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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> | |
a9572a15 | 27 | #include <linux/seq_file.h> |
2e635a27 | 28 | #include <linux/string.h> |
2e635a27 | 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> |
5a0e3ad6 | 41 | #include <linux/slab.h> |
90a887c9 | 42 | #include <linux/cleancache.h> |
830c4adb | 43 | #include <linux/mnt_namespace.h> |
4b4e25f2 | 44 | #include "compat.h" |
16cdcec7 | 45 | #include "delayed-inode.h" |
2e635a27 | 46 | #include "ctree.h" |
e20d96d6 | 47 | #include "disk-io.h" |
d5719762 | 48 | #include "transaction.h" |
2c90e5d6 | 49 | #include "btrfs_inode.h" |
c5739bba | 50 | #include "ioctl.h" |
3a686375 | 51 | #include "print-tree.h" |
5103e947 | 52 | #include "xattr.h" |
8a4b83cc | 53 | #include "volumes.h" |
b3c3da71 | 54 | #include "version.h" |
be6e8dc0 | 55 | #include "export.h" |
c8b97818 | 56 | #include "compression.h" |
2e635a27 | 57 | |
1abe9b8a | 58 | #define CREATE_TRACE_POINTS |
59 | #include <trace/events/btrfs.h> | |
60 | ||
b87221de | 61 | static const struct super_operations btrfs_super_ops; |
830c4adb | 62 | static struct file_system_type btrfs_fs_type; |
75dfe396 | 63 | |
acce952b | 64 | static const char *btrfs_decode_error(struct btrfs_fs_info *fs_info, int errno, |
65 | char nbuf[16]) | |
66 | { | |
67 | char *errstr = NULL; | |
68 | ||
69 | switch (errno) { | |
70 | case -EIO: | |
71 | errstr = "IO failure"; | |
72 | break; | |
73 | case -ENOMEM: | |
74 | errstr = "Out of memory"; | |
75 | break; | |
76 | case -EROFS: | |
77 | errstr = "Readonly filesystem"; | |
78 | break; | |
79 | default: | |
80 | if (nbuf) { | |
81 | if (snprintf(nbuf, 16, "error %d", -errno) >= 0) | |
82 | errstr = nbuf; | |
83 | } | |
84 | break; | |
85 | } | |
86 | ||
87 | return errstr; | |
88 | } | |
89 | ||
90 | static void __save_error_info(struct btrfs_fs_info *fs_info) | |
91 | { | |
92 | /* | |
93 | * today we only save the error info into ram. Long term we'll | |
94 | * also send it down to the disk | |
95 | */ | |
96 | fs_info->fs_state = BTRFS_SUPER_FLAG_ERROR; | |
97 | } | |
98 | ||
99 | /* NOTE: | |
100 | * We move write_super stuff at umount in order to avoid deadlock | |
101 | * for umount hold all lock. | |
102 | */ | |
103 | static void save_error_info(struct btrfs_fs_info *fs_info) | |
104 | { | |
105 | __save_error_info(fs_info); | |
106 | } | |
107 | ||
108 | /* btrfs handle error by forcing the filesystem readonly */ | |
109 | static void btrfs_handle_error(struct btrfs_fs_info *fs_info) | |
110 | { | |
111 | struct super_block *sb = fs_info->sb; | |
112 | ||
113 | if (sb->s_flags & MS_RDONLY) | |
114 | return; | |
115 | ||
116 | if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) { | |
117 | sb->s_flags |= MS_RDONLY; | |
118 | printk(KERN_INFO "btrfs is forced readonly\n"); | |
119 | } | |
120 | } | |
121 | ||
122 | /* | |
123 | * __btrfs_std_error decodes expected errors from the caller and | |
124 | * invokes the approciate error response. | |
125 | */ | |
126 | void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function, | |
127 | unsigned int line, int errno) | |
128 | { | |
129 | struct super_block *sb = fs_info->sb; | |
130 | char nbuf[16]; | |
131 | const char *errstr; | |
132 | ||
133 | /* | |
134 | * Special case: if the error is EROFS, and we're already | |
135 | * under MS_RDONLY, then it is safe here. | |
136 | */ | |
137 | if (errno == -EROFS && (sb->s_flags & MS_RDONLY)) | |
138 | return; | |
139 | ||
140 | errstr = btrfs_decode_error(fs_info, errno, nbuf); | |
141 | printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: %s\n", | |
142 | sb->s_id, function, line, errstr); | |
143 | save_error_info(fs_info); | |
144 | ||
145 | btrfs_handle_error(fs_info); | |
146 | } | |
147 | ||
d397712b | 148 | static void btrfs_put_super(struct super_block *sb) |
b18c6685 | 149 | { |
39279cc3 | 150 | struct btrfs_root *root = btrfs_sb(sb); |
b18c6685 | 151 | int ret; |
b18c6685 | 152 | |
39279cc3 | 153 | ret = close_ctree(root); |
39279cc3 | 154 | sb->s_fs_info = NULL; |
559af821 AK |
155 | |
156 | (void)ret; /* FIXME: need to fix VFS to return error? */ | |
75dfe396 CM |
157 | } |
158 | ||
95e05289 | 159 | enum { |
73f73415 | 160 | Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum, |
287a0ab9 JB |
161 | Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd, |
162 | Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress, | |
261507a0 LZ |
163 | Opt_compress_type, Opt_compress_force, Opt_compress_force_type, |
164 | Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard, | |
91435650 | 165 | Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed, |
4b9465cb | 166 | Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, |
af31f5e5 | 167 | Opt_inode_cache, Opt_no_space_cache, Opt_recovery, Opt_err, |
95e05289 CM |
168 | }; |
169 | ||
170 | static match_table_t tokens = { | |
dfe25020 | 171 | {Opt_degraded, "degraded"}, |
95e05289 | 172 | {Opt_subvol, "subvol=%s"}, |
73f73415 | 173 | {Opt_subvolid, "subvolid=%d"}, |
43e570b0 | 174 | {Opt_device, "device=%s"}, |
b6cda9bc | 175 | {Opt_nodatasum, "nodatasum"}, |
be20aa9d | 176 | {Opt_nodatacow, "nodatacow"}, |
21ad10cf | 177 | {Opt_nobarrier, "nobarrier"}, |
6f568d35 | 178 | {Opt_max_inline, "max_inline=%s"}, |
8f662a76 | 179 | {Opt_alloc_start, "alloc_start=%s"}, |
4543df7e | 180 | {Opt_thread_pool, "thread_pool=%d"}, |
c8b97818 | 181 | {Opt_compress, "compress"}, |
261507a0 | 182 | {Opt_compress_type, "compress=%s"}, |
a555f810 | 183 | {Opt_compress_force, "compress-force"}, |
261507a0 | 184 | {Opt_compress_force_type, "compress-force=%s"}, |
e18e4809 | 185 | {Opt_ssd, "ssd"}, |
451d7585 | 186 | {Opt_ssd_spread, "ssd_spread"}, |
3b30c22f | 187 | {Opt_nossd, "nossd"}, |
33268eaf | 188 | {Opt_noacl, "noacl"}, |
3a5e1404 | 189 | {Opt_notreelog, "notreelog"}, |
dccae999 | 190 | {Opt_flushoncommit, "flushoncommit"}, |
97e728d4 | 191 | {Opt_ratio, "metadata_ratio=%d"}, |
e244a0ae | 192 | {Opt_discard, "discard"}, |
0af3d00b | 193 | {Opt_space_cache, "space_cache"}, |
88c2ba3b | 194 | {Opt_clear_cache, "clear_cache"}, |
4260f7c7 | 195 | {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"}, |
91435650 | 196 | {Opt_enospc_debug, "enospc_debug"}, |
e15d0542 | 197 | {Opt_subvolrootid, "subvolrootid=%d"}, |
4cb5300b | 198 | {Opt_defrag, "autodefrag"}, |
4b9465cb | 199 | {Opt_inode_cache, "inode_cache"}, |
