2455}
2456
2457#endif
2458
2459/*
2460 * this can truncate away extent items, csum items and directory items.
2461 * It starts at a high offset and removes keys until it can't find
2462 * any higher than new_size
2463 *
2464 * csum items that cross the new i_size are truncated to the new size
2465 * as well.
2466 *
2467 * min_type is the minimum key type to truncate down to. If set to 0, this
2468 * will kill all the items on this inode, including the INODE_ITEM_KEY.
2469 */
2470noinline int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
2471 struct btrfs_root *root,
2472 struct inode *inode,
2473 u64 new_size, u32 min_type)
2474{
2475 int ret;
2476 struct btrfs_path *path;
2477 struct btrfs_key key;
2478 struct btrfs_key found_key;
2479 u32 found_type;
2480 struct extent_buffer *leaf;
2481 struct btrfs_file_extent_item *fi;
2482 u64 extent_start = 0;
2483 u64 extent_num_bytes = 0;
2484 u64 item_end = 0;
2485 u64 root_gen = 0;
2486 u64 root_owner = 0;
2487 int found_extent;
2488 int del_item;
2489 int pending_del_nr = 0;
2490 int pending_del_slot = 0;
2491 int extent_type = -1;
2492 int encoding;
2493 u64 mask = root->sectorsize - 1;
2494
2495 if (root->ref_cows)
2496 btrfs_drop_extent_cache(inode, new_size & (~mask), (u64)-1, 0);
2497 path = btrfs_alloc_path();
2498 path->reada = -1;
2499 BUG_ON(!path);
2500
2501 /* FIXME, add redo link to tree so we don't leak on crash */
2502 key.objectid = inode->i_ino;
2503 key.offset = (u64)-1;
2504 key.type = (u8)-1;
2505
2506 btrfs_init_path(path);
2507
2508search_again:
2509 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2510 if (ret < 0)
2511 goto error;
2512
2513 if (ret > 0) {
2514 /* there are no items in the tree for us to truncate, we're
2515 * done
2516 */
2517 if (path->slots[0] == 0) {
2518 ret = 0;
2519 goto error;
2520 }
2521 path->slots[0]--;
2522 }
2523
2524 while (1) {
2525 fi = NULL;
2526 leaf = path->nodes[0];
2527 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2528 found_type = btrfs_key_type(&found_key);
2529 encoding = 0;
2530
2531 if (found_key.objectid != inode->i_ino)
2532 break;
2533
2534 if (found_type < min_type)
2535 break;
2536
2537 item_end = found_key.offset;
2538 if (found_type == BTRFS_EXTENT_DATA_KEY) {
2539 fi = btrfs_item_ptr(leaf, path->slots[0],
2540 struct btrfs_file_extent_item);
2541 extent_type = btrfs_file_extent_type(leaf, fi);
2542 encoding = btrfs_file_extent_compression(leaf, fi);
2543 encoding |= btrfs_file_extent_encryption(leaf, fi);
2544 encoding |= btrfs_file_extent_other_encoding(leaf, fi);
2545
2546 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
2547 item_end +=
2548 btrfs_file_extent_num_bytes(leaf, fi);
2549 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
2550 item_end += btrfs_file_extent_inline_len(leaf,
2551 fi);
2552 }
2553 item_end--;
2554 }
2555 if (item_end < new_size) {
2556 if (found_type == BTRFS_DIR_ITEM_KEY)
2557 found_type = BTRFS_INODE_ITEM_KEY;
2558 else if (found_type == BTRFS_EXTENT_ITEM_KEY)
2559 found_type = BTRFS_EXTENT_DATA_KEY;
2560 else if (found_type == BTRFS_EXTENT_DATA_KEY)
2561 found_type = BTRFS_XATTR_ITEM_KEY;
2562 else if (found_type == BTRFS_XATTR_ITEM_KEY)
2563 found_type = BTRFS_INODE_REF_KEY;
2564 else if (found_type)
2565 found_type--;
2566 else
2567 break;
2568 btrfs_set_key_type(&key, found_type);
2569 goto next;
2570 }
2571 if (found_key.offset >= new_size)
2572 del_item = 1;
2573 else
2574 del_item = 0;
2575 found_extent = 0;
2576
2577 /* FIXME, shrink the extent if the ref count is only 1 */
2578 if (found_type != BTRFS_EXTENT_DATA_KEY)
2579 goto delete;
2580
2581 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
2582 u64 num_dec;
2583 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
2584 if (!del_item && !encoding) {
2585 u64 orig_num_bytes =
2586 btrfs_file_extent_num_bytes(leaf, fi);
2587 extent_num_bytes = new_size -
2588 found_key.offset + root->sectorsize - 1;
2589 extent_num_bytes = extent_num_bytes &
2590 ~((u64)root->sectorsize - 1);
2591 btrfs_set_file_extent_num_bytes(leaf, fi,
2592 extent_num_bytes);
2593 num_dec = (orig_num_bytes -
2594 extent_num_bytes);
2595 if (root->ref_cows && extent_start != 0)
2596 inode_sub_bytes(inode, num_dec);
2597 btrfs_mark_buffer_dirty(leaf);
2598 } else {
2599 extent_num_bytes =
2600 btrfs_file_extent_disk_num_bytes(leaf,
2601 fi);
2602 /* FIXME blocksize != 4096 */
2603 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
2604 if (extent_start != 0) {
2605 found_extent = 1;
2606 if (root->ref_cows)
2607 inode_sub_bytes(inode, num_dec);
2608 }
2609 root_gen = btrfs_header_generation(leaf);
2610 root_owner = btrfs_header_owner(leaf);
2611 }
2612 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
2613 /*
2614 * we can't truncate inline items that have had
2615 * special encodings
2616 */
2617 if (!del_item &&
2618 btrfs_file_extent_compression(leaf, fi) == 0 &&
2619 btrfs_file_extent_encryption(leaf, fi) == 0 &&
2620 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
2621 u32 size = new_size - found_key.offset;
2622
2623 if (root->ref_cows) {
2624 inode_sub_bytes(inode, item_end + 1 -
2625 new_size);
2626 }
2627 size =
2628 btrfs_file_extent_calc_inline_size(size);
2629 ret = btrfs_truncate_item(trans, root, path,
2630 size, 1);
2631 BUG_ON(ret);
2632 } else if (root->ref_cows) {
2633 inode_sub_bytes(inode, item_end + 1 -
2634 found_key.offset);
2635 }
2636 }
2637delete:
2638 if (del_item) {
2639 if (!pending_del_nr) {
2640 /* no pending yet, add ourselves */
2641 pending_del_slot = path->slots[0];
2642 pending_del_nr = 1;
2643 } else if (pending_del_nr &&
2644 path->slots[0] + 1 == pending_del_slot) {
2645 /* hop on the pending chunk */
2646 pending_del_nr++;
2647 pending_del_slot = path->slots[0];
2648 } else {
2649 BUG();
2650 }
2651 } else {
2652 break;
2653 }
2654 if (found_extent) {
2655 ret = btrfs_free_extent(trans, root, extent_start,
2656 extent_num_bytes,
2657 leaf->start, root_owner,
2658 root_gen, inode->i_ino, 0);
2659 BUG_ON(ret);
2660 }
2661next:
2662 if (path->slots[0] == 0) {
2663 if (pending_del_nr)
2664 goto del_pending;
2665 btrfs_release_path(root, path);
2666 goto search_again;
2667 }
2668
2669 path->slots[0]--;
2670 if (pending_del_nr &&
2671 path->slots[0] + 1 != pending_del_slot) {
2672 struct btrfs_key debug;
2673del_pending:
2674 btrfs_item_key_to_cpu(path->nodes[0], &debug,
2675 pending_del_slot);
2676 ret = btrfs_del_items(trans, root, path,
2677 pending_del_slot,
2678 pending_del_nr);
2679 BUG_ON(ret);
2680 pending_del_nr = 0;
2681 btrfs_release_path(root, path);
2682 goto search_again;
2683 }
2684 }
2685 ret = 0;
2686error:
2687 if (pending_del_nr) {
2688 ret = btrfs_del_items(trans, root, path, pending_del_slot,
2689 pending_del_nr);
2690 }
2691 btrfs_free_path(path);
2692 inode->i_sb->s_dirt = 1;
2693 return ret;
2694}
2695
2696/*
2697 * taken from block_truncate_page, but does cow as it zeros out
2698 * any bytes left in the last page in the file.
