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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 (!di) { |
364 | /* |
365 | * Ok the default dir item isn't there. This is weird since |
366 | * it's always been there, but don't freak out, just try and |
367 | * mount to root most subvolume. |
368 | */ |
369 | btrfs_free_path(path); |
370 | dir_id = BTRFS_FIRST_FREE_OBJECTID; |
371 | new_root = root->fs_info->fs_root; |
372 | goto setup_root; |
373 | } |
374 | |
375 | btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location); |
376 | btrfs_free_path(path); |
377 | |
378 | find_root: |
379 | new_root = btrfs_read_fs_root_no_name(root->fs_info, &location); |
380 | if (IS_ERR(new_root)) |
381 | return ERR_PTR(PTR_ERR(new_root)); |
382 | |
383 | if (btrfs_root_refs(&new_root->root_item) == 0) |
384 | return ERR_PTR(-ENOENT); |
385 | |
386 | dir_id = btrfs_root_dirid(&new_root->root_item); |
387 | setup_root: |
388 | location.objectid = dir_id; |
389 | location.type = BTRFS_INODE_ITEM_KEY; |
390 | location.offset = 0; |
391 | |
392 | inode = btrfs_iget(sb, &location, new_root, &new); |
393 | if (!inode) |
394 | return ERR_PTR(-ENOMEM); |
395 | |
396 | /* |
397 | * If we're just mounting the root most subvol put the inode and return |
398 | * a reference to the dentry. We will have already gotten a reference |
399 | * to the inode in btrfs_fill_super so we're good to go. |
400 | */ |
401 | if (!new && sb->s_root->d_inode == inode) { |
402 | iput(inode); |
403 | return dget(sb->s_root); |
404 | } |
405 | |
406 | if (new) { |
407 | const struct qstr name = { .name = "/", .len = 1 }; |
408 | |
409 | /* |
410 | * New inode, we need to make the dentry a sibling of s_root so |
411 | * everything gets cleaned up properly on unmount. |
412 | */ |
413 | dentry = d_alloc(sb->s_root, &name); |
414 | if (!dentry) { |
415 | iput(inode); |
416 | return ERR_PTR(-ENOMEM); |
417 | } |
418 | d_splice_alias(inode, dentry); |
419 | } else { |
420 | /* |
421 | * We found the inode in cache, just find a dentry for it and |
422 | * put the reference to the inode we just got. |
423 | */ |
424 | dentry = d_find_alias(inode); |
425 | iput(inode); |
426 | } |
427 | |
428 | return dentry; |
429 | } |
430 | |
431 | static int btrfs_fill_super(struct super_block *sb, |
432 | struct btrfs_fs_devices *fs_devices, |
433 | void *data, int silent) |
434 | { |
435 | struct inode *inode; |
436 | struct dentry *root_dentry; |
437 | struct btrfs_super_block *disk_super; |
438 | struct btrfs_root *tree_root; |
439 | struct btrfs_key key; |
440 | int err; |
441 | |
442 | sb->s_maxbytes = MAX_LFS_FILESIZE; |
443 | sb->s_magic = BTRFS_SUPER_MAGIC; |
444 | sb->s_op = &btrfs_super_ops; |
445 | sb->s_export_op = &btrfs_export_ops; |
446 | sb->s_xattr = btrfs_xattr_handlers; |
447 | sb->s_time_gran = 1; |
448 | #ifdef CONFIG_BTRFS_FS_POSIX_ACL |
449 | sb->s_flags |= MS_POSIXACL; |
450 | #endif |
451 | |
452 | tree_root = open_ctree(sb, fs_devices, (char *)data); |
453 | |
454 | if (IS_ERR(tree_root)) { |
455 | printk("btrfs: open_ctree failed\n"); |
456 | return PTR_ERR(tree_root); |
457 | } |
458 | sb->s_fs_info = tree_root; |
459 | disk_super = &tree_root->fs_info->super_copy; |
460 | |
461 | key.objectid = BTRFS_FIRST_FREE_OBJECTID; |
462 | key.type = BTRFS_INODE_ITEM_KEY; |
463 | key.offset = 0; |
464 | inode = btrfs_iget(sb, &key, tree_root->fs_info->fs_root, NULL); |
465 | if (IS_ERR(inode)) { |
