Commit | Line | Data |
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6cbd5570 CM |
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 | ||
4b82d6e4 | 19 | #include <linux/blkdev.h> |
2e635a27 | 20 | #include <linux/module.h> |
e20d96d6 | 21 | #include <linux/buffer_head.h> |
2e635a27 CM |
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/string.h> | |
28 | #include <linux/smp_lock.h> | |
29 | #include <linux/backing-dev.h> | |
4b82d6e4 | 30 | #include <linux/mount.h> |
dee26a9f | 31 | #include <linux/mpage.h> |
75dfe396 CM |
32 | #include <linux/swap.h> |
33 | #include <linux/writeback.h> | |
8fd17795 | 34 | #include <linux/statfs.h> |
08607c1b | 35 | #include <linux/compat.h> |
95e05289 | 36 | #include <linux/parser.h> |
c59f8951 | 37 | #include <linux/ctype.h> |
6da6abae | 38 | #include <linux/namei.h> |
a9218f6b | 39 | #include <linux/miscdevice.h> |
1bcbf313 | 40 | #include <linux/magic.h> |
4b4e25f2 | 41 | #include "compat.h" |
2e635a27 | 42 | #include "ctree.h" |
e20d96d6 | 43 | #include "disk-io.h" |
d5719762 | 44 | #include "transaction.h" |
2c90e5d6 | 45 | #include "btrfs_inode.h" |
c5739bba | 46 | #include "ioctl.h" |
3a686375 | 47 | #include "print-tree.h" |
5103e947 | 48 | #include "xattr.h" |
8a4b83cc | 49 | #include "volumes.h" |
b3c3da71 | 50 | #include "version.h" |
be6e8dc0 | 51 | #include "export.h" |
c8b97818 | 52 | #include "compression.h" |
2e635a27 | 53 | |
f254e52c | 54 | |
39279cc3 | 55 | static struct super_operations btrfs_super_ops; |
75dfe396 | 56 | |
d397712b | 57 | static void btrfs_put_super(struct super_block *sb) |
b18c6685 | 58 | { |
39279cc3 | 59 | struct btrfs_root *root = btrfs_sb(sb); |
b18c6685 | 60 | int ret; |
b18c6685 | 61 | |
39279cc3 | 62 | ret = close_ctree(root); |
39279cc3 | 63 | sb->s_fs_info = NULL; |
75dfe396 CM |
64 | } |
65 | ||
95e05289 | 66 | enum { |
43e570b0 | 67 | Opt_degraded, Opt_subvol, Opt_device, Opt_nodatasum, Opt_nodatacow, |
dfe25020 | 68 | Opt_max_extent, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, |
c8b97818 | 69 | Opt_ssd, Opt_thread_pool, Opt_noacl, Opt_compress, Opt_err, |
95e05289 CM |
70 | }; |
71 | ||
72 | static match_table_t tokens = { | |
dfe25020 | 73 | {Opt_degraded, "degraded"}, |
95e05289 | 74 | {Opt_subvol, "subvol=%s"}, |
43e570b0 | 75 | {Opt_device, "device=%s"}, |
b6cda9bc | 76 | {Opt_nodatasum, "nodatasum"}, |
be20aa9d | 77 | {Opt_nodatacow, "nodatacow"}, |
21ad10cf | 78 | {Opt_nobarrier, "nobarrier"}, |
c59f8951 | 79 | {Opt_max_extent, "max_extent=%s"}, |
6f568d35 | 80 | {Opt_max_inline, "max_inline=%s"}, |
8f662a76 | 81 | {Opt_alloc_start, "alloc_start=%s"}, |
4543df7e | 82 | {Opt_thread_pool, "thread_pool=%d"}, |
c8b97818 | 83 | {Opt_compress, "compress"}, |
e18e4809 | 84 | {Opt_ssd, "ssd"}, |
33268eaf JB |
85 | {Opt_noacl, "noacl"}, |
86 | {Opt_err, NULL}, | |
95e05289 CM |
87 | }; |
88 | ||
edbd8d4e | 89 | u64 btrfs_parse_size(char *str) |
c59f8951 | 90 | { |
edbd8d4e | 91 | u64 res; |
c59f8951 CM |
92 | int mult = 1; |
93 | char *end; | |
94 | char last; | |
95 | ||
96 | res = simple_strtoul(str, &end, 10); | |
97 | ||
98 | last = end[0]; | |
99 | if (isalpha(last)) { | |
100 | last = tolower(last); | |
101 | switch (last) { | |
