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