466 | err = PTR_ERR(inode); |
467 | goto fail_close; |
468 | } |
469 | |
470 | root_dentry = d_alloc_root(inode); |
471 | if (!root_dentry) { |
472 | iput(inode); |
473 | err = -ENOMEM; |
474 | goto fail_close; |
475 | } |
476 | |
477 | sb->s_root = root_dentry; |
478 | |
479 | save_mount_options(sb, data); |
480 | return 0; |
481 | |
482 | fail_close: |
483 | close_ctree(tree_root); |
484 | return err; |
485 | } |
486 | |
487 | int btrfs_sync_fs(struct super_block *sb, int wait) |
488 | { |
489 | struct btrfs_trans_handle *trans; |
490 | struct btrfs_root *root = btrfs_sb(sb); |
491 | int ret; |
492 | |
493 | if (!wait) { |
494 | filemap_flush(root->fs_info->btree_inode->i_mapping); |
495 | return 0; |
496 | } |
497 | |
498 | btrfs_start_delalloc_inodes(root, 0); |
499 | btrfs_wait_ordered_extents(root, 0, 0); |
500 | |
501 | trans = btrfs_start_transaction(root, 1); |
502 | ret = btrfs_commit_transaction(trans, root); |
503 | return ret; |
504 | } |
505 | |
506 | static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs) |
507 | { |
508 | struct btrfs_root *root = btrfs_sb(vfs->mnt_sb); |
509 | struct btrfs_fs_info *info = root->fs_info; |
510 | |
511 | if (btrfs_test_opt(root, DEGRADED)) |
512 | seq_puts(seq, ",degraded"); |
513 | if (btrfs_test_opt(root, NODATASUM)) |
514 | seq_puts(seq, ",nodatasum"); |
515 | if (btrfs_test_opt(root, NODATACOW)) |
516 | seq_puts(seq, ",nodatacow"); |
517 | if (btrfs_test_opt(root, NOBARRIER)) |
518 | seq_puts(seq, ",nobarrier"); |
519 | if (info->max_inline != 8192 * 1024) |
520 | seq_printf(seq, ",max_inline=%llu", |
521 | (unsigned long long)info->max_inline); |
522 | if (info->alloc_start != 0) |
523 | seq_printf(seq, ",alloc_start=%llu", |
524 | (unsigned long long)info->alloc_start); |
525 | if (info->thread_pool_size != min_t(unsigned long, |
526 | num_online_cpus() + 2, 8)) |
527 | seq_printf(seq, ",thread_pool=%d", info->thread_pool_size); |
528 | if (btrfs_test_opt(root, COMPRESS)) |
529 | seq_puts(seq, ",compress"); |
530 | if (btrfs_test_opt(root, NOSSD)) |
531 | seq_puts(seq, ",nossd"); |
532 | if (btrfs_test_opt(root, SSD_SPREAD)) |
533 | seq_puts(seq, ",ssd_spread"); |
534 | else if (btrfs_test_opt(root, SSD)) |
535 | seq_puts(seq, ",ssd"); |
536 | if (btrfs_test_opt(root, NOTREELOG)) |
537 | seq_puts(seq, ",notreelog"); |
538 | if (btrfs_test_opt(root, FLUSHONCOMMIT)) |
539 | seq_puts(seq, ",flushoncommit"); |
540 | if (btrfs_test_opt(root, DISCARD)) |
541 | seq_puts(seq, ",discard"); |
542 | if (!(root->fs_info->sb->s_flags & MS_POSIXACL)) |
543 | seq_puts(seq, ",noacl"); |
544 | return 0; |
545 | } |
546 | |
547 | static int btrfs_test_super(struct super_block *s, void *data) |
548 | { |
549 | struct btrfs_fs_devices *test_fs_devices = data; |
550 | struct btrfs_root *root = btrfs_sb(s); |
551 | |
552 | return root->fs_info->fs_devices == test_fs_devices; |
553 | } |
554 | |
555 | /* |
556 | * Find a superblock for the given device / mount point. |
557 | * |
558 | * Note: This is based on get_sb_bdev from fs/super.c with a few additions |
559 | * for multiple device setup. Make sure to keep it in sync. |
560 | */ |
561 | static int btrfs_get_sb(struct file_system_type *fs_type, int flags, |
562 | const char *dev_name, void *data, struct vfsmount *mnt) |
563 | { |
564 | struct block_device *bdev = NULL; |
565 | struct super_block *s; |
566 | struct dentry *root; |
567 | struct btrfs_fs_devices *fs_devices = NULL; |
