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Btrfs: Add back file data checksumming
[deliverable/linux.git] / fs / btrfs / inode.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/buffer_head.h>
20 #include <linux/fs.h>
21 #include <linux/pagemap.h>
22 #include <linux/highmem.h>
23 #include <linux/time.h>
24 #include <linux/init.h>
25 #include <linux/string.h>
26 #include <linux/smp_lock.h>
27 #include <linux/backing-dev.h>
28 #include <linux/mpage.h>
29 #include <linux/swap.h>
30 #include <linux/writeback.h>
31 #include <linux/statfs.h>
32 #include <linux/compat.h>
33 #include <linux/bit_spinlock.h>
34 #include <linux/version.h>
35 #include "ctree.h"
36 #include "disk-io.h"
37 #include "transaction.h"
38 #include "btrfs_inode.h"
39 #include "ioctl.h"
40 #include "print-tree.h"
41
42 struct btrfs_iget_args {
43 u64 ino;
44 struct btrfs_root *root;
45 };
46
47 static struct inode_operations btrfs_dir_inode_operations;
48 static struct inode_operations btrfs_symlink_inode_operations;
49 static struct inode_operations btrfs_dir_ro_inode_operations;
50 static struct inode_operations btrfs_special_inode_operations;
51 static struct inode_operations btrfs_file_inode_operations;
52 static struct address_space_operations btrfs_aops;
53 static struct address_space_operations btrfs_symlink_aops;
54 static struct file_operations btrfs_dir_file_operations;
55 static struct extent_map_ops btrfs_extent_map_ops;
56
57 static struct kmem_cache *btrfs_inode_cachep;
58 struct kmem_cache *btrfs_trans_handle_cachep;
59 struct kmem_cache *btrfs_transaction_cachep;
60 struct kmem_cache *btrfs_bit_radix_cachep;
61 struct kmem_cache *btrfs_path_cachep;
62
63 #define S_SHIFT 12
64 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
65 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
66 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
67 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
68 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
69 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
70 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
71 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
72 };
73
74 static int run_delalloc_range(struct inode *inode, u64 start, u64 end)
75 {
76 struct btrfs_root *root = BTRFS_I(inode)->root;
77 struct btrfs_trans_handle *trans;
78 struct btrfs_key ins;
79 u64 alloc_hint = 0;
80 u64 num_bytes;
81 int ret;
82 u64 blocksize = root->sectorsize;
83
84 mutex_lock(&root->fs_info->fs_mutex);
85 trans = btrfs_start_transaction(root, 1);
86 btrfs_set_trans_block_group(trans, inode);
87 BUG_ON(!trans);
88 num_bytes = (end - start + blocksize) & ~(blocksize - 1);
89 ret = btrfs_drop_extents(trans, root, inode,
90 start, start + num_bytes, start, &alloc_hint);
91
92 ret = btrfs_alloc_extent(trans, root, inode->i_ino, num_bytes, 0,
93 alloc_hint, (u64)-1, &ins, 1);
94 if (ret) {
95 WARN_ON(1);
96 goto out;
97 }
98 ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
99 start, ins.objectid, ins.offset,
100 ins.offset);
101 out:
102 btrfs_end_transaction(trans, root);
103 mutex_unlock(&root->fs_info->fs_mutex);
104 return ret;
105 }
106
107 int btrfs_writepage_io_hook(struct page *page, u64 start, u64 end)
108 {
109 struct inode *inode = page->mapping->host;
110 struct btrfs_root *root = BTRFS_I(inode)->root;
111 struct btrfs_trans_handle *trans;
112 char *kaddr;
113 int ret;
114 u64 page_start = page->index << PAGE_CACHE_SHIFT;
115 size_t offset = start - page_start;
116
117 mutex_lock(&root->fs_info->fs_mutex);
118 trans = btrfs_start_transaction(root, 1);
119 btrfs_set_trans_block_group(trans, inode);
120 kaddr = kmap(page);
121 btrfs_csum_file_block(trans, root, inode->i_ino,
122 start, kaddr + offset, end - start + 1);
123 kunmap(page);
124 ret = btrfs_end_transaction(trans, root);
125 BUG_ON(ret);
126 mutex_unlock(&root->fs_info->fs_mutex);
127 return ret;
128 }
129
130 int btrfs_readpage_io_hook(struct page *page, u64 start, u64 end)
131 {
132 int ret = 0;
133 struct inode *inode = page->mapping->host;
134 struct btrfs_root *root = BTRFS_I(inode)->root;
135 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
136 struct btrfs_csum_item *item;
137 struct btrfs_path *path = NULL;
138 u32 csum;
139
140 mutex_lock(&root->fs_info->fs_mutex);
141 path = btrfs_alloc_path();
142 item = btrfs_lookup_csum(NULL, root, path, inode->i_ino, start, 0);
143 if (IS_ERR(item)) {
144 ret = PTR_ERR(item);
145 /* a csum that isn't present is a preallocated region. */
146 if (ret == -ENOENT || ret == -EFBIG)
147 ret = 0;
148 csum = 0;
149 goto out;
150 }
151 read_extent_buffer(path->nodes[0], &csum, (unsigned long)item,
152 BTRFS_CRC32_SIZE);
153 set_state_private(em_tree, start, csum);
154 out:
155 if (path)
156 btrfs_free_path(path);
157 mutex_unlock(&root->fs_info->fs_mutex);
158 return ret;
159 }
160
161 int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end)
162 {
163 size_t offset = start - (page->index << PAGE_CACHE_SHIFT);
164 struct inode *inode = page->mapping->host;
165 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
166 char *kaddr;
167 u64 private;
168 int ret;
169 struct btrfs_root *root = BTRFS_I(inode)->root;
170 u32 csum = ~(u32)0;
171
172 ret = get_state_private(em_tree, start, &private);
173 kaddr = kmap_atomic(page, KM_IRQ0);
174 if (ret) {
175 goto zeroit;
176 }
177 csum = btrfs_csum_data(root, kaddr + offset, csum, end - start + 1);
178 btrfs_csum_final(csum, (char *)&csum);
179 if (csum != private) {
180 goto zeroit;
181 }
182 kunmap_atomic(kaddr, KM_IRQ0);
183 return 0;
184
185 zeroit:
186 printk("btrfs csum failed ino %lu off %llu\n",
187 page->mapping->host->i_ino, (unsigned long long)start);
188 memset(kaddr + offset, 1, end - start + 1);
189 flush_dcache_page(page);
190 kunmap_atomic(kaddr, KM_IRQ0);
191 return 0;
192 }
193
194 void btrfs_read_locked_inode(struct inode *inode)
195 {
196 struct btrfs_path *path;
197 struct extent_buffer *leaf;
198 struct btrfs_inode_item *inode_item;
199 struct btrfs_inode_timespec *tspec;
200 struct btrfs_root *root = BTRFS_I(inode)->root;
201 struct btrfs_key location;
202 u64 alloc_group_block;
203 u32 rdev;
204 int ret;
205
206 path = btrfs_alloc_path();
207 BUG_ON(!path);
208 mutex_lock(&root->fs_info->fs_mutex);
209
210 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
211 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
212 if (ret)
213 goto make_bad;
214
215 leaf = path->nodes[0];
216 inode_item = btrfs_item_ptr(leaf, path->slots[0],
217 struct btrfs_inode_item);
218
219 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
220 inode->i_nlink = btrfs_inode_nlink(leaf, inode_item);
221 inode->i_uid = btrfs_inode_uid(leaf, inode_item);
222 inode->i_gid = btrfs_inode_gid(leaf, inode_item);
223 inode->i_size = btrfs_inode_size(leaf, inode_item);
224
225 tspec = btrfs_inode_atime(inode_item);
226 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
227 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
228
229 tspec = btrfs_inode_mtime(inode_item);
230 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
231 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
232
233 tspec = btrfs_inode_ctime(inode_item);
234 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
235 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
236
237 inode->i_blocks = btrfs_inode_nblocks(leaf, inode_item);
238 inode->i_generation = btrfs_inode_generation(leaf, inode_item);
239 inode->i_rdev = 0;
240 rdev = btrfs_inode_rdev(leaf, inode_item);
241
242 alloc_group_block = btrfs_inode_block_group(leaf, inode_item);
243 BTRFS_I(inode)->block_group = btrfs_lookup_block_group(root->fs_info,
244 alloc_group_block);
245
246 btrfs_free_path(path);
247 inode_item = NULL;
248
249 mutex_unlock(&root->fs_info->fs_mutex);
250
251 switch (inode->i_mode & S_IFMT) {
252 case S_IFREG:
253 inode->i_mapping->a_ops = &btrfs_aops;
254 BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
255 inode->i_fop = &btrfs_file_operations;
256 inode->i_op = &btrfs_file_inode_operations;
257 break;
258 case S_IFDIR:
259 inode->i_fop = &btrfs_dir_file_operations;
260 if (root == root->fs_info->tree_root)
261 inode->i_op = &btrfs_dir_ro_inode_operations;
262 else
263 inode->i_op = &btrfs_dir_inode_operations;
264 break;
265 case S_IFLNK:
266 inode->i_op = &btrfs_symlink_inode_operations;
267 inode->i_mapping->a_ops = &btrfs_symlink_aops;
268 break;
269 default:
270 init_special_inode(inode, inode->i_mode, rdev);
271 break;
272 }
273 return;
274
275 make_bad:
276 btrfs_release_path(root, path);
277 btrfs_free_path(path);
278 mutex_unlock(&root->fs_info->fs_mutex);
279 make_bad_inode(inode);
280 }
281
282 static void fill_inode_item(struct extent_buffer *leaf,
283 struct btrfs_inode_item *item,
284 struct inode *inode)
285 {
286 btrfs_set_inode_uid(leaf, item, inode->i_uid);
287 btrfs_set_inode_gid(leaf, item, inode->i_gid);
288 btrfs_set_inode_size(leaf, item, inode->i_size);
289 btrfs_set_inode_mode(leaf, item, inode->i_mode);
290 btrfs_set_inode_nlink(leaf, item, inode->i_nlink);
291
292 btrfs_set_timespec_sec(leaf, btrfs_inode_atime(item),
293 inode->i_atime.tv_sec);
294 btrfs_set_timespec_nsec(leaf, btrfs_inode_atime(item),
295 inode->i_atime.tv_nsec);
296
297 btrfs_set_timespec_sec(leaf, btrfs_inode_mtime(item),
298 inode->i_mtime.tv_sec);
299 btrfs_set_timespec_nsec(leaf, btrfs_inode_mtime(item),
300 inode->i_mtime.tv_nsec);
301
302 btrfs_set_timespec_sec(leaf, btrfs_inode_ctime(item),
303 inode->i_ctime.tv_sec);
304 btrfs_set_timespec_nsec(leaf, btrfs_inode_ctime(item),
305 inode->i_ctime.tv_nsec);
306
307 btrfs_set_inode_nblocks(leaf, item, inode->i_blocks);
308 btrfs_set_inode_generation(leaf, item, inode->i_generation);
309 btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
310 btrfs_set_inode_block_group(leaf, item,
311 BTRFS_I(inode)->block_group->key.objectid);
312 }
313
314 int btrfs_update_inode(struct btrfs_trans_handle *trans,
315 struct btrfs_root *root,
316 struct inode *inode)
317 {
318 struct btrfs_inode_item *inode_item;
319 struct btrfs_path *path;
320 struct extent_buffer *leaf;
