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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/smp_lock.h> | |
30 | #include <linux/backing-dev.h> | |
31 | #include <linux/mount.h> | |
32 | #include <linux/mpage.h> | |
33 | #include <linux/swap.h> | |
34 | #include <linux/writeback.h> | |
35 | #include <linux/statfs.h> | |
36 | #include <linux/compat.h> | |
37 | #include <linux/parser.h> | |
38 | #include <linux/ctype.h> | |
39 | #include <linux/namei.h> | |
40 | #include <linux/miscdevice.h> | |
41 | #include <linux/magic.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 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_device, Opt_nodatasum, Opt_nodatacow, | |
68 | Opt_max_extent, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, | |
69 | Opt_ssd, Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, | |
70 | Opt_compress, Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_err, | |
71 | }; | |
72 | ||
73 | static match_table_t tokens = { | |
74 | {Opt_degraded, "degraded"}, | |
75 | {Opt_subvol, "subvol=%s"}, | |
76 | {Opt_device, "device=%s"}, | |
77 | {Opt_nodatasum, "nodatasum"}, | |
78 | {Opt_nodatacow, "nodatacow"}, | |
79 | {Opt_nobarrier, "nobarrier"}, | |
80 | {Opt_max_extent, "max_extent=%s"}, | |
81 | {Opt_max_inline, "max_inline=%s"}, | |
82 | {Opt_alloc_start, "alloc_start=%s"}, | |
83 | {Opt_thread_pool, "thread_pool=%d"}, | |
84 | {Opt_compress, "compress"}, | |
85 | {Opt_ssd, "ssd"}, | |
86 | {Opt_ssd_spread, "ssd_spread"}, | |
87 | {Opt_nossd, "nossd"}, | |
88 | {Opt_noacl, "noacl"}, | |
89 | {Opt_notreelog, "notreelog"}, | |
90 | {Opt_flushoncommit, "flushoncommit"}, | |
91 | {Opt_ratio, "metadata_ratio=%d"}, | |
92 | {Opt_err, NULL}, | |
93 | }; | |
94 | ||
95 | u64 btrfs_parse_size(char *str) | |
96 | { | |
97 | u64 res; | |
98 | int mult = 1; | |
99 | char *end; | |
100 | char last; | |
101 | ||
102 | res = simple_strtoul(str, &end, 10); | |
103 | ||
104 | last = end[0]; | |
105 | if (isalpha(last)) { | |
106 | last = tolower(last); | |
107 | switch (last) { | |
108 | case 'g': | |
109 | mult *= 1024; | |
110 | case 'm': | |
111 | mult *= 1024; | |
112 | case 'k': | |
113 | mult *= 1024; | |
114 | } | |
115 | res = res * mult; | |
116 | } | |
117 | return res; | |
118 | } | |
119 | ||
120 | /* | |
121 | * Regular mount options parser. Everything that is needed only when | |
122 | * reading in a new superblock is parsed here. | |
123 | */ | |
124 | int btrfs_parse_options(struct btrfs_root *root, char *options) | |
125 | { | |
126 | struct btrfs_fs_info *info = root->fs_info; | |
127 | substring_t args[MAX_OPT_ARGS]; | |
128 | char *p, *num; | |
129 | int intarg; | |
130 | ||
131 | if (!options) | |
132 | return 0; | |
133 | ||
134 | /* | |
135 | * strsep changes the string, duplicate it because parse_options | |
136 | * gets called twice | |
137 | */ | |
138 | options = kstrdup(options, GFP_NOFS); | |
139 | if (!options) | |
140 | return -ENOMEM; | |
141 | ||
142 | ||
143 | while ((p = strsep(&options, ",")) != NULL) { | |
144 | int token; | |
145 | if (!*p) | |
146 | continue; | |
147 | ||
148 | token = match_token(p, tokens, args); | |
149 | switch (token) { | |
150 | case Opt_degraded: | |
151 | printk(KERN_INFO "btrfs: allowing degraded mounts\n"); | |
152 | btrfs_set_opt(info->mount_opt, DEGRADED); | |
153 | break; | |
154 | case Opt_subvol: | |
155 | case Opt_device: | |
156 | /* | |
