1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/blkdev.h>
20 #include <linux/module.h>
21 #include <linux/buffer_head.h>
22 #include <linux/fs.h>
23 #include <linux/pagemap.h>
24 #include <linux/highmem.h>
25 #include <linux/time.h>
26 #include <linux/init.h>
27 #include <linux/seq_file.h>
28 #include <linux/string.h>
29 #include <linux/backing-dev.h>
30 #include <linux/mount.h>
31 #include <linux/mpage.h>
32 #include <linux/swap.h>
33 #include <linux/writeback.h>
34 #include <linux/statfs.h>
35 #include <linux/compat.h>
36 #include <linux/parser.h>
37 #include <linux/ctype.h>
38 #include <linux/namei.h>
39 #include <linux/miscdevice.h>
40 #include <linux/magic.h>
41 #include <linux/slab.h>
42 #include <linux/cleancache.h>
43 #include <linux/ratelimit.h>
44 #include <linux/btrfs.h>
45 #include "compat.h"
46 #include "delayed-inode.h"
47 #include "ctree.h"
48 #include "disk-io.h"
49 #include "transaction.h"
50 #include "btrfs_inode.h"
51 #include "print-tree.h"
52 #include "xattr.h"
53 #include "volumes.h"
54 #include "version.h"
55 #include "export.h"
56 #include "compression.h"
57 #include "rcu-string.h"
58 #include "dev-replace.h"
59 #include "free-space-cache.h"
60
61 #define CREATE_TRACE_POINTS
62 #include <trace/events/btrfs.h>
63
64 static const struct super_operations btrfs_super_ops;
65 static struct file_system_type btrfs_fs_type;
66
btrfs_decode_error(int errno)67 static const char *btrfs_decode_error(int errno)
68 {
69 char *errstr = "unknown";
70
71 switch (errno) {
72 case -EIO:
73 errstr = "IO failure";
74 break;
75 case -ENOMEM:
76 errstr = "Out of memory";
77 break;
78 case -EROFS:
79 errstr = "Readonly filesystem";
80 break;
81 case -EEXIST:
82 errstr = "Object already exists";
83 break;
84 case -ENOSPC:
85 errstr = "No space left";
86 break;
87 case -ENOENT:
88 errstr = "No such entry";
89 break;
90 }
91
92 return errstr;
93 }
94
save_error_info(struct btrfs_fs_info * fs_info)95 static void save_error_info(struct btrfs_fs_info *fs_info)
96 {
97 /*
98 * today we only save the error info into ram. Long term we'll
99 * also send it down to the disk
100 */
101 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
102 }
103
104 /* btrfs handle error by forcing the filesystem readonly */
btrfs_handle_error(struct btrfs_fs_info * fs_info)105 static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
106 {
107 struct super_block *sb = fs_info->sb;
108
109 if (sb->s_flags & MS_RDONLY)
110 return;
111
112 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
113 sb->s_flags |= MS_RDONLY;
114 btrfs_info(fs_info, "forced readonly");
115 /*
116 * Note that a running device replace operation is not
117 * canceled here although there is no way to update
118 * the progress. It would add the risk of a deadlock,
119 * therefore the canceling is ommited. The only penalty
120 * is that some I/O remains active until the procedure
121 * completes. The next time when the filesystem is
122 * mounted writeable again, the device replace
123 * operation continues.
124 */
125 }
126 }
127
128 #ifdef CONFIG_PRINTK
129 /*
130 * __btrfs_std_error decodes expected errors from the caller and
131 * invokes the approciate error response.
132 */
__btrfs_std_error(struct btrfs_fs_info * fs_info,const char * function,unsigned int line,int errno,const char * fmt,...)133 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
134 unsigned int line, int errno, const char *fmt, ...)
135 {
136 struct super_block *sb = fs_info->sb;
137 const char *errstr;
138
139 /*
140 * Special case: if the error is EROFS, and we're already
141 * under MS_RDONLY, then it is safe here.
142 */
143 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
144 return;
145
146 errstr = btrfs_decode_error(errno);
147 if (fmt) {
148 struct va_format vaf;
149 va_list args;
150
151 va_start(args, fmt);
152 vaf.fmt = fmt;
153 vaf.va = &args;
154
155 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: errno=%d %s (%pV)\n",
156 sb->s_id, function, line, errno, errstr, &vaf);
157 va_end(args);
158 } else {
159 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: errno=%d %s\n",
160 sb->s_id, function, line, errno, errstr);
161 }
162
163 /* Don't go through full error handling during mount */
164 save_error_info(fs_info);
165 if (sb->s_flags & MS_BORN)
166 btrfs_handle_error(fs_info);
167 }
168
169 static const char * const logtypes[] = {
170 "emergency",
171 "alert",
172 "critical",
173 "error",
174 "warning",
175 "notice",
176 "info",
177 "debug",
178 };
179
btrfs_printk(const struct btrfs_fs_info * fs_info,const char * fmt,...)180 void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
181 {
182 struct super_block *sb = fs_info->sb;
183 char lvl[4];
184 struct va_format vaf;
185 va_list args;
186 const char *type = logtypes[4];
187 int kern_level;
188
189 va_start(args, fmt);
190
191 kern_level = printk_get_level(fmt);
192 if (kern_level) {
193 size_t size = printk_skip_level(fmt) - fmt;
194 memcpy(lvl, fmt, size);
195 lvl[size] = '\0';
196 fmt += size;
197 type = logtypes[kern_level - '0'];
198 } else
199 *lvl = '\0';
200
201 vaf.fmt = fmt;
202 vaf.va = &args;
203
204 printk("%sBTRFS %s (device %s): %pV\n", lvl, type, sb->s_id, &vaf);
205
206 va_end(args);
207 }
208
209 #else
210
__btrfs_std_error(struct btrfs_fs_info * fs_info,const char * function,unsigned int line,int errno,const char * fmt,...)211 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
212 unsigned int line, int errno, const char *fmt, ...)
213 {
214 struct super_block *sb = fs_info->sb;
215
216 /*
217 * Special case: if the error is EROFS, and we're already
218 * under MS_RDONLY, then it is safe here.
219 */
220 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
221 return;
222
223 /* Don't go through full error handling during mount */
224 if (sb->s_flags & MS_BORN) {
225 save_error_info(fs_info);
226 btrfs_handle_error(fs_info);
227 }
228 }
229 #endif
230
231 /*
232 * We only mark the transaction aborted and then set the file system read-only.
233 * This will prevent new transactions from starting or trying to join this
234 * one.
235 *
236 * This means that error recovery at the call site is limited to freeing
237 * any local memory allocations and passing the error code up without
238 * further cleanup. The transaction should complete as it normally would
239 * in the call path but will return -EIO.
240 *
241 * We'll complete the cleanup in btrfs_end_transaction and
242 * btrfs_commit_transaction.
243 */
__btrfs_abort_transaction(struct btrfs_trans_handle * trans,struct btrfs_root * root,const char * function,unsigned int line,int errno)244 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
245 struct btrfs_root *root, const char *function,
246 unsigned int line, int errno)
247 {
248 /*
249 * Report first abort since mount
250 */
251 if (!test_and_set_bit(BTRFS_FS_STATE_TRANS_ABORTED,
252 &root->fs_info->fs_state)) {
253 WARN(1, KERN_DEBUG "btrfs: Transaction aborted (error %d)\n",
254 errno);
255 }
256 trans->aborted = errno;
257 /* Nothing used. The other threads that have joined this
258 * transaction may be able to continue. */
259 if (!trans->blocks_used) {
260 const char *errstr;
261
262 errstr = btrfs_decode_error(errno);
263 btrfs_warn(root->fs_info,
264 "%s:%d: Aborting unused transaction(%s).",
265 function, line, errstr);
266 return;
267 }
268 ACCESS_ONCE(trans->transaction->aborted) = errno;
269 __btrfs_std_error(root->fs_info, function, line, errno, NULL);
270 }
271 /*
272 * __btrfs_panic decodes unexpected, fatal errors from the caller,
273 * issues an alert, and either panics or BUGs, depending on mount options.