321 int ret;
322
323 path = btrfs_alloc_path();
324 BUG_ON(!path);
325 ret = btrfs_lookup_inode(trans, root, path,
326 &BTRFS_I(inode)->location, 1);
327 if (ret) {
328 if (ret > 0)
329 ret = -ENOENT;
330 goto failed;
331 }
332
333 leaf = path->nodes[0];
334 inode_item = btrfs_item_ptr(leaf, path->slots[0],
335 struct btrfs_inode_item);
336
337 fill_inode_item(leaf, inode_item, inode);
338 btrfs_mark_buffer_dirty(leaf);
339 btrfs_set_inode_last_trans(trans, inode);
340 ret = 0;
341 failed:
342 btrfs_release_path(root, path);
343 btrfs_free_path(path);
344 return ret;
345 }
346
347
348 static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
349 struct btrfs_root *root,
350 struct inode *dir,
351 struct dentry *dentry)
352 {
353 struct btrfs_path *path;
354 const char *name = dentry->d_name.name;
355 int name_len = dentry->d_name.len;
356 int ret = 0;
357 struct extent_buffer *leaf;
358 struct btrfs_dir_item *di;
359 struct btrfs_key key;
360
361 path = btrfs_alloc_path();
362 if (!path) {
363 ret = -ENOMEM;
364 goto err;
365 }
366
367 di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
368 name, name_len, -1);
369 if (IS_ERR(di)) {
370 ret = PTR_ERR(di);
371 goto err;
372 }
373 if (!di) {
374 ret = -ENOENT;
375 goto err;
376 }
377 leaf = path->nodes[0];
378 btrfs_dir_item_key_to_cpu(leaf, di, &key);
379 ret = btrfs_delete_one_dir_name(trans, root, path, di);
380 if (ret)
381 goto err;
382 btrfs_release_path(root, path);
383
384 di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
385 key.objectid, name, name_len, -1);
386 if (IS_ERR(di)) {
387 ret = PTR_ERR(di);
388 goto err;
389 }
390 if (!di) {
391 ret = -ENOENT;
392 goto err;
393 }
394 ret = btrfs_delete_one_dir_name(trans, root, path, di);
395
396 dentry->d_inode->i_ctime = dir->i_ctime;
397 err:
398 btrfs_free_path(path);
399 if (!ret) {
400 dir->i_size -= name_len * 2;
401 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
402 btrfs_update_inode(trans, root, dir);
403 drop_nlink(dentry->d_inode);
404 ret = btrfs_update_inode(trans, root, dentry->d_inode);
405 dir->i_sb->s_dirt = 1;
406 }
407 return ret;
408 }
409
410 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
411 {
412 struct btrfs_root *root;
413 struct btrfs_trans_handle *trans;
414 int ret;
415 unsigned long nr;
416
417 root = BTRFS_I(dir)->root;
418 mutex_lock(&root->fs_info->fs_mutex);
419 trans = btrfs_start_transaction(root, 1);
420
421 btrfs_set_trans_block_group(trans, dir);
422 ret = btrfs_unlink_trans(trans, root, dir, dentry);
423 nr = trans->blocks_used;
424
425 btrfs_end_transaction(trans, root);
426 mutex_unlock(&root->fs_info->fs_mutex);
427 btrfs_btree_balance_dirty(root, nr);
428
429 return ret;
430 }
431
432 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
433 {
434 struct inode *inode = dentry->d_inode;
435 int err;
436 int ret;
437 struct btrfs_root *root = BTRFS_I(dir)->root;
438 struct btrfs_path *path;
439 struct btrfs_key key;
440 struct btrfs_trans_handle *trans;
441 struct btrfs_key found_key;
442 int found_type;
443 struct extent_buffer *leaf;
444 char *goodnames = "..";
445 unsigned long nr;
446
447 path = btrfs_alloc_path();
448 BUG_ON(!path);
449 mutex_lock(&root->fs_info->fs_mutex);
450 trans = btrfs_start_transaction(root, 1);
451
452 btrfs_set_trans_block_group(trans, dir);
453 key.objectid = inode->i_ino;
454 key.offset = (u64)-1;
455 key.type = (u8)-1;
456 while(1) {
457 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
458 if (ret < 0) {
459 err = ret;
460 goto out;
461 }
462 BUG_ON(ret == 0);
463 if (path->slots[0] == 0) {
464 err = -ENOENT;
465 goto out;
466 }
467 path->slots[0]--;
468 leaf = path->nodes[0];
469 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
470 found_type = btrfs_key_type(&found_key);
471 if (found_key.objectid != inode->i_ino) {
472 err = -ENOENT;
473 goto out;
474 }
475 if ((found_type != BTRFS_DIR_ITEM_KEY &&
476 found_type != BTRFS_DIR_INDEX_KEY) ||
477 (!btrfs_match_dir_item_name(root, path, goodnames, 2) &&
478 !btrfs_match_dir_item_name(root, path, goodnames, 1))) {
479 err = -ENOTEMPTY;
480 goto out;
481 }
482 ret = btrfs_del_item(trans, root, path);
483 BUG_ON(ret);
484
485 if (found_type == BTRFS_DIR_ITEM_KEY && found_key.offset == 1)
486 break;
487 btrfs_release_path(root, path);
488 }
489 ret = 0;
490 btrfs_release_path(root, path);
491
492 /* now the directory is empty */
493 err = btrfs_unlink_trans(trans, root, dir, dentry);
494 if (!err) {
495 inode->i_size = 0;
496 }
497 out:
498 btrfs_release_path(root, path);
499 btrfs_free_path(path);
500 mutex_unlock(&root->fs_info->fs_mutex);
501 nr = trans->blocks_used;
502 ret = btrfs_end_transaction(trans, root);
503 btrfs_btree_balance_dirty(root, nr);
504 if (ret && !err)
505 err = ret;
506 return err;
507 }
508
509 static int btrfs_free_inode(struct btrfs_trans_handle *trans,
510 struct btrfs_root *root,
511 struct inode *inode)
512 {
513 struct btrfs_path *path;
514 int ret;
515
516 clear_inode(inode);
517
518 path = btrfs_alloc_path();
519 BUG_ON(!path);
520 ret = btrfs_lookup_inode(trans, root, path,
521 &BTRFS_I(inode)->location, -1);
522 if (ret > 0)
523 ret = -ENOENT;
524 if (!ret)
525 ret = btrfs_del_item(trans, root, path);
526 btrfs_free_path(path);
527 return ret;
528 }
529
530 /*
531 * this can truncate away extent items, csum items and directory items.
532 * It starts at a high offset and removes keys until it can't find
533 * any higher than i_size.
534 *
535 * csum items that cross the new i_size are truncated to the new size
536 * as well.
537 */
538 static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
539 struct btrfs_root *root,
540 struct inode *inode)
541 {
542 int ret;
543 struct btrfs_path *path;
544 struct btrfs_key key;
545 struct btrfs_key found_key;
546 u32 found_type;
547 struct extent_buffer *leaf;
548 struct btrfs_file_extent_item *fi;
549 u64 extent_start = 0;
550 u64 extent_num_bytes = 0;
551 u64 item_end = 0;
552 int found_extent;
553 int del_item;
554
555 btrfs_drop_extent_cache(inode, inode->i_size, (u64)-1);
556 path = btrfs_alloc_path();
557 path->reada = -1;
558 BUG_ON(!path);
559
560 /* FIXME, add redo link to tree so we don't leak on crash */
561 key.objectid = inode->i_ino;
562 key.offset = (u64)-1;
563 key.type = (u8)-1;
564
565 while(1) {
566 btrfs_init_path(path);
567 fi = NULL;
568 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
569 if (ret < 0) {
570 goto error;
571 }
572 if (ret > 0) {
573 BUG_ON(path->slots[0] == 0);
574 path->slots[0]--;
575 }
576 leaf = path->nodes[0];
577 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
578 found_type = btrfs_key_type(&found_key);
579
580 if (found_key.objectid != inode->i_ino)
581 break;
582
583 if (found_type != BTRFS_CSUM_ITEM_KEY &&
584 found_type != BTRFS_DIR_ITEM_KEY &&
585 found_type != BTRFS_DIR_INDEX_KEY &&
586 found_type != BTRFS_EXTENT_DATA_KEY)
587 break;
588
589 item_end = found_key.offset;
590 if (found_type == BTRFS_EXTENT_DATA_KEY) {
591 fi = btrfs_item_ptr(leaf, path->slots[0],
592 struct btrfs_file_extent_item);
593 if (btrfs_file_extent_type(leaf, fi) !=
594 BTRFS_FILE_EXTENT_INLINE) {
595 item_end +=
596 btrfs_file_extent_num_bytes(leaf, fi);
597 }
598 }
599 if (found_type == BTRFS_CSUM_ITEM_KEY) {
600 ret = btrfs_csum_truncate(trans, root, path,
601 inode->i_size);
602 BUG_ON(ret);
603 }
604 if (item_end < inode->i_size) {
605 if (found_type == BTRFS_DIR_ITEM_KEY) {
606 found_type = BTRFS_INODE_ITEM_KEY;
607 } else if (found_type == BTRFS_EXTENT_ITEM_KEY) {
608 found_type = BTRFS_CSUM_ITEM_KEY;
609 } else if (found_type) {
610 found_type--;
611 } else {
612 break;
613 }
614 btrfs_set_key_type(&key, found_type);
615 continue;
616 }
617 if (found_key.offset >= inode->i_size)
618 del_item = 1;
619 else
620 del_item = 0;
621 found_extent = 0;
622
623 /* FIXME, shrink the extent if the ref count is only 1 */
624 if (found_type == BTRFS_EXTENT_DATA_KEY &&
625 btrfs_file_extent_type(leaf, fi) !=
626 BTRFS_FILE_EXTENT_INLINE) {
627 u64 num_dec;
628 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
629 if (!del_item) {
630 u64 orig_num_bytes =
631 btrfs_file_extent_num_bytes(leaf, fi);
632 extent_num_bytes = inode->i_size -
633 found_key.offset + root->sectorsize - 1;
634 btrfs_set_file_extent_num_bytes(leaf, fi,
635 extent_num_bytes);
636 num_dec = (orig_num_bytes -
637 extent_num_bytes) >> 9;
638 if (extent_start != 0) {
639 inode->i_blocks -= num_dec;
640 }
641 btrfs_mark_buffer_dirty(leaf);
642 } else {
643 extent_num_bytes =
644 btrfs_file_extent_disk_num_bytes(leaf,
645 fi);
646 /* FIXME blocksize != 4096 */
647 num_dec = btrfs_file_extent_num_bytes(leaf,
648 fi) >> 9;
649 if (extent_start != 0) {
650 found_extent = 1;
651 inode->i_blocks -= num_dec;
652 }
653 }
654 }
655 if (del_item) {
656 ret = btrfs_del_item(trans, root, path);
657 if (ret)
658 goto error;
659 } else {
660 break;
661 }
662 btrfs_release_path(root, path);
663 if (found_extent) {
664 ret = btrfs_free_extent(trans, root, extent_start,
665 extent_num_bytes, 0);
666 BUG_ON(ret);
667 }
668 }
669 ret = 0;
670 error:
671 btrfs_release_path(root, path);
672 btrfs_free_path(path);
673 inode->i_sb->s_dirt = 1;
674 return ret;
675 }
676
677 static int btrfs_cow_one_page(struct inode *inode, struct page *page,
678 size_t zero_start)
679 {
680 char *kaddr;
681 int ret = 0;
682 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
683 u64 page_start = page->index << PAGE_CACHE_SHIFT;
684 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
685
686 set_page_extent_mapped(page);
687
688 lock_extent(em_tree, page_start, page_end, GFP_NOFS);
689 set_extent_delalloc(&BTRFS_I(inode)->extent_tree, page_start,
690 page_end, GFP_NOFS);
691 if (zero_start != PAGE_CACHE_SIZE) {
692 kaddr = kmap(page);
693 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
694 flush_dcache_page(page);
695 kunmap(page);
696 }
697 set_page_dirty(page);
698 unlock_extent(em_tree, page_start, page_end, GFP_NOFS);
699
700 return ret;
701 }
702
703 /*
704 * taken from block_truncate_page, but does cow as it zeros out
705 * any bytes left in the last page in the file.