8965593e | 200 | {Opt_no_space_cache, "nospace_cache"}, |
af31f5e5 | 201 | {Opt_recovery, "recovery"}, |
33268eaf | 202 | {Opt_err, NULL}, |
95e05289 CM |
203 | }; |
204 | ||
edf24abe CH |
205 | /* |
206 | * Regular mount options parser. Everything that is needed only when | |
207 | * reading in a new superblock is parsed here. | |
208 | */ | |
209 | int btrfs_parse_options(struct btrfs_root *root, char *options) | |
95e05289 | 210 | { |
edf24abe | 211 | struct btrfs_fs_info *info = root->fs_info; |
95e05289 | 212 | substring_t args[MAX_OPT_ARGS]; |
73bc1876 JB |
213 | char *p, *num, *orig = NULL; |
214 | u64 cache_gen; | |
4543df7e | 215 | int intarg; |
a7a3f7ca | 216 | int ret = 0; |
261507a0 LZ |
217 | char *compress_type; |
218 | bool compress_force = false; | |
b6cda9bc | 219 | |
6c41761f | 220 | cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy); |
73bc1876 JB |
221 | if (cache_gen) |
222 | btrfs_set_opt(info->mount_opt, SPACE_CACHE); | |
223 | ||
95e05289 | 224 | if (!options) |
73bc1876 | 225 | goto out; |
95e05289 | 226 | |
be20aa9d CM |
227 | /* |
228 | * strsep changes the string, duplicate it because parse_options | |
229 | * gets called twice | |
230 | */ | |
231 | options = kstrdup(options, GFP_NOFS); | |
232 | if (!options) | |
233 | return -ENOMEM; | |
234 | ||
da495ecc | 235 | orig = options; |
be20aa9d | 236 | |
edf24abe | 237 | while ((p = strsep(&options, ",")) != NULL) { |
95e05289 CM |
238 | int token; |
239 | if (!*p) | |
240 | continue; | |
241 | ||
242 | token = match_token(p, tokens, args); | |
243 | switch (token) { | |
dfe25020 | 244 | case Opt_degraded: |
edf24abe CH |
245 | printk(KERN_INFO "btrfs: allowing degraded mounts\n"); |
246 | btrfs_set_opt(info->mount_opt, DEGRADED); | |
dfe25020 | 247 | break; |
95e05289 | 248 | case Opt_subvol: |
73f73415 | 249 | case Opt_subvolid: |
e15d0542 | 250 | case Opt_subvolrootid: |
43e570b0 | 251 | case Opt_device: |
edf24abe | 252 | /* |
43e570b0 | 253 | * These are parsed by btrfs_parse_early_options |
edf24abe CH |
254 | * and can be happily ignored here. |
255 | */ | |
b6cda9bc CM |
256 | break; |
257 | case Opt_nodatasum: | |
067c28ad | 258 | printk(KERN_INFO "btrfs: setting nodatasum\n"); |
edf24abe | 259 | btrfs_set_opt(info->mount_opt, NODATASUM); |
be20aa9d CM |
260 | break; |
261 | case Opt_nodatacow: | |
edf24abe CH |
262 | printk(KERN_INFO "btrfs: setting nodatacow\n"); |
263 | btrfs_set_opt(info->mount_opt, NODATACOW); | |
264 | btrfs_set_opt(info->mount_opt, NODATASUM); | |
95e05289 | 265 | break; |
a555f810 | 266 | case Opt_compress_force: |
261507a0 LZ |
267 | case Opt_compress_force_type: |
268 | compress_force = true; | |
269 | case Opt_compress: | |
270 | case Opt_compress_type: | |
271 | if (token == Opt_compress || | |
272 | token == Opt_compress_force || | |
273 | strcmp(args[0].from, "zlib") == 0) { | |
274 | compress_type = "zlib"; | |
275 | info->compress_type = BTRFS_COMPRESS_ZLIB; | |
a6fa6fae LZ |
276 | } else if (strcmp(args[0].from, "lzo") == 0) { |
277 | compress_type = "lzo"; | |
278 | info->compress_type = BTRFS_COMPRESS_LZO; | |
261507a0 LZ |
279 | } else { |
280 | ret = -EINVAL; | |
281 | goto out; | |
282 | } | |
283 | ||
a555f810 | 284 | btrfs_set_opt(info->mount_opt, COMPRESS); |
261507a0 LZ |
285 | if (compress_force) { |
286 | btrfs_set_opt(info->mount_opt, FORCE_COMPRESS); | |
287 | pr_info("btrfs: force %s compression\n", | |
288 | compress_type); | |
289 | } else | |
290 | pr_info("btrfs: use %s compression\n", | |
291 | compress_type); | |
a555f810 | 292 | break; |
e18e4809 | 293 | case Opt_ssd: |
edf24abe CH |
294 | printk(KERN_INFO "btrfs: use ssd allocation scheme\n"); |
295 | btrfs_set_opt(info->mount_opt, SSD); | |
e18e4809 | 296 | break; |
451d7585 CM |
297 | case Opt_ssd_spread: |
298 | printk(KERN_INFO "btrfs: use spread ssd " | |
299 | "allocation scheme\n"); | |
300 | btrfs_set_opt(info->mount_opt, SSD); | |
301 | btrfs_set_opt(info->mount_opt, SSD_SPREAD); | |
302 | break; | |
3b30c22f | 303 | case Opt_nossd: |
451d7585 CM |
304 | printk(KERN_INFO "btrfs: not using ssd allocation " |
305 | "scheme\n"); | |
c289811c | 306 | btrfs_set_opt(info->mount_opt, NOSSD); |
3b30c22f | 307 | btrfs_clear_opt(info->mount_opt, SSD); |
451d7585 | 308 | btrfs_clear_opt(info->mount_opt, SSD_SPREAD); |
3b30c22f | 309 | break; |
21ad10cf | 310 | case Opt_nobarrier: |
edf24abe CH |
311 | printk(KERN_INFO "btrfs: turning off barriers\n"); |
312 | btrfs_set_opt(info->mount_opt, NOBARRIER); | |
21ad10cf | 313 | break; |
4543df7e CM |
314 | case Opt_thread_pool: |
315 | intarg = 0; | |
316 | match_int(&args[0], &intarg); | |
317 | if (intarg) { | |
318 | info->thread_pool_size = intarg; | |
319 | printk(KERN_INFO "btrfs: thread pool %d\n", | |
320 | info->thread_pool_size); | |
321 | } | |
322 | break; | |
6f568d35 | 323 | case Opt_max_inline: |
edf24abe CH |
324 | num = match_strdup(&args[0]); |
325 | if (num) { | |
91748467 | 326 | info->max_inline = memparse(num, NULL); |
edf24abe CH |
327 | kfree(num); |
328 | ||
15ada040 CM |
329 | if (info->max_inline) { |
330 | info->max_inline = max_t(u64, | |
331 | info->max_inline, | |
332 | root->sectorsize); | |
333 | } | |
edf24abe | 334 | printk(KERN_INFO "btrfs: max_inline at %llu\n", |
21380931 | 335 | (unsigned long long)info->max_inline); |
6f568d35 CM |
336 | } |
337 | break; | |
8f662a76 | 338 | case Opt_alloc_start: |
edf24abe CH |
339 | num = match_strdup(&args[0]); |
340 | if (num) { | |
91748467 | 341 | info->alloc_start = memparse(num, NULL); |
edf24abe CH |
342 | kfree(num); |
343 | printk(KERN_INFO | |
344 | "btrfs: allocations start at %llu\n", | |
21380931 | 345 | (unsigned long long)info->alloc_start); |
8f662a76 CM |
346 | } |
347 | break; | |
33268eaf JB |
348 | case Opt_noacl: |
349 | root->fs_info->sb->s_flags &= ~MS_POSIXACL; | |
350 | break; | |
3a5e1404 SW |
351 | case Opt_notreelog: |
352 | printk(KERN_INFO "btrfs: disabling tree log\n"); | |
353 | btrfs_set_opt(info->mount_opt, NOTREELOG); | |
354 | break; | |
dccae999 SW |
355 | case Opt_flushoncommit: |
356 | printk(KERN_INFO "btrfs: turning on flush-on-commit\n"); | |
357 | btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT); | |
358 | break; | |
97e728d4 JB |
359 | case Opt_ratio: |
360 | intarg = 0; | |
361 | match_int(&args[0], &intarg); | |
362 | if (intarg) { | |
363 | info->metadata_ratio = intarg; | |
