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Btrfs: Add support for multiple devices per filesystem
[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/bio.h>
20 #include <linux/buffer_head.h>
21 #include <linux/fs.h>
22 #include <linux/pagemap.h>
23 #include <linux/highmem.h>
24 #include <linux/time.h>
25 #include <linux/init.h>
26 #include <linux/string.h>
27 #include <linux/smp_lock.h>
28 #include <linux/backing-dev.h>
29 #include <linux/mpage.h>
30 #include <linux/swap.h>
31 #include <linux/writeback.h>
32 #include <linux/statfs.h>
33 #include <linux/compat.h>
34 #include <linux/bit_spinlock.h>
35 #include <linux/version.h>
36 #include <linux/xattr.h>
37 #include "ctree.h"
38 #include "disk-io.h"
39 #include "transaction.h"
40 #include "btrfs_inode.h"
41 #include "ioctl.h"
42 #include "print-tree.h"
43 #include "volumes.h"
44
45 struct btrfs_iget_args {
46 u64 ino;
47 struct btrfs_root *root;
48 };
49
50 static struct inode_operations btrfs_dir_inode_operations;
51 static struct inode_operations btrfs_symlink_inode_operations;
52 static struct inode_operations btrfs_dir_ro_inode_operations;
53 static struct inode_operations btrfs_special_inode_operations;
54 static struct inode_operations btrfs_file_inode_operations;
55 static struct address_space_operations btrfs_aops;
56 static struct address_space_operations btrfs_symlink_aops;
57 static struct file_operations btrfs_dir_file_operations;
58 static struct extent_io_ops btrfs_extent_io_ops;
59
60 static struct kmem_cache *btrfs_inode_cachep;
61 struct kmem_cache *btrfs_trans_handle_cachep;
62 struct kmem_cache *btrfs_transaction_cachep;
63 struct kmem_cache *btrfs_bit_radix_cachep;
64 struct kmem_cache *btrfs_path_cachep;
65
66 #define S_SHIFT 12
67 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
68 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
69 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
70 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
71 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
72 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
73 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
74 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
75 };
76
77 int btrfs_check_free_space(struct btrfs_root *root, u64 num_required,
78 int for_del)
79 {
80 u64 total = btrfs_super_total_bytes(&root->fs_info->super_copy);
81 u64 used = btrfs_super_bytes_used(&root->fs_info->super_copy);
82 u64 thresh;
83 int ret = 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 u64 orig_start = start;
108 u64 orig_num_bytes;
109 struct btrfs_key ins;
110 int ret;
111
112 trans = btrfs_start_transaction(root, 1);
113 BUG_ON(!trans);
114 btrfs_set_trans_block_group(trans, inode);
115
116 num_bytes = (end - start + blocksize) & ~(blocksize - 1);
117 num_bytes = max(blocksize, num_bytes);
118 ret = btrfs_drop_extents(trans, root, inode,
119 start, start + num_bytes, start, &alloc_hint);
120 orig_num_bytes = num_bytes;
121
122 if (alloc_hint == EXTENT_MAP_INLINE)
123 goto out;
124
125 while(num_bytes > 0) {
126 cur_alloc_size = min(num_bytes, root->fs_info->max_extent);
127 ret = btrfs_alloc_extent(trans, root, cur_alloc_size,
128 root->root_key.objectid,
129 trans->transid,
130 inode->i_ino, start, 0,
131 alloc_hint, (u64)-1, &ins, 1);
132 if (ret) {
133 WARN_ON(1);
134 goto out;
135 }
136 ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
137 start, ins.objectid, ins.offset,
138 ins.offset);
139 inode->i_blocks += ins.offset >> 9;
140 btrfs_check_file(root, inode);
141 num_bytes -= cur_alloc_size;
142 alloc_hint = ins.objectid + ins.offset;
143 start += cur_alloc_size;
144 }
145 btrfs_drop_extent_cache(inode, orig_start,
146 orig_start + orig_num_bytes - 1);
147 btrfs_add_ordered_inode(inode);
148 btrfs_update_inode(trans, root, inode);
149 out:
150 btrfs_end_transaction(trans, root);
151 return ret;
152 }
153
154 static int run_delalloc_nocow(struct inode *inode, u64 start, u64 end)
155 {
156 u64 extent_start;
157 u64 extent_end;
158 u64 bytenr;
159 u64 cow_end;
160 u64 loops = 0;
161 u64 total_fs_bytes;
162 struct btrfs_root *root = BTRFS_I(inode)->root;
163 struct extent_buffer *leaf;
164 int found_type;
165 struct btrfs_path *path;
166 struct btrfs_file_extent_item *item;
167 int ret;
168 int err;
169 struct btrfs_key found_key;
170
171 total_fs_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
172 path = btrfs_alloc_path();
173 BUG_ON(!path);
174 again:
175 ret = btrfs_lookup_file_extent(NULL, root, path,
176 inode->i_ino, start, 0);
177 if (ret < 0) {
178 btrfs_free_path(path);
179 return ret;
180 }
181
182 cow_end = end;
183 if (ret != 0) {
184 if (path->slots[0] == 0)
185 goto not_found;
186 path->slots[0]--;
187 }
188
189 leaf = path->nodes[0];
190 item = btrfs_item_ptr(leaf, path->slots[0],
191 struct btrfs_file_extent_item);
192
193 /* are we inside the extent that was found? */
194 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
195 found_type = btrfs_key_type(&found_key);
196 if (found_key.objectid != inode->i_ino ||
197 found_type != BTRFS_EXTENT_DATA_KEY) {
198 goto not_found;
199 }
200
201 found_type = btrfs_file_extent_type(leaf, item);
202 extent_start = found_key.offset;
203 if (found_type == BTRFS_FILE_EXTENT_REG) {
204 u64 extent_num_bytes;
205
206 extent_num_bytes = btrfs_file_extent_num_bytes(leaf, item);
207 extent_end = extent_start + extent_num_bytes;
208 err = 0;
209
210 if (loops && start != extent_start)
211 goto not_found;
212
213 if (start < extent_start || start >= extent_end)
214 goto not_found;
215
216 cow_end = min(end, extent_end - 1);
217 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
218 if (bytenr == 0)
219 goto not_found;
220
221 /*
222 * we may be called by the resizer, make sure we're inside
223 * the limits of the FS
224 */
225 if (bytenr + extent_num_bytes > total_fs_bytes)
226 goto not_found;
227
228 if (btrfs_count_snapshots_in_path(root, path, bytenr) != 1) {
229 goto not_found;
230 }
231
232 start = extent_end;
233 } else {
234 goto not_found;
235 }
236 loop:
237 if (start > end) {
238 btrfs_free_path(path);
239 return 0;
240 }
241 btrfs_release_path(root, path);
242 loops++;
243 goto again;
244
245 not_found:
246 cow_file_range(inode, start, cow_end);
247 start = cow_end + 1;
248 goto loop;
249 }
250
251 static int run_delalloc_range(struct inode *inode, u64 start, u64 end)
252 {
253 struct btrfs_root *root = BTRFS_I(inode)->root;
254 int ret;
255 mutex_lock(&root->fs_info->fs_mutex);
256 if (btrfs_test_opt(root, NODATACOW) ||
257 btrfs_test_flag(inode, NODATACOW))
258 ret = run_delalloc_nocow(inode, start, end);
259 else
260 ret = cow_file_range(inode, start, end);
261
262 mutex_unlock(&root->fs_info->fs_mutex);
263 return ret;
264 }
265
266 int btrfs_set_bit_hook(struct inode *inode, u64 start, u64 end,
267 unsigned long old, unsigned long bits)
268 {
269 if (!(old & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) {
270 struct btrfs_root *root = BTRFS_I(inode)->root;
271 spin_lock(&root->fs_info->delalloc_lock);
272 BTRFS_I(inode)->delalloc_bytes += end - start + 1;
273 root->fs_info->delalloc_bytes += end - start + 1;
274 spin_unlock(&root->fs_info->delalloc_lock);
275 }
276 return 0;
277 }
278
279 int btrfs_clear_bit_hook(struct inode *inode, u64 start, u64 end,
280 unsigned long old, unsigned long bits)
281 {
282 if ((old & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) {
283 struct btrfs_root *root = BTRFS_I(inode)->root;
284 spin_lock(&root->fs_info->delalloc_lock);
285 if (end - start + 1 > root->fs_info->delalloc_bytes) {
286 printk("warning: delalloc account %Lu %Lu\n",
287 end - start + 1, root->fs_info->delalloc_bytes);
288 root->fs_info->delalloc_bytes = 0;
289 BTRFS_I(inode)->delalloc_bytes = 0;
290 } else {
291 root->fs_info->delalloc_bytes -= end - start + 1;
292 BTRFS_I(inode)->delalloc_bytes -= end - start + 1;
293 }
294 spin_unlock(&root->fs_info->delalloc_lock);
295 }
296 return 0;
297 }
298
299 int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio)
300 {
301 struct btrfs_root *root = BTRFS_I(inode)->root;
302 struct btrfs_trans_handle *trans;
303 int ret = 0;
304
305 if (rw != WRITE) {
306 goto mapit;
307 }
308
309 if (btrfs_test_opt(root, NODATASUM) ||
310 btrfs_test_flag(inode, NODATASUM)) {
311 goto mapit;
312 }
313
314 mutex_lock(&root->fs_info->fs_mutex);
315 trans = btrfs_start_transaction(root, 1);
316 btrfs_set_trans_block_group(trans, inode);
317 btrfs_csum_file_blocks(trans, root, inode, bio);
318 ret = btrfs_end_transaction(trans, root);
319 BUG_ON(ret);
320 mutex_unlock(&root->fs_info->fs_mutex);
321 mapit:
322 return btrfs_map_bio(root, rw, bio);
323 }
324
325 int btrfs_readpage_io_hook(struct page *page, u64 start, u64 end)
326 {
327 int ret = 0;
328 struct inode *inode = page->mapping->host;
329 struct btrfs_root *root = BTRFS_I(inode)->root;
330 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
331 struct btrfs_csum_item *item;
332 struct btrfs_path *path = NULL;
333 u32 csum;
334 if (btrfs_test_opt(root, NODATASUM) ||
335 btrfs_test_flag(inode, NODATASUM))
336 return 0;
337 mutex_lock(&root->fs_info->fs_mutex);
338 path = btrfs_alloc_path();
339 item = btrfs_lookup_csum(NULL, root, path, inode->i_ino, start, 0);
340 if (IS_ERR(item)) {
341 ret = PTR_ERR(item);
342 /* a csum that isn't present is a preallocated region. */
343 if (ret == -ENOENT || ret == -EFBIG)
344 ret = 0;
345 csum = 0;
346 printk("no csum found for inode %lu start %Lu\n", inode->i_ino, start);
347 goto out;
348 }
349 read_extent_buffer(path->nodes[0], &csum, (unsigned long)item,
350 BTRFS_CRC32_SIZE);
351 set_state_private(io_tree, start, csum);
352 out:
353 if (path)
354 btrfs_free_path(path);
355 mutex_unlock(&root->fs_info->fs_mutex);
356 return ret;
357 }
358
359 int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
360 struct extent_state *state)
361 {
362 size_t offset = start - ((u64)page->index << PAGE_CACHE_SHIFT);
363 struct inode *inode = page->mapping->host;
364 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
365 char *kaddr;
366 u64 private = ~(u32)0;
367 int ret;
368 struct btrfs_root *root = BTRFS_I(inode)->root;
369 u32 csum = ~(u32)0;
370 unsigned long flags;
371
372 if (btrfs_test_opt(root, NODATASUM) ||