706 */
707 static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
708 {
709 struct inode *inode = mapping->host;
710 struct btrfs_root *root = BTRFS_I(inode)->root;
711 u32 blocksize = root->sectorsize;
712 pgoff_t index = from >> PAGE_CACHE_SHIFT;
713 unsigned offset = from & (PAGE_CACHE_SIZE-1);
714 struct page *page;
715 int ret = 0;
716 u64 page_start;
717
718 if ((offset & (blocksize - 1)) == 0)
719 goto out;
720
721 down_read(&root->snap_sem);
722 ret = -ENOMEM;
723 page = grab_cache_page(mapping, index);
724 if (!page)
725 goto out;
726 if (!PageUptodate(page)) {
727 ret = btrfs_readpage(NULL, page);
728 lock_page(page);
729 if (!PageUptodate(page)) {
730 ret = -EIO;
731 goto out;
732 }
733 }
734 page_start = page->index << PAGE_CACHE_SHIFT;
735
736 ret = btrfs_cow_one_page(inode, page, offset);
737
738 unlock_page(page);
739 page_cache_release(page);
740 up_read(&BTRFS_I(inode)->root->snap_sem);
741 out:
742 return ret;
743 }
744
745 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
746 {
747 struct inode *inode = dentry->d_inode;
748 int err;
749
750 err = inode_change_ok(inode, attr);
751 if (err)
752 return err;
753
754 if (S_ISREG(inode->i_mode) &&
755 attr->ia_valid & ATTR_SIZE && attr->ia_size > inode->i_size) {
756 struct btrfs_trans_handle *trans;
757 struct btrfs_root *root = BTRFS_I(inode)->root;
758 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
759
760 u64 mask = root->sectorsize - 1;
761 u64 pos = (inode->i_size + mask) & ~mask;
762 u64 block_end = attr->ia_size | mask;
763 u64 hole_size;
764 u64 alloc_hint;
765
766 if (attr->ia_size <= pos)
767 goto out;
768
769 btrfs_truncate_page(inode->i_mapping, inode->i_size);
770
771 lock_extent(em_tree, pos, block_end, GFP_NOFS);
772 hole_size = (attr->ia_size - pos + mask) & ~mask;
773
774 mutex_lock(&root->fs_info->fs_mutex);
775 trans = btrfs_start_transaction(root, 1);
776 btrfs_set_trans_block_group(trans, inode);
777 err = btrfs_drop_extents(trans, root, inode,
778 pos, pos + hole_size, pos,
779 &alloc_hint);
780
781 err = btrfs_insert_file_extent(trans, root, inode->i_ino,
782 pos, 0, 0, hole_size);
783 btrfs_end_transaction(trans, root);
784 mutex_unlock(&root->fs_info->fs_mutex);
785 unlock_extent(em_tree, pos, block_end, GFP_NOFS);
786 if (err)
787 return err;
788 }
789 out:
790 err = inode_setattr(inode, attr);
791
792 return err;
793 }
794 void btrfs_delete_inode(struct inode *inode)
795 {
796 struct btrfs_trans_handle *trans;
797 struct btrfs_root *root = BTRFS_I(inode)->root;
798 unsigned long nr;
799 int ret;
800
801 truncate_inode_pages(&inode->i_data, 0);
802 if (is_bad_inode(inode)) {
803 goto no_delete;
804 }
805
806 inode->i_size = 0;
807 mutex_lock(&root->fs_info->fs_mutex);
808 trans = btrfs_start_transaction(root, 1);
809
810 btrfs_set_trans_block_group(trans, inode);
811 ret = btrfs_truncate_in_trans(trans, root, inode);
812 if (ret)
813 goto no_delete_lock;
814 ret = btrfs_free_inode(trans, root, inode);
815 if (ret)
816 goto no_delete_lock;
817 nr = trans->blocks_used;
818
819 btrfs_end_transaction(trans, root);
820 mutex_unlock(&root->fs_info->fs_mutex);
821 btrfs_btree_balance_dirty(root, nr);
822 return;
823
824 no_delete_lock:
825 nr = trans->blocks_used;
826 btrfs_end_transaction(trans, root);
827 mutex_unlock(&root->fs_info->fs_mutex);
828 btrfs_btree_balance_dirty(root, nr);
829 no_delete:
830 clear_inode(inode);
831 }
832
833 /*
834 * this returns the key found in the dir entry in the location pointer.
835 * If no dir entries were found, location->objectid is 0.
836 */
837 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
838 struct btrfs_key *location)
839 {
840 const char *name = dentry->d_name.name;
841 int namelen = dentry->d_name.len;
842 struct btrfs_dir_item *di;
843 struct btrfs_path *path;
844 struct btrfs_root *root = BTRFS_I(dir)->root;
845 int ret;
846
847 path = btrfs_alloc_path();
848 BUG_ON(!path);
849 di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
850 namelen, 0);
851 if (!di || IS_ERR(di)) {
852 location->objectid = 0;
853 ret = 0;
854 goto out;
855 }
856 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
857 out:
858 btrfs_release_path(root, path);
859 btrfs_free_path(path);
860 return ret;
861 }
862
863 /*
864 * when we hit a tree root in a directory, the btrfs part of the inode
865 * needs to be changed to reflect the root directory of the tree root. This
866 * is kind of like crossing a mount point.
867 */
868 static int fixup_tree_root_location(struct btrfs_root *root,
869 struct btrfs_key *location,
870 struct btrfs_root **sub_root,
871 struct dentry *dentry)
872 {
873 struct btrfs_path *path;
874 struct btrfs_root_item *ri;
875
876 if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY)
877 return 0;
878 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
879 return 0;
880
881 path = btrfs_alloc_path();
882 BUG_ON(!path);
883 mutex_lock(&root->fs_info->fs_mutex);
884
885 *sub_root = btrfs_read_fs_root(root->fs_info, location,
886 dentry->d_name.name,
887 dentry->d_name.len);
888 if (IS_ERR(*sub_root))
889 return PTR_ERR(*sub_root);
890
891 ri = &(*sub_root)->root_item;
892 location->objectid = btrfs_root_dirid(ri);
893 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
894 location->offset = 0;
895
896 btrfs_free_path(path);
897 mutex_unlock(&root->fs_info->fs_mutex);
898 return 0;
899 }
900
901 static int btrfs_init_locked_inode(struct inode *inode, void *p)
902 {
903 struct btrfs_iget_args *args = p;
904 inode->i_ino = args->ino;
905 BTRFS_I(inode)->root = args->root;
906 extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
907 inode->i_mapping, GFP_NOFS);
908 return 0;
909 }
910
911 static int btrfs_find_actor(struct inode *inode, void *opaque)
912 {
913 struct btrfs_iget_args *args = opaque;
914 return (args->ino == inode->i_ino &&
915 args->root == BTRFS_I(inode)->root);
916 }
917
918 struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
919 struct btrfs_root *root)
920 {
921 struct inode *inode;
922 struct btrfs_iget_args args;
923 args.ino = objectid;
924 args.root = root;
925
926 inode = iget5_locked(s, objectid, btrfs_find_actor,
927 btrfs_init_locked_inode,
928 (void *)&args);
929 return inode;
930 }
931
932 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
933 struct nameidata *nd)
934 {
935 struct inode * inode;
936 struct btrfs_inode *bi = BTRFS_I(dir);
937 struct btrfs_root *root = bi->root;
938 struct btrfs_root *sub_root = root;
939 struct btrfs_key location;
940 int ret;
941
942 if (dentry->d_name.len > BTRFS_NAME_LEN)
943 return ERR_PTR(-ENAMETOOLONG);
944
945 mutex_lock(&root->fs_info->fs_mutex);
946 ret = btrfs_inode_by_name(dir, dentry, &location);
947 mutex_unlock(&root->fs_info->fs_mutex);
948
949 if (ret < 0)
950 return ERR_PTR(ret);
951
952 inode = NULL;
953 if (location.objectid) {
954 ret = fixup_tree_root_location(root, &location, &sub_root,
955 dentry);
956 if (ret < 0)
957 return ERR_PTR(ret);
958 if (ret > 0)
959 return ERR_PTR(-ENOENT);
960 inode = btrfs_iget_locked(dir->i_sb, location.objectid,
961 sub_root);
962 if (!inode)
963 return ERR_PTR(-EACCES);
964 if (inode->i_state & I_NEW) {
965 /* the inode and parent dir are two different roots */
966 if (sub_root != root) {
967 igrab(inode);
968 sub_root->inode = inode;
969 }
970 BTRFS_I(inode)->root = sub_root;
971 memcpy(&BTRFS_I(inode)->location, &location,
972 sizeof(location));
973 btrfs_read_locked_inode(inode);
974 unlock_new_inode(inode);
975 }
976 }
977 return d_splice_alias(inode, dentry);
978 }
979
980 static unsigned char btrfs_filetype_table[] = {
981 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
982 };
983
984 static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
985 {
986 struct inode *inode = filp->f_path.dentry->d_inode;
987 struct btrfs_root *root = BTRFS_I(inode)->root;
988 struct btrfs_item *item;
989 struct btrfs_dir_item *di;
990 struct btrfs_key key;
991 struct btrfs_key found_key;
992 struct btrfs_path *path;
993 int ret;
994 u32 nritems;
995 struct extent_buffer *leaf;
996 int slot;
997 int advance;
998 unsigned char d_type;
999 int over = 0;
1000 u32 di_cur;
1001 u32 di_total;
1002 u32 di_len;
1003 int key_type = BTRFS_DIR_INDEX_KEY;
1004 char tmp_name[32];
1005 char *name_ptr;
1006 int name_len;
1007
1008 /* FIXME, use a real flag for deciding about the key type */
1009 if (root->fs_info->tree_root == root)
1010 key_type = BTRFS_DIR_ITEM_KEY;
1011
1012 mutex_lock(&root->fs_info->fs_mutex);
1013 key.objectid = inode->i_ino;
1014 btrfs_set_key_type(&key, key_type);
1015 key.offset = filp->f_pos;
1016
1017 path = btrfs_alloc_path();
