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Btrfs: Optimize csum insertion to create larger items when possible
[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, 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 unsigned long flags;
172
173 ret = get_state_private(em_tree, start, &private);
174 local_irq_save(flags);
175 kaddr = kmap_atomic(page, KM_IRQ0);
176 if (ret) {
177 goto zeroit;
178 }
179 csum = btrfs_csum_data(root, kaddr + offset, csum, end - start + 1);
180 btrfs_csum_final(csum, (char *)&csum);
181 if (csum != private) {
182 goto zeroit;
183 }
184 kunmap_atomic(kaddr, KM_IRQ0);
185 local_irq_restore(flags);
186 return 0;
187
188 zeroit:
189 printk("btrfs csum failed ino %lu off %llu\n",
190 page->mapping->host->i_ino, (unsigned long long)start);
191 memset(kaddr + offset, 1, end - start + 1);
192 flush_dcache_page(page);
193 kunmap_atomic(kaddr, KM_IRQ0);
194 local_irq_restore(flags);
195 return 0;
196 }
197
198 void btrfs_read_locked_inode(struct inode *inode)
199 {
200 struct btrfs_path *path;
201 struct extent_buffer *leaf;
202 struct btrfs_inode_item *inode_item;
203 struct btrfs_inode_timespec *tspec;
204 struct btrfs_root *root = BTRFS_I(inode)->root;
205 struct btrfs_key location;
206 u64 alloc_group_block;
207 u32 rdev;
208 int ret;
209
210 path = btrfs_alloc_path();
211 BUG_ON(!path);
212 mutex_lock(&root->fs_info->fs_mutex);
213
214 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
215 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
216 if (ret)
217 goto make_bad;
218
219 leaf = path->nodes[0];
220 inode_item = btrfs_item_ptr(leaf, path->slots[0],
221 struct btrfs_inode_item);
222
223 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
224 inode->i_nlink = btrfs_inode_nlink(leaf, inode_item);
225 inode->i_uid = btrfs_inode_uid(leaf, inode_item);
226 inode->i_gid = btrfs_inode_gid(leaf, inode_item);
227 inode->i_size = btrfs_inode_size(leaf, inode_item);
228
229 tspec = btrfs_inode_atime(inode_item);
230 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
231 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
232
233 tspec = btrfs_inode_mtime(inode_item);
234 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
235 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
236
237 tspec = btrfs_inode_ctime(inode_item);
238 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
239 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
240
241 inode->i_blocks = btrfs_inode_nblocks(leaf, inode_item);
242 inode->i_generation = btrfs_inode_generation(leaf, inode_item);
243 inode->i_rdev = 0;
244 rdev = btrfs_inode_rdev(leaf, inode_item);
245
246 alloc_group_block = btrfs_inode_block_group(leaf, inode_item);
247 BTRFS_I(inode)->block_group = btrfs_lookup_block_group(root->fs_info,
248 alloc_group_block);
249
250 btrfs_free_path(path);
251 inode_item = NULL;
252
253 mutex_unlock(&root->fs_info->fs_mutex);
254
255 switch (inode->i_mode & S_IFMT) {
256 case S_IFREG:
257 inode->i_mapping->a_ops = &btrfs_aops;
258 BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
259 inode->i_fop = &btrfs_file_operations;
260 inode->i_op = &btrfs_file_inode_operations;
261 break;
262 case S_IFDIR:
263 inode->i_fop = &btrfs_dir_file_operations;
264 if (root == root->fs_info->tree_root)
265 inode->i_op = &btrfs_dir_ro_inode_operations;
266 else
267 inode->i_op = &btrfs_dir_inode_operations;
268 break;
269 case S_IFLNK:
270 inode->i_op = &btrfs_symlink_inode_operations;
271 inode->i_mapping->a_ops = &btrfs_symlink_aops;
272 break;
273 default:
274 init_special_inode(inode, inode->i_mode, rdev);
275 break;
276 }
277 return;
278
279 make_bad:
280 btrfs_release_path(root, path);
281 btrfs_free_path(path);
282 mutex_unlock(&root->fs_info->fs_mutex);
283 make_bad_inode(inode);
284 }
285
286 static void fill_inode_item(struct extent_buffer *leaf,
287 struct btrfs_inode_item *item,
288 struct inode *inode)
289 {
290 btrfs_set_inode_uid(leaf, item, inode->i_uid);
291 btrfs_set_inode_gid(leaf, item, inode->i_gid);
292 btrfs_set_inode_size(leaf, item, inode->i_size);
293 btrfs_set_inode_mode(leaf, item, inode->i_mode);
294 btrfs_set_inode_nlink(leaf, item, inode->i_nlink);
295
296 btrfs_set_timespec_sec(leaf, btrfs_inode_atime(item),
297 inode->i_atime.tv_sec);
298 btrfs_set_timespec_nsec(leaf, btrfs_inode_atime(item),
299 inode->i_atime.tv_nsec);
300
301 btrfs_set_timespec_sec(leaf, btrfs_inode_mtime(item),
302 inode->i_mtime.tv_sec);
303 btrfs_set_timespec_nsec(leaf, btrfs_inode_mtime(item),
304 inode->i_mtime.tv_nsec);
305
306 btrfs_set_timespec_sec(leaf, btrfs_inode_ctime(item),
307 inode->i_ctime.tv_sec);
308 btrfs_set_timespec_nsec(leaf, btrfs_inode_ctime(item),
309 inode->i_ctime.tv_nsec);
310
311 btrfs_set_inode_nblocks(leaf, item, inode->i_blocks);
312 btrfs_set_inode_generation(leaf, item, inode->i_generation);
313 btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
314 btrfs_set_inode_block_group(leaf, item,
315 BTRFS_I(inode)->block_group->key.objectid);
316 }
317
318 int btrfs_update_inode(struct btrfs_trans_handle *trans,
319 struct btrfs_root *root,
320 struct inode *inode)
321 {
322 struct btrfs_inode_item *inode_item;
323 struct btrfs_path *path;
324 struct extent_buffer *leaf;
325 int ret;
326
327 path = btrfs_alloc_path();
328 BUG_ON(!path);
329 ret = btrfs_lookup_inode(trans, root, path,
330 &BTRFS_I(inode)->location, 1);
331 if (ret) {
332 if (ret > 0)
333 ret = -ENOENT;
334 goto failed;
335 }
336
337 leaf = path->nodes[0];
338 inode_item = btrfs_item_ptr(leaf, path->slots[0],
339 struct btrfs_inode_item);
340
341 fill_inode_item(leaf, inode_item, inode);
342 btrfs_mark_buffer_dirty(leaf);
343 btrfs_set_inode_last_trans(trans, inode);
344 ret = 0;
345 failed:
346 btrfs_release_path(root, path);
347 btrfs_free_path(path);
348 return ret;
349 }
350
351
352 static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
353 struct btrfs_root *root,
354 struct inode *dir,
355 struct dentry *dentry)
356 {
357 struct btrfs_path *path;
358 const char *name = dentry->d_name.name;
359 int name_len = dentry->d_name.len;
360 int ret = 0;
361 struct extent_buffer *leaf;
362 struct btrfs_dir_item *di;
363 struct btrfs_key key;
364
365 path = btrfs_alloc_path();
366 if (!path) {
367 ret = -ENOMEM;
368 goto err;
369 }
370
371 di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
372 name, name_len, -1);
373 if (IS_ERR(di)) {
374 ret = PTR_ERR(di);
375 goto err;
376 }
377 if (!di) {
378 ret = -ENOENT;
379 goto err;
380 }
381 leaf = path->nodes[0];
382 btrfs_dir_item_key_to_cpu(leaf, di, &key);
383 ret = btrfs_delete_one_dir_name(trans, root, path, di);
384 if (ret)
385 goto err;
386 btrfs_release_path(root, path);
387
388 di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
389 key.objectid, name, name_len, -1);
390 if (IS_ERR(di)) {
391 ret = PTR_ERR(di);
392 goto err;
393 }
394 if (!di) {
395 ret = -ENOENT;
396 goto err;
397 }
398 ret = btrfs_delete_one_dir_name(trans, root, path, di);
399
400 dentry->d_inode->i_ctime = dir->i_ctime;
401 err:
402 btrfs_free_path(path);
403 if (!ret) {
404 dir->i_size -= name_len * 2;
405 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
406 btrfs_update_inode(trans, root, dir);
407 drop_nlink(dentry->d_inode);
408 ret = btrfs_update_inode(trans, root, dentry->d_inode);
409 dir->i_sb->s_dirt = 1;
410 }
411 return ret;
412 }
413
414 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
415 {
416 struct btrfs_root *root;
417 struct btrfs_trans_handle *trans;
418 int ret;
419 unsigned long nr;
420
421 root = BTRFS_I(dir)->root;
422 mutex_lock(&root->fs_info->fs_mutex);
423 trans = btrfs_start_transaction(root, 1);
424
425 btrfs_set_trans_block_group(trans, dir);
426 ret = btrfs_unlink_trans(trans, root, dir, dentry);
427 nr = trans->blocks_used;
428
429 btrfs_end_transaction(trans, root);
430 mutex_unlock(&root->fs_info->fs_mutex);
431 btrfs_btree_balance_dirty(root, nr);
432
433 return ret;
434 }
435
436 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
437 {
438 struct inode *inode = dentry->d_inode;
439 int err;
440 int ret;
441 struct btrfs_root *root = BTRFS_I(dir)->root;
442 struct btrfs_path *path;
443 struct btrfs_key key;
444 struct btrfs_trans_handle *trans;
445 struct btrfs_key found_key;
446 int found_type;
447 struct extent_buffer *leaf;
448 char *goodnames = "..";
449 unsigned long nr;
450
451 path = btrfs_alloc_path();
452 BUG_ON(!path);
453 mutex_lock(&root->fs_info->fs_mutex);
454 trans = btrfs_start_transaction(root, 1);
455
456 btrfs_set_trans_block_group(trans, dir);
457 key.objectid = inode->i_ino;
458 key.offset = (u64)-1;
459 key.type = (u8)-1;
460 while(1) {
461 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
462 if (ret < 0) {
463 err = ret;
464 goto out;
465 }
466 BUG_ON(ret == 0);
467 if (path->slots[0] == 0) {
468 err = -ENOENT;
469 goto out;
470 }
471 path->slots[0]--;
472 leaf = path->nodes[0];
473 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
474 found_type = btrfs_key_type(&found_key);
475 if (found_key.objectid != inode->i_ino) {
476 err = -ENOENT;
477 goto out;
478 }
479 if ((found_type != BTRFS_DIR_ITEM_KEY &&
480 found_type != BTRFS_DIR_INDEX_KEY) ||
481 (!btrfs_match_dir_item_name(root, path, goodnames, 2) &&
482 !btrfs_match_dir_item_name(root, path, goodnames, 1))) {
483 err = -ENOTEMPTY;
484 goto out;
485 }
486 ret = btrfs_del_item(trans, root, path);
487 BUG_ON(ret);
488
489 if (found_type == BTRFS_DIR_ITEM_KEY && found_key.offset == 1)
490 break;
491 btrfs_release_path(root, path);
492 }
493 ret = 0;
494 btrfs_release_path(root, path);
495
496 /* now the directory is empty */
497 err = btrfs_unlink_trans(trans, root, dir, dentry);
498 if (!err) {
499 inode->i_size = 0;
500 }
501 out:
502 btrfs_release_path(root, path);
503 btrfs_free_path(path);
504 mutex_unlock(&root->fs_info->fs_mutex);
505 nr = trans->blocks_used;
506 ret = btrfs_end_transaction(trans, root);
507 btrfs_btree_balance_dirty(root, nr);
508 if (ret && !err)
509 err = ret;
510 return err;
511 }
512
513 static int btrfs_free_inode(struct btrfs_trans_handle *trans,
514 struct btrfs_root *root,
515 struct inode *inode)
516 {
517 struct btrfs_path *path;
518 int ret;
519
520 clear_inode(inode);
521
522 path = btrfs_alloc_path();
523 BUG_ON(!path);
524 ret = btrfs_lookup_inode(trans, root, path,
525 &BTRFS_I(inode)->location, -1);
526 if (ret > 0)
527 ret = -ENOENT;
528 if (!ret)
529 ret = btrfs_del_item(trans, root, path);
530 btrfs_free_path(path);
531 return ret;
532 }
533
534 /*
535 * this can truncate away extent items, csum items and directory items.