274 */
__btrfs_panic(struct btrfs_fs_info * fs_info,const char * function,unsigned int line,int errno,const char * fmt,...)275 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
276 unsigned int line, int errno, const char *fmt, ...)
277 {
278 char *s_id = "<unknown>";
279 const char *errstr;
280 struct va_format vaf = { .fmt = fmt };
281 va_list args;
282
283 if (fs_info)
284 s_id = fs_info->sb->s_id;
285
286 va_start(args, fmt);
287 vaf.va = &args;
288
289 errstr = btrfs_decode_error(errno);
290 if (fs_info && (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR))
291 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
292 s_id, function, line, &vaf, errno, errstr);
293
294 printk(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
295 s_id, function, line, &vaf, errno, errstr);
296 va_end(args);
297 /* Caller calls BUG() */
298 }
299
btrfs_put_super(struct super_block * sb)300 static void btrfs_put_super(struct super_block *sb)
301 {
302 (void)close_ctree(btrfs_sb(sb)->tree_root);
303 /* FIXME: need to fix VFS to return error? */
304 /* AV: return it _where_? ->put_super() can be triggered by any number
305 * of async events, up to and including delivery of SIGKILL to the
306 * last process that kept it busy. Or segfault in the aforementioned
307 * process... Whom would you report that to?
308 */
309 }
310
311 enum {
312 Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
313 Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
314 Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
315 Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
316 Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
317 Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
318 Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_inode_cache,
319 Opt_no_space_cache, Opt_recovery, Opt_skip_balance,
320 Opt_check_integrity, Opt_check_integrity_including_extent_data,
321 Opt_check_integrity_print_mask, Opt_fatal_errors,
322 Opt_err,
323 };
324
325 static match_table_t tokens = {
326 {Opt_degraded, "degraded"},
327 {Opt_subvol, "subvol=%s"},
328 {Opt_subvolid, "subvolid=%d"},
329 {Opt_device, "device=%s"},
330 {Opt_nodatasum, "nodatasum"},
331 {Opt_nodatacow, "nodatacow"},
332 {Opt_nobarrier, "nobarrier"},
333 {Opt_max_inline, "max_inline=%s"},
334 {Opt_alloc_start, "alloc_start=%s"},
335 {Opt_thread_pool, "thread_pool=%d"},
336 {Opt_compress, "compress"},
337 {Opt_compress_type, "compress=%s"},
338 {Opt_compress_force, "compress-force"},
339 {Opt_compress_force_type, "compress-force=%s"},
340 {Opt_ssd, "ssd"},
341 {Opt_ssd_spread, "ssd_spread"},
342 {Opt_nossd, "nossd"},
343 {Opt_noacl, "noacl"},
344 {Opt_notreelog, "notreelog"},
345 {Opt_flushoncommit, "flushoncommit"},
346 {Opt_ratio, "metadata_ratio=%d"},
347 {Opt_discard, "discard"},
348 {Opt_space_cache, "space_cache"},
349 {Opt_clear_cache, "clear_cache"},
350 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
351 {Opt_enospc_debug, "enospc_debug"},
352 {Opt_subvolrootid, "subvolrootid=%d"},
353 {Opt_defrag, "autodefrag"},
354 {Opt_inode_cache, "inode_cache"},
355 {Opt_no_space_cache, "nospace_cache"},
356 {Opt_recovery, "recovery"},
357 {Opt_skip_balance, "skip_balance"},
358 {Opt_check_integrity, "check_int"},
359 {Opt_check_integrity_including_extent_data, "check_int_data"},
360 {Opt_check_integrity_print_mask, "check_int_print_mask=%d"},
361 {Opt_fatal_errors, "fatal_errors=%s"},
362 {Opt_err, NULL},
363 };
364
365 /*
366 * Regular mount options parser. Everything that is needed only when
367 * reading in a new superblock is parsed here.
368 * XXX JDM: This needs to be cleaned up for remount.
369 */
btrfs_parse_options(struct btrfs_root * root,char * options)370 int btrfs_parse_options(struct btrfs_root *root, char *options)
371 {
372 struct btrfs_fs_info *info = root->fs_info;
373 substring_t args[MAX_OPT_ARGS];
374 char *p, *num, *orig = NULL;
375 u64 cache_gen;
376 int intarg;
377 int ret = 0;
378 char *compress_type;
379 bool compress_force = false;
380
381 cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
382 if (cache_gen)
383 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
384
385 if (!options)
386 goto out;
387
388 /*
389 * strsep changes the string, duplicate it because parse_options
390 * gets called twice
391 */
392 options = kstrdup(options, GFP_NOFS);
393 if (!options)
394 return -ENOMEM;
395
396 orig = options;
397
398 while ((p = strsep(&options, ",")) != NULL) {
399 int token;
400 if (!*p)
401 continue;
402
403 token = match_token(p, tokens, args);
404 switch (token) {
405 case Opt_degraded:
406 printk(KERN_INFO "btrfs: allowing degraded mounts\n");
407 btrfs_set_opt(info->mount_opt, DEGRADED);
408 break;
409 case Opt_subvol:
410 case Opt_subvolid:
411 case Opt_subvolrootid:
412 case Opt_device:
413 /*
414 * These are parsed by btrfs_parse_early_options
415 * and can be happily ignored here.