1018 path->reada = 2;
1019 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1020 if (ret < 0)
1021 goto err;
1022 advance = 0;
1023 while(1) {
1024 leaf = path->nodes[0];
1025 nritems = btrfs_header_nritems(leaf);
1026 slot = path->slots[0];
1027 if (advance || slot >= nritems) {
1028 if (slot >= nritems -1) {
1029 ret = btrfs_next_leaf(root, path);
1030 if (ret)
1031 break;
1032 leaf = path->nodes[0];
1033 nritems = btrfs_header_nritems(leaf);
1034 slot = path->slots[0];
1035 } else {
1036 slot++;
1037 path->slots[0]++;
1038 }
1039 }
1040 advance = 1;
1041 item = btrfs_item_nr(leaf, slot);
1042 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1043
1044 if (found_key.objectid != key.objectid)
1045 break;
1046 if (btrfs_key_type(&found_key) != key_type)
1047 break;
1048 if (found_key.offset < filp->f_pos)
1049 continue;
1050
1051 filp->f_pos = found_key.offset;
1052 advance = 1;
1053 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
1054 di_cur = 0;
1055 di_total = btrfs_item_size(leaf, item);
1056 while(di_cur < di_total) {
1057 struct btrfs_key location;
1058
1059 name_len = btrfs_dir_name_len(leaf, di);
1060 if (name_len < 32) {
1061 name_ptr = tmp_name;
1062 } else {
1063 name_ptr = kmalloc(name_len, GFP_NOFS);
1064 BUG_ON(!name_ptr);
1065 }
1066 read_extent_buffer(leaf, name_ptr,
1067 (unsigned long)(di + 1), name_len);
1068
1069 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
1070 btrfs_dir_item_key_to_cpu(leaf, di, &location);
1071
1072 over = filldir(dirent, name_ptr, name_len,
1073 found_key.offset,
1074 location.objectid,
1075 d_type);
1076
1077 if (name_ptr != tmp_name)
1078 kfree(name_ptr);
1079
1080 if (over)
1081 goto nopos;
1082 di_len = btrfs_dir_name_len(leaf, di) + sizeof(*di);
1083 di_cur += di_len;
1084 di = (struct btrfs_dir_item *)((char *)di + di_len);
1085 }
1086 }
1087 filp->f_pos++;
1088 nopos:
1089 ret = 0;
1090 err:
1091 btrfs_release_path(root, path);
1092 btrfs_free_path(path);
1093 mutex_unlock(&root->fs_info->fs_mutex);
1094 return ret;
1095 }
1096
1097 int btrfs_write_inode(struct inode *inode, int wait)
1098 {
1099 struct btrfs_root *root = BTRFS_I(inode)->root;
1100 struct btrfs_trans_handle *trans;
1101 int ret = 0;
1102
1103 if (wait) {
1104 mutex_lock(&root->fs_info->fs_mutex);
1105 trans = btrfs_start_transaction(root, 1);
1106 btrfs_set_trans_block_group(trans, inode);
1107 ret = btrfs_commit_transaction(trans, root);
1108 mutex_unlock(&root->fs_info->fs_mutex);
1109 }
1110 return ret;
1111 }
1112
1113 /*
1114 * This is somewhat expensive, updating the tree every time the
1115 * inode changes. But, it is most likely to find the inode in cache.
1116 * FIXME, needs more benchmarking...there are no reasons other than performance
1117 * to keep or drop this code.
1118 */
1119 void btrfs_dirty_inode(struct inode *inode)
1120 {
1121 struct btrfs_root *root = BTRFS_I(inode)->root;
1122 struct btrfs_trans_handle *trans;
1123
1124 mutex_lock(&root->fs_info->fs_mutex);
1125 trans = btrfs_start_transaction(root, 1);
1126 btrfs_set_trans_block_group(trans, inode);
1127 btrfs_update_inode(trans, root, inode);
1128 btrfs_end_transaction(trans, root);
1129 mutex_unlock(&root->fs_info->fs_mutex);
1130 }
1131
1132 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
1133 struct btrfs_root *root,
1134 u64 objectid,
1135 struct btrfs_block_group_cache *group,
1136 int mode)
1137 {
1138 struct inode *inode;
1139 struct btrfs_inode_item *inode_item;
1140 struct btrfs_key *location;
1141 struct btrfs_path *path;
1142 int ret;
1143 int owner;
1144
1145 path = btrfs_alloc_path();
1146 BUG_ON(!path);
1147
1148 inode = new_inode(root->fs_info->sb);
1149 if (!inode)
1150 return ERR_PTR(-ENOMEM);
1151
1152 extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
1153 inode->i_mapping, GFP_NOFS);
1154 BTRFS_I(inode)->root = root;
1155
1156 if (mode & S_IFDIR)
1157 owner = 0;
1158 else
1159 owner = 1;
1160 group = btrfs_find_block_group(root, group, 0, 0, owner);
1161 BTRFS_I(inode)->block_group = group;
1162
1163 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
1164 if (ret)
1165 goto fail;
1166
1167 inode->i_uid = current->fsuid;
1168 inode->i_gid = current->fsgid;
1169 inode->i_mode = mode;
1170 inode->i_ino = objectid;
1171 inode->i_blocks = 0;
1172 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1173 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1174 struct btrfs_inode_item);
1175 fill_inode_item(path->nodes[0], inode_item, inode);
1176 btrfs_mark_buffer_dirty(path->nodes[0]);
1177 btrfs_free_path(path);
1178
1179 location = &BTRFS_I(inode)->location;
1180 location->objectid = objectid;
1181 location->offset = 0;
1182 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
1183
1184 insert_inode_hash(inode);
1185 return inode;
1186 fail:
1187 btrfs_free_path(path);
1188 return ERR_PTR(ret);
1189 }
1190
1191 static inline u8 btrfs_inode_type(struct inode *inode)
1192 {
1193 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
1194 }
1195
1196 static int btrfs_add_link(struct btrfs_trans_handle *trans,
1197 struct dentry *dentry, struct inode *inode)
1198 {
1199 int ret;
1200 struct btrfs_key key;
1201 struct btrfs_root *root = BTRFS_I(dentry->d_parent->d_inode)->root;
1202 struct inode *parent_inode;
1203
1204 key.objectid = inode->i_ino;
1205 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
1206 key.offset = 0;
1207
1208 ret = btrfs_insert_dir_item(trans, root,
1209 dentry->d_name.name, dentry->d_name.len,
1210 dentry->d_parent->d_inode->i_ino,
1211 &key, btrfs_inode_type(inode));
1212 if (ret == 0) {
1213 parent_inode = dentry->d_parent->d_inode;
1214 parent_inode->i_size += dentry->d_name.len * 2;
1215 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
1216 ret = btrfs_update_inode(trans, root,
1217 dentry->d_parent->d_inode);
1218 }
1219 return ret;
1220 }
1221
1222 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
1223 struct dentry *dentry, struct inode *inode)
1224 {
1225 int err = btrfs_add_link(trans, dentry, inode);
1226 if (!err) {
1227 d_instantiate(dentry, inode);
1228 return 0;
1229 }
1230 if (err > 0)
1231 err = -EEXIST;
1232 return err;
1233 }
1234
1235 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
1236 int mode, dev_t rdev)
1237 {
1238 struct btrfs_trans_handle *trans;
1239 struct btrfs_root *root = BTRFS_I(dir)->root;
1240 struct inode *inode;
1241 int err;
1242 int drop_inode = 0;
1243 u64 objectid;
1244 unsigned long nr;
1245
1246 if (!new_valid_dev(rdev))
1247 return -EINVAL;
1248
1249 mutex_lock(&root->fs_info->fs_mutex);
1250 trans = btrfs_start_transaction(root, 1);
1251 btrfs_set_trans_block_group(trans, dir);
1252
1253 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1254 if (err) {
1255 err = -ENOSPC;
1256 goto out_unlock;
1257 }
1258
1259 inode = btrfs_new_inode(trans, root, objectid,
1260 BTRFS_I(dir)->block_group, mode);
1261 err = PTR_ERR(inode);
1262 if (IS_ERR(inode))
1263 goto out_unlock;
1264
1265 btrfs_set_trans_block_group(trans, inode);
1266 err = btrfs_add_nondir(trans, dentry, inode);
1267 if (err)
1268 drop_inode = 1;
1269 else {
1270 inode->i_op = &btrfs_special_inode_operations;
1271 init_special_inode(inode, inode->i_mode, rdev);
1272 btrfs_update_inode(trans, root, inode);
1273 }
1274 dir->i_sb->s_dirt = 1;
1275 btrfs_update_inode_block_group(trans, inode);
1276 btrfs_update_inode_block_group(trans, dir);
1277 out_unlock:
1278 nr = trans->blocks_used;
1279 btrfs_end_transaction(trans, root);
1280 mutex_unlock(&root->fs_info->fs_mutex);
1281
1282 if (drop_inode) {
1283 inode_dec_link_count(inode);
1284 iput(inode);
1285 }
1286 btrfs_btree_balance_dirty(root, nr);
1287 return err;
1288 }
1289
1290 static int btrfs_create(struct inode *dir, struct dentry *dentry,
1291 int mode, struct nameidata *nd)
1292 {
1293 struct btrfs_trans_handle *trans;
1294 struct btrfs_root *root = BTRFS_I(dir)->root;
1295 struct inode *inode;
1296 int err;
1297 int drop_inode = 0;
1298 unsigned long nr;
1299 u64 objectid;
1300
1301 mutex_lock(&root->fs_info->fs_mutex);
1302 trans = btrfs_start_transaction(root, 1);
1303 btrfs_set_trans_block_group(trans, dir);
1304
1305 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1306 if (err) {
1307 err = -ENOSPC;
1308 goto out_unlock;
1309 }
1310
1311 inode = btrfs_new_inode(trans, root, objectid,
1312 BTRFS_I(dir)->block_group, mode);
1313 err = PTR_ERR(inode);
1314 if (IS_ERR(inode))
1315 goto out_unlock;
1316
1317 btrfs_set_trans_block_group(trans, inode);
1318 err = btrfs_add_nondir(trans, dentry, inode);
1319 if (err)
1320 drop_inode = 1;
1321 else {
1322 inode->i_mapping->a_ops = &btrfs_aops;
