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Btrfs: Add support for mirroring across drives
[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 int total_devs;
310 struct bio_vec *bvec;
311 int i;
312 int ret;
313
314 bio_for_each_segment(bvec, bio, i) {
315 length += bvec->bv_len;
316 }
317 map_tree = &root->fs_info->mapping_tree;
318 map_length = length;
319 ret = btrfs_map_block(map_tree, READ, 0, logical, &physical,
320 &map_length, &dev, &total_devs);
321 if (map_length < length + size) {
322 return 1;
323 }
324 return 0;
325 }
326
327 int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio)
328 {
329 struct btrfs_root *root = BTRFS_I(inode)->root;
330 struct btrfs_trans_handle *trans;
331 int ret = 0;
332
333 if (rw != WRITE) {
334 goto mapit;
335 }
336
337 if (btrfs_test_opt(root, NODATASUM) ||
338 btrfs_test_flag(inode, NODATASUM)) {
339 goto mapit;
340 }
341
342 mutex_lock(&root->fs_info->fs_mutex);
343 trans = btrfs_start_transaction(root, 1);
344 btrfs_set_trans_block_group(trans, inode);
345 btrfs_csum_file_blocks(trans, root, inode, bio);
346 ret = btrfs_end_transaction(trans, root);
347 BUG_ON(ret);
348 mutex_unlock(&root->fs_info->fs_mutex);
349 mapit:
350 return btrfs_map_bio(root, rw, bio);
351 }
352
353 int btrfs_readpage_io_hook(struct page *page, u64 start, u64 end)
354 {
355 int ret = 0;
356 struct inode *inode = page->mapping->host;
357 struct btrfs_root *root = BTRFS_I(inode)->root;
358 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
359 struct btrfs_csum_item *item;
360 struct btrfs_path *path = NULL;
361 u32 csum;
362 if (btrfs_test_opt(root, NODATASUM) ||
363 btrfs_test_flag(inode, NODATASUM))
364 return 0;
365 mutex_lock(&root->fs_info->fs_mutex);
366 path = btrfs_alloc_path();
367 item = btrfs_lookup_csum(NULL, root, path, inode->i_ino, start, 0);
368 if (IS_ERR(item)) {
369 ret = PTR_ERR(item);
370 /* a csum that isn't present is a preallocated region. */
371 if (ret == -ENOENT || ret == -EFBIG)
372 ret = 0;
373 csum = 0;
374 printk("no csum found for inode %lu start %Lu\n", inode->i_ino, start);
375 goto out;
376 }
377 read_extent_buffer(path->nodes[0], &csum, (unsigned long)item,
378 BTRFS_CRC32_SIZE);
379 set_state_private(io_tree, start, csum);
380 out:
381 if (path)
382 btrfs_free_path(path);
383 mutex_unlock(&root->fs_info->fs_mutex);
384 return ret;
385 }
386
387 int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
388 struct extent_state *state)
389 {
390 size_t offset = start - ((u64)page->index << PAGE_CACHE_SHIFT);
391 struct inode *inode = page->mapping->host;
392 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
393 char *kaddr;
394 u64 private = ~(u32)0;
395 int ret;
396 struct btrfs_root *root = BTRFS_I(inode)->root;
397 u32 csum = ~(u32)0;
398 unsigned long flags;
399
400 if (btrfs_test_opt(root, NODATASUM) ||
401 btrfs_test_flag(inode, NODATASUM))
402 return 0;
403 if (state && state->start == start) {
404 private = state->private;
405 ret = 0;
406 } else {
407 ret = get_state_private(io_tree, start, &private);
408 }
409 local_irq_save(flags);
410 kaddr = kmap_atomic(page, KM_IRQ0);
411 if (ret) {
412 goto zeroit;
413 }
414 csum = btrfs_csum_data(root, kaddr + offset, csum, end - start + 1);
415 btrfs_csum_final(csum, (char *)&csum);
416 if (csum != private) {
417 goto zeroit;
418 }
419 kunmap_atomic(kaddr, KM_IRQ0);
420 local_irq_restore(flags);
421 return 0;
422
423 zeroit:
424 printk("btrfs csum failed ino %lu off %llu csum %u private %Lu\n",
425 page->mapping->host->i_ino, (unsigned long long)start, csum,
426 private);
427 memset(kaddr + offset, 1, end - start + 1);
428 flush_dcache_page(page);
429 kunmap_atomic(kaddr, KM_IRQ0);
430 local_irq_restore(flags);
431 return 0;
432 }
433
434 void btrfs_read_locked_inode(struct inode *inode)
435 {
436 struct btrfs_path *path;
437 struct extent_buffer *leaf;
438 struct btrfs_inode_item *inode_item;
439 struct btrfs_timespec *tspec;
440 struct btrfs_root *root = BTRFS_I(inode)->root;
441 struct btrfs_key location;
442 u64 alloc_group_block;
443 u32 rdev;
444 int ret;
445
446 path = btrfs_alloc_path();
447 BUG_ON(!path);
448 mutex_lock(&root->fs_info->fs_mutex);
449 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
450
451 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
452 if (ret)
453 goto make_bad;
454
455 leaf = path->nodes[0];
456 inode_item = btrfs_item_ptr(leaf, path->slots[0],
457 struct btrfs_inode_item);
458
459 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
460 inode->i_nlink = btrfs_inode_nlink(leaf, inode_item);
461 inode->i_uid = btrfs_inode_uid(leaf, inode_item);
462 inode->i_gid = btrfs_inode_gid(leaf, inode_item);
463 inode->i_size = btrfs_inode_size(leaf, inode_item);
464
465 tspec = btrfs_inode_atime(inode_item);
466 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
467 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
468
469 tspec = btrfs_inode_mtime(inode_item);
470 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
471 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
472
473 tspec = btrfs_inode_ctime(inode_item);
474 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
475 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
476
477 inode->i_blocks = btrfs_inode_nblocks(leaf, inode_item);
478 inode->i_generation = btrfs_inode_generation(leaf, inode_item);
479 inode->i_rdev = 0;
480 rdev = btrfs_inode_rdev(leaf, inode_item);
481
482 alloc_group_block = btrfs_inode_block_group(leaf, inode_item);
483 BTRFS_I(inode)->block_group = btrfs_lookup_block_group(root->fs_info,
484 alloc_group_block);
485 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
486 if (!BTRFS_I(inode)->block_group) {
487 BTRFS_I(inode)->block_group = btrfs_find_block_group(root,
488 NULL, 0,
489 BTRFS_BLOCK_GROUP_METADATA, 0);
490 }
491 btrfs_free_path(path);
492 inode_item = NULL;
493
494 mutex_unlock(&root->fs_info->fs_mutex);
495
496 switch (inode->i_mode & S_IFMT) {
497 case S_IFREG:
498 inode->i_mapping->a_ops = &btrfs_aops;
499 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
500 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
501 inode->i_fop = &btrfs_file_operations;
502 inode->i_op = &btrfs_file_inode_operations;
503 break;
504 case S_IFDIR:
505 inode->i_fop = &btrfs_dir_file_operations;
506 if (root == root->fs_info->tree_root)
507 inode->i_op = &btrfs_dir_ro_inode_operations;
508 else
509 inode->i_op = &btrfs_dir_inode_operations;
510 break;
511 case S_IFLNK:
512 inode->i_op = &btrfs_symlink_inode_operations;
513 inode->i_mapping->a_ops = &btrfs_symlink_aops;
514 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
515 break;
516 default:
517 init_special_inode(inode, inode->i_mode, rdev);
518 break;
519 }
520 return;
521
522 make_bad:
523 btrfs_release_path(root, path);
524 btrfs_free_path(path);
525 mutex_unlock(&root->fs_info->fs_mutex);
526 make_bad_inode(inode);
527 }
528
529 static void fill_inode_item(struct extent_buffer *leaf,
530 struct btrfs_inode_item *item,
531 struct inode *inode)
532 {
533 btrfs_set_inode_uid(leaf, item, inode->i_uid);
534 btrfs_set_inode_gid(leaf, item, inode->i_gid);
535 btrfs_set_inode_size(leaf, item, inode->i_size);
536 btrfs_set_inode_mode(leaf, item, inode->i_mode);
537 btrfs_set_inode_nlink(leaf, item, inode->i_nlink);
538
539 btrfs_set_timespec_sec(leaf, btrfs_inode_atime(item),
540 inode->i_atime.tv_sec);
541 btrfs_set_timespec_nsec(leaf, btrfs_inode_atime(item),
542 inode->i_atime.tv_nsec);
543
544 btrfs_set_timespec_sec(leaf, btrfs_inode_mtime(item),
545 inode->i_mtime.tv_sec);
546 btrfs_set_timespec_nsec(leaf, btrfs_inode_mtime(item),
547 inode->i_mtime.tv_nsec);
548
549 btrfs_set_timespec_sec(leaf, btrfs_inode_ctime(item),
550 inode->i_ctime.tv_sec);
551 btrfs_set_timespec_nsec(leaf, btrfs_inode_ctime(item),
552 inode->i_ctime.tv_nsec);
553
554 btrfs_set_inode_nblocks(leaf, item, inode->i_blocks);
555 btrfs_set_inode_generation(leaf, item, inode->i_generation);
556 btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
557 btrfs_set_inode_flags(leaf, item, BTRFS_I(inode)->flags);
558 btrfs_set_inode_block_group(leaf, item,
559 BTRFS_I(inode)->block_group->key.objectid);
560 }
561
562 int btrfs_update_inode(struct btrfs_trans_handle *trans,
563 struct btrfs_root *root,
564 struct inode *inode)
565 {
566 struct btrfs_inode_item *inode_item;
567 struct btrfs_path *path;
568 struct extent_buffer *leaf;
569 int ret;
570
571 path = btrfs_alloc_path();
572 BUG_ON(!path);
573 ret = btrfs_lookup_inode(trans, root, path,
574 &BTRFS_I(inode)->location, 1);
575 if (ret) {
576 if (ret > 0)
577 ret = -ENOENT;
578 goto failed;
579 }
580
581 leaf = path->nodes[0];
582 inode_item = btrfs_item_ptr(leaf, path->slots[0],
583 struct btrfs_inode_item);
584
585 fill_inode_item(leaf, inode_item, inode);
586 btrfs_mark_buffer_dirty(leaf);
587 btrfs_set_inode_last_trans(trans, inode);
588 ret = 0;
589 failed:
590 btrfs_release_path(root, path);
591 btrfs_free_path(path);
592 return ret;
593 }
594
595
596 static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
597 struct btrfs_root *root,
598 struct inode *dir,
599 struct dentry *dentry)
600 {
601 struct btrfs_path *path;
602 const char *name = dentry->d_name.name;
603 int name_len = dentry->d_name.len;
604 int ret = 0;
605 struct extent_buffer *leaf;
606 struct btrfs_dir_item *di;
607 struct btrfs_key key;
608
609 path = btrfs_alloc_path();
610 if (!path) {
611 ret = -ENOMEM;
612 goto err;
613 }
614
615 di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
616 name, name_len, -1);
617 if (IS_ERR(di)) {
618 ret = PTR_ERR(di);
619 goto err;
620 }
621 if (!di) {
622 ret = -ENOENT;
623 goto err;
624 }
625 leaf = path->nodes[0];
626 btrfs_dir_item_key_to_cpu(leaf, di, &key);
627 ret = btrfs_delete_one_dir_name(trans, root, path, di);
628 if (ret)
629 goto err;
630 btrfs_release_path(root, path);
631
632 di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
633 key.objectid, name, name_len, -1);
634 if (IS_ERR(di)) {
635 ret = PTR_ERR(di);
636 goto err;
637 }
638 if (!di) {
639 ret = -ENOENT;
640 goto err;
641 }
642 ret = btrfs_delete_one_dir_name(trans, root, path, di);
643
644 dentry->d_inode->i_ctime = dir->i_ctime;
645 ret = btrfs_del_inode_ref(trans, root, name, name_len,
646 dentry->d_inode->i_ino,
647 dentry->d_parent->d_inode->i_ino);
648 if (ret) {
649 printk("failed to delete reference to %.*s, "
650 "inode %lu parent %lu\n", name_len, name,
651 dentry->d_inode->i_ino,
652 dentry->d_parent->d_inode->i_ino);
653 }
654 err:
655 btrfs_free_path(path);
656 if (!ret) {
657 dir->i_size -= name_len * 2;
658 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
659 btrfs_update_inode(trans, root, dir);
660 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
661 dentry->d_inode->i_nlink--;
662 #else
663 drop_nlink(dentry->d_inode);
664 #endif
665 ret = btrfs_update_inode(trans, root, dentry->d_inode);
666 dir->i_sb->s_dirt = 1;
667 }
668 return ret;
669 }
670
671 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
672 {
673 struct btrfs_root *root;
674 struct btrfs_trans_handle *trans;
675 struct inode *inode = dentry->d_inode;
676 int ret;
677 unsigned long nr = 0;
678
679 root = BTRFS_I(dir)->root;
680 mutex_lock(&root->fs_info->fs_mutex);
681
682 ret = btrfs_check_free_space(root, 1, 1);
683 if (ret)
684 goto fail;
685
686 trans = btrfs_start_transaction(root, 1);
687
688 btrfs_set_trans_block_group(trans, dir);
689 ret = btrfs_unlink_trans(trans, root, dir, dentry);
690 nr = trans->blocks_used;
691
692 if (inode->i_nlink == 0) {
693 int found;
694 /* if the inode isn't linked anywhere,
695 * we don't need to worry about
696 * data=ordered
697 */
698 found = btrfs_del_ordered_inode(inode);
699 if (found == 1) {
700 atomic_dec(&inode->i_count);
701 }
702 }
703
704 btrfs_end_transaction(trans, root);
705 fail:
706 mutex_unlock(&root->fs_info->fs_mutex);
707 btrfs_btree_balance_dirty(root, nr);
708 btrfs_throttle(root);
709 return ret;
710 }
711
712 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
713 {
714 struct inode *inode = dentry->d_inode;
715 int err = 0;
716 int ret;
717 struct btrfs_root *root = BTRFS_I(dir)->root;
718 struct btrfs_trans_handle *trans;
719 unsigned long nr = 0;
720
721 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
722 return -ENOTEMPTY;
723
724 mutex_lock(&root->fs_info->fs_mutex);
725 ret = btrfs_check_free_space(root, 1, 1);
726 if (ret)
727 goto fail;
728
729 trans = btrfs_start_transaction(root, 1);
730 btrfs_set_trans_block_group(trans, dir);
731
732 /* now the directory is empty */
733 err = btrfs_unlink_trans(trans, root, dir, dentry);
734 if (!err) {
735 inode->i_size = 0;
736 }
737
738 nr = trans->blocks_used;
739 ret = btrfs_end_transaction(trans, root);
740 fail:
741 mutex_unlock(&root->fs_info->fs_mutex);
742 btrfs_btree_balance_dirty(root, nr);
743 btrfs_throttle(root);
744
745 if (ret && !err)
746 err = ret;
747 return err;
748 }
749
750 /*
751 * this can truncate away extent items, csum items and directory items.