157 | * These are parsed by btrfs_parse_early_options | |
158 | * and can be happily ignored here. | |
159 | */ | |
160 | break; | |
161 | case Opt_nodatasum: | |
162 | printk(KERN_INFO "btrfs: setting nodatasum\n"); | |
163 | btrfs_set_opt(info->mount_opt, NODATASUM); | |
164 | break; | |
165 | case Opt_nodatacow: | |
166 | printk(KERN_INFO "btrfs: setting nodatacow\n"); | |
167 | btrfs_set_opt(info->mount_opt, NODATACOW); | |
168 | btrfs_set_opt(info->mount_opt, NODATASUM); | |
169 | break; | |
170 | case Opt_compress: | |
171 | printk(KERN_INFO "btrfs: use compression\n"); | |
172 | btrfs_set_opt(info->mount_opt, COMPRESS); | |
173 | break; | |
174 | case Opt_ssd: | |
175 | printk(KERN_INFO "btrfs: use ssd allocation scheme\n"); | |
176 | btrfs_set_opt(info->mount_opt, SSD); | |
177 | break; | |
178 | case Opt_ssd_spread: | |
179 | printk(KERN_INFO "btrfs: use spread ssd " | |
180 | "allocation scheme\n"); | |
181 | btrfs_set_opt(info->mount_opt, SSD); | |
182 | btrfs_set_opt(info->mount_opt, SSD_SPREAD); | |
183 | break; | |
184 | case Opt_nossd: | |
185 | printk(KERN_INFO "btrfs: not using ssd allocation " | |
186 | "scheme\n"); | |
187 | btrfs_set_opt(info->mount_opt, NOSSD); | |
188 | btrfs_clear_opt(info->mount_opt, SSD); | |
189 | btrfs_clear_opt(info->mount_opt, SSD_SPREAD); | |
190 | break; | |
191 | case Opt_nobarrier: | |
192 | printk(KERN_INFO "btrfs: turning off barriers\n"); | |
193 | btrfs_set_opt(info->mount_opt, NOBARRIER); | |
194 | break; | |
195 | case Opt_thread_pool: | |
196 | intarg = 0; | |
197 | match_int(&args[0], &intarg); | |
198 | if (intarg) { | |
199 | info->thread_pool_size = intarg; | |
200 | printk(KERN_INFO "btrfs: thread pool %d\n", | |
201 | info->thread_pool_size); | |
202 | } | |
203 | break; | |
204 | case Opt_max_extent: | |
205 | num = match_strdup(&args[0]); | |
206 | if (num) { | |
207 | info->max_extent = btrfs_parse_size(num); | |
208 | kfree(num); | |
209 | ||
210 | info->max_extent = max_t(u64, | |
211 | info->max_extent, root->sectorsize); | |
212 | printk(KERN_INFO "btrfs: max_extent at %llu\n", | |
213 | (unsigned long long)info->max_extent); | |
214 | } | |
215 | break; | |
216 | case Opt_max_inline: | |
217 | num = match_strdup(&args[0]); | |
218 | if (num) { | |
219 | info->max_inline = btrfs_parse_size(num); | |
220 | kfree(num); | |
221 | ||
222 | if (info->max_inline) { | |
223 | info->max_inline = max_t(u64, | |
224 | info->max_inline, | |
225 | root->sectorsize); | |
226 | } | |
227 | printk(KERN_INFO "btrfs: max_inline at %llu\n", | |
228 | (unsigned long long)info->max_inline); | |
229 | } | |
230 | break; | |
231 | case Opt_alloc_start: | |
232 | num = match_strdup(&args[0]); | |
233 | if (num) { | |
234 | info->alloc_start = btrfs_parse_size(num); | |
235 | kfree(num); | |
236 | printk(KERN_INFO | |
237 | "btrfs: allocations start at %llu\n", | |
238 | (unsigned long long)info->alloc_start); | |
239 | } | |
240 | break; | |
241 | case Opt_noacl: | |
242 | root->fs_info->sb->s_flags &= ~MS_POSIXACL; | |
243 | break; | |
244 | case Opt_notreelog: | |
245 | printk(KERN_INFO "btrfs: disabling tree log\n"); | |
246 | btrfs_set_opt(info->mount_opt, NOTREELOG); | |
247 | break; | |
248 | case Opt_flushoncommit: | |
249 | printk(KERN_INFO "btrfs: turning on flush-on-commit\n"); | |
250 | btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT); | |
251 | break; | |
252 | case Opt_ratio: | |
253 | intarg = 0; | |
