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1 | /* | |
2 | * Copyright (C) 2007 Oracle. All rights reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public | |
6 | * License v2 as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public | |
14 | * License along with this program; if not, write to the | |
15 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
16 | * Boston, MA 021110-1307, USA. | |
17 | */ | |
18 | ||
19 | #include <linux/blkdev.h> | |
20 | #include <linux/module.h> | |
21 | #include <linux/buffer_head.h> | |
22 | #include <linux/fs.h> | |
23 | #include <linux/pagemap.h> | |
24 | #include <linux/highmem.h> | |
25 | #include <linux/time.h> | |
26 | #include <linux/init.h> | |
27 | #include <linux/seq_file.h> | |
28 | #include <linux/string.h> | |
29 | #include <linux/backing-dev.h> | |
30 | #include <linux/mount.h> | |
31 | #include <linux/mpage.h> | |
32 | #include <linux/swap.h> | |
33 | #include <linux/writeback.h> | |
34 | #include <linux/statfs.h> | |
35 | #include <linux/compat.h> | |
36 | #include <linux/parser.h> | |
37 | #include <linux/ctype.h> | |
38 | #include <linux/namei.h> | |
39 | #include <linux/miscdevice.h> | |
40 | #include <linux/magic.h> | |
41 | #include <linux/slab.h> | |
42 | #include "compat.h" | |
43 | #include "ctree.h" | |
44 | #include "disk-io.h" | |
45 | #include "transaction.h" | |
46 | #include "btrfs_inode.h" | |
47 | #include "ioctl.h" | |
48 | #include "print-tree.h" | |
49 | #include "xattr.h" | |
50 | #include "volumes.h" | |
51 | #include "version.h" | |
52 | #include "export.h" | |
53 | #include "compression.h" | |
54 | ||
55 | static const struct super_operations btrfs_super_ops; | |
56 | ||
57 | static void btrfs_put_super(struct super_block *sb) | |
58 | { | |
59 | struct btrfs_root *root = btrfs_sb(sb); | |
60 | int ret; | |
61 | ||
62 | ret = close_ctree(root); | |
63 | sb->s_fs_info = NULL; | |
64 | } | |
65 | ||
66 | enum { | |
67 | Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum, | |
68 | Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd, | |
69 | Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress, | |
70 | Opt_compress_force, Opt_notreelog, Opt_ratio, Opt_flushoncommit, | |
71 | Opt_discard, Opt_err, | |
72 | }; | |
73 | ||
74 | static match_table_t tokens = { | |
75 | {Opt_degraded, "degraded"}, | |
76 | {Opt_subvol, "subvol=%s"}, | |
77 | {Opt_subvolid, "subvolid=%d"}, | |
78 | {Opt_device, "device=%s"}, | |
79 | {Opt_nodatasum, "nodatasum"}, | |
80 | {Opt_nodatacow, "nodatacow"}, | |
81 | {Opt_nobarrier, "nobarrier"}, | |
82 | {Opt_max_inline, "max_inline=%s"}, | |
83 | {Opt_alloc_start, "alloc_start=%s"}, | |
84 | {Opt_thread_pool, "thread_pool=%d"}, | |
85 | {Opt_compress, "compress"}, | |
86 | {Opt_compress_force, "compress-force"}, | |
87 | {Opt_ssd, "ssd"}, | |
88 | {Opt_ssd_spread, "ssd_spread"}, | |
89 | {Opt_nossd, "nossd"}, | |
90 | {Opt_noacl, "noacl"}, | |
91 | {Opt_notreelog, "notreelog"}, | |
92 | {Opt_flushoncommit, "flushoncommit"}, | |
93 | {Opt_ratio, "metadata_ratio=%d"}, | |
94 | {Opt_discard, "discard"}, | |
95 | {Opt_err, NULL}, | |
96 | }; | |
97 | ||
98 | /* | |
99 | * Regular mount options parser. Everything that is needed only when | |
100 | * reading in a new superblock is parsed here. | |
101 | */ | |
102 | int btrfs_parse_options(struct btrfs_root *root, char *options) | |
103 | { | |
104 | struct btrfs_fs_info *info = root->fs_info; | |
105 | substring_t args[MAX_OPT_ARGS]; | |
106 | char *p, *num, *orig; | |
107 | int intarg; | |
108 | int ret = 0; | |
109 | ||
110 | if (!options) | |
111 | return 0; | |
112 | ||
113 | /* | |
