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Btrfs: Switch to libcrc32c to avoid problems with cryptomgr on highmem machines
[net-next-2.6.git] / fs / btrfs / inode.c
CommitLineData
6cbd5570
CM		 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
39279cc3
CM		 19#include <linux/module.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>
9ebefb18 34#include <linux/bit_spinlock.h>
39279cc3
CM		 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
42struct btrfs_iget_args {
43 u64 ino;
44 struct btrfs_root *root;
45};
46
47static struct inode_operations btrfs_dir_inode_operations;
48static struct inode_operations btrfs_symlink_inode_operations;
49static struct inode_operations btrfs_dir_ro_inode_operations;
50static struct inode_operations btrfs_file_inode_operations;
51static struct address_space_operations btrfs_aops;
52static struct address_space_operations btrfs_symlink_aops;
53static struct file_operations btrfs_dir_file_operations;
54
55static struct kmem_cache *btrfs_inode_cachep;
56struct kmem_cache *btrfs_trans_handle_cachep;
57struct kmem_cache *btrfs_transaction_cachep;
58struct kmem_cache *btrfs_bit_radix_cachep;
59struct kmem_cache *btrfs_path_cachep;
60
61#define S_SHIFT 12
62static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
63 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
64 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
65 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
66 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
67 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
68 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
69 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
70};
71
72void btrfs_read_locked_inode(struct inode *inode)
73{
74 struct btrfs_path *path;
75 struct btrfs_inode_item *inode_item;
76 struct btrfs_root *root = BTRFS_I(inode)->root;
77 struct btrfs_key location;
78 u64 alloc_group_block;
79 int ret;
80
81 path = btrfs_alloc_path();
82 BUG_ON(!path);
39279cc3
CM		 83 mutex_lock(&root->fs_info->fs_mutex);
84
85 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
86 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
87 if (ret) {
88 btrfs_free_path(path);
89 goto make_bad;
90 }
91 inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
92 path->slots[0],
93 struct btrfs_inode_item);
94
95 inode->i_mode = btrfs_inode_mode(inode_item);
96 inode->i_nlink = btrfs_inode_nlink(inode_item);
97 inode->i_uid = btrfs_inode_uid(inode_item);
98 inode->i_gid = btrfs_inode_gid(inode_item);
99 inode->i_size = btrfs_inode_size(inode_item);
100 inode->i_atime.tv_sec = btrfs_timespec_sec(&inode_item->atime);
101 inode->i_atime.tv_nsec = btrfs_timespec_nsec(&inode_item->atime);
102 inode->i_mtime.tv_sec = btrfs_timespec_sec(&inode_item->mtime);
103 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(&inode_item->mtime);
104 inode->i_ctime.tv_sec = btrfs_timespec_sec(&inode_item->ctime);
105 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(&inode_item->ctime);
106 inode->i_blocks = btrfs_inode_nblocks(inode_item);
107 inode->i_generation = btrfs_inode_generation(inode_item);
108 alloc_group_block = btrfs_inode_block_group(inode_item);
109 BTRFS_I(inode)->block_group = btrfs_lookup_block_group(root->fs_info,
110 alloc_group_block);
111
112 btrfs_free_path(path);
113 inode_item = NULL;
114
115 mutex_unlock(&root->fs_info->fs_mutex);
116
117 switch (inode->i_mode & S_IFMT) {
118#if 0
119 default:
120 init_special_inode(inode, inode->i_mode,
121 btrfs_inode_rdev(inode_item));
122 break;
123#endif
124 case S_IFREG:
125 inode->i_mapping->a_ops = &btrfs_aops;
126 inode->i_fop = &btrfs_file_operations;
127 inode->i_op = &btrfs_file_inode_operations;
128 break;
129 case S_IFDIR:
130 inode->i_fop = &btrfs_dir_file_operations;
131 if (root == root->fs_info->tree_root)
132 inode->i_op = &btrfs_dir_ro_inode_operations;
133 else
134 inode->i_op = &btrfs_dir_inode_operations;
135 break;
136 case S_IFLNK:
137 inode->i_op = &btrfs_symlink_inode_operations;
138 inode->i_mapping->a_ops = &btrfs_symlink_aops;
139 break;
140 }
141 return;
142
143make_bad:
144 btrfs_release_path(root, path);
145 btrfs_free_path(path);
146 mutex_unlock(&root->fs_info->fs_mutex);
147 make_bad_inode(inode);
148}
149
150static void fill_inode_item(struct btrfs_inode_item *item,
151 struct inode *inode)
152{
153 btrfs_set_inode_uid(item, inode->i_uid);
154 btrfs_set_inode_gid(item, inode->i_gid);
155 btrfs_set_inode_size(item, inode->i_size);
156 btrfs_set_inode_mode(item, inode->i_mode);
157 btrfs_set_inode_nlink(item, inode->i_nlink);
158 btrfs_set_timespec_sec(&item->atime, inode->i_atime.tv_sec);
159 btrfs_set_timespec_nsec(&item->atime, inode->i_atime.tv_nsec);
160 btrfs_set_timespec_sec(&item->mtime, inode->i_mtime.tv_sec);
161 btrfs_set_timespec_nsec(&item->mtime, inode->i_mtime.tv_nsec);
162 btrfs_set_timespec_sec(&item->ctime, inode->i_ctime.tv_sec);
163 btrfs_set_timespec_nsec(&item->ctime, inode->i_ctime.tv_nsec);
164 btrfs_set_inode_nblocks(item, inode->i_blocks);
165 btrfs_set_inode_generation(item, inode->i_generation);
166 btrfs_set_inode_block_group(item,
167 BTRFS_I(inode)->block_group->key.objectid);
168}
169
170static int btrfs_update_inode(struct btrfs_trans_handle *trans,
171 struct btrfs_root *root,
172 struct inode *inode)
173{
174 struct btrfs_inode_item *inode_item;
175 struct btrfs_path *path;
176 int ret;
177
178 path = btrfs_alloc_path();
179 BUG_ON(!path);
39279cc3
CM		 180 ret = btrfs_lookup_inode(trans, root, path,
181 &BTRFS_I(inode)->location, 1);
182 if (ret) {
183 if (ret > 0)
184 ret = -ENOENT;
185 goto failed;
186 }
187
188 inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
189 path->slots[0],
190 struct btrfs_inode_item);
191
192 fill_inode_item(inode_item, inode);
193 btrfs_mark_buffer_dirty(path->nodes[0]);
194 ret = 0;
195failed:
196 btrfs_release_path(root, path);
197 btrfs_free_path(path);
198 return ret;
199}
200
201
202static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
203 struct btrfs_root *root,
204 struct inode *dir,
205 struct dentry *dentry)
206{
207 struct btrfs_path *path;
208 const char *name = dentry->d_name.name;
209 int name_len = dentry->d_name.len;
210 int ret = 0;
211 u64 objectid;
212 struct btrfs_dir_item *di;
213
214 path = btrfs_alloc_path();
215 BUG_ON(!path);
39279cc3
CM		 216 di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
217 name, name_len, -1);
218 if (IS_ERR(di)) {
219 ret = PTR_ERR(di);
220 goto err;
221 }
222 if (!di) {
223 ret = -ENOENT;
224 goto err;
225 }
226 objectid = btrfs_disk_key_objectid(&di->location);
227 ret = btrfs_delete_one_dir_name(trans, root, path, di);
228 BUG_ON(ret);
229 btrfs_release_path(root, path);
230
231 di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
232 objectid, name, name_len, -1);
233 if (IS_ERR(di)) {
234 ret = PTR_ERR(di);
235 goto err;
236 }
237 if (!di) {
238 ret = -ENOENT;
239 goto err;
240 }
241 ret = btrfs_delete_one_dir_name(trans, root, path, di);
242 BUG_ON(ret);
243
244 dentry->d_inode->i_ctime = dir->i_ctime;
245err:
246 btrfs_free_path(path);
247 if (!ret) {
248 dir->i_size -= name_len * 2;
249 btrfs_update_inode(trans, root, dir);
250 drop_nlink(dentry->d_inode);
251 btrfs_update_inode(trans, root, dentry->d_inode);
252 dir->i_sb->s_dirt = 1;
253 }
254 return ret;
255}
256
257static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
258{
259 struct btrfs_root *root;
260 struct btrfs_trans_handle *trans;
261 int ret;
262
263 root = BTRFS_I(dir)->root;
264 mutex_lock(&root->fs_info->fs_mutex);
265 trans = btrfs_start_transaction(root, 1);
266 btrfs_set_trans_block_group(trans, dir);
267 ret = btrfs_unlink_trans(trans, root, dir, dentry);
268 btrfs_end_transaction(trans, root);
269 mutex_unlock(&root->fs_info->fs_mutex);
270 btrfs_btree_balance_dirty(root);
271 return ret;
272}
273
274static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
275{
276 struct inode *inode = dentry->d_inode;
277 int err;
278 int ret;
279 struct btrfs_root *root = BTRFS_I(dir)->root;
280 struct btrfs_path *path;
281 struct btrfs_key key;
282 struct btrfs_trans_handle *trans;
283 struct btrfs_key found_key;
284 int found_type;
285 struct btrfs_leaf *leaf;
286 char *goodnames = "..";
287
288 path = btrfs_alloc_path();
289 BUG_ON(!path);
39279cc3
CM		 290 mutex_lock(&root->fs_info->fs_mutex);
291 trans = btrfs_start_transaction(root, 1);
292 btrfs_set_trans_block_group(trans, dir);
293 key.objectid = inode->i_ino;
294 key.offset = (u64)-1;
295 key.flags = (u32)-1;
296 while(1) {
297 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
298 if (ret < 0) {
299 err = ret;
300 goto out;
301 }
302 BUG_ON(ret == 0);
303 if (path->slots[0] == 0) {
304 err = -ENOENT;
305 goto out;
306 }
307 path->slots[0]--;
308 leaf = btrfs_buffer_leaf(path->nodes[0]);
309 btrfs_disk_key_to_cpu(&found_key,
310 &leaf->items[path->slots[0]].key);
311 found_type = btrfs_key_type(&found_key);
312 if (found_key.objectid != inode->i_ino) {
313 err = -ENOENT;
314 goto out;
315 }
316 if ((found_type != BTRFS_DIR_ITEM_KEY &&
317 found_type != BTRFS_DIR_INDEX_KEY) ||
318 (!btrfs_match_dir_item_name(root, path, goodnames, 2) &&
319 !btrfs_match_dir_item_name(root, path, goodnames, 1))) {
320 err = -ENOTEMPTY;
321 goto out;
322 }
323 ret = btrfs_del_item(trans, root, path);
324 BUG_ON(ret);
325
326 if (found_type == BTRFS_DIR_ITEM_KEY && found_key.offset == 1)
327 break;
328 btrfs_release_path(root, path);
329 }
330 ret = 0;
331 btrfs_release_path(root, path);
332
333 /* now the directory is empty */
334 err = btrfs_unlink_trans(trans, root, dir, dentry);
335 if (!err) {
336 inode->i_size = 0;
337 }
338out:
339 btrfs_release_path(root, path);
340 btrfs_free_path(path);
341 mutex_unlock(&root->fs_info->fs_mutex);
342 ret = btrfs_end_transaction(trans, root);
343 btrfs_btree_balance_dirty(root);
344 if (ret && !err)
345 err = ret;
346 return err;
347}
348
349static int btrfs_free_inode(struct btrfs_trans_handle *trans,
350 struct btrfs_root *root,
351 struct inode *inode)
352{
353 struct btrfs_path *path;
354 int ret;
355
356 clear_inode(inode);
357
358 path = btrfs_alloc_path();
359 BUG_ON(!path);
39279cc3
CM		 360 ret = btrfs_lookup_inode(trans, root, path,
361 &BTRFS_I(inode)->location, -1);
362 BUG_ON(ret);
363 ret = btrfs_del_item(trans, root, path);
364 BUG_ON(ret);
365 btrfs_free_path(path);
366 return ret;
367}
368
369/*
370 * truncates go from a high offset to a low offset. So, walk
371 * from hi to lo in the node and issue readas. Stop when you find
372 * keys from a different objectid
373 */
374static void reada_truncate(struct btrfs_root *root, struct btrfs_path *path,
375 u64 objectid)
376{
377 struct btrfs_node *node;
378 int i;
379 int nritems;
380 u64 item_objectid;
381 u64 blocknr;
382 int slot;
383 int ret;
384
385 if (!path->nodes[1])
386 return;
387 node = btrfs_buffer_node(path->nodes[1]);
388 slot = path->slots[1];
389 if (slot == 0)
390 return;
391 nritems = btrfs_header_nritems(&node->header);
392 for (i = slot - 1; i >= 0; i--) {
393 item_objectid = btrfs_disk_key_objectid(&node->ptrs[i].key);
394 if (item_objectid != objectid)
395 break;
396 blocknr = btrfs_node_blockptr(node, i);
397 ret = readahead_tree_block(root, blocknr);
398 if (ret)
399 break;
400 }
401}
402
403/*
404 * this can truncate away extent items, csum items and directory items.