536 * It starts at a high offset and removes keys until it can't find
537 * any higher than i_size.
538 *
539 * csum items that cross the new i_size are truncated to the new size
540 * as well.
541 */
542 static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
543 struct btrfs_root *root,
544 struct inode *inode)
545 {
546 int ret;
547 struct btrfs_path *path;
548 struct btrfs_key key;
549 struct btrfs_key found_key;
550 u32 found_type;
551 struct extent_buffer *leaf;
552 struct btrfs_file_extent_item *fi;
553 u64 extent_start = 0;
554 u64 extent_num_bytes = 0;
555 u64 item_end = 0;
556 int found_extent;
557 int del_item;
558
559 btrfs_drop_extent_cache(inode, inode->i_size, (u64)-1);
560 path = btrfs_alloc_path();
561 path->reada = -1;
562 BUG_ON(!path);
563
564 /* FIXME, add redo link to tree so we don't leak on crash */
565 key.objectid = inode->i_ino;
566 key.offset = (u64)-1;
567 key.type = (u8)-1;
568
569 while(1) {
570 btrfs_init_path(path);
571 fi = NULL;
572 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
573 if (ret < 0) {
574 goto error;
575 }
576 if (ret > 0) {
577 BUG_ON(path->slots[0] == 0);
578 path->slots[0]--;
579 }
580 leaf = path->nodes[0];
581 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
582 found_type = btrfs_key_type(&found_key);
583
584 if (found_key.objectid != inode->i_ino)
585 break;
586
587 if (found_type != BTRFS_CSUM_ITEM_KEY &&
588 found_type != BTRFS_DIR_ITEM_KEY &&
589 found_type != BTRFS_DIR_INDEX_KEY &&
590 found_type != BTRFS_EXTENT_DATA_KEY)
591 break;
592
593 item_end = found_key.offset;
594 if (found_type == BTRFS_EXTENT_DATA_KEY) {
595 fi = btrfs_item_ptr(leaf, path->slots[0],
596 struct btrfs_file_extent_item);
597 if (btrfs_file_extent_type(leaf, fi) !=
598 BTRFS_FILE_EXTENT_INLINE) {
599 item_end +=
600 btrfs_file_extent_num_bytes(leaf, fi);
601 }
602 }
603 if (found_type == BTRFS_CSUM_ITEM_KEY) {
604 ret = btrfs_csum_truncate(trans, root, path,
605 inode->i_size);
606 BUG_ON(ret);
607 }
608 if (item_end < inode->i_size) {
609 if (found_type == BTRFS_DIR_ITEM_KEY) {
610 found_type = BTRFS_INODE_ITEM_KEY;
611 } else if (found_type == BTRFS_EXTENT_ITEM_KEY) {
612 found_type = BTRFS_CSUM_ITEM_KEY;
613 } else if (found_type) {
614 found_type--;
615 } else {
616 break;
617 }
618 btrfs_set_key_type(&key, found_type);
619 continue;
620 }
621 if (found_key.offset >= inode->i_size)
622 del_item = 1;
623 else
624 del_item = 0;
625 found_extent = 0;
626
627 /* FIXME, shrink the extent if the ref count is only 1 */
628 if (found_type == BTRFS_EXTENT_DATA_KEY &&
629 btrfs_file_extent_type(leaf, fi) !=
630 BTRFS_FILE_EXTENT_INLINE) {
631 u64 num_dec;
632 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
633 if (!del_item) {
634 u64 orig_num_bytes =
635 btrfs_file_extent_num_bytes(leaf, fi);
636 extent_num_bytes = inode->i_size -
637 found_key.offset + root->sectorsize - 1;
638 btrfs_set_file_extent_num_bytes(leaf, fi,
639 extent_num_bytes);
640 num_dec = (orig_num_bytes -
641 extent_num_bytes) >> 9;
642 if (extent_start != 0) {
643 inode->i_blocks -= num_dec;
644 }
645 btrfs_mark_buffer_dirty(leaf);
646 } else {
647 extent_num_bytes =
648 btrfs_file_extent_disk_num_bytes(leaf,
649 fi);
650 /* FIXME blocksize != 4096 */
651 num_dec = btrfs_file_extent_num_bytes(leaf,
652 fi) >> 9;
653 if (extent_start != 0) {
654 found_extent = 1;
655 inode->i_blocks -= num_dec;
656 }
657 }
658 }
659 if (del_item) {
660 ret = btrfs_del_item(trans, root, path);
661 if (ret)
662 goto error;
663 } else {
664 break;
665 }
666 btrfs_release_path(root, path);
667 if (found_extent) {
668 ret = btrfs_free_extent(trans, root, extent_start,
669 extent_num_bytes, 0);
670 BUG_ON(ret);
671 }
672 }
673 ret = 0;
674 error:
675 btrfs_release_path(root, path);
676 btrfs_free_path(path);
677 inode->i_sb->s_dirt = 1;
678 return ret;
679 }
680
681 static int btrfs_cow_one_page(struct inode *inode, struct page *page,
682 size_t zero_start)
683 {
684 char *kaddr;
685 int ret = 0;
686 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
687 u64 page_start = page->index << PAGE_CACHE_SHIFT;
688 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
689
690 set_page_extent_mapped(page);
691
692 lock_extent(em_tree, page_start, page_end, GFP_NOFS);
693 set_extent_delalloc(&BTRFS_I(inode)->extent_tree, page_start,
694 page_end, GFP_NOFS);
695 if (zero_start != PAGE_CACHE_SIZE) {
696 kaddr = kmap(page);
697 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
698 flush_dcache_page(page);
699 kunmap(page);
700 }
701 set_page_dirty(page);
702 unlock_extent(em_tree, page_start, page_end, GFP_NOFS);
703
704 return ret;
705 }
706
707 /*
708 * taken from block_truncate_page, but does cow as it zeros out
709 * any bytes left in the last page in the file.