102 | case 'g': | |
103 | mult *= 1024; | |
104 | case 'm': | |
105 | mult *= 1024; | |
106 | case 'k': | |
107 | mult *= 1024; | |
108 | } | |
109 | res = res * mult; | |
110 | } | |
111 | return res; | |
112 | } | |
113 | ||
edf24abe CH |
114 | /* |
115 | * Regular mount options parser. Everything that is needed only when | |
116 | * reading in a new superblock is parsed here. | |
117 | */ | |
118 | int btrfs_parse_options(struct btrfs_root *root, char *options) | |
95e05289 | 119 | { |
edf24abe | 120 | struct btrfs_fs_info *info = root->fs_info; |
95e05289 | 121 | substring_t args[MAX_OPT_ARGS]; |
edf24abe | 122 | char *p, *num; |
4543df7e | 123 | int intarg; |
b6cda9bc | 124 | |
95e05289 | 125 | if (!options) |
edf24abe | 126 | return 0; |
95e05289 | 127 | |
be20aa9d CM |
128 | /* |
129 | * strsep changes the string, duplicate it because parse_options | |
130 | * gets called twice | |
131 | */ | |
132 | options = kstrdup(options, GFP_NOFS); | |
133 | if (!options) | |
134 | return -ENOMEM; | |
135 | ||
be20aa9d | 136 | |
edf24abe | 137 | while ((p = strsep(&options, ",")) != NULL) { |
95e05289 CM |
138 | int token; |
139 | if (!*p) | |
140 | continue; | |
141 | ||
142 | token = match_token(p, tokens, args); | |
143 | switch (token) { | |
dfe25020 | 144 | case Opt_degraded: |
edf24abe CH |
145 | printk(KERN_INFO "btrfs: allowing degraded mounts\n"); |
146 | btrfs_set_opt(info->mount_opt, DEGRADED); | |
dfe25020 | 147 | break; |
95e05289 | 148 | case Opt_subvol: |
43e570b0 | 149 | case Opt_device: |
edf24abe | 150 | /* |
43e570b0 | 151 | * These are parsed by btrfs_parse_early_options |
edf24abe CH |
152 | * and can be happily ignored here. |
153 | */ | |
b6cda9bc CM |
154 | break; |
155 | case Opt_nodatasum: | |
edf24abe CH |
156 | printk(KERN_INFO "btrfs: setting nodatacsum\n"); |
157 | btrfs_set_opt(info->mount_opt, NODATASUM); | |
be20aa9d CM |
158 | break; |
159 | case Opt_nodatacow: | |
edf24abe CH |
160 | printk(KERN_INFO "btrfs: setting nodatacow\n"); |
161 | btrfs_set_opt(info->mount_opt, NODATACOW); | |
162 | btrfs_set_opt(info->mount_opt, NODATASUM); | |
95e05289 | 163 | break; |
c8b97818 CM |
164 | case Opt_compress: |
165 | printk(KERN_INFO "btrfs: use compression\n"); | |
166 | btrfs_set_opt(info->mount_opt, COMPRESS); | |
167 | break; | |
e18e4809 | 168 | case Opt_ssd: |
edf24abe CH |
169 | printk(KERN_INFO "btrfs: use ssd allocation scheme\n"); |
170 | btrfs_set_opt(info->mount_opt, SSD); | |
e18e4809 | 171 | break; |
21ad10cf | 172 | case Opt_nobarrier: |
edf24abe CH |
173 | printk(KERN_INFO "btrfs: turning off barriers\n"); |
174 | btrfs_set_opt(info->mount_opt, NOBARRIER); | |
21ad10cf | 175 | break; |
4543df7e CM |
176 | case Opt_thread_pool: |
177 | intarg = 0; | |
178 | match_int(&args[0], &intarg); | |
179 | if (intarg) { | |
180 | info->thread_pool_size = intarg; | |
181 | printk(KERN_INFO "btrfs: thread pool %d\n", | |
182 | info->thread_pool_size); | |
183 | } | |
184 | break; | |
c59f8951 | 185 | case Opt_max_extent: |
edf24abe CH |
186 | num = match_strdup(&args[0]); |
187 | if (num) { | |
188 | info->max_extent = btrfs_parse_size(num); | |
189 | kfree(num); | |
190 | ||