373 btrfs_test_flag(inode, NODATASUM))
374 return 0;
375 if (state && state->start == start) {
376 private = state->private;
377 ret = 0;
378 } else {
379 ret = get_state_private(io_tree, start, &private);
380 }
381 local_irq_save(flags);
382 kaddr = kmap_atomic(page, KM_IRQ0);
383 if (ret) {
384 goto zeroit;
385 }
386 csum = btrfs_csum_data(root, kaddr + offset, csum, end - start + 1);
387 btrfs_csum_final(csum, (char *)&csum);
388 if (csum != private) {
389 goto zeroit;
390 }
391 kunmap_atomic(kaddr, KM_IRQ0);
392 local_irq_restore(flags);
393 return 0;
394
395 zeroit:
396 printk("btrfs csum failed ino %lu off %llu csum %u private %Lu\n",
397 page->mapping->host->i_ino, (unsigned long long)start, csum,
398 private);
399 memset(kaddr + offset, 1, end - start + 1);
400 flush_dcache_page(page);
401 kunmap_atomic(kaddr, KM_IRQ0);
402 local_irq_restore(flags);
403 return 0;
404 }
405
406 void btrfs_read_locked_inode(struct inode *inode)
407 {
408 struct btrfs_path *path;
409 struct extent_buffer *leaf;
410 struct btrfs_inode_item *inode_item;
411 struct btrfs_timespec *tspec;
412 struct btrfs_root *root = BTRFS_I(inode)->root;
413 struct btrfs_key location;
414 u64 alloc_group_block;
415 u32 rdev;
416 int ret;
417
418 path = btrfs_alloc_path();
419 BUG_ON(!path);
420 mutex_lock(&root->fs_info->fs_mutex);
421 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
422
423 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
424 if (ret)
425 goto make_bad;
426
427 leaf = path->nodes[0];
428 inode_item = btrfs_item_ptr(leaf, path->slots[0],
429 struct btrfs_inode_item);
430
431 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
432 inode->i_nlink = btrfs_inode_nlink(leaf, inode_item);
433 inode->i_uid = btrfs_inode_uid(leaf, inode_item);
434 inode->i_gid = btrfs_inode_gid(leaf, inode_item);
435 inode->i_size = btrfs_inode_size(leaf, inode_item);
436
437 tspec = btrfs_inode_atime(inode_item);
438 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
439 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
440
441 tspec = btrfs_inode_mtime(inode_item);
442 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
443 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
444
445 tspec = btrfs_inode_ctime(inode_item);
446 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
447 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
448
449 inode->i_blocks = btrfs_inode_nblocks(leaf, inode_item);
450 inode->i_generation = btrfs_inode_generation(leaf, inode_item);
451 inode->i_rdev = 0;
452 rdev = btrfs_inode_rdev(leaf, inode_item);
453
454 alloc_group_block = btrfs_inode_block_group(leaf, inode_item);
455 BTRFS_I(inode)->block_group = btrfs_lookup_block_group(root->fs_info,
456 alloc_group_block);
457 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
458 if (!BTRFS_I(inode)->block_group) {
459 BTRFS_I(inode)->block_group = btrfs_find_block_group(root,
460 NULL, 0,
461 BTRFS_BLOCK_GROUP_METADATA, 0);
462 }
463 btrfs_free_path(path);
464 inode_item = NULL;
465
466 mutex_unlock(&root->fs_info->fs_mutex);
467
468 switch (inode->i_mode & S_IFMT) {
469 case S_IFREG:
470 inode->i_mapping->a_ops = &btrfs_aops;
471 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
472 inode->i_fop = &btrfs_file_operations;
473 inode->i_op = &btrfs_file_inode_operations;
474 break;
475 case S_IFDIR:
476 inode->i_fop = &btrfs_dir_file_operations;
477 if (root == root->fs_info->tree_root)
478 inode->i_op = &btrfs_dir_ro_inode_operations;
479 else
480 inode->i_op = &btrfs_dir_inode_operations;
481 break;
482 case S_IFLNK:
483 inode->i_op = &btrfs_symlink_inode_operations;
484 inode->i_mapping->a_ops = &btrfs_symlink_aops;
485 break;
486 default:
487 init_special_inode(inode, inode->i_mode, rdev);
488 break;
489 }
490 return;
491
492 make_bad:
493 btrfs_release_path(root, path);
494 btrfs_free_path(path);
495 mutex_unlock(&root->fs_info->fs_mutex);
496 make_bad_inode(inode);
497 }
498
499 static void fill_inode_item(struct extent_buffer *leaf,
500 struct btrfs_inode_item *item,
501 struct inode *inode)
502 {
503 btrfs_set_inode_uid(leaf, item, inode->i_uid);
504 btrfs_set_inode_gid(leaf, item, inode->i_gid);
505 btrfs_set_inode_size(leaf, item, inode->i_size);
506 btrfs_set_inode_mode(leaf, item, inode->i_mode);
507 btrfs_set_inode_nlink(leaf, item, inode->i_nlink);
508
509 btrfs_set_timespec_sec(leaf, btrfs_inode_atime(item),
510 inode->i_atime.tv_sec);
511 btrfs_set_timespec_nsec(leaf, btrfs_inode_atime(item),
512 inode->i_atime.tv_nsec);
513
514 btrfs_set_timespec_sec(leaf, btrfs_inode_mtime(item),
515 inode->i_mtime.tv_sec);
516 btrfs_set_timespec_nsec(leaf, btrfs_inode_mtime(item),
517 inode->i_mtime.tv_nsec);
518
519 btrfs_set_timespec_sec(leaf, btrfs_inode_ctime(item),
520 inode->i_ctime.tv_sec);
521 btrfs_set_timespec_nsec(leaf, btrfs_inode_ctime(item),
522 inode->i_ctime.tv_nsec);
523
524 btrfs_set_inode_nblocks(leaf, item, inode->i_blocks);
525 btrfs_set_inode_generation(leaf, item, inode->i_generation);
526 btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
527 btrfs_set_inode_flags(leaf, item, BTRFS_I(inode)->flags);
528 btrfs_set_inode_block_group(leaf, item,
529 BTRFS_I(inode)->block_group->key.objectid);
530 }
531
532 int btrfs_update_inode(struct btrfs_trans_handle *trans,
533 struct btrfs_root *root,
534 struct inode *inode)
535 {
536 struct btrfs_inode_item *inode_item;
537 struct btrfs_path *path;
538 struct extent_buffer *leaf;
539 int ret;
540
541 path = btrfs_alloc_path();
542 BUG_ON(!path);
543 ret = btrfs_lookup_inode(trans, root, path,
544 &BTRFS_I(inode)->location, 1);
545 if (ret) {
546 if (ret > 0)
547 ret = -ENOENT;
548 goto failed;
549 }
550
551 leaf = path->nodes[0];
552 inode_item = btrfs_item_ptr(leaf, path->slots[0],
553 struct btrfs_inode_item);
554
555 fill_inode_item(leaf, inode_item, inode);
556 btrfs_mark_buffer_dirty(leaf);
557 btrfs_set_inode_last_trans(trans, inode);
558 ret = 0;
559 failed:
560 btrfs_release_path(root, path);
561 btrfs_free_path(path);
562 return ret;
563 }
564
565
566 static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
567 struct btrfs_root *root,
568 struct inode *dir,
569 struct dentry *dentry)
570 {
571 struct btrfs_path *path;
572 const char *name = dentry->d_name.name;
573 int name_len = dentry->d_name.len;
574 int ret = 0;
575 struct extent_buffer *leaf;
576 struct btrfs_dir_item *di;
577 struct btrfs_key key;
578
579 path = btrfs_alloc_path();
580 if (!path) {
581 ret = -ENOMEM;
582 goto err;
583 }
584
585 di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
586 name, name_len, -1);
587 if (IS_ERR(di)) {
588 ret = PTR_ERR(di);
589 goto err;
590 }
591 if (!di) {
592 ret = -ENOENT;
593 goto err;
594 }
595 leaf = path->nodes[0];
596 btrfs_dir_item_key_to_cpu(leaf, di, &key);
597 ret = btrfs_delete_one_dir_name(trans, root, path, di);
598 if (ret)
599 goto err;
600 btrfs_release_path(root, path);
601
602 di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
603 key.objectid, name, name_len, -1);
604 if (IS_ERR(di)) {
605 ret = PTR_ERR(di);
606 goto err;
607 }
608 if (!di) {
609 ret = -ENOENT;
610 goto err;
611 }
612 ret = btrfs_delete_one_dir_name(trans, root, path, di);
613
614 dentry->d_inode->i_ctime = dir->i_ctime;
615 ret = btrfs_del_inode_ref(trans, root, name, name_len,
616 dentry->d_inode->i_ino,
617 dentry->d_parent->d_inode->i_ino);
618 if (ret) {
619 printk("failed to delete reference to %.*s, "
620 "inode %lu parent %lu\n", name_len, name,
621 dentry->d_inode->i_ino,
622 dentry->d_parent->d_inode->i_ino);
623 }
624 err:
625 btrfs_free_path(path);
626 if (!ret) {
627 dir->i_size -= name_len * 2;
628 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
629 btrfs_update_inode(trans, root, dir);
630 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
631 dentry->d_inode->i_nlink--;
632 #else
633 drop_nlink(dentry->d_inode);
634 #endif
635 ret = btrfs_update_inode(trans, root, dentry->d_inode);
636 dir->i_sb->s_dirt = 1;
637 }
638 return ret;
639 }
640
641 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
642 {
643 struct btrfs_root *root;
644 struct btrfs_trans_handle *trans;
645 struct inode *inode = dentry->d_inode;
646 int ret;
647 unsigned long nr = 0;
648
649 root = BTRFS_I(dir)->root;
650 mutex_lock(&root->fs_info->fs_mutex);
651
652 ret = btrfs_check_free_space(root, 1, 1);
653 if (ret)
654 goto fail;
655
656 trans = btrfs_start_transaction(root, 1);
657
658 btrfs_set_trans_block_group(trans, dir);
659 ret = btrfs_unlink_trans(trans, root, dir, dentry);
660 nr = trans->blocks_used;
661
662 if (inode->i_nlink == 0) {
663 int found;
664 /* if the inode isn't linked anywhere,
665 * we don't need to worry about
666 * data=ordered
667 */
668 found = btrfs_del_ordered_inode(inode);
669 if (found == 1) {
670 atomic_dec(&inode->i_count);
671 }
672 }
673
674 btrfs_end_transaction(trans, root);
675 fail:
676 mutex_unlock(&root->fs_info->fs_mutex);
677 btrfs_btree_balance_dirty(root, nr);
678 btrfs_throttle(root);
679 return ret;
680 }
681
682 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
683 {
684 struct inode *inode = dentry->d_inode;
685 int err = 0;
686 int ret;
687 struct btrfs_root *root = BTRFS_I(dir)->root;
688 struct btrfs_trans_handle *trans;
689 unsigned long nr = 0;
690
691 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
692 return -ENOTEMPTY;
693
694 mutex_lock(&root->fs_info->fs_mutex);
695 ret = btrfs_check_free_space(root, 1, 1);
696 if (ret)
697 goto fail;
698
699 trans = btrfs_start_transaction(root, 1);
700 btrfs_set_trans_block_group(trans, dir);
701
702 /* now the directory is empty */
703 err = btrfs_unlink_trans(trans, root, dir, dentry);
704 if (!err) {
705 inode->i_size = 0;
706 }
707
708 nr = trans->blocks_used;
709 ret = btrfs_end_transaction(trans, root);
710 fail:
711 mutex_unlock(&root->fs_info->fs_mutex);
712 btrfs_btree_balance_dirty(root, nr);
713 btrfs_throttle(root);
714
715 if (ret && !err)
716 err = ret;
717 return err;
718 }
719
720 /*
721 * this can truncate away extent items, csum items and directory items.
722 * It starts at a high offset and removes keys until it can't find
723 * any higher than i_size.
724 *
725 * csum items that cross the new i_size are truncated to the new size
726 * as well.
