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Btrfs: fixup various fsx failures
[deliverable/linux.git] / fs / btrfs / super.c
1 #include <linux/module.h>
2 #include <linux/buffer_head.h>
3 #include <linux/fs.h>
4 #include <linux/pagemap.h>
5 #include <linux/highmem.h>
6 #include <linux/time.h>
7 #include <linux/init.h>
8 #include <linux/string.h>
9 #include <linux/smp_lock.h>
10 #include <linux/backing-dev.h>
11 #include <linux/mpage.h>
12 #include <linux/swap.h>
13 #include <linux/writeback.h>
14 #include <linux/statfs.h>
15 #include "ctree.h"
16 #include "disk-io.h"
17 #include "transaction.h"
18 #include "btrfs_inode.h"
19 #include "ioctl.h"
20 #include "print-tree.h"
21
22 struct btrfs_iget_args {
23 u64 ino;
24 struct btrfs_root *root;
25 };
26
27 #define BTRFS_SUPER_MAGIC 0x9123682E
28
29 static struct inode_operations btrfs_dir_inode_operations;
30 static struct inode_operations btrfs_symlink_inode_operations;
31 static struct inode_operations btrfs_dir_ro_inode_operations;
32 static struct super_operations btrfs_super_ops;
33 static struct file_operations btrfs_dir_file_operations;
34 static struct inode_operations btrfs_file_inode_operations;
35 static struct address_space_operations btrfs_aops;
36 static struct address_space_operations btrfs_symlink_aops;
37 static struct file_operations btrfs_file_operations;
38
39 static int drop_extents(struct btrfs_trans_handle *trans,
40 struct btrfs_root *root,
41 struct inode *inode,
42 u64 start, u64 end, u64 *hint_block);
43 static int btrfs_get_block(struct inode *inode, sector_t iblock,
44 struct buffer_head *result, int create);
45
46 static void btrfs_read_locked_inode(struct inode *inode)
47 {
48 struct btrfs_path *path;
49 struct btrfs_inode_item *inode_item;
50 struct btrfs_root *root = BTRFS_I(inode)->root;
51 struct btrfs_key location;
52 struct btrfs_block_group_cache *alloc_group;
53 u64 alloc_group_block;
54 int ret;
55
56 path = btrfs_alloc_path();
57 BUG_ON(!path);
58 btrfs_init_path(path);
59 mutex_lock(&root->fs_info->fs_mutex);
60
61 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
62 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
63 if (ret) {
64 btrfs_free_path(path);
65 goto make_bad;
66 }
67 inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
68 path->slots[0],
69 struct btrfs_inode_item);
70
71 inode->i_mode = btrfs_inode_mode(inode_item);
72 inode->i_nlink = btrfs_inode_nlink(inode_item);
73 inode->i_uid = btrfs_inode_uid(inode_item);
74 inode->i_gid = btrfs_inode_gid(inode_item);
75 inode->i_size = btrfs_inode_size(inode_item);
76 inode->i_atime.tv_sec = btrfs_timespec_sec(&inode_item->atime);
77 inode->i_atime.tv_nsec = btrfs_timespec_nsec(&inode_item->atime);
78 inode->i_mtime.tv_sec = btrfs_timespec_sec(&inode_item->mtime);
79 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(&inode_item->mtime);
80 inode->i_ctime.tv_sec = btrfs_timespec_sec(&inode_item->ctime);
81 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(&inode_item->ctime);
82 inode->i_blocks = btrfs_inode_nblocks(inode_item);
83 inode->i_generation = btrfs_inode_generation(inode_item);
84 alloc_group_block = btrfs_inode_block_group(inode_item);
85 ret = radix_tree_gang_lookup(&root->fs_info->block_group_radix,
86 (void **)&alloc_group,
87 alloc_group_block, 1);
88 BUG_ON(!ret);
89 BTRFS_I(inode)->block_group = alloc_group;
90
91 btrfs_free_path(path);
92 inode_item = NULL;
93
94 mutex_unlock(&root->fs_info->fs_mutex);
95
96 switch (inode->i_mode & S_IFMT) {
97 #if 0
98 default:
99 init_special_inode(inode, inode->i_mode,
100 btrfs_inode_rdev(inode_item));
101 break;
102 #endif
103 case S_IFREG:
104 inode->i_mapping->a_ops = &btrfs_aops;
105 inode->i_fop = &btrfs_file_operations;
106 inode->i_op = &btrfs_file_inode_operations;
107 break;
108 case S_IFDIR:
109 inode->i_fop = &btrfs_dir_file_operations;
110 if (root == root->fs_info->tree_root)
111 inode->i_op = &btrfs_dir_ro_inode_operations;
112 else
113 inode->i_op = &btrfs_dir_inode_operations;
114 break;
115 case S_IFLNK:
116 inode->i_op = &btrfs_symlink_inode_operations;
117 inode->i_mapping->a_ops = &btrfs_symlink_aops;
118 break;
119 }
120 return;
121
122 make_bad:
123 btrfs_release_path(root, path);
124 btrfs_free_path(path);
125 mutex_unlock(&root->fs_info->fs_mutex);
126 make_bad_inode(inode);
127 }
128
129 static void fill_inode_item(struct btrfs_inode_item *item,
130 struct inode *inode)
131 {
132 btrfs_set_inode_uid(item, inode->i_uid);
133 btrfs_set_inode_gid(item, inode->i_gid);
134 btrfs_set_inode_size(item, inode->i_size);
135 btrfs_set_inode_mode(item, inode->i_mode);
136 btrfs_set_inode_nlink(item, inode->i_nlink);
137 btrfs_set_timespec_sec(&item->atime, inode->i_atime.tv_sec);
138 btrfs_set_timespec_nsec(&item->atime, inode->i_atime.tv_nsec);
139 btrfs_set_timespec_sec(&item->mtime, inode->i_mtime.tv_sec);
140 btrfs_set_timespec_nsec(&item->mtime, inode->i_mtime.tv_nsec);
141 btrfs_set_timespec_sec(&item->ctime, inode->i_ctime.tv_sec);
142 btrfs_set_timespec_nsec(&item->ctime, inode->i_ctime.tv_nsec);
143 btrfs_set_inode_nblocks(item, inode->i_blocks);
144 btrfs_set_inode_generation(item, inode->i_generation);
145 btrfs_set_inode_block_group(item,
146 BTRFS_I(inode)->block_group->key.objectid);
147 }
148
149 static int btrfs_update_inode(struct btrfs_trans_handle *trans,
150 struct btrfs_root *root,
151 struct inode *inode)
152 {
153 struct btrfs_inode_item *inode_item;
154 struct btrfs_path *path;
155 int ret;
156
157 path = btrfs_alloc_path();
158 BUG_ON(!path);
159 btrfs_init_path(path);
160 ret = btrfs_lookup_inode(trans, root, path,
161 &BTRFS_I(inode)->location, 1);
162 if (ret) {
163 if (ret > 0)
164 ret = -ENOENT;
165 goto failed;
166 }
167
168 inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
169 path->slots[0],
170 struct btrfs_inode_item);
171
172 fill_inode_item(inode_item, inode);
173 btrfs_mark_buffer_dirty(path->nodes[0]);
174 ret = 0;
175 failed:
176 btrfs_release_path(root, path);
177 btrfs_free_path(path);
178 return ret;
179 }
180
181
182 static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
183 struct btrfs_root *root,
184 struct inode *dir,
185 struct dentry *dentry)
186 {
187 struct btrfs_path *path;
188 const char *name = dentry->d_name.name;
189 int name_len = dentry->d_name.len;
190 int ret = 0;
191 u64 objectid;
192 struct btrfs_dir_item *di;
193
194 path = btrfs_alloc_path();
195 BUG_ON(!path);
196 btrfs_init_path(path);
197 di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
198 name, name_len, -1);
199 if (IS_ERR(di)) {
200 ret = PTR_ERR(di);
201 goto err;
202 }
203 if (!di) {
204 ret = -ENOENT;
205 goto err;
206 }
207 objectid = btrfs_disk_key_objectid(&di->location);
208 ret = btrfs_delete_one_dir_name(trans, root, path, di);
209 BUG_ON(ret);
210 btrfs_release_path(root, path);
211
212 di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
213 objectid, name, name_len, -1);
214 if (IS_ERR(di)) {
215 ret = PTR_ERR(di);
216 goto err;
217 }
218 if (!di) {
219 ret = -ENOENT;
220 goto err;
221 }
222 ret = btrfs_delete_one_dir_name(trans, root, path, di);
223 BUG_ON(ret);
224
225 dentry->d_inode->i_ctime = dir->i_ctime;
226 err:
227 btrfs_free_path(path);
228 if (!ret) {
229 dir->i_size -= name_len * 2;
230 btrfs_update_inode(trans, root, dir);
231 drop_nlink(dentry->d_inode);
232 btrfs_update_inode(trans, root, dentry->d_inode);
233 dir->i_sb->s_dirt = 1;
234 }
235 return ret;
236 }
237
238 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
239 {
240 struct btrfs_root *root;
241 struct btrfs_trans_handle *trans;
242 int ret;
243
244 root = BTRFS_I(dir)->root;
245 mutex_lock(&root->fs_info->fs_mutex);
246 trans = btrfs_start_transaction(root, 1);
247 btrfs_set_trans_block_group(trans, dir);
248 ret = btrfs_unlink_trans(trans, root, dir, dentry);
249 btrfs_end_transaction(trans, root);
250 mutex_unlock(&root->fs_info->fs_mutex);
251 btrfs_btree_balance_dirty(root);
252 return ret;
253 }
254
255 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
256 {
257 struct inode *inode = dentry->d_inode;
258 int err;
259 int ret;
260 struct btrfs_root *root = BTRFS_I(dir)->root;
261 struct btrfs_path *path;
262 struct btrfs_key key;
263 struct btrfs_trans_handle *trans;
264 struct btrfs_key found_key;
265 int found_type;
266 struct btrfs_leaf *leaf;
267 char *goodnames = "..";
268
269 path = btrfs_alloc_path();
270 BUG_ON(!path);
271 btrfs_init_path(path);
272 mutex_lock(&root->fs_info->fs_mutex);
273 trans = btrfs_start_transaction(root, 1);
274 btrfs_set_trans_block_group(trans, dir);
275 key.objectid = inode->i_ino;
276 key.offset = (u64)-1;
277 key.flags = (u32)-1;
278 while(1) {
279 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
280 if (ret < 0) {
281 err = ret;
282 goto out;
283 }
284 BUG_ON(ret == 0);
285 if (path->slots[0] == 0) {
286 err = -ENOENT;
287 goto out;
288 }
289 path->slots[0]--;
290 leaf = btrfs_buffer_leaf(path->nodes[0]);
291 btrfs_disk_key_to_cpu(&found_key,
292 &leaf->items[path->slots[0]].key);
293 found_type = btrfs_key_type(&found_key);
294 if (found_key.objectid != inode->i_ino) {
295 err = -ENOENT;
296 goto out;
297 }
298 if ((found_type != BTRFS_DIR_ITEM_KEY &&
299 found_type != BTRFS_DIR_INDEX_KEY) ||
300 (!btrfs_match_dir_item_name(root, path, goodnames, 2) &&
301 !btrfs_match_dir_item_name(root, path, goodnames, 1))) {
302 err = -ENOTEMPTY;
303 goto out;
304 }
305 ret = btrfs_del_item(trans, root, path);
306 BUG_ON(ret);
307
308 if (found_type == BTRFS_DIR_ITEM_KEY && found_key.offset == 1)
309 break;
310 btrfs_release_path(root, path);
311 }
312 ret = 0;
313 btrfs_release_path(root, path);
314
315 /* now the directory is empty */
316 err = btrfs_unlink_trans(trans, root, dir, dentry);
317 if (!err) {
318 inode->i_size = 0;
319 }
320 out:
321 btrfs_release_path(root, path);
322 btrfs_free_path(path);
323 mutex_unlock(&root->fs_info->fs_mutex);
324 ret = btrfs_end_transaction(trans, root);
325 btrfs_btree_balance_dirty(root);
326 if (ret && !err)
327 err = ret;
328 return err;
329 }
330
331 static int btrfs_free_inode(struct btrfs_trans_handle *trans,
332 struct btrfs_root *root,
333 struct inode *inode)
334 {
335 struct btrfs_path *path;
336 int ret;
337
338 clear_inode(inode);
339
340 path = btrfs_alloc_path();
341 BUG_ON(!path);
342 btrfs_init_path(path);
343 ret = btrfs_lookup_inode(trans, root, path,
344 &BTRFS_I(inode)->location, -1);
345 BUG_ON(ret);
346 ret = btrfs_del_item(trans, root, path);
347 BUG_ON(ret);
348 btrfs_free_path(path);
349 return ret;
350 }
351
352 static void reada_truncate(struct btrfs_root *root, struct btrfs_path *path,
353 u64 objectid)
354 {
355 struct btrfs_node *node;
356 int i;
357 int nritems;
358 u64 item_objectid;
359 u64 blocknr;
360 int slot;
361 int ret;
362
363 if (!path->nodes[1])
364 return;
365 node = btrfs_buffer_node(path->nodes[1]);
366 slot = path->slots[1];
367 if (slot == 0)
368 return;
369 nritems = btrfs_header_nritems(&node->header);
370 for (i = slot - 1; i >= 0; i--) {
371 item_objectid = btrfs_disk_key_objectid(&node->ptrs[i].key);
372 if (item_objectid != objectid)
373 break;
374 blocknr = btrfs_node_blockptr(node, i);
375 ret = readahead_tree_block(root, blocknr);
376 if (ret)
377 break;
378 }