364 | printk(KERN_INFO "btrfs: metadata ratio %d\n", | |
365 | info->metadata_ratio); | |
366 | } | |
367 | break; | |
e244a0ae CH |
368 | case Opt_discard: |
369 | btrfs_set_opt(info->mount_opt, DISCARD); | |
370 | break; | |
0af3d00b | 371 | case Opt_space_cache: |
0af3d00b | 372 | btrfs_set_opt(info->mount_opt, SPACE_CACHE); |
0de90876 | 373 | break; |
73bc1876 JB |
374 | case Opt_no_space_cache: |
375 | printk(KERN_INFO "btrfs: disabling disk space caching\n"); | |
376 | btrfs_clear_opt(info->mount_opt, SPACE_CACHE); | |
377 | break; | |
4b9465cb CM |
378 | case Opt_inode_cache: |
379 | printk(KERN_INFO "btrfs: enabling inode map caching\n"); | |
380 | btrfs_set_opt(info->mount_opt, INODE_MAP_CACHE); | |
381 | break; | |
88c2ba3b JB |
382 | case Opt_clear_cache: |
383 | printk(KERN_INFO "btrfs: force clearing of disk cache\n"); | |
384 | btrfs_set_opt(info->mount_opt, CLEAR_CACHE); | |
0af3d00b | 385 | break; |
4260f7c7 SW |
386 | case Opt_user_subvol_rm_allowed: |
387 | btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED); | |
388 | break; | |
91435650 CM |
389 | case Opt_enospc_debug: |
390 | btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG); | |
391 | break; | |
4cb5300b CM |
392 | case Opt_defrag: |
393 | printk(KERN_INFO "btrfs: enabling auto defrag"); | |
394 | btrfs_set_opt(info->mount_opt, AUTO_DEFRAG); | |
395 | break; | |
af31f5e5 CM |
396 | case Opt_recovery: |
397 | printk(KERN_INFO "btrfs: enabling auto recovery"); | |
398 | btrfs_set_opt(info->mount_opt, RECOVERY); | |
399 | break; | |
a7a3f7ca SW |
400 | case Opt_err: |
401 | printk(KERN_INFO "btrfs: unrecognized mount option " | |
402 | "'%s'\n", p); | |
403 | ret = -EINVAL; | |
404 | goto out; | |
95e05289 | 405 | default: |
be20aa9d | 406 | break; |
95e05289 CM |
407 | } |
408 | } | |
a7a3f7ca | 409 | out: |
73bc1876 JB |
410 | if (!ret && btrfs_test_opt(root, SPACE_CACHE)) |
411 | printk(KERN_INFO "btrfs: disk space caching is enabled\n"); | |
da495ecc | 412 | kfree(orig); |
a7a3f7ca | 413 | return ret; |
edf24abe CH |
414 | } |
415 | ||
416 | /* | |
417 | * Parse mount options that are required early in the mount process. | |
418 | * | |
419 | * All other options will be parsed on much later in the mount process and | |
420 | * only when we need to allocate a new super block. | |
421 | */ | |
97288f2c | 422 | static int btrfs_parse_early_options(const char *options, fmode_t flags, |
73f73415 | 423 | void *holder, char **subvol_name, u64 *subvol_objectid, |
e15d0542 | 424 | u64 *subvol_rootid, struct btrfs_fs_devices **fs_devices) |
edf24abe CH |
425 | { |
426 | substring_t args[MAX_OPT_ARGS]; | |
83c8c9bd | 427 | char *device_name, *opts, *orig, *p; |
edf24abe | 428 | int error = 0; |
73f73415 | 429 | int intarg; |
edf24abe CH |
430 | |
431 | if (!options) | |
830c4adb | 432 | return 0; |
edf24abe CH |
433 | |
434 | /* | |
435 | * strsep changes the string, duplicate it because parse_options | |
436 | * gets called twice | |
437 | */ | |
438 | opts = kstrdup(options, GFP_KERNEL); | |
439 | if (!opts) | |
440 | return -ENOMEM; | |
3f3d0bc0 | 441 | orig = opts; |
edf24abe CH |
442 | |
443 | while ((p = strsep(&opts, ",")) != NULL) { | |
444 | int token; | |
445 | if (!*p) | |
446 | continue; | |
447 | ||
448 | token = match_token(p, tokens, args); | |
449 | switch (token) { | |
450 | case Opt_subvol: | |
a90e8b6f | 451 | kfree(*subvol_name); |
edf24abe CH |
452 | *subvol_name = match_strdup(&args[0]); |
453 | break; | |
73f73415 JB |
454 | case Opt_subvolid: |
455 | intarg = 0; | |
4849f01d JB |
456 | error = match_int(&args[0], &intarg); |
457 | if (!error) { | |
458 | /* we want the original fs_tree */ | |
459 | if (!intarg) | |
460 | *subvol_objectid = | |
461 | BTRFS_FS_TREE_OBJECTID; | |
462 | else | |
463 | *subvol_objectid = intarg; | |
464 | } | |
73f73415 | 465 | break; |
e15d0542 XZ |
466 | case Opt_subvolrootid: |
467 | intarg = 0; | |
468 | error = match_int(&args[0], &intarg); | |
469 | if (!error) { | |
470 | /* we want the original fs_tree */ | |
471 | if (!intarg) | |
472 | *subvol_rootid = | |
473 | BTRFS_FS_TREE_OBJECTID; | |
474 | else | |
475 | *subvol_rootid = intarg; | |
476 | } | |
477 | break; | |
43e570b0 | 478 | case Opt_device: |
83c8c9bd JL |
479 | device_name = match_strdup(&args[0]); |
480 | if (!device_name) { | |
481 | error = -ENOMEM; | |
482 | goto out; | |
483 | } | |
484 | error = btrfs_scan_one_device(device_name, | |
43e570b0 | 485 | flags, holder, fs_devices); |
83c8c9bd | 486 | kfree(device_name); |
43e570b0 | 487 | if (error) |
830c4adb | 488 | goto out; |
43e570b0 | 489 | break; |
edf24abe CH |
490 | default: |
491 | break; | |
492 | } | |
493 | } | |
494 | ||
830c4adb | 495 | out: |
3f3d0bc0 | 496 | kfree(orig); |
edf24abe | 497 | return error; |
95e05289 CM |
498 | } |
499 | ||
73f73415 JB |
500 | static struct dentry *get_default_root(struct super_block *sb, |
501 | u64 subvol_objectid) | |
502 | { | |
503 | struct btrfs_root *root = sb->s_fs_info; | |
504 | struct btrfs_root *new_root; | |
505 | struct btrfs_dir_item *di; | |
506 | struct btrfs_path *path; | |
507 | struct btrfs_key location; | |
508 | struct inode *inode; | |
73f73415 JB |
509 | u64 dir_id; |
510 | int new = 0; | |
511 | ||
512 | /* | |
513 | * We have a specific subvol we want to mount, just setup location and | |
514 | * go look up the root. | |
515 | */ | |
516 | if (subvol_objectid) { | |
517 | location.objectid = subvol_objectid; | |
518 | location.type = BTRFS_ROOT_ITEM_KEY; | |
519 | location.offset = (u64)-1; | |
520 | goto find_root; | |
521 | } | |
522 | ||
523 | path = btrfs_alloc_path(); | |
524 | if (!path) | |
525 | return ERR_PTR(-ENOMEM); | |
526 | path->leave_spinning = 1; | |
527 | ||
528 | /* | |
529 | * Find the "default" dir item which points to the root item that we | |
530 | * will mount by default if we haven't been given a specific subvolume | |
531 | * to mount. | |
532 | */ | |
6c41761f | 533 | dir_id = btrfs_super_root_dir(root->fs_info->super_copy); |
73f73415 | 534 | di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0); |
b0839166 JL |
535 | if (IS_ERR(di)) { |
536 | btrfs_free_path(path); | |
fb4f6f91 | 537 | return ERR_CAST(di); |
b0839166 | 538 | } |
73f73415 JB |
539 | if (!di) { |
540 | /* | |
541 | * Ok the default dir item isn't there. This is weird since | |
542 | * it's always been there, but don't freak out, just try and | |
543 | * mount to root most subvolume. | |