710 */
711 static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
712 {
713 struct inode *inode = mapping->host;
714 struct btrfs_root *root = BTRFS_I(inode)->root;
715 u32 blocksize = root->sectorsize;
716 pgoff_t index = from >> PAGE_CACHE_SHIFT;
717 unsigned offset = from & (PAGE_CACHE_SIZE-1);
718 struct page *page;
719 int ret = 0;
720 u64 page_start;
721
722 if ((offset & (blocksize - 1)) == 0)
723 goto out;
724
725 down_read(&root->snap_sem);
726 ret = -ENOMEM;
727 page = grab_cache_page(mapping, index);
728 if (!page)
729 goto out;
730 if (!PageUptodate(page)) {
731 ret = btrfs_readpage(NULL, page);
732 lock_page(page);
733 if (!PageUptodate(page)) {
734 ret = -EIO;
735 goto out;
736 }
737 }
738 page_start = page->index << PAGE_CACHE_SHIFT;
739
740 ret = btrfs_cow_one_page(inode, page, offset);
741
742 unlock_page(page);
743 page_cache_release(page);
744 up_read(&BTRFS_I(inode)->root->snap_sem);
745 out:
746 return ret;
747 }
748
749 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
750 {
751 struct inode *inode = dentry->d_inode;
752 int err;
753
754 err = inode_change_ok(inode, attr);
755 if (err)
756 return err;
757
758 if (S_ISREG(inode->i_mode) &&
759 attr->ia_valid & ATTR_SIZE && attr->ia_size > inode->i_size) {
760 struct btrfs_trans_handle *trans;
761 struct btrfs_root *root = BTRFS_I(inode)->root;
762 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
763
764 u64 mask = root->sectorsize - 1;
765 u64 pos = (inode->i_size + mask) & ~mask;
766 u64 block_end = attr->ia_size | mask;
767 u64 hole_size;
768 u64 alloc_hint;
769
770 if (attr->ia_size <= pos)
771 goto out;
772
773 btrfs_truncate_page(inode->i_mapping, inode->i_size);
774
775 lock_extent(em_tree, pos, block_end, GFP_NOFS);
776 hole_size = (attr->ia_size - pos + mask) & ~mask;
777
778 mutex_lock(&root->fs_info->fs_mutex);
779 trans = btrfs_start_transaction(root, 1);
780 btrfs_set_trans_block_group(trans, inode);
781 err = btrfs_drop_extents(trans, root, inode,
782 pos, pos + hole_size, pos,
783 &alloc_hint);
784
785 err = btrfs_insert_file_extent(trans, root, inode->i_ino,
786 pos, 0, 0, hole_size);
787 btrfs_end_transaction(trans, root);
788 mutex_unlock(&root->fs_info->fs_mutex);
789 unlock_extent(em_tree, pos, block_end, GFP_NOFS);
790 if (err)
791 return err;
792 }
793 out:
794 err = inode_setattr(inode, attr);
795
796 return err;
797 }
798 void btrfs_delete_inode(struct inode *inode)
799 {
800 struct btrfs_trans_handle *trans;
801 struct btrfs_root *root = BTRFS_I(inode)->root;
802 unsigned long nr;
803 int ret;
804
805 truncate_inode_pages(&inode->i_data, 0);
806 if (is_bad_inode(inode)) {
807 goto no_delete;
808 }
809
810 inode->i_size = 0;
811 mutex_lock(&root->fs_info->fs_mutex);
812 trans = btrfs_start_transaction(root, 1);
813
814 btrfs_set_trans_block_group(trans, inode);
815 ret = btrfs_truncate_in_trans(trans, root, inode);
816 if (ret)
817 goto no_delete_lock;
818 ret = btrfs_free_inode(trans, root, inode);
819 if (ret)
820 goto no_delete_lock;
821 nr = trans->blocks_used;
822
823 btrfs_end_transaction(trans, root);
824 mutex_unlock(&root->fs_info->fs_mutex);
825 btrfs_btree_balance_dirty(root, nr);
826 return;
827
828 no_delete_lock:
829 nr = trans->blocks_used;
830 btrfs_end_transaction(trans, root);
831 mutex_unlock(&root->fs_info->fs_mutex);
832 btrfs_btree_balance_dirty(root, nr);
833 no_delete:
834 clear_inode(inode);
835 }
836
837 /*
838 * this returns the key found in the dir entry in the location pointer.
839 * If no dir entries were found, location->objectid is 0.
840 */
841 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
842 struct btrfs_key *location)
843 {
844 const char *name = dentry->d_name.name;
845 int namelen = dentry->d_name.len;
846 struct btrfs_dir_item *di;
847 struct btrfs_path *path;
848 struct btrfs_root *root = BTRFS_I(dir)->root;
849 int ret;
850
851 path = btrfs_alloc_path();
852 BUG_ON(!path);
853 di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
854 namelen, 0);
855 if (!di || IS_ERR(di)) {
856 location->objectid = 0;
857 ret = 0;
858 goto out;
859 }
860 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
861 out:
862 btrfs_release_path(root, path);
863 btrfs_free_path(path);
864 return ret;
865 }
866
867 /*
868 * when we hit a tree root in a directory, the btrfs part of the inode
869 * needs to be changed to reflect the root directory of the tree root. This
870 * is kind of like crossing a mount point.
871 */
872 static int fixup_tree_root_location(struct btrfs_root *root,
873 struct btrfs_key *location,
874 struct btrfs_root **sub_root,
875 struct dentry *dentry)
876 {
877 struct btrfs_path *path;
878 struct btrfs_root_item *ri;
879
880 if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY)
881 return 0;
882 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
883 return 0;
884
885 path = btrfs_alloc_path();
886 BUG_ON(!path);
887 mutex_lock(&root->fs_info->fs_mutex);
888
889 *sub_root = btrfs_read_fs_root(root->fs_info, location,
890 dentry->d_name.name,
891 dentry->d_name.len);
892 if (IS_ERR(*sub_root))
893 return PTR_ERR(*sub_root);
894
895 ri = &(*sub_root)->root_item;
896 location->objectid = btrfs_root_dirid(ri);
897 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
898 location->offset = 0;
899
900 btrfs_free_path(path);
901 mutex_unlock(&root->fs_info->fs_mutex);
902 return 0;
903 }
904
905 static int btrfs_init_locked_inode(struct inode *inode, void *p)
906 {
907 struct btrfs_iget_args *args = p;
908 inode->i_ino = args->ino;
909 BTRFS_I(inode)->root = args->root;
910 extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
911 inode->i_mapping, GFP_NOFS);
912 return 0;
913 }
914
915 static int btrfs_find_actor(struct inode *inode, void *opaque)
916 {
917 struct btrfs_iget_args *args = opaque;
918 return (args->ino == inode->i_ino &&
919 args->root == BTRFS_I(inode)->root);
920 }
921
922 struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
923 struct btrfs_root *root)
924 {
925 struct inode *inode;
926 struct btrfs_iget_args args;
927 args.ino = objectid;
928 args.root = root;
929
930 inode = iget5_locked(s, objectid, btrfs_find_actor,
931 btrfs_init_locked_inode,
932 (void *)&args);
933 return inode;
934 }
935
936 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
937 struct nameidata *nd)
938 {
939 struct inode * inode;
940 struct btrfs_inode *bi = BTRFS_I(dir);
941 struct btrfs_root *root = bi->root;
942 struct btrfs_root *sub_root = root;
943 struct btrfs_key location;
944 int ret;
945
946 if (dentry->d_name.len > BTRFS_NAME_LEN)
947 return ERR_PTR(-ENAMETOOLONG);
948
949 mutex_lock(&root->fs_info->fs_mutex);
950 ret = btrfs_inode_by_name(dir, dentry, &location);
951 mutex_unlock(&root->fs_info->fs_mutex);
952
953 if (ret < 0)
954 return ERR_PTR(ret);
955
956 inode = NULL;
957 if (location.objectid) {
958 ret = fixup_tree_root_location(root, &location, &sub_root,
959 dentry);
960 if (ret < 0)
961 return ERR_PTR(ret);
962 if (ret > 0)
963 return ERR_PTR(-ENOENT);
964 inode = btrfs_iget_locked(dir->i_sb, location.objectid,
965 sub_root);
966 if (!inode)
967 return ERR_PTR(-EACCES);
968 if (inode->i_state & I_NEW) {
969 /* the inode and parent dir are two different roots */
970 if (sub_root != root) {
971 igrab(inode);
972 sub_root->inode = inode;
973 }
974 BTRFS_I(inode)->root = sub_root;
975 memcpy(&BTRFS_I(inode)->location, &location,
976 sizeof(location));
977 btrfs_read_locked_inode(inode);
978 unlock_new_inode(inode);
979 }
980 }
981 return d_splice_alias(inode, dentry);
982 }
983
984 static unsigned char btrfs_filetype_table[] = {
985 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
986 };
987
988 static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
989 {
990 struct inode *inode = filp->f_path.dentry->d_inode;
991 struct btrfs_root *root = BTRFS_I(inode)->root;
992 struct btrfs_item *item;
993 struct btrfs_dir_item *di;
994 struct btrfs_key key;
995 struct btrfs_key found_key;
996 struct btrfs_path *path;
997 int ret;
998 u32 nritems;
999 struct extent_buffer *leaf;
1000 int slot;
1001 int advance;
1002 unsigned char d_type;
1003 int over = 0;
1004 u32 di_cur;
1005 u32 di_total;
1006 u32 di_len;
1007 int key_type = BTRFS_DIR_INDEX_KEY;
1008 char tmp_name[32];
1009 char *name_ptr;
1010 int name_len;
1011
1012 /* FIXME, use a real flag for deciding about the key type */
1013 if (root->fs_info->tree_root == root)
1014 key_type = BTRFS_DIR_ITEM_KEY;
1015
1016 mutex_lock(&root->fs_info->fs_mutex);
1017 key.objectid = inode->i_ino;
1018 btrfs_set_key_type(&key, key_type);
1019 key.offset = filp->f_pos;
1020
1021 path = btrfs_alloc_path();
1022 path->reada = 2;
1023 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1024 if (ret < 0)
1025 goto err;
1026 advance = 0;
1027 while(1) {
1028 leaf = path->nodes[0];
1029 nritems = btrfs_header_nritems(leaf);
1030 slot = path->slots[0];
1031 if (advance || slot >= nritems) {
1032 if (slot >= nritems -1) {
1033 ret = btrfs_next_leaf(root, path);
1034 if (ret)
1035 break;
1036 leaf = path->nodes[0];
1037 nritems = btrfs_header_nritems(leaf);
1038 slot = path->slots[0];
1039 } else {
1040 slot++;
1041 path->slots[0]++;
1042 }
1043 }
1044 advance = 1;
1045 item = btrfs_item_nr(leaf, slot);
1046 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1047
1048 if (found_key.objectid != key.objectid)
1049 break;
1050 if (btrfs_key_type(&found_key) != key_type)
1051 break;
1052 if (found_key.offset < filp->f_pos)
1053 continue;
1054
1055 filp->f_pos = found_key.offset;
1056 advance = 1;
1057 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
1058 di_cur = 0;
1059 di_total = btrfs_item_size(leaf, item);
1060 while(di_cur < di_total) {
1061 struct btrfs_key location;
1062
1063 name_len = btrfs_dir_name_len(leaf, di);
1064 if (name_len < 32) {
1065 name_ptr = tmp_name;
1066 } else {
1067 name_ptr = kmalloc(name_len, GFP_NOFS);
1068 BUG_ON(!name_ptr);
1069 }
1070 read_extent_buffer(leaf, name_ptr,
1071 (unsigned long)(di + 1), name_len);
1072
1073 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
1074 btrfs_dir_item_key_to_cpu(leaf, di, &location);
1075
1076 over = filldir(dirent, name_ptr, name_len,
1077 found_key.offset,
1078 location.objectid,
1079 d_type);
1080
1081 if (name_ptr != tmp_name)
1082 kfree(name_ptr);
1083
1084 if (over)
1085 goto nopos;
1086 di_len = btrfs_dir_name_len(leaf, di) + sizeof(*di);
1087 di_cur += di_len;
1088 di = (struct btrfs_dir_item *)((char *)di + di_len);
1089 }
1090 }
1091 filp->f_pos++;
1092 nopos:
1093 ret = 0;
1094 err:
1095 btrfs_release_path(root, path);
1096 btrfs_free_path(path);
1097 mutex_unlock(&root->fs_info->fs_mutex);
1098 return ret;
1099 }
1100
1101 int btrfs_write_inode(struct inode *inode, int wait)
1102 {
1103 struct btrfs_root *root = BTRFS_I(inode)->root;
1104 struct btrfs_trans_handle *trans;
1105 int ret = 0;
1106
1107 if (wait) {
1108 mutex_lock(&root->fs_info->fs_mutex);
1109 trans = btrfs_start_transaction(root, 1);
1110 btrfs_set_trans_block_group(trans, inode);
1111 ret = btrfs_commit_transaction(trans, root);
1112 mutex_unlock(&root->fs_info->fs_mutex);
1113 }
1114 return ret;
1115 }
1116
1117 /*
1118 * This is somewhat expensive, updating the tree every time the
1119 * inode changes. But, it is most likely to find the inode in cache.
