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Btrfs: Add per-root block accounting and sysfs entries
[deliverable/linux.git] / fs / btrfs / inode.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/buffer_head.h>
20 #include <linux/fs.h>
21 #include <linux/pagemap.h>
22 #include <linux/highmem.h>
23 #include <linux/time.h>
24 #include <linux/init.h>
25 #include <linux/string.h>
26 #include <linux/smp_lock.h>
27 #include <linux/backing-dev.h>
28 #include <linux/mpage.h>
29 #include <linux/swap.h>
30 #include <linux/writeback.h>
31 #include <linux/statfs.h>
32 #include <linux/compat.h>
33 #include <linux/bit_spinlock.h>
34 #include <linux/version.h>
35 #include "ctree.h"
36 #include "disk-io.h"
37 #include "transaction.h"
38 #include "btrfs_inode.h"
39 #include "ioctl.h"
40 #include "print-tree.h"
41
42 struct btrfs_iget_args {
43 u64 ino;
44 struct btrfs_root *root;
45 };
46
47 static struct inode_operations btrfs_dir_inode_operations;
48 static struct inode_operations btrfs_symlink_inode_operations;
49 static struct inode_operations btrfs_dir_ro_inode_operations;
50 static struct inode_operations btrfs_special_inode_operations;
51 static struct inode_operations btrfs_file_inode_operations;
52 static struct address_space_operations btrfs_aops;
53 static struct address_space_operations btrfs_symlink_aops;
54 static struct file_operations btrfs_dir_file_operations;
55
56 static struct kmem_cache *btrfs_inode_cachep;
57 struct kmem_cache *btrfs_trans_handle_cachep;
58 struct kmem_cache *btrfs_transaction_cachep;
59 struct kmem_cache *btrfs_bit_radix_cachep;
60 struct kmem_cache *btrfs_path_cachep;
61
62 #define S_SHIFT 12
63 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
64 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
65 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
66 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
67 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
68 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
69 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
70 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
71 };
72
73 static int run_delalloc_range(struct inode *inode, u64 start, u64 end)
74 {
75 struct btrfs_root *root = BTRFS_I(inode)->root;
76 struct btrfs_trans_handle *trans;
77 struct btrfs_key ins;
78 u64 alloc_hint = 0;
79 u64 num_blocks;
80 int ret;
81 u64 blocksize = 1 << inode->i_blkbits;
82
83 mutex_lock(&root->fs_info->fs_mutex);
84 trans = btrfs_start_transaction(root, 1);
85 btrfs_set_trans_block_group(trans, inode);
86 BUG_ON(!trans);
87 num_blocks = (end - start + blocksize) & ~(blocksize - 1);
88 ret = btrfs_drop_extents(trans, root, inode,
89 start, start + num_blocks, &alloc_hint);
90 num_blocks = num_blocks >> inode->i_blkbits;
91 ret = btrfs_alloc_extent(trans, root, inode->i_ino, num_blocks, 0,
92 alloc_hint, (u64)-1, &ins, 1);
93 if (ret) {
94 WARN_ON(1);
95 goto out;
96 }
97 ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
98 start, ins.objectid, ins.offset,
99 ins.offset);
100 out:
101 btrfs_end_transaction(trans, root);
102 mutex_unlock(&root->fs_info->fs_mutex);
103 return ret;
104 }
105
106
107 void btrfs_read_locked_inode(struct inode *inode)
108 {
109 struct btrfs_path *path;
110 struct btrfs_inode_item *inode_item;
111 struct btrfs_root *root = BTRFS_I(inode)->root;
112 struct btrfs_key location;
113 u64 alloc_group_block;
114 u32 rdev;
115 int ret;
116
117 path = btrfs_alloc_path();
118 BUG_ON(!path);
119 mutex_lock(&root->fs_info->fs_mutex);
120
121 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
122 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
123 if (ret) {
124 btrfs_free_path(path);
125 goto make_bad;
126 }
127 inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
128 path->slots[0],
129 struct btrfs_inode_item);
130
131 inode->i_mode = btrfs_inode_mode(inode_item);
132 inode->i_nlink = btrfs_inode_nlink(inode_item);
133 inode->i_uid = btrfs_inode_uid(inode_item);
134 inode->i_gid = btrfs_inode_gid(inode_item);
135 inode->i_size = btrfs_inode_size(inode_item);
136 inode->i_atime.tv_sec = btrfs_timespec_sec(&inode_item->atime);
137 inode->i_atime.tv_nsec = btrfs_timespec_nsec(&inode_item->atime);
138 inode->i_mtime.tv_sec = btrfs_timespec_sec(&inode_item->mtime);
139 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(&inode_item->mtime);
140 inode->i_ctime.tv_sec = btrfs_timespec_sec(&inode_item->ctime);
141 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(&inode_item->ctime);
142 inode->i_blocks = btrfs_inode_nblocks(inode_item);
143 inode->i_generation = btrfs_inode_generation(inode_item);
144 inode->i_rdev = 0;
145 rdev = btrfs_inode_rdev(inode_item);
146 alloc_group_block = btrfs_inode_block_group(inode_item);
147 BTRFS_I(inode)->block_group = btrfs_lookup_block_group(root->fs_info,
148 alloc_group_block);
149
150 btrfs_free_path(path);
151 inode_item = NULL;
152
153 mutex_unlock(&root->fs_info->fs_mutex);
154
155 switch (inode->i_mode & S_IFMT) {
156 case S_IFREG:
157 inode->i_mapping->a_ops = &btrfs_aops;
158 BTRFS_I(inode)->extent_tree.fill_delalloc = run_delalloc_range;
159 inode->i_fop = &btrfs_file_operations;
160 inode->i_op = &btrfs_file_inode_operations;
161 break;
162 case S_IFDIR:
163 inode->i_fop = &btrfs_dir_file_operations;
164 if (root == root->fs_info->tree_root)
165 inode->i_op = &btrfs_dir_ro_inode_operations;
166 else
167 inode->i_op = &btrfs_dir_inode_operations;
168 break;
169 case S_IFLNK:
170 inode->i_op = &btrfs_symlink_inode_operations;
171 inode->i_mapping->a_ops = &btrfs_symlink_aops;
172 break;
173 default:
174 init_special_inode(inode, inode->i_mode, rdev);
175 break;
176 }
177 return;
178
179 make_bad:
180 btrfs_release_path(root, path);
181 btrfs_free_path(path);
182 mutex_unlock(&root->fs_info->fs_mutex);
183 make_bad_inode(inode);
184 }
185
186 static void fill_inode_item(struct btrfs_inode_item *item,
187 struct inode *inode)
188 {
189 btrfs_set_inode_uid(item, inode->i_uid);
190 btrfs_set_inode_gid(item, inode->i_gid);
191 btrfs_set_inode_size(item, inode->i_size);
192 btrfs_set_inode_mode(item, inode->i_mode);
193 btrfs_set_inode_nlink(item, inode->i_nlink);
194 btrfs_set_timespec_sec(&item->atime, inode->i_atime.tv_sec);
195 btrfs_set_timespec_nsec(&item->atime, inode->i_atime.tv_nsec);
196 btrfs_set_timespec_sec(&item->mtime, inode->i_mtime.tv_sec);
197 btrfs_set_timespec_nsec(&item->mtime, inode->i_mtime.tv_nsec);
198 btrfs_set_timespec_sec(&item->ctime, inode->i_ctime.tv_sec);
199 btrfs_set_timespec_nsec(&item->ctime, inode->i_ctime.tv_nsec);
200 btrfs_set_inode_nblocks(item, inode->i_blocks);
201 btrfs_set_inode_generation(item, inode->i_generation);
202 btrfs_set_inode_rdev(item, inode->i_rdev);
203 btrfs_set_inode_block_group(item,
204 BTRFS_I(inode)->block_group->key.objectid);
205 }
206
207 int btrfs_update_inode(struct btrfs_trans_handle *trans,
208 struct btrfs_root *root,
209 struct inode *inode)
210 {
211 struct btrfs_inode_item *inode_item;
212 struct btrfs_path *path;
213 int ret;
214
215 path = btrfs_alloc_path();
216 BUG_ON(!path);
217 ret = btrfs_lookup_inode(trans, root, path,
218 &BTRFS_I(inode)->location, 1);
219 if (ret) {
220 if (ret > 0)
221 ret = -ENOENT;
222 goto failed;
223 }
224
225 inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
226 path->slots[0],
227 struct btrfs_inode_item);
228
229 fill_inode_item(inode_item, inode);
230 btrfs_mark_buffer_dirty(path->nodes[0]);
231 btrfs_set_inode_last_trans(trans, inode);
232 ret = 0;
233 failed:
234 btrfs_release_path(root, path);
235 btrfs_free_path(path);
236 return ret;
237 }
238
239
240 static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
241 struct btrfs_root *root,
242 struct inode *dir,
243 struct dentry *dentry)
244 {
245 struct btrfs_path *path;
246 const char *name = dentry->d_name.name;
247 int name_len = dentry->d_name.len;
248 int ret = 0;
249 u64 objectid;
250 struct btrfs_dir_item *di;
251
252 path = btrfs_alloc_path();
253 if (!path) {
254 ret = -ENOMEM;
255 goto err;
256 }
257
258 di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
259 name, name_len, -1);
260 if (IS_ERR(di)) {
261 ret = PTR_ERR(di);
262 goto err;
263 }
264 if (!di) {
265 ret = -ENOENT;
266 goto err;
267 }
268 objectid = btrfs_disk_key_objectid(&di->location);
269 ret = btrfs_delete_one_dir_name(trans, root, path, di);
270 if (ret)
271 goto err;
272 btrfs_release_path(root, path);
273
274 di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
275 objectid, name, name_len, -1);
276 if (IS_ERR(di)) {
277 ret = PTR_ERR(di);
278 goto err;
279 }
280 if (!di) {