727 */
728 static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
729 struct btrfs_root *root,
730 struct inode *inode,
731 u32 min_type)
732 {
733 int ret;
734 struct btrfs_path *path;
735 struct btrfs_key key;
736 struct btrfs_key found_key;
737 u32 found_type;
738 struct extent_buffer *leaf;
739 struct btrfs_file_extent_item *fi;
740 u64 extent_start = 0;
741 u64 extent_num_bytes = 0;
742 u64 item_end = 0;
743 u64 root_gen = 0;
744 u64 root_owner = 0;
745 int found_extent;
746 int del_item;
747 int pending_del_nr = 0;
748 int pending_del_slot = 0;
749 int extent_type = -1;
750
751 btrfs_drop_extent_cache(inode, inode->i_size, (u64)-1);
752 path = btrfs_alloc_path();
753 path->reada = -1;
754 BUG_ON(!path);
755
756 /* FIXME, add redo link to tree so we don't leak on crash */
757 key.objectid = inode->i_ino;
758 key.offset = (u64)-1;
759 key.type = (u8)-1;
760
761 btrfs_init_path(path);
762 search_again:
763 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
764 if (ret < 0) {
765 goto error;
766 }
767 if (ret > 0) {
768 BUG_ON(path->slots[0] == 0);
769 path->slots[0]--;
770 }
771
772 while(1) {
773 fi = NULL;
774 leaf = path->nodes[0];
775 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
776 found_type = btrfs_key_type(&found_key);
777
778 if (found_key.objectid != inode->i_ino)
779 break;
780
781 if (found_type < min_type)
782 break;
783
784 item_end = found_key.offset;
785 if (found_type == BTRFS_EXTENT_DATA_KEY) {
786 fi = btrfs_item_ptr(leaf, path->slots[0],
787 struct btrfs_file_extent_item);
788 extent_type = btrfs_file_extent_type(leaf, fi);
789 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
790 item_end +=
791 btrfs_file_extent_num_bytes(leaf, fi);
792 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
793 struct btrfs_item *item = btrfs_item_nr(leaf,
794 path->slots[0]);
795 item_end += btrfs_file_extent_inline_len(leaf,
796 item);
797 }
798 item_end--;
799 }
800 if (found_type == BTRFS_CSUM_ITEM_KEY) {
801 ret = btrfs_csum_truncate(trans, root, path,
802 inode->i_size);
803 BUG_ON(ret);
804 }
805 if (item_end < inode->i_size) {
806 if (found_type == BTRFS_DIR_ITEM_KEY) {
807 found_type = BTRFS_INODE_ITEM_KEY;
808 } else if (found_type == BTRFS_EXTENT_ITEM_KEY) {
809 found_type = BTRFS_CSUM_ITEM_KEY;
810 } else if (found_type == BTRFS_EXTENT_DATA_KEY) {
811 found_type = BTRFS_XATTR_ITEM_KEY;
812 } else if (found_type == BTRFS_XATTR_ITEM_KEY) {
813 found_type = BTRFS_INODE_REF_KEY;
814 } else if (found_type) {
815 found_type--;
816 } else {
817 break;
818 }
819 btrfs_set_key_type(&key, found_type);
820 goto next;
821 }
822 if (found_key.offset >= inode->i_size)
823 del_item = 1;
824 else
825 del_item = 0;
826 found_extent = 0;
827
828 /* FIXME, shrink the extent if the ref count is only 1 */
829 if (found_type != BTRFS_EXTENT_DATA_KEY)
830 goto delete;
831
832 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
833 u64 num_dec;
834 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
835 if (!del_item) {
836 u64 orig_num_bytes =
837 btrfs_file_extent_num_bytes(leaf, fi);
838 extent_num_bytes = inode->i_size -
839 found_key.offset + root->sectorsize - 1;
840 extent_num_bytes = extent_num_bytes &
841 ~((u64)root->sectorsize - 1);
842 btrfs_set_file_extent_num_bytes(leaf, fi,
843 extent_num_bytes);
844 num_dec = (orig_num_bytes -
845 extent_num_bytes);
846 if (extent_start != 0)
847 dec_i_blocks(inode, num_dec);
848 btrfs_mark_buffer_dirty(leaf);
849 } else {
850 extent_num_bytes =
851 btrfs_file_extent_disk_num_bytes(leaf,
852 fi);
853 /* FIXME blocksize != 4096 */
854 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
855 if (extent_start != 0) {
856 found_extent = 1;
857 dec_i_blocks(inode, num_dec);
858 }
859 root_gen = btrfs_header_generation(leaf);
860 root_owner = btrfs_header_owner(leaf);
861 }
862 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
863 if (!del_item) {
864 u32 newsize = inode->i_size - found_key.offset;
865 dec_i_blocks(inode, item_end + 1 -
866 found_key.offset - newsize);
867 newsize =
868 btrfs_file_extent_calc_inline_size(newsize);
869 ret = btrfs_truncate_item(trans, root, path,
870 newsize, 1);
871 BUG_ON(ret);
872 } else {
873 dec_i_blocks(inode, item_end + 1 -
874 found_key.offset);
875 }
876 }
877 delete:
878 if (del_item) {
879 if (!pending_del_nr) {
880 /* no pending yet, add ourselves */
881 pending_del_slot = path->slots[0];
882 pending_del_nr = 1;
883 } else if (pending_del_nr &&
884 path->slots[0] + 1 == pending_del_slot) {
885 /* hop on the pending chunk */
886 pending_del_nr++;
887 pending_del_slot = path->slots[0];
888 } else {
889 printk("bad pending slot %d pending_del_nr %d pending_del_slot %d\n", path->slots[0], pending_del_nr, pending_del_slot);
890 }
891 } else {
892 break;
893 }
894 if (found_extent) {
895 ret = btrfs_free_extent(trans, root, extent_start,
896 extent_num_bytes,
897 root_owner,
898 root_gen, inode->i_ino,
899 found_key.offset, 0);
900 BUG_ON(ret);
901 }
902 next:
903 if (path->slots[0] == 0) {
904 if (pending_del_nr)
905 goto del_pending;
906 btrfs_release_path(root, path);
907 goto search_again;
908 }
909
910 path->slots[0]--;
911 if (pending_del_nr &&
912 path->slots[0] + 1 != pending_del_slot) {
913 struct btrfs_key debug;
914 del_pending:
915 btrfs_item_key_to_cpu(path->nodes[0], &debug,
916 pending_del_slot);
917 ret = btrfs_del_items(trans, root, path,
918 pending_del_slot,
919 pending_del_nr);
920 BUG_ON(ret);
921 pending_del_nr = 0;
922 btrfs_release_path(root, path);
923 goto search_again;
924 }
925 }
926 ret = 0;
927 error:
928 if (pending_del_nr) {
929 ret = btrfs_del_items(trans, root, path, pending_del_slot,
930 pending_del_nr);
931 }
932 btrfs_release_path(root, path);
933 btrfs_free_path(path);
934 inode->i_sb->s_dirt = 1;
935 return ret;
936 }
937
938 static int btrfs_cow_one_page(struct inode *inode, struct page *page,
939 size_t zero_start)
940 {
941 char *kaddr;
942 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
943 u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
944 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
945 int ret = 0;
946
947 WARN_ON(!PageLocked(page));
948 set_page_extent_mapped(page);
949
950 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
951 set_extent_delalloc(&BTRFS_I(inode)->io_tree, page_start,
952 page_end, GFP_NOFS);
953
954 if (zero_start != PAGE_CACHE_SIZE) {
955 kaddr = kmap(page);
956 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
957 flush_dcache_page(page);
958 kunmap(page);
959 }
960 set_page_dirty(page);
961 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
962
963 return ret;
964 }
965
966 /*
967 * taken from block_truncate_page, but does cow as it zeros out
968 * any bytes left in the last page in the file.
969 */
970 static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
971 {
972 struct inode *inode = mapping->host;
973 struct btrfs_root *root = BTRFS_I(inode)->root;
974 u32 blocksize = root->sectorsize;
975 pgoff_t index = from >> PAGE_CACHE_SHIFT;
976 unsigned offset = from & (PAGE_CACHE_SIZE-1);
977 struct page *page;
978 int ret = 0;
979 u64 page_start;
980
981 if ((offset & (blocksize - 1)) == 0)
982 goto out;
983
984 ret = -ENOMEM;
985 page = grab_cache_page(mapping, index);
986 if (!page)
987 goto out;
988 if (!PageUptodate(page)) {
989 ret = btrfs_readpage(NULL, page);
990 lock_page(page);
991 if (!PageUptodate(page)) {
992 ret = -EIO;
993 goto out;
994 }
995 }
996 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
997
998 ret = btrfs_cow_one_page(inode, page, offset);
999
1000 unlock_page(page);
1001 page_cache_release(page);
1002 out:
1003 return ret;
1004 }
1005
1006 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
1007 {
1008 struct inode *inode = dentry->d_inode;
1009 int err;
1010
1011 err = inode_change_ok(inode, attr);
1012 if (err)
1013 return err;
1014
1015 if (S_ISREG(inode->i_mode) &&
1016 attr->ia_valid & ATTR_SIZE && attr->ia_size > inode->i_size) {
1017 struct btrfs_trans_handle *trans;
1018 struct btrfs_root *root = BTRFS_I(inode)->root;
1019 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1020
1021 u64 mask = root->sectorsize - 1;
1022 u64 hole_start = (inode->i_size + mask) & ~mask;
1023 u64 block_end = (attr->ia_size + mask) & ~mask;
1024 u64 hole_size;
1025 u64 alloc_hint = 0;
1026
1027 if (attr->ia_size <= hole_start)
1028 goto out;
1029
1030 mutex_lock(&root->fs_info->fs_mutex);
1031 err = btrfs_check_free_space(root, 1, 0);
1032 mutex_unlock(&root->fs_info->fs_mutex);
1033 if (err)
1034 goto fail;
1035
1036 btrfs_truncate_page(inode->i_mapping, inode->i_size);
1037
1038 lock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS);
1039 hole_size = block_end - hole_start;
1040
1041 mutex_lock(&root->fs_info->fs_mutex);
1042 trans = btrfs_start_transaction(root, 1);
1043 btrfs_set_trans_block_group(trans, inode);
1044 err = btrfs_drop_extents(trans, root, inode,
1045 hole_start, block_end, hole_start,
1046 &alloc_hint);
1047
1048 if (alloc_hint != EXTENT_MAP_INLINE) {
1049 err = btrfs_insert_file_extent(trans, root,
1050 inode->i_ino,
1051 hole_start, 0, 0,
1052 hole_size);
1053 btrfs_drop_extent_cache(inode, hole_start,
1054 hole_size - 1);
1055 btrfs_check_file(root, inode);
1056 }
1057 btrfs_end_transaction(trans, root);
1058 mutex_unlock(&root->fs_info->fs_mutex);
1059 unlock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS);
1060 if (err)
1061 return err;
1062 }
1063 out:
1064 err = inode_setattr(inode, attr);
1065 fail:
1066 return err;
1067 }
1068
1069 void btrfs_put_inode(struct inode *inode)
1070 {
1071 int ret;
1072
1073 if (!BTRFS_I(inode)->ordered_trans) {
1074 return;
1075 }
1076
1077 if (mapping_tagged(inode->i_mapping, PAGECACHE_TAG_DIRTY) ||
1078 mapping_tagged(inode->i_mapping, PAGECACHE_TAG_WRITEBACK))
1079 return;
1080
1081 ret = btrfs_del_ordered_inode(inode);
1082 if (ret == 1) {
1083 atomic_dec(&inode->i_count);
1084 }
1085 }
1086
1087 void btrfs_delete_inode(struct inode *inode)
1088 {
1089 struct btrfs_trans_handle *trans;
1090 struct btrfs_root *root = BTRFS_I(inode)->root;
1091 unsigned long nr;
1092 int ret;
1093
1094 truncate_inode_pages(&inode->i_data, 0);
1095 if (is_bad_inode(inode)) {
1096 goto no_delete;
1097 }
1098
1099 inode->i_size = 0;
1100 mutex_lock(&root->fs_info->fs_mutex);
1101 trans = btrfs_start_transaction(root, 1);
1102
1103 btrfs_set_trans_block_group(trans, inode);
1104 ret = btrfs_truncate_in_trans(trans, root, inode, 0);
1105 if (ret)
1106 goto no_delete_lock;
1107
1108 nr = trans->blocks_used;
1109 clear_inode(inode);
1110
1111 btrfs_end_transaction(trans, root);
1112 mutex_unlock(&root->fs_info->fs_mutex);
1113 btrfs_btree_balance_dirty(root, nr);
1114 btrfs_throttle(root);
1115 return;
1116
1117 no_delete_lock:
1118 nr = trans->blocks_used;
1119 btrfs_end_transaction(trans, root);
1120 mutex_unlock(&root->fs_info->fs_mutex);
1121 btrfs_btree_balance_dirty(root, nr);
1122 btrfs_throttle(root);
1123 no_delete:
1124 clear_inode(inode);
1125 }
1126
1127 /*
1128 * this returns the key found in the dir entry in the location pointer.
1129 * If no dir entries were found, location->objectid is 0.
1130 */
1131 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
1132 struct btrfs_key *location)
1133 {
1134 const char *name = dentry->d_name.name;
1135 int namelen = dentry->d_name.len;
1136 struct btrfs_dir_item *di;
1137 struct btrfs_path *path;
1138 struct btrfs_root *root = BTRFS_I(dir)->root;
1139 int ret = 0;
1140
1141 if (namelen == 1 && strcmp(name, ".") == 0) {
1142 location->objectid = dir->i_ino;
1143 location->type = BTRFS_INODE_ITEM_KEY;
1144 location->offset = 0;
1145 return 0;
1146 }
1147 path = btrfs_alloc_path();
1148 BUG_ON(!path);
1149
1150 if (namelen == 2 && strcmp(name, "..") == 0) {
1151 struct btrfs_key key;
1152 struct extent_buffer *leaf;
1153 u32 nritems;
1154 int slot;
1155
1156 key.objectid = dir->i_ino;
1157 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
1158 key.offset = 0;
1159 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1160 BUG_ON(ret == 0);
1161 ret = 0;
1162
1163 leaf = path->nodes[0];
1164 slot = path->slots[0];
1165 nritems = btrfs_header_nritems(leaf);
1166 if (slot >= nritems)
1167 goto out_err;
1168
1169 btrfs_item_key_to_cpu(leaf, &key, slot);
1170 if (key.objectid != dir->i_ino ||
1171 key.type != BTRFS_INODE_REF_KEY) {
1172 goto out_err;
1173 }
1174 location->objectid = key.offset;
1175 location->type = BTRFS_INODE_ITEM_KEY;
1176 location->offset = 0;
1177 goto out;
1178 }
1179
1180 di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
1181 namelen, 0);
1182 if (IS_ERR(di))
1183 ret = PTR_ERR(di);
1184 if (!di || IS_ERR(di)) {
1185 goto out_err;
1186 }
1187 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
1188 out:
1189 btrfs_free_path(path);
1190 return ret;
1191 out_err:
1192 location->objectid = 0;
1193 goto out;
1194 }
1195
1196 /*
1197 * when we hit a tree root in a directory, the btrfs part of the inode
1198 * needs to be changed to reflect the root directory of the tree root. This
1199 * is kind of like crossing a mount point.