114 | * strsep changes the string, duplicate it because parse_options | |
115 | * gets called twice | |
116 | */ | |
117 | options = kstrdup(options, GFP_NOFS); | |
118 | if (!options) | |
119 | return -ENOMEM; | |
120 | ||
121 | orig = options; | |
122 | ||
123 | while ((p = strsep(&options, ",")) != NULL) { | |
124 | int token; | |
125 | if (!*p) | |
126 | continue; | |
127 | ||
128 | token = match_token(p, tokens, args); | |
129 | switch (token) { | |
130 | case Opt_degraded: | |
131 | printk(KERN_INFO "btrfs: allowing degraded mounts\n"); | |
132 | btrfs_set_opt(info->mount_opt, DEGRADED); | |
133 | break; | |
134 | case Opt_subvol: | |
135 | case Opt_subvolid: | |
136 | case Opt_device: | |
137 | /* | |
138 | * These are parsed by btrfs_parse_early_options | |
139 | * and can be happily ignored here. | |
140 | */ | |
141 | break; | |
142 | case Opt_nodatasum: | |
143 | printk(KERN_INFO "btrfs: setting nodatasum\n"); | |
144 | btrfs_set_opt(info->mount_opt, NODATASUM); | |
145 | break; | |
146 | case Opt_nodatacow: | |
147 | printk(KERN_INFO "btrfs: setting nodatacow\n"); | |
148 | btrfs_set_opt(info->mount_opt, NODATACOW); | |
149 | btrfs_set_opt(info->mount_opt, NODATASUM); | |
150 | break; | |
151 | case Opt_compress: | |
152 | printk(KERN_INFO "btrfs: use compression\n"); | |
153 | btrfs_set_opt(info->mount_opt, COMPRESS); | |
154 | break; | |
155 | case Opt_compress_force: | |
156 | printk(KERN_INFO "btrfs: forcing compression\n"); | |
157 | btrfs_set_opt(info->mount_opt, FORCE_COMPRESS); | |
158 | btrfs_set_opt(info->mount_opt, COMPRESS); | |
159 | break; | |
160 | case Opt_ssd: | |
161 | printk(KERN_INFO "btrfs: use ssd allocation scheme\n"); | |
162 | btrfs_set_opt(info->mount_opt, SSD); | |
163 | break; | |
164 | case Opt_ssd_spread: | |
165 | printk(KERN_INFO "btrfs: use spread ssd " | |
166 | "allocation scheme\n"); | |
167 | btrfs_set_opt(info->mount_opt, SSD); | |
168 | btrfs_set_opt(info->mount_opt, SSD_SPREAD); | |
169 | break; | |
170 | case Opt_nossd: | |
171 | printk(KERN_INFO "btrfs: not using ssd allocation " | |
172 | "scheme\n"); | |
173 | btrfs_set_opt(info->mount_opt, NOSSD); | |
174 | btrfs_clear_opt(info->mount_opt, SSD); | |
175 | btrfs_clear_opt(info->mount_opt, SSD_SPREAD); | |
176 | break; | |
177 | case Opt_nobarrier: | |
178 | printk(KERN_INFO "btrfs: turning off barriers\n"); | |
179 | btrfs_set_opt(info->mount_opt, NOBARRIER); | |
180 | break; | |
181 | case Opt_thread_pool: | |
182 | intarg = 0; | |
183 | match_int(&args[0], &intarg); | |
184 | if (intarg) { | |
185 | info->thread_pool_size = intarg; | |
186 | printk(KERN_INFO "btrfs: thread pool %d\n", | |
187 | info->thread_pool_size); | |
188 | } | |
189 | break; | |
190 | case Opt_max_inline: | |
191 | num = match_strdup(&args[0]); | |
192 | if (num) { | |
193 | info->max_inline = memparse(num, NULL); | |
194 | kfree(num); | |
195 | ||
196 | if (info->max_inline) { | |
197 | info->max_inline = max_t(u64, | |
198 | info->max_inline, | |
199 | root->sectorsize); | |
200 | } | |
201 | printk(KERN_INFO "btrfs: max_inline at %llu\n", | |
202 | (unsigned long long)info->max_inline); | |
203 | } | |
204 | break; | |
205 | case Opt_alloc_start: | |
206 | num = match_strdup(&args[0]); | |
207 | if (num) { | |
208 | info->alloc_start = memparse(num, NULL); | |
209 | kfree(num); | |
210 | printk(KERN_INFO | |
211 | "btrfs: allocations start at %llu\n", | |
212 | (unsigned long long)info->alloc_start); | |
213 | } | |
214 | break; | |
215 | case Opt_noacl: | |
216 | root->fs_info->sb->s_flags &= ~MS_POSIXACL; | |
217 | break; | |
218 | case Opt_notreelog: | |
219 | printk(KERN_INFO "btrfs: disabling tree log\n"); | |
220 | btrfs_set_opt(info->mount_opt, NOTREELOG); | |