281 ret = -ENOENT;
282 goto err;
283 }
284 ret = btrfs_delete_one_dir_name(trans, root, path, di);
285
286 dentry->d_inode->i_ctime = dir->i_ctime;
287 err:
288 btrfs_free_path(path);
289 if (!ret) {
290 dir->i_size -= name_len * 2;
291 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
292 btrfs_update_inode(trans, root, dir);
293 drop_nlink(dentry->d_inode);
294 ret = btrfs_update_inode(trans, root, dentry->d_inode);
295 dir->i_sb->s_dirt = 1;
296 }
297 return ret;
298 }
299
300 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
301 {
302 struct btrfs_root *root;
303 struct btrfs_trans_handle *trans;
304 int ret;
305
306 root = BTRFS_I(dir)->root;
307 mutex_lock(&root->fs_info->fs_mutex);
308 trans = btrfs_start_transaction(root, 1);
309 btrfs_set_trans_block_group(trans, dir);
310 ret = btrfs_unlink_trans(trans, root, dir, dentry);
311 btrfs_end_transaction(trans, root);
312 mutex_unlock(&root->fs_info->fs_mutex);
313 btrfs_btree_balance_dirty(root);
314 return ret;
315 }
316
317 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
318 {
319 struct inode *inode = dentry->d_inode;
320 int err;
321 int ret;
322 struct btrfs_root *root = BTRFS_I(dir)->root;
323 struct btrfs_path *path;
324 struct btrfs_key key;
325 struct btrfs_trans_handle *trans;
326 struct btrfs_key found_key;
327 int found_type;
328 struct btrfs_leaf *leaf;
329 char *goodnames = "..";
330
331 path = btrfs_alloc_path();
332 BUG_ON(!path);
333 mutex_lock(&root->fs_info->fs_mutex);
334 trans = btrfs_start_transaction(root, 1);
335 btrfs_set_trans_block_group(trans, dir);
336 key.objectid = inode->i_ino;
337 key.offset = (u64)-1;
338 key.flags = (u32)-1;
339 while(1) {
340 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
341 if (ret < 0) {
342 err = ret;
343 goto out;
344 }
345 BUG_ON(ret == 0);
346 if (path->slots[0] == 0) {
347 err = -ENOENT;
348 goto out;
349 }
350 path->slots[0]--;
351 leaf = btrfs_buffer_leaf(path->nodes[0]);
352 btrfs_disk_key_to_cpu(&found_key,
353 &leaf->items[path->slots[0]].key);
354 found_type = btrfs_key_type(&found_key);
355 if (found_key.objectid != inode->i_ino) {
356 err = -ENOENT;
357 goto out;
358 }
359 if ((found_type != BTRFS_DIR_ITEM_KEY &&
360 found_type != BTRFS_DIR_INDEX_KEY) ||
361 (!btrfs_match_dir_item_name(root, path, goodnames, 2) &&
362 !btrfs_match_dir_item_name(root, path, goodnames, 1))) {
363 err = -ENOTEMPTY;
364 goto out;
365 }
366 ret = btrfs_del_item(trans, root, path);
367 BUG_ON(ret);
368
369 if (found_type == BTRFS_DIR_ITEM_KEY && found_key.offset == 1)
370 break;
371 btrfs_release_path(root, path);
372 }
373 ret = 0;
374 btrfs_release_path(root, path);
375
376 /* now the directory is empty */
377 err = btrfs_unlink_trans(trans, root, dir, dentry);
378 if (!err) {
379 inode->i_size = 0;
380 }
381 out:
382 btrfs_release_path(root, path);
383 btrfs_free_path(path);
384 mutex_unlock(&root->fs_info->fs_mutex);
385 ret = btrfs_end_transaction(trans, root);
386 btrfs_btree_balance_dirty(root);
387 if (ret && !err)
388 err = ret;
389 return err;
390 }
391
392 static int btrfs_free_inode(struct btrfs_trans_handle *trans,
393 struct btrfs_root *root,
394 struct inode *inode)
395 {
396 struct btrfs_path *path;
397 int ret;
398
399 clear_inode(inode);
400
401 path = btrfs_alloc_path();
402 BUG_ON(!path);
403 ret = btrfs_lookup_inode(trans, root, path,
404 &BTRFS_I(inode)->location, -1);
405 if (ret > 0)
406 ret = -ENOENT;
407 if (!ret)
408 ret = btrfs_del_item(trans, root, path);
409 btrfs_free_path(path);
410 return ret;
411 }
412
413 /*
414 * this can truncate away extent items, csum items and directory items.
415 * It starts at a high offset and removes keys until it can't find
416 * any higher than i_size.
417 *
418 * csum items that cross the new i_size are truncated to the new size
419 * as well.
420 */
421 static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
422 struct btrfs_root *root,
423 struct inode *inode)
424 {
425 int ret;
426 struct btrfs_path *path;
427 struct btrfs_key key;
428 struct btrfs_disk_key *found_key;
429 u32 found_type;
430 struct btrfs_leaf *leaf;
431 struct btrfs_file_extent_item *fi;
432 u64 extent_start = 0;
433 u64 extent_num_blocks = 0;
434 u64 item_end = 0;
435 int found_extent;
436 int del_item;
437
438 btrfs_drop_extent_cache(inode, inode->i_size, (u64)-1);
439 path = btrfs_alloc_path();
440 path->reada = -1;
441 BUG_ON(!path);
442 /* FIXME, add redo link to tree so we don't leak on crash */
443 key.objectid = inode->i_ino;
444 key.offset = (u64)-1;
445 key.flags = (u32)-1;
446 while(1) {
447 btrfs_init_path(path);
448 fi = NULL;
449 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
450 if (ret < 0) {
451 goto error;
452 }
453 if (ret > 0) {
454 BUG_ON(path->slots[0] == 0);
455 path->slots[0]--;
456 }
457 leaf = btrfs_buffer_leaf(path->nodes[0]);
458 found_key = &leaf->items[path->slots[0]].key;
459 found_type = btrfs_disk_key_type(found_key);
460
461 if (btrfs_disk_key_objectid(found_key) != inode->i_ino)
462 break;
463 if (found_type != BTRFS_CSUM_ITEM_KEY &&
464 found_type != BTRFS_DIR_ITEM_KEY &&
465 found_type != BTRFS_DIR_INDEX_KEY &&
466 found_type != BTRFS_EXTENT_DATA_KEY)
467 break;
468
469 item_end = btrfs_disk_key_offset(found_key);
470 if (found_type == BTRFS_EXTENT_DATA_KEY) {
471 fi = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
472 path->slots[0],
473 struct btrfs_file_extent_item);
474 if (btrfs_file_extent_type(fi) !=
475 BTRFS_FILE_EXTENT_INLINE) {
476 item_end += btrfs_file_extent_num_blocks(fi) <<
477 inode->i_blkbits;
478 }
479 }
480 if (found_type == BTRFS_CSUM_ITEM_KEY) {
481 ret = btrfs_csum_truncate(trans, root, path,
482 inode->i_size);
483 BUG_ON(ret);
484 }
485 if (item_end < inode->i_size) {
486 if (found_type == BTRFS_DIR_ITEM_KEY) {
487 found_type = BTRFS_INODE_ITEM_KEY;
488 } else if (found_type == BTRFS_EXTENT_ITEM_KEY) {
489 found_type = BTRFS_CSUM_ITEM_KEY;
490 } else if (found_type) {
491 found_type--;
492 } else {
493 break;
494 }
495 btrfs_set_key_type(&key, found_type - 1);
496 continue;
497 }
498 if (btrfs_disk_key_offset(found_key) >= inode->i_size)
499 del_item = 1;
500 else
501 del_item = 0;
502 found_extent = 0;
503
504 /* FIXME, shrink the extent if the ref count is only 1 */
505 if (found_type == BTRFS_EXTENT_DATA_KEY &&
506 btrfs_file_extent_type(fi) !=
507 BTRFS_FILE_EXTENT_INLINE) {
508 u64 num_dec;
509 if (!del_item) {
510 u64 orig_num_blocks =
511 btrfs_file_extent_num_blocks(fi);
512 extent_num_blocks = inode->i_size -
513 btrfs_disk_key_offset(found_key) +
514 root->blocksize - 1;
515 extent_num_blocks >>= inode->i_blkbits;
516 btrfs_set_file_extent_num_blocks(fi,
517 extent_num_blocks);
518 inode->i_blocks -= (orig_num_blocks -
519 extent_num_blocks) << 3;
520 btrfs_mark_buffer_dirty(path->nodes[0]);
521 } else {
522 extent_start =
523 btrfs_file_extent_disk_blocknr(fi);
524 extent_num_blocks =
525 btrfs_file_extent_disk_num_blocks(fi);
526 /* FIXME blocksize != 4096 */
527 num_dec = btrfs_file_extent_num_blocks(fi) << 3;
528 if (extent_start != 0) {
529 found_extent = 1;
530 inode->i_blocks -= num_dec;
531 }
532 }
533 }
534 if (del_item) {
535 ret = btrfs_del_item(trans, root, path);
536 if (ret)
537 goto error;
538 } else {
539 break;
540 }
541 btrfs_release_path(root, path);
542 if (found_extent) {
543 ret = btrfs_free_extent(trans, root, extent_start,
544 extent_num_blocks, 0);
545 BUG_ON(ret);
546 }
547 }
548 ret = 0;
549 error:
550 btrfs_release_path(root, path);
551 btrfs_free_path(path);
552 inode->i_sb->s_dirt = 1;
553 return ret;
554 }
555
556 static int btrfs_cow_one_page(struct inode *inode, struct page *page,
557 size_t zero_start)
558 {
559 char *kaddr;
560 int ret = 0;
561 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
562 u64 page_start = page->index << PAGE_CACHE_SHIFT;
563 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
564
565 if (!PagePrivate(page)) {
566 SetPagePrivate(page);
567 set_page_private(page, 1);
568 WARN_ON(!page->mapping->a_ops->invalidatepage);
569 page_cache_get(page);
570 }
571
572 lock_extent(em_tree, page_start, page_end, GFP_NOFS);
573 set_extent_delalloc(&BTRFS_I(inode)->extent_tree, page_start,
574 page_end, GFP_NOFS);
575 if (zero_start != PAGE_CACHE_SIZE) {
576 kaddr = kmap(page);
577 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
578 flush_dcache_page(page);
579 kunmap(page);
580 }
581 set_page_dirty(page);
582 unlock_extent(em_tree, page_start, page_end, GFP_NOFS);
583
584 return ret;
585 }
586
587 /*
588 * taken from block_truncate_page, but does cow as it zeros out
589 * any bytes left in the last page in the file.
