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regulator: arizona-ldo1: Factor out generic initialization
[mirror_ubuntu-bionic-kernel.git] / fs / btrfs / super.c
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 "delayed-inode.h"
46 #include "ctree.h"
47 #include "disk-io.h"
48 #include "transaction.h"
49 #include "btrfs_inode.h"
50 #include "print-tree.h"
51 #include "hash.h"
52 #include "props.h"
53 #include "xattr.h"
54 #include "volumes.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 #include "backref.h"
61 #include "tests/btrfs-tests.h"
62
63 #include "qgroup.h"
64 #define CREATE_TRACE_POINTS
65 #include <trace/events/btrfs.h>
66
67 static const struct super_operations btrfs_super_ops;
68 static struct file_system_type btrfs_fs_type;
69
70 static int btrfs_remount(struct super_block *sb, int *flags, char *data);
71
72 const char *btrfs_decode_error(int errno)
73 {
74 char *errstr = "unknown";
75
76 switch (errno) {
77 case -EIO:
78 errstr = "IO failure";
79 break;
80 case -ENOMEM:
81 errstr = "Out of memory";
82 break;
83 case -EROFS:
84 errstr = "Readonly filesystem";
85 break;
86 case -EEXIST:
87 errstr = "Object already exists";
88 break;
89 case -ENOSPC:
90 errstr = "No space left";
91 break;
92 case -ENOENT:
93 errstr = "No such entry";
94 break;
95 }
96
97 return errstr;
98 }
99
100 /* btrfs handle error by forcing the filesystem readonly */
101 static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
102 {
103 struct super_block *sb = fs_info->sb;
104
105 if (sb->s_flags & MS_RDONLY)
106 return;
107
108 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
109 sb->s_flags |= MS_RDONLY;
110 btrfs_info(fs_info, "forced readonly");
111 /*
112 * Note that a running device replace operation is not
113 * canceled here although there is no way to update
114 * the progress. It would add the risk of a deadlock,
115 * therefore the canceling is omitted. The only penalty
116 * is that some I/O remains active until the procedure
117 * completes. The next time when the filesystem is
118 * mounted writeable again, the device replace
119 * operation continues.
120 */
121 }
122 }
123
124 /*
125 * __btrfs_handle_fs_error decodes expected errors from the caller and
126 * invokes the approciate error response.
127 */
128 __cold
129 void __btrfs_handle_fs_error(struct btrfs_fs_info *fs_info, const char *function,
130 unsigned int line, int errno, const char *fmt, ...)
131 {
132 struct super_block *sb = fs_info->sb;
133 #ifdef CONFIG_PRINTK
134 const char *errstr;
135 #endif
136
137 /*
138 * Special case: if the error is EROFS, and we're already
139 * under MS_RDONLY, then it is safe here.
140 */
141 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
142 return;
143
144 #ifdef CONFIG_PRINTK
145 errstr = btrfs_decode_error(errno);
146 if (fmt) {
147 struct va_format vaf;
148 va_list args;
149
150 va_start(args, fmt);
151 vaf.fmt = fmt;
152 vaf.va = &args;
153
154 pr_crit("BTRFS: error (device %s) in %s:%d: errno=%d %s (%pV)\n",
155 sb->s_id, function, line, errno, errstr, &vaf);
156 va_end(args);
157 } else {
158 pr_crit("BTRFS: error (device %s) in %s:%d: errno=%d %s\n",
159 sb->s_id, function, line, errno, errstr);
160 }
161 #endif
162
163 /*
164 * Today we only save the error info to memory. Long term we'll
165 * also send it down to the disk
166 */
167 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
168
169 /* Don't go through full error handling during mount */
170 if (sb->s_flags & MS_BORN)
171 btrfs_handle_error(fs_info);
172 }
173
174 #ifdef CONFIG_PRINTK
175 static const char * const logtypes[] = {
176 "emergency",
177 "alert",
178 "critical",
179 "error",
180 "warning",
181 "notice",
182 "info",
183 "debug",
184 };
185
186
187 /*
188 * Use one ratelimit state per log level so that a flood of less important
189 * messages doesn't cause more important ones to be dropped.
190 */
191 static struct ratelimit_state printk_limits[] = {
192 RATELIMIT_STATE_INIT(printk_limits[0], DEFAULT_RATELIMIT_INTERVAL, 100),
193 RATELIMIT_STATE_INIT(printk_limits[1], DEFAULT_RATELIMIT_INTERVAL, 100),
194 RATELIMIT_STATE_INIT(printk_limits[2], DEFAULT_RATELIMIT_INTERVAL, 100),
195 RATELIMIT_STATE_INIT(printk_limits[3], DEFAULT_RATELIMIT_INTERVAL, 100),
196 RATELIMIT_STATE_INIT(printk_limits[4], DEFAULT_RATELIMIT_INTERVAL, 100),
197 RATELIMIT_STATE_INIT(printk_limits[5], DEFAULT_RATELIMIT_INTERVAL, 100),
198 RATELIMIT_STATE_INIT(printk_limits[6], DEFAULT_RATELIMIT_INTERVAL, 100),
199 RATELIMIT_STATE_INIT(printk_limits[7], DEFAULT_RATELIMIT_INTERVAL, 100),
200 };
201
202 void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
203 {
204 struct super_block *sb = fs_info->sb;
205 char lvl[PRINTK_MAX_SINGLE_HEADER_LEN + 1] = "\0";
206 struct va_format vaf;
207 va_list args;
208 int kern_level;
209 const char *type = logtypes[4];
210 struct ratelimit_state *ratelimit = &printk_limits[4];
211
212 va_start(args, fmt);
213
214 while ((kern_level = printk_get_level(fmt)) != 0) {
215 size_t size = printk_skip_level(fmt) - fmt;
216
217 if (kern_level >= '0' && kern_level <= '7') {
218 memcpy(lvl, fmt, size);
219 lvl[size] = '\0';
220 type = logtypes[kern_level - '0'];
221 ratelimit = &printk_limits[kern_level - '0'];
222 }
223 fmt += size;
224 }
225
226 vaf.fmt = fmt;
227 vaf.va = &args;
228
229 if (__ratelimit(ratelimit))
230 printk("%sBTRFS %s (device %s): %pV\n", lvl, type, sb->s_id, &vaf);
231
232 va_end(args);
233 }
234 #endif
235
236 /*
237 * We only mark the transaction aborted and then set the file system read-only.
238 * This will prevent new transactions from starting or trying to join this
239 * one.
240 *
241 * This means that error recovery at the call site is limited to freeing
242 * any local memory allocations and passing the error code up without
243 * further cleanup. The transaction should complete as it normally would
244 * in the call path but will return -EIO.
245 *
246 * We'll complete the cleanup in btrfs_end_transaction and
247 * btrfs_commit_transaction.
248 */
249 __cold
250 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
251 const char *function,
252 unsigned int line, int errno)
253 {
254 struct btrfs_fs_info *fs_info = trans->fs_info;
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->dirty && list_empty(&trans->new_bgs)) {
260 const char *errstr;
261
262 errstr = btrfs_decode_error(errno);
263 btrfs_warn(fs_info,
264 "%s:%d: Aborting unused transaction(%s).",
265 function, line, errstr);
266 return;
267 }
268 WRITE_ONCE(trans->transaction->aborted, errno);
269 /* Wake up anybody who may be waiting on this transaction */
270 wake_up(&fs_info->transaction_wait);
271 wake_up(&fs_info->transaction_blocked_wait);
272 __btrfs_handle_fs_error(fs_info, function, line, errno, NULL);
273 }
274 /*
275 * __btrfs_panic decodes unexpected, fatal errors from the caller,
276 * issues an alert, and either panics or BUGs, depending on mount options.
277 */
278 __cold
279 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
280 unsigned int line, int errno, const char *fmt, ...)
281 {
282 char *s_id = "<unknown>";
283 const char *errstr;
284 struct va_format vaf = { .fmt = fmt };
285 va_list args;
286
287 if (fs_info)
288 s_id = fs_info->sb->s_id;
289
290 va_start(args, fmt);
291 vaf.va = &args;
292
293 errstr = btrfs_decode_error(errno);
294 if (fs_info && (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR))
295 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
296 s_id, function, line, &vaf, errno, errstr);
297
298 btrfs_crit(fs_info, "panic in %s:%d: %pV (errno=%d %s)",
299 function, line, &vaf, errno, errstr);
300 va_end(args);
301 /* Caller calls BUG() */
302 }
303
304 static void btrfs_put_super(struct super_block *sb)
305 {
306 close_ctree(btrfs_sb(sb));
307 }
308
309 enum {
310 Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
311 Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
312 Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
313 Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
314 Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
315 Opt_space_cache, Opt_space_cache_version, Opt_clear_cache,
316 Opt_user_subvol_rm_allowed, Opt_enospc_debug, Opt_subvolrootid,
317 Opt_defrag, Opt_inode_cache, Opt_no_space_cache, Opt_recovery,
318 Opt_skip_balance, Opt_check_integrity,
319 Opt_check_integrity_including_extent_data,
320 Opt_check_integrity_print_mask, Opt_fatal_errors, Opt_rescan_uuid_tree,
321 Opt_commit_interval, Opt_barrier, Opt_nodefrag, Opt_nodiscard,
322 Opt_noenospc_debug, Opt_noflushoncommit, Opt_acl, Opt_datacow,
323 Opt_datasum, Opt_treelog, Opt_noinode_cache, Opt_usebackuproot,
324 Opt_nologreplay, Opt_norecovery,
325 #ifdef CONFIG_BTRFS_DEBUG
326 Opt_fragment_data, Opt_fragment_metadata, Opt_fragment_all,
327 #endif
328 Opt_err,
329 };
330
331 static const match_table_t tokens = {
332 {Opt_degraded, "degraded"},
333 {Opt_subvol, "subvol=%s"},
334 {Opt_subvolid, "subvolid=%s"},
335 {Opt_device, "device=%s"},
336 {Opt_nodatasum, "nodatasum"},
337 {Opt_datasum, "datasum"},
338 {Opt_nodatacow, "nodatacow"},
339 {Opt_datacow, "datacow"},
340 {Opt_nobarrier, "nobarrier"},
341 {Opt_barrier, "barrier"},
342 {Opt_max_inline, "max_inline=%s"},
343 {Opt_alloc_start, "alloc_start=%s"},
344 {Opt_thread_pool, "thread_pool=%d"},
345 {Opt_compress, "compress"},
346 {Opt_compress_type, "compress=%s"},
347 {Opt_compress_force, "compress-force"},
348 {Opt_compress_force_type, "compress-force=%s"},
349 {Opt_ssd, "ssd"},
350 {Opt_ssd_spread, "ssd_spread"},
351 {Opt_nossd, "nossd"},
352 {Opt_acl, "acl"},
353 {Opt_noacl, "noacl"},
354 {Opt_notreelog, "notreelog"},
355 {Opt_treelog, "treelog"},
356 {Opt_nologreplay, "nologreplay"},
357 {Opt_norecovery, "norecovery"},
358 {Opt_flushoncommit, "flushoncommit"},
359 {Opt_noflushoncommit, "noflushoncommit"},
360 {Opt_ratio, "metadata_ratio=%d"},
361 {Opt_discard, "discard"},
362 {Opt_nodiscard, "nodiscard"},
363 {Opt_space_cache, "space_cache"},
364 {Opt_space_cache_version, "space_cache=%s"},
365 {Opt_clear_cache, "clear_cache"},
366 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
367 {Opt_enospc_debug, "enospc_debug"},
368 {Opt_noenospc_debug, "noenospc_debug"},
369 {Opt_subvolrootid, "subvolrootid=%d"},
370 {Opt_defrag, "autodefrag"},
371 {Opt_nodefrag, "noautodefrag"},
372 {Opt_inode_cache, "inode_cache"},
373 {Opt_noinode_cache, "noinode_cache"},
374 {Opt_no_space_cache, "nospace_cache"},
375 {Opt_recovery, "recovery"}, /* deprecated */
376 {Opt_usebackuproot, "usebackuproot"},
377 {Opt_skip_balance, "skip_balance"},
378 {Opt_check_integrity, "check_int"},
379 {Opt_check_integrity_including_extent_data, "check_int_data"},
380 {Opt_check_integrity_print_mask, "check_int_print_mask=%d"},
381 {Opt_rescan_uuid_tree, "rescan_uuid_tree"},
382 {Opt_fatal_errors, "fatal_errors=%s"},
383 {Opt_commit_interval, "commit=%d"},
384 #ifdef CONFIG_BTRFS_DEBUG
385 {Opt_fragment_data, "fragment=data"},
386 {Opt_fragment_metadata, "fragment=metadata"},
387 {Opt_fragment_all, "fragment=all"},
388 #endif
389 {Opt_err, NULL},
390 };
391
392 /*
393 * Regular mount options parser. Everything that is needed only when
394 * reading in a new superblock is parsed here.
