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Btrfs: Fix hole insertion corner cases
[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 return 0;
84
85 if (for_del)
86 thresh = total * 90;
87 else
88 thresh = total * 85;
89
90 do_div(thresh, 100);
91
92 spin_lock(&root->fs_info->delalloc_lock);
93 if (used + root->fs_info->delalloc_bytes + num_required > thresh)
94 ret = -ENOSPC;
95 spin_unlock(&root->fs_info->delalloc_lock);
96 return ret;
97 }
98
99 static int cow_file_range(struct inode *inode, u64 start, u64 end)
100 {
101 struct btrfs_root *root = BTRFS_I(inode)->root;
102 struct btrfs_trans_handle *trans;
103 u64 alloc_hint = 0;
104 u64 num_bytes;
105 u64 cur_alloc_size;
106 u64 blocksize = root->sectorsize;
107 struct btrfs_key ins;
108 int ret;
109
110 trans = btrfs_start_transaction(root, 1);
111 BUG_ON(!trans);
112 btrfs_set_trans_block_group(trans, inode);
113
114 num_bytes = (end - start + blocksize) & ~(blocksize - 1);
115 num_bytes = max(blocksize, num_bytes);
116 ret = btrfs_drop_extents(trans, root, inode,
117 start, start + num_bytes, start, &alloc_hint);
118
119 if (alloc_hint == EXTENT_MAP_INLINE)
120 goto out;
121
122 while(num_bytes > 0) {
123 cur_alloc_size = min(num_bytes, root->fs_info->max_extent);
124 ret = btrfs_alloc_extent(trans, root, cur_alloc_size,
125 root->root_key.objectid,
126 trans->transid,
127 inode->i_ino, start, 0,
128 alloc_hint, (u64)-1, &ins, 1);
129 if (ret) {
130 WARN_ON(1);
131 goto out;
132 }
133 ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
134 start, ins.objectid, ins.offset,
135 ins.offset);
136 btrfs_check_file(root, inode);
137 num_bytes -= cur_alloc_size;
138 alloc_hint = ins.objectid + ins.offset;
139 start += cur_alloc_size;
140 }
141 btrfs_add_ordered_inode(inode);
142 out:
143 btrfs_end_transaction(trans, root);
144 return ret;
145 }
146
147 static int run_delalloc_nocow(struct inode *inode, u64 start, u64 end)
148 {
149 u64 extent_start;
150 u64 extent_end;
151 u64 bytenr;
152 u64 cow_end;
153 u64 loops = 0;
154 u64 total_fs_bytes;
155 struct btrfs_root *root = BTRFS_I(inode)->root;
156 struct extent_buffer *leaf;
157 int found_type;
158 struct btrfs_path *path;
159 struct btrfs_file_extent_item *item;
160 int ret;
161 int err;
162 struct btrfs_key found_key;
163
164 total_fs_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
165 path = btrfs_alloc_path();
166 BUG_ON(!path);
167 again:
168 ret = btrfs_lookup_file_extent(NULL, root, path,
169 inode->i_ino, start, 0);
170 if (ret < 0) {
171 btrfs_free_path(path);
172 return ret;
173 }
174
175 cow_end = end;
176 if (ret != 0) {
177 if (path->slots[0] == 0)
178 goto not_found;
179 path->slots[0]--;
180 }
181
182 leaf = path->nodes[0];
183 item = btrfs_item_ptr(leaf, path->slots[0],
184 struct btrfs_file_extent_item);
185
186 /* are we inside the extent that was found? */
187 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
188 found_type = btrfs_key_type(&found_key);
189 if (found_key.objectid != inode->i_ino ||
190 found_type != BTRFS_EXTENT_DATA_KEY) {
191 goto not_found;
192 }
193
194 found_type = btrfs_file_extent_type(leaf, item);
195 extent_start = found_key.offset;
196 if (found_type == BTRFS_FILE_EXTENT_REG) {
197 u64 extent_num_bytes;
198
199 extent_num_bytes = btrfs_file_extent_num_bytes(leaf, item);
200 extent_end = extent_start + extent_num_bytes;
201 err = 0;
202
203 if (loops && start != extent_start)
204 goto not_found;
205
206 if (start < extent_start || start >= extent_end)
207 goto not_found;
208
209 cow_end = min(end, extent_end - 1);
210 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
211 if (bytenr == 0)
212 goto not_found;
213
214 /*
215 * we may be called by the resizer, make sure we're inside
216 * the limits of the FS
217 */
218 if (bytenr + extent_num_bytes > total_fs_bytes)
219 goto not_found;
220
221 if (btrfs_count_snapshots_in_path(root, path, bytenr) != 1) {
222 goto not_found;
223 }
224
225 start = extent_end;
226 } else {
227 goto not_found;
228 }
229 loop:
230 if (start > end) {
231 btrfs_free_path(path);
232 return 0;
233 }
234 btrfs_release_path(root, path);
235 loops++;
236 goto again;
237
238 not_found:
239 cow_file_range(inode, start, cow_end);
240 start = cow_end + 1;
241 goto loop;
242 }
243
244 static int run_delalloc_range(struct inode *inode, u64 start, u64 end)
245 {
246 struct btrfs_root *root = BTRFS_I(inode)->root;
247 u64 num_bytes;
248 int ret;
249 mutex_lock(&root->fs_info->fs_mutex);
250 if (btrfs_test_opt(root, NODATACOW) ||
251 btrfs_test_flag(inode, NODATACOW))
252 ret = run_delalloc_nocow(inode, start, end);
253 else
254 ret = cow_file_range(inode, start, end);
255
256 spin_lock(&root->fs_info->delalloc_lock);
257 num_bytes = end + 1 - start;
258 if (root->fs_info->delalloc_bytes < num_bytes) {
259 printk("delalloc accounting error total %llu sub %llu\n",
260 root->fs_info->delalloc_bytes, num_bytes);
261 } else {
262 root->fs_info->delalloc_bytes -= num_bytes;
263 }
264 spin_unlock(&root->fs_info->delalloc_lock);
265
266 mutex_unlock(&root->fs_info->fs_mutex);
267 return ret;
268 }
269
270 int btrfs_writepage_io_hook(struct page *page, u64 start, u64 end)
271 {
272 struct inode *inode = page->mapping->host;
273 struct btrfs_root *root = BTRFS_I(inode)->root;
274 struct btrfs_trans_handle *trans;
275 char *kaddr;
276 int ret = 0;
277 u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
278 size_t offset = start - page_start;
279 if (btrfs_test_opt(root, NODATASUM) ||
280 btrfs_test_flag(inode, NODATASUM))
281 return 0;
282 mutex_lock(&root->fs_info->fs_mutex);
283 trans = btrfs_start_transaction(root, 1);
284 btrfs_set_trans_block_group(trans, inode);
285 kaddr = kmap(page);
286 btrfs_csum_file_block(trans, root, inode, inode->i_ino,
287 start, kaddr + offset, end - start + 1);
288 kunmap(page);
289 ret = btrfs_end_transaction(trans, root);
290 BUG_ON(ret);
291 mutex_unlock(&root->fs_info->fs_mutex);
292 return ret;
293 }
294
295 int btrfs_readpage_io_hook(struct page *page, u64 start, u64 end)
296 {
297 int ret = 0;
298 struct inode *inode = page->mapping->host;
299 struct btrfs_root *root = BTRFS_I(inode)->root;
300 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
301 struct btrfs_csum_item *item;
302 struct btrfs_path *path = NULL;
303 u32 csum;
304 if (btrfs_test_opt(root, NODATASUM) ||
305 btrfs_test_flag(inode, NODATASUM))
306 return 0;
307 mutex_lock(&root->fs_info->fs_mutex);
308 path = btrfs_alloc_path();
309 item = btrfs_lookup_csum(NULL, root, path, inode->i_ino, start, 0);
310 if (IS_ERR(item)) {
311 ret = PTR_ERR(item);
312 /* a csum that isn't present is a preallocated region. */
313 if (ret == -ENOENT || ret == -EFBIG)
314 ret = 0;
315 csum = 0;
316 goto out;
317 }
318 read_extent_buffer(path->nodes[0], &csum, (unsigned long)item,
319 BTRFS_CRC32_SIZE);
320 set_state_private(em_tree, start, csum);
321 out:
322 if (path)
323 btrfs_free_path(path);
324 mutex_unlock(&root->fs_info->fs_mutex);
325 return ret;
326 }
327
328 int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end)
329 {
330 size_t offset = start - ((u64)page->index << PAGE_CACHE_SHIFT);
331 struct inode *inode = page->mapping->host;
332 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
333 char *kaddr;
334 u64 private;
335 int ret;
336 struct btrfs_root *root = BTRFS_I(inode)->root;
337 u32 csum = ~(u32)0;
338 unsigned long flags;
339 if (btrfs_test_opt(root, NODATASUM) ||
340 btrfs_test_flag(inode, NODATASUM))
341 return 0;
342 ret = get_state_private(em_tree, start, &private);
343 local_irq_save(flags);
344 kaddr = kmap_atomic(page, KM_IRQ0);
345 if (ret) {
346 goto zeroit;
347 }
348 csum = btrfs_csum_data(root, kaddr + offset, csum, end - start + 1);
349 btrfs_csum_final(csum, (char *)&csum);
350 if (csum != private) {
351 goto zeroit;
352 }
353 kunmap_atomic(kaddr, KM_IRQ0);
354 local_irq_restore(flags);
355 return 0;
356
357 zeroit:
358 printk("btrfs csum failed ino %lu off %llu\n",
359 page->mapping->host->i_ino, (unsigned long long)start);
360 memset(kaddr + offset, 1, end - start + 1);
361 flush_dcache_page(page);
362 kunmap_atomic(kaddr, KM_IRQ0);
363 local_irq_restore(flags);
364 return 0;
365 }
366
367 void btrfs_read_locked_inode(struct inode *inode)
368 {
369 struct btrfs_path *path;
370 struct extent_buffer *leaf;
371 struct btrfs_inode_item *inode_item;
372 struct btrfs_inode_timespec *tspec;
373 struct btrfs_root *root = BTRFS_I(inode)->root;
374 struct btrfs_key location;
375 u64 alloc_group_block;
376 u32 rdev;
377 int ret;
378
379 path = btrfs_alloc_path();
380 BUG_ON(!path);
381 mutex_lock(&root->fs_info->fs_mutex);
382 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
383
384 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
385 if (ret)
386 goto make_bad;
387
388 leaf = path->nodes[0];
389 inode_item = btrfs_item_ptr(leaf, path->slots[0],
390 struct btrfs_inode_item);
391
392 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
393 inode->i_nlink = btrfs_inode_nlink(leaf, inode_item);
394 inode->i_uid = btrfs_inode_uid(leaf, inode_item);
395 inode->i_gid = btrfs_inode_gid(leaf, inode_item);
396 inode->i_size = btrfs_inode_size(leaf, inode_item);
397
398 tspec = btrfs_inode_atime(inode_item);
399 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
400 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
401
402 tspec = btrfs_inode_mtime(inode_item);
403 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
404 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
405
406 tspec = btrfs_inode_ctime(inode_item);
407 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
408 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
409
410 inode->i_blocks = btrfs_inode_nblocks(leaf, inode_item);
411 inode->i_generation = btrfs_inode_generation(leaf, inode_item);
412 inode->i_rdev = 0;
413 rdev = btrfs_inode_rdev(leaf, inode_item);
414
415 alloc_group_block = btrfs_inode_block_group(leaf, inode_item);
416 BTRFS_I(inode)->block_group = btrfs_lookup_block_group(root->fs_info,
417 alloc_group_block);
418 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
419 if (!BTRFS_I(inode)->block_group) {
420 BTRFS_I(inode)->block_group = btrfs_find_block_group(root,
421 NULL, 0, 0, 0);
422 }
423 btrfs_free_path(path);
424 inode_item = NULL;
425
426 mutex_unlock(&root->fs_info->fs_mutex);
427
428 switch (inode->i_mode & S_IFMT) {
429 case S_IFREG:
430 inode->i_mapping->a_ops = &btrfs_aops;
431 BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
432 inode->i_fop = &btrfs_file_operations;
433 inode->i_op = &btrfs_file_inode_operations;
434 break;
435 case S_IFDIR:
436 inode->i_fop = &btrfs_dir_file_operations;
437 if (root == root->fs_info->tree_root)
438 inode->i_op = &btrfs_dir_ro_inode_operations;
439 else
440 inode->i_op = &btrfs_dir_inode_operations;
441 break;
442 case S_IFLNK:
443 inode->i_op = &btrfs_symlink_inode_operations;
444 inode->i_mapping->a_ops = &btrfs_symlink_aops;
445 break;
446 default:
447 init_special_inode(inode, inode->i_mode, rdev);
448 break;
449 }
450 return;
451
452 make_bad:
453 btrfs_release_path(root, path);
454 btrfs_free_path(path);
455 mutex_unlock(&root->fs_info->fs_mutex);
456 make_bad_inode(inode);
457 }
458
459 static void fill_inode_item(struct extent_buffer *leaf,
460 struct btrfs_inode_item *item,
461 struct inode *inode)
462 {
463 btrfs_set_inode_uid(leaf, item, inode->i_uid);
464 btrfs_set_inode_gid(leaf, item, inode->i_gid);
465 btrfs_set_inode_size(leaf, item, inode->i_size);
466 btrfs_set_inode_mode(leaf, item, inode->i_mode);
467 btrfs_set_inode_nlink(leaf, item, inode->i_nlink);
468
469 btrfs_set_timespec_sec(leaf, btrfs_inode_atime(item),
470 inode->i_atime.tv_sec);
471 btrfs_set_timespec_nsec(leaf, btrfs_inode_atime(item),
472 inode->i_atime.tv_nsec);
473
474 btrfs_set_timespec_sec(leaf, btrfs_inode_mtime(item),
475 inode->i_mtime.tv_sec);
476 btrfs_set_timespec_nsec(leaf, btrfs_inode_mtime(item),