254 | match_int(&args[0], &intarg); | |
255 | if (intarg) { | |
256 | info->metadata_ratio = intarg; | |
257 | printk(KERN_INFO "btrfs: metadata ratio %d\n", | |
258 | info->metadata_ratio); | |
259 | } | |
260 | break; | |
261 | default: | |
262 | break; | |
263 | } | |
264 | } | |
265 | kfree(options); | |
266 | return 0; | |
267 | } | |
268 | ||
269 | /* | |
270 | * Parse mount options that are required early in the mount process. | |
271 | * | |
272 | * All other options will be parsed on much later in the mount process and | |
273 | * only when we need to allocate a new super block. | |
274 | */ | |
275 | static int btrfs_parse_early_options(const char *options, fmode_t flags, | |
276 | void *holder, char **subvol_name, | |
277 | struct btrfs_fs_devices **fs_devices) | |
278 | { | |
279 | substring_t args[MAX_OPT_ARGS]; | |
280 | char *opts, *p; | |
281 | int error = 0; | |
282 | ||
283 | if (!options) | |
284 | goto out; | |
285 | ||
286 | /* | |
287 | * strsep changes the string, duplicate it because parse_options | |
288 | * gets called twice | |
289 | */ | |
290 | opts = kstrdup(options, GFP_KERNEL); | |
291 | if (!opts) | |
292 | return -ENOMEM; | |
293 | ||
294 | while ((p = strsep(&opts, ",")) != NULL) { | |
295 | int token; | |
296 | if (!*p) | |
297 | continue; | |
298 | ||
299 | token = match_token(p, tokens, args); | |
300 | switch (token) { | |
301 | case Opt_subvol: | |
302 | *subvol_name = match_strdup(&args[0]); | |
303 | break; | |
304 | case Opt_device: | |
305 | error = btrfs_scan_one_device(match_strdup(&args[0]), | |
306 | flags, holder, fs_devices); | |
307 | if (error) | |
308 | goto out_free_opts; | |
309 | break; | |
310 | default: | |
311 | break; | |
312 | } | |
313 | } | |
314 | ||
315 | out_free_opts: | |
316 | kfree(opts); | |
317 | out: | |
318 | /* | |
319 | * If no subvolume name is specified we use the default one. Allocate | |
320 | * a copy of the string "." here so that code later in the | |
321 | * mount path doesn't care if it's the default volume or another one. | |
322 | */ | |
323 | if (!*subvol_name) { | |
324 | *subvol_name = kstrdup(".", GFP_KERNEL); | |
325 | if (!*subvol_name) | |
326 | return -ENOMEM; | |
327 | } | |
328 | return error; | |
329 | } | |
330 | ||
331 | static int btrfs_fill_super(struct super_block *sb, | |
332 | struct btrfs_fs_devices *fs_devices, | |
333 | void *data, int silent) | |
334 | { | |
335 | struct inode *inode; | |
336 | struct dentry *root_dentry; | |
337 | struct btrfs_super_block *disk_super; | |
338 | struct btrfs_root *tree_root; | |
339 | struct btrfs_key key; | |
340 | int err; | |
341 | ||
342 | sb->s_maxbytes = MAX_LFS_FILESIZE; | |
343 | sb->s_magic = BTRFS_SUPER_MAGIC; | |
344 | sb->s_op = &btrfs_super_ops; | |
345 | sb->s_export_op = &btrfs_export_ops; | |
346 | sb->s_xattr = btrfs_xattr_handlers; | |
347 | sb->s_time_gran = 1; | |
348 | sb->s_flags |= MS_POSIXACL; | |
349 | ||
350 | tree_root = open_ctree(sb, fs_devices, (char *)data); | |
351 | ||
352 | if (IS_ERR(tree_root)) { | |
353 | printk("btrfs: open_ctree failed\n"); | |
354 | return PTR_ERR(tree_root); | |
355 | } | |
356 | sb->s_fs_info = tree_root; | |
357 | disk_super = &tree_root->fs_info->super_copy; | |
358 | ||
359 | key.objectid = BTRFS_FIRST_FREE_OBJECTID; | |
360 | key.type = BTRFS_INODE_ITEM_KEY; | |
361 | key.offset = 0; | |
362 | inode = btrfs_iget(sb, &key, tree_root->fs_info->fs_root); | |
