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Merge branch 'zstd-minimal' of git://git.kernel.org/pub/scm/linux/kernel/git/mason...
[mirror_ubuntu-bionic-kernel.git] / fs / btrfs / super.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/blkdev.h>
20 #include <linux/module.h>
21 #include <linux/buffer_head.h>
22 #include <linux/fs.h>
23 #include <linux/pagemap.h>
24 #include <linux/highmem.h>
25 #include <linux/time.h>
26 #include <linux/init.h>
27 #include <linux/seq_file.h>
28 #include <linux/string.h>
29 #include <linux/backing-dev.h>
30 #include <linux/mount.h>
31 #include <linux/mpage.h>
32 #include <linux/swap.h>
33 #include <linux/writeback.h>
34 #include <linux/statfs.h>
35 #include <linux/compat.h>
36 #include <linux/parser.h>
37 #include <linux/ctype.h>
38 #include <linux/namei.h>
39 #include <linux/miscdevice.h>
40 #include <linux/magic.h>
41 #include <linux/slab.h>
42 #include <linux/cleancache.h>
43 #include <linux/ratelimit.h>
44 #include <linux/btrfs.h>
45 #include "delayed-inode.h"
46 #include "ctree.h"
47 #include "disk-io.h"
48 #include "transaction.h"
49 #include "btrfs_inode.h"
50 #include "print-tree.h"
51 #include "hash.h"
52 #include "props.h"
53 #include "xattr.h"
54 #include "volumes.h"
55 #include "export.h"
56 #include "compression.h"
57 #include "rcu-string.h"
58 #include "dev-replace.h"
59 #include "free-space-cache.h"
60 #include "backref.h"
61 #include "tests/btrfs-tests.h"
62
63 #include "qgroup.h"
64 #include "backref.h"
65 #define CREATE_TRACE_POINTS
66 #include <trace/events/btrfs.h>
67
68 static const struct super_operations btrfs_super_ops;
69 static struct file_system_type btrfs_fs_type;
70
71 static int btrfs_remount(struct super_block *sb, int *flags, char *data);
72
73 const char *btrfs_decode_error(int errno)
74 {
75 char *errstr = "unknown";
76
77 switch (errno) {
78 case -EIO:
79 errstr = "IO failure";
80 break;
81 case -ENOMEM:
82 errstr = "Out of memory";
83 break;
84 case -EROFS:
85 errstr = "Readonly filesystem";
86 break;
87 case -EEXIST:
88 errstr = "Object already exists";
89 break;
90 case -ENOSPC:
91 errstr = "No space left";
92 break;
93 case -ENOENT:
94 errstr = "No such entry";
95 break;
96 }
97
98 return errstr;
99 }
100
101 /* btrfs handle error by forcing the filesystem readonly */
102 static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
103 {
104 struct super_block *sb = fs_info->sb;
105
106 if (sb->s_flags & MS_RDONLY)
107 return;
108
109 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
110 sb->s_flags |= MS_RDONLY;
111 btrfs_info(fs_info, "forced readonly");
112 /*
113 * Note that a running device replace operation is not
114 * canceled here although there is no way to update
115 * the progress. It would add the risk of a deadlock,
116 * therefore the canceling is omitted. The only penalty
117 * is that some I/O remains active until the procedure
118 * completes. The next time when the filesystem is
119 * mounted writeable again, the device replace
120 * operation continues.
121 */
122 }
123 }
124
125 /*
126 * __btrfs_handle_fs_error decodes expected errors from the caller and
127 * invokes the approciate error response.
128 */
129 __cold
130 void __btrfs_handle_fs_error(struct btrfs_fs_info *fs_info, const char *function,
131 unsigned int line, int errno, const char *fmt, ...)
132 {
133 struct super_block *sb = fs_info->sb;
134 #ifdef CONFIG_PRINTK
135 const char *errstr;
136 #endif
137
138 /*
139 * Special case: if the error is EROFS, and we're already
140 * under MS_RDONLY, then it is safe here.
141 */
142 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
143 return;
144
145 #ifdef CONFIG_PRINTK
146 errstr = btrfs_decode_error(errno);
147 if (fmt) {
148 struct va_format vaf;
149 va_list args;
150
151 va_start(args, fmt);
152 vaf.fmt = fmt;
153 vaf.va = &args;
154
155 pr_crit("BTRFS: error (device %s) in %s:%d: errno=%d %s (%pV)\n",
156 sb->s_id, function, line, errno, errstr, &vaf);
157 va_end(args);
158 } else {
159 pr_crit("BTRFS: error (device %s) in %s:%d: errno=%d %s\n",
160 sb->s_id, function, line, errno, errstr);
161 }
162 #endif
163
164 /*
165 * Today we only save the error info to memory. Long term we'll
166 * also send it down to the disk
167 */
168 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
169
170 /* Don't go through full error handling during mount */
171 if (sb->s_flags & MS_BORN)
172 btrfs_handle_error(fs_info);
173 }
174
175 #ifdef CONFIG_PRINTK
176 static const char * const logtypes[] = {
177 "emergency",
178 "alert",
179 "critical",
180 "error",
181 "warning",
182 "notice",
183 "info",
184 "debug",
185 };
186
187
188 /*
189 * Use one ratelimit state per log level so that a flood of less important
190 * messages doesn't cause more important ones to be dropped.
191 */
192 static struct ratelimit_state printk_limits[] = {
193 RATELIMIT_STATE_INIT(printk_limits[0], DEFAULT_RATELIMIT_INTERVAL, 100),
194 RATELIMIT_STATE_INIT(printk_limits[1], DEFAULT_RATELIMIT_INTERVAL, 100),
195 RATELIMIT_STATE_INIT(printk_limits[2], DEFAULT_RATELIMIT_INTERVAL, 100),
196 RATELIMIT_STATE_INIT(printk_limits[3], DEFAULT_RATELIMIT_INTERVAL, 100),
197 RATELIMIT_STATE_INIT(printk_limits[4], DEFAULT_RATELIMIT_INTERVAL, 100),
198 RATELIMIT_STATE_INIT(printk_limits[5], DEFAULT_RATELIMIT_INTERVAL, 100),
199 RATELIMIT_STATE_INIT(printk_limits[6], DEFAULT_RATELIMIT_INTERVAL, 100),
200 RATELIMIT_STATE_INIT(printk_limits[7], DEFAULT_RATELIMIT_INTERVAL, 100),
201 };
202
203 void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
204 {
205 struct super_block *sb = fs_info->sb;
206 char lvl[PRINTK_MAX_SINGLE_HEADER_LEN + 1] = "\0";
207 struct va_format vaf;
208 va_list args;
209 int kern_level;
210 const char *type = logtypes[4];
211 struct ratelimit_state *ratelimit = &printk_limits[4];
212
213 va_start(args, fmt);
214
215 while ((kern_level = printk_get_level(fmt)) != 0) {
216 size_t size = printk_skip_level(fmt) - fmt;
217
218 if (kern_level >= '0' && kern_level <= '7') {
219 memcpy(lvl, fmt, size);
220 lvl[size] = '\0';
221 type = logtypes[kern_level - '0'];
222 ratelimit = &printk_limits[kern_level - '0'];
223 }
224 fmt += size;
225 }
226
227 vaf.fmt = fmt;
228 vaf.va = &args;
229
230 if (__ratelimit(ratelimit))
231 printk("%sBTRFS %s (device %s): %pV\n", lvl, type, sb->s_id, &vaf);
232
233 va_end(args);
234 }
235 #endif
236
237 /*
238 * We only mark the transaction aborted and then set the file system read-only.
239 * This will prevent new transactions from starting or trying to join this
240 * one.
241 *
242 * This means that error recovery at the call site is limited to freeing
243 * any local memory allocations and passing the error code up without
244 * further cleanup. The transaction should complete as it normally would
245 * in the call path but will return -EIO.
246 *
247 * We'll complete the cleanup in btrfs_end_transaction and
248 * btrfs_commit_transaction.
249 */
250 __cold
251 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
252 const char *function,
253 unsigned int line, int errno)
254 {
255 struct btrfs_fs_info *fs_info = trans->fs_info;
256
257 trans->aborted = errno;
258 /* Nothing used. The other threads that have joined this
259 * transaction may be able to continue. */
260 if (!trans->dirty && list_empty(&trans->new_bgs)) {
261 const char *errstr;
262
263 errstr = btrfs_decode_error(errno);
264 btrfs_warn(fs_info,
265 "%s:%d: Aborting unused transaction(%s).",
266 function, line, errstr);
267 return;
268 }
269 WRITE_ONCE(trans->transaction->aborted, errno);
270 /* Wake up anybody who may be waiting on this transaction */
271 wake_up(&fs_info->transaction_wait);
272 wake_up(&fs_info->transaction_blocked_wait);
273 __btrfs_handle_fs_error(fs_info, function, line, errno, NULL);
274 }
275 /*
276 * __btrfs_panic decodes unexpected, fatal errors from the caller,
277 * issues an alert, and either panics or BUGs, depending on mount options.
278 */
279 __cold
280 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
281 unsigned int line, int errno, const char *fmt, ...)
