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Btrfs: Add drop inode func to avoid data=ordered deadlock
[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 <linux/xattr.h>
36 #include "ctree.h"
37 #include "disk-io.h"
38 #include "transaction.h"
39 #include "btrfs_inode.h"
40 #include "ioctl.h"
41 #include "print-tree.h"
42
43 struct btrfs_iget_args {
44 u64 ino;
45 struct btrfs_root *root;
46 };
47
48 static struct inode_operations btrfs_dir_inode_operations;
49 static struct inode_operations btrfs_symlink_inode_operations;
50 static struct inode_operations btrfs_dir_ro_inode_operations;
51 static struct inode_operations btrfs_special_inode_operations;
52 static struct inode_operations btrfs_file_inode_operations;
53 static struct address_space_operations btrfs_aops;
54 static struct address_space_operations btrfs_symlink_aops;
55 static struct file_operations btrfs_dir_file_operations;
56 static struct extent_map_ops btrfs_extent_map_ops;
57
58 static struct kmem_cache *btrfs_inode_cachep;
59 struct kmem_cache *btrfs_trans_handle_cachep;
60 struct kmem_cache *btrfs_transaction_cachep;
61 struct kmem_cache *btrfs_bit_radix_cachep;
62 struct kmem_cache *btrfs_path_cachep;
63
64 #define S_SHIFT 12
65 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
66 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
67 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
68 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
69 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
70 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
71 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
72 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
73 };
74
75 int btrfs_check_free_space(struct btrfs_root *root, u64 num_required,
76 int for_del)
77 {
78 u64 total = btrfs_super_total_bytes(&root->fs_info->super_copy);
79 u64 used = btrfs_super_bytes_used(&root->fs_info->super_copy);
80 u64 thresh;
81 int ret = 0;
82
83 if (for_del)
84 thresh = total * 90;
85 else
86 thresh = total * 85;
87
88 do_div(thresh, 100);
89
90 spin_lock(&root->fs_info->delalloc_lock);
91 if (used + root->fs_info->delalloc_bytes + num_required > thresh)
92 ret = -ENOSPC;
93 spin_unlock(&root->fs_info->delalloc_lock);
94 return ret;
95 }
96
97 static int cow_file_range(struct inode *inode, u64 start, u64 end)
98 {
99 struct btrfs_root *root = BTRFS_I(inode)->root;
100 struct btrfs_trans_handle *trans;
101 u64 alloc_hint = 0;
102 u64 num_bytes;
103 u64 cur_alloc_size;
104 u64 blocksize = root->sectorsize;
105 struct btrfs_key ins;
106 int ret;
107
108 trans = btrfs_start_transaction(root, 1);
109 BUG_ON(!trans);
110 btrfs_set_trans_block_group(trans, inode);
111
112 num_bytes = (end - start + blocksize) & ~(blocksize - 1);
113 num_bytes = max(blocksize, num_bytes);
114 ret = btrfs_drop_extents(trans, root, inode,
115 start, start + num_bytes, start, &alloc_hint);
116
117 if (alloc_hint == EXTENT_MAP_INLINE)
118 goto out;
119
120 while(num_bytes > 0) {
121 cur_alloc_size = min(num_bytes, root->fs_info->max_extent);
122 ret = btrfs_alloc_extent(trans, root, cur_alloc_size,
123 root->root_key.objectid,
124 trans->transid,
125 inode->i_ino, start, 0,
126 alloc_hint, (u64)-1, &ins, 1);
127 if (ret) {
128 WARN_ON(1);
129 goto out;
130 }
131 ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
132 start, ins.objectid, ins.offset,
133 ins.offset);
134 num_bytes -= cur_alloc_size;
135 alloc_hint = ins.objectid + ins.offset;
136 start += cur_alloc_size;
137 }
138 btrfs_add_ordered_inode(inode);
139 out:
140 btrfs_end_transaction(trans, root);
141 return ret;
142 }
143
144 static int run_delalloc_nocow(struct inode *inode, u64 start, u64 end)
145 {
146 u64 extent_start;
147 u64 extent_end;
148 u64 bytenr;
149 u64 cow_end;
150 u64 loops = 0;
151 u64 total_fs_bytes;
152 struct btrfs_root *root = BTRFS_I(inode)->root;
153 struct extent_buffer *leaf;
154 int found_type;
155 struct btrfs_path *path;
156 struct btrfs_file_extent_item *item;
157 int ret;
158 int err;
159 struct btrfs_key found_key;
160
161 total_fs_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
162 path = btrfs_alloc_path();
163 BUG_ON(!path);
164 again:
165 ret = btrfs_lookup_file_extent(NULL, root, path,
166 inode->i_ino, start, 0);
167 if (ret < 0) {
168 btrfs_free_path(path);
169 return ret;
170 }
171
172 cow_end = end;
173 if (ret != 0) {
174 if (path->slots[0] == 0)
175 goto not_found;
176 path->slots[0]--;
177 }
178
179 leaf = path->nodes[0];
180 item = btrfs_item_ptr(leaf, path->slots[0],
181 struct btrfs_file_extent_item);
182
183 /* are we inside the extent that was found? */
184 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
185 found_type = btrfs_key_type(&found_key);
186 if (found_key.objectid != inode->i_ino ||
187 found_type != BTRFS_EXTENT_DATA_KEY) {
188 goto not_found;
189 }
190
191 found_type = btrfs_file_extent_type(leaf, item);
192 extent_start = found_key.offset;
193 if (found_type == BTRFS_FILE_EXTENT_REG) {
194 u64 extent_num_bytes;
195
196 extent_num_bytes = btrfs_file_extent_num_bytes(leaf, item);
197 extent_end = extent_start + extent_num_bytes;
198 err = 0;
199
200 if (loops && start != extent_start)
201 goto not_found;
202
203 if (start < extent_start || start >= extent_end)
204 goto not_found;
205
206 cow_end = min(end, extent_end - 1);
207 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
208 if (bytenr == 0)
209 goto not_found;
210
211 /*
212 * we may be called by the resizer, make sure we're inside
213 * the limits of the FS
214 */
215 if (bytenr + extent_num_bytes > total_fs_bytes)
216 goto not_found;
217
218 if (btrfs_count_snapshots_in_path(root, path, bytenr) != 1) {
219 goto not_found;
220 }
221
222 start = extent_end;
223 } else {
224 goto not_found;
225 }
226 loop:
227 if (start > end) {
228 btrfs_free_path(path);
229 return 0;
230 }
231 btrfs_release_path(root, path);
232 loops++;
233 goto again;
234
235 not_found:
236 cow_file_range(inode, start, cow_end);
237 start = cow_end + 1;
238 goto loop;
239 }
240
241 static int run_delalloc_range(struct inode *inode, u64 start, u64 end)
242 {
243 struct btrfs_root *root = BTRFS_I(inode)->root;
244 u64 num_bytes;
245 int ret;
246 mutex_lock(&root->fs_info->fs_mutex);
247 if (btrfs_test_opt(root, NODATACOW) ||
248 btrfs_test_flag(inode, NODATACOW))
249 ret = run_delalloc_nocow(inode, start, end);
250 else
251 ret = cow_file_range(inode, start, end);
252
253 spin_lock(&root->fs_info->delalloc_lock);
254 num_bytes = end + 1 - start;
255 if (root->fs_info->delalloc_bytes < num_bytes) {
256 printk("delalloc accounting error total %llu sub %llu\n",
257 root->fs_info->delalloc_bytes, num_bytes);
258 } else {
259 root->fs_info->delalloc_bytes -= num_bytes;
260 }
261 spin_unlock(&root->fs_info->delalloc_lock);
262
263 mutex_unlock(&root->fs_info->fs_mutex);
264 return ret;
265 }
266
267 int btrfs_writepage_io_hook(struct page *page, u64 start, u64 end)
268 {
269 struct inode *inode = page->mapping->host;
270 struct btrfs_root *root = BTRFS_I(inode)->root;
271 struct btrfs_trans_handle *trans;
272 char *kaddr;
273 int ret = 0;
274 u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
275 size_t offset = start - page_start;
276 if (btrfs_test_opt(root, NODATASUM) ||
277 btrfs_test_flag(inode, NODATASUM))
278 return 0;
279 mutex_lock(&root->fs_info->fs_mutex);
280 trans = btrfs_start_transaction(root, 1);
281 btrfs_set_trans_block_group(trans, inode);
282 kaddr = kmap(page);
283 btrfs_csum_file_block(trans, root, inode, inode->i_ino,
284 start, kaddr + offset, end - start + 1);
285 kunmap(page);
286 ret = btrfs_end_transaction(trans, root);
287 BUG_ON(ret);
288 mutex_unlock(&root->fs_info->fs_mutex);
289 return ret;
290 }
291
292 int btrfs_readpage_io_hook(struct page *page, u64 start, u64 end)
293 {
294 int ret = 0;
295 struct inode *inode = page->mapping->host;
296 struct btrfs_root *root = BTRFS_I(inode)->root;
297 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
298 struct btrfs_csum_item *item;
299 struct btrfs_path *path = NULL;
300 u32 csum;
301 if (btrfs_test_opt(root, NODATASUM) ||
302 btrfs_test_flag(inode, NODATASUM))
303 return 0;
304 mutex_lock(&root->fs_info->fs_mutex);
305 path = btrfs_alloc_path();
306 item = btrfs_lookup_csum(NULL, root, path, inode->i_ino, start, 0);
307 if (IS_ERR(item)) {
308 ret = PTR_ERR(item);
309 /* a csum that isn't present is a preallocated region. */
310 if (ret == -ENOENT || ret == -EFBIG)
311 ret = 0;
312 csum = 0;
313 goto out;
314 }
315 read_extent_buffer(path->nodes[0], &csum, (unsigned long)item,
316 BTRFS_CRC32_SIZE);
317 set_state_private(em_tree, start, csum);
318 out:
319 if (path)
320 btrfs_free_path(path);
321 mutex_unlock(&root->fs_info->fs_mutex);
322 return ret;
323 }
324
325 int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end)
326 {
327 size_t offset = start - ((u64)page->index << PAGE_CACHE_SHIFT);
328 struct inode *inode = page->mapping->host;
329 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
330 char *kaddr;
331 u64 private;
332 int ret;
333 struct btrfs_root *root = BTRFS_I(inode)->root;
334 u32 csum = ~(u32)0;
335 unsigned long flags;
336 if (btrfs_test_opt(root, NODATASUM) ||
337 btrfs_test_flag(inode, NODATASUM))
338 return 0;
339 ret = get_state_private(em_tree, start, &private);
340 local_irq_save(flags);
341 kaddr = kmap_atomic(page, KM_IRQ0);
342 if (ret) {
343 goto zeroit;
344 }
345 csum = btrfs_csum_data(root, kaddr + offset, csum, end - start + 1);
346 btrfs_csum_final(csum, (char *)&csum);
347 if (csum != private) {
348 goto zeroit;
349 }
350 kunmap_atomic(kaddr, KM_IRQ0);
351 local_irq_restore(flags);
352 return 0;
353
354 zeroit:
355 printk("btrfs csum failed ino %lu off %llu\n",
