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Create a btrfs backing dev info
[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_merge_bio_hook(struct page *page, unsigned long offset,
300 size_t size, struct bio *bio)
301 {
302 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
303 struct btrfs_mapping_tree *map_tree;
304 struct btrfs_device *dev;
305 u64 logical = bio->bi_sector << 9;
306 u64 physical;
307 u64 length = 0;
308 u64 map_length;
309 struct bio_vec *bvec;
310 int i;
311 int ret;
312
313 bio_for_each_segment(bvec, bio, i) {
314 length += bvec->bv_len;
315 }
316 map_tree = &root->fs_info->mapping_tree;
317 map_length = length;
318 ret = btrfs_map_block(map_tree, logical, &physical, &map_length, &dev);
319 if (map_length < length + size) {
320 return 1;
321 }
322 return 0;
323 }
324
325 int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio)
326 {
327 struct btrfs_root *root = BTRFS_I(inode)->root;
328 struct btrfs_trans_handle *trans;
329 int ret = 0;
330
331 if (rw != WRITE) {
332 goto mapit;
333 }
334
335 if (btrfs_test_opt(root, NODATASUM) ||
336 btrfs_test_flag(inode, NODATASUM)) {
337 goto mapit;
338 }
339
340 mutex_lock(&root->fs_info->fs_mutex);
341 trans = btrfs_start_transaction(root, 1);
342 btrfs_set_trans_block_group(trans, inode);
343 btrfs_csum_file_blocks(trans, root, inode, bio);
344 ret = btrfs_end_transaction(trans, root);
345 BUG_ON(ret);
346 mutex_unlock(&root->fs_info->fs_mutex);
347 mapit:
348 return btrfs_map_bio(root, rw, bio);
349 }
350
351 int btrfs_readpage_io_hook(struct page *page, u64 start, u64 end)
352 {
353 int ret = 0;
354 struct inode *inode = page->mapping->host;
355 struct btrfs_root *root = BTRFS_I(inode)->root;
356 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
357 struct btrfs_csum_item *item;
358 struct btrfs_path *path = NULL;
359 u32 csum;
360 if (btrfs_test_opt(root, NODATASUM) ||
361 btrfs_test_flag(inode, NODATASUM))
362 return 0;
363 mutex_lock(&root->fs_info->fs_mutex);
364 path = btrfs_alloc_path();
365 item = btrfs_lookup_csum(NULL, root, path, inode->i_ino, start, 0);
366 if (IS_ERR(item)) {
367 ret = PTR_ERR(item);
368 /* a csum that isn't present is a preallocated region. */
369 if (ret == -ENOENT || ret == -EFBIG)
370 ret = 0;
371 csum = 0;
372 printk("no csum found for inode %lu start %Lu\n", inode->i_ino, start);
373 goto out;
374 }
375 read_extent_buffer(path->nodes[0], &csum, (unsigned long)item,
376 BTRFS_CRC32_SIZE);
377 set_state_private(io_tree, start, csum);
378 out:
379 if (path)
380 btrfs_free_path(path);
381 mutex_unlock(&root->fs_info->fs_mutex);
382 return ret;
383 }
384
385 int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
386 struct extent_state *state)
387 {
388 size_t offset = start - ((u64)page->index << PAGE_CACHE_SHIFT);
389 struct inode *inode = page->mapping->host;
390 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
391 char *kaddr;
392 u64 private = ~(u32)0;
393 int ret;
394 struct btrfs_root *root = BTRFS_I(inode)->root;
395 u32 csum = ~(u32)0;
396 unsigned long flags;
397
398 if (btrfs_test_opt(root, NODATASUM) ||
399 btrfs_test_flag(inode, NODATASUM))
400 return 0;
401 if (state && state->start == start) {
402 private = state->private;
403 ret = 0;
404 } else {
405 ret = get_state_private(io_tree, start, &private);
406 }
407 local_irq_save(flags);
408 kaddr = kmap_atomic(page, KM_IRQ0);
409 if (ret) {
410 goto zeroit;
411 }
412 csum = btrfs_csum_data(root, kaddr + offset, csum, end - start + 1);
413 btrfs_csum_final(csum, (char *)&csum);
414 if (csum != private) {
415 goto zeroit;
416 }
417 kunmap_atomic(kaddr, KM_IRQ0);
418 local_irq_restore(flags);
419 return 0;
420
421 zeroit:
422 printk("btrfs csum failed ino %lu off %llu csum %u private %Lu\n",
423 page->mapping->host->i_ino, (unsigned long long)start, csum,
424 private);
425 memset(kaddr + offset, 1, end - start + 1);
426 flush_dcache_page(page);
427 kunmap_atomic(kaddr, KM_IRQ0);
428 local_irq_restore(flags);
429 return 0;
430 }
431
432 void btrfs_read_locked_inode(struct inode *inode)
433 {
434 struct btrfs_path *path;
435 struct extent_buffer *leaf;
436 struct btrfs_inode_item *inode_item;
437 struct btrfs_timespec *tspec;
438 struct btrfs_root *root = BTRFS_I(inode)->root;
439 struct btrfs_key location;
440 u64 alloc_group_block;
441 u32 rdev;
442 int ret;
443
444 path = btrfs_alloc_path();
445 BUG_ON(!path);
446 mutex_lock(&root->fs_info->fs_mutex);
447 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
448
449 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
450 if (ret)
451 goto make_bad;
452
453 leaf = path->nodes[0];
454 inode_item = btrfs_item_ptr(leaf, path->slots[0],
455 struct btrfs_inode_item);
456
457 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
458 inode->i_nlink = btrfs_inode_nlink(leaf, inode_item);
459 inode->i_uid = btrfs_inode_uid(leaf, inode_item);
460 inode->i_gid = btrfs_inode_gid(leaf, inode_item);
461 inode->i_size = btrfs_inode_size(leaf, inode_item);
462
463 tspec = btrfs_inode_atime(inode_item);
464 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
465 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
466
467 tspec = btrfs_inode_mtime(inode_item);
468 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
469 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
470
471 tspec = btrfs_inode_ctime(inode_item);
472 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
473 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
474
475 inode->i_blocks = btrfs_inode_nblocks(leaf, inode_item);
476 inode->i_generation = btrfs_inode_generation(leaf, inode_item);
477 inode->i_rdev = 0;
478 rdev = btrfs_inode_rdev(leaf, inode_item);
479
480 alloc_group_block = btrfs_inode_block_group(leaf, inode_item);
481 BTRFS_I(inode)->block_group = btrfs_lookup_block_group(root->fs_info,
482 alloc_group_block);
483 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
484 if (!BTRFS_I(inode)->block_group) {
485 BTRFS_I(inode)->block_group = btrfs_find_block_group(root,
486 NULL, 0,
487 BTRFS_BLOCK_GROUP_METADATA, 0);
488 }
489 btrfs_free_path(path);
490 inode_item = NULL;
491
492 mutex_unlock(&root->fs_info->fs_mutex);
493
494 switch (inode->i_mode & S_IFMT) {
495 case S_IFREG:
496 inode->i_mapping->a_ops = &btrfs_aops;
497 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
498 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
499 inode->i_fop = &btrfs_file_operations;
500 inode->i_op = &btrfs_file_inode_operations;
501 break;
502 case S_IFDIR:
503 inode->i_fop = &btrfs_dir_file_operations;
504 if (root == root->fs_info->tree_root)
505 inode->i_op = &btrfs_dir_ro_inode_operations;
506 else
507 inode->i_op = &btrfs_dir_inode_operations;
508 break;
509 case S_IFLNK:
510 inode->i_op = &btrfs_symlink_inode_operations;
511 inode->i_mapping->a_ops = &btrfs_symlink_aops;
512 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
513 break;
514 default:
515 init_special_inode(inode, inode->i_mode, rdev);
516 break;
517 }
518 return;
519
520 make_bad:
521 btrfs_release_path(root, path);
522 btrfs_free_path(path);
523 mutex_unlock(&root->fs_info->fs_mutex);
524 make_bad_inode(inode);
525 }
526
527 static void fill_inode_item(struct extent_buffer *leaf,
528 struct btrfs_inode_item *item,
529 struct inode *inode)
530 {
531 btrfs_set_inode_uid(leaf, item, inode->i_uid);
532 btrfs_set_inode_gid(leaf, item, inode->i_gid);
533 btrfs_set_inode_size(leaf, item, inode->i_size);
534 btrfs_set_inode_mode(leaf, item, inode->i_mode);
535 btrfs_set_inode_nlink(leaf, item, inode->i_nlink);
536
537 btrfs_set_timespec_sec(leaf, btrfs_inode_atime(item),
538 inode->i_atime.tv_sec);
539 btrfs_set_timespec_nsec(leaf, btrfs_inode_atime(item),
540 inode->i_atime.tv_nsec);
541
542 btrfs_set_timespec_sec(leaf, btrfs_inode_mtime(item),
543 inode->i_mtime.tv_sec);
544 btrfs_set_timespec_nsec(leaf, btrfs_inode_mtime(item),
545 inode->i_mtime.tv_nsec);
546
547 btrfs_set_timespec_sec(leaf, btrfs_inode_ctime(item),
548 inode->i_ctime.tv_sec);
549 btrfs_set_timespec_nsec(leaf, btrfs_inode_ctime(item),
550 inode->i_ctime.tv_nsec);
551
552 btrfs_set_inode_nblocks(leaf, item, inode->i_blocks);
553 btrfs_set_inode_generation(leaf, item, inode->i_generation);
554 btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
555 btrfs_set_inode_flags(leaf, item, BTRFS_I(inode)->flags);
556 btrfs_set_inode_block_group(leaf, item,
557 BTRFS_I(inode)->block_group->key.objectid);
558 }
559
560 int btrfs_update_inode(struct btrfs_trans_handle *trans,
561 struct btrfs_root *root,
562 struct inode *inode)
563 {
564 struct btrfs_inode_item *inode_item;
565 struct btrfs_path *path;
566 struct extent_buffer *leaf;
567 int ret;
568
569 path = btrfs_alloc_path();
570 BUG_ON(!path);
571 ret = btrfs_lookup_inode(trans, root, path,
572 &BTRFS_I(inode)->location, 1);
573 if (ret) {
574 if (ret > 0)
575 ret = -ENOENT;
576 goto failed;
577 }
578
579 leaf = path->nodes[0];
580 inode_item = btrfs_item_ptr(leaf, path->slots[0],
581 struct btrfs_inode_item);
582
583 fill_inode_item(leaf, inode_item, inode);
584 btrfs_mark_buffer_dirty(leaf);
585 btrfs_set_inode_last_trans(trans, inode);
586 ret = 0;
587 failed:
588 btrfs_release_path(root, path);
589 btrfs_free_path(path);
590 return ret;
591 }
592
593
594 static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
595 struct btrfs_root *root,
596 struct inode *dir,
597 struct dentry *dentry)
598 {
599 struct btrfs_path *path;
600 const char *name = dentry->d_name.name;
601 int name_len = dentry->d_name.len;
602 int ret = 0;
603 struct extent_buffer *leaf;
604 struct btrfs_dir_item *di;
605 struct btrfs_key key;
606
607 path = btrfs_alloc_path();
608 if (!path) {
609 ret = -ENOMEM;
610 goto err;
611 }
612
613 di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
614 name, name_len, -1);
615 if (IS_ERR(di)) {
616 ret = PTR_ERR(di);
617 goto err;
618 }
619 if (!di) {
620 ret = -ENOENT;
621 goto err;
622 }
623 leaf = path->nodes[0];
624 btrfs_dir_item_key_to_cpu(leaf, di, &key);
625 ret = btrfs_delete_one_dir_name(trans, root, path, di);
626 if (ret)
627 goto err;
628 btrfs_release_path(root, path);
629
630 di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
631 key.objectid, name, name_len, -1);
632 if (IS_ERR(di)) {
633 ret = PTR_ERR(di);
634 goto err;
635 }
636 if (!di) {
637 ret = -ENOENT;
638 goto err;
639 }
640 ret = btrfs_delete_one_dir_name(trans, root, path, di);
641
642 dentry->d_inode->i_ctime = dir->i_ctime;
643 ret = btrfs_del_inode_ref(trans, root, name, name_len,
644 dentry->d_inode->i_ino,
645 dentry->d_parent->d_inode->i_ino);
646 if (ret) {
647 printk("failed to delete reference to %.*s, "
648 "inode %lu parent %lu\n", name_len, name,
649 dentry->d_inode->i_ino,
650 dentry->d_parent->d_inode->i_ino);
651 }
652 err:
653 btrfs_free_path(path);
654 if (!ret) {
655 dir->i_size -= name_len * 2;
656 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
657 btrfs_update_inode(trans, root, dir);
658 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
659 dentry->d_inode->i_nlink--;
660 #else
661 drop_nlink(dentry->d_inode);
662 #endif
663 ret = btrfs_update_inode(trans, root, dentry->d_inode);
664 dir->i_sb->s_dirt = 1;
665 }
666 return ret;
667 }
668
669 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
670 {
671 struct btrfs_root *root;
672 struct btrfs_trans_handle *trans;
673 struct inode *inode = dentry->d_inode;
674 int ret;
675 unsigned long nr = 0;
676
677 root = BTRFS_I(dir)->root;
678 mutex_lock(&root->fs_info->fs_mutex);
679
680 ret = btrfs_check_free_space(root, 1, 1);
681 if (ret)
682 goto fail;
683
684 trans = btrfs_start_transaction(root, 1);
685
686 btrfs_set_trans_block_group(trans, dir);
687 ret = btrfs_unlink_trans(trans, root, dir, dentry);
688 nr = trans->blocks_used;
689
690 if (inode->i_nlink == 0) {
691 int found;
692 /* if the inode isn't linked anywhere,
693 * we don't need to worry about
694 * data=ordered
695 */
696 found = btrfs_del_ordered_inode(inode);
697 if (found == 1) {
698 atomic_dec(&inode->i_count);
699 }
700 }
701
702 btrfs_end_transaction(trans, root);
703 fail:
704 mutex_unlock(&root->fs_info->fs_mutex);
705 btrfs_btree_balance_dirty(root, nr);
706 btrfs_throttle(root);
707 return ret;
708 }
709
710 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
711 {
712 struct inode *inode = dentry->d_inode;
713 int err = 0;
714 int ret;
715 struct btrfs_root *root = BTRFS_I(dir)->root;
716 struct btrfs_trans_handle *trans;
717 unsigned long nr = 0;
718
719 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
720 return -ENOTEMPTY;
721
722 mutex_lock(&root->fs_info->fs_mutex);
723 ret = btrfs_check_free_space(root, 1, 1);
724 if (ret)
725 goto fail;
726
727 trans = btrfs_start_transaction(root, 1);
728 btrfs_set_trans_block_group(trans, dir);
729
730 /* now the directory is empty */
731 err = btrfs_unlink_trans(trans, root, dir, dentry);
732 if (!err) {
733 inode->i_size = 0;
734 }
735
736 nr = trans->blocks_used;
737 ret = btrfs_end_transaction(trans, root);
738 fail:
739 mutex_unlock(&root->fs_info->fs_mutex);
740 btrfs_btree_balance_dirty(root, nr);
741 btrfs_throttle(root);
742
743 if (ret && !err)
744 err = ret;
745 return err;
746 }
747
748 /*
749 * this can truncate away extent items, csum items and directory items.