1120 * FIXME, needs more benchmarking...there are no reasons other than performance
1121 * to keep or drop this code.
1122 */
1123 void btrfs_dirty_inode(struct inode *inode)
1124 {
1125 struct btrfs_root *root = BTRFS_I(inode)->root;
1126 struct btrfs_trans_handle *trans;
1127
1128 mutex_lock(&root->fs_info->fs_mutex);
1129 trans = btrfs_start_transaction(root, 1);
1130 btrfs_set_trans_block_group(trans, inode);
1131 btrfs_update_inode(trans, root, inode);
1132 btrfs_end_transaction(trans, root);
1133 mutex_unlock(&root->fs_info->fs_mutex);
1134 }
1135
1136 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
1137 struct btrfs_root *root,
1138 u64 objectid,
1139 struct btrfs_block_group_cache *group,
1140 int mode)
1141 {
1142 struct inode *inode;
1143 struct btrfs_inode_item *inode_item;
1144 struct btrfs_key *location;
1145 struct btrfs_path *path;
1146 int ret;
1147 int owner;
1148
1149 path = btrfs_alloc_path();
1150 BUG_ON(!path);
1151
1152 inode = new_inode(root->fs_info->sb);
1153 if (!inode)
1154 return ERR_PTR(-ENOMEM);
1155
1156 extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
1157 inode->i_mapping, GFP_NOFS);
1158 BTRFS_I(inode)->root = root;
1159
1160 if (mode & S_IFDIR)
1161 owner = 0;
1162 else
1163 owner = 1;
1164 group = btrfs_find_block_group(root, group, 0, 0, owner);
1165 BTRFS_I(inode)->block_group = group;
1166
1167 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
1168 if (ret)
1169 goto fail;
1170
1171 inode->i_uid = current->fsuid;
1172 inode->i_gid = current->fsgid;
1173 inode->i_mode = mode;
1174 inode->i_ino = objectid;
1175 inode->i_blocks = 0;
1176 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1177 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1178 struct btrfs_inode_item);
1179 fill_inode_item(path->nodes[0], inode_item, inode);
1180 btrfs_mark_buffer_dirty(path->nodes[0]);
1181 btrfs_free_path(path);
1182
1183 location = &BTRFS_I(inode)->location;
1184 location->objectid = objectid;
1185 location->offset = 0;
1186 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
1187
1188 insert_inode_hash(inode);
1189 return inode;
1190 fail:
1191 btrfs_free_path(path);
1192 return ERR_PTR(ret);
1193 }
1194
1195 static inline u8 btrfs_inode_type(struct inode *inode)
1196 {
1197 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
1198 }
1199
1200 static int btrfs_add_link(struct btrfs_trans_handle *trans,
1201 struct dentry *dentry, struct inode *inode)
1202 {
1203 int ret;
1204 struct btrfs_key key;
1205 struct btrfs_root *root = BTRFS_I(dentry->d_parent->d_inode)->root;
1206 struct inode *parent_inode;
1207
1208 key.objectid = inode->i_ino;
1209 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
1210 key.offset = 0;
1211
1212 ret = btrfs_insert_dir_item(trans, root,
1213 dentry->d_name.name, dentry->d_name.len,
1214 dentry->d_parent->d_inode->i_ino,
1215 &key, btrfs_inode_type(inode));
1216 if (ret == 0) {
1217 parent_inode = dentry->d_parent->d_inode;
1218 parent_inode->i_size += dentry->d_name.len * 2;
1219 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
1220 ret = btrfs_update_inode(trans, root,
1221 dentry->d_parent->d_inode);
1222 }
1223 return ret;
1224 }
1225
1226 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
1227 struct dentry *dentry, struct inode *inode)
1228 {
1229 int err = btrfs_add_link(trans, dentry, inode);
1230 if (!err) {
1231 d_instantiate(dentry, inode);
1232 return 0;
1233 }
1234 if (err > 0)
1235 err = -EEXIST;
1236 return err;
1237 }
1238
1239 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
1240 int mode, dev_t rdev)
1241 {
1242 struct btrfs_trans_handle *trans;
1243 struct btrfs_root *root = BTRFS_I(dir)->root;
1244 struct inode *inode;
1245 int err;
1246 int drop_inode = 0;
1247 u64 objectid;
1248 unsigned long nr;
1249
1250 if (!new_valid_dev(rdev))
1251 return -EINVAL;
1252
1253 mutex_lock(&root->fs_info->fs_mutex);
1254 trans = btrfs_start_transaction(root, 1);
1255 btrfs_set_trans_block_group(trans, dir);
1256
1257 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1258 if (err) {
1259 err = -ENOSPC;
1260 goto out_unlock;
1261 }
1262
1263 inode = btrfs_new_inode(trans, root, objectid,
1264 BTRFS_I(dir)->block_group, mode);
1265 err = PTR_ERR(inode);
1266 if (IS_ERR(inode))
1267 goto out_unlock;
1268
1269 btrfs_set_trans_block_group(trans, inode);
1270 err = btrfs_add_nondir(trans, dentry, inode);
1271 if (err)
1272 drop_inode = 1;
1273 else {
1274 inode->i_op = &btrfs_special_inode_operations;
1275 init_special_inode(inode, inode->i_mode, rdev);
1276 btrfs_update_inode(trans, root, inode);
1277 }
1278 dir->i_sb->s_dirt = 1;
1279 btrfs_update_inode_block_group(trans, inode);
1280 btrfs_update_inode_block_group(trans, dir);
1281 out_unlock:
1282 nr = trans->blocks_used;
1283 btrfs_end_transaction(trans, root);
1284 mutex_unlock(&root->fs_info->fs_mutex);
1285
1286 if (drop_inode) {
1287 inode_dec_link_count(inode);
1288 iput(inode);
1289 }
1290 btrfs_btree_balance_dirty(root, nr);
1291 return err;
1292 }
1293
1294 static int btrfs_create(struct inode *dir, struct dentry *dentry,
1295 int mode, struct nameidata *nd)
1296 {
1297 struct btrfs_trans_handle *trans;
1298 struct btrfs_root *root = BTRFS_I(dir)->root;
1299 struct inode *inode;
1300 int err;
1301 int drop_inode = 0;
1302 unsigned long nr;
1303 u64 objectid;
1304
1305 mutex_lock(&root->fs_info->fs_mutex);
1306 trans = btrfs_start_transaction(root, 1);
1307 btrfs_set_trans_block_group(trans, dir);
1308
1309 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1310 if (err) {
1311 err = -ENOSPC;
1312 goto out_unlock;
1313 }
1314
1315 inode = btrfs_new_inode(trans, root, objectid,
1316 BTRFS_I(dir)->block_group, mode);
1317 err = PTR_ERR(inode);
1318 if (IS_ERR(inode))
1319 goto out_unlock;
1320
1321 btrfs_set_trans_block_group(trans, inode);
1322 err = btrfs_add_nondir(trans, dentry, inode);
1323 if (err)
1324 drop_inode = 1;
1325 else {
1326 inode->i_mapping->a_ops = &btrfs_aops;
1327 inode->i_fop = &btrfs_file_operations;
1328 inode->i_op = &btrfs_file_inode_operations;
1329 extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
1330 inode->i_mapping, GFP_NOFS);
1331 BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
1332 }
1333 dir->i_sb->s_dirt = 1;
1334 btrfs_update_inode_block_group(trans, inode);
1335 btrfs_update_inode_block_group(trans, dir);
1336 out_unlock:
1337 nr = trans->blocks_used;
1338 btrfs_end_transaction(trans, root);
1339 mutex_unlock(&root->fs_info->fs_mutex);
1340
1341 if (drop_inode) {
1342 inode_dec_link_count(inode);
1343 iput(inode);
1344 }
1345 btrfs_btree_balance_dirty(root, nr);
1346 return err;
1347 }
1348
1349 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
1350 struct dentry *dentry)
1351 {
1352 struct btrfs_trans_handle *trans;
1353 struct btrfs_root *root = BTRFS_I(dir)->root;
1354 struct inode *inode = old_dentry->d_inode;
1355 unsigned long nr;
1356 int err;
1357 int drop_inode = 0;
1358
1359 if (inode->i_nlink == 0)
1360 return -ENOENT;
1361
1362 inc_nlink(inode);
1363 mutex_lock(&root->fs_info->fs_mutex);
1364 trans = btrfs_start_transaction(root, 1);
1365
1366 btrfs_set_trans_block_group(trans, dir);
1367 atomic_inc(&inode->i_count);
1368 err = btrfs_add_nondir(trans, dentry, inode);
1369
1370 if (err)
1371 drop_inode = 1;
1372
1373 dir->i_sb->s_dirt = 1;
1374 btrfs_update_inode_block_group(trans, dir);
1375 err = btrfs_update_inode(trans, root, inode);
1376
1377 if (err)
1378 drop_inode = 1;
1379
1380 nr = trans->blocks_used;
1381 btrfs_end_transaction(trans, root);
1382 mutex_unlock(&root->fs_info->fs_mutex);
1383
1384 if (drop_inode) {
1385 inode_dec_link_count(inode);
1386 iput(inode);
1387 }
1388 btrfs_btree_balance_dirty(root, nr);
1389 return err;
1390 }
1391
1392 static int btrfs_make_empty_dir(struct btrfs_trans_handle *trans,
1393 struct btrfs_root *root,
1394 u64 objectid, u64 dirid)
1395 {
1396 int ret;
1397 char buf[2];
1398 struct btrfs_key key;
1399
1400 buf[0] = '.';
1401 buf[1] = '.';
1402
1403 key.objectid = objectid;
1404 key.offset = 0;
1405 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
1406
1407 ret = btrfs_insert_dir_item(trans, root, buf, 1, objectid,
1408 &key, BTRFS_FT_DIR);
1409 if (ret)
1410 goto error;
1411
1412 key.objectid = dirid;
1413 ret = btrfs_insert_dir_item(trans, root, buf, 2, objectid,
1414 &key, BTRFS_FT_DIR);
1415 if (ret)
1416 goto error;
1417 error:
1418 return ret;
1419 }
1420
1421 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1422 {
1423 struct inode *inode;
1424 struct btrfs_trans_handle *trans;
1425 struct btrfs_root *root = BTRFS_I(dir)->root;
1426 int err = 0;
1427 int drop_on_err = 0;
1428 u64 objectid;
1429 unsigned long nr = 1;
1430
1431 mutex_lock(&root->fs_info->fs_mutex);
1432 trans = btrfs_start_transaction(root, 1);