379 }
380
381 static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
382 struct btrfs_root *root,
383 struct inode *inode)
384 {
385 int ret;
386 struct btrfs_path *path;
387 struct btrfs_key key;
388 struct btrfs_disk_key *found_key;
389 u32 found_type;
390 struct btrfs_leaf *leaf;
391 struct btrfs_file_extent_item *fi;
392 u64 extent_start = 0;
393 u64 extent_num_blocks = 0;
394 u64 item_end = 0;
395 int found_extent;
396 int del_item;
397
398 path = btrfs_alloc_path();
399 BUG_ON(!path);
400 /* FIXME, add redo link to tree so we don't leak on crash */
401 key.objectid = inode->i_ino;
402 key.offset = (u64)-1;
403 key.flags = (u32)-1;
404 while(1) {
405 btrfs_init_path(path);
406 fi = NULL;
407 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
408 if (ret < 0) {
409 goto error;
410 }
411 if (ret > 0) {
412 BUG_ON(path->slots[0] == 0);
413 path->slots[0]--;
414 }
415 reada_truncate(root, path, inode->i_ino);
416 leaf = btrfs_buffer_leaf(path->nodes[0]);
417 found_key = &leaf->items[path->slots[0]].key;
418 found_type = btrfs_disk_key_type(found_key);
419 if (btrfs_disk_key_objectid(found_key) != inode->i_ino)
420 break;
421 if (found_type != BTRFS_CSUM_ITEM_KEY &&
422 found_type != BTRFS_DIR_ITEM_KEY &&
423 found_type != BTRFS_DIR_INDEX_KEY &&
424 found_type != BTRFS_EXTENT_DATA_KEY)
425 break;
426 item_end = btrfs_disk_key_offset(found_key);
427 if (found_type == BTRFS_EXTENT_DATA_KEY) {
428 fi = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
429 path->slots[0],
430 struct btrfs_file_extent_item);
431 if (btrfs_file_extent_type(fi) !=
432 BTRFS_FILE_EXTENT_INLINE) {
433 item_end += btrfs_file_extent_num_blocks(fi) <<
434 inode->i_blkbits;
435 }
436 }
437 if (found_type == BTRFS_CSUM_ITEM_KEY) {
438 ret = btrfs_csum_truncate(trans, root, path,
439 inode->i_size);
440 BUG_ON(ret);
441 }
442 if (item_end < inode->i_size) {
443 if (found_type) {
444 btrfs_set_key_type(&key, found_type - 1);
445 continue;
446 }
447 break;
448 }
449 if (btrfs_disk_key_offset(found_key) >= inode->i_size)
450 del_item = 1;
451 else
452 del_item = 0;
453 found_extent = 0;
454
455 if (found_type == BTRFS_EXTENT_DATA_KEY &&
456 btrfs_file_extent_type(fi) !=
457 BTRFS_FILE_EXTENT_INLINE) {
458 u64 num_dec;
459 if (!del_item) {
460 u64 orig_num_blocks =
461 btrfs_file_extent_num_blocks(fi);
462 extent_num_blocks = inode->i_size -
463 btrfs_disk_key_offset(found_key) +
464 root->blocksize - 1;
465 extent_num_blocks >>= inode->i_blkbits;
466 btrfs_set_file_extent_num_blocks(fi,
467 extent_num_blocks);
468 inode->i_blocks -= (orig_num_blocks -
469 extent_num_blocks) << 3;
470 mark_buffer_dirty(path->nodes[0]);
471 } else {
472 extent_start =
473 btrfs_file_extent_disk_blocknr(fi);
474 extent_num_blocks =
475 btrfs_file_extent_disk_num_blocks(fi);
476 /* FIXME blocksize != 4096 */
477 num_dec = btrfs_file_extent_num_blocks(fi) << 3;
478 if (extent_start != 0) {
479 found_extent = 1;
480 inode->i_blocks -= num_dec;
481 }
482 }
483 }
484 if (del_item) {
485 ret = btrfs_del_item(trans, root, path);
486 BUG_ON(ret);
487 } else {
488 break;
489 }
490 btrfs_release_path(root, path);
491 if (found_extent) {
492 ret = btrfs_free_extent(trans, root, extent_start,
493 extent_num_blocks, 0);
494 BUG_ON(ret);
495 }
496 }
497 ret = 0;
498 error:
499 btrfs_release_path(root, path);
500 btrfs_free_path(path);
501 inode->i_sb->s_dirt = 1;
502 return ret;
503 }
504
505 static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
506 {
507 struct inode *inode = mapping->host;
508 unsigned blocksize = 1 << inode->i_blkbits;
509 pgoff_t index = from >> PAGE_CACHE_SHIFT;
510 unsigned offset = from & (PAGE_CACHE_SIZE-1);
511 struct page *page;
512 char *kaddr;
513 int ret = 0;
514 struct btrfs_root *root = BTRFS_I(inode)->root;
515 u64 alloc_hint;
516 struct btrfs_key ins;
517 struct btrfs_trans_handle *trans;
518
519 if ((offset & (blocksize - 1)) == 0)
520 goto out;
521
522 ret = -ENOMEM;
523 page = grab_cache_page(mapping, index);
524 if (!page)
525 goto out;
526
527 if (!PageUptodate(page)) {
528 ret = mpage_readpage(page, btrfs_get_block);
529 lock_page(page);
530 if (!PageUptodate(page)) {
531 ret = -EIO;
532 goto out;
533 }
534 }
535 mutex_lock(&root->fs_info->fs_mutex);
536 trans = btrfs_start_transaction(root, 1);
537 btrfs_set_trans_block_group(trans, inode);
538
539 ret = drop_extents(trans, root, inode, page->index << PAGE_CACHE_SHIFT,
540 (page->index + 1) << PAGE_CACHE_SHIFT, &alloc_hint);
541 BUG_ON(ret);
542 ret = btrfs_alloc_extent(trans, root, inode->i_ino, 1,
543 alloc_hint, (u64)-1, &ins, 1);
544 BUG_ON(ret);
545 ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
546 page->index << PAGE_CACHE_SHIFT,
547 ins.objectid, 1, 1);
548 BUG_ON(ret);
549 SetPageChecked(page);
550 kaddr = kmap(page);
551 memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
552 flush_dcache_page(page);
553 btrfs_csum_file_block(trans, root, inode->i_ino,
554 page->index << PAGE_CACHE_SHIFT,
555 kaddr, PAGE_CACHE_SIZE);
556 kunmap(page);
557 btrfs_end_transaction(trans, root);
558 mutex_unlock(&root->fs_info->fs_mutex);
559
560 set_page_dirty(page);
561 unlock_page(page);
562 page_cache_release(page);
563 out:
564 return ret;
565 }
566
567 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
568 {
569 struct inode *inode = dentry->d_inode;
570 int err;
571
572 err = inode_change_ok(inode, attr);
573 if (err)
574 return err;
575
576 if (S_ISREG(inode->i_mode) &&
577 attr->ia_valid & ATTR_SIZE && attr->ia_size > inode->i_size) {
578 struct btrfs_trans_handle *trans;
579 struct btrfs_root *root = BTRFS_I(inode)->root;
580 u64 mask = root->blocksize - 1;
581 u64 pos = (inode->i_size + mask) & ~mask;
582 u64 hole_size;
583
584 if (attr->ia_size <= pos)
585 goto out;
586
587 btrfs_truncate_page(inode->i_mapping, inode->i_size);
588
589 hole_size = (attr->ia_size - pos + mask) & ~mask;
590 hole_size >>= inode->i_blkbits;
591
592 mutex_lock(&root->fs_info->fs_mutex);
593 trans = btrfs_start_transaction(root, 1);
594 btrfs_set_trans_block_group(trans, inode);
595 err = btrfs_insert_file_extent(trans, root, inode->i_ino,
596 pos, 0, 0, hole_size);
597 BUG_ON(err);
598 btrfs_end_transaction(trans, root);
599 mutex_unlock(&root->fs_info->fs_mutex);
600 }
601 out:
602 err = inode_setattr(inode, attr);
603
604 return err;
605 }
606 static void btrfs_delete_inode(struct inode *inode)
607 {
608 struct btrfs_trans_handle *trans;
609 struct btrfs_root *root = BTRFS_I(inode)->root;
610 int ret;
611
612 truncate_inode_pages(&inode->i_data, 0);
613 if (is_bad_inode(inode)) {
614 goto no_delete;
615 }
616 inode->i_size = 0;
617 mutex_lock(&root->fs_info->fs_mutex);
618 trans = btrfs_start_transaction(root, 1);
619 btrfs_set_trans_block_group(trans, inode);
620 ret = btrfs_truncate_in_trans(trans, root, inode);
621 BUG_ON(ret);
622 btrfs_free_inode(trans, root, inode);
623 btrfs_end_transaction(trans, root);
624 mutex_unlock(&root->fs_info->fs_mutex);
625 btrfs_btree_balance_dirty(root);
626 return;
627 no_delete:
628 clear_inode(inode);
629 }
630
631 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
632 struct btrfs_key *location)
633 {
634 const char *name = dentry->d_name.name;
635 int namelen = dentry->d_name.len;
636 struct btrfs_dir_item *di;
637 struct btrfs_path *path;
638 struct btrfs_root *root = BTRFS_I(dir)->root;
639 int ret;
640
641 path = btrfs_alloc_path();
642 BUG_ON(!path);
643 btrfs_init_path(path);
644 di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
645 namelen, 0);
646 if (!di || IS_ERR(di)) {
647 location->objectid = 0;
648 ret = 0;
649 goto out;
650 }
651 btrfs_disk_key_to_cpu(location, &di->location);
652 out:
653 btrfs_release_path(root, path);
654 btrfs_free_path(path);
655 return ret;
656 }
657
658 static int fixup_tree_root_location(struct btrfs_root *root,
659 struct btrfs_key *location,
660 struct btrfs_root **sub_root)
661 {
662 struct btrfs_path *path;
663 struct btrfs_root_item *ri;
664
665 if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY)
666 return 0;
667 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
668 return 0;
669
670 path = btrfs_alloc_path();
671 BUG_ON(!path);
672 mutex_lock(&root->fs_info->fs_mutex);
673
674 *sub_root = btrfs_read_fs_root(root->fs_info, location);
675 if (IS_ERR(*sub_root))
676 return PTR_ERR(*sub_root);
677
678 ri = &(*sub_root)->root_item;
679 location->objectid = btrfs_root_dirid(ri);
680 location->flags = 0;
681 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
682 location->offset = 0;
683
684 btrfs_free_path(path);
685 mutex_unlock(&root->fs_info->fs_mutex);
686 return 0;
687 }
688
689 static int btrfs_init_locked_inode(struct inode *inode, void *p)
690 {
691 struct btrfs_iget_args *args = p;
692 inode->i_ino = args->ino;
693 BTRFS_I(inode)->root = args->root;
694 return 0;
695 }
696
697 static int btrfs_find_actor(struct inode *inode, void *opaque)
698 {
699 struct btrfs_iget_args *args = opaque;
700 return (args->ino == inode->i_ino &&
701 args->root == BTRFS_I(inode)->root);
702 }
703
704 static struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
705 struct btrfs_root *root)
706 {
707 struct inode *inode;
708 struct btrfs_iget_args args;
709 args.ino = objectid;
710 args.root = root;
711
712 inode = iget5_locked(s, objectid, btrfs_find_actor,
713 btrfs_init_locked_inode,
714 (void *)&args);
715 return inode;
716 }
717
718 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
719 struct nameidata *nd)
720 {
721 struct inode * inode;
722 struct btrfs_inode *bi = BTRFS_I(dir);
723 struct btrfs_root *root = bi->root;
724 struct btrfs_root *sub_root = root;
725 struct btrfs_key location;
726 int ret;
727
728 if (dentry->d_name.len > BTRFS_NAME_LEN)
729 return ERR_PTR(-ENAMETOOLONG);
730 mutex_lock(&root->fs_info->fs_mutex);
731 ret = btrfs_inode_by_name(dir, dentry, &location);
732 mutex_unlock(&root->fs_info->fs_mutex);
733 if (ret < 0)
734 return ERR_PTR(ret);
735 inode = NULL;
736 if (location.objectid) {
737 ret = fixup_tree_root_location(root, &location, &sub_root);
738 if (ret < 0)
739 return ERR_PTR(ret);
740 if (ret > 0)
741 return ERR_PTR(-ENOENT);
742 inode = btrfs_iget_locked(dir->i_sb, location.objectid,
743 sub_root);
744 if (!inode)
745 return ERR_PTR(-EACCES);
746 if (inode->i_state & I_NEW) {
747 if (sub_root != root) {
748 printk("adding new root for inode %lu root %p (found %p)\n", inode->i_ino, sub_root, BTRFS_I(inode)->root);
749 igrab(inode);
750 sub_root->inode = inode;
751 }
752 BTRFS_I(inode)->root = sub_root;
753 memcpy(&BTRFS_I(inode)->location, &location,
754 sizeof(location));
755 btrfs_read_locked_inode(inode);
756 unlock_new_inode(inode);
757 }
758 }
759 return d_splice_alias(inode, dentry);
760 }
761
762 static void reada_leaves(struct btrfs_root *root, struct btrfs_path *path,
763 u64 objectid)
764 {
765 struct btrfs_node *node;
766 int i;
767 u32 nritems;
768 u64 item_objectid;
769 u64 blocknr;
770 int slot;
771 int ret;
772
773 if (!path->nodes[1])
774 return;
775 node = btrfs_buffer_node(path->nodes[1]);
776 slot = path->slots[1];
777 nritems = btrfs_header_nritems(&node->header);
778 for (i = slot + 1; i < nritems; i++) {
779 item_objectid = btrfs_disk_key_objectid(&node->ptrs[i].key);