356 page->mapping->host->i_ino, (unsigned long long)start);
357 memset(kaddr + offset, 1, end - start + 1);
358 flush_dcache_page(page);
359 kunmap_atomic(kaddr, KM_IRQ0);
360 local_irq_restore(flags);
361 return 0;
362 }
363
364 void btrfs_read_locked_inode(struct inode *inode)
365 {
366 struct btrfs_path *path;
367 struct extent_buffer *leaf;
368 struct btrfs_inode_item *inode_item;
369 struct btrfs_inode_timespec *tspec;
370 struct btrfs_root *root = BTRFS_I(inode)->root;
371 struct btrfs_key location;
372 u64 alloc_group_block;
373 u32 rdev;
374 int ret;
375
376 path = btrfs_alloc_path();
377 BUG_ON(!path);
378 mutex_lock(&root->fs_info->fs_mutex);
379 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
380
381 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
382 if (ret)
383 goto make_bad;
384
385 leaf = path->nodes[0];
386 inode_item = btrfs_item_ptr(leaf, path->slots[0],
387 struct btrfs_inode_item);
388
389 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
390 inode->i_nlink = btrfs_inode_nlink(leaf, inode_item);
391 inode->i_uid = btrfs_inode_uid(leaf, inode_item);
392 inode->i_gid = btrfs_inode_gid(leaf, inode_item);
393 inode->i_size = btrfs_inode_size(leaf, inode_item);
394
395 tspec = btrfs_inode_atime(inode_item);
396 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
397 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
398
399 tspec = btrfs_inode_mtime(inode_item);
400 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
401 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
402
403 tspec = btrfs_inode_ctime(inode_item);
404 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
405 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
406
407 inode->i_blocks = btrfs_inode_nblocks(leaf, inode_item);
408 inode->i_generation = btrfs_inode_generation(leaf, inode_item);
409 inode->i_rdev = 0;
410 rdev = btrfs_inode_rdev(leaf, inode_item);
411
412 alloc_group_block = btrfs_inode_block_group(leaf, inode_item);
413 BTRFS_I(inode)->block_group = btrfs_lookup_block_group(root->fs_info,
414 alloc_group_block);
415 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
416 if (!BTRFS_I(inode)->block_group) {
417 BTRFS_I(inode)->block_group = btrfs_find_block_group(root,
418 NULL, 0, 0, 0);
419 }
420 btrfs_free_path(path);
421 inode_item = NULL;
422
423 mutex_unlock(&root->fs_info->fs_mutex);
424
425 switch (inode->i_mode & S_IFMT) {
426 case S_IFREG:
427 inode->i_mapping->a_ops = &btrfs_aops;
428 BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
429 inode->i_fop = &btrfs_file_operations;
430 inode->i_op = &btrfs_file_inode_operations;
431 break;
432 case S_IFDIR:
433 inode->i_fop = &btrfs_dir_file_operations;
434 if (root == root->fs_info->tree_root)
435 inode->i_op = &btrfs_dir_ro_inode_operations;
436 else
437 inode->i_op = &btrfs_dir_inode_operations;
438 break;
439 case S_IFLNK:
440 inode->i_op = &btrfs_symlink_inode_operations;
441 inode->i_mapping->a_ops = &btrfs_symlink_aops;
442 break;
443 default:
444 init_special_inode(inode, inode->i_mode, rdev);
445 break;
446 }
447 return;
448
449 make_bad:
450 btrfs_release_path(root, path);
451 btrfs_free_path(path);
452 mutex_unlock(&root->fs_info->fs_mutex);
453 make_bad_inode(inode);
454 }
455
456 static void fill_inode_item(struct extent_buffer *leaf,
457 struct btrfs_inode_item *item,
458 struct inode *inode)
459 {
460 btrfs_set_inode_uid(leaf, item, inode->i_uid);
461 btrfs_set_inode_gid(leaf, item, inode->i_gid);
462 btrfs_set_inode_size(leaf, item, inode->i_size);
463 btrfs_set_inode_mode(leaf, item, inode->i_mode);
464 btrfs_set_inode_nlink(leaf, item, inode->i_nlink);
465
466 btrfs_set_timespec_sec(leaf, btrfs_inode_atime(item),
467 inode->i_atime.tv_sec);
468 btrfs_set_timespec_nsec(leaf, btrfs_inode_atime(item),
469 inode->i_atime.tv_nsec);
470
471 btrfs_set_timespec_sec(leaf, btrfs_inode_mtime(item),
472 inode->i_mtime.tv_sec);
473 btrfs_set_timespec_nsec(leaf, btrfs_inode_mtime(item),
474 inode->i_mtime.tv_nsec);
475
476 btrfs_set_timespec_sec(leaf, btrfs_inode_ctime(item),
477 inode->i_ctime.tv_sec);
478 btrfs_set_timespec_nsec(leaf, btrfs_inode_ctime(item),
479 inode->i_ctime.tv_nsec);
480
481 btrfs_set_inode_nblocks(leaf, item, inode->i_blocks);
482 btrfs_set_inode_generation(leaf, item, inode->i_generation);
483 btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
484 btrfs_set_inode_flags(leaf, item, BTRFS_I(inode)->flags);
485 btrfs_set_inode_block_group(leaf, item,
486 BTRFS_I(inode)->block_group->key.objectid);
487 }
488
489 int btrfs_update_inode(struct btrfs_trans_handle *trans,
490 struct btrfs_root *root,
491 struct inode *inode)
492 {
493 struct btrfs_inode_item *inode_item;
494 struct btrfs_path *path;
495 struct extent_buffer *leaf;
496 int ret;
497
498 path = btrfs_alloc_path();
499 BUG_ON(!path);
500 ret = btrfs_lookup_inode(trans, root, path,
501 &BTRFS_I(inode)->location, 1);
502 if (ret) {
503 if (ret > 0)
504 ret = -ENOENT;
505 goto failed;
506 }
507
508 leaf = path->nodes[0];
509 inode_item = btrfs_item_ptr(leaf, path->slots[0],
510 struct btrfs_inode_item);
511
512 fill_inode_item(leaf, inode_item, inode);
513 btrfs_mark_buffer_dirty(leaf);
514 btrfs_set_inode_last_trans(trans, inode);
515 ret = 0;
516 failed:
517 btrfs_release_path(root, path);
518 btrfs_free_path(path);
519 return ret;
520 }
521
522
523 static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
524 struct btrfs_root *root,
525 struct inode *dir,
526 struct dentry *dentry)
527 {
528 struct btrfs_path *path;
529 const char *name = dentry->d_name.name;
530 int name_len = dentry->d_name.len;
531 int ret = 0;
532 struct extent_buffer *leaf;
533 struct btrfs_dir_item *di;
534 struct btrfs_key key;
535
536 path = btrfs_alloc_path();
537 if (!path) {
538 ret = -ENOMEM;
539 goto err;
540 }
541
542 di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
543 name, name_len, -1);
544 if (IS_ERR(di)) {
545 ret = PTR_ERR(di);
546 goto err;
547 }
548 if (!di) {
549 ret = -ENOENT;
550 goto err;
551 }
552 leaf = path->nodes[0];
553 btrfs_dir_item_key_to_cpu(leaf, di, &key);
554 ret = btrfs_delete_one_dir_name(trans, root, path, di);
555 if (ret)
556 goto err;
557 btrfs_release_path(root, path);
558
559 di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
560 key.objectid, name, name_len, -1);
561 if (IS_ERR(di)) {
562 ret = PTR_ERR(di);
563 goto err;
564 }
565 if (!di) {
566 ret = -ENOENT;
567 goto err;
568 }
569 ret = btrfs_delete_one_dir_name(trans, root, path, di);
570
571 dentry->d_inode->i_ctime = dir->i_ctime;
572 ret = btrfs_del_inode_ref(trans, root, name, name_len,
573 dentry->d_inode->i_ino,
574 dentry->d_parent->d_inode->i_ino);
575 if (ret) {
576 printk("failed to delete reference to %.*s, "
577 "inode %lu parent %lu\n", name_len, name,
578 dentry->d_inode->i_ino,
579 dentry->d_parent->d_inode->i_ino);
580 }
581 err:
582 btrfs_free_path(path);
583 if (!ret) {
584 dir->i_size -= name_len * 2;
585 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
586 btrfs_update_inode(trans, root, dir);
587 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
588 dentry->d_inode->i_nlink--;
589 #else
590 drop_nlink(dentry->d_inode);
591 #endif
592 ret = btrfs_update_inode(trans, root, dentry->d_inode);
593 dir->i_sb->s_dirt = 1;
594 }
595 return ret;
596 }
597
598 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
599 {
600 struct btrfs_root *root;
601 struct btrfs_trans_handle *trans;
602 int ret;
603 unsigned long nr = 0;
604
605 root = BTRFS_I(dir)->root;
606 mutex_lock(&root->fs_info->fs_mutex);
607
608 ret = btrfs_check_free_space(root, 1, 1);
609 if (ret)
610 goto fail;
611
612 trans = btrfs_start_transaction(root, 1);
613
614 btrfs_set_trans_block_group(trans, dir);
615 ret = btrfs_unlink_trans(trans, root, dir, dentry);
616 nr = trans->blocks_used;
617
618 btrfs_end_transaction(trans, root);
619 fail:
620 mutex_unlock(&root->fs_info->fs_mutex);
621 btrfs_btree_balance_dirty(root, nr);
622 btrfs_throttle(root);
623 return ret;
624 }
625
626 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
627 {
628 struct inode *inode = dentry->d_inode;
629 int err = 0;
630 int ret;
631 struct btrfs_root *root = BTRFS_I(dir)->root;
632 struct btrfs_trans_handle *trans;
633 unsigned long nr = 0;
634
635 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
636 return -ENOTEMPTY;
637
638 mutex_lock(&root->fs_info->fs_mutex);
639 ret = btrfs_check_free_space(root, 1, 1);
640 if (ret)
641 goto fail;
642
643 trans = btrfs_start_transaction(root, 1);
644 btrfs_set_trans_block_group(trans, dir);
645
646 /* now the directory is empty */
647 err = btrfs_unlink_trans(trans, root, dir, dentry);
648 if (!err) {
649 inode->i_size = 0;
650 }
651
652 nr = trans->blocks_used;
653 ret = btrfs_end_transaction(trans, root);
654 fail:
655 mutex_unlock(&root->fs_info->fs_mutex);
656 btrfs_btree_balance_dirty(root, nr);
657 btrfs_throttle(root);
658
659 if (ret && !err)
660 err = ret;
661 return err;
662 }
663
664 static int btrfs_free_inode(struct btrfs_trans_handle *trans,
665 struct btrfs_root *root,
666 struct inode *inode)
667 {
668 struct btrfs_path *path;
669 int ret;
670
671 clear_inode(inode);
672
673 path = btrfs_alloc_path();
674 BUG_ON(!path);
675 ret = btrfs_lookup_inode(trans, root, path,
676 &BTRFS_I(inode)->location, -1);
677 if (ret > 0)
678 ret = -ENOENT;
679 if (!ret)
680 ret = btrfs_del_item(trans, root, path);
681 btrfs_free_path(path);
682 return ret;
683 }
684
685 /*
686 * this can truncate away extent items, csum items and directory items.
687 * It starts at a high offset and removes keys until it can't find
688 * any higher than i_size.
689 *
690 * csum items that cross the new i_size are truncated to the new size
691 * as well.