1200 */
1201 static int fixup_tree_root_location(struct btrfs_root *root,
1202 struct btrfs_key *location,
1203 struct btrfs_root **sub_root,
1204 struct dentry *dentry)
1205 {
1206 struct btrfs_path *path;
1207 struct btrfs_root_item *ri;
1208
1209 if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY)
1210 return 0;
1211 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1212 return 0;
1213
1214 path = btrfs_alloc_path();
1215 BUG_ON(!path);
1216 mutex_lock(&root->fs_info->fs_mutex);
1217
1218 *sub_root = btrfs_read_fs_root(root->fs_info, location,
1219 dentry->d_name.name,
1220 dentry->d_name.len);
1221 if (IS_ERR(*sub_root))
1222 return PTR_ERR(*sub_root);
1223
1224 ri = &(*sub_root)->root_item;
1225 location->objectid = btrfs_root_dirid(ri);
1226 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
1227 location->offset = 0;
1228
1229 btrfs_free_path(path);
1230 mutex_unlock(&root->fs_info->fs_mutex);
1231 return 0;
1232 }
1233
1234 static int btrfs_init_locked_inode(struct inode *inode, void *p)
1235 {
1236 struct btrfs_iget_args *args = p;
1237 inode->i_ino = args->ino;
1238 BTRFS_I(inode)->root = args->root;
1239 BTRFS_I(inode)->delalloc_bytes = 0;
1240 extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
1241 extent_io_tree_init(&BTRFS_I(inode)->io_tree,
1242 inode->i_mapping, GFP_NOFS);
1243 return 0;
1244 }
1245
1246 static int btrfs_find_actor(struct inode *inode, void *opaque)
1247 {
1248 struct btrfs_iget_args *args = opaque;
1249 return (args->ino == inode->i_ino &&
1250 args->root == BTRFS_I(inode)->root);
1251 }
1252
1253 struct inode *btrfs_ilookup(struct super_block *s, u64 objectid,
1254 u64 root_objectid)
1255 {
1256 struct btrfs_iget_args args;
1257 args.ino = objectid;
1258 args.root = btrfs_lookup_fs_root(btrfs_sb(s)->fs_info, root_objectid);
1259
1260 if (!args.root)
1261 return NULL;
1262
1263 return ilookup5(s, objectid, btrfs_find_actor, (void *)&args);
1264 }
1265
1266 struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
1267 struct btrfs_root *root)
1268 {
1269 struct inode *inode;
1270 struct btrfs_iget_args args;
1271 args.ino = objectid;
1272 args.root = root;
1273
1274 inode = iget5_locked(s, objectid, btrfs_find_actor,
1275 btrfs_init_locked_inode,
1276 (void *)&args);
1277 return inode;
1278 }
1279
1280 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
1281 struct nameidata *nd)
1282 {
1283 struct inode * inode;
1284 struct btrfs_inode *bi = BTRFS_I(dir);
1285 struct btrfs_root *root = bi->root;
1286 struct btrfs_root *sub_root = root;
1287 struct btrfs_key location;
1288 int ret;
1289
1290 if (dentry->d_name.len > BTRFS_NAME_LEN)
1291 return ERR_PTR(-ENAMETOOLONG);
1292
1293 mutex_lock(&root->fs_info->fs_mutex);
1294 ret = btrfs_inode_by_name(dir, dentry, &location);
1295 mutex_unlock(&root->fs_info->fs_mutex);
1296
1297 if (ret < 0)
1298 return ERR_PTR(ret);
1299
1300 inode = NULL;
1301 if (location.objectid) {
1302 ret = fixup_tree_root_location(root, &location, &sub_root,
1303 dentry);
1304 if (ret < 0)
1305 return ERR_PTR(ret);
1306 if (ret > 0)
1307 return ERR_PTR(-ENOENT);
1308 inode = btrfs_iget_locked(dir->i_sb, location.objectid,
1309 sub_root);
1310 if (!inode)
1311 return ERR_PTR(-EACCES);
1312 if (inode->i_state & I_NEW) {
1313 /* the inode and parent dir are two different roots */
1314 if (sub_root != root) {
1315 igrab(inode);
1316 sub_root->inode = inode;
1317 }
1318 BTRFS_I(inode)->root = sub_root;
1319 memcpy(&BTRFS_I(inode)->location, &location,
1320 sizeof(location));
1321 btrfs_read_locked_inode(inode);
1322 unlock_new_inode(inode);
1323 }
1324 }
1325 return d_splice_alias(inode, dentry);
1326 }
1327
1328 static unsigned char btrfs_filetype_table[] = {
1329 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
1330 };
1331
1332 static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
1333 {
1334 struct inode *inode = filp->f_dentry->d_inode;
1335 struct btrfs_root *root = BTRFS_I(inode)->root;
1336 struct btrfs_item *item;
1337 struct btrfs_dir_item *di;
1338 struct btrfs_key key;
1339 struct btrfs_key found_key;
1340 struct btrfs_path *path;
1341 int ret;
1342 u32 nritems;
1343 struct extent_buffer *leaf;
1344 int slot;
1345 int advance;
1346 unsigned char d_type;
1347 int over = 0;
1348 u32 di_cur;
1349 u32 di_total;
1350 u32 di_len;
1351 int key_type = BTRFS_DIR_INDEX_KEY;
1352 char tmp_name[32];
1353 char *name_ptr;
1354 int name_len;
1355
1356 /* FIXME, use a real flag for deciding about the key type */
1357 if (root->fs_info->tree_root == root)
1358 key_type = BTRFS_DIR_ITEM_KEY;
1359
1360 /* special case for "." */
1361 if (filp->f_pos == 0) {
1362 over = filldir(dirent, ".", 1,
1363 1, inode->i_ino,
1364 DT_DIR);
1365 if (over)
1366 return 0;
1367 filp->f_pos = 1;
1368 }
1369
1370 mutex_lock(&root->fs_info->fs_mutex);
1371 key.objectid = inode->i_ino;
1372 path = btrfs_alloc_path();
1373 path->reada = 2;
1374
1375 /* special case for .., just use the back ref */
1376 if (filp->f_pos == 1) {
1377 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
1378 key.offset = 0;
1379 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1380 BUG_ON(ret == 0);
1381 leaf = path->nodes[0];
1382 slot = path->slots[0];
1383 nritems = btrfs_header_nritems(leaf);
1384 if (slot >= nritems) {
1385 btrfs_release_path(root, path);
1386 goto read_dir_items;
1387 }
1388 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1389 btrfs_release_path(root, path);
1390 if (found_key.objectid != key.objectid ||
1391 found_key.type != BTRFS_INODE_REF_KEY)
1392 goto read_dir_items;
1393 over = filldir(dirent, "..", 2,
1394 2, found_key.offset, DT_DIR);
1395 if (over)
1396 goto nopos;
1397 filp->f_pos = 2;
1398 }
1399
1400 read_dir_items:
1401 btrfs_set_key_type(&key, key_type);
1402 key.offset = filp->f_pos;
1403
1404 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1405 if (ret < 0)
1406 goto err;
1407 advance = 0;
1408 while(1) {
1409 leaf = path->nodes[0];
1410 nritems = btrfs_header_nritems(leaf);
1411 slot = path->slots[0];
1412 if (advance || slot >= nritems) {
1413 if (slot >= nritems -1) {
1414 ret = btrfs_next_leaf(root, path);
1415 if (ret)
1416 break;
1417 leaf = path->nodes[0];
1418 nritems = btrfs_header_nritems(leaf);
1419 slot = path->slots[0];
1420 } else {
1421 slot++;
1422 path->slots[0]++;
1423 }
1424 }
1425 advance = 1;
1426 item = btrfs_item_nr(leaf, slot);
1427 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1428
1429 if (found_key.objectid != key.objectid)
1430 break;
1431 if (btrfs_key_type(&found_key) != key_type)
1432 break;
1433 if (found_key.offset < filp->f_pos)
1434 continue;
1435
1436 filp->f_pos = found_key.offset;
1437 advance = 1;
1438 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
1439 di_cur = 0;
1440 di_total = btrfs_item_size(leaf, item);
1441 while(di_cur < di_total) {
1442 struct btrfs_key location;
1443
1444 name_len = btrfs_dir_name_len(leaf, di);
1445 if (name_len < 32) {
1446 name_ptr = tmp_name;
1447 } else {
1448 name_ptr = kmalloc(name_len, GFP_NOFS);
1449 BUG_ON(!name_ptr);
1450 }
1451 read_extent_buffer(leaf, name_ptr,
1452 (unsigned long)(di + 1), name_len);
1453
1454 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
1455 btrfs_dir_item_key_to_cpu(leaf, di, &location);
1456 over = filldir(dirent, name_ptr, name_len,
1457 found_key.offset,
1458 location.objectid,
1459 d_type);
1460
1461 if (name_ptr != tmp_name)
1462 kfree(name_ptr);
1463
1464 if (over)
1465 goto nopos;
1466 di_len = btrfs_dir_name_len(leaf, di) +
1467 btrfs_dir_data_len(leaf, di) +sizeof(*di);
1468 di_cur += di_len;
1469 di = (struct btrfs_dir_item *)((char *)di + di_len);
1470 }
1471 }
1472 if (key_type == BTRFS_DIR_INDEX_KEY)
1473 filp->f_pos = INT_LIMIT(typeof(filp->f_pos));
1474 else
1475 filp->f_pos++;
1476 nopos:
1477 ret = 0;
1478 err:
1479 btrfs_release_path(root, path);
1480 btrfs_free_path(path);
1481 mutex_unlock(&root->fs_info->fs_mutex);
1482 return ret;
1483 }
1484
1485 int btrfs_write_inode(struct inode *inode, int wait)
1486 {
1487 struct btrfs_root *root = BTRFS_I(inode)->root;
1488 struct btrfs_trans_handle *trans;
1489 int ret = 0;
1490
1491 if (wait) {
1492 mutex_lock(&root->fs_info->fs_mutex);
1493 trans = btrfs_start_transaction(root, 1);
1494 btrfs_set_trans_block_group(trans, inode);
1495 ret = btrfs_commit_transaction(trans, root);
1496 mutex_unlock(&root->fs_info->fs_mutex);
1497 }
1498 return ret;
1499 }
1500
1501 /*
1502 * This is somewhat expensive, updating the tree every time the
1503 * inode changes. But, it is most likely to find the inode in cache.
1504 * FIXME, needs more benchmarking...there are no reasons other than performance
1505 * to keep or drop this code.
