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Btrfs: start of block group code
[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
21 void btrfs_fsinfo_release(struct kobject *obj)
22 {
23 struct btrfs_fs_info *fsinfo = container_of(obj,
24 struct btrfs_fs_info, kobj);
25 kfree(fsinfo);
26 }
27
28 struct kobj_type btrfs_fsinfo_ktype = {
29 .release = btrfs_fsinfo_release,
30 };
31
32 struct btrfs_iget_args {
33 u64 ino;
34 struct btrfs_root *root;
35 };
36
37 decl_subsys(btrfs, &btrfs_fsinfo_ktype, NULL);
38
39 #define BTRFS_SUPER_MAGIC 0x9123682E
40
41 static struct inode_operations btrfs_dir_inode_operations;
42 static struct inode_operations btrfs_dir_ro_inode_operations;
43 static struct super_operations btrfs_super_ops;
44 static struct file_operations btrfs_dir_file_operations;
45 static struct inode_operations btrfs_file_inode_operations;
46 static struct address_space_operations btrfs_aops;
47 static struct file_operations btrfs_file_operations;
48
49 static void btrfs_read_locked_inode(struct inode *inode)
50 {
51 struct btrfs_path *path;
52 struct btrfs_inode_item *inode_item;
53 struct btrfs_root *root = BTRFS_I(inode)->root;
54 struct btrfs_key location;
55 int ret;
56
57 path = btrfs_alloc_path();
58 BUG_ON(!path);
59 btrfs_init_path(path);
60 mutex_lock(&root->fs_info->fs_mutex);
61
62 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
63 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
64 if (ret) {
65 btrfs_free_path(path);
66 goto make_bad;
67 }
68 inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
69 path->slots[0],
70 struct btrfs_inode_item);
71
72 inode->i_mode = btrfs_inode_mode(inode_item);
73 inode->i_nlink = btrfs_inode_nlink(inode_item);
74 inode->i_uid = btrfs_inode_uid(inode_item);
75 inode->i_gid = btrfs_inode_gid(inode_item);
76 inode->i_size = btrfs_inode_size(inode_item);
77 inode->i_atime.tv_sec = btrfs_timespec_sec(&inode_item->atime);
78 inode->i_atime.tv_nsec = btrfs_timespec_nsec(&inode_item->atime);
79 inode->i_mtime.tv_sec = btrfs_timespec_sec(&inode_item->mtime);
80 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(&inode_item->mtime);
81 inode->i_ctime.tv_sec = btrfs_timespec_sec(&inode_item->ctime);
82 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(&inode_item->ctime);
83 inode->i_blocks = btrfs_inode_nblocks(inode_item);
84 inode->i_generation = btrfs_inode_generation(inode_item);
85
86 btrfs_free_path(path);
87 inode_item = NULL;
88
89 mutex_unlock(&root->fs_info->fs_mutex);
90
91 switch (inode->i_mode & S_IFMT) {
92 #if 0
93 default:
94 init_special_inode(inode, inode->i_mode,
95 btrfs_inode_rdev(inode_item));
96 break;
97 #endif
98 case S_IFREG:
99 inode->i_mapping->a_ops = &btrfs_aops;
100 inode->i_fop = &btrfs_file_operations;
101 inode->i_op = &btrfs_file_inode_operations;
102 break;
103 case S_IFDIR:
104 inode->i_fop = &btrfs_dir_file_operations;
105 if (root == root->fs_info->tree_root)
106 inode->i_op = &btrfs_dir_ro_inode_operations;
107 else
108 inode->i_op = &btrfs_dir_inode_operations;
109 break;
110 case S_IFLNK:
111 // inode->i_op = &page_symlink_inode_operations;
112 break;
113 }
114 return;
115
116 make_bad:
117 btrfs_release_path(root, path);
118 btrfs_free_path(path);
119 mutex_unlock(&root->fs_info->fs_mutex);
120 make_bad_inode(inode);
121 }
122
123 static void fill_inode_item(struct btrfs_inode_item *item,
124 struct inode *inode)
125 {
126 btrfs_set_inode_uid(item, inode->i_uid);
127 btrfs_set_inode_gid(item, inode->i_gid);
128 btrfs_set_inode_size(item, inode->i_size);
129 btrfs_set_inode_mode(item, inode->i_mode);
130 btrfs_set_inode_nlink(item, inode->i_nlink);
131 btrfs_set_timespec_sec(&item->atime, inode->i_atime.tv_sec);
132 btrfs_set_timespec_nsec(&item->atime, inode->i_atime.tv_nsec);
133 btrfs_set_timespec_sec(&item->mtime, inode->i_mtime.tv_sec);
134 btrfs_set_timespec_nsec(&item->mtime, inode->i_mtime.tv_nsec);
135 btrfs_set_timespec_sec(&item->ctime, inode->i_ctime.tv_sec);
136 btrfs_set_timespec_nsec(&item->ctime, inode->i_ctime.tv_nsec);
137 btrfs_set_inode_nblocks(item, inode->i_blocks);
138 btrfs_set_inode_generation(item, inode->i_generation);
139 }
140
141
142 static int btrfs_update_inode(struct btrfs_trans_handle *trans,
143 struct btrfs_root *root,
144 struct inode *inode)
145 {
146 struct btrfs_inode_item *inode_item;
147 struct btrfs_path *path;
148 int ret;
149
150 path = btrfs_alloc_path();
151 BUG_ON(!path);
152 btrfs_init_path(path);
153 ret = btrfs_lookup_inode(trans, root, path,
154 &BTRFS_I(inode)->location, 1);
155 if (ret) {
156 if (ret > 0)
157 ret = -ENOENT;
158 goto failed;
159 }
160
161 inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
162 path->slots[0],
163 struct btrfs_inode_item);
164
165 fill_inode_item(inode_item, inode);
166 btrfs_mark_buffer_dirty(path->nodes[0]);
167 ret = 0;
168 failed:
169 btrfs_release_path(root, path);
170 btrfs_free_path(path);
171 return ret;
172 }
173
174
175 static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
176 struct btrfs_root *root,
177 struct inode *dir,
178 struct dentry *dentry)
179 {
180 struct btrfs_path *path;
181 const char *name = dentry->d_name.name;
182 int name_len = dentry->d_name.len;
183 int ret = 0;
184 u64 objectid;
185 struct btrfs_dir_item *di;
186
187 path = btrfs_alloc_path();
188 BUG_ON(!path);
189 btrfs_init_path(path);
190 di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
191 name, name_len, -1);
192 if (IS_ERR(di)) {
193 ret = PTR_ERR(di);
194 goto err;
195 }
196 if (!di) {
197 ret = -ENOENT;
198 goto err;
199 }
200 objectid = btrfs_disk_key_objectid(&di->location);
201 ret = btrfs_delete_one_dir_name(trans, root, path, di);
202 BUG_ON(ret);
203 btrfs_release_path(root, path);
204
205 di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
206 objectid, name, name_len, -1);
207 if (IS_ERR(di)) {
208 ret = PTR_ERR(di);
209 goto err;
210 }
211 if (!di) {
212 ret = -ENOENT;
213 goto err;
214 }
215 ret = btrfs_delete_one_dir_name(trans, root, path, di);
216 BUG_ON(ret);
217
218 dentry->d_inode->i_ctime = dir->i_ctime;
219 err:
220 btrfs_free_path(path);
221 if (!ret) {
222 dir->i_size -= name_len * 2;
223 btrfs_update_inode(trans, root, dir);
224 drop_nlink(dentry->d_inode);
225 btrfs_update_inode(trans, root, dentry->d_inode);
226 }
227 return ret;
228 }
229
230 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
231 {
232 struct btrfs_root *root;
233 struct btrfs_trans_handle *trans;
234 int ret;
235
236 root = BTRFS_I(dir)->root;
237 mutex_lock(&root->fs_info->fs_mutex);
238 trans = btrfs_start_transaction(root, 1);
239 ret = btrfs_unlink_trans(trans, root, dir, dentry);
240 btrfs_end_transaction(trans, root);
241 mutex_unlock(&root->fs_info->fs_mutex);
242 return ret;
243 }
244
245 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
246 {
247 struct inode *inode = dentry->d_inode;
248 int err;
249 int ret;
250 struct btrfs_root *root = BTRFS_I(dir)->root;
251 struct btrfs_path *path;
252 struct btrfs_key key;
253 struct btrfs_trans_handle *trans;
254 struct btrfs_key found_key;
255 int found_type;
256 struct btrfs_leaf *leaf;
257 char *goodnames = "..";
258
259 path = btrfs_alloc_path();
260 BUG_ON(!path);
261 btrfs_init_path(path);
262 mutex_lock(&root->fs_info->fs_mutex);
263 trans = btrfs_start_transaction(root, 1);
264 key.objectid = inode->i_ino;
265 key.offset = (u64)-1;
266 key.flags = (u32)-1;
267 while(1) {
268 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
269 if (ret < 0) {
270 err = ret;
271 goto out;
272 }
273 BUG_ON(ret == 0);
274 if (path->slots[0] == 0) {
275 err = -ENOENT;
276 goto out;
277 }
278 path->slots[0]--;
279 leaf = btrfs_buffer_leaf(path->nodes[0]);
280 btrfs_disk_key_to_cpu(&found_key,
281 &leaf->items[path->slots[0]].key);
282 found_type = btrfs_key_type(&found_key);
283 if (found_key.objectid != inode->i_ino) {
284 err = -ENOENT;
285 goto out;
286 }
287 if ((found_type != BTRFS_DIR_ITEM_KEY &&
288 found_type != BTRFS_DIR_INDEX_KEY) ||
289 (!btrfs_match_dir_item_name(root, path, goodnames, 2) &&
290 !btrfs_match_dir_item_name(root, path, goodnames, 1))) {
291 err = -ENOTEMPTY;
292 goto out;
293 }
294 ret = btrfs_del_item(trans, root, path);
295 BUG_ON(ret);
296
297 if (found_type == BTRFS_DIR_ITEM_KEY && found_key.offset == 1)
298 break;
299 btrfs_release_path(root, path);
300 }
301 ret = 0;
302 btrfs_release_path(root, path);
303
304 /* now the directory is empty */
305 err = btrfs_unlink_trans(trans, root, dir, dentry);
306 if (!err) {
307 inode->i_size = 0;
308 }
309 out:
310 btrfs_release_path(root, path);
311 btrfs_free_path(path);
312 mutex_unlock(&root->fs_info->fs_mutex);
313 ret = btrfs_end_transaction(trans, root);
314 if (ret && !err)
315 err = ret;
316 return err;
317 }
318
319 static int btrfs_free_inode(struct btrfs_trans_handle *trans,
320 struct btrfs_root *root,
321 struct inode *inode)
322 {
323 struct btrfs_path *path;
324 int ret;
325
326 clear_inode(inode);
327
328 path = btrfs_alloc_path();
329 BUG_ON(!path);
330 btrfs_init_path(path);
331 ret = btrfs_lookup_inode(trans, root, path,
332 &BTRFS_I(inode)->location, -1);
333 BUG_ON(ret);
334 ret = btrfs_del_item(trans, root, path);
335 BUG_ON(ret);
336 btrfs_free_path(path);