363 | if (IS_ERR(inode)) { | |
364 | err = PTR_ERR(inode); | |
365 | goto fail_close; | |
366 | } | |
367 | ||
368 | root_dentry = d_alloc_root(inode); | |
369 | if (!root_dentry) { | |
370 | iput(inode); | |
371 | err = -ENOMEM; | |
372 | goto fail_close; | |
373 | } | |
374 | #if 0 | |
375 | /* this does the super kobj at the same time */ | |
376 | err = btrfs_sysfs_add_super(tree_root->fs_info); | |
377 | if (err) | |
378 | goto fail_close; | |
379 | #endif | |
380 | ||
381 | sb->s_root = root_dentry; | |
382 | ||
383 | save_mount_options(sb, data); | |
384 | return 0; | |
385 | ||
386 | fail_close: | |
387 | close_ctree(tree_root); | |
388 | return err; | |
389 | } | |
390 | ||
391 | int btrfs_sync_fs(struct super_block *sb, int wait) | |
392 | { | |
393 | struct btrfs_trans_handle *trans; | |
394 | struct btrfs_root *root = btrfs_sb(sb); | |
395 | int ret; | |
396 | ||
397 | if (sb->s_flags & MS_RDONLY) | |
398 | return 0; | |
399 | ||
400 | sb->s_dirt = 0; | |
401 | if (!wait) { | |
402 | filemap_flush(root->fs_info->btree_inode->i_mapping); | |
403 | return 0; | |
404 | } | |
405 | ||
406 | btrfs_start_delalloc_inodes(root); | |
407 | btrfs_wait_ordered_extents(root, 0); | |
408 | ||
409 | trans = btrfs_start_transaction(root, 1); | |
410 | ret = btrfs_commit_transaction(trans, root); | |
411 | sb->s_dirt = 0; | |
412 | return ret; | |
413 | } | |
414 | ||
415 | static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs) | |
416 | { | |
417 | struct btrfs_root *root = btrfs_sb(vfs->mnt_sb); | |
418 | struct btrfs_fs_info *info = root->fs_info; | |
419 | ||
420 | if (btrfs_test_opt(root, DEGRADED)) | |
421 | seq_puts(seq, ",degraded"); | |
422 | if (btrfs_test_opt(root, NODATASUM)) | |
423 | seq_puts(seq, ",nodatasum"); | |
424 | if (btrfs_test_opt(root, NODATACOW)) | |
425 | seq_puts(seq, ",nodatacow"); | |
426 | if (btrfs_test_opt(root, NOBARRIER)) | |
427 | seq_puts(seq, ",nobarrier"); | |
428 | if (info->max_extent != (u64)-1) | |
429 | seq_printf(seq, ",max_extent=%llu", | |
430 | (unsigned long long)info->max_extent); | |
431 | if (info->max_inline != 8192 * 1024) | |
432 | seq_printf(seq, ",max_inline=%llu", | |
433 | (unsigned long long)info->max_inline); | |
434 | if (info->alloc_start != 0) | |
435 | seq_printf(seq, ",alloc_start=%llu", | |
436 | (unsigned long long)info->alloc_start); | |
437 | if (info->thread_pool_size != min_t(unsigned long, | |
438 | num_online_cpus() + 2, 8)) | |
439 | seq_printf(seq, ",thread_pool=%d", info->thread_pool_size); | |
440 | if (btrfs_test_opt(root, COMPRESS)) | |
441 | seq_puts(seq, ",compress"); | |
442 | if (btrfs_test_opt(root, NOSSD)) | |
443 | seq_puts(seq, ",nossd"); | |
444 | if (btrfs_test_opt(root, SSD_SPREAD)) | |
445 | seq_puts(seq, ",ssd_spread"); | |
446 | else if (btrfs_test_opt(root, SSD)) | |
447 | seq_puts(seq, ",ssd"); | |
448 | if (btrfs_test_opt(root, NOTREELOG)) | |
449 | seq_puts(seq, ",notreelog"); | |
450 | if (btrfs_test_opt(root, FLUSHONCOMMIT)) | |
451 | seq_puts(seq, ",flushoncommit"); | |
452 | if (!(root->fs_info->sb->s_flags & MS_POSIXACL)) | |
453 | seq_puts(seq, ",noacl"); | |
454 | return 0; | |
455 | } | |
456 | ||
457 | static void btrfs_write_super(struct super_block *sb) | |
458 | { | |
459 | sb->s_dirt = 0; | |
460 | } | |
461 | ||
462 | static int btrfs_test_super(struct super_block *s, void *data) | |
463 | { | |
464 | struct btrfs_fs_devices *test_fs_devices = data; | |