405 * It starts at a high offset and removes keys until it can't find
406 * any higher than i_size.
407 *
408 * csum items that cross the new i_size are truncated to the new size
409 * as well.
410 */
411static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
412 struct btrfs_root *root,
413 struct inode *inode)
414{
415 int ret;
416 struct btrfs_path *path;
417 struct btrfs_key key;
418 struct btrfs_disk_key *found_key;
419 u32 found_type;
420 struct btrfs_leaf *leaf;
421 struct btrfs_file_extent_item *fi;
422 u64 extent_start = 0;
423 u64 extent_num_blocks = 0;
424 u64 item_end = 0;
425 int found_extent;
426 int del_item;
427
428 path = btrfs_alloc_path();
429 BUG_ON(!path);
430 /* FIXME, add redo link to tree so we don't leak on crash */
431 key.objectid = inode->i_ino;
432 key.offset = (u64)-1;
433 key.flags = (u32)-1;
434 while(1) {
435 btrfs_init_path(path);
436 fi = NULL;
437 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
438 if (ret < 0) {
439 goto error;
440 }
441 if (ret > 0) {
442 BUG_ON(path->slots[0] == 0);
443 path->slots[0]--;
444 }
445 reada_truncate(root, path, inode->i_ino);
446 leaf = btrfs_buffer_leaf(path->nodes[0]);
447 found_key = &leaf->items[path->slots[0]].key;
448 found_type = btrfs_disk_key_type(found_key);
449
450 if (btrfs_disk_key_objectid(found_key) != inode->i_ino)
451 break;
452 if (found_type != BTRFS_CSUM_ITEM_KEY &&
453 found_type != BTRFS_DIR_ITEM_KEY &&
454 found_type != BTRFS_DIR_INDEX_KEY &&
455 found_type != BTRFS_EXTENT_DATA_KEY)
456 break;
457
458 item_end = btrfs_disk_key_offset(found_key);
459 if (found_type == BTRFS_EXTENT_DATA_KEY) {
460 fi = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
461 path->slots[0],
462 struct btrfs_file_extent_item);
463 if (btrfs_file_extent_type(fi) !=
464 BTRFS_FILE_EXTENT_INLINE) {
465 item_end += btrfs_file_extent_num_blocks(fi) <<
466 inode->i_blkbits;
467 }
468 }
469 if (found_type == BTRFS_CSUM_ITEM_KEY) {
470 ret = btrfs_csum_truncate(trans, root, path,
471 inode->i_size);
472 BUG_ON(ret);
473 }
474 if (item_end < inode->i_size) {
475 if (found_type) {
476 btrfs_set_key_type(&key, found_type - 1);
477 continue;
478 }
479 break;
480 }
481 if (btrfs_disk_key_offset(found_key) >= inode->i_size)
482 del_item = 1;
483 else
484 del_item = 0;
485 found_extent = 0;
486
487 /* FIXME, shrink the extent if the ref count is only 1 */
488 if (found_type == BTRFS_EXTENT_DATA_KEY &&
489 btrfs_file_extent_type(fi) !=
490 BTRFS_FILE_EXTENT_INLINE) {
491 u64 num_dec;
492 if (!del_item) {
493 u64 orig_num_blocks =
494 btrfs_file_extent_num_blocks(fi);
495 extent_num_blocks = inode->i_size -
496 btrfs_disk_key_offset(found_key) +
497 root->blocksize - 1;
498 extent_num_blocks >>= inode->i_blkbits;
499 btrfs_set_file_extent_num_blocks(fi,
500 extent_num_blocks);
501 inode->i_blocks -= (orig_num_blocks -
502 extent_num_blocks) << 3;
503 mark_buffer_dirty(path->nodes[0]);
504 } else {
505 extent_start =
506 btrfs_file_extent_disk_blocknr(fi);
507 extent_num_blocks =
508 btrfs_file_extent_disk_num_blocks(fi);
509 /* FIXME blocksize != 4096 */
510 num_dec = btrfs_file_extent_num_blocks(fi) << 3;
511 if (extent_start != 0) {
512 found_extent = 1;
513 inode->i_blocks -= num_dec;
514 }
515 }
516 }
517 if (del_item) {
518 ret = btrfs_del_item(trans, root, path);
519 BUG_ON(ret);
520 } else {
521 break;
522 }
523 btrfs_release_path(root, path);
524 if (found_extent) {
525 ret = btrfs_free_extent(trans, root, extent_start,
526 extent_num_blocks, 0);
527 BUG_ON(ret);
528 }
529 }
530 ret = 0;
531error:
532 btrfs_release_path(root, path);
533 btrfs_free_path(path);
534 inode->i_sb->s_dirt = 1;
535 return ret;
536}
537
538/*
539 * taken from block_truncate_page, but does cow as it zeros out
540 * any bytes left in the last page in the file.
541 */
542static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
543{
544 struct inode *inode = mapping->host;
545 unsigned blocksize = 1 << inode->i_blkbits;
546 pgoff_t index = from >> PAGE_CACHE_SHIFT;
547 unsigned offset = from & (PAGE_CACHE_SIZE-1);
548 struct page *page;
549 char *kaddr;
550 int ret = 0;
551 struct btrfs_root *root = BTRFS_I(inode)->root;
552 u64 alloc_hint = 0;
553 struct btrfs_key ins;
554 struct btrfs_trans_handle *trans;
555
556 if ((offset & (blocksize - 1)) == 0)
557 goto out;
558
559 ret = -ENOMEM;
560 page = grab_cache_page(mapping, index);
561 if (!page)
562 goto out;
563
564 if (!PageUptodate(page)) {
9ebefb18 565 ret = btrfs_readpage(NULL, page);
39279cc3
CM		 566 lock_page(page);
567 if (!PageUptodate(page)) {
568 ret = -EIO;
569 goto out;
570 }
571 }
572 mutex_lock(&root->fs_info->fs_mutex);
573 trans = btrfs_start_transaction(root, 1);
574 btrfs_set_trans_block_group(trans, inode);
575
576 ret = btrfs_drop_extents(trans, root, inode,
577 page->index << PAGE_CACHE_SHIFT,
578 (page->index + 1) << PAGE_CACHE_SHIFT,
579 &alloc_hint);
580 BUG_ON(ret);
581 ret = btrfs_alloc_extent(trans, root, inode->i_ino, 1,
582 alloc_hint, (u64)-1, &ins, 1);
583 BUG_ON(ret);
584 ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
585 page->index << PAGE_CACHE_SHIFT,
586 ins.objectid, 1, 1);
587 BUG_ON(ret);
588 SetPageChecked(page);
589 kaddr = kmap(page);
590 memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
591 flush_dcache_page(page);
592 btrfs_csum_file_block(trans, root, inode->i_ino,
593 page->index << PAGE_CACHE_SHIFT,
594 kaddr, PAGE_CACHE_SIZE);
595 kunmap(page);
596 btrfs_end_transaction(trans, root);
597 mutex_unlock(&root->fs_info->fs_mutex);
598
599 set_page_dirty(page);
600 unlock_page(page);
601 page_cache_release(page);
602out:
603 return ret;
604}
605
606static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
607{
608 struct inode *inode = dentry->d_inode;
609 int err;
610
611 err = inode_change_ok(inode, attr);
612 if (err)
613 return err;
614
615 if (S_ISREG(inode->i_mode) &&
616 attr->ia_valid & ATTR_SIZE && attr->ia_size > inode->i_size) {
617 struct btrfs_trans_handle *trans;
618 struct btrfs_root *root = BTRFS_I(inode)->root;
619 u64 mask = root->blocksize - 1;
620 u64 pos = (inode->i_size + mask) & ~mask;
621 u64 hole_size;
622
623 if (attr->ia_size <= pos)
624 goto out;
625
626 btrfs_truncate_page(inode->i_mapping, inode->i_size);
627
628 hole_size = (attr->ia_size - pos + mask) & ~mask;
629 hole_size >>= inode->i_blkbits;
630
631 mutex_lock(&root->fs_info->fs_mutex);
632 trans = btrfs_start_transaction(root, 1);
633 btrfs_set_trans_block_group(trans, inode);
634 err = btrfs_insert_file_extent(trans, root, inode->i_ino,
635 pos, 0, 0, hole_size);
636 BUG_ON(err);
637 btrfs_end_transaction(trans, root);
638 mutex_unlock(&root->fs_info->fs_mutex);
639 }
640out:
641 err = inode_setattr(inode, attr);
642
643 return err;
644}
645void btrfs_delete_inode(struct inode *inode)
646{
647 struct btrfs_trans_handle *trans;
648 struct btrfs_root *root = BTRFS_I(inode)->root;
649 int ret;
650
651 truncate_inode_pages(&inode->i_data, 0);
652 if (is_bad_inode(inode)) {
653 goto no_delete;
654 }
655 inode->i_size = 0;
656 mutex_lock(&root->fs_info->fs_mutex);
657 trans = btrfs_start_transaction(root, 1);
658 btrfs_set_trans_block_group(trans, inode);
659 ret = btrfs_truncate_in_trans(trans, root, inode);
660 BUG_ON(ret);
661 btrfs_free_inode(trans, root, inode);
662 btrfs_end_transaction(trans, root);
663 mutex_unlock(&root->fs_info->fs_mutex);
664 btrfs_btree_balance_dirty(root);
665 return;
666no_delete:
667 clear_inode(inode);
668}
669
670/*
671 * this returns the key found in the dir entry in the location pointer.