1323 inode->i_fop = &btrfs_file_operations;
1324 inode->i_op = &btrfs_file_inode_operations;
1325 extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
1326 inode->i_mapping, GFP_NOFS);
1327 BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
1328 }
1329 dir->i_sb->s_dirt = 1;
1330 btrfs_update_inode_block_group(trans, inode);
1331 btrfs_update_inode_block_group(trans, dir);
1332 out_unlock:
1333 nr = trans->blocks_used;
1334 btrfs_end_transaction(trans, root);
1335 mutex_unlock(&root->fs_info->fs_mutex);
1336
1337 if (drop_inode) {
1338 inode_dec_link_count(inode);
1339 iput(inode);
1340 }
1341 btrfs_btree_balance_dirty(root, nr);
1342 return err;
1343 }
1344
1345 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
1346 struct dentry *dentry)
1347 {
1348 struct btrfs_trans_handle *trans;
1349 struct btrfs_root *root = BTRFS_I(dir)->root;
1350 struct inode *inode = old_dentry->d_inode;
1351 unsigned long nr;
1352 int err;
1353 int drop_inode = 0;
1354
1355 if (inode->i_nlink == 0)
1356 return -ENOENT;
1357
1358 inc_nlink(inode);
1359 mutex_lock(&root->fs_info->fs_mutex);
1360 trans = btrfs_start_transaction(root, 1);
1361
1362 btrfs_set_trans_block_group(trans, dir);
1363 atomic_inc(&inode->i_count);
1364 err = btrfs_add_nondir(trans, dentry, inode);
1365
1366 if (err)
1367 drop_inode = 1;
1368
1369 dir->i_sb->s_dirt = 1;
1370 btrfs_update_inode_block_group(trans, dir);
1371 err = btrfs_update_inode(trans, root, inode);
1372
1373 if (err)
1374 drop_inode = 1;
1375
1376 nr = trans->blocks_used;
1377 btrfs_end_transaction(trans, root);
1378 mutex_unlock(&root->fs_info->fs_mutex);
1379
1380 if (drop_inode) {
1381 inode_dec_link_count(inode);
1382 iput(inode);
1383 }
1384 btrfs_btree_balance_dirty(root, nr);
1385 return err;
1386 }
1387
1388 static int btrfs_make_empty_dir(struct btrfs_trans_handle *trans,
1389 struct btrfs_root *root,
1390 u64 objectid, u64 dirid)
1391 {
1392 int ret;
1393 char buf[2];
1394 struct btrfs_key key;
1395
1396 buf[0] = '.';
1397 buf[1] = '.';
1398
1399 key.objectid = objectid;
1400 key.offset = 0;
1401 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
1402
1403 ret = btrfs_insert_dir_item(trans, root, buf, 1, objectid,
1404 &key, BTRFS_FT_DIR);
1405 if (ret)
1406 goto error;
1407
1408 key.objectid = dirid;
1409 ret = btrfs_insert_dir_item(trans, root, buf, 2, objectid,
1410 &key, BTRFS_FT_DIR);
1411 if (ret)
1412 goto error;
1413 error:
1414 return ret;
1415 }
1416
1417 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1418 {
1419 struct inode *inode;
1420 struct btrfs_trans_handle *trans;
1421 struct btrfs_root *root = BTRFS_I(dir)->root;
1422 int err = 0;
1423 int drop_on_err = 0;
1424 u64 objectid;
1425 unsigned long nr = 1;
1426
1427 mutex_lock(&root->fs_info->fs_mutex);
1428 trans = btrfs_start_transaction(root, 1);
1429 btrfs_set_trans_block_group(trans, dir);
1430
1431 if (IS_ERR(trans)) {
1432 err = PTR_ERR(trans);
1433 goto out_unlock;
1434 }
1435
1436 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1437 if (err) {
1438 err = -ENOSPC;
1439 goto out_unlock;
1440 }
1441
1442 inode = btrfs_new_inode(trans, root, objectid,
1443 BTRFS_I(dir)->block_group, S_IFDIR | mode);
1444 if (IS_ERR(inode)) {
1445 err = PTR_ERR(inode);
1446 goto out_fail;
1447 }
1448
1449 drop_on_err = 1;
1450 inode->i_op = &btrfs_dir_inode_operations;
1451 inode->i_fop = &btrfs_dir_file_operations;
1452 btrfs_set_trans_block_group(trans, inode);
1453
1454 err = btrfs_make_empty_dir(trans, root, inode->i_ino, dir->i_ino);
1455 if (err)
1456 goto out_fail;
1457
1458 inode->i_size = 6;
1459 err = btrfs_update_inode(trans, root, inode);
1460 if (err)
1461 goto out_fail;
1462
1463 err = btrfs_add_link(trans, dentry, inode);
1464 if (err)
1465 goto out_fail;
1466
1467 d_instantiate(dentry, inode);
1468 drop_on_err = 0;
1469 dir->i_sb->s_dirt = 1;
1470 btrfs_update_inode_block_group(trans, inode);
1471 btrfs_update_inode_block_group(trans, dir);
1472
1473 out_fail:
1474 nr = trans->blocks_used;
1475 btrfs_end_transaction(trans, root);
1476
1477 out_unlock:
1478 mutex_unlock(&root->fs_info->fs_mutex);
1479 if (drop_on_err)
1480 iput(inode);
1481 btrfs_btree_balance_dirty(root, nr);
1482 return err;
1483 }
1484
1485 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
1486 size_t page_offset, u64 start, u64 end,
1487 int create)
1488 {
1489 int ret;
1490 int err = 0;
1491 u64 bytenr;
1492 u64 extent_start = 0;
1493 u64 extent_end = 0;
1494 u64 objectid = inode->i_ino;
1495 u32 found_type;
1496 int failed_insert = 0;
1497 struct btrfs_path *path;
1498 struct btrfs_root *root = BTRFS_I(inode)->root;
1499 struct btrfs_file_extent_item *item;
1500 struct extent_buffer *leaf;
1501 struct btrfs_key found_key;
1502 struct extent_map *em = NULL;
1503 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1504 struct btrfs_trans_handle *trans = NULL;
1505
1506 path = btrfs_alloc_path();
1507 BUG_ON(!path);
1508 mutex_lock(&root->fs_info->fs_mutex);
1509
1510 again:
1511 em = lookup_extent_mapping(em_tree, start, end);
1512 if (em) {
1513 goto out;
1514 }
1515 if (!em) {
1516 em = alloc_extent_map(GFP_NOFS);
1517 if (!em) {
1518 err = -ENOMEM;
1519 goto out;
1520 }
1521 em->start = EXTENT_MAP_HOLE;
1522 em->end = EXTENT_MAP_HOLE;
1523 }
1524 em->bdev = inode->i_sb->s_bdev;
1525 ret = btrfs_lookup_file_extent(NULL, root, path,
1526 objectid, start, 0);
1527 if (ret < 0) {
1528 err = ret;
1529 goto out;
1530 }
1531
1532 if (ret != 0) {
1533 if (path->slots[0] == 0)
1534 goto not_found;
1535 path->slots[0]--;
1536 }
1537
1538 leaf = path->nodes[0];
1539 item = btrfs_item_ptr(leaf, path->slots[0],
1540 struct btrfs_file_extent_item);
1541 /* are we inside the extent that was found? */
1542 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1543 found_type = btrfs_key_type(&found_key);
1544 if (found_key.objectid != objectid ||
1545 found_type != BTRFS_EXTENT_DATA_KEY) {
1546 goto not_found;
1547 }
1548
1549 found_type = btrfs_file_extent_type(leaf, item);
1550 extent_start = found_key.offset;
1551 if (found_type == BTRFS_FILE_EXTENT_REG) {
1552 extent_end = extent_start +
1553 btrfs_file_extent_num_bytes(leaf, item);
1554 err = 0;
1555 if (start < extent_start || start >= extent_end) {
1556 em->start = start;
1557 if (start < extent_start) {
1558 if (end < extent_start)
1559 goto not_found;
1560 em->end = extent_end - 1;
1561 } else {
1562 em->end = end;
1563 }
1564 goto not_found_em;
1565 }
1566 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
1567 if (bytenr == 0) {
1568 em->start = extent_start;
1569 em->end = extent_end - 1;
1570 em->block_start = EXTENT_MAP_HOLE;
1571 em->block_end = EXTENT_MAP_HOLE;
1572 goto insert;
1573 }
1574 bytenr += btrfs_file_extent_offset(leaf, item);
1575 em->block_start = bytenr;
1576 em->block_end = em->block_start +
1577 btrfs_file_extent_num_bytes(leaf, item) - 1;
1578 em->start = extent_start;
1579 em->end = extent_end - 1;
1580 goto insert;
1581 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
1582 unsigned long ptr;
1583 char *map;
1584 size_t size;
1585 size_t extent_offset;
1586 size_t copy_size;
1587
1588 size = btrfs_file_extent_inline_len(leaf, btrfs_item_nr(leaf,
1589 path->slots[0]));
1590
1591 extent_end = (extent_start + size) |
1592 ((u64)root->sectorsize - 1);
1593 if (start < extent_start || start >= extent_end) {
1594 em->start = start;
1595 if (start < extent_start) {
1596 if (end < extent_start)
1597 goto not_found;
1598 em->end = extent_end;
1599 } else {
1600 em->end = end;
1601 }
1602 goto not_found_em;
1603 }
1604
1605 extent_offset = (page->index << PAGE_CACHE_SHIFT) -
1606 extent_start;
1607 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
1608 map = kmap(page);
1609 copy_size = min(PAGE_CACHE_SIZE - page_offset,
1610 size - extent_offset);
1611
1612 em->block_start = EXTENT_MAP_INLINE;
1613 em->block_end = EXTENT_MAP_INLINE;
1614 em->start = extent_start + extent_offset;
1615 em->end = (em->start + copy_size -1) |
1616 ((u64)root->sectorsize -1);
1617
1618 if (!page) {
1619 goto insert;
1620 }
1621
1622 read_extent_buffer(leaf, map + page_offset, ptr, copy_size);
1623 /*
1624 memset(map + page_offset + copy_size, 0,
1625 PAGE_CACHE_SIZE - copy_size - page_offset);
1626 */
1627 flush_dcache_page(page);
1628 kunmap(page);
1629 set_extent_uptodate(em_tree, em->start, em->end, GFP_NOFS);
1630 goto insert;
1631 } else {
1632 printk("unkknown found_type %d\n", found_type);
1633 WARN_ON(1);
1634 }
1635 not_found:
1636 em->start = start;
1637 em->end = end;
1638 not_found_em:
1639 em->block_start = EXTENT_MAP_HOLE;
1640 em->block_end = EXTENT_MAP_HOLE;