221 | break; | |
222 | case Opt_flushoncommit: | |
223 | printk(KERN_INFO "btrfs: turning on flush-on-commit\n"); | |
224 | btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT); | |
225 | break; | |
226 | case Opt_ratio: | |
227 | intarg = 0; | |
228 | match_int(&args[0], &intarg); | |
229 | if (intarg) { | |
230 | info->metadata_ratio = intarg; | |
231 | printk(KERN_INFO "btrfs: metadata ratio %d\n", | |
232 | info->metadata_ratio); | |
233 | } | |
234 | break; | |
235 | case Opt_discard: | |
236 | btrfs_set_opt(info->mount_opt, DISCARD); | |
237 | break; | |
238 | case Opt_err: | |
239 | printk(KERN_INFO "btrfs: unrecognized mount option " | |
240 | "'%s'\n", p); | |
241 | ret = -EINVAL; | |
242 | goto out; | |
243 | default: | |
244 | break; | |
245 | } | |
246 | } | |
247 | out: | |
248 | kfree(orig); | |
249 | return ret; | |
250 | } | |
251 | ||
252 | /* | |
253 | * Parse mount options that are required early in the mount process. | |
254 | * | |
255 | * All other options will be parsed on much later in the mount process and | |
256 | * only when we need to allocate a new super block. | |
257 | */ | |
258 | static int btrfs_parse_early_options(const char *options, fmode_t flags, | |
259 | void *holder, char **subvol_name, u64 *subvol_objectid, | |
260 | struct btrfs_fs_devices **fs_devices) | |
261 | { | |
262 | substring_t args[MAX_OPT_ARGS]; | |
263 | char *opts, *p; | |
264 | int error = 0; | |
265 | int intarg; | |
266 | ||
267 | if (!options) | |
268 | goto out; | |
269 | ||
270 | /* | |
271 | * strsep changes the string, duplicate it because parse_options | |
272 | * gets called twice | |
273 | */ | |
274 | opts = kstrdup(options, GFP_KERNEL); | |
275 | if (!opts) | |
276 | return -ENOMEM; | |
277 | ||
278 | while ((p = strsep(&opts, ",")) != NULL) { | |
279 | int token; | |
280 | if (!*p) | |
281 | continue; | |
282 | ||
283 | token = match_token(p, tokens, args); | |
284 | switch (token) { | |
285 | case Opt_subvol: | |
286 | *subvol_name = match_strdup(&args[0]); | |
287 | break; | |
288 | case Opt_subvolid: | |
289 | intarg = 0; | |
290 | error = match_int(&args[0], &intarg); | |
291 | if (!error) { | |
292 | /* we want the original fs_tree */ | |
293 | if (!intarg) | |
294 | *subvol_objectid = | |
295 | BTRFS_FS_TREE_OBJECTID; | |
296 | else | |
297 | *subvol_objectid = intarg; | |
298 | } | |
299 | break; | |
300 | case Opt_device: | |
301 | error = btrfs_scan_one_device(match_strdup(&args[0]), | |
302 | flags, holder, fs_devices); | |
303 | if (error) | |
304 | goto out_free_opts; | |
305 | break; | |
306 | default: | |
307 | break; | |
308 | } | |
309 | } | |
310 | ||
311 | out_free_opts: | |
312 | kfree(opts); | |
313 | out: | |
314 | /* | |
315 | * If no subvolume name is specified we use the default one. Allocate | |
316 | * a copy of the string "." here so that code later in the | |
317 | * mount path doesn't care if it's the default volume or another one. | |
318 | */ | |
319 | if (!*subvol_name) { | |
320 | *subvol_name = kstrdup(".", GFP_KERNEL); | |
321 | if (!*subvol_name) | |
322 | return -ENOMEM; | |
323 | } | |
324 | return error; | |
325 | } | |
326 | ||
327 | static struct dentry *get_default_root(struct super_block *sb, | |
328 | u64 subvol_objectid) | |
329 | { | |
330 | struct btrfs_root *root = sb->s_fs_info; | |
331 | struct btrfs_root *new_root; | |
332 | struct btrfs_dir_item *di; | |
333 | struct btrfs_path *path; | |
334 | struct btrfs_key location; | |
335 | struct inode *inode; | |
336 | struct dentry *dentry; | |
337 | u64 dir_id; | |
338 | int new = 0; | |
339 | ||
340 | /* | |
341 | * We have a specific subvol we want to mount, just setup location and | |