1433 btrfs_set_trans_block_group(trans, dir);
1434
1435 if (IS_ERR(trans)) {
1436 err = PTR_ERR(trans);
1437 goto out_unlock;
1438 }
1439
1440 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1441 if (err) {
1442 err = -ENOSPC;
1443 goto out_unlock;
1444 }
1445
1446 inode = btrfs_new_inode(trans, root, objectid,
1447 BTRFS_I(dir)->block_group, S_IFDIR | mode);
1448 if (IS_ERR(inode)) {
1449 err = PTR_ERR(inode);
1450 goto out_fail;
1451 }
1452
1453 drop_on_err = 1;
1454 inode->i_op = &btrfs_dir_inode_operations;
1455 inode->i_fop = &btrfs_dir_file_operations;
1456 btrfs_set_trans_block_group(trans, inode);
1457
1458 err = btrfs_make_empty_dir(trans, root, inode->i_ino, dir->i_ino);
1459 if (err)
1460 goto out_fail;
1461
1462 inode->i_size = 6;
1463 err = btrfs_update_inode(trans, root, inode);
1464 if (err)
1465 goto out_fail;
1466
1467 err = btrfs_add_link(trans, dentry, inode);
1468 if (err)
1469 goto out_fail;
1470
1471 d_instantiate(dentry, inode);
1472 drop_on_err = 0;
1473 dir->i_sb->s_dirt = 1;
1474 btrfs_update_inode_block_group(trans, inode);
1475 btrfs_update_inode_block_group(trans, dir);
1476
1477 out_fail:
1478 nr = trans->blocks_used;
1479 btrfs_end_transaction(trans, root);
1480
1481 out_unlock:
1482 mutex_unlock(&root->fs_info->fs_mutex);
1483 if (drop_on_err)
1484 iput(inode);
1485 btrfs_btree_balance_dirty(root, nr);
1486 return err;
1487 }
1488
1489 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
1490 size_t page_offset, u64 start, u64 end,
1491 int create)
1492 {
1493 int ret;
1494 int err = 0;
1495 u64 bytenr;
1496 u64 extent_start = 0;
1497 u64 extent_end = 0;
1498 u64 objectid = inode->i_ino;
1499 u32 found_type;
1500 int failed_insert = 0;
1501 struct btrfs_path *path;
1502 struct btrfs_root *root = BTRFS_I(inode)->root;
1503 struct btrfs_file_extent_item *item;
1504 struct extent_buffer *leaf;
1505 struct btrfs_key found_key;
1506 struct extent_map *em = NULL;
1507 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1508 struct btrfs_trans_handle *trans = NULL;
1509
1510 path = btrfs_alloc_path();
1511 BUG_ON(!path);
1512 mutex_lock(&root->fs_info->fs_mutex);
1513
1514 again:
1515 em = lookup_extent_mapping(em_tree, start, end);
1516 if (em) {
1517 goto out;
1518 }
1519 if (!em) {
1520 em = alloc_extent_map(GFP_NOFS);
1521 if (!em) {
1522 err = -ENOMEM;
1523 goto out;
1524 }
1525 em->start = EXTENT_MAP_HOLE;
1526 em->end = EXTENT_MAP_HOLE;
1527 }
1528 em->bdev = inode->i_sb->s_bdev;
1529 ret = btrfs_lookup_file_extent(NULL, root, path,
1530 objectid, start, 0);
1531 if (ret < 0) {
1532 err = ret;
1533 goto out;
1534 }
1535
1536 if (ret != 0) {
1537 if (path->slots[0] == 0)
1538 goto not_found;
1539 path->slots[0]--;
1540 }
1541
1542 leaf = path->nodes[0];
1543 item = btrfs_item_ptr(leaf, path->slots[0],
1544 struct btrfs_file_extent_item);
1545 /* are we inside the extent that was found? */
1546 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1547 found_type = btrfs_key_type(&found_key);
1548 if (found_key.objectid != objectid ||
1549 found_type != BTRFS_EXTENT_DATA_KEY) {
1550 goto not_found;
1551 }
1552
1553 found_type = btrfs_file_extent_type(leaf, item);
1554 extent_start = found_key.offset;
1555 if (found_type == BTRFS_FILE_EXTENT_REG) {
1556 extent_end = extent_start +
1557 btrfs_file_extent_num_bytes(leaf, item);
1558 err = 0;
1559 if (start < extent_start || start >= extent_end) {
1560 em->start = start;
1561 if (start < extent_start) {
1562 if (end < extent_start)
1563 goto not_found;
1564 em->end = extent_end - 1;
1565 } else {
1566 em->end = end;
1567 }
1568 goto not_found_em;
1569 }
1570 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
1571 if (bytenr == 0) {
1572 em->start = extent_start;
1573 em->end = extent_end - 1;
1574 em->block_start = EXTENT_MAP_HOLE;
1575 em->block_end = EXTENT_MAP_HOLE;
1576 goto insert;
1577 }
1578 bytenr += btrfs_file_extent_offset(leaf, item);
1579 em->block_start = bytenr;
1580 em->block_end = em->block_start +
1581 btrfs_file_extent_num_bytes(leaf, item) - 1;
1582 em->start = extent_start;
1583 em->end = extent_end - 1;
1584 goto insert;
1585 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
1586 unsigned long ptr;
1587 char *map;
1588 size_t size;
1589 size_t extent_offset;
1590 size_t copy_size;
1591
1592 size = btrfs_file_extent_inline_len(leaf, btrfs_item_nr(leaf,
1593 path->slots[0]));
1594
1595 extent_end = (extent_start + size) |
1596 ((u64)root->sectorsize - 1);
1597 if (start < extent_start || start >= extent_end) {
1598 em->start = start;
1599 if (start < extent_start) {
1600 if (end < extent_start)
1601 goto not_found;
1602 em->end = extent_end;
1603 } else {
1604 em->end = end;
1605 }
1606 goto not_found_em;
1607 }
1608
1609 extent_offset = (page->index << PAGE_CACHE_SHIFT) -
1610 extent_start;
1611 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
1612 map = kmap(page);
1613 copy_size = min_t(u64, PAGE_CACHE_SIZE - page_offset,
1614 size - extent_offset);
1615
1616 em->block_start = EXTENT_MAP_INLINE;
1617 em->block_end = EXTENT_MAP_INLINE;
1618 em->start = extent_start + extent_offset;
1619 em->end = (em->start + copy_size -1) |
1620 ((u64)root->sectorsize -1);
1621
1622 if (!page) {
1623 goto insert;
1624 }
1625
1626 read_extent_buffer(leaf, map + page_offset, ptr, copy_size);
1627 /*
1628 memset(map + page_offset + copy_size, 0,
1629 PAGE_CACHE_SIZE - copy_size - page_offset);
1630 */
1631 flush_dcache_page(page);
1632 kunmap(page);
1633 set_extent_uptodate(em_tree, em->start, em->end, GFP_NOFS);
1634 goto insert;
1635 } else {
1636 printk("unkknown found_type %d\n", found_type);
1637 WARN_ON(1);
1638 }
1639 not_found:
1640 em->start = start;
1641 em->end = end;
1642 not_found_em:
1643 em->block_start = EXTENT_MAP_HOLE;
1644 em->block_end = EXTENT_MAP_HOLE;
1645 insert:
1646 btrfs_release_path(root, path);
1647 if (em->start > start || em->end < start) {
1648 printk("bad extent! em: [%Lu %Lu] passed [%Lu %Lu]\n", em->start, em->end, start, end);
1649 err = -EIO;
1650 goto out;
1651 }
1652 ret = add_extent_mapping(em_tree, em);
1653 if (ret == -EEXIST) {
1654 free_extent_map(em);
1655 em = NULL;
1656 failed_insert++;
1657 if (failed_insert > 5) {
1658 printk("failing to insert %Lu %Lu\n", start, end);
1659 err = -EIO;
1660 goto out;
1661 }
1662 goto again;
1663 }
1664 err = 0;
1665 out:
1666 btrfs_free_path(path);
1667 if (trans) {
1668 ret = btrfs_end_transaction(trans, root);
1669 if (!err)
1670 err = ret;
1671 }
1672 mutex_unlock(&root->fs_info->fs_mutex);
1673 if (err) {
1674 free_extent_map(em);
1675 WARN_ON(1);
1676 return ERR_PTR(err);
1677 }
1678 return em;
1679 }
1680
1681 static sector_t btrfs_bmap(struct address_space *mapping, sector_t iblock)
1682 {
1683 return extent_bmap(mapping, iblock, btrfs_get_extent);
1684 }
1685
1686 static int btrfs_prepare_write(struct file *file, struct page *page,
1687 unsigned from, unsigned to)
1688 {
1689 return extent_prepare_write(&BTRFS_I(page->mapping->host)->extent_tree,
1690 page->mapping->host, page, from, to,
1691 btrfs_get_extent);
1692 }
1693
1694 int btrfs_readpage(struct file *file, struct page *page)
1695 {
1696 struct extent_map_tree *tree;
1697 tree = &BTRFS_I(page->mapping->host)->extent_tree;
1698 return extent_read_full_page(tree, page, btrfs_get_extent);
1699 }
1700 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
1701 {
1702 struct extent_map_tree *tree;
1703
1704
1705 if (current->flags & PF_MEMALLOC) {
1706 redirty_page_for_writepage(wbc, page);
1707 unlock_page(page);
1708 return 0;
1709 }
1710 tree = &BTRFS_I(page->mapping->host)->extent_tree;
1711 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
1712 }
1713
1714 static int btrfs_releasepage(struct page *page, gfp_t unused_gfp_flags)
1715 {
1716 struct extent_map_tree *tree;
1717 int ret;
1718
1719 tree = &BTRFS_I(page->mapping->host)->extent_tree;
1720 ret = try_release_extent_mapping(tree, page);
1721 if (ret == 1) {
1722 ClearPagePrivate(page);
1723 set_page_private(page, 0);
1724 page_cache_release(page);
1725 }
1726 return ret;
1727 }
1728
1729 static void btrfs_invalidatepage(struct page *page, unsigned long offset)
1730 {
1731 struct extent_map_tree *tree;
1732
1733 tree = &BTRFS_I(page->mapping->host)->extent_tree;
1734 extent_invalidatepage(tree, page, offset);
1735 btrfs_releasepage(page, GFP_NOFS);
1736 }
1737
1738 /*
1739 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
1740 * called from a page fault handler when a page is first dirtied. Hence we must
1741 * be careful to check for EOF conditions here. We set the page up correctly
1742 * for a written page which means we get ENOSPC checking when writing into
1743 * holes and correct delalloc and unwritten extent mapping on filesystems that
1744 * support these features.
