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Rework btrfs_drop_inode to avoid scheduling
[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 if (!BTRFS_I(inode)->ordered_trans || inode->i_nlink) {
997 generic_drop_inode(inode);
998 return;
999 }
1000 /* FIXME, make sure this delete actually ends up in the transaction */
1001 btrfs_del_ordered_inode(inode);
1002 generic_drop_inode(inode);
1003 }
1004
1005 void btrfs_delete_inode(struct inode *inode)
1006 {
1007 struct btrfs_trans_handle *trans;
1008 struct btrfs_root *root = BTRFS_I(inode)->root;
1009 unsigned long nr;
1010 int ret;
1011
1012 truncate_inode_pages(&inode->i_data, 0);
1013 if (is_bad_inode(inode)) {
1014 goto no_delete;
1015 }
1016
1017 inode->i_size = 0;
1018 mutex_lock(&root->fs_info->fs_mutex);
1019 trans = btrfs_start_transaction(root, 1);
1020
1021 btrfs_set_trans_block_group(trans, inode);
1022 ret = btrfs_truncate_in_trans(trans, root, inode);
1023 if (ret)
1024 goto no_delete_lock;
1025 ret = btrfs_delete_xattrs(trans, root, inode);
1026 if (ret)
1027 goto no_delete_lock;
1028 ret = btrfs_free_inode(trans, root, inode);
1029 if (ret)
1030 goto no_delete_lock;
1031 nr = trans->blocks_used;
1032
1033 btrfs_end_transaction(trans, root);
1034 mutex_unlock(&root->fs_info->fs_mutex);
1035 btrfs_btree_balance_dirty(root, nr);
1036 btrfs_throttle(root);
1037 return;
1038
1039 no_delete_lock:
1040 nr = trans->blocks_used;
1041 btrfs_end_transaction(trans, root);
1042 mutex_unlock(&root->fs_info->fs_mutex);
1043 btrfs_btree_balance_dirty(root, nr);
1044 btrfs_throttle(root);
1045 no_delete:
1046 clear_inode(inode);
1047 }
1048
1049 /*
1050 * this returns the key found in the dir entry in the location pointer.
1051 * If no dir entries were found, location->objectid is 0.
1052 */
1053 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
1054 struct btrfs_key *location)
1055 {
1056 const char *name = dentry->d_name.name;
1057 int namelen = dentry->d_name.len;
1058 struct btrfs_dir_item *di;
1059 struct btrfs_path *path;
1060 struct btrfs_root *root = BTRFS_I(dir)->root;
1061 int ret = 0;
1062
1063 if (namelen == 1 && strcmp(name, ".") == 0) {
1064 location->objectid = dir->i_ino;
1065 location->type = BTRFS_INODE_ITEM_KEY;
1066 location->offset = 0;
1067 return 0;
1068 }
1069 path = btrfs_alloc_path();
1070 BUG_ON(!path);
1071
1072 if (namelen == 2 && strcmp(name, "..") == 0) {
1073 struct btrfs_key key;
1074 struct extent_buffer *leaf;
1075 u32 nritems;
1076 int slot;
1077
1078 key.objectid = dir->i_ino;
1079 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
1080 key.offset = 0;
1081 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1082 BUG_ON(ret == 0);
1083 ret = 0;
1084
1085 leaf = path->nodes[0];
1086 slot = path->slots[0];
1087 nritems = btrfs_header_nritems(leaf);
1088 if (slot >= nritems)
1089 goto out_err;
1090
1091 btrfs_item_key_to_cpu(leaf, &key, slot);
1092 if (key.objectid != dir->i_ino ||
1093 key.type != BTRFS_INODE_REF_KEY) {
1094 goto out_err;
1095 }
1096 location->objectid = key.offset;
1097 location->type = BTRFS_INODE_ITEM_KEY;
1098 location->offset = 0;
1099 goto out;
1100 }
1101
1102 di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
1103 namelen, 0);
1104 if (IS_ERR(di))
1105 ret = PTR_ERR(di);
1106 if (!di || IS_ERR(di)) {
1107 goto out_err;
1108 }
1109 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
1110 out:
1111 btrfs_free_path(path);
1112 return ret;
1113 out_err:
1114 location->objectid = 0;
1115 goto out;
1116 }
1117
1118 /*
1119 * when we hit a tree root in a directory, the btrfs part of the inode
1120 * needs to be changed to reflect the root directory of the tree root. This
1121 * is kind of like crossing a mount point.
1122 */
1123 static int fixup_tree_root_location(struct btrfs_root *root,
1124 struct btrfs_key *location,
1125 struct btrfs_root **sub_root,
1126 struct dentry *dentry)
1127 {
1128 struct btrfs_path *path;
1129 struct btrfs_root_item *ri;
1130
1131 if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY)
1132 return 0;
1133 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1134 return 0;
1135
1136 path = btrfs_alloc_path();
1137 BUG_ON(!path);
1138 mutex_lock(&root->fs_info->fs_mutex);
1139
1140 *sub_root = btrfs_read_fs_root(root->fs_info, location,
1141 dentry->d_name.name,
1142 dentry->d_name.len);
1143 if (IS_ERR(*sub_root))
1144 return PTR_ERR(*sub_root);
1145
1146 ri = &(*sub_root)->root_item;
1147 location->objectid = btrfs_root_dirid(ri);
1148 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
1149 location->offset = 0;
1150
1151 btrfs_free_path(path);
1152 mutex_unlock(&root->fs_info->fs_mutex);
1153 return 0;
1154 }
1155
1156 static int btrfs_init_locked_inode(struct inode *inode, void *p)
1157 {
1158 struct btrfs_iget_args *args = p;
1159 inode->i_ino = args->ino;
1160 BTRFS_I(inode)->root = args->root;
1161 extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
1162 inode->i_mapping, GFP_NOFS);
1163 return 0;
1164 }
1165
1166 static int btrfs_find_actor(struct inode *inode, void *opaque)
1167 {
1168 struct btrfs_iget_args *args = opaque;
1169 return (args->ino == inode->i_ino &&
1170 args->root == BTRFS_I(inode)->root);
1171 }
1172
1173 struct inode *btrfs_ilookup(struct super_block *s, u64 objectid,
1174 u64 root_objectid)
1175 {
1176 struct btrfs_iget_args args;
1177 args.ino = objectid;
1178 args.root = btrfs_lookup_fs_root(btrfs_sb(s)->fs_info, root_objectid);
1179
1180 if (!args.root)
1181 return NULL;
1182
1183 return ilookup5(s, objectid, btrfs_find_actor, (void *)&args);
1184 }
1185
1186 struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
1187 struct btrfs_root *root)
1188 {
1189 struct inode *inode;
1190 struct btrfs_iget_args args;
1191 args.ino = objectid;
1192 args.root = root;
1193
1194 inode = iget5_locked(s, objectid, btrfs_find_actor,
1195 btrfs_init_locked_inode,
1196 (void *)&args);
1197 return inode;
1198 }
1199
1200 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
1201 struct nameidata *nd)
1202 {
1203 struct inode * inode;
1204 struct btrfs_inode *bi = BTRFS_I(dir);