282 {
283 char *s_id = "<unknown>";
284 const char *errstr;
285 struct va_format vaf = { .fmt = fmt };
286 va_list args;
287
288 if (fs_info)
289 s_id = fs_info->sb->s_id;
290
291 va_start(args, fmt);
292 vaf.va = &args;
293
294 errstr = btrfs_decode_error(errno);
295 if (fs_info && (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR))
296 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
297 s_id, function, line, &vaf, errno, errstr);
298
299 btrfs_crit(fs_info, "panic in %s:%d: %pV (errno=%d %s)",
300 function, line, &vaf, errno, errstr);
301 va_end(args);
302 /* Caller calls BUG() */
303 }
304
305 static void btrfs_put_super(struct super_block *sb)
306 {
307 close_ctree(btrfs_sb(sb));
308 }
309
310 enum {
311 Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
312 Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
313 Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
314 Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
315 Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
316 Opt_space_cache, Opt_space_cache_version, Opt_clear_cache,
317 Opt_user_subvol_rm_allowed, Opt_enospc_debug, Opt_subvolrootid,
318 Opt_defrag, Opt_inode_cache, Opt_no_space_cache, Opt_recovery,
319 Opt_skip_balance, Opt_check_integrity,
320 Opt_check_integrity_including_extent_data,
321 Opt_check_integrity_print_mask, Opt_fatal_errors, Opt_rescan_uuid_tree,
322 Opt_commit_interval, Opt_barrier, Opt_nodefrag, Opt_nodiscard,
323 Opt_noenospc_debug, Opt_noflushoncommit, Opt_acl, Opt_datacow,
324 Opt_datasum, Opt_treelog, Opt_noinode_cache, Opt_usebackuproot,
325 Opt_nologreplay, Opt_norecovery,
326 #ifdef CONFIG_BTRFS_DEBUG
327 Opt_fragment_data, Opt_fragment_metadata, Opt_fragment_all,
328 #endif
329 Opt_err,
330 };
331
332 static const match_table_t tokens = {
333 {Opt_degraded, "degraded"},
334 {Opt_subvol, "subvol=%s"},
335 {Opt_subvolid, "subvolid=%s"},
336 {Opt_device, "device=%s"},
337 {Opt_nodatasum, "nodatasum"},
338 {Opt_datasum, "datasum"},
339 {Opt_nodatacow, "nodatacow"},
340 {Opt_datacow, "datacow"},
341 {Opt_nobarrier, "nobarrier"},
342 {Opt_barrier, "barrier"},
343 {Opt_max_inline, "max_inline=%s"},
344 {Opt_alloc_start, "alloc_start=%s"},
345 {Opt_thread_pool, "thread_pool=%d"},
346 {Opt_compress, "compress"},
347 {Opt_compress_type, "compress=%s"},
348 {Opt_compress_force, "compress-force"},
349 {Opt_compress_force_type, "compress-force=%s"},
350 {Opt_ssd, "ssd"},
351 {Opt_ssd_spread, "ssd_spread"},
352 {Opt_nossd, "nossd"},
353 {Opt_acl, "acl"},
354 {Opt_noacl, "noacl"},
355 {Opt_notreelog, "notreelog"},
356 {Opt_treelog, "treelog"},
357 {Opt_nologreplay, "nologreplay"},
358 {Opt_norecovery, "norecovery"},
359 {Opt_flushoncommit, "flushoncommit"},
360 {Opt_noflushoncommit, "noflushoncommit"},
361 {Opt_ratio, "metadata_ratio=%d"},
362 {Opt_discard, "discard"},
363 {Opt_nodiscard, "nodiscard"},
364 {Opt_space_cache, "space_cache"},
365 {Opt_space_cache_version, "space_cache=%s"},
366 {Opt_clear_cache, "clear_cache"},
367 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
368 {Opt_enospc_debug, "enospc_debug"},
369 {Opt_noenospc_debug, "noenospc_debug"},
370 {Opt_subvolrootid, "subvolrootid=%d"},
371 {Opt_defrag, "autodefrag"},
372 {Opt_nodefrag, "noautodefrag"},
373 {Opt_inode_cache, "inode_cache"},
374 {Opt_noinode_cache, "noinode_cache"},
375 {Opt_no_space_cache, "nospace_cache"},
376 {Opt_recovery, "recovery"}, /* deprecated */
377 {Opt_usebackuproot, "usebackuproot"},
378 {Opt_skip_balance, "skip_balance"},
379 {Opt_check_integrity, "check_int"},
380 {Opt_check_integrity_including_extent_data, "check_int_data"},
381 {Opt_check_integrity_print_mask, "check_int_print_mask=%d"},
382 {Opt_rescan_uuid_tree, "rescan_uuid_tree"},
383 {Opt_fatal_errors, "fatal_errors=%s"},
384 {Opt_commit_interval, "commit=%d"},
385 #ifdef CONFIG_BTRFS_DEBUG
386 {Opt_fragment_data, "fragment=data"},
387 {Opt_fragment_metadata, "fragment=metadata"},
388 {Opt_fragment_all, "fragment=all"},
389 #endif
390 {Opt_err, NULL},
391 };
392
393 /*
394 * Regular mount options parser. Everything that is needed only when
395 * reading in a new superblock is parsed here.
396 * XXX JDM: This needs to be cleaned up for remount.
397 */
398 int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
399 unsigned long new_flags)
400 {
401 substring_t args[MAX_OPT_ARGS];
402 char *p, *num, *orig = NULL;
403 u64 cache_gen;
404 int intarg;
405 int ret = 0;
406 char *compress_type;
407 bool compress_force = false;
408 enum btrfs_compression_type saved_compress_type;
409 bool saved_compress_force;
410 int no_compress = 0;
411
412 cache_gen = btrfs_super_cache_generation(info->super_copy);
413 if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE))
414 btrfs_set_opt(info->mount_opt, FREE_SPACE_TREE);
415 else if (cache_gen)
416 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
417
418 /*
419 * Even the options are empty, we still need to do extra check
420 * against new flags
421 */
422 if (!options)
423 goto check;
424
425 /*
426 * strsep changes the string, duplicate it because parse_options
427 * gets called twice
428 */
429 options = kstrdup(options, GFP_KERNEL);
430 if (!options)
431 return -ENOMEM;
432
433 orig = options;
434
435 while ((p = strsep(&options, ",")) != NULL) {
436 int token;
437 if (!*p)
438 continue;
439
440 token = match_token(p, tokens, args);
441 switch (token) {
442 case Opt_degraded:
443 btrfs_info(info, "allowing degraded mounts");
444 btrfs_set_opt(info->mount_opt, DEGRADED);
445 break;
446 case Opt_subvol:
447 case Opt_subvolid:
448 case Opt_subvolrootid:
449 case Opt_device:
450 /*
451 * These are parsed by btrfs_parse_early_options
452 * and can be happily ignored here.
453 */
454 break;
455 case Opt_nodatasum:
456 btrfs_set_and_info(info, NODATASUM,
457 "setting nodatasum");
458 break;
459 case Opt_datasum:
460 if (btrfs_test_opt(info, NODATASUM)) {
461 if (btrfs_test_opt(info, NODATACOW))
462 btrfs_info(info,
463 "setting datasum, datacow enabled");
464 else
465 btrfs_info(info, "setting datasum");
466 }
467 btrfs_clear_opt(info->mount_opt, NODATACOW);
468 btrfs_clear_opt(info->mount_opt, NODATASUM);
469 break;
470 case Opt_nodatacow:
471 if (!btrfs_test_opt(info, NODATACOW)) {
472 if (!btrfs_test_opt(info, COMPRESS) ||
473 !btrfs_test_opt(info, FORCE_COMPRESS)) {
474 btrfs_info(info,
475 "setting nodatacow, compression disabled");
476 } else {
477 btrfs_info(info, "setting nodatacow");
478 }
479 }
480 btrfs_clear_opt(info->mount_opt, COMPRESS);
481 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
482 btrfs_set_opt(info->mount_opt, NODATACOW);
483 btrfs_set_opt(info->mount_opt, NODATASUM);
484 break;
485 case Opt_datacow:
486 btrfs_clear_and_info(info, NODATACOW,
487 "setting datacow");
488 break;
489 case Opt_compress_force:
490 case Opt_compress_force_type:
491 compress_force = true;
492 /* Fallthrough */
493 case Opt_compress:
494 case Opt_compress_type:
495 saved_compress_type = btrfs_test_opt(info,
496 COMPRESS) ?
497 info->compress_type : BTRFS_COMPRESS_NONE;
498 saved_compress_force =
499 btrfs_test_opt(info, FORCE_COMPRESS);
500 if (token == Opt_compress ||
501 token == Opt_compress_force ||
502 strncmp(args[0].from, "zlib", 4) == 0) {
503 compress_type = "zlib";
504 info->compress_type = BTRFS_COMPRESS_ZLIB;
505 btrfs_set_opt(info->mount_opt, COMPRESS);
506 btrfs_clear_opt(info->mount_opt, NODATACOW);
507 btrfs_clear_opt(info->mount_opt, NODATASUM);
508 no_compress = 0;
509 } else if (strncmp(args[0].from, "lzo", 3) == 0) {
510 compress_type = "lzo";
511 info->compress_type = BTRFS_COMPRESS_LZO;
512 btrfs_set_opt(info->mount_opt, COMPRESS);
513 btrfs_clear_opt(info->mount_opt, NODATACOW);
514 btrfs_clear_opt(info->mount_opt, NODATASUM);
515 btrfs_set_fs_incompat(info, COMPRESS_LZO);
516 no_compress = 0;
517 } else if (strcmp(args[0].from, "zstd") == 0) {
518 compress_type = "zstd";
519 info->compress_type = BTRFS_COMPRESS_ZSTD;
520 btrfs_set_opt(info->mount_opt, COMPRESS);
521 btrfs_clear_opt(info->mount_opt, NODATACOW);
522 btrfs_clear_opt(info->mount_opt, NODATASUM);
523 btrfs_set_fs_incompat(info, COMPRESS_ZSTD);
524 no_compress = 0;
525 } else if (strncmp(args[0].from, "no", 2) == 0) {
526 compress_type = "no";
527 btrfs_clear_opt(info->mount_opt, COMPRESS);
528 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
529 compress_force = false;
530 no_compress++;
531 } else {
532 ret = -EINVAL;
533 goto out;
534 }
535
536 if (compress_force) {
537 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
538 } else {
539 /*
540 * If we remount from compress-force=xxx to
541 * compress=xxx, we need clear FORCE_COMPRESS
542 * flag, otherwise, there is no way for users
543 * to disable forcible compression separately.
