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1/*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19#include <linux/blkdev.h>
20#include <linux/module.h>
21#include <linux/buffer_head.h>
22#include <linux/fs.h>
23#include <linux/pagemap.h>
24#include <linux/highmem.h>
25#include <linux/time.h>
26#include <linux/init.h>
27#include <linux/seq_file.h>
28#include <linux/string.h>
29#include <linux/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
67static const struct super_operations btrfs_super_ops;
68static struct file_system_type btrfs_fs_type;
69
70static int btrfs_remount(struct super_block *sb, int *flags, char *data);
71
72const 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 */
101static 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
129void __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
175static 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 */
191static 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
202void 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
250void __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 ACCESS_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
279void __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
304static void btrfs_put_super(struct super_block *sb)
305{
306 close_ctree(btrfs_sb(sb));
307}
308
309enum {
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
331static 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 */
397int 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 }
832check:
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 }
841out:
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 */
863static 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
933out:
934 kfree(orig);
935 return error;
936}
937
938static 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
1068err:
1069 btrfs_free_path(path);
1070 kfree(name);
1071 return ERR_PTR(ret);
1072}
1073
1074static 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
1115static int btrfs_fill_super(struct super_block *sb,
1116 struct btrfs_fs_devices *fs_devices,
1117 void *data, int silent)
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
1162fail_close:
1163 close_ctree(fs_info);
1164 return err;
1165}
1166
1167int 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
1210static 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
1305static 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
1313static 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 */
1324static 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 */
1336static 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
1366static 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
1463out:
1464 mntput(mnt);
1465 kfree(newargs);
1466 kfree(subvol_name);
1467 return root;
1468}
1469
1470static 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
1489static 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 */
1526static 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 flags & MS_SILENT ? 1 : 0);
1616 }
1617 if (error) {
1618 deactivate_locked_super(s);
1619 goto error_sec_opts;
1620 }
1621
1622 fs_info = btrfs_sb(s);
1623 error = setup_security_options(fs_info, s, &new_sec_opts);
1624 if (error) {
1625 deactivate_locked_super(s);
1626 goto error_sec_opts;
1627 }
1628
1629 return dget(s->s_root);
1630
1631error_close_devices:
1632 btrfs_close_devices(fs_devices);
1633error_fs_info:
1634 free_fs_info(fs_info);
1635error_sec_opts:
1636 security_free_mnt_opts(&new_sec_opts);
1637 return ERR_PTR(error);
1638}
1639
1640static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1641 int new_pool_size, int old_pool_size)
1642{
1643 if (new_pool_size == old_pool_size)
1644 return;
1645
1646 fs_info->thread_pool_size = new_pool_size;
1647
1648 btrfs_info(fs_info, "resize thread pool %d -> %d",
1649 old_pool_size, new_pool_size);
1650
1651 btrfs_workqueue_set_max(fs_info->workers, new_pool_size);
1652 btrfs_workqueue_set_max(fs_info->delalloc_workers, new_pool_size);
1653 btrfs_workqueue_set_max(fs_info->submit_workers, new_pool_size);
1654 btrfs_workqueue_set_max(fs_info->caching_workers, new_pool_size);
1655 btrfs_workqueue_set_max(fs_info->endio_workers, new_pool_size);
1656 btrfs_workqueue_set_max(fs_info->endio_meta_workers, new_pool_size);
1657 btrfs_workqueue_set_max(fs_info->endio_meta_write_workers,
1658 new_pool_size);
1659 btrfs_workqueue_set_max(fs_info->endio_write_workers, new_pool_size);
1660 btrfs_workqueue_set_max(fs_info->endio_freespace_worker, new_pool_size);
1661 btrfs_workqueue_set_max(fs_info->delayed_workers, new_pool_size);
1662 btrfs_workqueue_set_max(fs_info->readahead_workers, new_pool_size);
1663 btrfs_workqueue_set_max(fs_info->scrub_wr_completion_workers,
1664 new_pool_size);
1665}
1666
1667static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info)
1668{
1669 set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1670}
1671
1672static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
1673 unsigned long old_opts, int flags)
1674{
1675 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1676 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1677 (flags & MS_RDONLY))) {
1678 /* wait for any defraggers to finish */
1679 wait_event(fs_info->transaction_wait,
1680 (atomic_read(&fs_info->defrag_running) == 0));
1681 if (flags & MS_RDONLY)
1682 sync_filesystem(fs_info->sb);
1683 }
1684}
1685
1686static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1687 unsigned long old_opts)
1688{
1689 /*
1690 * We need to cleanup all defragable inodes if the autodefragment is
1691 * close or the filesystem is read only.
1692 */
1693 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1694 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1695 (fs_info->sb->s_flags & MS_RDONLY))) {
1696 btrfs_cleanup_defrag_inodes(fs_info);
1697 }
1698
1699 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1700}
1701
1702static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1703{
1704 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1705 struct btrfs_root *root = fs_info->tree_root;
1706 unsigned old_flags = sb->s_flags;
1707 unsigned long old_opts = fs_info->mount_opt;
1708 unsigned long old_compress_type = fs_info->compress_type;
1709 u64 old_max_inline = fs_info->max_inline;
1710 u64 old_alloc_start = fs_info->alloc_start;
1711 int old_thread_pool_size = fs_info->thread_pool_size;
1712 unsigned int old_metadata_ratio = fs_info->metadata_ratio;
1713 int ret;
1714
1715 sync_filesystem(sb);
1716 btrfs_remount_prepare(fs_info);
1717
1718 if (data) {
1719 struct security_mnt_opts new_sec_opts;
1720
1721 security_init_mnt_opts(&new_sec_opts);
1722 ret = parse_security_options(data, &new_sec_opts);
1723 if (ret)
1724 goto restore;
1725 ret = setup_security_options(fs_info, sb,
1726 &new_sec_opts);
1727 if (ret) {
1728 security_free_mnt_opts(&new_sec_opts);
1729 goto restore;
1730 }
1731 }
1732
1733 ret = btrfs_parse_options(fs_info, data, *flags);
1734 if (ret) {
1735 ret = -EINVAL;
1736 goto restore;
1737 }
1738
1739 btrfs_remount_begin(fs_info, old_opts, *flags);
1740 btrfs_resize_thread_pool(fs_info,
1741 fs_info->thread_pool_size, old_thread_pool_size);
1742
1743 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1744 goto out;
1745
1746 if (*flags & MS_RDONLY) {
1747 /*
1748 * this also happens on 'umount -rf' or on shutdown, when
1749 * the filesystem is busy.
1750 */
1751 cancel_work_sync(&fs_info->async_reclaim_work);
1752
1753 /* wait for the uuid_scan task to finish */
1754 down(&fs_info->uuid_tree_rescan_sem);
1755 /* avoid complains from lockdep et al. */
1756 up(&fs_info->uuid_tree_rescan_sem);
1757
1758 sb->s_flags |= MS_RDONLY;
1759
1760 /*
1761 * Setting MS_RDONLY will put the cleaner thread to
1762 * sleep at the next loop if it's already active.
1763 * If it's already asleep, we'll leave unused block
1764 * groups on disk until we're mounted read-write again
1765 * unless we clean them up here.
1766 */
1767 btrfs_delete_unused_bgs(fs_info);
1768
1769 btrfs_dev_replace_suspend_for_unmount(fs_info);
1770 btrfs_scrub_cancel(fs_info);
1771 btrfs_pause_balance(fs_info);
1772
1773 ret = btrfs_commit_super(fs_info);
1774 if (ret)
1775 goto restore;
1776 } else {
1777 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
1778 btrfs_err(fs_info,
1779 "Remounting read-write after error is not allowed");
1780 ret = -EINVAL;
1781 goto restore;
1782 }
1783 if (fs_info->fs_devices->rw_devices == 0) {
1784 ret = -EACCES;
1785 goto restore;
1786 }
1787
1788 if (fs_info->fs_devices->missing_devices >
1789 fs_info->num_tolerated_disk_barrier_failures &&
1790 !(*flags & MS_RDONLY)) {
1791 btrfs_warn(fs_info,
1792 "too many missing devices, writeable remount is not allowed");
1793 ret = -EACCES;
1794 goto restore;
1795 }
1796
1797 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1798 ret = -EINVAL;
1799 goto restore;
1800 }
1801
1802 ret = btrfs_cleanup_fs_roots(fs_info);
1803 if (ret)
1804 goto restore;
1805
1806 /* recover relocation */
1807 mutex_lock(&fs_info->cleaner_mutex);
1808 ret = btrfs_recover_relocation(root);
1809 mutex_unlock(&fs_info->cleaner_mutex);
1810 if (ret)
1811 goto restore;
1812
1813 ret = btrfs_resume_balance_async(fs_info);
1814 if (ret)
1815 goto restore;
1816
1817 ret = btrfs_resume_dev_replace_async(fs_info);
1818 if (ret) {
1819 btrfs_warn(fs_info, "failed to resume dev_replace");
1820 goto restore;
1821 }
1822
1823 if (!fs_info->uuid_root) {
1824 btrfs_info(fs_info, "creating UUID tree");
1825 ret = btrfs_create_uuid_tree(fs_info);
1826 if (ret) {
1827 btrfs_warn(fs_info,
1828 "failed to create the UUID tree %d",
1829 ret);
1830 goto restore;
1831 }
1832 }
1833 sb->s_flags &= ~MS_RDONLY;
1834
1835 set_bit(BTRFS_FS_OPEN, &fs_info->flags);
1836 }
1837out:
1838 wake_up_process(fs_info->transaction_kthread);
1839 btrfs_remount_cleanup(fs_info, old_opts);
1840 return 0;
1841
1842restore:
1843 /* We've hit an error - don't reset MS_RDONLY */
1844 if (sb->s_flags & MS_RDONLY)
1845 old_flags |= MS_RDONLY;
1846 sb->s_flags = old_flags;
1847 fs_info->mount_opt = old_opts;
1848 fs_info->compress_type = old_compress_type;
1849 fs_info->max_inline = old_max_inline;
1850 mutex_lock(&fs_info->chunk_mutex);
1851 fs_info->alloc_start = old_alloc_start;
1852 mutex_unlock(&fs_info->chunk_mutex);
1853 btrfs_resize_thread_pool(fs_info,
1854 old_thread_pool_size, fs_info->thread_pool_size);
1855 fs_info->metadata_ratio = old_metadata_ratio;
1856 btrfs_remount_cleanup(fs_info, old_opts);
1857 return ret;
1858}
1859
1860/* Used to sort the devices by max_avail(descending sort) */
1861static int btrfs_cmp_device_free_bytes(const void *dev_info1,
1862 const void *dev_info2)
1863{
1864 if (((struct btrfs_device_info *)dev_info1)->max_avail >
1865 ((struct btrfs_device_info *)dev_info2)->max_avail)
1866 return -1;
1867 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1868 ((struct btrfs_device_info *)dev_info2)->max_avail)
1869 return 1;
1870 else
1871 return 0;
1872}
1873
1874/*
1875 * sort the devices by max_avail, in which max free extent size of each device
1876 * is stored.(Descending Sort)
1877 */
1878static inline void btrfs_descending_sort_devices(
1879 struct btrfs_device_info *devices,
1880 size_t nr_devices)
1881{
1882 sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1883 btrfs_cmp_device_free_bytes, NULL);
1884}
1885
1886/*
1887 * The helper to calc the free space on the devices that can be used to store
1888 * file data.
1889 */
1890static int btrfs_calc_avail_data_space(struct btrfs_fs_info *fs_info,
1891 u64 *free_bytes)
1892{
1893 struct btrfs_root *root = fs_info->tree_root;
1894 struct btrfs_device_info *devices_info;
1895 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1896 struct btrfs_device *device;
1897 u64 skip_space;
1898 u64 type;
1899 u64 avail_space;
1900 u64 used_space;
1901 u64 min_stripe_size;
1902 int min_stripes = 1, num_stripes = 1;
1903 int i = 0, nr_devices;
1904 int ret;
1905
1906 /*
1907 * We aren't under the device list lock, so this is racy-ish, but good
1908 * enough for our purposes.
1909 */
1910 nr_devices = fs_info->fs_devices->open_devices;
1911 if (!nr_devices) {
1912 smp_mb();
1913 nr_devices = fs_info->fs_devices->open_devices;
1914 ASSERT(nr_devices);
1915 if (!nr_devices) {
1916 *free_bytes = 0;
1917 return 0;
1918 }
1919 }
1920
1921 devices_info = kmalloc_array(nr_devices, sizeof(*devices_info),
1922 GFP_NOFS);
1923 if (!devices_info)
1924 return -ENOMEM;
1925
1926 /* calc min stripe number for data space allocation */
1927 type = btrfs_get_alloc_profile(root, 1);
1928 if (type & BTRFS_BLOCK_GROUP_RAID0) {
1929 min_stripes = 2;
1930 num_stripes = nr_devices;
1931 } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
1932 min_stripes = 2;
1933 num_stripes = 2;
1934 } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
1935 min_stripes = 4;
1936 num_stripes = 4;
1937 }
1938
1939 if (type & BTRFS_BLOCK_GROUP_DUP)
1940 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1941 else
1942 min_stripe_size = BTRFS_STRIPE_LEN;
1943
1944 if (fs_info->alloc_start)
1945 mutex_lock(&fs_devices->device_list_mutex);
1946 rcu_read_lock();
1947 list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
1948 if (!device->in_fs_metadata || !device->bdev ||
1949 device->is_tgtdev_for_dev_replace)
1950 continue;
1951
1952 if (i >= nr_devices)
1953 break;
1954
1955 avail_space = device->total_bytes - device->bytes_used;
1956
1957 /* align with stripe_len */
1958 avail_space = div_u64(avail_space, BTRFS_STRIPE_LEN);
1959 avail_space *= BTRFS_STRIPE_LEN;
1960
1961 /*
1962 * In order to avoid overwriting the superblock on the drive,
1963 * btrfs starts at an offset of at least 1MB when doing chunk
1964 * allocation.