2699 */
2700static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
2701{
2702 struct inode *inode = mapping->host;
2703 struct btrfs_root *root = BTRFS_I(inode)->root;
2704 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2705 struct btrfs_ordered_extent *ordered;
2706 char *kaddr;
2707 u32 blocksize = root->sectorsize;
2708 pgoff_t index = from >> PAGE_CACHE_SHIFT;
2709 unsigned offset = from & (PAGE_CACHE_SIZE-1);
2710 struct page *page;
2711 int ret = 0;
2712 u64 page_start;
2713 u64 page_end;
2714
2715 if ((offset & (blocksize - 1)) == 0)
2716 goto out;
2717
2718 ret = -ENOMEM;
2719again:
2720 page = grab_cache_page(mapping, index);
2721 if (!page)
2722 goto out;
2723
2724 page_start = page_offset(page);
2725 page_end = page_start + PAGE_CACHE_SIZE - 1;
2726
2727 if (!PageUptodate(page)) {
2728 ret = btrfs_readpage(NULL, page);
2729 lock_page(page);
2730 if (page->mapping != mapping) {
2731 unlock_page(page);
2732 page_cache_release(page);
2733 goto again;
2734 }
2735 if (!PageUptodate(page)) {
2736 ret = -EIO;
2737 goto out_unlock;
2738 }
2739 }
2740 wait_on_page_writeback(page);
2741
2742 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
2743 set_page_extent_mapped(page);
2744
2745 ordered = btrfs_lookup_ordered_extent(inode, page_start);
2746 if (ordered) {
2747 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
2748 unlock_page(page);
2749 page_cache_release(page);
2750 btrfs_start_ordered_extent(inode, ordered, 1);
2751 btrfs_put_ordered_extent(ordered);
2752 goto again;
2753 }
2754
2755 btrfs_set_extent_delalloc(inode, page_start, page_end);
2756 ret = 0;
2757 if (offset != PAGE_CACHE_SIZE) {
2758 kaddr = kmap(page);
2759 memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
2760 flush_dcache_page(page);
2761 kunmap(page);
2762 }
2763 ClearPageChecked(page);
2764 set_page_dirty(page);
2765 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
2766
2767out_unlock:
2768 unlock_page(page);
2769 page_cache_release(page);
2770out:
2771 return ret;
2772}
2773
2774int btrfs_cont_expand(struct inode *inode, loff_t size)
2775{
2776 struct btrfs_trans_handle *trans;
2777 struct btrfs_root *root = BTRFS_I(inode)->root;
2778 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2779 struct extent_map *em;
2780 u64 mask = root->sectorsize - 1;
2781 u64 hole_start = (inode->i_size + mask) & ~mask;
2782 u64 block_end = (size + mask) & ~mask;
2783 u64 last_byte;
2784 u64 cur_offset;
2785 u64 hole_size;
2786 int err;
2787
2788 if (size <= hole_start)
2789 return 0;
2790
2791 err = btrfs_check_free_space(root, 1, 0);
2792 if (err)
2793 return err;
2794
2795 btrfs_truncate_page(inode->i_mapping, inode->i_size);
2796
2797 while (1) {
2798 struct btrfs_ordered_extent *ordered;
2799 btrfs_wait_ordered_range(inode, hole_start,
2800 block_end - hole_start);
2801 lock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS);
2802 ordered = btrfs_lookup_ordered_extent(inode, hole_start);
2803 if (!ordered)
2804 break;
2805 unlock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS);
2806 btrfs_put_ordered_extent(ordered);
2807 }
2808
2809 trans = btrfs_start_transaction(root, 1);
2810 btrfs_set_trans_block_group(trans, inode);
2811
2812 cur_offset = hole_start;
2813 while (1) {
2814 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
2815 block_end - cur_offset, 0);
2816 BUG_ON(IS_ERR(em) || !em);
2817 last_byte = min(extent_map_end(em), block_end);
2818 last_byte = (last_byte + mask) & ~mask;
2819 if (test_bit(EXTENT_FLAG_VACANCY, &em->flags)) {
2820 u64 hint_byte = 0;
2821 hole_size = last_byte - cur_offset;
2822 err = btrfs_drop_extents(trans, root, inode,
2823 cur_offset,
2824 cur_offset + hole_size,
2825 cur_offset, &hint_byte);
2826 if (err)
2827 break;
2828 err = btrfs_insert_file_extent(trans, root,
2829 inode->i_ino, cur_offset, 0,
2830 0, hole_size, 0, hole_size,
2831 0, 0, 0);
2832 btrfs_drop_extent_cache(inode, hole_start,
2833 last_byte - 1, 0);
2834 }
2835 free_extent_map(em);
2836 cur_offset = last_byte;
2837 if (err || cur_offset >= block_end)
2838 break;
2839 }
2840
2841 btrfs_end_transaction(trans, root);
2842 unlock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS);
2843 return err;
2844}
2845
2846static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
2847{
2848 struct inode *inode = dentry->d_inode;
2849 int err;
2850
2851 err = inode_change_ok(inode, attr);
2852 if (err)
2853 return err;
2854
2855 if (S_ISREG(inode->i_mode) &&
2856 attr->ia_valid & ATTR_SIZE && attr->ia_size > inode->i_size) {
2857 err = btrfs_cont_expand(inode, attr->ia_size);
2858 if (err)
2859 return err;
2860 }
2861
2862 err = inode_setattr(inode, attr);
2863
2864 if (!err && ((attr->ia_valid & ATTR_MODE)))
2865 err = btrfs_acl_chmod(inode);
2866 return err;
2867}
2868
2869void btrfs_delete_inode(struct inode *inode)
2870{
2871 struct btrfs_trans_handle *trans;
2872 struct btrfs_root *root = BTRFS_I(inode)->root;
2873 unsigned long nr;
2874 int ret;
2875
2876 truncate_inode_pages(&inode->i_data, 0);
2877 if (is_bad_inode(inode)) {
2878 btrfs_orphan_del(NULL, inode);
2879 goto no_delete;
2880 }
2881 btrfs_wait_ordered_range(inode, 0, (u64)-1);
2882
2883 btrfs_i_size_write(inode, 0);
2884 trans = btrfs_join_transaction(root, 1);
2885
2886 btrfs_set_trans_block_group(trans, inode);
2887 ret = btrfs_truncate_inode_items(trans, root, inode, inode->i_size, 0);
2888 if (ret) {
2889 btrfs_orphan_del(NULL, inode);
2890 goto no_delete_lock;
2891 }
2892
2893 btrfs_orphan_del(trans, inode);
2894
2895 nr = trans->blocks_used;
2896 clear_inode(inode);
2897
2898 btrfs_end_transaction(trans, root);
2899 btrfs_btree_balance_dirty(root, nr);
2900 return;
2901
2902no_delete_lock:
2903 nr = trans->blocks_used;
2904 btrfs_end_transaction(trans, root);
2905 btrfs_btree_balance_dirty(root, nr);
2906no_delete:
2907 clear_inode(inode);
2908}
2909
2910/*
2911 * this returns the key found in the dir entry in the location pointer.
2912 * If no dir entries were found, location->objectid is 0.
2913 */
2914static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
2915 struct btrfs_key *location)
2916{
2917 const char *name = dentry->d_name.name;
2918 int namelen = dentry->d_name.len;
2919 struct btrfs_dir_item *di;
2920 struct btrfs_path *path;
2921 struct btrfs_root *root = BTRFS_I(dir)->root;
2922 int ret = 0;
2923
2924 path = btrfs_alloc_path();
2925 BUG_ON(!path);
2926
2927 di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
2928 namelen, 0);
2929 if (IS_ERR(di))
2930 ret = PTR_ERR(di);
2931
2932 if (!di || IS_ERR(di))
2933 goto out_err;
2934
2935 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
2936out:
2937 btrfs_free_path(path);
2938 return ret;
2939out_err:
2940 location->objectid = 0;
2941 goto out;
2942}
2943
2944/*
2945 * when we hit a tree root in a directory, the btrfs part of the inode
2946 * needs to be changed to reflect the root directory of the tree root. This
2947 * is kind of like crossing a mount point.
2948 */
2949static int fixup_tree_root_location(struct btrfs_root *root,
2950 struct btrfs_key *location,
2951 struct btrfs_root **sub_root,
2952 struct dentry *dentry)
2953{
2954 struct btrfs_root_item *ri;
2955
2956 if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY)
2957 return 0;
2958 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
2959 return 0;
2960
2961 *sub_root = btrfs_read_fs_root(root->fs_info, location,
2962 dentry->d_name.name,
2963 dentry->d_name.len);
2964 if (IS_ERR(*sub_root))
2965 return PTR_ERR(*sub_root);
2966
2967 ri = &(*sub_root)->root_item;
2968 location->objectid = btrfs_root_dirid(ri);
2969 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
2970 location->offset = 0;
2971
2972 return 0;
2973}
2974
2975static noinline void init_btrfs_i(struct inode *inode)
2976{
2977 struct btrfs_inode *bi = BTRFS_I(inode);
2978
2979 bi->i_acl = NULL;
2980 bi->i_default_acl = NULL;
2981
2982 bi->generation = 0;
2983 bi->sequence = 0;
2984 bi->last_trans = 0;
2985 bi->logged_trans = 0;
2986 bi->delalloc_bytes = 0;
2987 bi->disk_i_size = 0;
2988 bi->flags = 0;
2989 bi->index_cnt = (u64)-1;
2990 bi->log_dirty_trans = 0;
2991 extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
2992 extent_io_tree_init(&BTRFS_I(inode)->io_tree,
2993 inode->i_mapping, GFP_NOFS);
2994 extent_io_tree_init(&BTRFS_I(inode)->io_failure_tree,
2995 inode->i_mapping, GFP_NOFS);
2996 INIT_LIST_HEAD(&BTRFS_I(inode)->delalloc_inodes);
2997 btrfs_ordered_inode_tree_init(&BTRFS_I(inode)->ordered_tree);
2998 mutex_init(&BTRFS_I(inode)->extent_mutex);
2999 mutex_init(&BTRFS_I(inode)->log_mutex);
3000}
3001
3002static int btrfs_init_locked_inode(struct inode *inode, void *p)
3003{
3004 struct btrfs_iget_args *args = p;
3005 inode->i_ino = args->ino;
3006 init_btrfs_i(inode);
3007 BTRFS_I(inode)->root = args->root;
3008 return 0;
3009}
3010
3011static int btrfs_find_actor(struct inode *inode, void *opaque)
3012{
3013 struct btrfs_iget_args *args = opaque;
3014 return args->ino == inode->i_ino &&
3015 args->root == BTRFS_I(inode)->root;
3016}
3017
3018struct inode *btrfs_ilookup(struct super_block *s, u64 objectid,
3019 struct btrfs_root *root, int wait)
3020{
3021 struct inode *inode;
3022 struct btrfs_iget_args args;
3023 args.ino = objectid;
3024 args.root = root;
3025
3026 if (wait) {
3027 inode = ilookup5(s, objectid, btrfs_find_actor,
3028 (void *)&args);
3029 } else {
3030 inode = ilookup5_nowait(s, objectid, btrfs_find_actor,
3031 (void *)&args);
3032 }
3033 return inode;
3034}
3035
3036struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
3037 struct btrfs_root *root)
3038{
3039 struct inode *inode;
3040 struct btrfs_iget_args args;
3041 args.ino = objectid;
3042 args.root = root;
3043
3044 inode = iget5_locked(s, objectid, btrfs_find_actor,
3045 btrfs_init_locked_inode,
3046 (void *)&args);
3047 return inode;
3048}
3049
3050/* Get an inode object given its location and corresponding root.