342 | * go look up the root. | |
343 | */ | |
344 | if (subvol_objectid) { | |
345 | location.objectid = subvol_objectid; | |
346 | location.type = BTRFS_ROOT_ITEM_KEY; | |
347 | location.offset = (u64)-1; | |
348 | goto find_root; | |
349 | } | |
350 | ||
351 | path = btrfs_alloc_path(); | |
352 | if (!path) | |
353 | return ERR_PTR(-ENOMEM); | |
354 | path->leave_spinning = 1; | |
355 | ||
356 | /* | |
357 | * Find the "default" dir item which points to the root item that we | |
358 | * will mount by default if we haven't been given a specific subvolume | |
359 | * to mount. | |
360 | */ | |
361 | dir_id = btrfs_super_root_dir(&root->fs_info->super_copy); | |
362 | di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0); | |
363 | if (IS_ERR(di)) | |
364 | return ERR_CAST(di); | |
365 | if (!di) { | |
366 | /* | |
367 | * Ok the default dir item isn't there. This is weird since | |
368 | * it's always been there, but don't freak out, just try and | |
369 | * mount to root most subvolume. | |
370 | */ | |
371 | btrfs_free_path(path); | |
372 | dir_id = BTRFS_FIRST_FREE_OBJECTID; | |
373 | new_root = root->fs_info->fs_root; | |
374 | goto setup_root; | |
375 | } | |
376 | ||
377 | btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location); | |
378 | btrfs_free_path(path); | |
379 | ||
380 | find_root: | |
381 | new_root = btrfs_read_fs_root_no_name(root->fs_info, &location); | |
382 | if (IS_ERR(new_root)) | |
383 | return ERR_PTR(PTR_ERR(new_root)); | |
384 | ||
385 | if (btrfs_root_refs(&new_root->root_item) == 0) | |
386 | return ERR_PTR(-ENOENT); | |
387 | ||
388 | dir_id = btrfs_root_dirid(&new_root->root_item); | |
389 | setup_root: | |
390 | location.objectid = dir_id; | |
391 | location.type = BTRFS_INODE_ITEM_KEY; | |
392 | location.offset = 0; | |
393 | ||
394 | inode = btrfs_iget(sb, &location, new_root, &new); | |
395 | if (IS_ERR(inode)) | |
396 | return ERR_CAST(inode); | |
397 | ||
398 | /* | |
399 | * If we're just mounting the root most subvol put the inode and return | |
400 | * a reference to the dentry. We will have already gotten a reference | |
401 | * to the inode in btrfs_fill_super so we're good to go. | |
402 | */ | |
403 | if (!new && sb->s_root->d_inode == inode) { | |
404 | iput(inode); | |
405 | return dget(sb->s_root); | |
406 | } | |
407 | ||
408 | if (new) { | |
409 | const struct qstr name = { .name = "/", .len = 1 }; | |
410 | ||
411 | /* | |
412 | * New inode, we need to make the dentry a sibling of s_root so | |
413 | * everything gets cleaned up properly on unmount. | |
414 | */ | |
415 | dentry = d_alloc(sb->s_root, &name); | |
416 | if (!dentry) { | |
417 | iput(inode); | |
418 | return ERR_PTR(-ENOMEM); | |
419 | } | |
420 | d_splice_alias(inode, dentry); | |
421 | } else { | |
422 | /* | |
423 | * We found the inode in cache, just find a dentry for it and | |
424 | * put the reference to the inode we just got. | |
425 | */ | |
426 | dentry = d_find_alias(inode); | |
427 | iput(inode); | |
428 | } | |
429 | ||
430 | return dentry; | |
431 | } | |
432 | ||
433 | static int btrfs_fill_super(struct super_block *sb, | |
434 | struct btrfs_fs_devices *fs_devices, | |
435 | void *data, int silent) | |
436 | { | |
437 | struct inode *inode; | |
438 | struct dentry *root_dentry; | |
439 | struct btrfs_super_block *disk_super; | |
440 | struct btrfs_root *tree_root; | |
441 | struct btrfs_key key; | |
442 | int err; | |
443 | ||
444 | sb->s_maxbytes = MAX_LFS_FILESIZE; | |
445 | sb->s_magic = BTRFS_SUPER_MAGIC; | |
446 | sb->s_op = &btrfs_super_ops; | |
447 | sb->s_export_op = &btrfs_export_ops; | |