1205 struct btrfs_root *root = bi->root;
1206 struct btrfs_root *sub_root = root;
1207 struct btrfs_key location;
1208 int ret;
1209
1210 if (dentry->d_name.len > BTRFS_NAME_LEN)
1211 return ERR_PTR(-ENAMETOOLONG);
1212
1213 mutex_lock(&root->fs_info->fs_mutex);
1214 ret = btrfs_inode_by_name(dir, dentry, &location);
1215 mutex_unlock(&root->fs_info->fs_mutex);
1216
1217 if (ret < 0)
1218 return ERR_PTR(ret);
1219
1220 inode = NULL;
1221 if (location.objectid) {
1222 ret = fixup_tree_root_location(root, &location, &sub_root,
1223 dentry);
1224 if (ret < 0)
1225 return ERR_PTR(ret);
1226 if (ret > 0)
1227 return ERR_PTR(-ENOENT);
1228 inode = btrfs_iget_locked(dir->i_sb, location.objectid,
1229 sub_root);
1230 if (!inode)
1231 return ERR_PTR(-EACCES);
1232 if (inode->i_state & I_NEW) {
1233 /* the inode and parent dir are two different roots */
1234 if (sub_root != root) {
1235 igrab(inode);
1236 sub_root->inode = inode;
1237 }
1238 BTRFS_I(inode)->root = sub_root;
1239 memcpy(&BTRFS_I(inode)->location, &location,
1240 sizeof(location));
1241 btrfs_read_locked_inode(inode);
1242 unlock_new_inode(inode);
1243 }
1244 }
1245 return d_splice_alias(inode, dentry);
1246 }
1247
1248 static unsigned char btrfs_filetype_table[] = {
1249 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
1250 };
1251
1252 static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
1253 {
1254 struct inode *inode = filp->f_dentry->d_inode;
1255 struct btrfs_root *root = BTRFS_I(inode)->root;
1256 struct btrfs_item *item;
1257 struct btrfs_dir_item *di;
1258 struct btrfs_key key;
1259 struct btrfs_key found_key;
1260 struct btrfs_path *path;
1261 int ret;
1262 u32 nritems;
1263 struct extent_buffer *leaf;
1264 int slot;
1265 int advance;
1266 unsigned char d_type;
1267 int over = 0;
1268 u32 di_cur;
1269 u32 di_total;
1270 u32 di_len;
1271 int key_type = BTRFS_DIR_INDEX_KEY;
1272 char tmp_name[32];
1273 char *name_ptr;
1274 int name_len;
1275
1276 /* FIXME, use a real flag for deciding about the key type */
1277 if (root->fs_info->tree_root == root)
1278 key_type = BTRFS_DIR_ITEM_KEY;
1279
1280 /* special case for "." */
1281 if (filp->f_pos == 0) {
1282 over = filldir(dirent, ".", 1,
1283 1, inode->i_ino,
1284 DT_DIR);
1285 if (over)
1286 return 0;
1287 filp->f_pos = 1;
1288 }
1289
1290 mutex_lock(&root->fs_info->fs_mutex);
1291 key.objectid = inode->i_ino;
1292 path = btrfs_alloc_path();
1293 path->reada = 2;
1294
1295 /* special case for .., just use the back ref */
1296 if (filp->f_pos == 1) {
1297 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
1298 key.offset = 0;
1299 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1300 BUG_ON(ret == 0);
1301 leaf = path->nodes[0];
1302 slot = path->slots[0];
1303 nritems = btrfs_header_nritems(leaf);
1304 if (slot >= nritems) {
1305 btrfs_release_path(root, path);
1306 goto read_dir_items;
1307 }
1308 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1309 btrfs_release_path(root, path);
1310 if (found_key.objectid != key.objectid ||
1311 found_key.type != BTRFS_INODE_REF_KEY)
1312 goto read_dir_items;
1313 over = filldir(dirent, "..", 2,
1314 2, found_key.offset, DT_DIR);
1315 if (over)
1316 goto nopos;
1317 filp->f_pos = 2;
1318 }
1319
1320 read_dir_items:
1321 btrfs_set_key_type(&key, key_type);
1322 key.offset = filp->f_pos;
1323
1324 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1325 if (ret < 0)
1326 goto err;
1327 advance = 0;
1328 while(1) {
1329 leaf = path->nodes[0];
1330 nritems = btrfs_header_nritems(leaf);
1331 slot = path->slots[0];
1332 if (advance || slot >= nritems) {
1333 if (slot >= nritems -1) {
1334 ret = btrfs_next_leaf(root, path);
1335 if (ret)
1336 break;
1337 leaf = path->nodes[0];
1338 nritems = btrfs_header_nritems(leaf);
1339 slot = path->slots[0];
1340 } else {
1341 slot++;
1342 path->slots[0]++;
1343 }
1344 }
1345 advance = 1;
1346 item = btrfs_item_nr(leaf, slot);
1347 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1348
1349 if (found_key.objectid != key.objectid)
1350 break;
1351 if (btrfs_key_type(&found_key) != key_type)
1352 break;
1353 if (found_key.offset < filp->f_pos)
1354 continue;
1355
1356 filp->f_pos = found_key.offset;
1357 advance = 1;
1358 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
1359 di_cur = 0;
1360 di_total = btrfs_item_size(leaf, item);
1361 while(di_cur < di_total) {
1362 struct btrfs_key location;
1363
1364 name_len = btrfs_dir_name_len(leaf, di);
1365 if (name_len < 32) {
1366 name_ptr = tmp_name;
1367 } else {
1368 name_ptr = kmalloc(name_len, GFP_NOFS);
1369 BUG_ON(!name_ptr);
1370 }
1371 read_extent_buffer(leaf, name_ptr,
1372 (unsigned long)(di + 1), name_len);
1373
1374 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
1375 btrfs_dir_item_key_to_cpu(leaf, di, &location);
1376 over = filldir(dirent, name_ptr, name_len,
1377 found_key.offset,
1378 location.objectid,
1379 d_type);
1380
1381 if (name_ptr != tmp_name)
1382 kfree(name_ptr);
1383
1384 if (over)
1385 goto nopos;
1386 di_len = btrfs_dir_name_len(leaf, di) +
1387 btrfs_dir_data_len(leaf, di) +sizeof(*di);
1388 di_cur += di_len;
1389 di = (struct btrfs_dir_item *)((char *)di + di_len);
1390 }
1391 }
1392 filp->f_pos++;
1393 nopos:
1394 ret = 0;
1395 err:
1396 btrfs_release_path(root, path);
1397 btrfs_free_path(path);
1398 mutex_unlock(&root->fs_info->fs_mutex);
1399 return ret;
1400 }
1401
1402 int btrfs_write_inode(struct inode *inode, int wait)
1403 {
1404 struct btrfs_root *root = BTRFS_I(inode)->root;
1405 struct btrfs_trans_handle *trans;
1406 int ret = 0;
1407
1408 if (wait) {
1409 mutex_lock(&root->fs_info->fs_mutex);
1410 trans = btrfs_start_transaction(root, 1);
1411 btrfs_set_trans_block_group(trans, inode);
1412 ret = btrfs_commit_transaction(trans, root);
1413 mutex_unlock(&root->fs_info->fs_mutex);
1414 }
1415 return ret;
1416 }
1417
1418 /*
1419 * This is somewhat expensive, updating the tree every time the
1420 * inode changes. But, it is most likely to find the inode in cache.
1421 * FIXME, needs more benchmarking...there are no reasons other than performance
1422 * to keep or drop this code.
