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Merge tag 'sh-pfc-for-v5.1-tag2' of git://git.kernel.org/pub/scm/linux/kernel/git...
[mirror_ubuntu-focal-kernel.git] / fs / btrfs / super.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2007 Oracle. All rights reserved.
4 */
5
6 #include <linux/blkdev.h>
7 #include <linux/module.h>
8 #include <linux/fs.h>
9 #include <linux/pagemap.h>
10 #include <linux/highmem.h>
11 #include <linux/time.h>
12 #include <linux/init.h>
13 #include <linux/seq_file.h>
14 #include <linux/string.h>
15 #include <linux/backing-dev.h>
16 #include <linux/mount.h>
17 #include <linux/writeback.h>
18 #include <linux/statfs.h>
19 #include <linux/compat.h>
20 #include <linux/parser.h>
21 #include <linux/ctype.h>
22 #include <linux/namei.h>
23 #include <linux/miscdevice.h>
24 #include <linux/magic.h>
25 #include <linux/slab.h>
26 #include <linux/cleancache.h>
27 #include <linux/ratelimit.h>
28 #include <linux/crc32c.h>
29 #include <linux/btrfs.h>
30 #include "delayed-inode.h"
31 #include "ctree.h"
32 #include "disk-io.h"
33 #include "transaction.h"
34 #include "btrfs_inode.h"
35 #include "print-tree.h"
36 #include "props.h"
37 #include "xattr.h"
38 #include "volumes.h"
39 #include "export.h"
40 #include "compression.h"
41 #include "rcu-string.h"
42 #include "dev-replace.h"
43 #include "free-space-cache.h"
44 #include "backref.h"
45 #include "tests/btrfs-tests.h"
46
47 #include "qgroup.h"
48 #define CREATE_TRACE_POINTS
49 #include <trace/events/btrfs.h>
50
51 static const struct super_operations btrfs_super_ops;
52
53 /*
54 * Types for mounting the default subvolume and a subvolume explicitly
55 * requested by subvol=/path. That way the callchain is straightforward and we
56 * don't have to play tricks with the mount options and recursive calls to
57 * btrfs_mount.
58 *
59 * The new btrfs_root_fs_type also servers as a tag for the bdev_holder.
60 */
61 static struct file_system_type btrfs_fs_type;
62 static struct file_system_type btrfs_root_fs_type;
63
64 static int btrfs_remount(struct super_block *sb, int *flags, char *data);
65
66 const char *btrfs_decode_error(int errno)
67 {
68 char *errstr = "unknown";
69
70 switch (errno) {
71 case -EIO:
72 errstr = "IO failure";
73 break;
74 case -ENOMEM:
75 errstr = "Out of memory";
76 break;
77 case -EROFS:
78 errstr = "Readonly filesystem";
79 break;
80 case -EEXIST:
81 errstr = "Object already exists";
82 break;
83 case -ENOSPC:
84 errstr = "No space left";
85 break;
86 case -ENOENT:
87 errstr = "No such entry";
88 break;
89 }
90
91 return errstr;
92 }
93
94 /*
95 * __btrfs_handle_fs_error decodes expected errors from the caller and
96 * invokes the appropriate error response.
97 */
98 __cold
99 void __btrfs_handle_fs_error(struct btrfs_fs_info *fs_info, const char *function,
100 unsigned int line, int errno, const char *fmt, ...)
101 {
102 struct super_block *sb = fs_info->sb;
103 #ifdef CONFIG_PRINTK
104 const char *errstr;
105 #endif
106
107 /*
108 * Special case: if the error is EROFS, and we're already
109 * under SB_RDONLY, then it is safe here.
110 */
111 if (errno == -EROFS && sb_rdonly(sb))
112 return;
113
114 #ifdef CONFIG_PRINTK
115 errstr = btrfs_decode_error(errno);
116 if (fmt) {
117 struct va_format vaf;
118 va_list args;
119
120 va_start(args, fmt);
121 vaf.fmt = fmt;
122 vaf.va = &args;
123
124 pr_crit("BTRFS: error (device %s) in %s:%d: errno=%d %s (%pV)\n",
125 sb->s_id, function, line, errno, errstr, &vaf);
126 va_end(args);
127 } else {
128 pr_crit("BTRFS: error (device %s) in %s:%d: errno=%d %s\n",
129 sb->s_id, function, line, errno, errstr);
130 }
131 #endif
132
133 /*
134 * Today we only save the error info to memory. Long term we'll
135 * also send it down to the disk
136 */
137 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
138
139 /* Don't go through full error handling during mount */
140 if (!(sb->s_flags & SB_BORN))
141 return;
142
143 if (sb_rdonly(sb))
144 return;
145
146 /* btrfs handle error by forcing the filesystem readonly */
147 sb->s_flags |= SB_RDONLY;
148 btrfs_info(fs_info, "forced readonly");
149 /*
150 * Note that a running device replace operation is not canceled here
151 * although there is no way to update the progress. It would add the
152 * risk of a deadlock, therefore the canceling is omitted. The only
153 * penalty is that some I/O remains active until the procedure
154 * completes. The next time when the filesystem is mounted writable
155 * again, the device replace operation continues.
156 */
157 }
158
159 #ifdef CONFIG_PRINTK
160 static const char * const logtypes[] = {
161 "emergency",
162 "alert",
163 "critical",
164 "error",
165 "warning",
166 "notice",
167 "info",
168 "debug",
169 };
170
171
172 /*
173 * Use one ratelimit state per log level so that a flood of less important
174 * messages doesn't cause more important ones to be dropped.
175 */
176 static struct ratelimit_state printk_limits[] = {
177 RATELIMIT_STATE_INIT(printk_limits[0], DEFAULT_RATELIMIT_INTERVAL, 100),
178 RATELIMIT_STATE_INIT(printk_limits[1], DEFAULT_RATELIMIT_INTERVAL, 100),
179 RATELIMIT_STATE_INIT(printk_limits[2], DEFAULT_RATELIMIT_INTERVAL, 100),
180 RATELIMIT_STATE_INIT(printk_limits[3], DEFAULT_RATELIMIT_INTERVAL, 100),
181 RATELIMIT_STATE_INIT(printk_limits[4], DEFAULT_RATELIMIT_INTERVAL, 100),
182 RATELIMIT_STATE_INIT(printk_limits[5], DEFAULT_RATELIMIT_INTERVAL, 100),
183 RATELIMIT_STATE_INIT(printk_limits[6], DEFAULT_RATELIMIT_INTERVAL, 100),
184 RATELIMIT_STATE_INIT(printk_limits[7], DEFAULT_RATELIMIT_INTERVAL, 100),
185 };
186
187 void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
188 {
189 char lvl[PRINTK_MAX_SINGLE_HEADER_LEN + 1] = "\0";
190 struct va_format vaf;
191 va_list args;
192 int kern_level;
193 const char *type = logtypes[4];
194 struct ratelimit_state *ratelimit = &printk_limits[4];
195
196 va_start(args, fmt);
197
198 while ((kern_level = printk_get_level(fmt)) != 0) {
199 size_t size = printk_skip_level(fmt) - fmt;
200
201 if (kern_level >= '0' && kern_level <= '7') {
202 memcpy(lvl, fmt, size);
203 lvl[size] = '\0';
204 type = logtypes[kern_level - '0'];
205 ratelimit = &printk_limits[kern_level - '0'];
206 }
207 fmt += size;
208 }
209
210 vaf.fmt = fmt;
211 vaf.va = &args;
212
213 if (__ratelimit(ratelimit))
214 printk("%sBTRFS %s (device %s): %pV\n", lvl, type,
215 fs_info ? fs_info->sb->s_id : "<unknown>", &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
235 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
236 const char *function,
237 unsigned int line, int errno)
238 {
239 struct btrfs_fs_info *fs_info = trans->fs_info;
240
241 trans->aborted = errno;
242 /* Nothing used. The other threads that have joined this
243 * transaction may be able to continue. */
244 if (!trans->dirty && list_empty(&trans->new_bgs)) {
245 const char *errstr;
246
247 errstr = btrfs_decode_error(errno);
248 btrfs_warn(fs_info,
249 "%s:%d: Aborting unused transaction(%s).",
250 function, line, errstr);
251 return;
252 }
253 WRITE_ONCE(trans->transaction->aborted, errno);
254 /* Wake up anybody who may be waiting on this transaction */
255 wake_up(&fs_info->transaction_wait);
256 wake_up(&fs_info->transaction_blocked_wait);
257 __btrfs_handle_fs_error(fs_info, function, line, errno, NULL);
258 }
259 /*
260 * __btrfs_panic decodes unexpected, fatal errors from the caller,
261 * issues an alert, and either panics or BUGs, depending on mount options.
262 */
263 __cold
264 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
265 unsigned int line, int errno, const char *fmt, ...)