395 * XXX JDM: This needs to be cleaned up for remount.
396 */
397 int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
398 unsigned long new_flags)
399 {
400 substring_t args[MAX_OPT_ARGS];
401 char *p, *num, *orig = NULL;
402 u64 cache_gen;
403 int intarg;
404 int ret = 0;
405 char *compress_type;
406 bool compress_force = false;
407 enum btrfs_compression_type saved_compress_type;
408 bool saved_compress_force;
409 int no_compress = 0;
410
411 cache_gen = btrfs_super_cache_generation(info->super_copy);
412 if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE))
413 btrfs_set_opt(info->mount_opt, FREE_SPACE_TREE);
414 else if (cache_gen)
415 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
416
417 /*
418 * Even the options are empty, we still need to do extra check
419 * against new flags
420 */
421 if (!options)
422 goto check;
423
424 /*
425 * strsep changes the string, duplicate it because parse_options
426 * gets called twice
427 */
428 options = kstrdup(options, GFP_NOFS);
429 if (!options)
430 return -ENOMEM;
431
432 orig = options;
433
434 while ((p = strsep(&options, ",")) != NULL) {
435 int token;
436 if (!*p)
437 continue;
438
439 token = match_token(p, tokens, args);
440 switch (token) {
441 case Opt_degraded:
442 btrfs_info(info, "allowing degraded mounts");
443 btrfs_set_opt(info->mount_opt, DEGRADED);
444 break;
445 case Opt_subvol:
446 case Opt_subvolid:
447 case Opt_subvolrootid:
448 case Opt_device:
449 /*
450 * These are parsed by btrfs_parse_early_options
451 * and can be happily ignored here.
452 */
453 break;
454 case Opt_nodatasum:
455 btrfs_set_and_info(info, NODATASUM,
456 "setting nodatasum");
457 break;
458 case Opt_datasum:
459 if (btrfs_test_opt(info, NODATASUM)) {
460 if (btrfs_test_opt(info, NODATACOW))
461 btrfs_info(info,
462 "setting datasum, datacow enabled");
463 else
464 btrfs_info(info, "setting datasum");
465 }
466 btrfs_clear_opt(info->mount_opt, NODATACOW);
467 btrfs_clear_opt(info->mount_opt, NODATASUM);
468 break;
469 case Opt_nodatacow:
470 if (!btrfs_test_opt(info, NODATACOW)) {
471 if (!btrfs_test_opt(info, COMPRESS) ||
472 !btrfs_test_opt(info, FORCE_COMPRESS)) {
473 btrfs_info(info,
474 "setting nodatacow, compression disabled");
475 } else {
476 btrfs_info(info, "setting nodatacow");
477 }
478 }
479 btrfs_clear_opt(info->mount_opt, COMPRESS);
480 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
481 btrfs_set_opt(info->mount_opt, NODATACOW);
482 btrfs_set_opt(info->mount_opt, NODATASUM);
483 break;
484 case Opt_datacow:
485 btrfs_clear_and_info(info, NODATACOW,
486 "setting datacow");
487 break;
488 case Opt_compress_force:
489 case Opt_compress_force_type:
490 compress_force = true;
491 /* Fallthrough */
492 case Opt_compress:
493 case Opt_compress_type:
494 saved_compress_type = btrfs_test_opt(info,
495 COMPRESS) ?
496 info->compress_type : BTRFS_COMPRESS_NONE;
497 saved_compress_force =
498 btrfs_test_opt(info, FORCE_COMPRESS);
499 if (token == Opt_compress ||
500 token == Opt_compress_force ||
501 strcmp(args[0].from, "zlib") == 0) {
502 compress_type = "zlib";
503 info->compress_type = BTRFS_COMPRESS_ZLIB;
504 btrfs_set_opt(info->mount_opt, COMPRESS);
505 btrfs_clear_opt(info->mount_opt, NODATACOW);
506 btrfs_clear_opt(info->mount_opt, NODATASUM);
507 no_compress = 0;
508 } else if (strcmp(args[0].from, "lzo") == 0) {
509 compress_type = "lzo";
510 info->compress_type = BTRFS_COMPRESS_LZO;
511 btrfs_set_opt(info->mount_opt, COMPRESS);
512 btrfs_clear_opt(info->mount_opt, NODATACOW);
513 btrfs_clear_opt(info->mount_opt, NODATASUM);
514 btrfs_set_fs_incompat(info, COMPRESS_LZO);
515 no_compress = 0;
516 } else if (strncmp(args[0].from, "no", 2) == 0) {
517 compress_type = "no";
518 btrfs_clear_opt(info->mount_opt, COMPRESS);
519 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
520 compress_force = false;
521 no_compress++;
522 } else {
523 ret = -EINVAL;
524 goto out;
525 }
526
527 if (compress_force) {
528 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
529 } else {
530 /*
531 * If we remount from compress-force=xxx to
532 * compress=xxx, we need clear FORCE_COMPRESS
533 * flag, otherwise, there is no way for users
534 * to disable forcible compression separately.
535 */
536 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
537 }
538 if ((btrfs_test_opt(info, COMPRESS) &&
539 (info->compress_type != saved_compress_type ||
540 compress_force != saved_compress_force)) ||
541 (!btrfs_test_opt(info, COMPRESS) &&
542 no_compress == 1)) {
543 btrfs_info(info, "%s %s compression",
544 (compress_force) ? "force" : "use",
545 compress_type);
546 }
547 compress_force = false;
548 break;
549 case Opt_ssd:
550 btrfs_set_and_info(info, SSD,
551 "use ssd allocation scheme");
552 break;
553 case Opt_ssd_spread:
554 btrfs_set_and_info(info, SSD_SPREAD,
555 "use spread ssd allocation scheme");
556 btrfs_set_opt(info->mount_opt, SSD);
557 break;
558 case Opt_nossd:
559 btrfs_set_and_info(info, NOSSD,
560 "not using ssd allocation scheme");
561 btrfs_clear_opt(info->mount_opt, SSD);
562 break;
563 case Opt_barrier:
564 btrfs_clear_and_info(info, NOBARRIER,
565 "turning on barriers");
566 break;
567 case Opt_nobarrier:
568 btrfs_set_and_info(info, NOBARRIER,
569 "turning off barriers");
570 break;
571 case Opt_thread_pool:
572 ret = match_int(&args[0], &intarg);
573 if (ret) {
574 goto out;
575 } else if (intarg > 0) {
576 info->thread_pool_size = intarg;
577 } else {
578 ret = -EINVAL;
579 goto out;
580 }
581 break;
582 case Opt_max_inline:
583 num = match_strdup(&args[0]);
584 if (num) {
585 info->max_inline = memparse(num, NULL);
586 kfree(num);
587
588 if (info->max_inline) {
589 info->max_inline = min_t(u64,
590 info->max_inline,
591 info->sectorsize);
592 }
593 btrfs_info(info, "max_inline at %llu",
594 info->max_inline);
595 } else {
596 ret = -ENOMEM;
597 goto out;
598 }
599 break;
600 case Opt_alloc_start:
601 num = match_strdup(&args[0]);
602 if (num) {
603 mutex_lock(&info->chunk_mutex);
604 info->alloc_start = memparse(num, NULL);
605 mutex_unlock(&info->chunk_mutex);
606 kfree(num);
607 btrfs_info(info, "allocations start at %llu",
608 info->alloc_start);
609 } else {
610 ret = -ENOMEM;
611 goto out;
612 }
613 break;
614 case Opt_acl:
615 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
616 info->sb->s_flags |= MS_POSIXACL;
617 break;
618 #else
619 btrfs_err(info, "support for ACL not compiled in!");
620 ret = -EINVAL;
621 goto out;
622 #endif
623 case Opt_noacl:
624 info->sb->s_flags &= ~MS_POSIXACL;
625 break;
626 case Opt_notreelog:
627 btrfs_set_and_info(info, NOTREELOG,
628 "disabling tree log");
629 break;
630 case Opt_treelog:
631 btrfs_clear_and_info(info, NOTREELOG,
632 "enabling tree log");
633 break;
634 case Opt_norecovery:
635 case Opt_nologreplay:
636 btrfs_set_and_info(info, NOLOGREPLAY,
637 "disabling log replay at mount time");
638 break;
639 case Opt_flushoncommit:
640 btrfs_set_and_info(info, FLUSHONCOMMIT,
641 "turning on flush-on-commit");
642 break;
643 case Opt_noflushoncommit:
644 btrfs_clear_and_info(info, FLUSHONCOMMIT,
645 "turning off flush-on-commit");
646 break;
647 case Opt_ratio:
648 ret = match_int(&args[0], &intarg);
649 if (ret) {
650 goto out;
651 } else if (intarg >= 0) {
652 info->metadata_ratio = intarg;
653 btrfs_info(info, "metadata ratio %d",
654 info->metadata_ratio);
655 } else {
656 ret = -EINVAL;
657 goto out;
658 }
659 break;
660 case Opt_discard:
661 btrfs_set_and_info(info, DISCARD,
662 "turning on discard");
663 break;
664 case Opt_nodiscard:
665 btrfs_clear_and_info(info, DISCARD,
666 "turning off discard");
667 break;
668 case Opt_space_cache:
669 case Opt_space_cache_version:
670 if (token == Opt_space_cache ||
671 strcmp(args[0].from, "v1") == 0) {
672 btrfs_clear_opt(info->mount_opt,
673 FREE_SPACE_TREE);
674 btrfs_set_and_info(info, SPACE_CACHE,
675 "enabling disk space caching");
676 } else if (strcmp(args[0].from, "v2") == 0) {