750 * It starts at a high offset and removes keys until it can't find
751 * any higher than i_size.
752 *
753 * csum items that cross the new i_size are truncated to the new size
754 * as well.
755 */
756 static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
757 struct btrfs_root *root,
758 struct inode *inode,
759 u32 min_type)
760 {
761 int ret;
762 struct btrfs_path *path;
763 struct btrfs_key key;
764 struct btrfs_key found_key;
765 u32 found_type;
766 struct extent_buffer *leaf;
767 struct btrfs_file_extent_item *fi;
768 u64 extent_start = 0;
769 u64 extent_num_bytes = 0;
770 u64 item_end = 0;
771 u64 root_gen = 0;
772 u64 root_owner = 0;
773 int found_extent;
774 int del_item;
775 int pending_del_nr = 0;
776 int pending_del_slot = 0;
777 int extent_type = -1;
778
779 btrfs_drop_extent_cache(inode, inode->i_size, (u64)-1);
780 path = btrfs_alloc_path();
781 path->reada = -1;
782 BUG_ON(!path);
783
784 /* FIXME, add redo link to tree so we don't leak on crash */
785 key.objectid = inode->i_ino;
786 key.offset = (u64)-1;
787 key.type = (u8)-1;
788
789 btrfs_init_path(path);
790 search_again:
791 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
792 if (ret < 0) {
793 goto error;
794 }
795 if (ret > 0) {
796 BUG_ON(path->slots[0] == 0);
797 path->slots[0]--;
798 }
799
800 while(1) {
801 fi = NULL;
802 leaf = path->nodes[0];
803 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
804 found_type = btrfs_key_type(&found_key);
805
806 if (found_key.objectid != inode->i_ino)
807 break;
808
809 if (found_type < min_type)
810 break;
811
812 item_end = found_key.offset;
813 if (found_type == BTRFS_EXTENT_DATA_KEY) {
814 fi = btrfs_item_ptr(leaf, path->slots[0],
815 struct btrfs_file_extent_item);
816 extent_type = btrfs_file_extent_type(leaf, fi);
817 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
818 item_end +=
819 btrfs_file_extent_num_bytes(leaf, fi);
820 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
821 struct btrfs_item *item = btrfs_item_nr(leaf,
822 path->slots[0]);
823 item_end += btrfs_file_extent_inline_len(leaf,
824 item);
825 }
826 item_end--;
827 }
828 if (found_type == BTRFS_CSUM_ITEM_KEY) {
829 ret = btrfs_csum_truncate(trans, root, path,
830 inode->i_size);
831 BUG_ON(ret);
832 }
833 if (item_end < inode->i_size) {
834 if (found_type == BTRFS_DIR_ITEM_KEY) {
835 found_type = BTRFS_INODE_ITEM_KEY;
836 } else if (found_type == BTRFS_EXTENT_ITEM_KEY) {
837 found_type = BTRFS_CSUM_ITEM_KEY;
838 } else if (found_type == BTRFS_EXTENT_DATA_KEY) {
839 found_type = BTRFS_XATTR_ITEM_KEY;
840 } else if (found_type == BTRFS_XATTR_ITEM_KEY) {
841 found_type = BTRFS_INODE_REF_KEY;
842 } else if (found_type) {
843 found_type--;
844 } else {
845 break;
846 }
847 btrfs_set_key_type(&key, found_type);
848 goto next;
849 }
850 if (found_key.offset >= inode->i_size)
851 del_item = 1;
852 else
853 del_item = 0;
854 found_extent = 0;
855
856 /* FIXME, shrink the extent if the ref count is only 1 */
857 if (found_type != BTRFS_EXTENT_DATA_KEY)
858 goto delete;
859
860 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
861 u64 num_dec;
862 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
863 if (!del_item) {
864 u64 orig_num_bytes =
865 btrfs_file_extent_num_bytes(leaf, fi);
866 extent_num_bytes = inode->i_size -
867 found_key.offset + root->sectorsize - 1;
868 extent_num_bytes = extent_num_bytes &
869 ~((u64)root->sectorsize - 1);
870 btrfs_set_file_extent_num_bytes(leaf, fi,
871 extent_num_bytes);
872 num_dec = (orig_num_bytes -
873 extent_num_bytes);
874 if (extent_start != 0)
875 dec_i_blocks(inode, num_dec);
876 btrfs_mark_buffer_dirty(leaf);
877 } else {
878 extent_num_bytes =
879 btrfs_file_extent_disk_num_bytes(leaf,
880 fi);
881 /* FIXME blocksize != 4096 */
882 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
883 if (extent_start != 0) {
884 found_extent = 1;
885 dec_i_blocks(inode, num_dec);
886 }
887 root_gen = btrfs_header_generation(leaf);
888 root_owner = btrfs_header_owner(leaf);
889 }
890 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
891 if (!del_item) {
892 u32 newsize = inode->i_size - found_key.offset;
893 dec_i_blocks(inode, item_end + 1 -
894 found_key.offset - newsize);
895 newsize =
896 btrfs_file_extent_calc_inline_size(newsize);
897 ret = btrfs_truncate_item(trans, root, path,
898 newsize, 1);
899 BUG_ON(ret);
900 } else {
901 dec_i_blocks(inode, item_end + 1 -
902 found_key.offset);
903 }
904 }
905 delete:
906 if (del_item) {
907 if (!pending_del_nr) {
908 /* no pending yet, add ourselves */
909 pending_del_slot = path->slots[0];
910 pending_del_nr = 1;
911 } else if (pending_del_nr &&
912 path->slots[0] + 1 == pending_del_slot) {
913 /* hop on the pending chunk */
914 pending_del_nr++;
915 pending_del_slot = path->slots[0];
916 } else {
917 printk("bad pending slot %d pending_del_nr %d pending_del_slot %d\n", path->slots[0], pending_del_nr, pending_del_slot);
918 }
919 } else {
920 break;
921 }
922 if (found_extent) {
923 ret = btrfs_free_extent(trans, root, extent_start,
924 extent_num_bytes,
925 root_owner,
926 root_gen, inode->i_ino,
927 found_key.offset, 0);
928 BUG_ON(ret);
929 }
930 next:
931 if (path->slots[0] == 0) {
932 if (pending_del_nr)
933 goto del_pending;
934 btrfs_release_path(root, path);
935 goto search_again;
936 }
937
938 path->slots[0]--;
939 if (pending_del_nr &&
940 path->slots[0] + 1 != pending_del_slot) {
941 struct btrfs_key debug;
942 del_pending:
943 btrfs_item_key_to_cpu(path->nodes[0], &debug,
944 pending_del_slot);
945 ret = btrfs_del_items(trans, root, path,
946 pending_del_slot,
947 pending_del_nr);
948 BUG_ON(ret);
949 pending_del_nr = 0;
950 btrfs_release_path(root, path);
951 goto search_again;
952 }
953 }
954 ret = 0;
955 error:
956 if (pending_del_nr) {
957 ret = btrfs_del_items(trans, root, path, pending_del_slot,
958 pending_del_nr);
959 }
960 btrfs_release_path(root, path);
961 btrfs_free_path(path);
962 inode->i_sb->s_dirt = 1;
963 return ret;
964 }
965
966 static int btrfs_cow_one_page(struct inode *inode, struct page *page,
967 size_t zero_start)
968 {
969 char *kaddr;
970 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
971 u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
972 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
973 int ret = 0;
974
975 WARN_ON(!PageLocked(page));
976 set_page_extent_mapped(page);
977
978 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
979 set_extent_delalloc(&BTRFS_I(inode)->io_tree, page_start,
980 page_end, GFP_NOFS);
981
982 if (zero_start != PAGE_CACHE_SIZE) {
983 kaddr = kmap(page);
984 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
985 flush_dcache_page(page);
986 kunmap(page);
987 }
988 set_page_dirty(page);
989 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
990
991 return ret;
992 }
993
994 /*
995 * taken from block_truncate_page, but does cow as it zeros out
996 * any bytes left in the last page in the file.