568 | fmode_t mode = FMODE_READ; |
569 | char *subvol_name = NULL; |
570 | u64 subvol_objectid = 0; |
571 | int error = 0; |
572 | int found = 0; |
573 | |
574 | if (!(flags & MS_RDONLY)) |
575 | mode |= FMODE_WRITE; |
576 | |
577 | error = btrfs_parse_early_options(data, mode, fs_type, |
578 | &subvol_name, &subvol_objectid, |
579 | &fs_devices); |
580 | if (error) |
581 | return error; |
582 | |
583 | error = btrfs_scan_one_device(dev_name, mode, fs_type, &fs_devices); |
584 | if (error) |
585 | goto error_free_subvol_name; |
586 | |
587 | error = btrfs_open_devices(fs_devices, mode, fs_type); |
588 | if (error) |
589 | goto error_free_subvol_name; |
590 | |
591 | if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) { |
592 | error = -EACCES; |
593 | goto error_close_devices; |
594 | } |
595 | |
596 | bdev = fs_devices->latest_bdev; |
597 | s = sget(fs_type, btrfs_test_super, set_anon_super, fs_devices); |
598 | if (IS_ERR(s)) |
599 | goto error_s; |
600 | |
601 | if (s->s_root) { |
602 | if ((flags ^ s->s_flags) & MS_RDONLY) { |
603 | deactivate_locked_super(s); |
604 | error = -EBUSY; |
605 | goto error_close_devices; |
606 | } |
607 | |
608 | found = 1; |
609 | btrfs_close_devices(fs_devices); |
610 | } else { |
611 | char b[BDEVNAME_SIZE]; |
612 | |
613 | s->s_flags = flags; |
614 | strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id)); |
615 | error = btrfs_fill_super(s, fs_devices, data, |
616 | flags & MS_SILENT ? 1 : 0); |
617 | if (error) { |
618 | deactivate_locked_super(s); |
619 | goto error_free_subvol_name; |
620 | } |
621 | |
622 | btrfs_sb(s)->fs_info->bdev_holder = fs_type; |
623 | s->s_flags |= MS_ACTIVE; |
624 | } |
625 | |
626 | root = get_default_root(s, subvol_objectid); |
627 | if (IS_ERR(root)) { |
628 | error = PTR_ERR(root); |
629 | deactivate_locked_super(s); |
630 | goto error; |
631 | } |
632 | /* if they gave us a subvolume name bind mount into that */ |
633 | if (strcmp(subvol_name, ".")) { |
634 | struct dentry *new_root; |
635 | mutex_lock(&root->d_inode->i_mutex); |
636 | new_root = lookup_one_len(subvol_name, root, |
637 | strlen(subvol_name)); |
638 | mutex_unlock(&root->d_inode->i_mutex); |
639 | |
640 | if (IS_ERR(new_root)) { |
641 | deactivate_locked_super(s); |
642 | error = PTR_ERR(new_root); |
643 | dput(root); |
644 | goto error_close_devices; |
645 | } |
646 | if (!new_root->d_inode) { |
647 | dput(root); |
648 | dput(new_root); |
649 | deactivate_locked_super(s); |
650 | error = -ENXIO; |
651 | goto error_close_devices; |
652 | } |
653 | dput(root); |
654 | root = new_root; |
655 | } |
656 | |
657 | mnt->mnt_sb = s; |
658 | mnt->mnt_root = root; |
659 | |
660 | kfree(subvol_name); |
661 | return 0; |
662 | |
663 | error_s: |
664 | error = PTR_ERR(s); |
665 | error_close_devices: |
666 | btrfs_close_devices(fs_devices); |
667 | error_free_subvol_name: |
668 | kfree(subvol_name); |
669 | error: |
670 | return error; |
671 | } |
672 | |
673 | static int btrfs_remount(struct super_block *sb, int *flags, char *data) |
674 | { |
675 | struct btrfs_root *root = btrfs_sb(sb); |
676 | int ret; |
677 | |
678 | ret = btrfs_parse_options(root, data); |
679 | if (ret) |
680 | return -EINVAL; |
681 | |
682 | if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) |
683 | return 0; |
684 | |
685 | if (*flags & MS_RDONLY) { |
686 | sb->s_flags |= MS_RDONLY; |
687 | |
688 | ret = btrfs_commit_super(root); |