780 if (item_objectid != objectid)
781 break;
782 blocknr = btrfs_node_blockptr(node, i);
783 ret = readahead_tree_block(root, blocknr);
784 if (ret)
785 break;
786 }
787 }
788
789 static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
790 {
791 struct inode *inode = filp->f_path.dentry->d_inode;
792 struct btrfs_root *root = BTRFS_I(inode)->root;
793 struct btrfs_item *item;
794 struct btrfs_dir_item *di;
795 struct btrfs_key key;
796 struct btrfs_path *path;
797 int ret;
798 u32 nritems;
799 struct btrfs_leaf *leaf;
800 int slot;
801 int advance;
802 unsigned char d_type = DT_UNKNOWN;
803 int over = 0;
804 u32 di_cur;
805 u32 di_total;
806 u32 di_len;
807 int key_type = BTRFS_DIR_INDEX_KEY;
808
809 /* FIXME, use a real flag for deciding about the key type */
810 if (root->fs_info->tree_root == root)
811 key_type = BTRFS_DIR_ITEM_KEY;
812 mutex_lock(&root->fs_info->fs_mutex);
813 key.objectid = inode->i_ino;
814 key.flags = 0;
815 btrfs_set_key_type(&key, key_type);
816 key.offset = filp->f_pos;
817 path = btrfs_alloc_path();
818 btrfs_init_path(path);
819 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
820 if (ret < 0)
821 goto err;
822 advance = 0;
823 reada_leaves(root, path, inode->i_ino);
824 while(1) {
825 leaf = btrfs_buffer_leaf(path->nodes[0]);
826 nritems = btrfs_header_nritems(&leaf->header);
827 slot = path->slots[0];
828 if (advance || slot >= nritems) {
829 if (slot >= nritems -1) {
830 reada_leaves(root, path, inode->i_ino);
831 ret = btrfs_next_leaf(root, path);
832 if (ret)
833 break;
834 leaf = btrfs_buffer_leaf(path->nodes[0]);
835 nritems = btrfs_header_nritems(&leaf->header);
836 slot = path->slots[0];
837 } else {
838 slot++;
839 path->slots[0]++;
840 }
841 }
842 advance = 1;
843 item = leaf->items + slot;
844 if (btrfs_disk_key_objectid(&item->key) != key.objectid)
845 break;
846 if (btrfs_disk_key_type(&item->key) != key_type)
847 break;
848 if (btrfs_disk_key_offset(&item->key) < filp->f_pos)
849 continue;
850 filp->f_pos = btrfs_disk_key_offset(&item->key);
851 advance = 1;
852 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
853 di_cur = 0;
854 di_total = btrfs_item_size(leaf->items + slot);
855 while(di_cur < di_total) {
856 over = filldir(dirent, (const char *)(di + 1),
857 btrfs_dir_name_len(di),
858 btrfs_disk_key_offset(&item->key),
859 btrfs_disk_key_objectid(&di->location),
860 d_type);
861 if (over)
862 goto nopos;
863 di_len = btrfs_dir_name_len(di) + sizeof(*di);
864 di_cur += di_len;
865 di = (struct btrfs_dir_item *)((char *)di + di_len);
866 }
867 }
868 filp->f_pos++;
869 nopos:
870 ret = 0;
871 err:
872 btrfs_release_path(root, path);
873 btrfs_free_path(path);
874 mutex_unlock(&root->fs_info->fs_mutex);
875 return ret;
876 }
877
878 static void btrfs_put_super (struct super_block * sb)
879 {
880 struct btrfs_root *root = btrfs_sb(sb);
881 int ret;
882
883 ret = close_ctree(root);
884 if (ret) {
885 printk("close ctree returns %d\n", ret);
886 }
887 sb->s_fs_info = NULL;
888 }
889
890 static int btrfs_fill_super(struct super_block * sb, void * data, int silent)
891 {
892 struct inode * inode;
893 struct dentry * root_dentry;
894 struct btrfs_super_block *disk_super;
895 struct btrfs_root *tree_root;
896 struct btrfs_inode *bi;
897
898 sb->s_maxbytes = MAX_LFS_FILESIZE;
899 sb->s_magic = BTRFS_SUPER_MAGIC;
900 sb->s_op = &btrfs_super_ops;
901 sb->s_time_gran = 1;
902
903 tree_root = open_ctree(sb);
904
905 if (!tree_root) {
906 printk("btrfs: open_ctree failed\n");
907 return -EIO;
908 }
909 sb->s_fs_info = tree_root;
910 disk_super = tree_root->fs_info->disk_super;
911 printk("read in super total blocks %Lu root %Lu\n",
912 btrfs_super_total_blocks(disk_super),
913 btrfs_super_root_dir(disk_super));
914
915 inode = btrfs_iget_locked(sb, btrfs_super_root_dir(disk_super),
916 tree_root);
917 bi = BTRFS_I(inode);
918 bi->location.objectid = inode->i_ino;
919 bi->location.offset = 0;
920 bi->location.flags = 0;
921 bi->root = tree_root;
922 btrfs_set_key_type(&bi->location, BTRFS_INODE_ITEM_KEY);
923
924 if (!inode)
925 return -ENOMEM;
926 if (inode->i_state & I_NEW) {
927 btrfs_read_locked_inode(inode);
928 unlock_new_inode(inode);
929 }
930
931 root_dentry = d_alloc_root(inode);
932 if (!root_dentry) {
933 iput(inode);
934 return -ENOMEM;
935 }
936 sb->s_root = root_dentry;
937
938 return 0;
939 }
940
941 static int btrfs_write_inode(struct inode *inode, int wait)
942 {
943 struct btrfs_root *root = BTRFS_I(inode)->root;
944 struct btrfs_trans_handle *trans;
945 int ret = 0;
946
947 if (wait) {
948 mutex_lock(&root->fs_info->fs_mutex);
949 trans = btrfs_start_transaction(root, 1);
950 btrfs_set_trans_block_group(trans, inode);
951 ret = btrfs_commit_transaction(trans, root);
952 mutex_unlock(&root->fs_info->fs_mutex);
953 }
954 return ret;
955 }
956
957 static void btrfs_dirty_inode(struct inode *inode)
958 {
959 struct btrfs_root *root = BTRFS_I(inode)->root;
960 struct btrfs_trans_handle *trans;
961
962 mutex_lock(&root->fs_info->fs_mutex);
963 trans = btrfs_start_transaction(root, 1);
964 btrfs_set_trans_block_group(trans, inode);
965 btrfs_update_inode(trans, root, inode);
966 btrfs_end_transaction(trans, root);
967 mutex_unlock(&root->fs_info->fs_mutex);
968 btrfs_btree_balance_dirty(root);
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 BTRFS_I(inode)->root = root;
988 if (mode & S_IFDIR)
989 owner = 0;
990 else
991 owner = 1;
992 group = btrfs_find_block_group(root, group, 0, 0, owner);
993 BTRFS_I(inode)->block_group = group;
994
995 inode->i_uid = current->fsuid;
996 inode->i_gid = current->fsgid;
997 inode->i_mode = mode;
998 inode->i_ino = objectid;
999 inode->i_blocks = 0;
1000 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1001 fill_inode_item(&inode_item, inode);
1002 location = &BTRFS_I(inode)->location;
1003 location->objectid = objectid;
1004 location->flags = 0;
1005 location->offset = 0;
1006 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
1007
1008 ret = btrfs_insert_inode(trans, root, objectid, &inode_item);
1009 BUG_ON(ret);
1010
1011 insert_inode_hash(inode);
1012 return inode;
1013 }
1014
1015 static int btrfs_add_link(struct btrfs_trans_handle *trans,
1016 struct dentry *dentry, struct inode *inode)
1017 {
1018 int ret;
1019 struct btrfs_key key;
1020 struct btrfs_root *root = BTRFS_I(dentry->d_parent->d_inode)->root;
1021 key.objectid = inode->i_ino;
1022 key.flags = 0;
1023 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
1024 key.offset = 0;
1025
1026 ret = btrfs_insert_dir_item(trans, root,
1027 dentry->d_name.name, dentry->d_name.len,
1028 dentry->d_parent->d_inode->i_ino,
1029 &key, 0);
1030 if (ret == 0) {
1031 dentry->d_parent->d_inode->i_size += dentry->d_name.len * 2;
1032 ret = btrfs_update_inode(trans, root,
1033 dentry->d_parent->d_inode);
1034 }
1035 return ret;
1036 }
1037
1038 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
1039 struct dentry *dentry, struct inode *inode)
1040 {
1041 int err = btrfs_add_link(trans, dentry, inode);
1042 if (!err) {
1043 d_instantiate(dentry, inode);
1044 return 0;
1045 }
1046 if (err > 0)
1047 err = -EEXIST;
1048 return err;
1049 }
1050
1051 static int btrfs_create(struct inode *dir, struct dentry *dentry,
1052 int mode, struct nameidata *nd)
1053 {
1054 struct btrfs_trans_handle *trans;
1055 struct btrfs_root *root = BTRFS_I(dir)->root;
1056 struct inode *inode;
1057 int err;
1058 int drop_inode = 0;
1059 u64 objectid;
1060
1061 mutex_lock(&root->fs_info->fs_mutex);
1062 trans = btrfs_start_transaction(root, 1);
1063 btrfs_set_trans_block_group(trans, dir);
1064
1065 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1066 if (err) {
1067 err = -ENOSPC;
1068 goto out_unlock;
1069 }
1070
1071 inode = btrfs_new_inode(trans, root, objectid,
1072 BTRFS_I(dir)->block_group, mode);
1073 err = PTR_ERR(inode);
1074 if (IS_ERR(inode))
1075 goto out_unlock;
1076
1077 btrfs_set_trans_block_group(trans, inode);
1078 err = btrfs_add_nondir(trans, dentry, inode);
1079 if (err)
1080 drop_inode = 1;
1081 else {
1082 inode->i_mapping->a_ops = &btrfs_aops;
1083 inode->i_fop = &btrfs_file_operations;
1084 inode->i_op = &btrfs_file_inode_operations;
1085 }
1086 dir->i_sb->s_dirt = 1;
1087 btrfs_update_inode_block_group(trans, inode);
1088 btrfs_update_inode_block_group(trans, dir);
1089 out_unlock:
1090 btrfs_end_transaction(trans, root);
1091 mutex_unlock(&root->fs_info->fs_mutex);
1092
1093 if (drop_inode) {
1094 inode_dec_link_count(inode);
1095 iput(inode);
1096 }
1097 btrfs_btree_balance_dirty(root);
1098 return err;
1099 }
1100
1101 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
1102 struct dentry *dentry)
1103 {
1104 struct btrfs_trans_handle *trans;
1105 struct btrfs_root *root = BTRFS_I(dir)->root;
1106 struct inode *inode = old_dentry->d_inode;
1107 int err;
1108 int drop_inode = 0;
1109
1110 if (inode->i_nlink == 0)
1111 return -ENOENT;
1112
1113 inc_nlink(inode);
1114 mutex_lock(&root->fs_info->fs_mutex);
1115 trans = btrfs_start_transaction(root, 1);
1116 btrfs_set_trans_block_group(trans, dir);
1117 atomic_inc(&inode->i_count);
1118 err = btrfs_add_nondir(trans, dentry, inode);
1119 if (err)
1120 drop_inode = 1;
1121 dir->i_sb->s_dirt = 1;
1122 btrfs_update_inode_block_group(trans, dir);
1123 btrfs_update_inode(trans, root, inode);
1124
1125 btrfs_end_transaction(trans, root);
1126 mutex_unlock(&root->fs_info->fs_mutex);
1127
1128 if (drop_inode) {
1129 inode_dec_link_count(inode);
1130 iput(inode);
1131 }
1132 btrfs_btree_balance_dirty(root);
1133 return err;
1134 }
1135
1136 static int btrfs_make_empty_dir(struct btrfs_trans_handle *trans,
1137 struct btrfs_root *root,
1138 u64 objectid, u64 dirid)
1139 {
1140 int ret;
1141 char buf[2];
1142 struct btrfs_key key;
1143
1144 buf[0] = '.';
1145 buf[1] = '.';
1146
1147 key.objectid = objectid;
1148 key.offset = 0;
1149 key.flags = 0;
1150 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
1151
1152 ret = btrfs_insert_dir_item(trans, root, buf, 1, objectid,
1153 &key, 1);
1154 if (ret)
1155 goto error;
1156 key.objectid = dirid;
1157 ret = btrfs_insert_dir_item(trans, root, buf, 2, objectid,
1158 &key, 1);
1159 if (ret)
1160 goto error;
1161 error:
1162 return ret;
1163 }
1164
1165 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1166 {
1167 struct inode *inode;
1168 struct btrfs_trans_handle *trans;
1169 struct btrfs_root *root = BTRFS_I(dir)->root;
1170 int err = 0;
1171 int drop_on_err = 0;
1172 u64 objectid;
1173
1174 mutex_lock(&root->fs_info->fs_mutex);
1175 trans = btrfs_start_transaction(root, 1);
1176 btrfs_set_trans_block_group(trans, dir);
1177 if (IS_ERR(trans)) {
1178 err = PTR_ERR(trans);
1179 goto out_unlock;
1180 }
1181
1182 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1183 if (err) {
1184 err = -ENOSPC;
1185 goto out_unlock;
1186 }
1187
1188 inode = btrfs_new_inode(trans, root, objectid,
1189 BTRFS_I(dir)->block_group, S_IFDIR | mode);
1190 if (IS_ERR(inode)) {
1191 err = PTR_ERR(inode);
1192 goto out_fail;
1193 }
1194 drop_on_err = 1;
1195 inode->i_op = &btrfs_dir_inode_operations;
1196 inode->i_fop = &btrfs_dir_file_operations;
1197 btrfs_set_trans_block_group(trans, inode);
1198
1199 err = btrfs_make_empty_dir(trans, root, inode->i_ino, dir->i_ino);