1965 */
1966 skip_space = SZ_1M;
1967
1968 /* user can set the offset in fs_info->alloc_start. */
1969 if (fs_info->alloc_start &&
1970 fs_info->alloc_start + BTRFS_STRIPE_LEN <=
1971 device->total_bytes) {
1972 rcu_read_unlock();
1973 skip_space = max(fs_info->alloc_start, skip_space);
1974
1975 /*
1976 * btrfs can not use the free space in
1977 * [0, skip_space - 1], we must subtract it from the
1978 * total. In order to implement it, we account the used
1979 * space in this range first.
1980 */
1981 ret = btrfs_account_dev_extents_size(device, 0,
1982 skip_space - 1,
1983 &used_space);
1984 if (ret) {
1985 kfree(devices_info);
1986 mutex_unlock(&fs_devices->device_list_mutex);
1987 return ret;
1988 }
1989
1990 rcu_read_lock();
1991
1992 /* calc the free space in [0, skip_space - 1] */
1993 skip_space -= used_space;
1994 }
1995
1996 /*
1997 * we can use the free space in [0, skip_space - 1], subtract
1998 * it from the total.
1999 */
2000 if (avail_space && avail_space >= skip_space)
2001 avail_space -= skip_space;
2002 else
2003 avail_space = 0;
2004
2005 if (avail_space < min_stripe_size)
2006 continue;
2007
2008 devices_info[i].dev = device;
2009 devices_info[i].max_avail = avail_space;
2010
2011 i++;
2012 }
2013 rcu_read_unlock();
2014 if (fs_info->alloc_start)
2015 mutex_unlock(&fs_devices->device_list_mutex);
2016
2017 nr_devices = i;
2018
2019 btrfs_descending_sort_devices(devices_info, nr_devices);
2020
2021 i = nr_devices - 1;
2022 avail_space = 0;
2023 while (nr_devices >= min_stripes) {
2024 if (num_stripes > nr_devices)
2025 num_stripes = nr_devices;
2026
2027 if (devices_info[i].max_avail >= min_stripe_size) {
2028 int j;
2029 u64 alloc_size;
2030
2031 avail_space += devices_info[i].max_avail * num_stripes;
2032 alloc_size = devices_info[i].max_avail;
2033 for (j = i + 1 - num_stripes; j <= i; j++)
2034 devices_info[j].max_avail -= alloc_size;
2035 }
2036 i--;
2037 nr_devices--;
2038 }
2039
2040 kfree(devices_info);
2041 *free_bytes = avail_space;
2042 return 0;
2043}
2044
2045/*
2046 * Calculate numbers for 'df', pessimistic in case of mixed raid profiles.
2047 *
2048 * If there's a redundant raid level at DATA block groups, use the respective
2049 * multiplier to scale the sizes.
2050 *
2051 * Unused device space usage is based on simulating the chunk allocator
2052 * algorithm that respects the device sizes, order of allocations and the
2053 * 'alloc_start' value, this is a close approximation of the actual use but
2054 * there are other factors that may change the result (like a new metadata
2055 * chunk).
2056 *
2057 * If metadata is exhausted, f_bavail will be 0.
2058 */
2059static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
2060{
2061 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
2062 struct btrfs_super_block *disk_super = fs_info->super_copy;
2063 struct list_head *head = &fs_info->space_info;
2064 struct btrfs_space_info *found;
2065 u64 total_used = 0;
2066 u64 total_free_data = 0;
2067 u64 total_free_meta = 0;
2068 int bits = dentry->d_sb->s_blocksize_bits;
2069 __be32 *fsid = (__be32 *)fs_info->fsid;
2070 unsigned factor = 1;
2071 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
2072 int ret;
2073 u64 thresh = 0;
2074 int mixed = 0;
2075
2076 rcu_read_lock();
2077 list_for_each_entry_rcu(found, head, list) {
2078 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
2079 int i;
2080
2081 total_free_data += found->disk_total - found->disk_used;
2082 total_free_data -=
2083 btrfs_account_ro_block_groups_free_space(found);
2084
2085 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
2086 if (!list_empty(&found->block_groups[i])) {
2087 switch (i) {
2088 case BTRFS_RAID_DUP:
2089 case BTRFS_RAID_RAID1:
2090 case BTRFS_RAID_RAID10:
2091 factor = 2;
2092 }
2093 }
2094 }
2095 }
2096
2097 /*
2098 * Metadata in mixed block goup profiles are accounted in data
2099 */
2100 if (!mixed && found->flags & BTRFS_BLOCK_GROUP_METADATA) {
2101 if (found->flags & BTRFS_BLOCK_GROUP_DATA)
2102 mixed = 1;
2103 else
2104 total_free_meta += found->disk_total -
2105 found->disk_used;
2106 }
2107
2108 total_used += found->disk_used;
2109 }
2110
2111 rcu_read_unlock();
2112
2113 buf->f_blocks = div_u64(btrfs_super_total_bytes(disk_super), factor);
2114 buf->f_blocks >>= bits;
2115 buf->f_bfree = buf->f_blocks - (div_u64(total_used, factor) >> bits);
2116
2117 /* Account global block reserve as used, it's in logical size already */
2118 spin_lock(&block_rsv->lock);
2119 /* Mixed block groups accounting is not byte-accurate, avoid overflow */
2120 if (buf->f_bfree >= block_rsv->size >> bits)
2121 buf->f_bfree -= block_rsv->size >> bits;
2122 else
2123 buf->f_bfree = 0;
2124 spin_unlock(&block_rsv->lock);
2125
2126 buf->f_bavail = div_u64(total_free_data, factor);
2127 ret = btrfs_calc_avail_data_space(fs_info, &total_free_data);
2128 if (ret)
2129 return ret;
2130 buf->f_bavail += div_u64(total_free_data, factor);
2131 buf->f_bavail = buf->f_bavail >> bits;
2132
2133 /*
2134 * We calculate the remaining metadata space minus global reserve. If
2135 * this is (supposedly) smaller than zero, there's no space. But this
2136 * does not hold in practice, the exhausted state happens where's still
2137 * some positive delta. So we apply some guesswork and compare the
2138 * delta to a 4M threshold. (Practically observed delta was ~2M.)
2139 *
2140 * We probably cannot calculate the exact threshold value because this
2141 * depends on the internal reservations requested by various
2142 * operations, so some operations that consume a few metadata will
2143 * succeed even if the Avail is zero. But this is better than the other
2144 * way around.
2145 */
2146 thresh = 4 * 1024 * 1024;
2147
2148 if (!mixed && total_free_meta - thresh < block_rsv->size)
2149 buf->f_bavail = 0;
2150
2151 buf->f_type = BTRFS_SUPER_MAGIC;
2152 buf->f_bsize = dentry->d_sb->s_blocksize;
2153 buf->f_namelen = BTRFS_NAME_LEN;
2154
2155 /* We treat it as constant endianness (it doesn't matter _which_)
2156 because we want the fsid to come out the same whether mounted
2157 on a big-endian or little-endian host */
2158 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
2159 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
2160 /* Mask in the root object ID too, to disambiguate subvols */
2161 buf->f_fsid.val[0] ^= BTRFS_I(d_inode(dentry))->root->objectid >> 32;
2162 buf->f_fsid.val[1] ^= BTRFS_I(d_inode(dentry))->root->objectid;
2163
2164 return 0;
2165}
2166
2167static void btrfs_kill_super(struct super_block *sb)
2168{
2169 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2170 kill_anon_super(sb);
2171 free_fs_info(fs_info);
2172}
2173
2174static struct file_system_type btrfs_fs_type = {
2175 .owner = THIS_MODULE,
2176 .name = "btrfs",
2177 .mount = btrfs_mount,
2178 .kill_sb = btrfs_kill_super,
2179 .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA,
2180};
2181MODULE_ALIAS_FS("btrfs");
2182
2183static int btrfs_control_open(struct inode *inode, struct file *file)
2184{
2185 /*
2186 * The control file's private_data is used to hold the
2187 * transaction when it is started and is used to keep
2188 * track of whether a transaction is already in progress.
2189 */
2190 file->private_data = NULL;
2191 return 0;
2192}
2193
2194/*
2195 * used by btrfsctl to scan devices when no FS is mounted
2196 */
2197static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
2198 unsigned long arg)
2199{
2200 struct btrfs_ioctl_vol_args *vol;
2201 struct btrfs_fs_devices *fs_devices;
2202 int ret = -ENOTTY;
2203
2204 if (!capable(CAP_SYS_ADMIN))
2205 return -EPERM;
2206
2207 vol = memdup_user((void __user *)arg, sizeof(*vol));
2208 if (IS_ERR(vol))
2209 return PTR_ERR(vol);
2210
2211 switch (cmd) {
2212 case BTRFS_IOC_SCAN_DEV:
2213 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
2214 &btrfs_fs_type, &fs_devices);
2215 break;
2216 case BTRFS_IOC_DEVICES_READY:
2217 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
2218 &btrfs_fs_type, &fs_devices);
2219 if (ret)
2220 break;
2221 ret = !(fs_devices->num_devices == fs_devices->total_devices);
2222 break;
2223 case BTRFS_IOC_GET_SUPPORTED_FEATURES:
2224 ret = btrfs_ioctl_get_supported_features((void __user*)arg);
2225 break;
2226 }
2227
2228 kfree(vol);
2229 return ret;
2230}
2231
2232static int btrfs_freeze(struct super_block *sb)
2233{
2234 struct btrfs_trans_handle *trans;
2235 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2236 struct btrfs_root *root = fs_info->tree_root;
2237
2238 fs_info->fs_frozen = 1;
2239 /*
2240 * We don't need a barrier here, we'll wait for any transaction that
2241 * could be in progress on other threads (and do delayed iputs that
2242 * we want to avoid on a frozen filesystem), or do the commit
2243 * ourselves.
2244 */
2245 trans = btrfs_attach_transaction_barrier(root);
2246 if (IS_ERR(trans)) {
2247 /* no transaction, don't bother */
2248 if (PTR_ERR(trans) == -ENOENT)
2249 return 0;
2250 return PTR_ERR(trans);
2251 }
2252 return btrfs_commit_transaction(trans);
2253}
2254
2255static int btrfs_unfreeze(struct super_block *sb)
2256{
2257 btrfs_sb(sb)->fs_frozen = 0;
2258 return 0;
2259}
2260
2261static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
2262{
2263 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
2264 struct btrfs_fs_devices *cur_devices;
2265 struct btrfs_device *dev, *first_dev = NULL;
2266 struct list_head *head;
2267 struct rcu_string *name;
2268
2269 mutex_lock(&fs_info->fs_devices->device_list_mutex);
2270 cur_devices = fs_info->fs_devices;
2271 while (cur_devices) {
2272 head = &cur_devices->devices;
2273 list_for_each_entry(dev, head, dev_list) {
2274 if (dev->missing)
2275 continue;
2276 if (!dev->name)
2277 continue;
2278 if (!first_dev || dev->devid < first_dev->devid)
2279 first_dev = dev;
2280 }
2281 cur_devices = cur_devices->seed;
2282 }
2283
2284 if (first_dev) {
2285 rcu_read_lock();
2286 name = rcu_dereference(first_dev->name);
2287 seq_escape(m, name->str, " \t\n\\");
2288 rcu_read_unlock();
2289 } else {
2290 WARN_ON(1);
2291 }
2292 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2293 return 0;
2294}
2295
2296static const struct super_operations btrfs_super_ops = {
2297 .drop_inode = btrfs_drop_inode,
2298 .evict_inode = btrfs_evict_inode,
2299 .put_super = btrfs_put_super,
2300 .sync_fs = btrfs_sync_fs,
2301 .show_options = btrfs_show_options,
2302 .show_devname = btrfs_show_devname,
2303 .write_inode = btrfs_write_inode,
2304 .alloc_inode = btrfs_alloc_inode,
2305 .destroy_inode = btrfs_destroy_inode,
2306 .statfs = btrfs_statfs,
2307 .remount_fs = btrfs_remount,
2308 .freeze_fs = btrfs_freeze,
2309 .unfreeze_fs = btrfs_unfreeze,
2310};
2311
2312static const struct file_operations btrfs_ctl_fops = {
2313 .open = btrfs_control_open,
2314 .unlocked_ioctl = btrfs_control_ioctl,
2315 .compat_ioctl = btrfs_control_ioctl,
2316 .owner = THIS_MODULE,
2317 .llseek = noop_llseek,
2318};
2319
2320static struct miscdevice btrfs_misc = {
2321 .minor = BTRFS_MINOR,
2322 .name = "btrfs-control",
2323 .fops = &btrfs_ctl_fops
2324};
2325
2326MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
2327MODULE_ALIAS("devname:btrfs-control");
2328
2329static int btrfs_interface_init(void)
2330{
2331 return misc_register(&btrfs_misc);
2332}
2333
2334static void btrfs_interface_exit(void)
2335{
2336 misc_deregister(&btrfs_misc);
2337}
2338
2339static void btrfs_print_mod_info(void)
2340{
2341 pr_info("Btrfs loaded, crc32c=%s"
2342#ifdef CONFIG_BTRFS_DEBUG
2343 ", debug=on"
2344#endif
2345#ifdef CONFIG_BTRFS_ASSERT
2346 ", assert=on"
2347#endif
2348#ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2349 ", integrity-checker=on"
2350#endif
2351 "\n",
2352 btrfs_crc32c_impl());
2353}
2354
2355static int __init init_btrfs_fs(void)
2356{
2357 int err;
2358
2359 err = btrfs_hash_init();
2360 if (err)
2361 return err;
2362
2363 btrfs_props_init();
2364
2365 err = btrfs_init_sysfs();
2366 if (err)
2367 goto free_hash;
2368
2369 btrfs_init_compress();
2370
2371 err = btrfs_init_cachep();
2372 if (err)
2373 goto free_compress;
2374
2375 err = extent_io_init();
2376 if (err)
2377 goto free_cachep;
2378
2379 err = extent_map_init();
2380 if (err)
2381 goto free_extent_io;
2382
2383 err = ordered_data_init();
2384 if (err)
2385 goto free_extent_map;
2386
2387 err = btrfs_delayed_inode_init();
2388 if (err)
2389 goto free_ordered_data;
2390
2391 err = btrfs_auto_defrag_init();
2392 if (err)
2393 goto free_delayed_inode;
2394
2395 err = btrfs_delayed_ref_init();
2396 if (err)
2397 goto free_auto_defrag;
2398
2399 err = btrfs_prelim_ref_init();
2400 if (err)
2401 goto free_delayed_ref;
2402
2403 err = btrfs_end_io_wq_init();
2404 if (err)
2405 goto free_prelim_ref;
2406
2407 err = btrfs_interface_init();
2408 if (err)
2409 goto free_end_io_wq;
2410
2411 btrfs_init_lockdep();
2412
2413 btrfs_print_mod_info();
2414
2415 err = btrfs_run_sanity_tests();
2416 if (err)
2417 goto unregister_ioctl;
2418
2419 err = register_filesystem(&btrfs_fs_type);
2420 if (err)
2421 goto unregister_ioctl;
2422
2423 return 0;
2424
2425unregister_ioctl:
2426 btrfs_interface_exit();
2427free_end_io_wq:
2428 btrfs_end_io_wq_exit();
2429free_prelim_ref:
2430 btrfs_prelim_ref_exit();
2431free_delayed_ref:
2432 btrfs_delayed_ref_exit();
2433free_auto_defrag:
2434 btrfs_auto_defrag_exit();
2435free_delayed_inode:
2436 btrfs_delayed_inode_exit();
2437free_ordered_data:
2438 ordered_data_exit();
2439free_extent_map:
2440 extent_map_exit();
2441free_extent_io:
2442 extent_io_exit();
2443free_cachep:
2444 btrfs_destroy_cachep();
2445free_compress:
2446 btrfs_exit_compress();
2447 btrfs_exit_sysfs();
2448free_hash:
2449 btrfs_hash_exit();
2450 return err;
2451}
2452
2453static void __exit exit_btrfs_fs(void)
2454{
2455 btrfs_destroy_cachep();
2456 btrfs_delayed_ref_exit();
2457 btrfs_auto_defrag_exit();
2458 btrfs_delayed_inode_exit();
2459 btrfs_prelim_ref_exit();
2460 ordered_data_exit();
2461 extent_map_exit();
2462 extent_io_exit();
2463 btrfs_interface_exit();
2464 btrfs_end_io_wq_exit();
2465 unregister_filesystem(&btrfs_fs_type);
2466 btrfs_exit_sysfs();
2467 btrfs_cleanup_fs_uuids();
2468 btrfs_exit_compress();
2469 btrfs_hash_exit();
2470}
2471
2472late_initcall(init_btrfs_fs);
2473module_exit(exit_btrfs_fs)
2474
2475MODULE_LICENSE("GPL");
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
67static const struct super_operations btrfs_super_ops;
68static struct file_system_type btrfs_fs_type;
69
70static int btrfs_remount(struct super_block *sb, int *flags, char *data);
71
72const 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
100static void save_error_info(struct btrfs_fs_info *fs_info)
101{
102 /*
103 * today we only save the error info into ram. Long term we'll
104 * also send it down to the disk
105 */
106 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
107}
108
109/* btrfs handle error by forcing the filesystem readonly */
110static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
111{
112 struct super_block *sb = fs_info->sb;
113
114 if (sb->s_flags & MS_RDONLY)
115 return;
116
117 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
118 sb->s_flags |= MS_RDONLY;
119 btrfs_info(fs_info, "forced readonly");
120 /*
121 * Note that a running device replace operation is not
122 * canceled here although there is no way to update
123 * the progress. It would add the risk of a deadlock,
124 * therefore the canceling is ommited. The only penalty
125 * is that some I/O remains active until the procedure
126 * completes. The next time when the filesystem is
127 * mounted writeable again, the device replace
128 * operation continues.