416 */
417 break;
418 case Opt_nodatasum:
419 printk(KERN_INFO "btrfs: setting nodatasum\n");
420 btrfs_set_opt(info->mount_opt, NODATASUM);
421 break;
422 case Opt_nodatacow:
423 if (!btrfs_test_opt(root, COMPRESS) ||
424 !btrfs_test_opt(root, FORCE_COMPRESS)) {
425 printk(KERN_INFO "btrfs: setting nodatacow, compression disabled\n");
426 } else {
427 printk(KERN_INFO "btrfs: setting nodatacow\n");
428 }
429 info->compress_type = BTRFS_COMPRESS_NONE;
430 btrfs_clear_opt(info->mount_opt, COMPRESS);
431 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
432 btrfs_set_opt(info->mount_opt, NODATACOW);
433 btrfs_set_opt(info->mount_opt, NODATASUM);
434 break;
435 case Opt_compress_force:
436 case Opt_compress_force_type:
437 compress_force = true;
438 /* Fallthrough */
439 case Opt_compress:
440 case Opt_compress_type:
441 if (token == Opt_compress ||
442 token == Opt_compress_force ||
443 strcmp(args[0].from, "zlib") == 0) {
444 compress_type = "zlib";
445 info->compress_type = BTRFS_COMPRESS_ZLIB;
446 btrfs_set_opt(info->mount_opt, COMPRESS);
447 btrfs_clear_opt(info->mount_opt, NODATACOW);
448 btrfs_clear_opt(info->mount_opt, NODATASUM);
449 } else if (strcmp(args[0].from, "lzo") == 0) {
450 compress_type = "lzo";
451 info->compress_type = BTRFS_COMPRESS_LZO;
452 btrfs_set_opt(info->mount_opt, COMPRESS);
453 btrfs_clear_opt(info->mount_opt, NODATACOW);
454 btrfs_clear_opt(info->mount_opt, NODATASUM);
455 btrfs_set_fs_incompat(info, COMPRESS_LZO);
456 } else if (strncmp(args[0].from, "no", 2) == 0) {
457 compress_type = "no";
458 info->compress_type = BTRFS_COMPRESS_NONE;
459 btrfs_clear_opt(info->mount_opt, COMPRESS);
460 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
461 compress_force = false;
462 } else {
463 ret = -EINVAL;
464 goto out;
465 }
466
467 if (compress_force) {
468 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
469 pr_info("btrfs: force %s compression\n",
470 compress_type);
471 } else
472 pr_info("btrfs: use %s compression\n",
473 compress_type);
474 break;
475 case Opt_ssd:
476 printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
477 btrfs_set_opt(info->mount_opt, SSD);
478 break;
479 case Opt_ssd_spread:
480 printk(KERN_INFO "btrfs: use spread ssd "
481 "allocation scheme\n");
482 btrfs_set_opt(info->mount_opt, SSD);
483 btrfs_set_opt(info->mount_opt, SSD_SPREAD);
484 break;
485 case Opt_nossd:
486 printk(KERN_INFO "btrfs: not using ssd allocation "
487 "scheme\n");
488 btrfs_set_opt(info->mount_opt, NOSSD);
489 btrfs_clear_opt(info->mount_opt, SSD);
490 btrfs_clear_opt(info->mount_opt, SSD_SPREAD);
491 break;
492 case Opt_nobarrier:
493 printk(KERN_INFO "btrfs: turning off barriers\n");
494 btrfs_set_opt(info->mount_opt, NOBARRIER);
495 break;
496 case Opt_thread_pool:
497 intarg = 0;
498 match_int(&args[0], &intarg);
499 if (intarg)
500 info->thread_pool_size = intarg;
501 break;
502 case Opt_max_inline:
503 num = match_strdup(&args[0]);
504 if (num) {
505 info->max_inline = memparse(num, NULL);
506 kfree(num);
507
508 if (info->max_inline) {
509 info->max_inline = max_t(u64,
510 info->max_inline,
511 root->sectorsize);
512 }
513 printk(KERN_INFO "btrfs: max_inline at %llu\n",
514 (unsigned long long)info->max_inline);
515 }
516 break;
517 case Opt_alloc_start:
518 num = match_strdup(&args[0]);
519 if (num) {
520 mutex_lock(&info->chunk_mutex);
521 info->alloc_start = memparse(num, NULL);
522 mutex_unlock(&info->chunk_mutex);
523 kfree(num);
524 printk(KERN_INFO
525 "btrfs: allocations start at %llu\n",
526 (unsigned long long)info->alloc_start);
527 }
528 break;
529 case Opt_noacl:
530 root->fs_info->sb->s_flags &= ~MS_POSIXACL;
531 break;
532 case Opt_notreelog:
533 printk(KERN_INFO "btrfs: disabling tree log\n");
534 btrfs_set_opt(info->mount_opt, NOTREELOG);
535 break;
536 case Opt_flushoncommit:
537 printk(KERN_INFO "btrfs: turning on flush-on-commit\n");
538 btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT);
539 break;
540 case Opt_ratio:
541 intarg = 0;
542 match_int(&args[0], &intarg);
543 if (intarg) {
544 info->metadata_ratio = intarg;
545 printk(KERN_INFO "btrfs: metadata ratio %d\n",
546 info->metadata_ratio);
547 }
548 break;
549 case Opt_discard:
550 btrfs_set_opt(info->mount_opt, DISCARD);
551 break;
552 case Opt_space_cache:
553 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
554 break;
555 case Opt_no_space_cache:
556 printk(KERN_INFO "btrfs: disabling disk space caching\n");
557 btrfs_clear_opt(info->mount_opt, SPACE_CACHE);
558 break;
559 case Opt_inode_cache:
560 printk(KERN_INFO "btrfs: enabling inode map caching\n");
561 btrfs_set_opt(info->mount_opt, INODE_MAP_CACHE);
562 break;
563 case Opt_clear_cache:
564 printk(KERN_INFO "btrfs: force clearing of disk cache\n");
565 btrfs_set_opt(info->mount_opt, CLEAR_CACHE);
566 break;
567 case Opt_user_subvol_rm_allowed:
568 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
569 break;
570 case Opt_enospc_debug:
571 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
572 break;
573 case Opt_defrag:
574 printk(KERN_INFO "btrfs: enabling auto defrag\n");
575 btrfs_set_opt(info->mount_opt, AUTO_DEFRAG);
576 break;
577 case Opt_recovery:
578 printk(KERN_INFO "btrfs: enabling auto recovery\n");
579 btrfs_set_opt(info->mount_opt, RECOVERY);
580 break;
581 case Opt_skip_balance:
582 btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
583 break;
584 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
585 case Opt_check_integrity_including_extent_data:
586 printk(KERN_INFO "btrfs: enabling check integrity"
587 " including extent data\n");
588 btrfs_set_opt(info->mount_opt,
589 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
590 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
591 break;
592 case Opt_check_integrity:
593 printk(KERN_INFO "btrfs: enabling check integrity\n");
594 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
595 break;
596 case Opt_check_integrity_print_mask:
597 intarg = 0;
598 match_int(&args[0], &intarg);
599 if (intarg) {
600 info->check_integrity_print_mask = intarg;
601 printk(KERN_INFO "btrfs:"
602 " check_integrity_print_mask 0x%x\n",
603 info->check_integrity_print_mask);
604 }
605 break;
606 #else
607 case Opt_check_integrity_including_extent_data:
608 case Opt_check_integrity:
609 case Opt_check_integrity_print_mask:
610 printk(KERN_ERR "btrfs: support for check_integrity*"
611 " not compiled in!\n");
612 ret = -EINVAL;
613 goto out;
614 #endif
615 case Opt_fatal_errors:
616 if (strcmp(args[0].from, "panic") == 0)
617 btrfs_set_opt(info->mount_opt,
618 PANIC_ON_FATAL_ERROR);
619 else if (strcmp(args[0].from, "bug") == 0)
620 btrfs_clear_opt(info->mount_opt,
621 PANIC_ON_FATAL_ERROR);
622 else {
623 ret = -EINVAL;
624 goto out;
625 }
626 break;
627 case Opt_err:
628 printk(KERN_INFO "btrfs: unrecognized mount option "
629 "'%s'\n", p);
630 ret = -EINVAL;
631 goto out;
632 default:
633 break;
634 }
635 }
636 out:
637 if (!ret && btrfs_test_opt(root, SPACE_CACHE))
638 printk(KERN_INFO "btrfs: disk space caching is enabled\n");
639 kfree(orig);
640 return ret;
641 }
642
643 /*
644 * Parse mount options that are required early in the mount process.
645 *
646 * All other options will be parsed on much later in the mount process and
647 * only when we need to allocate a new super block.