477 inode->i_mtime.tv_nsec);
478
479 btrfs_set_timespec_sec(leaf, btrfs_inode_ctime(item),
480 inode->i_ctime.tv_sec);
481 btrfs_set_timespec_nsec(leaf, btrfs_inode_ctime(item),
482 inode->i_ctime.tv_nsec);
483
484 btrfs_set_inode_nblocks(leaf, item, inode->i_blocks);
485 btrfs_set_inode_generation(leaf, item, inode->i_generation);
486 btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
487 btrfs_set_inode_flags(leaf, item, BTRFS_I(inode)->flags);
488 btrfs_set_inode_block_group(leaf, item,
489 BTRFS_I(inode)->block_group->key.objectid);
490 }
491
492 int btrfs_update_inode(struct btrfs_trans_handle *trans,
493 struct btrfs_root *root,
494 struct inode *inode)
495 {
496 struct btrfs_inode_item *inode_item;
497 struct btrfs_path *path;
498 struct extent_buffer *leaf;
499 int ret;
500
501 path = btrfs_alloc_path();
502 BUG_ON(!path);
503 ret = btrfs_lookup_inode(trans, root, path,
504 &BTRFS_I(inode)->location, 1);
505 if (ret) {
506 if (ret > 0)
507 ret = -ENOENT;
508 goto failed;
509 }
510
511 leaf = path->nodes[0];
512 inode_item = btrfs_item_ptr(leaf, path->slots[0],
513 struct btrfs_inode_item);
514
515 fill_inode_item(leaf, inode_item, inode);
516 btrfs_mark_buffer_dirty(leaf);
517 btrfs_set_inode_last_trans(trans, inode);
518 ret = 0;
519 failed:
520 btrfs_release_path(root, path);
521 btrfs_free_path(path);
522 return ret;
523 }
524
525
526 static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
527 struct btrfs_root *root,
528 struct inode *dir,
529 struct dentry *dentry)
530 {
531 struct btrfs_path *path;
532 const char *name = dentry->d_name.name;
533 int name_len = dentry->d_name.len;
534 int ret = 0;
535 struct extent_buffer *leaf;
536 struct btrfs_dir_item *di;
537 struct btrfs_key key;
538
539 path = btrfs_alloc_path();
540 if (!path) {
541 ret = -ENOMEM;
542 goto err;
543 }
544
545 di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
546 name, name_len, -1);
547 if (IS_ERR(di)) {
548 ret = PTR_ERR(di);
549 goto err;
550 }
551 if (!di) {
552 ret = -ENOENT;
553 goto err;
554 }
555 leaf = path->nodes[0];
556 btrfs_dir_item_key_to_cpu(leaf, di, &key);
557 ret = btrfs_delete_one_dir_name(trans, root, path, di);
558 if (ret)
559 goto err;
560 btrfs_release_path(root, path);
561
562 di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
563 key.objectid, name, name_len, -1);
564 if (IS_ERR(di)) {
565 ret = PTR_ERR(di);
566 goto err;
567 }
568 if (!di) {
569 ret = -ENOENT;
570 goto err;
571 }
572 ret = btrfs_delete_one_dir_name(trans, root, path, di);
573
574 dentry->d_inode->i_ctime = dir->i_ctime;
575 ret = btrfs_del_inode_ref(trans, root, name, name_len,
576 dentry->d_inode->i_ino,
577 dentry->d_parent->d_inode->i_ino);
578 if (ret) {
579 printk("failed to delete reference to %.*s, "
580 "inode %lu parent %lu\n", name_len, name,
581 dentry->d_inode->i_ino,
582 dentry->d_parent->d_inode->i_ino);
583 }
584 err:
585 btrfs_free_path(path);
586 if (!ret) {
587 dir->i_size -= name_len * 2;
588 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
589 btrfs_update_inode(trans, root, dir);
590 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
591 dentry->d_inode->i_nlink--;
592 #else
593 drop_nlink(dentry->d_inode);
594 #endif
595 ret = btrfs_update_inode(trans, root, dentry->d_inode);
596 dir->i_sb->s_dirt = 1;
597 }
598 return ret;
599 }
600
601 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
602 {
603 struct btrfs_root *root;
604 struct btrfs_trans_handle *trans;
605 struct inode *inode = dentry->d_inode;
606 int ret;
607 unsigned long nr = 0;
608
609 root = BTRFS_I(dir)->root;
610 mutex_lock(&root->fs_info->fs_mutex);
611
612 ret = btrfs_check_free_space(root, 1, 1);
613 if (ret)
614 goto fail;
615
616 trans = btrfs_start_transaction(root, 1);
617
618 btrfs_set_trans_block_group(trans, dir);
619 ret = btrfs_unlink_trans(trans, root, dir, dentry);
620 nr = trans->blocks_used;
621
622 if (inode->i_nlink == 0) {
623 int found;
624 /* if the inode isn't linked anywhere,
625 * we don't need to worry about
626 * data=ordered
627 */
628 found = btrfs_del_ordered_inode(inode);
629 if (found == 1) {
630 atomic_dec(&inode->i_count);
631 }
632 }
633
634 btrfs_end_transaction(trans, root);
635 fail:
636 mutex_unlock(&root->fs_info->fs_mutex);
637 btrfs_btree_balance_dirty(root, nr);
638 btrfs_throttle(root);
639 return ret;
640 }
641
642 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
643 {
644 struct inode *inode = dentry->d_inode;
645 int err = 0;
646 int ret;
647 struct btrfs_root *root = BTRFS_I(dir)->root;
648 struct btrfs_trans_handle *trans;
649 unsigned long nr = 0;
650
651 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
652 return -ENOTEMPTY;
653
654 mutex_lock(&root->fs_info->fs_mutex);
655 ret = btrfs_check_free_space(root, 1, 1);
656 if (ret)
657 goto fail;
658
659 trans = btrfs_start_transaction(root, 1);
660 btrfs_set_trans_block_group(trans, dir);
661
662 /* now the directory is empty */
663 err = btrfs_unlink_trans(trans, root, dir, dentry);
664 if (!err) {
665 inode->i_size = 0;
666 }
667
668 nr = trans->blocks_used;
669 ret = btrfs_end_transaction(trans, root);
670 fail:
671 mutex_unlock(&root->fs_info->fs_mutex);
672 btrfs_btree_balance_dirty(root, nr);
673 btrfs_throttle(root);
674
675 if (ret && !err)
676 err = ret;
677 return err;
678 }
679
680 static int btrfs_free_inode(struct btrfs_trans_handle *trans,
681 struct btrfs_root *root,
682 struct inode *inode)
683 {
684 struct btrfs_path *path;
685 int ret;
686
687 clear_inode(inode);
688
689 path = btrfs_alloc_path();
690 BUG_ON(!path);
691 ret = btrfs_lookup_inode(trans, root, path,
692 &BTRFS_I(inode)->location, -1);
693 if (ret > 0)
694 ret = -ENOENT;
695 if (!ret)
696 ret = btrfs_del_item(trans, root, path);
697 btrfs_free_path(path);
698 return ret;
699 }
700
701 /*
702 * this can truncate away extent items, csum items and directory items.
703 * It starts at a high offset and removes keys until it can't find
704 * any higher than i_size.
705 *
706 * csum items that cross the new i_size are truncated to the new size
707 * as well.
708 */
709 static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
710 struct btrfs_root *root,
711 struct inode *inode)
712 {
713 int ret;
714 struct btrfs_path *path;
715 struct btrfs_key key;
716 struct btrfs_key found_key;
717 u32 found_type;
718 struct extent_buffer *leaf;
719 struct btrfs_file_extent_item *fi;
720 u64 extent_start = 0;
721 u64 extent_num_bytes = 0;
722 u64 item_end = 0;
723 u64 root_gen = 0;
724 u64 root_owner = 0;
725 int found_extent;
726 int del_item;
727 int extent_type = -1;
728
729 btrfs_drop_extent_cache(inode, inode->i_size, (u64)-1);
730 path = btrfs_alloc_path();
731 path->reada = -1;
732 BUG_ON(!path);
733
734 /* FIXME, add redo link to tree so we don't leak on crash */
735 key.objectid = inode->i_ino;
736 key.offset = (u64)-1;
737 key.type = (u8)-1;
738
739 while(1) {
740 btrfs_init_path(path);
741 fi = NULL;
742 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
743 if (ret < 0) {
744 goto error;
745 }
746 if (ret > 0) {
747 BUG_ON(path->slots[0] == 0);
748 path->slots[0]--;
749 }
750 leaf = path->nodes[0];
751 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
752 found_type = btrfs_key_type(&found_key);
753
754 if (found_key.objectid != inode->i_ino)
755 break;
756
757 if (found_type != BTRFS_CSUM_ITEM_KEY &&
758 found_type != BTRFS_DIR_ITEM_KEY &&
759 found_type != BTRFS_DIR_INDEX_KEY &&
760 found_type != BTRFS_EXTENT_DATA_KEY)
761 break;
762
763 item_end = found_key.offset;
764 if (found_type == BTRFS_EXTENT_DATA_KEY) {
765 fi = btrfs_item_ptr(leaf, path->slots[0],
766 struct btrfs_file_extent_item);
767 extent_type = btrfs_file_extent_type(leaf, fi);
768 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
769 item_end +=
770 btrfs_file_extent_num_bytes(leaf, fi);
771 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
772 struct btrfs_item *item = btrfs_item_nr(leaf,
773 path->slots[0]);
774 item_end += btrfs_file_extent_inline_len(leaf,
775 item);
776 }
777 item_end--;
778 }
779 if (found_type == BTRFS_CSUM_ITEM_KEY) {
780 ret = btrfs_csum_truncate(trans, root, path,
781 inode->i_size);
782 BUG_ON(ret);
783 }
784 if (item_end < inode->i_size) {
785 if (found_type == BTRFS_DIR_ITEM_KEY) {
786 found_type = BTRFS_INODE_ITEM_KEY;
787 } else if (found_type == BTRFS_EXTENT_ITEM_KEY) {
788 found_type = BTRFS_CSUM_ITEM_KEY;
789 } else if (found_type) {
790 found_type--;
791 } else {
792 break;
793 }
794 btrfs_set_key_type(&key, found_type);
795 btrfs_release_path(root, path);
796 continue;
797 }
798 if (found_key.offset >= inode->i_size)
799 del_item = 1;
800 else
801 del_item = 0;
802 found_extent = 0;
803
804 /* FIXME, shrink the extent if the ref count is only 1 */
805 if (found_type != BTRFS_EXTENT_DATA_KEY)
806 goto delete;
807
808 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
809 u64 num_dec;
810 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
811 if (!del_item) {
812 u64 orig_num_bytes =
813 btrfs_file_extent_num_bytes(leaf, fi);
814 extent_num_bytes = inode->i_size -
815 found_key.offset + root->sectorsize - 1;
816 btrfs_set_file_extent_num_bytes(leaf, fi,
817 extent_num_bytes);
818 num_dec = (orig_num_bytes -
819 extent_num_bytes) >> 9;
820 if (extent_start != 0) {
821 inode->i_blocks -= num_dec;
822 }
823 btrfs_mark_buffer_dirty(leaf);
824 } else {
825 extent_num_bytes =
826 btrfs_file_extent_disk_num_bytes(leaf,
827 fi);
828 /* FIXME blocksize != 4096 */
829 num_dec = btrfs_file_extent_num_bytes(leaf,
830 fi) >> 9;
831 if (extent_start != 0) {
832 found_extent = 1;
833 inode->i_blocks -= num_dec;
834 }
835 root_gen = btrfs_header_generation(leaf);
836 root_owner = btrfs_header_owner(leaf);
837 }
838 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE &&
839 !del_item) {
840 u32 newsize = inode->i_size - found_key.offset;
841 newsize = btrfs_file_extent_calc_inline_size(newsize);
842 ret = btrfs_truncate_item(trans, root, path,
843 newsize, 1);
844 BUG_ON(ret);
845 }
846 delete:
847 if (del_item) {
848 ret = btrfs_del_item(trans, root, path);
849 if (ret)
850 goto error;
851 } else {
852 break;
853 }
854 btrfs_release_path(root, path);
855 if (found_extent) {
856 ret = btrfs_free_extent(trans, root, extent_start,
857 extent_num_bytes,
858 root_owner,
859 root_gen, inode->i_ino,
860 found_key.offset, 0);
861 BUG_ON(ret);
862 }
863 }
864 ret = 0;
865 error:
866 btrfs_release_path(root, path);
867 btrfs_free_path(path);
868 inode->i_sb->s_dirt = 1;
869 return ret;
870 }
871
872 static int btrfs_cow_one_page(struct inode *inode, struct page *page,
873 size_t zero_start)
874 {
875 char *kaddr;
876 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
877 struct btrfs_root *root = BTRFS_I(inode)->root;
878 u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
879 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
880 u64 existing_delalloc;
881 u64 delalloc_start;
882 int ret = 0;
883
884 WARN_ON(!PageLocked(page));
885 set_page_extent_mapped(page);
886
887 lock_extent(em_tree, page_start, page_end, GFP_NOFS);
888 delalloc_start = page_start;
889 existing_delalloc = count_range_bits(&BTRFS_I(inode)->extent_tree,
890 &delalloc_start, page_end,
891 PAGE_CACHE_SIZE, EXTENT_DELALLOC);
892 set_extent_delalloc(&BTRFS_I(inode)->extent_tree, page_start,
893 page_end, GFP_NOFS);
894
895 spin_lock(&root->fs_info->delalloc_lock);
896 root->fs_info->delalloc_bytes += PAGE_CACHE_SIZE - existing_delalloc;
897 spin_unlock(&root->fs_info->delalloc_lock);
898
899 if (zero_start != PAGE_CACHE_SIZE) {
900 kaddr = kmap(page);
901 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
902 flush_dcache_page(page);
903 kunmap(page);
904 }
905 set_page_dirty(page);
906 unlock_extent(em_tree, page_start, page_end, GFP_NOFS);
907
908 return ret;
909 }
910
911 /*
912 * taken from block_truncate_page, but does cow as it zeros out
913 * any bytes left in the last page in the file.