672 * If no dir entries were found, location->objectid is 0.
673 */
674static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
675 struct btrfs_key *location)
676{
677 const char *name = dentry->d_name.name;
678 int namelen = dentry->d_name.len;
679 struct btrfs_dir_item *di;
680 struct btrfs_path *path;
681 struct btrfs_root *root = BTRFS_I(dir)->root;
682 int ret;
683
684 path = btrfs_alloc_path();
685 BUG_ON(!path);
39279cc3
CM		 686 di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
687 namelen, 0);
688 if (!di || IS_ERR(di)) {
689 location->objectid = 0;
690 ret = 0;
691 goto out;
692 }
693 btrfs_disk_key_to_cpu(location, &di->location);
694out:
695 btrfs_release_path(root, path);
696 btrfs_free_path(path);
697 return ret;
698}
699
700/*
701 * when we hit a tree root in a directory, the btrfs part of the inode
702 * needs to be changed to reflect the root directory of the tree root. This
703 * is kind of like crossing a mount point.
704 */
705static int fixup_tree_root_location(struct btrfs_root *root,
706 struct btrfs_key *location,
707 struct btrfs_root **sub_root)
708{
709 struct btrfs_path *path;
710 struct btrfs_root_item *ri;
711
712 if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY)
713 return 0;
714 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
715 return 0;
716
717 path = btrfs_alloc_path();
718 BUG_ON(!path);
719 mutex_lock(&root->fs_info->fs_mutex);
720
721 *sub_root = btrfs_read_fs_root(root->fs_info, location);
722 if (IS_ERR(*sub_root))
723 return PTR_ERR(*sub_root);
724
725 ri = &(*sub_root)->root_item;
726 location->objectid = btrfs_root_dirid(ri);
727 location->flags = 0;
728 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
729 location->offset = 0;
730
731 btrfs_free_path(path);
732 mutex_unlock(&root->fs_info->fs_mutex);
733 return 0;
734}
735
736static int btrfs_init_locked_inode(struct inode *inode, void *p)
737{
738 struct btrfs_iget_args *args = p;
739 inode->i_ino = args->ino;
740 BTRFS_I(inode)->root = args->root;
741 return 0;
742}
743
744static int btrfs_find_actor(struct inode *inode, void *opaque)
745{
746 struct btrfs_iget_args *args = opaque;
747 return (args->ino == inode->i_ino &&
748 args->root == BTRFS_I(inode)->root);
749}
750
751struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
752 struct btrfs_root *root)
753{
754 struct inode *inode;
755 struct btrfs_iget_args args;
756 args.ino = objectid;
757 args.root = root;
758
759 inode = iget5_locked(s, objectid, btrfs_find_actor,
760 btrfs_init_locked_inode,
761 (void *)&args);
762 return inode;
763}
764
765static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
766 struct nameidata *nd)
767{
768 struct inode * inode;
769 struct btrfs_inode *bi = BTRFS_I(dir);
770 struct btrfs_root *root = bi->root;
771 struct btrfs_root *sub_root = root;
772 struct btrfs_key location;
773 int ret;
774
775 if (dentry->d_name.len > BTRFS_NAME_LEN)
776 return ERR_PTR(-ENAMETOOLONG);
777 mutex_lock(&root->fs_info->fs_mutex);
778 ret = btrfs_inode_by_name(dir, dentry, &location);
779 mutex_unlock(&root->fs_info->fs_mutex);
780 if (ret < 0)
781 return ERR_PTR(ret);
782 inode = NULL;
783 if (location.objectid) {
784 ret = fixup_tree_root_location(root, &location, &sub_root);
785 if (ret < 0)
786 return ERR_PTR(ret);
787 if (ret > 0)
788 return ERR_PTR(-ENOENT);
789 inode = btrfs_iget_locked(dir->i_sb, location.objectid,
790 sub_root);
791 if (!inode)
792 return ERR_PTR(-EACCES);
793 if (inode->i_state & I_NEW) {
794 /* the inode and parent dir are two different roots */
795 if (sub_root != root) {
796 igrab(inode);
797 sub_root->inode = inode;
798 }
799 BTRFS_I(inode)->root = sub_root;
800 memcpy(&BTRFS_I(inode)->location, &location,
801 sizeof(location));
802 btrfs_read_locked_inode(inode);
803 unlock_new_inode(inode);
804 }
805 }
806 return d_splice_alias(inode, dentry);
807}
808
809/*
810 * readahead one full node of leaves as long as their keys include
811 * the objectid supplied
812 */
813static void reada_leaves(struct btrfs_root *root, struct btrfs_path *path,
814 u64 objectid)
815{
816 struct btrfs_node *node;
817 int i;
818 u32 nritems;
819 u64 item_objectid;
820 u64 blocknr;
821 int slot;
822 int ret;
823
824 if (!path->nodes[1])
825 return;
826 node = btrfs_buffer_node(path->nodes[1]);
827 slot = path->slots[1];
828 nritems = btrfs_header_nritems(&node->header);
829 for (i = slot + 1; i < nritems; i++) {
830 item_objectid = btrfs_disk_key_objectid(&node->ptrs[i].key);
831 if (item_objectid != objectid)
832 break;
833 blocknr = btrfs_node_blockptr(node, i);
834 ret = readahead_tree_block(root, blocknr);
835 if (ret)
836 break;
837 }
838}
839static unsigned char btrfs_filetype_table[] = {
840 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
841};
842
843static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
844{
845 struct inode *inode = filp->f_path.dentry->d_inode;
846 struct btrfs_root *root = BTRFS_I(inode)->root;
847 struct btrfs_item *item;
848 struct btrfs_dir_item *di;
849 struct btrfs_key key;
850 struct btrfs_path *path;
851 int ret;
852 u32 nritems;
853 struct btrfs_leaf *leaf;
854 int slot;
855 int advance;
856 unsigned char d_type;
857 int over = 0;
858 u32 di_cur;
859 u32 di_total;
860 u32 di_len;
861 int key_type = BTRFS_DIR_INDEX_KEY;
862
863 /* FIXME, use a real flag for deciding about the key type */
864 if (root->fs_info->tree_root == root)
865 key_type = BTRFS_DIR_ITEM_KEY;
866 mutex_lock(&root->fs_info->fs_mutex);
867 key.objectid = inode->i_ino;
868 key.flags = 0;
869 btrfs_set_key_type(&key, key_type);
870 key.offset = filp->f_pos;
871 path = btrfs_alloc_path();
39279cc3
CM		 872 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
873 if (ret < 0)
874 goto err;
875 advance = 0;
876 reada_leaves(root, path, inode->i_ino);
877 while(1) {
878 leaf = btrfs_buffer_leaf(path->nodes[0]);
879 nritems = btrfs_header_nritems(&leaf->header);
880 slot = path->slots[0];
881 if (advance || slot >= nritems) {
882 if (slot >= nritems -1) {
883 reada_leaves(root, path, inode->i_ino);
884 ret = btrfs_next_leaf(root, path);
885 if (ret)
886 break;
887 leaf = btrfs_buffer_leaf(path->nodes[0]);
888 nritems = btrfs_header_nritems(&leaf->header);
889 slot = path->slots[0];
890 } else {
891 slot++;
892 path->slots[0]++;
893 }
894 }
895 advance = 1;
896 item = leaf->items + slot;
897 if (btrfs_disk_key_objectid(&item->key) != key.objectid)
898 break;
899 if (btrfs_disk_key_type(&item->key) != key_type)
900 break;
901 if (btrfs_disk_key_offset(&item->key) < filp->f_pos)
902 continue;
903 filp->f_pos = btrfs_disk_key_offset(&item->key);
904 advance = 1;
905 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
906 di_cur = 0;
907 di_total = btrfs_item_size(leaf->items + slot);
908 while(di_cur < di_total) {
909 d_type = btrfs_filetype_table[btrfs_dir_type(di)];
910 over = filldir(dirent, (const char *)(di + 1),
911 btrfs_dir_name_len(di),
912 btrfs_disk_key_offset(&item->key),
913 btrfs_disk_key_objectid(&di->location),
914 d_type);
915 if (over)
916 goto nopos;
917 di_len = btrfs_dir_name_len(di) + sizeof(*di);
918 di_cur += di_len;
919 di = (struct btrfs_dir_item *)((char *)di + di_len);
920 }
921 }
922 filp->f_pos++;
923nopos:
924 ret = 0;
925err:
926 btrfs_release_path(root, path);
927 btrfs_free_path(path);
928 mutex_unlock(&root->fs_info->fs_mutex);
929 return ret;
930}
931
932int btrfs_write_inode(struct inode *inode, int wait)
933{
934 struct btrfs_root *root = BTRFS_I(inode)->root;
935 struct btrfs_trans_handle *trans;
936 int ret = 0;
937
938 if (wait) {
939 mutex_lock(&root->fs_info->fs_mutex);
940 trans = btrfs_start_transaction(root, 1);
941 btrfs_set_trans_block_group(trans, inode);
942 ret = btrfs_commit_transaction(trans, root);
943 mutex_unlock(&root->fs_info->fs_mutex);
944 }
945 return ret;
946}
947
948/*
949 * This is somewhat expense, updating the tree every time the
950 * inode changes. But, it is most likely to find the inode in cache.
951 * FIXME, needs more benchmarking...there are no reasons other than performance
952 * to keep or drop this code.
