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