544 | */ | |
545 | btrfs_free_path(path); | |
546 | dir_id = BTRFS_FIRST_FREE_OBJECTID; | |
547 | new_root = root->fs_info->fs_root; | |
548 | goto setup_root; | |
549 | } | |
550 | ||
551 | btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location); | |
552 | btrfs_free_path(path); | |
553 | ||
554 | find_root: | |
555 | new_root = btrfs_read_fs_root_no_name(root->fs_info, &location); | |
556 | if (IS_ERR(new_root)) | |
d0b678cb | 557 | return ERR_CAST(new_root); |
73f73415 JB |
558 | |
559 | if (btrfs_root_refs(&new_root->root_item) == 0) | |
560 | return ERR_PTR(-ENOENT); | |
561 | ||
562 | dir_id = btrfs_root_dirid(&new_root->root_item); | |
563 | setup_root: | |
564 | location.objectid = dir_id; | |
565 | location.type = BTRFS_INODE_ITEM_KEY; | |
566 | location.offset = 0; | |
567 | ||
568 | inode = btrfs_iget(sb, &location, new_root, &new); | |
4cbd1149 DC |
569 | if (IS_ERR(inode)) |
570 | return ERR_CAST(inode); | |
73f73415 JB |
571 | |
572 | /* | |
573 | * If we're just mounting the root most subvol put the inode and return | |
574 | * a reference to the dentry. We will have already gotten a reference | |
575 | * to the inode in btrfs_fill_super so we're good to go. | |
576 | */ | |
577 | if (!new && sb->s_root->d_inode == inode) { | |
578 | iput(inode); | |
579 | return dget(sb->s_root); | |
580 | } | |
581 | ||
ba5b8958 | 582 | return d_obtain_alias(inode); |
73f73415 JB |
583 | } |
584 | ||
d397712b | 585 | static int btrfs_fill_super(struct super_block *sb, |
8a4b83cc | 586 | struct btrfs_fs_devices *fs_devices, |
d397712b | 587 | void *data, int silent) |
75dfe396 | 588 | { |
d397712b CM |
589 | struct inode *inode; |
590 | struct dentry *root_dentry; | |
39279cc3 | 591 | struct btrfs_root *tree_root; |
5d4f98a2 | 592 | struct btrfs_key key; |
39279cc3 | 593 | int err; |
a429e513 | 594 | |
39279cc3 CM |
595 | sb->s_maxbytes = MAX_LFS_FILESIZE; |
596 | sb->s_magic = BTRFS_SUPER_MAGIC; | |
597 | sb->s_op = &btrfs_super_ops; | |
af53d29a | 598 | sb->s_d_op = &btrfs_dentry_operations; |
be6e8dc0 | 599 | sb->s_export_op = &btrfs_export_ops; |
5103e947 | 600 | sb->s_xattr = btrfs_xattr_handlers; |
39279cc3 | 601 | sb->s_time_gran = 1; |
0eda294d | 602 | #ifdef CONFIG_BTRFS_FS_POSIX_ACL |
33268eaf | 603 | sb->s_flags |= MS_POSIXACL; |
49cf6f45 | 604 | #endif |
a429e513 | 605 | |
dfe25020 | 606 | tree_root = open_ctree(sb, fs_devices, (char *)data); |
6567e837 | 607 | |
e58ca020 | 608 | if (IS_ERR(tree_root)) { |
39279cc3 | 609 | printk("btrfs: open_ctree failed\n"); |
e58ca020 | 610 | return PTR_ERR(tree_root); |
a429e513 | 611 | } |
39279cc3 | 612 | sb->s_fs_info = tree_root; |
a429e513 | 613 | |
5d4f98a2 YZ |
614 | key.objectid = BTRFS_FIRST_FREE_OBJECTID; |
615 | key.type = BTRFS_INODE_ITEM_KEY; | |
616 | key.offset = 0; | |
73f73415 | 617 | inode = btrfs_iget(sb, &key, tree_root->fs_info->fs_root, NULL); |
5d4f98a2 YZ |
618 | if (IS_ERR(inode)) { |
619 | err = PTR_ERR(inode); | |
39279cc3 | 620 | goto fail_close; |
f254e52c | 621 | } |
f254e52c | 622 | |
39279cc3 CM |
623 | root_dentry = d_alloc_root(inode); |
624 | if (!root_dentry) { | |
625 | iput(inode); | |
626 | err = -ENOMEM; | |
627 | goto fail_close; | |
f254e52c | 628 | } |
58176a96 | 629 | |
39279cc3 | 630 | sb->s_root = root_dentry; |
6885f308 | 631 | |
6885f308 | 632 | save_mount_options(sb, data); |
90a887c9 | 633 | cleancache_init_fs(sb); |
2619ba1f | 634 | return 0; |
39279cc3 CM |
635 | |
636 | fail_close: | |
637 | close_ctree(tree_root); | |
638 | return err; | |
2619ba1f CM |
639 | } |
640 | ||
6bf13c0c | 641 | int btrfs_sync_fs(struct super_block *sb, int wait) |
c5739bba CM |
642 | { |
643 | struct btrfs_trans_handle *trans; | |
dccae999 | 644 | struct btrfs_root *root = btrfs_sb(sb); |
c5739bba | 645 | int ret; |
2619ba1f | 646 | |
1abe9b8a | 647 | trace_btrfs_sync_fs(wait); |
648 | ||
39279cc3 CM |
649 | if (!wait) { |
650 | filemap_flush(root->fs_info->btree_inode->i_mapping); | |
651 | return 0; | |
652 | } | |
771ed689 | 653 | |
24bbcf04 YZ |
654 | btrfs_start_delalloc_inodes(root, 0); |
655 | btrfs_wait_ordered_extents(root, 0, 0); | |
771ed689 | 656 | |
a22285a6 | 657 | trans = btrfs_start_transaction(root, 0); |
98d5dc13 TI |
658 | if (IS_ERR(trans)) |
659 | return PTR_ERR(trans); | |
c5739bba | 660 | ret = btrfs_commit_transaction(trans, root); |
54aa1f4d | 661 | return ret; |
2c90e5d6 CM |
662 | } |
663 | ||
a9572a15 EP |
664 | static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs) |
665 | { | |
666 | struct btrfs_root *root = btrfs_sb(vfs->mnt_sb); | |
667 | struct btrfs_fs_info *info = root->fs_info; | |
200da64e | 668 | char *compress_type; |
a9572a15 EP |
669 | |
670 | if (btrfs_test_opt(root, DEGRADED)) | |
671 | seq_puts(seq, ",degraded"); | |
672 | if (btrfs_test_opt(root, NODATASUM)) | |
673 | seq_puts(seq, ",nodatasum"); | |
674 | if (btrfs_test_opt(root, NODATACOW)) | |
675 | seq_puts(seq, ",nodatacow"); | |
676 | if (btrfs_test_opt(root, NOBARRIER)) | |
677 | seq_puts(seq, ",nobarrier"); | |
a9572a15 | 678 | if (info->max_inline != 8192 * 1024) |
21380931 JB |
679 | seq_printf(seq, ",max_inline=%llu", |
680 | (unsigned long long)info->max_inline); | |
a9572a15 | 681 | if (info->alloc_start != 0) |
21380931 JB |
682 | seq_printf(seq, ",alloc_start=%llu", |
683 | (unsigned long long)info->alloc_start); | |
a9572a15 EP |
684 | if (info->thread_pool_size != min_t(unsigned long, |
685 | num_online_cpus() + 2, 8)) | |
686 | seq_printf(seq, ",thread_pool=%d", info->thread_pool_size); | |
200da64e TI |
687 | if (btrfs_test_opt(root, COMPRESS)) { |
688 | if (info->compress_type == BTRFS_COMPRESS_ZLIB) | |
689 | compress_type = "zlib"; | |
690 | else | |
691 | compress_type = "lzo"; | |
692 | if (btrfs_test_opt(root, FORCE_COMPRESS)) | |
693 | seq_printf(seq, ",compress-force=%s", compress_type); | |
694 | else | |
695 | seq_printf(seq, ",compress=%s", compress_type); | |
696 | } | |
c289811c CM |
697 | if (btrfs_test_opt(root, NOSSD)) |
698 | seq_puts(seq, ",nossd"); | |
451d7585 CM |
699 | if (btrfs_test_opt(root, SSD_SPREAD)) |
700 | seq_puts(seq, ",ssd_spread"); | |
701 | else if (btrfs_test_opt(root, SSD)) | |
a9572a15 | 702 | seq_puts(seq, ",ssd"); |
3a5e1404 | 703 | if (btrfs_test_opt(root, NOTREELOG)) |
6b65c5c6 | 704 | seq_puts(seq, ",notreelog"); |
dccae999 | 705 | if (btrfs_test_opt(root, FLUSHONCOMMIT)) |
6b65c5c6 | 706 | seq_puts(seq, ",flushoncommit"); |