448 | sb->s_xattr = btrfs_xattr_handlers; | |
449 | sb->s_time_gran = 1; | |
450 | #ifdef CONFIG_BTRFS_FS_POSIX_ACL | |
451 | sb->s_flags |= MS_POSIXACL; | |
452 | #endif | |
453 | ||
454 | tree_root = open_ctree(sb, fs_devices, (char *)data); | |
455 | ||
456 | if (IS_ERR(tree_root)) { | |
457 | printk("btrfs: open_ctree failed\n"); | |
458 | return PTR_ERR(tree_root); | |
459 | } | |
460 | sb->s_fs_info = tree_root; | |
461 | disk_super = &tree_root->fs_info->super_copy; | |
462 | ||
463 | key.objectid = BTRFS_FIRST_FREE_OBJECTID; | |
464 | key.type = BTRFS_INODE_ITEM_KEY; | |
465 | key.offset = 0; | |
466 | inode = btrfs_iget(sb, &key, tree_root->fs_info->fs_root, NULL); | |
467 | if (IS_ERR(inode)) { | |
468 | err = PTR_ERR(inode); | |
469 | goto fail_close; | |
470 | } | |
471 | ||
472 | root_dentry = d_alloc_root(inode); | |
473 | if (!root_dentry) { | |
474 | iput(inode); | |
475 | err = -ENOMEM; | |
476 | goto fail_close; | |
477 | } | |
478 | ||
479 | sb->s_root = root_dentry; | |
480 | ||
481 | save_mount_options(sb, data); | |
482 | return 0; | |
483 | ||
484 | fail_close: | |
485 | close_ctree(tree_root); | |
486 | return err; | |
487 | } | |
488 | ||
489 | int btrfs_sync_fs(struct super_block *sb, int wait) | |
490 | { | |
491 | struct btrfs_trans_handle *trans; | |
492 | struct btrfs_root *root = btrfs_sb(sb); | |
493 | int ret; | |
494 | ||
495 | if (!wait) { | |
496 | filemap_flush(root->fs_info->btree_inode->i_mapping); | |
497 | return 0; | |
498 | } | |
499 | ||
500 | btrfs_start_delalloc_inodes(root, 0); | |
501 | btrfs_wait_ordered_extents(root, 0, 0); | |
502 | ||
503 | trans = btrfs_start_transaction(root, 0); | |
504 | ret = btrfs_commit_transaction(trans, root); | |
505 | return ret; | |
506 | } | |
507 | ||
508 | static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs) | |
509 | { | |
510 | struct btrfs_root *root = btrfs_sb(vfs->mnt_sb); | |
511 | struct btrfs_fs_info *info = root->fs_info; | |
512 | ||
513 | if (btrfs_test_opt(root, DEGRADED)) | |
514 | seq_puts(seq, ",degraded"); | |
515 | if (btrfs_test_opt(root, NODATASUM)) | |
516 | seq_puts(seq, ",nodatasum"); | |
517 | if (btrfs_test_opt(root, NODATACOW)) | |
518 | seq_puts(seq, ",nodatacow"); | |
519 | if (btrfs_test_opt(root, NOBARRIER)) | |
520 | seq_puts(seq, ",nobarrier"); | |
521 | if (info->max_inline != 8192 * 1024) | |
522 | seq_printf(seq, ",max_inline=%llu", | |
523 | (unsigned long long)info->max_inline); | |
524 | if (info->alloc_start != 0) | |
525 | seq_printf(seq, ",alloc_start=%llu", | |
526 | (unsigned long long)info->alloc_start); | |
527 | if (info->thread_pool_size != min_t(unsigned long, | |
528 | num_online_cpus() + 2, 8)) | |
529 | seq_printf(seq, ",thread_pool=%d", info->thread_pool_size); | |
530 | if (btrfs_test_opt(root, COMPRESS)) | |
531 | seq_puts(seq, ",compress"); | |
532 | if (btrfs_test_opt(root, NOSSD)) | |
533 | seq_puts(seq, ",nossd"); | |
534 | if (btrfs_test_opt(root, SSD_SPREAD)) | |
535 | seq_puts(seq, ",ssd_spread"); | |
536 | else if (btrfs_test_opt(root, SSD)) | |
537 | seq_puts(seq, ",ssd"); | |
538 | if (btrfs_test_opt(root, NOTREELOG)) | |
539 | seq_puts(seq, ",notreelog"); | |
540 | if (btrfs_test_opt(root, FLUSHONCOMMIT)) | |
541 | seq_puts(seq, ",flushoncommit"); | |
542 | if (btrfs_test_opt(root, DISCARD)) | |
543 | seq_puts(seq, ",discard"); | |
544 | if (!(root->fs_info->sb->s_flags & MS_POSIXACL)) | |
545 | seq_puts(seq, ",noacl"); | |
546 | return 0; | |
547 | } | |
548 | ||
549 | static int btrfs_test_super(struct super_block *s, void *data) | |
550 | { | |
551 | struct btrfs_fs_devices *test_fs_devices = data; | |
552 | struct btrfs_root *root = btrfs_sb(s); | |