129 */
130 }
131}
132
133/*
134 * __btrfs_std_error decodes expected errors from the caller and
135 * invokes the approciate error response.
136 */
137__cold
138void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
139 unsigned int line, int errno, const char *fmt, ...)
140{
141 struct super_block *sb = fs_info->sb;
142#ifdef CONFIG_PRINTK
143 const char *errstr;
144#endif
145
146 /*
147 * Special case: if the error is EROFS, and we're already
148 * under MS_RDONLY, then it is safe here.
149 */
150 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
151 return;
152
153#ifdef CONFIG_PRINTK
154 errstr = btrfs_decode_error(errno);
155 if (fmt) {
156 struct va_format vaf;
157 va_list args;
158
159 va_start(args, fmt);
160 vaf.fmt = fmt;
161 vaf.va = &args;
162
163 printk(KERN_CRIT
164 "BTRFS: error (device %s) in %s:%d: errno=%d %s (%pV)\n",
165 sb->s_id, function, line, errno, errstr, &vaf);
166 va_end(args);
167 } else {
168 printk(KERN_CRIT "BTRFS: error (device %s) in %s:%d: errno=%d %s\n",
169 sb->s_id, function, line, errno, errstr);
170 }
171#endif
172
173 /* Don't go through full error handling during mount */
174 save_error_info(fs_info);
175 if (sb->s_flags & MS_BORN)
176 btrfs_handle_error(fs_info);
177}
178
179#ifdef CONFIG_PRINTK
180static const char * const logtypes[] = {
181 "emergency",
182 "alert",
183 "critical",
184 "error",
185 "warning",
186 "notice",
187 "info",
188 "debug",
189};
190
191void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
192{
193 struct super_block *sb = fs_info->sb;
194 char lvl[4];
195 struct va_format vaf;
196 va_list args;
197 const char *type = logtypes[4];
198 int kern_level;
199
200 va_start(args, fmt);
201
202 kern_level = printk_get_level(fmt);
203 if (kern_level) {
204 size_t size = printk_skip_level(fmt) - fmt;
205 memcpy(lvl, fmt, size);
206 lvl[size] = '\0';
207 fmt += size;
208 type = logtypes[kern_level - '0'];
209 } else
210 *lvl = '\0';
211
212 vaf.fmt = fmt;
213 vaf.va = &args;
214
215 printk("%sBTRFS %s (device %s): %pV\n", lvl, type, sb->s_id, &vaf);
216
217 va_end(args);
218}
219#endif
220
221/*
222 * We only mark the transaction aborted and then set the file system read-only.
223 * This will prevent new transactions from starting or trying to join this
224 * one.
225 *
226 * This means that error recovery at the call site is limited to freeing
227 * any local memory allocations and passing the error code up without
228 * further cleanup. The transaction should complete as it normally would
229 * in the call path but will return -EIO.
230 *
231 * We'll complete the cleanup in btrfs_end_transaction and
232 * btrfs_commit_transaction.
233 */
234__cold
235void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
236 struct btrfs_root *root, const char *function,
237 unsigned int line, int errno)
238{
239 trans->aborted = errno;
240 /* Nothing used. The other threads that have joined this
241 * transaction may be able to continue. */
242 if (!trans->blocks_used && list_empty(&trans->new_bgs)) {
243 const char *errstr;
244
245 errstr = btrfs_decode_error(errno);
246 btrfs_warn(root->fs_info,
247 "%s:%d: Aborting unused transaction(%s).",
248 function, line, errstr);
249 return;
250 }
251 ACCESS_ONCE(trans->transaction->aborted) = errno;
252 /* Wake up anybody who may be waiting on this transaction */
253 wake_up(&root->fs_info->transaction_wait);
254 wake_up(&root->fs_info->transaction_blocked_wait);
255 __btrfs_std_error(root->fs_info, function, line, errno, NULL);
256}
257/*
258 * __btrfs_panic decodes unexpected, fatal errors from the caller,
259 * issues an alert, and either panics or BUGs, depending on mount options.
260 */
261__cold
262void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
263 unsigned int line, int errno, const char *fmt, ...)
264{
265 char *s_id = "<unknown>";
266 const char *errstr;
267 struct va_format vaf = { .fmt = fmt };
268 va_list args;
269
270 if (fs_info)
271 s_id = fs_info->sb->s_id;
272
273 va_start(args, fmt);
274 vaf.va = &args;
275
276 errstr = btrfs_decode_error(errno);
277 if (fs_info && (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR))
278 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
279 s_id, function, line, &vaf, errno, errstr);
280
281 btrfs_crit(fs_info, "panic in %s:%d: %pV (errno=%d %s)",
282 function, line, &vaf, errno, errstr);
283 va_end(args);
284 /* Caller calls BUG() */
285}
286
287static void btrfs_put_super(struct super_block *sb)
288{
289 close_ctree(btrfs_sb(sb)->tree_root);
290}
291
292enum {
293 Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
294 Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
295 Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
296 Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
297 Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
298 Opt_space_cache, Opt_space_cache_version, Opt_clear_cache,
299 Opt_user_subvol_rm_allowed, Opt_enospc_debug, Opt_subvolrootid,
300 Opt_defrag, Opt_inode_cache, Opt_no_space_cache, Opt_recovery,
301 Opt_skip_balance, Opt_check_integrity,
302 Opt_check_integrity_including_extent_data,
303 Opt_check_integrity_print_mask, Opt_fatal_errors, Opt_rescan_uuid_tree,
304 Opt_commit_interval, Opt_barrier, Opt_nodefrag, Opt_nodiscard,
305 Opt_noenospc_debug, Opt_noflushoncommit, Opt_acl, Opt_datacow,
306 Opt_datasum, Opt_treelog, Opt_noinode_cache, Opt_usebackuproot,
307 Opt_nologreplay, Opt_norecovery,
308#ifdef CONFIG_BTRFS_DEBUG
309 Opt_fragment_data, Opt_fragment_metadata, Opt_fragment_all,
310#endif
311 Opt_err,
312};
313
314static const match_table_t tokens = {
315 {Opt_degraded, "degraded"},
316 {Opt_subvol, "subvol=%s"},
317 {Opt_subvolid, "subvolid=%s"},
318 {Opt_device, "device=%s"},
319 {Opt_nodatasum, "nodatasum"},
320 {Opt_datasum, "datasum"},
321 {Opt_nodatacow, "nodatacow"},
322 {Opt_datacow, "datacow"},
323 {Opt_nobarrier, "nobarrier"},
324 {Opt_barrier, "barrier"},
325 {Opt_max_inline, "max_inline=%s"},
326 {Opt_alloc_start, "alloc_start=%s"},
327 {Opt_thread_pool, "thread_pool=%d"},
328 {Opt_compress, "compress"},
329 {Opt_compress_type, "compress=%s"},
330 {Opt_compress_force, "compress-force"},
331 {Opt_compress_force_type, "compress-force=%s"},
332 {Opt_ssd, "ssd"},
333 {Opt_ssd_spread, "ssd_spread"},
334 {Opt_nossd, "nossd"},
335 {Opt_acl, "acl"},
336 {Opt_noacl, "noacl"},
337 {Opt_notreelog, "notreelog"},
338 {Opt_treelog, "treelog"},
339 {Opt_nologreplay, "nologreplay"},
340 {Opt_norecovery, "norecovery"},
341 {Opt_flushoncommit, "flushoncommit"},
342 {Opt_noflushoncommit, "noflushoncommit"},
343 {Opt_ratio, "metadata_ratio=%d"},
344 {Opt_discard, "discard"},
345 {Opt_nodiscard, "nodiscard"},
346 {Opt_space_cache, "space_cache"},
347 {Opt_space_cache_version, "space_cache=%s"},
348 {Opt_clear_cache, "clear_cache"},
349 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
350 {Opt_enospc_debug, "enospc_debug"},
351 {Opt_noenospc_debug, "noenospc_debug"},
352 {Opt_subvolrootid, "subvolrootid=%d"},
353 {Opt_defrag, "autodefrag"},
354 {Opt_nodefrag, "noautodefrag"},
355 {Opt_inode_cache, "inode_cache"},
356 {Opt_noinode_cache, "noinode_cache"},
357 {Opt_no_space_cache, "nospace_cache"},
358 {Opt_recovery, "recovery"}, /* deprecated */
359 {Opt_usebackuproot, "usebackuproot"},
360 {Opt_skip_balance, "skip_balance"},
361 {Opt_check_integrity, "check_int"},
362 {Opt_check_integrity_including_extent_data, "check_int_data"},
363 {Opt_check_integrity_print_mask, "check_int_print_mask=%d"},
364 {Opt_rescan_uuid_tree, "rescan_uuid_tree"},
365 {Opt_fatal_errors, "fatal_errors=%s"},
366 {Opt_commit_interval, "commit=%d"},
367#ifdef CONFIG_BTRFS_DEBUG
368 {Opt_fragment_data, "fragment=data"},
369 {Opt_fragment_metadata, "fragment=metadata"},
370 {Opt_fragment_all, "fragment=all"},
371#endif
372 {Opt_err, NULL},
373};
374
375/*
376 * Regular mount options parser. Everything that is needed only when
377 * reading in a new superblock is parsed here.
378 * XXX JDM: This needs to be cleaned up for remount.
379 */
380int btrfs_parse_options(struct btrfs_root *root, char *options,
381 unsigned long new_flags)
382{
383 struct btrfs_fs_info *info = root->fs_info;
384 substring_t args[MAX_OPT_ARGS];
385 char *p, *num, *orig = NULL;
386 u64 cache_gen;
387 int intarg;
388 int ret = 0;
389 char *compress_type;
390 bool compress_force = false;
391 enum btrfs_compression_type saved_compress_type;
392 bool saved_compress_force;
393 int no_compress = 0;
394
395 cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
396 if (btrfs_fs_compat_ro(root->fs_info, FREE_SPACE_TREE))
397 btrfs_set_opt(info->mount_opt, FREE_SPACE_TREE);
398 else if (cache_gen)
399 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
400
401 /*
402 * Even the options are empty, we still need to do extra check
403 * against new flags
404 */
405 if (!options)
406 goto check;
407
408 /*
409 * strsep changes the string, duplicate it because parse_options
410 * gets called twice
411 */
412 options = kstrdup(options, GFP_NOFS);
413 if (!options)
414 return -ENOMEM;
415
416 orig = options;
417
418 while ((p = strsep(&options, ",")) != NULL) {
419 int token;
420 if (!*p)
421 continue;
422
423 token = match_token(p, tokens, args);
424 switch (token) {
425 case Opt_degraded:
426 btrfs_info(root->fs_info, "allowing degraded mounts");
427 btrfs_set_opt(info->mount_opt, DEGRADED);
428 break;
429 case Opt_subvol:
430 case Opt_subvolid:
431 case Opt_subvolrootid:
432 case Opt_device:
433 /*
434 * These are parsed by btrfs_parse_early_options
435 * and can be happily ignored here.