677 btrfs_clear_opt(info->mount_opt,
678 SPACE_CACHE);
679 btrfs_set_and_info(info, FREE_SPACE_TREE,
680 "enabling free space tree");
681 } else {
682 ret = -EINVAL;
683 goto out;
684 }
685 break;
686 case Opt_rescan_uuid_tree:
687 btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE);
688 break;
689 case Opt_no_space_cache:
690 if (btrfs_test_opt(info, SPACE_CACHE)) {
691 btrfs_clear_and_info(info, SPACE_CACHE,
692 "disabling disk space caching");
693 }
694 if (btrfs_test_opt(info, FREE_SPACE_TREE)) {
695 btrfs_clear_and_info(info, FREE_SPACE_TREE,
696 "disabling free space tree");
697 }
698 break;
699 case Opt_inode_cache:
700 btrfs_set_pending_and_info(info, INODE_MAP_CACHE,
701 "enabling inode map caching");
702 break;
703 case Opt_noinode_cache:
704 btrfs_clear_pending_and_info(info, INODE_MAP_CACHE,
705 "disabling inode map caching");
706 break;
707 case Opt_clear_cache:
708 btrfs_set_and_info(info, CLEAR_CACHE,
709 "force clearing of disk cache");
710 break;
711 case Opt_user_subvol_rm_allowed:
712 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
713 break;
714 case Opt_enospc_debug:
715 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
716 break;
717 case Opt_noenospc_debug:
718 btrfs_clear_opt(info->mount_opt, ENOSPC_DEBUG);
719 break;
720 case Opt_defrag:
721 btrfs_set_and_info(info, AUTO_DEFRAG,
722 "enabling auto defrag");
723 break;
724 case Opt_nodefrag:
725 btrfs_clear_and_info(info, AUTO_DEFRAG,
726 "disabling auto defrag");
727 break;
728 case Opt_recovery:
729 btrfs_warn(info,
730 "'recovery' is deprecated, use 'usebackuproot' instead");
731 case Opt_usebackuproot:
732 btrfs_info(info,
733 "trying to use backup root at mount time");
734 btrfs_set_opt(info->mount_opt, USEBACKUPROOT);
735 break;
736 case Opt_skip_balance:
737 btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
738 break;
739 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
740 case Opt_check_integrity_including_extent_data:
741 btrfs_info(info,
742 "enabling check integrity including extent data");
743 btrfs_set_opt(info->mount_opt,
744 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
745 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
746 break;
747 case Opt_check_integrity:
748 btrfs_info(info, "enabling check integrity");
749 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
750 break;
751 case Opt_check_integrity_print_mask:
752 ret = match_int(&args[0], &intarg);
753 if (ret) {
754 goto out;
755 } else if (intarg >= 0) {
756 info->check_integrity_print_mask = intarg;
757 btrfs_info(info,
758 "check_integrity_print_mask 0x%x",
759 info->check_integrity_print_mask);
760 } else {
761 ret = -EINVAL;
762 goto out;
763 }
764 break;
765 #else
766 case Opt_check_integrity_including_extent_data:
767 case Opt_check_integrity:
768 case Opt_check_integrity_print_mask:
769 btrfs_err(info,
770 "support for check_integrity* not compiled in!");
771 ret = -EINVAL;
772 goto out;
773 #endif
774 case Opt_fatal_errors:
775 if (strcmp(args[0].from, "panic") == 0)
776 btrfs_set_opt(info->mount_opt,
777 PANIC_ON_FATAL_ERROR);
778 else if (strcmp(args[0].from, "bug") == 0)
779 btrfs_clear_opt(info->mount_opt,
780 PANIC_ON_FATAL_ERROR);
781 else {
782 ret = -EINVAL;
783 goto out;
784 }
785 break;
786 case Opt_commit_interval:
787 intarg = 0;
788 ret = match_int(&args[0], &intarg);
789 if (ret < 0) {
790 btrfs_err(info, "invalid commit interval");
791 ret = -EINVAL;
792 goto out;
793 }
794 if (intarg > 0) {
795 if (intarg > 300) {
796 btrfs_warn(info,
797 "excessive commit interval %d",
798 intarg);
799 }
800 info->commit_interval = intarg;
801 } else {
802 btrfs_info(info,
803 "using default commit interval %ds",
804 BTRFS_DEFAULT_COMMIT_INTERVAL);
805 info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
806 }
807 break;
808 #ifdef CONFIG_BTRFS_DEBUG
809 case Opt_fragment_all:
810 btrfs_info(info, "fragmenting all space");
811 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA);
812 btrfs_set_opt(info->mount_opt, FRAGMENT_METADATA);
813 break;
814 case Opt_fragment_metadata:
815 btrfs_info(info, "fragmenting metadata");
816 btrfs_set_opt(info->mount_opt,
817 FRAGMENT_METADATA);
818 break;
819 case Opt_fragment_data:
820 btrfs_info(info, "fragmenting data");
821 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA);
822 break;
823 #endif
824 case Opt_err:
825 btrfs_info(info, "unrecognized mount option '%s'", p);
826 ret = -EINVAL;
827 goto out;
828 default:
829 break;
830 }
831 }
832 check:
833 /*
834 * Extra check for current option against current flag
835 */
836 if (btrfs_test_opt(info, NOLOGREPLAY) && !(new_flags & MS_RDONLY)) {
837 btrfs_err(info,
838 "nologreplay must be used with ro mount option");
839 ret = -EINVAL;
840 }
841 out:
842 if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE) &&
843 !btrfs_test_opt(info, FREE_SPACE_TREE) &&
844 !btrfs_test_opt(info, CLEAR_CACHE)) {
845 btrfs_err(info, "cannot disable free space tree");
846 ret = -EINVAL;
847
848 }
849 if (!ret && btrfs_test_opt(info, SPACE_CACHE))
850 btrfs_info(info, "disk space caching is enabled");
851 if (!ret && btrfs_test_opt(info, FREE_SPACE_TREE))
852 btrfs_info(info, "using free space tree");
853 kfree(orig);
854 return ret;
855 }
856
857 /*
858 * Parse mount options that are required early in the mount process.
859 *
860 * All other options will be parsed on much later in the mount process and
861 * only when we need to allocate a new super block.
862 */
863 static int btrfs_parse_early_options(const char *options, fmode_t flags,
864 void *holder, char **subvol_name, u64 *subvol_objectid,
865 struct btrfs_fs_devices **fs_devices)
866 {
867 substring_t args[MAX_OPT_ARGS];
868 char *device_name, *opts, *orig, *p;
869 char *num = NULL;
870 int error = 0;
871
872 if (!options)
873 return 0;
874
875 /*
876 * strsep changes the string, duplicate it because parse_options
877 * gets called twice
878 */
879 opts = kstrdup(options, GFP_KERNEL);
880 if (!opts)
881 return -ENOMEM;
882 orig = opts;
883
884 while ((p = strsep(&opts, ",")) != NULL) {
885 int token;
886 if (!*p)
887 continue;
888
889 token = match_token(p, tokens, args);
890 switch (token) {
891 case Opt_subvol:
892 kfree(*subvol_name);
893 *subvol_name = match_strdup(&args[0]);
894 if (!*subvol_name) {
895 error = -ENOMEM;
896 goto out;
897 }
898 break;
899 case Opt_subvolid:
900 num = match_strdup(&args[0]);
901 if (num) {
902 *subvol_objectid = memparse(num, NULL);
903 kfree(num);
904 /* we want the original fs_tree */
905 if (!*subvol_objectid)
906 *subvol_objectid =
907 BTRFS_FS_TREE_OBJECTID;
908 } else {
909 error = -EINVAL;
910 goto out;
911 }
912 break;
913 case Opt_subvolrootid:
914 pr_warn("BTRFS: 'subvolrootid' mount option is deprecated and has no effect\n");
915 break;
916 case Opt_device:
917 device_name = match_strdup(&args[0]);
918 if (!device_name) {
919 error = -ENOMEM;
920 goto out;
921 }
922 error = btrfs_scan_one_device(device_name,
923 flags, holder, fs_devices);
924 kfree(device_name);
925 if (error)
926 goto out;
927 break;
928 default:
929 break;
930 }
931 }
932
933 out:
934 kfree(orig);
935 return error;
936 }
937
938 static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info,
939 u64 subvol_objectid)
940 {
941 struct btrfs_root *root = fs_info->tree_root;
942 struct btrfs_root *fs_root;
943 struct btrfs_root_ref *root_ref;
944 struct btrfs_inode_ref *inode_ref;
945 struct btrfs_key key;
946 struct btrfs_path *path = NULL;
947 char *name = NULL, *ptr;
948 u64 dirid;
949 int len;
950 int ret;
951
952 path = btrfs_alloc_path();
953 if (!path) {
954 ret = -ENOMEM;
955 goto err;
956 }
957 path->leave_spinning = 1;
958
959 name = kmalloc(PATH_MAX, GFP_NOFS);
960 if (!name) {
961 ret = -ENOMEM;
962 goto err;
963 }
964 ptr = name + PATH_MAX - 1;
965 ptr[0] = '\0';
966
967 /*
968 * Walk up the subvolume trees in the tree of tree roots by root
969 * backrefs until we hit the top-level subvolume.