1423 */
1424 void btrfs_dirty_inode(struct inode *inode)
1425 {
1426 struct btrfs_root *root = BTRFS_I(inode)->root;
1427 struct btrfs_trans_handle *trans;
1428
1429 mutex_lock(&root->fs_info->fs_mutex);
1430 trans = btrfs_start_transaction(root, 1);
1431 btrfs_set_trans_block_group(trans, inode);
1432 btrfs_update_inode(trans, root, inode);
1433 btrfs_end_transaction(trans, root);
1434 mutex_unlock(&root->fs_info->fs_mutex);
1435 }
1436
1437 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
1438 struct btrfs_root *root,
1439 u64 objectid,
1440 struct btrfs_block_group_cache *group,
1441 int mode)
1442 {
1443 struct inode *inode;
1444 struct btrfs_inode_item *inode_item;
1445 struct btrfs_key *location;
1446 struct btrfs_path *path;
1447 int ret;
1448 int owner;
1449
1450 path = btrfs_alloc_path();
1451 BUG_ON(!path);
1452
1453 inode = new_inode(root->fs_info->sb);
1454 if (!inode)
1455 return ERR_PTR(-ENOMEM);
1456
1457 extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
1458 inode->i_mapping, GFP_NOFS);
1459 BTRFS_I(inode)->root = root;
1460
1461 if (mode & S_IFDIR)
1462 owner = 0;
1463 else
1464 owner = 1;
1465 group = btrfs_find_block_group(root, group, 0, 0, owner);
1466 BTRFS_I(inode)->block_group = group;
1467 BTRFS_I(inode)->flags = 0;
1468 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
1469 if (ret)
1470 goto fail;
1471
1472 inode->i_uid = current->fsuid;
1473 inode->i_gid = current->fsgid;
1474 inode->i_mode = mode;
1475 inode->i_ino = objectid;
1476 inode->i_blocks = 0;
1477 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1478 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1479 struct btrfs_inode_item);
1480 fill_inode_item(path->nodes[0], inode_item, inode);
1481 btrfs_mark_buffer_dirty(path->nodes[0]);
1482 btrfs_free_path(path);
1483
1484 location = &BTRFS_I(inode)->location;
1485 location->objectid = objectid;
1486 location->offset = 0;
1487 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
1488
1489 insert_inode_hash(inode);
1490 return inode;
1491 fail:
1492 btrfs_free_path(path);
1493 return ERR_PTR(ret);
1494 }
1495
1496 static inline u8 btrfs_inode_type(struct inode *inode)
1497 {
1498 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
1499 }
1500
1501 static int btrfs_add_link(struct btrfs_trans_handle *trans,
1502 struct dentry *dentry, struct inode *inode)
1503 {
1504 int ret;
1505 struct btrfs_key key;
1506 struct btrfs_root *root = BTRFS_I(dentry->d_parent->d_inode)->root;
1507 struct inode *parent_inode;
1508
1509 key.objectid = inode->i_ino;
1510 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
1511 key.offset = 0;
1512
1513 ret = btrfs_insert_dir_item(trans, root,
1514 dentry->d_name.name, dentry->d_name.len,
1515 dentry->d_parent->d_inode->i_ino,
1516 &key, btrfs_inode_type(inode));
1517 if (ret == 0) {
1518 ret = btrfs_insert_inode_ref(trans, root,
1519 dentry->d_name.name,
1520 dentry->d_name.len,
1521 inode->i_ino,
1522 dentry->d_parent->d_inode->i_ino);
1523 parent_inode = dentry->d_parent->d_inode;
1524 parent_inode->i_size += dentry->d_name.len * 2;
1525 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
1526 ret = btrfs_update_inode(trans, root,
1527 dentry->d_parent->d_inode);
1528 }
1529 return ret;
1530 }
1531
1532 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
1533 struct dentry *dentry, struct inode *inode)
1534 {
1535 int err = btrfs_add_link(trans, dentry, inode);
1536 if (!err) {
1537 d_instantiate(dentry, inode);
1538 return 0;
1539 }
1540 if (err > 0)
1541 err = -EEXIST;
1542 return err;
1543 }
1544
1545 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
1546 int mode, dev_t rdev)
1547 {
1548 struct btrfs_trans_handle *trans;
1549 struct btrfs_root *root = BTRFS_I(dir)->root;
1550 struct inode *inode = NULL;
1551 int err;
1552 int drop_inode = 0;
1553 u64 objectid;
1554 unsigned long nr = 0;
1555
1556 if (!new_valid_dev(rdev))
1557 return -EINVAL;
1558
1559 mutex_lock(&root->fs_info->fs_mutex);
1560 err = btrfs_check_free_space(root, 1, 0);
1561 if (err)
1562 goto fail;
1563
1564 trans = btrfs_start_transaction(root, 1);
1565 btrfs_set_trans_block_group(trans, dir);
1566
1567 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1568 if (err) {
1569 err = -ENOSPC;
1570 goto out_unlock;
1571 }
1572
1573 inode = btrfs_new_inode(trans, root, objectid,
1574 BTRFS_I(dir)->block_group, mode);
1575 err = PTR_ERR(inode);
1576 if (IS_ERR(inode))
1577 goto out_unlock;
1578
1579 btrfs_set_trans_block_group(trans, inode);
1580 err = btrfs_add_nondir(trans, dentry, inode);
1581 if (err)
1582 drop_inode = 1;
1583 else {
1584 inode->i_op = &btrfs_special_inode_operations;
1585 init_special_inode(inode, inode->i_mode, rdev);
1586 btrfs_update_inode(trans, root, inode);
1587 }
1588 dir->i_sb->s_dirt = 1;
1589 btrfs_update_inode_block_group(trans, inode);
1590 btrfs_update_inode_block_group(trans, dir);
1591 out_unlock:
1592 nr = trans->blocks_used;
1593 btrfs_end_transaction(trans, root);
1594 fail:
1595 mutex_unlock(&root->fs_info->fs_mutex);
1596
1597 if (drop_inode) {
1598 inode_dec_link_count(inode);
1599 iput(inode);
1600 }
1601 btrfs_btree_balance_dirty(root, nr);
1602 btrfs_throttle(root);
1603 return err;
1604 }
1605
1606 static int btrfs_create(struct inode *dir, struct dentry *dentry,
1607 int mode, struct nameidata *nd)
1608 {
1609 struct btrfs_trans_handle *trans;
1610 struct btrfs_root *root = BTRFS_I(dir)->root;
1611 struct inode *inode = NULL;
1612 int err;
1613 int drop_inode = 0;
1614 unsigned long nr = 0;
1615 u64 objectid;
1616
1617 mutex_lock(&root->fs_info->fs_mutex);
1618 err = btrfs_check_free_space(root, 1, 0);
1619 if (err)
1620 goto fail;
1621 trans = btrfs_start_transaction(root, 1);
1622 btrfs_set_trans_block_group(trans, dir);
1623
1624 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1625 if (err) {
1626 err = -ENOSPC;
1627 goto out_unlock;
1628 }
1629
1630 inode = btrfs_new_inode(trans, root, objectid,
1631 BTRFS_I(dir)->block_group, mode);
1632 err = PTR_ERR(inode);
1633 if (IS_ERR(inode))
1634 goto out_unlock;
1635
1636 btrfs_set_trans_block_group(trans, inode);
1637 err = btrfs_add_nondir(trans, dentry, inode);
1638 if (err)
1639 drop_inode = 1;
1640 else {
1641 inode->i_mapping->a_ops = &btrfs_aops;
1642 inode->i_fop = &btrfs_file_operations;
1643 inode->i_op = &btrfs_file_inode_operations;
1644 extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
1645 inode->i_mapping, GFP_NOFS);
1646 BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
1647 }
1648 dir->i_sb->s_dirt = 1;
1649 btrfs_update_inode_block_group(trans, inode);
1650 btrfs_update_inode_block_group(trans, dir);
1651 out_unlock:
1652 nr = trans->blocks_used;
1653 btrfs_end_transaction(trans, root);
1654 fail:
1655 mutex_unlock(&root->fs_info->fs_mutex);
1656
1657 if (drop_inode) {
1658 inode_dec_link_count(inode);
1659 iput(inode);
1660 }
1661 btrfs_btree_balance_dirty(root, nr);
1662 btrfs_throttle(root);
1663 return err;
1664 }
1665
1666 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
1667 struct dentry *dentry)
1668 {
1669 struct btrfs_trans_handle *trans;
1670 struct btrfs_root *root = BTRFS_I(dir)->root;
1671 struct inode *inode = old_dentry->d_inode;
1672 unsigned long nr = 0;
1673 int err;
1674 int drop_inode = 0;
1675
1676 if (inode->i_nlink == 0)
1677 return -ENOENT;
1678