1506 */
1507 void btrfs_dirty_inode(struct inode *inode)
1508 {
1509 struct btrfs_root *root = BTRFS_I(inode)->root;
1510 struct btrfs_trans_handle *trans;
1511
1512 mutex_lock(&root->fs_info->fs_mutex);
1513 trans = btrfs_start_transaction(root, 1);
1514 btrfs_set_trans_block_group(trans, inode);
1515 btrfs_update_inode(trans, root, inode);
1516 btrfs_end_transaction(trans, root);
1517 mutex_unlock(&root->fs_info->fs_mutex);
1518 }
1519
1520 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
1521 struct btrfs_root *root,
1522 const char *name, int name_len,
1523 u64 ref_objectid,
1524 u64 objectid,
1525 struct btrfs_block_group_cache *group,
1526 int mode)
1527 {
1528 struct inode *inode;
1529 struct btrfs_inode_item *inode_item;
1530 struct btrfs_key *location;
1531 struct btrfs_path *path;
1532 struct btrfs_inode_ref *ref;
1533 struct btrfs_key key[2];
1534 u32 sizes[2];
1535 unsigned long ptr;
1536 int ret;
1537 int owner;
1538
1539 path = btrfs_alloc_path();
1540 BUG_ON(!path);
1541
1542 inode = new_inode(root->fs_info->sb);
1543 if (!inode)
1544 return ERR_PTR(-ENOMEM);
1545
1546 extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
1547 extent_io_tree_init(&BTRFS_I(inode)->io_tree,
1548 inode->i_mapping, GFP_NOFS);
1549 BTRFS_I(inode)->delalloc_bytes = 0;
1550 BTRFS_I(inode)->root = root;
1551
1552 if (mode & S_IFDIR)
1553 owner = 0;
1554 else
1555 owner = 1;
1556 group = btrfs_find_block_group(root, group, 0,
1557 BTRFS_BLOCK_GROUP_METADATA, owner);
1558 BTRFS_I(inode)->block_group = group;
1559 BTRFS_I(inode)->flags = 0;
1560
1561 key[0].objectid = objectid;
1562 btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
1563 key[0].offset = 0;
1564
1565 key[1].objectid = objectid;
1566 btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
1567 key[1].offset = ref_objectid;
1568
1569 sizes[0] = sizeof(struct btrfs_inode_item);
1570 sizes[1] = name_len + sizeof(*ref);
1571
1572 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
1573 if (ret != 0)
1574 goto fail;
1575
1576 if (objectid > root->highest_inode)
1577 root->highest_inode = objectid;
1578
1579 inode->i_uid = current->fsuid;
1580 inode->i_gid = current->fsgid;
1581 inode->i_mode = mode;
1582 inode->i_ino = objectid;
1583 inode->i_blocks = 0;
1584 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1585 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1586 struct btrfs_inode_item);
1587 fill_inode_item(path->nodes[0], inode_item, inode);
1588
1589 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
1590 struct btrfs_inode_ref);
1591 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
1592 ptr = (unsigned long)(ref + 1);
1593 write_extent_buffer(path->nodes[0], name, ptr, name_len);
1594
1595 btrfs_mark_buffer_dirty(path->nodes[0]);
1596 btrfs_free_path(path);
1597
1598 location = &BTRFS_I(inode)->location;
1599 location->objectid = objectid;
1600 location->offset = 0;
1601 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
1602
1603 insert_inode_hash(inode);
1604 return inode;
1605 fail:
1606 btrfs_free_path(path);
1607 return ERR_PTR(ret);
1608 }
1609
1610 static inline u8 btrfs_inode_type(struct inode *inode)
1611 {
1612 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
1613 }
1614
1615 static int btrfs_add_link(struct btrfs_trans_handle *trans,
1616 struct dentry *dentry, struct inode *inode,
1617 int add_backref)
1618 {
1619 int ret;
1620 struct btrfs_key key;
1621 struct btrfs_root *root = BTRFS_I(dentry->d_parent->d_inode)->root;
1622 struct inode *parent_inode;
1623
1624 key.objectid = inode->i_ino;
1625 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
1626 key.offset = 0;
1627
1628 ret = btrfs_insert_dir_item(trans, root,
1629 dentry->d_name.name, dentry->d_name.len,
1630 dentry->d_parent->d_inode->i_ino,
1631 &key, btrfs_inode_type(inode));
1632 if (ret == 0) {
1633 if (add_backref) {
1634 ret = btrfs_insert_inode_ref(trans, root,
1635 dentry->d_name.name,
1636 dentry->d_name.len,
1637 inode->i_ino,
1638 dentry->d_parent->d_inode->i_ino);
1639 }
1640 parent_inode = dentry->d_parent->d_inode;
1641 parent_inode->i_size += dentry->d_name.len * 2;
1642 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
1643 ret = btrfs_update_inode(trans, root,
1644 dentry->d_parent->d_inode);
1645 }
1646 return ret;
1647 }
1648
1649 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
1650 struct dentry *dentry, struct inode *inode,
1651 int backref)
1652 {
1653 int err = btrfs_add_link(trans, dentry, inode, backref);
1654 if (!err) {
1655 d_instantiate(dentry, inode);
1656 return 0;
1657 }
1658 if (err > 0)
1659 err = -EEXIST;
1660 return err;
1661 }
1662
1663 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
1664 int mode, dev_t rdev)
1665 {
1666 struct btrfs_trans_handle *trans;
1667 struct btrfs_root *root = BTRFS_I(dir)->root;
1668 struct inode *inode = NULL;
1669 int err;
1670 int drop_inode = 0;
1671 u64 objectid;
1672 unsigned long nr = 0;
1673
1674 if (!new_valid_dev(rdev))
1675 return -EINVAL;
1676
1677 mutex_lock(&root->fs_info->fs_mutex);
1678 err = btrfs_check_free_space(root, 1, 0);
1679 if (err)
1680 goto fail;
1681
1682 trans = btrfs_start_transaction(root, 1);
1683 btrfs_set_trans_block_group(trans, dir);
1684
1685 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1686 if (err) {
1687 err = -ENOSPC;
1688 goto out_unlock;
1689 }
1690
1691 inode = btrfs_new_inode(trans, root, dentry->d_name.name,
1692 dentry->d_name.len,
1693 dentry->d_parent->d_inode->i_ino, objectid,
1694 BTRFS_I(dir)->block_group, mode);
1695 err = PTR_ERR(inode);
1696 if (IS_ERR(inode))
1697 goto out_unlock;
1698
1699 btrfs_set_trans_block_group(trans, inode);
1700 err = btrfs_add_nondir(trans, dentry, inode, 0);
1701 if (err)
1702 drop_inode = 1;
1703 else {
1704 inode->i_op = &btrfs_special_inode_operations;
1705 init_special_inode(inode, inode->i_mode, rdev);
1706 btrfs_update_inode(trans, root, inode);
1707 }
1708 dir->i_sb->s_dirt = 1;
1709 btrfs_update_inode_block_group(trans, inode);
1710 btrfs_update_inode_block_group(trans, dir);
1711 out_unlock:
1712 nr = trans->blocks_used;
1713 btrfs_end_transaction(trans, root);
1714 fail:
1715 mutex_unlock(&root->fs_info->fs_mutex);
1716
1717 if (drop_inode) {
1718 inode_dec_link_count(inode);
1719 iput(inode);
1720 }
1721 btrfs_btree_balance_dirty(root, nr);
1722 btrfs_throttle(root);
1723 return err;
1724 }
1725
1726 static int btrfs_create(struct inode *dir, struct dentry *dentry,
1727 int mode, struct nameidata *nd)
1728 {
1729 struct btrfs_trans_handle *trans;
1730 struct btrfs_root *root = BTRFS_I(dir)->root;
1731 struct inode *inode = NULL;
1732 int err;
1733 int drop_inode = 0;
1734 unsigned long nr = 0;
1735 u64 objectid;
1736
1737 mutex_lock(&root->fs_info->fs_mutex);
1738 err = btrfs_check_free_space(root, 1, 0);
1739 if (err)
1740 goto fail;
1741 trans = btrfs_start_transaction(root, 1);
1742 btrfs_set_trans_block_group(trans, dir);
1743
1744 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1745 if (err) {
1746 err = -ENOSPC;
1747 goto out_unlock;
1748 }
1749
1750 inode = btrfs_new_inode(trans, root, dentry->d_name.name,
1751 dentry->d_name.len,
1752 dentry->d_parent->d_inode->i_ino,
1753 objectid, BTRFS_I(dir)->block_group, mode);
1754 err = PTR_ERR(inode);
1755 if (IS_ERR(inode))
1756 goto out_unlock;
1757
1758 btrfs_set_trans_block_group(trans, inode);
1759 err = btrfs_add_nondir(trans, dentry, inode, 0);
1760 if (err)
1761 drop_inode = 1;
1762 else {
1763 inode->i_mapping->a_ops = &btrfs_aops;
1764 inode->i_fop = &btrfs_file_operations;
1765 inode->i_op = &btrfs_file_inode_operations;
1766 extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
1767 extent_io_tree_init(&BTRFS_I(inode)->io_tree,
1768 inode->i_mapping, GFP_NOFS);
1769 BTRFS_I(inode)->delalloc_bytes = 0;
1770 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
1771 }
1772 dir->i_sb->s_dirt = 1;
1773 btrfs_update_inode_block_group(trans, inode);
1774 btrfs_update_inode_block_group(trans, dir);
1775 out_unlock:
1776 nr = trans->blocks_used;
1777 btrfs_end_transaction(trans, root);
1778 fail:
1779 mutex_unlock(&root->fs_info->fs_mutex);
1780
1781 if (drop_inode) {
1782 inode_dec_link_count(inode);
1783 iput(inode);
1784 }
1785 btrfs_btree_balance_dirty(root, nr);
1786 btrfs_throttle(root);
1787 return err;
1788 }
1789
1790 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
1791 struct dentry *dentry)
1792 {
1793 struct btrfs_trans_handle *trans;
1794 struct btrfs_root *root = BTRFS_I(dir)->root;
1795 struct inode *inode = old_dentry->d_inode;
1796 unsigned long nr = 0;
1797 int err;
1798 int drop_inode = 0;
1799
1800 if (inode->i_nlink == 0)
1801 return -ENOENT;
1802
1803 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
1804 inode->i_nlink++;
1805 #else
1806 inc_nlink(inode);
1807 #endif
1808 mutex_lock(&root->fs_info->fs_mutex);
1809 err = btrfs_check_free_space(root, 1, 0);
1810 if (err)
1811 goto fail;
1812 trans = btrfs_start_transaction(root, 1);
1813
1814 btrfs_set_trans_block_group(trans, dir);
1815 atomic_inc(&inode->i_count);
1816 err = btrfs_add_nondir(trans, dentry, inode, 1);
1817
1818 if (err)
1819 drop_inode = 1;
1820
1821 dir->i_sb->s_dirt = 1;
1822 btrfs_update_inode_block_group(trans, dir);
1823 err = btrfs_update_inode(trans, root, inode);
1824
1825 if (err)
1826 drop_inode = 1;
1827
1828 nr = trans->blocks_used;
1829 btrfs_end_transaction(trans, root);
1830 fail:
1831 mutex_unlock(&root->fs_info->fs_mutex);
1832
1833 if (drop_inode) {
1834 inode_dec_link_count(inode);
1835 iput(inode);
1836 }
1837 btrfs_btree_balance_dirty(root, nr);
1838 btrfs_throttle(root);
1839 return err;
1840 }
1841
1842 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1843 {
1844 struct inode *inode;
1845 struct btrfs_trans_handle *trans;
1846 struct btrfs_root *root = BTRFS_I(dir)->root;
1847 int err = 0;
1848 int drop_on_err = 0;
1849 u64 objectid;
1850 unsigned long nr = 1;
1851
1852 mutex_lock(&root->fs_info->fs_mutex);
1853 err = btrfs_check_free_space(root, 1, 0);
1854 if (err)
1855 goto out_unlock;
1856
1857 trans = btrfs_start_transaction(root, 1);
1858 btrfs_set_trans_block_group(trans, dir);
1859
1860 if (IS_ERR(trans)) {
1861 err = PTR_ERR(trans);
1862 goto out_unlock;
1863 }
1864
1865 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1866 if (err) {
1867 err = -ENOSPC;
1868 goto out_unlock;
1869 }
1870
1871 inode = btrfs_new_inode(trans, root, dentry->d_name.name,
1872 dentry->d_name.len,
1873 dentry->d_parent->d_inode->i_ino, objectid,
1874 BTRFS_I(dir)->block_group, S_IFDIR | mode);
1875 if (IS_ERR(inode)) {
1876 err = PTR_ERR(inode);
1877 goto out_fail;
1878 }
1879
1880 drop_on_err = 1;
1881 inode->i_op = &btrfs_dir_inode_operations;
1882 inode->i_fop = &btrfs_dir_file_operations;
1883 btrfs_set_trans_block_group(trans, inode);
1884
1885 inode->i_size = 0;
1886 err = btrfs_update_inode(trans, root, inode);
1887 if (err)
1888 goto out_fail;
1889
1890 err = btrfs_add_link(trans, dentry, inode, 0);
1891 if (err)
1892 goto out_fail;
1893
1894 d_instantiate(dentry, inode);
1895 drop_on_err = 0;
1896 dir->i_sb->s_dirt = 1;
1897 btrfs_update_inode_block_group(trans, inode);
1898 btrfs_update_inode_block_group(trans, dir);
1899
1900 out_fail:
1901 nr = trans->blocks_used;
1902 btrfs_end_transaction(trans, root);
1903
1904 out_unlock:
1905 mutex_unlock(&root->fs_info->fs_mutex);
1906 if (drop_on_err)
1907 iput(inode);