970 */
971 while (subvol_objectid != BTRFS_FS_TREE_OBJECTID) {
972 key.objectid = subvol_objectid;
973 key.type = BTRFS_ROOT_BACKREF_KEY;
974 key.offset = (u64)-1;
975
976 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
977 if (ret < 0) {
978 goto err;
979 } else if (ret > 0) {
980 ret = btrfs_previous_item(root, path, subvol_objectid,
981 BTRFS_ROOT_BACKREF_KEY);
982 if (ret < 0) {
983 goto err;
984 } else if (ret > 0) {
985 ret = -ENOENT;
986 goto err;
987 }
988 }
989
990 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
991 subvol_objectid = key.offset;
992
993 root_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
994 struct btrfs_root_ref);
995 len = btrfs_root_ref_name_len(path->nodes[0], root_ref);
996 ptr -= len + 1;
997 if (ptr < name) {
998 ret = -ENAMETOOLONG;
999 goto err;
1000 }
1001 read_extent_buffer(path->nodes[0], ptr + 1,
1002 (unsigned long)(root_ref + 1), len);
1003 ptr[0] = '/';
1004 dirid = btrfs_root_ref_dirid(path->nodes[0], root_ref);
1005 btrfs_release_path(path);
1006
1007 key.objectid = subvol_objectid;
1008 key.type = BTRFS_ROOT_ITEM_KEY;
1009 key.offset = (u64)-1;
1010 fs_root = btrfs_read_fs_root_no_name(fs_info, &key);
1011 if (IS_ERR(fs_root)) {
1012 ret = PTR_ERR(fs_root);
1013 goto err;
1014 }
1015
1016 /*
1017 * Walk up the filesystem tree by inode refs until we hit the
1018 * root directory.
1019 */
1020 while (dirid != BTRFS_FIRST_FREE_OBJECTID) {
1021 key.objectid = dirid;
1022 key.type = BTRFS_INODE_REF_KEY;
1023 key.offset = (u64)-1;
1024
1025 ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0);
1026 if (ret < 0) {
1027 goto err;
1028 } else if (ret > 0) {
1029 ret = btrfs_previous_item(fs_root, path, dirid,
1030 BTRFS_INODE_REF_KEY);
1031 if (ret < 0) {
1032 goto err;
1033 } else if (ret > 0) {
1034 ret = -ENOENT;
1035 goto err;
1036 }
1037 }
1038
1039 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1040 dirid = key.offset;
1041
1042 inode_ref = btrfs_item_ptr(path->nodes[0],
1043 path->slots[0],
1044 struct btrfs_inode_ref);
1045 len = btrfs_inode_ref_name_len(path->nodes[0],
1046 inode_ref);
1047 ptr -= len + 1;
1048 if (ptr < name) {
1049 ret = -ENAMETOOLONG;
1050 goto err;
1051 }
1052 read_extent_buffer(path->nodes[0], ptr + 1,
1053 (unsigned long)(inode_ref + 1), len);
1054 ptr[0] = '/';
1055 btrfs_release_path(path);
1056 }
1057 }
1058
1059 btrfs_free_path(path);
1060 if (ptr == name + PATH_MAX - 1) {
1061 name[0] = '/';
1062 name[1] = '\0';
1063 } else {
1064 memmove(name, ptr, name + PATH_MAX - ptr);
1065 }
1066 return name;
1067
1068 err:
1069 btrfs_free_path(path);
1070 kfree(name);
1071 return ERR_PTR(ret);
1072 }
1073
1074 static int get_default_subvol_objectid(struct btrfs_fs_info *fs_info, u64 *objectid)
1075 {
1076 struct btrfs_root *root = fs_info->tree_root;
1077 struct btrfs_dir_item *di;
1078 struct btrfs_path *path;
1079 struct btrfs_key location;
1080 u64 dir_id;
1081
1082 path = btrfs_alloc_path();
1083 if (!path)
1084 return -ENOMEM;
1085 path->leave_spinning = 1;
1086
1087 /*
1088 * Find the "default" dir item which points to the root item that we
1089 * will mount by default if we haven't been given a specific subvolume
1090 * to mount.
1091 */
1092 dir_id = btrfs_super_root_dir(fs_info->super_copy);
1093 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
1094 if (IS_ERR(di)) {
1095 btrfs_free_path(path);
1096 return PTR_ERR(di);
1097 }
1098 if (!di) {
1099 /*
1100 * Ok the default dir item isn't there. This is weird since
1101 * it's always been there, but don't freak out, just try and
1102 * mount the top-level subvolume.
1103 */
1104 btrfs_free_path(path);
1105 *objectid = BTRFS_FS_TREE_OBJECTID;
1106 return 0;
1107 }
1108
1109 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
1110 btrfs_free_path(path);
1111 *objectid = location.objectid;
1112 return 0;
1113 }
1114
1115 static int btrfs_fill_super(struct super_block *sb,
1116 struct btrfs_fs_devices *fs_devices,
1117 void *data)
1118 {
1119 struct inode *inode;
1120 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1121 struct btrfs_key key;
1122 int err;
1123
1124 sb->s_maxbytes = MAX_LFS_FILESIZE;
1125 sb->s_magic = BTRFS_SUPER_MAGIC;
1126 sb->s_op = &btrfs_super_ops;
1127 sb->s_d_op = &btrfs_dentry_operations;
1128 sb->s_export_op = &btrfs_export_ops;
1129 sb->s_xattr = btrfs_xattr_handlers;
1130 sb->s_time_gran = 1;
1131 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
1132 sb->s_flags |= MS_POSIXACL;
1133 #endif
1134 sb->s_flags |= MS_I_VERSION;
1135 sb->s_iflags |= SB_I_CGROUPWB;
1136 err = open_ctree(sb, fs_devices, (char *)data);
1137 if (err) {
1138 btrfs_err(fs_info, "open_ctree failed");
1139 return err;
1140 }
1141
1142 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
1143 key.type = BTRFS_INODE_ITEM_KEY;
1144 key.offset = 0;
1145 inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
1146 if (IS_ERR(inode)) {
1147 err = PTR_ERR(inode);
1148 goto fail_close;
1149 }
1150
1151 sb->s_root = d_make_root(inode);
1152 if (!sb->s_root) {
1153 err = -ENOMEM;
1154 goto fail_close;
1155 }
1156
1157 save_mount_options(sb, data);
1158 cleancache_init_fs(sb);
1159 sb->s_flags |= MS_ACTIVE;
1160 return 0;
1161
1162 fail_close:
1163 close_ctree(fs_info);
1164 return err;
1165 }
1166
1167 int btrfs_sync_fs(struct super_block *sb, int wait)
1168 {
1169 struct btrfs_trans_handle *trans;
1170 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1171 struct btrfs_root *root = fs_info->tree_root;
1172
1173 trace_btrfs_sync_fs(fs_info, wait);
1174
1175 if (!wait) {
1176 filemap_flush(fs_info->btree_inode->i_mapping);
1177 return 0;
1178 }
1179
1180 btrfs_wait_ordered_roots(fs_info, -1, 0, (u64)-1);
1181
1182 trans = btrfs_attach_transaction_barrier(root);
1183 if (IS_ERR(trans)) {
1184 /* no transaction, don't bother */
1185 if (PTR_ERR(trans) == -ENOENT) {
1186 /*
1187 * Exit unless we have some pending changes
1188 * that need to go through commit
1189 */
1190 if (fs_info->pending_changes == 0)
1191 return 0;
1192 /*
1193 * A non-blocking test if the fs is frozen. We must not
1194 * start a new transaction here otherwise a deadlock
1195 * happens. The pending operations are delayed to the
1196 * next commit after thawing.