1679 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
1680 inode->i_nlink++;
1681 #else
1682 inc_nlink(inode);
1683 #endif
1684 mutex_lock(&root->fs_info->fs_mutex);
1685 err = btrfs_check_free_space(root, 1, 0);
1686 if (err)
1687 goto fail;
1688 trans = btrfs_start_transaction(root, 1);
1689
1690 btrfs_set_trans_block_group(trans, dir);
1691 atomic_inc(&inode->i_count);
1692 err = btrfs_add_nondir(trans, dentry, inode);
1693
1694 if (err)
1695 drop_inode = 1;
1696
1697 dir->i_sb->s_dirt = 1;
1698 btrfs_update_inode_block_group(trans, dir);
1699 err = btrfs_update_inode(trans, root, inode);
1700
1701 if (err)
1702 drop_inode = 1;
1703
1704 nr = trans->blocks_used;
1705 btrfs_end_transaction(trans, root);
1706 fail:
1707 mutex_unlock(&root->fs_info->fs_mutex);
1708
1709 if (drop_inode) {
1710 inode_dec_link_count(inode);
1711 iput(inode);
1712 }
1713 btrfs_btree_balance_dirty(root, nr);
1714 btrfs_throttle(root);
1715 return err;
1716 }
1717
1718 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1719 {
1720 struct inode *inode;
1721 struct btrfs_trans_handle *trans;
1722 struct btrfs_root *root = BTRFS_I(dir)->root;
1723 int err = 0;
1724 int drop_on_err = 0;
1725 u64 objectid;
1726 unsigned long nr = 1;
1727
1728 mutex_lock(&root->fs_info->fs_mutex);
1729 err = btrfs_check_free_space(root, 1, 0);
1730 if (err)
1731 goto out_unlock;
1732
1733 trans = btrfs_start_transaction(root, 1);
1734 btrfs_set_trans_block_group(trans, dir);
1735
1736 if (IS_ERR(trans)) {
1737 err = PTR_ERR(trans);
1738 goto out_unlock;
1739 }
1740
1741 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1742 if (err) {
1743 err = -ENOSPC;
1744 goto out_unlock;
1745 }
1746
1747 inode = btrfs_new_inode(trans, root, objectid,
1748 BTRFS_I(dir)->block_group, S_IFDIR | mode);
1749 if (IS_ERR(inode)) {
1750 err = PTR_ERR(inode);
1751 goto out_fail;
1752 }
1753
1754 drop_on_err = 1;
1755 inode->i_op = &btrfs_dir_inode_operations;
1756 inode->i_fop = &btrfs_dir_file_operations;
1757 btrfs_set_trans_block_group(trans, inode);
1758
1759 inode->i_size = 0;
1760 err = btrfs_update_inode(trans, root, inode);
1761 if (err)
1762 goto out_fail;
1763
1764 err = btrfs_add_link(trans, dentry, inode);
1765 if (err)
1766 goto out_fail;
1767
1768 d_instantiate(dentry, inode);
1769 drop_on_err = 0;
1770 dir->i_sb->s_dirt = 1;
1771 btrfs_update_inode_block_group(trans, inode);
1772 btrfs_update_inode_block_group(trans, dir);
1773
1774 out_fail:
1775 nr = trans->blocks_used;
1776 btrfs_end_transaction(trans, root);
1777
1778 out_unlock:
1779 mutex_unlock(&root->fs_info->fs_mutex);
1780 if (drop_on_err)
1781 iput(inode);
1782 btrfs_btree_balance_dirty(root, nr);
1783 btrfs_throttle(root);
1784 return err;
1785 }
1786
1787 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
1788 size_t page_offset, u64 start, u64 end,
1789 int create)
1790 {
1791 int ret;
1792 int err = 0;
1793 u64 bytenr;
1794 u64 extent_start = 0;
1795 u64 extent_end = 0;
1796 u64 objectid = inode->i_ino;
1797 u32 found_type;
1798 int failed_insert = 0;
1799 struct btrfs_path *path;
1800 struct btrfs_root *root = BTRFS_I(inode)->root;
1801 struct btrfs_file_extent_item *item;
1802 struct extent_buffer *leaf;
1803 struct btrfs_key found_key;
1804 struct extent_map *em = NULL;
1805 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1806 struct btrfs_trans_handle *trans = NULL;
1807
1808 path = btrfs_alloc_path();
1809 BUG_ON(!path);
1810 mutex_lock(&root->fs_info->fs_mutex);
1811
1812 again:
1813 em = lookup_extent_mapping(em_tree, start, end);
1814 if (em) {
1815 if (em->start > start) {
1816 printk("get_extent start %Lu em start %Lu\n",
1817 start, em->start);
1818 WARN_ON(1);
1819 }
1820 goto out;
1821 }
1822 if (!em) {
1823 em = alloc_extent_map(GFP_NOFS);
1824 if (!em) {
1825 err = -ENOMEM;
1826 goto out;
1827 }
1828 em->start = EXTENT_MAP_HOLE;
1829 em->end = EXTENT_MAP_HOLE;
1830 }
1831 em->bdev = inode->i_sb->s_bdev;
1832 ret = btrfs_lookup_file_extent(trans, root, path,
1833 objectid, start, trans != NULL);
1834 if (ret < 0) {
1835 err = ret;
1836 goto out;
1837 }
1838
1839 if (ret != 0) {
1840 if (path->slots[0] == 0)
1841 goto not_found;
1842 path->slots[0]--;
1843 }
1844
1845 leaf = path->nodes[0];
1846 item = btrfs_item_ptr(leaf, path->slots[0],
1847 struct btrfs_file_extent_item);
1848 /* are we inside the extent that was found? */
1849 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1850 found_type = btrfs_key_type(&found_key);
1851 if (found_key.objectid != objectid ||
1852 found_type != BTRFS_EXTENT_DATA_KEY) {
1853 goto not_found;
1854 }
1855
1856 found_type = btrfs_file_extent_type(leaf, item);
1857 extent_start = found_key.offset;
1858 if (found_type == BTRFS_FILE_EXTENT_REG) {
1859 extent_end = extent_start +
1860 btrfs_file_extent_num_bytes(leaf, item);
1861 err = 0;
1862 if (start < extent_start || start >= extent_end) {
1863 em->start = start;
1864 if (start < extent_start) {
1865 if (end < extent_start)
1866 goto not_found;
1867 em->end = extent_end - 1;
1868 } else {
1869 em->end = end;
1870 }
1871 goto not_found_em;
1872 }
1873 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
1874 if (bytenr == 0) {
1875 em->start = extent_start;
1876 em->end = extent_end - 1;
1877 em->block_start = EXTENT_MAP_HOLE;
1878 em->block_end = EXTENT_MAP_HOLE;
1879 goto insert;
1880 }
1881 bytenr += btrfs_file_extent_offset(leaf, item);
1882 em->block_start = bytenr;
1883 em->block_end = em->block_start +
1884 btrfs_file_extent_num_bytes(leaf, item) - 1;
1885 em->start = extent_start;
1886 em->end = extent_end - 1;
1887 goto insert;
1888 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
1889 unsigned long ptr;
1890 char *map;
1891 size_t size;
1892 size_t extent_offset;
1893 size_t copy_size;
1894
1895 size = btrfs_file_extent_inline_len(leaf, btrfs_item_nr(leaf,
1896 path->slots[0]));
1897 extent_end = (extent_start + size - 1) |
1898 ((u64)root->sectorsize - 1);
1899 if (start < extent_start || start >= extent_end) {
1900 em->start = start;
1901 if (start < extent_start) {
1902 if (end < extent_start)
1903 goto not_found;
1904 em->end = extent_end;
1905 } else {
1906 em->end = end;
1907 }
1908 goto not_found_em;
1909 }
1910 em->block_start = EXTENT_MAP_INLINE;
1911 em->block_end = EXTENT_MAP_INLINE;
1912
1913 if (!page) {
1914 em->start = extent_start;
1915 em->end = extent_start + size - 1;
1916 goto out;
1917 }
1918
1919 extent_offset = ((u64)page->index << PAGE_CACHE_SHIFT) -
1920 extent_start + page_offset;
1921 copy_size = min_t(u64, PAGE_CACHE_SIZE - page_offset,
1922 size - extent_offset);
1923 em->start = extent_start + extent_offset;
1924 em->end = (em->start + copy_size -1) |
1925 ((u64)root->sectorsize -1);
1926 map = kmap(page);
1927 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
1928 if (create == 0 && !PageUptodate(page)) {
1929 read_extent_buffer(leaf, map + page_offset, ptr,
1930 copy_size);
1931 flush_dcache_page(page);
1932 } else if (create && PageUptodate(page)) {
1933 if (!trans) {
1934 kunmap(page);
1935 free_extent_map(em);
1936 em = NULL;
1937 btrfs_release_path(root, path);
1938 trans = btrfs_start_transaction(root, 1);
1939 goto again;
1940 }
1941 write_extent_buffer(leaf, map + page_offset, ptr,
1942 copy_size);
1943 btrfs_mark_buffer_dirty(leaf);
1944 }
1945 kunmap(page);
1946 set_extent_uptodate(em_tree, em->start, em->end, GFP_NOFS);