692 */
693 static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
694 struct btrfs_root *root,
695 struct inode *inode)
696 {
697 int ret;
698 struct btrfs_path *path;
699 struct btrfs_key key;
700 struct btrfs_key found_key;
701 u32 found_type;
702 struct extent_buffer *leaf;
703 struct btrfs_file_extent_item *fi;
704 u64 extent_start = 0;
705 u64 extent_num_bytes = 0;
706 u64 item_end = 0;
707 u64 root_gen = 0;
708 u64 root_owner = 0;
709 int found_extent;
710 int del_item;
711 int extent_type = -1;
712
713 btrfs_drop_extent_cache(inode, inode->i_size, (u64)-1);
714 path = btrfs_alloc_path();
715 path->reada = -1;
716 BUG_ON(!path);
717
718 /* FIXME, add redo link to tree so we don't leak on crash */
719 key.objectid = inode->i_ino;
720 key.offset = (u64)-1;
721 key.type = (u8)-1;
722
723 while(1) {
724 btrfs_init_path(path);
725 fi = NULL;
726 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
727 if (ret < 0) {
728 goto error;
729 }
730 if (ret > 0) {
731 BUG_ON(path->slots[0] == 0);
732 path->slots[0]--;
733 }
734 leaf = path->nodes[0];
735 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
736 found_type = btrfs_key_type(&found_key);
737
738 if (found_key.objectid != inode->i_ino)
739 break;
740
741 if (found_type != BTRFS_CSUM_ITEM_KEY &&
742 found_type != BTRFS_DIR_ITEM_KEY &&
743 found_type != BTRFS_DIR_INDEX_KEY &&
744 found_type != BTRFS_EXTENT_DATA_KEY)
745 break;
746
747 item_end = found_key.offset;
748 if (found_type == BTRFS_EXTENT_DATA_KEY) {
749 fi = btrfs_item_ptr(leaf, path->slots[0],
750 struct btrfs_file_extent_item);
751 extent_type = btrfs_file_extent_type(leaf, fi);
752 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
753 item_end +=
754 btrfs_file_extent_num_bytes(leaf, fi);
755 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
756 struct btrfs_item *item = btrfs_item_nr(leaf,
757 path->slots[0]);
758 item_end += btrfs_file_extent_inline_len(leaf,
759 item);
760 }
761 item_end--;
762 }
763 if (found_type == BTRFS_CSUM_ITEM_KEY) {
764 ret = btrfs_csum_truncate(trans, root, path,
765 inode->i_size);
766 BUG_ON(ret);
767 }
768 if (item_end < inode->i_size) {
769 if (found_type == BTRFS_DIR_ITEM_KEY) {
770 found_type = BTRFS_INODE_ITEM_KEY;
771 } else if (found_type == BTRFS_EXTENT_ITEM_KEY) {
772 found_type = BTRFS_CSUM_ITEM_KEY;
773 } else if (found_type) {
774 found_type--;
775 } else {
776 break;
777 }
778 btrfs_set_key_type(&key, found_type);
779 btrfs_release_path(root, path);
780 continue;
781 }
782 if (found_key.offset >= inode->i_size)
783 del_item = 1;
784 else
785 del_item = 0;
786 found_extent = 0;
787
788 /* FIXME, shrink the extent if the ref count is only 1 */
789 if (found_type != BTRFS_EXTENT_DATA_KEY)
790 goto delete;
791
792 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
793 u64 num_dec;
794 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
795 if (!del_item) {
796 u64 orig_num_bytes =
797 btrfs_file_extent_num_bytes(leaf, fi);
798 extent_num_bytes = inode->i_size -
799 found_key.offset + root->sectorsize - 1;
800 btrfs_set_file_extent_num_bytes(leaf, fi,
801 extent_num_bytes);
802 num_dec = (orig_num_bytes -
803 extent_num_bytes) >> 9;
804 if (extent_start != 0) {
805 inode->i_blocks -= num_dec;
806 }
807 btrfs_mark_buffer_dirty(leaf);
808 } else {
809 extent_num_bytes =
810 btrfs_file_extent_disk_num_bytes(leaf,
811 fi);
812 /* FIXME blocksize != 4096 */
813 num_dec = btrfs_file_extent_num_bytes(leaf,
814 fi) >> 9;
815 if (extent_start != 0) {
816 found_extent = 1;
817 inode->i_blocks -= num_dec;
818 }
819 root_gen = btrfs_header_generation(leaf);
820 root_owner = btrfs_header_owner(leaf);
821 }
822 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE &&
823 !del_item) {
824 u32 newsize = inode->i_size - found_key.offset;
825 newsize = btrfs_file_extent_calc_inline_size(newsize);
826 ret = btrfs_truncate_item(trans, root, path,
827 newsize, 1);
828 BUG_ON(ret);
829 }
830 delete:
831 if (del_item) {
832 ret = btrfs_del_item(trans, root, path);
833 if (ret)
834 goto error;
835 } else {
836 break;
837 }
838 btrfs_release_path(root, path);
839 if (found_extent) {
840 ret = btrfs_free_extent(trans, root, extent_start,
841 extent_num_bytes,
842 root_owner,
843 root_gen, inode->i_ino,
844 found_key.offset, 0);
845 BUG_ON(ret);
846 }
847 }
848 ret = 0;
849 error:
850 btrfs_release_path(root, path);
851 btrfs_free_path(path);
852 inode->i_sb->s_dirt = 1;
853 return ret;
854 }
855
856 static int btrfs_cow_one_page(struct inode *inode, struct page *page,
857 size_t zero_start)
858 {
859 char *kaddr;
860 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
861 struct btrfs_root *root = BTRFS_I(inode)->root;
862 u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
863 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
864 u64 existing_delalloc;
865 u64 delalloc_start;
866 int ret = 0;
867
868 WARN_ON(!PageLocked(page));
869 set_page_extent_mapped(page);
870
871 lock_extent(em_tree, page_start, page_end, GFP_NOFS);
872 delalloc_start = page_start;
873 existing_delalloc = count_range_bits(&BTRFS_I(inode)->extent_tree,
874 &delalloc_start, page_end,
875 PAGE_CACHE_SIZE, EXTENT_DELALLOC);
876 set_extent_delalloc(&BTRFS_I(inode)->extent_tree, page_start,
877 page_end, GFP_NOFS);
878
879 spin_lock(&root->fs_info->delalloc_lock);
880 root->fs_info->delalloc_bytes += PAGE_CACHE_SIZE - existing_delalloc;
881 spin_unlock(&root->fs_info->delalloc_lock);
882
883 if (zero_start != PAGE_CACHE_SIZE) {
884 kaddr = kmap(page);
885 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
886 flush_dcache_page(page);
887 kunmap(page);
888 }
889 set_page_dirty(page);
890 unlock_extent(em_tree, page_start, page_end, GFP_NOFS);
891
892 return ret;
893 }
894
895 /*
896 * taken from block_truncate_page, but does cow as it zeros out
897 * any bytes left in the last page in the file.
898 */
899 static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
900 {
901 struct inode *inode = mapping->host;
902 struct btrfs_root *root = BTRFS_I(inode)->root;
903 u32 blocksize = root->sectorsize;
904 pgoff_t index = from >> PAGE_CACHE_SHIFT;
905 unsigned offset = from & (PAGE_CACHE_SIZE-1);
906 struct page *page;
907 int ret = 0;
908 u64 page_start;
909
910 if ((offset & (blocksize - 1)) == 0)
911 goto out;
912
913 ret = -ENOMEM;
914 page = grab_cache_page(mapping, index);
915 if (!page)
916 goto out;
917 if (!PageUptodate(page)) {
918 ret = btrfs_readpage(NULL, page);
919 lock_page(page);
920 if (!PageUptodate(page)) {
921 ret = -EIO;
922 goto out;
923 }
924 }
925 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
926
927 ret = btrfs_cow_one_page(inode, page, offset);
928
929 unlock_page(page);
930 page_cache_release(page);
931 out:
932 return ret;
933 }
934
935 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
936 {
937 struct inode *inode = dentry->d_inode;
938 int err;
939
940 err = inode_change_ok(inode, attr);
941 if (err)
942 return err;
943
944 if (S_ISREG(inode->i_mode) &&
945 attr->ia_valid & ATTR_SIZE && attr->ia_size > inode->i_size) {
946 struct btrfs_trans_handle *trans;
947 struct btrfs_root *root = BTRFS_I(inode)->root;
948 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
949
950 u64 mask = root->sectorsize - 1;
951 u64 pos = (inode->i_size + mask) & ~mask;
952 u64 block_end = attr->ia_size | mask;
953 u64 hole_size;
954 u64 alloc_hint = 0;
955
956 if (attr->ia_size <= pos)
957 goto out;
958
959 mutex_lock(&root->fs_info->fs_mutex);
960 err = btrfs_check_free_space(root, 1, 0);
961 mutex_unlock(&root->fs_info->fs_mutex);
962 if (err)
963 goto fail;
964
965 btrfs_truncate_page(inode->i_mapping, inode->i_size);
966
967 lock_extent(em_tree, pos, block_end, GFP_NOFS);
968 hole_size = (attr->ia_size - pos + mask) & ~mask;
969
970 mutex_lock(&root->fs_info->fs_mutex);
971 trans = btrfs_start_transaction(root, 1);
972 btrfs_set_trans_block_group(trans, inode);
973 err = btrfs_drop_extents(trans, root, inode,
974 pos, pos + hole_size, pos,
975 &alloc_hint);
976
977 if (alloc_hint != EXTENT_MAP_INLINE) {
978 err = btrfs_insert_file_extent(trans, root,
979 inode->i_ino,
980 pos, 0, 0, hole_size);
981 }
982 btrfs_end_transaction(trans, root);
983 mutex_unlock(&root->fs_info->fs_mutex);
984 unlock_extent(em_tree, pos, block_end, GFP_NOFS);
985 if (err)
986 return err;
987 }
988 out:
989 err = inode_setattr(inode, attr);
990 fail:
991 return err;
992 }
993
994 void btrfs_drop_inode(struct inode *inode)
995 {
996 struct btrfs_trans_handle *trans;
997 struct btrfs_root *root = BTRFS_I(inode)->root;
998
999 if (!BTRFS_I(inode)->ordered_trans) {
1000 generic_drop_inode(inode);
1001 return;
1002 }
1003 /* nasty, but it prevents a deadlock with data=ordered by preventing
1004 * a commit until after this inode is done
1005 */
1006 trans = btrfs_start_transaction(root, 1);
1007 generic_drop_inode(inode);
1008 /* note, the inode is now untouchable */
1009 btrfs_end_transaction(trans, root);
1010 }
1011
1012 void btrfs_delete_inode(struct inode *inode)
1013 {
1014 struct btrfs_trans_handle *trans;
1015 struct btrfs_root *root = BTRFS_I(inode)->root;
1016 unsigned long nr;
1017 int ret;
1018
1019 truncate_inode_pages(&inode->i_data, 0);
1020 if (is_bad_inode(inode)) {
1021 goto no_delete;
1022 }
1023
1024 inode->i_size = 0;
1025 mutex_lock(&root->fs_info->fs_mutex);
1026 trans = btrfs_start_transaction(root, 1);
1027
1028 btrfs_set_trans_block_group(trans, inode);
1029 ret = btrfs_truncate_in_trans(trans, root, inode);
1030 if (ret)
1031 goto no_delete_lock;
1032 ret = btrfs_delete_xattrs(trans, root, inode);
1033 if (ret)
1034 goto no_delete_lock;
1035 ret = btrfs_free_inode(trans, root, inode);
1036 if (ret)
1037 goto no_delete_lock;
1038 nr = trans->blocks_used;
1039
1040 btrfs_end_transaction(trans, root);
1041 mutex_unlock(&root->fs_info->fs_mutex);
1042 btrfs_btree_balance_dirty(root, nr);
1043 btrfs_throttle(root);
1044 return;
1045
1046 no_delete_lock:
1047 nr = trans->blocks_used;
1048 btrfs_end_transaction(trans, root);
1049 mutex_unlock(&root->fs_info->fs_mutex);
1050 btrfs_btree_balance_dirty(root, nr);
1051 btrfs_throttle(root);
1052 no_delete:
1053 clear_inode(inode);
1054 }
1055
1056 /*
1057 * this returns the key found in the dir entry in the location pointer.
1058 * If no dir entries were found, location->objectid is 0.
1059 */
1060 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
1061 struct btrfs_key *location)
1062 {
1063 const char *name = dentry->d_name.name;
1064 int namelen = dentry->d_name.len;
1065 struct btrfs_dir_item *di;
1066 struct btrfs_path *path;
1067 struct btrfs_root *root = BTRFS_I(dir)->root;
1068 int ret = 0;
1069
1070 if (namelen == 1 && strcmp(name, ".") == 0) {
1071 location->objectid = dir->i_ino;
1072 location->type = BTRFS_INODE_ITEM_KEY;
1073 location->offset = 0;
1074 return 0;
1075 }
1076 path = btrfs_alloc_path();
1077 BUG_ON(!path);
1078
1079 if (namelen == 2 && strcmp(name, "..") == 0) {
1080 struct btrfs_key key;
1081 struct extent_buffer *leaf;
1082 u32 nritems;
1083 int slot;
1084
1085 key.objectid = dir->i_ino;
1086 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
1087 key.offset = 0;
1088 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1089 BUG_ON(ret == 0);
1090 ret = 0;
1091
1092 leaf = path->nodes[0];
1093 slot = path->slots[0];
1094 nritems = btrfs_header_nritems(leaf);
1095 if (slot >= nritems)
1096 goto out_err;
1097
1098 btrfs_item_key_to_cpu(leaf, &key, slot);
1099 if (key.objectid != dir->i_ino ||
1100 key.type != BTRFS_INODE_REF_KEY) {
1101 goto out_err;
1102 }
1103 location->objectid = key.offset;
1104 location->type = BTRFS_INODE_ITEM_KEY;
1105 location->offset = 0;
1106 goto out;
1107 }
1108
1109 di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
1110 namelen, 0);
1111 if (IS_ERR(di))
1112 ret = PTR_ERR(di);
1113 if (!di || IS_ERR(di)) {
1114 goto out_err;
1115 }
1116 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
1117 out:
1118 btrfs_free_path(path);
1119 return ret;
1120 out_err:
1121 location->objectid = 0;
1122 goto out;
1123 }
1124
1125 /*
1126 * when we hit a tree root in a directory, the btrfs part of the inode
1127 * needs to be changed to reflect the root directory of the tree root. This
1128 * is kind of like crossing a mount point.