191 | info->max_extent = max_t(u64, | |
192 | info->max_extent, root->sectorsize); | |
193 | printk(KERN_INFO "btrfs: max_extent at %llu\n", | |
194 | info->max_extent); | |
c59f8951 CM |
195 | } |
196 | break; | |
6f568d35 | 197 | case Opt_max_inline: |
edf24abe CH |
198 | num = match_strdup(&args[0]); |
199 | if (num) { | |
200 | info->max_inline = btrfs_parse_size(num); | |
201 | kfree(num); | |
202 | ||
15ada040 CM |
203 | if (info->max_inline) { |
204 | info->max_inline = max_t(u64, | |
205 | info->max_inline, | |
206 | root->sectorsize); | |
207 | } | |
edf24abe CH |
208 | printk(KERN_INFO "btrfs: max_inline at %llu\n", |
209 | info->max_inline); | |
6f568d35 CM |
210 | } |
211 | break; | |
8f662a76 | 212 | case Opt_alloc_start: |
edf24abe CH |
213 | num = match_strdup(&args[0]); |
214 | if (num) { | |
215 | info->alloc_start = btrfs_parse_size(num); | |
216 | kfree(num); | |
217 | printk(KERN_INFO | |
218 | "btrfs: allocations start at %llu\n", | |
219 | info->alloc_start); | |
8f662a76 CM |
220 | } |
221 | break; | |
33268eaf JB |
222 | case Opt_noacl: |
223 | root->fs_info->sb->s_flags &= ~MS_POSIXACL; | |
224 | break; | |
95e05289 | 225 | default: |
be20aa9d | 226 | break; |
95e05289 CM |
227 | } |
228 | } | |
be20aa9d | 229 | kfree(options); |
edf24abe CH |
230 | return 0; |
231 | } | |
232 | ||
233 | /* | |
234 | * Parse mount options that are required early in the mount process. | |
235 | * | |
236 | * All other options will be parsed on much later in the mount process and | |
237 | * only when we need to allocate a new super block. | |
238 | */ | |
97288f2c | 239 | static int btrfs_parse_early_options(const char *options, fmode_t flags, |
43e570b0 CH |
240 | void *holder, char **subvol_name, |
241 | struct btrfs_fs_devices **fs_devices) | |
edf24abe CH |
242 | { |
243 | substring_t args[MAX_OPT_ARGS]; | |
244 | char *opts, *p; | |
245 | int error = 0; | |
246 | ||
247 | if (!options) | |
248 | goto out; | |
249 | ||
250 | /* | |
251 | * strsep changes the string, duplicate it because parse_options | |
252 | * gets called twice | |
253 | */ | |
254 | opts = kstrdup(options, GFP_KERNEL); | |
255 | if (!opts) | |
256 | return -ENOMEM; | |
257 | ||
258 | while ((p = strsep(&opts, ",")) != NULL) { | |
259 | int token; | |
260 | if (!*p) | |
261 | continue; | |
262 | ||
263 | token = match_token(p, tokens, args); | |
264 | switch (token) { | |
265 | case Opt_subvol: | |
266 | *subvol_name = match_strdup(&args[0]); | |
267 | break; | |
43e570b0 CH |
268 | case Opt_device: |
269 | error = btrfs_scan_one_device(match_strdup(&args[0]), | |
270 | flags, holder, fs_devices); | |
271 | if (error) | |
272 | goto out_free_opts; | |
273 | break; | |
edf24abe CH |
274 | default: |
275 | break; | |
276 | } | |
277 | } | |
278 | ||
43e570b0 | 279 | out_free_opts: |
edf24abe CH |
280 | kfree(opts); |
281 | out: | |
282 | /* | |
283 | * If no subvolume name is specified we use the default one. Allocate | |
3de4586c | 284 | * a copy of the string "." here so that code later in the |
edf24abe CH |
285 | * mount path doesn't care if it's the default volume or another one. |
286 | */ | |
287 | if (!*subvol_name) { | |
3de4586c | 288 | *subvol_name = kstrdup(".", GFP_KERNEL); |
