1 // SPDX-License-Identifier: GPL-2.0 1
2 /*
3 * Copyright (C) 2007 Oracle. All rights rese
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/ratelimit.h>
27 #include <linux/crc32c.h>
28 #include <linux/btrfs.h>
29 #include <linux/security.h>
30 #include <linux/fs_parser.h>
31 #include <linux/swap.h>
32 #include "messages.h"
33 #include "delayed-inode.h"
34 #include "ctree.h"
35 #include "disk-io.h"
36 #include "transaction.h"
37 #include "btrfs_inode.h"
38 #include "direct-io.h"
39 #include "props.h"
40 #include "xattr.h"
41 #include "bio.h"
42 #include "export.h"
43 #include "compression.h"
44 #include "dev-replace.h"
45 #include "free-space-cache.h"
46 #include "backref.h"
47 #include "space-info.h"
48 #include "sysfs.h"
49 #include "zoned.h"
50 #include "tests/btrfs-tests.h"
51 #include "block-group.h"
52 #include "discard.h"
53 #include "qgroup.h"
54 #include "raid56.h"
55 #include "fs.h"
56 #include "accessors.h"
57 #include "defrag.h"
58 #include "dir-item.h"
59 #include "ioctl.h"
60 #include "scrub.h"
61 #include "verity.h"
62 #include "super.h"
63 #include "extent-tree.h"
64 #define CREATE_TRACE_POINTS
65 #include <trace/events/btrfs.h>
66
67 static const struct super_operations btrfs_sup
68 static struct file_system_type btrfs_fs_type;
69
70 static void btrfs_put_super(struct super_block
71 {
72 struct btrfs_fs_info *fs_info = btrfs_
73
74 btrfs_info(fs_info, "last unmount of f
75 close_ctree(fs_info);
76 }
77
78 /* Store the mount options related information
79 struct btrfs_fs_context {
80 char *subvol_name;
81 u64 subvol_objectid;
82 u64 max_inline;
83 u32 commit_interval;
84 u32 metadata_ratio;
85 u32 thread_pool_size;
86 unsigned long long mount_opt;
87 unsigned long compress_type:4;
88 unsigned int compress_level;
89 refcount_t refs;
90 };
91
92 enum {
93 Opt_acl,
94 Opt_clear_cache,
95 Opt_commit_interval,
96 Opt_compress,
97 Opt_compress_force,
98 Opt_compress_force_type,
99 Opt_compress_type,
100 Opt_degraded,
101 Opt_device,
102 Opt_fatal_errors,
103 Opt_flushoncommit,
104 Opt_max_inline,
105 Opt_barrier,
106 Opt_datacow,
107 Opt_datasum,
108 Opt_defrag,
109 Opt_discard,
110 Opt_discard_mode,
111 Opt_ratio,
112 Opt_rescan_uuid_tree,
113 Opt_skip_balance,
114 Opt_space_cache,
115 Opt_space_cache_version,
116 Opt_ssd,
117 Opt_ssd_spread,
118 Opt_subvol,
119 Opt_subvol_empty,
120 Opt_subvolid,
121 Opt_thread_pool,
122 Opt_treelog,
123 Opt_user_subvol_rm_allowed,
124 Opt_norecovery,
125
126 /* Rescue options */
127 Opt_rescue,
128 Opt_usebackuproot,
129 Opt_nologreplay,
130
131 /* Debugging options */
132 Opt_enospc_debug,
133 #ifdef CONFIG_BTRFS_DEBUG
134 Opt_fragment, Opt_fragment_data, Opt_f
135 #endif
136 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
137 Opt_ref_verify,
138 #endif
139 Opt_err,
140 };
141
142 enum {
143 Opt_fatal_errors_panic,
144 Opt_fatal_errors_bug,
145 };
146
147 static const struct constant_table btrfs_param
148 { "panic", Opt_fatal_errors_panic },
149 { "bug", Opt_fatal_errors_bug },
150 {}
151 };
152
153 enum {
154 Opt_discard_sync,
155 Opt_discard_async,
156 };
157
158 static const struct constant_table btrfs_param
159 { "sync", Opt_discard_sync },
160 { "async", Opt_discard_async },
161 {}
162 };
163
164 enum {
165 Opt_space_cache_v1,
166 Opt_space_cache_v2,
167 };
168
169 static const struct constant_table btrfs_param
170 { "v1", Opt_space_cache_v1 },
171 { "v2", Opt_space_cache_v2 },
172 {}
173 };
174
175 enum {
176 Opt_rescue_usebackuproot,
177 Opt_rescue_nologreplay,
178 Opt_rescue_ignorebadroots,
179 Opt_rescue_ignoredatacsums,
180 Opt_rescue_ignoremetacsums,
181 Opt_rescue_ignoresuperflags,
182 Opt_rescue_parameter_all,
183 };
184
185 static const struct constant_table btrfs_param
186 { "usebackuproot", Opt_rescue_usebacku
187 { "nologreplay", Opt_rescue_nologrepla
188 { "ignorebadroots", Opt_rescue_ignoreb
189 { "ibadroots", Opt_rescue_ignorebadroo
190 { "ignoredatacsums", Opt_rescue_ignore
191 { "ignoremetacsums", Opt_rescue_ignore
192 { "ignoresuperflags", Opt_rescue_ignor
193 { "idatacsums", Opt_rescue_ignoredatac
194 { "imetacsums", Opt_rescue_ignoremetac
195 { "isuperflags", Opt_rescue_ignoresupe
196 { "all", Opt_rescue_parameter_all },
197 {}
198 };
199
200 #ifdef CONFIG_BTRFS_DEBUG
201 enum {
202 Opt_fragment_parameter_data,
203 Opt_fragment_parameter_metadata,
204 Opt_fragment_parameter_all,
205 };
206
207 static const struct constant_table btrfs_param
208 { "data", Opt_fragment_parameter_data
209 { "metadata", Opt_fragment_parameter_m
210 { "all", Opt_fragment_parameter_all },
211 {}
212 };
213 #endif
214
215 static const struct fs_parameter_spec btrfs_fs
216 fsparam_flag_no("acl", Opt_acl),
217 fsparam_flag_no("autodefrag", Opt_defr
218 fsparam_flag_no("barrier", Opt_barrier
219 fsparam_flag("clear_cache", Opt_clear_
220 fsparam_u32("commit", Opt_commit_inter
221 fsparam_flag("compress", Opt_compress)
222 fsparam_string("compress", Opt_compres
223 fsparam_flag("compress-force", Opt_com
224 fsparam_string("compress-force", Opt_c
225 fsparam_flag_no("datacow", Opt_datacow