590 */
591 static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
592 {
593 struct inode *inode = mapping->host;
594 unsigned blocksize = 1 << inode->i_blkbits;
595 pgoff_t index = from >> PAGE_CACHE_SHIFT;
596 unsigned offset = from & (PAGE_CACHE_SIZE-1);
597 struct page *page;
598 int ret = 0;
599 u64 page_start;
600
601 if ((offset & (blocksize - 1)) == 0)
602 goto out;
603
604 ret = -ENOMEM;
605 page = grab_cache_page(mapping, index);
606 if (!page)
607 goto out;
608 if (!PageUptodate(page)) {
609 ret = btrfs_readpage(NULL, page);
610 lock_page(page);
611 if (!PageUptodate(page)) {
612 ret = -EIO;
613 goto out;
614 }
615 }
616 page_start = page->index << PAGE_CACHE_SHIFT;
617
618 ret = btrfs_cow_one_page(inode, page, offset);
619
620 unlock_page(page);
621 page_cache_release(page);
622 out:
623 return ret;
624 }
625
626 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
627 {
628 struct inode *inode = dentry->d_inode;
629 int err;
630
631 err = inode_change_ok(inode, attr);
632 if (err)
633 return err;
634
635 if (S_ISREG(inode->i_mode) &&
636 attr->ia_valid & ATTR_SIZE && attr->ia_size > inode->i_size) {
637 struct btrfs_trans_handle *trans;
638 struct btrfs_root *root = BTRFS_I(inode)->root;
639 u64 mask = root->blocksize - 1;
640 u64 pos = (inode->i_size + mask) & ~mask;
641 u64 hole_size;
642
643 if (attr->ia_size <= pos)
644 goto out;
645
646 btrfs_truncate_page(inode->i_mapping, inode->i_size);
647
648 hole_size = (attr->ia_size - pos + mask) & ~mask;
649 hole_size >>= inode->i_blkbits;
650
651 mutex_lock(&root->fs_info->fs_mutex);
652 trans = btrfs_start_transaction(root, 1);
653 btrfs_set_trans_block_group(trans, inode);
654 err = btrfs_insert_file_extent(trans, root, inode->i_ino,
655 pos, 0, 0, hole_size);
656 btrfs_end_transaction(trans, root);
657 mutex_unlock(&root->fs_info->fs_mutex);
658 if (err)
659 return err;
660 }
661 out:
662 err = inode_setattr(inode, attr);
663
664 return err;
665 }
666 void btrfs_delete_inode(struct inode *inode)
667 {
668 struct btrfs_trans_handle *trans;
669 struct btrfs_root *root = BTRFS_I(inode)->root;
670 int ret;
671
672 truncate_inode_pages(&inode->i_data, 0);
673 if (is_bad_inode(inode)) {
674 goto no_delete;
675 }
676 inode->i_size = 0;
677 mutex_lock(&root->fs_info->fs_mutex);
678 trans = btrfs_start_transaction(root, 1);
679 btrfs_set_trans_block_group(trans, inode);
680 ret = btrfs_truncate_in_trans(trans, root, inode);
681 if (ret)
682 goto no_delete_lock;
683 ret = btrfs_free_inode(trans, root, inode);
684 if (ret)
685 goto no_delete_lock;
686 btrfs_end_transaction(trans, root);
687 mutex_unlock(&root->fs_info->fs_mutex);
688 btrfs_btree_balance_dirty(root);
689 return;
690
691 no_delete_lock:
692 btrfs_end_transaction(trans, root);
693 mutex_unlock(&root->fs_info->fs_mutex);
694 btrfs_btree_balance_dirty(root);
695 no_delete:
696 clear_inode(inode);
697 }
698
699 /*
700 * this returns the key found in the dir entry in the location pointer.
701 * If no dir entries were found, location->objectid is 0.
702 */
703 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
704 struct btrfs_key *location)
705 {
706 const char *name = dentry->d_name.name;
707 int namelen = dentry->d_name.len;
708 struct btrfs_dir_item *di;
709 struct btrfs_path *path;
710 struct btrfs_root *root = BTRFS_I(dir)->root;
711 int ret;
712
713 path = btrfs_alloc_path();
714 BUG_ON(!path);
715 di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
716 namelen, 0);
717 if (!di || IS_ERR(di)) {
718 location->objectid = 0;
719 ret = 0;
720 goto out;
721 }
722 btrfs_disk_key_to_cpu(location, &di->location);
723 out:
724 btrfs_release_path(root, path);
725 btrfs_free_path(path);
726 return ret;
727 }
728
729 /*
730 * when we hit a tree root in a directory, the btrfs part of the inode
731 * needs to be changed to reflect the root directory of the tree root. This
732 * is kind of like crossing a mount point.
733 */
734 static int fixup_tree_root_location(struct btrfs_root *root,
735 struct btrfs_key *location,
736 struct btrfs_root **sub_root,
737 struct dentry *dentry)
738 {
739 struct btrfs_path *path;
740 struct btrfs_root_item *ri;
741
742 if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY)
743 return 0;
744 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
745 return 0;
746
747 path = btrfs_alloc_path();
748 BUG_ON(!path);
749 mutex_lock(&root->fs_info->fs_mutex);
750
751 *sub_root = btrfs_read_fs_root(root->fs_info, location,
752 dentry->d_name.name,
753 dentry->d_name.len);
754 if (IS_ERR(*sub_root))
755 return PTR_ERR(*sub_root);
756
757 ri = &(*sub_root)->root_item;
758 location->objectid = btrfs_root_dirid(ri);
759 location->flags = 0;
760 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
761 location->offset = 0;
762
763 btrfs_free_path(path);
764 mutex_unlock(&root->fs_info->fs_mutex);
765 return 0;
766 }
767
768 static int btrfs_init_locked_inode(struct inode *inode, void *p)
769 {
770 struct btrfs_iget_args *args = p;
771 inode->i_ino = args->ino;
772 BTRFS_I(inode)->root = args->root;
773 extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
774 inode->i_mapping, GFP_NOFS);
775 return 0;
776 }
777
778 static int btrfs_find_actor(struct inode *inode, void *opaque)
779 {
780 struct btrfs_iget_args *args = opaque;
781 return (args->ino == inode->i_ino &&
782 args->root == BTRFS_I(inode)->root);
783 }
784
785 struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
786 struct btrfs_root *root)
787 {
788 struct inode *inode;
789 struct btrfs_iget_args args;
790 args.ino = objectid;
791 args.root = root;
792
793 inode = iget5_locked(s, objectid, btrfs_find_actor,
794 btrfs_init_locked_inode,
795 (void *)&args);
796 return inode;
797 }
798
799 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
800 struct nameidata *nd)
801 {
802 struct inode * inode;
803 struct btrfs_inode *bi = BTRFS_I(dir);
804 struct btrfs_root *root = bi->root;
805 struct btrfs_root *sub_root = root;
806 struct btrfs_key location;
807 int ret;
808
809 if (dentry->d_name.len > BTRFS_NAME_LEN)
810 return ERR_PTR(-ENAMETOOLONG);
811 mutex_lock(&root->fs_info->fs_mutex);
812 ret = btrfs_inode_by_name(dir, dentry, &location);
813 mutex_unlock(&root->fs_info->fs_mutex);
814 if (ret < 0)
815 return ERR_PTR(ret);
816 inode = NULL;
817 if (location.objectid) {
818 ret = fixup_tree_root_location(root, &location, &sub_root,
819 dentry);
820 if (ret < 0)
821 return ERR_PTR(ret);
822 if (ret > 0)
823 return ERR_PTR(-ENOENT);
824 inode = btrfs_iget_locked(dir->i_sb, location.objectid,
825 sub_root);
826 if (!inode)
827 return ERR_PTR(-EACCES);
828 if (inode->i_state & I_NEW) {
829 /* the inode and parent dir are two different roots */
830 if (sub_root != root) {
831 igrab(inode);
832 sub_root->inode = inode;
833 }
834 BTRFS_I(inode)->root = sub_root;
835 memcpy(&BTRFS_I(inode)->location, &location,
836 sizeof(location));
837 btrfs_read_locked_inode(inode);
838 unlock_new_inode(inode);
839 }
840 }
841 return d_splice_alias(inode, dentry);
842 }
843
844 static unsigned char btrfs_filetype_table[] = {
845 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
846 };
847
848 static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
849 {
850 struct inode *inode = filp->f_path.dentry->d_inode;
851 struct btrfs_root *root = BTRFS_I(inode)->root;
852 struct btrfs_item *item;
853 struct btrfs_dir_item *di;
854 struct btrfs_key key;
855 struct btrfs_path *path;
856 int ret;
857 u32 nritems;
858 struct btrfs_leaf *leaf;
859 int slot;
860 int advance;
861 unsigned char d_type;
862 int over = 0;
863 u32 di_cur;
864 u32 di_total;
865 u32 di_len;
866 int key_type = BTRFS_DIR_INDEX_KEY;
867
868 /* FIXME, use a real flag for deciding about the key type */
869 if (root->fs_info->tree_root == root)
870 key_type = BTRFS_DIR_ITEM_KEY;
871 mutex_lock(&root->fs_info->fs_mutex);
872 key.objectid = inode->i_ino;
873 key.flags = 0;
874 btrfs_set_key_type(&key, key_type);
875 key.offset = filp->f_pos;
876 path = btrfs_alloc_path();
877 path->reada = 2;
878 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
879 if (ret < 0)
880 goto err;
881 advance = 0;
882 while(1) {
883 leaf = btrfs_buffer_leaf(path->nodes[0]);
884 nritems = btrfs_header_nritems(&leaf->header);
885 slot = path->slots[0];
886 if (advance || slot >= nritems) {
887 if (slot >= nritems -1) {
888 ret = btrfs_next_leaf(root, path);
889 if (ret)
890 break;
891 leaf = btrfs_buffer_leaf(path->nodes[0]);
892 nritems = btrfs_header_nritems(&leaf->header);
893 slot = path->slots[0];
894 } else {
895 slot++;
896 path->slots[0]++;
897 }
898 }
899 advance = 1;
900 item = leaf->items + slot;
901 if (btrfs_disk_key_objectid(&item->key) != key.objectid)
902 break;
903 if (btrfs_disk_key_type(&item->key) != key_type)
904 break;
905 if (btrfs_disk_key_offset(&item->key) < filp->f_pos)
906 continue;
907 filp->f_pos = btrfs_disk_key_offset(&item->key);
908 advance = 1;
909 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
910 di_cur = 0;
911 di_total = btrfs_item_size(leaf->items + slot);
912 while(di_cur < di_total) {
913 d_type = btrfs_filetype_table[btrfs_dir_type(di)];
914 over = filldir(dirent, (const char *)(di + 1),
915 btrfs_dir_name_len(di),
916 btrfs_disk_key_offset(&item->key),
917 btrfs_disk_key_objectid(&di->location),
918 d_type);
919 if (over)
920 goto nopos;
921 di_len = btrfs_dir_name_len(di) + sizeof(*di);
922 di_cur += di_len;
923 di = (struct btrfs_dir_item *)((char *)di + di_len);
924 }
925 }
926 filp->f_pos++;
927 nopos:
928 ret = 0;
929 err:
930 btrfs_release_path(root, path);
931 btrfs_free_path(path);
932 mutex_unlock(&root->fs_info->fs_mutex);
933 return ret;
934 }
935
936 int btrfs_write_inode(struct inode *inode, int wait)
937 {
938 struct btrfs_root *root = BTRFS_I(inode)->root;
939 struct btrfs_trans_handle *trans;
940 int ret = 0;
941
942 if (wait) {
943 mutex_lock(&root->fs_info->fs_mutex);
944 trans = btrfs_start_transaction(root, 1);
945 btrfs_set_trans_block_group(trans, inode);
946 ret = btrfs_commit_transaction(trans, root);
947 mutex_unlock(&root->fs_info->fs_mutex);
948 }
949 return ret;
950 }
951
952 /*
953 * This is somewhat expensive, updating the tree every time the
954 * inode changes. But, it is most likely to find the inode in cache.