752 * It starts at a high offset and removes keys until it can't find
753 * any higher than i_size.
754 *
755 * csum items that cross the new i_size are truncated to the new size
756 * as well.
757 */
758 static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
759 struct btrfs_root *root,
760 struct inode *inode,
761 u32 min_type)
762 {
763 int ret;
764 struct btrfs_path *path;
765 struct btrfs_key key;
766 struct btrfs_key found_key;
767 u32 found_type;
768 struct extent_buffer *leaf;
769 struct btrfs_file_extent_item *fi;
770 u64 extent_start = 0;
771 u64 extent_num_bytes = 0;
772 u64 item_end = 0;
773 u64 root_gen = 0;
774 u64 root_owner = 0;
775 int found_extent;
776 int del_item;
777 int pending_del_nr = 0;
778 int pending_del_slot = 0;
779 int extent_type = -1;
780
781 btrfs_drop_extent_cache(inode, inode->i_size, (u64)-1);
782 path = btrfs_alloc_path();
783 path->reada = -1;
784 BUG_ON(!path);
785
786 /* FIXME, add redo link to tree so we don't leak on crash */
787 key.objectid = inode->i_ino;
788 key.offset = (u64)-1;
789 key.type = (u8)-1;
790
791 btrfs_init_path(path);
792 search_again:
793 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
794 if (ret < 0) {
795 goto error;
796 }
797 if (ret > 0) {
798 BUG_ON(path->slots[0] == 0);
799 path->slots[0]--;
800 }
801
802 while(1) {
803 fi = NULL;
804 leaf = path->nodes[0];
805 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
806 found_type = btrfs_key_type(&found_key);
807
808 if (found_key.objectid != inode->i_ino)
809 break;
810
811 if (found_type < min_type)
812 break;
813
814 item_end = found_key.offset;
815 if (found_type == BTRFS_EXTENT_DATA_KEY) {
816 fi = btrfs_item_ptr(leaf, path->slots[0],
817 struct btrfs_file_extent_item);
818 extent_type = btrfs_file_extent_type(leaf, fi);
819 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
820 item_end +=
821 btrfs_file_extent_num_bytes(leaf, fi);
822 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
823 struct btrfs_item *item = btrfs_item_nr(leaf,
824 path->slots[0]);
825 item_end += btrfs_file_extent_inline_len(leaf,
826 item);
827 }
828 item_end--;
829 }
830 if (found_type == BTRFS_CSUM_ITEM_KEY) {
831 ret = btrfs_csum_truncate(trans, root, path,
832 inode->i_size);
833 BUG_ON(ret);
834 }
835 if (item_end < inode->i_size) {
836 if (found_type == BTRFS_DIR_ITEM_KEY) {
837 found_type = BTRFS_INODE_ITEM_KEY;
838 } else if (found_type == BTRFS_EXTENT_ITEM_KEY) {
839 found_type = BTRFS_CSUM_ITEM_KEY;
840 } else if (found_type == BTRFS_EXTENT_DATA_KEY) {
841 found_type = BTRFS_XATTR_ITEM_KEY;
842 } else if (found_type == BTRFS_XATTR_ITEM_KEY) {
843 found_type = BTRFS_INODE_REF_KEY;
844 } else if (found_type) {
845 found_type--;
846 } else {
847 break;
848 }
849 btrfs_set_key_type(&key, found_type);
850 goto next;
851 }
852 if (found_key.offset >= inode->i_size)
853 del_item = 1;
854 else
855 del_item = 0;
856 found_extent = 0;
857
858 /* FIXME, shrink the extent if the ref count is only 1 */
859 if (found_type != BTRFS_EXTENT_DATA_KEY)
860 goto delete;
861
862 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
863 u64 num_dec;
864 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
865 if (!del_item) {
866 u64 orig_num_bytes =
867 btrfs_file_extent_num_bytes(leaf, fi);
868 extent_num_bytes = inode->i_size -
869 found_key.offset + root->sectorsize - 1;
870 extent_num_bytes = extent_num_bytes &
871 ~((u64)root->sectorsize - 1);
872 btrfs_set_file_extent_num_bytes(leaf, fi,
873 extent_num_bytes);
874 num_dec = (orig_num_bytes -
875 extent_num_bytes);
876 if (extent_start != 0)
877 dec_i_blocks(inode, num_dec);
878 btrfs_mark_buffer_dirty(leaf);
879 } else {
880 extent_num_bytes =
881 btrfs_file_extent_disk_num_bytes(leaf,
882 fi);
883 /* FIXME blocksize != 4096 */
884 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
885 if (extent_start != 0) {
886 found_extent = 1;
887 dec_i_blocks(inode, num_dec);
888 }
889 root_gen = btrfs_header_generation(leaf);
890 root_owner = btrfs_header_owner(leaf);
891 }
892 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
893 if (!del_item) {
894 u32 newsize = inode->i_size - found_key.offset;
895 dec_i_blocks(inode, item_end + 1 -
896 found_key.offset - newsize);
897 newsize =
898 btrfs_file_extent_calc_inline_size(newsize);
899 ret = btrfs_truncate_item(trans, root, path,
900 newsize, 1);
901 BUG_ON(ret);
902 } else {
903 dec_i_blocks(inode, item_end + 1 -
904 found_key.offset);
905 }
906 }
907 delete:
908 if (del_item) {
909 if (!pending_del_nr) {
910 /* no pending yet, add ourselves */
911 pending_del_slot = path->slots[0];
912 pending_del_nr = 1;
913 } else if (pending_del_nr &&
914 path->slots[0] + 1 == pending_del_slot) {
915 /* hop on the pending chunk */
916 pending_del_nr++;
917 pending_del_slot = path->slots[0];
918 } else {
919 printk("bad pending slot %d pending_del_nr %d pending_del_slot %d\n", path->slots[0], pending_del_nr, pending_del_slot);
920 }
921 } else {
922 break;
923 }
924 if (found_extent) {
925 ret = btrfs_free_extent(trans, root, extent_start,
926 extent_num_bytes,
927 root_owner,
928 root_gen, inode->i_ino,
929 found_key.offset, 0);
930 BUG_ON(ret);
931 }
932 next:
933 if (path->slots[0] == 0) {
934 if (pending_del_nr)
935 goto del_pending;
936 btrfs_release_path(root, path);
937 goto search_again;
938 }
939
940 path->slots[0]--;
941 if (pending_del_nr &&
942 path->slots[0] + 1 != pending_del_slot) {
943 struct btrfs_key debug;
944 del_pending:
945 btrfs_item_key_to_cpu(path->nodes[0], &debug,
946 pending_del_slot);
947 ret = btrfs_del_items(trans, root, path,
948 pending_del_slot,
949 pending_del_nr);
950 BUG_ON(ret);
951 pending_del_nr = 0;
952 btrfs_release_path(root, path);
953 goto search_again;
954 }
955 }
956 ret = 0;
957 error:
958 if (pending_del_nr) {
959 ret = btrfs_del_items(trans, root, path, pending_del_slot,
960 pending_del_nr);
961 }
962 btrfs_release_path(root, path);
963 btrfs_free_path(path);
964 inode->i_sb->s_dirt = 1;
965 return ret;
966 }
967
968 static int btrfs_cow_one_page(struct inode *inode, struct page *page,
969 size_t zero_start)
970 {
971 char *kaddr;
972 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
973 u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
974 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
975 int ret = 0;
976
977 WARN_ON(!PageLocked(page));
978 set_page_extent_mapped(page);
979
980 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
981 set_extent_delalloc(&BTRFS_I(inode)->io_tree, page_start,
982 page_end, GFP_NOFS);
983
984 if (zero_start != PAGE_CACHE_SIZE) {
985 kaddr = kmap(page);
986 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
987 flush_dcache_page(page);
988 kunmap(page);
989 }
990 set_page_dirty(page);
991 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
992
993 return ret;
994 }
995
996 /*
997 * taken from block_truncate_page, but does cow as it zeros out
998 * any bytes left in the last page in the file.