266 {
267 char *s_id = "<unknown>";
268 const char *errstr;
269 struct va_format vaf = { .fmt = fmt };
270 va_list args;
271
272 if (fs_info)
273 s_id = fs_info->sb->s_id;
274
275 va_start(args, fmt);
276 vaf.va = &args;
277
278 errstr = btrfs_decode_error(errno);
279 if (fs_info && (btrfs_test_opt(fs_info, PANIC_ON_FATAL_ERROR)))
280 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
281 s_id, function, line, &vaf, errno, errstr);
282
283 btrfs_crit(fs_info, "panic in %s:%d: %pV (errno=%d %s)",
284 function, line, &vaf, errno, errstr);
285 va_end(args);
286 /* Caller calls BUG() */
287 }
288
289 static void btrfs_put_super(struct super_block *sb)
290 {
291 close_ctree(btrfs_sb(sb));
292 }
293
294 enum {
295 Opt_acl, Opt_noacl,
296 Opt_clear_cache,
297 Opt_commit_interval,
298 Opt_compress,
299 Opt_compress_force,
300 Opt_compress_force_type,
301 Opt_compress_type,
302 Opt_degraded,
303 Opt_device,
304 Opt_fatal_errors,
305 Opt_flushoncommit, Opt_noflushoncommit,
306 Opt_inode_cache, Opt_noinode_cache,
307 Opt_max_inline,
308 Opt_barrier, Opt_nobarrier,
309 Opt_datacow, Opt_nodatacow,
310 Opt_datasum, Opt_nodatasum,
311 Opt_defrag, Opt_nodefrag,
312 Opt_discard, Opt_nodiscard,
313 Opt_nologreplay,
314 Opt_norecovery,
315 Opt_ratio,
316 Opt_rescan_uuid_tree,
317 Opt_skip_balance,
318 Opt_space_cache, Opt_no_space_cache,
319 Opt_space_cache_version,
320 Opt_ssd, Opt_nossd,
321 Opt_ssd_spread, Opt_nossd_spread,
322 Opt_subvol,
323 Opt_subvol_empty,
324 Opt_subvolid,
325 Opt_thread_pool,
326 Opt_treelog, Opt_notreelog,
327 Opt_usebackuproot,
328 Opt_user_subvol_rm_allowed,
329
330 /* Deprecated options */
331 Opt_alloc_start,
332 Opt_recovery,
333 Opt_subvolrootid,
334
335 /* Debugging options */
336 Opt_check_integrity,
337 Opt_check_integrity_including_extent_data,
338 Opt_check_integrity_print_mask,
339 Opt_enospc_debug, Opt_noenospc_debug,
340 #ifdef CONFIG_BTRFS_DEBUG
341 Opt_fragment_data, Opt_fragment_metadata, Opt_fragment_all,
342 #endif
343 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
344 Opt_ref_verify,
345 #endif
346 Opt_err,
347 };
348
349 static const match_table_t tokens = {
350 {Opt_acl, "acl"},
351 {Opt_noacl, "noacl"},
352 {Opt_clear_cache, "clear_cache"},
353 {Opt_commit_interval, "commit=%u"},
354 {Opt_compress, "compress"},
355 {Opt_compress_type, "compress=%s"},
356 {Opt_compress_force, "compress-force"},
357 {Opt_compress_force_type, "compress-force=%s"},
358 {Opt_degraded, "degraded"},
359 {Opt_device, "device=%s"},
360 {Opt_fatal_errors, "fatal_errors=%s"},
361 {Opt_flushoncommit, "flushoncommit"},
362 {Opt_noflushoncommit, "noflushoncommit"},
363 {Opt_inode_cache, "inode_cache"},
364 {Opt_noinode_cache, "noinode_cache"},
365 {Opt_max_inline, "max_inline=%s"},
366 {Opt_barrier, "barrier"},
367 {Opt_nobarrier, "nobarrier"},
368 {Opt_datacow, "datacow"},
369 {Opt_nodatacow, "nodatacow"},
370 {Opt_datasum, "datasum"},
371 {Opt_nodatasum, "nodatasum"},
372 {Opt_defrag, "autodefrag"},
373 {Opt_nodefrag, "noautodefrag"},
374 {Opt_discard, "discard"},
375 {Opt_nodiscard, "nodiscard"},
376 {Opt_nologreplay, "nologreplay"},
377 {Opt_norecovery, "norecovery"},
378 {Opt_ratio, "metadata_ratio=%u"},
379 {Opt_rescan_uuid_tree, "rescan_uuid_tree"},
380 {Opt_skip_balance, "skip_balance"},
381 {Opt_space_cache, "space_cache"},
382 {Opt_no_space_cache, "nospace_cache"},
383 {Opt_space_cache_version, "space_cache=%s"},
384 {Opt_ssd, "ssd"},
385 {Opt_nossd, "nossd"},
386 {Opt_ssd_spread, "ssd_spread"},
387 {Opt_nossd_spread, "nossd_spread"},
388 {Opt_subvol, "subvol=%s"},
389 {Opt_subvol_empty, "subvol="},
390 {Opt_subvolid, "subvolid=%s"},
391 {Opt_thread_pool, "thread_pool=%u"},
392 {Opt_treelog, "treelog"},
393 {Opt_notreelog, "notreelog"},
394 {Opt_usebackuproot, "usebackuproot"},
395 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
396
397 /* Deprecated options */
398 {Opt_alloc_start, "alloc_start=%s"},
399 {Opt_recovery, "recovery"},
400 {Opt_subvolrootid, "subvolrootid=%d"},
401
402 /* Debugging options */
403 {Opt_check_integrity, "check_int"},
404 {Opt_check_integrity_including_extent_data, "check_int_data"},
405 {Opt_check_integrity_print_mask, "check_int_print_mask=%u"},
406 {Opt_enospc_debug, "enospc_debug"},
407 {Opt_noenospc_debug, "noenospc_debug"},
408 #ifdef CONFIG_BTRFS_DEBUG
409 {Opt_fragment_data, "fragment=data"},
410 {Opt_fragment_metadata, "fragment=metadata"},
411 {Opt_fragment_all, "fragment=all"},
412 #endif
413 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
414 {Opt_ref_verify, "ref_verify"},
415 #endif
416 {Opt_err, NULL},
417 };
418
419 /*
420 * Regular mount options parser. Everything that is needed only when
421 * reading in a new superblock is parsed here.
422 * XXX JDM: This needs to be cleaned up for remount.
423 */
424 int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
425 unsigned long new_flags)
426 {
427 substring_t args[MAX_OPT_ARGS];
428 char *p, *num;
429 u64 cache_gen;
430 int intarg;
431 int ret = 0;
432 char *compress_type;
433 bool compress_force = false;
434 enum btrfs_compression_type saved_compress_type;
435 bool saved_compress_force;
436 int no_compress = 0;
437
438 cache_gen = btrfs_super_cache_generation(info->super_copy);
439 if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE))
440 btrfs_set_opt(info->mount_opt, FREE_SPACE_TREE);
441 else if (cache_gen)
442 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
443
444 /*
445 * Even the options are empty, we still need to do extra check
446 * against new flags
447 */
448 if (!options)
449 goto check;
450
451 while ((p = strsep(&options, ",")) != NULL) {
452 int token;
453 if (!*p)
454 continue;
455
456 token = match_token(p, tokens, args);
457 switch (token) {
458 case Opt_degraded:
459 btrfs_info(info, "allowing degraded mounts");
460 btrfs_set_opt(info->mount_opt, DEGRADED);
461 break;
462 case Opt_subvol:
463 case Opt_subvol_empty:
464 case Opt_subvolid:
465 case Opt_subvolrootid:
466 case Opt_device:
467 /*
468 * These are parsed by btrfs_parse_subvol_options or
469 * btrfs_parse_device_options and can be ignored here.
470 */
471 break;
472 case Opt_nodatasum:
473 btrfs_set_and_info(info, NODATASUM,
474 "setting nodatasum");
475 break;
476 case Opt_datasum:
477 if (btrfs_test_opt(info, NODATASUM)) {
478 if (btrfs_test_opt(info, NODATACOW))
479 btrfs_info(info,
480 "setting datasum, datacow enabled");
481 else
482 btrfs_info(info, "setting datasum");
483 }
484 btrfs_clear_opt(info->mount_opt, NODATACOW);
485 btrfs_clear_opt(info->mount_opt, NODATASUM);
486 break;
487 case Opt_nodatacow:
488 if (!btrfs_test_opt(info, NODATACOW)) {
489 if (!btrfs_test_opt(info, COMPRESS) ||
490 !btrfs_test_opt(info, FORCE_COMPRESS)) {
491 btrfs_info(info,
492 "setting nodatacow, compression disabled");
493 } else {
494 btrfs_info(info, "setting nodatacow");
495 }
496 }
497 btrfs_clear_opt(info->mount_opt, COMPRESS);
498 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
499 btrfs_set_opt(info->mount_opt, NODATACOW);
500 btrfs_set_opt(info->mount_opt, NODATASUM);
501 break;
502 case Opt_datacow:
503 btrfs_clear_and_info(info, NODATACOW,
504 "setting datacow");
505 break;
506 case Opt_compress_force:
507 case Opt_compress_force_type:
508 compress_force = true;
509 /* Fallthrough */
510 case Opt_compress:
511 case Opt_compress_type:
512 saved_compress_type = btrfs_test_opt(info,
513 COMPRESS) ?
514 info->compress_type : BTRFS_COMPRESS_NONE;
515 saved_compress_force =
516 btrfs_test_opt(info, FORCE_COMPRESS);
517 if (token == Opt_compress ||
518 token == Opt_compress_force ||
519 strncmp(args[0].from, "zlib", 4) == 0) {
520 compress_type = "zlib";
521
522 info->compress_type = BTRFS_COMPRESS_ZLIB;
523 info->compress_level = BTRFS_ZLIB_DEFAULT_LEVEL;
524 /*
525 * args[0] contains uninitialized data since
526 * for these tokens we don't expect any
527 * parameter.
528 */
529 if (token != Opt_compress &&
530 token != Opt_compress_force)
531 info->compress_level =
532 btrfs_compress_str2level(args[0].from);
533 btrfs_set_opt(info->mount_opt, COMPRESS);
534 btrfs_clear_opt(info->mount_opt, NODATACOW);
535 btrfs_clear_opt(info->mount_opt, NODATASUM);
536 no_compress = 0;
537 } else if (strncmp(args[0].from, "lzo", 3) == 0) {
538 compress_type = "lzo";
539 info->compress_type = BTRFS_COMPRESS_LZO;
540 btrfs_set_opt(info->mount_opt, COMPRESS);
541 btrfs_clear_opt(info->mount_opt, NODATACOW);
542 btrfs_clear_opt(info->mount_opt, NODATASUM);
543 btrfs_set_fs_incompat(info, COMPRESS_LZO);
544 no_compress = 0;
545 } else if (strcmp(args[0].from, "zstd") == 0) {
546 compress_type = "zstd";
547 info->compress_type = BTRFS_COMPRESS_ZSTD;
548 btrfs_set_opt(info->mount_opt, COMPRESS);
549 btrfs_clear_opt(info->mount_opt, NODATACOW);
550 btrfs_clear_opt(info->mount_opt, NODATASUM);
551 btrfs_set_fs_incompat(info, COMPRESS_ZSTD);
552 no_compress = 0;
553 } else if (strncmp(args[0].from, "no", 2) == 0) {
554 compress_type = "no";
555 btrfs_clear_opt(info->mount_opt, COMPRESS);
556 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
557 compress_force = false;
558 no_compress++;
559 } else {
560 ret = -EINVAL;
561 goto out;
562 }
563
564 if (compress_force) {
565 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
566 } else {
567 /*
568 * If we remount from compress-force=xxx to
569 * compress=xxx, we need clear FORCE_COMPRESS
570 * flag, otherwise, there is no way for users
571 * to disable forcible compression separately.