226 fsparam_flag_no("datasum", Opt_datasum
227 fsparam_flag("degraded", Opt_degraded)
228 fsparam_string("device", Opt_device),
229 fsparam_flag_no("discard", Opt_discard
230 fsparam_enum("discard", Opt_discard_mo
231 fsparam_enum("fatal_errors", Opt_fatal
232 fsparam_flag_no("flushoncommit", Opt_f
233 fsparam_string("max_inline", Opt_max_i
234 fsparam_u32("metadata_ratio", Opt_rati
235 fsparam_flag("rescan_uuid_tree", Opt_r
236 fsparam_flag("skip_balance", Opt_skip_
237 fsparam_flag_no("space_cache", Opt_spa
238 fsparam_enum("space_cache", Opt_space_
239 fsparam_flag_no("ssd", Opt_ssd),
240 fsparam_flag_no("ssd_spread", Opt_ssd_
241 fsparam_string("subvol", Opt_subvol),
242 fsparam_flag("subvol=", Opt_subvol_emp
243 fsparam_u64("subvolid", Opt_subvolid),
244 fsparam_u32("thread_pool", Opt_thread_
245 fsparam_flag_no("treelog", Opt_treelog
246 fsparam_flag("user_subvol_rm_allowed",
247
248 /* Rescue options. */
249 fsparam_enum("rescue", Opt_rescue, btr
250 /* Deprecated, with alias rescue=nolog
251 __fsparam(NULL, "nologreplay", Opt_nol
252 /* Deprecated, with alias rescue=useba
253 __fsparam(NULL, "usebackuproot", Opt_u
254 /* For compatibility only, alias for "
255 fsparam_flag("norecovery", Opt_norecov
256
257 /* Debugging options. */
258 fsparam_flag_no("enospc_debug", Opt_en
259 #ifdef CONFIG_BTRFS_DEBUG
260 fsparam_enum("fragment", Opt_fragment,
261 #endif
262 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
263 fsparam_flag("ref_verify", Opt_ref_ver
264 #endif
265 {}
266 };
267
268 /* No support for restricting writes to btrfs
269 static inline blk_mode_t btrfs_open_mode(struc
270 {
271 return sb_open_mode(fc->sb_flags) & ~B
272 }
273
274 static int btrfs_parse_param(struct fs_context
275 {
276 struct btrfs_fs_context *ctx = fc->fs_
277 struct fs_parse_result result;
278 int opt;
279
280 opt = fs_parse(fc, btrfs_fs_parameters
281 if (opt < 0)
282 return opt;
283
284 switch (opt) {
285 case Opt_degraded:
286 btrfs_set_opt(ctx->mount_opt,
287 break;
288 case Opt_subvol_empty:
289 /*
290 * This exists because we used
291 * keeping it to maintain ABI.
292 * empty subvol= again").
293 */
294 break;
295 case Opt_subvol:
296 kfree(ctx->subvol_name);
297 ctx->subvol_name = kstrdup(par
298 if (!ctx->subvol_name)
299 return -ENOMEM;
300 break;
301 case Opt_subvolid:
302 ctx->subvol_objectid = result.
303
304 /* subvolid=0 means give me th
305 if (!ctx->subvol_objectid)
306 ctx->subvol_objectid =
307 break;
308 case Opt_device: {
309 struct btrfs_device *device;
310 blk_mode_t mode = btrfs_open_m
311
312 mutex_lock(&uuid_mutex);
313 device = btrfs_scan_one_device
314 mutex_unlock(&uuid_mutex);
315 if (IS_ERR(device))
316 return PTR_ERR(device)
317 break;
318 }
319 case Opt_datasum:
320 if (result.negated) {
321 btrfs_set_opt(ctx->mou
322 } else {
323 btrfs_clear_opt(ctx->m
324 btrfs_clear_opt(ctx->m
325 }
326 break;
327 case Opt_datacow:
328 if (result.negated) {
329 btrfs_clear_opt(ctx->m
330 btrfs_clear_opt(ctx->m
331 btrfs_set_opt(ctx->mou
332 btrfs_set_opt(ctx->mou
333 } else {
334 btrfs_clear_opt(ctx->m
335 }
336 break;
337 case Opt_compress_force:
338 case Opt_compress_force_type:
339 btrfs_set_opt(ctx->mount_opt,
340 fallthrough;
341 case Opt_compress:
342 case Opt_compress_type:
343 /*
344 * Provide the same semantics
345 * context, specifying the "co
346 * "force-compress" without th
347 * "compress-force=[no|none]"
348 */
349 if (opt != Opt_compress_force
350 btrfs_clear_opt(ctx->m
351
352 if (opt == Opt_compress || opt
353 ctx->compress_type = B
354 ctx->compress_level =
355 btrfs_set_opt(ctx->mou
356 btrfs_clear_opt(ctx->m
357 btrfs_clear_opt(ctx->m
358 } else if (strncmp(param->stri
359 ctx->compress_type = B
360 ctx->compress_level =
361 btrfs_compress
362
363 btrfs_set_opt(ctx->mou
364 btrfs_clear_opt(ctx->m
365 btrfs_clear_opt(ctx->m
366 } else if (strncmp(param->stri
367 ctx->compress_type = B
368 ctx->compress_level =
369 btrfs_set_opt(ctx->mou
370 btrfs_clear_opt(ctx->m
371 btrfs_clear_opt(ctx->m
372 } else if (strncmp(param->stri
373 ctx->compress_type = B
374 ctx->compress_level =
375 btrfs_compress
376
377 btrfs_set_opt(ctx->mou
378 btrfs_clear_opt(ctx->m
379 btrfs_clear_opt(ctx->m
380 } else if (strncmp(param->stri
381 ctx->compress_level =
382 ctx->compress_type = 0
383 btrfs_clear_opt(ctx->m
384 btrfs_clear_opt(ctx->m
385 } else {
386 btrfs_err(NULL, "unrec
387 param->strin
388 return -EINVAL;
389 }
390 break;
391 case Opt_ssd:
392 if (result.negated) {
393 btrfs_set_opt(ctx->mou
394 btrfs_clear_opt(ctx->m
395 btrfs_clear_opt(ctx->m
396 } else {
397 btrfs_set_opt(ctx->mou
398 btrfs_clear_opt(ctx->m
399 }
400 break;
401 case Opt_ssd_spread:
402 if (result.negated) {
403 btrfs_clear_opt(ctx->m
404 } else {
405 btrfs_set_opt(ctx->mou
406 btrfs_set_opt(ctx->mou
407 btrfs_clear_opt(ctx->m
408 }
409 break;
410 case Opt_barrier:
411 if (result.negated)
412 btrfs_set_opt(ctx->mou
413 else
414 btrfs_clear_opt(ctx->m
415 break;
416 case Opt_thread_pool:
417 if (result.uint_32 == 0) {
418 btrfs_err(NULL, "inval
419 return -EINVAL;
420 }