689 | WARN_ON(ret); |
690 | } else { |
691 | if (root->fs_info->fs_devices->rw_devices == 0) |
692 | return -EACCES; |
693 | |
694 | if (btrfs_super_log_root(&root->fs_info->super_copy) != 0) |
695 | return -EINVAL; |
696 | |
697 | /* recover relocation */ |
698 | ret = btrfs_recover_relocation(root); |
699 | WARN_ON(ret); |
700 | |
701 | ret = btrfs_cleanup_fs_roots(root->fs_info); |
702 | WARN_ON(ret); |
703 | |
704 | sb->s_flags &= ~MS_RDONLY; |
705 | } |
706 | |
707 | return 0; |
708 | } |
709 | |
710 | static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) |
711 | { |
712 | struct btrfs_root *root = btrfs_sb(dentry->d_sb); |
713 | struct btrfs_super_block *disk_super = &root->fs_info->super_copy; |
714 | struct list_head *head = &root->fs_info->space_info; |
715 | struct btrfs_space_info *found; |
716 | u64 total_used = 0; |
717 | u64 data_used = 0; |
718 | int bits = dentry->d_sb->s_blocksize_bits; |
719 | __be32 *fsid = (__be32 *)root->fs_info->fsid; |
720 | |
721 | rcu_read_lock(); |
722 | list_for_each_entry_rcu(found, head, list) { |
723 | if (found->flags & (BTRFS_BLOCK_GROUP_DUP| |
724 | BTRFS_BLOCK_GROUP_RAID10| |
725 | BTRFS_BLOCK_GROUP_RAID1)) { |
726 | total_used += found->bytes_used; |
727 | if (found->flags & BTRFS_BLOCK_GROUP_DATA) |
728 | data_used += found->bytes_used; |
729 | else |
730 | data_used += found->total_bytes; |
731 | } |
732 | |
733 | total_used += found->bytes_used; |
734 | if (found->flags & BTRFS_BLOCK_GROUP_DATA) |
735 | data_used += found->bytes_used; |
736 | else |
737 | data_used += found->total_bytes; |
738 | } |
739 | rcu_read_unlock(); |
740 | |
741 | buf->f_namelen = BTRFS_NAME_LEN; |
742 | buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits; |
743 | buf->f_bfree = buf->f_blocks - (total_used >> bits); |
744 | buf->f_bavail = buf->f_blocks - (data_used >> bits); |
745 | buf->f_bsize = dentry->d_sb->s_blocksize; |
746 | buf->f_type = BTRFS_SUPER_MAGIC; |
747 | |
748 | /* We treat it as constant endianness (it doesn't matter _which_) |
749 | because we want the fsid to come out the same whether mounted |
750 | on a big-endian or little-endian host */ |
751 | buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]); |
752 | buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]); |
753 | /* Mask in the root object ID too, to disambiguate subvols */ |
754 | buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32; |
755 | buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid; |
756 | |
757 | return 0; |
758 | } |
759 | |
760 | static struct file_system_type btrfs_fs_type = { |
761 | .owner = THIS_MODULE, |
762 | .name = "btrfs", |
763 | .get_sb = btrfs_get_sb, |
764 | .kill_sb = kill_anon_super, |
765 | .fs_flags = FS_REQUIRES_DEV, |
766 | }; |
767 | |
768 | /* |
769 | * used by btrfsctl to scan devices when no FS is mounted |
770 | */ |
771 | static long btrfs_control_ioctl(struct file *file, unsigned int cmd, |
772 | unsigned long arg) |
773 | { |
774 | struct btrfs_ioctl_vol_args *vol; |
775 | struct btrfs_fs_devices *fs_devices; |
776 | int ret = -ENOTTY; |
777 | |
778 | if (!capable(CAP_SYS_ADMIN)) |
779 | return -EPERM; |
780 | |
781 | vol = memdup_user((void __user *)arg, sizeof(*vol)); |
782 | if (IS_ERR(vol)) |
783 | return PTR_ERR(vol); |
784 | |
785 | switch (cmd) { |
786 | case BTRFS_IOC_SCAN_DEV: |
787 | ret = btrfs_scan_one_device(vol->name, FMODE_READ, |
788 | &btrfs_fs_type, &fs_devices); |