999 */
1000 static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
1001 {
1002 struct inode *inode = mapping->host;
1003 struct btrfs_root *root = BTRFS_I(inode)->root;
1004 u32 blocksize = root->sectorsize;
1005 pgoff_t index = from >> PAGE_CACHE_SHIFT;
1006 unsigned offset = from & (PAGE_CACHE_SIZE-1);
1007 struct page *page;
1008 int ret = 0;
1009 u64 page_start;
1010
1011 if ((offset & (blocksize - 1)) == 0)
1012 goto out;
1013
1014 ret = -ENOMEM;
1015 page = grab_cache_page(mapping, index);
1016 if (!page)
1017 goto out;
1018 if (!PageUptodate(page)) {
1019 ret = btrfs_readpage(NULL, page);
1020 lock_page(page);
1021 if (!PageUptodate(page)) {
1022 ret = -EIO;
1023 goto out;
1024 }
1025 }
1026 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
1027
1028 ret = btrfs_cow_one_page(inode, page, offset);
1029
1030 unlock_page(page);
1031 page_cache_release(page);
1032 out:
1033 return ret;
1034 }
1035
1036 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
1037 {
1038 struct inode *inode = dentry->d_inode;
1039 int err;
1040
1041 err = inode_change_ok(inode, attr);
1042 if (err)
1043 return err;
1044
1045 if (S_ISREG(inode->i_mode) &&
1046 attr->ia_valid & ATTR_SIZE && attr->ia_size > inode->i_size) {
1047 struct btrfs_trans_handle *trans;
1048 struct btrfs_root *root = BTRFS_I(inode)->root;
1049 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1050
1051 u64 mask = root->sectorsize - 1;
1052 u64 hole_start = (inode->i_size + mask) & ~mask;
1053 u64 block_end = (attr->ia_size + mask) & ~mask;
1054 u64 hole_size;
1055 u64 alloc_hint = 0;
1056
1057 if (attr->ia_size <= hole_start)
1058 goto out;
1059
1060 mutex_lock(&root->fs_info->fs_mutex);
1061 err = btrfs_check_free_space(root, 1, 0);
1062 mutex_unlock(&root->fs_info->fs_mutex);
1063 if (err)
1064 goto fail;
1065
1066 btrfs_truncate_page(inode->i_mapping, inode->i_size);
1067
1068 lock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS);
1069 hole_size = block_end - hole_start;
1070
1071 mutex_lock(&root->fs_info->fs_mutex);
1072 trans = btrfs_start_transaction(root, 1);
1073 btrfs_set_trans_block_group(trans, inode);
1074 err = btrfs_drop_extents(trans, root, inode,
1075 hole_start, block_end, hole_start,
1076 &alloc_hint);
1077
1078 if (alloc_hint != EXTENT_MAP_INLINE) {
1079 err = btrfs_insert_file_extent(trans, root,
1080 inode->i_ino,
1081 hole_start, 0, 0,
1082 hole_size);
1083 btrfs_drop_extent_cache(inode, hole_start,
1084 hole_size - 1);
1085 btrfs_check_file(root, inode);
1086 }
1087 btrfs_end_transaction(trans, root);
1088 mutex_unlock(&root->fs_info->fs_mutex);
1089 unlock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS);
1090 if (err)
1091 return err;
1092 }
1093 out:
1094 err = inode_setattr(inode, attr);
1095 fail:
1096 return err;
1097 }
1098
1099 void btrfs_put_inode(struct inode *inode)
1100 {
1101 int ret;
1102
1103 if (!BTRFS_I(inode)->ordered_trans) {
1104 return;
1105 }
1106
1107 if (mapping_tagged(inode->i_mapping, PAGECACHE_TAG_DIRTY) ||
1108 mapping_tagged(inode->i_mapping, PAGECACHE_TAG_WRITEBACK))
1109 return;
1110
1111 ret = btrfs_del_ordered_inode(inode);
1112 if (ret == 1) {
1113 atomic_dec(&inode->i_count);
1114 }
1115 }
1116
1117 void btrfs_delete_inode(struct inode *inode)
1118 {
1119 struct btrfs_trans_handle *trans;
1120 struct btrfs_root *root = BTRFS_I(inode)->root;
1121 unsigned long nr;
1122 int ret;
1123
1124 truncate_inode_pages(&inode->i_data, 0);
1125 if (is_bad_inode(inode)) {
1126 goto no_delete;
1127 }
1128
1129 inode->i_size = 0;
1130 mutex_lock(&root->fs_info->fs_mutex);
1131 trans = btrfs_start_transaction(root, 1);
1132
1133 btrfs_set_trans_block_group(trans, inode);
1134 ret = btrfs_truncate_in_trans(trans, root, inode, 0);
1135 if (ret)
1136 goto no_delete_lock;
1137
1138 nr = trans->blocks_used;
1139 clear_inode(inode);
1140
1141 btrfs_end_transaction(trans, root);
1142 mutex_unlock(&root->fs_info->fs_mutex);
1143 btrfs_btree_balance_dirty(root, nr);
1144 btrfs_throttle(root);
1145 return;
1146
1147 no_delete_lock:
1148 nr = trans->blocks_used;
1149 btrfs_end_transaction(trans, root);
1150 mutex_unlock(&root->fs_info->fs_mutex);
1151 btrfs_btree_balance_dirty(root, nr);
1152 btrfs_throttle(root);
1153 no_delete:
1154 clear_inode(inode);
1155 }
1156
1157 /*
1158 * this returns the key found in the dir entry in the location pointer.
1159 * If no dir entries were found, location->objectid is 0.
1160 */
1161 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
1162 struct btrfs_key *location)
1163 {
1164 const char *name = dentry->d_name.name;
1165 int namelen = dentry->d_name.len;
1166 struct btrfs_dir_item *di;
1167 struct btrfs_path *path;
1168 struct btrfs_root *root = BTRFS_I(dir)->root;
1169 int ret = 0;
1170
1171 if (namelen == 1 && strcmp(name, ".") == 0) {
1172 location->objectid = dir->i_ino;
1173 location->type = BTRFS_INODE_ITEM_KEY;
1174 location->offset = 0;
1175 return 0;
1176 }
1177 path = btrfs_alloc_path();
1178 BUG_ON(!path);
1179
1180 if (namelen == 2 && strcmp(name, "..") == 0) {
1181 struct btrfs_key key;
1182 struct extent_buffer *leaf;
1183 u32 nritems;
1184 int slot;
1185
1186 key.objectid = dir->i_ino;
1187 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
1188 key.offset = 0;
1189 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1190 BUG_ON(ret == 0);
1191 ret = 0;
1192
1193 leaf = path->nodes[0];
1194 slot = path->slots[0];
1195 nritems = btrfs_header_nritems(leaf);
1196 if (slot >= nritems)
1197 goto out_err;
1198
1199 btrfs_item_key_to_cpu(leaf, &key, slot);
1200 if (key.objectid != dir->i_ino ||
1201 key.type != BTRFS_INODE_REF_KEY) {
1202 goto out_err;
1203 }
1204 location->objectid = key.offset;
1205 location->type = BTRFS_INODE_ITEM_KEY;
1206 location->offset = 0;
1207 goto out;
1208 }
1209
1210 di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
1211 namelen, 0);
1212 if (IS_ERR(di))
1213 ret = PTR_ERR(di);
1214 if (!di || IS_ERR(di)) {
1215 goto out_err;
1216 }
1217 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
1218 out:
1219 btrfs_free_path(path);
1220 return ret;
1221 out_err:
1222 location->objectid = 0;
1223 goto out;
1224 }
1225
1226 /*
1227 * when we hit a tree root in a directory, the btrfs part of the inode
1228 * needs to be changed to reflect the root directory of the tree root. This
1229 * is kind of like crossing a mount point.
1230 */
1231 static int fixup_tree_root_location(struct btrfs_root *root,
1232 struct btrfs_key *location,
1233 struct btrfs_root **sub_root,
1234 struct dentry *dentry)
1235 {
1236 struct btrfs_path *path;
1237 struct btrfs_root_item *ri;
1238
1239 if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY)
1240 return 0;
1241 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1242 return 0;
1243
1244 path = btrfs_alloc_path();
1245 BUG_ON(!path);
1246 mutex_lock(&root->fs_info->fs_mutex);
1247
1248 *sub_root = btrfs_read_fs_root(root->fs_info, location,
1249 dentry->d_name.name,
1250 dentry->d_name.len);
1251 if (IS_ERR(*sub_root))
1252 return PTR_ERR(*sub_root);
1253
1254 ri = &(*sub_root)->root_item;
1255 location->objectid = btrfs_root_dirid(ri);
1256 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
1257 location->offset = 0;
1258
1259 btrfs_free_path(path);
1260 mutex_unlock(&root->fs_info->fs_mutex);
1261 return 0;
1262 }
1263
1264 static int btrfs_init_locked_inode(struct inode *inode, void *p)
1265 {
1266 struct btrfs_iget_args *args = p;
1267 inode->i_ino = args->ino;
1268 BTRFS_I(inode)->root = args->root;
1269 BTRFS_I(inode)->delalloc_bytes = 0;
1270 extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
1271 extent_io_tree_init(&BTRFS_I(inode)->io_tree,
1272 inode->i_mapping, GFP_NOFS);
1273 return 0;
1274 }
1275
1276 static int btrfs_find_actor(struct inode *inode, void *opaque)
1277 {
1278 struct btrfs_iget_args *args = opaque;
1279 return (args->ino == inode->i_ino &&
1280 args->root == BTRFS_I(inode)->root);
1281 }
1282
1283 struct inode *btrfs_ilookup(struct super_block *s, u64 objectid,
1284 u64 root_objectid)
1285 {
1286 struct btrfs_iget_args args;
1287 args.ino = objectid;
1288 args.root = btrfs_lookup_fs_root(btrfs_sb(s)->fs_info, root_objectid);
1289
1290 if (!args.root)
1291 return NULL;
1292
1293 return ilookup5(s, objectid, btrfs_find_actor, (void *)&args);
1294 }
1295
1296 struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
1297 struct btrfs_root *root)
1298 {
1299 struct inode *inode;
1300 struct btrfs_iget_args args;
1301 args.ino = objectid;
1302 args.root = root;
1303
1304 inode = iget5_locked(s, objectid, btrfs_find_actor,
1305 btrfs_init_locked_inode,
1306 (void *)&args);
1307 return inode;
1308 }
1309
1310 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
1311 struct nameidata *nd)
1312 {
1313 struct inode * inode;
1314 struct btrfs_inode *bi = BTRFS_I(dir);
1315 struct btrfs_root *root = bi->root;
1316 struct btrfs_root *sub_root = root;
1317 struct btrfs_key location;
1318 int ret;
1319
1320 if (dentry->d_name.len > BTRFS_NAME_LEN)
1321 return ERR_PTR(-ENAMETOOLONG);
1322
1323 mutex_lock(&root->fs_info->fs_mutex);
1324 ret = btrfs_inode_by_name(dir, dentry, &location);
1325 mutex_unlock(&root->fs_info->fs_mutex);
1326
1327 if (ret < 0)
1328 return ERR_PTR(ret);
1329
1330 inode = NULL;
1331 if (location.objectid) {
1332 ret = fixup_tree_root_location(root, &location, &sub_root,
1333 dentry);
1334 if (ret < 0)
1335 return ERR_PTR(ret);
1336 if (ret > 0)
1337 return ERR_PTR(-ENOENT);
1338 inode = btrfs_iget_locked(dir->i_sb, location.objectid,
1339 sub_root);
1340 if (!inode)
1341 return ERR_PTR(-EACCES);
1342 if (inode->i_state & I_NEW) {
1343 /* the inode and parent dir are two different roots */
1344 if (sub_root != root) {
1345 igrab(inode);
1346 sub_root->inode = inode;
1347 }
1348 BTRFS_I(inode)->root = sub_root;
1349 memcpy(&BTRFS_I(inode)->location, &location,
1350 sizeof(location));
1351 btrfs_read_locked_inode(inode);
1352 unlock_new_inode(inode);
1353 }
1354 }
1355 return d_splice_alias(inode, dentry);
1356 }
1357
1358 static unsigned char btrfs_filetype_table[] = {
1359 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
1360 };
1361
1362 static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