421 ctx->thread_pool_size = result
422 break;
423 case Opt_max_inline:
424 ctx->max_inline = memparse(par
425 break;
426 case Opt_acl:
427 if (result.negated) {
428 fc->sb_flags &= ~SB_PO
429 } else {
430 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
431 fc->sb_flags |= SB_POS
432 #else
433 btrfs_err(NULL, "suppo
434 return -EINVAL;
435 #endif
436 }
437 /*
438 * VFS limits the ability to t
439 * despite every file system a
440 * an oversight since we all d
441 * remounting. So don't set t
442 * btrfs_reconfigure and do th
443 */
444 if (fc->purpose != FS_CONTEXT_
445 fc->sb_flags_mask |= S
446 break;
447 case Opt_treelog:
448 if (result.negated)
449 btrfs_set_opt(ctx->mou
450 else
451 btrfs_clear_opt(ctx->m
452 break;
453 case Opt_nologreplay:
454 btrfs_warn(NULL,
455 "'nologreplay' is deprecated,
456 btrfs_set_opt(ctx->mount_opt,
457 break;
458 case Opt_norecovery:
459 btrfs_info(NULL,
460 "'norecovery' is for compatibility only, recom
461 btrfs_set_opt(ctx->mount_opt,
462 break;
463 case Opt_flushoncommit:
464 if (result.negated)
465 btrfs_clear_opt(ctx->m
466 else
467 btrfs_set_opt(ctx->mou
468 break;
469 case Opt_ratio:
470 ctx->metadata_ratio = result.u
471 break;
472 case Opt_discard:
473 if (result.negated) {
474 btrfs_clear_opt(ctx->m
475 btrfs_clear_opt(ctx->m
476 btrfs_set_opt(ctx->mou
477 } else {
478 btrfs_set_opt(ctx->mou
479 btrfs_clear_opt(ctx->m
480 }
481 break;
482 case Opt_discard_mode:
483 switch (result.uint_32) {
484 case Opt_discard_sync:
485 btrfs_clear_opt(ctx->m
486 btrfs_set_opt(ctx->mou
487 break;
488 case Opt_discard_async:
489 btrfs_clear_opt(ctx->m
490 btrfs_set_opt(ctx->mou
491 break;
492 default:
493 btrfs_err(NULL, "unrec
494 param->key);
495 return -EINVAL;
496 }
497 btrfs_clear_opt(ctx->mount_opt
498 break;
499 case Opt_space_cache:
500 if (result.negated) {
501 btrfs_set_opt(ctx->mou
502 btrfs_clear_opt(ctx->m
503 btrfs_clear_opt(ctx->m
504 } else {
505 btrfs_clear_opt(ctx->m
506 btrfs_set_opt(ctx->mou
507 }
508 break;
509 case Opt_space_cache_version:
510 switch (result.uint_32) {
511 case Opt_space_cache_v1:
512 btrfs_set_opt(ctx->mou
513 btrfs_clear_opt(ctx->m
514 break;
515 case Opt_space_cache_v2:
516 btrfs_clear_opt(ctx->m
517 btrfs_set_opt(ctx->mou
518 break;
519 default:
520 btrfs_err(NULL, "unrec
521 param->key);
522 return -EINVAL;
523 }
524 break;
525 case Opt_rescan_uuid_tree:
526 btrfs_set_opt(ctx->mount_opt,
527 break;
528 case Opt_clear_cache:
529 btrfs_set_opt(ctx->mount_opt,
530 break;
531 case Opt_user_subvol_rm_allowed:
532 btrfs_set_opt(ctx->mount_opt,
533 break;
534 case Opt_enospc_debug:
535 if (result.negated)
536 btrfs_clear_opt(ctx->m
537 else
538 btrfs_set_opt(ctx->mou
539 break;
540 case Opt_defrag:
541 if (result.negated)
542 btrfs_clear_opt(ctx->m
543 else
544 btrfs_set_opt(ctx->mou
545 break;
546 case Opt_usebackuproot:
547 btrfs_warn(NULL,
548 "'usebackuproot' is
549 btrfs_set_opt(ctx->mount_opt,
550
551 /* If we're loading the backup
552 btrfs_set_opt(ctx->mount_opt,
553 break;
554 case Opt_skip_balance:
555 btrfs_set_opt(ctx->mount_opt,
556 break;
557 case Opt_fatal_errors:
558 switch (result.uint_32) {
559 case Opt_fatal_errors_panic:
560 btrfs_set_opt(ctx->mou
561 break;
562 case Opt_fatal_errors_bug:
563 btrfs_clear_opt(ctx->m
564 break;
565 default:
566 btrfs_err(NULL, "unrec
567 param->key);
568 return -EINVAL;
569 }
570 break;
571 case Opt_commit_interval:
572 ctx->commit_interval = result.
573 if (ctx->commit_interval == 0)
574 ctx->commit_interval =
575 break;
576 case Opt_rescue:
577 switch (result.uint_32) {
578 case Opt_rescue_usebackuproot:
579 btrfs_set_opt(ctx->mou
580 break;
581 case Opt_rescue_nologreplay:
582 btrfs_set_opt(ctx->mou
583 break;
584 case Opt_rescue_ignorebadroots
585 btrfs_set_opt(ctx->mou
586 break;
587 case Opt_rescue_ignoredatacsum
588 btrfs_set_opt(ctx->mou
589 break;
590 case Opt_rescue_ignoremetacsum
591 btrfs_set_opt(ctx->mou
592 break;
593 case Opt_rescue_ignoresuperfla
594 btrfs_set_opt(ctx->mou
595 break;
596 case Opt_rescue_parameter_all:
597 btrfs_set_opt(ctx->mou
598 btrfs_set_opt(ctx->mou
599 btrfs_set_opt(ctx->mou
600 btrfs_set_opt(ctx->mou
601 btrfs_set_opt(ctx->mou
602 break;
603 default:
604 btrfs_info(NULL, "unre
605 param->key)
606 return -EINVAL;
607 }
608 break;
609 #ifdef CONFIG_BTRFS_DEBUG
610 case Opt_fragment:
611 switch (result.uint_32) {
612 case Opt_fragment_parameter_al
613 btrfs_set_opt(ctx->mou
614 btrfs_set_opt(ctx->mou
615 break;
616 case Opt_fragment_parameter_me
617 btrfs_set_opt(ctx->mou
618 break;
619 case Opt_fragment_parameter_da
620 btrfs_set_opt(ctx->mou
621 break;
622 default:
623 btrfs_info(NULL, "unre
624 param->key)
625 return -EINVAL;
626 }
627 break;
628 #endif
629 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
630 case Opt_ref_verify:
631 btrfs_set_opt(ctx->mount_opt,
632 break;
633 #endif
634 default:
635 btrfs_err(NULL, "unrecognized
636 return -EINVAL;
637 }
638
639 return 0;
640 }
641
642 /*
643 * Some options only have meaning at mount tim
644 * remounts, or be displayed. Clear these at t
645 * paths.