955 * FIXME, needs more benchmarking...there are no reasons other than performance
956 * to keep or drop this code.
957 */
958 void btrfs_dirty_inode(struct inode *inode)
959 {
960 struct btrfs_root *root = BTRFS_I(inode)->root;
961 struct btrfs_trans_handle *trans;
962
963 mutex_lock(&root->fs_info->fs_mutex);
964 trans = btrfs_start_transaction(root, 1);
965 btrfs_set_trans_block_group(trans, inode);
966 btrfs_update_inode(trans, root, inode);
967 btrfs_end_transaction(trans, root);
968 mutex_unlock(&root->fs_info->fs_mutex);
969 }
970
971 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
972 struct btrfs_root *root,
973 u64 objectid,
974 struct btrfs_block_group_cache *group,
975 int mode)
976 {
977 struct inode *inode;
978 struct btrfs_inode_item inode_item;
979 struct btrfs_key *location;
980 int ret;
981 int owner;
982
983 inode = new_inode(root->fs_info->sb);
984 if (!inode)
985 return ERR_PTR(-ENOMEM);
986
987 extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
988 inode->i_mapping, GFP_NOFS);
989 BTRFS_I(inode)->root = root;
990
991 if (mode & S_IFDIR)
992 owner = 0;
993 else
994 owner = 1;
995 group = btrfs_find_block_group(root, group, 0, 0, owner);
996 BTRFS_I(inode)->block_group = group;
997
998 inode->i_uid = current->fsuid;
999 inode->i_gid = current->fsgid;
1000 inode->i_mode = mode;
1001 inode->i_ino = objectid;
1002 inode->i_blocks = 0;
1003 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1004 fill_inode_item(&inode_item, inode);
1005 location = &BTRFS_I(inode)->location;
1006 location->objectid = objectid;
1007 location->flags = 0;
1008 location->offset = 0;
1009 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
1010
1011 ret = btrfs_insert_inode(trans, root, objectid, &inode_item);
1012 if (ret)
1013 return ERR_PTR(ret);
1014 insert_inode_hash(inode);
1015 return inode;
1016 }
1017
1018 static inline u8 btrfs_inode_type(struct inode *inode)
1019 {
1020 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
1021 }
1022
1023 static int btrfs_add_link(struct btrfs_trans_handle *trans,
1024 struct dentry *dentry, struct inode *inode)
1025 {
1026 int ret;
1027 struct btrfs_key key;
1028 struct btrfs_root *root = BTRFS_I(dentry->d_parent->d_inode)->root;
1029 struct inode *parent_inode;
1030 key.objectid = inode->i_ino;
1031 key.flags = 0;
1032 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
1033 key.offset = 0;
1034
1035 ret = btrfs_insert_dir_item(trans, root,
1036 dentry->d_name.name, dentry->d_name.len,
1037 dentry->d_parent->d_inode->i_ino,
1038 &key, btrfs_inode_type(inode));
1039 if (ret == 0) {
1040 parent_inode = dentry->d_parent->d_inode;
1041 parent_inode->i_size += dentry->d_name.len * 2;
1042 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
1043 ret = btrfs_update_inode(trans, root,
1044 dentry->d_parent->d_inode);
1045 }
1046 return ret;
1047 }
1048
1049 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
1050 struct dentry *dentry, struct inode *inode)
1051 {
1052 int err = btrfs_add_link(trans, dentry, inode);
1053 if (!err) {
1054 d_instantiate(dentry, inode);
1055 return 0;
1056 }
1057 if (err > 0)
1058 err = -EEXIST;
1059 return err;
1060 }
1061
1062 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
1063 int mode, dev_t rdev)
1064 {
1065 struct btrfs_trans_handle *trans;
1066 struct btrfs_root *root = BTRFS_I(dir)->root;
1067 struct inode *inode;
1068 int err;
1069 int drop_inode = 0;
1070 u64 objectid;
1071
1072 if (!new_valid_dev(rdev))
1073 return -EINVAL;
1074
1075 mutex_lock(&root->fs_info->fs_mutex);
1076 trans = btrfs_start_transaction(root, 1);
1077 btrfs_set_trans_block_group(trans, dir);
1078
1079 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1080 if (err) {
1081 err = -ENOSPC;
1082 goto out_unlock;
1083 }
1084
1085 inode = btrfs_new_inode(trans, root, objectid,
1086 BTRFS_I(dir)->block_group, mode);
1087 err = PTR_ERR(inode);
1088 if (IS_ERR(inode))
1089 goto out_unlock;
1090
1091 btrfs_set_trans_block_group(trans, inode);
1092 err = btrfs_add_nondir(trans, dentry, inode);
1093 if (err)
1094 drop_inode = 1;
1095 else {
1096 inode->i_op = &btrfs_special_inode_operations;
1097 init_special_inode(inode, inode->i_mode, rdev);
1098 }
1099 dir->i_sb->s_dirt = 1;
1100 btrfs_update_inode_block_group(trans, inode);
1101 btrfs_update_inode_block_group(trans, dir);
1102 out_unlock:
1103 btrfs_end_transaction(trans, root);
1104 mutex_unlock(&root->fs_info->fs_mutex);
1105
1106 if (drop_inode) {
1107 inode_dec_link_count(inode);
1108 iput(inode);
1109 }
1110 btrfs_btree_balance_dirty(root);
1111 return err;
1112 }
1113
1114 static int btrfs_create(struct inode *dir, struct dentry *dentry,
1115 int mode, struct nameidata *nd)
1116 {
1117 struct btrfs_trans_handle *trans;
1118 struct btrfs_root *root = BTRFS_I(dir)->root;
1119 struct inode *inode;
1120 int err;
1121 int drop_inode = 0;
1122 u64 objectid;
1123
1124 mutex_lock(&root->fs_info->fs_mutex);
1125 trans = btrfs_start_transaction(root, 1);
1126 btrfs_set_trans_block_group(trans, dir);
1127
1128 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1129 if (err) {
1130 err = -ENOSPC;
1131 goto out_unlock;
1132 }
1133
1134 inode = btrfs_new_inode(trans, root, objectid,
1135 BTRFS_I(dir)->block_group, mode);
1136 err = PTR_ERR(inode);
1137 if (IS_ERR(inode))
1138 goto out_unlock;
1139
1140 btrfs_set_trans_block_group(trans, inode);
1141 err = btrfs_add_nondir(trans, dentry, inode);
1142 if (err)
1143 drop_inode = 1;
1144 else {
1145 inode->i_mapping->a_ops = &btrfs_aops;
1146 inode->i_fop = &btrfs_file_operations;
1147 inode->i_op = &btrfs_file_inode_operations;
1148 extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
1149 inode->i_mapping, GFP_NOFS);
1150 BTRFS_I(inode)->extent_tree.fill_delalloc = run_delalloc_range;
1151 }
1152 dir->i_sb->s_dirt = 1;
1153 btrfs_update_inode_block_group(trans, inode);
1154 btrfs_update_inode_block_group(trans, dir);
1155 out_unlock:
1156 btrfs_end_transaction(trans, root);
1157 mutex_unlock(&root->fs_info->fs_mutex);
1158
1159 if (drop_inode) {
1160 inode_dec_link_count(inode);
1161 iput(inode);
1162 }
1163 btrfs_btree_balance_dirty(root);
1164 return err;
1165 }
1166
1167 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
1168 struct dentry *dentry)
1169 {
1170 struct btrfs_trans_handle *trans;
1171 struct btrfs_root *root = BTRFS_I(dir)->root;
1172 struct inode *inode = old_dentry->d_inode;
1173 int err;
1174 int drop_inode = 0;
1175
1176 if (inode->i_nlink == 0)
1177 return -ENOENT;
1178
1179 inc_nlink(inode);
1180 mutex_lock(&root->fs_info->fs_mutex);
1181 trans = btrfs_start_transaction(root, 1);
1182 btrfs_set_trans_block_group(trans, dir);
1183 atomic_inc(&inode->i_count);
1184 err = btrfs_add_nondir(trans, dentry, inode);
1185 if (err)
1186 drop_inode = 1;
1187 dir->i_sb->s_dirt = 1;
1188 btrfs_update_inode_block_group(trans, dir);
1189 err = btrfs_update_inode(trans, root, inode);
1190 if (err)
1191 drop_inode = 1;
1192
1193 btrfs_end_transaction(trans, root);
1194 mutex_unlock(&root->fs_info->fs_mutex);
1195
1196 if (drop_inode) {
1197 inode_dec_link_count(inode);
1198 iput(inode);
1199 }
1200 btrfs_btree_balance_dirty(root);
1201 return err;
1202 }
1203
1204 static int btrfs_make_empty_dir(struct btrfs_trans_handle *trans,
1205 struct btrfs_root *root,
1206 u64 objectid, u64 dirid)
1207 {
1208 int ret;
1209 char buf[2];
1210 struct btrfs_key key;
1211