1363 {
1364 struct inode *inode = filp->f_dentry->d_inode;
1365 struct btrfs_root *root = BTRFS_I(inode)->root;
1366 struct btrfs_item *item;
1367 struct btrfs_dir_item *di;
1368 struct btrfs_key key;
1369 struct btrfs_key found_key;
1370 struct btrfs_path *path;
1371 int ret;
1372 u32 nritems;
1373 struct extent_buffer *leaf;
1374 int slot;
1375 int advance;
1376 unsigned char d_type;
1377 int over = 0;
1378 u32 di_cur;
1379 u32 di_total;
1380 u32 di_len;
1381 int key_type = BTRFS_DIR_INDEX_KEY;
1382 char tmp_name[32];
1383 char *name_ptr;
1384 int name_len;
1385
1386 /* FIXME, use a real flag for deciding about the key type */
1387 if (root->fs_info->tree_root == root)
1388 key_type = BTRFS_DIR_ITEM_KEY;
1389
1390 /* special case for "." */
1391 if (filp->f_pos == 0) {
1392 over = filldir(dirent, ".", 1,
1393 1, inode->i_ino,
1394 DT_DIR);
1395 if (over)
1396 return 0;
1397 filp->f_pos = 1;
1398 }
1399
1400 mutex_lock(&root->fs_info->fs_mutex);
1401 key.objectid = inode->i_ino;
1402 path = btrfs_alloc_path();
1403 path->reada = 2;
1404
1405 /* special case for .., just use the back ref */
1406 if (filp->f_pos == 1) {
1407 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
1408 key.offset = 0;
1409 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1410 BUG_ON(ret == 0);
1411 leaf = path->nodes[0];
1412 slot = path->slots[0];
1413 nritems = btrfs_header_nritems(leaf);
1414 if (slot >= nritems) {
1415 btrfs_release_path(root, path);
1416 goto read_dir_items;
1417 }
1418 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1419 btrfs_release_path(root, path);
1420 if (found_key.objectid != key.objectid ||
1421 found_key.type != BTRFS_INODE_REF_KEY)
1422 goto read_dir_items;
1423 over = filldir(dirent, "..", 2,
1424 2, found_key.offset, DT_DIR);
1425 if (over)
1426 goto nopos;
1427 filp->f_pos = 2;
1428 }
1429
1430 read_dir_items:
1431 btrfs_set_key_type(&key, key_type);
1432 key.offset = filp->f_pos;
1433
1434 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1435 if (ret < 0)
1436 goto err;
1437 advance = 0;
1438 while(1) {
1439 leaf = path->nodes[0];
1440 nritems = btrfs_header_nritems(leaf);
1441 slot = path->slots[0];
1442 if (advance || slot >= nritems) {
1443 if (slot >= nritems -1) {
1444 ret = btrfs_next_leaf(root, path);
1445 if (ret)
1446 break;
1447 leaf = path->nodes[0];
1448 nritems = btrfs_header_nritems(leaf);
1449 slot = path->slots[0];
1450 } else {
1451 slot++;
1452 path->slots[0]++;
1453 }
1454 }
1455 advance = 1;
1456 item = btrfs_item_nr(leaf, slot);
1457 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1458
1459 if (found_key.objectid != key.objectid)
1460 break;
1461 if (btrfs_key_type(&found_key) != key_type)
1462 break;
1463 if (found_key.offset < filp->f_pos)
1464 continue;
1465
1466 filp->f_pos = found_key.offset;
1467 advance = 1;
1468 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
1469 di_cur = 0;
1470 di_total = btrfs_item_size(leaf, item);
1471 while(di_cur < di_total) {
1472 struct btrfs_key location;
1473
1474 name_len = btrfs_dir_name_len(leaf, di);
1475 if (name_len < 32) {
1476 name_ptr = tmp_name;
1477 } else {
1478 name_ptr = kmalloc(name_len, GFP_NOFS);
1479 BUG_ON(!name_ptr);
1480 }
1481 read_extent_buffer(leaf, name_ptr,
1482 (unsigned long)(di + 1), name_len);
1483
1484 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
1485 btrfs_dir_item_key_to_cpu(leaf, di, &location);
1486 over = filldir(dirent, name_ptr, name_len,
1487 found_key.offset,
1488 location.objectid,
1489 d_type);
1490
1491 if (name_ptr != tmp_name)
1492 kfree(name_ptr);
1493
1494 if (over)
1495 goto nopos;
1496 di_len = btrfs_dir_name_len(leaf, di) +
1497 btrfs_dir_data_len(leaf, di) +sizeof(*di);
1498 di_cur += di_len;
1499 di = (struct btrfs_dir_item *)((char *)di + di_len);
1500 }
1501 }
1502 if (key_type == BTRFS_DIR_INDEX_KEY)
1503 filp->f_pos = INT_LIMIT(typeof(filp->f_pos));
1504 else
1505 filp->f_pos++;
1506 nopos:
1507 ret = 0;
1508 err:
1509 btrfs_release_path(root, path);
1510 btrfs_free_path(path);
1511 mutex_unlock(&root->fs_info->fs_mutex);
1512 return ret;
1513 }
1514
1515 int btrfs_write_inode(struct inode *inode, int wait)
1516 {
1517 struct btrfs_root *root = BTRFS_I(inode)->root;
1518 struct btrfs_trans_handle *trans;
1519 int ret = 0;
1520
1521 if (wait) {
1522 mutex_lock(&root->fs_info->fs_mutex);
1523 trans = btrfs_start_transaction(root, 1);
1524 btrfs_set_trans_block_group(trans, inode);
1525 ret = btrfs_commit_transaction(trans, root);
1526 mutex_unlock(&root->fs_info->fs_mutex);
1527 }
1528 return ret;
1529 }
1530
1531 /*
1532 * This is somewhat expensive, updating the tree every time the
1533 * inode changes. But, it is most likely to find the inode in cache.
1534 * FIXME, needs more benchmarking...there are no reasons other than performance
1535 * to keep or drop this code.
1536 */
1537 void btrfs_dirty_inode(struct inode *inode)
1538 {
1539 struct btrfs_root *root = BTRFS_I(inode)->root;
1540 struct btrfs_trans_handle *trans;
1541
1542 mutex_lock(&root->fs_info->fs_mutex);
1543 trans = btrfs_start_transaction(root, 1);
1544 btrfs_set_trans_block_group(trans, inode);
1545 btrfs_update_inode(trans, root, inode);
1546 btrfs_end_transaction(trans, root);
1547 mutex_unlock(&root->fs_info->fs_mutex);
1548 }
1549
1550 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
1551 struct btrfs_root *root,
1552 const char *name, int name_len,
1553 u64 ref_objectid,
1554 u64 objectid,
1555 struct btrfs_block_group_cache *group,
1556 int mode)
1557 {
1558 struct inode *inode;
1559 struct btrfs_inode_item *inode_item;
1560 struct btrfs_block_group_cache *new_inode_group;
1561 struct btrfs_key *location;
1562 struct btrfs_path *path;
1563 struct btrfs_inode_ref *ref;
1564 struct btrfs_key key[2];
1565 u32 sizes[2];
1566 unsigned long ptr;
1567 int ret;
1568 int owner;
1569
1570 path = btrfs_alloc_path();
1571 BUG_ON(!path);
1572
1573 inode = new_inode(root->fs_info->sb);
1574 if (!inode)
1575 return ERR_PTR(-ENOMEM);
1576
1577 extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
1578 extent_io_tree_init(&BTRFS_I(inode)->io_tree,
1579 inode->i_mapping, GFP_NOFS);
1580 BTRFS_I(inode)->delalloc_bytes = 0;
1581 BTRFS_I(inode)->root = root;
1582
1583 if (mode & S_IFDIR)
1584 owner = 0;
1585 else
1586 owner = 1;
1587 new_inode_group = btrfs_find_block_group(root, group, 0,
1588 BTRFS_BLOCK_GROUP_METADATA, owner);
1589 if (!new_inode_group) {
1590 printk("find_block group failed\n");
1591 new_inode_group = group;
1592 }
1593 BTRFS_I(inode)->block_group = new_inode_group;
1594 BTRFS_I(inode)->flags = 0;
1595
1596 key[0].objectid = objectid;
1597 btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
1598 key[0].offset = 0;
1599
1600 key[1].objectid = objectid;
1601 btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
1602 key[1].offset = ref_objectid;
1603
1604 sizes[0] = sizeof(struct btrfs_inode_item);
1605 sizes[1] = name_len + sizeof(*ref);
1606
1607 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
1608 if (ret != 0)
1609 goto fail;
1610
1611 if (objectid > root->highest_inode)
1612 root->highest_inode = objectid;
1613
1614 inode->i_uid = current->fsuid;
1615 inode->i_gid = current->fsgid;
1616 inode->i_mode = mode;
1617 inode->i_ino = objectid;
1618 inode->i_blocks = 0;
1619 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1620 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1621 struct btrfs_inode_item);
1622 fill_inode_item(path->nodes[0], inode_item, inode);
1623
1624 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
1625 struct btrfs_inode_ref);
1626 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
1627 ptr = (unsigned long)(ref + 1);
1628 write_extent_buffer(path->nodes[0], name, ptr, name_len);
1629
1630 btrfs_mark_buffer_dirty(path->nodes[0]);
1631 btrfs_free_path(path);
1632
1633 location = &BTRFS_I(inode)->location;
1634 location->objectid = objectid;
1635 location->offset = 0;
1636 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
1637
1638 insert_inode_hash(inode);
1639 return inode;
1640 fail:
1641 btrfs_free_path(path);
1642 return ERR_PTR(ret);
1643 }
1644
1645 static inline u8 btrfs_inode_type(struct inode *inode)
1646 {
1647 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
1648 }
1649
1650 static int btrfs_add_link(struct btrfs_trans_handle *trans,
1651 struct dentry *dentry, struct inode *inode,
1652 int add_backref)
1653 {
1654 int ret;
1655 struct btrfs_key key;
1656 struct btrfs_root *root = BTRFS_I(dentry->d_parent->d_inode)->root;
1657 struct inode *parent_inode;
1658
1659 key.objectid = inode->i_ino;
1660 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
1661 key.offset = 0;
1662
1663 ret = btrfs_insert_dir_item(trans, root,
1664 dentry->d_name.name, dentry->d_name.len,
1665 dentry->d_parent->d_inode->i_ino,
1666 &key, btrfs_inode_type(inode));
1667 if (ret == 0) {
1668 if (add_backref) {
1669 ret = btrfs_insert_inode_ref(trans, root,
1670 dentry->d_name.name,
1671 dentry->d_name.len,
1672 inode->i_ino,
1673 dentry->d_parent->d_inode->i_ino);
1674 }
1675 parent_inode = dentry->d_parent->d_inode;
1676 parent_inode->i_size += dentry->d_name.len * 2;
1677 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
1678 ret = btrfs_update_inode(trans, root,
1679 dentry->d_parent->d_inode);
1680 }
1681 return ret;
1682 }
1683
1684 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
1685 struct dentry *dentry, struct inode *inode,
1686 int backref)
1687 {
1688 int err = btrfs_add_link(trans, dentry, inode, backref);
1689 if (!err) {
1690 d_instantiate(dentry, inode);
1691 return 0;
1692 }
1693 if (err > 0)
1694 err = -EEXIST;
1695 return err;
1696 }
1697
1698 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
1699 int mode, dev_t rdev)
1700 {
1701 struct btrfs_trans_handle *trans;
1702 struct btrfs_root *root = BTRFS_I(dir)->root;
1703 struct inode *inode = NULL;
1704 int err;
1705 int drop_inode = 0;
1706 u64 objectid;
1707 unsigned long nr = 0;
1708
1709 if (!new_valid_dev(rdev))
1710 return -EINVAL;
1711
1712 mutex_lock(&root->fs_info->fs_mutex);
1713 err = btrfs_check_free_space(root, 1, 0);
1714 if (err)
1715 goto fail;
1716