1947 goto insert;
1948 } else {
1949 printk("unkknown found_type %d\n", found_type);
1950 WARN_ON(1);
1951 }
1952 not_found:
1953 em->start = start;
1954 em->end = end;
1955 not_found_em:
1956 em->block_start = EXTENT_MAP_HOLE;
1957 em->block_end = EXTENT_MAP_HOLE;
1958 insert:
1959 btrfs_release_path(root, path);
1960 if (em->start > start || em->end < start) {
1961 printk("bad extent! em: [%Lu %Lu] passed [%Lu %Lu]\n", em->start, em->end, start, end);
1962 err = -EIO;
1963 goto out;
1964 }
1965 ret = add_extent_mapping(em_tree, em);
1966 if (ret == -EEXIST) {
1967 free_extent_map(em);
1968 em = NULL;
1969 if (0 && failed_insert == 1) {
1970 btrfs_drop_extent_cache(inode, start, end);
1971 }
1972 failed_insert++;
1973 if (failed_insert > 5) {
1974 printk("failing to insert %Lu %Lu\n", start, end);
1975 err = -EIO;
1976 goto out;
1977 }
1978 goto again;
1979 }
1980 err = 0;
1981 out:
1982 btrfs_free_path(path);
1983 if (trans) {
1984 ret = btrfs_end_transaction(trans, root);
1985 if (!err)
1986 err = ret;
1987 }
1988 mutex_unlock(&root->fs_info->fs_mutex);
1989 if (err) {
1990 free_extent_map(em);
1991 WARN_ON(1);
1992 return ERR_PTR(err);
1993 }
1994 return em;
1995 }
1996
1997 static sector_t btrfs_bmap(struct address_space *mapping, sector_t iblock)
1998 {
1999 return extent_bmap(mapping, iblock, btrfs_get_extent);
2000 }
2001
2002 int btrfs_readpage(struct file *file, struct page *page)
2003 {
2004 struct extent_map_tree *tree;
2005 tree = &BTRFS_I(page->mapping->host)->extent_tree;
2006 return extent_read_full_page(tree, page, btrfs_get_extent);
2007 }
2008
2009 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
2010 {
2011 struct extent_map_tree *tree;
2012
2013
2014 if (current->flags & PF_MEMALLOC) {
2015 redirty_page_for_writepage(wbc, page);
2016 unlock_page(page);
2017 return 0;
2018 }
2019 tree = &BTRFS_I(page->mapping->host)->extent_tree;
2020 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
2021 }
2022
2023 static int btrfs_writepages(struct address_space *mapping,
2024 struct writeback_control *wbc)
2025 {
2026 struct extent_map_tree *tree;
2027 tree = &BTRFS_I(mapping->host)->extent_tree;
2028 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
2029 }
2030
2031 static int
2032 btrfs_readpages(struct file *file, struct address_space *mapping,
2033 struct list_head *pages, unsigned nr_pages)
2034 {
2035 struct extent_map_tree *tree;
2036 tree = &BTRFS_I(mapping->host)->extent_tree;
2037 return extent_readpages(tree, mapping, pages, nr_pages,
2038 btrfs_get_extent);
2039 }
2040
2041 static int btrfs_releasepage(struct page *page, gfp_t unused_gfp_flags)
2042 {
2043 struct extent_map_tree *tree;
2044 int ret;
2045
2046 tree = &BTRFS_I(page->mapping->host)->extent_tree;
2047 ret = try_release_extent_mapping(tree, page);
2048 if (ret == 1) {
2049 ClearPagePrivate(page);
2050 set_page_private(page, 0);
2051 page_cache_release(page);
2052 }
2053 return ret;
2054 }
2055
2056 static void btrfs_invalidatepage(struct page *page, unsigned long offset)
2057 {
2058 struct extent_map_tree *tree;
2059
2060 tree = &BTRFS_I(page->mapping->host)->extent_tree;
2061 extent_invalidatepage(tree, page, offset);
2062 btrfs_releasepage(page, GFP_NOFS);
2063 }
2064
2065 /*
2066 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
2067 * called from a page fault handler when a page is first dirtied. Hence we must
2068 * be careful to check for EOF conditions here. We set the page up correctly
2069 * for a written page which means we get ENOSPC checking when writing into
2070 * holes and correct delalloc and unwritten extent mapping on filesystems that
2071 * support these features.
2072 *
2073 * We are not allowed to take the i_mutex here so we have to play games to
2074 * protect against truncate races as the page could now be beyond EOF. Because
2075 * vmtruncate() writes the inode size before removing pages, once we have the
2076 * page lock we can determine safely if the page is beyond EOF. If it is not
2077 * beyond EOF, then the page is guaranteed safe against truncation until we
2078 * unlock the page.
2079 */
2080 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
2081 {
2082 struct inode *inode = fdentry(vma->vm_file)->d_inode;
2083 struct btrfs_root *root = BTRFS_I(inode)->root;
2084 unsigned long end;
2085 loff_t size;
2086 int ret;
2087 u64 page_start;
2088
2089 mutex_lock(&root->fs_info->fs_mutex);
2090 ret = btrfs_check_free_space(root, PAGE_CACHE_SIZE, 0);
2091 mutex_unlock(&root->fs_info->fs_mutex);
2092 if (ret)
2093 goto out;
2094
2095 ret = -EINVAL;
2096
2097 lock_page(page);
2098 wait_on_page_writeback(page);
2099 size = i_size_read(inode);
2100 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2101
2102 if ((page->mapping != inode->i_mapping) ||
2103 (page_start > size)) {
2104 /* page got truncated out from underneath us */
2105 goto out_unlock;
2106 }
2107
2108 /* page is wholly or partially inside EOF */
2109 if (page_start + PAGE_CACHE_SIZE > size)
2110 end = size & ~PAGE_CACHE_MASK;
2111 else
2112 end = PAGE_CACHE_SIZE;
2113
2114 ret = btrfs_cow_one_page(inode, page, end);
2115
2116 out_unlock:
2117 unlock_page(page);
2118 out:
2119 return ret;
2120 }
2121
2122 static void btrfs_truncate(struct inode *inode)
2123 {
2124 struct btrfs_root *root = BTRFS_I(inode)->root;
2125 int ret;
2126 struct btrfs_trans_handle *trans;
2127 unsigned long nr;
2128
2129 if (!S_ISREG(inode->i_mode))
2130 return;
2131 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
2132 return;
2133
2134 btrfs_truncate_page(inode->i_mapping, inode->i_size);
2135
2136 mutex_lock(&root->fs_info->fs_mutex);
2137 trans = btrfs_start_transaction(root, 1);
2138 btrfs_set_trans_block_group(trans, inode);
2139
2140 /* FIXME, add redo link to tree so we don't leak on crash */
2141 ret = btrfs_truncate_in_trans(trans, root, inode);
2142 btrfs_update_inode(trans, root, inode);
2143 nr = trans->blocks_used;
2144
2145 ret = btrfs_end_transaction(trans, root);
2146 BUG_ON(ret);
2147 mutex_unlock(&root->fs_info->fs_mutex);
2148 btrfs_btree_balance_dirty(root, nr);
2149 btrfs_throttle(root);
2150 }
2151
2152 static int noinline create_subvol(struct btrfs_root *root, char *name,
2153 int namelen)
2154 {
2155 struct btrfs_trans_handle *trans;
2156 struct btrfs_key key;
2157 struct btrfs_root_item root_item;
2158 struct btrfs_inode_item *inode_item;
2159 struct extent_buffer *leaf;
2160 struct btrfs_root *new_root = root;
2161 struct inode *inode;
2162 struct inode *dir;
2163 int ret;
2164 int err;
2165 u64 objectid;
2166 u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
2167 unsigned long nr = 1;
2168
2169 mutex_lock(&root->fs_info->fs_mutex);
2170 ret = btrfs_check_free_space(root, 1, 0);
2171 if (ret)
2172 goto fail_commit;
2173
2174 trans = btrfs_start_transaction(root, 1);
2175 BUG_ON(!trans);
2176
2177 ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
2178 0, &objectid);
2179 if (ret)
2180 goto fail;
2181
2182 leaf = __btrfs_alloc_free_block(trans, root, root->leafsize,
2183 objectid, trans->transid, 0, 0,
2184 0, 0);
2185 if (IS_ERR(leaf))
2186 return PTR_ERR(leaf);
2187
2188 btrfs_set_header_nritems(leaf, 0);
2189 btrfs_set_header_level(leaf, 0);
2190 btrfs_set_header_bytenr(leaf, leaf->start);
2191 btrfs_set_header_generation(leaf, trans->transid);