553 | ||
554 | return root->fs_info->fs_devices == test_fs_devices; | |
555 | } | |
556 | ||
557 | /* | |
558 | * Find a superblock for the given device / mount point. | |
559 | * | |
560 | * Note: This is based on get_sb_bdev from fs/super.c with a few additions | |
561 | * for multiple device setup. Make sure to keep it in sync. | |
562 | */ | |
563 | static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags, | |
564 | const char *dev_name, void *data) | |
565 | { | |
566 | struct block_device *bdev = NULL; | |
567 | struct super_block *s; | |
568 | struct dentry *root; | |
569 | struct btrfs_fs_devices *fs_devices = NULL; | |
570 | fmode_t mode = FMODE_READ; | |
571 | char *subvol_name = NULL; | |
572 | u64 subvol_objectid = 0; | |
573 | int error = 0; | |
574 | int found = 0; | |
575 | ||
576 | if (!(flags & MS_RDONLY)) | |
577 | mode |= FMODE_WRITE; | |
578 | ||
579 | error = btrfs_parse_early_options(data, mode, fs_type, | |
580 | &subvol_name, &subvol_objectid, | |
581 | &fs_devices); | |
582 | if (error) | |
583 | return ERR_PTR(error); | |
584 | ||
585 | error = btrfs_scan_one_device(dev_name, mode, fs_type, &fs_devices); | |
586 | if (error) | |
587 | goto error_free_subvol_name; | |
588 | ||
589 | error = btrfs_open_devices(fs_devices, mode, fs_type); | |
590 | if (error) | |
591 | goto error_free_subvol_name; | |
592 | ||
593 | if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) { | |
594 | error = -EACCES; | |
595 | goto error_close_devices; | |
596 | } | |
597 | ||
598 | bdev = fs_devices->latest_bdev; | |
599 | s = sget(fs_type, btrfs_test_super, set_anon_super, fs_devices); | |
600 | if (IS_ERR(s)) | |
601 | goto error_s; | |
602 | ||
603 | if (s->s_root) { | |
604 | if ((flags ^ s->s_flags) & MS_RDONLY) { | |
605 | deactivate_locked_super(s); | |
606 | error = -EBUSY; | |
607 | goto error_close_devices; | |
608 | } | |
609 | ||
610 | found = 1; | |
611 | btrfs_close_devices(fs_devices); | |
612 | } else { | |
613 | char b[BDEVNAME_SIZE]; | |
614 | ||
615 | s->s_flags = flags; | |
616 | strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id)); | |
617 | error = btrfs_fill_super(s, fs_devices, data, | |
618 | flags & MS_SILENT ? 1 : 0); | |
619 | if (error) { | |
620 | deactivate_locked_super(s); | |
621 | goto error_free_subvol_name; | |
622 | } | |
623 | ||
624 | btrfs_sb(s)->fs_info->bdev_holder = fs_type; | |
625 | s->s_flags |= MS_ACTIVE; | |
626 | } | |
627 | ||
628 | root = get_default_root(s, subvol_objectid); | |
629 | if (IS_ERR(root)) { | |
630 | error = PTR_ERR(root); | |
631 | deactivate_locked_super(s); | |
632 | goto error; | |
633 | } | |
634 | /* if they gave us a subvolume name bind mount into that */ | |
635 | if (strcmp(subvol_name, ".")) { | |
636 | struct dentry *new_root; | |
637 | mutex_lock(&root->d_inode->i_mutex); | |
638 | new_root = lookup_one_len(subvol_name, root, | |
639 | strlen(subvol_name)); | |
640 | mutex_unlock(&root->d_inode->i_mutex); | |
641 | ||
642 | if (IS_ERR(new_root)) { | |
643 | deactivate_locked_super(s); | |
644 | error = PTR_ERR(new_root); | |
645 | dput(root); | |
646 | goto error_close_devices; | |
647 | } | |
648 | if (!new_root->d_inode) { | |
649 | dput(root); | |
650 | dput(new_root); | |
651 | deactivate_locked_super(s); | |
652 | error = -ENXIO; | |
653 | goto error_close_devices; | |
654 | } | |
655 | dput(root); | |
656 | root = new_root; | |
657 | } | |
658 | ||
659 | kfree(subvol_name); | |
660 | return root; | |
661 | ||
662 | error_s: | |
663 | error = PTR_ERR(s); | |
664 | error_close_devices: | |
665 | btrfs_close_devices(fs_devices); | |
666 | error_free_subvol_name: | |
667 | kfree(subvol_name); | |