648 */
btrfs_parse_early_options(const char * options,fmode_t flags,void * holder,char ** subvol_name,u64 * subvol_objectid,struct btrfs_fs_devices ** fs_devices)649 static int btrfs_parse_early_options(const char *options, fmode_t flags,
650 void *holder, char **subvol_name, u64 *subvol_objectid,
651 struct btrfs_fs_devices **fs_devices)
652 {
653 substring_t args[MAX_OPT_ARGS];
654 char *device_name, *opts, *orig, *p;
655 int error = 0;
656 int intarg;
657
658 if (!options)
659 return 0;
660
661 /*
662 * strsep changes the string, duplicate it because parse_options
663 * gets called twice
664 */
665 opts = kstrdup(options, GFP_KERNEL);
666 if (!opts)
667 return -ENOMEM;
668 orig = opts;
669
670 while ((p = strsep(&opts, ",")) != NULL) {
671 int token;
672 if (!*p)
673 continue;
674
675 token = match_token(p, tokens, args);
676 switch (token) {
677 case Opt_subvol:
678 kfree(*subvol_name);
679 *subvol_name = match_strdup(&args[0]);
680 break;
681 case Opt_subvolid:
682 intarg = 0;
683 error = match_int(&args[0], &intarg);
684 if (!error) {
685 /* we want the original fs_tree */
686 if (!intarg)
687 *subvol_objectid =
688 BTRFS_FS_TREE_OBJECTID;
689 else
690 *subvol_objectid = intarg;
691 }
692 break;
693 case Opt_subvolrootid:
694 printk(KERN_WARNING
695 "btrfs: 'subvolrootid' mount option is deprecated and has no effect\n");
696 break;
697 case Opt_device:
698 device_name = match_strdup(&args[0]);
699 if (!device_name) {
700 error = -ENOMEM;
701 goto out;
702 }
703 error = btrfs_scan_one_device(device_name,
704 flags, holder, fs_devices);
705 kfree(device_name);
706 if (error)
707 goto out;
708 break;
709 default:
710 break;
711 }
712 }
713
714 out:
715 kfree(orig);
716 return error;
717 }
718
get_default_root(struct super_block * sb,u64 subvol_objectid)719 static struct dentry *get_default_root(struct super_block *sb,
720 u64 subvol_objectid)
721 {
722 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
723 struct btrfs_root *root = fs_info->tree_root;
724 struct btrfs_root *new_root;
725 struct btrfs_dir_item *di;
726 struct btrfs_path *path;
727 struct btrfs_key location;
728 struct inode *inode;
729 u64 dir_id;
730 int new = 0;
731
732 /*
733 * We have a specific subvol we want to mount, just setup location and
734 * go look up the root.
735 */
736 if (subvol_objectid) {
737 location.objectid = subvol_objectid;
738 location.type = BTRFS_ROOT_ITEM_KEY;
739 location.offset = (u64)-1;
740 goto find_root;
741 }
742
743 path = btrfs_alloc_path();
744 if (!path)
745 return ERR_PTR(-ENOMEM);
746 path->leave_spinning = 1;
747
748 /*
749 * Find the "default" dir item which points to the root item that we
750 * will mount by default if we haven't been given a specific subvolume
751 * to mount.
752 */
753 dir_id = btrfs_super_root_dir(fs_info->super_copy);
754 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
755 if (IS_ERR(di)) {
756 btrfs_free_path(path);
757 return ERR_CAST(di);
758 }
759 if (!di) {
760 /*
761 * Ok the default dir item isn't there. This is weird since
762 * it's always been there, but don't freak out, just try and
763 * mount to root most subvolume.
764 */
765 btrfs_free_path(path);
766 dir_id = BTRFS_FIRST_FREE_OBJECTID;
767 new_root = fs_info->fs_root;
768 goto setup_root;
769 }
770
771 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
772 btrfs_free_path(path);
773
774 find_root:
775 new_root = btrfs_read_fs_root_no_name(fs_info, &location);
776 if (IS_ERR(new_root))
777 return ERR_CAST(new_root);
778
779 if (btrfs_root_refs(&new_root->root_item) == 0)
780 return ERR_PTR(-ENOENT);
781
782 dir_id = btrfs_root_dirid(&new_root->root_item);
783 setup_root:
784 location.objectid = dir_id;
785 location.type = BTRFS_INODE_ITEM_KEY;
786 location.offset = 0;
787
788 inode = btrfs_iget(sb, &location, new_root, &new);
789 if (IS_ERR(inode))
790 return ERR_CAST(inode);
791
792 /*
793 * If we're just mounting the root most subvol put the inode and return
794 * a reference to the dentry. We will have already gotten a reference
795 * to the inode in btrfs_fill_super so we're good to go.
796 */
797 if (!new && sb->s_root->d_inode == inode) {
798 iput(inode);
799 return dget(sb->s_root);
800 }
801
802 return d_obtain_alias(inode);
803 }
804
btrfs_fill_super(struct super_block * sb,struct btrfs_fs_devices * fs_devices,void * data,int silent)805 static int btrfs_fill_super(struct super_block *sb,
806 struct btrfs_fs_devices *fs_devices,
807 void *data, int silent)
808 {
809 struct inode *inode;
810 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
811 struct btrfs_key key;
812 int err;
813
814 sb->s_maxbytes = MAX_LFS_FILESIZE;
815 sb->s_magic = BTRFS_SUPER_MAGIC;
816 sb->s_op = &btrfs_super_ops;
817 sb->s_d_op = &btrfs_dentry_operations;
818 sb->s_export_op = &btrfs_export_ops;
819 sb->s_xattr = btrfs_xattr_handlers;
820 sb->s_time_gran = 1;
821 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
822 sb->s_flags |= MS_POSIXACL;
823 #endif
824 sb->s_flags |= MS_I_VERSION;
825 err = open_ctree(sb, fs_devices, (char *)data);
826 if (err) {
827 printk("btrfs: open_ctree failed\n");
828 return err;
829 }
830
831 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
832 key.type = BTRFS_INODE_ITEM_KEY;
833 key.offset = 0;
834 inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
835 if (IS_ERR(inode)) {
836 err = PTR_ERR(inode);
837 goto fail_close;
838 }
839
840 sb->s_root = d_make_root(inode);
841 if (!sb->s_root) {
842 err = -ENOMEM;
843 goto fail_close;
844 }
845
846 save_mount_options(sb, data);
847 cleancache_init_fs(sb);
848 sb->s_flags |= MS_ACTIVE;
849 return 0;
850
851 fail_close:
852 close_ctree(fs_info->tree_root);
853 return err;
854 }
855
btrfs_sync_fs(struct super_block * sb,int wait)856 int btrfs_sync_fs(struct super_block *sb, int wait)
857 {
858 struct btrfs_trans_handle *trans;
859 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
860 struct btrfs_root *root = fs_info->tree_root;
861
862 trace_btrfs_sync_fs(wait);
863
864 if (!wait) {
865 filemap_flush(fs_info->btree_inode->i_mapping);
866 return 0;
867 }
868
869 btrfs_wait_ordered_extents(root, 1);
870
871 trans = btrfs_attach_transaction_barrier(root);
872 if (IS_ERR(trans)) {
873 /* no transaction, don't bother */
874 if (PTR_ERR(trans) == -ENOENT)
875 return 0;
876 return PTR_ERR(trans);
877 }
878 return btrfs_commit_transaction(trans, root);
879 }
880
btrfs_show_options(struct seq_file * seq,struct dentry * dentry)881 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
882 {
883 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
884 struct btrfs_root *root = info->tree_root;
885 char *compress_type;
886
887 if (btrfs_test_opt(root, DEGRADED))
888 seq_puts(seq, ",degraded");
889 if (btrfs_test_opt(root, NODATASUM))