1641 insert:
1642 btrfs_release_path(root, path);
1643 if (em->start > start || em->end < start) {
1644 printk("bad extent! em: [%Lu %Lu] passed [%Lu %Lu]\n", em->start, em->end, start, end);
1645 err = -EIO;
1646 goto out;
1647 }
1648 ret = add_extent_mapping(em_tree, em);
1649 if (ret == -EEXIST) {
1650 free_extent_map(em);
1651 em = NULL;
1652 failed_insert++;
1653 if (failed_insert > 5) {
1654 printk("failing to insert %Lu %Lu\n", start, end);
1655 err = -EIO;
1656 goto out;
1657 }
1658 goto again;
1659 }
1660 err = 0;
1661 out:
1662 btrfs_free_path(path);
1663 if (trans) {
1664 ret = btrfs_end_transaction(trans, root);
1665 if (!err)
1666 err = ret;
1667 }
1668 mutex_unlock(&root->fs_info->fs_mutex);
1669 if (err) {
1670 free_extent_map(em);
1671 WARN_ON(1);
1672 return ERR_PTR(err);
1673 }
1674 return em;
1675 }
1676
1677 static sector_t btrfs_bmap(struct address_space *mapping, sector_t iblock)
1678 {
1679 return extent_bmap(mapping, iblock, btrfs_get_extent);
1680 }
1681
1682 static int btrfs_prepare_write(struct file *file, struct page *page,
1683 unsigned from, unsigned to)
1684 {
1685 return extent_prepare_write(&BTRFS_I(page->mapping->host)->extent_tree,
1686 page->mapping->host, page, from, to,
1687 btrfs_get_extent);
1688 }
1689
1690 int btrfs_readpage(struct file *file, struct page *page)
1691 {
1692 struct extent_map_tree *tree;
1693 tree = &BTRFS_I(page->mapping->host)->extent_tree;
1694 return extent_read_full_page(tree, page, btrfs_get_extent);
1695 }
1696 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
1697 {
1698 struct extent_map_tree *tree;
1699
1700
1701 if (current->flags & PF_MEMALLOC) {
1702 redirty_page_for_writepage(wbc, page);
1703 unlock_page(page);
1704 return 0;
1705 }
1706 tree = &BTRFS_I(page->mapping->host)->extent_tree;
1707 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
1708 }
1709
1710 static int btrfs_releasepage(struct page *page, gfp_t unused_gfp_flags)
1711 {
1712 struct extent_map_tree *tree;
1713 int ret;
1714
1715 tree = &BTRFS_I(page->mapping->host)->extent_tree;
1716 ret = try_release_extent_mapping(tree, page);
1717 if (ret == 1) {
1718 ClearPagePrivate(page);
1719 set_page_private(page, 0);
1720 page_cache_release(page);
1721 }
1722 return ret;
1723 }
1724
1725 static void btrfs_invalidatepage(struct page *page, unsigned long offset)
1726 {
1727 struct extent_map_tree *tree;
1728
1729 tree = &BTRFS_I(page->mapping->host)->extent_tree;
1730 extent_invalidatepage(tree, page, offset);
1731 btrfs_releasepage(page, GFP_NOFS);
1732 }
1733
1734 /*
1735 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
1736 * called from a page fault handler when a page is first dirtied. Hence we must
1737 * be careful to check for EOF conditions here. We set the page up correctly
1738 * for a written page which means we get ENOSPC checking when writing into
1739 * holes and correct delalloc and unwritten extent mapping on filesystems that
1740 * support these features.
1741 *
1742 * We are not allowed to take the i_mutex here so we have to play games to
1743 * protect against truncate races as the page could now be beyond EOF. Because
1744 * vmtruncate() writes the inode size before removing pages, once we have the
1745 * page lock we can determine safely if the page is beyond EOF. If it is not
1746 * beyond EOF, then the page is guaranteed safe against truncation until we
1747 * unlock the page.
1748 */
1749 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
1750 {
1751 struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
1752 unsigned long end;
1753 loff_t size;
1754 int ret = -EINVAL;
1755 u64 page_start;
1756
1757 down_read(&BTRFS_I(inode)->root->snap_sem);
1758 lock_page(page);
1759 wait_on_page_writeback(page);
1760 size = i_size_read(inode);
1761 page_start = page->index << PAGE_CACHE_SHIFT;
1762
1763 if ((page->mapping != inode->i_mapping) ||
1764 (page_start > size)) {
1765 /* page got truncated out from underneath us */
1766 goto out_unlock;
1767 }
1768
1769 /* page is wholly or partially inside EOF */
1770 if (page_start + PAGE_CACHE_SIZE > size)
1771 end = size & ~PAGE_CACHE_MASK;
1772 else
1773 end = PAGE_CACHE_SIZE;
1774
1775 ret = btrfs_cow_one_page(inode, page, end);
1776
1777 out_unlock:
1778 up_read(&BTRFS_I(inode)->root->snap_sem);
1779 unlock_page(page);
1780 return ret;
1781 }
1782
1783 static void btrfs_truncate(struct inode *inode)
1784 {
1785 struct btrfs_root *root = BTRFS_I(inode)->root;
1786 int ret;
1787 struct btrfs_trans_handle *trans;
1788 unsigned long nr;
1789
1790 if (!S_ISREG(inode->i_mode))
1791 return;
1792 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
1793 return;
1794
1795 btrfs_truncate_page(inode->i_mapping, inode->i_size);
1796
1797 mutex_lock(&root->fs_info->fs_mutex);
1798 trans = btrfs_start_transaction(root, 1);
1799 btrfs_set_trans_block_group(trans, inode);
1800
1801 /* FIXME, add redo link to tree so we don't leak on crash */
1802 ret = btrfs_truncate_in_trans(trans, root, inode);
1803 btrfs_update_inode(trans, root, inode);
1804 nr = trans->blocks_used;
1805
1806 ret = btrfs_end_transaction(trans, root);
1807 BUG_ON(ret);
1808 mutex_unlock(&root->fs_info->fs_mutex);
1809 btrfs_btree_balance_dirty(root, nr);
1810 }
1811
1812 int btrfs_commit_write(struct file *file, struct page *page,
1813 unsigned from, unsigned to)
1814 {
1815 return extent_commit_write(&BTRFS_I(page->mapping->host)->extent_tree,
1816 page->mapping->host, page, from, to);
1817 }
1818
1819 static int create_subvol(struct btrfs_root *root, char *name, int namelen)
1820 {
1821 struct btrfs_trans_handle *trans;
1822 struct btrfs_key key;
1823 struct btrfs_root_item root_item;
1824 struct btrfs_inode_item *inode_item;
1825 struct extent_buffer *leaf;
1826 struct btrfs_root *new_root;
1827 struct inode *inode;
1828 struct inode *dir;
1829 int ret;
1830 int err;
1831 u64 objectid;
1832 u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
1833 unsigned long nr = 1;
1834
1835 mutex_lock(&root->fs_info->fs_mutex);
1836 trans = btrfs_start_transaction(root, 1);
1837 BUG_ON(!trans);
1838
1839 leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0, 0);
1840 if (IS_ERR(leaf))
1841 return PTR_ERR(leaf);
1842
1843 btrfs_set_header_nritems(leaf, 0);
1844 btrfs_set_header_level(leaf, 0);
1845 btrfs_set_header_bytenr(leaf, leaf->start);
1846 btrfs_set_header_generation(leaf, trans->transid);
1847 btrfs_set_header_owner(leaf, root->root_key.objectid);
1848 write_extent_buffer(leaf, root->fs_info->fsid,
1849 (unsigned long)btrfs_header_fsid(leaf),
1850 BTRFS_FSID_SIZE);
1851 btrfs_mark_buffer_dirty(leaf);
1852
1853 inode_item = &root_item.inode;
1854 memset(inode_item, 0, sizeof(*inode_item));
1855 inode_item->generation = cpu_to_le64(1);
1856 inode_item->size = cpu_to_le64(3);
1857 inode_item->nlink = cpu_to_le32(1);
1858 inode_item->nblocks = cpu_to_le64(1);
1859 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
1860
1861 btrfs_set_root_bytenr(&root_item, leaf->start);
1862 btrfs_set_root_level(&root_item, 0);
1863 btrfs_set_root_refs(&root_item, 1);
1864 btrfs_set_root_used(&root_item, 0);
1865
1866 memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
1867 root_item.drop_level = 0;
1868
1869 free_extent_buffer(leaf);
1870 leaf = NULL;
1871
1872 ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
1873 0, &objectid);
1874 if (ret)
1875 goto fail;
1876
1877 btrfs_set_root_dirid(&root_item, new_dirid);
1878
1879 key.objectid = objectid;
1880 key.offset = 1;
1881 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
1882 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
1883 &root_item);
1884 if (ret)
1885 goto fail;
1886
1887 /*
1888 * insert the directory item
1889 */
1890 key.offset = (u64)-1;
1891 dir = root->fs_info->sb->s_root->d_inode;
1892 ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
1893 name, namelen, dir->i_ino, &key,
1894 BTRFS_FT_DIR);
1895 if (ret)
1896 goto fail;
1897
1898 ret = btrfs_commit_transaction(trans, root);
1899 if (ret)
1900 goto fail_commit;
1901
1902 new_root = btrfs_read_fs_root(root->fs_info, &key, name, namelen);
1903 BUG_ON(!new_root);
1904
1905 trans = btrfs_start_transaction(new_root, 1);
1906 BUG_ON(!trans);
1907
1908 inode = btrfs_new_inode(trans, new_root, new_dirid,
1909 BTRFS_I(dir)->block_group, S_IFDIR | 0700);
1910 if (IS_ERR(inode))
1911 goto fail;
1912 inode->i_op = &btrfs_dir_inode_operations;
1913 inode->i_fop = &btrfs_dir_file_operations;
1914 new_root->inode = inode;
1915
1916 ret = btrfs_make_empty_dir(trans, new_root, new_dirid, new_dirid);
1917 if (ret)
1918 goto fail;
1919