1129 */
1130 static int fixup_tree_root_location(struct btrfs_root *root,
1131 struct btrfs_key *location,
1132 struct btrfs_root **sub_root,
1133 struct dentry *dentry)
1134 {
1135 struct btrfs_path *path;
1136 struct btrfs_root_item *ri;
1137
1138 if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY)
1139 return 0;
1140 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1141 return 0;
1142
1143 path = btrfs_alloc_path();
1144 BUG_ON(!path);
1145 mutex_lock(&root->fs_info->fs_mutex);
1146
1147 *sub_root = btrfs_read_fs_root(root->fs_info, location,
1148 dentry->d_name.name,
1149 dentry->d_name.len);
1150 if (IS_ERR(*sub_root))
1151 return PTR_ERR(*sub_root);
1152
1153 ri = &(*sub_root)->root_item;
1154 location->objectid = btrfs_root_dirid(ri);
1155 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
1156 location->offset = 0;
1157
1158 btrfs_free_path(path);
1159 mutex_unlock(&root->fs_info->fs_mutex);
1160 return 0;
1161 }
1162
1163 static int btrfs_init_locked_inode(struct inode *inode, void *p)
1164 {
1165 struct btrfs_iget_args *args = p;
1166 inode->i_ino = args->ino;
1167 BTRFS_I(inode)->root = args->root;
1168 extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
1169 inode->i_mapping, GFP_NOFS);
1170 return 0;
1171 }
1172
1173 static int btrfs_find_actor(struct inode *inode, void *opaque)
1174 {
1175 struct btrfs_iget_args *args = opaque;
1176 return (args->ino == inode->i_ino &&
1177 args->root == BTRFS_I(inode)->root);
1178 }
1179
1180 struct inode *btrfs_ilookup(struct super_block *s, u64 objectid,
1181 u64 root_objectid)
1182 {
1183 struct btrfs_iget_args args;
1184 args.ino = objectid;
1185 args.root = btrfs_lookup_fs_root(btrfs_sb(s)->fs_info, root_objectid);
1186
1187 if (!args.root)
1188 return NULL;
1189
1190 return ilookup5(s, objectid, btrfs_find_actor, (void *)&args);
1191 }
1192
1193 struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
1194 struct btrfs_root *root)
1195 {
1196 struct inode *inode;
1197 struct btrfs_iget_args args;
1198 args.ino = objectid;
1199 args.root = root;
1200
1201 inode = iget5_locked(s, objectid, btrfs_find_actor,
1202 btrfs_init_locked_inode,
1203 (void *)&args);
1204 return inode;
1205 }
1206
1207 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
1208 struct nameidata *nd)
1209 {
1210 struct inode * inode;
1211 struct btrfs_inode *bi = BTRFS_I(dir);
1212 struct btrfs_root *root = bi->root;
1213 struct btrfs_root *sub_root = root;
1214 struct btrfs_key location;
1215 int ret;
1216
1217 if (dentry->d_name.len > BTRFS_NAME_LEN)
1218 return ERR_PTR(-ENAMETOOLONG);
1219
1220 mutex_lock(&root->fs_info->fs_mutex);
1221 ret = btrfs_inode_by_name(dir, dentry, &location);
1222 mutex_unlock(&root->fs_info->fs_mutex);
1223
1224 if (ret < 0)
1225 return ERR_PTR(ret);
1226
1227 inode = NULL;
1228 if (location.objectid) {
1229 ret = fixup_tree_root_location(root, &location, &sub_root,
1230 dentry);
1231 if (ret < 0)
1232 return ERR_PTR(ret);
1233 if (ret > 0)
1234 return ERR_PTR(-ENOENT);
1235 inode = btrfs_iget_locked(dir->i_sb, location.objectid,
1236 sub_root);
1237 if (!inode)
1238 return ERR_PTR(-EACCES);
1239 if (inode->i_state & I_NEW) {
1240 /* the inode and parent dir are two different roots */
1241 if (sub_root != root) {
1242 igrab(inode);
1243 sub_root->inode = inode;
1244 }
1245 BTRFS_I(inode)->root = sub_root;
1246 memcpy(&BTRFS_I(inode)->location, &location,
1247 sizeof(location));
1248 btrfs_read_locked_inode(inode);
1249 unlock_new_inode(inode);
1250 }
1251 }
1252 return d_splice_alias(inode, dentry);
1253 }
1254
1255 static unsigned char btrfs_filetype_table[] = {
1256 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
1257 };
1258
1259 static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
1260 {
1261 struct inode *inode = filp->f_dentry->d_inode;
1262 struct btrfs_root *root = BTRFS_I(inode)->root;
1263 struct btrfs_item *item;
1264 struct btrfs_dir_item *di;
1265 struct btrfs_key key;
1266 struct btrfs_key found_key;
1267 struct btrfs_path *path;
1268 int ret;
1269 u32 nritems;
1270 struct extent_buffer *leaf;
1271 int slot;
1272 int advance;
1273 unsigned char d_type;
1274 int over = 0;
1275 u32 di_cur;
1276 u32 di_total;
1277 u32 di_len;
1278 int key_type = BTRFS_DIR_INDEX_KEY;
1279 char tmp_name[32];
1280 char *name_ptr;
1281 int name_len;
1282
1283 /* FIXME, use a real flag for deciding about the key type */
1284 if (root->fs_info->tree_root == root)
1285 key_type = BTRFS_DIR_ITEM_KEY;
1286
1287 /* special case for "." */
1288 if (filp->f_pos == 0) {
1289 over = filldir(dirent, ".", 1,
1290 1, inode->i_ino,
1291 DT_DIR);
1292 if (over)
1293 return 0;
1294 filp->f_pos = 1;
1295 }
1296
1297 mutex_lock(&root->fs_info->fs_mutex);
1298 key.objectid = inode->i_ino;
1299 path = btrfs_alloc_path();
1300 path->reada = 2;
1301
1302 /* special case for .., just use the back ref */
1303 if (filp->f_pos == 1) {
1304 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
1305 key.offset = 0;
1306 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1307 BUG_ON(ret == 0);
1308 leaf = path->nodes[0];
1309 slot = path->slots[0];
1310 nritems = btrfs_header_nritems(leaf);
1311 if (slot >= nritems) {
1312 btrfs_release_path(root, path);
1313 goto read_dir_items;
1314 }
1315 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1316 btrfs_release_path(root, path);
1317 if (found_key.objectid != key.objectid ||
1318 found_key.type != BTRFS_INODE_REF_KEY)
1319 goto read_dir_items;
1320 over = filldir(dirent, "..", 2,
1321 2, found_key.offset, DT_DIR);
1322 if (over)
1323 goto nopos;
1324 filp->f_pos = 2;
1325 }
1326
1327 read_dir_items:
1328 btrfs_set_key_type(&key, key_type);
1329 key.offset = filp->f_pos;
1330
1331 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1332 if (ret < 0)
1333 goto err;
1334 advance = 0;
1335 while(1) {
1336 leaf = path->nodes[0];
1337 nritems = btrfs_header_nritems(leaf);
1338 slot = path->slots[0];
1339 if (advance || slot >= nritems) {
1340 if (slot >= nritems -1) {
1341 ret = btrfs_next_leaf(root, path);
1342 if (ret)
1343 break;
1344 leaf = path->nodes[0];
1345 nritems = btrfs_header_nritems(leaf);
1346 slot = path->slots[0];
1347 } else {
1348 slot++;
1349 path->slots[0]++;
1350 }
1351 }
1352 advance = 1;
1353 item = btrfs_item_nr(leaf, slot);
1354 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1355
1356 if (found_key.objectid != key.objectid)
1357 break;
1358 if (btrfs_key_type(&found_key) != key_type)
1359 break;
1360 if (found_key.offset < filp->f_pos)
1361 continue;
1362
1363 filp->f_pos = found_key.offset;
1364 advance = 1;
1365 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
1366 di_cur = 0;
1367 di_total = btrfs_item_size(leaf, item);
1368 while(di_cur < di_total) {
1369 struct btrfs_key location;
1370
1371 name_len = btrfs_dir_name_len(leaf, di);
1372 if (name_len < 32) {
1373 name_ptr = tmp_name;
1374 } else {
1375 name_ptr = kmalloc(name_len, GFP_NOFS);
1376 BUG_ON(!name_ptr);
1377 }
1378 read_extent_buffer(leaf, name_ptr,
1379 (unsigned long)(di + 1), name_len);
1380
1381 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
1382 btrfs_dir_item_key_to_cpu(leaf, di, &location);
1383 over = filldir(dirent, name_ptr, name_len,
1384 found_key.offset,
1385 location.objectid,
1386 d_type);
1387
1388 if (name_ptr != tmp_name)
1389 kfree(name_ptr);
1390
1391 if (over)
1392 goto nopos;
1393 di_len = btrfs_dir_name_len(leaf, di) +
1394 btrfs_dir_data_len(leaf, di) +sizeof(*di);
1395 di_cur += di_len;
1396 di = (struct btrfs_dir_item *)((char *)di + di_len);
1397 }
1398 }
1399 filp->f_pos++;
1400 nopos:
1401 ret = 0;
1402 err:
1403 btrfs_release_path(root, path);
1404 btrfs_free_path(path);
1405 mutex_unlock(&root->fs_info->fs_mutex);
1406 return ret;
1407 }
1408
1409 int btrfs_write_inode(struct inode *inode, int wait)
1410 {
1411 struct btrfs_root *root = BTRFS_I(inode)->root;
1412 struct btrfs_trans_handle *trans;
1413 int ret = 0;
1414
1415 if (wait) {
1416 mutex_lock(&root->fs_info->fs_mutex);
1417 trans = btrfs_start_transaction(root, 1);
1418 btrfs_set_trans_block_group(trans, inode);
1419 ret = btrfs_commit_transaction(trans, root);
1420 mutex_unlock(&root->fs_info->fs_mutex);
1421 }
1422 return ret;
1423 }
1424
1425 /*
1426 * This is somewhat expensive, updating the tree every time the
1427 * inode changes. But, it is most likely to find the inode in cache.
1428 * FIXME, needs more benchmarking...there are no reasons other than performance
1429 * to keep or drop this code.