436 */
437 break;
438 case Opt_nodatasum:
439 btrfs_set_and_info(root, NODATASUM,
440 "setting nodatasum");
441 break;
442 case Opt_datasum:
443 if (btrfs_test_opt(root, NODATASUM)) {
444 if (btrfs_test_opt(root, NODATACOW))
445 btrfs_info(root->fs_info, "setting datasum, datacow enabled");
446 else
447 btrfs_info(root->fs_info, "setting datasum");
448 }
449 btrfs_clear_opt(info->mount_opt, NODATACOW);
450 btrfs_clear_opt(info->mount_opt, NODATASUM);
451 break;
452 case Opt_nodatacow:
453 if (!btrfs_test_opt(root, NODATACOW)) {
454 if (!btrfs_test_opt(root, COMPRESS) ||
455 !btrfs_test_opt(root, FORCE_COMPRESS)) {
456 btrfs_info(root->fs_info,
457 "setting nodatacow, compression disabled");
458 } else {
459 btrfs_info(root->fs_info, "setting nodatacow");
460 }
461 }
462 btrfs_clear_opt(info->mount_opt, COMPRESS);
463 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
464 btrfs_set_opt(info->mount_opt, NODATACOW);
465 btrfs_set_opt(info->mount_opt, NODATASUM);
466 break;
467 case Opt_datacow:
468 btrfs_clear_and_info(root, NODATACOW,
469 "setting datacow");
470 break;
471 case Opt_compress_force:
472 case Opt_compress_force_type:
473 compress_force = true;
474 /* Fallthrough */
475 case Opt_compress:
476 case Opt_compress_type:
477 saved_compress_type = btrfs_test_opt(root, COMPRESS) ?
478 info->compress_type : BTRFS_COMPRESS_NONE;
479 saved_compress_force =
480 btrfs_test_opt(root, FORCE_COMPRESS);
481 if (token == Opt_compress ||
482 token == Opt_compress_force ||
483 strcmp(args[0].from, "zlib") == 0) {
484 compress_type = "zlib";
485 info->compress_type = BTRFS_COMPRESS_ZLIB;
486 btrfs_set_opt(info->mount_opt, COMPRESS);
487 btrfs_clear_opt(info->mount_opt, NODATACOW);
488 btrfs_clear_opt(info->mount_opt, NODATASUM);
489 no_compress = 0;
490 } else if (strcmp(args[0].from, "lzo") == 0) {
491 compress_type = "lzo";
492 info->compress_type = BTRFS_COMPRESS_LZO;
493 btrfs_set_opt(info->mount_opt, COMPRESS);
494 btrfs_clear_opt(info->mount_opt, NODATACOW);
495 btrfs_clear_opt(info->mount_opt, NODATASUM);
496 btrfs_set_fs_incompat(info, COMPRESS_LZO);
497 no_compress = 0;
498 } else if (strncmp(args[0].from, "no", 2) == 0) {
499 compress_type = "no";
500 btrfs_clear_opt(info->mount_opt, COMPRESS);
501 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
502 compress_force = false;
503 no_compress++;
504 } else {
505 ret = -EINVAL;
506 goto out;
507 }
508
509 if (compress_force) {
510 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
511 } else {
512 /*
513 * If we remount from compress-force=xxx to
514 * compress=xxx, we need clear FORCE_COMPRESS
515 * flag, otherwise, there is no way for users
516 * to disable forcible compression separately.
517 */
518 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
519 }
520 if ((btrfs_test_opt(root, COMPRESS) &&
521 (info->compress_type != saved_compress_type ||
522 compress_force != saved_compress_force)) ||
523 (!btrfs_test_opt(root, COMPRESS) &&
524 no_compress == 1)) {
525 btrfs_info(root->fs_info,
526 "%s %s compression",
527 (compress_force) ? "force" : "use",
528 compress_type);
529 }
530 compress_force = false;
531 break;
532 case Opt_ssd:
533 btrfs_set_and_info(root, SSD,
534 "use ssd allocation scheme");
535 break;
536 case Opt_ssd_spread:
537 btrfs_set_and_info(root, SSD_SPREAD,
538 "use spread ssd allocation scheme");
539 btrfs_set_opt(info->mount_opt, SSD);
540 break;
541 case Opt_nossd:
542 btrfs_set_and_info(root, NOSSD,
543 "not using ssd allocation scheme");
544 btrfs_clear_opt(info->mount_opt, SSD);
545 break;
546 case Opt_barrier:
547 btrfs_clear_and_info(root, NOBARRIER,
548 "turning on barriers");
549 break;
550 case Opt_nobarrier:
551 btrfs_set_and_info(root, NOBARRIER,
552 "turning off barriers");
553 break;
554 case Opt_thread_pool:
555 ret = match_int(&args[0], &intarg);
556 if (ret) {
557 goto out;
558 } else if (intarg > 0) {
559 info->thread_pool_size = intarg;
560 } else {
561 ret = -EINVAL;
562 goto out;
563 }
564 break;
565 case Opt_max_inline:
566 num = match_strdup(&args[0]);
567 if (num) {
568 info->max_inline = memparse(num, NULL);
569 kfree(num);
570
571 if (info->max_inline) {
572 info->max_inline = min_t(u64,
573 info->max_inline,
574 root->sectorsize);
575 }
576 btrfs_info(root->fs_info, "max_inline at %llu",
577 info->max_inline);
578 } else {
579 ret = -ENOMEM;
580 goto out;
581 }
582 break;
583 case Opt_alloc_start:
584 num = match_strdup(&args[0]);
585 if (num) {
586 mutex_lock(&info->chunk_mutex);
587 info->alloc_start = memparse(num, NULL);
588 mutex_unlock(&info->chunk_mutex);
589 kfree(num);
590 btrfs_info(root->fs_info, "allocations start at %llu",
591 info->alloc_start);
592 } else {
593 ret = -ENOMEM;
594 goto out;
595 }
596 break;
597 case Opt_acl:
598#ifdef CONFIG_BTRFS_FS_POSIX_ACL
599 root->fs_info->sb->s_flags |= MS_POSIXACL;
600 break;
601#else
602 btrfs_err(root->fs_info,
603 "support for ACL not compiled in!");
604 ret = -EINVAL;
605 goto out;
606#endif
607 case Opt_noacl:
608 root->fs_info->sb->s_flags &= ~MS_POSIXACL;
609 break;
610 case Opt_notreelog:
611 btrfs_set_and_info(root, NOTREELOG,
612 "disabling tree log");
613 break;
614 case Opt_treelog:
615 btrfs_clear_and_info(root, NOTREELOG,
616 "enabling tree log");
617 break;
618 case Opt_norecovery:
619 case Opt_nologreplay:
620 btrfs_set_and_info(root, NOLOGREPLAY,
621 "disabling log replay at mount time");
622 break;
623 case Opt_flushoncommit:
624 btrfs_set_and_info(root, FLUSHONCOMMIT,
625 "turning on flush-on-commit");
626 break;
627 case Opt_noflushoncommit:
628 btrfs_clear_and_info(root, FLUSHONCOMMIT,
629 "turning off flush-on-commit");
630 break;
631 case Opt_ratio:
632 ret = match_int(&args[0], &intarg);
633 if (ret) {
634 goto out;
635 } else if (intarg >= 0) {
636 info->metadata_ratio = intarg;
637 btrfs_info(root->fs_info, "metadata ratio %d",
638 info->metadata_ratio);
639 } else {
640 ret = -EINVAL;
641 goto out;
642 }
643 break;
644 case Opt_discard:
645 btrfs_set_and_info(root, DISCARD,
646 "turning on discard");
647 break;
648 case Opt_nodiscard:
649 btrfs_clear_and_info(root, DISCARD,
650 "turning off discard");
651 break;
652 case Opt_space_cache:
653 case Opt_space_cache_version:
654 if (token == Opt_space_cache ||
655 strcmp(args[0].from, "v1") == 0) {
656 btrfs_clear_opt(root->fs_info->mount_opt,
657 FREE_SPACE_TREE);
658 btrfs_set_and_info(root, SPACE_CACHE,
659 "enabling disk space caching");
660 } else if (strcmp(args[0].from, "v2") == 0) {
661 btrfs_clear_opt(root->fs_info->mount_opt,
662 SPACE_CACHE);
663 btrfs_set_and_info(root, FREE_SPACE_TREE,
664 "enabling free space tree");
665 } else {
666 ret = -EINVAL;
667 goto out;
668 }
669 break;
670 case Opt_rescan_uuid_tree:
671 btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE);
672 break;
673 case Opt_no_space_cache:
674 if (btrfs_test_opt(root, SPACE_CACHE)) {
675 btrfs_clear_and_info(root, SPACE_CACHE,
676 "disabling disk space caching");
677 }
678 if (btrfs_test_opt(root, FREE_SPACE_TREE)) {
679 btrfs_clear_and_info(root, FREE_SPACE_TREE,
680 "disabling free space tree");
681 }
682 break;
683 case Opt_inode_cache:
684 btrfs_set_pending_and_info(info, INODE_MAP_CACHE,
685 "enabling inode map caching");
686 break;
687 case Opt_noinode_cache:
688 btrfs_clear_pending_and_info(info, INODE_MAP_CACHE,
689 "disabling inode map caching");
690 break;
691 case Opt_clear_cache:
692 btrfs_set_and_info(root, CLEAR_CACHE,
693 "force clearing of disk cache");
694 break;
695 case Opt_user_subvol_rm_allowed:
696 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
697 break;
698 case Opt_enospc_debug:
699 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
700 break;
701 case Opt_noenospc_debug:
702 btrfs_clear_opt(info->mount_opt, ENOSPC_DEBUG);
703 break;
704 case Opt_defrag:
705 btrfs_set_and_info(root, AUTO_DEFRAG,
706 "enabling auto defrag");
707 break;
708 case Opt_nodefrag:
709 btrfs_clear_and_info(root, AUTO_DEFRAG,
710 "disabling auto defrag");
711 break;
712 case Opt_recovery:
713 btrfs_warn(root->fs_info,
714 "'recovery' is deprecated, use 'usebackuproot' instead");
715 case Opt_usebackuproot:
716 btrfs_info(root->fs_info,
717 "trying to use backup root at mount time");
718 btrfs_set_opt(info->mount_opt, USEBACKUPROOT);
719 break;
720 case Opt_skip_balance:
721 btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
722 break;
723#ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
724 case Opt_check_integrity_including_extent_data:
725 btrfs_info(root->fs_info,
726 "enabling check integrity including extent data");
727 btrfs_set_opt(info->mount_opt,
728 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
729 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
730 break;
731 case Opt_check_integrity:
732 btrfs_info(root->fs_info, "enabling check integrity");
733 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
734 break;
735 case Opt_check_integrity_print_mask:
736 ret = match_int(&args[0], &intarg);
737 if (ret) {
738 goto out;
739 } else if (intarg >= 0) {
740 info->check_integrity_print_mask = intarg;
741 btrfs_info(root->fs_info, "check_integrity_print_mask 0x%x",
742 info->check_integrity_print_mask);
743 } else {
744 ret = -EINVAL;
745 goto out;
746 }
747 break;
748#else
749 case Opt_check_integrity_including_extent_data:
750 case Opt_check_integrity:
751 case Opt_check_integrity_print_mask:
752 btrfs_err(root->fs_info,
753 "support for check_integrity* not compiled in!");
754 ret = -EINVAL;
755 goto out;
756#endif
757 case Opt_fatal_errors:
758 if (strcmp(args[0].from, "panic") == 0)
759 btrfs_set_opt(info->mount_opt,
760 PANIC_ON_FATAL_ERROR);
761 else if (strcmp(args[0].from, "bug") == 0)
762 btrfs_clear_opt(info->mount_opt,
763 PANIC_ON_FATAL_ERROR);
764 else {
765 ret = -EINVAL;
766 goto out;
767 }
768 break;
769 case Opt_commit_interval:
770 intarg = 0;
771 ret = match_int(&args[0], &intarg);
772 if (ret < 0) {
773 btrfs_err(root->fs_info, "invalid commit interval");
774 ret = -EINVAL;
775 goto out;
776 }
777 if (intarg > 0) {
778 if (intarg > 300) {
779 btrfs_warn(root->fs_info, "excessive commit interval %d",
780 intarg);
781 }
782 info->commit_interval = intarg;
783 } else {
784 btrfs_info(root->fs_info, "using default commit interval %ds",
785 BTRFS_DEFAULT_COMMIT_INTERVAL);
786 info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
787 }
788 break;
789#ifdef CONFIG_BTRFS_DEBUG
790 case Opt_fragment_all:
791 btrfs_info(root->fs_info, "fragmenting all space");
792 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA);
793 btrfs_set_opt(info->mount_opt, FRAGMENT_METADATA);
794 break;
795 case Opt_fragment_metadata:
796 btrfs_info(root->fs_info, "fragmenting metadata");
797 btrfs_set_opt(info->mount_opt,
798 FRAGMENT_METADATA);
799 break;
800 case Opt_fragment_data:
801 btrfs_info(root->fs_info, "fragmenting data");
802 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA);
803 break;
804#endif
805 case Opt_err:
806 btrfs_info(root->fs_info, "unrecognized mount option '%s'", p);
807 ret = -EINVAL;
808 goto out;
809 default:
810 break;
811 }
812 }
813check:
814 /*
815 * Extra check for current option against current flag
816 */
817 if (btrfs_test_opt(root, NOLOGREPLAY) && !(new_flags & MS_RDONLY)) {
818 btrfs_err(root->fs_info,
819 "nologreplay must be used with ro mount option");
820 ret = -EINVAL;
821 }
822out:
823 if (btrfs_fs_compat_ro(root->fs_info, FREE_SPACE_TREE) &&
824 !btrfs_test_opt(root, FREE_SPACE_TREE) &&
825 !btrfs_test_opt(root, CLEAR_CACHE)) {
826 btrfs_err(root->fs_info, "cannot disable free space tree");
827 ret = -EINVAL;
828
829 }
830 if (!ret && btrfs_test_opt(root, SPACE_CACHE))
831 btrfs_info(root->fs_info, "disk space caching is enabled");
832 if (!ret && btrfs_test_opt(root, FREE_SPACE_TREE))
833 btrfs_info(root->fs_info, "using free space tree");
834 kfree(orig);
835 return ret;
836}
837
838/*
839 * Parse mount options that are required early in the mount process.