1920 inode->i_nlink = 1;
1921 inode->i_size = 6;
1922 ret = btrfs_update_inode(trans, new_root, inode);
1923 if (ret)
1924 goto fail;
1925 fail:
1926 nr = trans->blocks_used;
1927 err = btrfs_commit_transaction(trans, root);
1928 if (err && !ret)
1929 ret = err;
1930 fail_commit:
1931 mutex_unlock(&root->fs_info->fs_mutex);
1932 btrfs_btree_balance_dirty(root, nr);
1933 return ret;
1934 }
1935
1936 static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
1937 {
1938 struct btrfs_trans_handle *trans;
1939 struct btrfs_key key;
1940 struct btrfs_root_item new_root_item;
1941 struct extent_buffer *tmp;
1942 int ret;
1943 int err;
1944 u64 objectid;
1945 unsigned long nr;
1946
1947 if (!root->ref_cows)
1948 return -EINVAL;
1949
1950 down_write(&root->snap_sem);
1951 freeze_bdev(root->fs_info->sb->s_bdev);
1952 thaw_bdev(root->fs_info->sb->s_bdev, root->fs_info->sb);
1953
1954 mutex_lock(&root->fs_info->fs_mutex);
1955 trans = btrfs_start_transaction(root, 1);
1956 BUG_ON(!trans);
1957
1958 ret = btrfs_update_inode(trans, root, root->inode);
1959 if (ret)
1960 goto fail;
1961
1962 ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
1963 0, &objectid);
1964 if (ret)
1965 goto fail;
1966
1967 memcpy(&new_root_item, &root->root_item,
1968 sizeof(new_root_item));
1969
1970 key.objectid = objectid;
1971 key.offset = 1;
1972 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
1973
1974 btrfs_cow_block(trans, root, root->node, NULL, 0, &tmp);
1975 btrfs_set_root_bytenr(&new_root_item, root->node->start);
1976 btrfs_set_root_level(&new_root_item, btrfs_header_level(root->node));
1977
1978 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
1979 &new_root_item);
1980 if (ret)
1981 goto fail;
1982
1983 /*
1984 * insert the directory item
1985 */
1986 key.offset = (u64)-1;
1987 ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
1988 name, namelen,
1989 root->fs_info->sb->s_root->d_inode->i_ino,
1990 &key, BTRFS_FT_DIR);
1991
1992 if (ret)
1993 goto fail;
1994
1995 ret = btrfs_inc_root_ref(trans, root);
1996 if (ret)
1997 goto fail;
1998 fail:
1999 nr = trans->blocks_used;
2000 err = btrfs_commit_transaction(trans, root);
2001
2002 if (err && !ret)
2003 ret = err;
2004
2005 mutex_unlock(&root->fs_info->fs_mutex);
2006 up_write(&root->snap_sem);
2007 btrfs_btree_balance_dirty(root, nr);
2008 return ret;
2009 }
2010
2011 static unsigned long force_ra(struct address_space *mapping,
2012 struct file_ra_state *ra, struct file *file,
2013 pgoff_t offset, pgoff_t last_index)
2014 {
2015 pgoff_t req_size;
2016
2017 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
2018 req_size = last_index - offset + 1;
2019 offset = page_cache_readahead(mapping, ra, file, offset, req_size);
2020 return offset;
2021 #else
2022 req_size = min(last_index - offset + 1, (pgoff_t)128);
2023 page_cache_sync_readahead(mapping, ra, file, offset, req_size);
2024 return offset + req_size;
2025 #endif
2026 }
2027
2028 int btrfs_defrag_file(struct file *file) {
2029 struct inode *inode = file->f_path.dentry->d_inode;
2030 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2031 struct page *page;
2032 unsigned long last_index;
2033 unsigned long ra_index = 0;
2034 u64 page_start;
2035 u64 page_end;
2036 unsigned long i;
2037
2038 mutex_lock(&inode->i_mutex);
2039 last_index = inode->i_size >> PAGE_CACHE_SHIFT;
2040 for (i = 0; i <= last_index; i++) {
2041 if (i == ra_index) {
2042 ra_index = force_ra(inode->i_mapping, &file->f_ra,
2043 file, ra_index, last_index);
2044 }
2045 page = grab_cache_page(inode->i_mapping, i);
2046 if (!page)
2047 goto out_unlock;
2048 if (!PageUptodate(page)) {
2049 btrfs_readpage(NULL, page);
2050 lock_page(page);
2051 if (!PageUptodate(page)) {
2052 unlock_page(page);
2053 page_cache_release(page);
2054 goto out_unlock;
2055 }
2056 }
2057 page_start = page->index << PAGE_CACHE_SHIFT;
2058 page_end = page_start + PAGE_CACHE_SIZE - 1;
2059
2060 lock_extent(em_tree, page_start, page_end, GFP_NOFS);
2061 set_extent_delalloc(em_tree, page_start,
2062 page_end, GFP_NOFS);
2063 unlock_extent(em_tree, page_start, page_end, GFP_NOFS);
2064 set_page_dirty(page);
2065 unlock_page(page);
2066 page_cache_release(page);
2067 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
2068 }
2069
2070 out_unlock:
2071 mutex_unlock(&inode->i_mutex);
2072 return 0;
2073 }
2074
2075 static int btrfs_ioctl_snap_create(struct btrfs_root *root, void __user *arg)
2076 {
2077 struct btrfs_ioctl_vol_args vol_args;
2078 struct btrfs_dir_item *di;
2079 struct btrfs_path *path;
2080 int namelen;
2081 u64 root_dirid;
2082
2083 if (copy_from_user(&vol_args, arg, sizeof(vol_args)))
2084 return -EFAULT;
2085
2086 namelen = strlen(vol_args.name);
2087 if (namelen > BTRFS_VOL_NAME_MAX)
2088 return -EINVAL;
2089 if (strchr(vol_args.name, '/'))
2090 return -EINVAL;
2091
2092 path = btrfs_alloc_path();
2093 if (!path)
2094 return -ENOMEM;
2095
2096 root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
2097 mutex_lock(&root->fs_info->fs_mutex);
2098 di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
2099 path, root_dirid,
2100 vol_args.name, namelen, 0);
2101 mutex_unlock(&root->fs_info->fs_mutex);
2102 btrfs_free_path(path);
2103 if (di && !IS_ERR(di))
2104 return -EEXIST;
2105 if (IS_ERR(di))
2106 return PTR_ERR(di);
2107
2108 if (root == root->fs_info->tree_root)
2109 return create_subvol(root, vol_args.name, namelen);
2110 return create_snapshot(root, vol_args.name, namelen);
2111 }
2112
2113 static int btrfs_ioctl_defrag(struct file *file)
2114 {
2115 struct inode *inode = file->f_path.dentry->d_inode;
2116 struct btrfs_root *root = BTRFS_I(inode)->root;
2117
2118 switch (inode->i_mode & S_IFMT) {
2119 case S_IFDIR:
2120 mutex_lock(&root->fs_info->fs_mutex);
2121 btrfs_defrag_root(root, 0);
2122 btrfs_defrag_root(root->fs_info->extent_root, 0);
2123 mutex_unlock(&root->fs_info->fs_mutex);
2124 break;
2125 case S_IFREG:
2126 btrfs_defrag_file(file);
2127 break;
2128 }
2129
2130 return 0;
2131 }
2132
2133 long btrfs_ioctl(struct file *file, unsigned int
2134 cmd, unsigned long arg)
2135 {
2136 struct btrfs_root *root = BTRFS_I(file->f_path.dentry->d_inode)->root;
2137
2138 switch (cmd) {
2139 case BTRFS_IOC_SNAP_CREATE:
2140 return btrfs_ioctl_snap_create(root, (void __user *)arg);
2141 case BTRFS_IOC_DEFRAG:
2142 return btrfs_ioctl_defrag(file);
2143 }
2144
2145 return -ENOTTY;
2146 }
2147
2148 /*
2149 * Called inside transaction, so use GFP_NOFS
2150 */
2151 struct inode *btrfs_alloc_inode(struct super_block *sb)
2152 {
2153 struct btrfs_inode *ei;
2154
2155 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
2156 if (!ei)
2157 return NULL;
2158 ei->last_trans = 0;
2159 return &ei->vfs_inode;
2160 }
2161
2162 void btrfs_destroy_inode(struct inode *inode)
2163 {
2164 WARN_ON(!list_empty(&inode->i_dentry));
2165 WARN_ON(inode->i_data.nrpages);
2166
2167 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
2168 }
2169
2170 static void init_once(void * foo, struct kmem_cache * cachep,
2171 unsigned long flags)
2172 {
2173 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
2174
2175 inode_init_once(&ei->vfs_inode);
2176 }
2177
2178 void btrfs_destroy_cachep(void)
2179 {
2180 if (btrfs_inode_cachep)
2181 kmem_cache_destroy(btrfs_inode_cachep);
2182 if (btrfs_trans_handle_cachep)
2183 kmem_cache_destroy(btrfs_trans_handle_cachep);
2184 if (btrfs_transaction_cachep)
2185 kmem_cache_destroy(btrfs_transaction_cachep);
2186 if (btrfs_bit_radix_cachep)
2187 kmem_cache_destroy(btrfs_bit_radix_cachep);
2188 if (btrfs_path_cachep)
2189 kmem_cache_destroy(btrfs_path_cachep);
2190 }
2191
2192 struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
2193 unsigned long extra_flags,
2194 void (*ctor)(void *, struct kmem_cache *,
2195 unsigned long))
2196 {
2197 return kmem_cache_create(name, size, 0, (SLAB_RECLAIM_ACCOUNT |
2198 SLAB_MEM_SPREAD | extra_flags), ctor
2199 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
2200 ,NULL
2201 #endif
2202 );
2203 }
2204
2205 int btrfs_init_cachep(void)
2206 {
2207 btrfs_inode_cachep = btrfs_cache_create("btrfs_inode_cache",
2208 sizeof(struct btrfs_inode),
2209 0, init_once);
2210 if (!btrfs_inode_cachep)
2211 goto fail;
2212 btrfs_trans_handle_cachep =
2213 btrfs_cache_create("btrfs_trans_handle_cache",
2214 sizeof(struct btrfs_trans_handle),
2215 0, NULL);
2216 if (!btrfs_trans_handle_cachep)
2217 goto fail;
2218 btrfs_transaction_cachep = btrfs_cache_create("btrfs_transaction_cache",
2219 sizeof(struct btrfs_transaction),
2220 0, NULL);
2221 if (!btrfs_transaction_cachep)
2222 goto fail;