890 seq_puts(seq, ",nodatasum");
891 if (btrfs_test_opt(root, NODATACOW))
892 seq_puts(seq, ",nodatacow");
893 if (btrfs_test_opt(root, NOBARRIER))
894 seq_puts(seq, ",nobarrier");
895 if (info->max_inline != 8192 * 1024)
896 seq_printf(seq, ",max_inline=%llu",
897 (unsigned long long)info->max_inline);
898 if (info->alloc_start != 0)
899 seq_printf(seq, ",alloc_start=%llu",
900 (unsigned long long)info->alloc_start);
901 if (info->thread_pool_size != min_t(unsigned long,
902 num_online_cpus() + 2, 8))
903 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
904 if (btrfs_test_opt(root, COMPRESS)) {
905 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
906 compress_type = "zlib";
907 else
908 compress_type = "lzo";
909 if (btrfs_test_opt(root, FORCE_COMPRESS))
910 seq_printf(seq, ",compress-force=%s", compress_type);
911 else
912 seq_printf(seq, ",compress=%s", compress_type);
913 }
914 if (btrfs_test_opt(root, NOSSD))
915 seq_puts(seq, ",nossd");
916 if (btrfs_test_opt(root, SSD_SPREAD))
917 seq_puts(seq, ",ssd_spread");
918 else if (btrfs_test_opt(root, SSD))
919 seq_puts(seq, ",ssd");
920 if (btrfs_test_opt(root, NOTREELOG))
921 seq_puts(seq, ",notreelog");
922 if (btrfs_test_opt(root, FLUSHONCOMMIT))
923 seq_puts(seq, ",flushoncommit");
924 if (btrfs_test_opt(root, DISCARD))
925 seq_puts(seq, ",discard");
926 if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
927 seq_puts(seq, ",noacl");
928 if (btrfs_test_opt(root, SPACE_CACHE))
929 seq_puts(seq, ",space_cache");
930 else
931 seq_puts(seq, ",nospace_cache");
932 if (btrfs_test_opt(root, CLEAR_CACHE))
933 seq_puts(seq, ",clear_cache");
934 if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
935 seq_puts(seq, ",user_subvol_rm_allowed");
936 if (btrfs_test_opt(root, ENOSPC_DEBUG))
937 seq_puts(seq, ",enospc_debug");
938 if (btrfs_test_opt(root, AUTO_DEFRAG))
939 seq_puts(seq, ",autodefrag");
940 if (btrfs_test_opt(root, INODE_MAP_CACHE))
941 seq_puts(seq, ",inode_cache");
942 if (btrfs_test_opt(root, SKIP_BALANCE))
943 seq_puts(seq, ",skip_balance");
944 if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR))
945 seq_puts(seq, ",fatal_errors=panic");
946 return 0;
947 }
948
btrfs_test_super(struct super_block * s,void * data)949 static int btrfs_test_super(struct super_block *s, void *data)
950 {
951 struct btrfs_fs_info *p = data;
952 struct btrfs_fs_info *fs_info = btrfs_sb(s);
953
954 return fs_info->fs_devices == p->fs_devices;
955 }
956
btrfs_set_super(struct super_block * s,void * data)957 static int btrfs_set_super(struct super_block *s, void *data)
958 {
959 int err = set_anon_super(s, data);
960 if (!err)
961 s->s_fs_info = data;
962 return err;
963 }
964
965 /*
966 * subvolumes are identified by ino 256
967 */
is_subvolume_inode(struct inode * inode)968 static inline int is_subvolume_inode(struct inode *inode)
969 {
970 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
971 return 1;
972 return 0;
973 }
974
975 /*
976 * This will strip out the subvol=%s argument for an argument string and add
977 * subvolid=0 to make sure we get the actual tree root for path walking to the
978 * subvol we want.
979 */
setup_root_args(char * args)980 static char *setup_root_args(char *args)
981 {
982 unsigned len = strlen(args) + 2 + 1;
983 char *src, *dst, *buf;
984
985 /*
986 * We need the same args as before, but with this substitution:
987 * s!subvol=[^,]+!subvolid=0!
988 *
989 * Since the replacement string is up to 2 bytes longer than the
990 * original, allocate strlen(args) + 2 + 1 bytes.
991 */
992
993 src = strstr(args, "subvol=");
994 /* This shouldn't happen, but just in case.. */
995 if (!src)
996 return NULL;
997
998 buf = dst = kmalloc(len, GFP_NOFS);
999 if (!buf)
1000 return NULL;
1001
1002 /*
1003 * If the subvol= arg is not at the start of the string,
1004 * copy whatever precedes it into buf.
1005 */
1006 if (src != args) {
1007 *src++ = '\0';
1008 strcpy(buf, args);
1009 dst += strlen(args);
1010 }
1011
1012 strcpy(dst, "subvolid=0");
1013 dst += strlen("subvolid=0");
1014
1015 /*
1016 * If there is a "," after the original subvol=... string,
1017 * copy that suffix into our buffer. Otherwise, we're done.
1018 */
1019 src = strchr(src, ',');
1020 if (src)
1021 strcpy(dst, src);
1022
1023 return buf;
1024 }
1025
mount_subvol(const char * subvol_name,int flags,const char * device_name,char * data)1026 static struct dentry *mount_subvol(const char *subvol_name, int flags,
1027 const char *device_name, char *data)
1028 {
1029 struct dentry *root;
1030 struct vfsmount *mnt;
1031 char *newargs;
1032
1033 newargs = setup_root_args(data);
1034 if (!newargs)
1035 return ERR_PTR(-ENOMEM);
1036 mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name,
1037 newargs);
1038 kfree(newargs);
1039 if (IS_ERR(mnt))
1040 return ERR_CAST(mnt);
1041
1042 root = mount_subtree(mnt, subvol_name);
1043
1044 if (!IS_ERR(root) && !is_subvolume_inode(root->d_inode)) {
1045 struct super_block *s = root->d_sb;
1046 dput(root);
1047 root = ERR_PTR(-EINVAL);
1048 deactivate_locked_super(s);
1049 printk(KERN_ERR "btrfs: '%s' is not a valid subvolume\n",
1050 subvol_name);
1051 }
1052
1053 return root;
1054 }
1055
1056 /*
1057 * Find a superblock for the given device / mount point.
1058 *
1059 * Note: This is based on get_sb_bdev from fs/super.c with a few additions
1060 * for multiple device setup. Make sure to keep it in sync.
1061 */
btrfs_mount(struct file_system_type * fs_type,int flags,const char * device_name,void * data)1062 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1063 const char *device_name, void *data)
1064 {
1065 struct block_device *bdev = NULL;
1066 struct super_block *s;
1067 struct dentry *root;
1068 struct btrfs_fs_devices *fs_devices = NULL;
1069 struct btrfs_fs_info *fs_info = NULL;
1070 fmode_t mode = FMODE_READ;
1071 char *subvol_name = NULL;
1072 u64 subvol_objectid = 0;
1073 int error = 0;
1074
1075 if (!(flags & MS_RDONLY))
1076 mode |= FMODE_WRITE;
1077
1078 error = btrfs_parse_early_options(data, mode, fs_type,
1079 &subvol_name, &subvol_objectid,
1080 &fs_devices);
1081 if (error) {
1082 kfree(subvol_name);
1083 return ERR_PTR(error);
1084 }
1085
1086 if (subvol_name) {
1087 root = mount_subvol(subvol_name, flags, device_name, data);
1088 kfree(subvol_name);
1089 return root;
1090 }
1091
1092 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
1093 if (error)
1094 return ERR_PTR(error);
1095
1096 /*
1097 * Setup a dummy root and fs_info for test/set super. This is because
1098 * we don't actually fill this stuff out until open_ctree, but we need
1099 * it for searching for existing supers, so this lets us do that and
1100 * then open_ctree will properly initialize everything later.