997 */
998 static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
999 {
1000 struct inode *inode = mapping->host;
1001 struct btrfs_root *root = BTRFS_I(inode)->root;
1002 u32 blocksize = root->sectorsize;
1003 pgoff_t index = from >> PAGE_CACHE_SHIFT;
1004 unsigned offset = from & (PAGE_CACHE_SIZE-1);
1005 struct page *page;
1006 int ret = 0;
1007 u64 page_start;
1008
1009 if ((offset & (blocksize - 1)) == 0)
1010 goto out;
1011
1012 ret = -ENOMEM;
1013 page = grab_cache_page(mapping, index);
1014 if (!page)
1015 goto out;
1016 if (!PageUptodate(page)) {
1017 ret = btrfs_readpage(NULL, page);
1018 lock_page(page);
1019 if (!PageUptodate(page)) {
1020 ret = -EIO;
1021 goto out;
1022 }
1023 }
1024 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
1025
1026 ret = btrfs_cow_one_page(inode, page, offset);
1027
1028 unlock_page(page);
1029 page_cache_release(page);
1030 out:
1031 return ret;
1032 }
1033
1034 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
1035 {
1036 struct inode *inode = dentry->d_inode;
1037 int err;
1038
1039 err = inode_change_ok(inode, attr);
1040 if (err)
1041 return err;
1042
1043 if (S_ISREG(inode->i_mode) &&
1044 attr->ia_valid & ATTR_SIZE && attr->ia_size > inode->i_size) {
1045 struct btrfs_trans_handle *trans;
1046 struct btrfs_root *root = BTRFS_I(inode)->root;
1047 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1048
1049 u64 mask = root->sectorsize - 1;
1050 u64 hole_start = (inode->i_size + mask) & ~mask;
1051 u64 block_end = (attr->ia_size + mask) & ~mask;
1052 u64 hole_size;
1053 u64 alloc_hint = 0;
1054
1055 if (attr->ia_size <= hole_start)
1056 goto out;
1057
1058 mutex_lock(&root->fs_info->fs_mutex);
1059 err = btrfs_check_free_space(root, 1, 0);
1060 mutex_unlock(&root->fs_info->fs_mutex);
1061 if (err)
1062 goto fail;
1063
1064 btrfs_truncate_page(inode->i_mapping, inode->i_size);
1065
1066 lock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS);
1067 hole_size = block_end - hole_start;
1068
1069 mutex_lock(&root->fs_info->fs_mutex);
1070 trans = btrfs_start_transaction(root, 1);
1071 btrfs_set_trans_block_group(trans, inode);
1072 err = btrfs_drop_extents(trans, root, inode,
1073 hole_start, block_end, hole_start,
1074 &alloc_hint);
1075
1076 if (alloc_hint != EXTENT_MAP_INLINE) {
1077 err = btrfs_insert_file_extent(trans, root,
1078 inode->i_ino,
1079 hole_start, 0, 0,
1080 hole_size);
1081 btrfs_drop_extent_cache(inode, hole_start,
1082 hole_size - 1);
1083 btrfs_check_file(root, inode);
1084 }
1085 btrfs_end_transaction(trans, root);
1086 mutex_unlock(&root->fs_info->fs_mutex);
1087 unlock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS);
1088 if (err)
1089 return err;
1090 }
1091 out:
1092 err = inode_setattr(inode, attr);
1093 fail:
1094 return err;
1095 }
1096
1097 void btrfs_put_inode(struct inode *inode)
1098 {
1099 int ret;
1100
1101 if (!BTRFS_I(inode)->ordered_trans) {
1102 return;
1103 }
1104
1105 if (mapping_tagged(inode->i_mapping, PAGECACHE_TAG_DIRTY) ||
1106 mapping_tagged(inode->i_mapping, PAGECACHE_TAG_WRITEBACK))
1107 return;
1108
1109 ret = btrfs_del_ordered_inode(inode);
1110 if (ret == 1) {
1111 atomic_dec(&inode->i_count);
1112 }
1113 }
1114
1115 void btrfs_delete_inode(struct inode *inode)
1116 {
1117 struct btrfs_trans_handle *trans;
1118 struct btrfs_root *root = BTRFS_I(inode)->root;
1119 unsigned long nr;
1120 int ret;
1121
1122 truncate_inode_pages(&inode->i_data, 0);
1123 if (is_bad_inode(inode)) {
1124 goto no_delete;
1125 }
1126
1127 inode->i_size = 0;
1128 mutex_lock(&root->fs_info->fs_mutex);
1129 trans = btrfs_start_transaction(root, 1);
1130
1131 btrfs_set_trans_block_group(trans, inode);
1132 ret = btrfs_truncate_in_trans(trans, root, inode, 0);
1133 if (ret)
1134 goto no_delete_lock;
1135
1136 nr = trans->blocks_used;
1137 clear_inode(inode);
1138
1139 btrfs_end_transaction(trans, root);
1140 mutex_unlock(&root->fs_info->fs_mutex);
1141 btrfs_btree_balance_dirty(root, nr);
1142 btrfs_throttle(root);
1143 return;
1144
1145 no_delete_lock:
1146 nr = trans->blocks_used;
1147 btrfs_end_transaction(trans, root);
1148 mutex_unlock(&root->fs_info->fs_mutex);
1149 btrfs_btree_balance_dirty(root, nr);
1150 btrfs_throttle(root);
1151 no_delete:
1152 clear_inode(inode);
1153 }
1154
1155 /*
1156 * this returns the key found in the dir entry in the location pointer.
1157 * If no dir entries were found, location->objectid is 0.
1158 */
1159 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
1160 struct btrfs_key *location)
1161 {
1162 const char *name = dentry->d_name.name;
1163 int namelen = dentry->d_name.len;
1164 struct btrfs_dir_item *di;
1165 struct btrfs_path *path;
1166 struct btrfs_root *root = BTRFS_I(dir)->root;
1167 int ret = 0;
1168
1169 if (namelen == 1 && strcmp(name, ".") == 0) {
1170 location->objectid = dir->i_ino;
1171 location->type = BTRFS_INODE_ITEM_KEY;
1172 location->offset = 0;
1173 return 0;
1174 }
1175 path = btrfs_alloc_path();
1176 BUG_ON(!path);
1177
1178 if (namelen == 2 && strcmp(name, "..") == 0) {
1179 struct btrfs_key key;
1180 struct extent_buffer *leaf;
1181 u32 nritems;
1182 int slot;
1183
1184 key.objectid = dir->i_ino;
1185 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
1186 key.offset = 0;
1187 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1188 BUG_ON(ret == 0);
1189 ret = 0;
1190
1191 leaf = path->nodes[0];
1192 slot = path->slots[0];
1193 nritems = btrfs_header_nritems(leaf);
1194 if (slot >= nritems)
1195 goto out_err;
1196
1197 btrfs_item_key_to_cpu(leaf, &key, slot);
1198 if (key.objectid != dir->i_ino ||
1199 key.type != BTRFS_INODE_REF_KEY) {
1200 goto out_err;
1201 }
1202 location->objectid = key.offset;
1203 location->type = BTRFS_INODE_ITEM_KEY;
1204 location->offset = 0;
1205 goto out;
1206 }
1207
1208 di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
1209 namelen, 0);
1210 if (IS_ERR(di))
1211 ret = PTR_ERR(di);
1212 if (!di || IS_ERR(di)) {
1213 goto out_err;
1214 }
1215 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
1216 out:
1217 btrfs_free_path(path);
1218 return ret;
1219 out_err:
1220 location->objectid = 0;
1221 goto out;
1222 }
1223
1224 /*
1225 * when we hit a tree root in a directory, the btrfs part of the inode
1226 * needs to be changed to reflect the root directory of the tree root. This
1227 * is kind of like crossing a mount point.
1228 */
1229 static int fixup_tree_root_location(struct btrfs_root *root,
1230 struct btrfs_key *location,
1231 struct btrfs_root **sub_root,
1232 struct dentry *dentry)
1233 {
1234 struct btrfs_path *path;
1235 struct btrfs_root_item *ri;
1236
1237 if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY)
1238 return 0;
1239 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1240 return 0;
1241
1242 path = btrfs_alloc_path();
1243 BUG_ON(!path);
1244 mutex_lock(&root->fs_info->fs_mutex);
1245
1246 *sub_root = btrfs_read_fs_root(root->fs_info, location,
1247 dentry->d_name.name,
1248 dentry->d_name.len);
1249 if (IS_ERR(*sub_root))
1250 return PTR_ERR(*sub_root);
1251
1252 ri = &(*sub_root)->root_item;
1253 location->objectid = btrfs_root_dirid(ri);
1254 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
1255 location->offset = 0;
1256
1257 btrfs_free_path(path);
1258 mutex_unlock(&root->fs_info->fs_mutex);
1259 return 0;
1260 }
1261
1262 static int btrfs_init_locked_inode(struct inode *inode, void *p)
1263 {
1264 struct btrfs_iget_args *args = p;
1265 inode->i_ino = args->ino;
1266 BTRFS_I(inode)->root = args->root;
1267 BTRFS_I(inode)->delalloc_bytes = 0;
1268 extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
1269 extent_io_tree_init(&BTRFS_I(inode)->io_tree,
1270 inode->i_mapping, GFP_NOFS);
1271 return 0;
1272 }
1273
1274 static int btrfs_find_actor(struct inode *inode, void *opaque)
1275 {
1276 struct btrfs_iget_args *args = opaque;
1277 return (args->ino == inode->i_ino &&
1278 args->root == BTRFS_I(inode)->root);
1279 }
1280
1281 struct inode *btrfs_ilookup(struct super_block *s, u64 objectid,
1282 u64 root_objectid)
1283 {
1284 struct btrfs_iget_args args;
1285 args.ino = objectid;
1286 args.root = btrfs_lookup_fs_root(btrfs_sb(s)->fs_info, root_objectid);
1287
1288 if (!args.root)
1289 return NULL;
1290
1291 return ilookup5(s, objectid, btrfs_find_actor, (void *)&args);
1292 }
1293
1294 struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
1295 struct btrfs_root *root)
1296 {
1297 struct inode *inode;
1298 struct btrfs_iget_args args;
1299 args.ino = objectid;
1300 args.root = root;
1301
1302 inode = iget5_locked(s, objectid, btrfs_find_actor,
1303 btrfs_init_locked_inode,
1304 (void *)&args);
1305 return inode;
1306 }
1307
1308 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
1309 struct nameidata *nd)
1310 {
1311 struct inode * inode;
1312 struct btrfs_inode *bi = BTRFS_I(dir);
1313 struct btrfs_root *root = bi->root;
1314 struct btrfs_root *sub_root = root;
1315 struct btrfs_key location;
1316 int ret;
1317
1318 if (dentry->d_name.len > BTRFS_NAME_LEN)
1319 return ERR_PTR(-ENAMETOOLONG);
1320
1321 mutex_lock(&root->fs_info->fs_mutex);
1322 ret = btrfs_inode_by_name(dir, dentry, &location);
1323 mutex_unlock(&root->fs_info->fs_mutex);
1324
1325 if (ret < 0)
1326 return ERR_PTR(ret);
1327
1328 inode = NULL;
1329 if (location.objectid) {
1330 ret = fixup_tree_root_location(root, &location, &sub_root,
1331 dentry);
1332 if (ret < 0)
1333 return ERR_PTR(ret);
1334 if (ret > 0)
1335 return ERR_PTR(-ENOENT);
1336 inode = btrfs_iget_locked(dir->i_sb, location.objectid,
1337 sub_root);
1338 if (!inode)
1339 return ERR_PTR(-EACCES);
1340 if (inode->i_state & I_NEW) {
1341 /* the inode and parent dir are two different roots */
1342 if (sub_root != root) {
1343 igrab(inode);
1344 sub_root->inode = inode;
1345 }
1346 BTRFS_I(inode)->root = sub_root;
1347 memcpy(&BTRFS_I(inode)->location, &location,
1348 sizeof(location));
1349 btrfs_read_locked_inode(inode);
1350 unlock_new_inode(inode);
1351 }
1352 }
1353 return d_splice_alias(inode, dentry);
1354 }
1355
1356 static unsigned char btrfs_filetype_table[] = {
1357 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
1358 };
1359
1360 static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