953 */
954void btrfs_dirty_inode(struct inode *inode)
955{
956 struct btrfs_root *root = BTRFS_I(inode)->root;
957 struct btrfs_trans_handle *trans;
958
959 mutex_lock(&root->fs_info->fs_mutex);
960 trans = btrfs_start_transaction(root, 1);
961 btrfs_set_trans_block_group(trans, inode);
962 btrfs_update_inode(trans, root, inode);
963 btrfs_end_transaction(trans, root);
964 mutex_unlock(&root->fs_info->fs_mutex);
39279cc3
CM		 965}
966
967static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
968 struct btrfs_root *root,
969 u64 objectid,
970 struct btrfs_block_group_cache *group,
971 int mode)
972{
973 struct inode *inode;
974 struct btrfs_inode_item inode_item;
975 struct btrfs_key *location;
976 int ret;
977 int owner;
978
979 inode = new_inode(root->fs_info->sb);
980 if (!inode)
981 return ERR_PTR(-ENOMEM);
982
983 BTRFS_I(inode)->root = root;
984 if (mode & S_IFDIR)
985 owner = 0;
986 else
987 owner = 1;
988 group = btrfs_find_block_group(root, group, 0, 0, owner);
989 BTRFS_I(inode)->block_group = group;
990
991 inode->i_uid = current->fsuid;
992 inode->i_gid = current->fsgid;
993 inode->i_mode = mode;
994 inode->i_ino = objectid;
995 inode->i_blocks = 0;
996 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
997 fill_inode_item(&inode_item, inode);
998 location = &BTRFS_I(inode)->location;
999 location->objectid = objectid;
1000 location->flags = 0;
1001 location->offset = 0;
1002 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
1003
1004 ret = btrfs_insert_inode(trans, root, objectid, &inode_item);
1005 BUG_ON(ret);
1006
1007 insert_inode_hash(inode);
1008 return inode;
1009}
1010
1011static inline u8 btrfs_inode_type(struct inode *inode)
1012{
1013 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
1014}
1015
1016static int btrfs_add_link(struct btrfs_trans_handle *trans,
1017 struct dentry *dentry, struct inode *inode)
1018{
1019 int ret;
1020 struct btrfs_key key;
1021 struct btrfs_root *root = BTRFS_I(dentry->d_parent->d_inode)->root;
1022 key.objectid = inode->i_ino;
1023 key.flags = 0;
1024 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
1025 key.offset = 0;
1026
1027 ret = btrfs_insert_dir_item(trans, root,
1028 dentry->d_name.name, dentry->d_name.len,
1029 dentry->d_parent->d_inode->i_ino,
1030 &key, btrfs_inode_type(inode));
1031 if (ret == 0) {
1032 dentry->d_parent->d_inode->i_size += dentry->d_name.len * 2;
1033 ret = btrfs_update_inode(trans, root,
1034 dentry->d_parent->d_inode);
1035 }
1036 return ret;
1037}
1038
1039static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
1040 struct dentry *dentry, struct inode *inode)
1041{
1042 int err = btrfs_add_link(trans, dentry, inode);
1043 if (!err) {
1044 d_instantiate(dentry, inode);
1045 return 0;
1046 }
1047 if (err > 0)
1048 err = -EEXIST;
1049 return err;
1050}
1051
1052static int btrfs_create(struct inode *dir, struct dentry *dentry,
1053 int mode, struct nameidata *nd)
1054{
1055 struct btrfs_trans_handle *trans;
1056 struct btrfs_root *root = BTRFS_I(dir)->root;
1057 struct inode *inode;
1058 int err;
1059 int drop_inode = 0;
1060 u64 objectid;
1061
1062 mutex_lock(&root->fs_info->fs_mutex);
1063 trans = btrfs_start_transaction(root, 1);
1064 btrfs_set_trans_block_group(trans, dir);
1065
1066 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1067 if (err) {
1068 err = -ENOSPC;
1069 goto out_unlock;
1070 }
1071
1072 inode = btrfs_new_inode(trans, root, objectid,
1073 BTRFS_I(dir)->block_group, mode);
1074 err = PTR_ERR(inode);
1075 if (IS_ERR(inode))
1076 goto out_unlock;
1077
1078 btrfs_set_trans_block_group(trans, inode);
1079 err = btrfs_add_nondir(trans, dentry, inode);
1080 if (err)
1081 drop_inode = 1;
1082 else {
1083 inode->i_mapping->a_ops = &btrfs_aops;
1084 inode->i_fop = &btrfs_file_operations;
1085 inode->i_op = &btrfs_file_inode_operations;
1086 }
1087 dir->i_sb->s_dirt = 1;
1088 btrfs_update_inode_block_group(trans, inode);
1089 btrfs_update_inode_block_group(trans, dir);
1090out_unlock:
1091 btrfs_end_transaction(trans, root);
1092 mutex_unlock(&root->fs_info->fs_mutex);
1093
1094 if (drop_inode) {
1095 inode_dec_link_count(inode);
1096 iput(inode);
1097 }
1098 btrfs_btree_balance_dirty(root);
1099 return err;
1100}
1101
1102static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
1103 struct dentry *dentry)
1104{
1105 struct btrfs_trans_handle *trans;
1106 struct btrfs_root *root = BTRFS_I(dir)->root;
1107 struct inode *inode = old_dentry->d_inode;
1108 int err;
1109 int drop_inode = 0;
1110
1111 if (inode->i_nlink == 0)
1112 return -ENOENT;
1113
1114 inc_nlink(inode);
1115 mutex_lock(&root->fs_info->fs_mutex);
1116 trans = btrfs_start_transaction(root, 1);
1117 btrfs_set_trans_block_group(trans, dir);
1118 atomic_inc(&inode->i_count);
1119 err = btrfs_add_nondir(trans, dentry, inode);
1120 if (err)
1121 drop_inode = 1;
1122 dir->i_sb->s_dirt = 1;
1123 btrfs_update_inode_block_group(trans, dir);
1124 btrfs_update_inode(trans, root, inode);
1125
1126 btrfs_end_transaction(trans, root);
1127 mutex_unlock(&root->fs_info->fs_mutex);
1128
1129 if (drop_inode) {
1130 inode_dec_link_count(inode);
1131 iput(inode);
1132 }
1133 btrfs_btree_balance_dirty(root);
1134 return err;
1135}
1136
1137static int btrfs_make_empty_dir(struct btrfs_trans_handle *trans,
1138 struct btrfs_root *root,
1139 u64 objectid, u64 dirid)
1140{
1141 int ret;
1142 char buf[2];
1143 struct btrfs_key key;
1144
1145 buf[0] = '.';
1146 buf[1] = '.';
1147
1148 key.objectid = objectid;
1149 key.offset = 0;
1150 key.flags = 0;
1151 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
1152
1153 ret = btrfs_insert_dir_item(trans, root, buf, 1, objectid,
1154 &key, BTRFS_FT_DIR);
1155 if (ret)
1156 goto error;
1157 key.objectid = dirid;
1158 ret = btrfs_insert_dir_item(trans, root, buf, 2, objectid,
1159 &key, BTRFS_FT_DIR);
1160 if (ret)
1161 goto error;
1162error:
1163 return ret;
1164}
1165
1166static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1167{
1168 struct inode *inode;
1169 struct btrfs_trans_handle *trans;
1170 struct btrfs_root *root = BTRFS_I(dir)->root;
1171 int err = 0;
1172 int drop_on_err = 0;
1173 u64 objectid;
1174
1175 mutex_lock(&root->fs_info->fs_mutex);
1176 trans = btrfs_start_transaction(root, 1);
1177 btrfs_set_trans_block_group(trans, dir);
1178 if (IS_ERR(trans)) {
1179 err = PTR_ERR(trans);
1180 goto out_unlock;
1181 }
1182
1183 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1184 if (err) {
1185 err = -ENOSPC;
1186 goto out_unlock;
1187 }
1188
1189 inode = btrfs_new_inode(trans, root, objectid,
1190 BTRFS_I(dir)->block_group, S_IFDIR | mode);
1191 if (IS_ERR(inode)) {
1192 err = PTR_ERR(inode);
1193 goto out_fail;
1194 }
1195 drop_on_err = 1;
1196 inode->i_op = &btrfs_dir_inode_operations;
1197 inode->i_fop = &btrfs_dir_file_operations;
1198 btrfs_set_trans_block_group(trans, inode);
1199
1200 err = btrfs_make_empty_dir(trans, root, inode->i_ino, dir->i_ino);
1201 if (err)
1202 goto out_fail;
1203
1204 inode->i_size = 6;
1205 err = btrfs_update_inode(trans, root, inode);
1206 if (err)
1207 goto out_fail;
1208 err = btrfs_add_link(trans, dentry, inode);
1209 if (err)
1210 goto out_fail;
1211 d_instantiate(dentry, inode);
1212 drop_on_err = 0;
1213 dir->i_sb->s_dirt = 1;
1214 btrfs_update_inode_block_group(trans, inode);
1215 btrfs_update_inode_block_group(trans, dir);
1216
1217out_fail:
1218 btrfs_end_transaction(trans, root);
1219out_unlock:
1220 mutex_unlock(&root->fs_info->fs_mutex);
1221 if (drop_on_err)
1222 iput(inode);
1223 btrfs_btree_balance_dirty(root);
1224 return err;
1225}
1226
1227/*
1228 * FIBMAP and others want to pass in a fake buffer head. They need to
1229 * use BTRFS_GET_BLOCK_NO_DIRECT to make sure we don't try to memcpy
1230 * any packed file data into the fake bh
1231 */
1232#define BTRFS_GET_BLOCK_NO_CREATE 0
1233#define BTRFS_GET_BLOCK_CREATE 1
1234#define BTRFS_GET_BLOCK_NO_DIRECT 2
1235
1236/*
1237 * FIXME create==1 doe not work.