1200 if (err)
1201 goto out_fail;
1202
1203 inode->i_size = 6;
1204 err = btrfs_update_inode(trans, root, inode);
1205 if (err)
1206 goto out_fail;
1207 err = btrfs_add_link(trans, dentry, inode);
1208 if (err)
1209 goto out_fail;
1210 d_instantiate(dentry, inode);
1211 drop_on_err = 0;
1212 dir->i_sb->s_dirt = 1;
1213 btrfs_update_inode_block_group(trans, inode);
1214 btrfs_update_inode_block_group(trans, dir);
1215
1216 out_fail:
1217 btrfs_end_transaction(trans, root);
1218 out_unlock:
1219 mutex_unlock(&root->fs_info->fs_mutex);
1220 if (drop_on_err)
1221 iput(inode);
1222 btrfs_btree_balance_dirty(root);
1223 return err;
1224 }
1225
1226 static int btrfs_sync_file(struct file *file,
1227 struct dentry *dentry, int datasync)
1228 {
1229 struct inode *inode = dentry->d_inode;
1230 struct btrfs_root *root = BTRFS_I(inode)->root;
1231 int ret;
1232 struct btrfs_trans_handle *trans;
1233
1234 mutex_lock(&root->fs_info->fs_mutex);
1235 trans = btrfs_start_transaction(root, 1);
1236 if (!trans) {
1237 ret = -ENOMEM;
1238 goto out;
1239 }
1240 ret = btrfs_commit_transaction(trans, root);
1241 mutex_unlock(&root->fs_info->fs_mutex);
1242 out:
1243 return ret > 0 ? EIO : ret;
1244 }
1245
1246 static int btrfs_sync_fs(struct super_block *sb, int wait)
1247 {
1248 struct btrfs_trans_handle *trans;
1249 struct btrfs_root *root;
1250 int ret;
1251 root = btrfs_sb(sb);
1252
1253 sb->s_dirt = 0;
1254 if (!wait) {
1255 filemap_flush(root->fs_info->btree_inode->i_mapping);
1256 return 0;
1257 }
1258 mutex_lock(&root->fs_info->fs_mutex);
1259 trans = btrfs_start_transaction(root, 1);
1260 ret = btrfs_commit_transaction(trans, root);
1261 sb->s_dirt = 0;
1262 BUG_ON(ret);
1263 printk("btrfs sync_fs\n");
1264 mutex_unlock(&root->fs_info->fs_mutex);
1265 return 0;
1266 }
1267
1268 static int btrfs_get_block_lock(struct inode *inode, sector_t iblock,
1269 struct buffer_head *result, int create)
1270 {
1271 int ret;
1272 int err = 0;
1273 u64 blocknr;
1274 u64 extent_start = 0;
1275 u64 extent_end = 0;
1276 u64 objectid = inode->i_ino;
1277 u32 found_type;
1278 u64 alloc_hint = 0;
1279 struct btrfs_path *path;
1280 struct btrfs_root *root = BTRFS_I(inode)->root;
1281 struct btrfs_file_extent_item *item;
1282 struct btrfs_leaf *leaf;
1283 struct btrfs_disk_key *found_key;
1284 struct btrfs_trans_handle *trans = NULL;
1285
1286 path = btrfs_alloc_path();
1287 BUG_ON(!path);
1288 btrfs_init_path(path);
1289 if (create) {
1290 WARN_ON(1);
1291 /* this almost but not quite works */
1292 trans = btrfs_start_transaction(root, 1);
1293 if (!trans) {
1294 err = -ENOMEM;
1295 goto out;
1296 }
1297 ret = drop_extents(trans, root, inode,
1298 iblock << inode->i_blkbits,
1299 (iblock + 1) << inode->i_blkbits,
1300 &alloc_hint);
1301 BUG_ON(ret);
1302 }
1303
1304 ret = btrfs_lookup_file_extent(NULL, root, path,
1305 inode->i_ino,
1306 iblock << inode->i_blkbits, 0);
1307 if (ret < 0) {
1308 err = ret;
1309 goto out;
1310 }
1311
1312 if (ret != 0) {
1313 if (path->slots[0] == 0) {
1314 btrfs_release_path(root, path);
1315 goto not_found;
1316 }
1317 path->slots[0]--;
1318 }
1319
1320 item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
1321 struct btrfs_file_extent_item);
1322 leaf = btrfs_buffer_leaf(path->nodes[0]);
1323 blocknr = btrfs_file_extent_disk_blocknr(item);
1324 blocknr += btrfs_file_extent_offset(item);
1325
1326 /* are we inside the extent that was found? */
1327 found_key = &leaf->items[path->slots[0]].key;
1328 found_type = btrfs_disk_key_type(found_key);
1329 if (btrfs_disk_key_objectid(found_key) != objectid ||
1330 found_type != BTRFS_EXTENT_DATA_KEY) {
1331 extent_end = 0;
1332 extent_start = 0;
1333 goto not_found;
1334 }
1335 found_type = btrfs_file_extent_type(item);
1336 extent_start = btrfs_disk_key_offset(&leaf->items[path->slots[0]].key);
1337 if (found_type == BTRFS_FILE_EXTENT_REG) {
1338 extent_start = extent_start >> inode->i_blkbits;
1339 extent_end = extent_start + btrfs_file_extent_num_blocks(item);
1340 err = 0;
1341 if (btrfs_file_extent_disk_blocknr(item) == 0)
1342 goto out;
1343 if (iblock >= extent_start && iblock < extent_end) {
1344 btrfs_map_bh_to_logical(root, result, blocknr +
1345 iblock - extent_start);
1346 goto out;
1347 }
1348 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
1349 char *ptr;
1350 char *map;
1351 u32 size;
1352 size = btrfs_file_extent_inline_len(leaf->items +
1353 path->slots[0]);
1354 extent_end = (extent_start + size) >> inode->i_blkbits;
1355 extent_start >>= inode->i_blkbits;
1356 if (iblock < extent_start || iblock > extent_end) {
1357 goto not_found;
1358 }
1359 ptr = btrfs_file_extent_inline_start(item);
1360 map = kmap(result->b_page);
1361 memcpy(map, ptr, size);
1362 memset(map + size, 0, PAGE_CACHE_SIZE - size);
1363 flush_dcache_page(result->b_page);
1364 kunmap(result->b_page);
1365 set_buffer_uptodate(result);
1366 SetPageChecked(result->b_page);
1367 btrfs_map_bh_to_logical(root, result, 0);
1368 }
1369 not_found:
1370 if (create) {
1371 struct btrfs_key ins;
1372 ret = btrfs_alloc_extent(trans, root, inode->i_ino,
1373 1, alloc_hint, (u64)-1,
1374 &ins, 1);
1375 BUG_ON(ret);
1376 ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
1377 iblock << inode->i_blkbits,
1378 ins.objectid, ins.offset,
1379 ins.offset);
1380 BUG_ON(ret);
1381 SetPageChecked(result->b_page);
1382 btrfs_map_bh_to_logical(root, result, ins.objectid);
1383 }
1384 out:
1385 if (trans)
1386 err = btrfs_end_transaction(trans, root);
1387 btrfs_free_path(path);
1388 return err;
1389 }
1390
1391 static int btrfs_get_block(struct inode *inode, sector_t iblock,
1392 struct buffer_head *result, int create)
1393 {
1394 int err;
1395 struct btrfs_root *root = BTRFS_I(inode)->root;
1396 mutex_lock(&root->fs_info->fs_mutex);
1397 err = btrfs_get_block_lock(inode, iblock, result, create);
1398 mutex_unlock(&root->fs_info->fs_mutex);
1399 return err;
1400 }
1401
1402 static int btrfs_prepare_write(struct file *file, struct page *page,
1403 unsigned from, unsigned to)
1404 {
1405 return block_prepare_write(page, from, to, btrfs_get_block);
1406 }
1407
1408 static void btrfs_write_super(struct super_block *sb)
1409 {
1410 btrfs_sync_fs(sb, 1);
1411 }
1412
1413 static int btrfs_readpage(struct file *file, struct page *page)
1414 {
1415 return mpage_readpage(page, btrfs_get_block);
1416 }
1417
1418 /*
1419 * While block_write_full_page is writing back the dirty buffers under
1420 * the page lock, whoever dirtied the buffers may decide to clean them
1421 * again at any time. We handle that by only looking at the buffer
1422 * state inside lock_buffer().
1423 *
1424 * If block_write_full_page() is called for regular writeback
1425 * (wbc->sync_mode == WB_SYNC_NONE) then it will redirty a page which has a
1426 * locked buffer. This only can happen if someone has written the buffer
1427 * directly, with submit_bh(). At the address_space level PageWriteback
1428 * prevents this contention from occurring.
1429 */
1430 static int __btrfs_write_full_page(struct inode *inode, struct page *page,
1431 struct writeback_control *wbc)
1432 {
1433 int err;
1434 sector_t block;
1435 sector_t last_block;
1436 struct buffer_head *bh, *head;
1437 const unsigned blocksize = 1 << inode->i_blkbits;
1438 int nr_underway = 0;
1439
1440 BUG_ON(!PageLocked(page));
1441
1442 last_block = (i_size_read(inode) - 1) >> inode->i_blkbits;
1443
1444 if (!page_has_buffers(page)) {
1445 create_empty_buffers(page, blocksize,
1446 (1 << BH_Dirty)|(1 << BH_Uptodate));
1447 }
1448
1449 /*
1450 * Be very careful. We have no exclusion from __set_page_dirty_buffers
1451 * here, and the (potentially unmapped) buffers may become dirty at
1452 * any time. If a buffer becomes dirty here after we've inspected it
1453 * then we just miss that fact, and the page stays dirty.
1454 *
1455 * Buffers outside i_size may be dirtied by __set_page_dirty_buffers;
1456 * handle that here by just cleaning them.
1457 */
1458
1459 block = (sector_t)page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
1460 head = page_buffers(page);
1461 bh = head;
1462
1463 /*
1464 * Get all the dirty buffers mapped to disk addresses and
1465 * handle any aliases from the underlying blockdev's mapping.
1466 */
1467 do {
1468 if (block > last_block) {
1469 /*
1470 * mapped buffers outside i_size will occur, because
1471 * this page can be outside i_size when there is a
1472 * truncate in progress.
1473 */
1474 /*
1475 * The buffer was zeroed by block_write_full_page()
1476 */
1477 clear_buffer_dirty(bh);
1478 set_buffer_uptodate(bh);
1479 } else if (!buffer_mapped(bh) && buffer_dirty(bh)) {
1480 WARN_ON(bh->b_size != blocksize);
1481 err = btrfs_get_block(inode, block, bh, 0);
1482 if (err) {
1483 printk("writepage going to recovery err %d\n", err);
1484 goto recover;
1485 }
1486 if (buffer_new(bh)) {
1487 /* blockdev mappings never come here */
1488 clear_buffer_new(bh);
1489 }
1490 }
1491 bh = bh->b_this_page;
1492 block++;
1493 } while (bh != head);
1494
1495 do {
1496 if (!buffer_mapped(bh))
1497 continue;
1498 /*
1499 * If it's a fully non-blocking write attempt and we cannot
1500 * lock the buffer then redirty the page. Note that this can
1501 * potentially cause a busy-wait loop from pdflush and kswapd
1502 * activity, but those code paths have their own higher-level
1503 * throttling.
1504 */
1505 if (wbc->sync_mode != WB_SYNC_NONE || !wbc->nonblocking) {
1506 lock_buffer(bh);
1507 } else if (test_set_buffer_locked(bh)) {
1508 redirty_page_for_writepage(wbc, page);
1509 continue;
1510 }
1511 if (test_clear_buffer_dirty(bh) && bh->b_blocknr != 0) {
1512 mark_buffer_async_write(bh);
1513 } else {
1514 unlock_buffer(bh);
1515 }
1516 } while ((bh = bh->b_this_page) != head);
1517
1518 /*
1519 * The page and its buffers are protected by PageWriteback(), so we can
1520 * drop the bh refcounts early.
1521 */
1522 BUG_ON(PageWriteback(page));
1523 set_page_writeback(page);
1524
1525 do {
1526 struct buffer_head *next = bh->b_this_page;
1527 if (buffer_async_write(bh)) {
1528 submit_bh(WRITE, bh);
1529 nr_underway++;
1530 }
1531 bh = next;
1532 } while (bh != head);
1533 unlock_page(page);
1534
1535 err = 0;
1536 done:
1537 if (nr_underway == 0) {
1538 /*
1539 * The page was marked dirty, but the buffers were
1540 * clean. Someone wrote them back by hand with
1541 * ll_rw_block/submit_bh. A rare case.
1542 */
1543 int uptodate = 1;
1544 do {
1545 if (!buffer_uptodate(bh)) {
1546 uptodate = 0;
1547 break;
1548 }
1549 bh = bh->b_this_page;
1550 } while (bh != head);
1551 if (uptodate)
1552 SetPageUptodate(page);
1553 end_page_writeback(page);
1554 }
1555 return err;
1556
1557 recover:
1558 /*
1559 * ENOSPC, or some other error. We may already have added some
1560 * blocks to the file, so we need to write these out to avoid
1561 * exposing stale data.
1562 * The page is currently locked and not marked for writeback
1563 */
1564 bh = head;
1565 /* Recovery: lock and submit the mapped buffers */
1566 do {
1567 if (buffer_mapped(bh) && buffer_dirty(bh)) {
1568 lock_buffer(bh);
1569 mark_buffer_async_write(bh);
1570 } else {
1571 /*
1572 * The buffer may have been set dirty during
1573 * attachment to a dirty page.