1212 buf[0] = '.';
1213 buf[1] = '.';
1214
1215 key.objectid = objectid;
1216 key.offset = 0;
1217 key.flags = 0;
1218 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
1219
1220 ret = btrfs_insert_dir_item(trans, root, buf, 1, objectid,
1221 &key, BTRFS_FT_DIR);
1222 if (ret)
1223 goto error;
1224 key.objectid = dirid;
1225 ret = btrfs_insert_dir_item(trans, root, buf, 2, objectid,
1226 &key, BTRFS_FT_DIR);
1227 if (ret)
1228 goto error;
1229 error:
1230 return ret;
1231 }
1232
1233 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1234 {
1235 struct inode *inode;
1236 struct btrfs_trans_handle *trans;
1237 struct btrfs_root *root = BTRFS_I(dir)->root;
1238 int err = 0;
1239 int drop_on_err = 0;
1240 u64 objectid;
1241
1242 mutex_lock(&root->fs_info->fs_mutex);
1243 trans = btrfs_start_transaction(root, 1);
1244 btrfs_set_trans_block_group(trans, dir);
1245 if (IS_ERR(trans)) {
1246 err = PTR_ERR(trans);
1247 goto out_unlock;
1248 }
1249
1250 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1251 if (err) {
1252 err = -ENOSPC;
1253 goto out_unlock;
1254 }
1255
1256 inode = btrfs_new_inode(trans, root, objectid,
1257 BTRFS_I(dir)->block_group, S_IFDIR | mode);
1258 if (IS_ERR(inode)) {
1259 err = PTR_ERR(inode);
1260 goto out_fail;
1261 }
1262 drop_on_err = 1;
1263 inode->i_op = &btrfs_dir_inode_operations;
1264 inode->i_fop = &btrfs_dir_file_operations;
1265 btrfs_set_trans_block_group(trans, inode);
1266
1267 err = btrfs_make_empty_dir(trans, root, inode->i_ino, dir->i_ino);
1268 if (err)
1269 goto out_fail;
1270
1271 inode->i_size = 6;
1272 err = btrfs_update_inode(trans, root, inode);
1273 if (err)
1274 goto out_fail;
1275 err = btrfs_add_link(trans, dentry, inode);
1276 if (err)
1277 goto out_fail;
1278 d_instantiate(dentry, inode);
1279 drop_on_err = 0;
1280 dir->i_sb->s_dirt = 1;
1281 btrfs_update_inode_block_group(trans, inode);
1282 btrfs_update_inode_block_group(trans, dir);
1283
1284 out_fail:
1285 btrfs_end_transaction(trans, root);
1286 out_unlock:
1287 mutex_unlock(&root->fs_info->fs_mutex);
1288 if (drop_on_err)
1289 iput(inode);
1290 btrfs_btree_balance_dirty(root);
1291 return err;
1292 }
1293
1294 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
1295 size_t page_offset, u64 start, u64 end,
1296 int create)
1297 {
1298 int ret;
1299 int err = 0;
1300 u64 blocknr;
1301 u64 extent_start = 0;
1302 u64 extent_end = 0;
1303 u64 objectid = inode->i_ino;
1304 u32 found_type;
1305 int failed_insert = 0;
1306 struct btrfs_path *path;
1307 struct btrfs_root *root = BTRFS_I(inode)->root;
1308 struct btrfs_file_extent_item *item;
1309 struct btrfs_leaf *leaf;
1310 struct btrfs_disk_key *found_key;
1311 struct extent_map *em = NULL;
1312 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1313 struct btrfs_trans_handle *trans = NULL;
1314
1315 path = btrfs_alloc_path();
1316 BUG_ON(!path);
1317 mutex_lock(&root->fs_info->fs_mutex);
1318
1319 again:
1320 em = lookup_extent_mapping(em_tree, start, end);
1321 if (em) {
1322 goto out;
1323 }
1324 if (!em) {
1325 em = alloc_extent_map(GFP_NOFS);
1326 if (!em) {
1327 err = -ENOMEM;
1328 goto out;
1329 }
1330 em->start = 0;
1331 em->end = 0;
1332 }
1333 em->bdev = inode->i_sb->s_bdev;
1334 ret = btrfs_lookup_file_extent(NULL, root, path,
1335 objectid, start, 0);
1336 if (ret < 0) {
1337 err = ret;
1338 goto out;
1339 }
1340
1341 if (ret != 0) {
1342 if (path->slots[0] == 0)
1343 goto not_found;
1344 path->slots[0]--;
1345 }
1346
1347 item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
1348 struct btrfs_file_extent_item);
1349 leaf = btrfs_buffer_leaf(path->nodes[0]);
1350 blocknr = btrfs_file_extent_disk_blocknr(item);
1351 blocknr += btrfs_file_extent_offset(item);
1352
1353 /* are we inside the extent that was found? */
1354 found_key = &leaf->items[path->slots[0]].key;
1355 found_type = btrfs_disk_key_type(found_key);
1356 if (btrfs_disk_key_objectid(found_key) != objectid ||
1357 found_type != BTRFS_EXTENT_DATA_KEY) {
1358 goto not_found;
1359 }
1360
1361 found_type = btrfs_file_extent_type(item);
1362 extent_start = btrfs_disk_key_offset(&leaf->items[path->slots[0]].key);
1363 if (found_type == BTRFS_FILE_EXTENT_REG) {
1364 extent_end = extent_start +
1365 (btrfs_file_extent_num_blocks(item) << inode->i_blkbits);
1366 err = 0;
1367 if (start < extent_start || start >= extent_end) {
1368 em->start = start;
1369 if (start < extent_start) {
1370 if (end < extent_start)
1371 goto not_found;
1372 em->end = extent_end - 1;
1373 } else {
1374 em->end = end;
1375 }
1376 goto not_found_em;
1377 }
1378 if (btrfs_file_extent_disk_blocknr(item) == 0) {
1379 em->start = extent_start;
1380 em->end = extent_end - 1;
1381 em->block_start = 0;
1382 em->block_end = 0;
1383 goto insert;
1384 }
1385 em->block_start = blocknr << inode->i_blkbits;
1386 em->block_end = em->block_start +
1387 (btrfs_file_extent_num_blocks(item) <<
1388 inode->i_blkbits) - 1;
1389 em->start = extent_start;
1390 em->end = extent_end - 1;
1391 goto insert;
1392 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
1393 char *ptr;
1394 char *map;
1395 u32 size;
1396
1397 size = btrfs_file_extent_inline_len(leaf->items +
1398 path->slots[0]);
1399 extent_end = extent_start + size;
1400 if (start < extent_start || start >= extent_end) {
1401 em->start = start;
1402 if (start < extent_start) {
1403 if (end < extent_start)
1404 goto not_found;
1405 em->end = extent_end - 1;
1406 } else {
1407 em->end = end;
1408 }
1409 goto not_found_em;
1410 }
1411 em->block_start = EXTENT_MAP_INLINE;
1412 em->block_end = EXTENT_MAP_INLINE;
1413 em->start = extent_start;
1414 em->end = extent_end - 1;
1415 if (!page) {
1416 goto insert;
1417 }
1418 ptr = btrfs_file_extent_inline_start(item);
1419 map = kmap(page);
1420 memcpy(map + page_offset, ptr, size);
1421 flush_dcache_page(result->b_page);
1422 kunmap(page);
1423 set_extent_uptodate(em_tree, extent_start,
1424 extent_end, GFP_NOFS);
1425 goto insert;
1426 } else {
1427 printk("unkknown found_type %d\n", found_type);
1428 WARN_ON(1);
1429 }
1430 not_found:
1431 em->start = start;
1432 em->end = end;
1433 not_found_em:
1434 em->block_start = 0;
1435 em->block_end = 0;
1436 insert:
1437 btrfs_release_path(root, path);
1438 if (em->start > start || em->end < start) {
1439 printk("bad extent! em: [%Lu %Lu] passed [%Lu %Lu]\n", em->start, em->end, start, end);
1440 err = -EIO;
1441 goto out;
1442 }
1443 ret = add_extent_mapping(em_tree, em);
1444 if (ret == -EEXIST) {
1445 free_extent_map(em);
1446 failed_insert++;
1447 if (failed_insert > 5) {
1448 printk("failing to insert %Lu %Lu\n", start, end);
1449 err = -EIO;
1450 goto out;
1451 }
1452 em = NULL;
1453 goto again;
1454 }
1455 err = 0;
1456 out:
1457 btrfs_free_path(path);
1458 if (trans) {
1459 ret = btrfs_end_transaction(trans, root);
1460 if (!err)
1461 err = ret;
1462 }
1463 mutex_unlock(&root->fs_info->fs_mutex);
1464 if (err) {
1465 free_extent_map(em);
1466 WARN_ON(1);
1467 return ERR_PTR(err);
1468 }
1469 return em;
1470 }
1471
1472
1473 /*
1474 * FIBMAP and others want to pass in a fake buffer head. They need to
1475 * use BTRFS_GET_BLOCK_NO_DIRECT to make sure we don't try to memcpy
1476 * any packed file data into the fake bh
1477 */
1478 #define BTRFS_GET_BLOCK_NO_CREATE 0
1479 #define BTRFS_GET_BLOCK_CREATE 1
1480 #define BTRFS_GET_BLOCK_NO_DIRECT 2
1481
1482 /*
1483 * FIXME create==1 doe not work.