1717 trans = btrfs_start_transaction(root, 1);
1718 btrfs_set_trans_block_group(trans, dir);
1719
1720 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1721 if (err) {
1722 err = -ENOSPC;
1723 goto out_unlock;
1724 }
1725
1726 inode = btrfs_new_inode(trans, root, dentry->d_name.name,
1727 dentry->d_name.len,
1728 dentry->d_parent->d_inode->i_ino, objectid,
1729 BTRFS_I(dir)->block_group, mode);
1730 err = PTR_ERR(inode);
1731 if (IS_ERR(inode))
1732 goto out_unlock;
1733
1734 btrfs_set_trans_block_group(trans, inode);
1735 err = btrfs_add_nondir(trans, dentry, inode, 0);
1736 if (err)
1737 drop_inode = 1;
1738 else {
1739 inode->i_op = &btrfs_special_inode_operations;
1740 init_special_inode(inode, inode->i_mode, rdev);
1741 btrfs_update_inode(trans, root, inode);
1742 }
1743 dir->i_sb->s_dirt = 1;
1744 btrfs_update_inode_block_group(trans, inode);
1745 btrfs_update_inode_block_group(trans, dir);
1746 out_unlock:
1747 nr = trans->blocks_used;
1748 btrfs_end_transaction(trans, root);
1749 fail:
1750 mutex_unlock(&root->fs_info->fs_mutex);
1751
1752 if (drop_inode) {
1753 inode_dec_link_count(inode);
1754 iput(inode);
1755 }
1756 btrfs_btree_balance_dirty(root, nr);
1757 btrfs_throttle(root);
1758 return err;
1759 }
1760
1761 static int btrfs_create(struct inode *dir, struct dentry *dentry,
1762 int mode, struct nameidata *nd)
1763 {
1764 struct btrfs_trans_handle *trans;
1765 struct btrfs_root *root = BTRFS_I(dir)->root;
1766 struct inode *inode = NULL;
1767 int err;
1768 int drop_inode = 0;
1769 unsigned long nr = 0;
1770 u64 objectid;
1771
1772 mutex_lock(&root->fs_info->fs_mutex);
1773 err = btrfs_check_free_space(root, 1, 0);
1774 if (err)
1775 goto fail;
1776 trans = btrfs_start_transaction(root, 1);
1777 btrfs_set_trans_block_group(trans, dir);
1778
1779 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1780 if (err) {
1781 err = -ENOSPC;
1782 goto out_unlock;
1783 }
1784
1785 inode = btrfs_new_inode(trans, root, dentry->d_name.name,
1786 dentry->d_name.len,
1787 dentry->d_parent->d_inode->i_ino,
1788 objectid, BTRFS_I(dir)->block_group, mode);
1789 err = PTR_ERR(inode);
1790 if (IS_ERR(inode))
1791 goto out_unlock;
1792
1793 btrfs_set_trans_block_group(trans, inode);
1794 err = btrfs_add_nondir(trans, dentry, inode, 0);
1795 if (err)
1796 drop_inode = 1;
1797 else {
1798 inode->i_mapping->a_ops = &btrfs_aops;
1799 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
1800 inode->i_fop = &btrfs_file_operations;
1801 inode->i_op = &btrfs_file_inode_operations;
1802 extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
1803 extent_io_tree_init(&BTRFS_I(inode)->io_tree,
1804 inode->i_mapping, GFP_NOFS);
1805 BTRFS_I(inode)->delalloc_bytes = 0;
1806 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
1807 }
1808 dir->i_sb->s_dirt = 1;
1809 btrfs_update_inode_block_group(trans, inode);
1810 btrfs_update_inode_block_group(trans, dir);
1811 out_unlock:
1812 nr = trans->blocks_used;
1813 btrfs_end_transaction(trans, root);
1814 fail:
1815 mutex_unlock(&root->fs_info->fs_mutex);
1816
1817 if (drop_inode) {
1818 inode_dec_link_count(inode);
1819 iput(inode);
1820 }
1821 btrfs_btree_balance_dirty(root, nr);
1822 btrfs_throttle(root);
1823 return err;
1824 }
1825
1826 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
1827 struct dentry *dentry)
1828 {
1829 struct btrfs_trans_handle *trans;
1830 struct btrfs_root *root = BTRFS_I(dir)->root;
1831 struct inode *inode = old_dentry->d_inode;
1832 unsigned long nr = 0;
1833 int err;
1834 int drop_inode = 0;
1835
1836 if (inode->i_nlink == 0)
1837 return -ENOENT;
1838
1839 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
1840 inode->i_nlink++;
1841 #else
1842 inc_nlink(inode);
1843 #endif
1844 mutex_lock(&root->fs_info->fs_mutex);
1845 err = btrfs_check_free_space(root, 1, 0);
1846 if (err)
1847 goto fail;
1848 trans = btrfs_start_transaction(root, 1);
1849
1850 btrfs_set_trans_block_group(trans, dir);
1851 atomic_inc(&inode->i_count);
1852 err = btrfs_add_nondir(trans, dentry, inode, 1);
1853
1854 if (err)
1855 drop_inode = 1;
1856
1857 dir->i_sb->s_dirt = 1;
1858 btrfs_update_inode_block_group(trans, dir);
1859 err = btrfs_update_inode(trans, root, inode);
1860
1861 if (err)
1862 drop_inode = 1;
1863
1864 nr = trans->blocks_used;
1865 btrfs_end_transaction(trans, root);
1866 fail:
1867 mutex_unlock(&root->fs_info->fs_mutex);
1868
1869 if (drop_inode) {
1870 inode_dec_link_count(inode);
1871 iput(inode);
1872 }
1873 btrfs_btree_balance_dirty(root, nr);
1874 btrfs_throttle(root);
1875 return err;
1876 }
1877
1878 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1879 {
1880 struct inode *inode;
1881 struct btrfs_trans_handle *trans;
1882 struct btrfs_root *root = BTRFS_I(dir)->root;
1883 int err = 0;
1884 int drop_on_err = 0;
1885 u64 objectid;
1886 unsigned long nr = 1;
1887
1888 mutex_lock(&root->fs_info->fs_mutex);
1889 err = btrfs_check_free_space(root, 1, 0);
1890 if (err)
1891 goto out_unlock;
1892
1893 trans = btrfs_start_transaction(root, 1);
1894 btrfs_set_trans_block_group(trans, dir);
1895
1896 if (IS_ERR(trans)) {
1897 err = PTR_ERR(trans);
1898 goto out_unlock;
1899 }
1900
1901 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1902 if (err) {
1903 err = -ENOSPC;
1904 goto out_unlock;
1905 }
1906
1907 inode = btrfs_new_inode(trans, root, dentry->d_name.name,
1908 dentry->d_name.len,
1909 dentry->d_parent->d_inode->i_ino, objectid,
1910 BTRFS_I(dir)->block_group, S_IFDIR | mode);
1911 if (IS_ERR(inode)) {
1912 err = PTR_ERR(inode);
1913 goto out_fail;
1914 }
1915
1916 drop_on_err = 1;
1917 inode->i_op = &btrfs_dir_inode_operations;
1918 inode->i_fop = &btrfs_dir_file_operations;
1919 btrfs_set_trans_block_group(trans, inode);
1920
1921 inode->i_size = 0;
1922 err = btrfs_update_inode(trans, root, inode);
1923 if (err)
1924 goto out_fail;
1925
1926 err = btrfs_add_link(trans, dentry, inode, 0);
1927 if (err)
1928 goto out_fail;
1929
1930 d_instantiate(dentry, inode);
1931 drop_on_err = 0;
1932 dir->i_sb->s_dirt = 1;
1933 btrfs_update_inode_block_group(trans, inode);
1934 btrfs_update_inode_block_group(trans, dir);
1935
1936 out_fail:
1937 nr = trans->blocks_used;
1938 btrfs_end_transaction(trans, root);
1939
1940 out_unlock:
1941 mutex_unlock(&root->fs_info->fs_mutex);
1942 if (drop_on_err)
1943 iput(inode);
1944 btrfs_btree_balance_dirty(root, nr);
1945 btrfs_throttle(root);
1946 return err;
1947 }
1948
1949 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
1950 size_t pg_offset, u64 start, u64 len,
1951 int create)
1952 {
1953 int ret;
1954 int err = 0;
1955 u64 bytenr;
1956 u64 extent_start = 0;
1957 u64 extent_end = 0;
1958 u64 objectid = inode->i_ino;
1959 u32 found_type;
1960 struct btrfs_path *path;
1961 struct btrfs_root *root = BTRFS_I(inode)->root;
1962 struct btrfs_file_extent_item *item;
1963 struct extent_buffer *leaf;
1964 struct btrfs_key found_key;
1965 struct extent_map *em = NULL;
1966 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1967 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1968 struct btrfs_trans_handle *trans = NULL;
1969
1970 path = btrfs_alloc_path();
1971 BUG_ON(!path);
1972 mutex_lock(&root->fs_info->fs_mutex);
1973
1974 again:
1975 spin_lock(&em_tree->lock);
1976 em = lookup_extent_mapping(em_tree, start, len);
1977 spin_unlock(&em_tree->lock);
1978
1979 if (em) {
1980 if (em->start > start) {
1981 printk("get_extent lookup [%Lu %Lu] em [%Lu %Lu]\n",
1982 start, len, em->start, em->len);
1983 WARN_ON(1);
1984 }
1985 if (em->block_start == EXTENT_MAP_INLINE && page)
1986 free_extent_map(em);
1987 else
1988 goto out;
1989 }
1990 em = alloc_extent_map(GFP_NOFS);
1991 if (!em) {
1992 err = -ENOMEM;
1993 goto out;
1994 }
1995
1996 em->start = EXTENT_MAP_HOLE;
1997 em->len = (u64)-1;
1998 em->bdev = inode->i_sb->s_bdev;
1999 ret = btrfs_lookup_file_extent(trans, root, path,
2000 objectid, start, trans != NULL);
2001 if (ret < 0) {
2002 err = ret;
2003 goto out;
2004 }
2005
2006 if (ret != 0) {
2007 if (path->slots[0] == 0)
2008 goto not_found;
2009 path->slots[0]--;
2010 }
2011
2012 leaf = path->nodes[0];
2013 item = btrfs_item_ptr(leaf, path->slots[0],
2014 struct btrfs_file_extent_item);
2015 /* are we inside the extent that was found? */
2016 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2017 found_type = btrfs_key_type(&found_key);
2018 if (found_key.objectid != objectid ||
2019 found_type != BTRFS_EXTENT_DATA_KEY) {
2020 goto not_found;
2021 }
2022
2023 found_type = btrfs_file_extent_type(leaf, item);
2024 extent_start = found_key.offset;
2025 if (found_type == BTRFS_FILE_EXTENT_REG) {
2026 extent_end = extent_start +
2027 btrfs_file_extent_num_bytes(leaf, item);
2028 err = 0;
2029 if (start < extent_start || start >= extent_end) {
2030 em->start = start;
2031 if (start < extent_start) {
2032 if (start + len <= extent_start)
2033 goto not_found;
2034 em->len = extent_end - extent_start;
2035 } else {
2036 em->len = len;
2037 }
2038 goto not_found_em;
2039 }
2040 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
2041 if (bytenr == 0) {
2042 em->start = extent_start;
2043 em->len = extent_end - extent_start;
2044 em->block_start = EXTENT_MAP_HOLE;
2045 goto insert;
2046 }
2047 bytenr += btrfs_file_extent_offset(leaf, item);
2048 em->block_start = bytenr;
2049 em->start = extent_start;
2050 em->len = extent_end - extent_start;
2051 goto insert;
2052 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
2053 u64 page_start;
2054 unsigned long ptr;
2055 char *map;
2056 size_t size;
2057 size_t extent_offset;
2058 size_t copy_size;
2059
2060 size = btrfs_file_extent_inline_len(leaf, btrfs_item_nr(leaf,
2061 path->slots[0]));
2062 extent_end = (extent_start + size + root->sectorsize - 1) &
2063 ~((u64)root->sectorsize - 1);
2064 if (start < extent_start || start >= extent_end) {
2065 em->start = start;
2066 if (start < extent_start) {
2067 if (start + len <= extent_start)
2068 goto not_found;
2069 em->len = extent_end - extent_start;
2070 } else {
2071 em->len = len;
2072 }
2073 goto not_found_em;
2074 }
2075 em->block_start = EXTENT_MAP_INLINE;
2076
2077 if (!page) {
2078 em->start = extent_start;
2079 em->len = size;
2080 goto out;
2081 }