572 */
573 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
574 }
575 if ((btrfs_test_opt(info, COMPRESS) &&
576 (info->compress_type != saved_compress_type ||
577 compress_force != saved_compress_force)) ||
578 (!btrfs_test_opt(info, COMPRESS) &&
579 no_compress == 1)) {
580 btrfs_info(info, "%s %s compression, level %d",
581 (compress_force) ? "force" : "use",
582 compress_type, info->compress_level);
583 }
584 compress_force = false;
585 break;
586 case Opt_ssd:
587 btrfs_set_and_info(info, SSD,
588 "enabling ssd optimizations");
589 btrfs_clear_opt(info->mount_opt, NOSSD);
590 break;
591 case Opt_ssd_spread:
592 btrfs_set_and_info(info, SSD,
593 "enabling ssd optimizations");
594 btrfs_set_and_info(info, SSD_SPREAD,
595 "using spread ssd allocation scheme");
596 btrfs_clear_opt(info->mount_opt, NOSSD);
597 break;
598 case Opt_nossd:
599 btrfs_set_opt(info->mount_opt, NOSSD);
600 btrfs_clear_and_info(info, SSD,
601 "not using ssd optimizations");
602 /* Fallthrough */
603 case Opt_nossd_spread:
604 btrfs_clear_and_info(info, SSD_SPREAD,
605 "not using spread ssd allocation scheme");
606 break;
607 case Opt_barrier:
608 btrfs_clear_and_info(info, NOBARRIER,
609 "turning on barriers");
610 break;
611 case Opt_nobarrier:
612 btrfs_set_and_info(info, NOBARRIER,
613 "turning off barriers");
614 break;
615 case Opt_thread_pool:
616 ret = match_int(&args[0], &intarg);
617 if (ret) {
618 goto out;
619 } else if (intarg == 0) {
620 ret = -EINVAL;
621 goto out;
622 }
623 info->thread_pool_size = intarg;
624 break;
625 case Opt_max_inline:
626 num = match_strdup(&args[0]);
627 if (num) {
628 info->max_inline = memparse(num, NULL);
629 kfree(num);
630
631 if (info->max_inline) {
632 info->max_inline = min_t(u64,
633 info->max_inline,
634 info->sectorsize);
635 }
636 btrfs_info(info, "max_inline at %llu",
637 info->max_inline);
638 } else {
639 ret = -ENOMEM;
640 goto out;
641 }
642 break;
643 case Opt_alloc_start:
644 btrfs_info(info,
645 "option alloc_start is obsolete, ignored");
646 break;
647 case Opt_acl:
648 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
649 info->sb->s_flags |= SB_POSIXACL;
650 break;
651 #else
652 btrfs_err(info, "support for ACL not compiled in!");
653 ret = -EINVAL;
654 goto out;
655 #endif
656 case Opt_noacl:
657 info->sb->s_flags &= ~SB_POSIXACL;
658 break;
659 case Opt_notreelog:
660 btrfs_set_and_info(info, NOTREELOG,
661 "disabling tree log");
662 break;
663 case Opt_treelog:
664 btrfs_clear_and_info(info, NOTREELOG,
665 "enabling tree log");
666 break;
667 case Opt_norecovery:
668 case Opt_nologreplay:
669 btrfs_set_and_info(info, NOLOGREPLAY,
670 "disabling log replay at mount time");
671 break;
672 case Opt_flushoncommit:
673 btrfs_set_and_info(info, FLUSHONCOMMIT,
674 "turning on flush-on-commit");
675 break;
676 case Opt_noflushoncommit:
677 btrfs_clear_and_info(info, FLUSHONCOMMIT,
678 "turning off flush-on-commit");
679 break;
680 case Opt_ratio:
681 ret = match_int(&args[0], &intarg);
682 if (ret)
683 goto out;
684 info->metadata_ratio = intarg;
685 btrfs_info(info, "metadata ratio %u",
686 info->metadata_ratio);
687 break;
688 case Opt_discard:
689 btrfs_set_and_info(info, DISCARD,
690 "turning on discard");
691 break;
692 case Opt_nodiscard:
693 btrfs_clear_and_info(info, DISCARD,
694 "turning off discard");
695 break;
696 case Opt_space_cache:
697 case Opt_space_cache_version:
698 if (token == Opt_space_cache ||
699 strcmp(args[0].from, "v1") == 0) {
700 btrfs_clear_opt(info->mount_opt,
701 FREE_SPACE_TREE);
702 btrfs_set_and_info(info, SPACE_CACHE,
703 "enabling disk space caching");
704 } else if (strcmp(args[0].from, "v2") == 0) {
705 btrfs_clear_opt(info->mount_opt,
706 SPACE_CACHE);
707 btrfs_set_and_info(info, FREE_SPACE_TREE,
708 "enabling free space tree");
709 } else {
710 ret = -EINVAL;
711 goto out;
712 }
713 break;
714 case Opt_rescan_uuid_tree:
715 btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE);
716 break;
717 case Opt_no_space_cache:
718 if (btrfs_test_opt(info, SPACE_CACHE)) {
719 btrfs_clear_and_info(info, SPACE_CACHE,
720 "disabling disk space caching");
721 }
722 if (btrfs_test_opt(info, FREE_SPACE_TREE)) {
723 btrfs_clear_and_info(info, FREE_SPACE_TREE,
724 "disabling free space tree");
725 }
726 break;
727 case Opt_inode_cache:
728 btrfs_set_pending_and_info(info, INODE_MAP_CACHE,
729 "enabling inode map caching");
730 break;
731 case Opt_noinode_cache:
732 btrfs_clear_pending_and_info(info, INODE_MAP_CACHE,
733 "disabling inode map caching");
734 break;
735 case Opt_clear_cache:
736 btrfs_set_and_info(info, CLEAR_CACHE,
737 "force clearing of disk cache");
738 break;
739 case Opt_user_subvol_rm_allowed:
740 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
741 break;
742 case Opt_enospc_debug:
743 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
744 break;
745 case Opt_noenospc_debug:
746 btrfs_clear_opt(info->mount_opt, ENOSPC_DEBUG);
747 break;
748 case Opt_defrag:
749 btrfs_set_and_info(info, AUTO_DEFRAG,
750 "enabling auto defrag");
751 break;
752 case Opt_nodefrag:
753 btrfs_clear_and_info(info, AUTO_DEFRAG,
754 "disabling auto defrag");
755 break;
756 case Opt_recovery:
757 btrfs_warn(info,
758 "'recovery' is deprecated, use 'usebackuproot' instead");
759 /* fall through */
760 case Opt_usebackuproot:
761 btrfs_info(info,
762 "trying to use backup root at mount time");
763 btrfs_set_opt(info->mount_opt, USEBACKUPROOT);
764 break;
765 case Opt_skip_balance:
766 btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
767 break;
768 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
769 case Opt_check_integrity_including_extent_data:
770 btrfs_info(info,
771 "enabling check integrity including extent data");
772 btrfs_set_opt(info->mount_opt,
773 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
774 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
775 break;
776 case Opt_check_integrity:
777 btrfs_info(info, "enabling check integrity");
778 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
779 break;
780 case Opt_check_integrity_print_mask:
781 ret = match_int(&args[0], &intarg);
782 if (ret)
783 goto out;
784 info->check_integrity_print_mask = intarg;
785 btrfs_info(info, "check_integrity_print_mask 0x%x",
786 info->check_integrity_print_mask);
787 break;
788 #else
789 case Opt_check_integrity_including_extent_data:
790 case Opt_check_integrity:
791 case Opt_check_integrity_print_mask:
792 btrfs_err(info,
793 "support for check_integrity* not compiled in!");
794 ret = -EINVAL;
795 goto out;
796 #endif
797 case Opt_fatal_errors:
798 if (strcmp(args[0].from, "panic") == 0)
799 btrfs_set_opt(info->mount_opt,
800 PANIC_ON_FATAL_ERROR);
801 else if (strcmp(args[0].from, "bug") == 0)
802 btrfs_clear_opt(info->mount_opt,
803 PANIC_ON_FATAL_ERROR);
804 else {
805 ret = -EINVAL;
806 goto out;
807 }
808 break;
809 case Opt_commit_interval:
810 intarg = 0;
811 ret = match_int(&args[0], &intarg);
812 if (ret)
813 goto out;
814 if (intarg == 0) {
815 btrfs_info(info,
816 "using default commit interval %us",
817 BTRFS_DEFAULT_COMMIT_INTERVAL);
818 intarg = BTRFS_DEFAULT_COMMIT_INTERVAL;
819 } else if (intarg > 300) {
820 btrfs_warn(info, "excessive commit interval %d",
821 intarg);
822 }
823 info->commit_interval = intarg;
824 break;
825 #ifdef CONFIG_BTRFS_DEBUG
826 case Opt_fragment_all:
827 btrfs_info(info, "fragmenting all space");
828 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA);
829 btrfs_set_opt(info->mount_opt, FRAGMENT_METADATA);
830 break;
831 case Opt_fragment_metadata:
832 btrfs_info(info, "fragmenting metadata");
833 btrfs_set_opt(info->mount_opt,
834 FRAGMENT_METADATA);
835 break;
836 case Opt_fragment_data:
837 btrfs_info(info, "fragmenting data");
838 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA);
839 break;
840 #endif
841 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
842 case Opt_ref_verify:
843 btrfs_info(info, "doing ref verification");
844 btrfs_set_opt(info->mount_opt, REF_VERIFY);
845 break;
846 #endif
847 case Opt_err:
848 btrfs_info(info, "unrecognized mount option '%s'", p);
849 ret = -EINVAL;
850 goto out;
851 default:
852 break;
853 }
854 }
855 check:
856 /*
857 * Extra check for current option against current flag
858 */
859 if (btrfs_test_opt(info, NOLOGREPLAY) && !(new_flags & SB_RDONLY)) {
860 btrfs_err(info,
861 "nologreplay must be used with ro mount option");
862 ret = -EINVAL;
863 }
864 out:
865 if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE) &&
866 !btrfs_test_opt(info, FREE_SPACE_TREE) &&
867 !btrfs_test_opt(info, CLEAR_CACHE)) {
868 btrfs_err(info, "cannot disable free space tree");
869 ret = -EINVAL;
870
871 }
872 if (!ret && btrfs_test_opt(info, SPACE_CACHE))
873 btrfs_info(info, "disk space caching is enabled");
874 if (!ret && btrfs_test_opt(info, FREE_SPACE_TREE))
875 btrfs_info(info, "using free space tree");
876 return ret;
877 }
878
879 /*
880 * Parse mount options that are required early in the mount process.
881 *
882 * All other options will be parsed on much later in the mount process and
883 * only when we need to allocate a new super block.