1101 */
1102 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
1103 if (!fs_info)
1104 return ERR_PTR(-ENOMEM);
1105
1106 fs_info->fs_devices = fs_devices;
1107
1108 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1109 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1110 if (!fs_info->super_copy || !fs_info->super_for_commit) {
1111 error = -ENOMEM;
1112 goto error_fs_info;
1113 }
1114
1115 error = btrfs_open_devices(fs_devices, mode, fs_type);
1116 if (error)
1117 goto error_fs_info;
1118
1119 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
1120 error = -EACCES;
1121 goto error_close_devices;
1122 }
1123
1124 bdev = fs_devices->latest_bdev;
1125 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | MS_NOSEC,
1126 fs_info);
1127 if (IS_ERR(s)) {
1128 error = PTR_ERR(s);
1129 goto error_close_devices;
1130 }
1131
1132 if (s->s_root) {
1133 btrfs_close_devices(fs_devices);
1134 free_fs_info(fs_info);
1135 if ((flags ^ s->s_flags) & MS_RDONLY)
1136 error = -EBUSY;
1137 } else {
1138 char b[BDEVNAME_SIZE];
1139
1140 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
1141 btrfs_sb(s)->bdev_holder = fs_type;
1142 error = btrfs_fill_super(s, fs_devices, data,
1143 flags & MS_SILENT ? 1 : 0);
1144 }
1145
1146 root = !error ? get_default_root(s, subvol_objectid) : ERR_PTR(error);
1147 if (IS_ERR(root))
1148 deactivate_locked_super(s);
1149
1150 return root;
1151
1152 error_close_devices:
1153 btrfs_close_devices(fs_devices);
1154 error_fs_info:
1155 free_fs_info(fs_info);
1156 return ERR_PTR(error);
1157 }
1158
btrfs_set_max_workers(struct btrfs_workers * workers,int new_limit)1159 static void btrfs_set_max_workers(struct btrfs_workers *workers, int new_limit)
1160 {
1161 spin_lock_irq(&workers->lock);
1162 workers->max_workers = new_limit;
1163 spin_unlock_irq(&workers->lock);
1164 }
1165
btrfs_resize_thread_pool(struct btrfs_fs_info * fs_info,int new_pool_size,int old_pool_size)1166 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1167 int new_pool_size, int old_pool_size)
1168 {
1169 if (new_pool_size == old_pool_size)
1170 return;
1171
1172 fs_info->thread_pool_size = new_pool_size;
1173
1174 printk(KERN_INFO "btrfs: resize thread pool %d -> %d\n",
1175 old_pool_size, new_pool_size);
1176
1177 btrfs_set_max_workers(&fs_info->generic_worker, new_pool_size);
1178 btrfs_set_max_workers(&fs_info->workers, new_pool_size);
1179 btrfs_set_max_workers(&fs_info->delalloc_workers, new_pool_size);
1180 btrfs_set_max_workers(&fs_info->submit_workers, new_pool_size);
1181 btrfs_set_max_workers(&fs_info->caching_workers, new_pool_size);
1182 btrfs_set_max_workers(&fs_info->fixup_workers, new_pool_size);
1183 btrfs_set_max_workers(&fs_info->endio_workers, new_pool_size);
1184 btrfs_set_max_workers(&fs_info->endio_meta_workers, new_pool_size);
1185 btrfs_set_max_workers(&fs_info->endio_meta_write_workers, new_pool_size);
1186 btrfs_set_max_workers(&fs_info->endio_write_workers, new_pool_size);
1187 btrfs_set_max_workers(&fs_info->endio_freespace_worker, new_pool_size);
1188 btrfs_set_max_workers(&fs_info->delayed_workers, new_pool_size);
1189 btrfs_set_max_workers(&fs_info->readahead_workers, new_pool_size);
1190 btrfs_set_max_workers(&fs_info->scrub_wr_completion_workers,
1191 new_pool_size);
1192 }
1193
btrfs_remount_prepare(struct btrfs_fs_info * fs_info)1194 static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info)
1195 {
1196 set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1197 }
1198
btrfs_remount_begin(struct btrfs_fs_info * fs_info,unsigned long old_opts,int flags)1199 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
1200 unsigned long old_opts, int flags)
1201 {
1202 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1203 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1204 (flags & MS_RDONLY))) {
1205 /* wait for any defraggers to finish */
1206 wait_event(fs_info->transaction_wait,
1207 (atomic_read(&fs_info->defrag_running) == 0));
1208 if (flags & MS_RDONLY)
1209 sync_filesystem(fs_info->sb);
1210 }
1211 }
1212
btrfs_remount_cleanup(struct btrfs_fs_info * fs_info,unsigned long old_opts)1213 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1214 unsigned long old_opts)
1215 {
1216 /*
1217 * We need cleanup all defragable inodes if the autodefragment is
1218 * close or the fs is R/O.
1219 */
1220 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1221 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1222 (fs_info->sb->s_flags & MS_RDONLY))) {
1223 btrfs_cleanup_defrag_inodes(fs_info);
1224 }
1225
1226 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1227 }
1228
btrfs_remount(struct super_block * sb,int * flags,char * data)1229 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1230 {
1231 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1232 struct btrfs_root *root = fs_info->tree_root;
1233 unsigned old_flags = sb->s_flags;
1234 unsigned long old_opts = fs_info->mount_opt;
1235 unsigned long old_compress_type = fs_info->compress_type;
1236 u64 old_max_inline = fs_info->max_inline;
1237 u64 old_alloc_start = fs_info->alloc_start;
1238 int old_thread_pool_size = fs_info->thread_pool_size;
1239 unsigned int old_metadata_ratio = fs_info->metadata_ratio;
1240 int ret;
1241
1242 sync_filesystem(sb);
1243 btrfs_remount_prepare(fs_info);
1244
1245 ret = btrfs_parse_options(root, data);
1246 if (ret) {
1247 ret = -EINVAL;
1248 goto restore;
1249 }
1250
1251 btrfs_remount_begin(fs_info, old_opts, *flags);
1252 btrfs_resize_thread_pool(fs_info,
1253 fs_info->thread_pool_size, old_thread_pool_size);
1254
1255 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1256 goto out;
1257
1258 if (*flags & MS_RDONLY) {
1259 /*
1260 * this also happens on 'umount -rf' or on shutdown, when
1261 * the filesystem is busy.
1262 */
1263 sb->s_flags |= MS_RDONLY;
1264
1265 btrfs_dev_replace_suspend_for_unmount(fs_info);
1266 btrfs_scrub_cancel(fs_info);
1267 btrfs_pause_balance(fs_info);
1268
1269 ret = btrfs_commit_super(root);
1270 if (ret)
1271 goto restore;
1272 } else {
1273 if (fs_info->fs_devices->rw_devices == 0) {
1274 ret = -EACCES;
1275 goto restore;
1276 }
1277
1278 if (fs_info->fs_devices->missing_devices >
1279 fs_info->num_tolerated_disk_barrier_failures &&
1280 !(*flags & MS_RDONLY)) {
1281 printk(KERN_WARNING
1282 "Btrfs: too many missing devices, writeable remount is not allowed\n");
1283 ret = -EACCES;
1284 goto restore;
1285 }
1286
1287 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1288 ret = -EINVAL;
1289 goto restore;
1290 }
1291
1292 ret = btrfs_cleanup_fs_roots(fs_info);
1293 if (ret)
1294 goto restore;
1295
1296 /* recover relocation */
1297 ret = btrfs_recover_relocation(root);
1298 if (ret)
1299 goto restore;
1300
1301 ret = btrfs_resume_balance_async(fs_info);
1302 if (ret)
1303 goto restore;
1304
1305 ret = btrfs_resume_dev_replace_async(fs_info);
1306 if (ret) {
1307 pr_warn("btrfs: failed to resume dev_replace\n");
1308 goto restore;
1309 }
1310 sb->s_flags &= ~MS_RDONLY;
1311 }
1312 out:
1313 btrfs_remount_cleanup(fs_info, old_opts);
1314 return 0;
1315
1316 restore:
1317 /* We've hit an error - don't reset MS_RDONLY */
1318 if (sb->s_flags & MS_RDONLY)
1319 old_flags |= MS_RDONLY;
1320 sb->s_flags = old_flags;
1321 fs_info->mount_opt = old_opts;
1322 fs_info->compress_type = old_compress_type;
1323 fs_info->max_inline = old_max_inline;
1324 mutex_lock(&fs_info->chunk_mutex);
1325 fs_info->alloc_start = old_alloc_start;
1326 mutex_unlock(&fs_info->chunk_mutex);
1327 btrfs_resize_thread_pool(fs_info,
1328 old_thread_pool_size, fs_info->thread_pool_size);
1329 fs_info->metadata_ratio = old_metadata_ratio;
1330 btrfs_remount_cleanup(fs_info, old_opts);
1331 return ret;
1332 }
1333
1334 /* Used to sort the devices by max_avail(descending sort) */
btrfs_cmp_device_free_bytes(const void * dev_info1,const void * dev_info2)1335 static int btrfs_cmp_device_free_bytes(const void *dev_info1,
1336 const void *dev_info2)
1337 {
1338 if (((struct btrfs_device_info *)dev_info1)->max_avail >
1339 ((struct btrfs_device_info *)dev_info2)->max_avail)
1340 return -1;
1341 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1342 ((struct btrfs_device_info *)dev_info2)->max_avail)
1343 return 1;
1344 else
1345 return 0;
1346 }
1347
1348 /*
1349 * sort the devices by max_avail, in which max free extent size of each device
1350 * is stored.(Descending Sort)
1351 */
btrfs_descending_sort_devices(struct btrfs_device_info * devices,size_t nr_devices)1352 static inline void btrfs_descending_sort_devices(
1353 struct btrfs_device_info *devices,
1354 size_t nr_devices)
1355 {
1356 sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1357 btrfs_cmp_device_free_bytes, NULL);
1358 }
1359
1360 /*
1361 * The helper to calc the free space on the devices that can be used to store
1362 * file data.