2082
2083 page_start = page_offset(page) + pg_offset;
2084 extent_offset = page_start - extent_start;
2085 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
2086 size - extent_offset);
2087 em->start = extent_start + extent_offset;
2088 em->len = (copy_size + root->sectorsize - 1) &
2089 ~((u64)root->sectorsize - 1);
2090 map = kmap(page);
2091 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
2092 if (create == 0 && !PageUptodate(page)) {
2093 read_extent_buffer(leaf, map + pg_offset, ptr,
2094 copy_size);
2095 flush_dcache_page(page);
2096 } else if (create && PageUptodate(page)) {
2097 if (!trans) {
2098 kunmap(page);
2099 free_extent_map(em);
2100 em = NULL;
2101 btrfs_release_path(root, path);
2102 trans = btrfs_start_transaction(root, 1);
2103 goto again;
2104 }
2105 write_extent_buffer(leaf, map + pg_offset, ptr,
2106 copy_size);
2107 btrfs_mark_buffer_dirty(leaf);
2108 }
2109 kunmap(page);
2110 set_extent_uptodate(io_tree, em->start,
2111 extent_map_end(em) - 1, GFP_NOFS);
2112 goto insert;
2113 } else {
2114 printk("unkknown found_type %d\n", found_type);
2115 WARN_ON(1);
2116 }
2117 not_found:
2118 em->start = start;
2119 em->len = len;
2120 not_found_em:
2121 em->block_start = EXTENT_MAP_HOLE;
2122 insert:
2123 btrfs_release_path(root, path);
2124 if (em->start > start || extent_map_end(em) <= start) {
2125 printk("bad extent! em: [%Lu %Lu] passed [%Lu %Lu]\n", em->start, em->len, start, len);
2126 err = -EIO;
2127 goto out;
2128 }
2129
2130 err = 0;
2131 spin_lock(&em_tree->lock);
2132 ret = add_extent_mapping(em_tree, em);
2133 if (ret == -EEXIST) {
2134 free_extent_map(em);
2135 em = lookup_extent_mapping(em_tree, start, len);
2136 if (!em) {
2137 err = -EIO;
2138 printk("failing to insert %Lu %Lu\n", start, len);
2139 }
2140 }
2141 spin_unlock(&em_tree->lock);
2142 out:
2143 btrfs_free_path(path);
2144 if (trans) {
2145 ret = btrfs_end_transaction(trans, root);
2146 if (!err)
2147 err = ret;
2148 }
2149 mutex_unlock(&root->fs_info->fs_mutex);
2150 if (err) {
2151 free_extent_map(em);
2152 WARN_ON(1);
2153 return ERR_PTR(err);
2154 }
2155 return em;
2156 }
2157
2158 static sector_t btrfs_bmap(struct address_space *mapping, sector_t iblock)
2159 {
2160 return extent_bmap(mapping, iblock, btrfs_get_extent);
2161 }
2162
2163 int btrfs_readpage(struct file *file, struct page *page)
2164 {
2165 struct extent_io_tree *tree;
2166 tree = &BTRFS_I(page->mapping->host)->io_tree;
2167 return extent_read_full_page(tree, page, btrfs_get_extent);
2168 }
2169
2170 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
2171 {
2172 struct extent_io_tree *tree;
2173
2174
2175 if (current->flags & PF_MEMALLOC) {
2176 redirty_page_for_writepage(wbc, page);
2177 unlock_page(page);
2178 return 0;
2179 }
2180 tree = &BTRFS_I(page->mapping->host)->io_tree;
2181 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
2182 }
2183
2184 static int btrfs_writepages(struct address_space *mapping,
2185 struct writeback_control *wbc)
2186 {
2187 struct extent_io_tree *tree;
2188 tree = &BTRFS_I(mapping->host)->io_tree;
2189 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
2190 }
2191
2192 static int
2193 btrfs_readpages(struct file *file, struct address_space *mapping,
2194 struct list_head *pages, unsigned nr_pages)
2195 {
2196 struct extent_io_tree *tree;
2197 tree = &BTRFS_I(mapping->host)->io_tree;
2198 return extent_readpages(tree, mapping, pages, nr_pages,
2199 btrfs_get_extent);
2200 }
2201
2202 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
2203 {
2204 struct extent_io_tree *tree;
2205 struct extent_map_tree *map;
2206 int ret;
2207
2208 tree = &BTRFS_I(page->mapping->host)->io_tree;
2209 map = &BTRFS_I(page->mapping->host)->extent_tree;
2210 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
2211 if (ret == 1) {
2212 ClearPagePrivate(page);
2213 set_page_private(page, 0);
2214 page_cache_release(page);
2215 }
2216 return ret;
2217 }
2218
2219 static void btrfs_invalidatepage(struct page *page, unsigned long offset)
2220 {
2221 struct extent_io_tree *tree;
2222
2223 tree = &BTRFS_I(page->mapping->host)->io_tree;
2224 extent_invalidatepage(tree, page, offset);
2225 btrfs_releasepage(page, GFP_NOFS);
2226 }
2227
2228 /*
2229 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
2230 * called from a page fault handler when a page is first dirtied. Hence we must
2231 * be careful to check for EOF conditions here. We set the page up correctly
2232 * for a written page which means we get ENOSPC checking when writing into
2233 * holes and correct delalloc and unwritten extent mapping on filesystems that
2234 * support these features.
2235 *
2236 * We are not allowed to take the i_mutex here so we have to play games to
2237 * protect against truncate races as the page could now be beyond EOF. Because
2238 * vmtruncate() writes the inode size before removing pages, once we have the
2239 * page lock we can determine safely if the page is beyond EOF. If it is not
2240 * beyond EOF, then the page is guaranteed safe against truncation until we
2241 * unlock the page.
2242 */
2243 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
2244 {
2245 struct inode *inode = fdentry(vma->vm_file)->d_inode;
2246 struct btrfs_root *root = BTRFS_I(inode)->root;
2247 unsigned long end;
2248 loff_t size;
2249 int ret;
2250 u64 page_start;
2251
2252 mutex_lock(&root->fs_info->fs_mutex);
2253 ret = btrfs_check_free_space(root, PAGE_CACHE_SIZE, 0);
2254 mutex_unlock(&root->fs_info->fs_mutex);
2255 if (ret)
2256 goto out;
2257
2258 ret = -EINVAL;
2259
2260 lock_page(page);
2261 wait_on_page_writeback(page);
2262 size = i_size_read(inode);
2263 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2264
2265 if ((page->mapping != inode->i_mapping) ||
2266 (page_start > size)) {
2267 /* page got truncated out from underneath us */
2268 goto out_unlock;
2269 }
2270
2271 /* page is wholly or partially inside EOF */
2272 if (page_start + PAGE_CACHE_SIZE > size)
2273 end = size & ~PAGE_CACHE_MASK;
2274 else
2275 end = PAGE_CACHE_SIZE;
2276
2277 ret = btrfs_cow_one_page(inode, page, end);
2278
2279 out_unlock:
2280 unlock_page(page);
2281 out:
2282 return ret;
2283 }
2284
2285 static void btrfs_truncate(struct inode *inode)
2286 {
2287 struct btrfs_root *root = BTRFS_I(inode)->root;
2288 int ret;
2289 struct btrfs_trans_handle *trans;
2290 unsigned long nr;
2291
2292 if (!S_ISREG(inode->i_mode))
2293 return;
2294 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
2295 return;
2296
2297 btrfs_truncate_page(inode->i_mapping, inode->i_size);
2298
2299 mutex_lock(&root->fs_info->fs_mutex);
2300 trans = btrfs_start_transaction(root, 1);
2301 btrfs_set_trans_block_group(trans, inode);
2302
2303 /* FIXME, add redo link to tree so we don't leak on crash */
2304 ret = btrfs_truncate_in_trans(trans, root, inode,
2305 BTRFS_EXTENT_DATA_KEY);
2306 btrfs_update_inode(trans, root, inode);
2307 nr = trans->blocks_used;
2308
2309 ret = btrfs_end_transaction(trans, root);
2310 BUG_ON(ret);
2311 mutex_unlock(&root->fs_info->fs_mutex);
2312 btrfs_btree_balance_dirty(root, nr);
2313 btrfs_throttle(root);
2314 }
2315
2316 static int noinline create_subvol(struct btrfs_root *root, char *name,
2317 int namelen)
2318 {
2319 struct btrfs_trans_handle *trans;
2320 struct btrfs_key key;
2321 struct btrfs_root_item root_item;
2322 struct btrfs_inode_item *inode_item;
2323 struct extent_buffer *leaf;
2324 struct btrfs_root *new_root = root;
2325 struct inode *inode;
2326 struct inode *dir;
2327 int ret;
2328 int err;
2329 u64 objectid;
2330 u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
2331 unsigned long nr = 1;
2332
2333 mutex_lock(&root->fs_info->fs_mutex);
2334 ret = btrfs_check_free_space(root, 1, 0);
2335 if (ret)
2336 goto fail_commit;
2337
2338 trans = btrfs_start_transaction(root, 1);
2339 BUG_ON(!trans);
2340
2341 ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
2342 0, &objectid);
2343 if (ret)
2344 goto fail;
2345
2346 leaf = __btrfs_alloc_free_block(trans, root, root->leafsize,
2347 objectid, trans->transid, 0, 0,
2348 0, 0);
2349 if (IS_ERR(leaf))
2350 return PTR_ERR(leaf);
2351
2352 btrfs_set_header_nritems(leaf, 0);
2353 btrfs_set_header_level(leaf, 0);
2354 btrfs_set_header_bytenr(leaf, leaf->start);
2355 btrfs_set_header_generation(leaf, trans->transid);
2356 btrfs_set_header_owner(leaf, objectid);
2357
2358 write_extent_buffer(leaf, root->fs_info->fsid,
2359 (unsigned long)btrfs_header_fsid(leaf),
2360 BTRFS_FSID_SIZE);
2361 btrfs_mark_buffer_dirty(leaf);
2362
2363 inode_item = &root_item.inode;
2364 memset(inode_item, 0, sizeof(*inode_item));
2365 inode_item->generation = cpu_to_le64(1);
2366 inode_item->size = cpu_to_le64(3);
2367 inode_item->nlink = cpu_to_le32(1);
2368 inode_item->nblocks = cpu_to_le64(1);
2369 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
2370
2371 btrfs_set_root_bytenr(&root_item, leaf->start);
2372 btrfs_set_root_level(&root_item, 0);
2373 btrfs_set_root_refs(&root_item, 1);
2374 btrfs_set_root_used(&root_item, 0);
2375
2376 memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
2377 root_item.drop_level = 0;
2378
2379 free_extent_buffer(leaf);
2380 leaf = NULL;
2381
2382 btrfs_set_root_dirid(&root_item, new_dirid);
2383
2384 key.objectid = objectid;
2385 key.offset = 1;
2386 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
2387 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
2388 &root_item);
2389 if (ret)
2390 goto fail;
2391
2392 /*
2393 * insert the directory item
2394 */
2395 key.offset = (u64)-1;
2396 dir = root->fs_info->sb->s_root->d_inode;
2397 ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
2398 name, namelen, dir->i_ino, &key,
2399 BTRFS_FT_DIR);
2400 if (ret)
2401 goto fail;
2402
2403 ret = btrfs_insert_inode_ref(trans, root->fs_info->tree_root,
2404 name, namelen, objectid,
2405 root->fs_info->sb->s_root->d_inode->i_ino);
2406 if (ret)
2407 goto fail;
2408
2409 ret = btrfs_commit_transaction(trans, root);
2410 if (ret)
2411 goto fail_commit;
2412
2413 new_root = btrfs_read_fs_root(root->fs_info, &key, name, namelen);
2414 BUG_ON(!new_root);
2415
2416 trans = btrfs_start_transaction(new_root, 1);
2417 BUG_ON(!trans);