646 */
647 static void btrfs_clear_oneshot_options(struct
648 {
649 btrfs_clear_opt(fs_info->mount_opt, US
650 btrfs_clear_opt(fs_info->mount_opt, CL
651 btrfs_clear_opt(fs_info->mount_opt, NO
652 }
653
654 static bool check_ro_option(const struct btrfs
655 unsigned long long
656 const char *opt_na
657 {
658 if (mount_opt & opt) {
659 btrfs_err(fs_info, "%s must be
660 opt_name);
661 return true;
662 }
663 return false;
664 }
665
666 bool btrfs_check_options(const struct btrfs_fs
667 unsigned long long *m
668 unsigned long flags)
669 {
670 bool ret = true;
671
672 if (!(flags & SB_RDONLY) &&
673 (check_ro_option(info, *mount_opt,
674 check_ro_option(info, *mount_opt,
675 check_ro_option(info, *mount_opt,
676 check_ro_option(info, *mount_opt,
677 check_ro_option(info, *mount_opt,
678 ret = false;
679
680 if (btrfs_fs_compat_ro(info, FREE_SPAC
681 !btrfs_raw_test_opt(*mount_opt, FR
682 !btrfs_raw_test_opt(*mount_opt, CL
683 btrfs_err(info, "cannot disabl
684 ret = false;
685 }
686 if (btrfs_fs_compat_ro(info, BLOCK_GRO
687 !btrfs_raw_test_opt(*mount_opt, F
688 btrfs_err(info, "cannot disabl
689 ret = false;
690 }
691
692 if (btrfs_check_mountopts_zoned(info,
693 ret = false;
694
695 if (!test_bit(BTRFS_FS_STATE_REMOUNTIN
696 if (btrfs_raw_test_opt(*mount_
697 btrfs_info(info, "disk
698 btrfs_warn(info,
699 "space cache v1 is being deprecated and will b
700 }
701 if (btrfs_raw_test_opt(*mount_
702 btrfs_info(info, "usin
703 }
704
705 return ret;
706 }
707
708 /*
709 * This is subtle, we only call this during op
710 * the mount options with the on-disk settings
711 * effect we would do this on mount and remoun
712 * only do this on the initial mount.
713 *
714 * This isn't a change in behavior, because we
715 * file system to set the current mount option
716 * options to disable these features and then
717 * settings, because mounting without these fe
718 * settings, so this being called on re-mount
719 */
720 void btrfs_set_free_space_cache_settings(struc
721 {
722 if (fs_info->sectorsize < PAGE_SIZE) {
723 btrfs_clear_opt(fs_info->mount
724 if (!btrfs_test_opt(fs_info, F
725 btrfs_info(fs_info,
726 "forcing fr
727 fs_info->se
728 btrfs_set_opt(fs_info-
729 }
730 }
731
732 /*
733 * At this point our mount options are
734 * these settings if we don't have any
735 */
736 if (btrfs_test_opt(fs_info, FREE_SPACE
737 return;
738
739 if (btrfs_is_zoned(fs_info) &&
740 btrfs_free_space_cache_v1_active(f
741 btrfs_info(fs_info, "zoned: cl
742 btrfs_set_super_cache_generati
743 return;
744 }
745
746 if (btrfs_test_opt(fs_info, SPACE_CACH
747 return;
748
749 if (btrfs_test_opt(fs_info, NOSPACECAC
750 return;
751
752 /*
753 * At this point we don't have explici
754 * them ourselves based on the state o
755 */
756 if (btrfs_fs_compat_ro(fs_info, FREE_S
757 btrfs_set_opt(fs_info->mount_o
758 else if (btrfs_free_space_cache_v1_act
759 btrfs_set_opt(fs_info->mount_o
760 }
761
762 static void set_device_specific_options(struct
763 {
764 if (!btrfs_test_opt(fs_info, NOSSD) &&
765 !fs_info->fs_devices->rotating)
766 btrfs_set_opt(fs_info->mount_o
767
768 /*
769 * For devices supporting discard turn
770 * unless it's already set or disabled
771 * nodiscard for the same mount.
772 *
773 * The zoned mode piggy backs on the d
774 * resetting a zone. There is no reaso
775 * fast enough. So, do not enable asyn
776 */
777 if (!(btrfs_test_opt(fs_info, DISCARD_
778 btrfs_test_opt(fs_info, DISCARD_
779 btrfs_test_opt(fs_info, NODISCAR
780 fs_info->fs_devices->discardable &
781 !btrfs_is_zoned(fs_info))
782 btrfs_set_opt(fs_info->mount_o
783 }
784
785 char *btrfs_get_subvol_name_from_objectid(stru
786 u64
787 {
788 struct btrfs_root *root = fs_info->tre
789 struct btrfs_root *fs_root = NULL;
790 struct btrfs_root_ref *root_ref;
791 struct btrfs_inode_ref *inode_ref;
792 struct btrfs_key key;
793 struct btrfs_path *path = NULL;
794 char *name = NULL, *ptr;
795 u64 dirid;
796 int len;
797 int ret;
798
799 path = btrfs_alloc_path();
800 if (!path) {
801 ret = -ENOMEM;
802 goto err;
803 }
804
805 name = kmalloc(PATH_MAX, GFP_KERNEL);
806 if (!name) {
807 ret = -ENOMEM;
808 goto err;
809 }
810 ptr = name + PATH_MAX - 1;
811 ptr[0] = '\0';
812
813 /*
814 * Walk up the subvolume trees in the
815 * backrefs until we hit the top-level
816 */
817 while (subvol_objectid != BTRFS_FS_TRE
818 key.objectid = subvol_objectid
819 key.type = BTRFS_ROOT_BACKREF_
820 key.offset = (u64)-1;
821
822 ret = btrfs_search_backwards(r
823 if (ret < 0) {
824 goto err;
825 } else if (ret > 0) {
826 ret = -ENOENT;
827 goto err;
828 }
829
830 subvol_objectid = key.offset;
831
832 root_ref = btrfs_item_ptr(path
833 stru
834 len = btrfs_root_ref_name_len(
835 ptr -= len + 1;
836 if (ptr < name) {
837 ret = -ENAMETOOLONG;
838 goto err;
839 }
840 read_extent_buffer(path->nodes
841 (unsigned l
842 ptr[0] = '/';
843 dirid = btrfs_root_ref_dirid(p
844 btrfs_release_path(path);
845
846 fs_root = btrfs_get_fs_root(fs
847 if (IS_ERR(fs_root)) {
848 ret = PTR_ERR(fs_root)
849 fs_root = NULL;
850 goto err;
851 }
852
853 /*
854 * Walk up the filesystem tree
855 * root directory.