337 return ret;
338 }
339
340 static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
341 struct btrfs_root *root,
342 struct inode *inode)
343 {
344 int ret;
345 struct btrfs_path *path;
346 struct btrfs_key key;
347 struct btrfs_disk_key *found_key;
348 struct btrfs_leaf *leaf;
349 struct btrfs_file_extent_item *fi = NULL;
350 u64 extent_start = 0;
351 u64 extent_num_blocks = 0;
352 int found_extent;
353
354 path = btrfs_alloc_path();
355 BUG_ON(!path);
356 /* FIXME, add redo link to tree so we don't leak on crash */
357 key.objectid = inode->i_ino;
358 key.offset = (u64)-1;
359 key.flags = 0;
360 /*
361 * use BTRFS_CSUM_ITEM_KEY because it is larger than inline keys
362 * or extent data
363 */
364 btrfs_set_key_type(&key, BTRFS_CSUM_ITEM_KEY);
365 while(1) {
366 btrfs_init_path(path);
367 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
368 if (ret < 0) {
369 goto error;
370 }
371 if (ret > 0) {
372 BUG_ON(path->slots[0] == 0);
373 path->slots[0]--;
374 }
375 leaf = btrfs_buffer_leaf(path->nodes[0]);
376 found_key = &leaf->items[path->slots[0]].key;
377 if (btrfs_disk_key_objectid(found_key) != inode->i_ino)
378 break;
379 if (btrfs_disk_key_type(found_key) != BTRFS_CSUM_ITEM_KEY &&
380 btrfs_disk_key_type(found_key) != BTRFS_EXTENT_DATA_KEY)
381 break;
382 if (btrfs_disk_key_offset(found_key) < inode->i_size)
383 break;
384 found_extent = 0;
385 if (btrfs_disk_key_type(found_key) == BTRFS_EXTENT_DATA_KEY) {
386 fi = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
387 path->slots[0],
388 struct btrfs_file_extent_item);
389 if (btrfs_file_extent_type(fi) !=
390 BTRFS_FILE_EXTENT_INLINE) {
391 extent_start =
392 btrfs_file_extent_disk_blocknr(fi);
393 extent_num_blocks =
394 btrfs_file_extent_disk_num_blocks(fi);
395 /* FIXME blocksize != 4096 */
396 inode->i_blocks -=
397 btrfs_file_extent_num_blocks(fi) << 3;
398 found_extent = 1;
399 }
400 }
401 ret = btrfs_del_item(trans, root, path);
402 BUG_ON(ret);
403 btrfs_release_path(root, path);
404 if (found_extent) {
405 ret = btrfs_free_extent(trans, root, extent_start,
406 extent_num_blocks, 0);
407 BUG_ON(ret);
408 }
409 }
410 ret = 0;
411 error:
412 btrfs_release_path(root, path);
413 btrfs_free_path(path);
414 return ret;
415 }
416
417 static void btrfs_delete_inode(struct inode *inode)
418 {
419 struct btrfs_trans_handle *trans;
420 struct btrfs_root *root = BTRFS_I(inode)->root;
421 int ret;
422
423 truncate_inode_pages(&inode->i_data, 0);
424 if (is_bad_inode(inode)) {
425 goto no_delete;
426 }
427 inode->i_size = 0;
428 mutex_lock(&root->fs_info->fs_mutex);
429 trans = btrfs_start_transaction(root, 1);
430 if (S_ISREG(inode->i_mode)) {
431 ret = btrfs_truncate_in_trans(trans, root, inode);
432 BUG_ON(ret);
433 }
434 btrfs_free_inode(trans, root, inode);
435 btrfs_end_transaction(trans, root);
436 mutex_unlock(&root->fs_info->fs_mutex);
437 return;
438 no_delete:
439 clear_inode(inode);
440 }
441
442 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
443 struct btrfs_key *location)
444 {
445 const char *name = dentry->d_name.name;
446 int namelen = dentry->d_name.len;
447 struct btrfs_dir_item *di;
448 struct btrfs_path *path;
449 struct btrfs_root *root = BTRFS_I(dir)->root;
450 int ret;
451
452 path = btrfs_alloc_path();
453 BUG_ON(!path);
454 btrfs_init_path(path);
455 di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
456 namelen, 0);
457 if (!di || IS_ERR(di)) {
458 location->objectid = 0;
459 ret = 0;
460 goto out;
461 }
462 btrfs_disk_key_to_cpu(location, &di->location);
463 out:
464 btrfs_release_path(root, path);
465 btrfs_free_path(path);
466 return ret;
467 }
468
469 int fixup_tree_root_location(struct btrfs_root *root,
470 struct btrfs_key *location,
471 struct btrfs_root **sub_root)
472 {
473 struct btrfs_path *path;
474 struct btrfs_root_item *ri;
475
476 if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY)
477 return 0;
478 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
479 return 0;
480
481 path = btrfs_alloc_path();
482 BUG_ON(!path);
483 mutex_lock(&root->fs_info->fs_mutex);
484
485 *sub_root = btrfs_read_fs_root(root->fs_info, location);
486 if (IS_ERR(*sub_root))
487 return PTR_ERR(*sub_root);
488
489 ri = &(*sub_root)->root_item;
490 location->objectid = btrfs_root_dirid(ri);
491 location->flags = 0;
492 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
493 location->offset = 0;
494
495 btrfs_free_path(path);
496 mutex_unlock(&root->fs_info->fs_mutex);
497 return 0;
498 }
499
500 int btrfs_init_locked_inode(struct inode *inode, void *p)
501 {
502 struct btrfs_iget_args *args = p;
503 inode->i_ino = args->ino;
504 BTRFS_I(inode)->root = args->root;
505 return 0;
506 }
507
508 int btrfs_find_actor(struct inode *inode, void *opaque)
509 {
510 struct btrfs_iget_args *args = opaque;
511 return (args->ino == inode->i_ino &&
512 args->root == BTRFS_I(inode)->root);
513 }
514
515 struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
516 struct btrfs_root *root)
517 {
518 struct inode *inode;
519 struct btrfs_iget_args args;
520 args.ino = objectid;
521 args.root = root;
522
523 inode = iget5_locked(s, objectid, btrfs_find_actor,
524 btrfs_init_locked_inode,
525 (void *)&args);
526 return inode;
527 }
528
529 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
530 struct nameidata *nd)
531 {
532 struct inode * inode;
533 struct btrfs_inode *bi = BTRFS_I(dir);
534 struct btrfs_root *root = bi->root;
535 struct btrfs_root *sub_root = root;
536 struct btrfs_key location;
537 int ret;
538
539 if (dentry->d_name.len > BTRFS_NAME_LEN)
540 return ERR_PTR(-ENAMETOOLONG);
541 mutex_lock(&root->fs_info->fs_mutex);
542 ret = btrfs_inode_by_name(dir, dentry, &location);
543 mutex_unlock(&root->fs_info->fs_mutex);
544 if (ret < 0)
545 return ERR_PTR(ret);
546 inode = NULL;
547 if (location.objectid) {
548 ret = fixup_tree_root_location(root, &location, &sub_root);
549 if (ret < 0)
550 return ERR_PTR(ret);
551 if (ret > 0)
552 return ERR_PTR(-ENOENT);
553 inode = btrfs_iget_locked(dir->i_sb, location.objectid,
554 sub_root);
555 if (!inode)
556 return ERR_PTR(-EACCES);
557 if (inode->i_state & I_NEW) {
558 if (sub_root != root) {
559 printk("adding new root for inode %lu root %p (found %p)\n", inode->i_ino, sub_root, BTRFS_I(inode)->root);
560 igrab(inode);
561 sub_root->inode = inode;
562 }
563 BTRFS_I(inode)->root = sub_root;
564 memcpy(&BTRFS_I(inode)->location, &location,
565 sizeof(location));
566 btrfs_read_locked_inode(inode);
567 unlock_new_inode(inode);
568 }
569 }
570 return d_splice_alias(inode, dentry);
571 }
572
573 static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
574 {
575 struct inode *inode = filp->f_path.dentry->d_inode;
576 struct btrfs_root *root = BTRFS_I(inode)->root;
577 struct btrfs_item *item;
578 struct btrfs_dir_item *di;
579 struct btrfs_key key;
580 struct btrfs_path *path;
581 int ret;
582 u32 nritems;
583 struct btrfs_leaf *leaf;
584 int slot;
585 int advance;
586 unsigned char d_type = DT_UNKNOWN;
587 int over = 0;
588 u32 di_cur;
589 u32 di_total;
590 u32 di_len;
591 int key_type = BTRFS_DIR_INDEX_KEY;
592
593 /* FIXME, use a real flag for deciding about the key type */
594 if (root->fs_info->tree_root == root)
595 key_type = BTRFS_DIR_ITEM_KEY;
596 mutex_lock(&root->fs_info->fs_mutex);
597 key.objectid = inode->i_ino;
598 key.flags = 0;
599 btrfs_set_key_type(&key, key_type);
600 key.offset = filp->f_pos;
601 path = btrfs_alloc_path();
602 btrfs_init_path(path);
603 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
604 if (ret < 0)
605 goto err;
606 advance = 0;
607 while(1) {
608 leaf = btrfs_buffer_leaf(path->nodes[0]);
609 nritems = btrfs_header_nritems(&leaf->header);
610 slot = path->slots[0];
611 if (advance || slot >= nritems) {
612 if (slot >= nritems -1) {
613 ret = btrfs_next_leaf(root, path);
614 if (ret)
615 break;
616 leaf = btrfs_buffer_leaf(path->nodes[0]);
617 nritems = btrfs_header_nritems(&leaf->header);
618 slot = path->slots[0];
619 } else {
620 slot++;
621 path->slots[0]++;
622 }
623 }
624 advance = 1;
625 item = leaf->items + slot;
626 if (btrfs_disk_key_objectid(&item->key) != key.objectid)
627 break;
628 if (btrfs_disk_key_type(&item->key) != key_type)
629 break;
630 if (btrfs_disk_key_offset(&item->key) < filp->f_pos)
631 continue;
632 filp->f_pos = btrfs_disk_key_offset(&item->key);
633 advance = 1;
634 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
635 di_cur = 0;
636 di_total = btrfs_item_size(leaf->items + slot);
637 while(di_cur < di_total) {
638 over = filldir(dirent, (const char *)(di + 1),
639 btrfs_dir_name_len(di),
640 btrfs_disk_key_offset(&item->key),
641 btrfs_disk_key_objectid(&di->location),
642 d_type);
643 if (over)
644 goto nopos;
645 di_len = btrfs_dir_name_len(di) + sizeof(*di);
646 di_cur += di_len;
647 di = (struct btrfs_dir_item *)((char *)di + di_len);
648 }
649 }
650 filp->f_pos++;
651 nopos:
652 ret = 0;
653 err:
654 btrfs_release_path(root, path);
655 btrfs_free_path(path);
656 mutex_unlock(&root->fs_info->fs_mutex);
657 return ret;
658 }
659
660 static void btrfs_put_super (struct super_block * sb)
661 {
662 struct btrfs_root *root = btrfs_sb(sb);
663 int ret;
664
665 ret = close_ctree(root);
666 if (ret) {