1430 */
1431 void btrfs_dirty_inode(struct inode *inode)
1432 {
1433 struct btrfs_root *root = BTRFS_I(inode)->root;
1434 struct btrfs_trans_handle *trans;
1435
1436 mutex_lock(&root->fs_info->fs_mutex);
1437 trans = btrfs_start_transaction(root, 1);
1438 btrfs_set_trans_block_group(trans, inode);
1439 btrfs_update_inode(trans, root, inode);
1440 btrfs_end_transaction(trans, root);
1441 mutex_unlock(&root->fs_info->fs_mutex);
1442 }
1443
1444 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
1445 struct btrfs_root *root,
1446 u64 objectid,
1447 struct btrfs_block_group_cache *group,
1448 int mode)
1449 {
1450 struct inode *inode;
1451 struct btrfs_inode_item *inode_item;
1452 struct btrfs_key *location;
1453 struct btrfs_path *path;
1454 int ret;
1455 int owner;
1456
1457 path = btrfs_alloc_path();
1458 BUG_ON(!path);
1459
1460 inode = new_inode(root->fs_info->sb);
1461 if (!inode)
1462 return ERR_PTR(-ENOMEM);
1463
1464 extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
1465 inode->i_mapping, GFP_NOFS);
1466 BTRFS_I(inode)->root = root;
1467
1468 if (mode & S_IFDIR)
1469 owner = 0;
1470 else
1471 owner = 1;
1472 group = btrfs_find_block_group(root, group, 0, 0, owner);
1473 BTRFS_I(inode)->block_group = group;
1474 BTRFS_I(inode)->flags = 0;
1475 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
1476 if (ret)
1477 goto fail;
1478
1479 inode->i_uid = current->fsuid;
1480 inode->i_gid = current->fsgid;
1481 inode->i_mode = mode;
1482 inode->i_ino = objectid;
1483 inode->i_blocks = 0;
1484 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1485 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1486 struct btrfs_inode_item);
1487 fill_inode_item(path->nodes[0], inode_item, inode);
1488 btrfs_mark_buffer_dirty(path->nodes[0]);
1489 btrfs_free_path(path);
1490
1491 location = &BTRFS_I(inode)->location;
1492 location->objectid = objectid;
1493 location->offset = 0;
1494 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
1495
1496 insert_inode_hash(inode);
1497 return inode;
1498 fail:
1499 btrfs_free_path(path);
1500 return ERR_PTR(ret);
1501 }
1502
1503 static inline u8 btrfs_inode_type(struct inode *inode)
1504 {
1505 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
1506 }
1507
1508 static int btrfs_add_link(struct btrfs_trans_handle *trans,
1509 struct dentry *dentry, struct inode *inode)
1510 {
1511 int ret;
1512 struct btrfs_key key;
1513 struct btrfs_root *root = BTRFS_I(dentry->d_parent->d_inode)->root;
1514 struct inode *parent_inode;
1515
1516 key.objectid = inode->i_ino;
1517 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
1518 key.offset = 0;
1519
1520 ret = btrfs_insert_dir_item(trans, root,
1521 dentry->d_name.name, dentry->d_name.len,
1522 dentry->d_parent->d_inode->i_ino,
1523 &key, btrfs_inode_type(inode));
1524 if (ret == 0) {
1525 ret = btrfs_insert_inode_ref(trans, root,
1526 dentry->d_name.name,
1527 dentry->d_name.len,
1528 inode->i_ino,
1529 dentry->d_parent->d_inode->i_ino);
1530 parent_inode = dentry->d_parent->d_inode;
1531 parent_inode->i_size += dentry->d_name.len * 2;
1532 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
1533 ret = btrfs_update_inode(trans, root,
1534 dentry->d_parent->d_inode);
1535 }
1536 return ret;
1537 }
1538
1539 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
1540 struct dentry *dentry, struct inode *inode)
1541 {
1542 int err = btrfs_add_link(trans, dentry, inode);
1543 if (!err) {
1544 d_instantiate(dentry, inode);
1545 return 0;
1546 }
1547 if (err > 0)
1548 err = -EEXIST;
1549 return err;
1550 }
1551
1552 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
1553 int mode, dev_t rdev)
1554 {
1555 struct btrfs_trans_handle *trans;
1556 struct btrfs_root *root = BTRFS_I(dir)->root;
1557 struct inode *inode = NULL;
1558 int err;
1559 int drop_inode = 0;
1560 u64 objectid;
1561 unsigned long nr = 0;
1562
1563 if (!new_valid_dev(rdev))
1564 return -EINVAL;
1565
1566 mutex_lock(&root->fs_info->fs_mutex);
1567 err = btrfs_check_free_space(root, 1, 0);
1568 if (err)
1569 goto fail;
1570
1571 trans = btrfs_start_transaction(root, 1);
1572 btrfs_set_trans_block_group(trans, dir);
1573
1574 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1575 if (err) {
1576 err = -ENOSPC;
1577 goto out_unlock;
1578 }
1579
1580 inode = btrfs_new_inode(trans, root, objectid,
1581 BTRFS_I(dir)->block_group, mode);
1582 err = PTR_ERR(inode);
1583 if (IS_ERR(inode))
1584 goto out_unlock;
1585
1586 btrfs_set_trans_block_group(trans, inode);
1587 err = btrfs_add_nondir(trans, dentry, inode);
1588 if (err)
1589 drop_inode = 1;
1590 else {
1591 inode->i_op = &btrfs_special_inode_operations;
1592 init_special_inode(inode, inode->i_mode, rdev);
1593 btrfs_update_inode(trans, root, inode);
1594 }
1595 dir->i_sb->s_dirt = 1;
1596 btrfs_update_inode_block_group(trans, inode);
1597 btrfs_update_inode_block_group(trans, dir);
1598 out_unlock:
1599 nr = trans->blocks_used;
1600 btrfs_end_transaction(trans, root);
1601 fail:
1602 mutex_unlock(&root->fs_info->fs_mutex);
1603
1604 if (drop_inode) {
1605 inode_dec_link_count(inode);
1606 iput(inode);
1607 }
1608 btrfs_btree_balance_dirty(root, nr);
1609 btrfs_throttle(root);
1610 return err;
1611 }
1612
1613 static int btrfs_create(struct inode *dir, struct dentry *dentry,
1614 int mode, struct nameidata *nd)
1615 {
1616 struct btrfs_trans_handle *trans;
1617 struct btrfs_root *root = BTRFS_I(dir)->root;
1618 struct inode *inode = NULL;
1619 int err;
1620 int drop_inode = 0;
1621 unsigned long nr = 0;
1622 u64 objectid;
1623
1624 mutex_lock(&root->fs_info->fs_mutex);
1625 err = btrfs_check_free_space(root, 1, 0);
1626 if (err)
1627 goto fail;
1628 trans = btrfs_start_transaction(root, 1);
1629 btrfs_set_trans_block_group(trans, dir);
1630
1631 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1632 if (err) {
1633 err = -ENOSPC;
1634 goto out_unlock;
1635 }
1636
1637 inode = btrfs_new_inode(trans, root, objectid,
1638 BTRFS_I(dir)->block_group, mode);
1639 err = PTR_ERR(inode);
1640 if (IS_ERR(inode))
1641 goto out_unlock;
1642
1643 btrfs_set_trans_block_group(trans, inode);
1644 err = btrfs_add_nondir(trans, dentry, inode);
1645 if (err)
1646 drop_inode = 1;
1647 else {
1648 inode->i_mapping->a_ops = &btrfs_aops;
1649 inode->i_fop = &btrfs_file_operations;
1650 inode->i_op = &btrfs_file_inode_operations;
1651 extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
1652 inode->i_mapping, GFP_NOFS);
1653 BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
1654 }
1655 dir->i_sb->s_dirt = 1;
1656 btrfs_update_inode_block_group(trans, inode);
1657 btrfs_update_inode_block_group(trans, dir);
1658 out_unlock:
1659 nr = trans->blocks_used;
1660 btrfs_end_transaction(trans, root);
1661 fail:
1662 mutex_unlock(&root->fs_info->fs_mutex);
1663
1664 if (drop_inode) {
1665 inode_dec_link_count(inode);
1666 iput(inode);
1667 }
1668 btrfs_btree_balance_dirty(root, nr);
1669 btrfs_throttle(root);
1670 return err;
1671 }
1672
1673 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
1674 struct dentry *dentry)
1675 {
1676 struct btrfs_trans_handle *trans;
1677 struct btrfs_root *root = BTRFS_I(dir)->root;
1678 struct inode *inode = old_dentry->d_inode;
1679 unsigned long nr = 0;
1680 int err;
1681 int drop_inode = 0;
1682
1683 if (inode->i_nlink == 0)
1684 return -ENOENT;
1685
1686 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
1687 inode->i_nlink++;
1688 #else
1689 inc_nlink(inode);
1690 #endif
1691 mutex_lock(&root->fs_info->fs_mutex);
1692 err = btrfs_check_free_space(root, 1, 0);
1693 if (err)
1694 goto fail;
1695 trans = btrfs_start_transaction(root, 1);
1696
1697 btrfs_set_trans_block_group(trans, dir);
1698 atomic_inc(&inode->i_count);
1699 err = btrfs_add_nondir(trans, dentry, inode);
1700
1701 if (err)
1702 drop_inode = 1;
1703
1704 dir->i_sb->s_dirt = 1;
1705 btrfs_update_inode_block_group(trans, dir);
1706 err = btrfs_update_inode(trans, root, inode);
1707
1708 if (err)
1709 drop_inode = 1;
1710
1711 nr = trans->blocks_used;
1712 btrfs_end_transaction(trans, root);
1713 fail:
1714 mutex_unlock(&root->fs_info->fs_mutex);
1715
1716 if (drop_inode) {
1717 inode_dec_link_count(inode);
1718 iput(inode);
1719 }
1720 btrfs_btree_balance_dirty(root, nr);
1721 btrfs_throttle(root);
1722 return err;
1723 }
1724
1725 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1726 {
1727 struct inode *inode;
1728 struct btrfs_trans_handle *trans;
1729 struct btrfs_root *root = BTRFS_I(dir)->root;
1730 int err = 0;
1731 int drop_on_err = 0;
1732 u64 objectid;
1733 unsigned long nr = 1;
1734
1735 mutex_lock(&root->fs_info->fs_mutex);
1736 err = btrfs_check_free_space(root, 1, 0);
1737 if (err)
1738 goto out_unlock;
1739
1740 trans = btrfs_start_transaction(root, 1);
1741 btrfs_set_trans_block_group(trans, dir);
1742
1743 if (IS_ERR(trans)) {
1744 err = PTR_ERR(trans);
1745 goto out_unlock;
1746 }
1747
1748 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1749 if (err) {
1750 err = -ENOSPC;
1751 goto out_unlock;
1752 }
1753
1754 inode = btrfs_new_inode(trans, root, objectid,
1755 BTRFS_I(dir)->block_group, S_IFDIR | mode);
1756 if (IS_ERR(inode)) {
1757 err = PTR_ERR(inode);
1758 goto out_fail;
1759 }
1760
1761 drop_on_err = 1;
1762 inode->i_op = &btrfs_dir_inode_operations;
1763 inode->i_fop = &btrfs_dir_file_operations;
1764 btrfs_set_trans_block_group(trans, inode);
1765
1766 inode->i_size = 0;
1767 err = btrfs_update_inode(trans, root, inode);
1768 if (err)
1769 goto out_fail;
1770
1771 err = btrfs_add_link(trans, dentry, inode);
1772 if (err)
1773 goto out_fail;
1774
1775 d_instantiate(dentry, inode);
1776 drop_on_err = 0;
1777 dir->i_sb->s_dirt = 1;
1778 btrfs_update_inode_block_group(trans, inode);
1779 btrfs_update_inode_block_group(trans, dir);
1780
1781 out_fail:
1782 nr = trans->blocks_used;
1783 btrfs_end_transaction(trans, root);
1784
1785 out_unlock:
1786 mutex_unlock(&root->fs_info->fs_mutex);
1787 if (drop_on_err)
1788 iput(inode);
1789 btrfs_btree_balance_dirty(root, nr);
1790 btrfs_throttle(root);
1791 return err;
1792 }
1793
1794 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
1795 size_t page_offset, u64 start, u64 end,
1796 int create)
1797 {
1798 int ret;
1799 int err = 0;
1800 u64 bytenr;
1801 u64 extent_start = 0;
1802 u64 extent_end = 0;
1803 u64 objectid = inode->i_ino;
1804 u32 found_type;
1805 int failed_insert = 0;
1806 struct btrfs_path *path;
1807 struct btrfs_root *root = BTRFS_I(inode)->root;
1808 struct btrfs_file_extent_item *item;
1809 struct extent_buffer *leaf;
1810 struct btrfs_key found_key;
1811 struct extent_map *em = NULL;
1812 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1813 struct btrfs_trans_handle *trans = NULL;
1814
1815 path = btrfs_alloc_path();
1816 BUG_ON(!path);
1817 mutex_lock(&root->fs_info->fs_mutex);
1818
1819 again:
1820 em = lookup_extent_mapping(em_tree, start, end);
1821 if (em) {
1822 if (em->start > start) {
1823 printk("get_extent start %Lu em start %Lu\n",
1824 start, em->start);
1825 WARN_ON(1);