1908 btrfs_btree_balance_dirty(root, nr);
1909 btrfs_throttle(root);
1910 return err;
1911 }
1912
1913 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
1914 size_t pg_offset, u64 start, u64 len,
1915 int create)
1916 {
1917 int ret;
1918 int err = 0;
1919 u64 bytenr;
1920 u64 extent_start = 0;
1921 u64 extent_end = 0;
1922 u64 objectid = inode->i_ino;
1923 u32 found_type;
1924 struct btrfs_path *path;
1925 struct btrfs_root *root = BTRFS_I(inode)->root;
1926 struct btrfs_file_extent_item *item;
1927 struct extent_buffer *leaf;
1928 struct btrfs_key found_key;
1929 struct extent_map *em = NULL;
1930 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1931 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1932 struct btrfs_trans_handle *trans = NULL;
1933
1934 path = btrfs_alloc_path();
1935 BUG_ON(!path);
1936 mutex_lock(&root->fs_info->fs_mutex);
1937
1938 again:
1939 spin_lock(&em_tree->lock);
1940 em = lookup_extent_mapping(em_tree, start, len);
1941 spin_unlock(&em_tree->lock);
1942
1943 if (em) {
1944 if (em->start > start) {
1945 printk("get_extent lookup [%Lu %Lu] em [%Lu %Lu]\n",
1946 start, len, em->start, em->len);
1947 WARN_ON(1);
1948 }
1949 if (em->block_start == EXTENT_MAP_INLINE && page)
1950 free_extent_map(em);
1951 else
1952 goto out;
1953 }
1954 em = alloc_extent_map(GFP_NOFS);
1955 if (!em) {
1956 err = -ENOMEM;
1957 goto out;
1958 }
1959
1960 em->start = EXTENT_MAP_HOLE;
1961 em->len = (u64)-1;
1962 em->bdev = inode->i_sb->s_bdev;
1963 ret = btrfs_lookup_file_extent(trans, root, path,
1964 objectid, start, trans != NULL);
1965 if (ret < 0) {
1966 err = ret;
1967 goto out;
1968 }
1969
1970 if (ret != 0) {
1971 if (path->slots[0] == 0)
1972 goto not_found;
1973 path->slots[0]--;
1974 }
1975
1976 leaf = path->nodes[0];
1977 item = btrfs_item_ptr(leaf, path->slots[0],
1978 struct btrfs_file_extent_item);
1979 /* are we inside the extent that was found? */
1980 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1981 found_type = btrfs_key_type(&found_key);
1982 if (found_key.objectid != objectid ||
1983 found_type != BTRFS_EXTENT_DATA_KEY) {
1984 goto not_found;
1985 }
1986
1987 found_type = btrfs_file_extent_type(leaf, item);
1988 extent_start = found_key.offset;
1989 if (found_type == BTRFS_FILE_EXTENT_REG) {
1990 extent_end = extent_start +
1991 btrfs_file_extent_num_bytes(leaf, item);
1992 err = 0;
1993 if (start < extent_start || start >= extent_end) {
1994 em->start = start;
1995 if (start < extent_start) {
1996 if (start + len <= extent_start)
1997 goto not_found;
1998 em->len = extent_end - extent_start;
1999 } else {
2000 em->len = len;
2001 }
2002 goto not_found_em;
2003 }
2004 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
2005 if (bytenr == 0) {
2006 em->start = extent_start;
2007 em->len = extent_end - extent_start;
2008 em->block_start = EXTENT_MAP_HOLE;
2009 goto insert;
2010 }
2011 bytenr += btrfs_file_extent_offset(leaf, item);
2012 em->block_start = bytenr;
2013 em->start = extent_start;
2014 em->len = extent_end - extent_start;
2015 goto insert;
2016 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
2017 u64 page_start;
2018 unsigned long ptr;
2019 char *map;
2020 size_t size;
2021 size_t extent_offset;
2022 size_t copy_size;
2023
2024 size = btrfs_file_extent_inline_len(leaf, btrfs_item_nr(leaf,
2025 path->slots[0]));
2026 extent_end = (extent_start + size + root->sectorsize - 1) &
2027 ~((u64)root->sectorsize - 1);
2028 if (start < extent_start || start >= extent_end) {
2029 em->start = start;
2030 if (start < extent_start) {
2031 if (start + len <= extent_start)
2032 goto not_found;
2033 em->len = extent_end - extent_start;
2034 } else {
2035 em->len = len;
2036 }
2037 goto not_found_em;
2038 }
2039 em->block_start = EXTENT_MAP_INLINE;
2040
2041 if (!page) {
2042 em->start = extent_start;
2043 em->len = size;
2044 goto out;
2045 }
2046
2047 page_start = page_offset(page) + pg_offset;
2048 extent_offset = page_start - extent_start;
2049 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
2050 size - extent_offset);
2051 em->start = extent_start + extent_offset;
2052 em->len = (copy_size + root->sectorsize - 1) &
2053 ~((u64)root->sectorsize - 1);
2054 map = kmap(page);
2055 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
2056 if (create == 0 && !PageUptodate(page)) {
2057 read_extent_buffer(leaf, map + pg_offset, ptr,
2058 copy_size);
2059 flush_dcache_page(page);
2060 } else if (create && PageUptodate(page)) {
2061 if (!trans) {
2062 kunmap(page);
2063 free_extent_map(em);
2064 em = NULL;
2065 btrfs_release_path(root, path);
2066 trans = btrfs_start_transaction(root, 1);
2067 goto again;
2068 }
2069 write_extent_buffer(leaf, map + pg_offset, ptr,
2070 copy_size);
2071 btrfs_mark_buffer_dirty(leaf);
2072 }
2073 kunmap(page);
2074 set_extent_uptodate(io_tree, em->start,
2075 extent_map_end(em) - 1, GFP_NOFS);
2076 goto insert;
2077 } else {
2078 printk("unkknown found_type %d\n", found_type);
2079 WARN_ON(1);
2080 }
2081 not_found:
2082 em->start = start;
2083 em->len = len;
2084 not_found_em:
2085 em->block_start = EXTENT_MAP_HOLE;
2086 insert:
2087 btrfs_release_path(root, path);
2088 if (em->start > start || extent_map_end(em) <= start) {
2089 printk("bad extent! em: [%Lu %Lu] passed [%Lu %Lu]\n", em->start, em->len, start, len);
2090 err = -EIO;
2091 goto out;
2092 }
2093
2094 err = 0;
2095 spin_lock(&em_tree->lock);
2096 ret = add_extent_mapping(em_tree, em);
2097 if (ret == -EEXIST) {
2098 free_extent_map(em);
2099 em = lookup_extent_mapping(em_tree, start, len);
2100 if (!em) {
2101 err = -EIO;
2102 printk("failing to insert %Lu %Lu\n", start, len);
2103 }
2104 }
2105 spin_unlock(&em_tree->lock);
2106 out:
2107 btrfs_free_path(path);
2108 if (trans) {
2109 ret = btrfs_end_transaction(trans, root);
2110 if (!err)
2111 err = ret;
2112 }
2113 mutex_unlock(&root->fs_info->fs_mutex);
2114 if (err) {
2115 free_extent_map(em);
2116 WARN_ON(1);
2117 return ERR_PTR(err);
2118 }
2119 return em;
2120 }
2121
2122 static sector_t btrfs_bmap(struct address_space *mapping, sector_t iblock)
2123 {
2124 return extent_bmap(mapping, iblock, btrfs_get_extent);
2125 }
2126
2127 int btrfs_readpage(struct file *file, struct page *page)
2128 {
2129 struct extent_io_tree *tree;
2130 tree = &BTRFS_I(page->mapping->host)->io_tree;
2131 return extent_read_full_page(tree, page, btrfs_get_extent);
2132 }
2133
2134 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
2135 {
2136 struct extent_io_tree *tree;
2137
2138
2139 if (current->flags & PF_MEMALLOC) {
2140 redirty_page_for_writepage(wbc, page);
2141 unlock_page(page);
2142 return 0;
2143 }
2144 tree = &BTRFS_I(page->mapping->host)->io_tree;
2145 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
2146 }
2147
2148 static int btrfs_writepages(struct address_space *mapping,
2149 struct writeback_control *wbc)
2150 {
2151 struct extent_io_tree *tree;
2152 tree = &BTRFS_I(mapping->host)->io_tree;
2153 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
2154 }
2155
2156 static int
2157 btrfs_readpages(struct file *file, struct address_space *mapping,
2158 struct list_head *pages, unsigned nr_pages)
2159 {
2160 struct extent_io_tree *tree;
2161 tree = &BTRFS_I(mapping->host)->io_tree;
2162 return extent_readpages(tree, mapping, pages, nr_pages,
2163 btrfs_get_extent);
2164 }
2165
2166 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
2167 {
2168 struct extent_io_tree *tree;
2169 struct extent_map_tree *map;
2170 int ret;
2171
2172 tree = &BTRFS_I(page->mapping->host)->io_tree;
2173 map = &BTRFS_I(page->mapping->host)->extent_tree;
2174 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
2175 if (ret == 1) {
2176 ClearPagePrivate(page);
2177 set_page_private(page, 0);
2178 page_cache_release(page);
2179 }
2180 return ret;
2181 }
2182
2183 static void btrfs_invalidatepage(struct page *page, unsigned long offset)
2184 {
2185 struct extent_io_tree *tree;
2186
2187 tree = &BTRFS_I(page->mapping->host)->io_tree;
2188 extent_invalidatepage(tree, page, offset);
2189 btrfs_releasepage(page, GFP_NOFS);
2190 }
2191
2192 /*
2193 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
2194 * called from a page fault handler when a page is first dirtied. Hence we must
2195 * be careful to check for EOF conditions here. We set the page up correctly
2196 * for a written page which means we get ENOSPC checking when writing into
2197 * holes and correct delalloc and unwritten extent mapping on filesystems that
2198 * support these features.
2199 *
2200 * We are not allowed to take the i_mutex here so we have to play games to
2201 * protect against truncate races as the page could now be beyond EOF. Because
2202 * vmtruncate() writes the inode size before removing pages, once we have the
2203 * page lock we can determine safely if the page is beyond EOF. If it is not
2204 * beyond EOF, then the page is guaranteed safe against truncation until we
2205 * unlock the page.
2206 */
2207 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
2208 {
2209 struct inode *inode = fdentry(vma->vm_file)->d_inode;
2210 struct btrfs_root *root = BTRFS_I(inode)->root;
2211 unsigned long end;
2212 loff_t size;
2213 int ret;
2214 u64 page_start;
2215
2216 mutex_lock(&root->fs_info->fs_mutex);
2217 ret = btrfs_check_free_space(root, PAGE_CACHE_SIZE, 0);
2218 mutex_unlock(&root->fs_info->fs_mutex);
2219 if (ret)
2220 goto out;
2221
2222 ret = -EINVAL;
2223
2224 lock_page(page);
2225 wait_on_page_writeback(page);
2226 size = i_size_read(inode);
2227 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2228
2229 if ((page->mapping != inode->i_mapping) ||
2230 (page_start > size)) {
2231 /* page got truncated out from underneath us */
2232 goto out_unlock;
2233 }
2234
2235 /* page is wholly or partially inside EOF */
2236 if (page_start + PAGE_CACHE_SIZE > size)
2237 end = size & ~PAGE_CACHE_MASK;
2238 else
2239 end = PAGE_CACHE_SIZE;
2240
2241 ret = btrfs_cow_one_page(inode, page, end);
2242
2243 out_unlock:
2244 unlock_page(page);
2245 out:
2246 return ret;
2247 }
2248
2249 static void btrfs_truncate(struct inode *inode)
2250 {
2251 struct btrfs_root *root = BTRFS_I(inode)->root;
2252 int ret;
2253 struct btrfs_trans_handle *trans;
2254 unsigned long nr;
2255
2256 if (!S_ISREG(inode->i_mode))
2257 return;
2258 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
2259 return;
2260
2261 btrfs_truncate_page(inode->i_mapping, inode->i_size);
2262
2263 mutex_lock(&root->fs_info->fs_mutex);
2264 trans = btrfs_start_transaction(root, 1);
2265 btrfs_set_trans_block_group(trans, inode);
2266
2267 /* FIXME, add redo link to tree so we don't leak on crash */
2268 ret = btrfs_truncate_in_trans(trans, root, inode,
2269 BTRFS_EXTENT_DATA_KEY);
2270 btrfs_update_inode(trans, root, inode);
2271 nr = trans->blocks_used;
2272
2273 ret = btrfs_end_transaction(trans, root);
2274 BUG_ON(ret);
2275 mutex_unlock(&root->fs_info->fs_mutex);
2276 btrfs_btree_balance_dirty(root, nr);
2277 btrfs_throttle(root);
2278 }
2279
2280 static int noinline create_subvol(struct btrfs_root *root, char *name,
2281 int namelen)
2282 {
2283 struct btrfs_trans_handle *trans;
2284 struct btrfs_key key;
2285 struct btrfs_root_item root_item;
2286 struct btrfs_inode_item *inode_item;
2287 struct extent_buffer *leaf;
2288 struct btrfs_root *new_root = root;
2289 struct inode *inode;
2290 struct inode *dir;
2291 int ret;
2292 int err;
2293 u64 objectid;