2192 btrfs_set_header_owner(leaf, objectid);
2193
2194 write_extent_buffer(leaf, root->fs_info->fsid,
2195 (unsigned long)btrfs_header_fsid(leaf),
2196 BTRFS_FSID_SIZE);
2197 btrfs_mark_buffer_dirty(leaf);
2198
2199 inode_item = &root_item.inode;
2200 memset(inode_item, 0, sizeof(*inode_item));
2201 inode_item->generation = cpu_to_le64(1);
2202 inode_item->size = cpu_to_le64(3);
2203 inode_item->nlink = cpu_to_le32(1);
2204 inode_item->nblocks = cpu_to_le64(1);
2205 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
2206
2207 btrfs_set_root_bytenr(&root_item, leaf->start);
2208 btrfs_set_root_level(&root_item, 0);
2209 btrfs_set_root_refs(&root_item, 1);
2210 btrfs_set_root_used(&root_item, 0);
2211
2212 memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
2213 root_item.drop_level = 0;
2214
2215 free_extent_buffer(leaf);
2216 leaf = NULL;
2217
2218 btrfs_set_root_dirid(&root_item, new_dirid);
2219
2220 key.objectid = objectid;
2221 key.offset = 1;
2222 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
2223 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
2224 &root_item);
2225 if (ret)
2226 goto fail;
2227
2228 /*
2229 * insert the directory item
2230 */
2231 key.offset = (u64)-1;
2232 dir = root->fs_info->sb->s_root->d_inode;
2233 ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
2234 name, namelen, dir->i_ino, &key,
2235 BTRFS_FT_DIR);
2236 if (ret)
2237 goto fail;
2238
2239 ret = btrfs_insert_inode_ref(trans, root->fs_info->tree_root,
2240 name, namelen, objectid,
2241 root->fs_info->sb->s_root->d_inode->i_ino);
2242 if (ret)
2243 goto fail;
2244
2245 ret = btrfs_commit_transaction(trans, root);
2246 if (ret)
2247 goto fail_commit;
2248
2249 new_root = btrfs_read_fs_root(root->fs_info, &key, name, namelen);
2250 BUG_ON(!new_root);
2251
2252 trans = btrfs_start_transaction(new_root, 1);
2253 BUG_ON(!trans);
2254
2255 inode = btrfs_new_inode(trans, new_root, new_dirid,
2256 BTRFS_I(dir)->block_group, S_IFDIR | 0700);
2257 if (IS_ERR(inode))
2258 goto fail;
2259 inode->i_op = &btrfs_dir_inode_operations;
2260 inode->i_fop = &btrfs_dir_file_operations;
2261 new_root->inode = inode;
2262
2263 ret = btrfs_insert_inode_ref(trans, new_root, "..", 2, new_dirid,
2264 new_dirid);
2265 inode->i_nlink = 1;
2266 inode->i_size = 0;
2267 ret = btrfs_update_inode(trans, new_root, inode);
2268 if (ret)
2269 goto fail;
2270 fail:
2271 nr = trans->blocks_used;
2272 err = btrfs_commit_transaction(trans, new_root);
2273 if (err && !ret)
2274 ret = err;
2275 fail_commit:
2276 mutex_unlock(&root->fs_info->fs_mutex);
2277 btrfs_btree_balance_dirty(root, nr);
2278 btrfs_throttle(root);
2279 return ret;
2280 }
2281
2282 static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
2283 {
2284 struct btrfs_pending_snapshot *pending_snapshot;
2285 struct btrfs_trans_handle *trans;
2286 int ret;
2287 int err;
2288 unsigned long nr = 0;
2289
2290 if (!root->ref_cows)
2291 return -EINVAL;
2292
2293 mutex_lock(&root->fs_info->fs_mutex);
2294 ret = btrfs_check_free_space(root, 1, 0);
2295 if (ret)
2296 goto fail_unlock;
2297
2298 pending_snapshot = kmalloc(sizeof(*pending_snapshot), GFP_NOFS);
2299 if (!pending_snapshot) {
2300 ret = -ENOMEM;
2301 goto fail_unlock;
2302 }
2303 pending_snapshot->name = kstrndup(name, namelen, GFP_NOFS);
2304 if (!pending_snapshot->name) {
2305 ret = -ENOMEM;
2306 kfree(pending_snapshot);
2307 goto fail_unlock;
2308 }
2309 trans = btrfs_start_transaction(root, 1);
2310 BUG_ON(!trans);
2311
2312 pending_snapshot->root = root;
2313 list_add(&pending_snapshot->list,
2314 &trans->transaction->pending_snapshots);
2315 ret = btrfs_update_inode(trans, root, root->inode);
2316 err = btrfs_commit_transaction(trans, root);
2317
2318 fail_unlock:
2319 mutex_unlock(&root->fs_info->fs_mutex);
2320 btrfs_btree_balance_dirty(root, nr);
2321 btrfs_throttle(root);
2322 return ret;
2323 }
2324
2325 unsigned long btrfs_force_ra(struct address_space *mapping,
2326 struct file_ra_state *ra, struct file *file,
2327 pgoff_t offset, pgoff_t last_index)
2328 {
2329 pgoff_t req_size;
2330
2331 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
2332 req_size = last_index - offset + 1;
2333 offset = page_cache_readahead(mapping, ra, file, offset, req_size);
2334 return offset;
2335 #else
2336 req_size = min(last_index - offset + 1, (pgoff_t)128);
2337 page_cache_sync_readahead(mapping, ra, file, offset, req_size);
2338 return offset + req_size;
2339 #endif
2340 }
2341
2342 int btrfs_defrag_file(struct file *file) {
2343 struct inode *inode = fdentry(file)->d_inode;
2344 struct btrfs_root *root = BTRFS_I(inode)->root;
2345 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2346 struct page *page;
2347 unsigned long last_index;
2348 unsigned long ra_index = 0;
2349 u64 page_start;
2350 u64 page_end;
2351 u64 delalloc_start;
2352 u64 existing_delalloc;
2353 unsigned long i;
2354 int ret;
2355
2356 mutex_lock(&root->fs_info->fs_mutex);
2357 ret = btrfs_check_free_space(root, inode->i_size, 0);
2358 mutex_unlock(&root->fs_info->fs_mutex);
2359 if (ret)
2360 return -ENOSPC;
2361
2362 mutex_lock(&inode->i_mutex);
2363 last_index = inode->i_size >> PAGE_CACHE_SHIFT;
2364 for (i = 0; i <= last_index; i++) {
2365 if (i == ra_index) {
2366 ra_index = btrfs_force_ra(inode->i_mapping,
2367 &file->f_ra,
2368 file, ra_index, last_index);
2369 }
2370 page = grab_cache_page(inode->i_mapping, i);
2371 if (!page)
2372 goto out_unlock;
2373 if (!PageUptodate(page)) {
2374 btrfs_readpage(NULL, page);
2375 lock_page(page);
2376 if (!PageUptodate(page)) {
2377 unlock_page(page);
2378 page_cache_release(page);
2379 goto out_unlock;
2380 }
2381 }
2382 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2383 page_end = page_start + PAGE_CACHE_SIZE - 1;
2384
2385 lock_extent(em_tree, page_start, page_end, GFP_NOFS);
2386 delalloc_start = page_start;
2387 existing_delalloc =
2388 count_range_bits(&BTRFS_I(inode)->extent_tree,
2389 &delalloc_start, page_end,
2390 PAGE_CACHE_SIZE, EXTENT_DELALLOC);
2391 set_extent_delalloc(em_tree, page_start,
2392 page_end, GFP_NOFS);
2393
2394 spin_lock(&root->fs_info->delalloc_lock);
2395 root->fs_info->delalloc_bytes += PAGE_CACHE_SIZE -
2396 existing_delalloc;
2397 spin_unlock(&root->fs_info->delalloc_lock);
2398
2399 unlock_extent(em_tree, page_start, page_end, GFP_NOFS);
2400 set_page_dirty(page);
2401 unlock_page(page);
2402 page_cache_release(page);
2403 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
2404 }
2405
2406 out_unlock:
2407 mutex_unlock(&inode->i_mutex);
2408 return 0;
2409 }
2410
2411 static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
2412 {
2413 u64 new_size;
2414 u64 old_size;
2415 struct btrfs_ioctl_vol_args *vol_args;
2416 struct btrfs_trans_handle *trans;
2417 char *sizestr;
2418 int ret = 0;
2419 int namelen;
2420 int mod = 0;
2421
2422 vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
2423
2424 if (!vol_args)
2425 return -ENOMEM;
2426
2427 if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
2428 ret = -EFAULT;
2429 goto out;
2430 }
2431 namelen = strlen(vol_args->name);
2432 if (namelen > BTRFS_VOL_NAME_MAX) {
2433 ret = -EINVAL;
2434 goto out;
2435 }
2436
2437 sizestr = vol_args->name;
2438 if (!strcmp(sizestr, "max"))
2439 new_size = root->fs_info->sb->s_bdev->bd_inode->i_size;
2440 else {
2441 if (sizestr[0] == '-') {
2442 mod = -1;