20a5239a MW |
707 | if (btrfs_test_opt(root, DISCARD)) |
708 | seq_puts(seq, ",discard"); | |
a9572a15 EP |
709 | if (!(root->fs_info->sb->s_flags & MS_POSIXACL)) |
710 | seq_puts(seq, ",noacl"); | |
200da64e TI |
711 | if (btrfs_test_opt(root, SPACE_CACHE)) |
712 | seq_puts(seq, ",space_cache"); | |
73bc1876 | 713 | else |
8965593e | 714 | seq_puts(seq, ",nospace_cache"); |
200da64e TI |
715 | if (btrfs_test_opt(root, CLEAR_CACHE)) |
716 | seq_puts(seq, ",clear_cache"); | |
717 | if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED)) | |
718 | seq_puts(seq, ",user_subvol_rm_allowed"); | |
0942caa3 DS |
719 | if (btrfs_test_opt(root, ENOSPC_DEBUG)) |
720 | seq_puts(seq, ",enospc_debug"); | |
721 | if (btrfs_test_opt(root, AUTO_DEFRAG)) | |
722 | seq_puts(seq, ",autodefrag"); | |
723 | if (btrfs_test_opt(root, INODE_MAP_CACHE)) | |
724 | seq_puts(seq, ",inode_cache"); | |
a9572a15 EP |
725 | return 0; |
726 | } | |
727 | ||
a061fc8d | 728 | static int btrfs_test_super(struct super_block *s, void *data) |
4b82d6e4 | 729 | { |
450ba0ea | 730 | struct btrfs_root *test_root = data; |
a061fc8d | 731 | struct btrfs_root *root = btrfs_sb(s); |
4b82d6e4 | 732 | |
619c8c76 IK |
733 | /* |
734 | * If this super block is going away, return false as it | |
735 | * can't match as an existing super block. | |
736 | */ | |
737 | if (!atomic_read(&s->s_active)) | |
738 | return 0; | |
450ba0ea | 739 | return root->fs_info->fs_devices == test_root->fs_info->fs_devices; |
4b82d6e4 Y |
740 | } |
741 | ||
450ba0ea JB |
742 | static int btrfs_set_super(struct super_block *s, void *data) |
743 | { | |
744 | s->s_fs_info = data; | |
745 | ||
746 | return set_anon_super(s, data); | |
4b82d6e4 Y |
747 | } |
748 | ||
f9d9ef62 DS |
749 | /* |
750 | * subvolumes are identified by ino 256 | |
751 | */ | |
752 | static inline int is_subvolume_inode(struct inode *inode) | |
753 | { | |
754 | if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) | |
755 | return 1; | |
756 | return 0; | |
757 | } | |
758 | ||
830c4adb JB |
759 | /* |
760 | * This will strip out the subvol=%s argument for an argument string and add | |
761 | * subvolid=0 to make sure we get the actual tree root for path walking to the | |
762 | * subvol we want. | |
763 | */ | |
764 | static char *setup_root_args(char *args) | |
765 | { | |
766 | unsigned copied = 0; | |
767 | unsigned len = strlen(args) + 2; | |
768 | char *pos; | |
769 | char *ret; | |
770 | ||
771 | /* | |
772 | * We need the same args as before, but minus | |
773 | * | |
774 | * subvol=a | |
775 | * | |
776 | * and add | |
777 | * | |
778 | * subvolid=0 | |
779 | * | |
780 | * which is a difference of 2 characters, so we allocate strlen(args) + | |
781 | * 2 characters. | |
782 | */ | |
783 | ret = kzalloc(len * sizeof(char), GFP_NOFS); | |
784 | if (!ret) | |
785 | return NULL; | |
786 | pos = strstr(args, "subvol="); | |
787 | ||
788 | /* This shouldn't happen, but just in case.. */ | |
789 | if (!pos) { | |
790 | kfree(ret); | |
791 | return NULL; | |
792 | } | |
793 | ||
794 | /* | |
795 | * The subvol=<> arg is not at the front of the string, copy everybody | |
796 | * up to that into ret. | |
797 | */ | |
798 | if (pos != args) { | |
799 | *pos = '\0'; | |
800 | strcpy(ret, args); | |
801 | copied += strlen(args); | |
802 | pos++; | |
803 | } | |
804 | ||
805 | strncpy(ret + copied, "subvolid=0", len - copied); | |
806 | ||
807 | /* Length of subvolid=0 */ | |
808 | copied += 10; | |
809 | ||
810 | /* | |
811 | * If there is no , after the subvol= option then we know there's no | |
812 | * other options and we can just return. | |
813 | */ | |
814 | pos = strchr(pos, ','); | |
815 | if (!pos) | |
816 | return ret; | |
817 | ||
818 | /* Copy the rest of the arguments into our buffer */ | |
819 | strncpy(ret + copied, pos, len - copied); | |
820 | copied += strlen(pos); | |
821 | ||
822 | return ret; | |
823 | } | |
824 | ||
825 | static struct dentry *mount_subvol(const char *subvol_name, int flags, | |
826 | const char *device_name, char *data) | |
827 | { | |
828 | struct super_block *s; | |
829 | struct dentry *root; | |
830 | struct vfsmount *mnt; | |
831 | struct mnt_namespace *ns_private; | |
832 | char *newargs; | |
833 | struct path path; | |
834 | int error; | |
835 | ||
836 | newargs = setup_root_args(data); | |
837 | if (!newargs) | |
838 | return ERR_PTR(-ENOMEM); | |
839 | mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name, | |
840 | newargs); | |
841 | kfree(newargs); | |
842 | if (IS_ERR(mnt)) | |
843 | return ERR_CAST(mnt); | |
844 | ||
845 | ns_private = create_mnt_ns(mnt); | |
c1334495 | 846 | if (IS_ERR(ns_private)) |
830c4adb | 847 | return ERR_CAST(ns_private); |
830c4adb JB |
848 | |
849 | /* | |
850 | * This will trigger the automount of the subvol so we can just | |
851 | * drop the mnt we have here and return the dentry that we | |
852 | * found. | |
853 | */ | |
854 | error = vfs_path_lookup(mnt->mnt_root, mnt, subvol_name, | |
855 | LOOKUP_FOLLOW, &path); | |
856 | put_mnt_ns(ns_private); | |
857 | if (error) | |
858 | return ERR_PTR(error); | |
859 | ||
f9d9ef62 DS |
860 | if (!is_subvolume_inode(path.dentry->d_inode)) { |
861 | path_put(&path); | |
f9d9ef62 DS |
862 | error = -EINVAL; |
863 | printk(KERN_ERR "btrfs: '%s' is not a valid subvolume\n", | |
864 | subvol_name); | |
865 | return ERR_PTR(-EINVAL); | |
866 | } | |
867 | ||
830c4adb JB |
868 | /* Get a ref to the sb and the dentry we found and return it */ |
869 | s = path.mnt->mnt_sb; | |
870 | atomic_inc(&s->s_active); | |
871 | root = dget(path.dentry); | |
872 | path_put(&path); | |
873 | down_write(&s->s_umount); | |
874 | ||
875 | return root; | |
876 | } | |
450ba0ea | 877 | |
edf24abe CH |
878 | /* |
879 | * Find a superblock for the given device / mount point. | |
880 | * | |
881 | * Note: This is based on get_sb_bdev from fs/super.c with a few additions | |
882 | * for multiple device setup. Make sure to keep it in sync. | |
883 | */ | |
061dbc6b | 884 | static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags, |
306e16ce | 885 | const char *device_name, void *data) |
4b82d6e4 Y |
886 | { |
887 | struct block_device *bdev = NULL; | |
888 | struct super_block *s; | |
889 | struct dentry *root; | |
8a4b83cc | 890 | struct btrfs_fs_devices *fs_devices = NULL; |
450ba0ea | 891 | struct btrfs_fs_info *fs_info = NULL; |