856 */
857 while (dirid != BTRFS_FIRST_FR
858 key.objectid = dirid;
859 key.type = BTRFS_INODE
860 key.offset = (u64)-1;
861
862 ret = btrfs_search_bac
863 if (ret < 0) {
864 goto err;
865 } else if (ret > 0) {
866 ret = -ENOENT;
867 goto err;
868 }
869
870 dirid = key.offset;
871
872 inode_ref = btrfs_item
873
874
875 len = btrfs_inode_ref_
876
877 ptr -= len + 1;
878 if (ptr < name) {
879 ret = -ENAMETO
880 goto err;
881 }
882 read_extent_buffer(pat
883 (un
884 ptr[0] = '/';
885 btrfs_release_path(pat
886 }
887 btrfs_put_root(fs_root);
888 fs_root = NULL;
889 }
890
891 btrfs_free_path(path);
892 if (ptr == name + PATH_MAX - 1) {
893 name[0] = '/';
894 name[1] = '\0';
895 } else {
896 memmove(name, ptr, name + PATH
897 }
898 return name;
899
900 err:
901 btrfs_put_root(fs_root);
902 btrfs_free_path(path);
903 kfree(name);
904 return ERR_PTR(ret);
905 }
906
907 static int get_default_subvol_objectid(struct
908 {
909 struct btrfs_root *root = fs_info->tre
910 struct btrfs_dir_item *di;
911 struct btrfs_path *path;
912 struct btrfs_key location;
913 struct fscrypt_str name = FSTR_INIT("d
914 u64 dir_id;
915
916 path = btrfs_alloc_path();
917 if (!path)
918 return -ENOMEM;
919
920 /*
921 * Find the "default" dir item which p
922 * will mount by default if we haven't
923 * to mount.
924 */
925 dir_id = btrfs_super_root_dir(fs_info-
926 di = btrfs_lookup_dir_item(NULL, root,
927 if (IS_ERR(di)) {
928 btrfs_free_path(path);
929 return PTR_ERR(di);
930 }
931 if (!di) {
932 /*
933 * Ok the default dir item isn
934 * it's always been there, but
935 * mount the top-level subvolu
936 */
937 btrfs_free_path(path);
938 *objectid = BTRFS_FS_TREE_OBJE
939 return 0;
940 }
941
942 btrfs_dir_item_key_to_cpu(path->nodes[
943 btrfs_free_path(path);
944 *objectid = location.objectid;
945 return 0;
946 }
947
948 static int btrfs_fill_super(struct super_block
949 struct btrfs_fs_de
950 void *data)
951 {
952 struct inode *inode;
953 struct btrfs_fs_info *fs_info = btrfs_
954 int err;
955
956 sb->s_maxbytes = MAX_LFS_FILESIZE;
957 sb->s_magic = BTRFS_SUPER_MAGIC;
958 sb->s_op = &btrfs_super_ops;
959 sb->s_d_op = &btrfs_dentry_operations;
960 sb->s_export_op = &btrfs_export_ops;
961 #ifdef CONFIG_FS_VERITY
962 sb->s_vop = &btrfs_verityops;
963 #endif
964 sb->s_xattr = btrfs_xattr_handlers;
965 sb->s_time_gran = 1;
966 sb->s_iflags |= SB_I_CGROUPWB;
967
968 err = super_setup_bdi(sb);
969 if (err) {
970 btrfs_err(fs_info, "super_setu
971 return err;
972 }
973
974 err = open_ctree(sb, fs_devices, (char
975 if (err) {
976 btrfs_err(fs_info, "open_ctree
977 return err;
978 }
979
980 inode = btrfs_iget(BTRFS_FIRST_FREE_OB
981 if (IS_ERR(inode)) {
982 err = PTR_ERR(inode);
983 btrfs_handle_fs_error(fs_info,
984 goto fail_close;
985 }
986
987 sb->s_root = d_make_root(inode);
988 if (!sb->s_root) {
989 err = -ENOMEM;
990 goto fail_close;
991 }
992
993 sb->s_flags |= SB_ACTIVE;
994 return 0;
995
996 fail_close:
997 close_ctree(fs_info);
998 return err;
999 }
1000
1001 int btrfs_sync_fs(struct super_block *sb, int
1002 {
1003 struct btrfs_trans_handle *trans;
1004 struct btrfs_fs_info *fs_info = btrfs
1005 struct btrfs_root *root = fs_info->tr
1006
1007 trace_btrfs_sync_fs(fs_info, wait);
1008
1009 if (!wait) {
1010 filemap_flush(fs_info->btree_
1011 return 0;
1012 }
1013
1014 btrfs_wait_ordered_roots(fs_info, U64
1015
1016 trans = btrfs_attach_transaction_barr
1017 if (IS_ERR(trans)) {
1018 /* no transaction, don't both
1019 if (PTR_ERR(trans) == -ENOENT
1020 /*
1021 * Exit unless we hav
1022 * that need to go th
1023 */
1024 if (!test_bit(BTRFS_F
1025 &fs_inf
1026 return 0;
1027 /*
1028 * A non-blocking tes
1029 * start a new transa
1030 * happens. The pendi
1031 * next commit after
1032 */
1033 if (sb_start_write_tr
1034 sb_end_write(
1035 else
1036 return 0;
1037 trans = btrfs_start_t
1038 }
1039 if (IS_ERR(trans))
1040 return PTR_ERR(trans)
1041 }
1042 return btrfs_commit_transaction(trans
1043 }
1044
1045 static void print_rescue_option(struct seq_fi
1046 {
1047 seq_printf(seq, "%s%s", (*printed) ?