2418
2419 inode = btrfs_new_inode(trans, new_root, "..", 2, new_dirid,
2420 new_dirid,
2421 BTRFS_I(dir)->block_group, S_IFDIR | 0700);
2422 if (IS_ERR(inode))
2423 goto fail;
2424 inode->i_op = &btrfs_dir_inode_operations;
2425 inode->i_fop = &btrfs_dir_file_operations;
2426 new_root->inode = inode;
2427
2428 ret = btrfs_insert_inode_ref(trans, new_root, "..", 2, new_dirid,
2429 new_dirid);
2430 inode->i_nlink = 1;
2431 inode->i_size = 0;
2432 ret = btrfs_update_inode(trans, new_root, inode);
2433 if (ret)
2434 goto fail;
2435 fail:
2436 nr = trans->blocks_used;
2437 err = btrfs_commit_transaction(trans, new_root);
2438 if (err && !ret)
2439 ret = err;
2440 fail_commit:
2441 mutex_unlock(&root->fs_info->fs_mutex);
2442 btrfs_btree_balance_dirty(root, nr);
2443 btrfs_throttle(root);
2444 return ret;
2445 }
2446
2447 static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
2448 {
2449 struct btrfs_pending_snapshot *pending_snapshot;
2450 struct btrfs_trans_handle *trans;
2451 int ret;
2452 int err;
2453 unsigned long nr = 0;
2454
2455 if (!root->ref_cows)
2456 return -EINVAL;
2457
2458 mutex_lock(&root->fs_info->fs_mutex);
2459 ret = btrfs_check_free_space(root, 1, 0);
2460 if (ret)
2461 goto fail_unlock;
2462
2463 pending_snapshot = kmalloc(sizeof(*pending_snapshot), GFP_NOFS);
2464 if (!pending_snapshot) {
2465 ret = -ENOMEM;
2466 goto fail_unlock;
2467 }
2468 pending_snapshot->name = kmalloc(namelen + 1, GFP_NOFS);
2469 if (!pending_snapshot->name) {
2470 ret = -ENOMEM;
2471 kfree(pending_snapshot);
2472 goto fail_unlock;
2473 }
2474 memcpy(pending_snapshot->name, name, namelen);
2475 pending_snapshot->name[namelen] = '\0';
2476 trans = btrfs_start_transaction(root, 1);
2477 BUG_ON(!trans);
2478 pending_snapshot->root = root;
2479 list_add(&pending_snapshot->list,
2480 &trans->transaction->pending_snapshots);
2481 ret = btrfs_update_inode(trans, root, root->inode);
2482 err = btrfs_commit_transaction(trans, root);
2483
2484 fail_unlock:
2485 mutex_unlock(&root->fs_info->fs_mutex);
2486 btrfs_btree_balance_dirty(root, nr);
2487 btrfs_throttle(root);
2488 return ret;
2489 }
2490
2491 unsigned long btrfs_force_ra(struct address_space *mapping,
2492 struct file_ra_state *ra, struct file *file,
2493 pgoff_t offset, pgoff_t last_index)
2494 {
2495 pgoff_t req_size;
2496
2497 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
2498 req_size = last_index - offset + 1;
2499 offset = page_cache_readahead(mapping, ra, file, offset, req_size);
2500 return offset;
2501 #else
2502 req_size = min(last_index - offset + 1, (pgoff_t)128);
2503 page_cache_sync_readahead(mapping, ra, file, offset, req_size);
2504 return offset + req_size;
2505 #endif
2506 }
2507
2508 int btrfs_defrag_file(struct file *file) {
2509 struct inode *inode = fdentry(file)->d_inode;
2510 struct btrfs_root *root = BTRFS_I(inode)->root;
2511 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2512 struct page *page;
2513 unsigned long last_index;
2514 unsigned long ra_index = 0;
2515 u64 page_start;
2516 u64 page_end;
2517 unsigned long i;
2518 int ret;
2519
2520 mutex_lock(&root->fs_info->fs_mutex);
2521 ret = btrfs_check_free_space(root, inode->i_size, 0);
2522 mutex_unlock(&root->fs_info->fs_mutex);
2523 if (ret)
2524 return -ENOSPC;
2525
2526 mutex_lock(&inode->i_mutex);
2527 last_index = inode->i_size >> PAGE_CACHE_SHIFT;
2528 for (i = 0; i <= last_index; i++) {
2529 if (i == ra_index) {
2530 ra_index = btrfs_force_ra(inode->i_mapping,
2531 &file->f_ra,
2532 file, ra_index, last_index);
2533 }
2534 page = grab_cache_page(inode->i_mapping, i);
2535 if (!page)
2536 goto out_unlock;
2537 if (!PageUptodate(page)) {
2538 btrfs_readpage(NULL, page);
2539 lock_page(page);
2540 if (!PageUptodate(page)) {
2541 unlock_page(page);
2542 page_cache_release(page);
2543 goto out_unlock;
2544 }
2545 }
2546 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2547 page_end = page_start + PAGE_CACHE_SIZE - 1;
2548
2549 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
2550 set_extent_delalloc(io_tree, page_start,
2551 page_end, GFP_NOFS);
2552
2553 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
2554 set_page_dirty(page);
2555 unlock_page(page);
2556 page_cache_release(page);
2557 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
2558 }
2559
2560 out_unlock:
2561 mutex_unlock(&inode->i_mutex);
2562 return 0;
2563 }
2564
2565 static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
2566 {
2567 u64 new_size;
2568 u64 old_size;
2569 struct btrfs_ioctl_vol_args *vol_args;
2570 struct btrfs_trans_handle *trans;
2571 char *sizestr;
2572 int ret = 0;
2573 int namelen;
2574 int mod = 0;
2575
2576 vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
2577
2578 if (!vol_args)
2579 return -ENOMEM;
2580
2581 if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
2582 ret = -EFAULT;
2583 goto out;
2584 }
2585 namelen = strlen(vol_args->name);
2586 if (namelen > BTRFS_VOL_NAME_MAX) {
2587 ret = -EINVAL;
2588 goto out;
2589 }
2590
2591 sizestr = vol_args->name;
2592 if (!strcmp(sizestr, "max"))
2593 new_size = root->fs_info->sb->s_bdev->bd_inode->i_size;
2594 else {
2595 if (sizestr[0] == '-') {
2596 mod = -1;
2597 sizestr++;
2598 } else if (sizestr[0] == '+') {
2599 mod = 1;
2600 sizestr++;
2601 }
2602 new_size = btrfs_parse_size(sizestr);
2603 if (new_size == 0) {
2604 ret = -EINVAL;
2605 goto out;
2606 }
2607 }
2608
2609 mutex_lock(&root->fs_info->fs_mutex);
2610 old_size = btrfs_super_total_bytes(&root->fs_info->super_copy);
2611
2612 if (mod < 0) {
2613 if (new_size > old_size) {
2614 ret = -EINVAL;
2615 goto out_unlock;
2616 }
2617 new_size = old_size - new_size;
2618 } else if (mod > 0) {
2619 new_size = old_size + new_size;
2620 }
2621
2622 if (new_size < 256 * 1024 * 1024) {
2623 ret = -EINVAL;
2624 goto out_unlock;
2625 }
2626 if (new_size > root->fs_info->sb->s_bdev->bd_inode->i_size) {
2627 ret = -EFBIG;
2628 goto out_unlock;
2629 }
2630
2631 do_div(new_size, root->sectorsize);
2632 new_size *= root->sectorsize;
2633
2634 printk("new size is %Lu\n", new_size);
2635 if (new_size > old_size) {
2636 trans = btrfs_start_transaction(root, 1);
2637 ret = btrfs_grow_extent_tree(trans, root, new_size);
2638 btrfs_commit_transaction(trans, root);
2639 } else {
2640 ret = btrfs_shrink_extent_tree(root, new_size);
2641 }
2642
2643 out_unlock:
2644 mutex_unlock(&root->fs_info->fs_mutex);
2645 out:
2646 kfree(vol_args);
2647 return ret;
2648 }
2649
2650 static int noinline btrfs_ioctl_snap_create(struct btrfs_root *root,
2651 void __user *arg)
2652 {
2653 struct btrfs_ioctl_vol_args *vol_args;
2654 struct btrfs_dir_item *di;
2655 struct btrfs_path *path;
2656 u64 root_dirid;
2657 int namelen;
2658 int ret;
2659
2660 vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
2661
2662 if (!vol_args)
2663 return -ENOMEM;
2664
2665 if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
2666 ret = -EFAULT;
2667 goto out;
2668 }
2669
2670 namelen = strlen(vol_args->name);
2671 if (namelen > BTRFS_VOL_NAME_MAX) {
2672 ret = -EINVAL;
2673 goto out;
2674 }
2675 if (strchr(vol_args->name, '/')) {
2676 ret = -EINVAL;
2677 goto out;
2678 }
2679
2680 path = btrfs_alloc_path();
2681 if (!path) {
2682 ret = -ENOMEM;
2683 goto out;
2684 }
2685
2686 root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
2687 mutex_lock(&root->fs_info->fs_mutex);
2688 di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
2689 path, root_dirid,
2690 vol_args->name, namelen, 0);
2691 mutex_unlock(&root->fs_info->fs_mutex);
2692 btrfs_free_path(path);
2693
2694 if (di && !IS_ERR(di)) {
2695 ret = -EEXIST;
2696 goto out;
2697 }
2698
2699 if (IS_ERR(di)) {
2700 ret = PTR_ERR(di);
2701 goto out;
2702 }
2703
2704 if (root == root->fs_info->tree_root)
2705 ret = create_subvol(root, vol_args->name, namelen);
2706 else
2707 ret = create_snapshot(root, vol_args->name, namelen);
2708 out:
2709 kfree(vol_args);
2710 return ret;
2711 }
2712
2713 static int btrfs_ioctl_defrag(struct file *file)
2714 {
2715 struct inode *inode = fdentry(file)->d_inode;
2716 struct btrfs_root *root = BTRFS_I(inode)->root;
2717
2718 switch (inode->i_mode & S_IFMT) {
2719 case S_IFDIR:
2720 mutex_lock(&root->fs_info->fs_mutex);
2721 btrfs_defrag_root(root, 0);
2722 btrfs_defrag_root(root->fs_info->extent_root, 0);
2723 mutex_unlock(&root->fs_info->fs_mutex);
2724 break;
2725 case S_IFREG:
2726 btrfs_defrag_file(file);
2727 break;
2728 }
2729
2730 return 0;
2731 }
2732
2733 long btrfs_ioctl(struct file *file, unsigned int
2734 cmd, unsigned long arg)
2735 {
2736 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
2737
2738 switch (cmd) {
2739 case BTRFS_IOC_SNAP_CREATE:
2740 return btrfs_ioctl_snap_create(root, (void __user *)arg);
2741 case BTRFS_IOC_DEFRAG:
2742 return btrfs_ioctl_defrag(file);
2743 case BTRFS_IOC_RESIZE:
2744 return btrfs_ioctl_resize(root, (void __user *)arg);
2745 }
2746
2747 return -ENOTTY;
2748 }
2749
2750 /*
2751 * Called inside transaction, so use GFP_NOFS
2752 */
2753 struct inode *btrfs_alloc_inode(struct super_block *sb)
2754 {
2755 struct btrfs_inode *ei;
2756
2757 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
2758 if (!ei)
2759 return NULL;
2760 ei->last_trans = 0;
2761 ei->ordered_trans = 0;
2762 return &ei->vfs_inode;
2763 }
2764
2765 void btrfs_destroy_inode(struct inode *inode)
2766 {
2767 WARN_ON(!list_empty(&inode->i_dentry));
2768 WARN_ON(inode->i_data.nrpages);
2769
2770 btrfs_drop_extent_cache(inode, 0, (u64)-1);
2771 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
2772 }
2773
2774 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
2775 static void init_once(struct kmem_cache * cachep, void *foo)
2776 #else
2777 static void init_once(void * foo, struct kmem_cache * cachep,
2778 unsigned long flags)
2779 #endif
2780 {
2781 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
2782
2783 inode_init_once(&ei->vfs_inode);
2784 }
2785
2786 void btrfs_destroy_cachep(void)
2787 {
2788 if (btrfs_inode_cachep)
2789 kmem_cache_destroy(btrfs_inode_cachep);
2790 if (btrfs_trans_handle_cachep)
2791 kmem_cache_destroy(btrfs_trans_handle_cachep);
2792 if (btrfs_transaction_cachep)
2793 kmem_cache_destroy(btrfs_transaction_cachep);