edf24abe CH |
289 | if (!*subvol_name) |
290 | return -ENOMEM; | |
291 | } | |
292 | return error; | |
95e05289 CM |
293 | } |
294 | ||
d397712b | 295 | static int btrfs_fill_super(struct super_block *sb, |
8a4b83cc | 296 | struct btrfs_fs_devices *fs_devices, |
d397712b | 297 | void *data, int silent) |
75dfe396 | 298 | { |
d397712b CM |
299 | struct inode *inode; |
300 | struct dentry *root_dentry; | |
39279cc3 CM |
301 | struct btrfs_super_block *disk_super; |
302 | struct btrfs_root *tree_root; | |
303 | struct btrfs_inode *bi; | |
304 | int err; | |
a429e513 | 305 | |
39279cc3 CM |
306 | sb->s_maxbytes = MAX_LFS_FILESIZE; |
307 | sb->s_magic = BTRFS_SUPER_MAGIC; | |
308 | sb->s_op = &btrfs_super_ops; | |
be6e8dc0 | 309 | sb->s_export_op = &btrfs_export_ops; |
5103e947 | 310 | sb->s_xattr = btrfs_xattr_handlers; |
39279cc3 | 311 | sb->s_time_gran = 1; |
33268eaf | 312 | sb->s_flags |= MS_POSIXACL; |
a429e513 | 313 | |
dfe25020 | 314 | tree_root = open_ctree(sb, fs_devices, (char *)data); |
6567e837 | 315 | |
e58ca020 | 316 | if (IS_ERR(tree_root)) { |
39279cc3 | 317 | printk("btrfs: open_ctree failed\n"); |
e58ca020 | 318 | return PTR_ERR(tree_root); |
a429e513 | 319 | } |
39279cc3 | 320 | sb->s_fs_info = tree_root; |
5f39d397 | 321 | disk_super = &tree_root->fs_info->super_copy; |
3de4586c CM |
322 | inode = btrfs_iget_locked(sb, BTRFS_FIRST_FREE_OBJECTID, |
323 | tree_root->fs_info->fs_root); | |
39279cc3 CM |
324 | bi = BTRFS_I(inode); |
325 | bi->location.objectid = inode->i_ino; | |
326 | bi->location.offset = 0; | |
3de4586c | 327 | bi->root = tree_root->fs_info->fs_root; |
b888db2b | 328 | |
39279cc3 | 329 | btrfs_set_key_type(&bi->location, BTRFS_INODE_ITEM_KEY); |
a429e513 | 330 | |
39279cc3 | 331 | if (!inode) { |
6567e837 | 332 | err = -ENOMEM; |
39279cc3 | 333 | goto fail_close; |
f254e52c | 334 | } |
39279cc3 CM |
335 | if (inode->i_state & I_NEW) { |
336 | btrfs_read_locked_inode(inode); | |
337 | unlock_new_inode(inode); | |
f254e52c | 338 | } |
f254e52c | 339 | |
39279cc3 CM |
340 | root_dentry = d_alloc_root(inode); |
341 | if (!root_dentry) { | |
342 | iput(inode); | |
343 | err = -ENOMEM; | |
344 | goto fail_close; | |
f254e52c | 345 | } |
e4404d6e | 346 | #if 0 |
58176a96 JB |
347 | /* this does the super kobj at the same time */ |
348 | err = btrfs_sysfs_add_super(tree_root->fs_info); | |
349 | if (err) | |
350 | goto fail_close; | |
e4404d6e | 351 | #endif |
58176a96 | 352 | |
39279cc3 | 353 | sb->s_root = root_dentry; |
6885f308 | 354 | |
6885f308 | 355 | save_mount_options(sb, data); |
2619ba1f | 356 | return 0; |
39279cc3 CM |
357 | |
358 | fail_close: | |
359 | close_ctree(tree_root); | |
360 | return err; | |
2619ba1f CM |
361 | } |
362 | ||
6bf13c0c | 363 | int btrfs_sync_fs(struct super_block *sb, int wait) |
c5739bba CM |
364 | { |
365 | struct btrfs_trans_handle *trans; | |
39279cc3 | 366 | struct btrfs_root *root; |
c5739bba | 367 | int ret; |
39279cc3 | 368 | root = btrfs_sb(sb); |
2619ba1f | 369 | |
c146afad YZ |
370 | if (sb->s_flags & MS_RDONLY) |
371 | return 0; | |
372 | ||
39279cc3 CM |
373 | sb->s_dirt = 0; |
374 | if (!wait) { | |
375 | filemap_flush(root->fs_info->btree_inode->i_mapping); | |
