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