789 | break; |
790 | } |
791 | |
792 | kfree(vol); |
793 | return ret; |
794 | } |
795 | |
796 | static int btrfs_freeze(struct super_block *sb) |
797 | { |
798 | struct btrfs_root *root = btrfs_sb(sb); |
799 | mutex_lock(&root->fs_info->transaction_kthread_mutex); |
800 | mutex_lock(&root->fs_info->cleaner_mutex); |
801 | return 0; |
802 | } |
803 | |
804 | static int btrfs_unfreeze(struct super_block *sb) |
805 | { |
806 | struct btrfs_root *root = btrfs_sb(sb); |
807 | mutex_unlock(&root->fs_info->cleaner_mutex); |
808 | mutex_unlock(&root->fs_info->transaction_kthread_mutex); |
809 | return 0; |
810 | } |
811 | |
812 | static const struct super_operations btrfs_super_ops = { |
813 | .drop_inode = btrfs_drop_inode, |
814 | .delete_inode = btrfs_delete_inode, |
815 | .put_super = btrfs_put_super, |
816 | .sync_fs = btrfs_sync_fs, |
817 | .show_options = btrfs_show_options, |
818 | .write_inode = btrfs_write_inode, |
819 | .dirty_inode = btrfs_dirty_inode, |
820 | .alloc_inode = btrfs_alloc_inode, |
821 | .destroy_inode = btrfs_destroy_inode, |
822 | .statfs = btrfs_statfs, |
823 | .remount_fs = btrfs_remount, |
824 | .freeze_fs = btrfs_freeze, |
825 | .unfreeze_fs = btrfs_unfreeze, |
826 | }; |
827 | |
828 | static const struct file_operations btrfs_ctl_fops = { |
829 | .unlocked_ioctl = btrfs_control_ioctl, |
830 | .compat_ioctl = btrfs_control_ioctl, |
831 | .owner = THIS_MODULE, |
832 | }; |
833 | |
834 | static struct miscdevice btrfs_misc = { |
835 | .minor = MISC_DYNAMIC_MINOR, |
836 | .name = "btrfs-control", |
837 | .fops = &btrfs_ctl_fops |
838 | }; |
839 | |
840 | static int btrfs_interface_init(void) |
841 | { |
842 | return misc_register(&btrfs_misc); |
843 | } |
844 | |
845 | static void btrfs_interface_exit(void) |
846 | { |
847 | if (misc_deregister(&btrfs_misc) < 0) |
848 | printk(KERN_INFO "misc_deregister failed for control device"); |
849 | } |
850 | |
851 | static int __init init_btrfs_fs(void) |
852 | { |
853 | int err; |
854 | |
855 | err = btrfs_init_sysfs(); |
856 | if (err) |
857 | return err; |
858 | |
859 | err = btrfs_init_cachep(); |
860 | if (err) |
861 | goto free_sysfs; |
862 | |
863 | err = extent_io_init(); |
864 | if (err) |
865 | goto free_cachep; |
866 | |
867 | err = extent_map_init(); |
868 | if (err) |
869 | goto free_extent_io; |
870 | |
871 | err = btrfs_interface_init(); |
872 | if (err) |
873 | goto free_extent_map; |
874 | |
875 | err = register_filesystem(&btrfs_fs_type); |
876 | if (err) |
877 | goto unregister_ioctl; |
878 | |
879 | printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION); |
880 | return 0; |
881 | |
882 | unregister_ioctl: |
883 | btrfs_interface_exit(); |
884 | free_extent_map: |
885 | extent_map_exit(); |
886 | free_extent_io: |
887 | extent_io_exit(); |
888 | free_cachep: |
889 | btrfs_destroy_cachep(); |
890 | free_sysfs: |
891 | btrfs_exit_sysfs(); |
892 | return err; |
893 | } |
894 | |
895 | static void __exit exit_btrfs_fs(void) |
896 | { |
897 | btrfs_destroy_cachep(); |
898 | extent_map_exit(); |
899 | extent_io_exit(); |
900 | btrfs_interface_exit(); |
901 | unregister_filesystem(&btrfs_fs_type); |
902 | btrfs_exit_sysfs(); |
903 | btrfs_cleanup_fs_uuids(); |
904 | btrfs_zlib_exit(); |
905 | } |
906 | |
907 | module_init(init_btrfs_fs) |
908 | module_exit(exit_btrfs_fs) |
909 | |
910 | MODULE_LICENSE("GPL"); |
911 |
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