1484 */
1485 static int btrfs_get_block_lock(struct inode *inode, sector_t iblock,
1486 struct buffer_head *result, int create)
1487 {
1488 int ret;
1489 int err = 0;
1490 u64 blocknr;
1491 u64 extent_start = 0;
1492 u64 extent_end = 0;
1493 u64 objectid = inode->i_ino;
1494 u32 found_type;
1495 u64 alloc_hint = 0;
1496 struct btrfs_path *path;
1497 struct btrfs_root *root = BTRFS_I(inode)->root;
1498 struct btrfs_file_extent_item *item;
1499 struct btrfs_leaf *leaf;
1500 struct btrfs_disk_key *found_key;
1501 struct btrfs_trans_handle *trans = NULL;
1502
1503 path = btrfs_alloc_path();
1504 BUG_ON(!path);
1505 if (create & BTRFS_GET_BLOCK_CREATE) {
1506 /*
1507 * danger!, this only works if the page is properly up
1508 * to date somehow
1509 */
1510 trans = btrfs_start_transaction(root, 1);
1511 if (!trans) {
1512 err = -ENOMEM;
1513 goto out;
1514 }
1515 ret = btrfs_drop_extents(trans, root, inode,
1516 iblock << inode->i_blkbits,
1517 (iblock + 1) << inode->i_blkbits,
1518 &alloc_hint);
1519 BUG_ON(ret);
1520 }
1521
1522 ret = btrfs_lookup_file_extent(NULL, root, path,
1523 objectid,
1524 iblock << inode->i_blkbits, 0);
1525 if (ret < 0) {
1526 err = ret;
1527 goto out;
1528 }
1529
1530 if (ret != 0) {
1531 if (path->slots[0] == 0) {
1532 btrfs_release_path(root, path);
1533 goto not_found;
1534 }
1535 path->slots[0]--;
1536 }
1537
1538 item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
1539 struct btrfs_file_extent_item);
1540 leaf = btrfs_buffer_leaf(path->nodes[0]);
1541 blocknr = btrfs_file_extent_disk_blocknr(item);
1542 blocknr += btrfs_file_extent_offset(item);
1543
1544 /* are we inside the extent that was found? */
1545 found_key = &leaf->items[path->slots[0]].key;
1546 found_type = btrfs_disk_key_type(found_key);
1547 if (btrfs_disk_key_objectid(found_key) != objectid ||
1548 found_type != BTRFS_EXTENT_DATA_KEY) {
1549 extent_end = 0;
1550 extent_start = 0;
1551 goto not_found;
1552 }
1553 found_type = btrfs_file_extent_type(item);
1554 extent_start = btrfs_disk_key_offset(&leaf->items[path->slots[0]].key);
1555 if (found_type == BTRFS_FILE_EXTENT_REG) {
1556 extent_start = extent_start >> inode->i_blkbits;
1557 extent_end = extent_start + btrfs_file_extent_num_blocks(item);
1558 err = 0;
1559 if (btrfs_file_extent_disk_blocknr(item) == 0)
1560 goto out;
1561 if (iblock >= extent_start && iblock < extent_end) {
1562 btrfs_map_bh_to_logical(root, result, blocknr +
1563 iblock - extent_start);
1564 goto out;
1565 }
1566 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
1567 char *ptr;
1568 char *map;
1569 u32 size;
1570
1571 if (create & BTRFS_GET_BLOCK_NO_DIRECT) {
1572 err = -EINVAL;
1573 goto out;
1574 }
1575 size = btrfs_file_extent_inline_len(leaf->items +
1576 path->slots[0]);
1577 extent_end = (extent_start + size) >> inode->i_blkbits;
1578 extent_start >>= inode->i_blkbits;
1579 if (iblock < extent_start || iblock > extent_end) {
1580 goto not_found;
1581 }
1582 ptr = btrfs_file_extent_inline_start(item);
1583 map = kmap(result->b_page);
1584 memcpy(map, ptr, size);
1585 memset(map + size, 0, PAGE_CACHE_SIZE - size);
1586 flush_dcache_page(result->b_page);
1587 kunmap(result->b_page);
1588 set_buffer_uptodate(result);
1589 SetPageChecked(result->b_page);
1590 btrfs_map_bh_to_logical(root, result, 0);
1591 }
1592 not_found:
1593 if (create & BTRFS_GET_BLOCK_CREATE) {
1594 struct btrfs_key ins;
1595 ret = btrfs_alloc_extent(trans, root, inode->i_ino,
1596 1, 0, alloc_hint, (u64)-1,
1597 &ins, 1);
1598 if (ret) {
1599 err = ret;
1600 goto out;
1601 }
1602 ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
1603 iblock << inode->i_blkbits,
1604 ins.objectid, ins.offset,
1605 ins.offset);
1606 if (ret) {
1607 err = ret;
1608 goto out;
1609 }
1610 btrfs_map_bh_to_logical(root, result, ins.objectid);
1611 }
1612 out:
1613 if (trans) {
1614 ret = btrfs_end_transaction(trans, root);
1615 if (!err)
1616 err = ret;
1617 }
1618 btrfs_free_path(path);
1619 return err;
1620 }
1621
1622 int btrfs_get_block(struct inode *inode, sector_t iblock,
1623 struct buffer_head *result, int create)
1624 {
1625 int err;
1626 struct btrfs_root *root = BTRFS_I(inode)->root;
1627 mutex_lock(&root->fs_info->fs_mutex);
1628 err = btrfs_get_block_lock(inode, iblock, result, create);
1629 mutex_unlock(&root->fs_info->fs_mutex);
1630 return err;
1631 }
1632
1633 static int btrfs_get_block_bmap(struct inode *inode, sector_t iblock,
1634 struct buffer_head *result, int create)
1635 {
1636 struct btrfs_root *root = BTRFS_I(inode)->root;
1637 u64 start = iblock << inode->i_blkbits;
1638 u64 end = start + root->blocksize -1;
1639 struct extent_map *em;
1640
1641 em = btrfs_get_extent(inode, NULL, 0, start, end, 0);
1642 if (em && !IS_ERR(em) && em->block_start != EXTENT_MAP_INLINE &&
1643 em->block_start != 0) {
1644 u64 offset;
1645 offset = start - em->start;
1646 start = (em->block_start + offset) >> inode->i_blkbits;
1647 btrfs_map_bh_to_logical(root, result, start);
1648 }
1649 return 0;
1650 }
1651
1652 static sector_t btrfs_bmap(struct address_space *as, sector_t block)
1653 {
1654 return generic_block_bmap(as, block, btrfs_get_block_bmap);
1655 }
1656
1657 static int btrfs_prepare_write(struct file *file, struct page *page,
1658 unsigned from, unsigned to)
1659 {
1660 return extent_prepare_write(&BTRFS_I(page->mapping->host)->extent_tree,
1661 page->mapping->host, page, from, to,
1662 btrfs_get_extent);
1663 }
1664
1665 int btrfs_readpage(struct file *file, struct page *page)
1666 {
1667 struct extent_map_tree *tree;
1668 tree = &BTRFS_I(page->mapping->host)->extent_tree;
1669 return extent_read_full_page(tree, page, btrfs_get_extent);
1670 }
1671 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
1672 {
1673 struct extent_map_tree *tree;
1674
1675
1676 if (current->flags & PF_MEMALLOC) {
1677 redirty_page_for_writepage(wbc, page);
1678 unlock_page(page);
1679 return 0;
1680 }
1681 tree = &BTRFS_I(page->mapping->host)->extent_tree;
1682 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
1683 }
1684
1685 static int btrfs_releasepage(struct page *page, gfp_t unused_gfp_flags)
1686 {
1687 struct extent_map_tree *tree;
1688 int ret;
1689
1690 if (page->private != 1) {
1691 WARN_ON(1);
1692 return try_to_free_buffers(page);
1693 }
1694 tree = &BTRFS_I(page->mapping->host)->extent_tree;
1695 ret = try_release_extent_mapping(tree, page);
1696 if (ret == 1) {
1697 ClearPagePrivate(page);
1698 set_page_private(page, 0);
1699 page_cache_release(page);
1700 }
1701 return ret;
1702 }
1703
1704 static void btrfs_invalidatepage(struct page *page, unsigned long offset)
1705 {
1706 struct extent_map_tree *tree;
1707
1708 tree = &BTRFS_I(page->mapping->host)->extent_tree;
1709 extent_invalidatepage(tree, page, offset);
1710 btrfs_releasepage(page, GFP_NOFS);
1711 }
1712
1713 /*
1714 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
1715 * called from a page fault handler when a page is first dirtied. Hence we must
1716 * be careful to check for EOF conditions here. We set the page up correctly
1717 * for a written page which means we get ENOSPC checking when writing into
1718 * holes and correct delalloc and unwritten extent mapping on filesystems that
1719 * support these features.
1720 *
1721 * We are not allowed to take the i_mutex here so we have to play games to
1722 * protect against truncate races as the page could now be beyond EOF. Because
1723 * vmtruncate() writes the inode size before removing pages, once we have the
1724 * page lock we can determine safely if the page is beyond EOF. If it is not
1725 * beyond EOF, then the page is guaranteed safe against truncation until we
1726 * unlock the page.
1727 */
1728 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
1729 {
1730 struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
1731 unsigned long end;
1732 loff_t size;
1733 int ret = -EINVAL;
1734 u64 page_start;
1735
1736 lock_page(page);
1737 wait_on_page_writeback(page);
1738 size = i_size_read(inode);
1739 page_start = page->index << PAGE_CACHE_SHIFT;
1740
1741 if ((page->mapping != inode->i_mapping) ||
1742 (page_start > size)) {
1743 /* page got truncated out from underneath us */
1744 goto out_unlock;
1745 }
1746
1747 /* page is wholly or partially inside EOF */
1748 if (page_start + PAGE_CACHE_SIZE > size)
1749 end = size & ~PAGE_CACHE_MASK;
1750 else
1751 end = PAGE_CACHE_SIZE;
1752
1753 ret = btrfs_cow_one_page(inode, page, end);
1754
1755 out_unlock:
1756 unlock_page(page);
1757 return ret;
1758 }
1759
1760 static void btrfs_truncate(struct inode *inode)
1761 {
1762 struct btrfs_root *root = BTRFS_I(inode)->root;
1763 int ret;
1764 struct btrfs_trans_handle *trans;
1765
1766 if (!S_ISREG(inode->i_mode))
1767 return;
1768 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
1769 return;
1770
1771 btrfs_truncate_page(inode->i_mapping, inode->i_size);
1772
1773 mutex_lock(&root->fs_info->fs_mutex);
1774 trans = btrfs_start_transaction(root, 1);
1775 btrfs_set_trans_block_group(trans, inode);
1776
1777 /* FIXME, add redo link to tree so we don't leak on crash */