3051 * Returns in *is_new if the inode was read from disk
3052 */
3053struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
3054 struct btrfs_root *root, int *is_new)
3055{
3056 struct inode *inode;
3057
3058 inode = btrfs_iget_locked(s, location->objectid, root);
3059 if (!inode)
3060 return ERR_PTR(-EACCES);
3061
3062 if (inode->i_state & I_NEW) {
3063 BTRFS_I(inode)->root = root;
3064 memcpy(&BTRFS_I(inode)->location, location, sizeof(*location));
3065 btrfs_read_locked_inode(inode);
3066 unlock_new_inode(inode);
3067 if (is_new)
3068 *is_new = 1;
3069 } else {
3070 if (is_new)
3071 *is_new = 0;
3072 }
3073
3074 return inode;
3075}
3076
3077struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
3078{
3079 struct inode *inode;
3080 struct btrfs_inode *bi = BTRFS_I(dir);
3081 struct btrfs_root *root = bi->root;
3082 struct btrfs_root *sub_root = root;
3083 struct btrfs_key location;
3084 int ret, new;
3085
3086 if (dentry->d_name.len > BTRFS_NAME_LEN)
3087 return ERR_PTR(-ENAMETOOLONG);
3088
3089 ret = btrfs_inode_by_name(dir, dentry, &location);
3090
3091 if (ret < 0)
3092 return ERR_PTR(ret);
3093
3094 inode = NULL;
3095 if (location.objectid) {
3096 ret = fixup_tree_root_location(root, &location, &sub_root,
3097 dentry);
3098 if (ret < 0)
3099 return ERR_PTR(ret);
3100 if (ret > 0)
3101 return ERR_PTR(-ENOENT);
3102 inode = btrfs_iget(dir->i_sb, &location, sub_root, &new);
3103 if (IS_ERR(inode))
3104 return ERR_CAST(inode);
3105 }
3106 return inode;
3107}
3108
3109static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
3110 struct nameidata *nd)
3111{
3112 struct inode *inode;
3113
3114 if (dentry->d_name.len > BTRFS_NAME_LEN)
3115 return ERR_PTR(-ENAMETOOLONG);
3116
3117 inode = btrfs_lookup_dentry(dir, dentry);
3118 if (IS_ERR(inode))
3119 return ERR_CAST(inode);
3120
3121 return d_splice_alias(inode, dentry);
3122}
3123
3124static unsigned char btrfs_filetype_table[] = {
3125 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
3126};
3127
3128static int btrfs_real_readdir(struct file *filp, void *dirent,
3129 filldir_t filldir)
3130{
3131 struct inode *inode = filp->f_dentry->d_inode;
3132 struct btrfs_root *root = BTRFS_I(inode)->root;
3133 struct btrfs_item *item;
3134 struct btrfs_dir_item *di;
3135 struct btrfs_key key;
3136 struct btrfs_key found_key;
3137 struct btrfs_path *path;
3138 int ret;
3139 u32 nritems;
3140 struct extent_buffer *leaf;
3141 int slot;
3142 int advance;
3143 unsigned char d_type;
3144 int over = 0;
3145 u32 di_cur;
3146 u32 di_total;
3147 u32 di_len;
3148 int key_type = BTRFS_DIR_INDEX_KEY;
3149 char tmp_name[32];
3150 char *name_ptr;
3151 int name_len;
3152
3153 /* FIXME, use a real flag for deciding about the key type */
3154 if (root->fs_info->tree_root == root)
3155 key_type = BTRFS_DIR_ITEM_KEY;
3156
3157 /* special case for "." */
3158 if (filp->f_pos == 0) {
3159 over = filldir(dirent, ".", 1,
3160 1, inode->i_ino,
3161 DT_DIR);
3162 if (over)
3163 return 0;
3164 filp->f_pos = 1;
3165 }
3166 /* special case for .., just use the back ref */
3167 if (filp->f_pos == 1) {
3168 u64 pino = parent_ino(filp->f_path.dentry);
3169 over = filldir(dirent, "..", 2,
3170 2, pino, DT_DIR);
3171 if (over)
3172 return 0;
3173 filp->f_pos = 2;
3174 }
3175 path = btrfs_alloc_path();
3176 path->reada = 2;
3177
3178 btrfs_set_key_type(&key, key_type);
3179 key.offset = filp->f_pos;
3180 key.objectid = inode->i_ino;
3181
3182 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3183 if (ret < 0)
3184 goto err;
3185 advance = 0;
3186
3187 while (1) {
3188 leaf = path->nodes[0];
3189 nritems = btrfs_header_nritems(leaf);
3190 slot = path->slots[0];
3191 if (advance || slot >= nritems) {
3192 if (slot >= nritems - 1) {
3193 ret = btrfs_next_leaf(root, path);
3194 if (ret)
3195 break;
3196 leaf = path->nodes[0];
3197 nritems = btrfs_header_nritems(leaf);
3198 slot = path->slots[0];
3199 } else {
3200 slot++;
3201 path->slots[0]++;
3202 }
3203 }
3204
3205 advance = 1;
3206 item = btrfs_item_nr(leaf, slot);
3207 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3208
3209 if (found_key.objectid != key.objectid)
3210 break;
3211 if (btrfs_key_type(&found_key) != key_type)
3212 break;
3213 if (found_key.offset < filp->f_pos)
3214 continue;
3215
3216 filp->f_pos = found_key.offset;
3217
3218 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
3219 di_cur = 0;
3220 di_total = btrfs_item_size(leaf, item);
3221
3222 while (di_cur < di_total) {
3223 struct btrfs_key location;
3224
3225 name_len = btrfs_dir_name_len(leaf, di);
3226 if (name_len <= sizeof(tmp_name)) {
3227 name_ptr = tmp_name;
3228 } else {
3229 name_ptr = kmalloc(name_len, GFP_NOFS);
3230 if (!name_ptr) {
3231 ret = -ENOMEM;
3232 goto err;
3233 }
3234 }
3235 read_extent_buffer(leaf, name_ptr,
3236 (unsigned long)(di + 1), name_len);
3237
3238 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
3239 btrfs_dir_item_key_to_cpu(leaf, di, &location);
3240
3241 /* is this a reference to our own snapshot? If so
3242 * skip it
3243 */
3244 if (location.type == BTRFS_ROOT_ITEM_KEY &&
3245 location.objectid == root->root_key.objectid) {
3246 over = 0;
3247 goto skip;
3248 }
3249 over = filldir(dirent, name_ptr, name_len,
3250 found_key.offset, location.objectid,
3251 d_type);
3252
3253skip:
3254 if (name_ptr != tmp_name)
3255 kfree(name_ptr);
3256
3257 if (over)
3258 goto nopos;
3259 di_len = btrfs_dir_name_len(leaf, di) +
3260 btrfs_dir_data_len(leaf, di) + sizeof(*di);
3261 di_cur += di_len;
3262 di = (struct btrfs_dir_item *)((char *)di + di_len);
3263 }
3264 }
3265
3266 /* Reached end of directory/root. Bump pos past the last item. */
3267 if (key_type == BTRFS_DIR_INDEX_KEY)
3268 filp->f_pos = INT_LIMIT(typeof(filp->f_pos));
3269 else
3270 filp->f_pos++;
3271nopos:
3272 ret = 0;
3273err:
3274 btrfs_free_path(path);
3275 return ret;
3276}
3277
3278int btrfs_write_inode(struct inode *inode, int wait)
3279{
3280 struct btrfs_root *root = BTRFS_I(inode)->root;
3281 struct btrfs_trans_handle *trans;
3282 int ret = 0;
3283
3284 if (root->fs_info->btree_inode == inode)
3285 return 0;
3286
3287 if (wait) {
3288 trans = btrfs_join_transaction(root, 1);
3289 btrfs_set_trans_block_group(trans, inode);
3290 ret = btrfs_commit_transaction(trans, root);
3291 }
3292 return ret;
3293}
3294
3295/*
3296 * This is somewhat expensive, updating the tree every time the
3297 * inode changes. But, it is most likely to find the inode in cache.
3298 * FIXME, needs more benchmarking...there are no reasons other than performance
3299 * to keep or drop this code.
3300 */
3301void btrfs_dirty_inode(struct inode *inode)
3302{
3303 struct btrfs_root *root = BTRFS_I(inode)->root;
3304 struct btrfs_trans_handle *trans;
3305
3306 trans = btrfs_join_transaction(root, 1);
3307 btrfs_set_trans_block_group(trans, inode);
3308 btrfs_update_inode(trans, root, inode);
3309 btrfs_end_transaction(trans, root);
3310}
3311
3312/*
3313 * find the highest existing sequence number in a directory
3314 * and then set the in-memory index_cnt variable to reflect
3315 * free sequence numbers
3316 */
3317static int btrfs_set_inode_index_count(struct inode *inode)
3318{
3319 struct btrfs_root *root = BTRFS_I(inode)->root;
3320 struct btrfs_key key, found_key;
3321 struct btrfs_path *path;
3322 struct extent_buffer *leaf;
3323 int ret;
3324
3325 key.objectid = inode->i_ino;
3326 btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
3327 key.offset = (u64)-1;
3328
3329 path = btrfs_alloc_path();
3330 if (!path)
3331 return -ENOMEM;
3332
3333 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3334 if (ret < 0)
3335 goto out;
3336 /* FIXME: we should be able to handle this */
3337 if (ret == 0)
3338 goto out;
3339 ret = 0;
3340
3341 /*
3342 * MAGIC NUMBER EXPLANATION:
3343 * since we search a directory based on f_pos we have to start at 2
3344 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
3345 * else has to start at 2
3346 */
3347 if (path->slots[0] == 0) {
3348 BTRFS_I(inode)->index_cnt = 2;
3349 goto out;
3350 }
3351
3352 path->slots[0]--;
3353
3354 leaf = path->nodes[0];
3355 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3356
3357 if (found_key.objectid != inode->i_ino ||
3358 btrfs_key_type(&found_key) != BTRFS_DIR_INDEX_KEY) {
3359 BTRFS_I(inode)->index_cnt = 2;
3360 goto out;
3361 }
3362
3363 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
3364out:
3365 btrfs_free_path(path);
3366 return ret;
3367}
3368
3369/*
3370 * helper to find a free sequence number in a given directory. This current
3371 * code is very simple, later versions will do smarter things in the btree
3372 */
3373int btrfs_set_inode_index(struct inode *dir, u64 *index)
3374{
3375 int ret = 0;
3376
3377 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
3378 ret = btrfs_set_inode_index_count(dir);
3379 if (ret)
3380 return ret;
3381 }
3382
3383 *index = BTRFS_I(dir)->index_cnt;
3384 BTRFS_I(dir)->index_cnt++;
3385
3386 return ret;
3387}
3388
3389static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
3390 struct btrfs_root *root,
3391 struct inode *dir,
3392 const char *name, int name_len,
3393 u64 ref_objectid, u64 objectid,
3394 u64 alloc_hint, int mode, u64 *index)
3395{
3396 struct inode *inode;
3397 struct btrfs_inode_item *inode_item;
3398 struct btrfs_key *location;
3399 struct btrfs_path *path;
3400 struct btrfs_inode_ref *ref;
3401 struct btrfs_key key[2];
3402 u32 sizes[2];
3403 unsigned long ptr;
3404 int ret;
3405 int owner;
3406
3407 path = btrfs_alloc_path();
3408 BUG_ON(!path);
3409
3410 inode = new_inode(root->fs_info->sb);
3411 if (!inode)
3412 return ERR_PTR(-ENOMEM);
3413
3414 if (dir) {
3415 ret = btrfs_set_inode_index(dir, index);
3416 if (ret)
3417 return ERR_PTR(ret);
3418 }
3419 /*
3420 * index_cnt is ignored for everything but a dir,
3421 * btrfs_get_inode_index_count has an explanation for the magic
3422 * number
3423 */
3424 init_btrfs_i(inode);
3425 BTRFS_I(inode)->index_cnt = 2;
3426 BTRFS_I(inode)->root = root;
3427 BTRFS_I(inode)->generation = trans->transid;
3428
3429 if (mode & S_IFDIR)
3430 owner = 0;
3431 else
3432 owner = 1;
3433 BTRFS_I(inode)->block_group =
3434 btrfs_find_block_group(root, 0, alloc_hint, owner);
3435 if ((mode & S_IFREG)) {
3436 if (btrfs_test_opt(root, NODATASUM))
3437 btrfs_set_flag(inode, NODATASUM);
3438 if (btrfs_test_opt(root, NODATACOW))
3439 btrfs_set_flag(inode, NODATACOW);
3440 }
3441
3442 key[0].objectid = objectid;
3443 btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
3444 key[0].offset = 0;
3445
3446 key[1].objectid = objectid;
3447 btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
3448 key[1].offset = ref_objectid;
3449
3450 sizes[0] = sizeof(struct btrfs_inode_item);
3451 sizes[1] = name_len + sizeof(*ref);
3452
3453 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
3454 if (ret != 0)
3455 goto fail;
3456
3457 if (objectid > root->highest_inode)
3458 root->highest_inode = objectid;
3459
3460 inode->i_uid = current_fsuid();
3461 inode->i_gid = current_fsgid();
3462 inode->i_mode = mode;
3463 inode->i_ino = objectid;
3464 inode_set_bytes(inode, 0);
3465 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
3466 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
3467 struct btrfs_inode_item);
3468 fill_inode_item(trans, path->nodes[0], inode_item, inode);
3469
3470 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
3471 struct btrfs_inode_ref);
3472 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
3473 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
3474 ptr = (unsigned long)(ref + 1);
3475 write_extent_buffer(path->nodes[0], name, ptr, name_len);
3476
3477 btrfs_mark_buffer_dirty(path->nodes[0]);
3478 btrfs_free_path(path);
3479
3480 location = &BTRFS_I(inode)->location;
3481 location->objectid = objectid;
3482 location->offset = 0;
3483 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
3484
3485 insert_inode_hash(inode);
3486 return inode;
3487fail:
3488 if (dir)
3489 BTRFS_I(dir)->index_cnt--;
3490 btrfs_free_path(path);
3491 return ERR_PTR(ret);
3492}
3493
3494static inline u8 btrfs_inode_type(struct inode *inode)
3495{
3496 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
3497}
3498
3499/*
3500 * utility function to add 'inode' into 'parent_inode' with
3501 * a give name and a given sequence number.