1361 {
1362 struct inode *inode = filp->f_dentry->d_inode;
1363 struct btrfs_root *root = BTRFS_I(inode)->root;
1364 struct btrfs_item *item;
1365 struct btrfs_dir_item *di;
1366 struct btrfs_key key;
1367 struct btrfs_key found_key;
1368 struct btrfs_path *path;
1369 int ret;
1370 u32 nritems;
1371 struct extent_buffer *leaf;
1372 int slot;
1373 int advance;
1374 unsigned char d_type;
1375 int over = 0;
1376 u32 di_cur;
1377 u32 di_total;
1378 u32 di_len;
1379 int key_type = BTRFS_DIR_INDEX_KEY;
1380 char tmp_name[32];
1381 char *name_ptr;
1382 int name_len;
1383
1384 /* FIXME, use a real flag for deciding about the key type */
1385 if (root->fs_info->tree_root == root)
1386 key_type = BTRFS_DIR_ITEM_KEY;
1387
1388 /* special case for "." */
1389 if (filp->f_pos == 0) {
1390 over = filldir(dirent, ".", 1,
1391 1, inode->i_ino,
1392 DT_DIR);
1393 if (over)
1394 return 0;
1395 filp->f_pos = 1;
1396 }
1397
1398 mutex_lock(&root->fs_info->fs_mutex);
1399 key.objectid = inode->i_ino;
1400 path = btrfs_alloc_path();
1401 path->reada = 2;
1402
1403 /* special case for .., just use the back ref */
1404 if (filp->f_pos == 1) {
1405 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
1406 key.offset = 0;
1407 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1408 BUG_ON(ret == 0);
1409 leaf = path->nodes[0];
1410 slot = path->slots[0];
1411 nritems = btrfs_header_nritems(leaf);
1412 if (slot >= nritems) {
1413 btrfs_release_path(root, path);
1414 goto read_dir_items;
1415 }
1416 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1417 btrfs_release_path(root, path);
1418 if (found_key.objectid != key.objectid ||
1419 found_key.type != BTRFS_INODE_REF_KEY)
1420 goto read_dir_items;
1421 over = filldir(dirent, "..", 2,
1422 2, found_key.offset, DT_DIR);
1423 if (over)
1424 goto nopos;
1425 filp->f_pos = 2;
1426 }
1427
1428 read_dir_items:
1429 btrfs_set_key_type(&key, key_type);
1430 key.offset = filp->f_pos;
1431
1432 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1433 if (ret < 0)
1434 goto err;
1435 advance = 0;
1436 while(1) {
1437 leaf = path->nodes[0];
1438 nritems = btrfs_header_nritems(leaf);
1439 slot = path->slots[0];
1440 if (advance || slot >= nritems) {
1441 if (slot >= nritems -1) {
1442 ret = btrfs_next_leaf(root, path);
1443 if (ret)
1444 break;
1445 leaf = path->nodes[0];
1446 nritems = btrfs_header_nritems(leaf);
1447 slot = path->slots[0];
1448 } else {
1449 slot++;
1450 path->slots[0]++;
1451 }
1452 }
1453 advance = 1;
1454 item = btrfs_item_nr(leaf, slot);
1455 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1456
1457 if (found_key.objectid != key.objectid)
1458 break;
1459 if (btrfs_key_type(&found_key) != key_type)
1460 break;
1461 if (found_key.offset < filp->f_pos)
1462 continue;
1463
1464 filp->f_pos = found_key.offset;
1465 advance = 1;
1466 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
1467 di_cur = 0;
1468 di_total = btrfs_item_size(leaf, item);
1469 while(di_cur < di_total) {
1470 struct btrfs_key location;
1471
1472 name_len = btrfs_dir_name_len(leaf, di);
1473 if (name_len < 32) {
1474 name_ptr = tmp_name;
1475 } else {
1476 name_ptr = kmalloc(name_len, GFP_NOFS);
1477 BUG_ON(!name_ptr);
1478 }
1479 read_extent_buffer(leaf, name_ptr,
1480 (unsigned long)(di + 1), name_len);
1481
1482 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
1483 btrfs_dir_item_key_to_cpu(leaf, di, &location);
1484 over = filldir(dirent, name_ptr, name_len,
1485 found_key.offset,
1486 location.objectid,
1487 d_type);
1488
1489 if (name_ptr != tmp_name)
1490 kfree(name_ptr);
1491
1492 if (over)
1493 goto nopos;
1494 di_len = btrfs_dir_name_len(leaf, di) +
1495 btrfs_dir_data_len(leaf, di) +sizeof(*di);
1496 di_cur += di_len;
1497 di = (struct btrfs_dir_item *)((char *)di + di_len);
1498 }
1499 }
1500 if (key_type == BTRFS_DIR_INDEX_KEY)
1501 filp->f_pos = INT_LIMIT(typeof(filp->f_pos));
1502 else
1503 filp->f_pos++;
1504 nopos:
1505 ret = 0;
1506 err:
1507 btrfs_release_path(root, path);
1508 btrfs_free_path(path);
1509 mutex_unlock(&root->fs_info->fs_mutex);
1510 return ret;
1511 }
1512
1513 int btrfs_write_inode(struct inode *inode, int wait)
1514 {
1515 struct btrfs_root *root = BTRFS_I(inode)->root;
1516 struct btrfs_trans_handle *trans;
1517 int ret = 0;
1518
1519 if (wait) {
1520 mutex_lock(&root->fs_info->fs_mutex);
1521 trans = btrfs_start_transaction(root, 1);
1522 btrfs_set_trans_block_group(trans, inode);
1523 ret = btrfs_commit_transaction(trans, root);
1524 mutex_unlock(&root->fs_info->fs_mutex);
1525 }
1526 return ret;
1527 }
1528
1529 /*
1530 * This is somewhat expensive, updating the tree every time the
1531 * inode changes. But, it is most likely to find the inode in cache.
1532 * FIXME, needs more benchmarking...there are no reasons other than performance
1533 * to keep or drop this code.
1534 */
1535 void btrfs_dirty_inode(struct inode *inode)
1536 {
1537 struct btrfs_root *root = BTRFS_I(inode)->root;
1538 struct btrfs_trans_handle *trans;
1539
1540 mutex_lock(&root->fs_info->fs_mutex);
1541 trans = btrfs_start_transaction(root, 1);
1542 btrfs_set_trans_block_group(trans, inode);
1543 btrfs_update_inode(trans, root, inode);
1544 btrfs_end_transaction(trans, root);
1545 mutex_unlock(&root->fs_info->fs_mutex);
1546 }
1547
1548 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
1549 struct btrfs_root *root,
1550 const char *name, int name_len,
1551 u64 ref_objectid,
1552 u64 objectid,
1553 struct btrfs_block_group_cache *group,
1554 int mode)
1555 {
1556 struct inode *inode;
1557 struct btrfs_inode_item *inode_item;
1558 struct btrfs_block_group_cache *new_inode_group;
1559 struct btrfs_key *location;
1560 struct btrfs_path *path;
1561 struct btrfs_inode_ref *ref;
1562 struct btrfs_key key[2];
1563 u32 sizes[2];
1564 unsigned long ptr;
1565 int ret;
1566 int owner;
1567
1568 path = btrfs_alloc_path();
1569 BUG_ON(!path);
1570
1571 inode = new_inode(root->fs_info->sb);
1572 if (!inode)
1573 return ERR_PTR(-ENOMEM);
1574
1575 extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
1576 extent_io_tree_init(&BTRFS_I(inode)->io_tree,
1577 inode->i_mapping, GFP_NOFS);
1578 BTRFS_I(inode)->delalloc_bytes = 0;
1579 BTRFS_I(inode)->root = root;
1580
1581 if (mode & S_IFDIR)
1582 owner = 0;
1583 else
1584 owner = 1;
1585 new_inode_group = btrfs_find_block_group(root, group, 0,
1586 BTRFS_BLOCK_GROUP_METADATA, owner);
1587 if (!new_inode_group) {
1588 printk("find_block group failed\n");
1589 new_inode_group = group;
1590 }
1591 BTRFS_I(inode)->block_group = new_inode_group;
1592 BTRFS_I(inode)->flags = 0;
1593
1594 key[0].objectid = objectid;
1595 btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
1596 key[0].offset = 0;
1597
1598 key[1].objectid = objectid;
1599 btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
1600 key[1].offset = ref_objectid;
1601
1602 sizes[0] = sizeof(struct btrfs_inode_item);
1603 sizes[1] = name_len + sizeof(*ref);
1604
1605 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
1606 if (ret != 0)
1607 goto fail;
1608
1609 if (objectid > root->highest_inode)
1610 root->highest_inode = objectid;
1611
1612 inode->i_uid = current->fsuid;
1613 inode->i_gid = current->fsgid;
1614 inode->i_mode = mode;
1615 inode->i_ino = objectid;
1616 inode->i_blocks = 0;
1617 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1618 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1619 struct btrfs_inode_item);
1620 fill_inode_item(path->nodes[0], inode_item, inode);
1621
1622 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
1623 struct btrfs_inode_ref);
1624 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
1625 ptr = (unsigned long)(ref + 1);
1626 write_extent_buffer(path->nodes[0], name, ptr, name_len);
1627
1628 btrfs_mark_buffer_dirty(path->nodes[0]);
1629 btrfs_free_path(path);
1630
1631 location = &BTRFS_I(inode)->location;
1632 location->objectid = objectid;
1633 location->offset = 0;
1634 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
1635
1636 insert_inode_hash(inode);
1637 return inode;
1638 fail:
1639 btrfs_free_path(path);
1640 return ERR_PTR(ret);
1641 }
1642
1643 static inline u8 btrfs_inode_type(struct inode *inode)
1644 {
1645 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
1646 }
1647
1648 static int btrfs_add_link(struct btrfs_trans_handle *trans,
1649 struct dentry *dentry, struct inode *inode,
1650 int add_backref)
1651 {
1652 int ret;
1653 struct btrfs_key key;
1654 struct btrfs_root *root = BTRFS_I(dentry->d_parent->d_inode)->root;
1655 struct inode *parent_inode;
1656
1657 key.objectid = inode->i_ino;
1658 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
1659 key.offset = 0;
1660
1661 ret = btrfs_insert_dir_item(trans, root,
1662 dentry->d_name.name, dentry->d_name.len,
1663 dentry->d_parent->d_inode->i_ino,
1664 &key, btrfs_inode_type(inode));
1665 if (ret == 0) {
1666 if (add_backref) {
1667 ret = btrfs_insert_inode_ref(trans, root,
1668 dentry->d_name.name,
1669 dentry->d_name.len,
1670 inode->i_ino,
1671 dentry->d_parent->d_inode->i_ino);
1672 }
1673 parent_inode = dentry->d_parent->d_inode;
1674 parent_inode->i_size += dentry->d_name.len * 2;
1675 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
1676 ret = btrfs_update_inode(trans, root,
1677 dentry->d_parent->d_inode);
1678 }
1679 return ret;
1680 }
1681
1682 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
1683 struct dentry *dentry, struct inode *inode,
1684 int backref)
1685 {
1686 int err = btrfs_add_link(trans, dentry, inode, backref);
1687 if (!err) {
1688 d_instantiate(dentry, inode);
1689 return 0;
1690 }
1691 if (err > 0)
1692 err = -EEXIST;
1693 return err;
1694 }
1695
1696 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
1697 int mode, dev_t rdev)
1698 {
1699 struct btrfs_trans_handle *trans;
1700 struct btrfs_root *root = BTRFS_I(dir)->root;
1701 struct inode *inode = NULL;
1702 int err;
1703 int drop_inode = 0;
1704 u64 objectid;
1705 unsigned long nr = 0;
1706
1707 if (!new_valid_dev(rdev))
1708 return -EINVAL;
1709
1710 mutex_lock(&root->fs_info->fs_mutex);
1711 err = btrfs_check_free_space(root, 1, 0);
1712 if (err)
1713 goto fail;
1714