914 */
915 static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
916 {
917 struct inode *inode = mapping->host;
918 struct btrfs_root *root = BTRFS_I(inode)->root;
919 u32 blocksize = root->sectorsize;
920 pgoff_t index = from >> PAGE_CACHE_SHIFT;
921 unsigned offset = from & (PAGE_CACHE_SIZE-1);
922 struct page *page;
923 int ret = 0;
924 u64 page_start;
925
926 if ((offset & (blocksize - 1)) == 0)
927 goto out;
928
929 ret = -ENOMEM;
930 page = grab_cache_page(mapping, index);
931 if (!page)
932 goto out;
933 if (!PageUptodate(page)) {
934 ret = btrfs_readpage(NULL, page);
935 lock_page(page);
936 if (!PageUptodate(page)) {
937 ret = -EIO;
938 goto out;
939 }
940 }
941 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
942
943 ret = btrfs_cow_one_page(inode, page, offset);
944
945 unlock_page(page);
946 page_cache_release(page);
947 out:
948 return ret;
949 }
950
951 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
952 {
953 struct inode *inode = dentry->d_inode;
954 int err;
955
956 err = inode_change_ok(inode, attr);
957 if (err)
958 return err;
959
960 if (S_ISREG(inode->i_mode) &&
961 attr->ia_valid & ATTR_SIZE && attr->ia_size > inode->i_size) {
962 struct btrfs_trans_handle *trans;
963 struct btrfs_root *root = BTRFS_I(inode)->root;
964 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
965
966 u64 mask = root->sectorsize - 1;
967 u64 pos = (inode->i_size + mask) & ~mask;
968 u64 block_end = attr->ia_size | mask;
969 u64 hole_start;
970 u64 hole_size;
971 u64 alloc_hint = 0;
972
973 if (attr->ia_size <= pos)
974 goto out;
975
976 if (pos != inode->i_size)
977 hole_start = pos + root->sectorsize;
978 else
979 hole_start = pos;
980
981 mutex_lock(&root->fs_info->fs_mutex);
982 err = btrfs_check_free_space(root, 1, 0);
983 mutex_unlock(&root->fs_info->fs_mutex);
984 if (err)
985 goto fail;
986
987 btrfs_truncate_page(inode->i_mapping, inode->i_size);
988
989 lock_extent(em_tree, pos, block_end, GFP_NOFS);
990 hole_size = block_end - hole_start;
991
992 mutex_lock(&root->fs_info->fs_mutex);
993 trans = btrfs_start_transaction(root, 1);
994 btrfs_set_trans_block_group(trans, inode);
995 err = btrfs_drop_extents(trans, root, inode,
996 pos, block_end, pos,
997 &alloc_hint);
998
999 if (alloc_hint != EXTENT_MAP_INLINE) {
1000 err = btrfs_insert_file_extent(trans, root,
1001 inode->i_ino,
1002 hole_start, 0, 0,
1003 hole_size);
1004 btrfs_check_file(root, inode);
1005 }
1006 btrfs_end_transaction(trans, root);
1007 mutex_unlock(&root->fs_info->fs_mutex);
1008 unlock_extent(em_tree, pos, block_end, GFP_NOFS);
1009 if (err)
1010 return err;
1011 }
1012 out:
1013 err = inode_setattr(inode, attr);
1014 fail:
1015 return err;
1016 }
1017
1018 void btrfs_put_inode(struct inode *inode)
1019 {
1020 int ret;
1021
1022 if (!BTRFS_I(inode)->ordered_trans) {
1023 return;
1024 }
1025
1026 if (mapping_tagged(inode->i_mapping, PAGECACHE_TAG_DIRTY) ||
1027 mapping_tagged(inode->i_mapping, PAGECACHE_TAG_WRITEBACK))
1028 return;
1029
1030 ret = btrfs_del_ordered_inode(inode);
1031 if (ret == 1) {
1032 atomic_dec(&inode->i_count);
1033 }
1034 }
1035
1036 void btrfs_delete_inode(struct inode *inode)
1037 {
1038 struct btrfs_trans_handle *trans;
1039 struct btrfs_root *root = BTRFS_I(inode)->root;
1040 unsigned long nr;
1041 int ret;
1042
1043 truncate_inode_pages(&inode->i_data, 0);
1044 if (is_bad_inode(inode)) {
1045 goto no_delete;
1046 }
1047
1048 inode->i_size = 0;
1049 mutex_lock(&root->fs_info->fs_mutex);
1050 trans = btrfs_start_transaction(root, 1);
1051
1052 btrfs_set_trans_block_group(trans, inode);
1053 ret = btrfs_truncate_in_trans(trans, root, inode);
1054 if (ret)
1055 goto no_delete_lock;
1056 ret = btrfs_delete_xattrs(trans, root, inode);
1057 if (ret)
1058 goto no_delete_lock;
1059 ret = btrfs_free_inode(trans, root, inode);
1060 if (ret)
1061 goto no_delete_lock;
1062 nr = trans->blocks_used;
1063
1064 btrfs_end_transaction(trans, root);
1065 mutex_unlock(&root->fs_info->fs_mutex);
1066 btrfs_btree_balance_dirty(root, nr);
1067 btrfs_throttle(root);
1068 return;
1069
1070 no_delete_lock:
1071 nr = trans->blocks_used;
1072 btrfs_end_transaction(trans, root);
1073 mutex_unlock(&root->fs_info->fs_mutex);
1074 btrfs_btree_balance_dirty(root, nr);
1075 btrfs_throttle(root);
1076 no_delete:
1077 clear_inode(inode);
1078 }
1079
1080 /*
1081 * this returns the key found in the dir entry in the location pointer.
1082 * If no dir entries were found, location->objectid is 0.
1083 */
1084 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
1085 struct btrfs_key *location)
1086 {
1087 const char *name = dentry->d_name.name;
1088 int namelen = dentry->d_name.len;
1089 struct btrfs_dir_item *di;
1090 struct btrfs_path *path;
1091 struct btrfs_root *root = BTRFS_I(dir)->root;
1092 int ret = 0;
1093
1094 if (namelen == 1 && strcmp(name, ".") == 0) {
1095 location->objectid = dir->i_ino;
1096 location->type = BTRFS_INODE_ITEM_KEY;
1097 location->offset = 0;
1098 return 0;
1099 }
1100 path = btrfs_alloc_path();
1101 BUG_ON(!path);
1102
1103 if (namelen == 2 && strcmp(name, "..") == 0) {
1104 struct btrfs_key key;
1105 struct extent_buffer *leaf;
1106 u32 nritems;
1107 int slot;
1108
1109 key.objectid = dir->i_ino;
1110 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
1111 key.offset = 0;
1112 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1113 BUG_ON(ret == 0);
1114 ret = 0;
1115
1116 leaf = path->nodes[0];
1117 slot = path->slots[0];
1118 nritems = btrfs_header_nritems(leaf);
1119 if (slot >= nritems)
1120 goto out_err;
1121
1122 btrfs_item_key_to_cpu(leaf, &key, slot);
1123 if (key.objectid != dir->i_ino ||
1124 key.type != BTRFS_INODE_REF_KEY) {
1125 goto out_err;
1126 }
1127 location->objectid = key.offset;
1128 location->type = BTRFS_INODE_ITEM_KEY;
1129 location->offset = 0;
1130 goto out;
1131 }
1132
1133 di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
1134 namelen, 0);
1135 if (IS_ERR(di))
1136 ret = PTR_ERR(di);
1137 if (!di || IS_ERR(di)) {
1138 goto out_err;
1139 }
1140 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
1141 out:
1142 btrfs_free_path(path);
1143 return ret;
1144 out_err:
1145 location->objectid = 0;
1146 goto out;
1147 }
1148
1149 /*
1150 * when we hit a tree root in a directory, the btrfs part of the inode
1151 * needs to be changed to reflect the root directory of the tree root. This
1152 * is kind of like crossing a mount point.