667 printk("close ctree returns %d\n", ret);
668 }
669 sb->s_fs_info = NULL;
670 }
671
672 static int btrfs_fill_super(struct super_block * sb, void * data, int silent)
673 {
674 struct inode * inode;
675 struct dentry * root_dentry;
676 struct btrfs_super_block *disk_super;
677 struct btrfs_root *tree_root;
678 struct btrfs_inode *bi;
679
680 sb->s_maxbytes = MAX_LFS_FILESIZE;
681 sb->s_magic = BTRFS_SUPER_MAGIC;
682 sb->s_op = &btrfs_super_ops;
683 sb->s_time_gran = 1;
684
685 tree_root = open_ctree(sb);
686
687 if (!tree_root) {
688 printk("btrfs: open_ctree failed\n");
689 return -EIO;
690 }
691 sb->s_fs_info = tree_root;
692 disk_super = tree_root->fs_info->disk_super;
693 printk("read in super total blocks %Lu root %Lu\n",
694 btrfs_super_total_blocks(disk_super),
695 btrfs_super_root_dir(disk_super));
696
697 inode = btrfs_iget_locked(sb, btrfs_super_root_dir(disk_super),
698 tree_root);
699 bi = BTRFS_I(inode);
700 bi->location.objectid = inode->i_ino;
701 bi->location.offset = 0;
702 bi->location.flags = 0;
703 bi->root = tree_root;
704 btrfs_set_key_type(&bi->location, BTRFS_INODE_ITEM_KEY);
705
706 if (!inode)
707 return -ENOMEM;
708 if (inode->i_state & I_NEW) {
709 btrfs_read_locked_inode(inode);
710 unlock_new_inode(inode);
711 }
712
713 root_dentry = d_alloc_root(inode);
714 if (!root_dentry) {
715 iput(inode);
716 return -ENOMEM;
717 }
718 sb->s_root = root_dentry;
719
720 return 0;
721 }
722
723 static int btrfs_write_inode(struct inode *inode, int wait)
724 {
725 struct btrfs_root *root = BTRFS_I(inode)->root;
726 struct btrfs_trans_handle *trans;
727 int ret = 0;
728
729 if (wait) {
730 mutex_lock(&root->fs_info->fs_mutex);
731 trans = btrfs_start_transaction(root, 1);
732 ret = btrfs_commit_transaction(trans, root);
733 mutex_unlock(&root->fs_info->fs_mutex);
734 }
735 return ret;
736 }
737
738 static void btrfs_dirty_inode(struct inode *inode)
739 {
740 struct btrfs_root *root = BTRFS_I(inode)->root;
741 struct btrfs_trans_handle *trans;
742
743 mutex_lock(&root->fs_info->fs_mutex);
744 trans = btrfs_start_transaction(root, 1);
745 btrfs_update_inode(trans, root, inode);
746 btrfs_end_transaction(trans, root);
747 mutex_unlock(&root->fs_info->fs_mutex);
748 }
749
750 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
751 struct btrfs_root *root,
752 u64 objectid, int mode)
753 {
754 struct inode *inode;
755 struct btrfs_inode_item inode_item;
756 struct btrfs_key *location;
757 int ret;
758
759 inode = new_inode(root->fs_info->sb);
760 if (!inode)
761 return ERR_PTR(-ENOMEM);
762
763 BTRFS_I(inode)->root = root;
764
765 inode->i_uid = current->fsuid;
766 inode->i_gid = current->fsgid;
767 inode->i_mode = mode;
768 inode->i_ino = objectid;
769 inode->i_blocks = 0;
770 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
771 fill_inode_item(&inode_item, inode);
772 location = &BTRFS_I(inode)->location;
773 location->objectid = objectid;
774 location->flags = 0;
775 location->offset = 0;
776 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
777
778 ret = btrfs_insert_inode(trans, root, objectid, &inode_item);
779 BUG_ON(ret);
780
781 insert_inode_hash(inode);
782 return inode;
783 }
784
785 static int btrfs_add_link(struct btrfs_trans_handle *trans,
786 struct dentry *dentry, struct inode *inode)
787 {
788 int ret;
789 struct btrfs_key key;
790 struct btrfs_root *root = BTRFS_I(dentry->d_parent->d_inode)->root;
791 key.objectid = inode->i_ino;
792 key.flags = 0;
793 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
794 key.offset = 0;
795
796 ret = btrfs_insert_dir_item(trans, root,
797 dentry->d_name.name, dentry->d_name.len,
798 dentry->d_parent->d_inode->i_ino,
799 &key, 0);
800 if (ret == 0) {
801 dentry->d_parent->d_inode->i_size += dentry->d_name.len * 2;
802 ret = btrfs_update_inode(trans, root,
803 dentry->d_parent->d_inode);
804 }
805 return ret;
806 }
807
808 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
809 struct dentry *dentry, struct inode *inode)
810 {
811 int err = btrfs_add_link(trans, dentry, inode);
812 if (!err) {
813 d_instantiate(dentry, inode);
814 return 0;
815 }
816 if (err > 0)
817 err = -EEXIST;
818 return err;
819 }
820
821 static int btrfs_create(struct inode *dir, struct dentry *dentry,
822 int mode, struct nameidata *nd)
823 {
824 struct btrfs_trans_handle *trans;
825 struct btrfs_root *root = BTRFS_I(dir)->root;
826 struct inode *inode;
827 int err;
828 int drop_inode = 0;
829 u64 objectid;
830
831 mutex_lock(&root->fs_info->fs_mutex);
832 trans = btrfs_start_transaction(root, 1);
833
834 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
835 if (err) {
836 err = -ENOSPC;
837 goto out_unlock;
838 }
839
840 inode = btrfs_new_inode(trans, root, objectid, mode);
841 err = PTR_ERR(inode);
842 if (IS_ERR(inode))
843 goto out_unlock;
844 // FIXME mark the inode dirty
845 err = btrfs_add_nondir(trans, dentry, inode);
846 if (err)
847 drop_inode = 1;
848 else {
849 inode->i_mapping->a_ops = &btrfs_aops;
850 inode->i_fop = &btrfs_file_operations;
851 inode->i_op = &btrfs_file_inode_operations;
852 }
853 dir->i_sb->s_dirt = 1;
854 out_unlock:
855 btrfs_end_transaction(trans, root);
856 mutex_unlock(&root->fs_info->fs_mutex);
857
858 if (drop_inode) {
859 inode_dec_link_count(inode);
860 iput(inode);
861 }
862 return err;
863 }
864
865 static int btrfs_make_empty_dir(struct btrfs_trans_handle *trans,
866 struct btrfs_root *root,
867 u64 objectid, u64 dirid)
868 {
869 int ret;
870 char buf[2];
871 struct btrfs_key key;
872
873 buf[0] = '.';
874 buf[1] = '.';
875
876 key.objectid = objectid;
877 key.offset = 0;
878 key.flags = 0;
879 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
880
881 ret = btrfs_insert_dir_item(trans, root, buf, 1, objectid,
882 &key, 1);
883 if (ret)
884 goto error;
885 key.objectid = dirid;
886 ret = btrfs_insert_dir_item(trans, root, buf, 2, objectid,
887 &key, 1);
888 if (ret)
889 goto error;
890 error:
891 return ret;
892 }
893
894 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
895 {
896 struct inode *inode;
897 struct btrfs_trans_handle *trans;
898 struct btrfs_root *root = BTRFS_I(dir)->root;
899 int err = 0;
900 int drop_on_err = 0;
901 u64 objectid;
902
903 mutex_lock(&root->fs_info->fs_mutex);
904 trans = btrfs_start_transaction(root, 1);
905 if (IS_ERR(trans)) {
906 err = PTR_ERR(trans);
907 goto out_unlock;
908 }
909
910 err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
911 if (err) {
912 err = -ENOSPC;
913 goto out_unlock;
914 }
915
916 inode = btrfs_new_inode(trans, root, objectid, S_IFDIR | mode);
917 if (IS_ERR(inode)) {
918 err = PTR_ERR(inode);
919 goto out_fail;
920 }
921 drop_on_err = 1;
922 inode->i_op = &btrfs_dir_inode_operations;
923 inode->i_fop = &btrfs_dir_file_operations;
924
925 err = btrfs_make_empty_dir(trans, root, inode->i_ino, dir->i_ino);
926 if (err)
927 goto out_fail;
928
929 inode->i_size = 6;
930 err = btrfs_update_inode(trans, root, inode);
931 if (err)
932 goto out_fail;
933 err = btrfs_add_link(trans, dentry, inode);
934 if (err)
935 goto out_fail;
936 d_instantiate(dentry, inode);
937 drop_on_err = 0;
938
939 out_fail:
940 btrfs_end_transaction(trans, root);
941 out_unlock:
942 mutex_unlock(&root->fs_info->fs_mutex);
943 if (drop_on_err)
944 iput(inode);
945 return err;
946 }
947
948 static int btrfs_sync_file(struct file *file,
949 struct dentry *dentry, int datasync)
950 {
951 struct inode *inode = dentry->d_inode;
952 struct btrfs_root *root = BTRFS_I(inode)->root;
953 int ret;
954 struct btrfs_trans_handle *trans;
955
956 mutex_lock(&root->fs_info->fs_mutex);
957 trans = btrfs_start_transaction(root, 1);
958 if (!trans) {
959 ret = -ENOMEM;
960 goto out;
961 }
962 ret = btrfs_commit_transaction(trans, root);
963 mutex_unlock(&root->fs_info->fs_mutex);
964 out:
965 return ret > 0 ? EIO : ret;
966 }
967
968 static int btrfs_sync_fs(struct super_block *sb, int wait)
969 {
970 struct btrfs_trans_handle *trans;
971 struct btrfs_root *root;
972 int ret;
973 root = btrfs_sb(sb);
974
975 sb->s_dirt = 0;
976 if (!wait) {
977 filemap_flush(root->fs_info->btree_inode->i_mapping);
978 return 0;
979 }
980 filemap_write_and_wait(root->fs_info->btree_inode->i_mapping);
981 mutex_lock(&root->fs_info->fs_mutex);
982 trans = btrfs_start_transaction(root, 1);
983 ret = btrfs_commit_transaction(trans, root);
984 sb->s_dirt = 0;
985 BUG_ON(ret);
986 printk("btrfs sync_fs\n");
987 mutex_unlock(&root->fs_info->fs_mutex);
988 return 0;
989 }
990
991 static int btrfs_get_block_lock(struct inode *inode, sector_t iblock,
992 struct buffer_head *result, int create)
993 {
994 int ret;
995 int err = 0;
996 u64 blocknr;
997 u64 extent_start = 0;
998 u64 extent_end = 0;
999 u64 objectid = inode->i_ino;
1000 u32 found_type;
1001 struct btrfs_path *path;
1002 struct btrfs_root *root = BTRFS_I(inode)->root;
1003 struct btrfs_file_extent_item *item;
1004 struct btrfs_leaf *leaf;
1005 struct btrfs_disk_key *found_key;
1006
1007 path = btrfs_alloc_path();
1008 BUG_ON(!path);
1009 btrfs_init_path(path);
1010 if (create) {
1011 WARN_ON(1);
1012 }
1013
1014 ret = btrfs_lookup_file_extent(NULL, root, path,
1015 inode->i_ino,
1016 iblock << inode->i_blkbits, 0);
1017 if (ret < 0) {
1018 err = ret;