840 *
841 * All other options will be parsed on much later in the mount process and
842 * only when we need to allocate a new super block.
843 */
844static int btrfs_parse_early_options(const char *options, fmode_t flags,
845 void *holder, char **subvol_name, u64 *subvol_objectid,
846 struct btrfs_fs_devices **fs_devices)
847{
848 substring_t args[MAX_OPT_ARGS];
849 char *device_name, *opts, *orig, *p;
850 char *num = NULL;
851 int error = 0;
852
853 if (!options)
854 return 0;
855
856 /*
857 * strsep changes the string, duplicate it because parse_options
858 * gets called twice
859 */
860 opts = kstrdup(options, GFP_KERNEL);
861 if (!opts)
862 return -ENOMEM;
863 orig = opts;
864
865 while ((p = strsep(&opts, ",")) != NULL) {
866 int token;
867 if (!*p)
868 continue;
869
870 token = match_token(p, tokens, args);
871 switch (token) {
872 case Opt_subvol:
873 kfree(*subvol_name);
874 *subvol_name = match_strdup(&args[0]);
875 if (!*subvol_name) {
876 error = -ENOMEM;
877 goto out;
878 }
879 break;
880 case Opt_subvolid:
881 num = match_strdup(&args[0]);
882 if (num) {
883 *subvol_objectid = memparse(num, NULL);
884 kfree(num);
885 /* we want the original fs_tree */
886 if (!*subvol_objectid)
887 *subvol_objectid =
888 BTRFS_FS_TREE_OBJECTID;
889 } else {
890 error = -EINVAL;
891 goto out;
892 }
893 break;
894 case Opt_subvolrootid:
895 printk(KERN_WARNING
896 "BTRFS: 'subvolrootid' mount option is deprecated and has "
897 "no effect\n");
898 break;
899 case Opt_device:
900 device_name = match_strdup(&args[0]);
901 if (!device_name) {
902 error = -ENOMEM;
903 goto out;
904 }
905 error = btrfs_scan_one_device(device_name,
906 flags, holder, fs_devices);
907 kfree(device_name);
908 if (error)
909 goto out;
910 break;
911 default:
912 break;
913 }
914 }
915
916out:
917 kfree(orig);
918 return error;
919}
920
921static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info,
922 u64 subvol_objectid)
923{
924 struct btrfs_root *root = fs_info->tree_root;
925 struct btrfs_root *fs_root;
926 struct btrfs_root_ref *root_ref;
927 struct btrfs_inode_ref *inode_ref;
928 struct btrfs_key key;
929 struct btrfs_path *path = NULL;
930 char *name = NULL, *ptr;
931 u64 dirid;
932 int len;
933 int ret;
934
935 path = btrfs_alloc_path();
936 if (!path) {
937 ret = -ENOMEM;
938 goto err;
939 }
940 path->leave_spinning = 1;
941
942 name = kmalloc(PATH_MAX, GFP_NOFS);
943 if (!name) {
944 ret = -ENOMEM;
945 goto err;
946 }
947 ptr = name + PATH_MAX - 1;
948 ptr[0] = '\0';
949
950 /*
951 * Walk up the subvolume trees in the tree of tree roots by root
952 * backrefs until we hit the top-level subvolume.
953 */
954 while (subvol_objectid != BTRFS_FS_TREE_OBJECTID) {
955 key.objectid = subvol_objectid;
956 key.type = BTRFS_ROOT_BACKREF_KEY;
957 key.offset = (u64)-1;
958
959 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
960 if (ret < 0) {
961 goto err;
962 } else if (ret > 0) {
963 ret = btrfs_previous_item(root, path, subvol_objectid,
964 BTRFS_ROOT_BACKREF_KEY);
965 if (ret < 0) {
966 goto err;
967 } else if (ret > 0) {
968 ret = -ENOENT;
969 goto err;
970 }
971 }
972
973 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
974 subvol_objectid = key.offset;
975
976 root_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
977 struct btrfs_root_ref);
978 len = btrfs_root_ref_name_len(path->nodes[0], root_ref);
979 ptr -= len + 1;
980 if (ptr < name) {
981 ret = -ENAMETOOLONG;
982 goto err;
983 }
984 read_extent_buffer(path->nodes[0], ptr + 1,
985 (unsigned long)(root_ref + 1), len);
986 ptr[0] = '/';
987 dirid = btrfs_root_ref_dirid(path->nodes[0], root_ref);
988 btrfs_release_path(path);
989
990 key.objectid = subvol_objectid;
991 key.type = BTRFS_ROOT_ITEM_KEY;
992 key.offset = (u64)-1;
993 fs_root = btrfs_read_fs_root_no_name(fs_info, &key);
994 if (IS_ERR(fs_root)) {
995 ret = PTR_ERR(fs_root);
996 goto err;
997 }
998
999 /*
1000 * Walk up the filesystem tree by inode refs until we hit the
1001 * root directory.
1002 */
1003 while (dirid != BTRFS_FIRST_FREE_OBJECTID) {
1004 key.objectid = dirid;
1005 key.type = BTRFS_INODE_REF_KEY;
1006 key.offset = (u64)-1;
1007
1008 ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0);
1009 if (ret < 0) {
1010 goto err;
1011 } else if (ret > 0) {
1012 ret = btrfs_previous_item(fs_root, path, dirid,
1013 BTRFS_INODE_REF_KEY);
1014 if (ret < 0) {
1015 goto err;
1016 } else if (ret > 0) {
1017 ret = -ENOENT;
1018 goto err;
1019 }
1020 }
1021
1022 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1023 dirid = key.offset;
1024
1025 inode_ref = btrfs_item_ptr(path->nodes[0],
1026 path->slots[0],
1027 struct btrfs_inode_ref);
1028 len = btrfs_inode_ref_name_len(path->nodes[0],
1029 inode_ref);
1030 ptr -= len + 1;
1031 if (ptr < name) {
1032 ret = -ENAMETOOLONG;
1033 goto err;
1034 }
1035 read_extent_buffer(path->nodes[0], ptr + 1,
1036 (unsigned long)(inode_ref + 1), len);
1037 ptr[0] = '/';
1038 btrfs_release_path(path);
1039 }
1040 }
1041
1042 btrfs_free_path(path);
1043 if (ptr == name + PATH_MAX - 1) {
1044 name[0] = '/';
1045 name[1] = '\0';
1046 } else {
1047 memmove(name, ptr, name + PATH_MAX - ptr);
1048 }
1049 return name;
1050
1051err:
1052 btrfs_free_path(path);
1053 kfree(name);
1054 return ERR_PTR(ret);
1055}
1056
1057static int get_default_subvol_objectid(struct btrfs_fs_info *fs_info, u64 *objectid)
1058{
1059 struct btrfs_root *root = fs_info->tree_root;
1060 struct btrfs_dir_item *di;
1061 struct btrfs_path *path;
1062 struct btrfs_key location;
1063 u64 dir_id;
1064
1065 path = btrfs_alloc_path();
1066 if (!path)
1067 return -ENOMEM;
1068 path->leave_spinning = 1;
1069
1070 /*
1071 * Find the "default" dir item which points to the root item that we
1072 * will mount by default if we haven't been given a specific subvolume
1073 * to mount.
1074 */
1075 dir_id = btrfs_super_root_dir(fs_info->super_copy);
1076 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
1077 if (IS_ERR(di)) {
1078 btrfs_free_path(path);
1079 return PTR_ERR(di);
1080 }
1081 if (!di) {
1082 /*
1083 * Ok the default dir item isn't there. This is weird since
1084 * it's always been there, but don't freak out, just try and
1085 * mount the top-level subvolume.
1086 */
1087 btrfs_free_path(path);
1088 *objectid = BTRFS_FS_TREE_OBJECTID;
1089 return 0;
1090 }
1091
1092 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
1093 btrfs_free_path(path);
1094 *objectid = location.objectid;
1095 return 0;
1096}
1097
1098static int btrfs_fill_super(struct super_block *sb,
1099 struct btrfs_fs_devices *fs_devices,
1100 void *data, int silent)
1101{
1102 struct inode *inode;
1103 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1104 struct btrfs_key key;
1105 int err;
1106
1107 sb->s_maxbytes = MAX_LFS_FILESIZE;
1108 sb->s_magic = BTRFS_SUPER_MAGIC;
1109 sb->s_op = &btrfs_super_ops;
1110 sb->s_d_op = &btrfs_dentry_operations;
1111 sb->s_export_op = &btrfs_export_ops;
1112 sb->s_xattr = btrfs_xattr_handlers;
1113 sb->s_time_gran = 1;
1114#ifdef CONFIG_BTRFS_FS_POSIX_ACL
1115 sb->s_flags |= MS_POSIXACL;
1116#endif
1117 sb->s_flags |= MS_I_VERSION;
1118 sb->s_iflags |= SB_I_CGROUPWB;
1119 err = open_ctree(sb, fs_devices, (char *)data);
1120 if (err) {
1121 printk(KERN_ERR "BTRFS: open_ctree failed\n");
1122 return err;
1123 }
1124
1125 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
1126 key.type = BTRFS_INODE_ITEM_KEY;
1127 key.offset = 0;
1128 inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
1129 if (IS_ERR(inode)) {
1130 err = PTR_ERR(inode);
1131 goto fail_close;
1132 }
1133
1134 sb->s_root = d_make_root(inode);
1135 if (!sb->s_root) {
1136 err = -ENOMEM;
1137 goto fail_close;
1138 }
1139
1140 save_mount_options(sb, data);
1141 cleancache_init_fs(sb);
1142 sb->s_flags |= MS_ACTIVE;
1143 return 0;
1144
1145fail_close:
1146 close_ctree(fs_info->tree_root);
1147 return err;
1148}
1149
1150int btrfs_sync_fs(struct super_block *sb, int wait)
1151{
1152 struct btrfs_trans_handle *trans;
1153 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1154 struct btrfs_root *root = fs_info->tree_root;
1155
1156 trace_btrfs_sync_fs(wait);
1157
1158 if (!wait) {
1159 filemap_flush(fs_info->btree_inode->i_mapping);
1160 return 0;
1161 }
1162
1163 btrfs_wait_ordered_roots(fs_info, -1);
1164
1165 trans = btrfs_attach_transaction_barrier(root);
1166 if (IS_ERR(trans)) {
1167 /* no transaction, don't bother */
1168 if (PTR_ERR(trans) == -ENOENT) {
1169 /*
1170 * Exit unless we have some pending changes
1171 * that need to go through commit
1172 */
1173 if (fs_info->pending_changes == 0)
1174 return 0;
1175 /*
1176 * A non-blocking test if the fs is frozen. We must not
1177 * start a new transaction here otherwise a deadlock
1178 * happens. The pending operations are delayed to the
1179 * next commit after thawing.