884 */
885 static int btrfs_parse_device_options(const char *options, fmode_t flags,
886 void *holder)
887 {
888 substring_t args[MAX_OPT_ARGS];
889 char *device_name, *opts, *orig, *p;
890 struct btrfs_device *device = NULL;
891 int error = 0;
892
893 lockdep_assert_held(&uuid_mutex);
894
895 if (!options)
896 return 0;
897
898 /*
899 * strsep changes the string, duplicate it because btrfs_parse_options
900 * gets called later
901 */
902 opts = kstrdup(options, GFP_KERNEL);
903 if (!opts)
904 return -ENOMEM;
905 orig = opts;
906
907 while ((p = strsep(&opts, ",")) != NULL) {
908 int token;
909
910 if (!*p)
911 continue;
912
913 token = match_token(p, tokens, args);
914 if (token == Opt_device) {
915 device_name = match_strdup(&args[0]);
916 if (!device_name) {
917 error = -ENOMEM;
918 goto out;
919 }
920 device = btrfs_scan_one_device(device_name, flags,
921 holder);
922 kfree(device_name);
923 if (IS_ERR(device)) {
924 error = PTR_ERR(device);
925 goto out;
926 }
927 }
928 }
929
930 out:
931 kfree(orig);
932 return error;
933 }
934
935 /*
936 * Parse mount options that are related to subvolume id
937 *
938 * The value is later passed to mount_subvol()
939 */
940 static int btrfs_parse_subvol_options(const char *options, char **subvol_name,
941 u64 *subvol_objectid)
942 {
943 substring_t args[MAX_OPT_ARGS];
944 char *opts, *orig, *p;
945 int error = 0;
946 u64 subvolid;
947
948 if (!options)
949 return 0;
950
951 /*
952 * strsep changes the string, duplicate it because
953 * btrfs_parse_device_options gets called later
954 */
955 opts = kstrdup(options, GFP_KERNEL);
956 if (!opts)
957 return -ENOMEM;
958 orig = opts;
959
960 while ((p = strsep(&opts, ",")) != NULL) {
961 int token;
962 if (!*p)
963 continue;
964
965 token = match_token(p, tokens, args);
966 switch (token) {
967 case Opt_subvol:
968 kfree(*subvol_name);
969 *subvol_name = match_strdup(&args[0]);
970 if (!*subvol_name) {
971 error = -ENOMEM;
972 goto out;
973 }
974 break;
975 case Opt_subvolid:
976 error = match_u64(&args[0], &subvolid);
977 if (error)
978 goto out;
979
980 /* we want the original fs_tree */
981 if (subvolid == 0)
982 subvolid = BTRFS_FS_TREE_OBJECTID;
983
984 *subvol_objectid = subvolid;
985 break;
986 case Opt_subvolrootid:
987 pr_warn("BTRFS: 'subvolrootid' mount option is deprecated and has no effect\n");
988 break;
989 default:
990 break;
991 }
992 }
993
994 out:
995 kfree(orig);
996 return error;
997 }
998
999 static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info,
1000 u64 subvol_objectid)
1001 {
1002 struct btrfs_root *root = fs_info->tree_root;
1003 struct btrfs_root *fs_root;
1004 struct btrfs_root_ref *root_ref;
1005 struct btrfs_inode_ref *inode_ref;
1006 struct btrfs_key key;
1007 struct btrfs_path *path = NULL;
1008 char *name = NULL, *ptr;
1009 u64 dirid;
1010 int len;
1011 int ret;
1012
1013 path = btrfs_alloc_path();
1014 if (!path) {
1015 ret = -ENOMEM;
1016 goto err;
1017 }
1018 path->leave_spinning = 1;
1019
1020 name = kmalloc(PATH_MAX, GFP_KERNEL);
1021 if (!name) {
1022 ret = -ENOMEM;
1023 goto err;
1024 }
1025 ptr = name + PATH_MAX - 1;
1026 ptr[0] = '\0';
1027
1028 /*
1029 * Walk up the subvolume trees in the tree of tree roots by root
1030 * backrefs until we hit the top-level subvolume.
1031 */
1032 while (subvol_objectid != BTRFS_FS_TREE_OBJECTID) {
1033 key.objectid = subvol_objectid;
1034 key.type = BTRFS_ROOT_BACKREF_KEY;
1035 key.offset = (u64)-1;
1036
1037 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1038 if (ret < 0) {
1039 goto err;
1040 } else if (ret > 0) {
1041 ret = btrfs_previous_item(root, path, subvol_objectid,
1042 BTRFS_ROOT_BACKREF_KEY);
1043 if (ret < 0) {
1044 goto err;
1045 } else if (ret > 0) {
1046 ret = -ENOENT;
1047 goto err;
1048 }
1049 }
1050
1051 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1052 subvol_objectid = key.offset;
1053
1054 root_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
1055 struct btrfs_root_ref);
1056 len = btrfs_root_ref_name_len(path->nodes[0], root_ref);
1057 ptr -= len + 1;
1058 if (ptr < name) {
1059 ret = -ENAMETOOLONG;
1060 goto err;
1061 }
1062 read_extent_buffer(path->nodes[0], ptr + 1,
1063 (unsigned long)(root_ref + 1), len);
1064 ptr[0] = '/';
1065 dirid = btrfs_root_ref_dirid(path->nodes[0], root_ref);
1066 btrfs_release_path(path);
1067
1068 key.objectid = subvol_objectid;
1069 key.type = BTRFS_ROOT_ITEM_KEY;
1070 key.offset = (u64)-1;
1071 fs_root = btrfs_read_fs_root_no_name(fs_info, &key);
1072 if (IS_ERR(fs_root)) {
1073 ret = PTR_ERR(fs_root);
1074 goto err;
1075 }
1076
1077 /*
1078 * Walk up the filesystem tree by inode refs until we hit the
1079 * root directory.
1080 */
1081 while (dirid != BTRFS_FIRST_FREE_OBJECTID) {
1082 key.objectid = dirid;
1083 key.type = BTRFS_INODE_REF_KEY;
1084 key.offset = (u64)-1;
1085
1086 ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0);
1087 if (ret < 0) {
1088 goto err;
1089 } else if (ret > 0) {
1090 ret = btrfs_previous_item(fs_root, path, dirid,
1091 BTRFS_INODE_REF_KEY);
1092 if (ret < 0) {
1093 goto err;
1094 } else if (ret > 0) {
1095 ret = -ENOENT;
1096 goto err;
1097 }
1098 }
1099
1100 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1101 dirid = key.offset;
1102
1103 inode_ref = btrfs_item_ptr(path->nodes[0],
1104 path->slots[0],
1105 struct btrfs_inode_ref);
1106 len = btrfs_inode_ref_name_len(path->nodes[0],
1107 inode_ref);
1108 ptr -= len + 1;
1109 if (ptr < name) {
1110 ret = -ENAMETOOLONG;
1111 goto err;
1112 }
1113 read_extent_buffer(path->nodes[0], ptr + 1,
1114 (unsigned long)(inode_ref + 1), len);
1115 ptr[0] = '/';
1116 btrfs_release_path(path);
1117 }
1118 }
1119
1120 btrfs_free_path(path);
1121 if (ptr == name + PATH_MAX - 1) {
1122 name[0] = '/';
1123 name[1] = '\0';
1124 } else {
1125 memmove(name, ptr, name + PATH_MAX - ptr);
1126 }
1127 return name;
1128
1129 err:
1130 btrfs_free_path(path);
1131 kfree(name);
1132 return ERR_PTR(ret);
1133 }
1134
1135 static int get_default_subvol_objectid(struct btrfs_fs_info *fs_info, u64 *objectid)
1136 {
1137 struct btrfs_root *root = fs_info->tree_root;
1138 struct btrfs_dir_item *di;
1139 struct btrfs_path *path;
1140 struct btrfs_key location;
1141 u64 dir_id;
1142
1143 path = btrfs_alloc_path();
1144 if (!path)
1145 return -ENOMEM;
1146 path->leave_spinning = 1;
1147
1148 /*
1149 * Find the "default" dir item which points to the root item that we
1150 * will mount by default if we haven't been given a specific subvolume
1151 * to mount.
1152 */
1153 dir_id = btrfs_super_root_dir(fs_info->super_copy);
1154 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
1155 if (IS_ERR(di)) {
1156 btrfs_free_path(path);
1157 return PTR_ERR(di);
1158 }
1159 if (!di) {
1160 /*
1161 * Ok the default dir item isn't there. This is weird since
1162 * it's always been there, but don't freak out, just try and
1163 * mount the top-level subvolume.
1164 */
1165 btrfs_free_path(path);
1166 *objectid = BTRFS_FS_TREE_OBJECTID;
1167 return 0;
1168 }
1169
1170 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
1171 btrfs_free_path(path);
1172 *objectid = location.objectid;
1173 return 0;
1174 }
1175
1176 static int btrfs_fill_super(struct super_block *sb,
1177 struct btrfs_fs_devices *fs_devices,
1178 void *data)
1179 {
1180 struct inode *inode;
1181 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1182 struct btrfs_key key;
1183 int err;
1184
1185 sb->s_maxbytes = MAX_LFS_FILESIZE;
1186 sb->s_magic = BTRFS_SUPER_MAGIC;
1187 sb->s_op = &btrfs_super_ops;
1188 sb->s_d_op = &btrfs_dentry_operations;
1189 sb->s_export_op = &btrfs_export_ops;
1190 sb->s_xattr = btrfs_xattr_handlers;
1191 sb->s_time_gran = 1;
1192 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
1193 sb->s_flags |= SB_POSIXACL;
1194 #endif
1195 sb->s_flags |= SB_I_VERSION;
1196 sb->s_iflags |= SB_I_CGROUPWB;
1197
1198 err = super_setup_bdi(sb);
1199 if (err) {
1200 btrfs_err(fs_info, "super_setup_bdi failed");
1201 return err;
1202 }
1203
1204 err = open_ctree(sb, fs_devices, (char *)data);
1205 if (err) {
1206 btrfs_err(fs_info, "open_ctree failed");
1207 return err;
1208 }
1209
1210 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
1211 key.type = BTRFS_INODE_ITEM_KEY;
1212 key.offset = 0;
1213 inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
1214 if (IS_ERR(inode)) {
1215 err = PTR_ERR(inode);
1216 goto fail_close;
1217 }
1218
1219 sb->s_root = d_make_root(inode);
1220 if (!sb->s_root) {
1221 err = -ENOMEM;
1222 goto fail_close;
1223 }
1224
1225 cleancache_init_fs(sb);
1226 sb->s_flags |= SB_ACTIVE;
1227 return 0;
1228
1229 fail_close:
1230 close_ctree(fs_info);
1231 return err;
1232 }
1233
1234 int btrfs_sync_fs(struct super_block *sb, int wait)
1235 {
1236 struct btrfs_trans_handle *trans;
1237 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1238 struct btrfs_root *root = fs_info->tree_root;
1239
1240 trace_btrfs_sync_fs(fs_info, wait);
1241
1242 if (!wait) {
1243 filemap_flush(fs_info->btree_inode->i_mapping);
1244 return 0;
1245 }
1246
1247 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
1248
1249 trans = btrfs_attach_transaction_barrier(root);
1250 if (IS_ERR(trans)) {
1251 /* no transaction, don't bother */
1252 if (PTR_ERR(trans) == -ENOENT) {
1253 /*
1254 * Exit unless we have some pending changes
1255 * that need to go through commit
1256 */
1257 if (fs_info->pending_changes == 0)
1258 return 0;
1259 /*
1260 * A non-blocking test if the fs is frozen. We must not
1261 * start a new transaction here otherwise a deadlock
1262 * happens. The pending operations are delayed to the
1263 * next commit after thawing.