544 */
545 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
546 }
547 if ((btrfs_test_opt(info, COMPRESS) &&
548 (info->compress_type != saved_compress_type ||
549 compress_force != saved_compress_force)) ||
550 (!btrfs_test_opt(info, COMPRESS) &&
551 no_compress == 1)) {
552 btrfs_info(info, "%s %s compression",
553 (compress_force) ? "force" : "use",
554 compress_type);
555 }
556 compress_force = false;
557 break;
558 case Opt_ssd:
559 btrfs_set_and_info(info, SSD,
560 "enabling ssd optimizations");
561 btrfs_clear_opt(info->mount_opt, NOSSD);
562 break;
563 case Opt_ssd_spread:
564 btrfs_set_and_info(info, SSD,
565 "enabling ssd optimizations");
566 btrfs_set_and_info(info, SSD_SPREAD,
567 "using spread ssd allocation scheme");
568 btrfs_clear_opt(info->mount_opt, NOSSD);
569 break;
570 case Opt_nossd:
571 btrfs_set_opt(info->mount_opt, NOSSD);
572 btrfs_clear_and_info(info, SSD,
573 "not using ssd optimizations");
574 btrfs_clear_and_info(info, SSD_SPREAD,
575 "not using spread ssd allocation scheme");
576 break;
577 case Opt_barrier:
578 btrfs_clear_and_info(info, NOBARRIER,
579 "turning on barriers");
580 break;
581 case Opt_nobarrier:
582 btrfs_set_and_info(info, NOBARRIER,
583 "turning off barriers");
584 break;
585 case Opt_thread_pool:
586 ret = match_int(&args[0], &intarg);
587 if (ret) {
588 goto out;
589 } else if (intarg > 0) {
590 info->thread_pool_size = intarg;
591 } else {
592 ret = -EINVAL;
593 goto out;
594 }
595 break;
596 case Opt_max_inline:
597 num = match_strdup(&args[0]);
598 if (num) {
599 info->max_inline = memparse(num, NULL);
600 kfree(num);
601
602 if (info->max_inline) {
603 info->max_inline = min_t(u64,
604 info->max_inline,
605 info->sectorsize);
606 }
607 btrfs_info(info, "max_inline at %llu",
608 info->max_inline);
609 } else {
610 ret = -ENOMEM;
611 goto out;
612 }
613 break;
614 case Opt_alloc_start:
615 btrfs_info(info,
616 "option alloc_start is obsolete, ignored");
617 break;
618 case Opt_acl:
619 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
620 info->sb->s_flags |= MS_POSIXACL;
621 break;
622 #else
623 btrfs_err(info, "support for ACL not compiled in!");
624 ret = -EINVAL;
625 goto out;
626 #endif
627 case Opt_noacl:
628 info->sb->s_flags &= ~MS_POSIXACL;
629 break;
630 case Opt_notreelog:
631 btrfs_set_and_info(info, NOTREELOG,
632 "disabling tree log");
633 break;
634 case Opt_treelog:
635 btrfs_clear_and_info(info, NOTREELOG,
636 "enabling tree log");
637 break;
638 case Opt_norecovery:
639 case Opt_nologreplay:
640 btrfs_set_and_info(info, NOLOGREPLAY,
641 "disabling log replay at mount time");
642 break;
643 case Opt_flushoncommit:
644 btrfs_set_and_info(info, FLUSHONCOMMIT,
645 "turning on flush-on-commit");
646 break;
647 case Opt_noflushoncommit:
648 btrfs_clear_and_info(info, FLUSHONCOMMIT,
649 "turning off flush-on-commit");
650 break;
651 case Opt_ratio:
652 ret = match_int(&args[0], &intarg);
653 if (ret) {
654 goto out;
655 } else if (intarg >= 0) {
656 info->metadata_ratio = intarg;
657 btrfs_info(info, "metadata ratio %d",
658 info->metadata_ratio);
659 } else {
660 ret = -EINVAL;
661 goto out;
662 }
663 break;
664 case Opt_discard:
665 btrfs_set_and_info(info, DISCARD,
666 "turning on discard");
667 break;
668 case Opt_nodiscard:
669 btrfs_clear_and_info(info, DISCARD,
670 "turning off discard");
671 break;
672 case Opt_space_cache:
673 case Opt_space_cache_version:
674 if (token == Opt_space_cache ||
675 strcmp(args[0].from, "v1") == 0) {
676 btrfs_clear_opt(info->mount_opt,
677 FREE_SPACE_TREE);
678 btrfs_set_and_info(info, SPACE_CACHE,
679 "enabling disk space caching");
680 } else if (strcmp(args[0].from, "v2") == 0) {
681 btrfs_clear_opt(info->mount_opt,
682 SPACE_CACHE);
683 btrfs_set_and_info(info, FREE_SPACE_TREE,
684 "enabling free space tree");
685 } else {
686 ret = -EINVAL;
687 goto out;
688 }
689 break;
690 case Opt_rescan_uuid_tree:
691 btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE);
692 break;
693 case Opt_no_space_cache:
694 if (btrfs_test_opt(info, SPACE_CACHE)) {
695 btrfs_clear_and_info(info, SPACE_CACHE,
696 "disabling disk space caching");
697 }
698 if (btrfs_test_opt(info, FREE_SPACE_TREE)) {
699 btrfs_clear_and_info(info, FREE_SPACE_TREE,
700 "disabling free space tree");
701 }
702 break;
703 case Opt_inode_cache:
704 btrfs_set_pending_and_info(info, INODE_MAP_CACHE,
705 "enabling inode map caching");
706 break;
707 case Opt_noinode_cache:
708 btrfs_clear_pending_and_info(info, INODE_MAP_CACHE,
709 "disabling inode map caching");
710 break;
711 case Opt_clear_cache:
712 btrfs_set_and_info(info, CLEAR_CACHE,
713 "force clearing of disk cache");
714 break;
715 case Opt_user_subvol_rm_allowed:
716 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
717 break;
718 case Opt_enospc_debug:
719 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
720 break;
721 case Opt_noenospc_debug:
722 btrfs_clear_opt(info->mount_opt, ENOSPC_DEBUG);
723 break;
724 case Opt_defrag:
725 btrfs_set_and_info(info, AUTO_DEFRAG,
726 "enabling auto defrag");
727 break;
728 case Opt_nodefrag:
729 btrfs_clear_and_info(info, AUTO_DEFRAG,
730 "disabling auto defrag");
731 break;
732 case Opt_recovery:
733 btrfs_warn(info,
734 "'recovery' is deprecated, use 'usebackuproot' instead");
735 case Opt_usebackuproot:
736 btrfs_info(info,
737 "trying to use backup root at mount time");
738 btrfs_set_opt(info->mount_opt, USEBACKUPROOT);
739 break;
740 case Opt_skip_balance:
741 btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
742 break;
743 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
744 case Opt_check_integrity_including_extent_data:
745 btrfs_info(info,
746 "enabling check integrity including extent data");
747 btrfs_set_opt(info->mount_opt,
748 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
749 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
750 break;
751 case Opt_check_integrity:
752 btrfs_info(info, "enabling check integrity");
753 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
754 break;
755 case Opt_check_integrity_print_mask:
756 ret = match_int(&args[0], &intarg);
757 if (ret) {
758 goto out;
759 } else if (intarg >= 0) {
760 info->check_integrity_print_mask = intarg;
761 btrfs_info(info,
762 "check_integrity_print_mask 0x%x",
763 info->check_integrity_print_mask);
764 } else {
765 ret = -EINVAL;
766 goto out;
767 }
768 break;
769 #else
770 case Opt_check_integrity_including_extent_data:
771 case Opt_check_integrity:
772 case Opt_check_integrity_print_mask:
773 btrfs_err(info,
774 "support for check_integrity* not compiled in!");
775 ret = -EINVAL;
776 goto out;
777 #endif
778 case Opt_fatal_errors:
779 if (strcmp(args[0].from, "panic") == 0)
780 btrfs_set_opt(info->mount_opt,
781 PANIC_ON_FATAL_ERROR);
782 else if (strcmp(args[0].from, "bug") == 0)
783 btrfs_clear_opt(info->mount_opt,
784 PANIC_ON_FATAL_ERROR);
785 else {
786 ret = -EINVAL;
787 goto out;
788 }
789 break;
790 case Opt_commit_interval:
791 intarg = 0;
792 ret = match_int(&args[0], &intarg);
793 if (ret < 0) {
794 btrfs_err(info, "invalid commit interval");
795 ret = -EINVAL;
796 goto out;
797 }
798 if (intarg > 0) {
799 if (intarg > 300) {
800 btrfs_warn(info,
801 "excessive commit interval %d",
802 intarg);
803 }
804 info->commit_interval = intarg;
805 } else {
806 btrfs_info(info,
807 "using default commit interval %ds",
808 BTRFS_DEFAULT_COMMIT_INTERVAL);
809 info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
810 }
811 break;
812 #ifdef CONFIG_BTRFS_DEBUG
813 case Opt_fragment_all:
814 btrfs_info(info, "fragmenting all space");
815 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA);
816 btrfs_set_opt(info->mount_opt, FRAGMENT_METADATA);
817 break;
818 case Opt_fragment_metadata:
819 btrfs_info(info, "fragmenting metadata");
820 btrfs_set_opt(info->mount_opt,
821 FRAGMENT_METADATA);
822 break;
823 case Opt_fragment_data:
824 btrfs_info(info, "fragmenting data");
825 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA);
826 break;
827 #endif
828 case Opt_err:
829 btrfs_info(info, "unrecognized mount option '%s'", p);
830 ret = -EINVAL;
831 goto out;
832 default:
833 break;
834 }
835 }
836 check:
837 /*
838 * Extra check for current option against current flag
839 */
840 if (btrfs_test_opt(info, NOLOGREPLAY) && !(new_flags & MS_RDONLY)) {
841 btrfs_err(info,
842 "nologreplay must be used with ro mount option");
843 ret = -EINVAL;
844 }
845 out:
846 if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE) &&
847 !btrfs_test_opt(info, FREE_SPACE_TREE) &&
848 !btrfs_test_opt(info, CLEAR_CACHE)) {
849 btrfs_err(info, "cannot disable free space tree");
850 ret = -EINVAL;
851
852 }
853 if (!ret && btrfs_test_opt(info, SPACE_CACHE))
854 btrfs_info(info, "disk space caching is enabled");
855 if (!ret && btrfs_test_opt(info, FREE_SPACE_TREE))
856 btrfs_info(info, "using free space tree");
857 kfree(orig);
858 return ret;
859 }
860
861 /*
862 * Parse mount options that are required early in the mount process.
863 *
864 * All other options will be parsed on much later in the mount process and
865 * only when we need to allocate a new super block.