668 | error: | |
669 | return ERR_PTR(error); | |
670 | } | |
671 | ||
672 | static int btrfs_remount(struct super_block *sb, int *flags, char *data) | |
673 | { | |
674 | struct btrfs_root *root = btrfs_sb(sb); | |
675 | int ret; | |
676 | ||
677 | ret = btrfs_parse_options(root, data); | |
678 | if (ret) | |
679 | return -EINVAL; | |
680 | ||
681 | if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) | |
682 | return 0; | |
683 | ||
684 | if (*flags & MS_RDONLY) { | |
685 | sb->s_flags |= MS_RDONLY; | |
686 | ||
687 | ret = btrfs_commit_super(root); | |
688 | WARN_ON(ret); | |
689 | } else { | |
690 | if (root->fs_info->fs_devices->rw_devices == 0) | |
691 | return -EACCES; | |
692 | ||
693 | if (btrfs_super_log_root(&root->fs_info->super_copy) != 0) | |
694 | return -EINVAL; | |
695 | ||
696 | ret = btrfs_cleanup_fs_roots(root->fs_info); | |
697 | WARN_ON(ret); | |
698 | ||
699 | /* recover relocation */ | |
700 | ret = btrfs_recover_relocation(root); | |
701 | WARN_ON(ret); | |
702 | ||
703 | sb->s_flags &= ~MS_RDONLY; | |
704 | } | |
705 | ||
706 | return 0; | |
707 | } | |
708 | ||
709 | static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) | |
710 | { | |
711 | struct btrfs_root *root = btrfs_sb(dentry->d_sb); | |
712 | struct btrfs_super_block *disk_super = &root->fs_info->super_copy; | |
713 | struct list_head *head = &root->fs_info->space_info; | |
714 | struct btrfs_space_info *found; | |
715 | u64 total_used = 0; | |
716 | int bits = dentry->d_sb->s_blocksize_bits; | |
717 | __be32 *fsid = (__be32 *)root->fs_info->fsid; | |
718 | ||
719 | rcu_read_lock(); | |
720 | list_for_each_entry_rcu(found, head, list) | |
721 | total_used += found->disk_used; | |
722 | rcu_read_unlock(); | |
723 | ||
724 | buf->f_namelen = BTRFS_NAME_LEN; | |
725 | buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits; | |
726 | buf->f_bfree = buf->f_blocks - (total_used >> bits); | |
727 | buf->f_bavail = buf->f_bfree; | |
728 | buf->f_bsize = dentry->d_sb->s_blocksize; | |
729 | buf->f_type = BTRFS_SUPER_MAGIC; | |
730 | ||
731 | /* We treat it as constant endianness (it doesn't matter _which_) | |
732 | because we want the fsid to come out the same whether mounted | |
733 | on a big-endian or little-endian host */ | |
734 | buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]); | |
735 | buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]); | |
736 | /* Mask in the root object ID too, to disambiguate subvols */ | |
737 | buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32; | |
738 | buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid; | |
739 | ||
740 | return 0; | |
741 | } | |
742 | ||
743 | static struct file_system_type btrfs_fs_type = { | |
744 | .owner = THIS_MODULE, | |
745 | .name = "btrfs", | |
746 | .mount = btrfs_mount, | |
747 | .kill_sb = kill_anon_super, | |
748 | .fs_flags = FS_REQUIRES_DEV, | |
749 | }; | |
750 | ||
751 | /* | |
752 | * used by btrfsctl to scan devices when no FS is mounted | |
753 | */ | |
754 | static long btrfs_control_ioctl(struct file *file, unsigned int cmd, | |
755 | unsigned long arg) | |
756 | { | |
757 | struct btrfs_ioctl_vol_args *vol; | |
758 | struct btrfs_fs_devices *fs_devices; | |
759 | int ret = -ENOTTY; | |
760 | ||
761 | if (!capable(CAP_SYS_ADMIN)) | |
762 | return -EPERM; | |
763 | ||
764 | vol = memdup_user((void __user *)arg, sizeof(*vol)); | |
765 | if (IS_ERR(vol)) | |
766 | return PTR_ERR(vol); | |
767 | ||
768 | switch (cmd) { | |
769 | case BTRFS_IOC_SCAN_DEV: | |
770 | ret = btrfs_scan_one_device(vol->name, FMODE_READ, | |
771 | &btrfs_fs_type, &fs_devices); | |
772 | break; | |
773 | } | |
774 | ||