376 | return 0; | |
377 | } | |
771ed689 CM |
378 | |
379 | btrfs_start_delalloc_inodes(root); | |
380 | btrfs_wait_ordered_extents(root, 0); | |
381 | ||
c5739bba | 382 | trans = btrfs_start_transaction(root, 1); |
c5739bba | 383 | ret = btrfs_commit_transaction(trans, root); |
39279cc3 | 384 | sb->s_dirt = 0; |
54aa1f4d | 385 | return ret; |
2c90e5d6 CM |
386 | } |
387 | ||
39279cc3 | 388 | static void btrfs_write_super(struct super_block *sb) |
2c90e5d6 | 389 | { |
39279cc3 | 390 | sb->s_dirt = 0; |
2c90e5d6 CM |
391 | } |
392 | ||
a061fc8d | 393 | static int btrfs_test_super(struct super_block *s, void *data) |
4b82d6e4 | 394 | { |
a061fc8d CM |
395 | struct btrfs_fs_devices *test_fs_devices = data; |
396 | struct btrfs_root *root = btrfs_sb(s); | |
4b82d6e4 | 397 | |
a061fc8d | 398 | return root->fs_info->fs_devices == test_fs_devices; |
4b82d6e4 Y |
399 | } |
400 | ||
edf24abe CH |
401 | /* |
402 | * Find a superblock for the given device / mount point. | |
403 | * | |
404 | * Note: This is based on get_sb_bdev from fs/super.c with a few additions | |
405 | * for multiple device setup. Make sure to keep it in sync. | |
406 | */ | |
407 | static int btrfs_get_sb(struct file_system_type *fs_type, int flags, | |
408 | const char *dev_name, void *data, struct vfsmount *mnt) | |
4b82d6e4 | 409 | { |
edf24abe | 410 | char *subvol_name = NULL; |
4b82d6e4 Y |
411 | struct block_device *bdev = NULL; |
412 | struct super_block *s; | |
413 | struct dentry *root; | |
8a4b83cc | 414 | struct btrfs_fs_devices *fs_devices = NULL; |
97288f2c | 415 | fmode_t mode = FMODE_READ; |
4b82d6e4 Y |
416 | int error = 0; |
417 | ||
97288f2c CH |
418 | if (!(flags & MS_RDONLY)) |
419 | mode |= FMODE_WRITE; | |
420 | ||
421 | error = btrfs_parse_early_options(data, mode, fs_type, | |
43e570b0 | 422 | &subvol_name, &fs_devices); |
edf24abe | 423 | if (error) |
1f483660 | 424 | return error; |
edf24abe | 425 | |
97288f2c | 426 | error = btrfs_scan_one_device(dev_name, mode, fs_type, &fs_devices); |
8a4b83cc | 427 | if (error) |
edf24abe | 428 | goto error_free_subvol_name; |
4b82d6e4 | 429 | |
97288f2c | 430 | error = btrfs_open_devices(fs_devices, mode, fs_type); |
8a4b83cc | 431 | if (error) |
edf24abe | 432 | goto error_free_subvol_name; |
8a4b83cc | 433 | |
2b82032c YZ |
434 | if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) { |
435 | error = -EACCES; | |
436 | goto error_close_devices; | |
437 | } | |
438 | ||
dfe25020 | 439 | bdev = fs_devices->latest_bdev; |
a061fc8d | 440 | s = sget(fs_type, btrfs_test_super, set_anon_super, fs_devices); |
4b82d6e4 Y |
441 | if (IS_ERR(s)) |
442 | goto error_s; | |
443 | ||
444 | if (s->s_root) { | |
445 | if ((flags ^ s->s_flags) & MS_RDONLY) { | |
446 | up_write(&s->s_umount); | |
447 | deactivate_super(s); | |
448 | error = -EBUSY; | |
c146afad | 449 | goto error_close_devices; |
4b82d6e4 Y |
450 | } |
451 | ||
2b82032c | 452 | btrfs_close_devices(fs_devices); |
4b82d6e4 Y |
453 | } else { |
454 | char b[BDEVNAME_SIZE]; | |
455 | ||
456 | s->s_flags = flags; | |
457 | strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id)); | |
8a4b83cc CM |
458 | error = btrfs_fill_super(s, fs_devices, data, |