1153 */
1154 static int fixup_tree_root_location(struct btrfs_root *root,
1155 struct btrfs_key *location,
1156 struct btrfs_root **sub_root,
1157 struct dentry *dentry)
1158 {
1159 struct btrfs_path *path;
1160 struct btrfs_root_item *ri;
1161
1162 if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY)
1163 return 0;
1164 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1165 return 0;
1166
1167 path = btrfs_alloc_path();
1168 BUG_ON(!path);
1169 mutex_lock(&root->fs_info->fs_mutex);
1170
1171 *sub_root = btrfs_read_fs_root(root->fs_info, location,
1172 dentry->d_name.name,
1173 dentry->d_name.len);
1174 if (IS_ERR(*sub_root))
1175 return PTR_ERR(*sub_root);
1176
1177 ri = &(*sub_root)->root_item;
1178 location->objectid = btrfs_root_dirid(ri);
1179 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
1180 location->offset = 0;
1181
1182 btrfs_free_path(path);
1183 mutex_unlock(&root->fs_info->fs_mutex);
1184 return 0;
1185 }
1186
1187 static int btrfs_init_locked_inode(struct inode *inode, void *p)
1188 {
1189 struct btrfs_iget_args *args = p;
1190 inode->i_ino = args->ino;
1191 BTRFS_I(inode)->root = args->root;
1192 extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
1193 inode->i_mapping, GFP_NOFS);
1194 return 0;
1195 }
1196
1197 static int btrfs_find_actor(struct inode *inode, void *opaque)
1198 {
1199 struct btrfs_iget_args *args = opaque;
1200 return (args->ino == inode->i_ino &&
1201 args->root == BTRFS_I(inode)->root);
1202 }
1203
1204 struct inode *btrfs_ilookup(struct super_block *s, u64 objectid,
1205 u64 root_objectid)
1206 {
1207 struct btrfs_iget_args args;
1208 args.ino = objectid;
1209 args.root = btrfs_lookup_fs_root(btrfs_sb(s)->fs_info, root_objectid);
1210
1211 if (!args.root)
1212 return NULL;
1213
1214 return ilookup5(s, objectid, btrfs_find_actor, (void *)&args);
1215 }
1216
1217 struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
1218 struct btrfs_root *root)
1219 {
1220 struct inode *inode;
1221 struct btrfs_iget_args args;
1222 args.ino = objectid;
1223 args.root = root;
1224
1225 inode = iget5_locked(s, objectid, btrfs_find_actor,
1226 btrfs_init_locked_inode,
1227 (void *)&args);
1228 return inode;
1229 }
1230
1231 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
1232 struct nameidata *nd)
1233 {
1234 struct inode * inode;
1235 struct btrfs_inode *bi = BTRFS_I(dir);
1236 struct btrfs_root *root = bi->root;
1237 struct btrfs_root *sub_root = root;
1238 struct btrfs_key location;
1239 int ret;
1240
1241 if (dentry->d_name.len > BTRFS_NAME_LEN)
1242 return ERR_PTR(-ENAMETOOLONG);
1243
1244 mutex_lock(&root->fs_info->fs_mutex);
1245 ret = btrfs_inode_by_name(dir, dentry, &location);
1246 mutex_unlock(&root->fs_info->fs_mutex);
1247
1248 if (ret < 0)
1249 return ERR_PTR(ret);
1250
1251 inode = NULL;
1252 if (location.objectid) {
1253 ret = fixup_tree_root_location(root, &location, &sub_root,
1254 dentry);
1255 if (ret < 0)
1256 return ERR_PTR(ret);
1257 if (ret > 0)
1258 return ERR_PTR(-ENOENT);
1259 inode = btrfs_iget_locked(dir->i_sb, location.objectid,
1260 sub_root);
1261 if (!inode)
1262 return ERR_PTR(-EACCES);
1263 if (inode->i_state & I_NEW) {
1264 /* the inode and parent dir are two different roots */
1265 if (sub_root != root) {
1266 igrab(inode);
1267 sub_root->inode = inode;
1268 }
1269 BTRFS_I(inode)->root = sub_root;
1270 memcpy(&BTRFS_I(inode)->location, &location,
1271 sizeof(location));
1272 btrfs_read_locked_inode(inode);
1273 unlock_new_inode(inode);
1274 }
1275 }
1276 return d_splice_alias(inode, dentry);
1277 }
1278
1279 static unsigned char btrfs_filetype_table[] = {
1280 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
1281 };
1282
1283 static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
1284 {
1285 struct inode *inode = filp->f_dentry->d_inode;
1286 struct btrfs_root *root = BTRFS_I(inode)->root;
1287 struct btrfs_item *item;
1288 struct btrfs_dir_item *di;
1289 struct btrfs_key key;
1290 struct btrfs_key found_key;
1291 struct btrfs_path *path;
1292 int ret;
1293 u32 nritems;
1294 struct extent_buffer *leaf;
1295 int slot;
1296 int advance;
1297 unsigned char d_type;
1298 int over = 0;
1299 u32 di_cur;
1300 u32 di_total;
1301 u32 di_len;
1302 int key_type = BTRFS_DIR_INDEX_KEY;
1303 char tmp_name[32];
1304 char *name_ptr;
1305 int name_len;
1306
1307 /* FIXME, use a real flag for deciding about the key type */
1308 if (root->fs_info->tree_root == root)
1309 key_type = BTRFS_DIR_ITEM_KEY;
1310
1311 /* special case for "." */
1312 if (filp->f_pos == 0) {
1313 over = filldir(dirent, ".", 1,
1314 1, inode->i_ino,
1315 DT_DIR);
1316 if (over)
1317 return 0;
1318 filp->f_pos = 1;
1319 }
1320
1321 mutex_lock(&root->fs_info->fs_mutex);
1322 key.objectid = inode->i_ino;
1323 path = btrfs_alloc_path();
1324 path->reada = 2;
1325
1326 /* special case for .., just use the back ref */
1327 if (filp->f_pos == 1) {
1328 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
1329 key.offset = 0;
1330 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1331 BUG_ON(ret == 0);
1332 leaf = path->nodes[0];
1333 slot = path->slots[0];
1334 nritems = btrfs_header_nritems(leaf);
1335 if (slot >= nritems) {
1336 btrfs_release_path(root, path);
1337 goto read_dir_items;
1338 }
1339 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1340 btrfs_release_path(root, path);
1341 if (found_key.objectid != key.objectid ||
1342 found_key.type != BTRFS_INODE_REF_KEY)
1343 goto read_dir_items;
1344 over = filldir(dirent, "..", 2,
1345 2, found_key.offset, DT_DIR);
1346 if (over)
1347 goto nopos;
1348 filp->f_pos = 2;
1349 }
1350
1351 read_dir_items:
1352 btrfs_set_key_type(&key, key_type);
1353 key.offset = filp->f_pos;
1354
1355 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1356 if (ret < 0)
1357 goto err;
1358 advance = 0;
1359 while(1) {
1360 leaf = path->nodes[0];
1361 nritems = btrfs_header_nritems(leaf);
1362 slot = path->slots[0];
1363 if (advance || slot >= nritems) {
1364 if (slot >= nritems -1) {
1365 ret = btrfs_next_leaf(root, path);
1366 if (ret)
1367 break;
1368 leaf = path->nodes[0];
1369 nritems = btrfs_header_nritems(leaf);
1370 slot = path->slots[0];
1371 } else {
1372 slot++;
1373 path->slots[0]++;
1374 }
1375 }
1376 advance = 1;
1377 item = btrfs_item_nr(leaf, slot);
1378 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1379
1380 if (found_key.objectid != key.objectid)
1381 break;
1382 if (btrfs_key_type(&found_key) != key_type)
1383 break;
1384 if (found_key.offset < filp->f_pos)
1385 continue;
1386
1387 filp->f_pos = found_key.offset;
1388 advance = 1;
1389 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
1390 di_cur = 0;
1391 di_total = btrfs_item_size(leaf, item);
1392 while(di_cur < di_total) {
1393 struct btrfs_key location;
1394
1395 name_len = btrfs_dir_name_len(leaf, di);
1396 if (name_len < 32) {
1397 name_ptr = tmp_name;
1398 } else {
1399 name_ptr = kmalloc(name_len, GFP_NOFS);
1400 BUG_ON(!name_ptr);
1401 }
1402 read_extent_buffer(leaf, name_ptr,
1403 (unsigned long)(di + 1), name_len);
1404
1405 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
1406 btrfs_dir_item_key_to_cpu(leaf, di, &location);
1407 over = filldir(dirent, name_ptr, name_len,
1408 found_key.offset,
1409 location.objectid,
1410 d_type);
1411
1412 if (name_ptr != tmp_name)
1413 kfree(name_ptr);
1414
1415 if (over)
1416 goto nopos;
1417 di_len = btrfs_dir_name_len(leaf, di) +
1418 btrfs_dir_data_len(leaf, di) +sizeof(*di);
1419 di_cur += di_len;
1420 di = (struct btrfs_dir_item *)((char *)di + di_len);
1421 }
1422 }
1423 filp->f_pos++;
1424 nopos:
1425 ret = 0;
1426 err:
1427 btrfs_release_path(root, path);
1428 btrfs_free_path(path);
1429 mutex_unlock(&root->fs_info->fs_mutex);
1430 return ret;
1431 }
1432
1433 int btrfs_write_inode(struct inode *inode, int wait)
1434 {
1435 struct btrfs_root *root = BTRFS_I(inode)->root;
1436 struct btrfs_trans_handle *trans;
1437 int ret = 0;
1438
1439 if (wait) {
1440 mutex_lock(&root->fs_info->fs_mutex);
1441 trans = btrfs_start_transaction(root, 1);
1442 btrfs_set_trans_block_group(trans, inode);
1443 ret = btrfs_commit_transaction(trans, root);
1444 mutex_unlock(&root->fs_info->fs_mutex);
1445 }
1446 return ret;
1447 }
1448
1449 /*
1450 * This is somewhat expensive, updating the tree every time the
1451 * inode changes. But, it is most likely to find the inode in cache.
1452 * FIXME, needs more benchmarking...there are no reasons other than performance
1453 * to keep or drop this code.
1454 */
1455 void btrfs_dirty_inode(struct inode *inode)
1456 {
1457 struct btrfs_root *root = BTRFS_I(inode)->root;
1458 struct btrfs_trans_handle *trans;
1459
1460 mutex_lock(&root->fs_info->fs_mutex);
1461 trans = btrfs_start_transaction(root, 1);
1462 btrfs_set_trans_block_group(trans, inode);
1463 btrfs_update_inode(trans, root, inode);
1464 btrfs_end_transaction(trans, root);
1465 mutex_unlock(&root->fs_info->fs_mutex);
1466 }
1467
1468 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
1469 struct btrfs_root *root,
1470 u64 objectid,
1471 struct btrfs_block_group_cache *group,
1472 int mode)
1473 {
1474 struct inode *inode;
1475 struct btrfs_inode_item *inode_item;
1476 struct btrfs_key *location;
1477 struct btrfs_path *path;
1478 int ret;
1479 int owner;
1480
1481 path = btrfs_alloc_path();
1482 BUG_ON(!path);
1483
1484 inode = new_inode(root->fs_info->sb);
1485 if (!inode)
1486 return ERR_PTR(-ENOMEM);
1487
1488 extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
1489 inode->i_mapping, GFP_NOFS);
1490 BTRFS_I(inode)->root = root;
1491
1492 if (mode & S_IFDIR)
1493 owner = 0;
1494 else
1495 owner = 1;
1496 group = btrfs_find_block_group(root, group, 0, 0, owner);
1497 BTRFS_I(inode)->block_group = group;
1498 BTRFS_I(inode)->flags = 0;
1499 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
1500 if (ret)
1501 goto fail;
1502
1503 inode->i_uid = current->fsuid;
1504 inode->i_gid = current->fsgid;
1505 inode->i_mode = mode;
1506 inode->i_ino = objectid;
1507 inode->i_blocks = 0;
1508 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1509 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1510 struct btrfs_inode_item);
1511 fill_inode_item(path->nodes[0], inode_item, inode);
1512 btrfs_mark_buffer_dirty(path->nodes[0]);
1513 btrfs_free_path(path);
1514
1515 location = &BTRFS_I(inode)->location;
1516 location->objectid = objectid;
1517 location->offset = 0;
1518 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
1519
1520 insert_inode_hash(inode);
1521 return inode;
1522 fail:
1523 btrfs_free_path(path);
1524 return ERR_PTR(ret);
1525 }
1526
1527 static inline u8 btrfs_inode_type(struct inode *inode)
1528 {
1529 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
1530 }
1531
1532 static int btrfs_add_link(struct btrfs_trans_handle *trans,
1533 struct dentry *dentry, struct inode *inode)
1534 {
1535 int ret;
1536 struct btrfs_key key;
1537 struct btrfs_root *root = BTRFS_I(dentry->d_parent->d_inode)->root;
1538 struct inode *parent_inode;
1539
1540 key.objectid = inode->i_ino;
1541 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
1542 key.offset = 0;
1543
1544 ret = btrfs_insert_dir_item(trans, root,
1545 dentry->d_name.name, dentry->d_name.len,
1546 dentry->d_parent->d_inode->i_ino,
1547 &key, btrfs_inode_type(inode));
1548 if (ret == 0) {
1549 ret = btrfs_insert_inode_ref(trans, root,
1550 dentry->d_name.name,
1551 dentry->d_name.len,
1552 inode->i_ino,
1553 dentry->d_parent->d_inode->i_ino);
1554 parent_inode = dentry->d_parent->d_inode;
1555 parent_inode->i_size += dentry->d_name.len * 2;
1556 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
1557 ret = btrfs_update_inode(trans, root,
1558 dentry->d_parent->d_inode);
1559 }
1560 return ret;
1561 }
1562
1563 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
1564 struct dentry *dentry, struct inode *inode)
1565 {
1566 int err = btrfs_add_link(trans, dentry, inode);
1567 if (!err) {
1568 d_instantiate(dentry, inode);
1569 return 0;
1570 }
1571 if (err > 0)
1572 err = -EEXIST;
1573 return err;
1574 }
1575
1576 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
1577 int mode, dev_t rdev)
1578 {
1579 struct btrfs_trans_handle *trans;
1580 struct btrfs_root *root = BTRFS_I(dir)->root;
1581 struct inode *inode = NULL;
1582 int err;
1583 int drop_inode = 0;
1584 u64 objectid;
1585 unsigned long nr = 0;
1586
1587 if (!new_valid_dev(rdev))
1588 return -EINVAL;
1589
1590 mutex_lock(&root->fs_info->fs_mutex);
1591 err = btrfs_check_free_space(root, 1, 0);
1592 if (err)
1593 goto fail;
1594
1595 trans = btrfs_start_transaction(root, 1);
1596 btrfs_set_trans_block_group(trans, dir);
1597
1598 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1599 if (err) {
1600 err = -ENOSPC;
1601 goto out_unlock;
1602 }
1603
1604 inode = btrfs_new_inode(trans, root, objectid,
1605 BTRFS_I(dir)->block_group, mode);
1606 err = PTR_ERR(inode);
1607 if (IS_ERR(inode))
1608 goto out_unlock;
1609
1610 btrfs_set_trans_block_group(trans, inode);
1611 err = btrfs_add_nondir(trans, dentry, inode);
1612 if (err)
1613 drop_inode = 1;
1614 else {
1615 inode->i_op = &btrfs_special_inode_operations;
1616 init_special_inode(inode, inode->i_mode, rdev);
1617 btrfs_update_inode(trans, root, inode);
1618 }
1619 dir->i_sb->s_dirt = 1;
1620 btrfs_update_inode_block_group(trans, inode);
1621 btrfs_update_inode_block_group(trans, dir);
1622 out_unlock:
1623 nr = trans->blocks_used;
1624 btrfs_end_transaction(trans, root);
1625 fail:
1626 mutex_unlock(&root->fs_info->fs_mutex);
1627
1628 if (drop_inode) {
1629 inode_dec_link_count(inode);
1630 iput(inode);
1631 }
1632 btrfs_btree_balance_dirty(root, nr);
1633 btrfs_throttle(root);
1634 return err;
1635 }
1636
1637 static int btrfs_create(struct inode *dir, struct dentry *dentry,
1638 int mode, struct nameidata *nd)
1639 {
1640 struct btrfs_trans_handle *trans;
1641 struct btrfs_root *root = BTRFS_I(dir)->root;
1642 struct inode *inode = NULL;
1643 int err;
1644 int drop_inode = 0;
1645 unsigned long nr = 0;
1646 u64 objectid;
1647
1648 mutex_lock(&root->fs_info->fs_mutex);
1649 err = btrfs_check_free_space(root, 1, 0);
1650 if (err)
1651 goto fail;
1652 trans = btrfs_start_transaction(root, 1);
1653 btrfs_set_trans_block_group(trans, dir);
1654
1655 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1656 if (err) {
1657 err = -ENOSPC;
1658 goto out_unlock;
1659 }
1660
1661 inode = btrfs_new_inode(trans, root, objectid,
1662 BTRFS_I(dir)->block_group, mode);
1663 err = PTR_ERR(inode);
1664 if (IS_ERR(inode))
1665 goto out_unlock;
1666
1667 btrfs_set_trans_block_group(trans, inode);
1668 err = btrfs_add_nondir(trans, dentry, inode);
1669 if (err)
1670 drop_inode = 1;
1671 else {
1672 inode->i_mapping->a_ops = &btrfs_aops;
1673 inode->i_fop = &btrfs_file_operations;
1674 inode->i_op = &btrfs_file_inode_operations;
1675 extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
1676 inode->i_mapping, GFP_NOFS);
1677 BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
1678 }
1679 dir->i_sb->s_dirt = 1;
1680 btrfs_update_inode_block_group(trans, inode);
1681 btrfs_update_inode_block_group(trans, dir);
1682 out_unlock:
1683 nr = trans->blocks_used;
1684 btrfs_end_transaction(trans, root);
1685 fail:
1686 mutex_unlock(&root->fs_info->fs_mutex);
1687
1688 if (drop_inode) {
1689 inode_dec_link_count(inode);
1690 iput(inode);
1691 }
1692 btrfs_btree_balance_dirty(root, nr);
1693 btrfs_throttle(root);
1694 return err;
1695 }
1696
1697 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
1698 struct dentry *dentry)
1699 {
1700 struct btrfs_trans_handle *trans;
1701 struct btrfs_root *root = BTRFS_I(dir)->root;
1702 struct inode *inode = old_dentry->d_inode;
1703 unsigned long nr = 0;
1704 int err;
1705 int drop_inode = 0;
1706
1707 if (inode->i_nlink == 0)
1708 return -ENOENT;
1709
1710 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
1711 inode->i_nlink++;
1712 #else
1713 inc_nlink(inode);
1714 #endif
1715 mutex_lock(&root->fs_info->fs_mutex);
1716 err = btrfs_check_free_space(root, 1, 0);
1717 if (err)
1718 goto fail;
1719 trans = btrfs_start_transaction(root, 1);
1720
1721 btrfs_set_trans_block_group(trans, dir);
1722 atomic_inc(&inode->i_count);
1723 err = btrfs_add_nondir(trans, dentry, inode);
1724
1725 if (err)
1726 drop_inode = 1;
1727
1728 dir->i_sb->s_dirt = 1;
1729 btrfs_update_inode_block_group(trans, dir);
1730 err = btrfs_update_inode(trans, root, inode);
1731
1732 if (err)
1733 drop_inode = 1;
1734
1735 nr = trans->blocks_used;
1736 btrfs_end_transaction(trans, root);
1737 fail:
1738 mutex_unlock(&root->fs_info->fs_mutex);
1739
1740 if (drop_inode) {
1741 inode_dec_link_count(inode);
1742 iput(inode);
1743 }
1744 btrfs_btree_balance_dirty(root, nr);
1745 btrfs_throttle(root);
1746 return err;
1747 }
1748
1749 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1750 {
1751 struct inode *inode;
1752 struct btrfs_trans_handle *trans;
1753 struct btrfs_root *root = BTRFS_I(dir)->root;
1754 int err = 0;
1755 int drop_on_err = 0;
1756 u64 objectid;
1757 unsigned long nr = 1;
1758
1759 mutex_lock(&root->fs_info->fs_mutex);
1760 err = btrfs_check_free_space(root, 1, 0);
1761 if (err)
1762 goto out_unlock;
1763
1764 trans = btrfs_start_transaction(root, 1);
1765 btrfs_set_trans_block_group(trans, dir);
1766
1767 if (IS_ERR(trans)) {
1768 err = PTR_ERR(trans);
1769 goto out_unlock;
1770 }
1771
1772 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1773 if (err) {
1774 err = -ENOSPC;
1775 goto out_unlock;
1776 }
1777
1778 inode = btrfs_new_inode(trans, root, objectid,
1779 BTRFS_I(dir)->block_group, S_IFDIR | mode);
1780 if (IS_ERR(inode)) {
1781 err = PTR_ERR(inode);
1782 goto out_fail;
1783 }
1784
1785 drop_on_err = 1;
1786 inode->i_op = &btrfs_dir_inode_operations;
1787 inode->i_fop = &btrfs_dir_file_operations;
1788 btrfs_set_trans_block_group(trans, inode);
1789
1790 inode->i_size = 0;
1791 err = btrfs_update_inode(trans, root, inode);
1792 if (err)
1793 goto out_fail;
1794
1795 err = btrfs_add_link(trans, dentry, inode);
1796 if (err)
1797 goto out_fail;
1798
1799 d_instantiate(dentry, inode);
1800 drop_on_err = 0;
1801 dir->i_sb->s_dirt = 1;
1802 btrfs_update_inode_block_group(trans, inode);
1803 btrfs_update_inode_block_group(trans, dir);
1804
1805 out_fail:
1806 nr = trans->blocks_used;
1807 btrfs_end_transaction(trans, root);
1808
1809 out_unlock:
1810 mutex_unlock(&root->fs_info->fs_mutex);
1811 if (drop_on_err)
1812 iput(inode);
1813 btrfs_btree_balance_dirty(root, nr);
1814 btrfs_throttle(root);
1815 return err;
1816 }
1817
1818 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
1819 size_t page_offset, u64 start, u64 end,
1820 int create)
1821 {
1822 int ret;
1823 int err = 0;
1824 u64 bytenr;
1825 u64 extent_start = 0;
1826 u64 extent_end = 0;
1827 u64 objectid = inode->i_ino;
1828 u32 found_type;
1829 int failed_insert = 0;
1830 struct btrfs_path *path;
1831 struct btrfs_root *root = BTRFS_I(inode)->root;
1832 struct btrfs_file_extent_item *item;
1833 struct extent_buffer *leaf;
1834 struct btrfs_key found_key;
1835 struct extent_map *em = NULL;
1836 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1837 struct btrfs_trans_handle *trans = NULL;
1838
1839 path = btrfs_alloc_path();
1840 BUG_ON(!path);
1841 mutex_lock(&root->fs_info->fs_mutex);
1842
1843 again:
1844 em = lookup_extent_mapping(em_tree, start, end);
1845 if (em) {
1846 if (em->start > start) {
1847 printk("get_extent start %Lu em start %Lu\n",
1848 start, em->start);
1849 WARN_ON(1);
1850 }
1851 goto out;
1852 }
1853 if (!em) {
1854 em = alloc_extent_map(GFP_NOFS);
1855 if (!em) {
1856 err = -ENOMEM;
1857 goto out;
1858 }
1859 em->start = EXTENT_MAP_HOLE;
1860 em->end = EXTENT_MAP_HOLE;
1861 }
1862 em->bdev = inode->i_sb->s_bdev;
1863 ret = btrfs_lookup_file_extent(trans, root, path,
1864 objectid, start, trans != NULL);
1865 if (ret < 0) {
1866 err = ret;
1867 goto out;
1868 }
1869
1870 if (ret != 0) {
1871 if (path->slots[0] == 0)
1872 goto not_found;
1873 path->slots[0]--;
1874 }
1875
1876 leaf = path->nodes[0];
1877 item = btrfs_item_ptr(leaf, path->slots[0],
1878 struct btrfs_file_extent_item);
1879 /* are we inside the extent that was found? */
1880 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1881 found_type = btrfs_key_type(&found_key);
1882 if (found_key.objectid != objectid ||
1883 found_type != BTRFS_EXTENT_DATA_KEY) {
1884 goto not_found;
1885 }
1886
1887 found_type = btrfs_file_extent_type(leaf, item);
1888 extent_start = found_key.offset;
1889 if (found_type == BTRFS_FILE_EXTENT_REG) {
1890 extent_end = extent_start +
1891 btrfs_file_extent_num_bytes(leaf, item);
1892 err = 0;
1893 if (start < extent_start || start >= extent_end) {
1894 em->start = start;
1895 if (start < extent_start) {
1896 if (end < extent_start)
1897 goto not_found;
1898 em->end = extent_end - 1;
1899 } else {
1900 em->end = end;
1901 }
1902 goto not_found_em;
1903 }
1904 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
1905 if (bytenr == 0) {
1906 em->start = extent_start;
1907 em->end = extent_end - 1;