1197 */
1198 if (__sb_start_write(sb, SB_FREEZE_WRITE, false))
1199 __sb_end_write(sb, SB_FREEZE_WRITE);
1200 else
1201 return 0;
1202 trans = btrfs_start_transaction(root, 0);
1203 }
1204 if (IS_ERR(trans))
1205 return PTR_ERR(trans);
1206 }
1207 return btrfs_commit_transaction(trans);
1208 }
1209
1210 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
1211 {
1212 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
1213 char *compress_type;
1214
1215 if (btrfs_test_opt(info, DEGRADED))
1216 seq_puts(seq, ",degraded");
1217 if (btrfs_test_opt(info, NODATASUM))
1218 seq_puts(seq, ",nodatasum");
1219 if (btrfs_test_opt(info, NODATACOW))
1220 seq_puts(seq, ",nodatacow");
1221 if (btrfs_test_opt(info, NOBARRIER))
1222 seq_puts(seq, ",nobarrier");
1223 if (info->max_inline != BTRFS_DEFAULT_MAX_INLINE)
1224 seq_printf(seq, ",max_inline=%llu", info->max_inline);
1225 if (info->alloc_start != 0)
1226 seq_printf(seq, ",alloc_start=%llu", info->alloc_start);
1227 if (info->thread_pool_size != min_t(unsigned long,
1228 num_online_cpus() + 2, 8))
1229 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
1230 if (btrfs_test_opt(info, COMPRESS)) {
1231 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
1232 compress_type = "zlib";
1233 else
1234 compress_type = "lzo";
1235 if (btrfs_test_opt(info, FORCE_COMPRESS))
1236 seq_printf(seq, ",compress-force=%s", compress_type);
1237 else
1238 seq_printf(seq, ",compress=%s", compress_type);
1239 }
1240 if (btrfs_test_opt(info, NOSSD))
1241 seq_puts(seq, ",nossd");
1242 if (btrfs_test_opt(info, SSD_SPREAD))
1243 seq_puts(seq, ",ssd_spread");
1244 else if (btrfs_test_opt(info, SSD))
1245 seq_puts(seq, ",ssd");
1246 if (btrfs_test_opt(info, NOTREELOG))
1247 seq_puts(seq, ",notreelog");
1248 if (btrfs_test_opt(info, NOLOGREPLAY))
1249 seq_puts(seq, ",nologreplay");
1250 if (btrfs_test_opt(info, FLUSHONCOMMIT))
1251 seq_puts(seq, ",flushoncommit");
1252 if (btrfs_test_opt(info, DISCARD))
1253 seq_puts(seq, ",discard");
1254 if (!(info->sb->s_flags & MS_POSIXACL))
1255 seq_puts(seq, ",noacl");
1256 if (btrfs_test_opt(info, SPACE_CACHE))
1257 seq_puts(seq, ",space_cache");
1258 else if (btrfs_test_opt(info, FREE_SPACE_TREE))
1259 seq_puts(seq, ",space_cache=v2");
1260 else
1261 seq_puts(seq, ",nospace_cache");
1262 if (btrfs_test_opt(info, RESCAN_UUID_TREE))
1263 seq_puts(seq, ",rescan_uuid_tree");
1264 if (btrfs_test_opt(info, CLEAR_CACHE))
1265 seq_puts(seq, ",clear_cache");
1266 if (btrfs_test_opt(info, USER_SUBVOL_RM_ALLOWED))
1267 seq_puts(seq, ",user_subvol_rm_allowed");
1268 if (btrfs_test_opt(info, ENOSPC_DEBUG))
1269 seq_puts(seq, ",enospc_debug");
1270 if (btrfs_test_opt(info, AUTO_DEFRAG))
1271 seq_puts(seq, ",autodefrag");
1272 if (btrfs_test_opt(info, INODE_MAP_CACHE))
1273 seq_puts(seq, ",inode_cache");
1274 if (btrfs_test_opt(info, SKIP_BALANCE))
1275 seq_puts(seq, ",skip_balance");
1276 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1277 if (btrfs_test_opt(info, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA))
1278 seq_puts(seq, ",check_int_data");
1279 else if (btrfs_test_opt(info, CHECK_INTEGRITY))
1280 seq_puts(seq, ",check_int");
1281 if (info->check_integrity_print_mask)
1282 seq_printf(seq, ",check_int_print_mask=%d",
1283 info->check_integrity_print_mask);
1284 #endif
1285 if (info->metadata_ratio)
1286 seq_printf(seq, ",metadata_ratio=%d",
1287 info->metadata_ratio);
1288 if (btrfs_test_opt(info, PANIC_ON_FATAL_ERROR))
1289 seq_puts(seq, ",fatal_errors=panic");
1290 if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL)
1291 seq_printf(seq, ",commit=%d", info->commit_interval);
1292 #ifdef CONFIG_BTRFS_DEBUG
1293 if (btrfs_test_opt(info, FRAGMENT_DATA))
1294 seq_puts(seq, ",fragment=data");
1295 if (btrfs_test_opt(info, FRAGMENT_METADATA))
1296 seq_puts(seq, ",fragment=metadata");
1297 #endif
1298 seq_printf(seq, ",subvolid=%llu",
1299 BTRFS_I(d_inode(dentry))->root->root_key.objectid);
1300 seq_puts(seq, ",subvol=");
1301 seq_dentry(seq, dentry, " \t\n\\");
1302 return 0;
1303 }
1304
1305 static int btrfs_test_super(struct super_block *s, void *data)
1306 {
1307 struct btrfs_fs_info *p = data;
1308 struct btrfs_fs_info *fs_info = btrfs_sb(s);
1309
1310 return fs_info->fs_devices == p->fs_devices;
1311 }
1312
1313 static int btrfs_set_super(struct super_block *s, void *data)
1314 {
1315 int err = set_anon_super(s, data);
1316 if (!err)
1317 s->s_fs_info = data;
1318 return err;
1319 }
1320
1321 /*
1322 * subvolumes are identified by ino 256
1323 */
1324 static inline int is_subvolume_inode(struct inode *inode)
1325 {
1326 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
1327 return 1;
1328 return 0;
1329 }
1330
1331 /*
1332 * This will add subvolid=0 to the argument string while removing any subvol=
1333 * and subvolid= arguments to make sure we get the top-level root for path
1334 * walking to the subvol we want.
1335 */
1336 static char *setup_root_args(char *args)
1337 {
1338 char *buf, *dst, *sep;
1339
1340 if (!args)
1341 return kstrdup("subvolid=0", GFP_NOFS);
1342
1343 /* The worst case is that we add ",subvolid=0" to the end. */
1344 buf = dst = kmalloc(strlen(args) + strlen(",subvolid=0") + 1, GFP_NOFS);
1345 if (!buf)
1346 return NULL;
1347
1348 while (1) {
1349 sep = strchrnul(args, ',');
1350 if (!strstarts(args, "subvol=") &&
1351 !strstarts(args, "subvolid=")) {
1352 memcpy(dst, args, sep - args);
1353 dst += sep - args;
1354 *dst++ = ',';
1355 }
1356 if (*sep)
1357 args = sep + 1;
1358 else
1359 break;
1360 }
1361 strcpy(dst, "subvolid=0");
1362
1363 return buf;
1364 }
1365
1366 static struct dentry *mount_subvol(const char *subvol_name, u64 subvol_objectid,
1367 int flags, const char *device_name,
1368 char *data)
1369 {
1370 struct dentry *root;
1371 struct vfsmount *mnt = NULL;
1372 char *newargs;
1373 int ret;
1374
1375 newargs = setup_root_args(data);
1376 if (!newargs) {
1377 root = ERR_PTR(-ENOMEM);
1378 goto out;
1379 }
1380
1381 mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name, newargs);
1382 if (PTR_ERR_OR_ZERO(mnt) == -EBUSY) {
1383 if (flags & MS_RDONLY) {
1384 mnt = vfs_kern_mount(&btrfs_fs_type, flags & ~MS_RDONLY,
1385 device_name, newargs);
1386 } else {
1387 mnt = vfs_kern_mount(&btrfs_fs_type, flags | MS_RDONLY,
1388 device_name, newargs);
1389 if (IS_ERR(mnt)) {
1390 root = ERR_CAST(mnt);
1391 mnt = NULL;
1392 goto out;
1393 }
1394
1395 down_write(&mnt->mnt_sb->s_umount);
1396 ret = btrfs_remount(mnt->mnt_sb, &flags, NULL);
1397 up_write(&mnt->mnt_sb->s_umount);
1398 if (ret < 0) {
1399 root = ERR_PTR(ret);
1400 goto out;
1401 }
1402 }
1403 }
1404 if (IS_ERR(mnt)) {
1405 root = ERR_CAST(mnt);
1406 mnt = NULL;
1407 goto out;
1408 }
1409
1410 if (!subvol_name) {
1411 if (!subvol_objectid) {
1412 ret = get_default_subvol_objectid(btrfs_sb(mnt->mnt_sb),
1413 &subvol_objectid);
1414 if (ret) {
1415 root = ERR_PTR(ret);
1416 goto out;
1417 }
1418 }
1419 subvol_name = get_subvol_name_from_objectid(btrfs_sb(mnt->mnt_sb),
1420 subvol_objectid);
1421 if (IS_ERR(subvol_name)) {
1422 root = ERR_CAST(subvol_name);
1423 subvol_name = NULL;
1424 goto out;
1425 }
1426
1427 }
1428
1429 root = mount_subtree(mnt, subvol_name);
1430 /* mount_subtree() drops our reference on the vfsmount. */
1431 mnt = NULL;
1432
1433 if (!IS_ERR(root)) {
1434 struct super_block *s = root->d_sb;
1435 struct btrfs_fs_info *fs_info = btrfs_sb(s);
1436 struct inode *root_inode = d_inode(root);
1437 u64 root_objectid = BTRFS_I(root_inode)->root->root_key.objectid;
1438
1439 ret = 0;
1440 if (!is_subvolume_inode(root_inode)) {
1441 btrfs_err(fs_info, "'%s' is not a valid subvolume",
1442 subvol_name);
1443 ret = -EINVAL;
1444 }
1445 if (subvol_objectid && root_objectid != subvol_objectid) {
1446 /*
1447 * This will also catch a race condition where a
1448 * subvolume which was passed by ID is renamed and
1449 * another subvolume is renamed over the old location.
1450 */
1451 btrfs_err(fs_info,
1452 "subvol '%s' does not match subvolid %llu",
1453 subvol_name, subvol_objectid);
1454 ret = -EINVAL;
1455 }
1456 if (ret) {
1457 dput(root);
1458 root = ERR_PTR(ret);
1459 deactivate_locked_super(s);
1460 }
1461 }
1462
1463 out:
1464 mntput(mnt);
1465 kfree(newargs);
1466 kfree(subvol_name);
1467 return root;
1468 }
1469
1470 static int parse_security_options(char *orig_opts,
1471 struct security_mnt_opts *sec_opts)
1472 {
1473 char *secdata = NULL;
1474 int ret = 0;
1475
1476 secdata = alloc_secdata();
1477 if (!secdata)
1478 return -ENOMEM;
1479 ret = security_sb_copy_data(orig_opts, secdata);
1480 if (ret) {
1481 free_secdata(secdata);
1482 return ret;
1483 }
1484 ret = security_sb_parse_opts_str(secdata, sec_opts);
1485 free_secdata(secdata);
1486 return ret;
1487 }
1488
1489 static int setup_security_options(struct btrfs_fs_info *fs_info,
1490 struct super_block *sb,
1491 struct security_mnt_opts *sec_opts)
1492 {
1493 int ret = 0;
1494
1495 /*
1496 * Call security_sb_set_mnt_opts() to check whether new sec_opts
1497 * is valid.
1498 */
1499 ret = security_sb_set_mnt_opts(sb, sec_opts, 0, NULL);
1500 if (ret)
1501 return ret;
1502
1503 #ifdef CONFIG_SECURITY
1504 if (!fs_info->security_opts.num_mnt_opts) {
1505 /* first time security setup, copy sec_opts to fs_info */
1506 memcpy(&fs_info->security_opts, sec_opts, sizeof(*sec_opts));
1507 } else {
1508 /*
1509 * Since SELinux (the only one supporting security_mnt_opts)
1510 * does NOT support changing context during remount/mount of
1511 * the same sb, this must be the same or part of the same
1512 * security options, just free it.
1513 */
1514 security_free_mnt_opts(sec_opts);
1515 }
1516 #endif
1517 return ret;
1518 }
1519
1520 /*
1521 * Find a superblock for the given device / mount point.
1522 *
1523 * Note: This is based on get_sb_bdev from fs/super.c with a few additions
1524 * for multiple device setup. Make sure to keep it in sync.