1264 */
1265 if (sb_start_write_trylock(sb))
1266 sb_end_write(sb);
1267 else
1268 return 0;
1269 trans = btrfs_start_transaction(root, 0);
1270 }
1271 if (IS_ERR(trans))
1272 return PTR_ERR(trans);
1273 }
1274 return btrfs_commit_transaction(trans);
1275 }
1276
1277 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
1278 {
1279 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
1280 const char *compress_type;
1281
1282 if (btrfs_test_opt(info, DEGRADED))
1283 seq_puts(seq, ",degraded");
1284 if (btrfs_test_opt(info, NODATASUM))
1285 seq_puts(seq, ",nodatasum");
1286 if (btrfs_test_opt(info, NODATACOW))
1287 seq_puts(seq, ",nodatacow");
1288 if (btrfs_test_opt(info, NOBARRIER))
1289 seq_puts(seq, ",nobarrier");
1290 if (info->max_inline != BTRFS_DEFAULT_MAX_INLINE)
1291 seq_printf(seq, ",max_inline=%llu", info->max_inline);
1292 if (info->thread_pool_size != min_t(unsigned long,
1293 num_online_cpus() + 2, 8))
1294 seq_printf(seq, ",thread_pool=%u", info->thread_pool_size);
1295 if (btrfs_test_opt(info, COMPRESS)) {
1296 compress_type = btrfs_compress_type2str(info->compress_type);
1297 if (btrfs_test_opt(info, FORCE_COMPRESS))
1298 seq_printf(seq, ",compress-force=%s", compress_type);
1299 else
1300 seq_printf(seq, ",compress=%s", compress_type);
1301 if (info->compress_level)
1302 seq_printf(seq, ":%d", info->compress_level);
1303 }
1304 if (btrfs_test_opt(info, NOSSD))
1305 seq_puts(seq, ",nossd");
1306 if (btrfs_test_opt(info, SSD_SPREAD))
1307 seq_puts(seq, ",ssd_spread");
1308 else if (btrfs_test_opt(info, SSD))
1309 seq_puts(seq, ",ssd");
1310 if (btrfs_test_opt(info, NOTREELOG))
1311 seq_puts(seq, ",notreelog");
1312 if (btrfs_test_opt(info, NOLOGREPLAY))
1313 seq_puts(seq, ",nologreplay");
1314 if (btrfs_test_opt(info, FLUSHONCOMMIT))
1315 seq_puts(seq, ",flushoncommit");
1316 if (btrfs_test_opt(info, DISCARD))
1317 seq_puts(seq, ",discard");
1318 if (!(info->sb->s_flags & SB_POSIXACL))
1319 seq_puts(seq, ",noacl");
1320 if (btrfs_test_opt(info, SPACE_CACHE))
1321 seq_puts(seq, ",space_cache");
1322 else if (btrfs_test_opt(info, FREE_SPACE_TREE))
1323 seq_puts(seq, ",space_cache=v2");
1324 else
1325 seq_puts(seq, ",nospace_cache");
1326 if (btrfs_test_opt(info, RESCAN_UUID_TREE))
1327 seq_puts(seq, ",rescan_uuid_tree");
1328 if (btrfs_test_opt(info, CLEAR_CACHE))
1329 seq_puts(seq, ",clear_cache");
1330 if (btrfs_test_opt(info, USER_SUBVOL_RM_ALLOWED))
1331 seq_puts(seq, ",user_subvol_rm_allowed");
1332 if (btrfs_test_opt(info, ENOSPC_DEBUG))
1333 seq_puts(seq, ",enospc_debug");
1334 if (btrfs_test_opt(info, AUTO_DEFRAG))
1335 seq_puts(seq, ",autodefrag");
1336 if (btrfs_test_opt(info, INODE_MAP_CACHE))
1337 seq_puts(seq, ",inode_cache");
1338 if (btrfs_test_opt(info, SKIP_BALANCE))
1339 seq_puts(seq, ",skip_balance");
1340 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1341 if (btrfs_test_opt(info, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA))
1342 seq_puts(seq, ",check_int_data");
1343 else if (btrfs_test_opt(info, CHECK_INTEGRITY))
1344 seq_puts(seq, ",check_int");
1345 if (info->check_integrity_print_mask)
1346 seq_printf(seq, ",check_int_print_mask=%d",
1347 info->check_integrity_print_mask);
1348 #endif
1349 if (info->metadata_ratio)
1350 seq_printf(seq, ",metadata_ratio=%u", info->metadata_ratio);
1351 if (btrfs_test_opt(info, PANIC_ON_FATAL_ERROR))
1352 seq_puts(seq, ",fatal_errors=panic");
1353 if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL)
1354 seq_printf(seq, ",commit=%u", info->commit_interval);
1355 #ifdef CONFIG_BTRFS_DEBUG
1356 if (btrfs_test_opt(info, FRAGMENT_DATA))
1357 seq_puts(seq, ",fragment=data");
1358 if (btrfs_test_opt(info, FRAGMENT_METADATA))
1359 seq_puts(seq, ",fragment=metadata");
1360 #endif
1361 if (btrfs_test_opt(info, REF_VERIFY))
1362 seq_puts(seq, ",ref_verify");
1363 seq_printf(seq, ",subvolid=%llu",
1364 BTRFS_I(d_inode(dentry))->root->root_key.objectid);
1365 seq_puts(seq, ",subvol=");
1366 seq_dentry(seq, dentry, " \t\n\\");
1367 return 0;
1368 }
1369
1370 static int btrfs_test_super(struct super_block *s, void *data)
1371 {
1372 struct btrfs_fs_info *p = data;
1373 struct btrfs_fs_info *fs_info = btrfs_sb(s);
1374
1375 return fs_info->fs_devices == p->fs_devices;
1376 }
1377
1378 static int btrfs_set_super(struct super_block *s, void *data)
1379 {
1380 int err = set_anon_super(s, data);
1381 if (!err)
1382 s->s_fs_info = data;
1383 return err;
1384 }
1385
1386 /*
1387 * subvolumes are identified by ino 256
1388 */
1389 static inline int is_subvolume_inode(struct inode *inode)
1390 {
1391 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
1392 return 1;
1393 return 0;
1394 }
1395
1396 static struct dentry *mount_subvol(const char *subvol_name, u64 subvol_objectid,
1397 const char *device_name, struct vfsmount *mnt)
1398 {
1399 struct dentry *root;
1400 int ret;
1401
1402 if (!subvol_name) {
1403 if (!subvol_objectid) {
1404 ret = get_default_subvol_objectid(btrfs_sb(mnt->mnt_sb),
1405 &subvol_objectid);
1406 if (ret) {
1407 root = ERR_PTR(ret);
1408 goto out;
1409 }
1410 }
1411 subvol_name = get_subvol_name_from_objectid(btrfs_sb(mnt->mnt_sb),
1412 subvol_objectid);
1413 if (IS_ERR(subvol_name)) {
1414 root = ERR_CAST(subvol_name);
1415 subvol_name = NULL;
1416 goto out;
1417 }
1418
1419 }
1420
1421 root = mount_subtree(mnt, subvol_name);
1422 /* mount_subtree() drops our reference on the vfsmount. */
1423 mnt = NULL;
1424
1425 if (!IS_ERR(root)) {
1426 struct super_block *s = root->d_sb;
1427 struct btrfs_fs_info *fs_info = btrfs_sb(s);
1428 struct inode *root_inode = d_inode(root);
1429 u64 root_objectid = BTRFS_I(root_inode)->root->root_key.objectid;
1430
1431 ret = 0;
1432 if (!is_subvolume_inode(root_inode)) {
1433 btrfs_err(fs_info, "'%s' is not a valid subvolume",
1434 subvol_name);
1435 ret = -EINVAL;
1436 }
1437 if (subvol_objectid && root_objectid != subvol_objectid) {
1438 /*
1439 * This will also catch a race condition where a
1440 * subvolume which was passed by ID is renamed and
1441 * another subvolume is renamed over the old location.
1442 */
1443 btrfs_err(fs_info,
1444 "subvol '%s' does not match subvolid %llu",
1445 subvol_name, subvol_objectid);
1446 ret = -EINVAL;
1447 }
1448 if (ret) {
1449 dput(root);
1450 root = ERR_PTR(ret);
1451 deactivate_locked_super(s);
1452 }
1453 }
1454
1455 out:
1456 mntput(mnt);
1457 kfree(subvol_name);
1458 return root;
1459 }
1460
1461 /*
1462 * Find a superblock for the given device / mount point.
1463 *
1464 * Note: This is based on mount_bdev from fs/super.c with a few additions
1465 * for multiple device setup. Make sure to keep it in sync.
1466 */
1467 static struct dentry *btrfs_mount_root(struct file_system_type *fs_type,
1468 int flags, const char *device_name, void *data)
1469 {
1470 struct block_device *bdev = NULL;
1471 struct super_block *s;
1472 struct btrfs_device *device = NULL;
1473 struct btrfs_fs_devices *fs_devices = NULL;
1474 struct btrfs_fs_info *fs_info = NULL;
1475 void *new_sec_opts = NULL;
1476 fmode_t mode = FMODE_READ;
1477 int error = 0;
1478
1479 if (!(flags & SB_RDONLY))
1480 mode |= FMODE_WRITE;
1481
1482 if (data) {
1483 error = security_sb_eat_lsm_opts(data, &new_sec_opts);
1484 if (error)
1485 return ERR_PTR(error);
1486 }
1487
1488 /*
1489 * Setup a dummy root and fs_info for test/set super. This is because
1490 * we don't actually fill this stuff out until open_ctree, but we need
1491 * it for searching for existing supers, so this lets us do that and
1492 * then open_ctree will properly initialize everything later.