97288f2c | 892 | fmode_t mode = FMODE_READ; |
73f73415 JB |
893 | char *subvol_name = NULL; |
894 | u64 subvol_objectid = 0; | |
e15d0542 | 895 | u64 subvol_rootid = 0; |
4b82d6e4 Y |
896 | int error = 0; |
897 | ||
97288f2c CH |
898 | if (!(flags & MS_RDONLY)) |
899 | mode |= FMODE_WRITE; | |
900 | ||
901 | error = btrfs_parse_early_options(data, mode, fs_type, | |
73f73415 | 902 | &subvol_name, &subvol_objectid, |
e15d0542 | 903 | &subvol_rootid, &fs_devices); |
f23c8af8 ID |
904 | if (error) { |
905 | kfree(subvol_name); | |
061dbc6b | 906 | return ERR_PTR(error); |
f23c8af8 | 907 | } |
edf24abe | 908 | |
830c4adb JB |
909 | if (subvol_name) { |
910 | root = mount_subvol(subvol_name, flags, device_name, data); | |
911 | kfree(subvol_name); | |
912 | return root; | |
913 | } | |
914 | ||
306e16ce | 915 | error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices); |
8a4b83cc | 916 | if (error) |
830c4adb | 917 | return ERR_PTR(error); |
4b82d6e4 | 918 | |
450ba0ea JB |
919 | /* |
920 | * Setup a dummy root and fs_info for test/set super. This is because | |
921 | * we don't actually fill this stuff out until open_ctree, but we need | |
922 | * it for searching for existing supers, so this lets us do that and | |
923 | * then open_ctree will properly initialize everything later. | |
924 | */ | |
925 | fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS); | |
04d21a24 ID |
926 | if (!fs_info) |
927 | return ERR_PTR(-ENOMEM); | |
928 | ||
929 | fs_info->tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS); | |
930 | if (!fs_info->tree_root) { | |
450ba0ea | 931 | error = -ENOMEM; |
04d21a24 | 932 | goto error_fs_info; |
450ba0ea | 933 | } |
04d21a24 | 934 | fs_info->tree_root->fs_info = fs_info; |
450ba0ea | 935 | fs_info->fs_devices = fs_devices; |
450ba0ea | 936 | |
6c41761f DS |
937 | fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS); |
938 | fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS); | |
939 | if (!fs_info->super_copy || !fs_info->super_for_commit) { | |
940 | error = -ENOMEM; | |
04d21a24 ID |
941 | goto error_fs_info; |
942 | } | |
943 | ||
944 | error = btrfs_open_devices(fs_devices, mode, fs_type); | |
945 | if (error) | |
946 | goto error_fs_info; | |
947 | ||
948 | if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) { | |
949 | error = -EACCES; | |
6c41761f DS |
950 | goto error_close_devices; |
951 | } | |
952 | ||
dfe25020 | 953 | bdev = fs_devices->latest_bdev; |
04d21a24 ID |
954 | s = sget(fs_type, btrfs_test_super, btrfs_set_super, |
955 | fs_info->tree_root); | |
830c4adb JB |
956 | if (IS_ERR(s)) { |
957 | error = PTR_ERR(s); | |
958 | goto error_close_devices; | |
959 | } | |
4b82d6e4 Y |
960 | |
961 | if (s->s_root) { | |
962 | if ((flags ^ s->s_flags) & MS_RDONLY) { | |
6f5bbff9 | 963 | deactivate_locked_super(s); |
04d21a24 ID |
964 | error = -EBUSY; |
965 | goto error_close_devices; | |
4b82d6e4 Y |
966 | } |
967 | ||
2b82032c | 968 | btrfs_close_devices(fs_devices); |
6c41761f | 969 | free_fs_info(fs_info); |
4b82d6e4 Y |
970 | } else { |
971 | char b[BDEVNAME_SIZE]; | |
972 | ||
9e1f1de0 | 973 | s->s_flags = flags | MS_NOSEC; |
4b82d6e4 | 974 | strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id)); |
5f524444 | 975 | btrfs_sb(s)->fs_info->bdev_holder = fs_type; |
8a4b83cc CM |
976 | error = btrfs_fill_super(s, fs_devices, data, |
977 | flags & MS_SILENT ? 1 : 0); | |
4b82d6e4 | 978 | if (error) { |
6f5bbff9 | 979 | deactivate_locked_super(s); |
830c4adb | 980 | return ERR_PTR(error); |
4b82d6e4 Y |
981 | } |
982 | ||
983 | s->s_flags |= MS_ACTIVE; | |
984 | } | |
985 | ||
830c4adb JB |
986 | root = get_default_root(s, subvol_objectid); |
987 | if (IS_ERR(root)) { | |
988 | deactivate_locked_super(s); | |
989 | return root; | |
4b82d6e4 Y |
990 | } |
991 | ||
061dbc6b | 992 | return root; |
4b82d6e4 | 993 | |
c146afad | 994 | error_close_devices: |
8a4b83cc | 995 | btrfs_close_devices(fs_devices); |
04d21a24 | 996 | error_fs_info: |
6c41761f | 997 | free_fs_info(fs_info); |
061dbc6b | 998 | return ERR_PTR(error); |
4b82d6e4 | 999 | } |
2e635a27 | 1000 | |
c146afad YZ |
1001 | static int btrfs_remount(struct super_block *sb, int *flags, char *data) |
1002 | { | |
1003 | struct btrfs_root *root = btrfs_sb(sb); | |
1004 | int ret; | |
1005 | ||
b288052e CM |
1006 | ret = btrfs_parse_options(root, data); |
1007 | if (ret) | |
1008 | return -EINVAL; | |
1009 | ||
c146afad YZ |
1010 | if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) |
1011 | return 0; | |
1012 | ||
1013 | if (*flags & MS_RDONLY) { | |
1014 | sb->s_flags |= MS_RDONLY; | |
1015 | ||
1016 | ret = btrfs_commit_super(root); | |
1017 | WARN_ON(ret); | |
1018 | } else { | |
2b82032c YZ |
1019 | if (root->fs_info->fs_devices->rw_devices == 0) |
1020 | return -EACCES; | |
1021 | ||
6c41761f | 1022 | if (btrfs_super_log_root(root->fs_info->super_copy) != 0) |
c146afad YZ |
1023 | return -EINVAL; |
1024 | ||
d68fc57b | 1025 | ret = btrfs_cleanup_fs_roots(root->fs_info); |
c146afad YZ |
1026 | WARN_ON(ret); |
1027 | ||
d68fc57b YZ |
1028 | /* recover relocation */ |
1029 | ret = btrfs_recover_relocation(root); | |
c146afad YZ |
1030 | WARN_ON(ret); |
1031 | ||
1032 | sb->s_flags &= ~MS_RDONLY; | |
1033 | } | |
1034 | ||
1035 | return 0; | |
1036 | } | |
1037 | ||
bcd53741 AJ |
1038 | /* Used to sort the devices by max_avail(descending sort) */ |
1039 | static int btrfs_cmp_device_free_bytes(const void *dev_info1, | |
1040 | const void *dev_info2) | |
1041 | { | |
1042 | if (((struct btrfs_device_info *)dev_info1)->max_avail > | |
1043 | ((struct btrfs_device_info *)dev_info2)->max_avail) | |
1044 | return -1; | |
1045 | else if (((struct btrfs_device_info *)dev_info1)->max_avail < | |
1046 | ((struct btrfs_device_info *)dev_info2)->max_avail) | |
1047 | return 1; | |
1048 | else | |
1049 | return 0; | |
1050 | } | |
1051 | ||
1052 | /* | |
1053 | * sort the devices by max_avail, in which max free extent size of each device | |
1054 | * is stored.(Descending Sort) | |
1055 | */ | |
1056 | static inline void btrfs_descending_sort_devices( | |
1057 | struct btrfs_device_info *devices, | |
1058 | size_t nr_devices) | |
1059 | { | |
1060 | sort(devices, nr_devices, sizeof(struct btrfs_device_info), | |
1061 | btrfs_cmp_device_free_bytes, NULL); | |
1062 | } | |
1063 | ||
6d07bcec MX |
1064 | /* |
1065 | * The helper to calc the free space on the devices that can be used to store | |