1826 }
1827 goto out;
1828 }
1829 if (!em) {
1830 em = alloc_extent_map(GFP_NOFS);
1831 if (!em) {
1832 err = -ENOMEM;
1833 goto out;
1834 }
1835 em->start = EXTENT_MAP_HOLE;
1836 em->end = EXTENT_MAP_HOLE;
1837 }
1838 em->bdev = inode->i_sb->s_bdev;
1839 ret = btrfs_lookup_file_extent(trans, root, path,
1840 objectid, start, trans != NULL);
1841 if (ret < 0) {
1842 err = ret;
1843 goto out;
1844 }
1845
1846 if (ret != 0) {
1847 if (path->slots[0] == 0)
1848 goto not_found;
1849 path->slots[0]--;
1850 }
1851
1852 leaf = path->nodes[0];
1853 item = btrfs_item_ptr(leaf, path->slots[0],
1854 struct btrfs_file_extent_item);
1855 /* are we inside the extent that was found? */
1856 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1857 found_type = btrfs_key_type(&found_key);
1858 if (found_key.objectid != objectid ||
1859 found_type != BTRFS_EXTENT_DATA_KEY) {
1860 goto not_found;
1861 }
1862
1863 found_type = btrfs_file_extent_type(leaf, item);
1864 extent_start = found_key.offset;
1865 if (found_type == BTRFS_FILE_EXTENT_REG) {
1866 extent_end = extent_start +
1867 btrfs_file_extent_num_bytes(leaf, item);
1868 err = 0;
1869 if (start < extent_start || start >= extent_end) {
1870 em->start = start;
1871 if (start < extent_start) {
1872 if (end < extent_start)
1873 goto not_found;
1874 em->end = extent_end - 1;
1875 } else {
1876 em->end = end;
1877 }
1878 goto not_found_em;
1879 }
1880 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
1881 if (bytenr == 0) {
1882 em->start = extent_start;
1883 em->end = extent_end - 1;
1884 em->block_start = EXTENT_MAP_HOLE;
1885 em->block_end = EXTENT_MAP_HOLE;
1886 goto insert;
1887 }
1888 bytenr += btrfs_file_extent_offset(leaf, item);
1889 em->block_start = bytenr;
1890 em->block_end = em->block_start +
1891 btrfs_file_extent_num_bytes(leaf, item) - 1;
1892 em->start = extent_start;
1893 em->end = extent_end - 1;
1894 goto insert;
1895 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
1896 unsigned long ptr;
1897 char *map;
1898 size_t size;
1899 size_t extent_offset;
1900 size_t copy_size;
1901
1902 size = btrfs_file_extent_inline_len(leaf, btrfs_item_nr(leaf,
1903 path->slots[0]));
1904 extent_end = (extent_start + size - 1) |
1905 ((u64)root->sectorsize - 1);
1906 if (start < extent_start || start >= extent_end) {
1907 em->start = start;
1908 if (start < extent_start) {
1909 if (end < extent_start)
1910 goto not_found;
1911 em->end = extent_end;
1912 } else {
1913 em->end = end;
1914 }
1915 goto not_found_em;
1916 }
1917 em->block_start = EXTENT_MAP_INLINE;
1918 em->block_end = EXTENT_MAP_INLINE;
1919
1920 if (!page) {
1921 em->start = extent_start;
1922 em->end = extent_start + size - 1;
1923 goto out;
1924 }
1925
1926 extent_offset = ((u64)page->index << PAGE_CACHE_SHIFT) -
1927 extent_start + page_offset;
1928 copy_size = min_t(u64, PAGE_CACHE_SIZE - page_offset,
1929 size - extent_offset);
1930 em->start = extent_start + extent_offset;
1931 em->end = (em->start + copy_size -1) |
1932 ((u64)root->sectorsize -1);
1933 map = kmap(page);
1934 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
1935 if (create == 0 && !PageUptodate(page)) {
1936 read_extent_buffer(leaf, map + page_offset, ptr,
1937 copy_size);
1938 flush_dcache_page(page);
1939 } else if (create && PageUptodate(page)) {
1940 if (!trans) {
1941 kunmap(page);
1942 free_extent_map(em);
1943 em = NULL;
1944 btrfs_release_path(root, path);
1945 trans = btrfs_start_transaction(root, 1);
1946 goto again;
1947 }
1948 write_extent_buffer(leaf, map + page_offset, ptr,
1949 copy_size);
1950 btrfs_mark_buffer_dirty(leaf);
1951 }
1952 kunmap(page);
1953 set_extent_uptodate(em_tree, em->start, em->end, GFP_NOFS);
1954 goto insert;
1955 } else {
1956 printk("unkknown found_type %d\n", found_type);
1957 WARN_ON(1);
1958 }
1959 not_found:
1960 em->start = start;
1961 em->end = end;
1962 not_found_em:
1963 em->block_start = EXTENT_MAP_HOLE;
1964 em->block_end = EXTENT_MAP_HOLE;
1965 insert:
1966 btrfs_release_path(root, path);
1967 if (em->start > start || em->end < start) {
1968 printk("bad extent! em: [%Lu %Lu] passed [%Lu %Lu]\n", em->start, em->end, start, end);
1969 err = -EIO;
1970 goto out;
1971 }
1972 ret = add_extent_mapping(em_tree, em);
1973 if (ret == -EEXIST) {
1974 free_extent_map(em);
1975 em = NULL;
1976 if (0 && failed_insert == 1) {
1977 btrfs_drop_extent_cache(inode, start, end);
1978 }
1979 failed_insert++;
1980 if (failed_insert > 5) {
1981 printk("failing to insert %Lu %Lu\n", start, end);
1982 err = -EIO;
1983 goto out;
1984 }
1985 goto again;
1986 }
1987 err = 0;
1988 out:
1989 btrfs_free_path(path);
1990 if (trans) {
1991 ret = btrfs_end_transaction(trans, root);
1992 if (!err)
1993 err = ret;
1994 }
1995 mutex_unlock(&root->fs_info->fs_mutex);
1996 if (err) {
1997 free_extent_map(em);
1998 WARN_ON(1);
1999 return ERR_PTR(err);
2000 }
2001 return em;
2002 }
2003
2004 static sector_t btrfs_bmap(struct address_space *mapping, sector_t iblock)
2005 {
2006 return extent_bmap(mapping, iblock, btrfs_get_extent);
2007 }
2008
2009 int btrfs_readpage(struct file *file, struct page *page)
2010 {
2011 struct extent_map_tree *tree;
2012 tree = &BTRFS_I(page->mapping->host)->extent_tree;
2013 return extent_read_full_page(tree, page, btrfs_get_extent);
2014 }
2015
2016 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
2017 {
2018 struct extent_map_tree *tree;
2019
2020
2021 if (current->flags & PF_MEMALLOC) {
2022 redirty_page_for_writepage(wbc, page);
2023 unlock_page(page);
2024 return 0;
2025 }
2026 tree = &BTRFS_I(page->mapping->host)->extent_tree;
2027 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
2028 }
2029
2030 static int btrfs_writepages(struct address_space *mapping,
2031 struct writeback_control *wbc)
2032 {
2033 struct extent_map_tree *tree;
2034 tree = &BTRFS_I(mapping->host)->extent_tree;
2035 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
2036 }
2037
2038 static int
2039 btrfs_readpages(struct file *file, struct address_space *mapping,
2040 struct list_head *pages, unsigned nr_pages)
2041 {
2042 struct extent_map_tree *tree;
2043 tree = &BTRFS_I(mapping->host)->extent_tree;
2044 return extent_readpages(tree, mapping, pages, nr_pages,
2045 btrfs_get_extent);
2046 }
2047
2048 static int btrfs_releasepage(struct page *page, gfp_t unused_gfp_flags)
2049 {
2050 struct extent_map_tree *tree;
2051 int ret;
2052
2053 tree = &BTRFS_I(page->mapping->host)->extent_tree;
2054 ret = try_release_extent_mapping(tree, page);
2055 if (ret == 1) {
2056 ClearPagePrivate(page);
2057 set_page_private(page, 0);
2058 page_cache_release(page);
2059 }
2060 return ret;
2061 }
2062
2063 static void btrfs_invalidatepage(struct page *page, unsigned long offset)
2064 {
2065 struct extent_map_tree *tree;
2066
2067 tree = &BTRFS_I(page->mapping->host)->extent_tree;
2068 extent_invalidatepage(tree, page, offset);
2069 btrfs_releasepage(page, GFP_NOFS);
2070 }
2071
2072 /*
2073 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
2074 * called from a page fault handler when a page is first dirtied. Hence we must
2075 * be careful to check for EOF conditions here. We set the page up correctly
2076 * for a written page which means we get ENOSPC checking when writing into
2077 * holes and correct delalloc and unwritten extent mapping on filesystems that
2078 * support these features.
2079 *
2080 * We are not allowed to take the i_mutex here so we have to play games to
2081 * protect against truncate races as the page could now be beyond EOF. Because
2082 * vmtruncate() writes the inode size before removing pages, once we have the
2083 * page lock we can determine safely if the page is beyond EOF. If it is not
2084 * beyond EOF, then the page is guaranteed safe against truncation until we
2085 * unlock the page.
2086 */
2087 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
2088 {
2089 struct inode *inode = fdentry(vma->vm_file)->d_inode;
2090 struct btrfs_root *root = BTRFS_I(inode)->root;
2091 unsigned long end;
2092 loff_t size;
2093 int ret;
2094 u64 page_start;
2095
2096 mutex_lock(&root->fs_info->fs_mutex);
2097 ret = btrfs_check_free_space(root, PAGE_CACHE_SIZE, 0);
2098 mutex_unlock(&root->fs_info->fs_mutex);
2099 if (ret)
2100 goto out;
2101
2102 ret = -EINVAL;
2103
2104 lock_page(page);
2105 wait_on_page_writeback(page);
2106 size = i_size_read(inode);
2107 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2108
2109 if ((page->mapping != inode->i_mapping) ||
2110 (page_start > size)) {
2111 /* page got truncated out from underneath us */
2112 goto out_unlock;
2113 }
2114
2115 /* page is wholly or partially inside EOF */
2116 if (page_start + PAGE_CACHE_SIZE > size)
2117 end = size & ~PAGE_CACHE_MASK;
2118 else
2119 end = PAGE_CACHE_SIZE;
2120
2121 ret = btrfs_cow_one_page(inode, page, end);
2122
2123 out_unlock:
2124 unlock_page(page);
2125 out:
2126 return ret;
2127 }
2128
2129 static void btrfs_truncate(struct inode *inode)
2130 {
2131 struct btrfs_root *root = BTRFS_I(inode)->root;
2132 int ret;
2133 struct btrfs_trans_handle *trans;
2134 unsigned long nr;
2135
2136 if (!S_ISREG(inode->i_mode))
2137 return;
2138 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
2139 return;
2140
2141 btrfs_truncate_page(inode->i_mapping, inode->i_size);
2142
2143 mutex_lock(&root->fs_info->fs_mutex);
2144 trans = btrfs_start_transaction(root, 1);
2145 btrfs_set_trans_block_group(trans, inode);
2146
2147 /* FIXME, add redo link to tree so we don't leak on crash */
2148 ret = btrfs_truncate_in_trans(trans, root, inode);
2149 btrfs_update_inode(trans, root, inode);
2150 nr = trans->blocks_used;
2151
2152 ret = btrfs_end_transaction(trans, root);
2153 BUG_ON(ret);
2154 mutex_unlock(&root->fs_info->fs_mutex);
2155 btrfs_btree_balance_dirty(root, nr);
2156 btrfs_throttle(root);
2157 }
2158
2159 static int noinline create_subvol(struct btrfs_root *root, char *name,
2160 int namelen)
2161 {
2162 struct btrfs_trans_handle *trans;
2163 struct btrfs_key key;
2164 struct btrfs_root_item root_item;
2165 struct btrfs_inode_item *inode_item;
2166 struct extent_buffer *leaf;
2167 struct btrfs_root *new_root = root;
2168 struct inode *inode;
2169 struct inode *dir;
2170 int ret;
2171 int err;
2172 u64 objectid;
2173 u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
2174 unsigned long nr = 1;
2175
2176 mutex_lock(&root->fs_info->fs_mutex);
2177 ret = btrfs_check_free_space(root, 1, 0);
2178 if (ret)
2179 goto fail_commit;
2180
2181 trans = btrfs_start_transaction(root, 1);
2182 BUG_ON(!trans);
2183
2184 ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
2185 0, &objectid);
2186 if (ret)
2187 goto fail;
2188
2189 leaf = __btrfs_alloc_free_block(trans, root, root->leafsize,
2190 objectid, trans->transid, 0, 0,
2191 0, 0);
2192 if (IS_ERR(leaf))
2193 return PTR_ERR(leaf);
2194
2195 btrfs_set_header_nritems(leaf, 0);
2196 btrfs_set_header_level(leaf, 0);
2197 btrfs_set_header_bytenr(leaf, leaf->start);
2198 btrfs_set_header_generation(leaf, trans->transid);