465 | struct btrfs_root *root = btrfs_sb(s); | |
466 | ||
467 | return root->fs_info->fs_devices == test_fs_devices; | |
468 | } | |
469 | ||
470 | /* | |
471 | * Find a superblock for the given device / mount point. | |
472 | * | |
473 | * Note: This is based on get_sb_bdev from fs/super.c with a few additions | |
474 | * for multiple device setup. Make sure to keep it in sync. | |
475 | */ | |
476 | static int btrfs_get_sb(struct file_system_type *fs_type, int flags, | |
477 | const char *dev_name, void *data, struct vfsmount *mnt) | |
478 | { | |
479 | char *subvol_name = NULL; | |
480 | struct block_device *bdev = NULL; | |
481 | struct super_block *s; | |
482 | struct dentry *root; | |
483 | struct btrfs_fs_devices *fs_devices = NULL; | |
484 | fmode_t mode = FMODE_READ; | |
485 | int error = 0; | |
486 | ||
487 | if (!(flags & MS_RDONLY)) | |
488 | mode |= FMODE_WRITE; | |
489 | ||
490 | error = btrfs_parse_early_options(data, mode, fs_type, | |
491 | &subvol_name, &fs_devices); | |
492 | if (error) | |
493 | return error; | |
494 | ||
495 | error = btrfs_scan_one_device(dev_name, mode, fs_type, &fs_devices); | |
496 | if (error) | |
497 | goto error_free_subvol_name; | |
498 | ||
499 | error = btrfs_open_devices(fs_devices, mode, fs_type); | |
500 | if (error) | |
501 | goto error_free_subvol_name; | |
502 | ||
503 | if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) { | |
504 | error = -EACCES; | |
505 | goto error_close_devices; | |
506 | } | |
507 | ||
508 | bdev = fs_devices->latest_bdev; | |
509 | s = sget(fs_type, btrfs_test_super, set_anon_super, fs_devices); | |
510 | if (IS_ERR(s)) | |
511 | goto error_s; | |
512 | ||
513 | if (s->s_root) { | |
514 | if ((flags ^ s->s_flags) & MS_RDONLY) { | |
515 | deactivate_locked_super(s); | |
516 | error = -EBUSY; | |
517 | goto error_close_devices; | |
518 | } | |
519 | ||
520 | btrfs_close_devices(fs_devices); | |
521 | } else { | |
522 | char b[BDEVNAME_SIZE]; | |
523 | ||
524 | s->s_flags = flags; | |
525 | strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id)); | |
526 | error = btrfs_fill_super(s, fs_devices, data, | |
527 | flags & MS_SILENT ? 1 : 0); | |
528 | if (error) { | |
529 | deactivate_locked_super(s); | |
530 | goto error_free_subvol_name; | |
531 | } | |
532 | ||
533 | btrfs_sb(s)->fs_info->bdev_holder = fs_type; | |
534 | s->s_flags |= MS_ACTIVE; | |
535 | } | |
536 | ||
537 | if (!strcmp(subvol_name, ".")) | |
538 | root = dget(s->s_root); | |
539 | else { | |
540 | mutex_lock(&s->s_root->d_inode->i_mutex); | |
541 | root = lookup_one_len(subvol_name, s->s_root, | |
542 | strlen(subvol_name)); | |
543 | mutex_unlock(&s->s_root->d_inode->i_mutex); | |
544 | ||
545 | if (IS_ERR(root)) { | |
546 | deactivate_locked_super(s); | |
547 | error = PTR_ERR(root); | |
548 | goto error_free_subvol_name; | |
549 | } | |
550 | if (!root->d_inode) { | |
551 | dput(root); | |
552 | deactivate_locked_super(s); | |
553 | error = -ENXIO; | |
554 | goto error_free_subvol_name; | |
555 | } | |
556 | } | |
557 | ||
558 | mnt->mnt_sb = s; | |
559 | mnt->mnt_root = root; | |
560 | ||
561 | kfree(subvol_name); | |
562 | return 0; | |
563 | ||
564 | error_s: | |
565 | error = PTR_ERR(s); | |
566 | error_close_devices: | |
567 | btrfs_close_devices(fs_devices); | |
568 | error_free_subvol_name: | |
569 | kfree(subvol_name); | |
570 | return error; | |
571 | } | |
572 | ||