1493 */
1494 fs_info = kvzalloc(sizeof(struct btrfs_fs_info), GFP_KERNEL);
1495 if (!fs_info) {
1496 error = -ENOMEM;
1497 goto error_sec_opts;
1498 }
1499
1500 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL);
1501 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL);
1502 if (!fs_info->super_copy || !fs_info->super_for_commit) {
1503 error = -ENOMEM;
1504 goto error_fs_info;
1505 }
1506
1507 mutex_lock(&uuid_mutex);
1508 error = btrfs_parse_device_options(data, mode, fs_type);
1509 if (error) {
1510 mutex_unlock(&uuid_mutex);
1511 goto error_fs_info;
1512 }
1513
1514 device = btrfs_scan_one_device(device_name, mode, fs_type);
1515 if (IS_ERR(device)) {
1516 mutex_unlock(&uuid_mutex);
1517 error = PTR_ERR(device);
1518 goto error_fs_info;
1519 }
1520
1521 fs_devices = device->fs_devices;
1522 fs_info->fs_devices = fs_devices;
1523
1524 error = btrfs_open_devices(fs_devices, mode, fs_type);
1525 mutex_unlock(&uuid_mutex);
1526 if (error)
1527 goto error_fs_info;
1528
1529 if (!(flags & SB_RDONLY) && fs_devices->rw_devices == 0) {
1530 error = -EACCES;
1531 goto error_close_devices;
1532 }
1533
1534 bdev = fs_devices->latest_bdev;
1535 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | SB_NOSEC,
1536 fs_info);
1537 if (IS_ERR(s)) {
1538 error = PTR_ERR(s);
1539 goto error_close_devices;
1540 }
1541
1542 if (s->s_root) {
1543 btrfs_close_devices(fs_devices);
1544 free_fs_info(fs_info);
1545 if ((flags ^ s->s_flags) & SB_RDONLY)
1546 error = -EBUSY;
1547 } else {
1548 snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev);
1549 btrfs_sb(s)->bdev_holder = fs_type;
1550 error = btrfs_fill_super(s, fs_devices, data);
1551 }
1552 if (!error)
1553 error = security_sb_set_mnt_opts(s, new_sec_opts, 0, NULL);
1554 security_free_mnt_opts(&new_sec_opts);
1555 if (error) {
1556 deactivate_locked_super(s);
1557 return ERR_PTR(error);
1558 }
1559
1560 return dget(s->s_root);
1561
1562 error_close_devices:
1563 btrfs_close_devices(fs_devices);
1564 error_fs_info:
1565 free_fs_info(fs_info);
1566 error_sec_opts:
1567 security_free_mnt_opts(&new_sec_opts);
1568 return ERR_PTR(error);
1569 }
1570
1571 /*
1572 * Mount function which is called by VFS layer.
1573 *
1574 * In order to allow mounting a subvolume directly, btrfs uses mount_subtree()
1575 * which needs vfsmount* of device's root (/). This means device's root has to
1576 * be mounted internally in any case.
1577 *
1578 * Operation flow:
1579 * 1. Parse subvol id related options for later use in mount_subvol().
1580 *
1581 * 2. Mount device's root (/) by calling vfs_kern_mount().
1582 *
1583 * NOTE: vfs_kern_mount() is used by VFS to call btrfs_mount() in the
1584 * first place. In order to avoid calling btrfs_mount() again, we use
1585 * different file_system_type which is not registered to VFS by
1586 * register_filesystem() (btrfs_root_fs_type). As a result,
1587 * btrfs_mount_root() is called. The return value will be used by
1588 * mount_subtree() in mount_subvol().
1589 *
1590 * 3. Call mount_subvol() to get the dentry of subvolume. Since there is
1591 * "btrfs subvolume set-default", mount_subvol() is called always.
1592 */
1593 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1594 const char *device_name, void *data)
1595 {
1596 struct vfsmount *mnt_root;
1597 struct dentry *root;
1598 fmode_t mode = FMODE_READ;
1599 char *subvol_name = NULL;
1600 u64 subvol_objectid = 0;
1601 int error = 0;
1602
1603 if (!(flags & SB_RDONLY))
1604 mode |= FMODE_WRITE;
1605
1606 error = btrfs_parse_subvol_options(data, &subvol_name,
1607 &subvol_objectid);
1608 if (error) {
1609 kfree(subvol_name);
1610 return ERR_PTR(error);
1611 }
1612
1613 /* mount device's root (/) */
1614 mnt_root = vfs_kern_mount(&btrfs_root_fs_type, flags, device_name, data);
1615 if (PTR_ERR_OR_ZERO(mnt_root) == -EBUSY) {
1616 if (flags & SB_RDONLY) {
1617 mnt_root = vfs_kern_mount(&btrfs_root_fs_type,
1618 flags & ~SB_RDONLY, device_name, data);
1619 } else {
1620 mnt_root = vfs_kern_mount(&btrfs_root_fs_type,
1621 flags | SB_RDONLY, device_name, data);
1622 if (IS_ERR(mnt_root)) {
1623 root = ERR_CAST(mnt_root);
1624 kfree(subvol_name);
1625 goto out;
1626 }
1627
1628 down_write(&mnt_root->mnt_sb->s_umount);
1629 error = btrfs_remount(mnt_root->mnt_sb, &flags, NULL);
1630 up_write(&mnt_root->mnt_sb->s_umount);
1631 if (error < 0) {
1632 root = ERR_PTR(error);
1633 mntput(mnt_root);
1634 kfree(subvol_name);
1635 goto out;
1636 }
1637 }
1638 }
1639 if (IS_ERR(mnt_root)) {
1640 root = ERR_CAST(mnt_root);
1641 kfree(subvol_name);
1642 goto out;
1643 }
1644
1645 /* mount_subvol() will free subvol_name and mnt_root */
1646 root = mount_subvol(subvol_name, subvol_objectid, device_name, mnt_root);
1647
1648 out:
1649 return root;
1650 }
1651
1652 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1653 u32 new_pool_size, u32 old_pool_size)
1654 {
1655 if (new_pool_size == old_pool_size)
1656 return;
1657
1658 fs_info->thread_pool_size = new_pool_size;
1659
1660 btrfs_info(fs_info, "resize thread pool %d -> %d",
1661 old_pool_size, new_pool_size);
1662
1663 btrfs_workqueue_set_max(fs_info->workers, new_pool_size);
1664 btrfs_workqueue_set_max(fs_info->delalloc_workers, new_pool_size);
1665 btrfs_workqueue_set_max(fs_info->submit_workers, new_pool_size);
1666 btrfs_workqueue_set_max(fs_info->caching_workers, new_pool_size);
1667 btrfs_workqueue_set_max(fs_info->endio_workers, new_pool_size);
1668 btrfs_workqueue_set_max(fs_info->endio_meta_workers, new_pool_size);
1669 btrfs_workqueue_set_max(fs_info->endio_meta_write_workers,
1670 new_pool_size);
1671 btrfs_workqueue_set_max(fs_info->endio_write_workers, new_pool_size);
1672 btrfs_workqueue_set_max(fs_info->endio_freespace_worker, new_pool_size);
1673 btrfs_workqueue_set_max(fs_info->delayed_workers, new_pool_size);
1674 btrfs_workqueue_set_max(fs_info->readahead_workers, new_pool_size);
1675 btrfs_workqueue_set_max(fs_info->scrub_wr_completion_workers,
1676 new_pool_size);
1677 }
1678
1679 static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info)
1680 {
1681 set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1682 }
1683
1684 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
1685 unsigned long old_opts, int flags)
1686 {
1687 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1688 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1689 (flags & SB_RDONLY))) {
1690 /* wait for any defraggers to finish */
1691 wait_event(fs_info->transaction_wait,
1692 (atomic_read(&fs_info->defrag_running) == 0));
1693 if (flags & SB_RDONLY)
1694 sync_filesystem(fs_info->sb);
1695 }
1696 }
1697
1698 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1699 unsigned long old_opts)
1700 {
1701 /*
1702 * We need to cleanup all defragable inodes if the autodefragment is
1703 * close or the filesystem is read only.
1704 */
1705 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1706 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) || sb_rdonly(fs_info->sb))) {
1707 btrfs_cleanup_defrag_inodes(fs_info);
1708 }
1709
1710 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1711 }
1712
1713 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1714 {
1715 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1716 struct btrfs_root *root = fs_info->tree_root;
1717 unsigned old_flags = sb->s_flags;
1718 unsigned long old_opts = fs_info->mount_opt;
1719 unsigned long old_compress_type = fs_info->compress_type;
1720 u64 old_max_inline = fs_info->max_inline;
1721 u32 old_thread_pool_size = fs_info->thread_pool_size;
1722 u32 old_metadata_ratio = fs_info->metadata_ratio;
1723 int ret;
1724
1725 sync_filesystem(sb);
1726 btrfs_remount_prepare(fs_info);
1727
1728 if (data) {
1729 void *new_sec_opts = NULL;
1730
1731 ret = security_sb_eat_lsm_opts(data, &new_sec_opts);
1732 if (!ret)
1733 ret = security_sb_remount(sb, new_sec_opts);
1734 security_free_mnt_opts(&new_sec_opts);
1735 if (ret)
1736 goto restore;
1737 }
1738
1739 ret = btrfs_parse_options(fs_info, data, *flags);
1740 if (ret)
1741 goto restore;
1742
1743 btrfs_remount_begin(fs_info, old_opts, *flags);
1744 btrfs_resize_thread_pool(fs_info,
1745 fs_info->thread_pool_size, old_thread_pool_size);
1746
1747 if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1748 goto out;
1749
1750 if (*flags & SB_RDONLY) {
1751 /*
1752 * this also happens on 'umount -rf' or on shutdown, when
1753 * the filesystem is busy.
1754 */
1755 cancel_work_sync(&fs_info->async_reclaim_work);
1756
1757 /* wait for the uuid_scan task to finish */
1758 down(&fs_info->uuid_tree_rescan_sem);
1759 /* avoid complains from lockdep et al. */
1760 up(&fs_info->uuid_tree_rescan_sem);
1761
1762 sb->s_flags |= SB_RDONLY;
1763
1764 /*
1765 * Setting SB_RDONLY will put the cleaner thread to
1766 * sleep at the next loop if it's already active.
1767 * If it's already asleep, we'll leave unused block
1768 * groups on disk until we're mounted read-write again
1769 * unless we clean them up here.