2223 btrfs_path_cachep = btrfs_cache_create("btrfs_path_cache",
2224 sizeof(struct btrfs_path),
2225 0, NULL);
2226 if (!btrfs_path_cachep)
2227 goto fail;
2228 btrfs_bit_radix_cachep = btrfs_cache_create("btrfs_radix", 256,
2229 SLAB_DESTROY_BY_RCU, NULL);
2230 if (!btrfs_bit_radix_cachep)
2231 goto fail;
2232 return 0;
2233 fail:
2234 btrfs_destroy_cachep();
2235 return -ENOMEM;
2236 }
2237
2238 static int btrfs_getattr(struct vfsmount *mnt,
2239 struct dentry *dentry, struct kstat *stat)
2240 {
2241 struct inode *inode = dentry->d_inode;
2242 generic_fillattr(inode, stat);
2243 stat->blksize = 256 * 1024;
2244 return 0;
2245 }
2246
2247 static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
2248 struct inode * new_dir,struct dentry *new_dentry)
2249 {
2250 struct btrfs_trans_handle *trans;
2251 struct btrfs_root *root = BTRFS_I(old_dir)->root;
2252 struct inode *new_inode = new_dentry->d_inode;
2253 struct inode *old_inode = old_dentry->d_inode;
2254 struct timespec ctime = CURRENT_TIME;
2255 struct btrfs_path *path;
2256 struct btrfs_dir_item *di;
2257 int ret;
2258
2259 if (S_ISDIR(old_inode->i_mode) && new_inode &&
2260 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
2261 return -ENOTEMPTY;
2262 }
2263
2264 mutex_lock(&root->fs_info->fs_mutex);
2265 trans = btrfs_start_transaction(root, 1);
2266
2267 btrfs_set_trans_block_group(trans, new_dir);
2268 path = btrfs_alloc_path();
2269 if (!path) {
2270 ret = -ENOMEM;
2271 goto out_fail;
2272 }
2273
2274 old_dentry->d_inode->i_nlink++;
2275 old_dir->i_ctime = old_dir->i_mtime = ctime;
2276 new_dir->i_ctime = new_dir->i_mtime = ctime;
2277 old_inode->i_ctime = ctime;
2278
2279 if (S_ISDIR(old_inode->i_mode) && old_dir != new_dir) {
2280 struct btrfs_key *location = &BTRFS_I(new_dir)->location;
2281 struct btrfs_key old_parent_key;
2282 di = btrfs_lookup_dir_item(trans, root, path, old_inode->i_ino,
2283 "..", 2, -1);
2284 if (IS_ERR(di)) {
2285 ret = PTR_ERR(di);
2286 goto out_fail;
2287 }
2288 if (!di) {
2289 ret = -ENOENT;
2290 goto out_fail;
2291 }
2292 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &old_parent_key);
2293 ret = btrfs_del_item(trans, root, path);
2294 if (ret) {
2295 goto out_fail;
2296 }
2297 btrfs_release_path(root, path);
2298
2299 di = btrfs_lookup_dir_index_item(trans, root, path,
2300 old_inode->i_ino,
2301 old_parent_key.objectid,
2302 "..", 2, -1);
2303 if (IS_ERR(di)) {
2304 ret = PTR_ERR(di);
2305 goto out_fail;
2306 }
2307 if (!di) {
2308 ret = -ENOENT;
2309 goto out_fail;
2310 }
2311 ret = btrfs_del_item(trans, root, path);
2312 if (ret) {
2313 goto out_fail;
2314 }
2315 btrfs_release_path(root, path);
2316
2317 ret = btrfs_insert_dir_item(trans, root, "..", 2,
2318 old_inode->i_ino, location,
2319 BTRFS_FT_DIR);
2320 if (ret)
2321 goto out_fail;
2322 }
2323
2324
2325 ret = btrfs_unlink_trans(trans, root, old_dir, old_dentry);
2326 if (ret)
2327 goto out_fail;
2328
2329 if (new_inode) {
2330 new_inode->i_ctime = CURRENT_TIME;
2331 ret = btrfs_unlink_trans(trans, root, new_dir, new_dentry);
2332 if (ret)
2333 goto out_fail;
2334 }
2335 ret = btrfs_add_link(trans, new_dentry, old_inode);
2336 if (ret)
2337 goto out_fail;
2338
2339 out_fail:
2340 btrfs_free_path(path);
2341 btrfs_end_transaction(trans, root);
2342 mutex_unlock(&root->fs_info->fs_mutex);
2343 return ret;
2344 }
2345
2346 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
2347 const char *symname)
2348 {
2349 struct btrfs_trans_handle *trans;
2350 struct btrfs_root *root = BTRFS_I(dir)->root;
2351 struct btrfs_path *path;
2352 struct btrfs_key key;
2353 struct inode *inode;
2354 int err;
2355 int drop_inode = 0;
2356 u64 objectid;
2357 int name_len;
2358 int datasize;
2359 unsigned long ptr;
2360 struct btrfs_file_extent_item *ei;
2361 struct extent_buffer *leaf;
2362 unsigned long nr;
2363
2364 name_len = strlen(symname) + 1;
2365 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
2366 return -ENAMETOOLONG;
2367 mutex_lock(&root->fs_info->fs_mutex);
2368 trans = btrfs_start_transaction(root, 1);
2369 btrfs_set_trans_block_group(trans, dir);
2370
2371 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
2372 if (err) {
2373 err = -ENOSPC;
2374 goto out_unlock;
2375 }
2376
2377 inode = btrfs_new_inode(trans, root, objectid,
2378 BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO);
2379 err = PTR_ERR(inode);
2380 if (IS_ERR(inode))
2381 goto out_unlock;
2382
2383 btrfs_set_trans_block_group(trans, inode);
2384 err = btrfs_add_nondir(trans, dentry, inode);
2385 if (err)
2386 drop_inode = 1;
2387 else {
2388 inode->i_mapping->a_ops = &btrfs_aops;
2389 inode->i_fop = &btrfs_file_operations;
2390 inode->i_op = &btrfs_file_inode_operations;
2391 extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
2392 inode->i_mapping, GFP_NOFS);
2393 BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
2394 }
2395 dir->i_sb->s_dirt = 1;
2396 btrfs_update_inode_block_group(trans, inode);
2397 btrfs_update_inode_block_group(trans, dir);
2398 if (drop_inode)
2399 goto out_unlock;
2400
2401 path = btrfs_alloc_path();
2402 BUG_ON(!path);
2403 key.objectid = inode->i_ino;
2404 key.offset = 0;
2405 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
2406 datasize = btrfs_file_extent_calc_inline_size(name_len);
2407 err = btrfs_insert_empty_item(trans, root, path, &key,
2408 datasize);
2409 if (err) {
2410 drop_inode = 1;
2411 goto out_unlock;
2412 }
2413 leaf = path->nodes[0];
2414 ei = btrfs_item_ptr(leaf, path->slots[0],
2415 struct btrfs_file_extent_item);
2416 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
2417 btrfs_set_file_extent_type(leaf, ei,
2418 BTRFS_FILE_EXTENT_INLINE);
2419 ptr = btrfs_file_extent_inline_start(ei);
2420 write_extent_buffer(leaf, symname, ptr, name_len);
2421 btrfs_mark_buffer_dirty(leaf);
2422 btrfs_free_path(path);
2423
2424 inode->i_op = &btrfs_symlink_inode_operations;
2425 inode->i_mapping->a_ops = &btrfs_symlink_aops;
2426 inode->i_size = name_len - 1;
2427 err = btrfs_update_inode(trans, root, inode);
2428 if (err)
2429 drop_inode = 1;
2430
2431 out_unlock:
2432 nr = trans->blocks_used;
2433 btrfs_end_transaction(trans, root);
2434 mutex_unlock(&root->fs_info->fs_mutex);
2435 if (drop_inode) {
2436 inode_dec_link_count(inode);
2437 iput(inode);
2438 }
2439 btrfs_btree_balance_dirty(root, nr);
2440 return err;
2441 }
2442
2443 static struct inode_operations btrfs_dir_inode_operations = {
2444 .lookup = btrfs_lookup,
2445 .create = btrfs_create,
2446 .unlink = btrfs_unlink,
2447 .link = btrfs_link,
2448 .mkdir = btrfs_mkdir,
2449 .rmdir = btrfs_rmdir,
2450 .rename = btrfs_rename,
2451 .symlink = btrfs_symlink,
2452 .setattr = btrfs_setattr,
2453 .mknod = btrfs_mknod,
2454 };
2455
2456 static struct inode_operations btrfs_dir_ro_inode_operations = {
2457 .lookup = btrfs_lookup,
2458 };
2459
2460 static struct file_operations btrfs_dir_file_operations = {
2461 .llseek = generic_file_llseek,
2462 .read = generic_read_dir,
2463 .readdir = btrfs_readdir,
2464 .unlocked_ioctl = btrfs_ioctl,
2465 #ifdef CONFIG_COMPAT
2466 .compat_ioctl = btrfs_ioctl,
2467 #endif
2468 };
2469
2470 static struct extent_map_ops btrfs_extent_map_ops = {
2471 .fill_delalloc = run_delalloc_range,
2472 .writepage_io_hook = btrfs_writepage_io_hook,
2473 .readpage_io_hook = btrfs_readpage_io_hook,
2474 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
2475 };
2476
2477 static struct address_space_operations btrfs_aops = {
2478 .readpage = btrfs_readpage,
2479 .writepage = btrfs_writepage,
2480 .sync_page = block_sync_page,
2481 .prepare_write = btrfs_prepare_write,
2482 .commit_write = btrfs_commit_write,
2483 .bmap = btrfs_bmap,
2484 .invalidatepage = btrfs_invalidatepage,
2485 .releasepage = btrfs_releasepage,
2486 .set_page_dirty = __set_page_dirty_nobuffers,
2487 };
2488
2489 static struct address_space_operations btrfs_symlink_aops = {
2490 .readpage = btrfs_readpage,
2491 .writepage = btrfs_writepage,
2492 .invalidatepage = btrfs_invalidatepage,
2493 .releasepage = btrfs_releasepage,
2494 };
2495
2496 static struct inode_operations btrfs_file_inode_operations = {
2497 .truncate = btrfs_truncate,
2498 .getattr = btrfs_getattr,
2499 .setattr = btrfs_setattr,
2500 };
2501
2502 static struct inode_operations btrfs_special_inode_operations = {
2503 .getattr = btrfs_getattr,
2504 .setattr = btrfs_setattr,
2505 };
2506
2507 static struct inode_operations btrfs_symlink_inode_operations = {
2508 .readlink = generic_readlink,
2509 .follow_link = page_follow_link_light,
2510 .put_link = page_put_link,
2511 };
Linux kernel - Deliverables
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