1525 */
1526 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1527 const char *device_name, void *data)
1528 {
1529 struct block_device *bdev = NULL;
1530 struct super_block *s;
1531 struct btrfs_fs_devices *fs_devices = NULL;
1532 struct btrfs_fs_info *fs_info = NULL;
1533 struct security_mnt_opts new_sec_opts;
1534 fmode_t mode = FMODE_READ;
1535 char *subvol_name = NULL;
1536 u64 subvol_objectid = 0;
1537 int error = 0;
1538
1539 if (!(flags & MS_RDONLY))
1540 mode |= FMODE_WRITE;
1541
1542 error = btrfs_parse_early_options(data, mode, fs_type,
1543 &subvol_name, &subvol_objectid,
1544 &fs_devices);
1545 if (error) {
1546 kfree(subvol_name);
1547 return ERR_PTR(error);
1548 }
1549
1550 if (subvol_name || subvol_objectid != BTRFS_FS_TREE_OBJECTID) {
1551 /* mount_subvol() will free subvol_name. */
1552 return mount_subvol(subvol_name, subvol_objectid, flags,
1553 device_name, data);
1554 }
1555
1556 security_init_mnt_opts(&new_sec_opts);
1557 if (data) {
1558 error = parse_security_options(data, &new_sec_opts);
1559 if (error)
1560 return ERR_PTR(error);
1561 }
1562
1563 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
1564 if (error)
1565 goto error_sec_opts;
1566
1567 /*
1568 * Setup a dummy root and fs_info for test/set super. This is because
1569 * we don't actually fill this stuff out until open_ctree, but we need
1570 * it for searching for existing supers, so this lets us do that and
1571 * then open_ctree will properly initialize everything later.
1572 */
1573 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
1574 if (!fs_info) {
1575 error = -ENOMEM;
1576 goto error_sec_opts;
1577 }
1578
1579 fs_info->fs_devices = fs_devices;
1580
1581 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1582 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1583 security_init_mnt_opts(&fs_info->security_opts);
1584 if (!fs_info->super_copy || !fs_info->super_for_commit) {
1585 error = -ENOMEM;
1586 goto error_fs_info;
1587 }
1588
1589 error = btrfs_open_devices(fs_devices, mode, fs_type);
1590 if (error)
1591 goto error_fs_info;
1592
1593 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
1594 error = -EACCES;
1595 goto error_close_devices;
1596 }
1597
1598 bdev = fs_devices->latest_bdev;
1599 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | MS_NOSEC,
1600 fs_info);
1601 if (IS_ERR(s)) {
1602 error = PTR_ERR(s);
1603 goto error_close_devices;
1604 }
1605
1606 if (s->s_root) {
1607 btrfs_close_devices(fs_devices);
1608 free_fs_info(fs_info);
1609 if ((flags ^ s->s_flags) & MS_RDONLY)
1610 error = -EBUSY;
1611 } else {
1612 snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev);
1613 btrfs_sb(s)->bdev_holder = fs_type;
1614 error = btrfs_fill_super(s, fs_devices, data);
1615 }
1616 if (error) {
1617 deactivate_locked_super(s);
1618 goto error_sec_opts;
1619 }
1620
1621 fs_info = btrfs_sb(s);
1622 error = setup_security_options(fs_info, s, &new_sec_opts);
1623 if (error) {
1624 deactivate_locked_super(s);
1625 goto error_sec_opts;
1626 }
1627
1628 return dget(s->s_root);
1629
1630 error_close_devices:
1631 btrfs_close_devices(fs_devices);
1632 error_fs_info:
1633 free_fs_info(fs_info);
1634 error_sec_opts:
1635 security_free_mnt_opts(&new_sec_opts);
1636 return ERR_PTR(error);
1637 }
1638
1639 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1640 int new_pool_size, int old_pool_size)
1641 {
1642 if (new_pool_size == old_pool_size)
1643 return;
1644
1645 fs_info->thread_pool_size = new_pool_size;
1646
1647 btrfs_info(fs_info, "resize thread pool %d -> %d",
1648 old_pool_size, new_pool_size);
1649
1650 btrfs_workqueue_set_max(fs_info->workers, new_pool_size);
1651 btrfs_workqueue_set_max(fs_info->delalloc_workers, new_pool_size);
1652 btrfs_workqueue_set_max(fs_info->submit_workers, new_pool_size);
1653 btrfs_workqueue_set_max(fs_info->caching_workers, new_pool_size);
1654 btrfs_workqueue_set_max(fs_info->endio_workers, new_pool_size);
1655 btrfs_workqueue_set_max(fs_info->endio_meta_workers, new_pool_size);
1656 btrfs_workqueue_set_max(fs_info->endio_meta_write_workers,
1657 new_pool_size);
1658 btrfs_workqueue_set_max(fs_info->endio_write_workers, new_pool_size);
1659 btrfs_workqueue_set_max(fs_info->endio_freespace_worker, new_pool_size);
1660 btrfs_workqueue_set_max(fs_info->delayed_workers, new_pool_size);
1661 btrfs_workqueue_set_max(fs_info->readahead_workers, new_pool_size);
1662 btrfs_workqueue_set_max(fs_info->scrub_wr_completion_workers,
1663 new_pool_size);
1664 }
1665
1666 static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info)
1667 {
1668 set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1669 }
1670
1671 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
1672 unsigned long old_opts, int flags)
1673 {
1674 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1675 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1676 (flags & MS_RDONLY))) {
1677 /* wait for any defraggers to finish */
1678 wait_event(fs_info->transaction_wait,
1679 (atomic_read(&fs_info->defrag_running) == 0));
1680 if (flags & MS_RDONLY)
1681 sync_filesystem(fs_info->sb);
1682 }
1683 }
1684
1685 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1686 unsigned long old_opts)
1687 {
1688 /*
1689 * We need to cleanup all defragable inodes if the autodefragment is
1690 * close or the filesystem is read only.
1691 */
1692 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1693 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1694 (fs_info->sb->s_flags & MS_RDONLY))) {
1695 btrfs_cleanup_defrag_inodes(fs_info);
1696 }
1697
1698 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1699 }
1700
1701 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1702 {
1703 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1704 struct btrfs_root *root = fs_info->tree_root;
1705 unsigned old_flags = sb->s_flags;
1706 unsigned long old_opts = fs_info->mount_opt;
1707 unsigned long old_compress_type = fs_info->compress_type;
1708 u64 old_max_inline = fs_info->max_inline;
1709 u64 old_alloc_start = fs_info->alloc_start;
1710 int old_thread_pool_size = fs_info->thread_pool_size;
1711 unsigned int old_metadata_ratio = fs_info->metadata_ratio;
1712 int ret;
1713
1714 sync_filesystem(sb);
1715 btrfs_remount_prepare(fs_info);
1716
1717 if (data) {
1718 struct security_mnt_opts new_sec_opts;
1719
1720 security_init_mnt_opts(&new_sec_opts);
1721 ret = parse_security_options(data, &new_sec_opts);
1722 if (ret)
1723 goto restore;
1724 ret = setup_security_options(fs_info, sb,
1725 &new_sec_opts);
1726 if (ret) {
1727 security_free_mnt_opts(&new_sec_opts);
1728 goto restore;
1729 }
1730 }
1731
1732 ret = btrfs_parse_options(fs_info, data, *flags);
1733 if (ret) {
1734 ret = -EINVAL;
1735 goto restore;
1736 }
1737
1738 btrfs_remount_begin(fs_info, old_opts, *flags);
1739 btrfs_resize_thread_pool(fs_info,
1740 fs_info->thread_pool_size, old_thread_pool_size);
1741
1742 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1743 goto out;
1744
1745 if (*flags & MS_RDONLY) {
1746 /*
1747 * this also happens on 'umount -rf' or on shutdown, when
1748 * the filesystem is busy.
1749 */
1750 cancel_work_sync(&fs_info->async_reclaim_work);
1751
1752 /* wait for the uuid_scan task to finish */
1753 down(&fs_info->uuid_tree_rescan_sem);
1754 /* avoid complains from lockdep et al. */
1755 up(&fs_info->uuid_tree_rescan_sem);
1756
1757 sb->s_flags |= MS_RDONLY;
1758
1759 /*
1760 * Setting MS_RDONLY will put the cleaner thread to
1761 * sleep at the next loop if it's already active.
1762 * If it's already asleep, we'll leave unused block
1763 * groups on disk until we're mounted read-write again
1764 * unless we clean them up here.
1765 */
1766 btrfs_delete_unused_bgs(fs_info);
1767
1768 btrfs_dev_replace_suspend_for_unmount(fs_info);
1769 btrfs_scrub_cancel(fs_info);
1770 btrfs_pause_balance(fs_info);
1771
1772 ret = btrfs_commit_super(fs_info);
1773 if (ret)
1774 goto restore;
1775 } else {
1776 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
1777 btrfs_err(fs_info,
1778 "Remounting read-write after error is not allowed");
1779 ret = -EINVAL;
1780 goto restore;
1781 }
1782 if (fs_info->fs_devices->rw_devices == 0) {
1783 ret = -EACCES;
1784 goto restore;
1785 }
1786
1787 if (fs_info->fs_devices->missing_devices >
1788 fs_info->num_tolerated_disk_barrier_failures &&
1789 !(*flags & MS_RDONLY)) {
1790 btrfs_warn(fs_info,
1791 "too many missing devices, writeable remount is not allowed");
1792 ret = -EACCES;
1793 goto restore;
1794 }
1795
1796 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1797 ret = -EINVAL;
1798 goto restore;
1799 }
1800
1801 ret = btrfs_cleanup_fs_roots(fs_info);
1802 if (ret)
1803 goto restore;
1804
1805 /* recover relocation */
1806 mutex_lock(&fs_info->cleaner_mutex);
1807 ret = btrfs_recover_relocation(root);
1808 mutex_unlock(&fs_info->cleaner_mutex);
1809 if (ret)
1810 goto restore;
1811
1812 ret = btrfs_resume_balance_async(fs_info);
1813 if (ret)
1814 goto restore;
1815
1816 ret = btrfs_resume_dev_replace_async(fs_info);
1817 if (ret) {
1818 btrfs_warn(fs_info, "failed to resume dev_replace");
1819 goto restore;
1820 }
1821
1822 if (!fs_info->uuid_root) {
1823 btrfs_info(fs_info, "creating UUID tree");
1824 ret = btrfs_create_uuid_tree(fs_info);
1825 if (ret) {
1826 btrfs_warn(fs_info,
1827 "failed to create the UUID tree %d",
1828 ret);
1829 goto restore;
1830 }
1831 }
1832 sb->s_flags &= ~MS_RDONLY;
1833
1834 set_bit(BTRFS_FS_OPEN, &fs_info->flags);
1835 }
1836 out:
1837 wake_up_process(fs_info->transaction_kthread);
1838 btrfs_remount_cleanup(fs_info, old_opts);
1839 return 0;
1840
1841 restore:
1842 /* We've hit an error - don't reset MS_RDONLY */
1843 if (sb->s_flags & MS_RDONLY)
1844 old_flags |= MS_RDONLY;
1845 sb->s_flags = old_flags;
1846 fs_info->mount_opt = old_opts;
1847 fs_info->compress_type = old_compress_type;
1848 fs_info->max_inline = old_max_inline;
1849 mutex_lock(&fs_info->chunk_mutex);
1850 fs_info->alloc_start = old_alloc_start;
1851 mutex_unlock(&fs_info->chunk_mutex);
1852 btrfs_resize_thread_pool(fs_info,
1853 old_thread_pool_size, fs_info->thread_pool_size);
1854 fs_info->metadata_ratio = old_metadata_ratio;
1855 btrfs_remount_cleanup(fs_info, old_opts);
1856 return ret;
1857 }
1858
1859 /* Used to sort the devices by max_avail(descending sort) */
1860 static int btrfs_cmp_device_free_bytes(const void *dev_info1,
1861 const void *dev_info2)
1862 {
1863 if (((struct btrfs_device_info *)dev_info1)->max_avail >
1864 ((struct btrfs_device_info *)dev_info2)->max_avail)
1865 return -1;
1866 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1867 ((struct btrfs_device_info *)dev_info2)->max_avail)
1868 return 1;
1869 else
1870 return 0;
1871 }
1872
1873 /*
1874 * sort the devices by max_avail, in which max free extent size of each device
1875 * is stored.(Descending Sort)
1876 */
1877 static inline void btrfs_descending_sort_devices(
1878 struct btrfs_device_info *devices,
1879 size_t nr_devices)
1880 {
1881 sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1882 btrfs_cmp_device_free_bytes, NULL);
1883 }
1884
1885 /*
1886 * The helper to calc the free space on the devices that can be used to store
1887 * file data.