2294 u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
2295 unsigned long nr = 1;
2296
2297 mutex_lock(&root->fs_info->fs_mutex);
2298 ret = btrfs_check_free_space(root, 1, 0);
2299 if (ret)
2300 goto fail_commit;
2301
2302 trans = btrfs_start_transaction(root, 1);
2303 BUG_ON(!trans);
2304
2305 ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
2306 0, &objectid);
2307 if (ret)
2308 goto fail;
2309
2310 leaf = __btrfs_alloc_free_block(trans, root, root->leafsize,
2311 objectid, trans->transid, 0, 0,
2312 0, 0);
2313 if (IS_ERR(leaf))
2314 return PTR_ERR(leaf);
2315
2316 btrfs_set_header_nritems(leaf, 0);
2317 btrfs_set_header_level(leaf, 0);
2318 btrfs_set_header_bytenr(leaf, leaf->start);
2319 btrfs_set_header_generation(leaf, trans->transid);
2320 btrfs_set_header_owner(leaf, objectid);
2321
2322 write_extent_buffer(leaf, root->fs_info->fsid,
2323 (unsigned long)btrfs_header_fsid(leaf),
2324 BTRFS_FSID_SIZE);
2325 btrfs_mark_buffer_dirty(leaf);
2326
2327 inode_item = &root_item.inode;
2328 memset(inode_item, 0, sizeof(*inode_item));
2329 inode_item->generation = cpu_to_le64(1);
2330 inode_item->size = cpu_to_le64(3);
2331 inode_item->nlink = cpu_to_le32(1);
2332 inode_item->nblocks = cpu_to_le64(1);
2333 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
2334
2335 btrfs_set_root_bytenr(&root_item, leaf->start);
2336 btrfs_set_root_level(&root_item, 0);
2337 btrfs_set_root_refs(&root_item, 1);
2338 btrfs_set_root_used(&root_item, 0);
2339
2340 memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
2341 root_item.drop_level = 0;
2342
2343 free_extent_buffer(leaf);
2344 leaf = NULL;
2345
2346 btrfs_set_root_dirid(&root_item, new_dirid);
2347
2348 key.objectid = objectid;
2349 key.offset = 1;
2350 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
2351 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
2352 &root_item);
2353 if (ret)
2354 goto fail;
2355
2356 /*
2357 * insert the directory item
2358 */
2359 key.offset = (u64)-1;
2360 dir = root->fs_info->sb->s_root->d_inode;
2361 ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
2362 name, namelen, dir->i_ino, &key,
2363 BTRFS_FT_DIR);
2364 if (ret)
2365 goto fail;
2366
2367 ret = btrfs_insert_inode_ref(trans, root->fs_info->tree_root,
2368 name, namelen, objectid,
2369 root->fs_info->sb->s_root->d_inode->i_ino);
2370 if (ret)
2371 goto fail;
2372
2373 ret = btrfs_commit_transaction(trans, root);
2374 if (ret)
2375 goto fail_commit;
2376
2377 new_root = btrfs_read_fs_root(root->fs_info, &key, name, namelen);
2378 BUG_ON(!new_root);
2379
2380 trans = btrfs_start_transaction(new_root, 1);
2381 BUG_ON(!trans);
2382
2383 inode = btrfs_new_inode(trans, new_root, "..", 2, new_dirid,
2384 new_dirid,
2385 BTRFS_I(dir)->block_group, S_IFDIR | 0700);
2386 if (IS_ERR(inode))
2387 goto fail;
2388 inode->i_op = &btrfs_dir_inode_operations;
2389 inode->i_fop = &btrfs_dir_file_operations;
2390 new_root->inode = inode;
2391
2392 ret = btrfs_insert_inode_ref(trans, new_root, "..", 2, new_dirid,
2393 new_dirid);
2394 inode->i_nlink = 1;
2395 inode->i_size = 0;
2396 ret = btrfs_update_inode(trans, new_root, inode);
2397 if (ret)
2398 goto fail;
2399 fail:
2400 nr = trans->blocks_used;
2401 err = btrfs_commit_transaction(trans, new_root);
2402 if (err && !ret)
2403 ret = err;
2404 fail_commit:
2405 mutex_unlock(&root->fs_info->fs_mutex);
2406 btrfs_btree_balance_dirty(root, nr);
2407 btrfs_throttle(root);
2408 return ret;
2409 }
2410
2411 static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
2412 {
2413 struct btrfs_pending_snapshot *pending_snapshot;
2414 struct btrfs_trans_handle *trans;
2415 int ret;
2416 int err;
2417 unsigned long nr = 0;
2418
2419 if (!root->ref_cows)
2420 return -EINVAL;
2421
2422 mutex_lock(&root->fs_info->fs_mutex);
2423 ret = btrfs_check_free_space(root, 1, 0);
2424 if (ret)
2425 goto fail_unlock;
2426
2427 pending_snapshot = kmalloc(sizeof(*pending_snapshot), GFP_NOFS);
2428 if (!pending_snapshot) {
2429 ret = -ENOMEM;
2430 goto fail_unlock;
2431 }
2432 pending_snapshot->name = kmalloc(namelen + 1, GFP_NOFS);
2433 if (!pending_snapshot->name) {
2434 ret = -ENOMEM;
2435 kfree(pending_snapshot);
2436 goto fail_unlock;
2437 }
2438 memcpy(pending_snapshot->name, name, namelen);
2439 pending_snapshot->name[namelen] = '\0';
2440 trans = btrfs_start_transaction(root, 1);
2441 BUG_ON(!trans);
2442 pending_snapshot->root = root;
2443 list_add(&pending_snapshot->list,
2444 &trans->transaction->pending_snapshots);
2445 ret = btrfs_update_inode(trans, root, root->inode);
2446 err = btrfs_commit_transaction(trans, root);
2447
2448 fail_unlock:
2449 mutex_unlock(&root->fs_info->fs_mutex);
2450 btrfs_btree_balance_dirty(root, nr);
2451 btrfs_throttle(root);
2452 return ret;
2453 }
2454
2455 unsigned long btrfs_force_ra(struct address_space *mapping,
2456 struct file_ra_state *ra, struct file *file,
2457 pgoff_t offset, pgoff_t last_index)
2458 {
2459 pgoff_t req_size;
2460
2461 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
2462 req_size = last_index - offset + 1;
2463 offset = page_cache_readahead(mapping, ra, file, offset, req_size);
2464 return offset;
2465 #else
2466 req_size = min(last_index - offset + 1, (pgoff_t)128);
2467 page_cache_sync_readahead(mapping, ra, file, offset, req_size);
2468 return offset + req_size;
2469 #endif
2470 }
2471
2472 int btrfs_defrag_file(struct file *file) {
2473 struct inode *inode = fdentry(file)->d_inode;
2474 struct btrfs_root *root = BTRFS_I(inode)->root;
2475 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2476 struct page *page;
2477 unsigned long last_index;
2478 unsigned long ra_index = 0;
2479 u64 page_start;
2480 u64 page_end;
2481 unsigned long i;
2482 int ret;
2483
2484 mutex_lock(&root->fs_info->fs_mutex);
2485 ret = btrfs_check_free_space(root, inode->i_size, 0);
2486 mutex_unlock(&root->fs_info->fs_mutex);
2487 if (ret)
2488 return -ENOSPC;
2489
2490 mutex_lock(&inode->i_mutex);
2491 last_index = inode->i_size >> PAGE_CACHE_SHIFT;
2492 for (i = 0; i <= last_index; i++) {
2493 if (i == ra_index) {
2494 ra_index = btrfs_force_ra(inode->i_mapping,
2495 &file->f_ra,
2496 file, ra_index, last_index);
2497 }
2498 page = grab_cache_page(inode->i_mapping, i);
2499 if (!page)
2500 goto out_unlock;
2501 if (!PageUptodate(page)) {
2502 btrfs_readpage(NULL, page);
2503 lock_page(page);
2504 if (!PageUptodate(page)) {
2505 unlock_page(page);
2506 page_cache_release(page);
2507 goto out_unlock;
2508 }
2509 }
2510 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2511 page_end = page_start + PAGE_CACHE_SIZE - 1;
2512
2513 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
2514 set_extent_delalloc(io_tree, page_start,
2515 page_end, GFP_NOFS);
2516
2517 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
2518 set_page_dirty(page);
2519 unlock_page(page);
2520 page_cache_release(page);
2521 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
2522 }
2523
2524 out_unlock:
2525 mutex_unlock(&inode->i_mutex);
2526 return 0;
2527 }
2528
2529 static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
2530 {
2531 u64 new_size;
2532 u64 old_size;
2533 struct btrfs_ioctl_vol_args *vol_args;
2534 struct btrfs_trans_handle *trans;
2535 char *sizestr;
2536 int ret = 0;
2537 int namelen;
2538 int mod = 0;
2539
2540 vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
2541
2542 if (!vol_args)
2543 return -ENOMEM;
2544
2545 if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
2546 ret = -EFAULT;
2547 goto out;
2548 }
2549 namelen = strlen(vol_args->name);
2550 if (namelen > BTRFS_VOL_NAME_MAX) {
2551 ret = -EINVAL;
2552 goto out;
2553 }
2554
2555 sizestr = vol_args->name;
2556 if (!strcmp(sizestr, "max"))
2557 new_size = root->fs_info->sb->s_bdev->bd_inode->i_size;
2558 else {
2559 if (sizestr[0] == '-') {
2560 mod = -1;
2561 sizestr++;
2562 } else if (sizestr[0] == '+') {
2563 mod = 1;
2564 sizestr++;
2565 }
2566 new_size = btrfs_parse_size(sizestr);
2567 if (new_size == 0) {
2568 ret = -EINVAL;
2569 goto out;
2570 }
2571 }
2572
2573 mutex_lock(&root->fs_info->fs_mutex);
2574 old_size = btrfs_super_total_bytes(&root->fs_info->super_copy);
2575
2576 if (mod < 0) {
2577 if (new_size > old_size) {
2578 ret = -EINVAL;
2579 goto out_unlock;
2580 }
2581 new_size = old_size - new_size;
2582 } else if (mod > 0) {
2583 new_size = old_size + new_size;
2584 }
2585
2586 if (new_size < 256 * 1024 * 1024) {
2587 ret = -EINVAL;
2588 goto out_unlock;
2589 }
2590 if (new_size > root->fs_info->sb->s_bdev->bd_inode->i_size) {
2591 ret = -EFBIG;
2592 goto out_unlock;
2593 }
2594
2595 do_div(new_size, root->sectorsize);
2596 new_size *= root->sectorsize;
2597
2598 printk("new size is %Lu\n", new_size);
2599 if (new_size > old_size) {
2600 trans = btrfs_start_transaction(root, 1);
2601 ret = btrfs_grow_extent_tree(trans, root, new_size);
2602 btrfs_commit_transaction(trans, root);
2603 } else {
2604 ret = btrfs_shrink_extent_tree(root, new_size);
2605 }
2606
2607 out_unlock:
2608 mutex_unlock(&root->fs_info->fs_mutex);
2609 out:
2610 kfree(vol_args);
2611 return ret;
2612 }
2613
2614 static int noinline btrfs_ioctl_snap_create(struct btrfs_root *root,
2615 void __user *arg)
2616 {
2617 struct btrfs_ioctl_vol_args *vol_args;
2618 struct btrfs_dir_item *di;
2619 struct btrfs_path *path;
2620 u64 root_dirid;
2621 int namelen;
2622 int ret;
2623
2624 vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
2625
2626 if (!vol_args)
2627 return -ENOMEM;
2628
2629 if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
2630 ret = -EFAULT;
2631 goto out;
2632 }
2633
2634 namelen = strlen(vol_args->name);
2635 if (namelen > BTRFS_VOL_NAME_MAX) {
2636 ret = -EINVAL;
2637 goto out;
2638 }
2639 if (strchr(vol_args->name, '/')) {
2640 ret = -EINVAL;
2641 goto out;
2642 }
2643
2644 path = btrfs_alloc_path();
2645 if (!path) {
2646 ret = -ENOMEM;
2647 goto out;
2648 }
2649
2650 root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
2651 mutex_lock(&root->fs_info->fs_mutex);
2652 di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
2653 path, root_dirid,
2654 vol_args->name, namelen, 0);
2655 mutex_unlock(&root->fs_info->fs_mutex);
2656 btrfs_free_path(path);
2657
2658 if (di && !IS_ERR(di)) {
2659 ret = -EEXIST;
2660 goto out;
2661 }
2662
2663 if (IS_ERR(di)) {
2664 ret = PTR_ERR(di);
2665 goto out;
2666 }
2667
2668 if (root == root->fs_info->tree_root)
2669 ret = create_subvol(root, vol_args->name, namelen);
2670 else
2671 ret = create_snapshot(root, vol_args->name, namelen);
2672 out:
2673 kfree(vol_args);
2674 return ret;
2675 }
2676
2677 static int btrfs_ioctl_defrag(struct file *file)
2678 {
2679 struct inode *inode = fdentry(file)->d_inode;
2680 struct btrfs_root *root = BTRFS_I(inode)->root;
2681
2682 switch (inode->i_mode & S_IFMT) {
2683 case S_IFDIR:
2684 mutex_lock(&root->fs_info->fs_mutex);
2685 btrfs_defrag_root(root, 0);
2686 btrfs_defrag_root(root->fs_info->extent_root, 0);
2687 mutex_unlock(&root->fs_info->fs_mutex);
2688 break;
2689 case S_IFREG:
2690 btrfs_defrag_file(file);
2691 break;
2692 }
2693
2694 return 0;
2695 }
2696
2697 long btrfs_ioctl(struct file *file, unsigned int
2698 cmd, unsigned long arg)
2699 {
2700 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
2701
2702 switch (cmd) {
2703 case BTRFS_IOC_SNAP_CREATE:
2704 return btrfs_ioctl_snap_create(root, (void __user *)arg);
2705 case BTRFS_IOC_DEFRAG:
2706 return btrfs_ioctl_defrag(file);