1770 */
1771 btrfs_delete_unused_bgs(fs_info);
1772
1773 btrfs_dev_replace_suspend_for_unmount(fs_info);
1774 btrfs_scrub_cancel(fs_info);
1775 btrfs_pause_balance(fs_info);
1776
1777 ret = btrfs_commit_super(fs_info);
1778 if (ret)
1779 goto restore;
1780 } else {
1781 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
1782 btrfs_err(fs_info,
1783 "Remounting read-write after error is not allowed");
1784 ret = -EINVAL;
1785 goto restore;
1786 }
1787 if (fs_info->fs_devices->rw_devices == 0) {
1788 ret = -EACCES;
1789 goto restore;
1790 }
1791
1792 if (!btrfs_check_rw_degradable(fs_info, NULL)) {
1793 btrfs_warn(fs_info,
1794 "too many missing devices, writable remount is not allowed");
1795 ret = -EACCES;
1796 goto restore;
1797 }
1798
1799 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1800 ret = -EINVAL;
1801 goto restore;
1802 }
1803
1804 ret = btrfs_cleanup_fs_roots(fs_info);
1805 if (ret)
1806 goto restore;
1807
1808 /* recover relocation */
1809 mutex_lock(&fs_info->cleaner_mutex);
1810 ret = btrfs_recover_relocation(root);
1811 mutex_unlock(&fs_info->cleaner_mutex);
1812 if (ret)
1813 goto restore;
1814
1815 ret = btrfs_resume_balance_async(fs_info);
1816 if (ret)
1817 goto restore;
1818
1819 ret = btrfs_resume_dev_replace_async(fs_info);
1820 if (ret) {
1821 btrfs_warn(fs_info, "failed to resume dev_replace");
1822 goto restore;
1823 }
1824
1825 btrfs_qgroup_rescan_resume(fs_info);
1826
1827 if (!fs_info->uuid_root) {
1828 btrfs_info(fs_info, "creating UUID tree");
1829 ret = btrfs_create_uuid_tree(fs_info);
1830 if (ret) {
1831 btrfs_warn(fs_info,
1832 "failed to create the UUID tree %d",
1833 ret);
1834 goto restore;
1835 }
1836 }
1837 sb->s_flags &= ~SB_RDONLY;
1838
1839 set_bit(BTRFS_FS_OPEN, &fs_info->flags);
1840 }
1841 out:
1842 wake_up_process(fs_info->transaction_kthread);
1843 btrfs_remount_cleanup(fs_info, old_opts);
1844 return 0;
1845
1846 restore:
1847 /* We've hit an error - don't reset SB_RDONLY */
1848 if (sb_rdonly(sb))
1849 old_flags |= SB_RDONLY;
1850 sb->s_flags = old_flags;
1851 fs_info->mount_opt = old_opts;
1852 fs_info->compress_type = old_compress_type;
1853 fs_info->max_inline = old_max_inline;
1854 btrfs_resize_thread_pool(fs_info,
1855 old_thread_pool_size, fs_info->thread_pool_size);
1856 fs_info->metadata_ratio = old_metadata_ratio;
1857 btrfs_remount_cleanup(fs_info, old_opts);
1858 return ret;
1859 }
1860
1861 /* Used to sort the devices by max_avail(descending sort) */
1862 static inline int btrfs_cmp_device_free_bytes(const void *dev_info1,
1863 const void *dev_info2)
1864 {
1865 if (((struct btrfs_device_info *)dev_info1)->max_avail >
1866 ((struct btrfs_device_info *)dev_info2)->max_avail)
1867 return -1;
1868 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1869 ((struct btrfs_device_info *)dev_info2)->max_avail)
1870 return 1;
1871 else
1872 return 0;
1873 }
1874
1875 /*
1876 * sort the devices by max_avail, in which max free extent size of each device
1877 * is stored.(Descending Sort)
1878 */
1879 static inline void btrfs_descending_sort_devices(
1880 struct btrfs_device_info *devices,
1881 size_t nr_devices)
1882 {
1883 sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1884 btrfs_cmp_device_free_bytes, NULL);
1885 }
1886
1887 /*
1888 * The helper to calc the free space on the devices that can be used to store
1889 * file data.
1890 */
1891 static inline int btrfs_calc_avail_data_space(struct btrfs_fs_info *fs_info,
1892 u64 *free_bytes)
1893 {
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 min_stripe_size;
1901 int min_stripes = 1, num_stripes = 1;
1902 int i = 0, nr_devices;
1903
1904 /*
1905 * We aren't under the device list lock, so this is racy-ish, but good
1906 * enough for our purposes.
1907 */
1908 nr_devices = fs_info->fs_devices->open_devices;
1909 if (!nr_devices) {
1910 smp_mb();
1911 nr_devices = fs_info->fs_devices->open_devices;
1912 ASSERT(nr_devices);
1913 if (!nr_devices) {
1914 *free_bytes = 0;
1915 return 0;
1916 }
1917 }
1918
1919 devices_info = kmalloc_array(nr_devices, sizeof(*devices_info),
1920 GFP_KERNEL);
1921 if (!devices_info)
1922 return -ENOMEM;
1923
1924 /* calc min stripe number for data space allocation */
1925 type = btrfs_data_alloc_profile(fs_info);
1926 if (type & BTRFS_BLOCK_GROUP_RAID0) {
1927 min_stripes = 2;
1928 num_stripes = nr_devices;
1929 } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
1930 min_stripes = 2;
1931 num_stripes = 2;
1932 } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
1933 min_stripes = 4;
1934 num_stripes = 4;
1935 }
1936
1937 if (type & BTRFS_BLOCK_GROUP_DUP)
1938 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1939 else
1940 min_stripe_size = BTRFS_STRIPE_LEN;
1941
1942 rcu_read_lock();
1943 list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
1944 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
1945 &device->dev_state) ||
1946 !device->bdev ||
1947 test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state))
1948 continue;
1949
1950 if (i >= nr_devices)
1951 break;
1952
1953 avail_space = device->total_bytes - device->bytes_used;
1954
1955 /* align with stripe_len */
1956 avail_space = div_u64(avail_space, BTRFS_STRIPE_LEN);
1957 avail_space *= BTRFS_STRIPE_LEN;
1958
1959 /*
1960 * In order to avoid overwriting the superblock on the drive,
1961 * btrfs starts at an offset of at least 1MB when doing chunk
1962 * allocation.
1963 */
1964 skip_space = SZ_1M;
1965
1966 /*
1967 * we can use the free space in [0, skip_space - 1], subtract
1968 * it from the total.
1969 */
1970 if (avail_space && avail_space >= skip_space)
1971 avail_space -= skip_space;
1972 else
1973 avail_space = 0;
1974
1975 if (avail_space < min_stripe_size)
1976 continue;
1977
1978 devices_info[i].dev = device;
1979 devices_info[i].max_avail = avail_space;
1980
1981 i++;
1982 }
1983 rcu_read_unlock();
1984
1985 nr_devices = i;
1986
1987 btrfs_descending_sort_devices(devices_info, nr_devices);
1988
1989 i = nr_devices - 1;
1990 avail_space = 0;
1991 while (nr_devices >= min_stripes) {
1992 if (num_stripes > nr_devices)
1993 num_stripes = nr_devices;
1994
1995 if (devices_info[i].max_avail >= min_stripe_size) {
1996 int j;
1997 u64 alloc_size;
1998
1999 avail_space += devices_info[i].max_avail * num_stripes;
2000 alloc_size = devices_info[i].max_avail;
2001 for (j = i + 1 - num_stripes; j <= i; j++)
2002 devices_info[j].max_avail -= alloc_size;
2003 }
2004 i--;
2005 nr_devices--;
2006 }
2007
2008 kfree(devices_info);
2009 *free_bytes = avail_space;
2010 return 0;
2011 }
2012
2013 /*
2014 * Calculate numbers for 'df', pessimistic in case of mixed raid profiles.
2015 *
2016 * If there's a redundant raid level at DATA block groups, use the respective
2017 * multiplier to scale the sizes.
2018 *
2019 * Unused device space usage is based on simulating the chunk allocator
2020 * algorithm that respects the device sizes and order of allocations. This is
2021 * a close approximation of the actual use but there are other factors that may
2022 * change the result (like a new metadata chunk).
2023 *
2024 * If metadata is exhausted, f_bavail will be 0.
2025 */
2026 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
2027 {
2028 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
2029 struct btrfs_super_block *disk_super = fs_info->super_copy;
2030 struct list_head *head = &fs_info->space_info;
2031 struct btrfs_space_info *found;
2032 u64 total_used = 0;
2033 u64 total_free_data = 0;
2034 u64 total_free_meta = 0;
2035 int bits = dentry->d_sb->s_blocksize_bits;
2036 __be32 *fsid = (__be32 *)fs_info->fs_devices->fsid;
2037 unsigned factor = 1;
2038 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
2039 int ret;
2040 u64 thresh = 0;
2041 int mixed = 0;
2042
2043 rcu_read_lock();
2044 list_for_each_entry_rcu(found, head, list) {
2045 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
2046 int i;
2047
2048 total_free_data += found->disk_total - found->disk_used;
2049 total_free_data -=
2050 btrfs_account_ro_block_groups_free_space(found);
2051
2052 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
2053 if (!list_empty(&found->block_groups[i]))
2054 factor = btrfs_bg_type_to_factor(
2055 btrfs_raid_array[i].bg_flag);
2056 }
2057 }
2058
2059 /*
2060 * Metadata in mixed block goup profiles are accounted in data
2061 */
2062 if (!mixed && found->flags & BTRFS_BLOCK_GROUP_METADATA) {
2063 if (found->flags & BTRFS_BLOCK_GROUP_DATA)
2064 mixed = 1;
2065 else
2066 total_free_meta += found->disk_total -
2067 found->disk_used;
2068 }
2069
2070 total_used += found->disk_used;
2071 }
2072
2073 rcu_read_unlock();
2074
2075 buf->f_blocks = div_u64(btrfs_super_total_bytes(disk_super), factor);
2076 buf->f_blocks >>= bits;
2077 buf->f_bfree = buf->f_blocks - (div_u64(total_used, factor) >> bits);
2078
2079 /* Account global block reserve as used, it's in logical size already */
2080 spin_lock(&block_rsv->lock);
2081 /* Mixed block groups accounting is not byte-accurate, avoid overflow */
2082 if (buf->f_bfree >= block_rsv->size >> bits)
2083 buf->f_bfree -= block_rsv->size >> bits;
2084 else
2085 buf->f_bfree = 0;
2086 spin_unlock(&block_rsv->lock);
2087
2088 buf->f_bavail = div_u64(total_free_data, factor);
2089 ret = btrfs_calc_avail_data_space(fs_info, &total_free_data);
2090 if (ret)
2091 return ret;
2092 buf->f_bavail += div_u64(total_free_data, factor);
2093 buf->f_bavail = buf->f_bavail >> bits;
2094
2095 /*
2096 * We calculate the remaining metadata space minus global reserve. If
2097 * this is (supposedly) smaller than zero, there's no space. But this
2098 * does not hold in practice, the exhausted state happens where's still
2099 * some positive delta. So we apply some guesswork and compare the
2100 * delta to a 4M threshold. (Practically observed delta was ~2M.)
2101 *
2102 * We probably cannot calculate the exact threshold value because this
2103 * depends on the internal reservations requested by various
2104 * operations, so some operations that consume a few metadata will
2105 * succeed even if the Avail is zero. But this is better than the other
2106 * way around.