1908 em->block_start = EXTENT_MAP_HOLE;
1909 em->block_end = EXTENT_MAP_HOLE;
1910 goto insert;
1911 }
1912 bytenr += btrfs_file_extent_offset(leaf, item);
1913 em->block_start = bytenr;
1914 em->block_end = em->block_start +
1915 btrfs_file_extent_num_bytes(leaf, item) - 1;
1916 em->start = extent_start;
1917 em->end = extent_end - 1;
1918 goto insert;
1919 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
1920 unsigned long ptr;
1921 char *map;
1922 size_t size;
1923 size_t extent_offset;
1924 size_t copy_size;
1925
1926 size = btrfs_file_extent_inline_len(leaf, btrfs_item_nr(leaf,
1927 path->slots[0]));
1928 extent_end = (extent_start + size - 1) |
1929 ((u64)root->sectorsize - 1);
1930 if (start < extent_start || start >= extent_end) {
1931 em->start = start;
1932 if (start < extent_start) {
1933 if (end < extent_start)
1934 goto not_found;
1935 em->end = extent_end;
1936 } else {
1937 em->end = end;
1938 }
1939 goto not_found_em;
1940 }
1941 em->block_start = EXTENT_MAP_INLINE;
1942 em->block_end = EXTENT_MAP_INLINE;
1943
1944 if (!page) {
1945 em->start = extent_start;
1946 em->end = extent_start + size - 1;
1947 goto out;
1948 }
1949
1950 extent_offset = ((u64)page->index << PAGE_CACHE_SHIFT) -
1951 extent_start + page_offset;
1952 copy_size = min_t(u64, PAGE_CACHE_SIZE - page_offset,
1953 size - extent_offset);
1954 em->start = extent_start + extent_offset;
1955 em->end = (em->start + copy_size -1) |
1956 ((u64)root->sectorsize -1);
1957 map = kmap(page);
1958 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
1959 if (create == 0 && !PageUptodate(page)) {
1960 read_extent_buffer(leaf, map + page_offset, ptr,
1961 copy_size);
1962 flush_dcache_page(page);
1963 } else if (create && PageUptodate(page)) {
1964 if (!trans) {
1965 kunmap(page);
1966 free_extent_map(em);
1967 em = NULL;
1968 btrfs_release_path(root, path);
1969 trans = btrfs_start_transaction(root, 1);
1970 goto again;
1971 }
1972 write_extent_buffer(leaf, map + page_offset, ptr,
1973 copy_size);
1974 btrfs_mark_buffer_dirty(leaf);
1975 }
1976 kunmap(page);
1977 set_extent_uptodate(em_tree, em->start, em->end, GFP_NOFS);
1978 goto insert;
1979 } else {
1980 printk("unkknown found_type %d\n", found_type);
1981 WARN_ON(1);
1982 }
1983 not_found:
1984 em->start = start;
1985 em->end = end;
1986 not_found_em:
1987 em->block_start = EXTENT_MAP_HOLE;
1988 em->block_end = EXTENT_MAP_HOLE;
1989 insert:
1990 btrfs_release_path(root, path);
1991 if (em->start > start || em->end < start) {
1992 printk("bad extent! em: [%Lu %Lu] passed [%Lu %Lu]\n", em->start, em->end, start, end);
1993 err = -EIO;
1994 goto out;
1995 }
1996 ret = add_extent_mapping(em_tree, em);
1997 if (ret == -EEXIST) {
1998 free_extent_map(em);
1999 em = NULL;
2000 if (0 && failed_insert == 1) {
2001 btrfs_drop_extent_cache(inode, start, end);
2002 }
2003 failed_insert++;
2004 if (failed_insert > 5) {
2005 printk("failing to insert %Lu %Lu\n", start, end);
2006 err = -EIO;
2007 goto out;
2008 }
2009 goto again;
2010 }
2011 err = 0;
2012 out:
2013 btrfs_free_path(path);
2014 if (trans) {
2015 ret = btrfs_end_transaction(trans, root);
2016 if (!err)
2017 err = ret;
2018 }
2019 mutex_unlock(&root->fs_info->fs_mutex);
2020 if (err) {
2021 free_extent_map(em);
2022 WARN_ON(1);
2023 return ERR_PTR(err);
2024 }
2025 return em;
2026 }
2027
2028 static sector_t btrfs_bmap(struct address_space *mapping, sector_t iblock)
2029 {
2030 return extent_bmap(mapping, iblock, btrfs_get_extent);
2031 }
2032
2033 int btrfs_readpage(struct file *file, struct page *page)
2034 {
2035 struct extent_map_tree *tree;
2036 tree = &BTRFS_I(page->mapping->host)->extent_tree;
2037 return extent_read_full_page(tree, page, btrfs_get_extent);
2038 }
2039
2040 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
2041 {
2042 struct extent_map_tree *tree;
2043
2044
2045 if (current->flags & PF_MEMALLOC) {
2046 redirty_page_for_writepage(wbc, page);
2047 unlock_page(page);
2048 return 0;
2049 }
2050 tree = &BTRFS_I(page->mapping->host)->extent_tree;
2051 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
2052 }
2053
2054 static int btrfs_writepages(struct address_space *mapping,
2055 struct writeback_control *wbc)
2056 {
2057 struct extent_map_tree *tree;
2058 tree = &BTRFS_I(mapping->host)->extent_tree;
2059 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
2060 }
2061
2062 static int
2063 btrfs_readpages(struct file *file, struct address_space *mapping,
2064 struct list_head *pages, unsigned nr_pages)
2065 {
2066 struct extent_map_tree *tree;
2067 tree = &BTRFS_I(mapping->host)->extent_tree;
2068 return extent_readpages(tree, mapping, pages, nr_pages,
2069 btrfs_get_extent);
2070 }
2071
2072 static int btrfs_releasepage(struct page *page, gfp_t unused_gfp_flags)
2073 {
2074 struct extent_map_tree *tree;
2075 int ret;
2076
2077 tree = &BTRFS_I(page->mapping->host)->extent_tree;
2078 ret = try_release_extent_mapping(tree, page);
2079 if (ret == 1) {
2080 ClearPagePrivate(page);
2081 set_page_private(page, 0);
2082 page_cache_release(page);
2083 }
2084 return ret;
2085 }
2086
2087 static void btrfs_invalidatepage(struct page *page, unsigned long offset)
2088 {
2089 struct extent_map_tree *tree;
2090
2091 tree = &BTRFS_I(page->mapping->host)->extent_tree;
2092 extent_invalidatepage(tree, page, offset);
2093 btrfs_releasepage(page, GFP_NOFS);
2094 }
2095
2096 /*
2097 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
2098 * called from a page fault handler when a page is first dirtied. Hence we must
2099 * be careful to check for EOF conditions here. We set the page up correctly
2100 * for a written page which means we get ENOSPC checking when writing into
2101 * holes and correct delalloc and unwritten extent mapping on filesystems that
2102 * support these features.
2103 *
2104 * We are not allowed to take the i_mutex here so we have to play games to
2105 * protect against truncate races as the page could now be beyond EOF. Because
2106 * vmtruncate() writes the inode size before removing pages, once we have the
2107 * page lock we can determine safely if the page is beyond EOF. If it is not
2108 * beyond EOF, then the page is guaranteed safe against truncation until we
2109 * unlock the page.
2110 */
2111 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
2112 {
2113 struct inode *inode = fdentry(vma->vm_file)->d_inode;
2114 struct btrfs_root *root = BTRFS_I(inode)->root;
2115 unsigned long end;
2116 loff_t size;
2117 int ret;
2118 u64 page_start;
2119
2120 mutex_lock(&root->fs_info->fs_mutex);
2121 ret = btrfs_check_free_space(root, PAGE_CACHE_SIZE, 0);
2122 mutex_unlock(&root->fs_info->fs_mutex);
2123 if (ret)
2124 goto out;
2125
2126 ret = -EINVAL;
2127
2128 lock_page(page);
2129 wait_on_page_writeback(page);
2130 size = i_size_read(inode);
2131 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2132
2133 if ((page->mapping != inode->i_mapping) ||
2134 (page_start > size)) {
2135 /* page got truncated out from underneath us */
2136 goto out_unlock;
2137 }
2138
2139 /* page is wholly or partially inside EOF */
2140 if (page_start + PAGE_CACHE_SIZE > size)
2141 end = size & ~PAGE_CACHE_MASK;
2142 else
2143 end = PAGE_CACHE_SIZE;
2144
2145 ret = btrfs_cow_one_page(inode, page, end);
2146
2147 out_unlock:
2148 unlock_page(page);
2149 out:
2150 return ret;
2151 }
2152
2153 static void btrfs_truncate(struct inode *inode)
2154 {
2155 struct btrfs_root *root = BTRFS_I(inode)->root;
2156 int ret;
2157 struct btrfs_trans_handle *trans;
2158 unsigned long nr;
2159
2160 if (!S_ISREG(inode->i_mode))
2161 return;
2162 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
2163 return;
2164
2165 btrfs_truncate_page(inode->i_mapping, inode->i_size);
2166
2167 mutex_lock(&root->fs_info->fs_mutex);
2168 trans = btrfs_start_transaction(root, 1);
2169 btrfs_set_trans_block_group(trans, inode);
2170
2171 /* FIXME, add redo link to tree so we don't leak on crash */
2172 ret = btrfs_truncate_in_trans(trans, root, inode);
2173 btrfs_update_inode(trans, root, inode);
2174 nr = trans->blocks_used;
2175
2176 ret = btrfs_end_transaction(trans, root);
2177 BUG_ON(ret);
2178 mutex_unlock(&root->fs_info->fs_mutex);
2179 btrfs_btree_balance_dirty(root, nr);
2180 btrfs_throttle(root);
2181 }
2182
2183 static int noinline create_subvol(struct btrfs_root *root, char *name,
2184 int namelen)
2185 {
2186 struct btrfs_trans_handle *trans;
2187 struct btrfs_key key;
2188 struct btrfs_root_item root_item;
2189 struct btrfs_inode_item *inode_item;
2190 struct extent_buffer *leaf;
2191 struct btrfs_root *new_root = root;
2192 struct inode *inode;
2193 struct inode *dir;
2194 int ret;
2195 int err;
2196 u64 objectid;
2197 u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
2198 unsigned long nr = 1;
2199
2200 mutex_lock(&root->fs_info->fs_mutex);
2201 ret = btrfs_check_free_space(root, 1, 0);
2202 if (ret)
2203 goto fail_commit;
2204
2205 trans = btrfs_start_transaction(root, 1);
2206 BUG_ON(!trans);
2207
2208 ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
2209 0, &objectid);
2210 if (ret)
2211 goto fail;
2212
2213 leaf = __btrfs_alloc_free_block(trans, root, root->leafsize,
2214 objectid, trans->transid, 0, 0,
2215 0, 0);
2216 if (IS_ERR(leaf))
2217 return PTR_ERR(leaf);
2218
2219 btrfs_set_header_nritems(leaf, 0);
2220 btrfs_set_header_level(leaf, 0);
2221 btrfs_set_header_bytenr(leaf, leaf->start);
2222 btrfs_set_header_generation(leaf, trans->transid);
2223 btrfs_set_header_owner(leaf, objectid);
2224
2225 write_extent_buffer(leaf, root->fs_info->fsid,
2226 (unsigned long)btrfs_header_fsid(leaf),
2227 BTRFS_FSID_SIZE);
2228 btrfs_mark_buffer_dirty(leaf);
2229
2230 inode_item = &root_item.inode;
2231 memset(inode_item, 0, sizeof(*inode_item));
2232 inode_item->generation = cpu_to_le64(1);
2233 inode_item->size = cpu_to_le64(3);
2234 inode_item->nlink = cpu_to_le32(1);
2235 inode_item->nblocks = cpu_to_le64(1);
2236 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
2237
2238 btrfs_set_root_bytenr(&root_item, leaf->start);
2239 btrfs_set_root_level(&root_item, 0);
2240 btrfs_set_root_refs(&root_item, 1);
2241 btrfs_set_root_used(&root_item, 0);
2242
2243 memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
2244 root_item.drop_level = 0;
2245
2246 free_extent_buffer(leaf);
2247 leaf = NULL;
2248
2249 btrfs_set_root_dirid(&root_item, new_dirid);
2250
2251 key.objectid = objectid;
2252 key.offset = 1;
2253 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
2254 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