2707 case BTRFS_IOC_RESIZE:
2708 return btrfs_ioctl_resize(root, (void __user *)arg);
2709 }
2710
2711 return -ENOTTY;
2712 }
2713
2714 /*
2715 * Called inside transaction, so use GFP_NOFS
2716 */
2717 struct inode *btrfs_alloc_inode(struct super_block *sb)
2718 {
2719 struct btrfs_inode *ei;
2720
2721 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
2722 if (!ei)
2723 return NULL;
2724 ei->last_trans = 0;
2725 ei->ordered_trans = 0;
2726 return &ei->vfs_inode;
2727 }
2728
2729 void btrfs_destroy_inode(struct inode *inode)
2730 {
2731 WARN_ON(!list_empty(&inode->i_dentry));
2732 WARN_ON(inode->i_data.nrpages);
2733
2734 btrfs_drop_extent_cache(inode, 0, (u64)-1);
2735 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
2736 }
2737
2738 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
2739 static void init_once(struct kmem_cache * cachep, void *foo)
2740 #else
2741 static void init_once(void * foo, struct kmem_cache * cachep,
2742 unsigned long flags)
2743 #endif
2744 {
2745 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
2746
2747 inode_init_once(&ei->vfs_inode);
2748 }
2749
2750 void btrfs_destroy_cachep(void)
2751 {
2752 if (btrfs_inode_cachep)
2753 kmem_cache_destroy(btrfs_inode_cachep);
2754 if (btrfs_trans_handle_cachep)
2755 kmem_cache_destroy(btrfs_trans_handle_cachep);
2756 if (btrfs_transaction_cachep)
2757 kmem_cache_destroy(btrfs_transaction_cachep);
2758 if (btrfs_bit_radix_cachep)
2759 kmem_cache_destroy(btrfs_bit_radix_cachep);
2760 if (btrfs_path_cachep)
2761 kmem_cache_destroy(btrfs_path_cachep);
2762 }
2763
2764 struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
2765 unsigned long extra_flags,
2766 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
2767 void (*ctor)(struct kmem_cache *, void *)
2768 #else
2769 void (*ctor)(void *, struct kmem_cache *,
2770 unsigned long)
2771 #endif
2772 )
2773 {
2774 return kmem_cache_create(name, size, 0, (SLAB_RECLAIM_ACCOUNT |
2775 SLAB_MEM_SPREAD | extra_flags), ctor
2776 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
2777 ,NULL
2778 #endif
2779 );
2780 }
2781
2782 int btrfs_init_cachep(void)
2783 {
2784 btrfs_inode_cachep = btrfs_cache_create("btrfs_inode_cache",
2785 sizeof(struct btrfs_inode),
2786 0, init_once);
2787 if (!btrfs_inode_cachep)
2788 goto fail;
2789 btrfs_trans_handle_cachep =
2790 btrfs_cache_create("btrfs_trans_handle_cache",
2791 sizeof(struct btrfs_trans_handle),
2792 0, NULL);
2793 if (!btrfs_trans_handle_cachep)
2794 goto fail;
2795 btrfs_transaction_cachep = btrfs_cache_create("btrfs_transaction_cache",
2796 sizeof(struct btrfs_transaction),
2797 0, NULL);
2798 if (!btrfs_transaction_cachep)
2799 goto fail;
2800 btrfs_path_cachep = btrfs_cache_create("btrfs_path_cache",
2801 sizeof(struct btrfs_path),
2802 0, NULL);
2803 if (!btrfs_path_cachep)
2804 goto fail;
2805 btrfs_bit_radix_cachep = btrfs_cache_create("btrfs_radix", 256,
2806 SLAB_DESTROY_BY_RCU, NULL);
2807 if (!btrfs_bit_radix_cachep)
2808 goto fail;
2809 return 0;
2810 fail:
2811 btrfs_destroy_cachep();
2812 return -ENOMEM;
2813 }
2814
2815 static int btrfs_getattr(struct vfsmount *mnt,
2816 struct dentry *dentry, struct kstat *stat)
2817 {
2818 struct inode *inode = dentry->d_inode;
2819 generic_fillattr(inode, stat);
2820 stat->blksize = PAGE_CACHE_SIZE;
2821 stat->blocks = inode->i_blocks + (BTRFS_I(inode)->delalloc_bytes >> 9);
2822 return 0;
2823 }
2824
2825 static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
2826 struct inode * new_dir,struct dentry *new_dentry)
2827 {
2828 struct btrfs_trans_handle *trans;
2829 struct btrfs_root *root = BTRFS_I(old_dir)->root;
2830 struct inode *new_inode = new_dentry->d_inode;
2831 struct inode *old_inode = old_dentry->d_inode;
2832 struct timespec ctime = CURRENT_TIME;
2833 struct btrfs_path *path;
2834 int ret;
2835
2836 if (S_ISDIR(old_inode->i_mode) && new_inode &&
2837 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
2838 return -ENOTEMPTY;
2839 }
2840
2841 mutex_lock(&root->fs_info->fs_mutex);
2842 ret = btrfs_check_free_space(root, 1, 0);
2843 if (ret)
2844 goto out_unlock;
2845
2846 trans = btrfs_start_transaction(root, 1);
2847
2848 btrfs_set_trans_block_group(trans, new_dir);
2849 path = btrfs_alloc_path();
2850 if (!path) {
2851 ret = -ENOMEM;
2852 goto out_fail;
2853 }
2854
2855 old_dentry->d_inode->i_nlink++;
2856 old_dir->i_ctime = old_dir->i_mtime = ctime;
2857 new_dir->i_ctime = new_dir->i_mtime = ctime;
2858 old_inode->i_ctime = ctime;
2859
2860 ret = btrfs_unlink_trans(trans, root, old_dir, old_dentry);
2861 if (ret)
2862 goto out_fail;
2863
2864 if (new_inode) {
2865 new_inode->i_ctime = CURRENT_TIME;
2866 ret = btrfs_unlink_trans(trans, root, new_dir, new_dentry);
2867 if (ret)
2868 goto out_fail;
2869 }
2870 ret = btrfs_add_link(trans, new_dentry, old_inode, 1);
2871 if (ret)
2872 goto out_fail;
2873
2874 out_fail:
2875 btrfs_free_path(path);
2876 btrfs_end_transaction(trans, root);
2877 out_unlock:
2878 mutex_unlock(&root->fs_info->fs_mutex);
2879 return ret;
2880 }
2881
2882 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
2883 const char *symname)
2884 {
2885 struct btrfs_trans_handle *trans;
2886 struct btrfs_root *root = BTRFS_I(dir)->root;
2887 struct btrfs_path *path;
2888 struct btrfs_key key;
2889 struct inode *inode = NULL;
2890 int err;
2891 int drop_inode = 0;
2892 u64 objectid;
2893 int name_len;
2894 int datasize;
2895 unsigned long ptr;
2896 struct btrfs_file_extent_item *ei;
2897 struct extent_buffer *leaf;
2898 unsigned long nr = 0;
2899
2900 name_len = strlen(symname) + 1;
2901 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
2902 return -ENAMETOOLONG;
2903
2904 mutex_lock(&root->fs_info->fs_mutex);
2905 err = btrfs_check_free_space(root, 1, 0);
2906 if (err)
2907 goto out_fail;
2908
2909 trans = btrfs_start_transaction(root, 1);
2910 btrfs_set_trans_block_group(trans, dir);
2911
2912 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
2913 if (err) {
2914 err = -ENOSPC;
2915 goto out_unlock;
2916 }
2917
2918 inode = btrfs_new_inode(trans, root, dentry->d_name.name,
2919 dentry->d_name.len,
2920 dentry->d_parent->d_inode->i_ino, objectid,
2921 BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO);
2922 err = PTR_ERR(inode);
2923 if (IS_ERR(inode))
2924 goto out_unlock;
2925
2926 btrfs_set_trans_block_group(trans, inode);
2927 err = btrfs_add_nondir(trans, dentry, inode, 0);
2928 if (err)
2929 drop_inode = 1;
2930 else {
2931 inode->i_mapping->a_ops = &btrfs_aops;
2932 inode->i_fop = &btrfs_file_operations;
2933 inode->i_op = &btrfs_file_inode_operations;
2934 extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
2935 extent_io_tree_init(&BTRFS_I(inode)->io_tree,
2936 inode->i_mapping, GFP_NOFS);
2937 BTRFS_I(inode)->delalloc_bytes = 0;
2938 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
2939 }
2940 dir->i_sb->s_dirt = 1;
2941 btrfs_update_inode_block_group(trans, inode);
2942 btrfs_update_inode_block_group(trans, dir);
2943 if (drop_inode)
2944 goto out_unlock;
2945
2946 path = btrfs_alloc_path();
2947 BUG_ON(!path);
2948 key.objectid = inode->i_ino;
2949 key.offset = 0;
2950 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
2951 datasize = btrfs_file_extent_calc_inline_size(name_len);
2952 err = btrfs_insert_empty_item(trans, root, path, &key,
2953 datasize);
2954 if (err) {
2955 drop_inode = 1;
2956 goto out_unlock;
2957 }
2958 leaf = path->nodes[0];
2959 ei = btrfs_item_ptr(leaf, path->slots[0],
2960 struct btrfs_file_extent_item);
2961 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
2962 btrfs_set_file_extent_type(leaf, ei,
2963 BTRFS_FILE_EXTENT_INLINE);
2964 ptr = btrfs_file_extent_inline_start(ei);
2965 write_extent_buffer(leaf, symname, ptr, name_len);
2966 btrfs_mark_buffer_dirty(leaf);
2967 btrfs_free_path(path);
2968
2969 inode->i_op = &btrfs_symlink_inode_operations;
2970 inode->i_mapping->a_ops = &btrfs_symlink_aops;
2971 inode->i_size = name_len - 1;
2972 err = btrfs_update_inode(trans, root, inode);
2973 if (err)
2974 drop_inode = 1;
2975
2976 out_unlock:
2977 nr = trans->blocks_used;
2978 btrfs_end_transaction(trans, root);
2979 out_fail:
2980 mutex_unlock(&root->fs_info->fs_mutex);
2981 if (drop_inode) {
2982 inode_dec_link_count(inode);
2983 iput(inode);
2984 }
2985 btrfs_btree_balance_dirty(root, nr);
2986 btrfs_throttle(root);
2987 return err;
2988 }
2989 static int btrfs_permission(struct inode *inode, int mask,
2990 struct nameidata *nd)
2991 {
2992 if (btrfs_test_flag(inode, READONLY) && (mask & MAY_WRITE))
2993 return -EACCES;
2994 return generic_permission(inode, mask, NULL);
2995 }
2996
2997 static struct inode_operations btrfs_dir_inode_operations = {
2998 .lookup = btrfs_lookup,
2999 .create = btrfs_create,
3000 .unlink = btrfs_unlink,
3001 .link = btrfs_link,
3002 .mkdir = btrfs_mkdir,
3003 .rmdir = btrfs_rmdir,
3004 .rename = btrfs_rename,
3005 .symlink = btrfs_symlink,
3006 .setattr = btrfs_setattr,
3007 .mknod = btrfs_mknod,
3008 .setxattr = generic_setxattr,
3009 .getxattr = generic_getxattr,
3010 .listxattr = btrfs_listxattr,
3011 .removexattr = generic_removexattr,
3012 .permission = btrfs_permission,
3013 };
3014 static struct inode_operations btrfs_dir_ro_inode_operations = {
3015 .lookup = btrfs_lookup,
3016 .permission = btrfs_permission,
3017 };
3018 static struct file_operations btrfs_dir_file_operations = {
3019 .llseek = generic_file_llseek,
3020 .read = generic_read_dir,
3021 .readdir = btrfs_readdir,
3022 .unlocked_ioctl = btrfs_ioctl,
3023 #ifdef CONFIG_COMPAT
3024 .compat_ioctl = btrfs_ioctl,
3025 #endif
3026 };
3027
3028 static struct extent_io_ops btrfs_extent_io_ops = {
3029 .fill_delalloc = run_delalloc_range,
3030 .submit_bio_hook = btrfs_submit_bio_hook,
3031 .readpage_io_hook = btrfs_readpage_io_hook,
3032 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
3033 .set_bit_hook = btrfs_set_bit_hook,
3034 .clear_bit_hook = btrfs_clear_bit_hook,
3035 };
3036
3037 static struct address_space_operations btrfs_aops = {
3038 .readpage = btrfs_readpage,
3039 .writepage = btrfs_writepage,
3040 .writepages = btrfs_writepages,
3041 .readpages = btrfs_readpages,
3042 .sync_page = block_sync_page,
3043 .bmap = btrfs_bmap,
3044 .invalidatepage = btrfs_invalidatepage,
3045 .releasepage = btrfs_releasepage,
3046 .set_page_dirty = __set_page_dirty_nobuffers,
3047 };
3048
3049 static struct address_space_operations btrfs_symlink_aops = {
3050 .readpage = btrfs_readpage,
3051 .writepage = btrfs_writepage,
3052 .invalidatepage = btrfs_invalidatepage,
3053 .releasepage = btrfs_releasepage,
3054 };
3055
3056 static struct inode_operations btrfs_file_inode_operations = {
3057 .truncate = btrfs_truncate,
3058 .getattr = btrfs_getattr,
3059 .setattr = btrfs_setattr,
3060 .setxattr = generic_setxattr,
3061 .getxattr = generic_getxattr,
3062 .listxattr = btrfs_listxattr,
3063 .removexattr = generic_removexattr,
3064 .permission = btrfs_permission,
3065 };
3066 static struct inode_operations btrfs_special_inode_operations = {
3067 .getattr = btrfs_getattr,
3068 .setattr = btrfs_setattr,
3069 .permission = btrfs_permission,
3070 };
3071 static struct inode_operations btrfs_symlink_inode_operations = {
3072 .readlink = generic_readlink,
3073 .follow_link = page_follow_link_light,
3074 .put_link = page_put_link,
3075 .permission = btrfs_permission,
3076 };
Linux kernel - Deliverables
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