1180 */
1181 if (__sb_start_write(sb, SB_FREEZE_WRITE, false))
1182 __sb_end_write(sb, SB_FREEZE_WRITE);
1183 else
1184 return 0;
1185 trans = btrfs_start_transaction(root, 0);
1186 }
1187 if (IS_ERR(trans))
1188 return PTR_ERR(trans);
1189 }
1190 return btrfs_commit_transaction(trans, root);
1191}
1192
1193static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
1194{
1195 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
1196 struct btrfs_root *root = info->tree_root;
1197 char *compress_type;
1198
1199 if (btrfs_test_opt(root, DEGRADED))
1200 seq_puts(seq, ",degraded");
1201 if (btrfs_test_opt(root, NODATASUM))
1202 seq_puts(seq, ",nodatasum");
1203 if (btrfs_test_opt(root, NODATACOW))
1204 seq_puts(seq, ",nodatacow");
1205 if (btrfs_test_opt(root, NOBARRIER))
1206 seq_puts(seq, ",nobarrier");
1207 if (info->max_inline != BTRFS_DEFAULT_MAX_INLINE)
1208 seq_printf(seq, ",max_inline=%llu", info->max_inline);
1209 if (info->alloc_start != 0)
1210 seq_printf(seq, ",alloc_start=%llu", info->alloc_start);
1211 if (info->thread_pool_size != min_t(unsigned long,
1212 num_online_cpus() + 2, 8))
1213 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
1214 if (btrfs_test_opt(root, COMPRESS)) {
1215 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
1216 compress_type = "zlib";
1217 else
1218 compress_type = "lzo";
1219 if (btrfs_test_opt(root, FORCE_COMPRESS))
1220 seq_printf(seq, ",compress-force=%s", compress_type);
1221 else
1222 seq_printf(seq, ",compress=%s", compress_type);
1223 }
1224 if (btrfs_test_opt(root, NOSSD))
1225 seq_puts(seq, ",nossd");
1226 if (btrfs_test_opt(root, SSD_SPREAD))
1227 seq_puts(seq, ",ssd_spread");
1228 else if (btrfs_test_opt(root, SSD))
1229 seq_puts(seq, ",ssd");
1230 if (btrfs_test_opt(root, NOTREELOG))
1231 seq_puts(seq, ",notreelog");
1232 if (btrfs_test_opt(root, NOLOGREPLAY))
1233 seq_puts(seq, ",nologreplay");
1234 if (btrfs_test_opt(root, FLUSHONCOMMIT))
1235 seq_puts(seq, ",flushoncommit");
1236 if (btrfs_test_opt(root, DISCARD))
1237 seq_puts(seq, ",discard");
1238 if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
1239 seq_puts(seq, ",noacl");
1240 if (btrfs_test_opt(root, SPACE_CACHE))
1241 seq_puts(seq, ",space_cache");
1242 else if (btrfs_test_opt(root, FREE_SPACE_TREE))
1243 seq_puts(seq, ",space_cache=v2");
1244 else
1245 seq_puts(seq, ",nospace_cache");
1246 if (btrfs_test_opt(root, RESCAN_UUID_TREE))
1247 seq_puts(seq, ",rescan_uuid_tree");
1248 if (btrfs_test_opt(root, CLEAR_CACHE))
1249 seq_puts(seq, ",clear_cache");
1250 if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
1251 seq_puts(seq, ",user_subvol_rm_allowed");
1252 if (btrfs_test_opt(root, ENOSPC_DEBUG))
1253 seq_puts(seq, ",enospc_debug");
1254 if (btrfs_test_opt(root, AUTO_DEFRAG))
1255 seq_puts(seq, ",autodefrag");
1256 if (btrfs_test_opt(root, INODE_MAP_CACHE))
1257 seq_puts(seq, ",inode_cache");
1258 if (btrfs_test_opt(root, SKIP_BALANCE))
1259 seq_puts(seq, ",skip_balance");
1260#ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1261 if (btrfs_test_opt(root, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA))
1262 seq_puts(seq, ",check_int_data");
1263 else if (btrfs_test_opt(root, CHECK_INTEGRITY))
1264 seq_puts(seq, ",check_int");
1265 if (info->check_integrity_print_mask)
1266 seq_printf(seq, ",check_int_print_mask=%d",
1267 info->check_integrity_print_mask);
1268#endif
1269 if (info->metadata_ratio)
1270 seq_printf(seq, ",metadata_ratio=%d",
1271 info->metadata_ratio);
1272 if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR))
1273 seq_puts(seq, ",fatal_errors=panic");
1274 if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL)
1275 seq_printf(seq, ",commit=%d", info->commit_interval);
1276#ifdef CONFIG_BTRFS_DEBUG
1277 if (btrfs_test_opt(root, FRAGMENT_DATA))
1278 seq_puts(seq, ",fragment=data");
1279 if (btrfs_test_opt(root, FRAGMENT_METADATA))
1280 seq_puts(seq, ",fragment=metadata");
1281#endif
1282 seq_printf(seq, ",subvolid=%llu",
1283 BTRFS_I(d_inode(dentry))->root->root_key.objectid);
1284 seq_puts(seq, ",subvol=");
1285 seq_dentry(seq, dentry, " \t\n\\");
1286 return 0;
1287}
1288
1289static int btrfs_test_super(struct super_block *s, void *data)
1290{
1291 struct btrfs_fs_info *p = data;
1292 struct btrfs_fs_info *fs_info = btrfs_sb(s);
1293
1294 return fs_info->fs_devices == p->fs_devices;
1295}
1296
1297static int btrfs_set_super(struct super_block *s, void *data)
1298{
1299 int err = set_anon_super(s, data);
1300 if (!err)
1301 s->s_fs_info = data;
1302 return err;
1303}
1304
1305/*
1306 * subvolumes are identified by ino 256
1307 */
1308static inline int is_subvolume_inode(struct inode *inode)
1309{
1310 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
1311 return 1;
1312 return 0;
1313}
1314
1315/*
1316 * This will add subvolid=0 to the argument string while removing any subvol=
1317 * and subvolid= arguments to make sure we get the top-level root for path
1318 * walking to the subvol we want.
1319 */
1320static char *setup_root_args(char *args)
1321{
1322 char *buf, *dst, *sep;
1323
1324 if (!args)
1325 return kstrdup("subvolid=0", GFP_NOFS);
1326
1327 /* The worst case is that we add ",subvolid=0" to the end. */
1328 buf = dst = kmalloc(strlen(args) + strlen(",subvolid=0") + 1, GFP_NOFS);
1329 if (!buf)
1330 return NULL;
1331
1332 while (1) {
1333 sep = strchrnul(args, ',');
1334 if (!strstarts(args, "subvol=") &&
1335 !strstarts(args, "subvolid=")) {
1336 memcpy(dst, args, sep - args);
1337 dst += sep - args;
1338 *dst++ = ',';
1339 }
1340 if (*sep)
1341 args = sep + 1;
1342 else
1343 break;
1344 }
1345 strcpy(dst, "subvolid=0");
1346
1347 return buf;
1348}
1349
1350static struct dentry *mount_subvol(const char *subvol_name, u64 subvol_objectid,
1351 int flags, const char *device_name,
1352 char *data)
1353{
1354 struct dentry *root;
1355 struct vfsmount *mnt = NULL;
1356 char *newargs;
1357 int ret;
1358
1359 newargs = setup_root_args(data);
1360 if (!newargs) {
1361 root = ERR_PTR(-ENOMEM);
1362 goto out;
1363 }
1364
1365 mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name, newargs);
1366 if (PTR_ERR_OR_ZERO(mnt) == -EBUSY) {
1367 if (flags & MS_RDONLY) {
1368 mnt = vfs_kern_mount(&btrfs_fs_type, flags & ~MS_RDONLY,
1369 device_name, newargs);
1370 } else {
1371 mnt = vfs_kern_mount(&btrfs_fs_type, flags | MS_RDONLY,
1372 device_name, newargs);
1373 if (IS_ERR(mnt)) {
1374 root = ERR_CAST(mnt);
1375 mnt = NULL;
1376 goto out;
1377 }
1378
1379 down_write(&mnt->mnt_sb->s_umount);
1380 ret = btrfs_remount(mnt->mnt_sb, &flags, NULL);
1381 up_write(&mnt->mnt_sb->s_umount);
1382 if (ret < 0) {
1383 root = ERR_PTR(ret);
1384 goto out;
1385 }
1386 }
1387 }
1388 if (IS_ERR(mnt)) {
1389 root = ERR_CAST(mnt);
1390 mnt = NULL;
1391 goto out;
1392 }
1393
1394 if (!subvol_name) {
1395 if (!subvol_objectid) {
1396 ret = get_default_subvol_objectid(btrfs_sb(mnt->mnt_sb),
1397 &subvol_objectid);
1398 if (ret) {
1399 root = ERR_PTR(ret);
1400 goto out;
1401 }
1402 }
1403 subvol_name = get_subvol_name_from_objectid(btrfs_sb(mnt->mnt_sb),
1404 subvol_objectid);
1405 if (IS_ERR(subvol_name)) {
1406 root = ERR_CAST(subvol_name);
1407 subvol_name = NULL;
1408 goto out;
1409 }
1410
1411 }
1412
1413 root = mount_subtree(mnt, subvol_name);
1414 /* mount_subtree() drops our reference on the vfsmount. */
1415 mnt = NULL;
1416
1417 if (!IS_ERR(root)) {
1418 struct super_block *s = root->d_sb;
1419 struct inode *root_inode = d_inode(root);
1420 u64 root_objectid = BTRFS_I(root_inode)->root->root_key.objectid;
1421
1422 ret = 0;
1423 if (!is_subvolume_inode(root_inode)) {
1424 pr_err("BTRFS: '%s' is not a valid subvolume\n",
1425 subvol_name);
1426 ret = -EINVAL;
1427 }
1428 if (subvol_objectid && root_objectid != subvol_objectid) {
1429 /*
1430 * This will also catch a race condition where a
1431 * subvolume which was passed by ID is renamed and
1432 * another subvolume is renamed over the old location.
1433 */
1434 pr_err("BTRFS: subvol '%s' does not match subvolid %llu\n",
1435 subvol_name, subvol_objectid);
1436 ret = -EINVAL;
1437 }
1438 if (ret) {
1439 dput(root);
1440 root = ERR_PTR(ret);
1441 deactivate_locked_super(s);
1442 }
1443 }
1444
1445out:
1446 mntput(mnt);
1447 kfree(newargs);
1448 kfree(subvol_name);
1449 return root;
1450}
1451
1452static int parse_security_options(char *orig_opts,
1453 struct security_mnt_opts *sec_opts)
1454{
1455 char *secdata = NULL;
1456 int ret = 0;
1457
1458 secdata = alloc_secdata();
1459 if (!secdata)
1460 return -ENOMEM;
1461 ret = security_sb_copy_data(orig_opts, secdata);
1462 if (ret) {
1463 free_secdata(secdata);
1464 return ret;
1465 }
1466 ret = security_sb_parse_opts_str(secdata, sec_opts);
1467 free_secdata(secdata);
1468 return ret;
1469}
1470
1471static int setup_security_options(struct btrfs_fs_info *fs_info,
1472 struct super_block *sb,
1473 struct security_mnt_opts *sec_opts)
1474{
1475 int ret = 0;
1476
1477 /*
1478 * Call security_sb_set_mnt_opts() to check whether new sec_opts
1479 * is valid.
1480 */
1481 ret = security_sb_set_mnt_opts(sb, sec_opts, 0, NULL);
1482 if (ret)
1483 return ret;
1484
1485#ifdef CONFIG_SECURITY
1486 if (!fs_info->security_opts.num_mnt_opts) {
1487 /* first time security setup, copy sec_opts to fs_info */
1488 memcpy(&fs_info->security_opts, sec_opts, sizeof(*sec_opts));
1489 } else {
1490 /*
1491 * Since SELinux(the only one supports security_mnt_opts) does
1492 * NOT support changing context during remount/mount same sb,
1493 * This must be the same or part of the same security options,
1494 * just free it.
1495 */
1496 security_free_mnt_opts(sec_opts);
1497 }
1498#endif
1499 return ret;
1500}
1501
1502/*
1503 * Find a superblock for the given device / mount point.
1504 *
1505 * Note: This is based on get_sb_bdev from fs/super.c with a few additions
1506 * for multiple device setup. Make sure to keep it in sync.
1507 */
1508static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1509 const char *device_name, void *data)
1510{
1511 struct block_device *bdev = NULL;
1512 struct super_block *s;
1513 struct btrfs_fs_devices *fs_devices = NULL;
1514 struct btrfs_fs_info *fs_info = NULL;
1515 struct security_mnt_opts new_sec_opts;
1516 fmode_t mode = FMODE_READ;
1517 char *subvol_name = NULL;
1518 u64 subvol_objectid = 0;
1519 int error = 0;
1520
1521 if (!(flags & MS_RDONLY))
1522 mode |= FMODE_WRITE;
1523
1524 error = btrfs_parse_early_options(data, mode, fs_type,
1525 &subvol_name, &subvol_objectid,
1526 &fs_devices);
1527 if (error) {
1528 kfree(subvol_name);
1529 return ERR_PTR(error);
1530 }
1531
1532 if (subvol_name || subvol_objectid != BTRFS_FS_TREE_OBJECTID) {
1533 /* mount_subvol() will free subvol_name. */
1534 return mount_subvol(subvol_name, subvol_objectid, flags,
1535 device_name, data);
1536 }
1537
1538 security_init_mnt_opts(&new_sec_opts);
1539 if (data) {
1540 error = parse_security_options(data, &new_sec_opts);
1541 if (error)
1542 return ERR_PTR(error);
1543 }
1544
1545 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
1546 if (error)
1547 goto error_sec_opts;
1548
1549 /*
1550 * Setup a dummy root and fs_info for test/set super. This is because
1551 * we don't actually fill this stuff out until open_ctree, but we need
1552 * it for searching for existing supers, so this lets us do that and
1553 * then open_ctree will properly initialize everything later.
1554 */
1555 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
1556 if (!fs_info) {
1557 error = -ENOMEM;
1558 goto error_sec_opts;
1559 }
1560
1561 fs_info->fs_devices = fs_devices;
1562
1563 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1564 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1565 security_init_mnt_opts(&fs_info->security_opts);
1566 if (!fs_info->super_copy || !fs_info->super_for_commit) {
1567 error = -ENOMEM;
1568 goto error_fs_info;
1569 }
1570
1571 error = btrfs_open_devices(fs_devices, mode, fs_type);
1572 if (error)
1573 goto error_fs_info;
1574
1575 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
1576 error = -EACCES;
1577 goto error_close_devices;
1578 }
1579
1580 bdev = fs_devices->latest_bdev;
1581 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | MS_NOSEC,
1582 fs_info);
1583 if (IS_ERR(s)) {
1584 error = PTR_ERR(s);
1585 goto error_close_devices;
1586 }
1587
1588 if (s->s_root) {
1589 btrfs_close_devices(fs_devices);
1590 free_fs_info(fs_info);
1591 if ((flags ^ s->s_flags) & MS_RDONLY)
1592 error = -EBUSY;
1593 } else {
1594 snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev);
1595 btrfs_sb(s)->bdev_holder = fs_type;
1596 error = btrfs_fill_super(s, fs_devices, data,
1597 flags & MS_SILENT ? 1 : 0);
1598 }
1599 if (error) {
1600 deactivate_locked_super(s);
1601 goto error_sec_opts;
1602 }
1603
1604 fs_info = btrfs_sb(s);
1605 error = setup_security_options(fs_info, s, &new_sec_opts);
1606 if (error) {
1607 deactivate_locked_super(s);
1608 goto error_sec_opts;
1609 }
1610
1611 return dget(s->s_root);
1612
1613error_close_devices:
1614 btrfs_close_devices(fs_devices);
1615error_fs_info:
1616 free_fs_info(fs_info);
1617error_sec_opts:
1618 security_free_mnt_opts(&new_sec_opts);
1619 return ERR_PTR(error);
1620}
1621
1622static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1623 int new_pool_size, int old_pool_size)
1624{
1625 if (new_pool_size == old_pool_size)
1626 return;
1627
1628 fs_info->thread_pool_size = new_pool_size;
1629
1630 btrfs_info(fs_info, "resize thread pool %d -> %d",
1631 old_pool_size, new_pool_size);
1632
1633 btrfs_workqueue_set_max(fs_info->workers, new_pool_size);
1634 btrfs_workqueue_set_max(fs_info->delalloc_workers, new_pool_size);
1635 btrfs_workqueue_set_max(fs_info->submit_workers, new_pool_size);
1636 btrfs_workqueue_set_max(fs_info->caching_workers, new_pool_size);
1637 btrfs_workqueue_set_max(fs_info->endio_workers, new_pool_size);
1638 btrfs_workqueue_set_max(fs_info->endio_meta_workers, new_pool_size);
1639 btrfs_workqueue_set_max(fs_info->endio_meta_write_workers,
1640 new_pool_size);
1641 btrfs_workqueue_set_max(fs_info->endio_write_workers, new_pool_size);
1642 btrfs_workqueue_set_max(fs_info->endio_freespace_worker, new_pool_size);
1643 btrfs_workqueue_set_max(fs_info->delayed_workers, new_pool_size);
1644 btrfs_workqueue_set_max(fs_info->readahead_workers, new_pool_size);
1645 btrfs_workqueue_set_max(fs_info->scrub_wr_completion_workers,
1646 new_pool_size);
1647}
1648
1649static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info)
1650{
1651 set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1652}
1653
1654static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
1655 unsigned long old_opts, int flags)
1656{
1657 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1658 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1659 (flags & MS_RDONLY))) {
1660 /* wait for any defraggers to finish */
1661 wait_event(fs_info->transaction_wait,
1662 (atomic_read(&fs_info->defrag_running) == 0));
1663 if (flags & MS_RDONLY)
1664 sync_filesystem(fs_info->sb);
1665 }
1666}
1667
1668static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1669 unsigned long old_opts)
1670{
1671 /*
1672 * We need cleanup all defragable inodes if the autodefragment is
1673 * close or the fs is R/O.