1363 */
btrfs_calc_avail_data_space(struct btrfs_root * root,u64 * free_bytes)1364 static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
1365 {
1366 struct btrfs_fs_info *fs_info = root->fs_info;
1367 struct btrfs_device_info *devices_info;
1368 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1369 struct btrfs_device *device;
1370 u64 skip_space;
1371 u64 type;
1372 u64 avail_space;
1373 u64 used_space;
1374 u64 min_stripe_size;
1375 int min_stripes = 1, num_stripes = 1;
1376 int i = 0, nr_devices;
1377 int ret;
1378
1379 nr_devices = fs_info->fs_devices->open_devices;
1380 BUG_ON(!nr_devices);
1381
1382 devices_info = kmalloc(sizeof(*devices_info) * nr_devices,
1383 GFP_NOFS);
1384 if (!devices_info)
1385 return -ENOMEM;
1386
1387 /* calc min stripe number for data space alloction */
1388 type = btrfs_get_alloc_profile(root, 1);
1389 if (type & BTRFS_BLOCK_GROUP_RAID0) {
1390 min_stripes = 2;
1391 num_stripes = nr_devices;
1392 } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
1393 min_stripes = 2;
1394 num_stripes = 2;
1395 } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
1396 min_stripes = 4;
1397 num_stripes = 4;
1398 }
1399
1400 if (type & BTRFS_BLOCK_GROUP_DUP)
1401 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1402 else
1403 min_stripe_size = BTRFS_STRIPE_LEN;
1404
1405 list_for_each_entry(device, &fs_devices->devices, dev_list) {
1406 if (!device->in_fs_metadata || !device->bdev ||
1407 device->is_tgtdev_for_dev_replace)
1408 continue;
1409
1410 avail_space = device->total_bytes - device->bytes_used;
1411
1412 /* align with stripe_len */
1413 do_div(avail_space, BTRFS_STRIPE_LEN);
1414 avail_space *= BTRFS_STRIPE_LEN;
1415
1416 /*
1417 * In order to avoid overwritting the superblock on the drive,
1418 * btrfs starts at an offset of at least 1MB when doing chunk
1419 * allocation.
1420 */
1421 skip_space = 1024 * 1024;
1422
1423 /* user can set the offset in fs_info->alloc_start. */
1424 if (fs_info->alloc_start + BTRFS_STRIPE_LEN <=
1425 device->total_bytes)
1426 skip_space = max(fs_info->alloc_start, skip_space);
1427
1428 /*
1429 * btrfs can not use the free space in [0, skip_space - 1],
1430 * we must subtract it from the total. In order to implement
1431 * it, we account the used space in this range first.
1432 */
1433 ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1,
1434 &used_space);
1435 if (ret) {
1436 kfree(devices_info);
1437 return ret;
1438 }
1439
1440 /* calc the free space in [0, skip_space - 1] */
1441 skip_space -= used_space;
1442
1443 /*
1444 * we can use the free space in [0, skip_space - 1], subtract
1445 * it from the total.
1446 */
1447 if (avail_space && avail_space >= skip_space)
1448 avail_space -= skip_space;
1449 else
1450 avail_space = 0;
1451
1452 if (avail_space < min_stripe_size)
1453 continue;
1454
1455 devices_info[i].dev = device;
1456 devices_info[i].max_avail = avail_space;
1457
1458 i++;
1459 }
1460
1461 nr_devices = i;
1462
1463 btrfs_descending_sort_devices(devices_info, nr_devices);
1464
1465 i = nr_devices - 1;
1466 avail_space = 0;
1467 while (nr_devices >= min_stripes) {
1468 if (num_stripes > nr_devices)
1469 num_stripes = nr_devices;
1470
1471 if (devices_info[i].max_avail >= min_stripe_size) {
1472 int j;
1473 u64 alloc_size;
1474
1475 avail_space += devices_info[i].max_avail * num_stripes;
1476 alloc_size = devices_info[i].max_avail;
1477 for (j = i + 1 - num_stripes; j <= i; j++)
1478 devices_info[j].max_avail -= alloc_size;
1479 }
1480 i--;
1481 nr_devices--;
1482 }
1483
1484 kfree(devices_info);
1485 *free_bytes = avail_space;
1486 return 0;
1487 }
1488
btrfs_statfs(struct dentry * dentry,struct kstatfs * buf)1489 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
1490 {
1491 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
1492 struct btrfs_super_block *disk_super = fs_info->super_copy;
1493 struct list_head *head = &fs_info->space_info;
1494 struct btrfs_space_info *found;
1495 u64 total_used = 0;
1496 u64 total_free_data = 0;
1497 int bits = dentry->d_sb->s_blocksize_bits;
1498 __be32 *fsid = (__be32 *)fs_info->fsid;
1499 int ret;
1500
1501 /* holding chunk_muext to avoid allocating new chunks */
1502 mutex_lock(&fs_info->chunk_mutex);
1503 rcu_read_lock();
1504 list_for_each_entry_rcu(found, head, list) {
1505 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
1506 total_free_data += found->disk_total - found->disk_used;
1507 total_free_data -=
1508 btrfs_account_ro_block_groups_free_space(found);
1509 }
1510
1511 total_used += found->disk_used;
1512 }
1513 rcu_read_unlock();
1514
1515 buf->f_namelen = BTRFS_NAME_LEN;
1516 buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
1517 buf->f_bfree = buf->f_blocks - (total_used >> bits);
1518 buf->f_bsize = dentry->d_sb->s_blocksize;
1519 buf->f_type = BTRFS_SUPER_MAGIC;
1520 buf->f_bavail = total_free_data;
1521 ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data);
1522 if (ret) {
1523 mutex_unlock(&fs_info->chunk_mutex);
1524 return ret;
1525 }
1526 buf->f_bavail += total_free_data;
1527 buf->f_bavail = buf->f_bavail >> bits;
1528 mutex_unlock(&fs_info->chunk_mutex);
1529
1530 /* We treat it as constant endianness (it doesn't matter _which_)
1531 because we want the fsid to come out the same whether mounted
1532 on a big-endian or little-endian host */
1533 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
1534 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
1535 /* Mask in the root object ID too, to disambiguate subvols */
1536 buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32;
1537 buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid;
1538
1539 return 0;
1540 }
1541
btrfs_kill_super(struct super_block * sb)1542 static void btrfs_kill_super(struct super_block *sb)
1543 {
1544 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1545 kill_anon_super(sb);
1546 free_fs_info(fs_info);
1547 }
1548
1549 static struct file_system_type btrfs_fs_type = {
1550 .owner = THIS_MODULE,
1551 .name = "btrfs",
1552 .mount = btrfs_mount,
1553 .kill_sb = btrfs_kill_super,
1554 .fs_flags = FS_REQUIRES_DEV,
1555 };
1556 MODULE_ALIAS_FS("btrfs");