1888 */
1889 static int btrfs_calc_avail_data_space(struct btrfs_fs_info *fs_info,
1890 u64 *free_bytes)
1891 {
1892 struct btrfs_root *root = fs_info->tree_root;
1893 struct btrfs_device_info *devices_info;
1894 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1895 struct btrfs_device *device;
1896 u64 skip_space;
1897 u64 type;
1898 u64 avail_space;
1899 u64 used_space;
1900 u64 min_stripe_size;
1901 int min_stripes = 1, num_stripes = 1;
1902 int i = 0, nr_devices;
1903 int ret;
1904
1905 /*
1906 * We aren't under the device list lock, so this is racy-ish, but good
1907 * enough for our purposes.
1908 */
1909 nr_devices = fs_info->fs_devices->open_devices;
1910 if (!nr_devices) {
1911 smp_mb();
1912 nr_devices = fs_info->fs_devices->open_devices;
1913 ASSERT(nr_devices);
1914 if (!nr_devices) {
1915 *free_bytes = 0;
1916 return 0;
1917 }
1918 }
1919
1920 devices_info = kmalloc_array(nr_devices, sizeof(*devices_info),
1921 GFP_NOFS);
1922 if (!devices_info)
1923 return -ENOMEM;
1924
1925 /* calc min stripe number for data space allocation */
1926 type = btrfs_get_alloc_profile(root, 1);
1927 if (type & BTRFS_BLOCK_GROUP_RAID0) {
1928 min_stripes = 2;
1929 num_stripes = nr_devices;
1930 } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
1931 min_stripes = 2;
1932 num_stripes = 2;
1933 } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
1934 min_stripes = 4;
1935 num_stripes = 4;
1936 }
1937
1938 if (type & BTRFS_BLOCK_GROUP_DUP)
1939 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1940 else
1941 min_stripe_size = BTRFS_STRIPE_LEN;
1942
1943 if (fs_info->alloc_start)
1944 mutex_lock(&fs_devices->device_list_mutex);
1945 rcu_read_lock();
1946 list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
1947 if (!device->in_fs_metadata || !device->bdev ||
1948 device->is_tgtdev_for_dev_replace)
1949 continue;
1950
1951 if (i >= nr_devices)
1952 break;
1953
1954 avail_space = device->total_bytes - device->bytes_used;
1955
1956 /* align with stripe_len */
1957 avail_space = div_u64(avail_space, BTRFS_STRIPE_LEN);
1958 avail_space *= BTRFS_STRIPE_LEN;
1959
1960 /*
1961 * In order to avoid overwriting the superblock on the drive,
1962 * btrfs starts at an offset of at least 1MB when doing chunk
1963 * allocation.
1964 */
1965 skip_space = SZ_1M;
1966
1967 /* user can set the offset in fs_info->alloc_start. */
1968 if (fs_info->alloc_start &&
1969 fs_info->alloc_start + BTRFS_STRIPE_LEN <=
1970 device->total_bytes) {
1971 rcu_read_unlock();
1972 skip_space = max(fs_info->alloc_start, skip_space);
1973
1974 /*
1975 * btrfs can not use the free space in
1976 * [0, skip_space - 1], we must subtract it from the
1977 * total. In order to implement it, we account the used
1978 * space in this range first.
1979 */
1980 ret = btrfs_account_dev_extents_size(device, 0,
1981 skip_space - 1,
1982 &used_space);
1983 if (ret) {
1984 kfree(devices_info);
1985 mutex_unlock(&fs_devices->device_list_mutex);
1986 return ret;
1987 }
1988
1989 rcu_read_lock();
1990
1991 /* calc the free space in [0, skip_space - 1] */
1992 skip_space -= used_space;
1993 }
1994
1995 /*
1996 * we can use the free space in [0, skip_space - 1], subtract
1997 * it from the total.
1998 */
1999 if (avail_space && avail_space >= skip_space)
2000 avail_space -= skip_space;
2001 else
2002 avail_space = 0;
2003
2004 if (avail_space < min_stripe_size)
2005 continue;
2006
2007 devices_info[i].dev = device;
2008 devices_info[i].max_avail = avail_space;
2009
2010 i++;
2011 }
2012 rcu_read_unlock();
2013 if (fs_info->alloc_start)
2014 mutex_unlock(&fs_devices->device_list_mutex);
2015
2016 nr_devices = i;
2017
2018 btrfs_descending_sort_devices(devices_info, nr_devices);
2019
2020 i = nr_devices - 1;
2021 avail_space = 0;
2022 while (nr_devices >= min_stripes) {
2023 if (num_stripes > nr_devices)
2024 num_stripes = nr_devices;
2025
2026 if (devices_info[i].max_avail >= min_stripe_size) {
2027 int j;
2028 u64 alloc_size;
2029
2030 avail_space += devices_info[i].max_avail * num_stripes;
2031 alloc_size = devices_info[i].max_avail;
2032 for (j = i + 1 - num_stripes; j <= i; j++)
2033 devices_info[j].max_avail -= alloc_size;
2034 }
2035 i--;
2036 nr_devices--;
2037 }
2038
2039 kfree(devices_info);
2040 *free_bytes = avail_space;
2041 return 0;
2042 }
2043
2044 /*
2045 * Calculate numbers for 'df', pessimistic in case of mixed raid profiles.
2046 *
2047 * If there's a redundant raid level at DATA block groups, use the respective
2048 * multiplier to scale the sizes.
2049 *
2050 * Unused device space usage is based on simulating the chunk allocator
2051 * algorithm that respects the device sizes, order of allocations and the
2052 * 'alloc_start' value, this is a close approximation of the actual use but
2053 * there are other factors that may change the result (like a new metadata
2054 * chunk).
2055 *
2056 * If metadata is exhausted, f_bavail will be 0.
2057 */
2058 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
2059 {
2060 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
2061 struct btrfs_super_block *disk_super = fs_info->super_copy;
2062 struct list_head *head = &fs_info->space_info;
2063 struct btrfs_space_info *found;
2064 u64 total_used = 0;
2065 u64 total_free_data = 0;
2066 u64 total_free_meta = 0;
2067 int bits = dentry->d_sb->s_blocksize_bits;
2068 __be32 *fsid = (__be32 *)fs_info->fsid;
2069 unsigned factor = 1;
2070 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
2071 int ret;
2072 u64 thresh = 0;
2073 int mixed = 0;
2074
2075 rcu_read_lock();
2076 list_for_each_entry_rcu(found, head, list) {
2077 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
2078 int i;
2079
2080 total_free_data += found->disk_total - found->disk_used;
2081 total_free_data -=
2082 btrfs_account_ro_block_groups_free_space(found);
2083
2084 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
2085 if (!list_empty(&found->block_groups[i])) {
2086 switch (i) {
2087 case BTRFS_RAID_DUP:
2088 case BTRFS_RAID_RAID1:
2089 case BTRFS_RAID_RAID10:
2090 factor = 2;
2091 }
2092 }
2093 }
2094 }
2095
2096 /*
2097 * Metadata in mixed block goup profiles are accounted in data
2098 */
2099 if (!mixed && found->flags & BTRFS_BLOCK_GROUP_METADATA) {
2100 if (found->flags & BTRFS_BLOCK_GROUP_DATA)
2101 mixed = 1;
2102 else
2103 total_free_meta += found->disk_total -
2104 found->disk_used;
2105 }
2106
2107 total_used += found->disk_used;
2108 }
2109
2110 rcu_read_unlock();
2111
2112 buf->f_blocks = div_u64(btrfs_super_total_bytes(disk_super), factor);
2113 buf->f_blocks >>= bits;
2114 buf->f_bfree = buf->f_blocks - (div_u64(total_used, factor) >> bits);
2115
2116 /* Account global block reserve as used, it's in logical size already */
2117 spin_lock(&block_rsv->lock);
2118 /* Mixed block groups accounting is not byte-accurate, avoid overflow */
2119 if (buf->f_bfree >= block_rsv->size >> bits)
2120 buf->f_bfree -= block_rsv->size >> bits;
2121 else
2122 buf->f_bfree = 0;
2123 spin_unlock(&block_rsv->lock);
2124
2125 buf->f_bavail = div_u64(total_free_data, factor);
2126 ret = btrfs_calc_avail_data_space(fs_info, &total_free_data);
2127 if (ret)
2128 return ret;
2129 buf->f_bavail += div_u64(total_free_data, factor);
2130 buf->f_bavail = buf->f_bavail >> bits;
2131
2132 /*
2133 * We calculate the remaining metadata space minus global reserve. If
2134 * this is (supposedly) smaller than zero, there's no space. But this
2135 * does not hold in practice, the exhausted state happens where's still
2136 * some positive delta. So we apply some guesswork and compare the
2137 * delta to a 4M threshold. (Practically observed delta was ~2M.)
2138 *
2139 * We probably cannot calculate the exact threshold value because this
2140 * depends on the internal reservations requested by various
2141 * operations, so some operations that consume a few metadata will
2142 * succeed even if the Avail is zero. But this is better than the other
2143 * way around.