866 */
867 static int btrfs_parse_early_options(const char *options, fmode_t flags,
868 void *holder, char **subvol_name, u64 *subvol_objectid,
869 struct btrfs_fs_devices **fs_devices)
870 {
871 substring_t args[MAX_OPT_ARGS];
872 char *device_name, *opts, *orig, *p;
873 char *num = NULL;
874 int error = 0;
875
876 if (!options)
877 return 0;
878
879 /*
880 * strsep changes the string, duplicate it because parse_options
881 * gets called twice
882 */
883 opts = kstrdup(options, GFP_KERNEL);
884 if (!opts)
885 return -ENOMEM;
886 orig = opts;
887
888 while ((p = strsep(&opts, ",")) != NULL) {
889 int token;
890 if (!*p)
891 continue;
892
893 token = match_token(p, tokens, args);
894 switch (token) {
895 case Opt_subvol:
896 kfree(*subvol_name);
897 *subvol_name = match_strdup(&args[0]);
898 if (!*subvol_name) {
899 error = -ENOMEM;
900 goto out;
901 }
902 break;
903 case Opt_subvolid:
904 num = match_strdup(&args[0]);
905 if (num) {
906 *subvol_objectid = memparse(num, NULL);
907 kfree(num);
908 /* we want the original fs_tree */
909 if (!*subvol_objectid)
910 *subvol_objectid =
911 BTRFS_FS_TREE_OBJECTID;
912 } else {
913 error = -EINVAL;
914 goto out;
915 }
916 break;
917 case Opt_subvolrootid:
918 pr_warn("BTRFS: 'subvolrootid' mount option is deprecated and has no effect\n");
919 break;
920 case Opt_device:
921 device_name = match_strdup(&args[0]);
922 if (!device_name) {
923 error = -ENOMEM;
924 goto out;
925 }
926 error = btrfs_scan_one_device(device_name,
927 flags, holder, fs_devices);
928 kfree(device_name);
929 if (error)
930 goto out;
931 break;
932 default:
933 break;
934 }
935 }
936
937 out:
938 kfree(orig);
939 return error;
940 }
941
942 static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info,
943 u64 subvol_objectid)
944 {
945 struct btrfs_root *root = fs_info->tree_root;
946 struct btrfs_root *fs_root;
947 struct btrfs_root_ref *root_ref;
948 struct btrfs_inode_ref *inode_ref;
949 struct btrfs_key key;
950 struct btrfs_path *path = NULL;
951 char *name = NULL, *ptr;
952 u64 dirid;
953 int len;
954 int ret;
955
956 path = btrfs_alloc_path();
957 if (!path) {
958 ret = -ENOMEM;
959 goto err;
960 }
961 path->leave_spinning = 1;
962
963 name = kmalloc(PATH_MAX, GFP_KERNEL);
964 if (!name) {
965 ret = -ENOMEM;
966 goto err;
967 }
968 ptr = name + PATH_MAX - 1;
969 ptr[0] = '\0';
970
971 /*
972 * Walk up the subvolume trees in the tree of tree roots by root
973 * backrefs until we hit the top-level subvolume.
974 */
975 while (subvol_objectid != BTRFS_FS_TREE_OBJECTID) {
976 key.objectid = subvol_objectid;
977 key.type = BTRFS_ROOT_BACKREF_KEY;
978 key.offset = (u64)-1;
979
980 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
981 if (ret < 0) {
982 goto err;
983 } else if (ret > 0) {
984 ret = btrfs_previous_item(root, path, subvol_objectid,
985 BTRFS_ROOT_BACKREF_KEY);
986 if (ret < 0) {
987 goto err;
988 } else if (ret > 0) {
989 ret = -ENOENT;
990 goto err;
991 }
992 }
993
994 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
995 subvol_objectid = key.offset;
996
997 root_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
998 struct btrfs_root_ref);
999 len = btrfs_root_ref_name_len(path->nodes[0], root_ref);
1000 ptr -= len + 1;
1001 if (ptr < name) {
1002 ret = -ENAMETOOLONG;
1003 goto err;
1004 }
1005 read_extent_buffer(path->nodes[0], ptr + 1,
1006 (unsigned long)(root_ref + 1), len);
1007 ptr[0] = '/';
1008 dirid = btrfs_root_ref_dirid(path->nodes[0], root_ref);
1009 btrfs_release_path(path);
1010
1011 key.objectid = subvol_objectid;
1012 key.type = BTRFS_ROOT_ITEM_KEY;
1013 key.offset = (u64)-1;
1014 fs_root = btrfs_read_fs_root_no_name(fs_info, &key);
1015 if (IS_ERR(fs_root)) {
1016 ret = PTR_ERR(fs_root);
1017 goto err;
1018 }
1019
1020 /*
1021 * Walk up the filesystem tree by inode refs until we hit the
1022 * root directory.
1023 */
1024 while (dirid != BTRFS_FIRST_FREE_OBJECTID) {
1025 key.objectid = dirid;
1026 key.type = BTRFS_INODE_REF_KEY;
1027 key.offset = (u64)-1;
1028
1029 ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0);
1030 if (ret < 0) {
1031 goto err;
1032 } else if (ret > 0) {
1033 ret = btrfs_previous_item(fs_root, path, dirid,
1034 BTRFS_INODE_REF_KEY);
1035 if (ret < 0) {
1036 goto err;
1037 } else if (ret > 0) {
1038 ret = -ENOENT;
1039 goto err;
1040 }
1041 }
1042
1043 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1044 dirid = key.offset;
1045
1046 inode_ref = btrfs_item_ptr(path->nodes[0],
1047 path->slots[0],
1048 struct btrfs_inode_ref);
1049 len = btrfs_inode_ref_name_len(path->nodes[0],
1050 inode_ref);
1051 ptr -= len + 1;
1052 if (ptr < name) {
1053 ret = -ENAMETOOLONG;
1054 goto err;
1055 }
1056 read_extent_buffer(path->nodes[0], ptr + 1,
1057 (unsigned long)(inode_ref + 1), len);
1058 ptr[0] = '/';
1059 btrfs_release_path(path);
1060 }
1061 }
1062
1063 btrfs_free_path(path);
1064 if (ptr == name + PATH_MAX - 1) {
1065 name[0] = '/';
1066 name[1] = '\0';
1067 } else {
1068 memmove(name, ptr, name + PATH_MAX - ptr);
1069 }
1070 return name;
1071
1072 err:
1073 btrfs_free_path(path);
1074 kfree(name);
1075 return ERR_PTR(ret);
1076 }
1077
1078 static int get_default_subvol_objectid(struct btrfs_fs_info *fs_info, u64 *objectid)
1079 {
1080 struct btrfs_root *root = fs_info->tree_root;
1081 struct btrfs_dir_item *di;
1082 struct btrfs_path *path;
1083 struct btrfs_key location;
1084 u64 dir_id;
1085
1086 path = btrfs_alloc_path();
1087 if (!path)
1088 return -ENOMEM;
1089 path->leave_spinning = 1;
1090
1091 /*
1092 * Find the "default" dir item which points to the root item that we
1093 * will mount by default if we haven't been given a specific subvolume
1094 * to mount.
1095 */
1096 dir_id = btrfs_super_root_dir(fs_info->super_copy);
1097 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
1098 if (IS_ERR(di)) {
1099 btrfs_free_path(path);
1100 return PTR_ERR(di);
1101 }
1102 if (!di) {
1103 /*
1104 * Ok the default dir item isn't there. This is weird since
1105 * it's always been there, but don't freak out, just try and
1106 * mount the top-level subvolume.
1107 */
1108 btrfs_free_path(path);
1109 *objectid = BTRFS_FS_TREE_OBJECTID;
1110 return 0;
1111 }
1112
1113 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
1114 btrfs_free_path(path);
1115 *objectid = location.objectid;
1116 return 0;
1117 }
1118
1119 static int btrfs_fill_super(struct super_block *sb,
1120 struct btrfs_fs_devices *fs_devices,
1121 void *data)
1122 {
1123 struct inode *inode;
1124 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1125 struct btrfs_key key;
1126 int err;
1127
1128 sb->s_maxbytes = MAX_LFS_FILESIZE;
1129 sb->s_magic = BTRFS_SUPER_MAGIC;
1130 sb->s_op = &btrfs_super_ops;
1131 sb->s_d_op = &btrfs_dentry_operations;
1132 sb->s_export_op = &btrfs_export_ops;
1133 sb->s_xattr = btrfs_xattr_handlers;
1134 sb->s_time_gran = 1;
1135 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
1136 sb->s_flags |= MS_POSIXACL;
1137 #endif
1138 sb->s_flags |= MS_I_VERSION;
1139 sb->s_iflags |= SB_I_CGROUPWB;
1140
1141 err = super_setup_bdi(sb);
1142 if (err) {
1143 btrfs_err(fs_info, "super_setup_bdi failed");
1144 return err;
1145 }
1146
1147 err = open_ctree(sb, fs_devices, (char *)data);
1148 if (err) {
1149 btrfs_err(fs_info, "open_ctree failed");
1150 return err;
1151 }
1152
1153 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
1154 key.type = BTRFS_INODE_ITEM_KEY;
1155 key.offset = 0;
1156 inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
1157 if (IS_ERR(inode)) {
1158 err = PTR_ERR(inode);
1159 goto fail_close;
1160 }
1161
1162 sb->s_root = d_make_root(inode);
1163 if (!sb->s_root) {
1164 err = -ENOMEM;
1165 goto fail_close;
1166 }
1167
1168 cleancache_init_fs(sb);
1169 sb->s_flags |= MS_ACTIVE;
1170 return 0;
1171
1172 fail_close:
1173 close_ctree(fs_info);
1174 return err;
1175 }
1176
1177 int btrfs_sync_fs(struct super_block *sb, int wait)
1178 {
1179 struct btrfs_trans_handle *trans;
1180 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1181 struct btrfs_root *root = fs_info->tree_root;
1182
1183 trace_btrfs_sync_fs(fs_info, wait);
1184
1185 if (!wait) {
1186 filemap_flush(fs_info->btree_inode->i_mapping);
1187 return 0;
1188 }
1189
1190 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
1191
1192 trans = btrfs_attach_transaction_barrier(root);
1193 if (IS_ERR(trans)) {
1194 /* no transaction, don't bother */
1195 if (PTR_ERR(trans) == -ENOENT) {
1196 /*
1197 * Exit unless we have some pending changes
1198 * that need to go through commit
1199 */
1200 if (fs_info->pending_changes == 0)
1201 return 0;
1202 /*
1203 * A non-blocking test if the fs is frozen. We must not
1204 * start a new transaction here otherwise a deadlock
1205 * happens. The pending operations are delayed to the
1206 * next commit after thawing.