1238 */
1239static int btrfs_get_block_lock(struct inode *inode, sector_t iblock,
1240 struct buffer_head *result, int create)
1241{
1242 int ret;
1243 int err = 0;
1244 u64 blocknr;
1245 u64 extent_start = 0;
1246 u64 extent_end = 0;
1247 u64 objectid = inode->i_ino;
1248 u32 found_type;
1249 u64 alloc_hint = 0;
1250 struct btrfs_path *path;
1251 struct btrfs_root *root = BTRFS_I(inode)->root;
1252 struct btrfs_file_extent_item *item;
1253 struct btrfs_leaf *leaf;
1254 struct btrfs_disk_key *found_key;
1255 struct btrfs_trans_handle *trans = NULL;
1256
1257 path = btrfs_alloc_path();
1258 BUG_ON(!path);
39279cc3 1259 if (create & BTRFS_GET_BLOCK_CREATE) {
9ebefb18
CM		 1260 /*
1261 * danger!, this only works if the page is properly up
1262 * to date somehow
1263 */
39279cc3
CM		 1264 trans = btrfs_start_transaction(root, 1);
1265 if (!trans) {
1266 err = -ENOMEM;
1267 goto out;
1268 }
1269 ret = btrfs_drop_extents(trans, root, inode,
1270 iblock << inode->i_blkbits,
1271 (iblock + 1) << inode->i_blkbits,
1272 &alloc_hint);
1273 BUG_ON(ret);
1274 }
1275
1276 ret = btrfs_lookup_file_extent(NULL, root, path,
f1ace244 1277 objectid,
39279cc3
CM		 1278 iblock << inode->i_blkbits, 0);
1279 if (ret < 0) {
1280 err = ret;
1281 goto out;
1282 }
1283
1284 if (ret != 0) {
1285 if (path->slots[0] == 0) {
1286 btrfs_release_path(root, path);
1287 goto not_found;
1288 }
1289 path->slots[0]--;
1290 }
1291
1292 item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
1293 struct btrfs_file_extent_item);
1294 leaf = btrfs_buffer_leaf(path->nodes[0]);
1295 blocknr = btrfs_file_extent_disk_blocknr(item);
1296 blocknr += btrfs_file_extent_offset(item);
1297
1298 /* are we inside the extent that was found? */
1299 found_key = &leaf->items[path->slots[0]].key;
1300 found_type = btrfs_disk_key_type(found_key);
1301 if (btrfs_disk_key_objectid(found_key) != objectid ||
1302 found_type != BTRFS_EXTENT_DATA_KEY) {
1303 extent_end = 0;
1304 extent_start = 0;
1305 goto not_found;
1306 }
1307 found_type = btrfs_file_extent_type(item);
1308 extent_start = btrfs_disk_key_offset(&leaf->items[path->slots[0]].key);
1309 if (found_type == BTRFS_FILE_EXTENT_REG) {
1310 extent_start = extent_start >> inode->i_blkbits;
1311 extent_end = extent_start + btrfs_file_extent_num_blocks(item);
1312 err = 0;
1313 if (btrfs_file_extent_disk_blocknr(item) == 0)
1314 goto out;
1315 if (iblock >= extent_start && iblock < extent_end) {
1316 btrfs_map_bh_to_logical(root, result, blocknr +
1317 iblock - extent_start);
1318 goto out;
1319 }
1320 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
1321 char *ptr;
1322 char *map;
1323 u32 size;
1324
1325 if (create & BTRFS_GET_BLOCK_NO_DIRECT) {
1326 err = -EINVAL;
1327 goto out;
1328 }
1329 size = btrfs_file_extent_inline_len(leaf->items +
1330 path->slots[0]);
1331 extent_end = (extent_start + size) >> inode->i_blkbits;
1332 extent_start >>= inode->i_blkbits;
1333 if (iblock < extent_start || iblock > extent_end) {
1334 goto not_found;
1335 }
1336 ptr = btrfs_file_extent_inline_start(item);
1337 map = kmap(result->b_page);
1338 memcpy(map, ptr, size);
1339 memset(map + size, 0, PAGE_CACHE_SIZE - size);
1340 flush_dcache_page(result->b_page);
1341 kunmap(result->b_page);
1342 set_buffer_uptodate(result);
1343 SetPageChecked(result->b_page);
1344 btrfs_map_bh_to_logical(root, result, 0);
1345 }
1346not_found:
1347 if (create & BTRFS_GET_BLOCK_CREATE) {
1348 struct btrfs_key ins;
1349 ret = btrfs_alloc_extent(trans, root, inode->i_ino,
1350 1, alloc_hint, (u64)-1,
1351 &ins, 1);
1352 BUG_ON(ret);
1353 ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
1354 iblock << inode->i_blkbits,
1355 ins.objectid, ins.offset,
1356 ins.offset);
1357 BUG_ON(ret);
39279cc3
CM		 1358 btrfs_map_bh_to_logical(root, result, ins.objectid);
1359 }
1360out:
1361 if (trans)
1362 err = btrfs_end_transaction(trans, root);
1363 btrfs_free_path(path);
1364 return err;
1365}
1366
1367int btrfs_get_block(struct inode *inode, sector_t iblock,
1368 struct buffer_head *result, int create)
1369{
1370 int err;
1371 struct btrfs_root *root = BTRFS_I(inode)->root;
1372 mutex_lock(&root->fs_info->fs_mutex);
1373 err = btrfs_get_block_lock(inode, iblock, result, create);
1374 mutex_unlock(&root->fs_info->fs_mutex);
1375 return err;
1376}
1377
9ebefb18
CM		 1378int btrfs_get_block_csum(struct inode *inode, sector_t iblock,
1379 struct buffer_head *result, int create)
1380{
1381 int ret;
1382 struct btrfs_root *root = BTRFS_I(inode)->root;
1383 struct page *page = result->b_page;
1384 u64 offset = (page->index << PAGE_CACHE_SHIFT) + bh_offset(result);
1385 struct btrfs_csum_item *item;
1386 struct btrfs_path *path = NULL;
1387
1388 mutex_lock(&root->fs_info->fs_mutex);
1389 ret = btrfs_get_block_lock(inode, iblock, result, create);
1390 if (ret)
1391 goto out;
1392
1393 path = btrfs_alloc_path();
1394 item = btrfs_lookup_csum(NULL, root, path, inode->i_ino, offset, 0);
1395 if (IS_ERR(item)) {
1396 ret = PTR_ERR(item);
1397 /* a csum that isn't present is a preallocated region. */
1398 if (ret == -ENOENT || ret == -EFBIG)
1399 ret = 0;
1400 result->b_private = 0;
1401 goto out;
1402 }
1403 memcpy((char *)&result->b_private, &item->csum, BTRFS_CRC32_SIZE);
9ebefb18
CM		 1404out:
1405 if (path)
1406 btrfs_free_path(path);
1407 mutex_unlock(&root->fs_info->fs_mutex);
1408 return ret;
1409}
1410
39279cc3
CM		 1411static int btrfs_get_block_bmap(struct inode *inode, sector_t iblock,
1412 struct buffer_head *result, int create)
1413{
1414 struct btrfs_root *root = BTRFS_I(inode)->root;
1415 mutex_lock(&root->fs_info->fs_mutex);
1416 btrfs_get_block_lock(inode, iblock, result, BTRFS_GET_BLOCK_NO_DIRECT);
1417 mutex_unlock(&root->fs_info->fs_mutex);
1418 return 0;
1419}
1420
1421static sector_t btrfs_bmap(struct address_space *as, sector_t block)
1422{
1423 return generic_block_bmap(as, block, btrfs_get_block_bmap);
1424}
1425
1426static int btrfs_prepare_write(struct file *file, struct page *page,
1427 unsigned from, unsigned to)
1428{
1429 return block_prepare_write(page, from, to, btrfs_get_block);
1430}
1431
9ebefb18
CM		 1432static void buffer_io_error(struct buffer_head *bh)
1433{
1434 char b[BDEVNAME_SIZE];
1435
1436 printk(KERN_ERR "Buffer I/O error on device %s, logical block %Lu\n",
1437 bdevname(bh->b_bdev, b),
1438 (unsigned long long)bh->b_blocknr);
1439}
1440
1441/*
1442 * I/O completion handler for block_read_full_page() - pages
1443 * which come unlocked at the end of I/O.
1444 */
1445static void btrfs_end_buffer_async_read(struct buffer_head *bh, int uptodate)
39279cc3 1446{
9ebefb18
CM		 1447 unsigned long flags;
1448 struct buffer_head *first;
1449 struct buffer_head *tmp;
1450 struct page *page;
1451 int page_uptodate = 1;
1452 struct inode *inode;
1453 int ret;
1454
1455 BUG_ON(!buffer_async_read(bh));
1456
1457 page = bh->b_page;
1458 inode = page->mapping->host;
1459 if (uptodate) {
1460 void *kaddr;
1461 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1462 if (bh->b_private) {
1463 char csum[BTRFS_CRC32_SIZE];
1464 kaddr = kmap_atomic(page, KM_IRQ0);
1465 ret = btrfs_csum_data(root, kaddr + bh_offset(bh),
1466 bh->b_size, csum);
1467 BUG_ON(ret);
1468 if (memcmp(csum, &bh->b_private, BTRFS_CRC32_SIZE)) {
1469 u64 offset;
1470 offset = (page->index << PAGE_CACHE_SHIFT) +
1471 bh_offset(bh);
1472 printk("btrfs csum failed ino %lu off %llu\n",
1473 page->mapping->host->i_ino,
1474 (unsigned long long)offset);
1475 memset(kaddr + bh_offset(bh), 1, bh->b_size);
1476 flush_dcache_page(page);
9ebefb18
CM		 1477 }
1478 kunmap_atomic(kaddr, KM_IRQ0);
1479 }
1480 set_buffer_uptodate(bh);
1481 } else {
1482 clear_buffer_uptodate(bh);
1483 if (printk_ratelimit())
1484 buffer_io_error(bh);
1485 SetPageError(page);
1486 }
1487
1488 /*
1489 * Be _very_ careful from here on. Bad things can happen if
1490 * two buffer heads end IO at almost the same time and both
1491 * decide that the page is now completely done.
1492 */
1493 first = page_buffers(page);
1494 local_irq_save(flags);
1495 bit_spin_lock(BH_Uptodate_Lock, &first->b_state);
1496 clear_buffer_async_read(bh);
1497 unlock_buffer(bh);
1498 tmp = bh;
1499 do {
1500 if (!buffer_uptodate(tmp))
1501 page_uptodate = 0;
1502 if (buffer_async_read(tmp)) {
1503 BUG_ON(!buffer_locked(tmp));
1504 goto still_busy;
1505 }
1506 tmp = tmp->b_this_page;
1507 } while (tmp != bh);
1508 bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
1509 local_irq_restore(flags);
1510
1511 /*
1512 * If none of the buffers had errors and they are all
1513 * uptodate then we can set the page uptodate.
1514 */
1515 if (page_uptodate && !PageError(page))
1516 SetPageUptodate(page);
1517 unlock_page(page);
1518 return;
1519
1520still_busy:
1521 bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
1522 local_irq_restore(flags);
1523 return;
1524}
1525
1526/*
1527 * Generic "read page" function for block devices that have the normal
1528 * get_block functionality. This is most of the block device filesystems.
1529 * Reads the page asynchronously --- the unlock_buffer() and
1530 * set/clear_buffer_uptodate() functions propagate buffer state into the
1531 * page struct once IO has completed.
1532 */
1533int btrfs_readpage(struct file *file, struct page *page)
1534{
1535 struct inode *inode = page->mapping->host;
1536 sector_t iblock, lblock;
1537 struct buffer_head *bh, *head, *arr[MAX_BUF_PER_PAGE];
1538 unsigned int blocksize;
1539 int nr, i;
1540 int fully_mapped = 1;
1541
1542 BUG_ON(!PageLocked(page));
1543 blocksize = 1 << inode->i_blkbits;
1544 if (!page_has_buffers(page))
1545 create_empty_buffers(page, blocksize, 0);
1546 head = page_buffers(page);
1547
1548 iblock = (sector_t)page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
1549 lblock = (i_size_read(inode)+blocksize-1) >> inode->i_blkbits;
1550 bh = head;
1551 nr = 0;
1552 i = 0;
1553
1554 do {
1555 if (buffer_uptodate(bh))
1556 continue;
1557
1558 if (!buffer_mapped(bh)) {
1559 int err = 0;
1560
1561 fully_mapped = 0;
1562 if (iblock < lblock) {
1563 WARN_ON(bh->b_size != blocksize);
1564 err = btrfs_get_block_csum(inode, iblock,
1565 bh, 0);
1566 if (err)
1567 SetPageError(page);
1568 }
1569 if (!buffer_mapped(bh)) {
1570 void *kaddr = kmap_atomic(page, KM_USER0);
1571 memset(kaddr + i * blocksize, 0, blocksize);
1572 flush_dcache_page(page);
1573 kunmap_atomic(kaddr, KM_USER0);
1574 if (!err)
1575 set_buffer_uptodate(bh);
1576 continue;
1577 }
1578 /*
1579 * get_block() might have updated the buffer
1580 * synchronously
1581 */
1582 if (buffer_uptodate(bh))
1583 continue;
1584 }
1585 arr[nr++] = bh;
1586 } while (i++, iblock++, (bh = bh->b_this_page) != head);
1587
1588 if (fully_mapped)
1589 SetPageMappedToDisk(page);
1590
1591 if (!nr) {
1592 /*
1593 * All buffers are uptodate - we can set the page uptodate
1594 * as well. But not if get_block() returned an error.
1595 */
1596 if (!PageError(page))
1597 SetPageUptodate(page);
1598 unlock_page(page);
1599 return 0;
1600 }
1601
1602 /* Stage two: lock the buffers */
1603 for (i = 0; i < nr; i++) {
1604 bh = arr[i];
1605 lock_buffer(bh);
1606 bh->b_end_io = btrfs_end_buffer_async_read;
1607 set_buffer_async_read(bh);
1608 }
1609
1610 /*
1611 * Stage 3: start the IO. Check for uptodateness
1612 * inside the buffer lock in case another process reading
1613 * the underlying blockdev brought it uptodate (the sct fix).