1715 trans = btrfs_start_transaction(root, 1);
1716 btrfs_set_trans_block_group(trans, dir);
1717
1718 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1719 if (err) {
1720 err = -ENOSPC;
1721 goto out_unlock;
1722 }
1723
1724 inode = btrfs_new_inode(trans, root, dentry->d_name.name,
1725 dentry->d_name.len,
1726 dentry->d_parent->d_inode->i_ino, objectid,
1727 BTRFS_I(dir)->block_group, mode);
1728 err = PTR_ERR(inode);
1729 if (IS_ERR(inode))
1730 goto out_unlock;
1731
1732 btrfs_set_trans_block_group(trans, inode);
1733 err = btrfs_add_nondir(trans, dentry, inode, 0);
1734 if (err)
1735 drop_inode = 1;
1736 else {
1737 inode->i_op = &btrfs_special_inode_operations;
1738 init_special_inode(inode, inode->i_mode, rdev);
1739 btrfs_update_inode(trans, root, inode);
1740 }
1741 dir->i_sb->s_dirt = 1;
1742 btrfs_update_inode_block_group(trans, inode);
1743 btrfs_update_inode_block_group(trans, dir);
1744 out_unlock:
1745 nr = trans->blocks_used;
1746 btrfs_end_transaction(trans, root);
1747 fail:
1748 mutex_unlock(&root->fs_info->fs_mutex);
1749
1750 if (drop_inode) {
1751 inode_dec_link_count(inode);
1752 iput(inode);
1753 }
1754 btrfs_btree_balance_dirty(root, nr);
1755 btrfs_throttle(root);
1756 return err;
1757 }
1758
1759 static int btrfs_create(struct inode *dir, struct dentry *dentry,
1760 int mode, struct nameidata *nd)
1761 {
1762 struct btrfs_trans_handle *trans;
1763 struct btrfs_root *root = BTRFS_I(dir)->root;
1764 struct inode *inode = NULL;
1765 int err;
1766 int drop_inode = 0;
1767 unsigned long nr = 0;
1768 u64 objectid;
1769
1770 mutex_lock(&root->fs_info->fs_mutex);
1771 err = btrfs_check_free_space(root, 1, 0);
1772 if (err)
1773 goto fail;
1774 trans = btrfs_start_transaction(root, 1);
1775 btrfs_set_trans_block_group(trans, dir);
1776
1777 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1778 if (err) {
1779 err = -ENOSPC;
1780 goto out_unlock;
1781 }
1782
1783 inode = btrfs_new_inode(trans, root, dentry->d_name.name,
1784 dentry->d_name.len,
1785 dentry->d_parent->d_inode->i_ino,
1786 objectid, BTRFS_I(dir)->block_group, mode);
1787 err = PTR_ERR(inode);
1788 if (IS_ERR(inode))
1789 goto out_unlock;
1790
1791 btrfs_set_trans_block_group(trans, inode);
1792 err = btrfs_add_nondir(trans, dentry, inode, 0);
1793 if (err)
1794 drop_inode = 1;
1795 else {
1796 inode->i_mapping->a_ops = &btrfs_aops;
1797 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
1798 inode->i_fop = &btrfs_file_operations;
1799 inode->i_op = &btrfs_file_inode_operations;
1800 extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
1801 extent_io_tree_init(&BTRFS_I(inode)->io_tree,
1802 inode->i_mapping, GFP_NOFS);
1803 BTRFS_I(inode)->delalloc_bytes = 0;
1804 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
1805 }
1806 dir->i_sb->s_dirt = 1;
1807 btrfs_update_inode_block_group(trans, inode);
1808 btrfs_update_inode_block_group(trans, dir);
1809 out_unlock:
1810 nr = trans->blocks_used;
1811 btrfs_end_transaction(trans, root);
1812 fail:
1813 mutex_unlock(&root->fs_info->fs_mutex);
1814
1815 if (drop_inode) {
1816 inode_dec_link_count(inode);
1817 iput(inode);
1818 }
1819 btrfs_btree_balance_dirty(root, nr);
1820 btrfs_throttle(root);
1821 return err;
1822 }
1823
1824 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
1825 struct dentry *dentry)
1826 {
1827 struct btrfs_trans_handle *trans;
1828 struct btrfs_root *root = BTRFS_I(dir)->root;
1829 struct inode *inode = old_dentry->d_inode;
1830 unsigned long nr = 0;
1831 int err;
1832 int drop_inode = 0;
1833
1834 if (inode->i_nlink == 0)
1835 return -ENOENT;
1836
1837 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
1838 inode->i_nlink++;
1839 #else
1840 inc_nlink(inode);
1841 #endif
1842 mutex_lock(&root->fs_info->fs_mutex);
1843 err = btrfs_check_free_space(root, 1, 0);
1844 if (err)
1845 goto fail;
1846 trans = btrfs_start_transaction(root, 1);
1847
1848 btrfs_set_trans_block_group(trans, dir);
1849 atomic_inc(&inode->i_count);
1850 err = btrfs_add_nondir(trans, dentry, inode, 1);
1851
1852 if (err)
1853 drop_inode = 1;
1854
1855 dir->i_sb->s_dirt = 1;
1856 btrfs_update_inode_block_group(trans, dir);
1857 err = btrfs_update_inode(trans, root, inode);
1858
1859 if (err)
1860 drop_inode = 1;
1861
1862 nr = trans->blocks_used;
1863 btrfs_end_transaction(trans, root);
1864 fail:
1865 mutex_unlock(&root->fs_info->fs_mutex);
1866
1867 if (drop_inode) {
1868 inode_dec_link_count(inode);
1869 iput(inode);
1870 }
1871 btrfs_btree_balance_dirty(root, nr);
1872 btrfs_throttle(root);
1873 return err;
1874 }
1875
1876 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1877 {
1878 struct inode *inode;
1879 struct btrfs_trans_handle *trans;
1880 struct btrfs_root *root = BTRFS_I(dir)->root;
1881 int err = 0;
1882 int drop_on_err = 0;
1883 u64 objectid;
1884 unsigned long nr = 1;
1885
1886 mutex_lock(&root->fs_info->fs_mutex);
1887 err = btrfs_check_free_space(root, 1, 0);
1888 if (err)
1889 goto out_unlock;
1890
1891 trans = btrfs_start_transaction(root, 1);
1892 btrfs_set_trans_block_group(trans, dir);
1893
1894 if (IS_ERR(trans)) {
1895 err = PTR_ERR(trans);
1896 goto out_unlock;
1897 }
1898
1899 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1900 if (err) {
1901 err = -ENOSPC;
1902 goto out_unlock;
1903 }
1904
1905 inode = btrfs_new_inode(trans, root, dentry->d_name.name,
1906 dentry->d_name.len,
1907 dentry->d_parent->d_inode->i_ino, objectid,
1908 BTRFS_I(dir)->block_group, S_IFDIR | mode);
1909 if (IS_ERR(inode)) {
1910 err = PTR_ERR(inode);
1911 goto out_fail;
1912 }
1913
1914 drop_on_err = 1;
1915 inode->i_op = &btrfs_dir_inode_operations;
1916 inode->i_fop = &btrfs_dir_file_operations;
1917 btrfs_set_trans_block_group(trans, inode);
1918
1919 inode->i_size = 0;
1920 err = btrfs_update_inode(trans, root, inode);
1921 if (err)
1922 goto out_fail;
1923
1924 err = btrfs_add_link(trans, dentry, inode, 0);
1925 if (err)
1926 goto out_fail;
1927
1928 d_instantiate(dentry, inode);
1929 drop_on_err = 0;
1930 dir->i_sb->s_dirt = 1;
1931 btrfs_update_inode_block_group(trans, inode);
1932 btrfs_update_inode_block_group(trans, dir);
1933
1934 out_fail:
1935 nr = trans->blocks_used;
1936 btrfs_end_transaction(trans, root);
1937
1938 out_unlock:
1939 mutex_unlock(&root->fs_info->fs_mutex);
1940 if (drop_on_err)
1941 iput(inode);
1942 btrfs_btree_balance_dirty(root, nr);
1943 btrfs_throttle(root);
1944 return err;
1945 }
1946
1947 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
1948 size_t pg_offset, u64 start, u64 len,
1949 int create)
1950 {
1951 int ret;
1952 int err = 0;
1953 u64 bytenr;
1954 u64 extent_start = 0;
1955 u64 extent_end = 0;
1956 u64 objectid = inode->i_ino;
1957 u32 found_type;
1958 struct btrfs_path *path;
1959 struct btrfs_root *root = BTRFS_I(inode)->root;
1960 struct btrfs_file_extent_item *item;
1961 struct extent_buffer *leaf;
1962 struct btrfs_key found_key;
1963 struct extent_map *em = NULL;
1964 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1965 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1966 struct btrfs_trans_handle *trans = NULL;
1967
1968 path = btrfs_alloc_path();
1969 BUG_ON(!path);
1970 mutex_lock(&root->fs_info->fs_mutex);
1971
1972 again:
1973 spin_lock(&em_tree->lock);
1974 em = lookup_extent_mapping(em_tree, start, len);
1975 spin_unlock(&em_tree->lock);
1976
1977 if (em) {
1978 if (em->start > start) {
1979 printk("get_extent lookup [%Lu %Lu] em [%Lu %Lu]\n",
1980 start, len, em->start, em->len);
1981 WARN_ON(1);
1982 }
1983 if (em->block_start == EXTENT_MAP_INLINE && page)
1984 free_extent_map(em);
1985 else
1986 goto out;
1987 }
1988 em = alloc_extent_map(GFP_NOFS);
1989 if (!em) {
1990 err = -ENOMEM;
1991 goto out;
1992 }
1993
1994 em->start = EXTENT_MAP_HOLE;
1995 em->len = (u64)-1;
1996 em->bdev = inode->i_sb->s_bdev;
1997 ret = btrfs_lookup_file_extent(trans, root, path,
1998 objectid, start, trans != NULL);
1999 if (ret < 0) {
2000 err = ret;
2001 goto out;
2002 }
2003
2004 if (ret != 0) {
2005 if (path->slots[0] == 0)
2006 goto not_found;
2007 path->slots[0]--;
2008 }
2009
2010 leaf = path->nodes[0];
2011 item = btrfs_item_ptr(leaf, path->slots[0],
2012 struct btrfs_file_extent_item);
2013 /* are we inside the extent that was found? */
2014 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2015 found_type = btrfs_key_type(&found_key);
2016 if (found_key.objectid != objectid ||
2017 found_type != BTRFS_EXTENT_DATA_KEY) {
2018 goto not_found;
2019 }
2020
2021 found_type = btrfs_file_extent_type(leaf, item);
2022 extent_start = found_key.offset;
2023 if (found_type == BTRFS_FILE_EXTENT_REG) {
2024 extent_end = extent_start +
2025 btrfs_file_extent_num_bytes(leaf, item);
2026 err = 0;
2027 if (start < extent_start || start >= extent_end) {
2028 em->start = start;
2029 if (start < extent_start) {
2030 if (start + len <= extent_start)
2031 goto not_found;
2032 em->len = extent_end - extent_start;
2033 } else {
2034 em->len = len;
2035 }
2036 goto not_found_em;
2037 }
2038 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
2039 if (bytenr == 0) {
2040 em->start = extent_start;
2041 em->len = extent_end - extent_start;
2042 em->block_start = EXTENT_MAP_HOLE;
2043 goto insert;
2044 }
2045 bytenr += btrfs_file_extent_offset(leaf, item);
2046 em->block_start = bytenr;
2047 em->start = extent_start;
2048 em->len = extent_end - extent_start;
2049 goto insert;
2050 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
2051 u64 page_start;
2052 unsigned long ptr;
2053 char *map;
2054 size_t size;
2055 size_t extent_offset;
2056 size_t copy_size;
2057
2058 size = btrfs_file_extent_inline_len(leaf, btrfs_item_nr(leaf,
2059 path->slots[0]));
2060 extent_end = (extent_start + size + root->sectorsize - 1) &
2061 ~((u64)root->sectorsize - 1);
2062 if (start < extent_start || start >= extent_end) {
2063 em->start = start;
2064 if (start < extent_start) {
2065 if (start + len <= extent_start)
2066 goto not_found;
2067 em->len = extent_end - extent_start;
2068 } else {
2069 em->len = len;
2070 }
2071 goto not_found_em;
2072 }
2073 em->block_start = EXTENT_MAP_INLINE;
2074
2075 if (!page) {
2076 em->start = extent_start;
2077 em->len = size;
2078 goto out;
2079 }