2199 btrfs_set_header_owner(leaf, objectid);
2200
2201 write_extent_buffer(leaf, root->fs_info->fsid,
2202 (unsigned long)btrfs_header_fsid(leaf),
2203 BTRFS_FSID_SIZE);
2204 btrfs_mark_buffer_dirty(leaf);
2205
2206 inode_item = &root_item.inode;
2207 memset(inode_item, 0, sizeof(*inode_item));
2208 inode_item->generation = cpu_to_le64(1);
2209 inode_item->size = cpu_to_le64(3);
2210 inode_item->nlink = cpu_to_le32(1);
2211 inode_item->nblocks = cpu_to_le64(1);
2212 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
2213
2214 btrfs_set_root_bytenr(&root_item, leaf->start);
2215 btrfs_set_root_level(&root_item, 0);
2216 btrfs_set_root_refs(&root_item, 1);
2217 btrfs_set_root_used(&root_item, 0);
2218
2219 memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
2220 root_item.drop_level = 0;
2221
2222 free_extent_buffer(leaf);
2223 leaf = NULL;
2224
2225 btrfs_set_root_dirid(&root_item, new_dirid);
2226
2227 key.objectid = objectid;
2228 key.offset = 1;
2229 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
2230 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
2231 &root_item);
2232 if (ret)
2233 goto fail;
2234
2235 /*
2236 * insert the directory item
2237 */
2238 key.offset = (u64)-1;
2239 dir = root->fs_info->sb->s_root->d_inode;
2240 ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
2241 name, namelen, dir->i_ino, &key,
2242 BTRFS_FT_DIR);
2243 if (ret)
2244 goto fail;
2245
2246 ret = btrfs_insert_inode_ref(trans, root->fs_info->tree_root,
2247 name, namelen, objectid,
2248 root->fs_info->sb->s_root->d_inode->i_ino);
2249 if (ret)
2250 goto fail;
2251
2252 ret = btrfs_commit_transaction(trans, root);
2253 if (ret)
2254 goto fail_commit;
2255
2256 new_root = btrfs_read_fs_root(root->fs_info, &key, name, namelen);
2257 BUG_ON(!new_root);
2258
2259 trans = btrfs_start_transaction(new_root, 1);
2260 BUG_ON(!trans);
2261
2262 inode = btrfs_new_inode(trans, new_root, new_dirid,
2263 BTRFS_I(dir)->block_group, S_IFDIR | 0700);
2264 if (IS_ERR(inode))
2265 goto fail;
2266 inode->i_op = &btrfs_dir_inode_operations;
2267 inode->i_fop = &btrfs_dir_file_operations;
2268 new_root->inode = inode;
2269
2270 ret = btrfs_insert_inode_ref(trans, new_root, "..", 2, new_dirid,
2271 new_dirid);
2272 inode->i_nlink = 1;
2273 inode->i_size = 0;
2274 ret = btrfs_update_inode(trans, new_root, inode);
2275 if (ret)
2276 goto fail;
2277 fail:
2278 nr = trans->blocks_used;
2279 err = btrfs_commit_transaction(trans, new_root);
2280 if (err && !ret)
2281 ret = err;
2282 fail_commit:
2283 mutex_unlock(&root->fs_info->fs_mutex);
2284 btrfs_btree_balance_dirty(root, nr);
2285 btrfs_throttle(root);
2286 return ret;
2287 }
2288
2289 static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
2290 {
2291 struct btrfs_pending_snapshot *pending_snapshot;
2292 struct btrfs_trans_handle *trans;
2293 int ret;
2294 int err;
2295 unsigned long nr = 0;
2296
2297 if (!root->ref_cows)
2298 return -EINVAL;
2299
2300 mutex_lock(&root->fs_info->fs_mutex);
2301 ret = btrfs_check_free_space(root, 1, 0);
2302 if (ret)
2303 goto fail_unlock;
2304
2305 pending_snapshot = kmalloc(sizeof(*pending_snapshot), GFP_NOFS);
2306 if (!pending_snapshot) {
2307 ret = -ENOMEM;
2308 goto fail_unlock;
2309 }
2310 pending_snapshot->name = kstrndup(name, namelen, GFP_NOFS);
2311 if (!pending_snapshot->name) {
2312 ret = -ENOMEM;
2313 kfree(pending_snapshot);
2314 goto fail_unlock;
2315 }
2316 trans = btrfs_start_transaction(root, 1);
2317 BUG_ON(!trans);
2318
2319 pending_snapshot->root = root;
2320 list_add(&pending_snapshot->list,
2321 &trans->transaction->pending_snapshots);
2322 ret = btrfs_update_inode(trans, root, root->inode);
2323 err = btrfs_commit_transaction(trans, root);
2324
2325 fail_unlock:
2326 mutex_unlock(&root->fs_info->fs_mutex);
2327 btrfs_btree_balance_dirty(root, nr);
2328 btrfs_throttle(root);
2329 return ret;
2330 }
2331
2332 unsigned long btrfs_force_ra(struct address_space *mapping,
2333 struct file_ra_state *ra, struct file *file,
2334 pgoff_t offset, pgoff_t last_index)
2335 {
2336 pgoff_t req_size;
2337
2338 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
2339 req_size = last_index - offset + 1;
2340 offset = page_cache_readahead(mapping, ra, file, offset, req_size);
2341 return offset;
2342 #else
2343 req_size = min(last_index - offset + 1, (pgoff_t)128);
2344 page_cache_sync_readahead(mapping, ra, file, offset, req_size);
2345 return offset + req_size;
2346 #endif
2347 }
2348
2349 int btrfs_defrag_file(struct file *file) {
2350 struct inode *inode = fdentry(file)->d_inode;
2351 struct btrfs_root *root = BTRFS_I(inode)->root;
2352 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2353 struct page *page;
2354 unsigned long last_index;
2355 unsigned long ra_index = 0;
2356 u64 page_start;
2357 u64 page_end;
2358 u64 delalloc_start;
2359 u64 existing_delalloc;
2360 unsigned long i;
2361 int ret;
2362
2363 mutex_lock(&root->fs_info->fs_mutex);
2364 ret = btrfs_check_free_space(root, inode->i_size, 0);
2365 mutex_unlock(&root->fs_info->fs_mutex);
2366 if (ret)
2367 return -ENOSPC;
2368
2369 mutex_lock(&inode->i_mutex);
2370 last_index = inode->i_size >> PAGE_CACHE_SHIFT;
2371 for (i = 0; i <= last_index; i++) {
2372 if (i == ra_index) {
2373 ra_index = btrfs_force_ra(inode->i_mapping,
2374 &file->f_ra,
2375 file, ra_index, last_index);
2376 }
2377 page = grab_cache_page(inode->i_mapping, i);
2378 if (!page)
2379 goto out_unlock;
2380 if (!PageUptodate(page)) {
2381 btrfs_readpage(NULL, page);
2382 lock_page(page);
2383 if (!PageUptodate(page)) {
2384 unlock_page(page);
2385 page_cache_release(page);
2386 goto out_unlock;
2387 }
2388 }
2389 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2390 page_end = page_start + PAGE_CACHE_SIZE - 1;
2391
2392 lock_extent(em_tree, page_start, page_end, GFP_NOFS);
2393 delalloc_start = page_start;
2394 existing_delalloc =
2395 count_range_bits(&BTRFS_I(inode)->extent_tree,
2396 &delalloc_start, page_end,
2397 PAGE_CACHE_SIZE, EXTENT_DELALLOC);
2398 set_extent_delalloc(em_tree, page_start,
2399 page_end, GFP_NOFS);
2400
2401 spin_lock(&root->fs_info->delalloc_lock);
2402 root->fs_info->delalloc_bytes += PAGE_CACHE_SIZE -
2403 existing_delalloc;
2404 spin_unlock(&root->fs_info->delalloc_lock);
2405
2406 unlock_extent(em_tree, page_start, page_end, GFP_NOFS);
2407 set_page_dirty(page);
2408 unlock_page(page);
2409 page_cache_release(page);
2410 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
2411 }
2412
2413 out_unlock:
2414 mutex_unlock(&inode->i_mutex);
2415 return 0;
2416 }
2417
2418 static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
2419 {
2420 u64 new_size;
2421 u64 old_size;
2422 struct btrfs_ioctl_vol_args *vol_args;
2423 struct btrfs_trans_handle *trans;
2424 char *sizestr;
2425 int ret = 0;
2426 int namelen;
2427 int mod = 0;
2428
2429 vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
2430
2431 if (!vol_args)
2432 return -ENOMEM;
2433
2434 if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
2435 ret = -EFAULT;
2436 goto out;
2437 }
2438 namelen = strlen(vol_args->name);
2439 if (namelen > BTRFS_VOL_NAME_MAX) {
2440 ret = -EINVAL;
2441 goto out;
2442 }
2443
2444 sizestr = vol_args->name;
2445 if (!strcmp(sizestr, "max"))
2446 new_size = root->fs_info->sb->s_bdev->bd_inode->i_size;
2447 else {
2448 if (sizestr[0] == '-') {
2449 mod = -1;
2450 sizestr++;
2451 } else if (sizestr[0] == '+') {
2452 mod = 1;
2453 sizestr++;
2454 }
2455 new_size = btrfs_parse_size(sizestr);
2456 if (new_size == 0) {
2457 ret = -EINVAL;
2458 goto out;
2459 }
2460 }
2461
2462 mutex_lock(&root->fs_info->fs_mutex);
2463 old_size = btrfs_super_total_bytes(&root->fs_info->super_copy);
2464
2465 if (mod < 0) {
2466 if (new_size > old_size) {
2467 ret = -EINVAL;
2468 goto out_unlock;
2469 }
2470 new_size = old_size - new_size;
2471 } else if (mod > 0) {
2472 new_size = old_size + new_size;
2473 }
2474
2475 if (new_size < 256 * 1024 * 1024) {
2476 ret = -EINVAL;
2477 goto out_unlock;
2478 }
2479 if (new_size > root->fs_info->sb->s_bdev->bd_inode->i_size) {
2480 ret = -EFBIG;
2481 goto out_unlock;
2482 }
2483
2484 do_div(new_size, root->sectorsize);
2485 new_size *= root->sectorsize;
2486
2487 printk("new size is %Lu\n", new_size);
2488 if (new_size > old_size) {
2489 trans = btrfs_start_transaction(root, 1);
2490 ret = btrfs_grow_extent_tree(trans, root, new_size);
2491 btrfs_commit_transaction(trans, root);
2492 } else {
2493 ret = btrfs_shrink_extent_tree(root, new_size);
2494 }
2495
2496 out_unlock:
2497 mutex_unlock(&root->fs_info->fs_mutex);
2498 out:
2499 kfree(vol_args);
2500 return ret;
2501 }
2502
2503 static int noinline btrfs_ioctl_snap_create(struct btrfs_root *root,
2504 void __user *arg)
2505 {
2506 struct btrfs_ioctl_vol_args *vol_args;
2507 struct btrfs_dir_item *di;
2508 struct btrfs_path *path;
2509 u64 root_dirid;
2510 int namelen;
2511 int ret;
2512
2513 vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
2514
2515 if (!vol_args)
2516 return -ENOMEM;
2517
2518 if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
2519 ret = -EFAULT;
2520 goto out;
2521 }
2522
2523 namelen = strlen(vol_args->name);
2524 if (namelen > BTRFS_VOL_NAME_MAX) {
2525 ret = -EINVAL;
2526 goto out;
2527 }
2528 if (strchr(vol_args->name, '/')) {
2529 ret = -EINVAL;
2530 goto out;
2531 }
2532
2533 path = btrfs_alloc_path();
2534 if (!path) {
2535 ret = -ENOMEM;
2536 goto out;
2537 }
2538
2539 root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
2540 mutex_lock(&root->fs_info->fs_mutex);
2541 di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
2542 path, root_dirid,
2543 vol_args->name, namelen, 0);
2544 mutex_unlock(&root->fs_info->fs_mutex);
2545 btrfs_free_path(path);
2546
2547 if (di && !IS_ERR(di)) {
2548 ret = -EEXIST;
2549 goto out;
2550 }
2551
2552 if (IS_ERR(di)) {
2553 ret = PTR_ERR(di);
2554 goto out;
2555 }
2556
2557 if (root == root->fs_info->tree_root)
2558 ret = create_subvol(root, vol_args->name, namelen);
2559 else
2560 ret = create_snapshot(root, vol_args->name, namelen);
2561 out:
2562 kfree(vol_args);
2563 return ret;
2564 }
2565
2566 static int btrfs_ioctl_defrag(struct file *file)
2567 {
2568 struct inode *inode = fdentry(file)->d_inode;
2569 struct btrfs_root *root = BTRFS_I(inode)->root;
2570
2571 switch (inode->i_mode & S_IFMT) {
2572 case S_IFDIR:
2573 mutex_lock(&root->fs_info->fs_mutex);
2574 btrfs_defrag_root(root, 0);
2575 btrfs_defrag_root(root->fs_info->extent_root, 0);
2576 mutex_unlock(&root->fs_info->fs_mutex);
2577 break;
2578 case S_IFREG:
2579 btrfs_defrag_file(file);
2580 break;
2581 }
2582
2583 return 0;
2584 }
2585
2586 long btrfs_ioctl(struct file *file, unsigned int
2587 cmd, unsigned long arg)
2588 {
2589 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
2590
2591 switch (cmd) {
2592 case BTRFS_IOC_SNAP_CREATE:
2593 return btrfs_ioctl_snap_create(root, (void __user *)arg);
2594 case BTRFS_IOC_DEFRAG:
2595 return btrfs_ioctl_defrag(file);
2596 case BTRFS_IOC_RESIZE:
2597 return btrfs_ioctl_resize(root, (void __user *)arg);