1019 goto out;
1020 }
1021
1022 if (ret != 0) {
1023 if (path->slots[0] == 0) {
1024 btrfs_release_path(root, path);
1025 goto out;
1026 }
1027 path->slots[0]--;
1028 }
1029
1030 item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
1031 struct btrfs_file_extent_item);
1032 leaf = btrfs_buffer_leaf(path->nodes[0]);
1033 blocknr = btrfs_file_extent_disk_blocknr(item);
1034 blocknr += btrfs_file_extent_offset(item);
1035
1036 /* are we inside the extent that was found? */
1037 found_key = &leaf->items[path->slots[0]].key;
1038 found_type = btrfs_disk_key_type(found_key);
1039 if (btrfs_disk_key_objectid(found_key) != objectid ||
1040 found_type != BTRFS_EXTENT_DATA_KEY) {
1041 extent_end = 0;
1042 extent_start = 0;
1043 btrfs_release_path(root, path);
1044 goto out;
1045 }
1046 found_type = btrfs_file_extent_type(item);
1047 extent_start = btrfs_disk_key_offset(&leaf->items[path->slots[0]].key);
1048 if (found_type == BTRFS_FILE_EXTENT_REG) {
1049 extent_start = extent_start >> inode->i_blkbits;
1050 extent_end = extent_start + btrfs_file_extent_num_blocks(item);
1051 if (iblock >= extent_start && iblock < extent_end) {
1052 err = 0;
1053 btrfs_map_bh_to_logical(root, result, blocknr +
1054 iblock - extent_start);
1055 goto out;
1056 }
1057 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
1058 char *ptr;
1059 char *map;
1060 u32 size;
1061 size = btrfs_file_extent_inline_len(leaf->items +
1062 path->slots[0]);
1063 extent_end = (extent_start + size) >> inode->i_blkbits;
1064 extent_start >>= inode->i_blkbits;
1065 if (iblock < extent_start || iblock > extent_end) {
1066 goto out;
1067 }
1068 ptr = btrfs_file_extent_inline_start(item);
1069 map = kmap(result->b_page);
1070 memcpy(map, ptr, size);
1071 memset(map + size, 0, PAGE_CACHE_SIZE - size);
1072 flush_dcache_page(result->b_page);
1073 kunmap(result->b_page);
1074 set_buffer_uptodate(result);
1075 SetPageChecked(result->b_page);
1076 btrfs_map_bh_to_logical(root, result, 0);
1077 }
1078 out:
1079 btrfs_release_path(root, path);
1080 btrfs_free_path(path);
1081 return err;
1082 }
1083
1084 static int btrfs_get_block(struct inode *inode, sector_t iblock,
1085 struct buffer_head *result, int create)
1086 {
1087 int err;
1088 struct btrfs_root *root = BTRFS_I(inode)->root;
1089 mutex_lock(&root->fs_info->fs_mutex);
1090 err = btrfs_get_block_lock(inode, iblock, result, create);
1091 mutex_unlock(&root->fs_info->fs_mutex);
1092 return err;
1093 }
1094
1095 static int btrfs_prepare_write(struct file *file, struct page *page,
1096 unsigned from, unsigned to)
1097 {
1098 return nobh_prepare_write(page, from, to, btrfs_get_block);
1099 }
1100
1101 static void btrfs_write_super(struct super_block *sb)
1102 {
1103 btrfs_sync_fs(sb, 1);
1104 }
1105
1106 static int btrfs_readpage(struct file *file, struct page *page)
1107 {
1108 return mpage_readpage(page, btrfs_get_block);
1109 }
1110
1111 /*
1112 * While block_write_full_page is writing back the dirty buffers under
1113 * the page lock, whoever dirtied the buffers may decide to clean them
1114 * again at any time. We handle that by only looking at the buffer
1115 * state inside lock_buffer().
1116 *
1117 * If block_write_full_page() is called for regular writeback
1118 * (wbc->sync_mode == WB_SYNC_NONE) then it will redirty a page which has a
1119 * locked buffer. This only can happen if someone has written the buffer
1120 * directly, with submit_bh(). At the address_space level PageWriteback
1121 * prevents this contention from occurring.
1122 */
1123 static int __btrfs_write_full_page(struct inode *inode, struct page *page,
1124 struct writeback_control *wbc)
1125 {
1126 int err;
1127 sector_t block;
1128 sector_t last_block;
1129 struct buffer_head *bh, *head;
1130 const unsigned blocksize = 1 << inode->i_blkbits;
1131 int nr_underway = 0;
1132
1133 BUG_ON(!PageLocked(page));
1134
1135 last_block = (i_size_read(inode) - 1) >> inode->i_blkbits;
1136
1137 if (!page_has_buffers(page)) {
1138 create_empty_buffers(page, blocksize,
1139 (1 << BH_Dirty)|(1 << BH_Uptodate));
1140 }
1141
1142 /*
1143 * Be very careful. We have no exclusion from __set_page_dirty_buffers
1144 * here, and the (potentially unmapped) buffers may become dirty at
1145 * any time. If a buffer becomes dirty here after we've inspected it
1146 * then we just miss that fact, and the page stays dirty.
1147 *
1148 * Buffers outside i_size may be dirtied by __set_page_dirty_buffers;
1149 * handle that here by just cleaning them.
1150 */
1151
1152 block = (sector_t)page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
1153 head = page_buffers(page);
1154 bh = head;
1155
1156 /*
1157 * Get all the dirty buffers mapped to disk addresses and
1158 * handle any aliases from the underlying blockdev's mapping.
1159 */
1160 do {
1161 if (block > last_block) {
1162 /*
1163 * mapped buffers outside i_size will occur, because
1164 * this page can be outside i_size when there is a
1165 * truncate in progress.
1166 */
1167 /*
1168 * The buffer was zeroed by block_write_full_page()
1169 */
1170 clear_buffer_dirty(bh);
1171 set_buffer_uptodate(bh);
1172 } else if (!buffer_mapped(bh) && buffer_dirty(bh)) {
1173 WARN_ON(bh->b_size != blocksize);
1174 err = btrfs_get_block(inode, block, bh, 0);
1175 if (err)
1176 goto recover;
1177 if (buffer_new(bh)) {
1178 /* blockdev mappings never come here */
1179 clear_buffer_new(bh);
1180 unmap_underlying_metadata(bh->b_bdev,
1181 bh->b_blocknr);
1182 }
1183 }
1184 bh = bh->b_this_page;
1185 block++;
1186 } while (bh != head);
1187
1188 do {
1189 if (!buffer_mapped(bh))
1190 continue;
1191 /*
1192 * If it's a fully non-blocking write attempt and we cannot
1193 * lock the buffer then redirty the page. Note that this can
1194 * potentially cause a busy-wait loop from pdflush and kswapd
1195 * activity, but those code paths have their own higher-level
1196 * throttling.
1197 */
1198 if (wbc->sync_mode != WB_SYNC_NONE || !wbc->nonblocking) {
1199 lock_buffer(bh);
1200 } else if (test_set_buffer_locked(bh)) {
1201 redirty_page_for_writepage(wbc, page);
1202 continue;
1203 }
1204 if (test_clear_buffer_dirty(bh) && bh->b_blocknr != 0) {
1205 mark_buffer_async_write(bh);
1206 } else {
1207 unlock_buffer(bh);
1208 }
1209 } while ((bh = bh->b_this_page) != head);
1210
1211 /*
1212 * The page and its buffers are protected by PageWriteback(), so we can
1213 * drop the bh refcounts early.
1214 */
1215 BUG_ON(PageWriteback(page));
1216 set_page_writeback(page);
1217
1218 do {
1219 struct buffer_head *next = bh->b_this_page;
1220 if (buffer_async_write(bh)) {
1221 submit_bh(WRITE, bh);
1222 nr_underway++;
1223 }
1224 bh = next;
1225 } while (bh != head);
1226 unlock_page(page);
1227
1228 err = 0;
1229 done:
1230 if (nr_underway == 0) {
1231 /*
1232 * The page was marked dirty, but the buffers were
1233 * clean. Someone wrote them back by hand with
1234 * ll_rw_block/submit_bh. A rare case.
1235 */
1236 int uptodate = 1;
1237 do {
1238 if (!buffer_uptodate(bh)) {
1239 uptodate = 0;
1240 break;
1241 }
1242 bh = bh->b_this_page;
1243 } while (bh != head);
1244 if (uptodate)
1245 SetPageUptodate(page);
1246 end_page_writeback(page);
1247 /*
1248 * The page and buffer_heads can be released at any time from
1249 * here on.
1250 */
1251 wbc->pages_skipped++; /* We didn't write this page */
1252 }
1253 return err;
1254
1255 recover:
1256 /*
1257 * ENOSPC, or some other error. We may already have added some
1258 * blocks to the file, so we need to write these out to avoid
1259 * exposing stale data.
1260 * The page is currently locked and not marked for writeback
1261 */
1262 bh = head;
1263 /* Recovery: lock and submit the mapped buffers */
1264 do {
1265 if (buffer_mapped(bh) && buffer_dirty(bh)) {
1266 lock_buffer(bh);
1267 mark_buffer_async_write(bh);
1268 } else {
1269 /*
1270 * The buffer may have been set dirty during
1271 * attachment to a dirty page.
1272 */
1273 clear_buffer_dirty(bh);
1274 }
1275 } while ((bh = bh->b_this_page) != head);
1276 SetPageError(page);
1277 BUG_ON(PageWriteback(page));
1278 set_page_writeback(page);
1279 do {
1280 struct buffer_head *next = bh->b_this_page;
1281 if (buffer_async_write(bh)) {
1282 clear_buffer_dirty(bh);
1283 submit_bh(WRITE, bh);
1284 nr_underway++;
1285 }
1286 bh = next;
1287 } while (bh != head);
1288 unlock_page(page);
1289 goto done;
1290 }
1291
1292 /*
1293 * The generic ->writepage function for buffer-backed address_spaces
1294 */
1295 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
1296 {
1297 struct inode * const inode = page->mapping->host;
1298 loff_t i_size = i_size_read(inode);
1299 const pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
1300 unsigned offset;
1301 void *kaddr;
1302
1303 /* Is the page fully inside i_size? */
1304 if (page->index < end_index)
1305 return __btrfs_write_full_page(inode, page, wbc);
1306
1307 /* Is the page fully outside i_size? (truncate in progress) */
1308 offset = i_size & (PAGE_CACHE_SIZE-1);
1309 if (page->index >= end_index+1 || !offset) {
1310 /*
1311 * The page may have dirty, unmapped buffers. For example,
1312 * they may have been added in ext3_writepage(). Make them
1313 * freeable here, so the page does not leak.