2080
2081 page_start = page_offset(page) + pg_offset;
2082 extent_offset = page_start - extent_start;
2083 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
2084 size - extent_offset);
2085 em->start = extent_start + extent_offset;
2086 em->len = (copy_size + root->sectorsize - 1) &
2087 ~((u64)root->sectorsize - 1);
2088 map = kmap(page);
2089 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
2090 if (create == 0 && !PageUptodate(page)) {
2091 read_extent_buffer(leaf, map + pg_offset, ptr,
2092 copy_size);
2093 flush_dcache_page(page);
2094 } else if (create && PageUptodate(page)) {
2095 if (!trans) {
2096 kunmap(page);
2097 free_extent_map(em);
2098 em = NULL;
2099 btrfs_release_path(root, path);
2100 trans = btrfs_start_transaction(root, 1);
2101 goto again;
2102 }
2103 write_extent_buffer(leaf, map + pg_offset, ptr,
2104 copy_size);
2105 btrfs_mark_buffer_dirty(leaf);
2106 }
2107 kunmap(page);
2108 set_extent_uptodate(io_tree, em->start,
2109 extent_map_end(em) - 1, GFP_NOFS);
2110 goto insert;
2111 } else {
2112 printk("unkknown found_type %d\n", found_type);
2113 WARN_ON(1);
2114 }
2115 not_found:
2116 em->start = start;
2117 em->len = len;
2118 not_found_em:
2119 em->block_start = EXTENT_MAP_HOLE;
2120 insert:
2121 btrfs_release_path(root, path);
2122 if (em->start > start || extent_map_end(em) <= start) {
2123 printk("bad extent! em: [%Lu %Lu] passed [%Lu %Lu]\n", em->start, em->len, start, len);
2124 err = -EIO;
2125 goto out;
2126 }
2127
2128 err = 0;
2129 spin_lock(&em_tree->lock);
2130 ret = add_extent_mapping(em_tree, em);
2131 if (ret == -EEXIST) {
2132 free_extent_map(em);
2133 em = lookup_extent_mapping(em_tree, start, len);
2134 if (!em) {
2135 err = -EIO;
2136 printk("failing to insert %Lu %Lu\n", start, len);
2137 }
2138 }
2139 spin_unlock(&em_tree->lock);
2140 out:
2141 btrfs_free_path(path);
2142 if (trans) {
2143 ret = btrfs_end_transaction(trans, root);
2144 if (!err)
2145 err = ret;
2146 }
2147 mutex_unlock(&root->fs_info->fs_mutex);
2148 if (err) {
2149 free_extent_map(em);
2150 WARN_ON(1);
2151 return ERR_PTR(err);
2152 }
2153 return em;
2154 }
2155
2156 static sector_t btrfs_bmap(struct address_space *mapping, sector_t iblock)
2157 {
2158 return extent_bmap(mapping, iblock, btrfs_get_extent);
2159 }
2160
2161 int btrfs_readpage(struct file *file, struct page *page)
2162 {
2163 struct extent_io_tree *tree;
2164 tree = &BTRFS_I(page->mapping->host)->io_tree;
2165 return extent_read_full_page(tree, page, btrfs_get_extent);
2166 }
2167
2168 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
2169 {
2170 struct extent_io_tree *tree;
2171
2172
2173 if (current->flags & PF_MEMALLOC) {
2174 redirty_page_for_writepage(wbc, page);
2175 unlock_page(page);
2176 return 0;
2177 }
2178 tree = &BTRFS_I(page->mapping->host)->io_tree;
2179 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
2180 }
2181
2182 static int btrfs_writepages(struct address_space *mapping,
2183 struct writeback_control *wbc)
2184 {
2185 struct extent_io_tree *tree;
2186 tree = &BTRFS_I(mapping->host)->io_tree;
2187 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
2188 }
2189
2190 static int
2191 btrfs_readpages(struct file *file, struct address_space *mapping,
2192 struct list_head *pages, unsigned nr_pages)
2193 {
2194 struct extent_io_tree *tree;
2195 tree = &BTRFS_I(mapping->host)->io_tree;
2196 return extent_readpages(tree, mapping, pages, nr_pages,
2197 btrfs_get_extent);
2198 }
2199
2200 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
2201 {
2202 struct extent_io_tree *tree;
2203 struct extent_map_tree *map;
2204 int ret;
2205
2206 tree = &BTRFS_I(page->mapping->host)->io_tree;
2207 map = &BTRFS_I(page->mapping->host)->extent_tree;
2208 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
2209 if (ret == 1) {
2210 ClearPagePrivate(page);
2211 set_page_private(page, 0);
2212 page_cache_release(page);
2213 }
2214 return ret;
2215 }
2216
2217 static void btrfs_invalidatepage(struct page *page, unsigned long offset)
2218 {
2219 struct extent_io_tree *tree;
2220
2221 tree = &BTRFS_I(page->mapping->host)->io_tree;
2222 extent_invalidatepage(tree, page, offset);
2223 btrfs_releasepage(page, GFP_NOFS);
2224 }
2225
2226 /*
2227 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
2228 * called from a page fault handler when a page is first dirtied. Hence we must
2229 * be careful to check for EOF conditions here. We set the page up correctly
2230 * for a written page which means we get ENOSPC checking when writing into
2231 * holes and correct delalloc and unwritten extent mapping on filesystems that
2232 * support these features.
2233 *
2234 * We are not allowed to take the i_mutex here so we have to play games to
2235 * protect against truncate races as the page could now be beyond EOF. Because
2236 * vmtruncate() writes the inode size before removing pages, once we have the
2237 * page lock we can determine safely if the page is beyond EOF. If it is not
2238 * beyond EOF, then the page is guaranteed safe against truncation until we
2239 * unlock the page.
2240 */
2241 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
2242 {
2243 struct inode *inode = fdentry(vma->vm_file)->d_inode;
2244 struct btrfs_root *root = BTRFS_I(inode)->root;
2245 unsigned long end;
2246 loff_t size;
2247 int ret;
2248 u64 page_start;
2249
2250 mutex_lock(&root->fs_info->fs_mutex);
2251 ret = btrfs_check_free_space(root, PAGE_CACHE_SIZE, 0);
2252 mutex_unlock(&root->fs_info->fs_mutex);
2253 if (ret)
2254 goto out;
2255
2256 ret = -EINVAL;
2257
2258 lock_page(page);
2259 wait_on_page_writeback(page);
2260 size = i_size_read(inode);
2261 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2262
2263 if ((page->mapping != inode->i_mapping) ||
2264 (page_start > size)) {
2265 /* page got truncated out from underneath us */
2266 goto out_unlock;
2267 }
2268
2269 /* page is wholly or partially inside EOF */
2270 if (page_start + PAGE_CACHE_SIZE > size)
2271 end = size & ~PAGE_CACHE_MASK;
2272 else
2273 end = PAGE_CACHE_SIZE;
2274
2275 ret = btrfs_cow_one_page(inode, page, end);
2276
2277 out_unlock:
2278 unlock_page(page);
2279 out:
2280 return ret;
2281 }
2282
2283 static void btrfs_truncate(struct inode *inode)
2284 {
2285 struct btrfs_root *root = BTRFS_I(inode)->root;
2286 int ret;
2287 struct btrfs_trans_handle *trans;
2288 unsigned long nr;
2289
2290 if (!S_ISREG(inode->i_mode))
2291 return;
2292 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
2293 return;
2294
2295 btrfs_truncate_page(inode->i_mapping, inode->i_size);
2296
2297 mutex_lock(&root->fs_info->fs_mutex);
2298 trans = btrfs_start_transaction(root, 1);
2299 btrfs_set_trans_block_group(trans, inode);
2300
2301 /* FIXME, add redo link to tree so we don't leak on crash */
2302 ret = btrfs_truncate_in_trans(trans, root, inode,
2303 BTRFS_EXTENT_DATA_KEY);
2304 btrfs_update_inode(trans, root, inode);
2305 nr = trans->blocks_used;
2306
2307 ret = btrfs_end_transaction(trans, root);
2308 BUG_ON(ret);
2309 mutex_unlock(&root->fs_info->fs_mutex);
2310 btrfs_btree_balance_dirty(root, nr);
2311 btrfs_throttle(root);
2312 }
2313
2314 static int noinline create_subvol(struct btrfs_root *root, char *name,
2315 int namelen)
2316 {
2317 struct btrfs_trans_handle *trans;
2318 struct btrfs_key key;
2319 struct btrfs_root_item root_item;
2320 struct btrfs_inode_item *inode_item;
2321 struct extent_buffer *leaf;
2322 struct btrfs_root *new_root = root;
2323 struct inode *inode;
2324 struct inode *dir;
2325 int ret;
2326 int err;
2327 u64 objectid;
2328 u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
2329 unsigned long nr = 1;
2330
2331 mutex_lock(&root->fs_info->fs_mutex);
2332 ret = btrfs_check_free_space(root, 1, 0);
2333 if (ret)
2334 goto fail_commit;
2335
2336 trans = btrfs_start_transaction(root, 1);
2337 BUG_ON(!trans);
2338
2339 ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
2340 0, &objectid);
2341 if (ret)
2342 goto fail;
2343
2344 leaf = __btrfs_alloc_free_block(trans, root, root->leafsize,
2345 objectid, trans->transid, 0, 0,
2346 0, 0);
2347 if (IS_ERR(leaf))
2348 return PTR_ERR(leaf);
2349
2350 btrfs_set_header_nritems(leaf, 0);
2351 btrfs_set_header_level(leaf, 0);
2352 btrfs_set_header_bytenr(leaf, leaf->start);
2353 btrfs_set_header_generation(leaf, trans->transid);
2354 btrfs_set_header_owner(leaf, objectid);
2355
2356 write_extent_buffer(leaf, root->fs_info->fsid,
2357 (unsigned long)btrfs_header_fsid(leaf),
2358 BTRFS_FSID_SIZE);
2359 btrfs_mark_buffer_dirty(leaf);
2360
2361 inode_item = &root_item.inode;
2362 memset(inode_item, 0, sizeof(*inode_item));
2363 inode_item->generation = cpu_to_le64(1);
2364 inode_item->size = cpu_to_le64(3);
2365 inode_item->nlink = cpu_to_le32(1);
2366 inode_item->nblocks = cpu_to_le64(1);
2367 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
2368
2369 btrfs_set_root_bytenr(&root_item, leaf->start);
2370 btrfs_set_root_level(&root_item, 0);
2371 btrfs_set_root_refs(&root_item, 1);
2372 btrfs_set_root_used(&root_item, 0);
2373
2374 memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
2375 root_item.drop_level = 0;
2376
2377 free_extent_buffer(leaf);
2378 leaf = NULL;
2379
2380 btrfs_set_root_dirid(&root_item, new_dirid);
2381
2382 key.objectid = objectid;
2383 key.offset = 1;
2384 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
2385 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
2386 &root_item);
2387 if (ret)
2388 goto fail;
2389
2390 /*
2391 * insert the directory item
2392 */
2393 key.offset = (u64)-1;
2394 dir = root->fs_info->sb->s_root->d_inode;
2395 ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
2396 name, namelen, dir->i_ino, &key,
2397 BTRFS_FT_DIR);
2398 if (ret)
2399 goto fail;
2400
2401 ret = btrfs_insert_inode_ref(trans, root->fs_info->tree_root,
2402 name, namelen, objectid,
2403 root->fs_info->sb->s_root->d_inode->i_ino);
2404 if (ret)
2405 goto fail;
2406
2407 ret = btrfs_commit_transaction(trans, root);
2408 if (ret)
2409 goto fail_commit;
2410
2411 new_root = btrfs_read_fs_root(root->fs_info, &key, name, namelen);
2412 BUG_ON(!new_root);
2413
2414 trans = btrfs_start_transaction(new_root, 1);
2415 BUG_ON(!trans);