1048 *printed = true;
1049 }
1050
1051 static int btrfs_show_options(struct seq_file
1052 {
1053 struct btrfs_fs_info *info = btrfs_sb
1054 const char *compress_type;
1055 const char *subvol_name;
1056 bool printed = false;
1057
1058 if (btrfs_test_opt(info, DEGRADED))
1059 seq_puts(seq, ",degraded");
1060 if (btrfs_test_opt(info, NODATASUM))
1061 seq_puts(seq, ",nodatasum");
1062 if (btrfs_test_opt(info, NODATACOW))
1063 seq_puts(seq, ",nodatacow");
1064 if (btrfs_test_opt(info, NOBARRIER))
1065 seq_puts(seq, ",nobarrier");
1066 if (info->max_inline != BTRFS_DEFAULT
1067 seq_printf(seq, ",max_inline=
1068 if (info->thread_pool_size != min_t(
1069
1070 seq_printf(seq, ",thread_pool
1071 if (btrfs_test_opt(info, COMPRESS)) {
1072 compress_type = btrfs_compres
1073 if (btrfs_test_opt(info, FORC
1074 seq_printf(seq, ",com
1075 else
1076 seq_printf(seq, ",com
1077 if (info->compress_level)
1078 seq_printf(seq, ":%d"
1079 }
1080 if (btrfs_test_opt(info, NOSSD))
1081 seq_puts(seq, ",nossd");
1082 if (btrfs_test_opt(info, SSD_SPREAD))
1083 seq_puts(seq, ",ssd_spread");
1084 else if (btrfs_test_opt(info, SSD))
1085 seq_puts(seq, ",ssd");
1086 if (btrfs_test_opt(info, NOTREELOG))
1087 seq_puts(seq, ",notreelog");
1088 if (btrfs_test_opt(info, NOLOGREPLAY)
1089 print_rescue_option(seq, "nol
1090 if (btrfs_test_opt(info, USEBACKUPROO
1091 print_rescue_option(seq, "use
1092 if (btrfs_test_opt(info, IGNOREBADROO
1093 print_rescue_option(seq, "ign
1094 if (btrfs_test_opt(info, IGNOREDATACS
1095 print_rescue_option(seq, "ign
1096 if (btrfs_test_opt(info, IGNOREMETACS
1097 print_rescue_option(seq, "ign
1098 if (btrfs_test_opt(info, IGNORESUPERF
1099 print_rescue_option(seq, "ign
1100 if (btrfs_test_opt(info, FLUSHONCOMMI
1101 seq_puts(seq, ",flushoncommit
1102 if (btrfs_test_opt(info, DISCARD_SYNC
1103 seq_puts(seq, ",discard");
1104 if (btrfs_test_opt(info, DISCARD_ASYN
1105 seq_puts(seq, ",discard=async
1106 if (!(info->sb->s_flags & SB_POSIXACL
1107 seq_puts(seq, ",noacl");
1108 if (btrfs_free_space_cache_v1_active(
1109 seq_puts(seq, ",space_cache")
1110 else if (btrfs_fs_compat_ro(info, FRE
1111 seq_puts(seq, ",space_cache=v
1112 else
1113 seq_puts(seq, ",nospace_cache
1114 if (btrfs_test_opt(info, RESCAN_UUID_
1115 seq_puts(seq, ",rescan_uuid_t
1116 if (btrfs_test_opt(info, CLEAR_CACHE)
1117 seq_puts(seq, ",clear_cache")
1118 if (btrfs_test_opt(info, USER_SUBVOL_
1119 seq_puts(seq, ",user_subvol_r
1120 if (btrfs_test_opt(info, ENOSPC_DEBUG
1121 seq_puts(seq, ",enospc_debug"
1122 if (btrfs_test_opt(info, AUTO_DEFRAG)
1123 seq_puts(seq, ",autodefrag");
1124 if (btrfs_test_opt(info, SKIP_BALANCE
1125 seq_puts(seq, ",skip_balance"
1126 if (info->metadata_ratio)
1127 seq_printf(seq, ",metadata_ra
1128 if (btrfs_test_opt(info, PANIC_ON_FAT
1129 seq_puts(seq, ",fatal_errors=
1130 if (info->commit_interval != BTRFS_DE
1131 seq_printf(seq, ",commit=%u",
1132 #ifdef CONFIG_BTRFS_DEBUG
1133 if (btrfs_test_opt(info, FRAGMENT_DAT
1134 seq_puts(seq, ",fragment=data
1135 if (btrfs_test_opt(info, FRAGMENT_MET
1136 seq_puts(seq, ",fragment=meta
1137 #endif
1138 if (btrfs_test_opt(info, REF_VERIFY))
1139 seq_puts(seq, ",ref_verify");
1140 seq_printf(seq, ",subvolid=%llu", btr
1141 subvol_name = btrfs_get_subvol_name_f
1142 btrfs_root_id(BTRFS_I
1143 if (!IS_ERR(subvol_name)) {
1144 seq_puts(seq, ",subvol=");
1145 seq_escape(seq, subvol_name,
1146 kfree(subvol_name);
1147 }
1148 return 0;
1149 }
1150
1151 /*
1152 * subvolumes are identified by ino 256
1153 */
1154 static inline int is_subvolume_inode(struct i
1155 {
1156 if (inode && inode->i_ino == BTRFS_FI
1157 return 1;
1158 return 0;
1159 }
1160
1161 static struct dentry *mount_subvol(const char
1162 struct vfs
1163 {
1164 struct dentry *root;
1165 int ret;
1166
1167 if (!subvol_name) {
1168 if (!subvol_objectid) {
1169 ret = get_default_sub
1170
1171 if (ret) {
1172 root = ERR_PT
1173 goto out;
1174 }
1175 }
1176 subvol_name = btrfs_get_subvo
1177 btrfs
1178 if (IS_ERR(subvol_name)) {
1179 root = ERR_CAST(subvo
1180 subvol_name = NULL;
1181 goto out;
1182 }
1183
1184 }
1185
1186 root = mount_subtree(mnt, subvol_name
1187 /* mount_subtree() drops our referenc
1188 mnt = NULL;
1189
1190 if (!IS_ERR(root)) {
1191 struct super_block *s = root-
1192 struct btrfs_fs_info *fs_info
1193 struct inode *root_inode = d_
1194 u64 root_objectid = btrfs_roo
1195
1196 ret = 0;
1197 if (!is_subvolume_inode(root_
1198 btrfs_err(fs_info, "'
1199 subvol_name);
1200 ret = -EINVAL;
1201 }
1202 if (subvol_objectid && root_o
1203 /*
1204 * This will also cat
1205 * subvolume which wa
1206 * another subvolume
1207 */
1208 btrfs_err(fs_info,