1614 */
1615 for (i = 0; i < nr; i++) {
1616 bh = arr[i];
1617 if (buffer_uptodate(bh))
1618 btrfs_end_buffer_async_read(bh, 1);
1619 else
1620 submit_bh(READ, bh);
1621 }
1622 return 0;
39279cc3
CM		 1623}
1624
1625/*
1626 * Aside from a tiny bit of packed file data handling, this is the
1627 * same as the generic code.
1628 *
1629 * While block_write_full_page is writing back the dirty buffers under
1630 * the page lock, whoever dirtied the buffers may decide to clean them
1631 * again at any time. We handle that by only looking at the buffer
1632 * state inside lock_buffer().
1633 *
1634 * If block_write_full_page() is called for regular writeback
1635 * (wbc->sync_mode == WB_SYNC_NONE) then it will redirty a page which has a
1636 * locked buffer. This only can happen if someone has written the buffer
1637 * directly, with submit_bh(). At the address_space level PageWriteback
1638 * prevents this contention from occurring.
1639 */
1640static int __btrfs_write_full_page(struct inode *inode, struct page *page,
1641 struct writeback_control *wbc)
1642{
1643 int err;
1644 sector_t block;
1645 sector_t last_block;
1646 struct buffer_head *bh, *head;
1647 const unsigned blocksize = 1 << inode->i_blkbits;
1648 int nr_underway = 0;
9ebefb18 1649 struct btrfs_root *root = BTRFS_I(inode)->root;
39279cc3
CM		 1650
1651 BUG_ON(!PageLocked(page));
1652
1653 last_block = (i_size_read(inode) - 1) >> inode->i_blkbits;
1654
8c2383c3
CM		 1655 /* no csumming allowed when from PF_MEMALLOC */
1656 if (current->flags & PF_MEMALLOC) {
1657 redirty_page_for_writepage(wbc, page);
1658 unlock_page(page);
1659 return 0;
1660 }
1661
39279cc3
CM		 1662 if (!page_has_buffers(page)) {
1663 create_empty_buffers(page, blocksize,
1664 (1 << BH_Dirty)|(1 << BH_Uptodate));
1665 }
1666
1667 /*
1668 * Be very careful. We have no exclusion from __set_page_dirty_buffers
1669 * here, and the (potentially unmapped) buffers may become dirty at
1670 * any time. If a buffer becomes dirty here after we've inspected it
1671 * then we just miss that fact, and the page stays dirty.
1672 *
1673 * Buffers outside i_size may be dirtied by __set_page_dirty_buffers;
1674 * handle that here by just cleaning them.
1675 */
1676
1677 block = (sector_t)page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
1678 head = page_buffers(page);
1679 bh = head;
1680
1681 /*
1682 * Get all the dirty buffers mapped to disk addresses and
1683 * handle any aliases from the underlying blockdev's mapping.
1684 */
1685 do {
1686 if (block > last_block) {
1687 /*
1688 * mapped buffers outside i_size will occur, because
1689 * this page can be outside i_size when there is a
1690 * truncate in progress.
1691 */
1692 /*
1693 * The buffer was zeroed by block_write_full_page()
1694 */
1695 clear_buffer_dirty(bh);
1696 set_buffer_uptodate(bh);
1697 } else if (!buffer_mapped(bh) && buffer_dirty(bh)) {
1698 WARN_ON(bh->b_size != blocksize);
1699 err = btrfs_get_block(inode, block, bh, 0);
1700 if (err) {
1701 goto recover;
1702 }
1703 if (buffer_new(bh)) {
1704 /* blockdev mappings never come here */
1705 clear_buffer_new(bh);
1706 }
1707 }
1708 bh = bh->b_this_page;
1709 block++;
1710 } while (bh != head);
1711
1712 do {
1713 if (!buffer_mapped(bh))
1714 continue;
1715 /*
1716 * If it's a fully non-blocking write attempt and we cannot
1717 * lock the buffer then redirty the page. Note that this can
1718 * potentially cause a busy-wait loop from pdflush and kswapd
1719 * activity, but those code paths have their own higher-level
1720 * throttling.
1721 */
1722 if (wbc->sync_mode != WB_SYNC_NONE || !wbc->nonblocking) {
1723 lock_buffer(bh);
1724 } else if (test_set_buffer_locked(bh)) {
1725 redirty_page_for_writepage(wbc, page);
1726 continue;
1727 }
1728 if (test_clear_buffer_dirty(bh) && bh->b_blocknr != 0) {
9ebefb18
CM		 1729 struct btrfs_trans_handle *trans;
1730 int ret;
1731 u64 off = page->index << PAGE_CACHE_SHIFT;
1732 char *kaddr;
1733
1734 off += bh_offset(bh);
1735 mutex_lock(&root->fs_info->fs_mutex);
1736 trans = btrfs_start_transaction(root, 1);
1737 btrfs_set_trans_block_group(trans, inode);
1738 kaddr = kmap(page);
1739 ret = btrfs_csum_file_block(trans, root, inode->i_ino,
1740 off, kaddr + bh_offset(bh),
1741 bh->b_size);
1742 kunmap(page);
1743 BUG_ON(ret);
1744 ret = btrfs_end_transaction(trans, root);
1745 BUG_ON(ret);
1746 mutex_unlock(&root->fs_info->fs_mutex);
39279cc3
CM		 1747 mark_buffer_async_write(bh);
1748 } else {
1749 unlock_buffer(bh);
1750 }
1751 } while ((bh = bh->b_this_page) != head);
1752
1753 /*
1754 * The page and its buffers are protected by PageWriteback(), so we can
1755 * drop the bh refcounts early.
1756 */
1757 BUG_ON(PageWriteback(page));
1758 set_page_writeback(page);
1759
1760 do {
1761 struct buffer_head *next = bh->b_this_page;
1762 if (buffer_async_write(bh)) {
1763 submit_bh(WRITE, bh);
1764 nr_underway++;
1765 }
1766 bh = next;
1767 } while (bh != head);
1768 unlock_page(page);
1769
1770 err = 0;
1771done:
1772 if (nr_underway == 0) {
1773 /*
1774 * The page was marked dirty, but the buffers were
1775 * clean. Someone wrote them back by hand with
1776 * ll_rw_block/submit_bh. A rare case.
1777 */
1778 int uptodate = 1;
1779 do {
1780 if (!buffer_uptodate(bh)) {
1781 uptodate = 0;
1782 break;
1783 }
1784 bh = bh->b_this_page;
1785 } while (bh != head);
1786 if (uptodate)
1787 SetPageUptodate(page);
1788 end_page_writeback(page);
1789 }
1790 return err;
1791
1792recover:
1793 /*
1794 * ENOSPC, or some other error. We may already have added some
1795 * blocks to the file, so we need to write these out to avoid
1796 * exposing stale data.
1797 * The page is currently locked and not marked for writeback
1798 */
1799 bh = head;
1800 /* Recovery: lock and submit the mapped buffers */
1801 do {
1802 if (buffer_mapped(bh) && buffer_dirty(bh)) {
1803 lock_buffer(bh);
1804 mark_buffer_async_write(bh);
1805 } else {
1806 /*
1807 * The buffer may have been set dirty during
1808 * attachment to a dirty page.
1809 */
1810 clear_buffer_dirty(bh);
1811 }
1812 } while ((bh = bh->b_this_page) != head);
1813 SetPageError(page);
1814 BUG_ON(PageWriteback(page));
1815 set_page_writeback(page);
1816 do {
1817 struct buffer_head *next = bh->b_this_page;
1818 if (buffer_async_write(bh)) {
1819 clear_buffer_dirty(bh);
1820 submit_bh(WRITE, bh);
1821 nr_underway++;
1822 }
1823 bh = next;
1824 } while (bh != head);
1825 unlock_page(page);
1826 goto done;
1827}
1828
1829static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
1830{
1831 struct inode * const inode = page->mapping->host;
1832 loff_t i_size = i_size_read(inode);
1833 const pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
1834 unsigned offset;
1835 void *kaddr;
1836
1837 /* Is the page fully inside i_size? */
1838 if (page->index < end_index)
1839 return __btrfs_write_full_page(inode, page, wbc);
1840
1841 /* Is the page fully outside i_size? (truncate in progress) */
1842 offset = i_size & (PAGE_CACHE_SIZE-1);
1843 if (page->index >= end_index+1 || !offset) {
1844 /*
1845 * The page may have dirty, unmapped buffers. For example,
1846 * they may have been added in ext3_writepage(). Make them
1847 * freeable here, so the page does not leak.
1848 */
1849 block_invalidatepage(page, 0);
1850 unlock_page(page);
1851 return 0; /* don't care */
1852 }
1853
1854 /*
1855 * The page straddles i_size. It must be zeroed out on each and every
1856 * writepage invokation because it may be mmapped. "A file is mapped
1857 * in multiples of the page size. For a file that is not a multiple of
1858 * the page size, the remaining memory is zeroed when mapped, and
1859 * writes to that region are not written out to the file."
1860 */
1861 kaddr = kmap_atomic(page, KM_USER0);
1862 memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
1863 flush_dcache_page(page);
1864 kunmap_atomic(kaddr, KM_USER0);
1865 return __btrfs_write_full_page(inode, page, wbc);
1866}
1867
9ebefb18
CM		 1868/*
1869 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
1870 * called from a page fault handler when a page is first dirtied. Hence we must
1871 * be careful to check for EOF conditions here. We set the page up correctly
1872 * for a written page which means we get ENOSPC checking when writing into
1873 * holes and correct delalloc and unwritten extent mapping on filesystems that
1874 * support these features.
1875 *
1876 * We are not allowed to take the i_mutex here so we have to play games to
1877 * protect against truncate races as the page could now be beyond EOF. Because
1878 * vmtruncate() writes the inode size before removing pages, once we have the
1879 * page lock we can determine safely if the page is beyond EOF. If it is not
1880 * beyond EOF, then the page is guaranteed safe against truncation until we
1881 * unlock the page.