1314 */
1315 block_invalidatepage(page, 0);
1316 unlock_page(page);
1317 return 0; /* don't care */
1318 }
1319
1320 /*
1321 * The page straddles i_size. It must be zeroed out on each and every
1322 * writepage invokation because it may be mmapped. "A file is mapped
1323 * in multiples of the page size. For a file that is not a multiple of
1324 * the page size, the remaining memory is zeroed when mapped, and
1325 * writes to that region are not written out to the file."
1326 */
1327 kaddr = kmap_atomic(page, KM_USER0);
1328 memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
1329 flush_dcache_page(page);
1330 kunmap_atomic(kaddr, KM_USER0);
1331 return __btrfs_write_full_page(inode, page, wbc);
1332 }
1333
1334 static void btrfs_truncate(struct inode *inode)
1335 {
1336 struct btrfs_root *root = BTRFS_I(inode)->root;
1337 int ret;
1338 struct btrfs_trans_handle *trans;
1339
1340 if (!S_ISREG(inode->i_mode))
1341 return;
1342 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
1343 return;
1344
1345 nobh_truncate_page(inode->i_mapping, inode->i_size);
1346
1347 /* FIXME, add redo link to tree so we don't leak on crash */
1348 mutex_lock(&root->fs_info->fs_mutex);
1349 trans = btrfs_start_transaction(root, 1);
1350 ret = btrfs_truncate_in_trans(trans, root, inode);
1351 BUG_ON(ret);
1352 ret = btrfs_end_transaction(trans, root);
1353 BUG_ON(ret);
1354 mutex_unlock(&root->fs_info->fs_mutex);
1355 mark_inode_dirty(inode);
1356 }
1357
1358 /*
1359 * Make sure any changes to nobh_commit_write() are reflected in
1360 * nobh_truncate_page(), since it doesn't call commit_write().
1361 */
1362 static int btrfs_commit_write(struct file *file, struct page *page,
1363 unsigned from, unsigned to)
1364 {
1365 struct inode *inode = page->mapping->host;
1366 struct buffer_head *bh;
1367 loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
1368
1369 SetPageUptodate(page);
1370 bh = page_buffers(page);
1371 if (buffer_mapped(bh) && bh->b_blocknr != 0) {
1372 set_page_dirty(page);
1373 }
1374 if (pos > inode->i_size) {
1375 i_size_write(inode, pos);
1376 mark_inode_dirty(inode);
1377 }
1378 return 0;
1379 }
1380
1381 static int btrfs_copy_from_user(loff_t pos, int num_pages, int write_bytes,
1382 struct page **prepared_pages,
1383 const char __user * buf)
1384 {
1385 long page_fault = 0;
1386 int i;
1387 int offset = pos & (PAGE_CACHE_SIZE - 1);
1388
1389 for (i = 0; i < num_pages && write_bytes > 0; i++, offset = 0) {
1390 size_t count = min_t(size_t,
1391 PAGE_CACHE_SIZE - offset, write_bytes);
1392 struct page *page = prepared_pages[i];
1393 fault_in_pages_readable(buf, count);
1394
1395 /* Copy data from userspace to the current page */
1396 kmap(page);
1397 page_fault = __copy_from_user(page_address(page) + offset,
1398 buf, count);
1399 /* Flush processor's dcache for this page */
1400 flush_dcache_page(page);
1401 kunmap(page);
1402 buf += count;
1403 write_bytes -= count;
1404
1405 if (page_fault)
1406 break;
1407 }
1408 return page_fault ? -EFAULT : 0;
1409 }
1410
1411 static void btrfs_drop_pages(struct page **pages, size_t num_pages)
1412 {
1413 size_t i;
1414 for (i = 0; i < num_pages; i++) {
1415 if (!pages[i])
1416 break;
1417 unlock_page(pages[i]);
1418 mark_page_accessed(pages[i]);
1419 page_cache_release(pages[i]);
1420 }
1421 }
1422 static int dirty_and_release_pages(struct btrfs_trans_handle *trans,
1423 struct btrfs_root *root,
1424 struct file *file,
1425 struct page **pages,
1426 size_t num_pages,
1427 loff_t pos,
1428 size_t write_bytes)
1429 {
1430 int i;
1431 int offset;
1432 int err = 0;
1433 int ret;
1434 int this_write;
1435 struct inode *inode = file->f_path.dentry->d_inode;
1436 struct buffer_head *bh;
1437 struct btrfs_file_extent_item *ei;
1438
1439 for (i = 0; i < num_pages; i++) {
1440 offset = pos & (PAGE_CACHE_SIZE -1);
1441 this_write = min(PAGE_CACHE_SIZE - offset, write_bytes);
1442 /* FIXME, one block at a time */
1443
1444 mutex_lock(&root->fs_info->fs_mutex);
1445 trans = btrfs_start_transaction(root, 1);
1446
1447 bh = page_buffers(pages[i]);
1448 if (buffer_mapped(bh) && bh->b_blocknr == 0) {
1449 struct btrfs_key key;
1450 struct btrfs_path *path;
1451 char *ptr;
1452 u32 datasize;
1453
1454 path = btrfs_alloc_path();
1455 BUG_ON(!path);
1456 key.objectid = inode->i_ino;
1457 key.offset = pages[i]->index << PAGE_CACHE_SHIFT;
1458 key.flags = 0;
1459 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
1460 BUG_ON(write_bytes >= PAGE_CACHE_SIZE);
1461 datasize = offset +
1462 btrfs_file_extent_calc_inline_size(write_bytes);
1463 ret = btrfs_insert_empty_item(trans, root, path, &key,
1464 datasize);
1465 BUG_ON(ret);
1466 ei = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
1467 path->slots[0], struct btrfs_file_extent_item);
1468 btrfs_set_file_extent_generation(ei, trans->transid);
1469 btrfs_set_file_extent_type(ei,
1470 BTRFS_FILE_EXTENT_INLINE);
1471 ptr = btrfs_file_extent_inline_start(ei);
1472 memcpy(ptr, bh->b_data, offset + write_bytes);
1473 mark_buffer_dirty(path->nodes[0]);
1474 btrfs_free_path(path);
1475 } else {
1476 btrfs_csum_file_block(trans, root, inode->i_ino,
1477 pages[i]->index << PAGE_CACHE_SHIFT,
1478 kmap(pages[i]), PAGE_CACHE_SIZE);
1479 kunmap(pages[i]);
1480 }
1481 SetPageChecked(pages[i]);
1482 ret = btrfs_end_transaction(trans, root);
1483 BUG_ON(ret);
1484 mutex_unlock(&root->fs_info->fs_mutex);
1485
1486 ret = btrfs_commit_write(file, pages[i], offset,
1487 offset + this_write);
1488 pos += this_write;
1489 if (ret) {
1490 err = ret;
1491 goto failed;
1492 }
1493 WARN_ON(this_write > write_bytes);
1494 write_bytes -= this_write;
1495 }
1496 failed:
1497 return err;
1498 }
1499
1500 static int drop_extents(struct btrfs_trans_handle *trans,
1501 struct btrfs_root *root,
1502 struct inode *inode,
1503 u64 start, u64 end)
1504 {
1505 int ret;
1506 struct btrfs_key key;
1507 struct btrfs_leaf *leaf;
1508 int slot;
1509 struct btrfs_file_extent_item *extent;
1510 u64 extent_end = 0;
1511 int keep;
1512 struct btrfs_file_extent_item old;
1513 struct btrfs_path *path;
1514 u64 search_start = start;
1515 int bookend;
1516 int found_type;
1517 int found_extent;
1518 int found_inline;
1519
1520 path = btrfs_alloc_path();
1521 if (!path)
1522 return -ENOMEM;
1523 while(1) {
1524 btrfs_release_path(root, path);
1525 ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
1526 search_start, -1);
1527 if (ret < 0)
1528 goto out;
1529 if (ret > 0) {
1530 if (path->slots[0] == 0) {
1531 ret = 0;
1532 goto out;
1533 }
1534 path->slots[0]--;
1535 }
1536 keep = 0;
1537 bookend = 0;
1538 found_extent = 0;
1539 found_inline = 0;
1540 extent = NULL;
1541 leaf = btrfs_buffer_leaf(path->nodes[0]);
1542 slot = path->slots[0];
1543 btrfs_disk_key_to_cpu(&key, &leaf->items[slot].key);
1544 if (key.offset >= end || key.objectid != inode->i_ino) {
1545 ret = 0;
1546 goto out;
1547 }
1548 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) {
1549 ret = 0;
1550 goto out;
1551 }
1552 extent = btrfs_item_ptr(leaf, slot,
1553 struct btrfs_file_extent_item);
1554 found_type = btrfs_file_extent_type(extent);
1555 if (found_type == BTRFS_FILE_EXTENT_REG) {
1556 extent_end = key.offset +
1557 (btrfs_file_extent_num_blocks(extent) <<
1558 inode->i_blkbits);
1559 found_extent = 1;
1560 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
1561 found_inline = 1;
1562 extent_end = key.offset +
1563 btrfs_file_extent_inline_len(leaf->items + slot);
1564 }
1565
1566 if (!found_extent && !found_inline) {
1567 ret = 0;
1568 goto out;
1569 }
1570
1571 if (search_start >= extent_end) {
1572 ret = 0;
1573 goto out;
1574 }
1575
1576 search_start = extent_end;
1577
1578 if (end < extent_end && end >= key.offset) {
1579 if (found_extent) {
1580 memcpy(&old, extent, sizeof(old));
1581 ret = btrfs_inc_extent_ref(trans, root,
1582 btrfs_file_extent_disk_blocknr(&old),
1583 btrfs_file_extent_disk_num_blocks(&old));
1584 BUG_ON(ret);
1585 }
1586 WARN_ON(found_inline);
1587 bookend = 1;
1588 }
1589
1590 if (start > key.offset) {
1591 u64 new_num;
1592 u64 old_num;
1593 /* truncate existing extent */
1594 keep = 1;
1595 WARN_ON(start & (root->blocksize - 1));
1596 if (found_extent) {
1597 new_num = (start - key.offset) >>
1598 inode->i_blkbits;
1599 old_num = btrfs_file_extent_num_blocks(extent);
1600 inode->i_blocks -= (old_num - new_num) << 3;
1601 btrfs_set_file_extent_num_blocks(extent,
1602 new_num);
1603 mark_buffer_dirty(path->nodes[0]);
1604 } else {
1605 WARN_ON(1);
1606 /*
1607 ret = btrfs_truncate_item(trans, root, path,
1608 start - key.offset);
1609 BUG_ON(ret);
1610 */
1611 }
1612 }
1613 if (!keep) {
1614 u64 disk_blocknr = 0;
1615 u64 disk_num_blocks = 0;
1616 u64 extent_num_blocks = 0;
1617 if (found_extent) {
1618 disk_blocknr =
1619 btrfs_file_extent_disk_blocknr(extent);
1620 disk_num_blocks =
1621 btrfs_file_extent_disk_num_blocks(extent);
1622 extent_num_blocks =