3502 * if 'add_backref' is true, also insert a backref from the
3503 * inode to the parent directory.
3504 */
3505int btrfs_add_link(struct btrfs_trans_handle *trans,
3506 struct inode *parent_inode, struct inode *inode,
3507 const char *name, int name_len, int add_backref, u64 index)
3508{
3509 int ret;
3510 struct btrfs_key key;
3511 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
3512
3513 key.objectid = inode->i_ino;
3514 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
3515 key.offset = 0;
3516
3517 ret = btrfs_insert_dir_item(trans, root, name, name_len,
3518 parent_inode->i_ino,
3519 &key, btrfs_inode_type(inode),
3520 index);
3521 if (ret == 0) {
3522 if (add_backref) {
3523 ret = btrfs_insert_inode_ref(trans, root,
3524 name, name_len,
3525 inode->i_ino,
3526 parent_inode->i_ino,
3527 index);
3528 }
3529 btrfs_i_size_write(parent_inode, parent_inode->i_size +
3530 name_len * 2);
3531 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
3532 ret = btrfs_update_inode(trans, root, parent_inode);
3533 }
3534 return ret;
3535}
3536
3537static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
3538 struct dentry *dentry, struct inode *inode,
3539 int backref, u64 index)
3540{
3541 int err = btrfs_add_link(trans, dentry->d_parent->d_inode,
3542 inode, dentry->d_name.name,
3543 dentry->d_name.len, backref, index);
3544 if (!err) {
3545 d_instantiate(dentry, inode);
3546 return 0;
3547 }
3548 if (err > 0)
3549 err = -EEXIST;
3550 return err;
3551}
3552
3553static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
3554 int mode, dev_t rdev)
3555{
3556 struct btrfs_trans_handle *trans;
3557 struct btrfs_root *root = BTRFS_I(dir)->root;
3558 struct inode *inode = NULL;
3559 int err;
3560 int drop_inode = 0;
3561 u64 objectid;
3562 unsigned long nr = 0;
3563 u64 index = 0;
3564
3565 if (!new_valid_dev(rdev))
3566 return -EINVAL;
3567
3568 err = btrfs_check_free_space(root, 1, 0);
3569 if (err)
3570 goto fail;
3571
3572 trans = btrfs_start_transaction(root, 1);
3573 btrfs_set_trans_block_group(trans, dir);
3574
3575 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
3576 if (err) {
3577 err = -ENOSPC;
3578 goto out_unlock;
3579 }
3580
3581 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
3582 dentry->d_name.len,
3583 dentry->d_parent->d_inode->i_ino, objectid,
3584 BTRFS_I(dir)->block_group, mode, &index);
3585 err = PTR_ERR(inode);
3586 if (IS_ERR(inode))
3587 goto out_unlock;
3588
3589 err = btrfs_init_acl(inode, dir);
3590 if (err) {
3591 drop_inode = 1;
3592 goto out_unlock;
3593 }
3594
3595 btrfs_set_trans_block_group(trans, inode);
3596 err = btrfs_add_nondir(trans, dentry, inode, 0, index);
3597 if (err)
3598 drop_inode = 1;
3599 else {
3600 inode->i_op = &btrfs_special_inode_operations;
3601 init_special_inode(inode, inode->i_mode, rdev);
3602 btrfs_update_inode(trans, root, inode);
3603 }
3604 dir->i_sb->s_dirt = 1;
3605 btrfs_update_inode_block_group(trans, inode);
3606 btrfs_update_inode_block_group(trans, dir);
3607out_unlock:
3608 nr = trans->blocks_used;
3609 btrfs_end_transaction_throttle(trans, root);
3610fail:
3611 if (drop_inode) {
3612 inode_dec_link_count(inode);
3613 iput(inode);
3614 }
3615 btrfs_btree_balance_dirty(root, nr);
3616 return err;
3617}
3618
3619static int btrfs_create(struct inode *dir, struct dentry *dentry,
3620 int mode, struct nameidata *nd)
3621{
3622 struct btrfs_trans_handle *trans;
3623 struct btrfs_root *root = BTRFS_I(dir)->root;
3624 struct inode *inode = NULL;
3625 int err;
3626 int drop_inode = 0;
3627 unsigned long nr = 0;
3628 u64 objectid;
3629 u64 index = 0;
3630
3631 err = btrfs_check_free_space(root, 1, 0);
3632 if (err)
3633 goto fail;
3634 trans = btrfs_start_transaction(root, 1);
3635 btrfs_set_trans_block_group(trans, dir);
3636
3637 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
3638 if (err) {
3639 err = -ENOSPC;
3640 goto out_unlock;
3641 }
3642
3643 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
3644 dentry->d_name.len,
3645 dentry->d_parent->d_inode->i_ino,
3646 objectid, BTRFS_I(dir)->block_group, mode,
3647 &index);
3648 err = PTR_ERR(inode);
3649 if (IS_ERR(inode))
3650 goto out_unlock;
3651
3652 err = btrfs_init_acl(inode, dir);
3653 if (err) {
3654 drop_inode = 1;
3655 goto out_unlock;
3656 }
3657
3658 btrfs_set_trans_block_group(trans, inode);
3659 err = btrfs_add_nondir(trans, dentry, inode, 0, index);
3660 if (err)
3661 drop_inode = 1;
3662 else {
3663 inode->i_mapping->a_ops = &btrfs_aops;
3664 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3665 inode->i_fop = &btrfs_file_operations;
3666 inode->i_op = &btrfs_file_inode_operations;
3667 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3668 }
3669 dir->i_sb->s_dirt = 1;
3670 btrfs_update_inode_block_group(trans, inode);
3671 btrfs_update_inode_block_group(trans, dir);
3672out_unlock:
3673 nr = trans->blocks_used;
3674 btrfs_end_transaction_throttle(trans, root);
3675fail:
3676 if (drop_inode) {
3677 inode_dec_link_count(inode);
3678 iput(inode);
3679 }
3680 btrfs_btree_balance_dirty(root, nr);
3681 return err;
3682}
3683
3684static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
3685 struct dentry *dentry)
3686{
3687 struct btrfs_trans_handle *trans;
3688 struct btrfs_root *root = BTRFS_I(dir)->root;
3689 struct inode *inode = old_dentry->d_inode;
3690 u64 index;
3691 unsigned long nr = 0;
3692 int err;
3693 int drop_inode = 0;
3694
3695 if (inode->i_nlink == 0)
3696 return -ENOENT;
3697
3698 btrfs_inc_nlink(inode);
3699 err = btrfs_check_free_space(root, 1, 0);
3700 if (err)
3701 goto fail;
3702 err = btrfs_set_inode_index(dir, &index);
3703 if (err)
3704 goto fail;
3705
3706 trans = btrfs_start_transaction(root, 1);
3707
3708 btrfs_set_trans_block_group(trans, dir);
3709 atomic_inc(&inode->i_count);
3710
3711 err = btrfs_add_nondir(trans, dentry, inode, 1, index);
3712
3713 if (err)
3714 drop_inode = 1;
3715
3716 dir->i_sb->s_dirt = 1;
3717 btrfs_update_inode_block_group(trans, dir);
3718 err = btrfs_update_inode(trans, root, inode);
3719
3720 if (err)
3721 drop_inode = 1;
3722
3723 nr = trans->blocks_used;
3724 btrfs_end_transaction_throttle(trans, root);
3725fail:
3726 if (drop_inode) {
3727 inode_dec_link_count(inode);
3728 iput(inode);
3729 }
3730 btrfs_btree_balance_dirty(root, nr);
3731 return err;
3732}
3733
3734static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
3735{
3736 struct inode *inode = NULL;
3737 struct btrfs_trans_handle *trans;
3738 struct btrfs_root *root = BTRFS_I(dir)->root;
3739 int err = 0;
3740 int drop_on_err = 0;
3741 u64 objectid = 0;
3742 u64 index = 0;
3743 unsigned long nr = 1;
3744
3745 err = btrfs_check_free_space(root, 1, 0);
3746 if (err)
3747 goto out_unlock;
3748
3749 trans = btrfs_start_transaction(root, 1);
3750 btrfs_set_trans_block_group(trans, dir);
3751
3752 if (IS_ERR(trans)) {
3753 err = PTR_ERR(trans);
3754 goto out_unlock;
3755 }
3756
3757 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
3758 if (err) {
3759 err = -ENOSPC;
3760 goto out_unlock;
3761 }
3762
3763 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
3764 dentry->d_name.len,
3765 dentry->d_parent->d_inode->i_ino, objectid,
3766 BTRFS_I(dir)->block_group, S_IFDIR | mode,
3767 &index);
3768 if (IS_ERR(inode)) {
3769 err = PTR_ERR(inode);
3770 goto out_fail;
3771 }
3772
3773 drop_on_err = 1;
3774
3775 err = btrfs_init_acl(inode, dir);
3776 if (err)
3777 goto out_fail;
3778
3779 inode->i_op = &btrfs_dir_inode_operations;
3780 inode->i_fop = &btrfs_dir_file_operations;
3781 btrfs_set_trans_block_group(trans, inode);
3782
3783 btrfs_i_size_write(inode, 0);
3784 err = btrfs_update_inode(trans, root, inode);
3785 if (err)
3786 goto out_fail;
3787
3788 err = btrfs_add_link(trans, dentry->d_parent->d_inode,
3789 inode, dentry->d_name.name,
3790 dentry->d_name.len, 0, index);
3791 if (err)
3792 goto out_fail;
3793
3794 d_instantiate(dentry, inode);
3795 drop_on_err = 0;
3796 dir->i_sb->s_dirt = 1;
3797 btrfs_update_inode_block_group(trans, inode);
3798 btrfs_update_inode_block_group(trans, dir);
3799
3800out_fail:
3801 nr = trans->blocks_used;
3802 btrfs_end_transaction_throttle(trans, root);
3803
3804out_unlock:
3805 if (drop_on_err)
3806 iput(inode);
3807 btrfs_btree_balance_dirty(root, nr);
3808 return err;
3809}
3810
3811/* helper for btfs_get_extent. Given an existing extent in the tree,
3812 * and an extent that you want to insert, deal with overlap and insert
3813 * the new extent into the tree.