1745 *
1746 * We are not allowed to take the i_mutex here so we have to play games to
1747 * protect against truncate races as the page could now be beyond EOF. Because
1748 * vmtruncate() writes the inode size before removing pages, once we have the
1749 * page lock we can determine safely if the page is beyond EOF. If it is not
1750 * beyond EOF, then the page is guaranteed safe against truncation until we
1751 * unlock the page.
1752 */
1753 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
1754 {
1755 struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
1756 unsigned long end;
1757 loff_t size;
1758 int ret = -EINVAL;
1759 u64 page_start;
1760
1761 down_read(&BTRFS_I(inode)->root->snap_sem);
1762 lock_page(page);
1763 wait_on_page_writeback(page);
1764 size = i_size_read(inode);
1765 page_start = page->index << PAGE_CACHE_SHIFT;
1766
1767 if ((page->mapping != inode->i_mapping) ||
1768 (page_start > size)) {
1769 /* page got truncated out from underneath us */
1770 goto out_unlock;
1771 }
1772
1773 /* page is wholly or partially inside EOF */
1774 if (page_start + PAGE_CACHE_SIZE > size)
1775 end = size & ~PAGE_CACHE_MASK;
1776 else
1777 end = PAGE_CACHE_SIZE;
1778
1779 ret = btrfs_cow_one_page(inode, page, end);
1780
1781 out_unlock:
1782 up_read(&BTRFS_I(inode)->root->snap_sem);
1783 unlock_page(page);
1784 return ret;
1785 }
1786
1787 static void btrfs_truncate(struct inode *inode)
1788 {
1789 struct btrfs_root *root = BTRFS_I(inode)->root;
1790 int ret;
1791 struct btrfs_trans_handle *trans;
1792 unsigned long nr;
1793
1794 if (!S_ISREG(inode->i_mode))
1795 return;
1796 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
1797 return;
1798
1799 btrfs_truncate_page(inode->i_mapping, inode->i_size);
1800
1801 mutex_lock(&root->fs_info->fs_mutex);
1802 trans = btrfs_start_transaction(root, 1);
1803 btrfs_set_trans_block_group(trans, inode);
1804
1805 /* FIXME, add redo link to tree so we don't leak on crash */
1806 ret = btrfs_truncate_in_trans(trans, root, inode);
1807 btrfs_update_inode(trans, root, inode);
1808 nr = trans->blocks_used;
1809
1810 ret = btrfs_end_transaction(trans, root);
1811 BUG_ON(ret);
1812 mutex_unlock(&root->fs_info->fs_mutex);
1813 btrfs_btree_balance_dirty(root, nr);
1814 }
1815
1816 int btrfs_commit_write(struct file *file, struct page *page,
1817 unsigned from, unsigned to)
1818 {
1819 return extent_commit_write(&BTRFS_I(page->mapping->host)->extent_tree,
1820 page->mapping->host, page, from, to);
1821 }
1822
1823 static int create_subvol(struct btrfs_root *root, char *name, int namelen)
1824 {
1825 struct btrfs_trans_handle *trans;
1826 struct btrfs_key key;
1827 struct btrfs_root_item root_item;
1828 struct btrfs_inode_item *inode_item;
1829 struct extent_buffer *leaf;
1830 struct btrfs_root *new_root;
1831 struct inode *inode;
1832 struct inode *dir;
1833 int ret;
1834 int err;
1835 u64 objectid;
1836 u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
1837 unsigned long nr = 1;
1838
1839 mutex_lock(&root->fs_info->fs_mutex);
1840 trans = btrfs_start_transaction(root, 1);
1841 BUG_ON(!trans);
1842
1843 leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0, 0);
1844 if (IS_ERR(leaf))
1845 return PTR_ERR(leaf);
1846
1847 btrfs_set_header_nritems(leaf, 0);
1848 btrfs_set_header_level(leaf, 0);
1849 btrfs_set_header_bytenr(leaf, leaf->start);
1850 btrfs_set_header_generation(leaf, trans->transid);
1851 btrfs_set_header_owner(leaf, root->root_key.objectid);
1852 write_extent_buffer(leaf, root->fs_info->fsid,
1853 (unsigned long)btrfs_header_fsid(leaf),
1854 BTRFS_FSID_SIZE);
1855 btrfs_mark_buffer_dirty(leaf);
1856
1857 inode_item = &root_item.inode;
1858 memset(inode_item, 0, sizeof(*inode_item));
1859 inode_item->generation = cpu_to_le64(1);
1860 inode_item->size = cpu_to_le64(3);
1861 inode_item->nlink = cpu_to_le32(1);
1862 inode_item->nblocks = cpu_to_le64(1);
1863 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
1864
1865 btrfs_set_root_bytenr(&root_item, leaf->start);
1866 btrfs_set_root_level(&root_item, 0);
1867 btrfs_set_root_refs(&root_item, 1);
1868 btrfs_set_root_used(&root_item, 0);
1869
1870 memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
1871 root_item.drop_level = 0;
1872
1873 free_extent_buffer(leaf);
1874 leaf = NULL;
1875
1876 ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
1877 0, &objectid);
1878 if (ret)
1879 goto fail;
1880
1881 btrfs_set_root_dirid(&root_item, new_dirid);
1882
1883 key.objectid = objectid;
1884 key.offset = 1;
1885 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
1886 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
1887 &root_item);
1888 if (ret)
1889 goto fail;
1890
1891 /*
1892 * insert the directory item
1893 */
1894 key.offset = (u64)-1;
1895 dir = root->fs_info->sb->s_root->d_inode;
1896 ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
1897 name, namelen, dir->i_ino, &key,
1898 BTRFS_FT_DIR);
1899 if (ret)
1900 goto fail;
1901
1902 ret = btrfs_commit_transaction(trans, root);
1903 if (ret)
1904 goto fail_commit;
1905
1906 new_root = btrfs_read_fs_root(root->fs_info, &key, name, namelen);
1907 BUG_ON(!new_root);
1908
1909 trans = btrfs_start_transaction(new_root, 1);
1910 BUG_ON(!trans);
1911
1912 inode = btrfs_new_inode(trans, new_root, new_dirid,
1913 BTRFS_I(dir)->block_group, S_IFDIR | 0700);
1914 if (IS_ERR(inode))
1915 goto fail;
1916 inode->i_op = &btrfs_dir_inode_operations;
1917 inode->i_fop = &btrfs_dir_file_operations;
1918 new_root->inode = inode;
1919
1920 ret = btrfs_make_empty_dir(trans, new_root, new_dirid, new_dirid);
1921 if (ret)
1922 goto fail;
1923
1924 inode->i_nlink = 1;
1925 inode->i_size = 6;
1926 ret = btrfs_update_inode(trans, new_root, inode);
1927 if (ret)
1928 goto fail;
1929 fail:
1930 nr = trans->blocks_used;
1931 err = btrfs_commit_transaction(trans, root);
1932 if (err && !ret)
1933 ret = err;
1934 fail_commit:
1935 mutex_unlock(&root->fs_info->fs_mutex);
1936 btrfs_btree_balance_dirty(root, nr);
1937 return ret;
1938 }
1939
1940 static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
1941 {
1942 struct btrfs_trans_handle *trans;
1943 struct btrfs_key key;
1944 struct btrfs_root_item new_root_item;
1945 struct extent_buffer *tmp;
1946 int ret;
1947 int err;
1948 u64 objectid;
1949 unsigned long nr;
1950
1951 if (!root->ref_cows)
1952 return -EINVAL;
1953
1954 down_write(&root->snap_sem);
1955 freeze_bdev(root->fs_info->sb->s_bdev);
1956 thaw_bdev(root->fs_info->sb->s_bdev, root->fs_info->sb);
1957
1958 mutex_lock(&root->fs_info->fs_mutex);
1959 trans = btrfs_start_transaction(root, 1);
1960 BUG_ON(!trans);
1961
1962 ret = btrfs_update_inode(trans, root, root->inode);
1963 if (ret)
1964 goto fail;
1965
1966 ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
1967 0, &objectid);
1968 if (ret)
1969 goto fail;
1970
1971 memcpy(&new_root_item, &root->root_item,
1972 sizeof(new_root_item));
1973
1974 key.objectid = objectid;
1975 key.offset = 1;
1976 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
1977
1978 btrfs_cow_block(trans, root, root->node, NULL, 0, &tmp);
1979 btrfs_set_root_bytenr(&new_root_item, root->node->start);
1980 btrfs_set_root_level(&new_root_item, btrfs_header_level(root->node));
1981
1982 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
1983 &new_root_item);
1984 if (ret)
1985 goto fail;
1986
1987 /*
1988 * insert the directory item
1989 */
1990 key.offset = (u64)-1;
1991 ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
1992 name, namelen,
1993 root->fs_info->sb->s_root->d_inode->i_ino,
1994 &key, BTRFS_FT_DIR);
1995
1996 if (ret)
1997 goto fail;