1066 | * file data. | |
1067 | */ | |
1068 | static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes) | |
1069 | { | |
1070 | struct btrfs_fs_info *fs_info = root->fs_info; | |
1071 | struct btrfs_device_info *devices_info; | |
1072 | struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; | |
1073 | struct btrfs_device *device; | |
1074 | u64 skip_space; | |
1075 | u64 type; | |
1076 | u64 avail_space; | |
1077 | u64 used_space; | |
1078 | u64 min_stripe_size; | |
1079 | int min_stripes = 1; | |
1080 | int i = 0, nr_devices; | |
1081 | int ret; | |
1082 | ||
1083 | nr_devices = fs_info->fs_devices->rw_devices; | |
1084 | BUG_ON(!nr_devices); | |
1085 | ||
1086 | devices_info = kmalloc(sizeof(*devices_info) * nr_devices, | |
1087 | GFP_NOFS); | |
1088 | if (!devices_info) | |
1089 | return -ENOMEM; | |
1090 | ||
1091 | /* calc min stripe number for data space alloction */ | |
1092 | type = btrfs_get_alloc_profile(root, 1); | |
1093 | if (type & BTRFS_BLOCK_GROUP_RAID0) | |
1094 | min_stripes = 2; | |
1095 | else if (type & BTRFS_BLOCK_GROUP_RAID1) | |
1096 | min_stripes = 2; | |
1097 | else if (type & BTRFS_BLOCK_GROUP_RAID10) | |
1098 | min_stripes = 4; | |
1099 | ||
1100 | if (type & BTRFS_BLOCK_GROUP_DUP) | |
1101 | min_stripe_size = 2 * BTRFS_STRIPE_LEN; | |
1102 | else | |
1103 | min_stripe_size = BTRFS_STRIPE_LEN; | |
1104 | ||
1105 | list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) { | |
1106 | if (!device->in_fs_metadata) | |
1107 | continue; | |
1108 | ||
1109 | avail_space = device->total_bytes - device->bytes_used; | |
1110 | ||
1111 | /* align with stripe_len */ | |
1112 | do_div(avail_space, BTRFS_STRIPE_LEN); | |
1113 | avail_space *= BTRFS_STRIPE_LEN; | |
1114 | ||
1115 | /* | |
1116 | * In order to avoid overwritting the superblock on the drive, | |
1117 | * btrfs starts at an offset of at least 1MB when doing chunk | |
1118 | * allocation. | |
1119 | */ | |
1120 | skip_space = 1024 * 1024; | |
1121 | ||
1122 | /* user can set the offset in fs_info->alloc_start. */ | |
1123 | if (fs_info->alloc_start + BTRFS_STRIPE_LEN <= | |
1124 | device->total_bytes) | |
1125 | skip_space = max(fs_info->alloc_start, skip_space); | |
1126 | ||
1127 | /* | |
1128 | * btrfs can not use the free space in [0, skip_space - 1], | |
1129 | * we must subtract it from the total. In order to implement | |
1130 | * it, we account the used space in this range first. | |
1131 | */ | |
1132 | ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1, | |
1133 | &used_space); | |
1134 | if (ret) { | |
1135 | kfree(devices_info); | |
1136 | return ret; | |
1137 | } | |
1138 | ||
1139 | /* calc the free space in [0, skip_space - 1] */ | |
1140 | skip_space -= used_space; | |
1141 | ||
1142 | /* | |
1143 | * we can use the free space in [0, skip_space - 1], subtract | |
1144 | * it from the total. | |
1145 | */ | |
1146 | if (avail_space && avail_space >= skip_space) | |
1147 | avail_space -= skip_space; | |
1148 | else | |
1149 | avail_space = 0; | |
1150 | ||
1151 | if (avail_space < min_stripe_size) | |
1152 | continue; | |
1153 | ||
1154 | devices_info[i].dev = device; | |
1155 | devices_info[i].max_avail = avail_space; | |
1156 | ||
1157 | i++; | |
1158 | } | |
1159 | ||
1160 | nr_devices = i; | |
1161 | ||
1162 | btrfs_descending_sort_devices(devices_info, nr_devices); | |
1163 | ||
1164 | i = nr_devices - 1; | |
1165 | avail_space = 0; | |
1166 | while (nr_devices >= min_stripes) { | |
1167 | if (devices_info[i].max_avail >= min_stripe_size) { | |
1168 | int j; | |
1169 | u64 alloc_size; | |
1170 | ||
1171 | avail_space += devices_info[i].max_avail * min_stripes; | |
1172 | alloc_size = devices_info[i].max_avail; | |
1173 | for (j = i + 1 - min_stripes; j <= i; j++) | |
1174 | devices_info[j].max_avail -= alloc_size; | |
1175 | } | |
1176 | i--; | |
1177 | nr_devices--; | |
1178 | } | |
1179 | ||
1180 | kfree(devices_info); | |
1181 | *free_bytes = avail_space; | |
1182 | return 0; | |
1183 | } | |
1184 | ||
8fd17795 CM |
1185 | static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) |
1186 | { | |
1187 | struct btrfs_root *root = btrfs_sb(dentry->d_sb); | |
6c41761f | 1188 | struct btrfs_super_block *disk_super = root->fs_info->super_copy; |
bd4d1088 JB |
1189 | struct list_head *head = &root->fs_info->space_info; |
1190 | struct btrfs_space_info *found; | |
1191 | u64 total_used = 0; | |
6d07bcec | 1192 | u64 total_free_data = 0; |
db94535d | 1193 | int bits = dentry->d_sb->s_blocksize_bits; |
9d03632e | 1194 | __be32 *fsid = (__be32 *)root->fs_info->fsid; |
6d07bcec | 1195 | int ret; |
8fd17795 | 1196 | |
6d07bcec MX |
1197 | /* holding chunk_muext to avoid allocating new chunks */ |
1198 | mutex_lock(&root->fs_info->chunk_mutex); | |
bd4d1088 | 1199 | rcu_read_lock(); |
89a55897 | 1200 | list_for_each_entry_rcu(found, head, list) { |
6d07bcec MX |
1201 | if (found->flags & BTRFS_BLOCK_GROUP_DATA) { |
1202 | total_free_data += found->disk_total - found->disk_used; | |
1203 | total_free_data -= | |
1204 | btrfs_account_ro_block_groups_free_space(found); | |
1205 | } | |
1206 | ||
b742bb82 | 1207 | total_used += found->disk_used; |
89a55897 | 1208 | } |
bd4d1088 JB |
1209 | rcu_read_unlock(); |
1210 | ||
8fd17795 | 1211 | buf->f_namelen = BTRFS_NAME_LEN; |
db94535d | 1212 | buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits; |
bd4d1088 | 1213 | buf->f_bfree = buf->f_blocks - (total_used >> bits); |
8fd17795 CM |
1214 | buf->f_bsize = dentry->d_sb->s_blocksize; |
1215 | buf->f_type = BTRFS_SUPER_MAGIC; | |
6d07bcec MX |
1216 | buf->f_bavail = total_free_data; |
1217 | ret = btrfs_calc_avail_data_space(root, &total_free_data); | |
1218 | if (ret) { | |
1219 | mutex_unlock(&root->fs_info->chunk_mutex); | |
1220 | return ret; | |
1221 | } | |
1222 | buf->f_bavail += total_free_data; | |
1223 | buf->f_bavail = buf->f_bavail >> bits; | |
1224 | mutex_unlock(&root->fs_info->chunk_mutex); | |
d397712b | 1225 | |
9d03632e | 1226 | /* We treat it as constant endianness (it doesn't matter _which_) |
d397712b | 1227 | because we want the fsid to come out the same whether mounted |
9d03632e DW |
1228 | on a big-endian or little-endian host */ |
1229 | buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]); | |
1230 | buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]); | |
32d48fa1 DW |
1231 | /* Mask in the root object ID too, to disambiguate subvols */ |