3814 */
3815static int merge_extent_mapping(struct extent_map_tree *em_tree,
3816 struct extent_map *existing,
3817 struct extent_map *em,
3818 u64 map_start, u64 map_len)
3819{
3820 u64 start_diff;
3821
3822 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
3823 start_diff = map_start - em->start;
3824 em->start = map_start;
3825 em->len = map_len;
3826 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
3827 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
3828 em->block_start += start_diff;
3829 em->block_len -= start_diff;
3830 }
3831 return add_extent_mapping(em_tree, em);
3832}
3833
3834static noinline int uncompress_inline(struct btrfs_path *path,
3835 struct inode *inode, struct page *page,
3836 size_t pg_offset, u64 extent_offset,
3837 struct btrfs_file_extent_item *item)
3838{
3839 int ret;
3840 struct extent_buffer *leaf = path->nodes[0];
3841 char *tmp;
3842 size_t max_size;
3843 unsigned long inline_size;
3844 unsigned long ptr;
3845
3846 WARN_ON(pg_offset != 0);
3847 max_size = btrfs_file_extent_ram_bytes(leaf, item);
3848 inline_size = btrfs_file_extent_inline_item_len(leaf,
3849 btrfs_item_nr(leaf, path->slots[0]));
3850 tmp = kmalloc(inline_size, GFP_NOFS);
3851 ptr = btrfs_file_extent_inline_start(item);
3852
3853 read_extent_buffer(leaf, tmp, ptr, inline_size);
3854
3855 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
3856 ret = btrfs_zlib_decompress(tmp, page, extent_offset,
3857 inline_size, max_size);
3858 if (ret) {
3859 char *kaddr = kmap_atomic(page, KM_USER0);
3860 unsigned long copy_size = min_t(u64,
3861 PAGE_CACHE_SIZE - pg_offset,
3862 max_size - extent_offset);
3863 memset(kaddr + pg_offset, 0, copy_size);
3864 kunmap_atomic(kaddr, KM_USER0);
3865 }
3866 kfree(tmp);
3867 return 0;
3868}
3869
3870/*
3871 * a bit scary, this does extent mapping from logical file offset to the disk.
3872 * the ugly parts come from merging extents from the disk with the in-ram
3873 * representation. This gets more complex because of the data=ordered code,
3874 * where the in-ram extents might be locked pending data=ordered completion.
3875 *
3876 * This also copies inline extents directly into the page.
3877 */
3878
3879struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
3880 size_t pg_offset, u64 start, u64 len,
3881 int create)
3882{
3883 int ret;
3884 int err = 0;
3885 u64 bytenr;
3886 u64 extent_start = 0;
3887 u64 extent_end = 0;
3888 u64 objectid = inode->i_ino;
3889 u32 found_type;
3890 struct btrfs_path *path = NULL;
3891 struct btrfs_root *root = BTRFS_I(inode)->root;
3892 struct btrfs_file_extent_item *item;
3893 struct extent_buffer *leaf;
3894 struct btrfs_key found_key;
3895 struct extent_map *em = NULL;
3896 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
3897 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3898 struct btrfs_trans_handle *trans = NULL;
3899 int compressed;
3900
3901again:
3902 spin_lock(&em_tree->lock);
3903 em = lookup_extent_mapping(em_tree, start, len);
3904 if (em)
3905 em->bdev = root->fs_info->fs_devices->latest_bdev;
3906 spin_unlock(&em_tree->lock);
3907
3908 if (em) {
3909 if (em->start > start || em->start + em->len <= start)
3910 free_extent_map(em);
3911 else if (em->block_start == EXTENT_MAP_INLINE && page)
3912 free_extent_map(em);
3913 else
3914 goto out;
3915 }
3916 em = alloc_extent_map(GFP_NOFS);
3917 if (!em) {
3918 err = -ENOMEM;
3919 goto out;
3920 }
3921 em->bdev = root->fs_info->fs_devices->latest_bdev;
3922 em->start = EXTENT_MAP_HOLE;
3923 em->orig_start = EXTENT_MAP_HOLE;
3924 em->len = (u64)-1;
3925 em->block_len = (u64)-1;
3926
3927 if (!path) {
3928 path = btrfs_alloc_path();
3929 BUG_ON(!path);
3930 }
3931
3932 ret = btrfs_lookup_file_extent(trans, root, path,
3933 objectid, start, trans != NULL);
3934 if (ret < 0) {
3935 err = ret;
3936 goto out;
3937 }
3938
3939 if (ret != 0) {
3940 if (path->slots[0] == 0)
3941 goto not_found;
3942 path->slots[0]--;
3943 }
3944
3945 leaf = path->nodes[0];
3946 item = btrfs_item_ptr(leaf, path->slots[0],
3947 struct btrfs_file_extent_item);
3948 /* are we inside the extent that was found? */
3949 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3950 found_type = btrfs_key_type(&found_key);
3951 if (found_key.objectid != objectid ||
3952 found_type != BTRFS_EXTENT_DATA_KEY) {
3953 goto not_found;
3954 }
3955
3956 found_type = btrfs_file_extent_type(leaf, item);
3957 extent_start = found_key.offset;
3958 compressed = btrfs_file_extent_compression(leaf, item);
3959 if (found_type == BTRFS_FILE_EXTENT_REG ||
3960 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
3961 extent_end = extent_start +
3962 btrfs_file_extent_num_bytes(leaf, item);
3963 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
3964 size_t size;
3965 size = btrfs_file_extent_inline_len(leaf, item);
3966 extent_end = (extent_start + size + root->sectorsize - 1) &
3967 ~((u64)root->sectorsize - 1);
3968 }
3969
3970 if (start >= extent_end) {
3971 path->slots[0]++;
3972 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
3973 ret = btrfs_next_leaf(root, path);
3974 if (ret < 0) {
3975 err = ret;
3976 goto out;
3977 }
3978 if (ret > 0)
3979 goto not_found;
3980 leaf = path->nodes[0];
3981 }
3982 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3983 if (found_key.objectid != objectid ||
3984 found_key.type != BTRFS_EXTENT_DATA_KEY)
3985 goto not_found;
3986 if (start + len <= found_key.offset)
3987 goto not_found;
3988 em->start = start;
3989 em->len = found_key.offset - start;
3990 goto not_found_em;
3991 }
3992
3993 if (found_type == BTRFS_FILE_EXTENT_REG ||
3994 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
3995 em->start = extent_start;
3996 em->len = extent_end - extent_start;
3997 em->orig_start = extent_start -
3998 btrfs_file_extent_offset(leaf, item);
3999 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
4000 if (bytenr == 0) {
4001 em->block_start = EXTENT_MAP_HOLE;
4002 goto insert;
4003 }
4004 if (compressed) {
4005 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
4006 em->block_start = bytenr;
4007 em->block_len = btrfs_file_extent_disk_num_bytes(leaf,
4008 item);
4009 } else {
4010 bytenr += btrfs_file_extent_offset(leaf, item);
4011 em->block_start = bytenr;
4012 em->block_len = em->len;
4013 if (found_type == BTRFS_FILE_EXTENT_PREALLOC)
4014 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
4015 }
4016 goto insert;
4017 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
4018 unsigned long ptr;
4019 char *map;
4020 size_t size;
4021 size_t extent_offset;
4022 size_t copy_size;
4023
4024 em->block_start = EXTENT_MAP_INLINE;
4025 if (!page || create) {
4026 em->start = extent_start;
4027 em->len = extent_end - extent_start;
4028 goto out;
4029 }
4030
4031 size = btrfs_file_extent_inline_len(leaf, item);
4032 extent_offset = page_offset(page) + pg_offset - extent_start;
4033 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
4034 size - extent_offset);
4035 em->start = extent_start + extent_offset;
4036 em->len = (copy_size + root->sectorsize - 1) &
4037 ~((u64)root->sectorsize - 1);
4038 em->orig_start = EXTENT_MAP_INLINE;
4039 if (compressed)
4040 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
4041 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
4042 if (create == 0 && !PageUptodate(page)) {
4043 if (btrfs_file_extent_compression(leaf, item) ==
4044 BTRFS_COMPRESS_ZLIB) {
4045 ret = uncompress_inline(path, inode, page,
4046 pg_offset,
4047 extent_offset, item);
4048 BUG_ON(ret);
4049 } else {
4050 map = kmap(page);
4051 read_extent_buffer(leaf, map + pg_offset, ptr,
4052 copy_size);
4053 kunmap(page);
4054 }
4055 flush_dcache_page(page);
4056 } else if (create && PageUptodate(page)) {
4057 if (!trans) {
4058 kunmap(page);
4059 free_extent_map(em);
4060 em = NULL;
4061 btrfs_release_path(root, path);
4062 trans = btrfs_join_transaction(root, 1);
4063 goto again;
4064 }
4065 map = kmap(page);
4066 write_extent_buffer(leaf, map + pg_offset, ptr,
4067 copy_size);
4068 kunmap(page);
4069 btrfs_mark_buffer_dirty(leaf);
4070 }
4071 set_extent_uptodate(io_tree, em->start,
4072 extent_map_end(em) - 1, GFP_NOFS);
4073 goto insert;
4074 } else {
4075 printk(KERN_ERR "btrfs unknown found_type %d\n", found_type);
4076 WARN_ON(1);
4077 }
4078not_found:
4079 em->start = start;
4080 em->len = len;
4081not_found_em:
4082 em->block_start = EXTENT_MAP_HOLE;
4083 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
4084insert:
4085 btrfs_release_path(root, path);
4086 if (em->start > start || extent_map_end(em) <= start) {
4087 printk(KERN_ERR "Btrfs: bad extent! em: [%llu %llu] passed "
4088 "[%llu %llu]\n", (unsigned long long)em->start,
4089 (unsigned long long)em->len,
4090 (unsigned long long)start,
4091 (unsigned long long)len);
4092 err = -EIO;
4093 goto out;
4094 }
4095
4096 err = 0;
4097 spin_lock(&em_tree->lock);
4098 ret = add_extent_mapping(em_tree, em);
4099 /* it is possible that someone inserted the extent into the tree