2107 */
2108 thresh = SZ_4M;
2109
2110 if (!mixed && total_free_meta - thresh < block_rsv->size)
2111 buf->f_bavail = 0;
2112
2113 buf->f_type = BTRFS_SUPER_MAGIC;
2114 buf->f_bsize = dentry->d_sb->s_blocksize;
2115 buf->f_namelen = BTRFS_NAME_LEN;
2116
2117 /* We treat it as constant endianness (it doesn't matter _which_)
2118 because we want the fsid to come out the same whether mounted
2119 on a big-endian or little-endian host */
2120 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
2121 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
2122 /* Mask in the root object ID too, to disambiguate subvols */
2123 buf->f_fsid.val[0] ^=
2124 BTRFS_I(d_inode(dentry))->root->root_key.objectid >> 32;
2125 buf->f_fsid.val[1] ^=
2126 BTRFS_I(d_inode(dentry))->root->root_key.objectid;
2127
2128 return 0;
2129 }
2130
2131 static void btrfs_kill_super(struct super_block *sb)
2132 {
2133 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2134 kill_anon_super(sb);
2135 free_fs_info(fs_info);
2136 }
2137
2138 static struct file_system_type btrfs_fs_type = {
2139 .owner = THIS_MODULE,
2140 .name = "btrfs",
2141 .mount = btrfs_mount,
2142 .kill_sb = btrfs_kill_super,
2143 .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA,
2144 };
2145
2146 static struct file_system_type btrfs_root_fs_type = {
2147 .owner = THIS_MODULE,
2148 .name = "btrfs",
2149 .mount = btrfs_mount_root,
2150 .kill_sb = btrfs_kill_super,
2151 .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA,
2152 };
2153
2154 MODULE_ALIAS_FS("btrfs");
2155
2156 static int btrfs_control_open(struct inode *inode, struct file *file)
2157 {
2158 /*
2159 * The control file's private_data is used to hold the
2160 * transaction when it is started and is used to keep
2161 * track of whether a transaction is already in progress.
2162 */
2163 file->private_data = NULL;
2164 return 0;
2165 }
2166
2167 /*
2168 * used by btrfsctl to scan devices when no FS is mounted
2169 */
2170 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
2171 unsigned long arg)
2172 {
2173 struct btrfs_ioctl_vol_args *vol;
2174 struct btrfs_device *device = NULL;
2175 int ret = -ENOTTY;
2176
2177 if (!capable(CAP_SYS_ADMIN))
2178 return -EPERM;
2179
2180 vol = memdup_user((void __user *)arg, sizeof(*vol));
2181 if (IS_ERR(vol))
2182 return PTR_ERR(vol);
2183 vol->name[BTRFS_PATH_NAME_MAX] = '\0';
2184
2185 switch (cmd) {
2186 case BTRFS_IOC_SCAN_DEV:
2187 mutex_lock(&uuid_mutex);
2188 device = btrfs_scan_one_device(vol->name, FMODE_READ,
2189 &btrfs_root_fs_type);
2190 ret = PTR_ERR_OR_ZERO(device);
2191 mutex_unlock(&uuid_mutex);
2192 break;
2193 case BTRFS_IOC_DEVICES_READY:
2194 mutex_lock(&uuid_mutex);
2195 device = btrfs_scan_one_device(vol->name, FMODE_READ,
2196 &btrfs_root_fs_type);
2197 if (IS_ERR(device)) {
2198 mutex_unlock(&uuid_mutex);
2199 ret = PTR_ERR(device);
2200 break;
2201 }
2202 ret = !(device->fs_devices->num_devices ==
2203 device->fs_devices->total_devices);
2204 mutex_unlock(&uuid_mutex);
2205 break;
2206 case BTRFS_IOC_GET_SUPPORTED_FEATURES:
2207 ret = btrfs_ioctl_get_supported_features((void __user*)arg);
2208 break;
2209 }
2210
2211 kfree(vol);
2212 return ret;
2213 }
2214
2215 static int btrfs_freeze(struct super_block *sb)
2216 {
2217 struct btrfs_trans_handle *trans;
2218 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2219 struct btrfs_root *root = fs_info->tree_root;
2220
2221 set_bit(BTRFS_FS_FROZEN, &fs_info->flags);
2222 /*
2223 * We don't need a barrier here, we'll wait for any transaction that
2224 * could be in progress on other threads (and do delayed iputs that
2225 * we want to avoid on a frozen filesystem), or do the commit
2226 * ourselves.
2227 */
2228 trans = btrfs_attach_transaction_barrier(root);
2229 if (IS_ERR(trans)) {
2230 /* no transaction, don't bother */
2231 if (PTR_ERR(trans) == -ENOENT)
2232 return 0;
2233 return PTR_ERR(trans);
2234 }
2235 return btrfs_commit_transaction(trans);
2236 }
2237
2238 static int btrfs_unfreeze(struct super_block *sb)
2239 {
2240 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2241
2242 clear_bit(BTRFS_FS_FROZEN, &fs_info->flags);
2243 return 0;
2244 }
2245
2246 static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
2247 {
2248 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
2249 struct btrfs_fs_devices *cur_devices;
2250 struct btrfs_device *dev, *first_dev = NULL;
2251 struct list_head *head;
2252
2253 /*
2254 * Lightweight locking of the devices. We should not need
2255 * device_list_mutex here as we only read the device data and the list
2256 * is protected by RCU. Even if a device is deleted during the list
2257 * traversals, we'll get valid data, the freeing callback will wait at
2258 * least until the rcu_read_unlock.
2259 */
2260 rcu_read_lock();
2261 cur_devices = fs_info->fs_devices;
2262 while (cur_devices) {
2263 head = &cur_devices->devices;
2264 list_for_each_entry_rcu(dev, head, dev_list) {
2265 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state))
2266 continue;
2267 if (!dev->name)
2268 continue;
2269 if (!first_dev || dev->devid < first_dev->devid)
2270 first_dev = dev;
2271 }
2272 cur_devices = cur_devices->seed;
2273 }
2274
2275 if (first_dev)
2276 seq_escape(m, rcu_str_deref(first_dev->name), " \t\n\\");
2277 else
2278 WARN_ON(1);
2279 rcu_read_unlock();
2280 return 0;
2281 }
2282
2283 static const struct super_operations btrfs_super_ops = {
2284 .drop_inode = btrfs_drop_inode,
2285 .evict_inode = btrfs_evict_inode,
2286 .put_super = btrfs_put_super,
2287 .sync_fs = btrfs_sync_fs,
2288 .show_options = btrfs_show_options,
2289 .show_devname = btrfs_show_devname,
2290 .alloc_inode = btrfs_alloc_inode,
2291 .destroy_inode = btrfs_destroy_inode,
2292 .statfs = btrfs_statfs,
2293 .remount_fs = btrfs_remount,
2294 .freeze_fs = btrfs_freeze,
2295 .unfreeze_fs = btrfs_unfreeze,
2296 };
2297
2298 static const struct file_operations btrfs_ctl_fops = {
2299 .open = btrfs_control_open,
2300 .unlocked_ioctl = btrfs_control_ioctl,
2301 .compat_ioctl = btrfs_control_ioctl,
2302 .owner = THIS_MODULE,
2303 .llseek = noop_llseek,
2304 };
2305
2306 static struct miscdevice btrfs_misc = {
2307 .minor = BTRFS_MINOR,
2308 .name = "btrfs-control",
2309 .fops = &btrfs_ctl_fops
2310 };
2311
2312 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
2313 MODULE_ALIAS("devname:btrfs-control");
2314
2315 static int __init btrfs_interface_init(void)
2316 {
2317 return misc_register(&btrfs_misc);
2318 }
2319
2320 static __cold void btrfs_interface_exit(void)
2321 {
2322 misc_deregister(&btrfs_misc);
2323 }
2324
2325 static void __init btrfs_print_mod_info(void)
2326 {
2327 static const char options[] = ""
2328 #ifdef CONFIG_BTRFS_DEBUG
2329 ", debug=on"
2330 #endif
2331 #ifdef CONFIG_BTRFS_ASSERT
2332 ", assert=on"
2333 #endif
2334 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2335 ", integrity-checker=on"
2336 #endif
2337 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
2338 ", ref-verify=on"
2339 #endif
2340 ;
2341 pr_info("Btrfs loaded, crc32c=%s%s\n", crc32c_impl(), options);
2342 }
2343
2344 static int __init init_btrfs_fs(void)
2345 {
2346 int err;
2347
2348 btrfs_props_init();
2349
2350 err = btrfs_init_sysfs();
2351 if (err)
2352 return err;
2353
2354 btrfs_init_compress();
2355
2356 err = btrfs_init_cachep();
2357 if (err)
2358 goto free_compress;
2359
2360 err = extent_io_init();
2361 if (err)
2362 goto free_cachep;
2363
2364 err = extent_map_init();
2365 if (err)
2366 goto free_extent_io;
2367
2368 err = ordered_data_init();
2369 if (err)
2370 goto free_extent_map;
2371
2372 err = btrfs_delayed_inode_init();
2373 if (err)
2374 goto free_ordered_data;
2375
2376 err = btrfs_auto_defrag_init();
2377 if (err)
2378 goto free_delayed_inode;
2379
2380 err = btrfs_delayed_ref_init();
2381 if (err)
2382 goto free_auto_defrag;
2383
2384 err = btrfs_prelim_ref_init();
2385 if (err)
2386 goto free_delayed_ref;
2387
2388 err = btrfs_end_io_wq_init();
2389 if (err)
2390 goto free_prelim_ref;
2391
2392 err = btrfs_interface_init();
2393 if (err)
2394 goto free_end_io_wq;
2395
2396 btrfs_init_lockdep();
2397
2398 btrfs_print_mod_info();
2399
2400 err = btrfs_run_sanity_tests();
2401 if (err)
2402 goto unregister_ioctl;
2403
2404 err = register_filesystem(&btrfs_fs_type);
2405 if (err)
2406 goto unregister_ioctl;
2407
2408 return 0;
2409
2410 unregister_ioctl:
2411 btrfs_interface_exit();
2412 free_end_io_wq:
2413 btrfs_end_io_wq_exit();
2414 free_prelim_ref:
2415 btrfs_prelim_ref_exit();
2416 free_delayed_ref:
2417 btrfs_delayed_ref_exit();
2418 free_auto_defrag:
2419 btrfs_auto_defrag_exit();
2420 free_delayed_inode:
2421 btrfs_delayed_inode_exit();
2422 free_ordered_data:
2423 ordered_data_exit();
2424 free_extent_map:
2425 extent_map_exit();
2426 free_extent_io:
2427 extent_io_exit();
2428 free_cachep:
2429 btrfs_destroy_cachep();
2430 free_compress:
2431 btrfs_exit_compress();
2432 btrfs_exit_sysfs();
2433
2434 return err;
2435 }
2436
2437 static void __exit exit_btrfs_fs(void)
2438 {
2439 btrfs_destroy_cachep();
2440 btrfs_delayed_ref_exit();
2441 btrfs_auto_defrag_exit();
2442 btrfs_delayed_inode_exit();
2443 btrfs_prelim_ref_exit();
2444 ordered_data_exit();
2445 extent_map_exit();
2446 extent_io_exit();
2447 btrfs_interface_exit();
2448 btrfs_end_io_wq_exit();
2449 unregister_filesystem(&btrfs_fs_type);
2450 btrfs_exit_sysfs();
2451 btrfs_cleanup_fs_uuids();
2452 btrfs_exit_compress();
2453 }
2454
2455 late_initcall(init_btrfs_fs);
2456 module_exit(exit_btrfs_fs)
2457
2458 MODULE_LICENSE("GPL");
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