459 | flags & MS_SILENT ? 1 : 0); | |
4b82d6e4 Y |
460 | if (error) { |
461 | up_write(&s->s_umount); | |
462 | deactivate_super(s); | |
1f483660 | 463 | goto error_free_subvol_name; |
4b82d6e4 Y |
464 | } |
465 | ||
788f20eb | 466 | btrfs_sb(s)->fs_info->bdev_holder = fs_type; |
4b82d6e4 Y |
467 | s->s_flags |= MS_ACTIVE; |
468 | } | |
469 | ||
76fcef19 DW |
470 | if (!strcmp(subvol_name, ".")) |
471 | root = dget(s->s_root); | |
472 | else { | |
473 | mutex_lock(&s->s_root->d_inode->i_mutex); | |
d397712b CM |
474 | root = lookup_one_len(subvol_name, s->s_root, |
475 | strlen(subvol_name)); | |
76fcef19 | 476 | mutex_unlock(&s->s_root->d_inode->i_mutex); |
d397712b | 477 | |
76fcef19 DW |
478 | if (IS_ERR(root)) { |
479 | up_write(&s->s_umount); | |
480 | deactivate_super(s); | |
481 | error = PTR_ERR(root); | |
1f483660 | 482 | goto error_free_subvol_name; |
76fcef19 DW |
483 | } |
484 | if (!root->d_inode) { | |
485 | dput(root); | |
486 | up_write(&s->s_umount); | |
487 | deactivate_super(s); | |
488 | error = -ENXIO; | |
1f483660 | 489 | goto error_free_subvol_name; |
76fcef19 | 490 | } |
4b82d6e4 Y |
491 | } |
492 | ||
493 | mnt->mnt_sb = s; | |
494 | mnt->mnt_root = root; | |
edf24abe CH |
495 | |
496 | kfree(subvol_name); | |
4b82d6e4 Y |
497 | return 0; |
498 | ||
499 | error_s: | |
500 | error = PTR_ERR(s); | |
c146afad | 501 | error_close_devices: |
8a4b83cc | 502 | btrfs_close_devices(fs_devices); |
edf24abe CH |
503 | error_free_subvol_name: |
504 | kfree(subvol_name); | |
4b82d6e4 Y |
505 | return error; |
506 | } | |
2e635a27 | 507 | |
c146afad YZ |
508 | static int btrfs_remount(struct super_block *sb, int *flags, char *data) |
509 | { | |
510 | struct btrfs_root *root = btrfs_sb(sb); | |
511 | int ret; | |
512 | ||
b288052e CM |
513 | ret = btrfs_parse_options(root, data); |
514 | if (ret) | |
515 | return -EINVAL; | |
516 | ||
c146afad YZ |
517 | if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) |
518 | return 0; | |
519 | ||
520 | if (*flags & MS_RDONLY) { | |
521 | sb->s_flags |= MS_RDONLY; | |
522 | ||
523 | ret = btrfs_commit_super(root); | |
524 | WARN_ON(ret); | |
525 | } else { | |
2b82032c YZ |
526 | if (root->fs_info->fs_devices->rw_devices == 0) |
527 | return -EACCES; | |
528 | ||
c146afad YZ |
529 | if (btrfs_super_log_root(&root->fs_info->super_copy) != 0) |
530 | return -EINVAL; | |
531 | ||
532 | ret = btrfs_cleanup_reloc_trees(root); | |
533 | WARN_ON(ret); | |
534 | ||
535 | ret = btrfs_cleanup_fs_roots(root->fs_info); | |
536 | WARN_ON(ret); | |
537 | ||
538 | sb->s_flags &= ~MS_RDONLY; | |
539 | } | |
540 | ||
541 | return 0; | |
542 | } | |
543 | ||
8fd17795 CM |
544 | static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) |
545 | { | |
546 | struct btrfs_root *root = btrfs_sb(dentry->d_sb); | |
4b52dff6 | 547 | struct btrfs_super_block *disk_super = &root->fs_info->super_copy; |
db94535d | 548 | int bits = dentry->d_sb->s_blocksize_bits; |
9d03632e | 549 | __be32 *fsid = (__be32 *)root->fs_info->fsid; |
8fd17795 CM |
550 | |
551 | buf->f_namelen = BTRFS_NAME_LEN; | |
db94535d CM |
552 | buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits; |