2255 &root_item);
2256 if (ret)
2257 goto fail;
2258
2259 /*
2260 * insert the directory item
2261 */
2262 key.offset = (u64)-1;
2263 dir = root->fs_info->sb->s_root->d_inode;
2264 ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
2265 name, namelen, dir->i_ino, &key,
2266 BTRFS_FT_DIR);
2267 if (ret)
2268 goto fail;
2269
2270 ret = btrfs_insert_inode_ref(trans, root->fs_info->tree_root,
2271 name, namelen, objectid,
2272 root->fs_info->sb->s_root->d_inode->i_ino);
2273 if (ret)
2274 goto fail;
2275
2276 ret = btrfs_commit_transaction(trans, root);
2277 if (ret)
2278 goto fail_commit;
2279
2280 new_root = btrfs_read_fs_root(root->fs_info, &key, name, namelen);
2281 BUG_ON(!new_root);
2282
2283 trans = btrfs_start_transaction(new_root, 1);
2284 BUG_ON(!trans);
2285
2286 inode = btrfs_new_inode(trans, new_root, new_dirid,
2287 BTRFS_I(dir)->block_group, S_IFDIR | 0700);
2288 if (IS_ERR(inode))
2289 goto fail;
2290 inode->i_op = &btrfs_dir_inode_operations;
2291 inode->i_fop = &btrfs_dir_file_operations;
2292 new_root->inode = inode;
2293
2294 ret = btrfs_insert_inode_ref(trans, new_root, "..", 2, new_dirid,
2295 new_dirid);
2296 inode->i_nlink = 1;
2297 inode->i_size = 0;
2298 ret = btrfs_update_inode(trans, new_root, inode);
2299 if (ret)
2300 goto fail;
2301 fail:
2302 nr = trans->blocks_used;
2303 err = btrfs_commit_transaction(trans, new_root);
2304 if (err && !ret)
2305 ret = err;
2306 fail_commit:
2307 mutex_unlock(&root->fs_info->fs_mutex);
2308 btrfs_btree_balance_dirty(root, nr);
2309 btrfs_throttle(root);
2310 return ret;
2311 }
2312
2313 static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
2314 {
2315 struct btrfs_pending_snapshot *pending_snapshot;
2316 struct btrfs_trans_handle *trans;
2317 int ret;
2318 int err;
2319 unsigned long nr = 0;
2320
2321 if (!root->ref_cows)
2322 return -EINVAL;
2323
2324 mutex_lock(&root->fs_info->fs_mutex);
2325 ret = btrfs_check_free_space(root, 1, 0);
2326 if (ret)
2327 goto fail_unlock;
2328
2329 pending_snapshot = kmalloc(sizeof(*pending_snapshot), GFP_NOFS);
2330 if (!pending_snapshot) {
2331 ret = -ENOMEM;
2332 goto fail_unlock;
2333 }
2334 pending_snapshot->name = kmalloc(namelen + 1, GFP_NOFS);
2335 if (!pending_snapshot->name) {
2336 ret = -ENOMEM;
2337 kfree(pending_snapshot);
2338 goto fail_unlock;
2339 }
2340 memcpy(pending_snapshot->name, name, namelen);
2341 pending_snapshot->name[namelen] = '\0';
2342 trans = btrfs_start_transaction(root, 1);
2343 BUG_ON(!trans);
2344 pending_snapshot->root = root;
2345 list_add(&pending_snapshot->list,
2346 &trans->transaction->pending_snapshots);
2347 ret = btrfs_update_inode(trans, root, root->inode);
2348 err = btrfs_commit_transaction(trans, root);
2349
2350 fail_unlock:
2351 mutex_unlock(&root->fs_info->fs_mutex);
2352 btrfs_btree_balance_dirty(root, nr);
2353 btrfs_throttle(root);
2354 return ret;
2355 }
2356
2357 unsigned long btrfs_force_ra(struct address_space *mapping,
2358 struct file_ra_state *ra, struct file *file,
2359 pgoff_t offset, pgoff_t last_index)
2360 {
2361 pgoff_t req_size;
2362
2363 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
2364 req_size = last_index - offset + 1;
2365 offset = page_cache_readahead(mapping, ra, file, offset, req_size);
2366 return offset;
2367 #else
2368 req_size = min(last_index - offset + 1, (pgoff_t)128);
2369 page_cache_sync_readahead(mapping, ra, file, offset, req_size);
2370 return offset + req_size;
2371 #endif
2372 }
2373
2374 int btrfs_defrag_file(struct file *file) {
2375 struct inode *inode = fdentry(file)->d_inode;
2376 struct btrfs_root *root = BTRFS_I(inode)->root;
2377 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2378 struct page *page;
2379 unsigned long last_index;
2380 unsigned long ra_index = 0;
2381 u64 page_start;
2382 u64 page_end;
2383 u64 delalloc_start;
2384 u64 existing_delalloc;
2385 unsigned long i;
2386 int ret;
2387
2388 mutex_lock(&root->fs_info->fs_mutex);
2389 ret = btrfs_check_free_space(root, inode->i_size, 0);
2390 mutex_unlock(&root->fs_info->fs_mutex);
2391 if (ret)
2392 return -ENOSPC;
2393
2394 mutex_lock(&inode->i_mutex);
2395 last_index = inode->i_size >> PAGE_CACHE_SHIFT;
2396 for (i = 0; i <= last_index; i++) {
2397 if (i == ra_index) {
2398 ra_index = btrfs_force_ra(inode->i_mapping,
2399 &file->f_ra,
2400 file, ra_index, last_index);
2401 }
2402 page = grab_cache_page(inode->i_mapping, i);
2403 if (!page)
2404 goto out_unlock;
2405 if (!PageUptodate(page)) {
2406 btrfs_readpage(NULL, page);
2407 lock_page(page);
2408 if (!PageUptodate(page)) {
2409 unlock_page(page);
2410 page_cache_release(page);
2411 goto out_unlock;
2412 }
2413 }
2414 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2415 page_end = page_start + PAGE_CACHE_SIZE - 1;
2416
2417 lock_extent(em_tree, page_start, page_end, GFP_NOFS);
2418 delalloc_start = page_start;
2419 existing_delalloc =
2420 count_range_bits(&BTRFS_I(inode)->extent_tree,
2421 &delalloc_start, page_end,
2422 PAGE_CACHE_SIZE, EXTENT_DELALLOC);
2423 set_extent_delalloc(em_tree, page_start,
2424 page_end, GFP_NOFS);
2425
2426 spin_lock(&root->fs_info->delalloc_lock);
2427 root->fs_info->delalloc_bytes += PAGE_CACHE_SIZE -
2428 existing_delalloc;
2429 spin_unlock(&root->fs_info->delalloc_lock);
2430
2431 unlock_extent(em_tree, page_start, page_end, GFP_NOFS);
2432 set_page_dirty(page);
2433 unlock_page(page);
2434 page_cache_release(page);
2435 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
2436 }
2437
2438 out_unlock:
2439 mutex_unlock(&inode->i_mutex);
2440 return 0;
2441 }
2442
2443 static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
2444 {
2445 u64 new_size;
2446 u64 old_size;
2447 struct btrfs_ioctl_vol_args *vol_args;
2448 struct btrfs_trans_handle *trans;
2449 char *sizestr;
2450 int ret = 0;
2451 int namelen;
2452 int mod = 0;
2453
2454 vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
2455
2456 if (!vol_args)
2457 return -ENOMEM;
2458
2459 if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
2460 ret = -EFAULT;
2461 goto out;
2462 }
2463 namelen = strlen(vol_args->name);
2464 if (namelen > BTRFS_VOL_NAME_MAX) {
2465 ret = -EINVAL;
2466 goto out;
2467 }
2468
2469 sizestr = vol_args->name;
2470 if (!strcmp(sizestr, "max"))
2471 new_size = root->fs_info->sb->s_bdev->bd_inode->i_size;
2472 else {
2473 if (sizestr[0] == '-') {
2474 mod = -1;
2475 sizestr++;
2476 } else if (sizestr[0] == '+') {
2477 mod = 1;
2478 sizestr++;
2479 }
2480 new_size = btrfs_parse_size(sizestr);
2481 if (new_size == 0) {
2482 ret = -EINVAL;
2483 goto out;
2484 }
2485 }
2486
2487 mutex_lock(&root->fs_info->fs_mutex);
2488 old_size = btrfs_super_total_bytes(&root->fs_info->super_copy);
2489
2490 if (mod < 0) {
2491 if (new_size > old_size) {
2492 ret = -EINVAL;
2493 goto out_unlock;
2494 }
2495 new_size = old_size - new_size;
2496 } else if (mod > 0) {
2497 new_size = old_size + new_size;
2498 }
2499
2500 if (new_size < 256 * 1024 * 1024) {
2501 ret = -EINVAL;
2502 goto out_unlock;
2503 }
2504 if (new_size > root->fs_info->sb->s_bdev->bd_inode->i_size) {
2505 ret = -EFBIG;
2506 goto out_unlock;
2507 }
2508
2509 do_div(new_size, root->sectorsize);
2510 new_size *= root->sectorsize;
2511
2512 printk("new size is %Lu\n", new_size);
2513 if (new_size > old_size) {
2514 trans = btrfs_start_transaction(root, 1);
2515 ret = btrfs_grow_extent_tree(trans, root, new_size);
2516 btrfs_commit_transaction(trans, root);
2517 } else {
2518 ret = btrfs_shrink_extent_tree(root, new_size);
2519 }
2520
2521 out_unlock:
2522 mutex_unlock(&root->fs_info->fs_mutex);
2523 out:
2524 kfree(vol_args);
2525 return ret;
2526 }
2527
2528 static int noinline btrfs_ioctl_snap_create(struct btrfs_root *root,
2529 void __user *arg)
2530 {
2531 struct btrfs_ioctl_vol_args *vol_args;
2532 struct btrfs_dir_item *di;
2533 struct btrfs_path *path;
2534 u64 root_dirid;
2535 int namelen;
2536 int ret;
2537
2538 vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
2539
2540 if (!vol_args)
2541 return -ENOMEM;
2542
2543 if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
2544 ret = -EFAULT;
2545 goto out;
2546 }
2547
2548 namelen = strlen(vol_args->name);
2549 if (namelen > BTRFS_VOL_NAME_MAX) {
2550 ret = -EINVAL;
2551 goto out;
2552 }
2553 if (strchr(vol_args->name, '/')) {
2554 ret = -EINVAL;
2555 goto out;
2556 }
2557
2558 path = btrfs_alloc_path();
2559 if (!path) {
2560 ret = -ENOMEM;
2561 goto out;
2562 }
2563
2564 root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
2565 mutex_lock(&root->fs_info->fs_mutex);
2566 di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
2567 path, root_dirid,
2568 vol_args->name, namelen, 0);
2569 mutex_unlock(&root->fs_info->fs_mutex);
2570 btrfs_free_path(path);
2571
2572 if (di && !IS_ERR(di)) {
2573 ret = -EEXIST;
2574 goto out;
2575 }
2576
2577 if (IS_ERR(di)) {
2578 ret = PTR_ERR(di);
2579 goto out;
2580 }
2581
2582 if (root == root->fs_info->tree_root)
2583 ret = create_subvol(root, vol_args->name, namelen);
2584 else
2585 ret = create_snapshot(root, vol_args->name, namelen);
2586 out:
2587 kfree(vol_args);
2588 return ret;
2589 }
2590
2591 static int btrfs_ioctl_defrag(struct file *file)
2592 {
2593 struct inode *inode = fdentry(file)->d_inode;
2594 struct btrfs_root *root = BTRFS_I(inode)->root;
2595
2596 switch (inode->i_mode & S_IFMT) {
2597 case S_IFDIR:
2598 mutex_lock(&root->fs_info->fs_mutex);
2599 btrfs_defrag_root(root, 0);
2600 btrfs_defrag_root(root->fs_info->extent_root, 0);
2601 mutex_unlock(&root->fs_info->fs_mutex);
2602 break;
2603 case S_IFREG:
2604 btrfs_defrag_file(file);
2605 break;
2606 }
2607
2608 return 0;
2609 }
2610
2611 long btrfs_ioctl(struct file *file, unsigned int
2612 cmd, unsigned long arg)
2613 {
2614 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
2615
2616 switch (cmd) {
2617 case BTRFS_IOC_SNAP_CREATE:
2618 return btrfs_ioctl_snap_create(root, (void __user *)arg);
2619 case BTRFS_IOC_DEFRAG:
2620 return btrfs_ioctl_defrag(file);
2621 case BTRFS_IOC_RESIZE:
2622 return btrfs_ioctl_resize(root, (void __user *)arg);
2623 }
2624
2625 return -ENOTTY;
2626 }
2627
2628 /*
2629 * Called inside transaction, so use GFP_NOFS
2630 */
2631 struct inode *btrfs_alloc_inode(struct super_block *sb)
2632 {
2633 struct btrfs_inode *ei;
2634
2635 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
2636 if (!ei)
2637 return NULL;
2638 ei->last_trans = 0;
2639 ei->ordered_trans = 0;
2640 return &ei->vfs_inode;
2641 }
2642
2643 void btrfs_destroy_inode(struct inode *inode)
2644 {