1574 */
1575 clear_buffer_dirty(bh);
1576 }
1577 } while ((bh = bh->b_this_page) != head);
1578 SetPageError(page);
1579 BUG_ON(PageWriteback(page));
1580 set_page_writeback(page);
1581 do {
1582 struct buffer_head *next = bh->b_this_page;
1583 if (buffer_async_write(bh)) {
1584 clear_buffer_dirty(bh);
1585 submit_bh(WRITE, bh);
1586 nr_underway++;
1587 }
1588 bh = next;
1589 } while (bh != head);
1590 unlock_page(page);
1591 goto done;
1592 }
1593
1594 /*
1595 * The generic ->writepage function for buffer-backed address_spaces
1596 */
1597 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
1598 {
1599 struct inode * const inode = page->mapping->host;
1600 loff_t i_size = i_size_read(inode);
1601 const pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
1602 unsigned offset;
1603 void *kaddr;
1604
1605 /* Is the page fully inside i_size? */
1606 if (page->index < end_index)
1607 return __btrfs_write_full_page(inode, page, wbc);
1608
1609 /* Is the page fully outside i_size? (truncate in progress) */
1610 offset = i_size & (PAGE_CACHE_SIZE-1);
1611 if (page->index >= end_index+1 || !offset) {
1612 /*
1613 * The page may have dirty, unmapped buffers. For example,
1614 * they may have been added in ext3_writepage(). Make them
1615 * freeable here, so the page does not leak.
1616 */
1617 block_invalidatepage(page, 0);
1618 unlock_page(page);
1619 return 0; /* don't care */
1620 }
1621
1622 /*
1623 * The page straddles i_size. It must be zeroed out on each and every
1624 * writepage invokation because it may be mmapped. "A file is mapped
1625 * in multiples of the page size. For a file that is not a multiple of
1626 * the page size, the remaining memory is zeroed when mapped, and
1627 * writes to that region are not written out to the file."
1628 */
1629 kaddr = kmap_atomic(page, KM_USER0);
1630 memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
1631 flush_dcache_page(page);
1632 kunmap_atomic(kaddr, KM_USER0);
1633 return __btrfs_write_full_page(inode, page, wbc);
1634 }
1635
1636 static void btrfs_truncate(struct inode *inode)
1637 {
1638 struct btrfs_root *root = BTRFS_I(inode)->root;
1639 int ret;
1640 struct btrfs_trans_handle *trans;
1641
1642 if (!S_ISREG(inode->i_mode))
1643 return;
1644 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
1645 return;
1646
1647 btrfs_truncate_page(inode->i_mapping, inode->i_size);
1648
1649 mutex_lock(&root->fs_info->fs_mutex);
1650 trans = btrfs_start_transaction(root, 1);
1651 btrfs_set_trans_block_group(trans, inode);
1652
1653 /* FIXME, add redo link to tree so we don't leak on crash */
1654 ret = btrfs_truncate_in_trans(trans, root, inode);
1655 BUG_ON(ret);
1656 btrfs_update_inode(trans, root, inode);
1657 ret = btrfs_end_transaction(trans, root);
1658 BUG_ON(ret);
1659 mutex_unlock(&root->fs_info->fs_mutex);
1660 btrfs_btree_balance_dirty(root);
1661 }
1662
1663 static int btrfs_commit_write(struct file *file, struct page *page,
1664 unsigned from, unsigned to)
1665 {
1666 struct inode *inode = page->mapping->host;
1667 struct buffer_head *bh;
1668 loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
1669
1670 SetPageUptodate(page);
1671 bh = page_buffers(page);
1672 set_buffer_uptodate(bh);
1673 if (buffer_mapped(bh) && bh->b_blocknr != 0) {
1674 set_page_dirty(page);
1675 }
1676 if (pos > inode->i_size) {
1677 i_size_write(inode, pos);
1678 mark_inode_dirty(inode);
1679 }
1680 return 0;
1681 }
1682
1683 static int btrfs_copy_from_user(loff_t pos, int num_pages, int write_bytes,
1684 struct page **prepared_pages,
1685 const char __user * buf)
1686 {
1687 long page_fault = 0;
1688 int i;
1689 int offset = pos & (PAGE_CACHE_SIZE - 1);
1690
1691 for (i = 0; i < num_pages && write_bytes > 0; i++, offset = 0) {
1692 size_t count = min_t(size_t,
1693 PAGE_CACHE_SIZE - offset, write_bytes);
1694 struct page *page = prepared_pages[i];
1695 fault_in_pages_readable(buf, count);
1696
1697 /* Copy data from userspace to the current page */
1698 kmap(page);
1699 page_fault = __copy_from_user(page_address(page) + offset,
1700 buf, count);
1701 /* Flush processor's dcache for this page */
1702 flush_dcache_page(page);
1703 kunmap(page);
1704 buf += count;
1705 write_bytes -= count;
1706
1707 if (page_fault)
1708 break;
1709 }
1710 return page_fault ? -EFAULT : 0;
1711 }
1712
1713 static void btrfs_drop_pages(struct page **pages, size_t num_pages)
1714 {
1715 size_t i;
1716 for (i = 0; i < num_pages; i++) {
1717 if (!pages[i])
1718 break;
1719 unlock_page(pages[i]);
1720 mark_page_accessed(pages[i]);
1721 page_cache_release(pages[i]);
1722 }
1723 }
1724 static int dirty_and_release_pages(struct btrfs_trans_handle *trans,
1725 struct btrfs_root *root,
1726 struct file *file,
1727 struct page **pages,
1728 size_t num_pages,
1729 loff_t pos,
1730 size_t write_bytes)
1731 {
1732 int i;
1733 int offset;
1734 int err = 0;
1735 int ret;
1736 int this_write;
1737 struct inode *inode = file->f_path.dentry->d_inode;
1738 struct buffer_head *bh;
1739 struct btrfs_file_extent_item *ei;
1740
1741 for (i = 0; i < num_pages; i++) {
1742 offset = pos & (PAGE_CACHE_SIZE -1);
1743 this_write = min(PAGE_CACHE_SIZE - offset, write_bytes);
1744 /* FIXME, one block at a time */
1745
1746 mutex_lock(&root->fs_info->fs_mutex);
1747 trans = btrfs_start_transaction(root, 1);
1748 btrfs_set_trans_block_group(trans, inode);
1749
1750 bh = page_buffers(pages[i]);
1751 if (buffer_mapped(bh) && bh->b_blocknr == 0) {
1752 struct btrfs_key key;
1753 struct btrfs_path *path;
1754 char *ptr;
1755 u32 datasize;
1756
1757 path = btrfs_alloc_path();
1758 BUG_ON(!path);
1759 key.objectid = inode->i_ino;
1760 key.offset = pages[i]->index << PAGE_CACHE_SHIFT;
1761 key.flags = 0;
1762 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
1763 BUG_ON(write_bytes >= PAGE_CACHE_SIZE);
1764 datasize = offset +
1765 btrfs_file_extent_calc_inline_size(write_bytes);
1766 ret = btrfs_insert_empty_item(trans, root, path, &key,
1767 datasize);
1768 BUG_ON(ret);
1769 ei = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
1770 path->slots[0], struct btrfs_file_extent_item);
1771 btrfs_set_file_extent_generation(ei, trans->transid);
1772 btrfs_set_file_extent_type(ei,
1773 BTRFS_FILE_EXTENT_INLINE);
1774 ptr = btrfs_file_extent_inline_start(ei);
1775 btrfs_memcpy(root, path->nodes[0]->b_data,
1776 ptr, bh->b_data, offset + write_bytes);
1777 mark_buffer_dirty(path->nodes[0]);
1778 btrfs_free_path(path);
1779 } else if (buffer_mapped(bh)) {
1780 btrfs_csum_file_block(trans, root, inode->i_ino,
1781 pages[i]->index << PAGE_CACHE_SHIFT,
1782 kmap(pages[i]), PAGE_CACHE_SIZE);
1783 kunmap(pages[i]);
1784 }
1785 SetPageChecked(pages[i]);
1786 // btrfs_update_inode_block_group(trans, inode);
1787 ret = btrfs_end_transaction(trans, root);
1788 BUG_ON(ret);
1789 mutex_unlock(&root->fs_info->fs_mutex);
1790
1791 ret = btrfs_commit_write(file, pages[i], offset,
1792 offset + this_write);
1793 pos += this_write;
1794 if (ret) {
1795 err = ret;
1796 goto failed;
1797 }
1798 WARN_ON(this_write > write_bytes);
1799 write_bytes -= this_write;
1800 }
1801 failed:
1802 return err;
1803 }
1804
1805 static int drop_extents(struct btrfs_trans_handle *trans,
1806 struct btrfs_root *root,
1807 struct inode *inode,
1808 u64 start, u64 end, u64 *hint_block)
1809 {
1810 int ret;
1811 struct btrfs_key key;
1812 struct btrfs_leaf *leaf;
1813 int slot;
1814 struct btrfs_file_extent_item *extent;
1815 u64 extent_end = 0;
1816 int keep;
1817 struct btrfs_file_extent_item old;
1818 struct btrfs_path *path;
1819 u64 search_start = start;
1820 int bookend;
1821 int found_type;
1822 int found_extent;
1823 int found_inline;
1824
1825 path = btrfs_alloc_path();
1826 if (!path)
1827 return -ENOMEM;
1828 while(1) {
1829 btrfs_release_path(root, path);
1830 ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
1831 search_start, -1);
1832 if (ret < 0)
1833 goto out;
1834 if (ret > 0) {
1835 if (path->slots[0] == 0) {
1836 ret = 0;
1837 goto out;
1838 }
1839 path->slots[0]--;
1840 }
1841 keep = 0;
1842 bookend = 0;
1843 found_extent = 0;
1844 found_inline = 0;
1845 extent = NULL;
1846 leaf = btrfs_buffer_leaf(path->nodes[0]);
1847 slot = path->slots[0];
1848 btrfs_disk_key_to_cpu(&key, &leaf->items[slot].key);
1849 if (key.offset >= end || key.objectid != inode->i_ino) {
1850 ret = 0;
1851 goto out;
1852 }
1853 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) {
1854 ret = 0;
1855 goto out;
1856 }
1857 extent = btrfs_item_ptr(leaf, slot,
1858 struct btrfs_file_extent_item);
1859 found_type = btrfs_file_extent_type(extent);
1860 if (found_type == BTRFS_FILE_EXTENT_REG) {
1861 extent_end = key.offset +
1862 (btrfs_file_extent_num_blocks(extent) <<
1863 inode->i_blkbits);
1864 found_extent = 1;
1865 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
1866 found_inline = 1;
1867 extent_end = key.offset +
1868 btrfs_file_extent_inline_len(leaf->items + slot);
1869 }
1870
1871 if (!found_extent && !found_inline) {
1872 ret = 0;
1873 goto out;
1874 }
1875
1876 if (search_start >= extent_end) {
1877 ret = 0;
1878 goto out;
1879 }
1880
1881 if (found_inline) {
1882 u64 mask = root->blocksize - 1;
1883 search_start = (extent_end + mask) & ~mask;
1884 } else
1885 search_start = extent_end;
1886
1887 if (end < extent_end && end >= key.offset) {
1888 if (found_extent) {
1889 u64 disk_blocknr =
1890 btrfs_file_extent_disk_blocknr(extent);
1891 u64 disk_num_blocks =
1892 btrfs_file_extent_disk_num_blocks(extent);
1893 memcpy(&old, extent, sizeof(old));
1894 if (disk_blocknr != 0) {
1895 ret = btrfs_inc_extent_ref(trans, root,
1896 disk_blocknr, disk_num_blocks);
1897 BUG_ON(ret);
1898 }
1899 }
1900 WARN_ON(found_inline);
1901 bookend = 1;
1902 }
1903
1904 if (start > key.offset) {
1905 u64 new_num;
1906 u64 old_num;
1907 /* truncate existing extent */
1908 keep = 1;
1909 WARN_ON(start & (root->blocksize - 1));
1910 if (found_extent) {
1911 new_num = (start - key.offset) >>
1912 inode->i_blkbits;
1913 old_num = btrfs_file_extent_num_blocks(extent);
1914 *hint_block =
1915 btrfs_file_extent_disk_blocknr(extent);
1916 if (btrfs_file_extent_disk_blocknr(extent)) {
1917 inode->i_blocks -=
1918 (old_num - new_num) << 3;
1919 }
1920 btrfs_set_file_extent_num_blocks(extent,
1921 new_num);
1922 mark_buffer_dirty(path->nodes[0]);
1923 } else {
1924 WARN_ON(1);
1925 }
1926 }
1927 if (!keep) {
1928 u64 disk_blocknr = 0;
1929 u64 disk_num_blocks = 0;
1930 u64 extent_num_blocks = 0;
1931 if (found_extent) {
1932 disk_blocknr =
1933 btrfs_file_extent_disk_blocknr(extent);
1934 disk_num_blocks =
1935 btrfs_file_extent_disk_num_blocks(extent);
1936 extent_num_blocks =
1937 btrfs_file_extent_num_blocks(extent);
1938 *hint_block =
1939 btrfs_file_extent_disk_blocknr(extent);
1940 }
1941 ret = btrfs_del_item(trans, root, path);
1942 BUG_ON(ret);
1943 btrfs_release_path(root, path);
1944 extent = NULL;
1945 if (found_extent && disk_blocknr != 0) {
1946 inode->i_blocks -= extent_num_blocks << 3;
1947 ret = btrfs_free_extent(trans, root,
1948 disk_blocknr,
1949 disk_num_blocks, 0);