4100 * while we had the lock dropped. It is also possible that
4101 * an overlapping map exists in the tree
4102 */
4103 if (ret == -EEXIST) {
4104 struct extent_map *existing;
4105
4106 ret = 0;
4107
4108 existing = lookup_extent_mapping(em_tree, start, len);
4109 if (existing && (existing->start > start ||
4110 existing->start + existing->len <= start)) {
4111 free_extent_map(existing);
4112 existing = NULL;
4113 }
4114 if (!existing) {
4115 existing = lookup_extent_mapping(em_tree, em->start,
4116 em->len);
4117 if (existing) {
4118 err = merge_extent_mapping(em_tree, existing,
4119 em, start,
4120 root->sectorsize);
4121 free_extent_map(existing);
4122 if (err) {
4123 free_extent_map(em);
4124 em = NULL;
4125 }
4126 } else {
4127 err = -EIO;
4128 free_extent_map(em);
4129 em = NULL;
4130 }
4131 } else {
4132 free_extent_map(em);
4133 em = existing;
4134 err = 0;
4135 }
4136 }
4137 spin_unlock(&em_tree->lock);
4138out:
4139 if (path)
4140 btrfs_free_path(path);
4141 if (trans) {
4142 ret = btrfs_end_transaction(trans, root);
4143 if (!err)
4144 err = ret;
4145 }
4146 if (err) {
4147 free_extent_map(em);
4148 WARN_ON(1);
4149 return ERR_PTR(err);
4150 }
4151 return em;
4152}
4153
4154static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
4155 const struct iovec *iov, loff_t offset,
4156 unsigned long nr_segs)
4157{
4158 return -EINVAL;
4159}
4160
4161static sector_t btrfs_bmap(struct address_space *mapping, sector_t iblock)
4162{
4163 return extent_bmap(mapping, iblock, btrfs_get_extent);
4164}
4165
4166int btrfs_readpage(struct file *file, struct page *page)
4167{
4168 struct extent_io_tree *tree;
4169 tree = &BTRFS_I(page->mapping->host)->io_tree;
4170 return extent_read_full_page(tree, page, btrfs_get_extent);
4171}
4172
4173static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
4174{
4175 struct extent_io_tree *tree;
4176
4177
4178 if (current->flags & PF_MEMALLOC) {
4179 redirty_page_for_writepage(wbc, page);
4180 unlock_page(page);
4181 return 0;
4182 }
4183 tree = &BTRFS_I(page->mapping->host)->io_tree;
4184 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
4185}
4186
4187int btrfs_writepages(struct address_space *mapping,
4188 struct writeback_control *wbc)
4189{
4190 struct extent_io_tree *tree;
4191
4192 tree = &BTRFS_I(mapping->host)->io_tree;
4193 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
4194}
4195
4196static int
4197btrfs_readpages(struct file *file, struct address_space *mapping,
4198 struct list_head *pages, unsigned nr_pages)
4199{
4200 struct extent_io_tree *tree;
4201 tree = &BTRFS_I(mapping->host)->io_tree;
4202 return extent_readpages(tree, mapping, pages, nr_pages,
4203 btrfs_get_extent);
4204}
4205static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
4206{
4207 struct extent_io_tree *tree;
4208 struct extent_map_tree *map;
4209 int ret;
4210
4211 tree = &BTRFS_I(page->mapping->host)->io_tree;
4212 map = &BTRFS_I(page->mapping->host)->extent_tree;
4213 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
4214 if (ret == 1) {
4215 ClearPagePrivate(page);
4216 set_page_private(page, 0);
4217 page_cache_release(page);
4218 }
4219 return ret;
4220}
4221
4222static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
4223{
4224 if (PageWriteback(page) || PageDirty(page))
4225 return 0;
4226 return __btrfs_releasepage(page, gfp_flags);
4227}
4228
4229static void btrfs_invalidatepage(struct page *page, unsigned long offset)
4230{
4231 struct extent_io_tree *tree;
4232 struct btrfs_ordered_extent *ordered;
4233 u64 page_start = page_offset(page);
4234 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
4235
4236 wait_on_page_writeback(page);
4237 tree = &BTRFS_I(page->mapping->host)->io_tree;
4238 if (offset) {
4239 btrfs_releasepage(page, GFP_NOFS);
4240 return;
4241 }
4242
4243 lock_extent(tree, page_start, page_end, GFP_NOFS);
4244 ordered = btrfs_lookup_ordered_extent(page->mapping->host,
4245 page_offset(page));
4246 if (ordered) {
4247 /*
4248 * IO on this page will never be started, so we need
4249 * to account for any ordered extents now
4250 */
4251 clear_extent_bit(tree, page_start, page_end,
4252 EXTENT_DIRTY | EXTENT_DELALLOC |
4253 EXTENT_LOCKED, 1, 0, GFP_NOFS);
4254 btrfs_finish_ordered_io(page->mapping->host,
4255 page_start, page_end);
4256 btrfs_put_ordered_extent(ordered);
4257 lock_extent(tree, page_start, page_end, GFP_NOFS);
4258 }
4259 clear_extent_bit(tree, page_start, page_end,
4260 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
4261 EXTENT_ORDERED,
4262 1, 1, GFP_NOFS);
4263 __btrfs_releasepage(page, GFP_NOFS);
4264
4265 ClearPageChecked(page);
4266 if (PagePrivate(page)) {
4267 ClearPagePrivate(page);
4268 set_page_private(page, 0);
4269 page_cache_release(page);
4270 }
4271}
4272
4273/*
4274 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
4275 * called from a page fault handler when a page is first dirtied. Hence we must
4276 * be careful to check for EOF conditions here. We set the page up correctly
4277 * for a written page which means we get ENOSPC checking when writing into
4278 * holes and correct delalloc and unwritten extent mapping on filesystems that
4279 * support these features.
4280 *
4281 * We are not allowed to take the i_mutex here so we have to play games to
4282 * protect against truncate races as the page could now be beyond EOF. Because
4283 * vmtruncate() writes the inode size before removing pages, once we have the
4284 * page lock we can determine safely if the page is beyond EOF. If it is not
4285 * beyond EOF, then the page is guaranteed safe against truncation until we
4286 * unlock the page.
4287 */
4288int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
4289{
4290 struct inode *inode = fdentry(vma->vm_file)->d_inode;
4291 struct btrfs_root *root = BTRFS_I(inode)->root;
4292 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4293 struct btrfs_ordered_extent *ordered;
4294 char *kaddr;
4295 unsigned long zero_start;
4296 loff_t size;
4297 int ret;
4298 u64 page_start;
4299 u64 page_end;
4300
4301 ret = btrfs_check_free_space(root, PAGE_CACHE_SIZE, 0);
4302 if (ret)
4303 goto out;
4304
4305 ret = -EINVAL;
4306again:
4307 lock_page(page);
4308 size = i_size_read(inode);
4309 page_start = page_offset(page);
4310 page_end = page_start + PAGE_CACHE_SIZE - 1;
4311
4312 if ((page->mapping != inode->i_mapping) ||
4313 (page_start >= size)) {
4314 /* page got truncated out from underneath us */
4315 goto out_unlock;
4316 }
4317 wait_on_page_writeback(page);
4318
4319 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
4320 set_page_extent_mapped(page);
4321
4322 /*
4323 * we can't set the delalloc bits if there are pending ordered
4324 * extents. Drop our locks and wait for them to finish
4325 */
4326 ordered = btrfs_lookup_ordered_extent(inode, page_start);
4327 if (ordered) {
4328 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
4329 unlock_page(page);
4330 btrfs_start_ordered_extent(inode, ordered, 1);
4331 btrfs_put_ordered_extent(ordered);
4332 goto again;
4333 }
4334
4335 btrfs_set_extent_delalloc(inode, page_start, page_end);
4336 ret = 0;
4337
4338 /* page is wholly or partially inside EOF */
4339 if (page_start + PAGE_CACHE_SIZE > size)
4340 zero_start = size & ~PAGE_CACHE_MASK;
4341 else
4342 zero_start = PAGE_CACHE_SIZE;
4343
4344 if (zero_start != PAGE_CACHE_SIZE) {
4345 kaddr = kmap(page);
4346 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
4347 flush_dcache_page(page);
4348 kunmap(page);
4349 }
4350 ClearPageChecked(page);
4351 set_page_dirty(page);
4352 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
4353
4354out_unlock:
4355 unlock_page(page);
4356out:
4357 return ret;
4358}
4359
4360static void btrfs_truncate(struct inode *inode)
4361{
4362 struct btrfs_root *root = BTRFS_I(inode)->root;
4363 int ret;
4364 struct btrfs_trans_handle *trans;
4365 unsigned long nr;
4366 u64 mask = root->sectorsize - 1;
4367
4368 if (!S_ISREG(inode->i_mode))
4369 return;
4370 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
4371 return;
4372
4373 btrfs_truncate_page(inode->i_mapping, inode->i_size);
4374 btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
4375
4376 trans = btrfs_start_transaction(root, 1);
4377 btrfs_set_trans_block_group(trans, inode);
4378 btrfs_i_size_write(inode, inode->i_size);
4379
4380 ret = btrfs_orphan_add(trans, inode);
4381 if (ret)
4382 goto out;
4383 /* FIXME, add redo link to tree so we don't leak on crash */
4384 ret = btrfs_truncate_inode_items(trans, root, inode, inode->i_size,
4385 BTRFS_EXTENT_DATA_KEY);
4386 btrfs_update_inode(trans, root, inode);
4387
4388 ret = btrfs_orphan_del(trans, inode);
4389 BUG_ON(ret);
4390
4391out:
4392 nr = trans->blocks_used;
4393 ret = btrfs_end_transaction_throttle(trans, root);
4394 BUG_ON(ret);
4395 btrfs_btree_balance_dirty(root, nr);
4396}
4397
4398/*
4399 * create a new subvolume directory/inode (helper for the ioctl).