2794 if (btrfs_bit_radix_cachep)
2795 kmem_cache_destroy(btrfs_bit_radix_cachep);
2796 if (btrfs_path_cachep)
2797 kmem_cache_destroy(btrfs_path_cachep);
2798 }
2799
2800 struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
2801 unsigned long extra_flags,
2802 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
2803 void (*ctor)(struct kmem_cache *, void *)
2804 #else
2805 void (*ctor)(void *, struct kmem_cache *,
2806 unsigned long)
2807 #endif
2808 )
2809 {
2810 return kmem_cache_create(name, size, 0, (SLAB_RECLAIM_ACCOUNT |
2811 SLAB_MEM_SPREAD | extra_flags), ctor
2812 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
2813 ,NULL
2814 #endif
2815 );
2816 }
2817
2818 int btrfs_init_cachep(void)
2819 {
2820 btrfs_inode_cachep = btrfs_cache_create("btrfs_inode_cache",
2821 sizeof(struct btrfs_inode),
2822 0, init_once);
2823 if (!btrfs_inode_cachep)
2824 goto fail;
2825 btrfs_trans_handle_cachep =
2826 btrfs_cache_create("btrfs_trans_handle_cache",
2827 sizeof(struct btrfs_trans_handle),
2828 0, NULL);
2829 if (!btrfs_trans_handle_cachep)
2830 goto fail;
2831 btrfs_transaction_cachep = btrfs_cache_create("btrfs_transaction_cache",
2832 sizeof(struct btrfs_transaction),
2833 0, NULL);
2834 if (!btrfs_transaction_cachep)
2835 goto fail;
2836 btrfs_path_cachep = btrfs_cache_create("btrfs_path_cache",
2837 sizeof(struct btrfs_path),
2838 0, NULL);
2839 if (!btrfs_path_cachep)
2840 goto fail;
2841 btrfs_bit_radix_cachep = btrfs_cache_create("btrfs_radix", 256,
2842 SLAB_DESTROY_BY_RCU, NULL);
2843 if (!btrfs_bit_radix_cachep)
2844 goto fail;
2845 return 0;
2846 fail:
2847 btrfs_destroy_cachep();
2848 return -ENOMEM;
2849 }
2850
2851 static int btrfs_getattr(struct vfsmount *mnt,
2852 struct dentry *dentry, struct kstat *stat)
2853 {
2854 struct inode *inode = dentry->d_inode;
2855 generic_fillattr(inode, stat);
2856 stat->blksize = PAGE_CACHE_SIZE;
2857 stat->blocks = inode->i_blocks + (BTRFS_I(inode)->delalloc_bytes >> 9);
2858 return 0;
2859 }
2860
2861 static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
2862 struct inode * new_dir,struct dentry *new_dentry)
2863 {
2864 struct btrfs_trans_handle *trans;
2865 struct btrfs_root *root = BTRFS_I(old_dir)->root;
2866 struct inode *new_inode = new_dentry->d_inode;
2867 struct inode *old_inode = old_dentry->d_inode;
2868 struct timespec ctime = CURRENT_TIME;
2869 struct btrfs_path *path;
2870 int ret;
2871
2872 if (S_ISDIR(old_inode->i_mode) && new_inode &&
2873 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
2874 return -ENOTEMPTY;
2875 }
2876
2877 mutex_lock(&root->fs_info->fs_mutex);
2878 ret = btrfs_check_free_space(root, 1, 0);
2879 if (ret)
2880 goto out_unlock;
2881
2882 trans = btrfs_start_transaction(root, 1);
2883
2884 btrfs_set_trans_block_group(trans, new_dir);
2885 path = btrfs_alloc_path();
2886 if (!path) {
2887 ret = -ENOMEM;
2888 goto out_fail;
2889 }
2890
2891 old_dentry->d_inode->i_nlink++;
2892 old_dir->i_ctime = old_dir->i_mtime = ctime;
2893 new_dir->i_ctime = new_dir->i_mtime = ctime;
2894 old_inode->i_ctime = ctime;
2895
2896 ret = btrfs_unlink_trans(trans, root, old_dir, old_dentry);
2897 if (ret)
2898 goto out_fail;
2899
2900 if (new_inode) {
2901 new_inode->i_ctime = CURRENT_TIME;
2902 ret = btrfs_unlink_trans(trans, root, new_dir, new_dentry);
2903 if (ret)
2904 goto out_fail;
2905 }
2906 ret = btrfs_add_link(trans, new_dentry, old_inode, 1);
2907 if (ret)
2908 goto out_fail;
2909
2910 out_fail:
2911 btrfs_free_path(path);
2912 btrfs_end_transaction(trans, root);
2913 out_unlock:
2914 mutex_unlock(&root->fs_info->fs_mutex);
2915 return ret;
2916 }
2917
2918 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
2919 const char *symname)
2920 {
2921 struct btrfs_trans_handle *trans;
2922 struct btrfs_root *root = BTRFS_I(dir)->root;
2923 struct btrfs_path *path;
2924 struct btrfs_key key;
2925 struct inode *inode = NULL;
2926 int err;
2927 int drop_inode = 0;
2928 u64 objectid;
2929 int name_len;
2930 int datasize;
2931 unsigned long ptr;
2932 struct btrfs_file_extent_item *ei;
2933 struct extent_buffer *leaf;
2934 unsigned long nr = 0;
2935
2936 name_len = strlen(symname) + 1;
2937 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
2938 return -ENAMETOOLONG;
2939
2940 mutex_lock(&root->fs_info->fs_mutex);
2941 err = btrfs_check_free_space(root, 1, 0);
2942 if (err)
2943 goto out_fail;
2944
2945 trans = btrfs_start_transaction(root, 1);
2946 btrfs_set_trans_block_group(trans, dir);
2947
2948 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
2949 if (err) {
2950 err = -ENOSPC;
2951 goto out_unlock;
2952 }
2953
2954 inode = btrfs_new_inode(trans, root, dentry->d_name.name,
2955 dentry->d_name.len,
2956 dentry->d_parent->d_inode->i_ino, objectid,
2957 BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO);
2958 err = PTR_ERR(inode);
2959 if (IS_ERR(inode))
2960 goto out_unlock;
2961
2962 btrfs_set_trans_block_group(trans, inode);
2963 err = btrfs_add_nondir(trans, dentry, inode, 0);
2964 if (err)
2965 drop_inode = 1;
2966 else {
2967 inode->i_mapping->a_ops = &btrfs_aops;
2968 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
2969 inode->i_fop = &btrfs_file_operations;
2970 inode->i_op = &btrfs_file_inode_operations;
2971 extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
2972 extent_io_tree_init(&BTRFS_I(inode)->io_tree,
2973 inode->i_mapping, GFP_NOFS);
2974 BTRFS_I(inode)->delalloc_bytes = 0;
2975 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
2976 }
2977 dir->i_sb->s_dirt = 1;
2978 btrfs_update_inode_block_group(trans, inode);
2979 btrfs_update_inode_block_group(trans, dir);
2980 if (drop_inode)
2981 goto out_unlock;
2982
2983 path = btrfs_alloc_path();
2984 BUG_ON(!path);
2985 key.objectid = inode->i_ino;
2986 key.offset = 0;
2987 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
2988 datasize = btrfs_file_extent_calc_inline_size(name_len);
2989 err = btrfs_insert_empty_item(trans, root, path, &key,
2990 datasize);
2991 if (err) {
2992 drop_inode = 1;
2993 goto out_unlock;
2994 }
2995 leaf = path->nodes[0];
2996 ei = btrfs_item_ptr(leaf, path->slots[0],
2997 struct btrfs_file_extent_item);
2998 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
2999 btrfs_set_file_extent_type(leaf, ei,
3000 BTRFS_FILE_EXTENT_INLINE);
3001 ptr = btrfs_file_extent_inline_start(ei);
3002 write_extent_buffer(leaf, symname, ptr, name_len);
3003 btrfs_mark_buffer_dirty(leaf);
3004 btrfs_free_path(path);
3005
3006 inode->i_op = &btrfs_symlink_inode_operations;
3007 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3008 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3009 inode->i_size = name_len - 1;
3010 err = btrfs_update_inode(trans, root, inode);
3011 if (err)
3012 drop_inode = 1;
3013
3014 out_unlock:
3015 nr = trans->blocks_used;
3016 btrfs_end_transaction(trans, root);
3017 out_fail:
3018 mutex_unlock(&root->fs_info->fs_mutex);
3019 if (drop_inode) {
3020 inode_dec_link_count(inode);
3021 iput(inode);
3022 }
3023 btrfs_btree_balance_dirty(root, nr);
3024 btrfs_throttle(root);
3025 return err;
3026 }
3027 static int btrfs_permission(struct inode *inode, int mask,
3028 struct nameidata *nd)
3029 {
3030 if (btrfs_test_flag(inode, READONLY) && (mask & MAY_WRITE))
3031 return -EACCES;
3032 return generic_permission(inode, mask, NULL);
3033 }
3034
3035 static struct inode_operations btrfs_dir_inode_operations = {
3036 .lookup = btrfs_lookup,
3037 .create = btrfs_create,
3038 .unlink = btrfs_unlink,
3039 .link = btrfs_link,
3040 .mkdir = btrfs_mkdir,
3041 .rmdir = btrfs_rmdir,
3042 .rename = btrfs_rename,
3043 .symlink = btrfs_symlink,
3044 .setattr = btrfs_setattr,
3045 .mknod = btrfs_mknod,
3046 .setxattr = generic_setxattr,
3047 .getxattr = generic_getxattr,
3048 .listxattr = btrfs_listxattr,
3049 .removexattr = generic_removexattr,
3050 .permission = btrfs_permission,
3051 };
3052 static struct inode_operations btrfs_dir_ro_inode_operations = {
3053 .lookup = btrfs_lookup,
3054 .permission = btrfs_permission,
3055 };
3056 static struct file_operations btrfs_dir_file_operations = {
3057 .llseek = generic_file_llseek,
3058 .read = generic_read_dir,
3059 .readdir = btrfs_readdir,
3060 .unlocked_ioctl = btrfs_ioctl,
3061 #ifdef CONFIG_COMPAT
3062 .compat_ioctl = btrfs_ioctl,
3063 #endif
3064 };
3065
3066 static struct extent_io_ops btrfs_extent_io_ops = {
3067 .fill_delalloc = run_delalloc_range,
3068 .submit_bio_hook = btrfs_submit_bio_hook,
3069 .merge_bio_hook = btrfs_merge_bio_hook,
3070 .readpage_io_hook = btrfs_readpage_io_hook,
3071 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
3072 .set_bit_hook = btrfs_set_bit_hook,
3073 .clear_bit_hook = btrfs_clear_bit_hook,
3074 };
3075
3076 static struct address_space_operations btrfs_aops = {
3077 .readpage = btrfs_readpage,
3078 .writepage = btrfs_writepage,
3079 .writepages = btrfs_writepages,
3080 .readpages = btrfs_readpages,
3081 .sync_page = block_sync_page,
3082 .bmap = btrfs_bmap,
3083 .invalidatepage = btrfs_invalidatepage,
3084 .releasepage = btrfs_releasepage,
3085 .set_page_dirty = __set_page_dirty_nobuffers,
3086 };
3087
3088 static struct address_space_operations btrfs_symlink_aops = {
3089 .readpage = btrfs_readpage,
3090 .writepage = btrfs_writepage,
3091 .invalidatepage = btrfs_invalidatepage,
3092 .releasepage = btrfs_releasepage,
3093 };
3094
3095 static struct inode_operations btrfs_file_inode_operations = {
3096 .truncate = btrfs_truncate,
3097 .getattr = btrfs_getattr,
3098 .setattr = btrfs_setattr,
3099 .setxattr = generic_setxattr,
3100 .getxattr = generic_getxattr,
3101 .listxattr = btrfs_listxattr,
3102 .removexattr = generic_removexattr,
3103 .permission = btrfs_permission,
3104 };
3105 static struct inode_operations btrfs_special_inode_operations = {
3106 .getattr = btrfs_getattr,
3107 .setattr = btrfs_setattr,
3108 .permission = btrfs_permission,
3109 };
3110 static struct inode_operations btrfs_symlink_inode_operations = {
3111 .readlink = generic_readlink,
3112 .follow_link = page_follow_link_light,
3113 .put_link = page_put_link,
3114 .permission = btrfs_permission,
3115 };
Linux kernel - Deliverables
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