2443 sizestr++;
2444 } else if (sizestr[0] == '+') {
2445 mod = 1;
2446 sizestr++;
2447 }
2448 new_size = btrfs_parse_size(sizestr);
2449 if (new_size == 0) {
2450 ret = -EINVAL;
2451 goto out;
2452 }
2453 }
2454
2455 mutex_lock(&root->fs_info->fs_mutex);
2456 old_size = btrfs_super_total_bytes(&root->fs_info->super_copy);
2457
2458 if (mod < 0) {
2459 if (new_size > old_size) {
2460 ret = -EINVAL;
2461 goto out_unlock;
2462 }
2463 new_size = old_size - new_size;
2464 } else if (mod > 0) {
2465 new_size = old_size + new_size;
2466 }
2467
2468 if (new_size < 256 * 1024 * 1024) {
2469 ret = -EINVAL;
2470 goto out_unlock;
2471 }
2472 if (new_size > root->fs_info->sb->s_bdev->bd_inode->i_size) {
2473 ret = -EFBIG;
2474 goto out_unlock;
2475 }
2476
2477 do_div(new_size, root->sectorsize);
2478 new_size *= root->sectorsize;
2479
2480 printk("new size is %Lu\n", new_size);
2481 if (new_size > old_size) {
2482 trans = btrfs_start_transaction(root, 1);
2483 ret = btrfs_grow_extent_tree(trans, root, new_size);
2484 btrfs_commit_transaction(trans, root);
2485 } else {
2486 ret = btrfs_shrink_extent_tree(root, new_size);
2487 }
2488
2489 out_unlock:
2490 mutex_unlock(&root->fs_info->fs_mutex);
2491 out:
2492 kfree(vol_args);
2493 return ret;
2494 }
2495
2496 static int noinline btrfs_ioctl_snap_create(struct btrfs_root *root,
2497 void __user *arg)
2498 {
2499 struct btrfs_ioctl_vol_args *vol_args;
2500 struct btrfs_dir_item *di;
2501 struct btrfs_path *path;
2502 u64 root_dirid;
2503 int namelen;
2504 int ret;
2505
2506 vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
2507
2508 if (!vol_args)
2509 return -ENOMEM;
2510
2511 if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
2512 ret = -EFAULT;
2513 goto out;
2514 }
2515
2516 namelen = strlen(vol_args->name);
2517 if (namelen > BTRFS_VOL_NAME_MAX) {
2518 ret = -EINVAL;
2519 goto out;
2520 }
2521 if (strchr(vol_args->name, '/')) {
2522 ret = -EINVAL;
2523 goto out;
2524 }
2525
2526 path = btrfs_alloc_path();
2527 if (!path) {
2528 ret = -ENOMEM;
2529 goto out;
2530 }
2531
2532 root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
2533 mutex_lock(&root->fs_info->fs_mutex);
2534 di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
2535 path, root_dirid,
2536 vol_args->name, namelen, 0);
2537 mutex_unlock(&root->fs_info->fs_mutex);
2538 btrfs_free_path(path);
2539
2540 if (di && !IS_ERR(di)) {
2541 ret = -EEXIST;
2542 goto out;
2543 }
2544
2545 if (IS_ERR(di)) {
2546 ret = PTR_ERR(di);
2547 goto out;
2548 }
2549
2550 if (root == root->fs_info->tree_root)
2551 ret = create_subvol(root, vol_args->name, namelen);
2552 else
2553 ret = create_snapshot(root, vol_args->name, namelen);
2554 out:
2555 kfree(vol_args);
2556 return ret;
2557 }
2558
2559 static int btrfs_ioctl_defrag(struct file *file)
2560 {
2561 struct inode *inode = fdentry(file)->d_inode;
2562 struct btrfs_root *root = BTRFS_I(inode)->root;
2563
2564 switch (inode->i_mode & S_IFMT) {
2565 case S_IFDIR:
2566 mutex_lock(&root->fs_info->fs_mutex);
2567 btrfs_defrag_root(root, 0);
2568 btrfs_defrag_root(root->fs_info->extent_root, 0);
2569 mutex_unlock(&root->fs_info->fs_mutex);
2570 break;
2571 case S_IFREG:
2572 btrfs_defrag_file(file);
2573 break;
2574 }
2575
2576 return 0;
2577 }
2578
2579 long btrfs_ioctl(struct file *file, unsigned int
2580 cmd, unsigned long arg)
2581 {
2582 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
2583
2584 switch (cmd) {
2585 case BTRFS_IOC_SNAP_CREATE:
2586 return btrfs_ioctl_snap_create(root, (void __user *)arg);
2587 case BTRFS_IOC_DEFRAG:
2588 return btrfs_ioctl_defrag(file);
2589 case BTRFS_IOC_RESIZE:
2590 return btrfs_ioctl_resize(root, (void __user *)arg);
2591 }
2592
2593 return -ENOTTY;
2594 }
2595
2596 /*
2597 * Called inside transaction, so use GFP_NOFS
2598 */
2599 struct inode *btrfs_alloc_inode(struct super_block *sb)
2600 {
2601 struct btrfs_inode *ei;
2602
2603 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
2604 if (!ei)
2605 return NULL;
2606 ei->last_trans = 0;
2607 ei->ordered_trans = 0;
2608 return &ei->vfs_inode;
2609 }
2610
2611 void btrfs_destroy_inode(struct inode *inode)
2612 {
2613 WARN_ON(!list_empty(&inode->i_dentry));
2614 WARN_ON(inode->i_data.nrpages);
2615
2616 btrfs_drop_extent_cache(inode, 0, (u64)-1);
2617 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
2618 }
2619
2620 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
2621 static void init_once(struct kmem_cache * cachep, void *foo)
2622 #else
2623 static void init_once(void * foo, struct kmem_cache * cachep,
2624 unsigned long flags)
2625 #endif
2626 {
2627 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
2628
2629 inode_init_once(&ei->vfs_inode);
2630 }
2631
2632 void btrfs_destroy_cachep(void)
2633 {
2634 if (btrfs_inode_cachep)
2635 kmem_cache_destroy(btrfs_inode_cachep);
2636 if (btrfs_trans_handle_cachep)
2637 kmem_cache_destroy(btrfs_trans_handle_cachep);
2638 if (btrfs_transaction_cachep)
2639 kmem_cache_destroy(btrfs_transaction_cachep);
2640 if (btrfs_bit_radix_cachep)
2641 kmem_cache_destroy(btrfs_bit_radix_cachep);
2642 if (btrfs_path_cachep)
2643 kmem_cache_destroy(btrfs_path_cachep);
2644 }
2645
2646 struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
2647 unsigned long extra_flags,
2648 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
2649 void (*ctor)(struct kmem_cache *, void *)
2650 #else
2651 void (*ctor)(void *, struct kmem_cache *,
2652 unsigned long)
2653 #endif
2654 )
2655 {
2656 return kmem_cache_create(name, size, 0, (SLAB_RECLAIM_ACCOUNT |
2657 SLAB_MEM_SPREAD | extra_flags), ctor
2658 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
2659 ,NULL
2660 #endif
2661 );
2662 }
2663
2664 int btrfs_init_cachep(void)
2665 {
2666 btrfs_inode_cachep = btrfs_cache_create("btrfs_inode_cache",
2667 sizeof(struct btrfs_inode),
2668 0, init_once);
2669 if (!btrfs_inode_cachep)
2670 goto fail;
2671 btrfs_trans_handle_cachep =
2672 btrfs_cache_create("btrfs_trans_handle_cache",
2673 sizeof(struct btrfs_trans_handle),
2674 0, NULL);
2675 if (!btrfs_trans_handle_cachep)
2676 goto fail;
2677 btrfs_transaction_cachep = btrfs_cache_create("btrfs_transaction_cache",
2678 sizeof(struct btrfs_transaction),
2679 0, NULL);
2680 if (!btrfs_transaction_cachep)
2681 goto fail;
2682 btrfs_path_cachep = btrfs_cache_create("btrfs_path_cache",
2683 sizeof(struct btrfs_path),
2684 0, NULL);
2685 if (!btrfs_path_cachep)
2686 goto fail;
2687 btrfs_bit_radix_cachep = btrfs_cache_create("btrfs_radix", 256,
2688 SLAB_DESTROY_BY_RCU, NULL);
2689 if (!btrfs_bit_radix_cachep)
2690 goto fail;
2691 return 0;
2692 fail:
2693 btrfs_destroy_cachep();
2694 return -ENOMEM;
2695 }
2696
2697 static int btrfs_getattr(struct vfsmount *mnt,
2698 struct dentry *dentry, struct kstat *stat)
2699 {
2700 struct inode *inode = dentry->d_inode;
2701 generic_fillattr(inode, stat);
2702 stat->blksize = PAGE_CACHE_SIZE;
2703 return 0;
2704 }
2705
2706 static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
2707 struct inode * new_dir,struct dentry *new_dentry)
2708 {
2709 struct btrfs_trans_handle *trans;
2710 struct btrfs_root *root = BTRFS_I(old_dir)->root;
2711 struct inode *new_inode = new_dentry->d_inode;
2712 struct inode *old_inode = old_dentry->d_inode;
2713 struct timespec ctime = CURRENT_TIME;
2714 struct btrfs_path *path;
2715 int ret;