4400 */
4401int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
4402 struct btrfs_root *new_root, struct dentry *dentry,
4403 u64 new_dirid, u64 alloc_hint)
4404{
4405 struct inode *inode;
4406 int error;
4407 u64 index = 0;
4408
4409 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2, new_dirid,
4410 new_dirid, alloc_hint, S_IFDIR | 0700, &index);
4411 if (IS_ERR(inode))
4412 return PTR_ERR(inode);
4413 inode->i_op = &btrfs_dir_inode_operations;
4414 inode->i_fop = &btrfs_dir_file_operations;
4415
4416 inode->i_nlink = 1;
4417 btrfs_i_size_write(inode, 0);
4418
4419 error = btrfs_update_inode(trans, new_root, inode);
4420 if (error)
4421 return error;
4422
4423 d_instantiate(dentry, inode);
4424 return 0;
4425}
4426
4427/* helper function for file defrag and space balancing. This
4428 * forces readahead on a given range of bytes in an inode
4429 */
4430unsigned long btrfs_force_ra(struct address_space *mapping,
4431 struct file_ra_state *ra, struct file *file,
4432 pgoff_t offset, pgoff_t last_index)
4433{
4434 pgoff_t req_size = last_index - offset + 1;
4435
4436 page_cache_sync_readahead(mapping, ra, file, offset, req_size);
4437 return offset + req_size;
4438}
4439
4440struct inode *btrfs_alloc_inode(struct super_block *sb)
4441{
4442 struct btrfs_inode *ei;
4443
4444 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
4445 if (!ei)
4446 return NULL;
4447 ei->last_trans = 0;
4448 ei->logged_trans = 0;
4449 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
4450 ei->i_acl = BTRFS_ACL_NOT_CACHED;
4451 ei->i_default_acl = BTRFS_ACL_NOT_CACHED;
4452 INIT_LIST_HEAD(&ei->i_orphan);
4453 return &ei->vfs_inode;
4454}
4455
4456void btrfs_destroy_inode(struct inode *inode)
4457{
4458 struct btrfs_ordered_extent *ordered;
4459 WARN_ON(!list_empty(&inode->i_dentry));
4460 WARN_ON(inode->i_data.nrpages);
4461
4462 if (BTRFS_I(inode)->i_acl &&
4463 BTRFS_I(inode)->i_acl != BTRFS_ACL_NOT_CACHED)
4464 posix_acl_release(BTRFS_I(inode)->i_acl);
4465 if (BTRFS_I(inode)->i_default_acl &&
4466 BTRFS_I(inode)->i_default_acl != BTRFS_ACL_NOT_CACHED)
4467 posix_acl_release(BTRFS_I(inode)->i_default_acl);
4468
4469 spin_lock(&BTRFS_I(inode)->root->list_lock);
4470 if (!list_empty(&BTRFS_I(inode)->i_orphan)) {
4471 printk(KERN_ERR "BTRFS: inode %lu: inode still on the orphan"
4472 " list\n", inode->i_ino);
4473 dump_stack();
4474 }
4475 spin_unlock(&BTRFS_I(inode)->root->list_lock);
4476
4477 while (1) {
4478 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
4479 if (!ordered)
4480 break;
4481 else {
4482 printk(KERN_ERR "btrfs found ordered "
4483 "extent %llu %llu on inode cleanup\n",
4484 (unsigned long long)ordered->file_offset,
4485 (unsigned long long)ordered->len);
4486 btrfs_remove_ordered_extent(inode, ordered);
4487 btrfs_put_ordered_extent(ordered);
4488 btrfs_put_ordered_extent(ordered);
4489 }
4490 }
4491 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
4492 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
4493}
4494
4495static void init_once(void *foo)
4496{
4497 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
4498
4499 inode_init_once(&ei->vfs_inode);
4500}
4501
4502void btrfs_destroy_cachep(void)
4503{
4504 if (btrfs_inode_cachep)
4505 kmem_cache_destroy(btrfs_inode_cachep);
4506 if (btrfs_trans_handle_cachep)
4507 kmem_cache_destroy(btrfs_trans_handle_cachep);
4508 if (btrfs_transaction_cachep)
4509 kmem_cache_destroy(btrfs_transaction_cachep);
4510 if (btrfs_bit_radix_cachep)
4511 kmem_cache_destroy(btrfs_bit_radix_cachep);
4512 if (btrfs_path_cachep)
4513 kmem_cache_destroy(btrfs_path_cachep);
4514}
4515
4516struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
4517 unsigned long extra_flags,
4518 void (*ctor)(void *))
4519{
4520 return kmem_cache_create(name, size, 0, (SLAB_RECLAIM_ACCOUNT |
4521 SLAB_MEM_SPREAD | extra_flags), ctor);
4522}
4523
4524int btrfs_init_cachep(void)
4525{
4526 btrfs_inode_cachep = btrfs_cache_create("btrfs_inode_cache",
4527 sizeof(struct btrfs_inode),
4528 0, init_once);
4529 if (!btrfs_inode_cachep)
4530 goto fail;
4531 btrfs_trans_handle_cachep =
4532 btrfs_cache_create("btrfs_trans_handle_cache",
4533 sizeof(struct btrfs_trans_handle),
4534 0, NULL);
4535 if (!btrfs_trans_handle_cachep)
4536 goto fail;
4537 btrfs_transaction_cachep = btrfs_cache_create("btrfs_transaction_cache",
4538 sizeof(struct btrfs_transaction),
4539 0, NULL);
4540 if (!btrfs_transaction_cachep)
4541 goto fail;
4542 btrfs_path_cachep = btrfs_cache_create("btrfs_path_cache",
4543 sizeof(struct btrfs_path),
4544 0, NULL);
4545 if (!btrfs_path_cachep)
4546 goto fail;
4547 btrfs_bit_radix_cachep = btrfs_cache_create("btrfs_radix", 256,
4548 SLAB_DESTROY_BY_RCU, NULL);
4549 if (!btrfs_bit_radix_cachep)
4550 goto fail;
4551 return 0;
4552fail:
4553 btrfs_destroy_cachep();
4554 return -ENOMEM;
4555}
4556
4557static int btrfs_getattr(struct vfsmount *mnt,
4558 struct dentry *dentry, struct kstat *stat)
4559{
4560 struct inode *inode = dentry->d_inode;
4561 generic_fillattr(inode, stat);
4562 stat->dev = BTRFS_I(inode)->root->anon_super.s_dev;
4563 stat->blksize = PAGE_CACHE_SIZE;
4564 stat->blocks = (inode_get_bytes(inode) +
4565 BTRFS_I(inode)->delalloc_bytes) >> 9;
4566 return 0;
4567}
4568
4569static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
4570 struct inode *new_dir, struct dentry *new_dentry)
4571{
4572 struct btrfs_trans_handle *trans;
4573 struct btrfs_root *root = BTRFS_I(old_dir)->root;
4574 struct inode *new_inode = new_dentry->d_inode;
4575 struct inode *old_inode = old_dentry->d_inode;
4576 struct timespec ctime = CURRENT_TIME;
4577 u64 index = 0;
4578 int ret;
4579
4580 /* we're not allowed to rename between subvolumes */
4581 if (BTRFS_I(old_inode)->root->root_key.objectid !=
4582 BTRFS_I(new_dir)->root->root_key.objectid)
4583 return -EXDEV;
4584
4585 if (S_ISDIR(old_inode->i_mode) && new_inode &&
4586 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
4587 return -ENOTEMPTY;
4588 }
4589
4590 /* to rename a snapshot or subvolume, we need to juggle the
4591 * backrefs. This isn't coded yet
4592 */
4593 if (old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
4594 return -EXDEV;
4595
4596 ret = btrfs_check_free_space(root, 1, 0);
4597 if (ret)
4598 goto out_unlock;
4599
4600 trans = btrfs_start_transaction(root, 1);
4601
4602 btrfs_set_trans_block_group(trans, new_dir);
4603
4604 btrfs_inc_nlink(old_dentry->d_inode);
4605 old_dir->i_ctime = old_dir->i_mtime = ctime;
4606 new_dir->i_ctime = new_dir->i_mtime = ctime;
4607 old_inode->i_ctime = ctime;
4608
4609 ret = btrfs_unlink_inode(trans, root, old_dir, old_dentry->d_inode,
4610 old_dentry->d_name.name,
4611 old_dentry->d_name.len);
4612 if (ret)
4613 goto out_fail;
4614
4615 if (new_inode) {
4616 new_inode->i_ctime = CURRENT_TIME;
4617 ret = btrfs_unlink_inode(trans, root, new_dir,
4618 new_dentry->d_inode,
4619 new_dentry->d_name.name,
4620 new_dentry->d_name.len);
4621 if (ret)
4622 goto out_fail;
4623 if (new_inode->i_nlink == 0) {
4624 ret = btrfs_orphan_add(trans, new_dentry->d_inode);
4625 if (ret)
4626 goto out_fail;
4627 }
4628
4629 }
4630 ret = btrfs_set_inode_index(new_dir, &index);
4631 if (ret)
4632 goto out_fail;
4633
4634 ret = btrfs_add_link(trans, new_dentry->d_parent->d_inode,
4635 old_inode, new_dentry->d_name.name,
4636 new_dentry->d_name.len, 1, index);
4637 if (ret)
4638 goto out_fail;
4639
4640out_fail:
4641 btrfs_end_transaction_throttle(trans, root);
4642out_unlock:
4643 return ret;
4644}
4645
4646/*
4647 * some fairly slow code that needs optimization. This walks the list
4648 * of all the inodes with pending delalloc and forces them to disk.
4649 */
4650int btrfs_start_delalloc_inodes(struct btrfs_root *root)
4651{
4652 struct list_head *head = &root->fs_info->delalloc_inodes;
4653 struct btrfs_inode *binode;
4654 struct inode *inode;
4655
4656 if (root->fs_info->sb->s_flags & MS_RDONLY)
4657 return -EROFS;
4658
4659 spin_lock(&root->fs_info->delalloc_lock);
4660 while (!list_empty(head)) {
4661 binode = list_entry(head->next, struct btrfs_inode,
4662 delalloc_inodes);
4663 inode = igrab(&binode->vfs_inode);
4664 if (!inode)
4665 list_del_init(&binode->delalloc_inodes);
4666 spin_unlock(&root->fs_info->delalloc_lock);
4667 if (inode) {
4668 filemap_flush(inode->i_mapping);
4669 iput(inode);
4670 }
4671 cond_resched();
4672 spin_lock(&root->fs_info->delalloc_lock);
4673 }
4674 spin_unlock(&root->fs_info->delalloc_lock);
4675
4676 /* the filemap_flush will queue IO into the worker threads, but
4677 * we have to make sure the IO is actually started and that
4678 * ordered extents get created before we return
4679 */
4680 atomic_inc(&root->fs_info->async_submit_draining);
4681 while (atomic_read(&root->fs_info->nr_async_submits) ||
4682 atomic_read(&root->fs_info->async_delalloc_pages)) {
4683 wait_event(root->fs_info->async_submit_wait,
4684 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
4685 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
4686 }
4687 atomic_dec(&root->fs_info->async_submit_draining);
4688 return 0;
4689}
4690
4691static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
4692 const char *symname)
4693{
4694 struct btrfs_trans_handle *trans;
4695 struct btrfs_root *root = BTRFS_I(dir)->root;
4696 struct btrfs_path *path;
4697 struct btrfs_key key;
4698 struct inode *inode = NULL;
4699 int err;
4700 int drop_inode = 0;
4701 u64 objectid;
4702 u64 index = 0 ;
4703 int name_len;
4704 int datasize;
4705 unsigned long ptr;
4706 struct btrfs_file_extent_item *ei;
4707 struct extent_buffer *leaf;
4708 unsigned long nr = 0;
4709
4710 name_len = strlen(symname) + 1;
4711 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
4712 return -ENAMETOOLONG;
4713