1998
1999 ret = btrfs_inc_root_ref(trans, root);
2000 if (ret)
2001 goto fail;
2002 fail:
2003 nr = trans->blocks_used;
2004 err = btrfs_commit_transaction(trans, root);
2005
2006 if (err && !ret)
2007 ret = err;
2008
2009 mutex_unlock(&root->fs_info->fs_mutex);
2010 up_write(&root->snap_sem);
2011 btrfs_btree_balance_dirty(root, nr);
2012 return ret;
2013 }
2014
2015 static unsigned long force_ra(struct address_space *mapping,
2016 struct file_ra_state *ra, struct file *file,
2017 pgoff_t offset, pgoff_t last_index)
2018 {
2019 pgoff_t req_size;
2020
2021 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
2022 req_size = last_index - offset + 1;
2023 offset = page_cache_readahead(mapping, ra, file, offset, req_size);
2024 return offset;
2025 #else
2026 req_size = min(last_index - offset + 1, (pgoff_t)128);
2027 page_cache_sync_readahead(mapping, ra, file, offset, req_size);
2028 return offset + req_size;
2029 #endif
2030 }
2031
2032 int btrfs_defrag_file(struct file *file) {
2033 struct inode *inode = file->f_path.dentry->d_inode;
2034 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2035 struct page *page;
2036 unsigned long last_index;
2037 unsigned long ra_index = 0;
2038 u64 page_start;
2039 u64 page_end;
2040 unsigned long i;
2041
2042 mutex_lock(&inode->i_mutex);
2043 last_index = inode->i_size >> PAGE_CACHE_SHIFT;
2044 for (i = 0; i <= last_index; i++) {
2045 if (i == ra_index) {
2046 ra_index = force_ra(inode->i_mapping, &file->f_ra,
2047 file, ra_index, last_index);
2048 }
2049 page = grab_cache_page(inode->i_mapping, i);
2050 if (!page)
2051 goto out_unlock;
2052 if (!PageUptodate(page)) {
2053 btrfs_readpage(NULL, page);
2054 lock_page(page);
2055 if (!PageUptodate(page)) {
2056 unlock_page(page);
2057 page_cache_release(page);
2058 goto out_unlock;
2059 }
2060 }
2061 page_start = page->index << PAGE_CACHE_SHIFT;
2062 page_end = page_start + PAGE_CACHE_SIZE - 1;
2063
2064 lock_extent(em_tree, page_start, page_end, GFP_NOFS);
2065 set_extent_delalloc(em_tree, page_start,
2066 page_end, GFP_NOFS);
2067 unlock_extent(em_tree, page_start, page_end, GFP_NOFS);
2068 set_page_dirty(page);
2069 unlock_page(page);
2070 page_cache_release(page);
2071 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
2072 }
2073
2074 out_unlock:
2075 mutex_unlock(&inode->i_mutex);
2076 return 0;
2077 }
2078
2079 static int btrfs_ioctl_snap_create(struct btrfs_root *root, void __user *arg)
2080 {
2081 struct btrfs_ioctl_vol_args vol_args;
2082 struct btrfs_dir_item *di;
2083 struct btrfs_path *path;
2084 int namelen;
2085 u64 root_dirid;
2086
2087 if (copy_from_user(&vol_args, arg, sizeof(vol_args)))
2088 return -EFAULT;
2089
2090 namelen = strlen(vol_args.name);
2091 if (namelen > BTRFS_VOL_NAME_MAX)
2092 return -EINVAL;
2093 if (strchr(vol_args.name, '/'))
2094 return -EINVAL;
2095
2096 path = btrfs_alloc_path();
2097 if (!path)
2098 return -ENOMEM;
2099
2100 root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
2101 mutex_lock(&root->fs_info->fs_mutex);
2102 di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
2103 path, root_dirid,
2104 vol_args.name, namelen, 0);
2105 mutex_unlock(&root->fs_info->fs_mutex);
2106 btrfs_free_path(path);
2107 if (di && !IS_ERR(di))
2108 return -EEXIST;
2109 if (IS_ERR(di))
2110 return PTR_ERR(di);
2111
2112 if (root == root->fs_info->tree_root)
2113 return create_subvol(root, vol_args.name, namelen);
2114 return create_snapshot(root, vol_args.name, namelen);
2115 }
2116
2117 static int btrfs_ioctl_defrag(struct file *file)
2118 {
2119 struct inode *inode = file->f_path.dentry->d_inode;
2120 struct btrfs_root *root = BTRFS_I(inode)->root;
2121
2122 switch (inode->i_mode & S_IFMT) {
2123 case S_IFDIR:
2124 mutex_lock(&root->fs_info->fs_mutex);
2125 btrfs_defrag_root(root, 0);
2126 btrfs_defrag_root(root->fs_info->extent_root, 0);
2127 mutex_unlock(&root->fs_info->fs_mutex);
2128 break;
2129 case S_IFREG:
2130 btrfs_defrag_file(file);
2131 break;
2132 }
2133
2134 return 0;
2135 }
2136
2137 long btrfs_ioctl(struct file *file, unsigned int
2138 cmd, unsigned long arg)
2139 {
2140 struct btrfs_root *root = BTRFS_I(file->f_path.dentry->d_inode)->root;
2141
2142 switch (cmd) {
2143 case BTRFS_IOC_SNAP_CREATE:
2144 return btrfs_ioctl_snap_create(root, (void __user *)arg);
2145 case BTRFS_IOC_DEFRAG:
2146 return btrfs_ioctl_defrag(file);
2147 }
2148
2149 return -ENOTTY;
2150 }
2151
2152 /*
2153 * Called inside transaction, so use GFP_NOFS
2154 */
2155 struct inode *btrfs_alloc_inode(struct super_block *sb)
2156 {
2157 struct btrfs_inode *ei;
2158
2159 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
2160 if (!ei)
2161 return NULL;
2162 ei->last_trans = 0;
2163 return &ei->vfs_inode;
2164 }
2165
2166 void btrfs_destroy_inode(struct inode *inode)
2167 {
2168 WARN_ON(!list_empty(&inode->i_dentry));
2169 WARN_ON(inode->i_data.nrpages);
2170
2171 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
2172 }
2173
2174 static void init_once(void * foo, struct kmem_cache * cachep,
2175 unsigned long flags)
2176 {
2177 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
2178
2179 inode_init_once(&ei->vfs_inode);
2180 }
2181
2182 void btrfs_destroy_cachep(void)
2183 {
2184 if (btrfs_inode_cachep)
2185 kmem_cache_destroy(btrfs_inode_cachep);
2186 if (btrfs_trans_handle_cachep)
2187 kmem_cache_destroy(btrfs_trans_handle_cachep);
2188 if (btrfs_transaction_cachep)
2189 kmem_cache_destroy(btrfs_transaction_cachep);
2190 if (btrfs_bit_radix_cachep)
2191 kmem_cache_destroy(btrfs_bit_radix_cachep);
2192 if (btrfs_path_cachep)
2193 kmem_cache_destroy(btrfs_path_cachep);
2194 }
2195
2196 struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
2197 unsigned long extra_flags,
2198 void (*ctor)(void *, struct kmem_cache *,
2199 unsigned long))
2200 {
2201 return kmem_cache_create(name, size, 0, (SLAB_RECLAIM_ACCOUNT |
2202 SLAB_MEM_SPREAD | extra_flags), ctor
2203 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
2204 ,NULL
2205 #endif
2206 );
2207 }
2208
2209 int btrfs_init_cachep(void)
2210 {
2211 btrfs_inode_cachep = btrfs_cache_create("btrfs_inode_cache",
2212 sizeof(struct btrfs_inode),
2213 0, init_once);
2214 if (!btrfs_inode_cachep)
2215 goto fail;
2216 btrfs_trans_handle_cachep =
2217 btrfs_cache_create("btrfs_trans_handle_cache",
2218 sizeof(struct btrfs_trans_handle),
2219 0, NULL);
2220 if (!btrfs_trans_handle_cachep)
2221 goto fail;
2222 btrfs_transaction_cachep = btrfs_cache_create("btrfs_transaction_cache",
2223 sizeof(struct btrfs_transaction),
2224 0, NULL);
2225 if (!btrfs_transaction_cachep)
2226 goto fail;
2227 btrfs_path_cachep = btrfs_cache_create("btrfs_path_cache",
2228 sizeof(struct btrfs_path),
2229 0, NULL);
2230 if (!btrfs_path_cachep)
2231 goto fail;
2232 btrfs_bit_radix_cachep = btrfs_cache_create("btrfs_radix", 256,
2233 SLAB_DESTROY_BY_RCU, NULL);
2234 if (!btrfs_bit_radix_cachep)
2235 goto fail;
2236 return 0;
2237 fail:
2238 btrfs_destroy_cachep();
2239 return -ENOMEM;
2240 }
2241
2242 static int btrfs_getattr(struct vfsmount *mnt,
2243 struct dentry *dentry, struct kstat *stat)
2244 {
2245 struct inode *inode = dentry->d_inode;
2246 generic_fillattr(inode, stat);
2247 stat->blksize = 256 * 1024;
2248 return 0;
2249 }
2250
2251 static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
2252 struct inode * new_dir,struct dentry *new_dentry)
2253 {
2254 struct btrfs_trans_handle *trans;
2255 struct btrfs_root *root = BTRFS_I(old_dir)->root;
2256 struct inode *new_inode = new_dentry->d_inode;
2257 struct inode *old_inode = old_dentry->d_inode;
2258 struct timespec ctime = CURRENT_TIME;