1207 */
1208 if (__sb_start_write(sb, SB_FREEZE_WRITE, false))
1209 __sb_end_write(sb, SB_FREEZE_WRITE);
1210 else
1211 return 0;
1212 trans = btrfs_start_transaction(root, 0);
1213 }
1214 if (IS_ERR(trans))
1215 return PTR_ERR(trans);
1216 }
1217 return btrfs_commit_transaction(trans);
1218 }
1219
1220 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
1221 {
1222 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
1223 char *compress_type;
1224
1225 if (btrfs_test_opt(info, DEGRADED))
1226 seq_puts(seq, ",degraded");
1227 if (btrfs_test_opt(info, NODATASUM))
1228 seq_puts(seq, ",nodatasum");
1229 if (btrfs_test_opt(info, NODATACOW))
1230 seq_puts(seq, ",nodatacow");
1231 if (btrfs_test_opt(info, NOBARRIER))
1232 seq_puts(seq, ",nobarrier");
1233 if (info->max_inline != BTRFS_DEFAULT_MAX_INLINE)
1234 seq_printf(seq, ",max_inline=%llu", info->max_inline);
1235 if (info->thread_pool_size != min_t(unsigned long,
1236 num_online_cpus() + 2, 8))
1237 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
1238 if (btrfs_test_opt(info, COMPRESS)) {
1239 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
1240 compress_type = "zlib";
1241 else if (info->compress_type == BTRFS_COMPRESS_LZO)
1242 compress_type = "lzo";
1243 else
1244 compress_type = "zstd";
1245 if (btrfs_test_opt(info, FORCE_COMPRESS))
1246 seq_printf(seq, ",compress-force=%s", compress_type);
1247 else
1248 seq_printf(seq, ",compress=%s", compress_type);
1249 }
1250 if (btrfs_test_opt(info, NOSSD))
1251 seq_puts(seq, ",nossd");
1252 if (btrfs_test_opt(info, SSD_SPREAD))
1253 seq_puts(seq, ",ssd_spread");
1254 else if (btrfs_test_opt(info, SSD))
1255 seq_puts(seq, ",ssd");
1256 if (btrfs_test_opt(info, NOTREELOG))
1257 seq_puts(seq, ",notreelog");
1258 if (btrfs_test_opt(info, NOLOGREPLAY))
1259 seq_puts(seq, ",nologreplay");
1260 if (btrfs_test_opt(info, FLUSHONCOMMIT))
1261 seq_puts(seq, ",flushoncommit");
1262 if (btrfs_test_opt(info, DISCARD))
1263 seq_puts(seq, ",discard");
1264 if (!(info->sb->s_flags & MS_POSIXACL))
1265 seq_puts(seq, ",noacl");
1266 if (btrfs_test_opt(info, SPACE_CACHE))
1267 seq_puts(seq, ",space_cache");
1268 else if (btrfs_test_opt(info, FREE_SPACE_TREE))
1269 seq_puts(seq, ",space_cache=v2");
1270 else
1271 seq_puts(seq, ",nospace_cache");
1272 if (btrfs_test_opt(info, RESCAN_UUID_TREE))
1273 seq_puts(seq, ",rescan_uuid_tree");
1274 if (btrfs_test_opt(info, CLEAR_CACHE))
1275 seq_puts(seq, ",clear_cache");
1276 if (btrfs_test_opt(info, USER_SUBVOL_RM_ALLOWED))
1277 seq_puts(seq, ",user_subvol_rm_allowed");
1278 if (btrfs_test_opt(info, ENOSPC_DEBUG))
1279 seq_puts(seq, ",enospc_debug");
1280 if (btrfs_test_opt(info, AUTO_DEFRAG))
1281 seq_puts(seq, ",autodefrag");
1282 if (btrfs_test_opt(info, INODE_MAP_CACHE))
1283 seq_puts(seq, ",inode_cache");
1284 if (btrfs_test_opt(info, SKIP_BALANCE))
1285 seq_puts(seq, ",skip_balance");
1286 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1287 if (btrfs_test_opt(info, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA))
1288 seq_puts(seq, ",check_int_data");
1289 else if (btrfs_test_opt(info, CHECK_INTEGRITY))
1290 seq_puts(seq, ",check_int");
1291 if (info->check_integrity_print_mask)
1292 seq_printf(seq, ",check_int_print_mask=%d",
1293 info->check_integrity_print_mask);
1294 #endif
1295 if (info->metadata_ratio)
1296 seq_printf(seq, ",metadata_ratio=%d",
1297 info->metadata_ratio);
1298 if (btrfs_test_opt(info, PANIC_ON_FATAL_ERROR))
1299 seq_puts(seq, ",fatal_errors=panic");
1300 if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL)
1301 seq_printf(seq, ",commit=%d", info->commit_interval);
1302 #ifdef CONFIG_BTRFS_DEBUG
1303 if (btrfs_test_opt(info, FRAGMENT_DATA))
1304 seq_puts(seq, ",fragment=data");
1305 if (btrfs_test_opt(info, FRAGMENT_METADATA))
1306 seq_puts(seq, ",fragment=metadata");
1307 #endif
1308 seq_printf(seq, ",subvolid=%llu",
1309 BTRFS_I(d_inode(dentry))->root->root_key.objectid);
1310 seq_puts(seq, ",subvol=");
1311 seq_dentry(seq, dentry, " \t\n\\");
1312 return 0;
1313 }
1314
1315 static int btrfs_test_super(struct super_block *s, void *data)
1316 {
1317 struct btrfs_fs_info *p = data;
1318 struct btrfs_fs_info *fs_info = btrfs_sb(s);
1319
1320 return fs_info->fs_devices == p->fs_devices;
1321 }
1322
1323 static int btrfs_set_super(struct super_block *s, void *data)
1324 {
1325 int err = set_anon_super(s, data);
1326 if (!err)
1327 s->s_fs_info = data;
1328 return err;
1329 }
1330
1331 /*
1332 * subvolumes are identified by ino 256
1333 */
1334 static inline int is_subvolume_inode(struct inode *inode)
1335 {
1336 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
1337 return 1;
1338 return 0;
1339 }
1340
1341 /*
1342 * This will add subvolid=0 to the argument string while removing any subvol=
1343 * and subvolid= arguments to make sure we get the top-level root for path
1344 * walking to the subvol we want.
1345 */
1346 static char *setup_root_args(char *args)
1347 {
1348 char *buf, *dst, *sep;
1349
1350 if (!args)
1351 return kstrdup("subvolid=0", GFP_KERNEL);
1352
1353 /* The worst case is that we add ",subvolid=0" to the end. */
1354 buf = dst = kmalloc(strlen(args) + strlen(",subvolid=0") + 1,
1355 GFP_KERNEL);
1356 if (!buf)
1357 return NULL;
1358
1359 while (1) {
1360 sep = strchrnul(args, ',');
1361 if (!strstarts(args, "subvol=") &&
1362 !strstarts(args, "subvolid=")) {
1363 memcpy(dst, args, sep - args);
1364 dst += sep - args;
1365 *dst++ = ',';
1366 }
1367 if (*sep)
1368 args = sep + 1;
1369 else
1370 break;
1371 }
1372 strcpy(dst, "subvolid=0");
1373
1374 return buf;
1375 }
1376
1377 static struct dentry *mount_subvol(const char *subvol_name, u64 subvol_objectid,
1378 int flags, const char *device_name,
1379 char *data)
1380 {
1381 struct dentry *root;
1382 struct vfsmount *mnt = NULL;
1383 char *newargs;
1384 int ret;
1385
1386 newargs = setup_root_args(data);
1387 if (!newargs) {
1388 root = ERR_PTR(-ENOMEM);
1389 goto out;
1390 }
1391
1392 mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name, newargs);
1393 if (PTR_ERR_OR_ZERO(mnt) == -EBUSY) {
1394 if (flags & MS_RDONLY) {
1395 mnt = vfs_kern_mount(&btrfs_fs_type, flags & ~MS_RDONLY,
1396 device_name, newargs);
1397 } else {
1398 mnt = vfs_kern_mount(&btrfs_fs_type, flags | MS_RDONLY,
1399 device_name, newargs);
1400 if (IS_ERR(mnt)) {
1401 root = ERR_CAST(mnt);
1402 mnt = NULL;
1403 goto out;
1404 }
1405
1406 down_write(&mnt->mnt_sb->s_umount);
1407 ret = btrfs_remount(mnt->mnt_sb, &flags, NULL);
1408 up_write(&mnt->mnt_sb->s_umount);
1409 if (ret < 0) {
1410 root = ERR_PTR(ret);
1411 goto out;
1412 }
1413 }
1414 }
1415 if (IS_ERR(mnt)) {
1416 root = ERR_CAST(mnt);
1417 mnt = NULL;
1418 goto out;
1419 }
1420
1421 if (!subvol_name) {
1422 if (!subvol_objectid) {
1423 ret = get_default_subvol_objectid(btrfs_sb(mnt->mnt_sb),
1424 &subvol_objectid);
1425 if (ret) {
1426 root = ERR_PTR(ret);
1427 goto out;
1428 }
1429 }
1430 subvol_name = get_subvol_name_from_objectid(btrfs_sb(mnt->mnt_sb),
1431 subvol_objectid);
1432 if (IS_ERR(subvol_name)) {
1433 root = ERR_CAST(subvol_name);
1434 subvol_name = NULL;
1435 goto out;
1436 }
1437
1438 }
1439
1440 root = mount_subtree(mnt, subvol_name);
1441 /* mount_subtree() drops our reference on the vfsmount. */
1442 mnt = NULL;
1443
1444 if (!IS_ERR(root)) {
1445 struct super_block *s = root->d_sb;
1446 struct btrfs_fs_info *fs_info = btrfs_sb(s);
1447 struct inode *root_inode = d_inode(root);
1448 u64 root_objectid = BTRFS_I(root_inode)->root->root_key.objectid;
1449
1450 ret = 0;
1451 if (!is_subvolume_inode(root_inode)) {
1452 btrfs_err(fs_info, "'%s' is not a valid subvolume",
1453 subvol_name);
1454 ret = -EINVAL;
1455 }
1456 if (subvol_objectid && root_objectid != subvol_objectid) {
1457 /*
1458 * This will also catch a race condition where a
1459 * subvolume which was passed by ID is renamed and
1460 * another subvolume is renamed over the old location.