553 | buf->f_bfree = buf->f_blocks - | |
554 | (btrfs_super_bytes_used(disk_super) >> bits); | |
8fd17795 CM |
555 | buf->f_bavail = buf->f_bfree; |
556 | buf->f_bsize = dentry->d_sb->s_blocksize; | |
557 | buf->f_type = BTRFS_SUPER_MAGIC; | |
d397712b | 558 | |
9d03632e | 559 | /* We treat it as constant endianness (it doesn't matter _which_) |
d397712b | 560 | because we want the fsid to come out the same whether mounted |
9d03632e DW |
561 | on a big-endian or little-endian host */ |
562 | buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]); | |
563 | buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]); | |
32d48fa1 DW |
564 | /* Mask in the root object ID too, to disambiguate subvols */ |
565 | buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32; | |
566 | buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid; | |
567 | ||
8fd17795 CM |
568 | return 0; |
569 | } | |
b5133862 | 570 | |
2e635a27 CM |
571 | static struct file_system_type btrfs_fs_type = { |
572 | .owner = THIS_MODULE, | |
573 | .name = "btrfs", | |
574 | .get_sb = btrfs_get_sb, | |
a061fc8d | 575 | .kill_sb = kill_anon_super, |
2e635a27 CM |
576 | .fs_flags = FS_REQUIRES_DEV, |
577 | }; | |
a9218f6b | 578 | |
d352ac68 CM |
579 | /* |
580 | * used by btrfsctl to scan devices when no FS is mounted | |
581 | */ | |
8a4b83cc CM |
582 | static long btrfs_control_ioctl(struct file *file, unsigned int cmd, |
583 | unsigned long arg) | |
584 | { | |
585 | struct btrfs_ioctl_vol_args *vol; | |
586 | struct btrfs_fs_devices *fs_devices; | |
c071fcfd | 587 | int ret = -ENOTTY; |
8a4b83cc | 588 | |
e441d54d CM |
589 | if (!capable(CAP_SYS_ADMIN)) |
590 | return -EPERM; | |
591 | ||
8a4b83cc | 592 | vol = kmalloc(sizeof(*vol), GFP_KERNEL); |
19d00cc1 WC |
593 | if (!vol) |
594 | return -ENOMEM; | |
595 | ||
8a4b83cc CM |
596 | if (copy_from_user(vol, (void __user *)arg, sizeof(*vol))) { |
597 | ret = -EFAULT; | |
598 | goto out; | |
599 | } | |
c071fcfd | 600 | |
8a4b83cc CM |
601 | switch (cmd) { |
602 | case BTRFS_IOC_SCAN_DEV: | |
97288f2c | 603 | ret = btrfs_scan_one_device(vol->name, FMODE_READ, |
8a4b83cc CM |
604 | &btrfs_fs_type, &fs_devices); |
605 | break; | |
606 | } | |
607 | out: | |
608 | kfree(vol); | |
f819d837 | 609 | return ret; |
8a4b83cc CM |
610 | } |
611 | ||
0176260f | 612 | static int btrfs_freeze(struct super_block *sb) |
ed0dab6b Y |
613 | { |
614 | struct btrfs_root *root = btrfs_sb(sb); | |
a74a4b97 CM |
615 | mutex_lock(&root->fs_info->transaction_kthread_mutex); |
616 | mutex_lock(&root->fs_info->cleaner_mutex); | |
0176260f | 617 | return 0; |
ed0dab6b Y |
618 | } |
619 | ||
0176260f | 620 | static int btrfs_unfreeze(struct super_block *sb) |
ed0dab6b Y |
621 | { |
622 | struct btrfs_root *root = btrfs_sb(sb); | |
a74a4b97 CM |
623 | mutex_unlock(&root->fs_info->cleaner_mutex); |
624 | mutex_unlock(&root->fs_info->transaction_kthread_mutex); | |
0176260f | 625 | return 0; |
ed0dab6b | 626 | } |
2e635a27 | 627 | |
e20d96d6 | 628 | static struct super_operations btrfs_super_ops = { |
134e9731 | 629 | .delete_inode = btrfs_delete_inode, |
e20d96d6 | 630 | .put_super = btrfs_put_super, |
d5719762 CM |
631 | .write_super = btrfs_write_super, |