4714 err = btrfs_check_free_space(root, 1, 0);
4715 if (err)
4716 goto out_fail;
4717
4718 trans = btrfs_start_transaction(root, 1);
4719 btrfs_set_trans_block_group(trans, dir);
4720
4721 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
4722 if (err) {
4723 err = -ENOSPC;
4724 goto out_unlock;
4725 }
4726
4727 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
4728 dentry->d_name.len,
4729 dentry->d_parent->d_inode->i_ino, objectid,
4730 BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO,
4731 &index);
4732 err = PTR_ERR(inode);
4733 if (IS_ERR(inode))
4734 goto out_unlock;
4735
4736 err = btrfs_init_acl(inode, dir);
4737 if (err) {
4738 drop_inode = 1;
4739 goto out_unlock;
4740 }
4741
4742 btrfs_set_trans_block_group(trans, inode);
4743 err = btrfs_add_nondir(trans, 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;
4752 }
4753 dir->i_sb->s_dirt = 1;
4754 btrfs_update_inode_block_group(trans, inode);
4755 btrfs_update_inode_block_group(trans, dir);
4756 if (drop_inode)
4757 goto out_unlock;
4758
4759 path = btrfs_alloc_path();
4760 BUG_ON(!path);
4761 key.objectid = inode->i_ino;
4762 key.offset = 0;
4763 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
4764 datasize = btrfs_file_extent_calc_inline_size(name_len);
4765 err = btrfs_insert_empty_item(trans, root, path, &key,
4766 datasize);
4767 if (err) {
4768 drop_inode = 1;
4769 goto out_unlock;
4770 }
4771 leaf = path->nodes[0];
4772 ei = btrfs_item_ptr(leaf, path->slots[0],
4773 struct btrfs_file_extent_item);
4774 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
4775 btrfs_set_file_extent_type(leaf, ei,
4776 BTRFS_FILE_EXTENT_INLINE);
4777 btrfs_set_file_extent_encryption(leaf, ei, 0);
4778 btrfs_set_file_extent_compression(leaf, ei, 0);
4779 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
4780 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
4781
4782 ptr = btrfs_file_extent_inline_start(ei);
4783 write_extent_buffer(leaf, symname, ptr, name_len);
4784 btrfs_mark_buffer_dirty(leaf);
4785 btrfs_free_path(path);
4786
4787 inode->i_op = &btrfs_symlink_inode_operations;
4788 inode->i_mapping->a_ops = &btrfs_symlink_aops;
4789 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
4790 inode_set_bytes(inode, name_len);
4791 btrfs_i_size_write(inode, name_len - 1);
4792 err = btrfs_update_inode(trans, root, inode);
4793 if (err)
4794 drop_inode = 1;
4795
4796out_unlock:
4797 nr = trans->blocks_used;
4798 btrfs_end_transaction_throttle(trans, root);
4799out_fail:
4800 if (drop_inode) {
4801 inode_dec_link_count(inode);
4802 iput(inode);
4803 }
4804 btrfs_btree_balance_dirty(root, nr);
4805 return err;
4806}
4807
4808static int prealloc_file_range(struct inode *inode, u64 start, u64 end,
4809 u64 alloc_hint, int mode)
4810{
4811 struct btrfs_trans_handle *trans;
4812 struct btrfs_root *root = BTRFS_I(inode)->root;
4813 struct btrfs_key ins;
4814 u64 alloc_size;
4815 u64 cur_offset = start;
4816 u64 num_bytes = end - start;
4817 int ret = 0;
4818
4819 trans = btrfs_join_transaction(root, 1);
4820 BUG_ON(!trans);
4821 btrfs_set_trans_block_group(trans, inode);
4822
4823 while (num_bytes > 0) {
4824 alloc_size = min(num_bytes, root->fs_info->max_extent);
4825 ret = btrfs_reserve_extent(trans, root, alloc_size,
4826 root->sectorsize, 0, alloc_hint,
4827 (u64)-1, &ins, 1);
4828 if (ret) {
4829 WARN_ON(1);
4830 goto out;
4831 }
4832 ret = insert_reserved_file_extent(trans, inode,
4833 cur_offset, ins.objectid,
4834 ins.offset, ins.offset,
4835 ins.offset, 0, 0, 0,
4836 BTRFS_FILE_EXTENT_PREALLOC);
4837 BUG_ON(ret);
4838 num_bytes -= ins.offset;
4839 cur_offset += ins.offset;
4840 alloc_hint = ins.objectid + ins.offset;
4841 }
4842out:
4843 if (cur_offset > start) {
4844 inode->i_ctime = CURRENT_TIME;
4845 btrfs_set_flag(inode, PREALLOC);
4846 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
4847 cur_offset > i_size_read(inode))
4848 btrfs_i_size_write(inode, cur_offset);
4849 ret = btrfs_update_inode(trans, root, inode);
4850 BUG_ON(ret);
4851 }
4852
4853 btrfs_end_transaction(trans, root);
4854 return ret;
4855}
4856
4857static long btrfs_fallocate(struct inode *inode, int mode,
4858 loff_t offset, loff_t len)
4859{
4860 u64 cur_offset;
4861 u64 last_byte;
4862 u64 alloc_start;
4863 u64 alloc_end;
4864 u64 alloc_hint = 0;
4865 u64 mask = BTRFS_I(inode)->root->sectorsize - 1;
4866 struct extent_map *em;
4867 int ret;
4868
4869 alloc_start = offset & ~mask;
4870 alloc_end = (offset + len + mask) & ~mask;
4871
4872 mutex_lock(&inode->i_mutex);
4873 if (alloc_start > inode->i_size) {
4874 ret = btrfs_cont_expand(inode, alloc_start);
4875 if (ret)
4876 goto out;
4877 }
4878
4879 while (1) {
4880 struct btrfs_ordered_extent *ordered;
4881 lock_extent(&BTRFS_I(inode)->io_tree, alloc_start,
4882 alloc_end - 1, GFP_NOFS);
4883 ordered = btrfs_lookup_first_ordered_extent(inode,
4884 alloc_end - 1);
4885 if (ordered &&
4886 ordered->file_offset + ordered->len > alloc_start &&
4887 ordered->file_offset < alloc_end) {
4888 btrfs_put_ordered_extent(ordered);
4889 unlock_extent(&BTRFS_I(inode)->io_tree,
4890 alloc_start, alloc_end - 1, GFP_NOFS);
4891 btrfs_wait_ordered_range(inode, alloc_start,
4892 alloc_end - alloc_start);
4893 } else {
4894 if (ordered)
4895 btrfs_put_ordered_extent(ordered);
4896 break;
4897 }
4898 }
4899
4900 cur_offset = alloc_start;
4901 while (1) {
4902 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
4903 alloc_end - cur_offset, 0);
4904 BUG_ON(IS_ERR(em) || !em);
4905 last_byte = min(extent_map_end(em), alloc_end);
4906 last_byte = (last_byte + mask) & ~mask;
4907 if (em->block_start == EXTENT_MAP_HOLE) {
4908 ret = prealloc_file_range(inode, cur_offset,
4909 last_byte, alloc_hint, mode);
4910 if (ret < 0) {
4911 free_extent_map(em);
4912 break;
4913 }
4914 }
4915 if (em->block_start <= EXTENT_MAP_LAST_BYTE)
4916 alloc_hint = em->block_start;
4917 free_extent_map(em);
4918
4919 cur_offset = last_byte;
4920 if (cur_offset >= alloc_end) {
4921 ret = 0;
4922 break;
4923 }
4924 }
4925 unlock_extent(&BTRFS_I(inode)->io_tree, alloc_start, alloc_end - 1,
4926 GFP_NOFS);
4927out:
4928 mutex_unlock(&inode->i_mutex);
4929 return ret;
4930}
4931
4932static int btrfs_set_page_dirty(struct page *page)
4933{
4934 return __set_page_dirty_nobuffers(page);
4935}
4936
4937static int btrfs_permission(struct inode *inode, int mask)
4938{
4939 if (btrfs_test_flag(inode, READONLY) && (mask & MAY_WRITE))
4940 return -EACCES;
4941 return generic_permission(inode, mask, btrfs_check_acl);
4942}
4943
4944static struct inode_operations btrfs_dir_inode_operations = {
4945 .getattr = btrfs_getattr,
4946 .lookup = btrfs_lookup,
4947 .create = btrfs_create,
4948 .unlink = btrfs_unlink,
4949 .link = btrfs_link,
4950 .mkdir = btrfs_mkdir,
4951 .rmdir = btrfs_rmdir,
4952 .rename = btrfs_rename,
4953 .symlink = btrfs_symlink,
4954 .setattr = btrfs_setattr,
4955 .mknod = btrfs_mknod,
4956 .setxattr = btrfs_setxattr,
4957 .getxattr = btrfs_getxattr,
4958 .listxattr = btrfs_listxattr,
4959 .removexattr = btrfs_removexattr,
4960 .permission = btrfs_permission,
4961};
4962static struct inode_operations btrfs_dir_ro_inode_operations = {
4963 .lookup = btrfs_lookup,
4964 .permission = btrfs_permission,
4965};
4966static struct file_operations btrfs_dir_file_operations = {
4967 .llseek = generic_file_llseek,
4968 .read = generic_read_dir,
4969 .readdir = btrfs_real_readdir,
4970 .unlocked_ioctl = btrfs_ioctl,
4971#ifdef CONFIG_COMPAT
4972 .compat_ioctl = btrfs_ioctl,
4973#endif
4974 .release = btrfs_release_file,
4975 .fsync = btrfs_sync_file,
4976};
4977
4978static struct extent_io_ops btrfs_extent_io_ops = {
4979 .fill_delalloc = run_delalloc_range,
4980 .submit_bio_hook = btrfs_submit_bio_hook,
4981 .merge_bio_hook = btrfs_merge_bio_hook,
4982 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
4983 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
4984 .writepage_start_hook = btrfs_writepage_start_hook,
4985 .readpage_io_failed_hook = btrfs_io_failed_hook,
4986 .set_bit_hook = btrfs_set_bit_hook,
4987 .clear_bit_hook = btrfs_clear_bit_hook,
4988};
4989
4990static struct address_space_operations btrfs_aops = {
4991 .readpage = btrfs_readpage,
4992 .writepage = btrfs_writepage,
4993 .writepages = btrfs_writepages,
4994 .readpages = btrfs_readpages,
4995 .sync_page = block_sync_page,
4996 .bmap = btrfs_bmap,
4997 .direct_IO = btrfs_direct_IO,
4998 .invalidatepage = btrfs_invalidatepage,
4999 .releasepage = btrfs_releasepage,
5000 .set_page_dirty = btrfs_set_page_dirty,
5001};
5002
5003static struct address_space_operations btrfs_symlink_aops = {
5004 .readpage = btrfs_readpage,
5005 .writepage = btrfs_writepage,
5006 .invalidatepage = btrfs_invalidatepage,
5007 .releasepage = btrfs_releasepage,
5008};
5009
5010static struct inode_operations btrfs_file_inode_operations = {
5011 .truncate = btrfs_truncate,
5012 .getattr = btrfs_getattr,
5013 .setattr = btrfs_setattr,
5014 .setxattr = btrfs_setxattr,
5015 .getxattr = btrfs_getxattr,
5016 .listxattr = btrfs_listxattr,
5017 .removexattr = btrfs_removexattr,
5018 .permission = btrfs_permission,
5019 .fallocate = btrfs_fallocate,
5020};
5021static struct inode_operations btrfs_special_inode_operations = {
5022 .getattr = btrfs_getattr,
5023 .setattr = btrfs_setattr,
5024 .permission = btrfs_permission,
5025 .setxattr = btrfs_setxattr,
5026 .getxattr = btrfs_getxattr,
5027 .listxattr = btrfs_listxattr,
5028 .removexattr = btrfs_removexattr,
5029};
5030static struct inode_operations btrfs_symlink_inode_operations = {
5031 .readlink = generic_readlink,
5032 .follow_link = page_follow_link_light,
5033 .put_link = page_put_link,
5034 .permission = btrfs_permission,
5035};
generated by cgit v1.2.2 (git 2.25.0) at 2025-12-11 02:49:10 -0500