1674 */
1675 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1676 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1677 (fs_info->sb->s_flags & MS_RDONLY))) {
1678 btrfs_cleanup_defrag_inodes(fs_info);
1679 }
1680
1681 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1682}
1683
1684static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1685{
1686 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1687 struct btrfs_root *root = fs_info->tree_root;
1688 unsigned old_flags = sb->s_flags;
1689 unsigned long old_opts = fs_info->mount_opt;
1690 unsigned long old_compress_type = fs_info->compress_type;
1691 u64 old_max_inline = fs_info->max_inline;
1692 u64 old_alloc_start = fs_info->alloc_start;
1693 int old_thread_pool_size = fs_info->thread_pool_size;
1694 unsigned int old_metadata_ratio = fs_info->metadata_ratio;
1695 int ret;
1696
1697 sync_filesystem(sb);
1698 btrfs_remount_prepare(fs_info);
1699
1700 if (data) {
1701 struct security_mnt_opts new_sec_opts;
1702
1703 security_init_mnt_opts(&new_sec_opts);
1704 ret = parse_security_options(data, &new_sec_opts);
1705 if (ret)
1706 goto restore;
1707 ret = setup_security_options(fs_info, sb,
1708 &new_sec_opts);
1709 if (ret) {
1710 security_free_mnt_opts(&new_sec_opts);
1711 goto restore;
1712 }
1713 }
1714
1715 ret = btrfs_parse_options(root, data, *flags);
1716 if (ret) {
1717 ret = -EINVAL;
1718 goto restore;
1719 }
1720
1721 btrfs_remount_begin(fs_info, old_opts, *flags);
1722 btrfs_resize_thread_pool(fs_info,
1723 fs_info->thread_pool_size, old_thread_pool_size);
1724
1725 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1726 goto out;
1727
1728 if (*flags & MS_RDONLY) {
1729 /*
1730 * this also happens on 'umount -rf' or on shutdown, when
1731 * the filesystem is busy.
1732 */
1733 cancel_work_sync(&fs_info->async_reclaim_work);
1734
1735 /* wait for the uuid_scan task to finish */
1736 down(&fs_info->uuid_tree_rescan_sem);
1737 /* avoid complains from lockdep et al. */
1738 up(&fs_info->uuid_tree_rescan_sem);
1739
1740 sb->s_flags |= MS_RDONLY;
1741
1742 /*
1743 * Setting MS_RDONLY will put the cleaner thread to
1744 * sleep at the next loop if it's already active.
1745 * If it's already asleep, we'll leave unused block
1746 * groups on disk until we're mounted read-write again
1747 * unless we clean them up here.
1748 */
1749 btrfs_delete_unused_bgs(fs_info);
1750
1751 btrfs_dev_replace_suspend_for_unmount(fs_info);
1752 btrfs_scrub_cancel(fs_info);
1753 btrfs_pause_balance(fs_info);
1754
1755 ret = btrfs_commit_super(root);
1756 if (ret)
1757 goto restore;
1758 } else {
1759 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) {
1760 btrfs_err(fs_info,
1761 "Remounting read-write after error is not allowed");
1762 ret = -EINVAL;
1763 goto restore;
1764 }
1765 if (fs_info->fs_devices->rw_devices == 0) {
1766 ret = -EACCES;
1767 goto restore;
1768 }
1769
1770 if (fs_info->fs_devices->missing_devices >
1771 fs_info->num_tolerated_disk_barrier_failures &&
1772 !(*flags & MS_RDONLY)) {
1773 btrfs_warn(fs_info,
1774 "too many missing devices, writeable remount is not allowed");
1775 ret = -EACCES;
1776 goto restore;
1777 }
1778
1779 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1780 ret = -EINVAL;
1781 goto restore;
1782 }
1783
1784 ret = btrfs_cleanup_fs_roots(fs_info);
1785 if (ret)
1786 goto restore;
1787
1788 /* recover relocation */
1789 mutex_lock(&fs_info->cleaner_mutex);
1790 ret = btrfs_recover_relocation(root);
1791 mutex_unlock(&fs_info->cleaner_mutex);
1792 if (ret)
1793 goto restore;
1794
1795 ret = btrfs_resume_balance_async(fs_info);
1796 if (ret)
1797 goto restore;
1798
1799 ret = btrfs_resume_dev_replace_async(fs_info);
1800 if (ret) {
1801 btrfs_warn(fs_info, "failed to resume dev_replace");
1802 goto restore;
1803 }
1804
1805 if (!fs_info->uuid_root) {
1806 btrfs_info(fs_info, "creating UUID tree");
1807 ret = btrfs_create_uuid_tree(fs_info);
1808 if (ret) {
1809 btrfs_warn(fs_info, "failed to create the UUID tree %d", ret);
1810 goto restore;
1811 }
1812 }
1813 sb->s_flags &= ~MS_RDONLY;
1814 }
1815out:
1816 wake_up_process(fs_info->transaction_kthread);
1817 btrfs_remount_cleanup(fs_info, old_opts);
1818 return 0;
1819
1820restore:
1821 /* We've hit an error - don't reset MS_RDONLY */
1822 if (sb->s_flags & MS_RDONLY)
1823 old_flags |= MS_RDONLY;
1824 sb->s_flags = old_flags;
1825 fs_info->mount_opt = old_opts;
1826 fs_info->compress_type = old_compress_type;
1827 fs_info->max_inline = old_max_inline;
1828 mutex_lock(&fs_info->chunk_mutex);
1829 fs_info->alloc_start = old_alloc_start;
1830 mutex_unlock(&fs_info->chunk_mutex);
1831 btrfs_resize_thread_pool(fs_info,
1832 old_thread_pool_size, fs_info->thread_pool_size);
1833 fs_info->metadata_ratio = old_metadata_ratio;
1834 btrfs_remount_cleanup(fs_info, old_opts);
1835 return ret;
1836}
1837
1838/* Used to sort the devices by max_avail(descending sort) */
1839static int btrfs_cmp_device_free_bytes(const void *dev_info1,
1840 const void *dev_info2)
1841{
1842 if (((struct btrfs_device_info *)dev_info1)->max_avail >
1843 ((struct btrfs_device_info *)dev_info2)->max_avail)
1844 return -1;
1845 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1846 ((struct btrfs_device_info *)dev_info2)->max_avail)
1847 return 1;
1848 else
1849 return 0;
1850}
1851
1852/*
1853 * sort the devices by max_avail, in which max free extent size of each device
1854 * is stored.(Descending Sort)
1855 */
1856static inline void btrfs_descending_sort_devices(
1857 struct btrfs_device_info *devices,
1858 size_t nr_devices)
1859{
1860 sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1861 btrfs_cmp_device_free_bytes, NULL);
1862}
1863
1864/*
1865 * The helper to calc the free space on the devices that can be used to store
1866 * file data.
1867 */
1868static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
1869{
1870 struct btrfs_fs_info *fs_info = root->fs_info;
1871 struct btrfs_device_info *devices_info;
1872 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1873 struct btrfs_device *device;
1874 u64 skip_space;
1875 u64 type;
1876 u64 avail_space;
1877 u64 used_space;
1878 u64 min_stripe_size;
1879 int min_stripes = 1, num_stripes = 1;
1880 int i = 0, nr_devices;
1881 int ret;
1882
1883 /*
1884 * We aren't under the device list lock, so this is racey-ish, but good
1885 * enough for our purposes.
1886 */
1887 nr_devices = fs_info->fs_devices->open_devices;
1888 if (!nr_devices) {
1889 smp_mb();
1890 nr_devices = fs_info->fs_devices->open_devices;
1891 ASSERT(nr_devices);
1892 if (!nr_devices) {
1893 *free_bytes = 0;
1894 return 0;
1895 }
1896 }
1897
1898 devices_info = kmalloc_array(nr_devices, sizeof(*devices_info),
1899 GFP_NOFS);
1900 if (!devices_info)
1901 return -ENOMEM;
1902
1903 /* calc min stripe number for data space alloction */
1904 type = btrfs_get_alloc_profile(root, 1);
1905 if (type & BTRFS_BLOCK_GROUP_RAID0) {
1906 min_stripes = 2;
1907 num_stripes = nr_devices;
1908 } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
1909 min_stripes = 2;
1910 num_stripes = 2;
1911 } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
1912 min_stripes = 4;
1913 num_stripes = 4;
1914 }
1915
1916 if (type & BTRFS_BLOCK_GROUP_DUP)
1917 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1918 else
1919 min_stripe_size = BTRFS_STRIPE_LEN;
1920
1921 if (fs_info->alloc_start)
1922 mutex_lock(&fs_devices->device_list_mutex);
1923 rcu_read_lock();
1924 list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
1925 if (!device->in_fs_metadata || !device->bdev ||
1926 device->is_tgtdev_for_dev_replace)
1927 continue;
1928
1929 if (i >= nr_devices)
1930 break;
1931
1932 avail_space = device->total_bytes - device->bytes_used;
1933
1934 /* align with stripe_len */
1935 avail_space = div_u64(avail_space, BTRFS_STRIPE_LEN);
1936 avail_space *= BTRFS_STRIPE_LEN;
1937
1938 /*
1939 * In order to avoid overwritting the superblock on the drive,
1940 * btrfs starts at an offset of at least 1MB when doing chunk
1941 * allocation.
1942 */
1943 skip_space = SZ_1M;
1944
1945 /* user can set the offset in fs_info->alloc_start. */
1946 if (fs_info->alloc_start &&
1947 fs_info->alloc_start + BTRFS_STRIPE_LEN <=
1948 device->total_bytes) {
1949 rcu_read_unlock();
1950 skip_space = max(fs_info->alloc_start, skip_space);
1951
1952 /*
1953 * btrfs can not use the free space in
1954 * [0, skip_space - 1], we must subtract it from the
1955 * total. In order to implement it, we account the used
1956 * space in this range first.
1957 */
1958 ret = btrfs_account_dev_extents_size(device, 0,
1959 skip_space - 1,
1960 &used_space);
1961 if (ret) {
1962 kfree(devices_info);
1963 mutex_unlock(&fs_devices->device_list_mutex);
1964 return ret;
1965 }
1966
1967 rcu_read_lock();
1968
1969 /* calc the free space in [0, skip_space - 1] */
1970 skip_space -= used_space;
1971 }
1972
1973 /*
1974 * we can use the free space in [0, skip_space - 1], subtract
1975 * it from the total.
1976 */
1977 if (avail_space && avail_space >= skip_space)
1978 avail_space -= skip_space;
1979 else
1980 avail_space = 0;
1981
1982 if (avail_space < min_stripe_size)
1983 continue;
1984
1985 devices_info[i].dev = device;
1986 devices_info[i].max_avail = avail_space;
1987
1988 i++;
1989 }
1990 rcu_read_unlock();
1991 if (fs_info->alloc_start)
1992 mutex_unlock(&fs_devices->device_list_mutex);
1993
1994 nr_devices = i;
1995
1996 btrfs_descending_sort_devices(devices_info, nr_devices);
1997
1998 i = nr_devices - 1;
1999 avail_space = 0;
2000 while (nr_devices >= min_stripes) {
2001 if (num_stripes > nr_devices)
2002 num_stripes = nr_devices;
2003
2004 if (devices_info[i].max_avail >= min_stripe_size) {
2005 int j;
2006 u64 alloc_size;
2007
2008 avail_space += devices_info[i].max_avail * num_stripes;
2009 alloc_size = devices_info[i].max_avail;
2010 for (j = i + 1 - num_stripes; j <= i; j++)
2011 devices_info[j].max_avail -= alloc_size;
2012 }
2013 i--;
2014 nr_devices--;
2015 }
2016
2017 kfree(devices_info);
2018 *free_bytes = avail_space;
2019 return 0;
2020}
2021
2022/*
2023 * Calculate numbers for 'df', pessimistic in case of mixed raid profiles.
2024 *
2025 * If there's a redundant raid level at DATA block groups, use the respective
2026 * multiplier to scale the sizes.