1461 */
1462 btrfs_err(fs_info,
1463 "subvol '%s' does not match subvolid %llu",
1464 subvol_name, subvol_objectid);
1465 ret = -EINVAL;
1466 }
1467 if (ret) {
1468 dput(root);
1469 root = ERR_PTR(ret);
1470 deactivate_locked_super(s);
1471 }
1472 }
1473
1474 out:
1475 mntput(mnt);
1476 kfree(newargs);
1477 kfree(subvol_name);
1478 return root;
1479 }
1480
1481 static int parse_security_options(char *orig_opts,
1482 struct security_mnt_opts *sec_opts)
1483 {
1484 char *secdata = NULL;
1485 int ret = 0;
1486
1487 secdata = alloc_secdata();
1488 if (!secdata)
1489 return -ENOMEM;
1490 ret = security_sb_copy_data(orig_opts, secdata);
1491 if (ret) {
1492 free_secdata(secdata);
1493 return ret;
1494 }
1495 ret = security_sb_parse_opts_str(secdata, sec_opts);
1496 free_secdata(secdata);
1497 return ret;
1498 }
1499
1500 static int setup_security_options(struct btrfs_fs_info *fs_info,
1501 struct super_block *sb,
1502 struct security_mnt_opts *sec_opts)
1503 {
1504 int ret = 0;
1505
1506 /*
1507 * Call security_sb_set_mnt_opts() to check whether new sec_opts
1508 * is valid.
1509 */
1510 ret = security_sb_set_mnt_opts(sb, sec_opts, 0, NULL);
1511 if (ret)
1512 return ret;
1513
1514 #ifdef CONFIG_SECURITY
1515 if (!fs_info->security_opts.num_mnt_opts) {
1516 /* first time security setup, copy sec_opts to fs_info */
1517 memcpy(&fs_info->security_opts, sec_opts, sizeof(*sec_opts));
1518 } else {
1519 /*
1520 * Since SELinux (the only one supporting security_mnt_opts)
1521 * does NOT support changing context during remount/mount of
1522 * the same sb, this must be the same or part of the same
1523 * security options, just free it.
1524 */
1525 security_free_mnt_opts(sec_opts);
1526 }
1527 #endif
1528 return ret;
1529 }
1530
1531 /*
1532 * Find a superblock for the given device / mount point.
1533 *
1534 * Note: This is based on get_sb_bdev from fs/super.c with a few additions
1535 * for multiple device setup. Make sure to keep it in sync.
1536 */
1537 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1538 const char *device_name, void *data)
1539 {
1540 struct block_device *bdev = NULL;
1541 struct super_block *s;
1542 struct btrfs_fs_devices *fs_devices = NULL;
1543 struct btrfs_fs_info *fs_info = NULL;
1544 struct security_mnt_opts new_sec_opts;
1545 fmode_t mode = FMODE_READ;
1546 char *subvol_name = NULL;
1547 u64 subvol_objectid = 0;
1548 int error = 0;
1549
1550 if (!(flags & MS_RDONLY))
1551 mode |= FMODE_WRITE;
1552
1553 error = btrfs_parse_early_options(data, mode, fs_type,
1554 &subvol_name, &subvol_objectid,
1555 &fs_devices);
1556 if (error) {
1557 kfree(subvol_name);
1558 return ERR_PTR(error);
1559 }
1560
1561 if (subvol_name || subvol_objectid != BTRFS_FS_TREE_OBJECTID) {
1562 /* mount_subvol() will free subvol_name. */
1563 return mount_subvol(subvol_name, subvol_objectid, flags,
1564 device_name, data);
1565 }
1566
1567 security_init_mnt_opts(&new_sec_opts);
1568 if (data) {
1569 error = parse_security_options(data, &new_sec_opts);
1570 if (error)
1571 return ERR_PTR(error);
1572 }
1573
1574 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
1575 if (error)
1576 goto error_sec_opts;
1577
1578 /*
1579 * Setup a dummy root and fs_info for test/set super. This is because
1580 * we don't actually fill this stuff out until open_ctree, but we need
1581 * it for searching for existing supers, so this lets us do that and
1582 * then open_ctree will properly initialize everything later.
1583 */
1584 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_KERNEL);
1585 if (!fs_info) {
1586 error = -ENOMEM;
1587 goto error_sec_opts;
1588 }
1589
1590 fs_info->fs_devices = fs_devices;
1591
1592 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL);
1593 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL);
1594 security_init_mnt_opts(&fs_info->security_opts);
1595 if (!fs_info->super_copy || !fs_info->super_for_commit) {
1596 error = -ENOMEM;
1597 goto error_fs_info;
1598 }
1599
1600 error = btrfs_open_devices(fs_devices, mode, fs_type);
1601 if (error)
1602 goto error_fs_info;
1603
1604 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
1605 error = -EACCES;
1606 goto error_close_devices;
1607 }
1608
1609 bdev = fs_devices->latest_bdev;
1610 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | MS_NOSEC,
1611 fs_info);
1612 if (IS_ERR(s)) {
1613 error = PTR_ERR(s);
1614 goto error_close_devices;
1615 }
1616
1617 if (s->s_root) {
1618 btrfs_close_devices(fs_devices);
1619 free_fs_info(fs_info);
1620 if ((flags ^ s->s_flags) & MS_RDONLY)
1621 error = -EBUSY;
1622 } else {
1623 snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev);
1624 btrfs_sb(s)->bdev_holder = fs_type;
1625 error = btrfs_fill_super(s, fs_devices, data);
1626 }
1627 if (error) {
1628 deactivate_locked_super(s);
1629 goto error_sec_opts;
1630 }
1631
1632 fs_info = btrfs_sb(s);
1633 error = setup_security_options(fs_info, s, &new_sec_opts);
1634 if (error) {
1635 deactivate_locked_super(s);
1636 goto error_sec_opts;
1637 }
1638
1639 return dget(s->s_root);
1640
1641 error_close_devices:
1642 btrfs_close_devices(fs_devices);
1643 error_fs_info:
1644 free_fs_info(fs_info);
1645 error_sec_opts:
1646 security_free_mnt_opts(&new_sec_opts);
1647 return ERR_PTR(error);
1648 }
1649
1650 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1651 int new_pool_size, int old_pool_size)
1652 {
1653 if (new_pool_size == old_pool_size)
1654 return;
1655
1656 fs_info->thread_pool_size = new_pool_size;
1657
1658 btrfs_info(fs_info, "resize thread pool %d -> %d",
1659 old_pool_size, new_pool_size);
1660
1661 btrfs_workqueue_set_max(fs_info->workers, new_pool_size);
1662 btrfs_workqueue_set_max(fs_info->delalloc_workers, new_pool_size);
1663 btrfs_workqueue_set_max(fs_info->submit_workers, new_pool_size);
1664 btrfs_workqueue_set_max(fs_info->caching_workers, new_pool_size);
1665 btrfs_workqueue_set_max(fs_info->endio_workers, new_pool_size);
1666 btrfs_workqueue_set_max(fs_info->endio_meta_workers, new_pool_size);
1667 btrfs_workqueue_set_max(fs_info->endio_meta_write_workers,
1668 new_pool_size);
1669 btrfs_workqueue_set_max(fs_info->endio_write_workers, new_pool_size);
1670 btrfs_workqueue_set_max(fs_info->endio_freespace_worker, new_pool_size);
1671 btrfs_workqueue_set_max(fs_info->delayed_workers, new_pool_size);
1672 btrfs_workqueue_set_max(fs_info->readahead_workers, new_pool_size);
1673 btrfs_workqueue_set_max(fs_info->scrub_wr_completion_workers,
1674 new_pool_size);
1675 }
1676
1677 static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info)
1678 {
1679 set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1680 }
1681
1682 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
1683 unsigned long old_opts, int flags)
1684 {
1685 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1686 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1687 (flags & MS_RDONLY))) {
1688 /* wait for any defraggers to finish */
1689 wait_event(fs_info->transaction_wait,
1690 (atomic_read(&fs_info->defrag_running) == 0));
1691 if (flags & MS_RDONLY)
1692 sync_filesystem(fs_info->sb);
1693 }
1694 }
1695
1696 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1697 unsigned long old_opts)
1698 {
1699 /*
1700 * We need to cleanup all defragable inodes if the autodefragment is
1701 * close or the filesystem is read only.
1702 */
1703 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1704 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1705 (fs_info->sb->s_flags & MS_RDONLY))) {
1706 btrfs_cleanup_defrag_inodes(fs_info);
1707 }
1708
1709 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1710 }
1711
1712 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1713 {
1714 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1715 struct btrfs_root *root = fs_info->tree_root;
1716 unsigned old_flags = sb->s_flags;
1717 unsigned long old_opts = fs_info->mount_opt;
1718 unsigned long old_compress_type = fs_info->compress_type;
1719 u64 old_max_inline = fs_info->max_inline;
1720 int old_thread_pool_size = fs_info->thread_pool_size;
1721 unsigned int old_metadata_ratio = fs_info->metadata_ratio;
1722 int ret;
1723
1724 sync_filesystem(sb);
1725 btrfs_remount_prepare(fs_info);
1726
1727 if (data) {
1728 struct security_mnt_opts new_sec_opts;
1729
1730 security_init_mnt_opts(&new_sec_opts);
1731 ret = parse_security_options(data, &new_sec_opts);
1732 if (ret)
1733 goto restore;
1734 ret = setup_security_options(fs_info, sb,
1735 &new_sec_opts);
1736 if (ret) {
1737 security_free_mnt_opts(&new_sec_opts);
1738 goto restore;
1739 }
1740 }
1741
1742 ret = btrfs_parse_options(fs_info, data, *flags);
1743 if (ret) {
1744 ret = -EINVAL;
1745 goto restore;
1746 }
1747
1748 btrfs_remount_begin(fs_info, old_opts, *flags);
1749 btrfs_resize_thread_pool(fs_info,
1750 fs_info->thread_pool_size, old_thread_pool_size);
1751
1752 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1753 goto out;
1754
1755 if (*flags & MS_RDONLY) {
1756 /*
1757 * this also happens on 'umount -rf' or on shutdown, when
1758 * the filesystem is busy.