632 | .sync_fs = btrfs_sync_fs, | |
6885f308 | 633 | .show_options = generic_show_options, |
4730a4bc | 634 | .write_inode = btrfs_write_inode, |
b5133862 | 635 | .dirty_inode = btrfs_dirty_inode, |
2c90e5d6 CM |
636 | .alloc_inode = btrfs_alloc_inode, |
637 | .destroy_inode = btrfs_destroy_inode, | |
8fd17795 | 638 | .statfs = btrfs_statfs, |
c146afad | 639 | .remount_fs = btrfs_remount, |
0176260f LT |
640 | .freeze_fs = btrfs_freeze, |
641 | .unfreeze_fs = btrfs_unfreeze, | |
e20d96d6 | 642 | }; |
a9218f6b CM |
643 | |
644 | static const struct file_operations btrfs_ctl_fops = { | |
645 | .unlocked_ioctl = btrfs_control_ioctl, | |
646 | .compat_ioctl = btrfs_control_ioctl, | |
647 | .owner = THIS_MODULE, | |
648 | }; | |
649 | ||
650 | static struct miscdevice btrfs_misc = { | |
651 | .minor = MISC_DYNAMIC_MINOR, | |
652 | .name = "btrfs-control", | |
653 | .fops = &btrfs_ctl_fops | |
654 | }; | |
655 | ||
656 | static int btrfs_interface_init(void) | |
657 | { | |
658 | return misc_register(&btrfs_misc); | |
659 | } | |
660 | ||
b2950863 | 661 | static void btrfs_interface_exit(void) |
a9218f6b CM |
662 | { |
663 | if (misc_deregister(&btrfs_misc) < 0) | |
d397712b | 664 | printk(KERN_INFO "misc_deregister failed for control device"); |
a9218f6b CM |
665 | } |
666 | ||
2e635a27 CM |
667 | static int __init init_btrfs_fs(void) |
668 | { | |
2c90e5d6 | 669 | int err; |
58176a96 JB |
670 | |
671 | err = btrfs_init_sysfs(); | |
672 | if (err) | |
673 | return err; | |
674 | ||
39279cc3 | 675 | err = btrfs_init_cachep(); |
2c90e5d6 | 676 | if (err) |
a74a4b97 | 677 | goto free_sysfs; |
d1310b2e CM |
678 | |
679 | err = extent_io_init(); | |
2f4cbe64 WB |
680 | if (err) |
681 | goto free_cachep; | |
682 | ||
d1310b2e CM |
683 | err = extent_map_init(); |
684 | if (err) | |
685 | goto free_extent_io; | |
686 | ||
a9218f6b | 687 | err = btrfs_interface_init(); |
2f4cbe64 WB |
688 | if (err) |
689 | goto free_extent_map; | |
c8b97818 | 690 | |
a9218f6b CM |
691 | err = register_filesystem(&btrfs_fs_type); |
692 | if (err) | |
693 | goto unregister_ioctl; | |
b3c3da71 CM |
694 | |
695 | printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION); | |
2f4cbe64 WB |
696 | return 0; |
697 | ||
a9218f6b CM |
698 | unregister_ioctl: |
699 | btrfs_interface_exit(); | |
2f4cbe64 WB |
700 | free_extent_map: |
701 | extent_map_exit(); | |
d1310b2e CM |
702 | free_extent_io: |
703 | extent_io_exit(); | |
2f4cbe64 WB |
704 | free_cachep: |
705 | btrfs_destroy_cachep(); | |
a74a4b97 | 706 | free_sysfs: |
2f4cbe64 WB |
707 | btrfs_exit_sysfs(); |
708 | return err; | |
2e635a27 CM |
709 | } |
710 | ||
711 | static void __exit exit_btrfs_fs(void) | |
712 | { | |
39279cc3 | 713 | btrfs_destroy_cachep(); |
a52d9a80 | 714 | extent_map_exit(); |
d1310b2e | 715 | extent_io_exit(); |
a9218f6b | 716 | btrfs_interface_exit(); |
2e635a27 | 717 | unregister_filesystem(&btrfs_fs_type); |
58176a96 | 718 | btrfs_exit_sysfs(); |
8a4b83cc | 719 | btrfs_cleanup_fs_uuids(); |
c8b97818 | 720 | btrfs_zlib_exit(); |
2e635a27 CM |
721 | } |
722 | ||
723 | module_init(init_btrfs_fs) | |
724 | module_exit(exit_btrfs_fs) | |
725 | ||
726 | MODULE_LICENSE("GPL"); |