1209 "subvol '%s
1210 subvol_name
1211 ret = -EINVAL;
1212 }
1213 if (ret) {
1214 dput(root);
1215 root = ERR_PTR(ret);
1216 deactivate_locked_sup
1217 }
1218 }
1219
1220 out:
1221 mntput(mnt);
1222 kfree(subvol_name);
1223 return root;
1224 }
1225
1226 static void btrfs_resize_thread_pool(struct b
1227 u32 new_
1228 {
1229 if (new_pool_size == old_pool_size)
1230 return;
1231
1232 fs_info->thread_pool_size = new_pool_
1233
1234 btrfs_info(fs_info, "resize thread po
1235 old_pool_size, new_pool_size);
1236
1237 btrfs_workqueue_set_max(fs_info->work
1238 btrfs_workqueue_set_max(fs_info->dela
1239 btrfs_workqueue_set_max(fs_info->cach
1240 workqueue_set_max_active(fs_info->end
1241 workqueue_set_max_active(fs_info->end
1242 btrfs_workqueue_set_max(fs_info->endi
1243 btrfs_workqueue_set_max(fs_info->endi
1244 btrfs_workqueue_set_max(fs_info->dela
1245 }
1246
1247 static inline void btrfs_remount_begin(struct
1248 unsign
1249 {
1250 if (btrfs_raw_test_opt(old_opts, AUTO
1251 (!btrfs_raw_test_opt(fs_info->mou
1252 (flags & SB_RDONLY))) {
1253 /* wait for any defraggers to
1254 wait_event(fs_info->transacti
1255 (atomic_read(&fs_i
1256 if (flags & SB_RDONLY)
1257 sync_filesystem(fs_in
1258 }
1259 }
1260
1261 static inline void btrfs_remount_cleanup(stru
1262 unsi
1263 {
1264 const bool cache_opt = btrfs_test_opt
1265
1266 /*
1267 * We need to cleanup all defragable
1268 * close or the filesystem is read on
1269 */
1270 if (btrfs_raw_test_opt(old_opts, AUTO
1271 (!btrfs_raw_test_opt(fs_info->mou
1272 btrfs_cleanup_defrag_inodes(f
1273 }
1274
1275 /* If we toggled discard async */
1276 if (!btrfs_raw_test_opt(old_opts, DIS
1277 btrfs_test_opt(fs_info, DISCARD_A
1278 btrfs_discard_resume(fs_info)
1279 else if (btrfs_raw_test_opt(old_opts,
1280 !btrfs_test_opt(fs_info, DIS
1281 btrfs_discard_cleanup(fs_info
1282
1283 /* If we toggled space cache */
1284 if (cache_opt != btrfs_free_space_cac
1285 btrfs_set_free_space_cache_v1
1286 }
1287
1288 static int btrfs_remount_rw(struct btrfs_fs_i
1289 {
1290 int ret;
1291
1292 if (BTRFS_FS_ERROR(fs_info)) {
1293 btrfs_err(fs_info,
1294 "remounting read-wr
1295 return -EINVAL;
1296 }
1297
1298 if (fs_info->fs_devices->rw_devices =
1299 return -EACCES;
1300
1301 if (!btrfs_check_rw_degradable(fs_inf
1302 btrfs_warn(fs_info,
1303 "too many missing
1304 return -EACCES;
1305 }
1306
1307 if (btrfs_super_log_root(fs_info->sup
1308 btrfs_warn(fs_info,
1309 "mount required to
1310 return -EINVAL;
1311 }
1312
1313 /*
1314 * NOTE: when remounting with a chang
1315 * anywhere above this point, as we a
1316 * until we pass the above checks.
1317 */
1318 ret = btrfs_start_pre_rw_mount(fs_inf
1319 if (ret)
1320 return ret;
1321
1322 btrfs_clear_sb_rdonly(fs_info->sb);
1323
1324 set_bit(BTRFS_FS_OPEN, &fs_info->flag
1325
1326 /*
1327 * If we've gone from readonly -> rea
1328 * sync/async discard lists in the ri
1329 */
1330 btrfs_discard_resume(fs_info);
1331
1332 return 0;
1333 }
1334
1335 static int btrfs_remount_ro(struct btrfs_fs_i
1336 {
1337 /*
1338 * This also happens on 'umount -rf'
1339 * filesystem is busy.
1340 */
1341 cancel_work_sync(&fs_info->async_recl
1342 cancel_work_sync(&fs_info->async_data
1343
1344 btrfs_discard_cleanup(fs_info);
1345
1346 /* Wait for the uuid_scan task to fin
1347 down(&fs_info->uuid_tree_rescan_sem);
1348 /* Avoid complains from lockdep et al
1349 up(&fs_info->uuid_tree_rescan_sem);
1350
1351 btrfs_set_sb_rdonly(fs_info->sb);
1352
1353 /*
1354 * Setting SB_RDONLY will put the cle
1355 * loop if it's already active. If i
1356 * unused block groups on disk until
1357 * unless we clean them up here.
1358 */
1359 btrfs_delete_unused_bgs(fs_info);
1360
1361 /*
1362 * The cleaner task could be already
1363 * BTRFS_FS_STATE_RO (and SB_RDONLY i
1364 * sure that after we finish the remo
1365 * btrfs_commit_super(), the cleaner
1366 * - either because it was dropping a
1367 * or deleting an unused block grou
1368 * group from the list of unused bl
1369 * in the previous call to btrfs_de
1370 */
1371 wait_on_bit(&fs_info->flags, BTRFS_FS
1372
1373 /*
1374 * We've set the superblock to RO mod
1375 * cleaner task sleep without running
1376 * through all the delayed iputs here
1377 * without remounting RW we don't end
1378 * with a non-empty list of delayed i
1379 */
1380 btrfs_run_delayed_iputs(fs_info);
1381
1382 btrfs_dev_replace_suspend_for_unmount
1383 btrfs_scrub_cancel(fs_info);
1384 btrfs_pause_balance(fs_info);
1385
1386 /*
1387 * Pause the qgroup rescan worker if
1388 * be still running after we are in R
1389 * we unmount, it might have left a t
1390 * the transaction and/or crash.