1759 */
1760 cancel_work_sync(&fs_info->async_reclaim_work);
1761
1762 /* wait for the uuid_scan task to finish */
1763 down(&fs_info->uuid_tree_rescan_sem);
1764 /* avoid complains from lockdep et al. */
1765 up(&fs_info->uuid_tree_rescan_sem);
1766
1767 sb->s_flags |= MS_RDONLY;
1768
1769 /*
1770 * Setting MS_RDONLY will put the cleaner thread to
1771 * sleep at the next loop if it's already active.
1772 * If it's already asleep, we'll leave unused block
1773 * groups on disk until we're mounted read-write again
1774 * unless we clean them up here.
1775 */
1776 btrfs_delete_unused_bgs(fs_info);
1777
1778 btrfs_dev_replace_suspend_for_unmount(fs_info);
1779 btrfs_scrub_cancel(fs_info);
1780 btrfs_pause_balance(fs_info);
1781
1782 ret = btrfs_commit_super(fs_info);
1783 if (ret)
1784 goto restore;
1785 } else {
1786 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
1787 btrfs_err(fs_info,
1788 "Remounting read-write after error is not allowed");
1789 ret = -EINVAL;
1790 goto restore;
1791 }
1792 if (fs_info->fs_devices->rw_devices == 0) {
1793 ret = -EACCES;
1794 goto restore;
1795 }
1796
1797 if (!btrfs_check_rw_degradable(fs_info)) {
1798 btrfs_warn(fs_info,
1799 "too many missing devices, writeable remount is not allowed");
1800 ret = -EACCES;
1801 goto restore;
1802 }
1803
1804 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1805 ret = -EINVAL;
1806 goto restore;
1807 }
1808
1809 ret = btrfs_cleanup_fs_roots(fs_info);
1810 if (ret)
1811 goto restore;
1812
1813 /* recover relocation */
1814 mutex_lock(&fs_info->cleaner_mutex);
1815 ret = btrfs_recover_relocation(root);
1816 mutex_unlock(&fs_info->cleaner_mutex);
1817 if (ret)
1818 goto restore;
1819
1820 ret = btrfs_resume_balance_async(fs_info);
1821 if (ret)
1822 goto restore;
1823
1824 ret = btrfs_resume_dev_replace_async(fs_info);
1825 if (ret) {
1826 btrfs_warn(fs_info, "failed to resume dev_replace");
1827 goto restore;
1828 }
1829
1830 btrfs_qgroup_rescan_resume(fs_info);
1831
1832 if (!fs_info->uuid_root) {
1833 btrfs_info(fs_info, "creating UUID tree");
1834 ret = btrfs_create_uuid_tree(fs_info);
1835 if (ret) {
1836 btrfs_warn(fs_info,
1837 "failed to create the UUID tree %d",
1838 ret);
1839 goto restore;
1840 }
1841 }
1842 sb->s_flags &= ~MS_RDONLY;
1843
1844 set_bit(BTRFS_FS_OPEN, &fs_info->flags);
1845 }
1846 out:
1847 wake_up_process(fs_info->transaction_kthread);
1848 btrfs_remount_cleanup(fs_info, old_opts);
1849 return 0;
1850
1851 restore:
1852 /* We've hit an error - don't reset MS_RDONLY */
1853 if (sb->s_flags & MS_RDONLY)
1854 old_flags |= MS_RDONLY;
1855 sb->s_flags = old_flags;
1856 fs_info->mount_opt = old_opts;
1857 fs_info->compress_type = old_compress_type;
1858 fs_info->max_inline = old_max_inline;
1859 btrfs_resize_thread_pool(fs_info,
1860 old_thread_pool_size, fs_info->thread_pool_size);
1861 fs_info->metadata_ratio = old_metadata_ratio;
1862 btrfs_remount_cleanup(fs_info, old_opts);
1863 return ret;
1864 }
1865
1866 /* Used to sort the devices by max_avail(descending sort) */
1867 static int btrfs_cmp_device_free_bytes(const void *dev_info1,
1868 const void *dev_info2)
1869 {
1870 if (((struct btrfs_device_info *)dev_info1)->max_avail >
1871 ((struct btrfs_device_info *)dev_info2)->max_avail)
1872 return -1;
1873 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1874 ((struct btrfs_device_info *)dev_info2)->max_avail)
1875 return 1;
1876 else
1877 return 0;
1878 }
1879
1880 /*
1881 * sort the devices by max_avail, in which max free extent size of each device
1882 * is stored.(Descending Sort)
1883 */
1884 static inline void btrfs_descending_sort_devices(
1885 struct btrfs_device_info *devices,
1886 size_t nr_devices)
1887 {
1888 sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1889 btrfs_cmp_device_free_bytes, NULL);
1890 }
1891
1892 /*
1893 * The helper to calc the free space on the devices that can be used to store
1894 * file data.
1895 */
1896 static int btrfs_calc_avail_data_space(struct btrfs_fs_info *fs_info,
1897 u64 *free_bytes)
1898 {
1899 struct btrfs_device_info *devices_info;
1900 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1901 struct btrfs_device *device;
1902 u64 skip_space;
1903 u64 type;
1904 u64 avail_space;
1905 u64 min_stripe_size;
1906 int min_stripes = 1, num_stripes = 1;
1907 int i = 0, nr_devices;
1908
1909 /*
1910 * We aren't under the device list lock, so this is racy-ish, but good
1911 * enough for our purposes.
1912 */
1913 nr_devices = fs_info->fs_devices->open_devices;
1914 if (!nr_devices) {
1915 smp_mb();
1916 nr_devices = fs_info->fs_devices->open_devices;
1917 ASSERT(nr_devices);
1918 if (!nr_devices) {
1919 *free_bytes = 0;
1920 return 0;
1921 }
1922 }
1923
1924 devices_info = kmalloc_array(nr_devices, sizeof(*devices_info),
1925 GFP_KERNEL);
1926 if (!devices_info)
1927 return -ENOMEM;
1928
1929 /* calc min stripe number for data space allocation */
1930 type = btrfs_data_alloc_profile(fs_info);
1931 if (type & BTRFS_BLOCK_GROUP_RAID0) {
1932 min_stripes = 2;
1933 num_stripes = nr_devices;
1934 } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
1935 min_stripes = 2;
1936 num_stripes = 2;
1937 } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
1938 min_stripes = 4;
1939 num_stripes = 4;
1940 }
1941
1942 if (type & BTRFS_BLOCK_GROUP_DUP)
1943 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1944 else
1945 min_stripe_size = BTRFS_STRIPE_LEN;
1946
1947 rcu_read_lock();
1948 list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
1949 if (!device->in_fs_metadata || !device->bdev ||
1950 device->is_tgtdev_for_dev_replace)
1951 continue;
1952
1953 if (i >= nr_devices)
1954 break;
1955
1956 avail_space = device->total_bytes - device->bytes_used;
1957
1958 /* align with stripe_len */
1959 avail_space = div_u64(avail_space, BTRFS_STRIPE_LEN);
1960 avail_space *= BTRFS_STRIPE_LEN;
1961
1962 /*
1963 * In order to avoid overwriting the superblock on the drive,
1964 * btrfs starts at an offset of at least 1MB when doing chunk
1965 * allocation.
1966 */
1967 skip_space = SZ_1M;
1968
1969 /*
1970 * we can use the free space in [0, skip_space - 1], subtract
1971 * it from the total.
1972 */
1973 if (avail_space && avail_space >= skip_space)
1974 avail_space -= skip_space;
1975 else
1976 avail_space = 0;
1977
1978 if (avail_space < min_stripe_size)
1979 continue;
1980
1981 devices_info[i].dev = device;
1982 devices_info[i].max_avail = avail_space;
1983
1984 i++;
1985 }
1986 rcu_read_unlock();
1987
1988 nr_devices = i;
1989
1990 btrfs_descending_sort_devices(devices_info, nr_devices);
1991
1992 i = nr_devices - 1;
1993 avail_space = 0;
1994 while (nr_devices >= min_stripes) {
1995 if (num_stripes > nr_devices)
1996 num_stripes = nr_devices;
1997
1998 if (devices_info[i].max_avail >= min_stripe_size) {
1999 int j;
2000 u64 alloc_size;
2001
2002 avail_space += devices_info[i].max_avail * num_stripes;
2003 alloc_size = devices_info[i].max_avail;
2004 for (j = i + 1 - num_stripes; j <= i; j++)
2005 devices_info[j].max_avail -= alloc_size;
2006 }
2007 i--;
2008 nr_devices--;
2009 }
2010
2011 kfree(devices_info);
2012 *free_bytes = avail_space;
2013 return 0;
2014 }
2015
2016 /*
2017 * Calculate numbers for 'df', pessimistic in case of mixed raid profiles.
2018 *
2019 * If there's a redundant raid level at DATA block groups, use the respective
2020 * multiplier to scale the sizes.
2021 *
2022 * Unused device space usage is based on simulating the chunk allocator
2023 * algorithm that respects the device sizes and order of allocations. This is
2024 * a close approximation of the actual use but there are other factors that may
2025 * change the result (like a new metadata chunk).
2026 *
2027 * If metadata is exhausted, f_bavail will be 0.