1232 | buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32; | |
1233 | buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid; | |
1234 | ||
8fd17795 CM |
1235 | return 0; |
1236 | } | |
b5133862 | 1237 | |
2e635a27 CM |
1238 | static struct file_system_type btrfs_fs_type = { |
1239 | .owner = THIS_MODULE, | |
1240 | .name = "btrfs", | |
061dbc6b | 1241 | .mount = btrfs_mount, |
a061fc8d | 1242 | .kill_sb = kill_anon_super, |
2e635a27 CM |
1243 | .fs_flags = FS_REQUIRES_DEV, |
1244 | }; | |
a9218f6b | 1245 | |
d352ac68 CM |
1246 | /* |
1247 | * used by btrfsctl to scan devices when no FS is mounted | |
1248 | */ | |
8a4b83cc CM |
1249 | static long btrfs_control_ioctl(struct file *file, unsigned int cmd, |
1250 | unsigned long arg) | |
1251 | { | |
1252 | struct btrfs_ioctl_vol_args *vol; | |
1253 | struct btrfs_fs_devices *fs_devices; | |
c071fcfd | 1254 | int ret = -ENOTTY; |
8a4b83cc | 1255 | |
e441d54d CM |
1256 | if (!capable(CAP_SYS_ADMIN)) |
1257 | return -EPERM; | |
1258 | ||
dae7b665 LZ |
1259 | vol = memdup_user((void __user *)arg, sizeof(*vol)); |
1260 | if (IS_ERR(vol)) | |
1261 | return PTR_ERR(vol); | |
c071fcfd | 1262 | |
8a4b83cc CM |
1263 | switch (cmd) { |
1264 | case BTRFS_IOC_SCAN_DEV: | |
97288f2c | 1265 | ret = btrfs_scan_one_device(vol->name, FMODE_READ, |
8a4b83cc CM |
1266 | &btrfs_fs_type, &fs_devices); |
1267 | break; | |
1268 | } | |
dae7b665 | 1269 | |
8a4b83cc | 1270 | kfree(vol); |
f819d837 | 1271 | return ret; |
8a4b83cc CM |
1272 | } |
1273 | ||
0176260f | 1274 | static int btrfs_freeze(struct super_block *sb) |
ed0dab6b Y |
1275 | { |
1276 | struct btrfs_root *root = btrfs_sb(sb); | |
a74a4b97 CM |
1277 | mutex_lock(&root->fs_info->transaction_kthread_mutex); |
1278 | mutex_lock(&root->fs_info->cleaner_mutex); | |
0176260f | 1279 | return 0; |
ed0dab6b Y |
1280 | } |
1281 | ||
0176260f | 1282 | static int btrfs_unfreeze(struct super_block *sb) |
ed0dab6b Y |
1283 | { |
1284 | struct btrfs_root *root = btrfs_sb(sb); | |
a74a4b97 CM |
1285 | mutex_unlock(&root->fs_info->cleaner_mutex); |
1286 | mutex_unlock(&root->fs_info->transaction_kthread_mutex); | |
0176260f | 1287 | return 0; |
ed0dab6b | 1288 | } |
2e635a27 | 1289 | |
b87221de | 1290 | static const struct super_operations btrfs_super_ops = { |
76dda93c | 1291 | .drop_inode = btrfs_drop_inode, |
bd555975 | 1292 | .evict_inode = btrfs_evict_inode, |
e20d96d6 | 1293 | .put_super = btrfs_put_super, |
d5719762 | 1294 | .sync_fs = btrfs_sync_fs, |
a9572a15 | 1295 | .show_options = btrfs_show_options, |
4730a4bc | 1296 | .write_inode = btrfs_write_inode, |
b5133862 | 1297 | .dirty_inode = btrfs_dirty_inode, |
2c90e5d6 CM |
1298 | .alloc_inode = btrfs_alloc_inode, |
1299 | .destroy_inode = btrfs_destroy_inode, | |
8fd17795 | 1300 | .statfs = btrfs_statfs, |
c146afad | 1301 | .remount_fs = btrfs_remount, |
0176260f LT |
1302 | .freeze_fs = btrfs_freeze, |
1303 | .unfreeze_fs = btrfs_unfreeze, | |
e20d96d6 | 1304 | }; |
a9218f6b CM |
1305 | |
1306 | static const struct file_operations btrfs_ctl_fops = { | |
1307 | .unlocked_ioctl = btrfs_control_ioctl, | |
1308 | .compat_ioctl = btrfs_control_ioctl, | |
1309 | .owner = THIS_MODULE, | |
6038f373 | 1310 | .llseek = noop_llseek, |
a9218f6b CM |
1311 | }; |
1312 | ||
1313 | static struct miscdevice btrfs_misc = { | |
578454ff | 1314 | .minor = BTRFS_MINOR, |
a9218f6b CM |
1315 | .name = "btrfs-control", |
1316 | .fops = &btrfs_ctl_fops | |
1317 | }; | |
1318 | ||
578454ff KS |
1319 | MODULE_ALIAS_MISCDEV(BTRFS_MINOR); |
1320 | MODULE_ALIAS("devname:btrfs-control"); | |
1321 | ||
a9218f6b CM |
1322 | static int btrfs_interface_init(void) |
1323 | { | |
1324 | return misc_register(&btrfs_misc); | |
1325 | } | |
1326 | ||
b2950863 | 1327 | static void btrfs_interface_exit(void) |
a9218f6b CM |
1328 | { |
1329 | if (misc_deregister(&btrfs_misc) < 0) | |
d397712b | 1330 | printk(KERN_INFO "misc_deregister failed for control device"); |
a9218f6b CM |
1331 | } |
1332 | ||
2e635a27 CM |
1333 | static int __init init_btrfs_fs(void) |
1334 | { | |
2c90e5d6 | 1335 | int err; |
58176a96 JB |
1336 | |
1337 | err = btrfs_init_sysfs(); | |
1338 | if (err) | |
1339 | return err; | |
1340 | ||
261507a0 | 1341 | err = btrfs_init_compress(); |
2c90e5d6 | 1342 | if (err) |
a74a4b97 | 1343 | goto free_sysfs; |
d1310b2e | 1344 | |
261507a0 LZ |
1345 | err = btrfs_init_cachep(); |
1346 | if (err) | |
1347 | goto free_compress; | |
1348 | ||
d1310b2e | 1349 | err = extent_io_init(); |
2f4cbe64 WB |
1350 | if (err) |
1351 | goto free_cachep; | |
1352 | ||
d1310b2e CM |
1353 | err = extent_map_init(); |
1354 | if (err) | |
1355 | goto free_extent_io; | |
1356 | ||
16cdcec7 | 1357 | err = btrfs_delayed_inode_init(); |
2f4cbe64 WB |
1358 | if (err) |
1359 | goto free_extent_map; | |
c8b97818 | 1360 | |
16cdcec7 MX |
1361 | err = btrfs_interface_init(); |
1362 | if (err) | |
1363 | goto free_delayed_inode; | |
1364 | ||
a9218f6b CM |
1365 | err = register_filesystem(&btrfs_fs_type); |
1366 | if (err) | |
1367 | goto unregister_ioctl; | |
b3c3da71 CM |
1368 | |
1369 | printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION); | |
2f4cbe64 WB |
1370 | return 0; |
1371 | ||
a9218f6b CM |
1372 | unregister_ioctl: |
1373 | btrfs_interface_exit(); | |
16cdcec7 MX |
1374 | free_delayed_inode: |
1375 | btrfs_delayed_inode_exit(); | |
2f4cbe64 WB |
1376 | free_extent_map: |
1377 | extent_map_exit(); | |
d1310b2e CM |
1378 | free_extent_io: |
1379 | extent_io_exit(); | |
2f4cbe64 WB |
1380 | free_cachep: |
1381 | btrfs_destroy_cachep(); | |
261507a0 LZ |
1382 | free_compress: |
1383 | btrfs_exit_compress(); | |
a74a4b97 | 1384 | free_sysfs: |
2f4cbe64 WB |
1385 | btrfs_exit_sysfs(); |
1386 | return err; | |
2e635a27 CM |
1387 | } |
1388 | ||
1389 | static void __exit exit_btrfs_fs(void) | |
1390 | { | |
39279cc3 | 1391 | btrfs_destroy_cachep(); |
16cdcec7 | 1392 | btrfs_delayed_inode_exit(); |
a52d9a80 | 1393 | extent_map_exit(); |
d1310b2e | 1394 | extent_io_exit(); |
a9218f6b | 1395 | btrfs_interface_exit(); |
2e635a27 | 1396 | unregister_filesystem(&btrfs_fs_type); |
58176a96 | 1397 | btrfs_exit_sysfs(); |
8a4b83cc | 1398 | btrfs_cleanup_fs_uuids(); |
261507a0 | 1399 | btrfs_exit_compress(); |
2e635a27 CM |
1400 | } |
1401 | ||
1402 | module_init(init_btrfs_fs) | |
1403 | module_exit(exit_btrfs_fs) | |
1404 | ||
1405 | MODULE_LICENSE("GPL"); |