2416
2417 inode = btrfs_new_inode(trans, new_root, "..", 2, new_dirid,
2418 new_dirid,
2419 BTRFS_I(dir)->block_group, S_IFDIR | 0700);
2420 if (IS_ERR(inode))
2421 goto fail;
2422 inode->i_op = &btrfs_dir_inode_operations;
2423 inode->i_fop = &btrfs_dir_file_operations;
2424 new_root->inode = inode;
2425
2426 ret = btrfs_insert_inode_ref(trans, new_root, "..", 2, new_dirid,
2427 new_dirid);
2428 inode->i_nlink = 1;
2429 inode->i_size = 0;
2430 ret = btrfs_update_inode(trans, new_root, inode);
2431 if (ret)
2432 goto fail;
2433 fail:
2434 nr = trans->blocks_used;
2435 err = btrfs_commit_transaction(trans, new_root);
2436 if (err && !ret)
2437 ret = err;
2438 fail_commit:
2439 mutex_unlock(&root->fs_info->fs_mutex);
2440 btrfs_btree_balance_dirty(root, nr);
2441 btrfs_throttle(root);
2442 return ret;
2443 }
2444
2445 static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
2446 {
2447 struct btrfs_pending_snapshot *pending_snapshot;
2448 struct btrfs_trans_handle *trans;
2449 int ret;
2450 int err;
2451 unsigned long nr = 0;
2452
2453 if (!root->ref_cows)
2454 return -EINVAL;
2455
2456 mutex_lock(&root->fs_info->fs_mutex);
2457 ret = btrfs_check_free_space(root, 1, 0);
2458 if (ret)
2459 goto fail_unlock;
2460
2461 pending_snapshot = kmalloc(sizeof(*pending_snapshot), GFP_NOFS);
2462 if (!pending_snapshot) {
2463 ret = -ENOMEM;
2464 goto fail_unlock;
2465 }
2466 pending_snapshot->name = kmalloc(namelen + 1, GFP_NOFS);
2467 if (!pending_snapshot->name) {
2468 ret = -ENOMEM;
2469 kfree(pending_snapshot);
2470 goto fail_unlock;
2471 }
2472 memcpy(pending_snapshot->name, name, namelen);
2473 pending_snapshot->name[namelen] = '\0';
2474 trans = btrfs_start_transaction(root, 1);
2475 BUG_ON(!trans);
2476 pending_snapshot->root = root;
2477 list_add(&pending_snapshot->list,
2478 &trans->transaction->pending_snapshots);
2479 ret = btrfs_update_inode(trans, root, root->inode);
2480 err = btrfs_commit_transaction(trans, root);
2481
2482 fail_unlock:
2483 mutex_unlock(&root->fs_info->fs_mutex);
2484 btrfs_btree_balance_dirty(root, nr);
2485 btrfs_throttle(root);
2486 return ret;
2487 }
2488
2489 unsigned long btrfs_force_ra(struct address_space *mapping,
2490 struct file_ra_state *ra, struct file *file,
2491 pgoff_t offset, pgoff_t last_index)
2492 {
2493 pgoff_t req_size;
2494
2495 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
2496 req_size = last_index - offset + 1;
2497 offset = page_cache_readahead(mapping, ra, file, offset, req_size);
2498 return offset;
2499 #else
2500 req_size = min(last_index - offset + 1, (pgoff_t)128);
2501 page_cache_sync_readahead(mapping, ra, file, offset, req_size);
2502 return offset + req_size;
2503 #endif
2504 }
2505
2506 int btrfs_defrag_file(struct file *file) {
2507 struct inode *inode = fdentry(file)->d_inode;
2508 struct btrfs_root *root = BTRFS_I(inode)->root;
2509 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2510 struct page *page;
2511 unsigned long last_index;
2512 unsigned long ra_index = 0;
2513 u64 page_start;
2514 u64 page_end;
2515 unsigned long i;
2516 int ret;
2517
2518 mutex_lock(&root->fs_info->fs_mutex);
2519 ret = btrfs_check_free_space(root, inode->i_size, 0);
2520 mutex_unlock(&root->fs_info->fs_mutex);
2521 if (ret)
2522 return -ENOSPC;
2523
2524 mutex_lock(&inode->i_mutex);
2525 last_index = inode->i_size >> PAGE_CACHE_SHIFT;
2526 for (i = 0; i <= last_index; i++) {
2527 if (i == ra_index) {
2528 ra_index = btrfs_force_ra(inode->i_mapping,
2529 &file->f_ra,
2530 file, ra_index, last_index);
2531 }
2532 page = grab_cache_page(inode->i_mapping, i);
2533 if (!page)
2534 goto out_unlock;
2535 if (!PageUptodate(page)) {
2536 btrfs_readpage(NULL, page);
2537 lock_page(page);
2538 if (!PageUptodate(page)) {
2539 unlock_page(page);
2540 page_cache_release(page);
2541 goto out_unlock;
2542 }
2543 }
2544 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2545 page_end = page_start + PAGE_CACHE_SIZE - 1;
2546
2547 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
2548 set_extent_delalloc(io_tree, page_start,
2549 page_end, GFP_NOFS);
2550
2551 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
2552 set_page_dirty(page);
2553 unlock_page(page);
2554 page_cache_release(page);
2555 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
2556 }
2557
2558 out_unlock:
2559 mutex_unlock(&inode->i_mutex);
2560 return 0;
2561 }
2562
2563 static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
2564 {
2565 u64 new_size;
2566 u64 old_size;
2567 struct btrfs_ioctl_vol_args *vol_args;
2568 struct btrfs_trans_handle *trans;
2569 char *sizestr;
2570 int ret = 0;
2571 int namelen;
2572 int mod = 0;
2573
2574 vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
2575
2576 if (!vol_args)
2577 return -ENOMEM;
2578
2579 if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
2580 ret = -EFAULT;
2581 goto out;
2582 }
2583 namelen = strlen(vol_args->name);
2584 if (namelen > BTRFS_VOL_NAME_MAX) {
2585 ret = -EINVAL;
2586 goto out;
2587 }
2588
2589 sizestr = vol_args->name;
2590 if (!strcmp(sizestr, "max"))
2591 new_size = root->fs_info->sb->s_bdev->bd_inode->i_size;
2592 else {
2593 if (sizestr[0] == '-') {
2594 mod = -1;
2595 sizestr++;
2596 } else if (sizestr[0] == '+') {
2597 mod = 1;
2598 sizestr++;
2599 }
2600 new_size = btrfs_parse_size(sizestr);
2601 if (new_size == 0) {
2602 ret = -EINVAL;
2603 goto out;
2604 }
2605 }
2606
2607 mutex_lock(&root->fs_info->fs_mutex);
2608 old_size = btrfs_super_total_bytes(&root->fs_info->super_copy);
2609
2610 if (mod < 0) {
2611 if (new_size > old_size) {
2612 ret = -EINVAL;
2613 goto out_unlock;
2614 }
2615 new_size = old_size - new_size;
2616 } else if (mod > 0) {
2617 new_size = old_size + new_size;
2618 }
2619
2620 if (new_size < 256 * 1024 * 1024) {
2621 ret = -EINVAL;
2622 goto out_unlock;
2623 }
2624 if (new_size > root->fs_info->sb->s_bdev->bd_inode->i_size) {
2625 ret = -EFBIG;
2626 goto out_unlock;
2627 }
2628
2629 do_div(new_size, root->sectorsize);
2630 new_size *= root->sectorsize;
2631
2632 printk("new size is %Lu\n", new_size);
2633 if (new_size > old_size) {
2634 trans = btrfs_start_transaction(root, 1);
2635 ret = btrfs_grow_extent_tree(trans, root, new_size);
2636 btrfs_commit_transaction(trans, root);
2637 } else {
2638 ret = btrfs_shrink_extent_tree(root, new_size);
2639 }
2640
2641 out_unlock:
2642 mutex_unlock(&root->fs_info->fs_mutex);
2643 out:
2644 kfree(vol_args);
2645 return ret;
2646 }
2647
2648 static int noinline btrfs_ioctl_snap_create(struct btrfs_root *root,
2649 void __user *arg)
2650 {
2651 struct btrfs_ioctl_vol_args *vol_args;
2652 struct btrfs_dir_item *di;
2653 struct btrfs_path *path;
2654 u64 root_dirid;
2655 int namelen;
2656 int ret;
2657
2658 vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
2659
2660 if (!vol_args)
2661 return -ENOMEM;
2662
2663 if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
2664 ret = -EFAULT;
2665 goto out;
2666 }
2667
2668 namelen = strlen(vol_args->name);
2669 if (namelen > BTRFS_VOL_NAME_MAX) {
2670 ret = -EINVAL;
2671 goto out;
2672 }
2673 if (strchr(vol_args->name, '/')) {
2674 ret = -EINVAL;
2675 goto out;
2676 }
2677
2678 path = btrfs_alloc_path();
2679 if (!path) {
2680 ret = -ENOMEM;
2681 goto out;
2682 }
2683
2684 root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
2685 mutex_lock(&root->fs_info->fs_mutex);
2686 di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
2687 path, root_dirid,
2688 vol_args->name, namelen, 0);
2689 mutex_unlock(&root->fs_info->fs_mutex);
2690 btrfs_free_path(path);
2691
2692 if (di && !IS_ERR(di)) {
2693 ret = -EEXIST;
2694 goto out;
2695 }
2696
2697 if (IS_ERR(di)) {
2698 ret = PTR_ERR(di);
2699 goto out;
2700 }
2701
2702 if (root == root->fs_info->tree_root)
2703 ret = create_subvol(root, vol_args->name, namelen);
2704 else
2705 ret = create_snapshot(root, vol_args->name, namelen);
2706 out:
2707 kfree(vol_args);
2708 return ret;
2709 }
2710
2711 static int btrfs_ioctl_defrag(struct file *file)
2712 {
2713 struct inode *inode = fdentry(file)->d_inode;
2714 struct btrfs_root *root = BTRFS_I(inode)->root;
2715
2716 switch (inode->i_mode & S_IFMT) {
2717 case S_IFDIR:
2718 mutex_lock(&root->fs_info->fs_mutex);
2719 btrfs_defrag_root(root, 0);
2720 btrfs_defrag_root(root->fs_info->extent_root, 0);
2721 mutex_unlock(&root->fs_info->fs_mutex);
2722 break;
2723 case S_IFREG:
2724 btrfs_defrag_file(file);
2725 break;
2726 }
2727
2728 return 0;
2729 }
2730
2731 long btrfs_ioctl(struct file *file, unsigned int
2732 cmd, unsigned long arg)
2733 {
2734 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
2735
2736 switch (cmd) {
2737 case BTRFS_IOC_SNAP_CREATE:
2738 return btrfs_ioctl_snap_create(root, (void __user *)arg);
2739 case BTRFS_IOC_DEFRAG:
2740 return btrfs_ioctl_defrag(file);
2741 case BTRFS_IOC_RESIZE:
2742 return btrfs_ioctl_resize(root, (void __user *)arg);
2743 }
2744
2745 return -ENOTTY;
2746 }
2747
2748 /*
2749 * Called inside transaction, so use GFP_NOFS
2750 */
2751 struct inode *btrfs_alloc_inode(struct super_block *sb)
2752 {
2753 struct btrfs_inode *ei;
2754
2755 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
2756 if (!ei)
2757 return NULL;
2758 ei->last_trans = 0;
2759 ei->ordered_trans = 0;
2760 return &ei->vfs_inode;
2761 }
2762
2763 void btrfs_destroy_inode(struct inode *inode)
2764 {
2765 WARN_ON(!list_empty(&inode->i_dentry));
2766 WARN_ON(inode->i_data.nrpages);
2767
2768 btrfs_drop_extent_cache(inode, 0, (u64)-1);
2769 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
2770 }
2771
2772 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
2773 static void init_once(struct kmem_cache * cachep, void *foo)
2774 #else
2775 static void init_once(void * foo, struct kmem_cache * cachep,
2776 unsigned long flags)
2777 #endif
2778 {
2779 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
2780
2781 inode_init_once(&ei->vfs_inode);
2782 }
2783
2784 void btrfs_destroy_cachep(void)
2785 {
2786 if (btrfs_inode_cachep)
2787 kmem_cache_destroy(btrfs_inode_cachep);
2788 if (btrfs_trans_handle_cachep)
2789 kmem_cache_destroy(btrfs_trans_handle_cachep);
2790 if (btrfs_transaction_cachep)
2791 kmem_cache_destroy(btrfs_transaction_cachep);