1778 ret = btrfs_truncate_in_trans(trans, root, inode);
1779 btrfs_update_inode(trans, root, inode);
1780 ret = btrfs_end_transaction(trans, root);
1781 BUG_ON(ret);
1782 mutex_unlock(&root->fs_info->fs_mutex);
1783 btrfs_btree_balance_dirty(root);
1784 }
1785
1786 int btrfs_commit_write(struct file *file, struct page *page,
1787 unsigned from, unsigned to)
1788 {
1789 return extent_commit_write(&BTRFS_I(page->mapping->host)->extent_tree,
1790 page->mapping->host, page, from, to);
1791 }
1792
1793 static int create_subvol(struct btrfs_root *root, char *name, int namelen)
1794 {
1795 struct btrfs_trans_handle *trans;
1796 struct btrfs_key key;
1797 struct btrfs_root_item root_item;
1798 struct btrfs_inode_item *inode_item;
1799 struct buffer_head *subvol;
1800 struct btrfs_leaf *leaf;
1801 struct btrfs_root *new_root;
1802 struct inode *inode;
1803 struct inode *dir;
1804 int ret;
1805 int err;
1806 u64 objectid;
1807 u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
1808
1809 mutex_lock(&root->fs_info->fs_mutex);
1810 trans = btrfs_start_transaction(root, 1);
1811 BUG_ON(!trans);
1812
1813 subvol = btrfs_alloc_free_block(trans, root, 0, 0);
1814 if (IS_ERR(subvol))
1815 return PTR_ERR(subvol);
1816 leaf = btrfs_buffer_leaf(subvol);
1817 btrfs_set_header_nritems(&leaf->header, 0);
1818 btrfs_set_header_level(&leaf->header, 0);
1819 btrfs_set_header_blocknr(&leaf->header, bh_blocknr(subvol));
1820 btrfs_set_header_generation(&leaf->header, trans->transid);
1821 btrfs_set_header_owner(&leaf->header, root->root_key.objectid);
1822 memcpy(leaf->header.fsid, root->fs_info->disk_super->fsid,
1823 sizeof(leaf->header.fsid));
1824 btrfs_mark_buffer_dirty(subvol);
1825
1826 inode_item = &root_item.inode;
1827 memset(inode_item, 0, sizeof(*inode_item));
1828 btrfs_set_inode_generation(inode_item, 1);
1829 btrfs_set_inode_size(inode_item, 3);
1830 btrfs_set_inode_nlink(inode_item, 1);
1831 btrfs_set_inode_nblocks(inode_item, 1);
1832 btrfs_set_inode_mode(inode_item, S_IFDIR | 0755);
1833
1834 btrfs_set_root_blocknr(&root_item, bh_blocknr(subvol));
1835 btrfs_set_root_refs(&root_item, 1);
1836 btrfs_set_root_blocks_used(&root_item, 0);
1837 memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
1838 root_item.drop_level = 0;
1839 brelse(subvol);
1840 subvol = NULL;
1841
1842 ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
1843 0, &objectid);
1844 if (ret)
1845 goto fail;
1846
1847 btrfs_set_root_dirid(&root_item, new_dirid);
1848
1849 key.objectid = objectid;
1850 key.offset = 1;
1851 key.flags = 0;
1852 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
1853 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
1854 &root_item);
1855 if (ret)
1856 goto fail;
1857
1858 /*
1859 * insert the directory item
1860 */
1861 key.offset = (u64)-1;
1862 dir = root->fs_info->sb->s_root->d_inode;
1863 ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
1864 name, namelen, dir->i_ino, &key,
1865 BTRFS_FT_DIR);
1866 if (ret)
1867 goto fail;
1868
1869 ret = btrfs_commit_transaction(trans, root);
1870 if (ret)
1871 goto fail_commit;
1872
1873 new_root = btrfs_read_fs_root(root->fs_info, &key, name, namelen);
1874 BUG_ON(!new_root);
1875
1876 trans = btrfs_start_transaction(new_root, 1);
1877 BUG_ON(!trans);
1878
1879 inode = btrfs_new_inode(trans, new_root, new_dirid,
1880 BTRFS_I(dir)->block_group, S_IFDIR | 0700);
1881 if (IS_ERR(inode))
1882 goto fail;
1883 inode->i_op = &btrfs_dir_inode_operations;
1884 inode->i_fop = &btrfs_dir_file_operations;
1885 new_root->inode = inode;
1886
1887 ret = btrfs_make_empty_dir(trans, new_root, new_dirid, new_dirid);
1888 if (ret)
1889 goto fail;
1890
1891 inode->i_nlink = 1;
1892 inode->i_size = 6;
1893 ret = btrfs_update_inode(trans, new_root, inode);
1894 if (ret)
1895 goto fail;
1896 fail:
1897 err = btrfs_commit_transaction(trans, root);
1898 if (err && !ret)
1899 ret = err;
1900 fail_commit:
1901 mutex_unlock(&root->fs_info->fs_mutex);
1902 btrfs_btree_balance_dirty(root);
1903 return ret;
1904 }
1905
1906 static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
1907 {
1908 struct btrfs_trans_handle *trans;
1909 struct btrfs_key key;
1910 struct btrfs_root_item new_root_item;
1911 struct buffer_head *tmp;
1912 int ret;
1913 int err;
1914 u64 objectid;
1915
1916 if (!root->ref_cows)
1917 return -EINVAL;
1918
1919 mutex_lock(&root->fs_info->fs_mutex);
1920 trans = btrfs_start_transaction(root, 1);
1921 BUG_ON(!trans);
1922
1923 ret = btrfs_update_inode(trans, root, root->inode);
1924 if (ret)
1925 goto fail;
1926
1927 ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
1928 0, &objectid);
1929 if (ret)
1930 goto fail;
1931
1932 memcpy(&new_root_item, &root->root_item,
1933 sizeof(new_root_item));
1934
1935 key.objectid = objectid;
1936 key.offset = 1;
1937 key.flags = 0;
1938 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
1939 btrfs_cow_block(trans, root, root->node, NULL, 0, &tmp);
1940 btrfs_set_root_blocknr(&new_root_item, bh_blocknr(root->node));
1941
1942 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
1943 &new_root_item);
1944 if (ret)
1945 goto fail;
1946
1947 /*
1948 * insert the directory item
1949 */
1950 key.offset = (u64)-1;
1951 ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
1952 name, namelen,
1953 root->fs_info->sb->s_root->d_inode->i_ino,
1954 &key, BTRFS_FT_DIR);
1955
1956 if (ret)
1957 goto fail;
1958
1959 ret = btrfs_inc_root_ref(trans, root);
1960 if (ret)
1961 goto fail;
1962
1963 fail:
1964 err = btrfs_commit_transaction(trans, root);
1965 if (err && !ret)
1966 ret = err;
1967 mutex_unlock(&root->fs_info->fs_mutex);
1968 btrfs_btree_balance_dirty(root);
1969 return ret;
1970 }
1971
1972 int btrfs_ioctl(struct inode *inode, struct file *filp, unsigned int
1973 cmd, unsigned long arg)
1974 {
1975 struct btrfs_root *root = BTRFS_I(inode)->root;
1976 struct btrfs_ioctl_vol_args vol_args;
1977 int ret = 0;
1978 struct btrfs_dir_item *di;
1979 int namelen;
1980 struct btrfs_path *path;
1981 u64 root_dirid;
1982
1983 switch (cmd) {
1984 case BTRFS_IOC_SNAP_CREATE:
1985 if (copy_from_user(&vol_args,
1986 (struct btrfs_ioctl_vol_args __user *)arg,
1987 sizeof(vol_args)))
1988 return -EFAULT;
1989 namelen = strlen(vol_args.name);
1990 if (namelen > BTRFS_VOL_NAME_MAX)
1991 return -EINVAL;
1992 if (strchr(vol_args.name, '/'))
1993 return -EINVAL;
1994 path = btrfs_alloc_path();
1995 if (!path)
1996 return -ENOMEM;
1997 root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
1998 mutex_lock(&root->fs_info->fs_mutex);
1999 di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
2000 path, root_dirid,
2001 vol_args.name, namelen, 0);
2002 mutex_unlock(&root->fs_info->fs_mutex);
2003 btrfs_free_path(path);
2004 if (di && !IS_ERR(di))
2005 return -EEXIST;
2006 if (IS_ERR(di))
2007 return PTR_ERR(di);
2008
2009 if (root == root->fs_info->tree_root)
2010 ret = create_subvol(root, vol_args.name, namelen);
2011 else
2012 ret = create_snapshot(root, vol_args.name, namelen);
2013 break;
2014
2015 case BTRFS_IOC_DEFRAG:
2016 mutex_lock(&root->fs_info->fs_mutex);
2017 btrfs_defrag_root(root, 0);
2018 btrfs_defrag_root(root->fs_info->extent_root, 0);
2019 mutex_unlock(&root->fs_info->fs_mutex);
2020 ret = 0;
2021 break;
2022 default:
2023 return -ENOTTY;
2024 }
2025 return ret;
2026 }
2027
2028 #ifdef CONFIG_COMPAT
2029 long btrfs_compat_ioctl(struct file *file, unsigned int cmd,
2030 unsigned long arg)
2031 {
2032 struct inode *inode = file->f_path.dentry->d_inode;
2033 int ret;
2034 lock_kernel();
2035 ret = btrfs_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
2036 unlock_kernel();
2037 return ret;
2038
2039 }
2040 #endif
2041
2042 /*
2043 * Called inside transaction, so use GFP_NOFS
2044 */
2045 struct inode *btrfs_alloc_inode(struct super_block *sb)
2046 {
2047 struct btrfs_inode *ei;
2048
2049 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
2050 if (!ei)
2051 return NULL;
2052 ei->last_trans = 0;
2053 return &ei->vfs_inode;
2054 }
2055
2056 void btrfs_destroy_inode(struct inode *inode)
2057 {
2058 WARN_ON(!list_empty(&inode->i_dentry));
2059 WARN_ON(inode->i_data.nrpages);
2060
2061 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
2062 }
2063
2064 static void init_once(void * foo, struct kmem_cache * cachep,
2065 unsigned long flags)
2066 {
2067 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
2068
2069 inode_init_once(&ei->vfs_inode);
2070 }
2071
2072 void btrfs_destroy_cachep(void)
2073 {
2074 if (btrfs_inode_cachep)
2075 kmem_cache_destroy(btrfs_inode_cachep);
2076 if (btrfs_trans_handle_cachep)
2077 kmem_cache_destroy(btrfs_trans_handle_cachep);
2078 if (btrfs_transaction_cachep)
2079 kmem_cache_destroy(btrfs_transaction_cachep);
2080 if (btrfs_bit_radix_cachep)
2081 kmem_cache_destroy(btrfs_bit_radix_cachep);
2082 if (btrfs_path_cachep)
2083 kmem_cache_destroy(btrfs_path_cachep);
2084 }
2085
2086 static struct kmem_cache *cache_create(const char *name, size_t size,
2087 unsigned long extra_flags,
2088 void (*ctor)(void *, struct kmem_cache *,
2089 unsigned long))
2090 {
2091 return kmem_cache_create(name, size, 0, (SLAB_RECLAIM_ACCOUNT |