2144 */
2145 thresh = 4 * 1024 * 1024;
2146
2147 if (!mixed && total_free_meta - thresh < block_rsv->size)
2148 buf->f_bavail = 0;
2149
2150 buf->f_type = BTRFS_SUPER_MAGIC;
2151 buf->f_bsize = dentry->d_sb->s_blocksize;
2152 buf->f_namelen = BTRFS_NAME_LEN;
2153
2154 /* We treat it as constant endianness (it doesn't matter _which_)
2155 because we want the fsid to come out the same whether mounted
2156 on a big-endian or little-endian host */
2157 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
2158 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
2159 /* Mask in the root object ID too, to disambiguate subvols */
2160 buf->f_fsid.val[0] ^= BTRFS_I(d_inode(dentry))->root->objectid >> 32;
2161 buf->f_fsid.val[1] ^= BTRFS_I(d_inode(dentry))->root->objectid;
2162
2163 return 0;
2164 }
2165
2166 static void btrfs_kill_super(struct super_block *sb)
2167 {
2168 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2169 kill_anon_super(sb);
2170 free_fs_info(fs_info);
2171 }
2172
2173 static struct file_system_type btrfs_fs_type = {
2174 .owner = THIS_MODULE,
2175 .name = "btrfs",
2176 .mount = btrfs_mount,
2177 .kill_sb = btrfs_kill_super,
2178 .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA,
2179 };
2180 MODULE_ALIAS_FS("btrfs");
2181
2182 static int btrfs_control_open(struct inode *inode, struct file *file)
2183 {
2184 /*
2185 * The control file's private_data is used to hold the
2186 * transaction when it is started and is used to keep
2187 * track of whether a transaction is already in progress.
2188 */
2189 file->private_data = NULL;
2190 return 0;
2191 }
2192
2193 /*
2194 * used by btrfsctl to scan devices when no FS is mounted
2195 */
2196 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
2197 unsigned long arg)
2198 {
2199 struct btrfs_ioctl_vol_args *vol;
2200 struct btrfs_fs_devices *fs_devices;
2201 int ret = -ENOTTY;
2202
2203 if (!capable(CAP_SYS_ADMIN))
2204 return -EPERM;
2205
2206 vol = memdup_user((void __user *)arg, sizeof(*vol));
2207 if (IS_ERR(vol))
2208 return PTR_ERR(vol);
2209
2210 switch (cmd) {
2211 case BTRFS_IOC_SCAN_DEV:
2212 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
2213 &btrfs_fs_type, &fs_devices);
2214 break;
2215 case BTRFS_IOC_DEVICES_READY:
2216 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
2217 &btrfs_fs_type, &fs_devices);
2218 if (ret)
2219 break;
2220 ret = !(fs_devices->num_devices == fs_devices->total_devices);
2221 break;
2222 case BTRFS_IOC_GET_SUPPORTED_FEATURES:
2223 ret = btrfs_ioctl_get_supported_features((void __user*)arg);
2224 break;
2225 }
2226
2227 kfree(vol);
2228 return ret;
2229 }
2230
2231 static int btrfs_freeze(struct super_block *sb)
2232 {
2233 struct btrfs_trans_handle *trans;
2234 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2235 struct btrfs_root *root = fs_info->tree_root;
2236
2237 fs_info->fs_frozen = 1;
2238 /*
2239 * We don't need a barrier here, we'll wait for any transaction that
2240 * could be in progress on other threads (and do delayed iputs that
2241 * we want to avoid on a frozen filesystem), or do the commit
2242 * ourselves.
2243 */
2244 trans = btrfs_attach_transaction_barrier(root);
2245 if (IS_ERR(trans)) {
2246 /* no transaction, don't bother */
2247 if (PTR_ERR(trans) == -ENOENT)
2248 return 0;
2249 return PTR_ERR(trans);
2250 }
2251 return btrfs_commit_transaction(trans);
2252 }
2253
2254 static int btrfs_unfreeze(struct super_block *sb)
2255 {
2256 btrfs_sb(sb)->fs_frozen = 0;
2257 return 0;
2258 }
2259
2260 static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
2261 {
2262 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
2263 struct btrfs_fs_devices *cur_devices;
2264 struct btrfs_device *dev, *first_dev = NULL;
2265 struct list_head *head;
2266 struct rcu_string *name;
2267
2268 mutex_lock(&fs_info->fs_devices->device_list_mutex);
2269 cur_devices = fs_info->fs_devices;
2270 while (cur_devices) {
2271 head = &cur_devices->devices;
2272 list_for_each_entry(dev, head, dev_list) {
2273 if (dev->missing)
2274 continue;
2275 if (!dev->name)
2276 continue;
2277 if (!first_dev || dev->devid < first_dev->devid)
2278 first_dev = dev;
2279 }
2280 cur_devices = cur_devices->seed;
2281 }
2282
2283 if (first_dev) {
2284 rcu_read_lock();
2285 name = rcu_dereference(first_dev->name);
2286 seq_escape(m, name->str, " \t\n\\");
2287 rcu_read_unlock();
2288 } else {
2289 WARN_ON(1);
2290 }
2291 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2292 return 0;
2293 }
2294
2295 static const struct super_operations btrfs_super_ops = {
2296 .drop_inode = btrfs_drop_inode,
2297 .evict_inode = btrfs_evict_inode,
2298 .put_super = btrfs_put_super,
2299 .sync_fs = btrfs_sync_fs,
2300 .show_options = btrfs_show_options,
2301 .show_devname = btrfs_show_devname,
2302 .write_inode = btrfs_write_inode,
2303 .alloc_inode = btrfs_alloc_inode,
2304 .destroy_inode = btrfs_destroy_inode,
2305 .statfs = btrfs_statfs,
2306 .remount_fs = btrfs_remount,
2307 .freeze_fs = btrfs_freeze,
2308 .unfreeze_fs = btrfs_unfreeze,
2309 };
2310
2311 static const struct file_operations btrfs_ctl_fops = {
2312 .open = btrfs_control_open,
2313 .unlocked_ioctl = btrfs_control_ioctl,
2314 .compat_ioctl = btrfs_control_ioctl,
2315 .owner = THIS_MODULE,
2316 .llseek = noop_llseek,
2317 };
2318
2319 static struct miscdevice btrfs_misc = {
2320 .minor = BTRFS_MINOR,
2321 .name = "btrfs-control",
2322 .fops = &btrfs_ctl_fops
2323 };
2324
2325 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
2326 MODULE_ALIAS("devname:btrfs-control");
2327
2328 static int btrfs_interface_init(void)
2329 {
2330 return misc_register(&btrfs_misc);
2331 }
2332
2333 static void btrfs_interface_exit(void)
2334 {
2335 misc_deregister(&btrfs_misc);
2336 }
2337
2338 static void btrfs_print_mod_info(void)
2339 {
2340 pr_info("Btrfs loaded, crc32c=%s"
2341 #ifdef CONFIG_BTRFS_DEBUG
2342 ", debug=on"
2343 #endif
2344 #ifdef CONFIG_BTRFS_ASSERT
2345 ", assert=on"
2346 #endif
2347 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2348 ", integrity-checker=on"
2349 #endif
2350 "\n",
2351 btrfs_crc32c_impl());
2352 }
2353
2354 static int __init init_btrfs_fs(void)
2355 {
2356 int err;
2357
2358 err = btrfs_hash_init();
2359 if (err)
2360 return err;
2361
2362 btrfs_props_init();
2363
2364 err = btrfs_init_sysfs();
2365 if (err)
2366 goto free_hash;
2367
2368 btrfs_init_compress();
2369
2370 err = btrfs_init_cachep();
2371 if (err)
2372 goto free_compress;
2373
2374 err = extent_io_init();
2375 if (err)
2376 goto free_cachep;
2377
2378 err = extent_map_init();
2379 if (err)
2380 goto free_extent_io;
2381
2382 err = ordered_data_init();
2383 if (err)
2384 goto free_extent_map;
2385
2386 err = btrfs_delayed_inode_init();
2387 if (err)
2388 goto free_ordered_data;
2389
2390 err = btrfs_auto_defrag_init();
2391 if (err)
2392 goto free_delayed_inode;
2393
2394 err = btrfs_delayed_ref_init();
2395 if (err)
2396 goto free_auto_defrag;
2397
2398 err = btrfs_prelim_ref_init();
2399 if (err)
2400 goto free_delayed_ref;
2401
2402 err = btrfs_end_io_wq_init();
2403 if (err)
2404 goto free_prelim_ref;
2405
2406 err = btrfs_interface_init();
2407 if (err)
2408 goto free_end_io_wq;
2409
2410 btrfs_init_lockdep();
2411
2412 btrfs_print_mod_info();
2413
2414 err = btrfs_run_sanity_tests();
2415 if (err)
2416 goto unregister_ioctl;
2417
2418 err = register_filesystem(&btrfs_fs_type);
2419 if (err)
2420 goto unregister_ioctl;
2421
2422 return 0;
2423
2424 unregister_ioctl:
2425 btrfs_interface_exit();
2426 free_end_io_wq:
2427 btrfs_end_io_wq_exit();
2428 free_prelim_ref:
2429 btrfs_prelim_ref_exit();
2430 free_delayed_ref:
2431 btrfs_delayed_ref_exit();
2432 free_auto_defrag:
2433 btrfs_auto_defrag_exit();
2434 free_delayed_inode:
2435 btrfs_delayed_inode_exit();
2436 free_ordered_data:
2437 ordered_data_exit();
2438 free_extent_map:
2439 extent_map_exit();
2440 free_extent_io:
2441 extent_io_exit();
2442 free_cachep:
2443 btrfs_destroy_cachep();
2444 free_compress:
2445 btrfs_exit_compress();
2446 btrfs_exit_sysfs();
2447 free_hash:
2448 btrfs_hash_exit();
2449 return err;
2450 }
2451
2452 static void __exit exit_btrfs_fs(void)
2453 {
2454 btrfs_destroy_cachep();
2455 btrfs_delayed_ref_exit();
2456 btrfs_auto_defrag_exit();
2457 btrfs_delayed_inode_exit();
2458 btrfs_prelim_ref_exit();
2459 ordered_data_exit();
2460 extent_map_exit();
2461 extent_io_exit();
2462 btrfs_interface_exit();
2463 btrfs_end_io_wq_exit();
2464 unregister_filesystem(&btrfs_fs_type);
2465 btrfs_exit_sysfs();
2466 btrfs_cleanup_fs_uuids();
2467 btrfs_exit_compress();
2468 btrfs_hash_exit();
2469 }
2470
2471 late_initcall(init_btrfs_fs);
2472 module_exit(exit_btrfs_fs)
2473
2474 MODULE_LICENSE("GPL");
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