2792 if (btrfs_bit_radix_cachep)
2793 kmem_cache_destroy(btrfs_bit_radix_cachep);
2794 if (btrfs_path_cachep)
2795 kmem_cache_destroy(btrfs_path_cachep);
2796 }
2797
2798 struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
2799 unsigned long extra_flags,
2800 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
2801 void (*ctor)(struct kmem_cache *, void *)
2802 #else
2803 void (*ctor)(void *, struct kmem_cache *,
2804 unsigned long)
2805 #endif
2806 )
2807 {
2808 return kmem_cache_create(name, size, 0, (SLAB_RECLAIM_ACCOUNT |
2809 SLAB_MEM_SPREAD | extra_flags), ctor
2810 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
2811 ,NULL
2812 #endif
2813 );
2814 }
2815
2816 int btrfs_init_cachep(void)
2817 {
2818 btrfs_inode_cachep = btrfs_cache_create("btrfs_inode_cache",
2819 sizeof(struct btrfs_inode),
2820 0, init_once);
2821 if (!btrfs_inode_cachep)
2822 goto fail;
2823 btrfs_trans_handle_cachep =
2824 btrfs_cache_create("btrfs_trans_handle_cache",
2825 sizeof(struct btrfs_trans_handle),
2826 0, NULL);
2827 if (!btrfs_trans_handle_cachep)
2828 goto fail;
2829 btrfs_transaction_cachep = btrfs_cache_create("btrfs_transaction_cache",
2830 sizeof(struct btrfs_transaction),
2831 0, NULL);
2832 if (!btrfs_transaction_cachep)
2833 goto fail;
2834 btrfs_path_cachep = btrfs_cache_create("btrfs_path_cache",
2835 sizeof(struct btrfs_path),
2836 0, NULL);
2837 if (!btrfs_path_cachep)
2838 goto fail;
2839 btrfs_bit_radix_cachep = btrfs_cache_create("btrfs_radix", 256,
2840 SLAB_DESTROY_BY_RCU, NULL);
2841 if (!btrfs_bit_radix_cachep)
2842 goto fail;
2843 return 0;
2844 fail:
2845 btrfs_destroy_cachep();
2846 return -ENOMEM;
2847 }
2848
2849 static int btrfs_getattr(struct vfsmount *mnt,
2850 struct dentry *dentry, struct kstat *stat)
2851 {
2852 struct inode *inode = dentry->d_inode;
2853 generic_fillattr(inode, stat);
2854 stat->blksize = PAGE_CACHE_SIZE;
2855 stat->blocks = inode->i_blocks + (BTRFS_I(inode)->delalloc_bytes >> 9);
2856 return 0;
2857 }
2858
2859 static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
2860 struct inode * new_dir,struct dentry *new_dentry)
2861 {
2862 struct btrfs_trans_handle *trans;
2863 struct btrfs_root *root = BTRFS_I(old_dir)->root;
2864 struct inode *new_inode = new_dentry->d_inode;
2865 struct inode *old_inode = old_dentry->d_inode;
2866 struct timespec ctime = CURRENT_TIME;
2867 struct btrfs_path *path;
2868 int ret;
2869
2870 if (S_ISDIR(old_inode->i_mode) && new_inode &&
2871 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
2872 return -ENOTEMPTY;
2873 }
2874
2875 mutex_lock(&root->fs_info->fs_mutex);
2876 ret = btrfs_check_free_space(root, 1, 0);
2877 if (ret)
2878 goto out_unlock;
2879
2880 trans = btrfs_start_transaction(root, 1);
2881
2882 btrfs_set_trans_block_group(trans, new_dir);
2883 path = btrfs_alloc_path();
2884 if (!path) {
2885 ret = -ENOMEM;
2886 goto out_fail;
2887 }
2888
2889 old_dentry->d_inode->i_nlink++;
2890 old_dir->i_ctime = old_dir->i_mtime = ctime;
2891 new_dir->i_ctime = new_dir->i_mtime = ctime;
2892 old_inode->i_ctime = ctime;
2893
2894 ret = btrfs_unlink_trans(trans, root, old_dir, old_dentry);
2895 if (ret)
2896 goto out_fail;
2897
2898 if (new_inode) {
2899 new_inode->i_ctime = CURRENT_TIME;
2900 ret = btrfs_unlink_trans(trans, root, new_dir, new_dentry);
2901 if (ret)
2902 goto out_fail;
2903 }
2904 ret = btrfs_add_link(trans, new_dentry, old_inode, 1);
2905 if (ret)
2906 goto out_fail;
2907
2908 out_fail:
2909 btrfs_free_path(path);
2910 btrfs_end_transaction(trans, root);
2911 out_unlock:
2912 mutex_unlock(&root->fs_info->fs_mutex);
2913 return ret;
2914 }
2915
2916 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
2917 const char *symname)
2918 {
2919 struct btrfs_trans_handle *trans;
2920 struct btrfs_root *root = BTRFS_I(dir)->root;
2921 struct btrfs_path *path;
2922 struct btrfs_key key;
2923 struct inode *inode = NULL;
2924 int err;
2925 int drop_inode = 0;
2926 u64 objectid;
2927 int name_len;
2928 int datasize;
2929 unsigned long ptr;
2930 struct btrfs_file_extent_item *ei;
2931 struct extent_buffer *leaf;
2932 unsigned long nr = 0;
2933
2934 name_len = strlen(symname) + 1;
2935 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
2936 return -ENAMETOOLONG;
2937
2938 mutex_lock(&root->fs_info->fs_mutex);
2939 err = btrfs_check_free_space(root, 1, 0);
2940 if (err)
2941 goto out_fail;
2942
2943 trans = btrfs_start_transaction(root, 1);
2944 btrfs_set_trans_block_group(trans, dir);
2945
2946 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
2947 if (err) {
2948 err = -ENOSPC;
2949 goto out_unlock;
2950 }
2951
2952 inode = btrfs_new_inode(trans, root, dentry->d_name.name,
2953 dentry->d_name.len,
2954 dentry->d_parent->d_inode->i_ino, objectid,
2955 BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO);
2956 err = PTR_ERR(inode);
2957 if (IS_ERR(inode))
2958 goto out_unlock;
2959
2960 btrfs_set_trans_block_group(trans, inode);
2961 err = btrfs_add_nondir(trans, dentry, inode, 0);
2962 if (err)
2963 drop_inode = 1;
2964 else {
2965 inode->i_mapping->a_ops = &btrfs_aops;
2966 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
2967 inode->i_fop = &btrfs_file_operations;
2968 inode->i_op = &btrfs_file_inode_operations;
2969 extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
2970 extent_io_tree_init(&BTRFS_I(inode)->io_tree,
2971 inode->i_mapping, GFP_NOFS);
2972 BTRFS_I(inode)->delalloc_bytes = 0;
2973 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
2974 }
2975 dir->i_sb->s_dirt = 1;
2976 btrfs_update_inode_block_group(trans, inode);
2977 btrfs_update_inode_block_group(trans, dir);
2978 if (drop_inode)
2979 goto out_unlock;
2980
2981 path = btrfs_alloc_path();
2982 BUG_ON(!path);
2983 key.objectid = inode->i_ino;
2984 key.offset = 0;
2985 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
2986 datasize = btrfs_file_extent_calc_inline_size(name_len);
2987 err = btrfs_insert_empty_item(trans, root, path, &key,
2988 datasize);
2989 if (err) {
2990 drop_inode = 1;
2991 goto out_unlock;
2992 }
2993 leaf = path->nodes[0];
2994 ei = btrfs_item_ptr(leaf, path->slots[0],
2995 struct btrfs_file_extent_item);
2996 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
2997 btrfs_set_file_extent_type(leaf, ei,
2998 BTRFS_FILE_EXTENT_INLINE);
2999 ptr = btrfs_file_extent_inline_start(ei);
3000 write_extent_buffer(leaf, symname, ptr, name_len);
3001 btrfs_mark_buffer_dirty(leaf);
3002 btrfs_free_path(path);
3003
3004 inode->i_op = &btrfs_symlink_inode_operations;
3005 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3006 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3007 inode->i_size = name_len - 1;
3008 err = btrfs_update_inode(trans, root, inode);
3009 if (err)
3010 drop_inode = 1;
3011
3012 out_unlock:
3013 nr = trans->blocks_used;
3014 btrfs_end_transaction(trans, root);
3015 out_fail:
3016 mutex_unlock(&root->fs_info->fs_mutex);
3017 if (drop_inode) {
3018 inode_dec_link_count(inode);
3019 iput(inode);
3020 }
3021 btrfs_btree_balance_dirty(root, nr);
3022 btrfs_throttle(root);
3023 return err;
3024 }
3025 static int btrfs_permission(struct inode *inode, int mask,
3026 struct nameidata *nd)
3027 {
3028 if (btrfs_test_flag(inode, READONLY) && (mask & MAY_WRITE))
3029 return -EACCES;
3030 return generic_permission(inode, mask, NULL);
3031 }
3032
3033 static struct inode_operations btrfs_dir_inode_operations = {
3034 .lookup = btrfs_lookup,
3035 .create = btrfs_create,
3036 .unlink = btrfs_unlink,
3037 .link = btrfs_link,
3038 .mkdir = btrfs_mkdir,
3039 .rmdir = btrfs_rmdir,
3040 .rename = btrfs_rename,
3041 .symlink = btrfs_symlink,
3042 .setattr = btrfs_setattr,
3043 .mknod = btrfs_mknod,
3044 .setxattr = generic_setxattr,
3045 .getxattr = generic_getxattr,
3046 .listxattr = btrfs_listxattr,
3047 .removexattr = generic_removexattr,
3048 .permission = btrfs_permission,
3049 };
3050 static struct inode_operations btrfs_dir_ro_inode_operations = {
3051 .lookup = btrfs_lookup,
3052 .permission = btrfs_permission,
3053 };
3054 static struct file_operations btrfs_dir_file_operations = {
3055 .llseek = generic_file_llseek,
3056 .read = generic_read_dir,
3057 .readdir = btrfs_readdir,
3058 .unlocked_ioctl = btrfs_ioctl,
3059 #ifdef CONFIG_COMPAT
3060 .compat_ioctl = btrfs_ioctl,
3061 #endif
3062 };
3063
3064 static struct extent_io_ops btrfs_extent_io_ops = {
3065 .fill_delalloc = run_delalloc_range,
3066 .submit_bio_hook = btrfs_submit_bio_hook,
3067 .merge_bio_hook = btrfs_merge_bio_hook,
3068 .readpage_io_hook = btrfs_readpage_io_hook,
3069 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
3070 .set_bit_hook = btrfs_set_bit_hook,
3071 .clear_bit_hook = btrfs_clear_bit_hook,
3072 };
3073
3074 static struct address_space_operations btrfs_aops = {
3075 .readpage = btrfs_readpage,
3076 .writepage = btrfs_writepage,
3077 .writepages = btrfs_writepages,
3078 .readpages = btrfs_readpages,
3079 .sync_page = block_sync_page,
3080 .bmap = btrfs_bmap,
3081 .invalidatepage = btrfs_invalidatepage,
3082 .releasepage = btrfs_releasepage,
3083 .set_page_dirty = __set_page_dirty_nobuffers,
3084 };
3085
3086 static struct address_space_operations btrfs_symlink_aops = {
3087 .readpage = btrfs_readpage,
3088 .writepage = btrfs_writepage,
3089 .invalidatepage = btrfs_invalidatepage,
3090 .releasepage = btrfs_releasepage,
3091 };
3092
3093 static struct inode_operations btrfs_file_inode_operations = {
3094 .truncate = btrfs_truncate,
3095 .getattr = btrfs_getattr,
3096 .setattr = btrfs_setattr,
3097 .setxattr = generic_setxattr,
3098 .getxattr = generic_getxattr,
3099 .listxattr = btrfs_listxattr,
3100 .removexattr = generic_removexattr,
3101 .permission = btrfs_permission,
3102 };
3103 static struct inode_operations btrfs_special_inode_operations = {
3104 .getattr = btrfs_getattr,
3105 .setattr = btrfs_setattr,
3106 .permission = btrfs_permission,
3107 };
3108 static struct inode_operations btrfs_symlink_inode_operations = {
3109 .readlink = generic_readlink,
3110 .follow_link = page_follow_link_light,
3111 .put_link = page_put_link,
3112 .permission = btrfs_permission,
3113 };
Linux kernel - Deliverables
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