2259 struct btrfs_path *path;
2260 struct btrfs_dir_item *di;
2261 int ret;
2262
2263 if (S_ISDIR(old_inode->i_mode) && new_inode &&
2264 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
2265 return -ENOTEMPTY;
2266 }
2267
2268 mutex_lock(&root->fs_info->fs_mutex);
2269 trans = btrfs_start_transaction(root, 1);
2270
2271 btrfs_set_trans_block_group(trans, new_dir);
2272 path = btrfs_alloc_path();
2273 if (!path) {
2274 ret = -ENOMEM;
2275 goto out_fail;
2276 }
2277
2278 old_dentry->d_inode->i_nlink++;
2279 old_dir->i_ctime = old_dir->i_mtime = ctime;
2280 new_dir->i_ctime = new_dir->i_mtime = ctime;
2281 old_inode->i_ctime = ctime;
2282
2283 if (S_ISDIR(old_inode->i_mode) && old_dir != new_dir) {
2284 struct btrfs_key *location = &BTRFS_I(new_dir)->location;
2285 struct btrfs_key old_parent_key;
2286 di = btrfs_lookup_dir_item(trans, root, path, old_inode->i_ino,
2287 "..", 2, -1);
2288 if (IS_ERR(di)) {
2289 ret = PTR_ERR(di);
2290 goto out_fail;
2291 }
2292 if (!di) {
2293 ret = -ENOENT;
2294 goto out_fail;
2295 }
2296 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &old_parent_key);
2297 ret = btrfs_del_item(trans, root, path);
2298 if (ret) {
2299 goto out_fail;
2300 }
2301 btrfs_release_path(root, path);
2302
2303 di = btrfs_lookup_dir_index_item(trans, root, path,
2304 old_inode->i_ino,
2305 old_parent_key.objectid,
2306 "..", 2, -1);
2307 if (IS_ERR(di)) {
2308 ret = PTR_ERR(di);
2309 goto out_fail;
2310 }
2311 if (!di) {
2312 ret = -ENOENT;
2313 goto out_fail;
2314 }
2315 ret = btrfs_del_item(trans, root, path);
2316 if (ret) {
2317 goto out_fail;
2318 }
2319 btrfs_release_path(root, path);
2320
2321 ret = btrfs_insert_dir_item(trans, root, "..", 2,
2322 old_inode->i_ino, location,
2323 BTRFS_FT_DIR);
2324 if (ret)
2325 goto out_fail;
2326 }
2327
2328
2329 ret = btrfs_unlink_trans(trans, root, old_dir, old_dentry);
2330 if (ret)
2331 goto out_fail;
2332
2333 if (new_inode) {
2334 new_inode->i_ctime = CURRENT_TIME;
2335 ret = btrfs_unlink_trans(trans, root, new_dir, new_dentry);
2336 if (ret)
2337 goto out_fail;
2338 }
2339 ret = btrfs_add_link(trans, new_dentry, old_inode);
2340 if (ret)
2341 goto out_fail;
2342
2343 out_fail:
2344 btrfs_free_path(path);
2345 btrfs_end_transaction(trans, root);
2346 mutex_unlock(&root->fs_info->fs_mutex);
2347 return ret;
2348 }
2349
2350 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
2351 const char *symname)
2352 {
2353 struct btrfs_trans_handle *trans;
2354 struct btrfs_root *root = BTRFS_I(dir)->root;
2355 struct btrfs_path *path;
2356 struct btrfs_key key;
2357 struct inode *inode;
2358 int err;
2359 int drop_inode = 0;
2360 u64 objectid;
2361 int name_len;
2362 int datasize;
2363 unsigned long ptr;
2364 struct btrfs_file_extent_item *ei;
2365 struct extent_buffer *leaf;
2366 unsigned long nr;
2367
2368 name_len = strlen(symname) + 1;
2369 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
2370 return -ENAMETOOLONG;
2371 mutex_lock(&root->fs_info->fs_mutex);
2372 trans = btrfs_start_transaction(root, 1);
2373 btrfs_set_trans_block_group(trans, dir);
2374
2375 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
2376 if (err) {
2377 err = -ENOSPC;
2378 goto out_unlock;
2379 }
2380
2381 inode = btrfs_new_inode(trans, root, objectid,
2382 BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO);
2383 err = PTR_ERR(inode);
2384 if (IS_ERR(inode))
2385 goto out_unlock;
2386
2387 btrfs_set_trans_block_group(trans, inode);
2388 err = btrfs_add_nondir(trans, dentry, inode);
2389 if (err)
2390 drop_inode = 1;
2391 else {
2392 inode->i_mapping->a_ops = &btrfs_aops;
2393 inode->i_fop = &btrfs_file_operations;
2394 inode->i_op = &btrfs_file_inode_operations;
2395 extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
2396 inode->i_mapping, GFP_NOFS);
2397 BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
2398 }
2399 dir->i_sb->s_dirt = 1;
2400 btrfs_update_inode_block_group(trans, inode);
2401 btrfs_update_inode_block_group(trans, dir);
2402 if (drop_inode)
2403 goto out_unlock;
2404
2405 path = btrfs_alloc_path();
2406 BUG_ON(!path);
2407 key.objectid = inode->i_ino;
2408 key.offset = 0;
2409 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
2410 datasize = btrfs_file_extent_calc_inline_size(name_len);
2411 err = btrfs_insert_empty_item(trans, root, path, &key,
2412 datasize);
2413 if (err) {
2414 drop_inode = 1;
2415 goto out_unlock;
2416 }
2417 leaf = path->nodes[0];
2418 ei = btrfs_item_ptr(leaf, path->slots[0],
2419 struct btrfs_file_extent_item);
2420 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
2421 btrfs_set_file_extent_type(leaf, ei,
2422 BTRFS_FILE_EXTENT_INLINE);
2423 ptr = btrfs_file_extent_inline_start(ei);
2424 write_extent_buffer(leaf, symname, ptr, name_len);
2425 btrfs_mark_buffer_dirty(leaf);
2426 btrfs_free_path(path);
2427
2428 inode->i_op = &btrfs_symlink_inode_operations;
2429 inode->i_mapping->a_ops = &btrfs_symlink_aops;
2430 inode->i_size = name_len - 1;
2431 err = btrfs_update_inode(trans, root, inode);
2432 if (err)
2433 drop_inode = 1;
2434
2435 out_unlock:
2436 nr = trans->blocks_used;
2437 btrfs_end_transaction(trans, root);
2438 mutex_unlock(&root->fs_info->fs_mutex);
2439 if (drop_inode) {
2440 inode_dec_link_count(inode);
2441 iput(inode);
2442 }
2443 btrfs_btree_balance_dirty(root, nr);
2444 return err;
2445 }
2446
2447 static struct inode_operations btrfs_dir_inode_operations = {
2448 .lookup = btrfs_lookup,
2449 .create = btrfs_create,
2450 .unlink = btrfs_unlink,
2451 .link = btrfs_link,
2452 .mkdir = btrfs_mkdir,
2453 .rmdir = btrfs_rmdir,
2454 .rename = btrfs_rename,
2455 .symlink = btrfs_symlink,
2456 .setattr = btrfs_setattr,
2457 .mknod = btrfs_mknod,
2458 };
2459
2460 static struct inode_operations btrfs_dir_ro_inode_operations = {
2461 .lookup = btrfs_lookup,
2462 };
2463
2464 static struct file_operations btrfs_dir_file_operations = {
2465 .llseek = generic_file_llseek,
2466 .read = generic_read_dir,
2467 .readdir = btrfs_readdir,
2468 .unlocked_ioctl = btrfs_ioctl,
2469 #ifdef CONFIG_COMPAT
2470 .compat_ioctl = btrfs_ioctl,
2471 #endif
2472 };
2473
2474 static struct extent_map_ops btrfs_extent_map_ops = {
2475 .fill_delalloc = run_delalloc_range,
2476 .writepage_io_hook = btrfs_writepage_io_hook,
2477 .readpage_io_hook = btrfs_readpage_io_hook,
2478 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
2479 };
2480
2481 static struct address_space_operations btrfs_aops = {
2482 .readpage = btrfs_readpage,
2483 .writepage = btrfs_writepage,
2484 .sync_page = block_sync_page,
2485 .prepare_write = btrfs_prepare_write,
2486 .commit_write = btrfs_commit_write,
2487 .bmap = btrfs_bmap,
2488 .invalidatepage = btrfs_invalidatepage,
2489 .releasepage = btrfs_releasepage,
2490 .set_page_dirty = __set_page_dirty_nobuffers,
2491 };
2492
2493 static struct address_space_operations btrfs_symlink_aops = {
2494 .readpage = btrfs_readpage,
2495 .writepage = btrfs_writepage,
2496 .invalidatepage = btrfs_invalidatepage,
2497 .releasepage = btrfs_releasepage,
2498 };
2499
2500 static struct inode_operations btrfs_file_inode_operations = {
2501 .truncate = btrfs_truncate,
2502 .getattr = btrfs_getattr,
2503 .setattr = btrfs_setattr,
2504 };
2505
2506 static struct inode_operations btrfs_special_inode_operations = {
2507 .getattr = btrfs_getattr,
2508 .setattr = btrfs_setattr,
2509 };
2510
2511 static struct inode_operations btrfs_symlink_inode_operations = {
2512 .readlink = generic_readlink,
2513 .follow_link = page_follow_link_light,
2514 .put_link = page_put_link,
2515 };
Linux kernel - Deliverables
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