1950 }
1951
1952 BUG_ON(ret);
1953 if (!bookend && search_start >= end) {
1954 ret = 0;
1955 goto out;
1956 }
1957 if (!bookend)
1958 continue;
1959 }
1960 if (bookend && found_extent) {
1961 /* create bookend */
1962 struct btrfs_key ins;
1963 ins.objectid = inode->i_ino;
1964 ins.offset = end;
1965 ins.flags = 0;
1966 btrfs_set_key_type(&ins, BTRFS_EXTENT_DATA_KEY);
1967
1968 btrfs_release_path(root, path);
1969 ret = btrfs_insert_empty_item(trans, root, path, &ins,
1970 sizeof(*extent));
1971 BUG_ON(ret);
1972 extent = btrfs_item_ptr(
1973 btrfs_buffer_leaf(path->nodes[0]),
1974 path->slots[0],
1975 struct btrfs_file_extent_item);
1976 btrfs_set_file_extent_disk_blocknr(extent,
1977 btrfs_file_extent_disk_blocknr(&old));
1978 btrfs_set_file_extent_disk_num_blocks(extent,
1979 btrfs_file_extent_disk_num_blocks(&old));
1980
1981 btrfs_set_file_extent_offset(extent,
1982 btrfs_file_extent_offset(&old) +
1983 ((end - key.offset) >> inode->i_blkbits));
1984 WARN_ON(btrfs_file_extent_num_blocks(&old) <
1985 (extent_end - end) >> inode->i_blkbits);
1986 btrfs_set_file_extent_num_blocks(extent,
1987 (extent_end - end) >> inode->i_blkbits);
1988
1989 btrfs_set_file_extent_type(extent,
1990 BTRFS_FILE_EXTENT_REG);
1991 btrfs_set_file_extent_generation(extent,
1992 btrfs_file_extent_generation(&old));
1993 btrfs_mark_buffer_dirty(path->nodes[0]);
1994 if (btrfs_file_extent_disk_blocknr(&old) != 0) {
1995 inode->i_blocks +=
1996 btrfs_file_extent_num_blocks(extent) << 3;
1997 }
1998 ret = 0;
1999 goto out;
2000 }
2001 }
2002 out:
2003 btrfs_free_path(path);
2004 return ret;
2005 }
2006
2007 static int prepare_pages(struct btrfs_root *root,
2008 struct file *file,
2009 struct page **pages,
2010 size_t num_pages,
2011 loff_t pos,
2012 unsigned long first_index,
2013 unsigned long last_index,
2014 size_t write_bytes,
2015 u64 alloc_extent_start)
2016 {
2017 int i;
2018 unsigned long index = pos >> PAGE_CACHE_SHIFT;
2019 struct inode *inode = file->f_path.dentry->d_inode;
2020 int offset;
2021 int err = 0;
2022 int this_write;
2023 struct buffer_head *bh;
2024 struct buffer_head *head;
2025 loff_t isize = i_size_read(inode);
2026
2027 memset(pages, 0, num_pages * sizeof(struct page *));
2028
2029 for (i = 0; i < num_pages; i++) {
2030 pages[i] = grab_cache_page(inode->i_mapping, index + i);
2031 if (!pages[i]) {
2032 err = -ENOMEM;
2033 goto failed_release;
2034 }
2035 cancel_dirty_page(pages[i], PAGE_CACHE_SIZE);
2036 wait_on_page_writeback(pages[i]);
2037 offset = pos & (PAGE_CACHE_SIZE -1);
2038 this_write = min(PAGE_CACHE_SIZE - offset, write_bytes);
2039 if (!page_has_buffers(pages[i])) {
2040 create_empty_buffers(pages[i],
2041 root->fs_info->sb->s_blocksize,
2042 (1 << BH_Uptodate));
2043 }
2044 head = page_buffers(pages[i]);
2045 bh = head;
2046 do {
2047 err = btrfs_map_bh_to_logical(root, bh,
2048 alloc_extent_start);
2049 BUG_ON(err);
2050 if (err)
2051 goto failed_truncate;
2052 bh = bh->b_this_page;
2053 if (alloc_extent_start)
2054 alloc_extent_start++;
2055 } while (bh != head);
2056 pos += this_write;
2057 WARN_ON(this_write > write_bytes);
2058 write_bytes -= this_write;
2059 }
2060 return 0;
2061
2062 failed_release:
2063 btrfs_drop_pages(pages, num_pages);
2064 return err;
2065
2066 failed_truncate:
2067 btrfs_drop_pages(pages, num_pages);
2068 if (pos > isize)
2069 vmtruncate(inode, isize);
2070 return err;
2071 }
2072
2073 static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
2074 size_t count, loff_t *ppos)
2075 {
2076 loff_t pos;
2077 size_t num_written = 0;
2078 int err = 0;
2079 int ret = 0;
2080 struct inode *inode = file->f_path.dentry->d_inode;
2081 struct btrfs_root *root = BTRFS_I(inode)->root;
2082 struct page *pages[8];
2083 struct page *pinned[2];
2084 unsigned long first_index;
2085 unsigned long last_index;
2086 u64 start_pos;
2087 u64 num_blocks;
2088 u64 alloc_extent_start;
2089 u64 hint_block;
2090 struct btrfs_trans_handle *trans;
2091 struct btrfs_key ins;
2092 pinned[0] = NULL;
2093 pinned[1] = NULL;
2094 if (file->f_flags & O_DIRECT)
2095 return -EINVAL;
2096 pos = *ppos;
2097 vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
2098 current->backing_dev_info = inode->i_mapping->backing_dev_info;
2099 err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
2100 if (err)
2101 goto out;
2102 if (count == 0)
2103 goto out;
2104 err = remove_suid(file->f_path.dentry);
2105 if (err)
2106 goto out;
2107 file_update_time(file);
2108
2109 start_pos = pos & ~((u64)PAGE_CACHE_SIZE - 1);
2110 num_blocks = (count + pos - start_pos + root->blocksize - 1) >>
2111 inode->i_blkbits;
2112
2113 mutex_lock(&inode->i_mutex);
2114 first_index = pos >> PAGE_CACHE_SHIFT;
2115 last_index = (pos + count) >> PAGE_CACHE_SHIFT;
2116
2117 if ((pos & (PAGE_CACHE_SIZE - 1))) {
2118 pinned[0] = grab_cache_page(inode->i_mapping, first_index);
2119 if (!PageUptodate(pinned[0])) {
2120 ret = mpage_readpage(pinned[0], btrfs_get_block);
2121 BUG_ON(ret);
2122 wait_on_page_locked(pinned[0]);
2123 } else {
2124 unlock_page(pinned[0]);
2125 }
2126 }
2127 if ((pos + count) & (PAGE_CACHE_SIZE - 1)) {
2128 pinned[1] = grab_cache_page(inode->i_mapping, last_index);
2129 if (!PageUptodate(pinned[1])) {
2130 ret = mpage_readpage(pinned[1], btrfs_get_block);
2131 BUG_ON(ret);
2132 wait_on_page_locked(pinned[1]);
2133 } else {
2134 unlock_page(pinned[1]);
2135 }
2136 }
2137
2138 mutex_lock(&root->fs_info->fs_mutex);
2139 trans = btrfs_start_transaction(root, 1);
2140 if (!trans) {
2141 err = -ENOMEM;
2142 mutex_unlock(&root->fs_info->fs_mutex);
2143 goto out_unlock;
2144 }
2145 btrfs_set_trans_block_group(trans, inode);
2146 /* FIXME blocksize != 4096 */
2147 inode->i_blocks += num_blocks << 3;
2148 hint_block = 0;
2149 if (start_pos < inode->i_size) {
2150 /* FIXME blocksize != pagesize */
2151 ret = drop_extents(trans, root, inode,
2152 start_pos,
2153 (pos + count + root->blocksize -1) &
2154 ~((u64)root->blocksize - 1), &hint_block);
2155 BUG_ON(ret);
2156 }
2157 if (inode->i_size < start_pos) {
2158 u64 last_pos_in_file;
2159 u64 hole_size;
2160 u64 mask = root->blocksize - 1;
2161 last_pos_in_file = (inode->i_size + mask) & ~mask;
2162 hole_size = (start_pos - last_pos_in_file + mask) & ~mask;
2163 hole_size >>= inode->i_blkbits;
2164 if (last_pos_in_file < start_pos) {
2165 ret = btrfs_insert_file_extent(trans, root,
2166 inode->i_ino,
2167 last_pos_in_file,
2168 0, 0, hole_size);
2169 }
2170 BUG_ON(ret);
2171 }
2172 if (inode->i_size >= PAGE_CACHE_SIZE || pos + count < inode->i_size ||
2173 pos + count - start_pos > BTRFS_MAX_INLINE_DATA_SIZE(root)) {
2174 ret = btrfs_alloc_extent(trans, root, inode->i_ino,
2175 num_blocks, hint_block, (u64)-1,
2176 &ins, 1);
2177 BUG_ON(ret);
2178 ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
2179 start_pos, ins.objectid, ins.offset,
2180 ins.offset);
2181 BUG_ON(ret);
2182 } else {
2183 ins.offset = 0;
2184 ins.objectid = 0;
2185 }
2186 BUG_ON(ret);
2187 alloc_extent_start = ins.objectid;
2188 // btrfs_update_inode_block_group(trans, inode);
2189 ret = btrfs_end_transaction(trans, root);
2190 mutex_unlock(&root->fs_info->fs_mutex);
2191
2192 while(count > 0) {
2193 size_t offset = pos & (PAGE_CACHE_SIZE - 1);
2194 size_t write_bytes = min(count, PAGE_CACHE_SIZE - offset);
2195 size_t num_pages = (write_bytes + PAGE_CACHE_SIZE - 1) >>
2196 PAGE_CACHE_SHIFT;
2197
2198 memset(pages, 0, sizeof(pages));
2199 ret = prepare_pages(root, file, pages, num_pages,
2200 pos, first_index, last_index,
2201 write_bytes, alloc_extent_start);
2202 BUG_ON(ret);
2203
2204 /* FIXME blocks != pagesize */
2205 if (alloc_extent_start)
2206 alloc_extent_start += num_pages;
2207 ret = btrfs_copy_from_user(pos, num_pages,
2208 write_bytes, pages, buf);
2209 BUG_ON(ret);
2210
2211 ret = dirty_and_release_pages(NULL, root, file, pages,
2212 num_pages, pos, write_bytes);
2213 BUG_ON(ret);
2214 btrfs_drop_pages(pages, num_pages);
2215
2216 buf += write_bytes;
2217 count -= write_bytes;
2218 pos += write_bytes;
2219 num_written += write_bytes;
2220
2221 balance_dirty_pages_ratelimited(inode->i_mapping);
2222 btrfs_btree_balance_dirty(root);
2223 cond_resched();
2224 }
2225 out_unlock:
2226 mutex_unlock(&inode->i_mutex);
2227 out:
2228 if (pinned[0])
2229 page_cache_release(pinned[0]);
2230 if (pinned[1])
2231 page_cache_release(pinned[1]);
2232 *ppos = pos;
2233 current->backing_dev_info = NULL;
2234 mark_inode_dirty(inode);
2235 return num_written ? num_written : err;
2236 }
2237
2238 static int btrfs_read_actor(read_descriptor_t *desc, struct page *page,
2239 unsigned long offset, unsigned long size)
2240 {
2241 char *kaddr;
2242 unsigned long left, count = desc->count;
2243 struct inode *inode = page->mapping->host;
2244
2245 if (size > count)
2246 size = count;
2247
2248 if (!PageChecked(page)) {
2249 /* FIXME, do it per block */
2250 struct btrfs_root *root = BTRFS_I(inode)->root;
2251 int ret;
2252 struct buffer_head *bh;
2253
2254 if (page_has_buffers(page)) {
2255 bh = page_buffers(page);
2256 if (!buffer_mapped(bh)) {
2257 SetPageChecked(page);
2258 goto checked;
2259 }
2260 }
2261
2262 ret = btrfs_csum_verify_file_block(root,
2263 page->mapping->host->i_ino,
2264 page->index << PAGE_CACHE_SHIFT,
2265 kmap(page), PAGE_CACHE_SIZE);
2266 if (ret) {
2267 if (ret != -ENOENT) {
2268 printk("failed to verify ino %lu page %lu ret %d\n",
2269 page->mapping->host->i_ino,
2270 page->index, ret);
2271 memset(page_address(page), 1, PAGE_CACHE_SIZE);
2272 flush_dcache_page(page);
2273 }
2274 }
2275 SetPageChecked(page);
2276 kunmap(page);
2277 }
2278 checked:
2279 /*
2280 * Faults on the destination of a read are common, so do it before
2281 * taking the kmap.
2282 */
2283 if (!fault_in_pages_writeable(desc->arg.buf, size)) {
2284 kaddr = kmap_atomic(page, KM_USER0);
2285 left = __copy_to_user_inatomic(desc->arg.buf,
2286 kaddr + offset, size);
2287 kunmap_atomic(kaddr, KM_USER0);
2288 if (left == 0)
2289 goto success;
2290 }
2291
2292 /* Do it the slow way */
2293 kaddr = kmap(page);
2294 left = __copy_to_user(desc->arg.buf, kaddr + offset, size);
2295 kunmap(page);
2296
2297 if (left) {
2298 size -= left;
2299 desc->error = -EFAULT;
2300 }
2301 success:
2302 desc->count = count - size;
2303 desc->written += size;
2304 desc->arg.buf += size;
2305 return size;
2306 }
2307
2308 /**
2309 * btrfs_file_aio_read - filesystem read routine
2310 * @iocb: kernel I/O control block
2311 * @iov: io vector request
2312 * @nr_segs: number of segments in the iovec
2313 * @pos: current file position
2314 */
2315 static ssize_t btrfs_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
2316 unsigned long nr_segs, loff_t pos)
2317 {
2318 struct file *filp = iocb->ki_filp;
2319 ssize_t retval;
2320 unsigned long seg;
2321 size_t count;
2322 loff_t *ppos = &iocb->ki_pos;
2323
2324 count = 0;
2325 for (seg = 0; seg < nr_segs; seg++) {
2326 const struct iovec *iv = &iov[seg];
2327
2328 /*
2329 * If any segment has a negative length, or the cumulative
2330 * length ever wraps negative then return -EINVAL.