1623 btrfs_file_extent_num_blocks(extent);
1624 }
1625 ret = btrfs_del_item(trans, root, path);
1626 BUG_ON(ret);
1627 btrfs_release_path(root, path);
1628 if (found_extent) {
1629 inode->i_blocks -=
1630 btrfs_file_extent_num_blocks(extent) << 3;
1631 ret = btrfs_free_extent(trans, root,
1632 disk_blocknr,
1633 disk_num_blocks, 0);
1634 }
1635
1636 BUG_ON(ret);
1637 if (!bookend && search_start >= end) {
1638 ret = 0;
1639 goto out;
1640 }
1641 if (!bookend)
1642 continue;
1643 }
1644 if (bookend && found_extent) {
1645 /* create bookend */
1646 struct btrfs_key ins;
1647 ins.objectid = inode->i_ino;
1648 ins.offset = end;
1649 ins.flags = 0;
1650 btrfs_set_key_type(&ins, BTRFS_EXTENT_DATA_KEY);
1651
1652 btrfs_release_path(root, path);
1653 ret = btrfs_insert_empty_item(trans, root, path, &ins,
1654 sizeof(*extent));
1655 BUG_ON(ret);
1656 extent = btrfs_item_ptr(
1657 btrfs_buffer_leaf(path->nodes[0]),
1658 path->slots[0],
1659 struct btrfs_file_extent_item);
1660 btrfs_set_file_extent_disk_blocknr(extent,
1661 btrfs_file_extent_disk_blocknr(&old));
1662 btrfs_set_file_extent_disk_num_blocks(extent,
1663 btrfs_file_extent_disk_num_blocks(&old));
1664
1665 btrfs_set_file_extent_offset(extent,
1666 btrfs_file_extent_offset(&old) +
1667 ((end - key.offset) >> inode->i_blkbits));
1668 WARN_ON(btrfs_file_extent_num_blocks(&old) <
1669 (end - key.offset) >> inode->i_blkbits);
1670 btrfs_set_file_extent_num_blocks(extent,
1671 btrfs_file_extent_num_blocks(&old) -
1672 ((end - key.offset) >> inode->i_blkbits));
1673
1674 btrfs_set_file_extent_type(extent,
1675 BTRFS_FILE_EXTENT_REG);
1676 btrfs_set_file_extent_generation(extent,
1677 btrfs_file_extent_generation(&old));
1678 btrfs_mark_buffer_dirty(path->nodes[0]);
1679 inode->i_blocks +=
1680 btrfs_file_extent_num_blocks(extent) << 3;
1681 ret = 0;
1682 goto out;
1683 }
1684 }
1685 out:
1686 btrfs_free_path(path);
1687 return ret;
1688 }
1689
1690 static int prepare_pages(struct btrfs_root *root,
1691 struct file *file,
1692 struct page **pages,
1693 size_t num_pages,
1694 loff_t pos,
1695 unsigned long first_index,
1696 unsigned long last_index,
1697 size_t write_bytes,
1698 u64 alloc_extent_start)
1699 {
1700 int i;
1701 unsigned long index = pos >> PAGE_CACHE_SHIFT;
1702 struct inode *inode = file->f_path.dentry->d_inode;
1703 int offset;
1704 int err = 0;
1705 int this_write;
1706 struct buffer_head *bh;
1707 struct buffer_head *head;
1708 loff_t isize = i_size_read(inode);
1709
1710 memset(pages, 0, num_pages * sizeof(struct page *));
1711
1712 for (i = 0; i < num_pages; i++) {
1713 pages[i] = grab_cache_page(inode->i_mapping, index + i);
1714 if (!pages[i]) {
1715 err = -ENOMEM;
1716 goto failed_release;
1717 }
1718 offset = pos & (PAGE_CACHE_SIZE -1);
1719 this_write = min(PAGE_CACHE_SIZE - offset, write_bytes);
1720 create_empty_buffers(pages[i], root->fs_info->sb->s_blocksize,
1721 (1 << BH_Uptodate));
1722 head = page_buffers(pages[i]);
1723 bh = head;
1724 do {
1725 err = btrfs_map_bh_to_logical(root, bh,
1726 alloc_extent_start);
1727 BUG_ON(err);
1728 if (err)
1729 goto failed_truncate;
1730 bh = bh->b_this_page;
1731 if (alloc_extent_start)
1732 alloc_extent_start++;
1733 } while (bh != head);
1734 pos += this_write;
1735 WARN_ON(this_write > write_bytes);
1736 write_bytes -= this_write;
1737 }
1738 return 0;
1739
1740 failed_release:
1741 btrfs_drop_pages(pages, num_pages);
1742 return err;
1743
1744 failed_truncate:
1745 btrfs_drop_pages(pages, num_pages);
1746 if (pos > isize)
1747 vmtruncate(inode, isize);
1748 return err;
1749 }
1750
1751 static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
1752 size_t count, loff_t *ppos)
1753 {
1754 loff_t pos;
1755 size_t num_written = 0;
1756 int err = 0;
1757 int ret = 0;
1758 struct inode *inode = file->f_path.dentry->d_inode;
1759 struct btrfs_root *root = BTRFS_I(inode)->root;
1760 struct page *pages[8];
1761 struct page *pinned[2] = { NULL, NULL };
1762 unsigned long first_index;
1763 unsigned long last_index;
1764 u64 start_pos;
1765 u64 num_blocks;
1766 u64 alloc_extent_start;
1767 struct btrfs_trans_handle *trans;
1768 struct btrfs_key ins;
1769
1770 if (file->f_flags & O_DIRECT)
1771 return -EINVAL;
1772 pos = *ppos;
1773 vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
1774 current->backing_dev_info = inode->i_mapping->backing_dev_info;
1775 err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
1776 if (err)
1777 goto out;
1778 if (count == 0)
1779 goto out;
1780 err = remove_suid(file->f_path.dentry);
1781 if (err)
1782 goto out;
1783 file_update_time(file);
1784
1785 start_pos = pos & ~((u64)PAGE_CACHE_SIZE - 1);
1786 num_blocks = (count + pos - start_pos + root->blocksize - 1) >>
1787 inode->i_blkbits;
1788
1789 mutex_lock(&inode->i_mutex);
1790 first_index = pos >> PAGE_CACHE_SHIFT;
1791 last_index = (pos + count) >> PAGE_CACHE_SHIFT;
1792
1793 if ((first_index << PAGE_CACHE_SHIFT) < inode->i_size &&
1794 (pos & (PAGE_CACHE_SIZE - 1))) {
1795 pinned[0] = grab_cache_page(inode->i_mapping, first_index);
1796 if (!PageUptodate(pinned[0])) {
1797 ret = mpage_readpage(pinned[0], btrfs_get_block);
1798 BUG_ON(ret);
1799 } else {
1800 unlock_page(pinned[0]);
1801 }
1802 }
1803 if (first_index != last_index &&
1804 (last_index << PAGE_CACHE_SHIFT) < inode->i_size &&
1805 (count & (PAGE_CACHE_SIZE - 1))) {
1806 pinned[1] = grab_cache_page(inode->i_mapping, last_index);
1807 if (!PageUptodate(pinned[1])) {
1808 ret = mpage_readpage(pinned[1], btrfs_get_block);
1809 BUG_ON(ret);
1810 } else {
1811 unlock_page(pinned[1]);
1812 }
1813 }
1814
1815 mutex_lock(&root->fs_info->fs_mutex);
1816 trans = btrfs_start_transaction(root, 1);
1817 if (!trans) {
1818 err = -ENOMEM;
1819 mutex_unlock(&root->fs_info->fs_mutex);
1820 goto out_unlock;
1821 }
1822 /* FIXME blocksize != 4096 */
1823 inode->i_blocks += num_blocks << 3;
1824 if (start_pos < inode->i_size) {
1825 /* FIXME blocksize != pagesize */
1826 ret = drop_extents(trans, root, inode,
1827 start_pos,
1828 (pos + count + root->blocksize -1) &
1829 ~((u64)root->blocksize - 1));
1830 BUG_ON(ret);
1831 }
1832 if (inode->i_size >= PAGE_CACHE_SIZE || pos + count < inode->i_size ||
1833 pos + count - start_pos > BTRFS_MAX_INLINE_DATA_SIZE(root)) {
1834 ret = btrfs_alloc_extent(trans, root, inode->i_ino,
1835 num_blocks, 1, (u64)-1, &ins);
1836 BUG_ON(ret);
1837 ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
1838 start_pos, ins.objectid, ins.offset);
1839 BUG_ON(ret);
1840 } else {
1841 ins.offset = 0;
1842 ins.objectid = 0;
1843 }
1844 BUG_ON(ret);
1845 alloc_extent_start = ins.objectid;
1846 ret = btrfs_end_transaction(trans, root);
1847 mutex_unlock(&root->fs_info->fs_mutex);
1848
1849 while(count > 0) {
1850 size_t offset = pos & (PAGE_CACHE_SIZE - 1);
1851 size_t write_bytes = min(count, PAGE_CACHE_SIZE - offset);
1852 size_t num_pages = (write_bytes + PAGE_CACHE_SIZE - 1) >>
1853 PAGE_CACHE_SHIFT;
1854
1855 memset(pages, 0, sizeof(pages));
1856 ret = prepare_pages(root, file, pages, num_pages,
1857 pos, first_index, last_index,
1858 write_bytes, alloc_extent_start);
1859 BUG_ON(ret);
1860
1861 /* FIXME blocks != pagesize */
1862 if (alloc_extent_start)
1863 alloc_extent_start += num_pages;
1864 ret = btrfs_copy_from_user(pos, num_pages,
1865 write_bytes, pages, buf);
1866 BUG_ON(ret);
1867
1868 ret = dirty_and_release_pages(NULL, root, file, pages,
1869 num_pages, pos, write_bytes);
1870 BUG_ON(ret);
1871 btrfs_drop_pages(pages, num_pages);
1872
1873 buf += write_bytes;
1874 count -= write_bytes;
1875 pos += write_bytes;
1876 num_written += write_bytes;
1877
1878 balance_dirty_pages_ratelimited(inode->i_mapping);
1879 cond_resched();
1880 }
1881 out_unlock:
1882 mutex_unlock(&inode->i_mutex);
1883 out:
1884 if (pinned[0])
1885 page_cache_release(pinned[0]);
1886 if (pinned[1])
1887 page_cache_release(pinned[1]);
1888 *ppos = pos;
1889 current->backing_dev_info = NULL;
1890 mark_inode_dirty(inode);
1891 return num_written ? num_written : err;
1892 }
1893
1894 static int btrfs_read_actor(read_descriptor_t *desc, struct page *page,
1895 unsigned long offset, unsigned long size)
1896 {
1897 char *kaddr;
1898 unsigned long left, count = desc->count;
1899 struct inode *inode = page->mapping->host;
1900
1901 if (size > count)
1902 size = count;
1903
1904 if (!PageChecked(page)) {
1905 /* FIXME, do it per block */
1906 struct btrfs_root *root = BTRFS_I(inode)->root;
1907
1908 int ret = btrfs_csum_verify_file_block(root,
1909 page->mapping->host->i_ino,
1910 page->index << PAGE_CACHE_SHIFT,
1911 kmap(page), PAGE_CACHE_SIZE);
1912 if (ret) {
1913 printk("failed to verify ino %lu page %lu\n",
1914 page->mapping->host->i_ino,
1915 page->index);
1916 memset(page_address(page), 0, PAGE_CACHE_SIZE);
1917 }
1918 SetPageChecked(page);
1919 kunmap(page);
1920 }
1921 /*
1922 * Faults on the destination of a read are common, so do it before
1923 * taking the kmap.