775 | kfree(vol); | |
776 | return ret; | |
777 | } | |
778 | ||
779 | static int btrfs_freeze(struct super_block *sb) | |
780 | { | |
781 | struct btrfs_root *root = btrfs_sb(sb); | |
782 | mutex_lock(&root->fs_info->transaction_kthread_mutex); | |
783 | mutex_lock(&root->fs_info->cleaner_mutex); | |
784 | return 0; | |
785 | } | |
786 | ||
787 | static int btrfs_unfreeze(struct super_block *sb) | |
788 | { | |
789 | struct btrfs_root *root = btrfs_sb(sb); | |
790 | mutex_unlock(&root->fs_info->cleaner_mutex); | |
791 | mutex_unlock(&root->fs_info->transaction_kthread_mutex); | |
792 | return 0; | |
793 | } | |
794 | ||
795 | static const struct super_operations btrfs_super_ops = { | |
796 | .drop_inode = btrfs_drop_inode, | |
797 | .evict_inode = btrfs_evict_inode, | |
798 | .put_super = btrfs_put_super, | |
799 | .sync_fs = btrfs_sync_fs, | |
800 | .show_options = btrfs_show_options, | |
801 | .write_inode = btrfs_write_inode, | |
802 | .dirty_inode = btrfs_dirty_inode, | |
803 | .alloc_inode = btrfs_alloc_inode, | |
804 | .destroy_inode = btrfs_destroy_inode, | |
805 | .statfs = btrfs_statfs, | |
806 | .remount_fs = btrfs_remount, | |
807 | .freeze_fs = btrfs_freeze, | |
808 | .unfreeze_fs = btrfs_unfreeze, | |
809 | }; | |
810 | ||
811 | static const struct file_operations btrfs_ctl_fops = { | |
812 | .unlocked_ioctl = btrfs_control_ioctl, | |
813 | .compat_ioctl = btrfs_control_ioctl, | |
814 | .owner = THIS_MODULE, | |
815 | .llseek = noop_llseek, | |
816 | }; | |
817 | ||
818 | static struct miscdevice btrfs_misc = { | |
819 | .minor = BTRFS_MINOR, | |
820 | .name = "btrfs-control", | |
821 | .fops = &btrfs_ctl_fops | |
822 | }; | |
823 | ||
824 | MODULE_ALIAS_MISCDEV(BTRFS_MINOR); | |
825 | MODULE_ALIAS("devname:btrfs-control"); | |
826 | ||
827 | static int btrfs_interface_init(void) | |
828 | { | |
829 | return misc_register(&btrfs_misc); | |
830 | } | |
831 | ||
832 | static void btrfs_interface_exit(void) | |
833 | { | |
834 | if (misc_deregister(&btrfs_misc) < 0) | |
835 | printk(KERN_INFO "misc_deregister failed for control device"); | |
836 | } | |
837 | ||
838 | static int __init init_btrfs_fs(void) | |
839 | { | |
840 | int err; | |
841 | ||
842 | err = btrfs_init_sysfs(); | |
843 | if (err) | |
844 | return err; | |
845 | ||
846 | err = btrfs_init_cachep(); | |
847 | if (err) | |
848 | goto free_sysfs; | |
849 | ||
850 | err = extent_io_init(); | |
851 | if (err) | |
852 | goto free_cachep; | |
853 | ||
854 | err = extent_map_init(); | |
855 | if (err) | |
856 | goto free_extent_io; | |
857 | ||
858 | err = btrfs_interface_init(); | |
859 | if (err) | |
860 | goto free_extent_map; | |
861 | ||
862 | err = register_filesystem(&btrfs_fs_type); | |
863 | if (err) | |
864 | goto unregister_ioctl; | |
865 | ||
866 | printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION); | |
867 | return 0; | |
868 | ||
869 | unregister_ioctl: | |
870 | btrfs_interface_exit(); | |
871 | free_extent_map: | |
872 | extent_map_exit(); | |
873 | free_extent_io: | |
874 | extent_io_exit(); | |
875 | free_cachep: | |
876 | btrfs_destroy_cachep(); | |
877 | free_sysfs: | |
878 | btrfs_exit_sysfs(); | |
879 | return err; | |
880 | } | |
881 | ||
882 | static void __exit exit_btrfs_fs(void) | |
883 | { | |
884 | btrfs_destroy_cachep(); | |
885 | extent_map_exit(); | |
886 | extent_io_exit(); | |
887 | btrfs_interface_exit(); | |
888 | unregister_filesystem(&btrfs_fs_type); | |
889 | btrfs_exit_sysfs(); | |
890 | btrfs_cleanup_fs_uuids(); | |
891 | btrfs_zlib_exit(); | |
892 | } | |
893 | ||
894 | module_init(init_btrfs_fs) | |
895 | module_exit(exit_btrfs_fs) | |
896 | ||
897 | MODULE_LICENSE("GPL"); |