2331 */
2332 count += iv->iov_len;
2333 if (unlikely((ssize_t)(count|iv->iov_len) < 0))
2334 return -EINVAL;
2335 if (access_ok(VERIFY_WRITE, iv->iov_base, iv->iov_len))
2336 continue;
2337 if (seg == 0)
2338 return -EFAULT;
2339 nr_segs = seg;
2340 count -= iv->iov_len; /* This segment is no good */
2341 break;
2342 }
2343 retval = 0;
2344 if (count) {
2345 for (seg = 0; seg < nr_segs; seg++) {
2346 read_descriptor_t desc;
2347
2348 desc.written = 0;
2349 desc.arg.buf = iov[seg].iov_base;
2350 desc.count = iov[seg].iov_len;
2351 if (desc.count == 0)
2352 continue;
2353 desc.error = 0;
2354 do_generic_file_read(filp, ppos, &desc,
2355 btrfs_read_actor);
2356 retval += desc.written;
2357 if (desc.error) {
2358 retval = retval ?: desc.error;
2359 break;
2360 }
2361 }
2362 }
2363 return retval;
2364 }
2365
2366 static int create_subvol(struct btrfs_root *root, char *name, int namelen)
2367 {
2368 struct btrfs_trans_handle *trans;
2369 struct btrfs_key key;
2370 struct btrfs_root_item root_item;
2371 struct btrfs_inode_item *inode_item;
2372 struct buffer_head *subvol;
2373 struct btrfs_leaf *leaf;
2374 struct btrfs_root *new_root;
2375 struct inode *inode;
2376 struct inode *dir;
2377 int ret;
2378 u64 objectid;
2379 u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
2380
2381 mutex_lock(&root->fs_info->fs_mutex);
2382 trans = btrfs_start_transaction(root, 1);
2383 BUG_ON(!trans);
2384
2385 subvol = btrfs_alloc_free_block(trans, root, 0);
2386 if (subvol == NULL)
2387 return -ENOSPC;
2388 leaf = btrfs_buffer_leaf(subvol);
2389 btrfs_set_header_nritems(&leaf->header, 0);
2390 btrfs_set_header_level(&leaf->header, 0);
2391 btrfs_set_header_blocknr(&leaf->header, bh_blocknr(subvol));
2392 btrfs_set_header_generation(&leaf->header, trans->transid);
2393 btrfs_set_header_owner(&leaf->header, root->root_key.objectid);
2394 memcpy(leaf->header.fsid, root->fs_info->disk_super->fsid,
2395 sizeof(leaf->header.fsid));
2396 mark_buffer_dirty(subvol);
2397
2398 inode_item = &root_item.inode;
2399 memset(inode_item, 0, sizeof(*inode_item));
2400 btrfs_set_inode_generation(inode_item, 1);
2401 btrfs_set_inode_size(inode_item, 3);
2402 btrfs_set_inode_nlink(inode_item, 1);
2403 btrfs_set_inode_nblocks(inode_item, 1);
2404 btrfs_set_inode_mode(inode_item, S_IFDIR | 0755);
2405
2406 btrfs_set_root_blocknr(&root_item, bh_blocknr(subvol));
2407 btrfs_set_root_refs(&root_item, 1);
2408 brelse(subvol);
2409 subvol = NULL;
2410
2411 ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
2412 0, &objectid);
2413 BUG_ON(ret);
2414
2415 btrfs_set_root_dirid(&root_item, new_dirid);
2416
2417 key.objectid = objectid;
2418 key.offset = 1;
2419 key.flags = 0;
2420 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
2421 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
2422 &root_item);
2423 BUG_ON(ret);
2424
2425 /*
2426 * insert the directory item
2427 */
2428 key.offset = (u64)-1;
2429 dir = root->fs_info->sb->s_root->d_inode;
2430 ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
2431 name, namelen, dir->i_ino, &key, 0);
2432 BUG_ON(ret);
2433
2434 ret = btrfs_commit_transaction(trans, root);
2435 BUG_ON(ret);
2436
2437 new_root = btrfs_read_fs_root(root->fs_info, &key);
2438 BUG_ON(!new_root);
2439
2440 trans = btrfs_start_transaction(new_root, 1);
2441 BUG_ON(!trans);
2442
2443 inode = btrfs_new_inode(trans, new_root, new_dirid,
2444 BTRFS_I(dir)->block_group, S_IFDIR | 0700);
2445 inode->i_op = &btrfs_dir_inode_operations;
2446 inode->i_fop = &btrfs_dir_file_operations;
2447
2448 ret = btrfs_make_empty_dir(trans, new_root, new_dirid, new_dirid);
2449 BUG_ON(ret);
2450
2451 inode->i_nlink = 1;
2452 inode->i_size = 6;
2453 ret = btrfs_update_inode(trans, new_root, inode);
2454 BUG_ON(ret);
2455
2456 ret = btrfs_commit_transaction(trans, new_root);
2457 BUG_ON(ret);
2458
2459 iput(inode);
2460
2461 mutex_unlock(&root->fs_info->fs_mutex);
2462 btrfs_btree_balance_dirty(root);
2463 return 0;
2464 }
2465
2466 static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
2467 {
2468 struct btrfs_trans_handle *trans;
2469 struct btrfs_key key;
2470 struct btrfs_root_item new_root_item;
2471 int ret;
2472 u64 objectid;
2473
2474 if (!root->ref_cows)
2475 return -EINVAL;
2476
2477 mutex_lock(&root->fs_info->fs_mutex);
2478 trans = btrfs_start_transaction(root, 1);
2479 BUG_ON(!trans);
2480
2481 ret = btrfs_update_inode(trans, root, root->inode);
2482 BUG_ON(ret);
2483
2484 ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
2485 0, &objectid);
2486 BUG_ON(ret);
2487
2488 memcpy(&new_root_item, &root->root_item,
2489 sizeof(new_root_item));
2490
2491 key.objectid = objectid;
2492 key.offset = 1;
2493 key.flags = 0;
2494 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
2495 btrfs_set_root_blocknr(&new_root_item, bh_blocknr(root->node));
2496
2497 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
2498 &new_root_item);
2499 BUG_ON(ret);
2500
2501 /*
2502 * insert the directory item
2503 */
2504 key.offset = (u64)-1;
2505 ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
2506 name, namelen,
2507 root->fs_info->sb->s_root->d_inode->i_ino,
2508 &key, 0);
2509
2510 BUG_ON(ret);
2511
2512 ret = btrfs_inc_root_ref(trans, root);
2513 BUG_ON(ret);
2514
2515 ret = btrfs_commit_transaction(trans, root);
2516 BUG_ON(ret);
2517 mutex_unlock(&root->fs_info->fs_mutex);
2518 btrfs_btree_balance_dirty(root);
2519 return 0;
2520 }
2521
2522 static int add_disk(struct btrfs_root *root, char *name, int namelen)
2523 {
2524 struct block_device *bdev;
2525 struct btrfs_path *path;
2526 struct super_block *sb = root->fs_info->sb;
2527 struct btrfs_root *dev_root = root->fs_info->dev_root;
2528 struct btrfs_trans_handle *trans;
2529 struct btrfs_device_item *dev_item;
2530 struct btrfs_key key;
2531 u16 item_size;
2532 u64 num_blocks;
2533 u64 new_blocks;
2534 u64 device_id;
2535 int ret;
2536
2537 printk("adding disk %s\n", name);
2538 path = btrfs_alloc_path();
2539 if (!path)
2540 return -ENOMEM;
2541 num_blocks = btrfs_super_total_blocks(root->fs_info->disk_super);
2542 bdev = open_bdev_excl(name, O_RDWR, sb);
2543 if (IS_ERR(bdev)) {
2544 ret = PTR_ERR(bdev);
2545 printk("open bdev excl failed ret %d\n", ret);
2546 goto out_nolock;
2547 }
2548 set_blocksize(bdev, sb->s_blocksize);
2549 new_blocks = bdev->bd_inode->i_size >> sb->s_blocksize_bits;
2550 key.objectid = num_blocks;
2551 key.offset = new_blocks;
2552 key.flags = 0;
2553 btrfs_set_key_type(&key, BTRFS_DEV_ITEM_KEY);
2554
2555 mutex_lock(&dev_root->fs_info->fs_mutex);
2556 trans = btrfs_start_transaction(dev_root, 1);
2557 item_size = sizeof(*dev_item) + namelen;
2558 printk("insert empty on %Lu %Lu %u size %d\n", num_blocks, new_blocks, key.flags, item_size);
2559 ret = btrfs_insert_empty_item(trans, dev_root, path, &key, item_size);
2560 if (ret) {
2561 printk("insert failed %d\n", ret);
2562 close_bdev_excl(bdev);
2563 if (ret > 0)
2564 ret = -EEXIST;
2565 goto out;
2566 }
2567 dev_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
2568 path->slots[0], struct btrfs_device_item);
2569 btrfs_set_device_pathlen(dev_item, namelen);
2570 memcpy(dev_item + 1, name, namelen);
2571
2572 device_id = btrfs_super_last_device_id(root->fs_info->disk_super) + 1;
2573 btrfs_set_super_last_device_id(root->fs_info->disk_super, device_id);
2574 btrfs_set_device_id(dev_item, device_id);
2575 mark_buffer_dirty(path->nodes[0]);
2576
2577 ret = btrfs_insert_dev_radix(root, bdev, device_id, num_blocks,
2578 new_blocks);
2579
2580 if (!ret) {
2581 btrfs_set_super_total_blocks(root->fs_info->disk_super,
2582 num_blocks + new_blocks);
2583 i_size_write(root->fs_info->btree_inode,
2584 (num_blocks + new_blocks) <<
2585 root->fs_info->btree_inode->i_blkbits);
2586 }
2587
2588 out:
2589 ret = btrfs_commit_transaction(trans, dev_root);
2590 BUG_ON(ret);
2591 mutex_unlock(&root->fs_info->fs_mutex);
2592 out_nolock:
2593 btrfs_free_path(path);
2594 btrfs_btree_balance_dirty(root);
2595
2596 return ret;
2597 }
2598
2599 static int btrfs_ioctl(struct inode *inode, struct file *filp, unsigned int
2600 cmd, unsigned long arg)
2601 {
2602 struct btrfs_root *root = BTRFS_I(inode)->root;
2603 struct btrfs_ioctl_vol_args vol_args;
2604 int ret = 0;
2605 struct btrfs_dir_item *di;
2606 int namelen;
2607 struct btrfs_path *path;
2608 u64 root_dirid;
2609
2610 switch (cmd) {
2611 case BTRFS_IOC_SNAP_CREATE:
2612 if (copy_from_user(&vol_args,
2613 (struct btrfs_ioctl_vol_args __user *)arg,
2614 sizeof(vol_args)))
2615 return -EFAULT;
2616 namelen = strlen(vol_args.name);
2617 if (namelen > BTRFS_VOL_NAME_MAX)
2618 return -EINVAL;
2619 path = btrfs_alloc_path();
2620 if (!path)
2621 return -ENOMEM;
2622 root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
2623 mutex_lock(&root->fs_info->fs_mutex);
2624 di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
2625 path, root_dirid,
2626 vol_args.name, namelen, 0);
2627 mutex_unlock(&root->fs_info->fs_mutex);
2628 btrfs_free_path(path);
2629 if (di && !IS_ERR(di))
2630 return -EEXIST;
2631
2632 if (root == root->fs_info->tree_root)
2633 ret = create_subvol(root, vol_args.name, namelen);
2634 else
2635 ret = create_snapshot(root, vol_args.name, namelen);
2636 WARN_ON(ret);
2637 break;
2638 case BTRFS_IOC_ADD_DISK:
2639 if (copy_from_user(&vol_args,
2640 (struct btrfs_ioctl_vol_args __user *)arg,
2641 sizeof(vol_args)))
2642 return -EFAULT;
2643 namelen = strlen(vol_args.name);
2644 if (namelen > BTRFS_VOL_NAME_MAX)
2645 return -EINVAL;
2646 vol_args.name[namelen] = '\0';
2647 ret = add_disk(root, vol_args.name, namelen);
2648 break;
2649 default:
2650 return -ENOTTY;
2651 }
2652 return ret;
2653 }
2654
2655 static struct kmem_cache *btrfs_inode_cachep;
2656 struct kmem_cache *btrfs_trans_handle_cachep;
2657 struct kmem_cache *btrfs_transaction_cachep;
2658 struct kmem_cache *btrfs_bit_radix_cachep;
2659 struct kmem_cache *btrfs_path_cachep;
2660
2661 /*
2662 * Called inside transaction, so use GFP_NOFS
2663 */
2664 static struct inode *btrfs_alloc_inode(struct super_block *sb)
2665 {
2666 struct btrfs_inode *ei;
2667
2668 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
2669 if (!ei)
2670 return NULL;
2671 return &ei->vfs_inode;
2672 }
2673
2674 static void btrfs_destroy_inode(struct inode *inode)
2675 {
2676 WARN_ON(!list_empty(&inode->i_dentry));
2677 WARN_ON(inode->i_data.nrpages);
2678
2679 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
2680 }
2681
2682 static void init_once(void * foo, struct kmem_cache * cachep,
2683 unsigned long flags)
2684 {
2685 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
2686
2687 if ((flags & (SLAB_CTOR_CONSTRUCTOR)) ==
2688 SLAB_CTOR_CONSTRUCTOR) {
2689 inode_init_once(&ei->vfs_inode);
2690 }
2691 }
2692
2693 static int init_inodecache(void)
2694 {
2695 btrfs_inode_cachep = kmem_cache_create("btrfs_inode_cache",
2696 sizeof(struct btrfs_inode),