1924 */
1925 if (!fault_in_pages_writeable(desc->arg.buf, size)) {
1926 kaddr = kmap_atomic(page, KM_USER0);
1927 left = __copy_to_user_inatomic(desc->arg.buf,
1928 kaddr + offset, size);
1929 kunmap_atomic(kaddr, KM_USER0);
1930 if (left == 0)
1931 goto success;
1932 }
1933
1934 /* Do it the slow way */
1935 kaddr = kmap(page);
1936 left = __copy_to_user(desc->arg.buf, kaddr + offset, size);
1937 kunmap(page);
1938
1939 if (left) {
1940 size -= left;
1941 desc->error = -EFAULT;
1942 }
1943 success:
1944 desc->count = count - size;
1945 desc->written += size;
1946 desc->arg.buf += size;
1947 return size;
1948 }
1949
1950 /**
1951 * btrfs_file_aio_read - filesystem read routine
1952 * @iocb: kernel I/O control block
1953 * @iov: io vector request
1954 * @nr_segs: number of segments in the iovec
1955 * @pos: current file position
1956 */
1957 static ssize_t btrfs_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
1958 unsigned long nr_segs, loff_t pos)
1959 {
1960 struct file *filp = iocb->ki_filp;
1961 ssize_t retval;
1962 unsigned long seg;
1963 size_t count;
1964 loff_t *ppos = &iocb->ki_pos;
1965
1966 count = 0;
1967 for (seg = 0; seg < nr_segs; seg++) {
1968 const struct iovec *iv = &iov[seg];
1969
1970 /*
1971 * If any segment has a negative length, or the cumulative
1972 * length ever wraps negative then return -EINVAL.
1973 */
1974 count += iv->iov_len;
1975 if (unlikely((ssize_t)(count|iv->iov_len) < 0))
1976 return -EINVAL;
1977 if (access_ok(VERIFY_WRITE, iv->iov_base, iv->iov_len))
1978 continue;
1979 if (seg == 0)
1980 return -EFAULT;
1981 nr_segs = seg;
1982 count -= iv->iov_len; /* This segment is no good */
1983 break;
1984 }
1985 retval = 0;
1986 if (count) {
1987 for (seg = 0; seg < nr_segs; seg++) {
1988 read_descriptor_t desc;
1989
1990 desc.written = 0;
1991 desc.arg.buf = iov[seg].iov_base;
1992 desc.count = iov[seg].iov_len;
1993 if (desc.count == 0)
1994 continue;
1995 desc.error = 0;
1996 do_generic_file_read(filp, ppos, &desc,
1997 btrfs_read_actor);
1998 retval += desc.written;
1999 if (desc.error) {
2000 retval = retval ?: desc.error;
2001 break;
2002 }
2003 }
2004 }
2005 return retval;
2006 }
2007
2008 static int create_subvol(struct btrfs_root *root, char *name, int namelen)
2009 {
2010 struct btrfs_trans_handle *trans;
2011 struct btrfs_key key;
2012 struct btrfs_root_item root_item;
2013 struct btrfs_inode_item *inode_item;
2014 struct buffer_head *subvol;
2015 struct btrfs_leaf *leaf;
2016 struct btrfs_root *new_root;
2017 struct inode *inode;
2018 int ret;
2019 u64 objectid;
2020 u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
2021
2022 mutex_lock(&root->fs_info->fs_mutex);
2023 trans = btrfs_start_transaction(root, 1);
2024 BUG_ON(!trans);
2025
2026 subvol = btrfs_alloc_free_block(trans, root);
2027 if (subvol == NULL)
2028 return -ENOSPC;
2029 leaf = btrfs_buffer_leaf(subvol);
2030 btrfs_set_header_nritems(&leaf->header, 0);
2031 btrfs_set_header_level(&leaf->header, 0);
2032 btrfs_set_header_blocknr(&leaf->header, bh_blocknr(subvol));
2033 btrfs_set_header_generation(&leaf->header, trans->transid);
2034 btrfs_set_header_owner(&leaf->header, root->root_key.objectid);
2035 memcpy(leaf->header.fsid, root->fs_info->disk_super->fsid,
2036 sizeof(leaf->header.fsid));
2037 mark_buffer_dirty(subvol);
2038
2039 inode_item = &root_item.inode;
2040 memset(inode_item, 0, sizeof(*inode_item));
2041 btrfs_set_inode_generation(inode_item, 1);
2042 btrfs_set_inode_size(inode_item, 3);
2043 btrfs_set_inode_nlink(inode_item, 1);
2044 btrfs_set_inode_nblocks(inode_item, 1);
2045 btrfs_set_inode_mode(inode_item, S_IFDIR | 0755);
2046
2047 btrfs_set_root_blocknr(&root_item, bh_blocknr(subvol));
2048 btrfs_set_root_refs(&root_item, 1);
2049 brelse(subvol);
2050 subvol = NULL;
2051
2052 ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
2053 0, &objectid);
2054 BUG_ON(ret);
2055
2056 btrfs_set_root_dirid(&root_item, new_dirid);
2057
2058 key.objectid = objectid;
2059 key.offset = 1;
2060 key.flags = 0;
2061 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
2062 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
2063 &root_item);
2064 BUG_ON(ret);
2065
2066 /*
2067 * insert the directory item
2068 */
2069 key.offset = (u64)-1;
2070 ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
2071 name, namelen,
2072 root->fs_info->sb->s_root->d_inode->i_ino,
2073 &key, 0);
2074 BUG_ON(ret);
2075
2076 ret = btrfs_commit_transaction(trans, root);
2077 BUG_ON(ret);
2078
2079 new_root = btrfs_read_fs_root(root->fs_info, &key);
2080 BUG_ON(!new_root);
2081
2082 trans = btrfs_start_transaction(new_root, 1);
2083 BUG_ON(!trans);
2084
2085 inode = btrfs_new_inode(trans, new_root, new_dirid, S_IFDIR | 0700);
2086 inode->i_op = &btrfs_dir_inode_operations;
2087 inode->i_fop = &btrfs_dir_file_operations;
2088
2089 ret = btrfs_make_empty_dir(trans, new_root, new_dirid, new_dirid);
2090 BUG_ON(ret);
2091
2092 inode->i_nlink = 1;
2093 inode->i_size = 6;
2094 ret = btrfs_update_inode(trans, new_root, inode);
2095 BUG_ON(ret);
2096
2097 ret = btrfs_commit_transaction(trans, new_root);
2098 BUG_ON(ret);
2099
2100 iput(inode);
2101
2102 mutex_unlock(&root->fs_info->fs_mutex);
2103 return 0;
2104 }
2105
2106 static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
2107 {
2108 struct btrfs_trans_handle *trans;
2109 struct btrfs_key key;
2110 struct btrfs_root_item new_root_item;
2111 int ret;
2112 u64 objectid;
2113
2114 if (!root->ref_cows)
2115 return -EINVAL;
2116
2117 mutex_lock(&root->fs_info->fs_mutex);
2118 trans = btrfs_start_transaction(root, 1);
2119 BUG_ON(!trans);
2120
2121 ret = btrfs_update_inode(trans, root, root->inode);
2122 BUG_ON(ret);
2123
2124 ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
2125 0, &objectid);
2126 BUG_ON(ret);
2127
2128 memcpy(&new_root_item, &root->root_item,
2129 sizeof(new_root_item));
2130
2131 key.objectid = objectid;
2132 key.offset = 1;
2133 key.flags = 0;
2134 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
2135 btrfs_set_root_blocknr(&new_root_item, bh_blocknr(root->node));
2136
2137 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
2138 &new_root_item);
2139 BUG_ON(ret);
2140
2141 /*
2142 * insert the directory item
2143 */
2144 key.offset = (u64)-1;
2145 ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
2146 name, namelen,
2147 root->fs_info->sb->s_root->d_inode->i_ino,
2148 &key, 0);
2149
2150 BUG_ON(ret);
2151
2152 ret = btrfs_inc_root_ref(trans, root);
2153 BUG_ON(ret);
2154
2155 ret = btrfs_commit_transaction(trans, root);
2156 BUG_ON(ret);
2157 mutex_unlock(&root->fs_info->fs_mutex);
2158 return 0;
2159 }
2160
2161 static int add_disk(struct btrfs_root *root, char *name, int namelen)
2162 {
2163 struct block_device *bdev;
2164 struct btrfs_path *path;
2165 struct super_block *sb = root->fs_info->sb;
2166 struct btrfs_root *dev_root = root->fs_info->dev_root;
2167 struct btrfs_trans_handle *trans;
2168 struct btrfs_device_item *dev_item;
2169 struct btrfs_key key;
2170 u16 item_size;
2171 u64 num_blocks;
2172 u64 new_blocks;
2173 u64 device_id;
2174 int ret;
2175
2176 printk("adding disk %s\n", name);
2177 path = btrfs_alloc_path();
2178 if (!path)
2179 return -ENOMEM;
2180 num_blocks = btrfs_super_total_blocks(root->fs_info->disk_super);
2181 bdev = open_bdev_excl(name, O_RDWR, sb);
2182 if (IS_ERR(bdev)) {
2183 ret = PTR_ERR(bdev);
2184 printk("open bdev excl failed ret %d\n", ret);
2185 goto out_nolock;
2186 }
2187 set_blocksize(bdev, sb->s_blocksize);
2188 new_blocks = bdev->bd_inode->i_size >> sb->s_blocksize_bits;
2189 key.objectid = num_blocks;
2190 key.offset = new_blocks;
2191 key.flags = 0;
2192 btrfs_set_key_type(&key, BTRFS_DEV_ITEM_KEY);
2193
2194 mutex_lock(&dev_root->fs_info->fs_mutex);
2195 trans = btrfs_start_transaction(dev_root, 1);
2196 item_size = sizeof(*dev_item) + namelen;
2197 printk("insert empty on %Lu %Lu %u size %d\n", num_blocks, new_blocks, key.flags, item_size);
2198 ret = btrfs_insert_empty_item(trans, dev_root, path, &key, item_size);
2199 if (ret) {
2200 printk("insert failed %d\n", ret);
2201 close_bdev_excl(bdev);
2202 if (ret > 0)
2203 ret = -EEXIST;
2204 goto out;
2205 }
2206 dev_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
2207 path->slots[0], struct btrfs_device_item);
2208 btrfs_set_device_pathlen(dev_item, namelen);
2209 memcpy(dev_item + 1, name, namelen);
2210
2211 device_id = btrfs_super_last_device_id(root->fs_info->disk_super) + 1;
2212 btrfs_set_super_last_device_id(root->fs_info->disk_super, device_id);