2598 }
2599
2600 return -ENOTTY;
2601 }
2602
2603 /*
2604 * Called inside transaction, so use GFP_NOFS
2605 */
2606 struct inode *btrfs_alloc_inode(struct super_block *sb)
2607 {
2608 struct btrfs_inode *ei;
2609
2610 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
2611 if (!ei)
2612 return NULL;
2613 ei->last_trans = 0;
2614 ei->ordered_trans = 0;
2615 return &ei->vfs_inode;
2616 }
2617
2618 void btrfs_destroy_inode(struct inode *inode)
2619 {
2620 WARN_ON(!list_empty(&inode->i_dentry));
2621 WARN_ON(inode->i_data.nrpages);
2622
2623 btrfs_drop_extent_cache(inode, 0, (u64)-1);
2624 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
2625 }
2626
2627 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
2628 static void init_once(struct kmem_cache * cachep, void *foo)
2629 #else
2630 static void init_once(void * foo, struct kmem_cache * cachep,
2631 unsigned long flags)
2632 #endif
2633 {
2634 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
2635
2636 inode_init_once(&ei->vfs_inode);
2637 }
2638
2639 void btrfs_destroy_cachep(void)
2640 {
2641 if (btrfs_inode_cachep)
2642 kmem_cache_destroy(btrfs_inode_cachep);
2643 if (btrfs_trans_handle_cachep)
2644 kmem_cache_destroy(btrfs_trans_handle_cachep);
2645 if (btrfs_transaction_cachep)
2646 kmem_cache_destroy(btrfs_transaction_cachep);
2647 if (btrfs_bit_radix_cachep)
2648 kmem_cache_destroy(btrfs_bit_radix_cachep);
2649 if (btrfs_path_cachep)
2650 kmem_cache_destroy(btrfs_path_cachep);
2651 }
2652
2653 struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
2654 unsigned long extra_flags,
2655 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
2656 void (*ctor)(struct kmem_cache *, void *)
2657 #else
2658 void (*ctor)(void *, struct kmem_cache *,
2659 unsigned long)
2660 #endif
2661 )
2662 {
2663 return kmem_cache_create(name, size, 0, (SLAB_RECLAIM_ACCOUNT |
2664 SLAB_MEM_SPREAD | extra_flags), ctor
2665 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
2666 ,NULL
2667 #endif
2668 );
2669 }
2670
2671 int btrfs_init_cachep(void)
2672 {
2673 btrfs_inode_cachep = btrfs_cache_create("btrfs_inode_cache",
2674 sizeof(struct btrfs_inode),
2675 0, init_once);
2676 if (!btrfs_inode_cachep)
2677 goto fail;
2678 btrfs_trans_handle_cachep =
2679 btrfs_cache_create("btrfs_trans_handle_cache",
2680 sizeof(struct btrfs_trans_handle),
2681 0, NULL);
2682 if (!btrfs_trans_handle_cachep)
2683 goto fail;
2684 btrfs_transaction_cachep = btrfs_cache_create("btrfs_transaction_cache",
2685 sizeof(struct btrfs_transaction),
2686 0, NULL);
2687 if (!btrfs_transaction_cachep)
2688 goto fail;
2689 btrfs_path_cachep = btrfs_cache_create("btrfs_path_cache",
2690 sizeof(struct btrfs_path),
2691 0, NULL);
2692 if (!btrfs_path_cachep)
2693 goto fail;
2694 btrfs_bit_radix_cachep = btrfs_cache_create("btrfs_radix", 256,
2695 SLAB_DESTROY_BY_RCU, NULL);
2696 if (!btrfs_bit_radix_cachep)
2697 goto fail;
2698 return 0;
2699 fail:
2700 btrfs_destroy_cachep();
2701 return -ENOMEM;
2702 }
2703
2704 static int btrfs_getattr(struct vfsmount *mnt,
2705 struct dentry *dentry, struct kstat *stat)
2706 {
2707 struct inode *inode = dentry->d_inode;
2708 generic_fillattr(inode, stat);
2709 stat->blksize = PAGE_CACHE_SIZE;
2710 return 0;
2711 }
2712
2713 static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
2714 struct inode * new_dir,struct dentry *new_dentry)
2715 {
2716 struct btrfs_trans_handle *trans;
2717 struct btrfs_root *root = BTRFS_I(old_dir)->root;
2718 struct inode *new_inode = new_dentry->d_inode;
2719 struct inode *old_inode = old_dentry->d_inode;
2720 struct timespec ctime = CURRENT_TIME;
2721 struct btrfs_path *path;
2722 int ret;
2723
2724 if (S_ISDIR(old_inode->i_mode) && new_inode &&
2725 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
2726 return -ENOTEMPTY;
2727 }
2728
2729 mutex_lock(&root->fs_info->fs_mutex);
2730 ret = btrfs_check_free_space(root, 1, 0);
2731 if (ret)
2732 goto out_unlock;
2733
2734 trans = btrfs_start_transaction(root, 1);
2735
2736 btrfs_set_trans_block_group(trans, new_dir);
2737 path = btrfs_alloc_path();
2738 if (!path) {
2739 ret = -ENOMEM;
2740 goto out_fail;
2741 }
2742
2743 old_dentry->d_inode->i_nlink++;
2744 old_dir->i_ctime = old_dir->i_mtime = ctime;
2745 new_dir->i_ctime = new_dir->i_mtime = ctime;
2746 old_inode->i_ctime = ctime;
2747
2748 ret = btrfs_unlink_trans(trans, root, old_dir, old_dentry);
2749 if (ret)
2750 goto out_fail;
2751
2752 if (new_inode) {
2753 new_inode->i_ctime = CURRENT_TIME;
2754 ret = btrfs_unlink_trans(trans, root, new_dir, new_dentry);
2755 if (ret)
2756 goto out_fail;
2757 }
2758 ret = btrfs_add_link(trans, new_dentry, old_inode);
2759 if (ret)
2760 goto out_fail;
2761
2762 out_fail:
2763 btrfs_free_path(path);
2764 btrfs_end_transaction(trans, root);
2765 out_unlock:
2766 mutex_unlock(&root->fs_info->fs_mutex);
2767 return ret;
2768 }
2769
2770 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
2771 const char *symname)
2772 {
2773 struct btrfs_trans_handle *trans;
2774 struct btrfs_root *root = BTRFS_I(dir)->root;
2775 struct btrfs_path *path;
2776 struct btrfs_key key;
2777 struct inode *inode = NULL;
2778 int err;
2779 int drop_inode = 0;
2780 u64 objectid;
2781 int name_len;
2782 int datasize;
2783 unsigned long ptr;
2784 struct btrfs_file_extent_item *ei;
2785 struct extent_buffer *leaf;
2786 unsigned long nr = 0;
2787
2788 name_len = strlen(symname) + 1;
2789 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
2790 return -ENAMETOOLONG;
2791
2792 mutex_lock(&root->fs_info->fs_mutex);
2793 err = btrfs_check_free_space(root, 1, 0);
2794 if (err)
2795 goto out_fail;
2796
2797 trans = btrfs_start_transaction(root, 1);
2798 btrfs_set_trans_block_group(trans, dir);
2799
2800 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
2801 if (err) {
2802 err = -ENOSPC;
2803 goto out_unlock;
2804 }
2805
2806 inode = btrfs_new_inode(trans, root, objectid,
2807 BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO);
2808 err = PTR_ERR(inode);
2809 if (IS_ERR(inode))
2810 goto out_unlock;
2811
2812 btrfs_set_trans_block_group(trans, inode);
2813 err = btrfs_add_nondir(trans, dentry, inode);
2814 if (err)
2815 drop_inode = 1;
2816 else {
2817 inode->i_mapping->a_ops = &btrfs_aops;
2818 inode->i_fop = &btrfs_file_operations;
2819 inode->i_op = &btrfs_file_inode_operations;
2820 extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
2821 inode->i_mapping, GFP_NOFS);
2822 BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
2823 }
2824 dir->i_sb->s_dirt = 1;
2825 btrfs_update_inode_block_group(trans, inode);
2826 btrfs_update_inode_block_group(trans, dir);
2827 if (drop_inode)
2828 goto out_unlock;
2829
2830 path = btrfs_alloc_path();
2831 BUG_ON(!path);
2832 key.objectid = inode->i_ino;
2833 key.offset = 0;
2834 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
2835 datasize = btrfs_file_extent_calc_inline_size(name_len);
2836 err = btrfs_insert_empty_item(trans, root, path, &key,
2837 datasize);
2838 if (err) {
2839 drop_inode = 1;
2840 goto out_unlock;
2841 }
2842 leaf = path->nodes[0];
2843 ei = btrfs_item_ptr(leaf, path->slots[0],
2844 struct btrfs_file_extent_item);
2845 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
2846 btrfs_set_file_extent_type(leaf, ei,
2847 BTRFS_FILE_EXTENT_INLINE);
2848 ptr = btrfs_file_extent_inline_start(ei);
2849 write_extent_buffer(leaf, symname, ptr, name_len);
2850 btrfs_mark_buffer_dirty(leaf);
2851 btrfs_free_path(path);
2852
2853 inode->i_op = &btrfs_symlink_inode_operations;
2854 inode->i_mapping->a_ops = &btrfs_symlink_aops;
2855 inode->i_size = name_len - 1;
2856 err = btrfs_update_inode(trans, root, inode);
2857 if (err)
2858 drop_inode = 1;
2859
2860 out_unlock:
2861 nr = trans->blocks_used;
2862 btrfs_end_transaction(trans, root);
2863 out_fail:
2864 mutex_unlock(&root->fs_info->fs_mutex);
2865 if (drop_inode) {
2866 inode_dec_link_count(inode);
2867 iput(inode);
2868 }
2869 btrfs_btree_balance_dirty(root, nr);
2870 btrfs_throttle(root);
2871 return err;
2872 }
2873 static int btrfs_permission(struct inode *inode, int mask,
2874 struct nameidata *nd)
2875 {
2876 if (btrfs_test_flag(inode, READONLY) && (mask & MAY_WRITE))
2877 return -EACCES;
2878 return generic_permission(inode, mask, NULL);
2879 }
2880
2881 static struct inode_operations btrfs_dir_inode_operations = {
2882 .lookup = btrfs_lookup,
2883 .create = btrfs_create,
2884 .unlink = btrfs_unlink,
2885 .link = btrfs_link,
2886 .mkdir = btrfs_mkdir,
2887 .rmdir = btrfs_rmdir,
2888 .rename = btrfs_rename,
2889 .symlink = btrfs_symlink,
2890 .setattr = btrfs_setattr,
2891 .mknod = btrfs_mknod,
2892 .setxattr = generic_setxattr,
2893 .getxattr = generic_getxattr,
2894 .listxattr = btrfs_listxattr,
2895 .removexattr = generic_removexattr,
2896 .permission = btrfs_permission,
2897 };
2898 static struct inode_operations btrfs_dir_ro_inode_operations = {
2899 .lookup = btrfs_lookup,
2900 .permission = btrfs_permission,
2901 };
2902 static struct file_operations btrfs_dir_file_operations = {
2903 .llseek = generic_file_llseek,
2904 .read = generic_read_dir,
2905 .readdir = btrfs_readdir,
2906 .unlocked_ioctl = btrfs_ioctl,
2907 #ifdef CONFIG_COMPAT
2908 .compat_ioctl = btrfs_ioctl,
2909 #endif
2910 };
2911
2912 static struct extent_map_ops btrfs_extent_map_ops = {
2913 .fill_delalloc = run_delalloc_range,
2914 .writepage_io_hook = btrfs_writepage_io_hook,
2915 .readpage_io_hook = btrfs_readpage_io_hook,
2916 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
2917 };
2918
2919 static struct address_space_operations btrfs_aops = {
2920 .readpage = btrfs_readpage,
2921 .writepage = btrfs_writepage,
2922 .writepages = btrfs_writepages,
2923 .readpages = btrfs_readpages,
2924 .sync_page = block_sync_page,
2925 .bmap = btrfs_bmap,
2926 .invalidatepage = btrfs_invalidatepage,
2927 .releasepage = btrfs_releasepage,
2928 .set_page_dirty = __set_page_dirty_nobuffers,
2929 };
2930
2931 static struct address_space_operations btrfs_symlink_aops = {
2932 .readpage = btrfs_readpage,
2933 .writepage = btrfs_writepage,
2934 .invalidatepage = btrfs_invalidatepage,
2935 .releasepage = btrfs_releasepage,
2936 };
2937
2938 static struct inode_operations btrfs_file_inode_operations = {
2939 .truncate = btrfs_truncate,
2940 .getattr = btrfs_getattr,
2941 .setattr = btrfs_setattr,
2942 .setxattr = generic_setxattr,
2943 .getxattr = generic_getxattr,
2944 .listxattr = btrfs_listxattr,
2945 .removexattr = generic_removexattr,
2946 .permission = btrfs_permission,
2947 };
2948 static struct inode_operations btrfs_special_inode_operations = {
2949 .getattr = btrfs_getattr,
2950 .setattr = btrfs_setattr,
2951 .permission = btrfs_permission,
2952 };
2953 static struct inode_operations btrfs_symlink_inode_operations = {
2954 .readlink = generic_readlink,
2955 .follow_link = page_follow_link_light,
2956 .put_link = page_put_link,
2957 .permission = btrfs_permission,
2958 };
Linux kernel - Deliverables
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