1882 */
1883int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
1884{
1885 struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
1886 unsigned long end;
1887 loff_t size;
1888 int ret = -EINVAL;
1889
1890 lock_page(page);
1891 wait_on_page_writeback(page);
9ebefb18
CM		 1892 size = i_size_read(inode);
1893 if ((page->mapping != inode->i_mapping) ||
1894 ((page->index << PAGE_CACHE_SHIFT) > size)) {
1895 /* page got truncated out from underneath us */
1896 goto out_unlock;
1897 }
1898
1899 /* page is wholly or partially inside EOF */
1900 if (((page->index + 1) << PAGE_CACHE_SHIFT) > size)
1901 end = size & ~PAGE_CACHE_MASK;
1902 else
1903 end = PAGE_CACHE_SIZE;
1904
1905 ret = btrfs_prepare_write(NULL, page, 0, end);
1906 if (!ret)
1907 ret = btrfs_commit_write(NULL, page, 0, end);
1908
1909out_unlock:
1910 unlock_page(page);
1911 return ret;
1912}
1913
39279cc3
CM		 1914static void btrfs_truncate(struct inode *inode)
1915{
1916 struct btrfs_root *root = BTRFS_I(inode)->root;
1917 int ret;
1918 struct btrfs_trans_handle *trans;
1919
1920 if (!S_ISREG(inode->i_mode))
1921 return;
1922 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
1923 return;
1924
1925 btrfs_truncate_page(inode->i_mapping, inode->i_size);
1926
1927 mutex_lock(&root->fs_info->fs_mutex);
1928 trans = btrfs_start_transaction(root, 1);
1929 btrfs_set_trans_block_group(trans, inode);
1930
1931 /* FIXME, add redo link to tree so we don't leak on crash */
1932 ret = btrfs_truncate_in_trans(trans, root, inode);
1933 BUG_ON(ret);
1934 btrfs_update_inode(trans, root, inode);
1935 ret = btrfs_end_transaction(trans, root);
1936 BUG_ON(ret);
1937 mutex_unlock(&root->fs_info->fs_mutex);
1938 btrfs_btree_balance_dirty(root);
1939}
1940
1941int btrfs_commit_write(struct file *file, struct page *page,
1942 unsigned from, unsigned to)
1943{
1944 struct inode *inode = page->mapping->host;
1945 struct buffer_head *bh;
1946 loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
1947
1948 SetPageUptodate(page);
1949 bh = page_buffers(page);
1950 set_buffer_uptodate(bh);
1951 if (buffer_mapped(bh) && bh->b_blocknr != 0) {
1952 set_page_dirty(page);
1953 }
1954 if (pos > inode->i_size) {
1955 i_size_write(inode, pos);
1956 mark_inode_dirty(inode);
1957 }
1958 return 0;
1959}
1960
1961static int create_subvol(struct btrfs_root *root, char *name, int namelen)
1962{
1963 struct btrfs_trans_handle *trans;
1964 struct btrfs_key key;
1965 struct btrfs_root_item root_item;
1966 struct btrfs_inode_item *inode_item;
1967 struct buffer_head *subvol;
1968 struct btrfs_leaf *leaf;
1969 struct btrfs_root *new_root;
1970 struct inode *inode;
1971 struct inode *dir;
1972 int ret;
1973 u64 objectid;
1974 u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
1975
1976 mutex_lock(&root->fs_info->fs_mutex);
1977 trans = btrfs_start_transaction(root, 1);
1978 BUG_ON(!trans);
1979
1980 subvol = btrfs_alloc_free_block(trans, root, 0);
1981 if (subvol == NULL)
1982 return -ENOSPC;
1983 leaf = btrfs_buffer_leaf(subvol);
1984 btrfs_set_header_nritems(&leaf->header, 0);
1985 btrfs_set_header_level(&leaf->header, 0);
1986 btrfs_set_header_blocknr(&leaf->header, bh_blocknr(subvol));
1987 btrfs_set_header_generation(&leaf->header, trans->transid);
1988 btrfs_set_header_owner(&leaf->header, root->root_key.objectid);
1989 memcpy(leaf->header.fsid, root->fs_info->disk_super->fsid,
1990 sizeof(leaf->header.fsid));
1991 mark_buffer_dirty(subvol);
1992
1993 inode_item = &root_item.inode;
1994 memset(inode_item, 0, sizeof(*inode_item));
1995 btrfs_set_inode_generation(inode_item, 1);
1996 btrfs_set_inode_size(inode_item, 3);
1997 btrfs_set_inode_nlink(inode_item, 1);
1998 btrfs_set_inode_nblocks(inode_item, 1);
1999 btrfs_set_inode_mode(inode_item, S_IFDIR | 0755);
2000
2001 btrfs_set_root_blocknr(&root_item, bh_blocknr(subvol));
2002 btrfs_set_root_refs(&root_item, 1);
2003 brelse(subvol);
2004 subvol = NULL;
2005
2006 ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
2007 0, &objectid);
2008 BUG_ON(ret);
2009
2010 btrfs_set_root_dirid(&root_item, new_dirid);
2011
2012 key.objectid = objectid;
2013 key.offset = 1;
2014 key.flags = 0;
2015 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
2016 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
2017 &root_item);
2018 BUG_ON(ret);
2019
2020 /*
2021 * insert the directory item
2022 */
2023 key.offset = (u64)-1;
2024 dir = root->fs_info->sb->s_root->d_inode;
2025 ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
2026 name, namelen, dir->i_ino, &key,
2027 BTRFS_FT_DIR);
2028 BUG_ON(ret);
2029
2030 ret = btrfs_commit_transaction(trans, root);
2031 BUG_ON(ret);
2032
2033 new_root = btrfs_read_fs_root(root->fs_info, &key);
2034 BUG_ON(!new_root);
2035
2036 trans = btrfs_start_transaction(new_root, 1);
2037 BUG_ON(!trans);
2038
2039 inode = btrfs_new_inode(trans, new_root, new_dirid,
2040 BTRFS_I(dir)->block_group, S_IFDIR | 0700);
2041 inode->i_op = &btrfs_dir_inode_operations;
2042 inode->i_fop = &btrfs_dir_file_operations;
34088780 2043 new_root->inode = inode;
39279cc3
CM		 2044
2045 ret = btrfs_make_empty_dir(trans, new_root, new_dirid, new_dirid);
2046 BUG_ON(ret);
2047
2048 inode->i_nlink = 1;
2049 inode->i_size = 6;
2050 ret = btrfs_update_inode(trans, new_root, inode);
2051 BUG_ON(ret);
2052
2053 ret = btrfs_commit_transaction(trans, new_root);
2054 BUG_ON(ret);
2055
39279cc3
CM		 2056 mutex_unlock(&root->fs_info->fs_mutex);
2057 btrfs_btree_balance_dirty(root);
2058 return 0;
2059}
2060
2061static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
2062{
2063 struct btrfs_trans_handle *trans;
2064 struct btrfs_key key;
2065 struct btrfs_root_item new_root_item;
2066 int ret;
2067 u64 objectid;
2068
2069 if (!root->ref_cows)
2070 return -EINVAL;
2071
2072 mutex_lock(&root->fs_info->fs_mutex);
2073 trans = btrfs_start_transaction(root, 1);
2074 BUG_ON(!trans);
2075
2076 ret = btrfs_update_inode(trans, root, root->inode);
2077 BUG_ON(ret);
2078
2079 ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
2080 0, &objectid);
2081 BUG_ON(ret);
2082
2083 memcpy(&new_root_item, &root->root_item,
2084 sizeof(new_root_item));
2085
2086 key.objectid = objectid;
2087 key.offset = 1;
2088 key.flags = 0;
2089 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
2090 btrfs_set_root_blocknr(&new_root_item, bh_blocknr(root->node));
2091
2092 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
2093 &new_root_item);
2094 BUG_ON(ret);
2095
2096 /*
2097 * insert the directory item
2098 */
2099 key.offset = (u64)-1;
2100 ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
2101 name, namelen,
2102 root->fs_info->sb->s_root->d_inode->i_ino,
2103 &key, BTRFS_FT_DIR);
2104
2105 BUG_ON(ret);
2106
2107 ret = btrfs_inc_root_ref(trans, root);
2108 BUG_ON(ret);
2109
2110 ret = btrfs_commit_transaction(trans, root);
2111 BUG_ON(ret);
2112 mutex_unlock(&root->fs_info->fs_mutex);
2113 btrfs_btree_balance_dirty(root);
2114 return 0;
2115}
2116
2117int btrfs_ioctl(struct inode *inode, struct file *filp, unsigned int
2118 cmd, unsigned long arg)
2119{
2120 struct btrfs_root *root = BTRFS_I(inode)->root;
2121 struct btrfs_ioctl_vol_args vol_args;
2122 int ret = 0;
2123 struct btrfs_dir_item *di;
2124 int namelen;
2125 struct btrfs_path *path;
2126 u64 root_dirid;
2127
2128 switch (cmd) {
2129 case BTRFS_IOC_SNAP_CREATE:
2130 if (copy_from_user(&vol_args,
2131 (struct btrfs_ioctl_vol_args __user *)arg,
2132 sizeof(vol_args)))
2133 return -EFAULT;
2134 namelen = strlen(vol_args.name);
2135 if (namelen > BTRFS_VOL_NAME_MAX)
2136 return -EINVAL;
8a712645
CM		 2137 if (strchr(vol_args.name, '/'))
2138 return -EINVAL;
39279cc3
CM		 2139 path = btrfs_alloc_path();
2140 if (!path)
2141 return -ENOMEM;
2142 root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
2143 mutex_lock(&root->fs_info->fs_mutex);
2144 di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
2145 path, root_dirid,
2146 vol_args.name, namelen, 0);
2147 mutex_unlock(&root->fs_info->fs_mutex);
2148 btrfs_free_path(path);
2149 if (di && !IS_ERR(di))
2150 return -EEXIST;
2151
2152 if (root == root->fs_info->tree_root)
2153 ret = create_subvol(root, vol_args.name, namelen);
2154 else
2155 ret = create_snapshot(root, vol_args.name, namelen);
2156 WARN_ON(ret);
2157 break;
2158 default:
2159 return -ENOTTY;
2160 }
2161 return ret;
2162}
2163
2164#ifdef CONFIG_COMPAT
2165long btrfs_compat_ioctl(struct file *file, unsigned int cmd,
2166 unsigned long arg)
2167{
2168 struct inode *inode = file->f_path.dentry->d_inode;
2169 int ret;
2170 lock_kernel();
2171 ret = btrfs_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
2172 unlock_kernel();
2173 return ret;
2174
2175}
2176#endif
2177
2178/*
2179 * Called inside transaction, so use GFP_NOFS
2180 */
2181struct inode *btrfs_alloc_inode(struct super_block *sb)
2182{
2183 struct btrfs_inode *ei;
2184
2185 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
2186 if (!ei)
2187 return NULL;
2188 return &ei->vfs_inode;
2189}
2190
2191void btrfs_destroy_inode(struct inode *inode)
2192{
2193 WARN_ON(!list_empty(&inode->i_dentry));
2194 WARN_ON(inode->i_data.nrpages);
2195
2196 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
2197}
2198
2199static void init_once(void * foo, struct kmem_cache * cachep,