2716
2717 if (S_ISDIR(old_inode->i_mode) && new_inode &&
2718 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
2719 return -ENOTEMPTY;
2720 }
2721
2722 mutex_lock(&root->fs_info->fs_mutex);
2723 ret = btrfs_check_free_space(root, 1, 0);
2724 if (ret)
2725 goto out_unlock;
2726
2727 trans = btrfs_start_transaction(root, 1);
2728
2729 btrfs_set_trans_block_group(trans, new_dir);
2730 path = btrfs_alloc_path();
2731 if (!path) {
2732 ret = -ENOMEM;
2733 goto out_fail;
2734 }
2735
2736 old_dentry->d_inode->i_nlink++;
2737 old_dir->i_ctime = old_dir->i_mtime = ctime;
2738 new_dir->i_ctime = new_dir->i_mtime = ctime;
2739 old_inode->i_ctime = ctime;
2740
2741 ret = btrfs_unlink_trans(trans, root, old_dir, old_dentry);
2742 if (ret)
2743 goto out_fail;
2744
2745 if (new_inode) {
2746 new_inode->i_ctime = CURRENT_TIME;
2747 ret = btrfs_unlink_trans(trans, root, new_dir, new_dentry);
2748 if (ret)
2749 goto out_fail;
2750 }
2751 ret = btrfs_add_link(trans, new_dentry, old_inode);
2752 if (ret)
2753 goto out_fail;
2754
2755 out_fail:
2756 btrfs_free_path(path);
2757 btrfs_end_transaction(trans, root);
2758 out_unlock:
2759 mutex_unlock(&root->fs_info->fs_mutex);
2760 return ret;
2761 }
2762
2763 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
2764 const char *symname)
2765 {
2766 struct btrfs_trans_handle *trans;
2767 struct btrfs_root *root = BTRFS_I(dir)->root;
2768 struct btrfs_path *path;
2769 struct btrfs_key key;
2770 struct inode *inode = NULL;
2771 int err;
2772 int drop_inode = 0;
2773 u64 objectid;
2774 int name_len;
2775 int datasize;
2776 unsigned long ptr;
2777 struct btrfs_file_extent_item *ei;
2778 struct extent_buffer *leaf;
2779 unsigned long nr = 0;
2780
2781 name_len = strlen(symname) + 1;
2782 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
2783 return -ENAMETOOLONG;
2784
2785 mutex_lock(&root->fs_info->fs_mutex);
2786 err = btrfs_check_free_space(root, 1, 0);
2787 if (err)
2788 goto out_fail;
2789
2790 trans = btrfs_start_transaction(root, 1);
2791 btrfs_set_trans_block_group(trans, dir);
2792
2793 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
2794 if (err) {
2795 err = -ENOSPC;
2796 goto out_unlock;
2797 }
2798
2799 inode = btrfs_new_inode(trans, root, objectid,
2800 BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO);
2801 err = PTR_ERR(inode);
2802 if (IS_ERR(inode))
2803 goto out_unlock;
2804
2805 btrfs_set_trans_block_group(trans, inode);
2806 err = btrfs_add_nondir(trans, dentry, inode);
2807 if (err)
2808 drop_inode = 1;
2809 else {
2810 inode->i_mapping->a_ops = &btrfs_aops;
2811 inode->i_fop = &btrfs_file_operations;
2812 inode->i_op = &btrfs_file_inode_operations;
2813 extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
2814 inode->i_mapping, GFP_NOFS);
2815 BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
2816 }
2817 dir->i_sb->s_dirt = 1;
2818 btrfs_update_inode_block_group(trans, inode);
2819 btrfs_update_inode_block_group(trans, dir);
2820 if (drop_inode)
2821 goto out_unlock;
2822
2823 path = btrfs_alloc_path();
2824 BUG_ON(!path);
2825 key.objectid = inode->i_ino;
2826 key.offset = 0;
2827 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
2828 datasize = btrfs_file_extent_calc_inline_size(name_len);
2829 err = btrfs_insert_empty_item(trans, root, path, &key,
2830 datasize);
2831 if (err) {
2832 drop_inode = 1;
2833 goto out_unlock;
2834 }
2835 leaf = path->nodes[0];
2836 ei = btrfs_item_ptr(leaf, path->slots[0],
2837 struct btrfs_file_extent_item);
2838 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
2839 btrfs_set_file_extent_type(leaf, ei,
2840 BTRFS_FILE_EXTENT_INLINE);
2841 ptr = btrfs_file_extent_inline_start(ei);
2842 write_extent_buffer(leaf, symname, ptr, name_len);
2843 btrfs_mark_buffer_dirty(leaf);
2844 btrfs_free_path(path);
2845
2846 inode->i_op = &btrfs_symlink_inode_operations;
2847 inode->i_mapping->a_ops = &btrfs_symlink_aops;
2848 inode->i_size = name_len - 1;
2849 err = btrfs_update_inode(trans, root, inode);
2850 if (err)
2851 drop_inode = 1;
2852
2853 out_unlock:
2854 nr = trans->blocks_used;
2855 btrfs_end_transaction(trans, root);
2856 out_fail:
2857 mutex_unlock(&root->fs_info->fs_mutex);
2858 if (drop_inode) {
2859 inode_dec_link_count(inode);
2860 iput(inode);
2861 }
2862 btrfs_btree_balance_dirty(root, nr);
2863 btrfs_throttle(root);
2864 return err;
2865 }
2866 static int btrfs_permission(struct inode *inode, int mask,
2867 struct nameidata *nd)
2868 {
2869 if (btrfs_test_flag(inode, READONLY) && (mask & MAY_WRITE))
2870 return -EACCES;
2871 return generic_permission(inode, mask, NULL);
2872 }
2873
2874 static struct inode_operations btrfs_dir_inode_operations = {
2875 .lookup = btrfs_lookup,
2876 .create = btrfs_create,
2877 .unlink = btrfs_unlink,
2878 .link = btrfs_link,
2879 .mkdir = btrfs_mkdir,
2880 .rmdir = btrfs_rmdir,
2881 .rename = btrfs_rename,
2882 .symlink = btrfs_symlink,
2883 .setattr = btrfs_setattr,
2884 .mknod = btrfs_mknod,
2885 .setxattr = generic_setxattr,
2886 .getxattr = generic_getxattr,
2887 .listxattr = btrfs_listxattr,
2888 .removexattr = generic_removexattr,
2889 .permission = btrfs_permission,
2890 };
2891 static struct inode_operations btrfs_dir_ro_inode_operations = {
2892 .lookup = btrfs_lookup,
2893 .permission = btrfs_permission,
2894 };
2895 static struct file_operations btrfs_dir_file_operations = {
2896 .llseek = generic_file_llseek,
2897 .read = generic_read_dir,
2898 .readdir = btrfs_readdir,
2899 .unlocked_ioctl = btrfs_ioctl,
2900 #ifdef CONFIG_COMPAT
2901 .compat_ioctl = btrfs_ioctl,
2902 #endif
2903 };
2904
2905 static struct extent_map_ops btrfs_extent_map_ops = {
2906 .fill_delalloc = run_delalloc_range,
2907 .writepage_io_hook = btrfs_writepage_io_hook,
2908 .readpage_io_hook = btrfs_readpage_io_hook,
2909 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
2910 };
2911
2912 static struct address_space_operations btrfs_aops = {
2913 .readpage = btrfs_readpage,
2914 .writepage = btrfs_writepage,
2915 .writepages = btrfs_writepages,
2916 .readpages = btrfs_readpages,
2917 .sync_page = block_sync_page,
2918 .bmap = btrfs_bmap,
2919 .invalidatepage = btrfs_invalidatepage,
2920 .releasepage = btrfs_releasepage,
2921 .set_page_dirty = __set_page_dirty_nobuffers,
2922 };
2923
2924 static struct address_space_operations btrfs_symlink_aops = {
2925 .readpage = btrfs_readpage,
2926 .writepage = btrfs_writepage,
2927 .invalidatepage = btrfs_invalidatepage,
2928 .releasepage = btrfs_releasepage,
2929 };
2930
2931 static struct inode_operations btrfs_file_inode_operations = {
2932 .truncate = btrfs_truncate,
2933 .getattr = btrfs_getattr,
2934 .setattr = btrfs_setattr,
2935 .setxattr = generic_setxattr,
2936 .getxattr = generic_getxattr,
2937 .listxattr = btrfs_listxattr,
2938 .removexattr = generic_removexattr,
2939 .permission = btrfs_permission,
2940 };
2941 static struct inode_operations btrfs_special_inode_operations = {
2942 .getattr = btrfs_getattr,
2943 .setattr = btrfs_setattr,
2944 .permission = btrfs_permission,
2945 };
2946 static struct inode_operations btrfs_symlink_inode_operations = {
2947 .readlink = generic_readlink,
2948 .follow_link = page_follow_link_light,
2949 .put_link = page_put_link,
2950 .permission = btrfs_permission,
2951 };
Linux kernel - Deliverables
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