2092 SLAB_MEM_SPREAD | extra_flags), ctor
2093 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
2094 ,NULL
2095 #endif
2096 );
2097 }
2098
2099 int btrfs_init_cachep(void)
2100 {
2101 btrfs_inode_cachep = cache_create("btrfs_inode_cache",
2102 sizeof(struct btrfs_inode),
2103 0, init_once);
2104 if (!btrfs_inode_cachep)
2105 goto fail;
2106 btrfs_trans_handle_cachep = cache_create("btrfs_trans_handle_cache",
2107 sizeof(struct btrfs_trans_handle),
2108 0, NULL);
2109 if (!btrfs_trans_handle_cachep)
2110 goto fail;
2111 btrfs_transaction_cachep = cache_create("btrfs_transaction_cache",
2112 sizeof(struct btrfs_transaction),
2113 0, NULL);
2114 if (!btrfs_transaction_cachep)
2115 goto fail;
2116 btrfs_path_cachep = cache_create("btrfs_path_cache",
2117 sizeof(struct btrfs_transaction),
2118 0, NULL);
2119 if (!btrfs_path_cachep)
2120 goto fail;
2121 btrfs_bit_radix_cachep = cache_create("btrfs_radix", 256,
2122 SLAB_DESTROY_BY_RCU, NULL);
2123 if (!btrfs_bit_radix_cachep)
2124 goto fail;
2125 return 0;
2126 fail:
2127 btrfs_destroy_cachep();
2128 return -ENOMEM;
2129 }
2130
2131 static int btrfs_getattr(struct vfsmount *mnt,
2132 struct dentry *dentry, struct kstat *stat)
2133 {
2134 struct inode *inode = dentry->d_inode;
2135 generic_fillattr(inode, stat);
2136 stat->blksize = 256 * 1024;
2137 return 0;
2138 }
2139
2140 static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
2141 struct inode * new_dir,struct dentry *new_dentry)
2142 {
2143 struct btrfs_trans_handle *trans;
2144 struct btrfs_root *root = BTRFS_I(old_dir)->root;
2145 struct inode *new_inode = new_dentry->d_inode;
2146 struct inode *old_inode = old_dentry->d_inode;
2147 struct timespec ctime = CURRENT_TIME;
2148 struct btrfs_path *path;
2149 struct btrfs_dir_item *di;
2150 int ret;
2151
2152 if (S_ISDIR(old_inode->i_mode) && new_inode &&
2153 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
2154 return -ENOTEMPTY;
2155 }
2156 mutex_lock(&root->fs_info->fs_mutex);
2157 trans = btrfs_start_transaction(root, 1);
2158 btrfs_set_trans_block_group(trans, new_dir);
2159 path = btrfs_alloc_path();
2160 if (!path) {
2161 ret = -ENOMEM;
2162 goto out_fail;
2163 }
2164
2165 old_dentry->d_inode->i_nlink++;
2166 old_dir->i_ctime = old_dir->i_mtime = ctime;
2167 new_dir->i_ctime = new_dir->i_mtime = ctime;
2168 old_inode->i_ctime = ctime;
2169 if (S_ISDIR(old_inode->i_mode) && old_dir != new_dir) {
2170 struct btrfs_key *location = &BTRFS_I(new_dir)->location;
2171 u64 old_parent_oid;
2172 di = btrfs_lookup_dir_item(trans, root, path, old_inode->i_ino,
2173 "..", 2, -1);
2174 if (IS_ERR(di)) {
2175 ret = PTR_ERR(di);
2176 goto out_fail;
2177 }
2178 if (!di) {
2179 ret = -ENOENT;
2180 goto out_fail;
2181 }
2182 old_parent_oid = btrfs_disk_key_objectid(&di->location);
2183 ret = btrfs_del_item(trans, root, path);
2184 if (ret) {
2185 goto out_fail;
2186 }
2187 btrfs_release_path(root, path);
2188
2189 di = btrfs_lookup_dir_index_item(trans, root, path,
2190 old_inode->i_ino,
2191 old_parent_oid,
2192 "..", 2, -1);
2193 if (IS_ERR(di)) {
2194 ret = PTR_ERR(di);
2195 goto out_fail;
2196 }
2197 if (!di) {
2198 ret = -ENOENT;
2199 goto out_fail;
2200 }
2201 ret = btrfs_del_item(trans, root, path);
2202 if (ret) {
2203 goto out_fail;
2204 }
2205 btrfs_release_path(root, path);
2206
2207 ret = btrfs_insert_dir_item(trans, root, "..", 2,
2208 old_inode->i_ino, location,
2209 BTRFS_FT_DIR);
2210 if (ret)
2211 goto out_fail;
2212 }
2213
2214
2215 ret = btrfs_unlink_trans(trans, root, old_dir, old_dentry);
2216 if (ret)
2217 goto out_fail;
2218
2219 if (new_inode) {
2220 new_inode->i_ctime = CURRENT_TIME;
2221 ret = btrfs_unlink_trans(trans, root, new_dir, new_dentry);
2222 if (ret)
2223 goto out_fail;
2224 if (S_ISDIR(new_inode->i_mode))
2225 clear_nlink(new_inode);
2226 else
2227 drop_nlink(new_inode);
2228 ret = btrfs_update_inode(trans, root, new_inode);
2229 if (ret)
2230 goto out_fail;
2231 }
2232 ret = btrfs_add_link(trans, new_dentry, old_inode);
2233 if (ret)
2234 goto out_fail;
2235
2236 out_fail:
2237 btrfs_free_path(path);
2238 btrfs_end_transaction(trans, root);
2239 mutex_unlock(&root->fs_info->fs_mutex);
2240 return ret;
2241 }
2242
2243 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
2244 const char *symname)
2245 {
2246 struct btrfs_trans_handle *trans;
2247 struct btrfs_root *root = BTRFS_I(dir)->root;
2248 struct btrfs_path *path;
2249 struct btrfs_key key;
2250 struct inode *inode;
2251 int err;
2252 int drop_inode = 0;
2253 u64 objectid;
2254 int name_len;
2255 int datasize;
2256 char *ptr;
2257 struct btrfs_file_extent_item *ei;
2258
2259 name_len = strlen(symname) + 1;
2260 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
2261 return -ENAMETOOLONG;
2262 mutex_lock(&root->fs_info->fs_mutex);
2263 trans = btrfs_start_transaction(root, 1);
2264 btrfs_set_trans_block_group(trans, dir);
2265
2266 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
2267 if (err) {
2268 err = -ENOSPC;
2269 goto out_unlock;
2270 }
2271
2272 inode = btrfs_new_inode(trans, root, objectid,
2273 BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO);
2274 err = PTR_ERR(inode);
2275 if (IS_ERR(inode))
2276 goto out_unlock;
2277
2278 btrfs_set_trans_block_group(trans, inode);
2279 err = btrfs_add_nondir(trans, dentry, inode);
2280 if (err)
2281 drop_inode = 1;
2282 else {
2283 inode->i_mapping->a_ops = &btrfs_aops;
2284 inode->i_fop = &btrfs_file_operations;
2285 inode->i_op = &btrfs_file_inode_operations;
2286 extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
2287 inode->i_mapping, GFP_NOFS);
2288 BTRFS_I(inode)->extent_tree.fill_delalloc = run_delalloc_range;
2289 }
2290 dir->i_sb->s_dirt = 1;
2291 btrfs_update_inode_block_group(trans, inode);
2292 btrfs_update_inode_block_group(trans, dir);
2293 if (drop_inode)
2294 goto out_unlock;
2295
2296 path = btrfs_alloc_path();
2297 BUG_ON(!path);
2298 key.objectid = inode->i_ino;
2299 key.offset = 0;
2300 key.flags = 0;
2301 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
2302 datasize = btrfs_file_extent_calc_inline_size(name_len);
2303 err = btrfs_insert_empty_item(trans, root, path, &key,
2304 datasize);
2305 if (err) {
2306 drop_inode = 1;
2307 goto out_unlock;
2308 }
2309 ei = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
2310 path->slots[0], struct btrfs_file_extent_item);
2311 btrfs_set_file_extent_generation(ei, trans->transid);
2312 btrfs_set_file_extent_type(ei,
2313 BTRFS_FILE_EXTENT_INLINE);
2314 ptr = btrfs_file_extent_inline_start(ei);
2315 btrfs_memcpy(root, path->nodes[0]->b_data,
2316 ptr, symname, name_len);
2317 btrfs_mark_buffer_dirty(path->nodes[0]);
2318 btrfs_free_path(path);
2319 inode->i_op = &btrfs_symlink_inode_operations;
2320 inode->i_mapping->a_ops = &btrfs_symlink_aops;
2321 inode->i_size = name_len - 1;
2322 err = btrfs_update_inode(trans, root, inode);
2323 if (err)
2324 drop_inode = 1;
2325
2326 out_unlock:
2327 btrfs_end_transaction(trans, root);
2328 mutex_unlock(&root->fs_info->fs_mutex);
2329 if (drop_inode) {
2330 inode_dec_link_count(inode);
2331 iput(inode);
2332 }
2333 btrfs_btree_balance_dirty(root);
2334 return err;
2335 }
2336
2337 static struct inode_operations btrfs_dir_inode_operations = {
2338 .lookup = btrfs_lookup,
2339 .create = btrfs_create,
2340 .unlink = btrfs_unlink,
2341 .link = btrfs_link,
2342 .mkdir = btrfs_mkdir,
2343 .rmdir = btrfs_rmdir,
2344 .rename = btrfs_rename,
2345 .symlink = btrfs_symlink,
2346 .setattr = btrfs_setattr,
2347 .mknod = btrfs_mknod,
2348 };
2349
2350 static struct inode_operations btrfs_dir_ro_inode_operations = {
2351 .lookup = btrfs_lookup,
2352 };
2353
2354 static struct file_operations btrfs_dir_file_operations = {
2355 .llseek = generic_file_llseek,
2356 .read = generic_read_dir,
2357 .readdir = btrfs_readdir,
2358 .ioctl = btrfs_ioctl,
2359 #ifdef CONFIG_COMPAT
2360 .compat_ioctl = btrfs_compat_ioctl,
2361 #endif
2362 };
2363
2364 static struct address_space_operations btrfs_aops = {
2365 .readpage = btrfs_readpage,
2366 .writepage = btrfs_writepage,
2367 .sync_page = block_sync_page,
2368 .prepare_write = btrfs_prepare_write,
2369 .commit_write = btrfs_commit_write,
2370 .bmap = btrfs_bmap,
2371 .invalidatepage = btrfs_invalidatepage,
2372 .releasepage = btrfs_releasepage,
2373 .set_page_dirty = __set_page_dirty_nobuffers,
2374 };
2375
2376 static struct address_space_operations btrfs_symlink_aops = {
2377 .readpage = btrfs_readpage,
2378 .writepage = btrfs_writepage,
2379 };
2380
2381 static struct inode_operations btrfs_file_inode_operations = {
2382 .truncate = btrfs_truncate,
2383 .getattr = btrfs_getattr,
2384 .setattr = btrfs_setattr,
2385 };
2386
2387 static struct inode_operations btrfs_special_inode_operations = {
2388 .getattr = btrfs_getattr,
2389 .setattr = btrfs_setattr,
2390 };
2391
2392 static struct inode_operations btrfs_symlink_inode_operations = {
2393 .readlink = generic_readlink,
2394 .follow_link = page_follow_link_light,
2395 .put_link = page_put_link,
2396 };
Linux kernel - Deliverables
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