2028 */
2029 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
2030 {
2031 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
2032 struct btrfs_super_block *disk_super = fs_info->super_copy;
2033 struct list_head *head = &fs_info->space_info;
2034 struct btrfs_space_info *found;
2035 u64 total_used = 0;
2036 u64 total_free_data = 0;
2037 u64 total_free_meta = 0;
2038 int bits = dentry->d_sb->s_blocksize_bits;
2039 __be32 *fsid = (__be32 *)fs_info->fsid;
2040 unsigned factor = 1;
2041 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
2042 int ret;
2043 u64 thresh = 0;
2044 int mixed = 0;
2045
2046 rcu_read_lock();
2047 list_for_each_entry_rcu(found, head, list) {
2048 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
2049 int i;
2050
2051 total_free_data += found->disk_total - found->disk_used;
2052 total_free_data -=
2053 btrfs_account_ro_block_groups_free_space(found);
2054
2055 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
2056 if (!list_empty(&found->block_groups[i])) {
2057 switch (i) {
2058 case BTRFS_RAID_DUP:
2059 case BTRFS_RAID_RAID1:
2060 case BTRFS_RAID_RAID10:
2061 factor = 2;
2062 }
2063 }
2064 }
2065 }
2066
2067 /*
2068 * Metadata in mixed block goup profiles are accounted in data
2069 */
2070 if (!mixed && found->flags & BTRFS_BLOCK_GROUP_METADATA) {
2071 if (found->flags & BTRFS_BLOCK_GROUP_DATA)
2072 mixed = 1;
2073 else
2074 total_free_meta += found->disk_total -
2075 found->disk_used;
2076 }
2077
2078 total_used += found->disk_used;
2079 }
2080
2081 rcu_read_unlock();
2082
2083 buf->f_blocks = div_u64(btrfs_super_total_bytes(disk_super), factor);
2084 buf->f_blocks >>= bits;
2085 buf->f_bfree = buf->f_blocks - (div_u64(total_used, factor) >> bits);
2086
2087 /* Account global block reserve as used, it's in logical size already */
2088 spin_lock(&block_rsv->lock);
2089 /* Mixed block groups accounting is not byte-accurate, avoid overflow */
2090 if (buf->f_bfree >= block_rsv->size >> bits)
2091 buf->f_bfree -= block_rsv->size >> bits;
2092 else
2093 buf->f_bfree = 0;
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, &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 (!mixed && 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
2137 static 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
2144 static 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 };
2151 MODULE_ALIAS_FS("btrfs");
2152
2153 static 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 */
2167 static 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
2202 static int btrfs_freeze(struct super_block *sb)
2203 {
2204 struct btrfs_trans_handle *trans;
2205 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2206 struct btrfs_root *root = fs_info->tree_root;
2207
2208 set_bit(BTRFS_FS_FROZEN, &fs_info->flags);
2209 /*
2210 * We don't need a barrier here, we'll wait for any transaction that
2211 * could be in progress on other threads (and do delayed iputs that
2212 * we want to avoid on a frozen filesystem), or do the commit
2213 * ourselves.
2214 */
2215 trans = btrfs_attach_transaction_barrier(root);
2216 if (IS_ERR(trans)) {
2217 /* no transaction, don't bother */
2218 if (PTR_ERR(trans) == -ENOENT)
2219 return 0;
2220 return PTR_ERR(trans);
2221 }
2222 return btrfs_commit_transaction(trans);
2223 }
2224
2225 static int btrfs_unfreeze(struct super_block *sb)
2226 {
2227 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2228
2229 clear_bit(BTRFS_FS_FROZEN, &fs_info->flags);
2230 return 0;
2231 }
2232
2233 static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
2234 {
2235 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
2236 struct btrfs_fs_devices *cur_devices;
2237 struct btrfs_device *dev, *first_dev = NULL;
2238 struct list_head *head;
2239 struct rcu_string *name;
2240
2241 mutex_lock(&fs_info->fs_devices->device_list_mutex);
2242 cur_devices = fs_info->fs_devices;
2243 while (cur_devices) {
2244 head = &cur_devices->devices;
2245 list_for_each_entry(dev, head, dev_list) {
2246 if (dev->missing)
2247 continue;
2248 if (!dev->name)
2249 continue;
2250 if (!first_dev || dev->devid < first_dev->devid)
2251 first_dev = dev;
2252 }
2253 cur_devices = cur_devices->seed;
2254 }
2255
2256 if (first_dev) {
2257 rcu_read_lock();
2258 name = rcu_dereference(first_dev->name);
2259 seq_escape(m, name->str, " \t\n\\");
2260 rcu_read_unlock();
2261 } else {
2262 WARN_ON(1);
2263 }
2264 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2265 return 0;
2266 }
2267
2268 static const struct super_operations btrfs_super_ops = {
2269 .drop_inode = btrfs_drop_inode,
2270 .evict_inode = btrfs_evict_inode,
2271 .put_super = btrfs_put_super,
2272 .sync_fs = btrfs_sync_fs,
2273 .show_options = btrfs_show_options,
2274 .show_devname = btrfs_show_devname,
2275 .write_inode = btrfs_write_inode,
2276 .alloc_inode = btrfs_alloc_inode,
2277 .destroy_inode = btrfs_destroy_inode,
2278 .statfs = btrfs_statfs,
2279 .remount_fs = btrfs_remount,
2280 .freeze_fs = btrfs_freeze,
2281 .unfreeze_fs = btrfs_unfreeze,
2282 };
2283
2284 static const struct file_operations btrfs_ctl_fops = {
2285 .open = btrfs_control_open,
2286 .unlocked_ioctl = btrfs_control_ioctl,
2287 .compat_ioctl = btrfs_control_ioctl,
2288 .owner = THIS_MODULE,
2289 .llseek = noop_llseek,
2290 };
2291
2292 static struct miscdevice btrfs_misc = {
2293 .minor = BTRFS_MINOR,
2294 .name = "btrfs-control",
2295 .fops = &btrfs_ctl_fops
2296 };
2297
2298 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
2299 MODULE_ALIAS("devname:btrfs-control");
2300
2301 static int btrfs_interface_init(void)
2302 {
2303 return misc_register(&btrfs_misc);
2304 }
2305
2306 static void btrfs_interface_exit(void)
2307 {
2308 misc_deregister(&btrfs_misc);
2309 }
2310
2311 static void btrfs_print_mod_info(void)
2312 {
2313 pr_info("Btrfs loaded, crc32c=%s"
2314 #ifdef CONFIG_BTRFS_DEBUG
2315 ", debug=on"
2316 #endif
2317 #ifdef CONFIG_BTRFS_ASSERT
2318 ", assert=on"
2319 #endif
2320 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2321 ", integrity-checker=on"
2322 #endif
2323 "\n",
2324 btrfs_crc32c_impl());
2325 }
2326
2327 static int __init init_btrfs_fs(void)
2328 {
2329 int err;
2330
2331 err = btrfs_hash_init();
2332 if (err)
2333 return err;
2334
2335 btrfs_props_init();
2336
2337 err = btrfs_init_sysfs();
2338 if (err)
2339 goto free_hash;
2340
2341 btrfs_init_compress();
2342
2343 err = btrfs_init_cachep();
2344 if (err)
2345 goto free_compress;
2346
2347 err = extent_io_init();
2348 if (err)
2349 goto free_cachep;
2350
2351 err = extent_map_init();
2352 if (err)
2353 goto free_extent_io;
2354
2355 err = ordered_data_init();
2356 if (err)
2357 goto free_extent_map;
2358
2359 err = btrfs_delayed_inode_init();
2360 if (err)
2361 goto free_ordered_data;
2362
2363 err = btrfs_auto_defrag_init();
2364 if (err)
2365 goto free_delayed_inode;
2366
2367 err = btrfs_delayed_ref_init();
2368 if (err)
2369 goto free_auto_defrag;
2370
2371 err = btrfs_prelim_ref_init();
2372 if (err)
2373 goto free_delayed_ref;
2374
2375 err = btrfs_end_io_wq_init();
2376 if (err)
2377 goto free_prelim_ref;
2378
2379 err = btrfs_interface_init();
2380 if (err)
2381 goto free_end_io_wq;
2382
2383 btrfs_init_lockdep();
2384
2385 btrfs_print_mod_info();
2386
2387 err = btrfs_run_sanity_tests();
2388 if (err)
2389 goto unregister_ioctl;
2390
2391 err = register_filesystem(&btrfs_fs_type);
2392 if (err)
2393 goto unregister_ioctl;
2394
2395 return 0;
2396
2397 unregister_ioctl:
2398 btrfs_interface_exit();
2399 free_end_io_wq:
2400 btrfs_end_io_wq_exit();
2401 free_prelim_ref:
2402 btrfs_prelim_ref_exit();
2403 free_delayed_ref:
2404 btrfs_delayed_ref_exit();
2405 free_auto_defrag:
2406 btrfs_auto_defrag_exit();
2407 free_delayed_inode:
2408 btrfs_delayed_inode_exit();
2409 free_ordered_data:
2410 ordered_data_exit();
2411 free_extent_map:
2412 extent_map_exit();
2413 free_extent_io:
2414 extent_io_exit();
2415 free_cachep:
2416 btrfs_destroy_cachep();
2417 free_compress:
2418 btrfs_exit_compress();
2419 btrfs_exit_sysfs();
2420 free_hash:
2421 btrfs_hash_exit();
2422 return err;
2423 }
2424
2425 static void __exit exit_btrfs_fs(void)
2426 {
2427 btrfs_destroy_cachep();
2428 btrfs_delayed_ref_exit();
2429 btrfs_auto_defrag_exit();
2430 btrfs_delayed_inode_exit();
2431 btrfs_prelim_ref_exit();
2432 ordered_data_exit();
2433 extent_map_exit();
2434 extent_io_exit();
2435 btrfs_interface_exit();
2436 btrfs_end_io_wq_exit();
2437 unregister_filesystem(&btrfs_fs_type);
2438 btrfs_exit_sysfs();
2439 btrfs_cleanup_fs_uuids();
2440 btrfs_exit_compress();
2441 btrfs_hash_exit();
2442 }
2443
2444 late_initcall(init_btrfs_fs);
2445 module_exit(exit_btrfs_fs)
2446
2447 MODULE_LICENSE("GPL");
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