1557
1558 /*
1559 * used by btrfsctl to scan devices when no FS is mounted
1560 */
btrfs_control_ioctl(struct file * file,unsigned int cmd,unsigned long arg)1561 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
1562 unsigned long arg)
1563 {
1564 struct btrfs_ioctl_vol_args *vol;
1565 struct btrfs_fs_devices *fs_devices;
1566 int ret = -ENOTTY;
1567
1568 if (!capable(CAP_SYS_ADMIN))
1569 return -EPERM;
1570
1571 vol = memdup_user((void __user *)arg, sizeof(*vol));
1572 if (IS_ERR(vol))
1573 return PTR_ERR(vol);
1574
1575 switch (cmd) {
1576 case BTRFS_IOC_SCAN_DEV:
1577 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1578 &btrfs_fs_type, &fs_devices);
1579 break;
1580 case BTRFS_IOC_DEVICES_READY:
1581 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1582 &btrfs_fs_type, &fs_devices);
1583 if (ret)
1584 break;
1585 ret = !(fs_devices->num_devices == fs_devices->total_devices);
1586 break;
1587 }
1588
1589 kfree(vol);
1590 return ret;
1591 }
1592
btrfs_freeze(struct super_block * sb)1593 static int btrfs_freeze(struct super_block *sb)
1594 {
1595 struct btrfs_trans_handle *trans;
1596 struct btrfs_root *root = btrfs_sb(sb)->tree_root;
1597
1598 trans = btrfs_attach_transaction_barrier(root);
1599 if (IS_ERR(trans)) {
1600 /* no transaction, don't bother */
1601 if (PTR_ERR(trans) == -ENOENT)
1602 return 0;
1603 return PTR_ERR(trans);
1604 }
1605 return btrfs_commit_transaction(trans, root);
1606 }
1607
btrfs_unfreeze(struct super_block * sb)1608 static int btrfs_unfreeze(struct super_block *sb)
1609 {
1610 return 0;
1611 }
1612
btrfs_show_devname(struct seq_file * m,struct dentry * root)1613 static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
1614 {
1615 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
1616 struct btrfs_fs_devices *cur_devices;
1617 struct btrfs_device *dev, *first_dev = NULL;
1618 struct list_head *head;
1619 struct rcu_string *name;
1620
1621 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1622 cur_devices = fs_info->fs_devices;
1623 while (cur_devices) {
1624 head = &cur_devices->devices;
1625 list_for_each_entry(dev, head, dev_list) {
1626 if (dev->missing)
1627 continue;
1628 if (!first_dev || dev->devid < first_dev->devid)
1629 first_dev = dev;
1630 }
1631 cur_devices = cur_devices->seed;
1632 }
1633
1634 if (first_dev) {
1635 rcu_read_lock();
1636 name = rcu_dereference(first_dev->name);
1637 seq_escape(m, name->str, " \t\n\\");
1638 rcu_read_unlock();
1639 } else {
1640 WARN_ON(1);
1641 }
1642 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1643 return 0;
1644 }
1645
1646 static const struct super_operations btrfs_super_ops = {
1647 .drop_inode = btrfs_drop_inode,
1648 .evict_inode = btrfs_evict_inode,
1649 .put_super = btrfs_put_super,
1650 .sync_fs = btrfs_sync_fs,
1651 .show_options = btrfs_show_options,
1652 .show_devname = btrfs_show_devname,
1653 .write_inode = btrfs_write_inode,
1654 .alloc_inode = btrfs_alloc_inode,
1655 .destroy_inode = btrfs_destroy_inode,
1656 .statfs = btrfs_statfs,
1657 .remount_fs = btrfs_remount,
1658 .freeze_fs = btrfs_freeze,
1659 .unfreeze_fs = btrfs_unfreeze,
1660 };
1661
1662 static const struct file_operations btrfs_ctl_fops = {
1663 .unlocked_ioctl = btrfs_control_ioctl,
1664 .compat_ioctl = btrfs_control_ioctl,
1665 .owner = THIS_MODULE,
1666 .llseek = noop_llseek,
1667 };
1668
1669 static struct miscdevice btrfs_misc = {
1670 .minor = BTRFS_MINOR,
1671 .name = "btrfs-control",
1672 .fops = &btrfs_ctl_fops
1673 };
1674
1675 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
1676 MODULE_ALIAS("devname:btrfs-control");
1677
btrfs_interface_init(void)1678 static int btrfs_interface_init(void)
1679 {
1680 return misc_register(&btrfs_misc);
1681 }
1682
btrfs_interface_exit(void)1683 static void btrfs_interface_exit(void)
1684 {
1685 if (misc_deregister(&btrfs_misc) < 0)
1686 printk(KERN_INFO "btrfs: misc_deregister failed for control device\n");
1687 }
1688
init_btrfs_fs(void)1689 static int __init init_btrfs_fs(void)
1690 {
1691 int err;
1692
1693 err = btrfs_init_sysfs();
1694 if (err)
1695 return err;
1696
1697 btrfs_init_compress();
1698
1699 err = btrfs_init_cachep();
1700 if (err)
1701 goto free_compress;
1702
1703 err = extent_io_init();
1704 if (err)
1705 goto free_cachep;
1706
1707 err = extent_map_init();
1708 if (err)
1709 goto free_extent_io;
1710
1711 err = ordered_data_init();
1712 if (err)
1713 goto free_extent_map;
1714
1715 err = btrfs_delayed_inode_init();
1716 if (err)
1717 goto free_ordered_data;
1718
1719 err = btrfs_auto_defrag_init();
1720 if (err)
1721 goto free_delayed_inode;
1722
1723 err = btrfs_delayed_ref_init();
1724 if (err)
1725 goto free_auto_defrag;
1726
1727 err = btrfs_interface_init();
1728 if (err)
1729 goto free_delayed_ref;
1730
1731 err = register_filesystem(&btrfs_fs_type);
1732 if (err)
1733 goto unregister_ioctl;
1734
1735 btrfs_init_lockdep();
1736
1737 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
1738 btrfs_test_free_space_cache();
1739 #endif
1740
1741 printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION);
1742 return 0;
1743
1744 unregister_ioctl:
1745 btrfs_interface_exit();
1746 free_delayed_ref:
1747 btrfs_delayed_ref_exit();
1748 free_auto_defrag:
1749 btrfs_auto_defrag_exit();
1750 free_delayed_inode:
1751 btrfs_delayed_inode_exit();
1752 free_ordered_data:
1753 ordered_data_exit();
1754 free_extent_map:
1755 extent_map_exit();
1756 free_extent_io:
1757 extent_io_exit();
1758 free_cachep:
1759 btrfs_destroy_cachep();
1760 free_compress:
1761 btrfs_exit_compress();
1762 btrfs_exit_sysfs();
1763 return err;
1764 }
1765
exit_btrfs_fs(void)1766 static void __exit exit_btrfs_fs(void)
1767 {
1768 btrfs_destroy_cachep();
1769 btrfs_delayed_ref_exit();
1770 btrfs_auto_defrag_exit();
1771 btrfs_delayed_inode_exit();
1772 ordered_data_exit();
1773 extent_map_exit();
1774 extent_io_exit();
1775 btrfs_interface_exit();
1776 unregister_filesystem(&btrfs_fs_type);
1777 btrfs_exit_sysfs();
1778 btrfs_cleanup_fs_uuids();
1779 btrfs_exit_compress();
1780 }
1781
1782 module_init(init_btrfs_fs)
1783 module_exit(exit_btrfs_fs)
1784
1785 MODULE_LICENSE("GPL");
1786