573 | static int btrfs_remount(struct super_block *sb, int *flags, char *data) | |
574 | { | |
575 | struct btrfs_root *root = btrfs_sb(sb); | |
576 | int ret; | |
577 | ||
578 | ret = btrfs_parse_options(root, data); | |
579 | if (ret) | |
580 | return -EINVAL; | |
581 | ||
582 | if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) | |
583 | return 0; | |
584 | ||
585 | if (*flags & MS_RDONLY) { | |
586 | sb->s_flags |= MS_RDONLY; | |
587 | ||
588 | ret = btrfs_commit_super(root); | |
589 | WARN_ON(ret); | |
590 | } else { | |
591 | if (root->fs_info->fs_devices->rw_devices == 0) | |
592 | return -EACCES; | |
593 | ||
594 | if (btrfs_super_log_root(&root->fs_info->super_copy) != 0) | |
595 | return -EINVAL; | |
596 | ||
597 | /* recover relocation */ | |
598 | ret = btrfs_recover_relocation(root); | |
599 | WARN_ON(ret); | |
600 | ||
601 | ret = btrfs_cleanup_fs_roots(root->fs_info); | |
602 | WARN_ON(ret); | |
603 | ||
604 | sb->s_flags &= ~MS_RDONLY; | |
605 | } | |
606 | ||
607 | return 0; | |
608 | } | |
609 | ||
610 | static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) | |
611 | { | |
612 | struct btrfs_root *root = btrfs_sb(dentry->d_sb); | |
613 | struct btrfs_super_block *disk_super = &root->fs_info->super_copy; | |
614 | int bits = dentry->d_sb->s_blocksize_bits; | |
615 | __be32 *fsid = (__be32 *)root->fs_info->fsid; | |
616 | ||
617 | buf->f_namelen = BTRFS_NAME_LEN; | |
618 | buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits; | |
619 | buf->f_bfree = buf->f_blocks - | |
620 | (btrfs_super_bytes_used(disk_super) >> bits); | |
621 | buf->f_bavail = buf->f_bfree; | |
622 | buf->f_bsize = dentry->d_sb->s_blocksize; | |
623 | buf->f_type = BTRFS_SUPER_MAGIC; | |
624 | ||
625 | /* We treat it as constant endianness (it doesn't matter _which_) | |
626 | because we want the fsid to come out the same whether mounted | |
627 | on a big-endian or little-endian host */ | |
628 | buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]); | |
629 | buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]); | |
630 | /* Mask in the root object ID too, to disambiguate subvols */ | |
631 | buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32; | |
632 | buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid; | |
633 | ||
634 | return 0; | |
635 | } | |
636 | ||
637 | static struct file_system_type btrfs_fs_type = { | |
638 | .owner = THIS_MODULE, | |
639 | .name = "btrfs", | |
640 | .get_sb = btrfs_get_sb, | |
641 | .kill_sb = kill_anon_super, | |
642 | .fs_flags = FS_REQUIRES_DEV, | |
643 | }; | |
644 | ||
645 | /* | |
646 | * used by btrfsctl to scan devices when no FS is mounted | |
647 | */ | |
648 | static long btrfs_control_ioctl(struct file *file, unsigned int cmd, | |
649 | unsigned long arg) | |
650 | { | |
651 | struct btrfs_ioctl_vol_args *vol; | |
652 | struct btrfs_fs_devices *fs_devices; | |
653 | int ret = -ENOTTY; | |
654 | ||
655 | if (!capable(CAP_SYS_ADMIN)) | |
656 | return -EPERM; | |
657 | ||
658 | vol = memdup_user((void __user *)arg, sizeof(*vol)); | |
659 | if (IS_ERR(vol)) | |
660 | return PTR_ERR(vol); | |
661 | ||
662 | switch (cmd) { | |
663 | case BTRFS_IOC_SCAN_DEV: | |
664 | ret = btrfs_scan_one_device(vol->name, FMODE_READ, | |
665 | &btrfs_fs_type, &fs_devices); | |
666 | break; | |
667 | } | |
668 | ||
669 | kfree(vol); | |
670 | return ret; | |
671 | } | |
672 | ||
673 | static int btrfs_freeze(struct super_block *sb) | |