2027 *
2028 * Unused device space usage is based on simulating the chunk allocator
2029 * algorithm that respects the device sizes, order of allocations and the
2030 * 'alloc_start' value, this is a close approximation of the actual use but
2031 * there are other factors that may change the result (like a new metadata
2032 * chunk).
2033 *
2034 * If metadata is exhausted, f_bavail will be 0.
2035 *
2036 * FIXME: not accurate for mixed block groups, total and free/used are ok,
2037 * available appears slightly larger.
2038 */
2039static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
2040{
2041 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
2042 struct btrfs_super_block *disk_super = fs_info->super_copy;
2043 struct list_head *head = &fs_info->space_info;
2044 struct btrfs_space_info *found;
2045 u64 total_used = 0;
2046 u64 total_free_data = 0;
2047 u64 total_free_meta = 0;
2048 int bits = dentry->d_sb->s_blocksize_bits;
2049 __be32 *fsid = (__be32 *)fs_info->fsid;
2050 unsigned factor = 1;
2051 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
2052 int ret;
2053 u64 thresh = 0;
2054
2055 /*
2056 * holding chunk_muext to avoid allocating new chunks, holding
2057 * device_list_mutex to avoid the device being removed
2058 */
2059 rcu_read_lock();
2060 list_for_each_entry_rcu(found, head, list) {
2061 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
2062 int i;
2063
2064 total_free_data += found->disk_total - found->disk_used;
2065 total_free_data -=
2066 btrfs_account_ro_block_groups_free_space(found);
2067
2068 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
2069 if (!list_empty(&found->block_groups[i])) {
2070 switch (i) {
2071 case BTRFS_RAID_DUP:
2072 case BTRFS_RAID_RAID1:
2073 case BTRFS_RAID_RAID10:
2074 factor = 2;
2075 }
2076 }
2077 }
2078 }
2079 if (found->flags & BTRFS_BLOCK_GROUP_METADATA)
2080 total_free_meta += found->disk_total - found->disk_used;
2081
2082 total_used += found->disk_used;
2083 }
2084
2085 rcu_read_unlock();
2086
2087 buf->f_blocks = div_u64(btrfs_super_total_bytes(disk_super), factor);
2088 buf->f_blocks >>= bits;
2089 buf->f_bfree = buf->f_blocks - (div_u64(total_used, factor) >> bits);
2090
2091 /* Account global block reserve as used, it's in logical size already */
2092 spin_lock(&block_rsv->lock);
2093 buf->f_bfree -= block_rsv->size >> bits;
2094 spin_unlock(&block_rsv->lock);
2095
2096 buf->f_bavail = div_u64(total_free_data, factor);
2097 ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data);
2098 if (ret)
2099 return ret;
2100 buf->f_bavail += div_u64(total_free_data, factor);
2101 buf->f_bavail = buf->f_bavail >> bits;
2102
2103 /*
2104 * We calculate the remaining metadata space minus global reserve. If
2105 * this is (supposedly) smaller than zero, there's no space. But this
2106 * does not hold in practice, the exhausted state happens where's still
2107 * some positive delta. So we apply some guesswork and compare the
2108 * delta to a 4M threshold. (Practically observed delta was ~2M.)
2109 *
2110 * We probably cannot calculate the exact threshold value because this
2111 * depends on the internal reservations requested by various
2112 * operations, so some operations that consume a few metadata will
2113 * succeed even if the Avail is zero. But this is better than the other
2114 * way around.
2115 */
2116 thresh = 4 * 1024 * 1024;
2117
2118 if (total_free_meta - thresh < block_rsv->size)
2119 buf->f_bavail = 0;
2120
2121 buf->f_type = BTRFS_SUPER_MAGIC;
2122 buf->f_bsize = dentry->d_sb->s_blocksize;
2123 buf->f_namelen = BTRFS_NAME_LEN;
2124
2125 /* We treat it as constant endianness (it doesn't matter _which_)
2126 because we want the fsid to come out the same whether mounted
2127 on a big-endian or little-endian host */
2128 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
2129 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
2130 /* Mask in the root object ID too, to disambiguate subvols */
2131 buf->f_fsid.val[0] ^= BTRFS_I(d_inode(dentry))->root->objectid >> 32;
2132 buf->f_fsid.val[1] ^= BTRFS_I(d_inode(dentry))->root->objectid;
2133
2134 return 0;
2135}
2136
2137static void btrfs_kill_super(struct super_block *sb)
2138{
2139 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2140 kill_anon_super(sb);
2141 free_fs_info(fs_info);
2142}
2143
2144static struct file_system_type btrfs_fs_type = {
2145 .owner = THIS_MODULE,
2146 .name = "btrfs",
2147 .mount = btrfs_mount,
2148 .kill_sb = btrfs_kill_super,
2149 .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA,
2150};
2151MODULE_ALIAS_FS("btrfs");
2152
2153static int btrfs_control_open(struct inode *inode, struct file *file)
2154{
2155 /*
2156 * The control file's private_data is used to hold the
2157 * transaction when it is started and is used to keep
2158 * track of whether a transaction is already in progress.
2159 */
2160 file->private_data = NULL;
2161 return 0;
2162}
2163
2164/*
2165 * used by btrfsctl to scan devices when no FS is mounted
2166 */
2167static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
2168 unsigned long arg)
2169{
2170 struct btrfs_ioctl_vol_args *vol;
2171 struct btrfs_fs_devices *fs_devices;
2172 int ret = -ENOTTY;
2173
2174 if (!capable(CAP_SYS_ADMIN))
2175 return -EPERM;
2176
2177 vol = memdup_user((void __user *)arg, sizeof(*vol));
2178 if (IS_ERR(vol))
2179 return PTR_ERR(vol);
2180
2181 switch (cmd) {
2182 case BTRFS_IOC_SCAN_DEV:
2183 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
2184 &btrfs_fs_type, &fs_devices);
2185 break;
2186 case BTRFS_IOC_DEVICES_READY:
2187 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
2188 &btrfs_fs_type, &fs_devices);
2189 if (ret)
2190 break;
2191 ret = !(fs_devices->num_devices == fs_devices->total_devices);
2192 break;
2193 case BTRFS_IOC_GET_SUPPORTED_FEATURES:
2194 ret = btrfs_ioctl_get_supported_features((void __user*)arg);
2195 break;
2196 }
2197
2198 kfree(vol);
2199 return ret;
2200}
2201
2202static int btrfs_freeze(struct super_block *sb)
2203{
2204 struct btrfs_trans_handle *trans;
2205 struct btrfs_root *root = btrfs_sb(sb)->tree_root;
2206
2207 trans = btrfs_attach_transaction_barrier(root);
2208 if (IS_ERR(trans)) {
2209 /* no transaction, don't bother */
2210 if (PTR_ERR(trans) == -ENOENT)
2211 return 0;
2212 return PTR_ERR(trans);
2213 }
2214 return btrfs_commit_transaction(trans, root);
2215}
2216
2217static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
2218{
2219 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
2220 struct btrfs_fs_devices *cur_devices;
2221 struct btrfs_device *dev, *first_dev = NULL;
2222 struct list_head *head;
2223 struct rcu_string *name;
2224
2225 mutex_lock(&fs_info->fs_devices->device_list_mutex);
2226 cur_devices = fs_info->fs_devices;
2227 while (cur_devices) {
2228 head = &cur_devices->devices;
2229 list_for_each_entry(dev, head, dev_list) {
2230 if (dev->missing)
2231 continue;
2232 if (!dev->name)
2233 continue;
2234 if (!first_dev || dev->devid < first_dev->devid)
2235 first_dev = dev;
2236 }
2237 cur_devices = cur_devices->seed;
2238 }
2239
2240 if (first_dev) {
2241 rcu_read_lock();
2242 name = rcu_dereference(first_dev->name);
2243 seq_escape(m, name->str, " \t\n\\");
2244 rcu_read_unlock();
2245 } else {
2246 WARN_ON(1);
2247 }
2248 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2249 return 0;
2250}
2251
2252static const struct super_operations btrfs_super_ops = {
2253 .drop_inode = btrfs_drop_inode,
2254 .evict_inode = btrfs_evict_inode,
2255 .put_super = btrfs_put_super,
2256 .sync_fs = btrfs_sync_fs,
2257 .show_options = btrfs_show_options,
2258 .show_devname = btrfs_show_devname,
2259 .write_inode = btrfs_write_inode,
2260 .alloc_inode = btrfs_alloc_inode,
2261 .destroy_inode = btrfs_destroy_inode,
2262 .statfs = btrfs_statfs,
2263 .remount_fs = btrfs_remount,
2264 .freeze_fs = btrfs_freeze,
2265};
2266
2267static const struct file_operations btrfs_ctl_fops = {
2268 .open = btrfs_control_open,
2269 .unlocked_ioctl = btrfs_control_ioctl,
2270 .compat_ioctl = btrfs_control_ioctl,
2271 .owner = THIS_MODULE,
2272 .llseek = noop_llseek,
2273};
2274
2275static struct miscdevice btrfs_misc = {
2276 .minor = BTRFS_MINOR,
2277 .name = "btrfs-control",
2278 .fops = &btrfs_ctl_fops
2279};
2280
2281MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
2282MODULE_ALIAS("devname:btrfs-control");
2283
2284static int btrfs_interface_init(void)
2285{
2286 return misc_register(&btrfs_misc);
2287}
2288
2289static void btrfs_interface_exit(void)
2290{
2291 misc_deregister(&btrfs_misc);
2292}
2293
2294static void btrfs_print_mod_info(void)
2295{
2296 printk(KERN_INFO "Btrfs loaded"
2297#ifdef CONFIG_BTRFS_DEBUG
2298 ", debug=on"
2299#endif
2300#ifdef CONFIG_BTRFS_ASSERT
2301 ", assert=on"
2302#endif
2303#ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2304 ", integrity-checker=on"
2305#endif
2306 "\n");
2307}
2308
2309static int btrfs_run_sanity_tests(void)
2310{
2311 int ret;
2312
2313 ret = btrfs_init_test_fs();
2314 if (ret)
2315 return ret;
2316
2317 ret = btrfs_test_free_space_cache();
2318 if (ret)
2319 goto out;
2320 ret = btrfs_test_extent_buffer_operations();
2321 if (ret)
2322 goto out;
2323 ret = btrfs_test_extent_io();
2324 if (ret)
2325 goto out;
2326 ret = btrfs_test_inodes();
2327 if (ret)
2328 goto out;
2329 ret = btrfs_test_qgroups();
2330 if (ret)
2331 goto out;
2332 ret = btrfs_test_free_space_tree();
2333out:
2334 btrfs_destroy_test_fs();
2335 return ret;
2336}
2337
2338static int __init init_btrfs_fs(void)
2339{
2340 int err;
2341
2342 err = btrfs_hash_init();
2343 if (err)
2344 return err;
2345
2346 btrfs_props_init();
2347
2348 err = btrfs_init_sysfs();
2349 if (err)
2350 goto free_hash;
2351
2352 btrfs_init_compress();
2353
2354 err = btrfs_init_cachep();
2355 if (err)
2356 goto free_compress;
2357
2358 err = extent_io_init();
2359 if (err)
2360 goto free_cachep;
2361
2362 err = extent_map_init();
2363 if (err)
2364 goto free_extent_io;
2365
2366 err = ordered_data_init();
2367 if (err)
2368 goto free_extent_map;
2369
2370 err = btrfs_delayed_inode_init();
2371 if (err)
2372 goto free_ordered_data;
2373
2374 err = btrfs_auto_defrag_init();
2375 if (err)
2376 goto free_delayed_inode;
2377
2378 err = btrfs_delayed_ref_init();
2379 if (err)
2380 goto free_auto_defrag;
2381
2382 err = btrfs_prelim_ref_init();
2383 if (err)
2384 goto free_delayed_ref;
2385
2386 err = btrfs_end_io_wq_init();
2387 if (err)
2388 goto free_prelim_ref;
2389
2390 err = btrfs_interface_init();
2391 if (err)
2392 goto free_end_io_wq;
2393
2394 btrfs_init_lockdep();
2395
2396 btrfs_print_mod_info();
2397
2398 err = btrfs_run_sanity_tests();
2399 if (err)
2400 goto unregister_ioctl;
2401
2402 err = register_filesystem(&btrfs_fs_type);
2403 if (err)
2404 goto unregister_ioctl;
2405
2406 return 0;
2407
2408unregister_ioctl:
2409 btrfs_interface_exit();
2410free_end_io_wq:
2411 btrfs_end_io_wq_exit();
2412free_prelim_ref:
2413 btrfs_prelim_ref_exit();
2414free_delayed_ref:
2415 btrfs_delayed_ref_exit();
2416free_auto_defrag:
2417 btrfs_auto_defrag_exit();
2418free_delayed_inode:
2419 btrfs_delayed_inode_exit();
2420free_ordered_data:
2421 ordered_data_exit();
2422free_extent_map:
2423 extent_map_exit();
2424free_extent_io:
2425 extent_io_exit();
2426free_cachep:
2427 btrfs_destroy_cachep();
2428free_compress:
2429 btrfs_exit_compress();
2430 btrfs_exit_sysfs();
2431free_hash:
2432 btrfs_hash_exit();
2433 return err;
2434}
2435
2436static void __exit exit_btrfs_fs(void)
2437{
2438 btrfs_destroy_cachep();
2439 btrfs_delayed_ref_exit();
2440 btrfs_auto_defrag_exit();
2441 btrfs_delayed_inode_exit();
2442 btrfs_prelim_ref_exit();
2443 ordered_data_exit();
2444 extent_map_exit();
2445 extent_io_exit();
2446 btrfs_interface_exit();
2447 btrfs_end_io_wq_exit();
2448 unregister_filesystem(&btrfs_fs_type);
2449 btrfs_exit_sysfs();
2450 btrfs_cleanup_fs_uuids();
2451 btrfs_exit_compress();
2452 btrfs_hash_exit();
2453}
2454
2455late_initcall(init_btrfs_fs);
2456module_exit(exit_btrfs_fs)
2457
2458MODULE_LICENSE("GPL");