2645 WARN_ON(!list_empty(&inode->i_dentry));
2646 WARN_ON(inode->i_data.nrpages);
2647
2648 btrfs_drop_extent_cache(inode, 0, (u64)-1);
2649 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
2650 }
2651
2652 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
2653 static void init_once(struct kmem_cache * cachep, void *foo)
2654 #else
2655 static void init_once(void * foo, struct kmem_cache * cachep,
2656 unsigned long flags)
2657 #endif
2658 {
2659 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
2660
2661 inode_init_once(&ei->vfs_inode);
2662 }
2663
2664 void btrfs_destroy_cachep(void)
2665 {
2666 if (btrfs_inode_cachep)
2667 kmem_cache_destroy(btrfs_inode_cachep);
2668 if (btrfs_trans_handle_cachep)
2669 kmem_cache_destroy(btrfs_trans_handle_cachep);
2670 if (btrfs_transaction_cachep)
2671 kmem_cache_destroy(btrfs_transaction_cachep);
2672 if (btrfs_bit_radix_cachep)
2673 kmem_cache_destroy(btrfs_bit_radix_cachep);
2674 if (btrfs_path_cachep)
2675 kmem_cache_destroy(btrfs_path_cachep);
2676 }
2677
2678 struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
2679 unsigned long extra_flags,
2680 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
2681 void (*ctor)(struct kmem_cache *, void *)
2682 #else
2683 void (*ctor)(void *, struct kmem_cache *,
2684 unsigned long)
2685 #endif
2686 )
2687 {
2688 return kmem_cache_create(name, size, 0, (SLAB_RECLAIM_ACCOUNT |
2689 SLAB_MEM_SPREAD | extra_flags), ctor
2690 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
2691 ,NULL
2692 #endif
2693 );
2694 }
2695
2696 int btrfs_init_cachep(void)
2697 {
2698 btrfs_inode_cachep = btrfs_cache_create("btrfs_inode_cache",
2699 sizeof(struct btrfs_inode),
2700 0, init_once);
2701 if (!btrfs_inode_cachep)
2702 goto fail;
2703 btrfs_trans_handle_cachep =
2704 btrfs_cache_create("btrfs_trans_handle_cache",
2705 sizeof(struct btrfs_trans_handle),
2706 0, NULL);
2707 if (!btrfs_trans_handle_cachep)
2708 goto fail;
2709 btrfs_transaction_cachep = btrfs_cache_create("btrfs_transaction_cache",
2710 sizeof(struct btrfs_transaction),
2711 0, NULL);
2712 if (!btrfs_transaction_cachep)
2713 goto fail;
2714 btrfs_path_cachep = btrfs_cache_create("btrfs_path_cache",
2715 sizeof(struct btrfs_path),
2716 0, NULL);
2717 if (!btrfs_path_cachep)
2718 goto fail;
2719 btrfs_bit_radix_cachep = btrfs_cache_create("btrfs_radix", 256,
2720 SLAB_DESTROY_BY_RCU, NULL);
2721 if (!btrfs_bit_radix_cachep)
2722 goto fail;
2723 return 0;
2724 fail:
2725 btrfs_destroy_cachep();
2726 return -ENOMEM;
2727 }
2728
2729 static int btrfs_getattr(struct vfsmount *mnt,
2730 struct dentry *dentry, struct kstat *stat)
2731 {
2732 struct inode *inode = dentry->d_inode;
2733 generic_fillattr(inode, stat);
2734 stat->blksize = PAGE_CACHE_SIZE;
2735 return 0;
2736 }
2737
2738 static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
2739 struct inode * new_dir,struct dentry *new_dentry)
2740 {
2741 struct btrfs_trans_handle *trans;
2742 struct btrfs_root *root = BTRFS_I(old_dir)->root;
2743 struct inode *new_inode = new_dentry->d_inode;
2744 struct inode *old_inode = old_dentry->d_inode;
2745 struct timespec ctime = CURRENT_TIME;
2746 struct btrfs_path *path;
2747 int ret;
2748
2749 if (S_ISDIR(old_inode->i_mode) && new_inode &&
2750 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
2751 return -ENOTEMPTY;
2752 }
2753
2754 mutex_lock(&root->fs_info->fs_mutex);
2755 ret = btrfs_check_free_space(root, 1, 0);
2756 if (ret)
2757 goto out_unlock;
2758
2759 trans = btrfs_start_transaction(root, 1);
2760
2761 btrfs_set_trans_block_group(trans, new_dir);
2762 path = btrfs_alloc_path();
2763 if (!path) {
2764 ret = -ENOMEM;
2765 goto out_fail;
2766 }
2767
2768 old_dentry->d_inode->i_nlink++;
2769 old_dir->i_ctime = old_dir->i_mtime = ctime;
2770 new_dir->i_ctime = new_dir->i_mtime = ctime;
2771 old_inode->i_ctime = ctime;
2772
2773 ret = btrfs_unlink_trans(trans, root, old_dir, old_dentry);
2774 if (ret)
2775 goto out_fail;
2776
2777 if (new_inode) {
2778 new_inode->i_ctime = CURRENT_TIME;
2779 ret = btrfs_unlink_trans(trans, root, new_dir, new_dentry);
2780 if (ret)
2781 goto out_fail;
2782 }
2783 ret = btrfs_add_link(trans, new_dentry, old_inode);
2784 if (ret)
2785 goto out_fail;
2786
2787 out_fail:
2788 btrfs_free_path(path);
2789 btrfs_end_transaction(trans, root);
2790 out_unlock:
2791 mutex_unlock(&root->fs_info->fs_mutex);
2792 return ret;
2793 }
2794
2795 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
2796 const char *symname)
2797 {
2798 struct btrfs_trans_handle *trans;
2799 struct btrfs_root *root = BTRFS_I(dir)->root;
2800 struct btrfs_path *path;
2801 struct btrfs_key key;
2802 struct inode *inode = NULL;
2803 int err;
2804 int drop_inode = 0;
2805 u64 objectid;
2806 int name_len;
2807 int datasize;
2808 unsigned long ptr;
2809 struct btrfs_file_extent_item *ei;
2810 struct extent_buffer *leaf;
2811 unsigned long nr = 0;
2812
2813 name_len = strlen(symname) + 1;
2814 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
2815 return -ENAMETOOLONG;
2816
2817 mutex_lock(&root->fs_info->fs_mutex);
2818 err = btrfs_check_free_space(root, 1, 0);
2819 if (err)
2820 goto out_fail;
2821
2822 trans = btrfs_start_transaction(root, 1);
2823 btrfs_set_trans_block_group(trans, dir);
2824
2825 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
2826 if (err) {
2827 err = -ENOSPC;
2828 goto out_unlock;
2829 }
2830
2831 inode = btrfs_new_inode(trans, root, objectid,
2832 BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO);
2833 err = PTR_ERR(inode);
2834 if (IS_ERR(inode))
2835 goto out_unlock;
2836
2837 btrfs_set_trans_block_group(trans, inode);
2838 err = btrfs_add_nondir(trans, dentry, inode);
2839 if (err)
2840 drop_inode = 1;
2841 else {
2842 inode->i_mapping->a_ops = &btrfs_aops;
2843 inode->i_fop = &btrfs_file_operations;
2844 inode->i_op = &btrfs_file_inode_operations;
2845 extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
2846 inode->i_mapping, GFP_NOFS);
2847 BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
2848 }
2849 dir->i_sb->s_dirt = 1;
2850 btrfs_update_inode_block_group(trans, inode);
2851 btrfs_update_inode_block_group(trans, dir);
2852 if (drop_inode)
2853 goto out_unlock;
2854
2855 path = btrfs_alloc_path();
2856 BUG_ON(!path);
2857 key.objectid = inode->i_ino;
2858 key.offset = 0;
2859 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
2860 datasize = btrfs_file_extent_calc_inline_size(name_len);
2861 err = btrfs_insert_empty_item(trans, root, path, &key,
2862 datasize);
2863 if (err) {
2864 drop_inode = 1;
2865 goto out_unlock;
2866 }
2867 leaf = path->nodes[0];
2868 ei = btrfs_item_ptr(leaf, path->slots[0],
2869 struct btrfs_file_extent_item);
2870 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
2871 btrfs_set_file_extent_type(leaf, ei,
2872 BTRFS_FILE_EXTENT_INLINE);
2873 ptr = btrfs_file_extent_inline_start(ei);
2874 write_extent_buffer(leaf, symname, ptr, name_len);
2875 btrfs_mark_buffer_dirty(leaf);
2876 btrfs_free_path(path);
2877
2878 inode->i_op = &btrfs_symlink_inode_operations;
2879 inode->i_mapping->a_ops = &btrfs_symlink_aops;
2880 inode->i_size = name_len - 1;
2881 err = btrfs_update_inode(trans, root, inode);
2882 if (err)
2883 drop_inode = 1;
2884
2885 out_unlock:
2886 nr = trans->blocks_used;
2887 btrfs_end_transaction(trans, root);
2888 out_fail:
2889 mutex_unlock(&root->fs_info->fs_mutex);
2890 if (drop_inode) {
2891 inode_dec_link_count(inode);
2892 iput(inode);
2893 }
2894 btrfs_btree_balance_dirty(root, nr);
2895 btrfs_throttle(root);
2896 return err;
2897 }
2898 static int btrfs_permission(struct inode *inode, int mask,
2899 struct nameidata *nd)
2900 {
2901 if (btrfs_test_flag(inode, READONLY) && (mask & MAY_WRITE))
2902 return -EACCES;
2903 return generic_permission(inode, mask, NULL);
2904 }
2905
2906 static struct inode_operations btrfs_dir_inode_operations = {
2907 .lookup = btrfs_lookup,
2908 .create = btrfs_create,
2909 .unlink = btrfs_unlink,
2910 .link = btrfs_link,
2911 .mkdir = btrfs_mkdir,
2912 .rmdir = btrfs_rmdir,
2913 .rename = btrfs_rename,
2914 .symlink = btrfs_symlink,
2915 .setattr = btrfs_setattr,
2916 .mknod = btrfs_mknod,
2917 .setxattr = generic_setxattr,
2918 .getxattr = generic_getxattr,
2919 .listxattr = btrfs_listxattr,
2920 .removexattr = generic_removexattr,
2921 .permission = btrfs_permission,
2922 };
2923 static struct inode_operations btrfs_dir_ro_inode_operations = {
2924 .lookup = btrfs_lookup,
2925 .permission = btrfs_permission,
2926 };
2927 static struct file_operations btrfs_dir_file_operations = {
2928 .llseek = generic_file_llseek,
2929 .read = generic_read_dir,
2930 .readdir = btrfs_readdir,
2931 .unlocked_ioctl = btrfs_ioctl,
2932 #ifdef CONFIG_COMPAT
2933 .compat_ioctl = btrfs_ioctl,
2934 #endif
2935 };
2936
2937 static struct extent_map_ops btrfs_extent_map_ops = {
2938 .fill_delalloc = run_delalloc_range,
2939 .writepage_io_hook = btrfs_writepage_io_hook,
2940 .readpage_io_hook = btrfs_readpage_io_hook,
2941 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
2942 };
2943
2944 static struct address_space_operations btrfs_aops = {
2945 .readpage = btrfs_readpage,
2946 .writepage = btrfs_writepage,
2947 .writepages = btrfs_writepages,
2948 .readpages = btrfs_readpages,
2949 .sync_page = block_sync_page,
2950 .bmap = btrfs_bmap,
2951 .invalidatepage = btrfs_invalidatepage,
2952 .releasepage = btrfs_releasepage,
2953 .set_page_dirty = __set_page_dirty_nobuffers,
2954 };
2955
2956 static struct address_space_operations btrfs_symlink_aops = {
2957 .readpage = btrfs_readpage,
2958 .writepage = btrfs_writepage,
2959 .invalidatepage = btrfs_invalidatepage,
2960 .releasepage = btrfs_releasepage,
2961 };
2962
2963 static struct inode_operations btrfs_file_inode_operations = {
2964 .truncate = btrfs_truncate,
2965 .getattr = btrfs_getattr,
2966 .setattr = btrfs_setattr,
2967 .setxattr = generic_setxattr,
2968 .getxattr = generic_getxattr,
2969 .listxattr = btrfs_listxattr,
2970 .removexattr = generic_removexattr,
2971 .permission = btrfs_permission,
2972 };
2973 static struct inode_operations btrfs_special_inode_operations = {
2974 .getattr = btrfs_getattr,
2975 .setattr = btrfs_setattr,
2976 .permission = btrfs_permission,
2977 };
2978 static struct inode_operations btrfs_symlink_inode_operations = {
2979 .readlink = generic_readlink,
2980 .follow_link = page_follow_link_light,
2981 .put_link = page_put_link,
2982 .permission = btrfs_permission,
2983 };
Linux kernel - Deliverables
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