674 | { | |
675 | struct btrfs_root *root = btrfs_sb(sb); | |
676 | mutex_lock(&root->fs_info->transaction_kthread_mutex); | |
677 | mutex_lock(&root->fs_info->cleaner_mutex); | |
678 | return 0; | |
679 | } | |
680 | ||
681 | static int btrfs_unfreeze(struct super_block *sb) | |
682 | { | |
683 | struct btrfs_root *root = btrfs_sb(sb); | |
684 | mutex_unlock(&root->fs_info->cleaner_mutex); | |
685 | mutex_unlock(&root->fs_info->transaction_kthread_mutex); | |
686 | return 0; | |
687 | } | |
688 | ||
689 | static struct super_operations btrfs_super_ops = { | |
690 | .delete_inode = btrfs_delete_inode, | |
691 | .put_super = btrfs_put_super, | |
692 | .write_super = btrfs_write_super, | |
693 | .sync_fs = btrfs_sync_fs, | |
694 | .show_options = btrfs_show_options, | |
695 | .write_inode = btrfs_write_inode, | |
696 | .dirty_inode = btrfs_dirty_inode, | |
697 | .alloc_inode = btrfs_alloc_inode, | |
698 | .destroy_inode = btrfs_destroy_inode, | |
699 | .statfs = btrfs_statfs, | |
700 | .remount_fs = btrfs_remount, | |
701 | .freeze_fs = btrfs_freeze, | |
702 | .unfreeze_fs = btrfs_unfreeze, | |
703 | }; | |
704 | ||
705 | static const struct file_operations btrfs_ctl_fops = { | |
706 | .unlocked_ioctl = btrfs_control_ioctl, | |
707 | .compat_ioctl = btrfs_control_ioctl, | |
708 | .owner = THIS_MODULE, | |
709 | }; | |
710 | ||
711 | static struct miscdevice btrfs_misc = { | |
712 | .minor = MISC_DYNAMIC_MINOR, | |
713 | .name = "btrfs-control", | |
714 | .fops = &btrfs_ctl_fops | |
715 | }; | |
716 | ||
717 | static int btrfs_interface_init(void) | |
718 | { | |
719 | return misc_register(&btrfs_misc); | |
720 | } | |
721 | ||
722 | static void btrfs_interface_exit(void) | |
723 | { | |
724 | if (misc_deregister(&btrfs_misc) < 0) | |
725 | printk(KERN_INFO "misc_deregister failed for control device"); | |
726 | } | |
727 | ||
728 | static int __init init_btrfs_fs(void) | |
729 | { | |
730 | int err; | |
731 | ||
732 | err = btrfs_init_sysfs(); | |
733 | if (err) | |
734 | return err; | |
735 | ||
736 | err = btrfs_init_cachep(); | |
737 | if (err) | |
738 | goto free_sysfs; | |
739 | ||
740 | err = extent_io_init(); | |
741 | if (err) | |
742 | goto free_cachep; | |
743 | ||
744 | err = extent_map_init(); | |
745 | if (err) | |
746 | goto free_extent_io; | |
747 | ||
748 | err = btrfs_interface_init(); | |
749 | if (err) | |
750 | goto free_extent_map; | |
751 | ||
752 | err = register_filesystem(&btrfs_fs_type); | |
753 | if (err) | |
754 | goto unregister_ioctl; | |
755 | ||
756 | printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION); | |
757 | return 0; | |
758 | ||
759 | unregister_ioctl: | |
760 | btrfs_interface_exit(); | |
761 | free_extent_map: | |
762 | extent_map_exit(); | |
763 | free_extent_io: | |
764 | extent_io_exit(); | |
765 | free_cachep: | |
766 | btrfs_destroy_cachep(); | |
767 | free_sysfs: | |
768 | btrfs_exit_sysfs(); | |
769 | return err; | |
770 | } | |
771 | ||
772 | static void __exit exit_btrfs_fs(void) | |
773 | { | |
774 | btrfs_destroy_cachep(); | |
775 | extent_map_exit(); | |
776 | extent_io_exit(); | |
777 | btrfs_interface_exit(); | |
778 | unregister_filesystem(&btrfs_fs_type); | |
779 | btrfs_exit_sysfs(); | |
780 | btrfs_cleanup_fs_uuids(); | |
781 | btrfs_zlib_exit(); | |
782 | } | |
783 | ||
784 | module_init(init_btrfs_fs) | |
785 | module_exit(exit_btrfs_fs) | |
786 | ||
787 | MODULE_LICENSE("GPL"); |