2697 0, (SLAB_RECLAIM_ACCOUNT|
2698 SLAB_MEM_SPREAD),
2699 init_once, NULL);
2700 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle_cache",
2701 sizeof(struct btrfs_trans_handle),
2702 0, (SLAB_RECLAIM_ACCOUNT|
2703 SLAB_MEM_SPREAD),
2704 NULL, NULL);
2705 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction_cache",
2706 sizeof(struct btrfs_transaction),
2707 0, (SLAB_RECLAIM_ACCOUNT|
2708 SLAB_MEM_SPREAD),
2709 NULL, NULL);
2710 btrfs_path_cachep = kmem_cache_create("btrfs_path_cache",
2711 sizeof(struct btrfs_transaction),
2712 0, (SLAB_RECLAIM_ACCOUNT|
2713 SLAB_MEM_SPREAD),
2714 NULL, NULL);
2715 btrfs_bit_radix_cachep = kmem_cache_create("btrfs_radix",
2716 256,
2717 0, (SLAB_RECLAIM_ACCOUNT|
2718 SLAB_MEM_SPREAD |
2719 SLAB_DESTROY_BY_RCU),
2720 NULL, NULL);
2721 if (btrfs_inode_cachep == NULL || btrfs_trans_handle_cachep == NULL ||
2722 btrfs_transaction_cachep == NULL || btrfs_bit_radix_cachep == NULL)
2723 return -ENOMEM;
2724 return 0;
2725 }
2726
2727 static void destroy_inodecache(void)
2728 {
2729 kmem_cache_destroy(btrfs_inode_cachep);
2730 kmem_cache_destroy(btrfs_trans_handle_cachep);
2731 kmem_cache_destroy(btrfs_transaction_cachep);
2732 kmem_cache_destroy(btrfs_bit_radix_cachep);
2733 kmem_cache_destroy(btrfs_path_cachep);
2734 }
2735
2736 static int btrfs_get_sb(struct file_system_type *fs_type,
2737 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
2738 {
2739 return get_sb_bdev(fs_type, flags, dev_name, data,
2740 btrfs_fill_super, mnt);
2741 }
2742
2743 static int btrfs_getattr(struct vfsmount *mnt,
2744 struct dentry *dentry, struct kstat *stat)
2745 {
2746 struct inode *inode = dentry->d_inode;
2747 generic_fillattr(inode, stat);
2748 stat->blksize = 256 * 1024;
2749 return 0;
2750 }
2751
2752 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
2753 {
2754 struct btrfs_root *root = btrfs_sb(dentry->d_sb);
2755 struct btrfs_super_block *disk_super = root->fs_info->disk_super;
2756
2757 buf->f_namelen = BTRFS_NAME_LEN;
2758 buf->f_blocks = btrfs_super_total_blocks(disk_super);
2759 buf->f_bfree = buf->f_blocks - btrfs_super_blocks_used(disk_super);
2760 buf->f_bavail = buf->f_bfree;
2761 buf->f_bsize = dentry->d_sb->s_blocksize;
2762 buf->f_type = BTRFS_SUPER_MAGIC;
2763 return 0;
2764 }
2765
2766 static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
2767 struct inode * new_dir,struct dentry *new_dentry)
2768 {
2769 struct btrfs_trans_handle *trans;
2770 struct btrfs_root *root = BTRFS_I(old_dir)->root;
2771 struct inode *new_inode = new_dentry->d_inode;
2772 struct inode *old_inode = old_dentry->d_inode;
2773 struct timespec ctime = CURRENT_TIME;
2774 struct btrfs_path *path;
2775 struct btrfs_dir_item *di;
2776 int ret;
2777
2778 if (S_ISDIR(old_inode->i_mode) && new_inode &&
2779 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
2780 return -ENOTEMPTY;
2781 }
2782 mutex_lock(&root->fs_info->fs_mutex);
2783 trans = btrfs_start_transaction(root, 1);
2784 btrfs_set_trans_block_group(trans, new_dir);
2785 path = btrfs_alloc_path();
2786 if (!path) {
2787 ret = -ENOMEM;
2788 goto out_fail;
2789 }
2790
2791 old_dentry->d_inode->i_nlink++;
2792 old_dir->i_ctime = old_dir->i_mtime = ctime;
2793 new_dir->i_ctime = new_dir->i_mtime = ctime;
2794 old_inode->i_ctime = ctime;
2795 if (S_ISDIR(old_inode->i_mode) && old_dir != new_dir) {
2796 struct btrfs_key *location = &BTRFS_I(new_dir)->location;
2797 u64 old_parent_oid;
2798 di = btrfs_lookup_dir_item(trans, root, path, old_inode->i_ino,
2799 "..", 2, -1);
2800 if (IS_ERR(di)) {
2801 ret = PTR_ERR(di);
2802 goto out_fail;
2803 }
2804 if (!di) {
2805 ret = -ENOENT;
2806 goto out_fail;
2807 }
2808 old_parent_oid = btrfs_disk_key_objectid(&di->location);
2809 ret = btrfs_del_item(trans, root, path);
2810 if (ret) {
2811 ret = -EIO;
2812 goto out_fail;
2813 }
2814 btrfs_release_path(root, path);
2815
2816 di = btrfs_lookup_dir_index_item(trans, root, path,
2817 old_inode->i_ino,
2818 old_parent_oid,
2819 "..", 2, -1);
2820 if (IS_ERR(di)) {
2821 ret = PTR_ERR(di);
2822 goto out_fail;
2823 }
2824 if (!di) {
2825 ret = -ENOENT;
2826 goto out_fail;
2827 }
2828 ret = btrfs_del_item(trans, root, path);
2829 if (ret) {
2830 ret = -EIO;
2831 goto out_fail;
2832 }
2833 btrfs_release_path(root, path);
2834
2835 ret = btrfs_insert_dir_item(trans, root, "..", 2,
2836 old_inode->i_ino, location, 0);
2837 if (ret)
2838 goto out_fail;
2839 }
2840
2841
2842 ret = btrfs_unlink_trans(trans, root, old_dir, old_dentry);
2843 if (ret)
2844 goto out_fail;
2845
2846 if (new_inode) {
2847 new_inode->i_ctime = CURRENT_TIME;
2848 ret = btrfs_unlink_trans(trans, root, new_dir, new_dentry);
2849 if (ret)
2850 goto out_fail;
2851 if (S_ISDIR(new_inode->i_mode))
2852 clear_nlink(new_inode);
2853 else
2854 drop_nlink(new_inode);
2855 btrfs_update_inode(trans, root, new_inode);
2856 }
2857 ret = btrfs_add_link(trans, new_dentry, old_inode);
2858 if (ret)
2859 goto out_fail;
2860
2861 out_fail:
2862 btrfs_free_path(path);
2863 btrfs_end_transaction(trans, root);
2864 mutex_unlock(&root->fs_info->fs_mutex);
2865 return ret;
2866 }
2867
2868 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
2869 const char *symname)
2870 {
2871 struct btrfs_trans_handle *trans;
2872 struct btrfs_root *root = BTRFS_I(dir)->root;
2873 struct btrfs_path *path;
2874 struct btrfs_key key;
2875 struct inode *inode;
2876 int err;
2877 int drop_inode = 0;
2878 u64 objectid;
2879 int name_len;
2880 int datasize;
2881 char *ptr;
2882 struct btrfs_file_extent_item *ei;
2883
2884 name_len = strlen(symname) + 1;
2885 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
2886 return -ENAMETOOLONG;
2887 mutex_lock(&root->fs_info->fs_mutex);
2888 trans = btrfs_start_transaction(root, 1);
2889 btrfs_set_trans_block_group(trans, dir);
2890
2891 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
2892 if (err) {
2893 err = -ENOSPC;
2894 goto out_unlock;
2895 }
2896
2897 inode = btrfs_new_inode(trans, root, objectid,
2898 BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO);
2899 err = PTR_ERR(inode);
2900 if (IS_ERR(inode))
2901 goto out_unlock;
2902
2903 btrfs_set_trans_block_group(trans, inode);
2904 err = btrfs_add_nondir(trans, dentry, inode);
2905 if (err)
2906 drop_inode = 1;
2907 else {
2908 inode->i_mapping->a_ops = &btrfs_aops;
2909 inode->i_fop = &btrfs_file_operations;
2910 inode->i_op = &btrfs_file_inode_operations;
2911 }
2912 dir->i_sb->s_dirt = 1;
2913 btrfs_update_inode_block_group(trans, inode);
2914 btrfs_update_inode_block_group(trans, dir);
2915 if (drop_inode)
2916 goto out_unlock;
2917
2918 path = btrfs_alloc_path();
2919 BUG_ON(!path);
2920 key.objectid = inode->i_ino;
2921 key.offset = 0;
2922 key.flags = 0;
2923 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
2924 datasize = btrfs_file_extent_calc_inline_size(name_len);
2925 err = btrfs_insert_empty_item(trans, root, path, &key,
2926 datasize);
2927 BUG_ON(err);
2928 ei = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
2929 path->slots[0], struct btrfs_file_extent_item);
2930 btrfs_set_file_extent_generation(ei, trans->transid);
2931 btrfs_set_file_extent_type(ei,
2932 BTRFS_FILE_EXTENT_INLINE);
2933 ptr = btrfs_file_extent_inline_start(ei);
2934 btrfs_memcpy(root, path->nodes[0]->b_data,
2935 ptr, symname, name_len);
2936 mark_buffer_dirty(path->nodes[0]);
2937 btrfs_free_path(path);
2938 inode->i_op = &btrfs_symlink_inode_operations;
2939 inode->i_mapping->a_ops = &btrfs_symlink_aops;
2940 inode->i_size = name_len - 1;
2941 btrfs_update_inode(trans, root, inode);
2942 err = 0;
2943
2944 out_unlock:
2945 btrfs_end_transaction(trans, root);
2946 mutex_unlock(&root->fs_info->fs_mutex);
2947
2948 if (drop_inode) {
2949 inode_dec_link_count(inode);
2950 iput(inode);
2951 }
2952 btrfs_btree_balance_dirty(root);
2953 return err;
2954 }
2955
2956 static struct file_system_type btrfs_fs_type = {
2957 .owner = THIS_MODULE,
2958 .name = "btrfs",
2959 .get_sb = btrfs_get_sb,
2960 .kill_sb = kill_block_super,
2961 .fs_flags = FS_REQUIRES_DEV,
2962 };
2963
2964 static struct super_operations btrfs_super_ops = {
2965 .delete_inode = btrfs_delete_inode,
2966 .put_super = btrfs_put_super,
2967 .read_inode = btrfs_read_locked_inode,
2968 .write_super = btrfs_write_super,
2969 .sync_fs = btrfs_sync_fs,
2970 .write_inode = btrfs_write_inode,
2971 .dirty_inode = btrfs_dirty_inode,
2972 .alloc_inode = btrfs_alloc_inode,
2973 .destroy_inode = btrfs_destroy_inode,
2974 .statfs = btrfs_statfs,
2975 };
2976
2977 static struct inode_operations btrfs_dir_inode_operations = {
2978 .lookup = btrfs_lookup,
2979 .create = btrfs_create,
2980 .unlink = btrfs_unlink,
2981 .link = btrfs_link,
2982 .mkdir = btrfs_mkdir,
2983 .rmdir = btrfs_rmdir,
2984 .rename = btrfs_rename,
2985 .symlink = btrfs_symlink,
2986 .setattr = btrfs_setattr,
2987 };
2988
2989 static struct inode_operations btrfs_dir_ro_inode_operations = {
2990 .lookup = btrfs_lookup,
2991 };
2992
2993 static struct file_operations btrfs_dir_file_operations = {
2994 .llseek = generic_file_llseek,
2995 .read = generic_read_dir,
2996 .readdir = btrfs_readdir,
2997 .ioctl = btrfs_ioctl,
2998 };
2999
3000 static struct address_space_operations btrfs_aops = {
3001 .readpage = btrfs_readpage,
3002 .writepage = btrfs_writepage,
3003 .sync_page = block_sync_page,
3004 .prepare_write = btrfs_prepare_write,
3005 .commit_write = btrfs_commit_write,
3006 };
3007
3008 static struct address_space_operations btrfs_symlink_aops = {
3009 .readpage = btrfs_readpage,
3010 .writepage = btrfs_writepage,
3011 };
3012
3013 static struct inode_operations btrfs_file_inode_operations = {
3014 .truncate = btrfs_truncate,
3015 .getattr = btrfs_getattr,
3016 .setattr = btrfs_setattr,
3017 };
3018
3019 static struct file_operations btrfs_file_operations = {
3020 .llseek = generic_file_llseek,
3021 .read = do_sync_read,
3022 .aio_read = btrfs_file_aio_read,
3023 .write = btrfs_file_write,
3024 .mmap = generic_file_mmap,
3025 .open = generic_file_open,
3026 .ioctl = btrfs_ioctl,
3027 .fsync = btrfs_sync_file,
3028 };
3029
3030 static struct inode_operations btrfs_symlink_inode_operations = {
3031 .readlink = generic_readlink,
3032 .follow_link = page_follow_link_light,
3033 .put_link = page_put_link,
3034 };
3035
3036 static int __init init_btrfs_fs(void)
3037 {
3038 int err;
3039 printk("btrfs loaded!\n");
3040 err = init_inodecache();
3041 if (err)
3042 return err;
3043 return register_filesystem(&btrfs_fs_type);
3044 destroy_inodecache();
3045 return err;
3046 }
3047
3048 static void __exit exit_btrfs_fs(void)
3049 {
3050 destroy_inodecache();
3051 unregister_filesystem(&btrfs_fs_type);
3052 printk("btrfs unloaded\n");
3053 }
3054
3055 module_init(init_btrfs_fs)
3056 module_exit(exit_btrfs_fs)
3057
3058 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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