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