2200 unsigned long flags)
2201{
2202 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
2203
2204 inode_init_once(&ei->vfs_inode);
2205}
2206
2207void btrfs_destroy_cachep(void)
2208{
2209 if (btrfs_inode_cachep)
2210 kmem_cache_destroy(btrfs_inode_cachep);
2211 if (btrfs_trans_handle_cachep)
2212 kmem_cache_destroy(btrfs_trans_handle_cachep);
2213 if (btrfs_transaction_cachep)
2214 kmem_cache_destroy(btrfs_transaction_cachep);
2215 if (btrfs_bit_radix_cachep)
2216 kmem_cache_destroy(btrfs_bit_radix_cachep);
2217 if (btrfs_path_cachep)
2218 kmem_cache_destroy(btrfs_path_cachep);
2219}
2220
2221int btrfs_init_cachep(void)
2222{
2223 btrfs_inode_cachep = kmem_cache_create("btrfs_inode_cache",
2224 sizeof(struct btrfs_inode),
2225 0, (SLAB_RECLAIM_ACCOUNT|
2226 SLAB_MEM_SPREAD),
2227 init_once, NULL);
2228 if (!btrfs_inode_cachep)
2229 goto fail;
2230 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle_cache",
2231 sizeof(struct btrfs_trans_handle),
2232 0, (SLAB_RECLAIM_ACCOUNT|
2233 SLAB_MEM_SPREAD),
2234 NULL, NULL);
2235 if (!btrfs_trans_handle_cachep)
2236 goto fail;
2237 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction_cache",
2238 sizeof(struct btrfs_transaction),
2239 0, (SLAB_RECLAIM_ACCOUNT|
2240 SLAB_MEM_SPREAD),
2241 NULL, NULL);
2242 if (!btrfs_transaction_cachep)
2243 goto fail;
2244 btrfs_path_cachep = kmem_cache_create("btrfs_path_cache",
2245 sizeof(struct btrfs_transaction),
2246 0, (SLAB_RECLAIM_ACCOUNT|
2247 SLAB_MEM_SPREAD),
2248 NULL, NULL);
2249 if (!btrfs_path_cachep)
2250 goto fail;
2251 btrfs_bit_radix_cachep = kmem_cache_create("btrfs_radix",
2252 256,
2253 0, (SLAB_RECLAIM_ACCOUNT|
2254 SLAB_MEM_SPREAD |
2255 SLAB_DESTROY_BY_RCU),
2256 NULL, NULL);
2257 if (!btrfs_bit_radix_cachep)
2258 goto fail;
2259 return 0;
2260fail:
2261 btrfs_destroy_cachep();
2262 return -ENOMEM;
2263}
2264
2265static int btrfs_getattr(struct vfsmount *mnt,
2266 struct dentry *dentry, struct kstat *stat)
2267{
2268 struct inode *inode = dentry->d_inode;
2269 generic_fillattr(inode, stat);
2270 stat->blksize = 256 * 1024;
2271 return 0;
2272}
2273
2274static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
2275 struct inode * new_dir,struct dentry *new_dentry)
2276{
2277 struct btrfs_trans_handle *trans;
2278 struct btrfs_root *root = BTRFS_I(old_dir)->root;
2279 struct inode *new_inode = new_dentry->d_inode;
2280 struct inode *old_inode = old_dentry->d_inode;
2281 struct timespec ctime = CURRENT_TIME;
2282 struct btrfs_path *path;
2283 struct btrfs_dir_item *di;
2284 int ret;
2285
2286 if (S_ISDIR(old_inode->i_mode) && new_inode &&
2287 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
2288 return -ENOTEMPTY;
2289 }
2290 mutex_lock(&root->fs_info->fs_mutex);
2291 trans = btrfs_start_transaction(root, 1);
2292 btrfs_set_trans_block_group(trans, new_dir);
2293 path = btrfs_alloc_path();
2294 if (!path) {
2295 ret = -ENOMEM;
2296 goto out_fail;
2297 }
2298
2299 old_dentry->d_inode->i_nlink++;
2300 old_dir->i_ctime = old_dir->i_mtime = ctime;
2301 new_dir->i_ctime = new_dir->i_mtime = ctime;
2302 old_inode->i_ctime = ctime;
2303 if (S_ISDIR(old_inode->i_mode) && old_dir != new_dir) {
2304 struct btrfs_key *location = &BTRFS_I(new_dir)->location;
2305 u64 old_parent_oid;
2306 di = btrfs_lookup_dir_item(trans, root, path, old_inode->i_ino,
2307 "..", 2, -1);
2308 if (IS_ERR(di)) {
2309 ret = PTR_ERR(di);
2310 goto out_fail;
2311 }
2312 if (!di) {
2313 ret = -ENOENT;
2314 goto out_fail;
2315 }
2316 old_parent_oid = btrfs_disk_key_objectid(&di->location);
2317 ret = btrfs_del_item(trans, root, path);
2318 if (ret) {
2319 ret = -EIO;
2320 goto out_fail;
2321 }
2322 btrfs_release_path(root, path);
2323
2324 di = btrfs_lookup_dir_index_item(trans, root, path,
2325 old_inode->i_ino,
2326 old_parent_oid,
2327 "..", 2, -1);
2328 if (IS_ERR(di)) {
2329 ret = PTR_ERR(di);
2330 goto out_fail;
2331 }
2332 if (!di) {
2333 ret = -ENOENT;
2334 goto out_fail;
2335 }
2336 ret = btrfs_del_item(trans, root, path);
2337 if (ret) {
2338 ret = -EIO;
2339 goto out_fail;
2340 }
2341 btrfs_release_path(root, path);
2342
2343 ret = btrfs_insert_dir_item(trans, root, "..", 2,
2344 old_inode->i_ino, location,
2345 BTRFS_FT_DIR);
2346 if (ret)
2347 goto out_fail;
2348 }
2349
2350
2351 ret = btrfs_unlink_trans(trans, root, old_dir, old_dentry);
2352 if (ret)
2353 goto out_fail;
2354
2355 if (new_inode) {
2356 new_inode->i_ctime = CURRENT_TIME;
2357 ret = btrfs_unlink_trans(trans, root, new_dir, new_dentry);
2358 if (ret)
2359 goto out_fail;
2360 if (S_ISDIR(new_inode->i_mode))
2361 clear_nlink(new_inode);
2362 else
2363 drop_nlink(new_inode);
2364 btrfs_update_inode(trans, root, new_inode);
2365 }
2366 ret = btrfs_add_link(trans, new_dentry, old_inode);
2367 if (ret)
2368 goto out_fail;
2369
2370out_fail:
2371 btrfs_free_path(path);
2372 btrfs_end_transaction(trans, root);
2373 mutex_unlock(&root->fs_info->fs_mutex);
2374 return ret;
2375}
2376
2377static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
2378 const char *symname)
2379{
2380 struct btrfs_trans_handle *trans;
2381 struct btrfs_root *root = BTRFS_I(dir)->root;
2382 struct btrfs_path *path;
2383 struct btrfs_key key;
2384 struct inode *inode;
2385 int err;
2386 int drop_inode = 0;
2387 u64 objectid;
2388 int name_len;
2389 int datasize;
2390 char *ptr;
2391 struct btrfs_file_extent_item *ei;
2392
2393 name_len = strlen(symname) + 1;
2394 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
2395 return -ENAMETOOLONG;
2396 mutex_lock(&root->fs_info->fs_mutex);
2397 trans = btrfs_start_transaction(root, 1);
2398 btrfs_set_trans_block_group(trans, dir);
2399
2400 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
2401 if (err) {
2402 err = -ENOSPC;
2403 goto out_unlock;
2404 }
2405
2406 inode = btrfs_new_inode(trans, root, objectid,
2407 BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO);
2408 err = PTR_ERR(inode);
2409 if (IS_ERR(inode))
2410 goto out_unlock;
2411
2412 btrfs_set_trans_block_group(trans, inode);
2413 err = btrfs_add_nondir(trans, dentry, inode);
2414 if (err)
2415 drop_inode = 1;
2416 else {
2417 inode->i_mapping->a_ops = &btrfs_aops;
2418 inode->i_fop = &btrfs_file_operations;
2419 inode->i_op = &btrfs_file_inode_operations;
2420 }
2421 dir->i_sb->s_dirt = 1;
2422 btrfs_update_inode_block_group(trans, inode);
2423 btrfs_update_inode_block_group(trans, dir);
2424 if (drop_inode)
2425 goto out_unlock;
2426
2427 path = btrfs_alloc_path();
2428 BUG_ON(!path);
2429 key.objectid = inode->i_ino;
2430 key.offset = 0;
2431 key.flags = 0;
2432 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
2433 datasize = btrfs_file_extent_calc_inline_size(name_len);
2434 err = btrfs_insert_empty_item(trans, root, path, &key,
2435 datasize);
2436 BUG_ON(err);
2437 ei = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
2438 path->slots[0], struct btrfs_file_extent_item);
2439 btrfs_set_file_extent_generation(ei, trans->transid);
2440 btrfs_set_file_extent_type(ei,
2441 BTRFS_FILE_EXTENT_INLINE);
2442 ptr = btrfs_file_extent_inline_start(ei);
2443 btrfs_memcpy(root, path->nodes[0]->b_data,
2444 ptr, symname, name_len);
2445 mark_buffer_dirty(path->nodes[0]);
2446 btrfs_free_path(path);
2447 inode->i_op = &btrfs_symlink_inode_operations;
2448 inode->i_mapping->a_ops = &btrfs_symlink_aops;
2449 inode->i_size = name_len - 1;
2450 btrfs_update_inode(trans, root, inode);
2451 err = 0;
2452
2453out_unlock:
2454 btrfs_end_transaction(trans, root);
2455 mutex_unlock(&root->fs_info->fs_mutex);
2456
2457 if (drop_inode) {
2458 inode_dec_link_count(inode);
2459 iput(inode);
2460 }
2461 btrfs_btree_balance_dirty(root);
2462 return err;
2463}
2464
2465static struct inode_operations btrfs_dir_inode_operations = {
2466 .lookup = btrfs_lookup,
2467 .create = btrfs_create,
2468 .unlink = btrfs_unlink,
2469 .link = btrfs_link,
2470 .mkdir = btrfs_mkdir,
2471 .rmdir = btrfs_rmdir,
2472 .rename = btrfs_rename,
2473 .symlink = btrfs_symlink,
2474 .setattr = btrfs_setattr,
2475};
2476
2477static struct inode_operations btrfs_dir_ro_inode_operations = {
2478 .lookup = btrfs_lookup,
2479};
2480
2481static struct file_operations btrfs_dir_file_operations = {
2482 .llseek = generic_file_llseek,
2483 .read = generic_read_dir,
2484 .readdir = btrfs_readdir,
2485 .ioctl = btrfs_ioctl,
2486#ifdef CONFIG_COMPAT
2487 .compat_ioctl = btrfs_compat_ioctl,
2488#endif
2489};
2490
2491static struct address_space_operations btrfs_aops = {
2492 .readpage = btrfs_readpage,
2493 .writepage = btrfs_writepage,
2494 .sync_page = block_sync_page,
2495 .prepare_write = btrfs_prepare_write,
2496 .commit_write = btrfs_commit_write,
2497 .bmap = btrfs_bmap,
2498};
2499
2500static struct address_space_operations btrfs_symlink_aops = {
2501 .readpage = btrfs_readpage,
2502 .writepage = btrfs_writepage,
2503};
2504
2505static struct inode_operations btrfs_file_inode_operations = {
2506 .truncate = btrfs_truncate,
2507 .getattr = btrfs_getattr,
2508 .setattr = btrfs_setattr,
2509};
2510
2511static struct inode_operations btrfs_symlink_inode_operations = {
2512 .readlink = generic_readlink,
2513 .follow_link = page_follow_link_light,
2514 .put_link = page_put_link,
2515};
Clone of davem's net-next-2.6 tree