2213 btrfs_set_device_id(dev_item, device_id);
2214 mark_buffer_dirty(path->nodes[0]);
2215
2216 ret = btrfs_insert_dev_radix(root, bdev, device_id, num_blocks,
2217 new_blocks);
2218
2219 if (!ret) {
2220 btrfs_set_super_total_blocks(root->fs_info->disk_super,
2221 num_blocks + new_blocks);
2222 i_size_write(root->fs_info->btree_inode,
2223 (num_blocks + new_blocks) <<
2224 root->fs_info->btree_inode->i_blkbits);
2225 }
2226
2227 out:
2228 ret = btrfs_commit_transaction(trans, dev_root);
2229 BUG_ON(ret);
2230 mutex_unlock(&root->fs_info->fs_mutex);
2231 out_nolock:
2232 btrfs_free_path(path);
2233
2234 return ret;
2235 }
2236
2237 static int btrfs_ioctl(struct inode *inode, struct file *filp, unsigned int
2238 cmd, unsigned long arg)
2239 {
2240 struct btrfs_root *root = BTRFS_I(inode)->root;
2241 struct btrfs_ioctl_vol_args vol_args;
2242 int ret = 0;
2243 struct btrfs_dir_item *di;
2244 int namelen;
2245 struct btrfs_path *path;
2246 u64 root_dirid;
2247
2248 switch (cmd) {
2249 case BTRFS_IOC_SNAP_CREATE:
2250 if (copy_from_user(&vol_args,
2251 (struct btrfs_ioctl_vol_args __user *)arg,
2252 sizeof(vol_args)))
2253 return -EFAULT;
2254 namelen = strlen(vol_args.name);
2255 if (namelen > BTRFS_VOL_NAME_MAX)
2256 return -EINVAL;
2257 path = btrfs_alloc_path();
2258 if (!path)
2259 return -ENOMEM;
2260 root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
2261 mutex_lock(&root->fs_info->fs_mutex);
2262 di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
2263 path, root_dirid,
2264 vol_args.name, namelen, 0);
2265 mutex_unlock(&root->fs_info->fs_mutex);
2266 btrfs_free_path(path);
2267 if (di && !IS_ERR(di))
2268 return -EEXIST;
2269
2270 if (root == root->fs_info->tree_root)
2271 ret = create_subvol(root, vol_args.name, namelen);
2272 else
2273 ret = create_snapshot(root, vol_args.name, namelen);
2274 WARN_ON(ret);
2275 break;
2276 case BTRFS_IOC_ADD_DISK:
2277 if (copy_from_user(&vol_args,
2278 (struct btrfs_ioctl_vol_args __user *)arg,
2279 sizeof(vol_args)))
2280 return -EFAULT;
2281 namelen = strlen(vol_args.name);
2282 if (namelen > BTRFS_VOL_NAME_MAX)
2283 return -EINVAL;
2284 vol_args.name[namelen] = '\0';
2285 ret = add_disk(root, vol_args.name, namelen);
2286 break;
2287 default:
2288 return -ENOTTY;
2289 }
2290 return ret;
2291 }
2292
2293 static struct kmem_cache *btrfs_inode_cachep;
2294 struct kmem_cache *btrfs_trans_handle_cachep;
2295 struct kmem_cache *btrfs_transaction_cachep;
2296 struct kmem_cache *btrfs_bit_radix_cachep;
2297 struct kmem_cache *btrfs_path_cachep;
2298
2299 /*
2300 * Called inside transaction, so use GFP_NOFS
2301 */
2302 static struct inode *btrfs_alloc_inode(struct super_block *sb)
2303 {
2304 struct btrfs_inode *ei;
2305
2306 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
2307 if (!ei)
2308 return NULL;
2309 return &ei->vfs_inode;
2310 }
2311
2312 static void btrfs_destroy_inode(struct inode *inode)
2313 {
2314 WARN_ON(!list_empty(&inode->i_dentry));
2315 WARN_ON(inode->i_data.nrpages);
2316
2317 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
2318 }
2319
2320 static void init_once(void * foo, struct kmem_cache * cachep,
2321 unsigned long flags)
2322 {
2323 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
2324
2325 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
2326 SLAB_CTOR_CONSTRUCTOR) {
2327 inode_init_once(&ei->vfs_inode);
2328 }
2329 }
2330
2331 static int init_inodecache(void)
2332 {
2333 btrfs_inode_cachep = kmem_cache_create("btrfs_inode_cache",
2334 sizeof(struct btrfs_inode),
2335 0, (SLAB_RECLAIM_ACCOUNT|
2336 SLAB_MEM_SPREAD),
2337 init_once, NULL);
2338 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle_cache",
2339 sizeof(struct btrfs_trans_handle),
2340 0, (SLAB_RECLAIM_ACCOUNT|
2341 SLAB_MEM_SPREAD),
2342 NULL, NULL);
2343 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction_cache",
2344 sizeof(struct btrfs_transaction),
2345 0, (SLAB_RECLAIM_ACCOUNT|
2346 SLAB_MEM_SPREAD),
2347 NULL, NULL);
2348 btrfs_path_cachep = kmem_cache_create("btrfs_path_cache",
2349 sizeof(struct btrfs_transaction),
2350 0, (SLAB_RECLAIM_ACCOUNT|
2351 SLAB_MEM_SPREAD),
2352 NULL, NULL);
2353 btrfs_bit_radix_cachep = kmem_cache_create("btrfs_radix",
2354 256,
2355 0, (SLAB_RECLAIM_ACCOUNT|
2356 SLAB_MEM_SPREAD |
2357 SLAB_DESTROY_BY_RCU),
2358 NULL, NULL);
2359 if (btrfs_inode_cachep == NULL || btrfs_trans_handle_cachep == NULL ||
2360 btrfs_transaction_cachep == NULL || btrfs_bit_radix_cachep == NULL)
2361 return -ENOMEM;
2362 return 0;
2363 }
2364
2365 static void destroy_inodecache(void)
2366 {
2367 kmem_cache_destroy(btrfs_inode_cachep);
2368 kmem_cache_destroy(btrfs_trans_handle_cachep);
2369 kmem_cache_destroy(btrfs_transaction_cachep);
2370 kmem_cache_destroy(btrfs_bit_radix_cachep);
2371 kmem_cache_destroy(btrfs_path_cachep);
2372 }
2373
2374 static int btrfs_get_sb(struct file_system_type *fs_type,
2375 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
2376 {
2377 return get_sb_bdev(fs_type, flags, dev_name, data,
2378 btrfs_fill_super, mnt);
2379 }
2380
2381
2382 static int btrfs_getattr(struct vfsmount *mnt,
2383 struct dentry *dentry, struct kstat *stat)
2384 {
2385 struct inode *inode = dentry->d_inode;
2386 generic_fillattr(inode, stat);
2387 stat->blksize = 256 * 1024;
2388 return 0;
2389 }
2390
2391 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
2392 {
2393 struct btrfs_root *root = btrfs_sb(dentry->d_sb);
2394 struct btrfs_super_block *disk_super = root->fs_info->disk_super;
2395
2396 buf->f_namelen = BTRFS_NAME_LEN;
2397 buf->f_blocks = btrfs_super_total_blocks(disk_super);
2398 buf->f_bfree = buf->f_blocks - btrfs_super_blocks_used(disk_super);
2399 buf->f_bavail = buf->f_bfree;
2400 buf->f_bsize = dentry->d_sb->s_blocksize;
2401 buf->f_type = BTRFS_SUPER_MAGIC;
2402 return 0;
2403 }
2404
2405 static struct file_system_type btrfs_fs_type = {
2406 .owner = THIS_MODULE,
2407 .name = "btrfs",
2408 .get_sb = btrfs_get_sb,
2409 .kill_sb = kill_block_super,
2410 .fs_flags = FS_REQUIRES_DEV,
2411 };
2412
2413 static struct super_operations btrfs_super_ops = {
2414 .delete_inode = btrfs_delete_inode,
2415 .put_super = btrfs_put_super,
2416 .read_inode = btrfs_read_locked_inode,
2417 .write_super = btrfs_write_super,
2418 .sync_fs = btrfs_sync_fs,
2419 .write_inode = btrfs_write_inode,
2420 .dirty_inode = btrfs_dirty_inode,
2421 .alloc_inode = btrfs_alloc_inode,
2422 .destroy_inode = btrfs_destroy_inode,
2423 .statfs = btrfs_statfs,
2424 };
2425
2426 static struct inode_operations btrfs_dir_inode_operations = {
2427 .lookup = btrfs_lookup,
2428 .create = btrfs_create,
2429 .unlink = btrfs_unlink,
2430 .mkdir = btrfs_mkdir,
2431 .rmdir = btrfs_rmdir,
2432 };
2433
2434 static struct inode_operations btrfs_dir_ro_inode_operations = {
2435 .lookup = btrfs_lookup,
2436 };
2437
2438 static struct file_operations btrfs_dir_file_operations = {
2439 .llseek = generic_file_llseek,
2440 .read = generic_read_dir,
2441 .readdir = btrfs_readdir,
2442 .ioctl = btrfs_ioctl,
2443 };
2444
2445 static struct address_space_operations btrfs_aops = {
2446 .readpage = btrfs_readpage,
2447 .writepage = btrfs_writepage,
2448 .sync_page = block_sync_page,
2449 .prepare_write = btrfs_prepare_write,
2450 .commit_write = btrfs_commit_write,
2451 };
2452
2453 static struct inode_operations btrfs_file_inode_operations = {
2454 .truncate = btrfs_truncate,
2455 .getattr = btrfs_getattr,
2456 };
2457
2458 static struct file_operations btrfs_file_operations = {
2459 .llseek = generic_file_llseek,
2460 .read = do_sync_read,
2461 .aio_read = btrfs_file_aio_read,
2462 .write = btrfs_file_write,
2463 .mmap = generic_file_mmap,
2464 .open = generic_file_open,
2465 .ioctl = btrfs_ioctl,
2466 .fsync = btrfs_sync_file,
2467 };
2468
2469 static int __init init_btrfs_fs(void)
2470 {
2471 int err;
2472 printk("btrfs loaded!\n");
2473 err = init_inodecache();
2474 if (err)
2475 return err;
2476 kset_set_kset_s(&btrfs_subsys, fs_subsys);
2477 err = subsystem_register(&btrfs_subsys);
2478 if (err)
2479 goto out;
2480 return register_filesystem(&btrfs_fs_type);
2481 out:
2482 destroy_inodecache();
2483 return err;
2484 }
2485
2486 static void __exit exit_btrfs_fs(void)
2487 {
2488 destroy_inodecache();
2489 unregister_filesystem(&btrfs_fs_type);
2490 subsystem_unregister(&btrfs_subsys);
2491 printk("btrfs unloaded\n");
2492 }
2493
2494 module_init(init_btrfs_fs)
2495 module_exit(exit_btrfs_fs)
2496
2497 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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