1391 */
1392 btrfs_qgroup_wait_for_completion(fs_i
1393
1394 return btrfs_commit_super(fs_info);
1395 }
1396
1397 static void btrfs_ctx_to_info(struct btrfs_fs
1398 {
1399 fs_info->max_inline = ctx->max_inline
1400 fs_info->commit_interval = ctx->commi
1401 fs_info->metadata_ratio = ctx->metada
1402 fs_info->thread_pool_size = ctx->thre
1403 fs_info->mount_opt = ctx->mount_opt;
1404 fs_info->compress_type = ctx->compres
1405 fs_info->compress_level = ctx->compre
1406 }
1407
1408 static void btrfs_info_to_ctx(struct btrfs_fs
1409 {
1410 ctx->max_inline = fs_info->max_inline
1411 ctx->commit_interval = fs_info->commi
1412 ctx->metadata_ratio = fs_info->metada
1413 ctx->thread_pool_size = fs_info->thre
1414 ctx->mount_opt = fs_info->mount_opt;
1415 ctx->compress_type = fs_info->compres
1416 ctx->compress_level = fs_info->compre
1417 }
1418
1419 #define btrfs_info_if_set(fs_info, old_ctx, o
1420 do {
1421 if ((!old_ctx || !btrfs_raw_test_opt(
1422 btrfs_raw_test_opt(fs_info->mount
1423 btrfs_info(fs_info, fmt, ##ar
1424 } while (0)
1425
1426 #define btrfs_info_if_unset(fs_info, old_ctx,
1427 do {
1428 if ((old_ctx && btrfs_raw_test_opt(ol
1429 !btrfs_raw_test_opt(fs_info->moun
1430 btrfs_info(fs_info, fmt, ##ar
1431 } while (0)
1432
1433 static void btrfs_emit_options(struct btrfs_f
1434 struct btrfs_f
1435 {
1436 btrfs_info_if_set(info, old, NODATASU
1437 btrfs_info_if_set(info, old, DEGRADED
1438 btrfs_info_if_set(info, old, NODATASU
1439 btrfs_info_if_set(info, old, SSD, "en
1440 btrfs_info_if_set(info, old, SSD_SPRE
1441 btrfs_info_if_set(info, old, NOBARRIE
1442 btrfs_info_if_set(info, old, NOTREELO
1443 btrfs_info_if_set(info, old, NOLOGREP
1444 btrfs_info_if_set(info, old, FLUSHONC
1445 btrfs_info_if_set(info, old, DISCARD_
1446 btrfs_info_if_set(info, old, DISCARD_
1447 btrfs_info_if_set(info, old, FREE_SPA
1448 btrfs_info_if_set(info, old, SPACE_CA
1449 btrfs_info_if_set(info, old, CLEAR_CA
1450 btrfs_info_if_set(info, old, AUTO_DEF
1451 btrfs_info_if_set(info, old, FRAGMENT
1452 btrfs_info_if_set(info, old, FRAGMENT
1453 btrfs_info_if_set(info, old, REF_VERI
1454 btrfs_info_if_set(info, old, USEBACKU
1455 btrfs_info_if_set(info, old, IGNOREBA
1456 btrfs_info_if_set(info, old, IGNOREDA
1457 btrfs_info_if_set(info, old, IGNOREME
1458 btrfs_info_if_set(info, old, IGNORESU
1459
1460 btrfs_info_if_unset(info, old, NODATA
1461 btrfs_info_if_unset(info, old, SSD, "
1462 btrfs_info_if_unset(info, old, SSD_SP
1463 btrfs_info_if_unset(info, old, NOBARR
1464 btrfs_info_if_unset(info, old, NOTREE
1465 btrfs_info_if_unset(info, old, SPACE_
1466 btrfs_info_if_unset(info, old, FREE_S
1467 btrfs_info_if_unset(info, old, AUTO_D
1468 btrfs_info_if_unset(info, old, COMPRE
1469
1470 /* Did the compression settings chang
1471 if (btrfs_test_opt(info, COMPRESS) &&
1472 (!old ||
1473 old->compress_type != info->comp
1474 old->compress_level != info->com
1475 (!btrfs_raw_test_opt(old->mount_
1476 btrfs_raw_test_opt(info->mount_
1477 const char *compress_type = b
1478
1479 btrfs_info(info, "%s %s compr
1480 btrfs_test_opt(inf
1481 compress_type, inf
1482 }
1483
1484 if (info->max_inline != BTRFS_DEFAULT
1485 btrfs_info(info, "max_inline
1486 }
1487
1488 static int btrfs_reconfigure(struct fs_contex
1489 {
1490 struct super_block *sb = fc->root->d_
1491 struct btrfs_fs_info *fs_info = btrfs
1492 struct btrfs_fs_context *ctx = fc->fs
1493 struct btrfs_fs_context old_ctx;
1494 int ret = 0;
1495 bool mount_reconfigure = (fc->s_fs_in
1496
1497 btrfs_info_to_ctx(fs_info, &old_ctx);
1498
1499 /*
1500 * This is our "bind mount" trick, we
1501 * anything other than mount a differ
1502 * all of the mount options should be
1503 */
1504 if (mount_reconfigure)
1505 ctx->mount_opt = old_ctx.moun
1506
1507 sync_filesystem(sb);
1508 set_bit(BTRFS_FS_STATE_REMOUNTING, &f
1509
1510 if (!btrfs_check_options(fs_info, &ct
1511 return -EINVAL;
1512
1513 ret = btrfs_check_features(fs_info, !
1514 if (ret < 0)
1515 return ret;
1516
1517 btrfs_ctx_to_info(fs_info, ctx);
1518 btrfs_remount_begin(fs_info, old_ctx.
1519 btrfs_resize_thread_pool(fs_info, fs_
1520 old_ctx.thre
1521
1522 if ((bool)btrfs_test_opt(fs_info, FRE
1523 (bool)btrfs_fs_compat_ro(fs_info,
1524 (!sb_rdonly(sb) || (fc->sb_flags
1525 btrfs_warn(fs_info,
1526 "remount supports changing fr
1527 /* Make sure free space cache
1528 if (btrfs_fs_compat_ro(fs_inf
1529 btrfs_set_opt(fs_info
1530 btrfs_clear_opt(fs_in
1531 }
1532 if (btrfs_free_space_cache_v1
1533 btrfs_clear_opt(fs_in
1534 btrfs_set_opt(fs_info
1535 }
1536 }
1537
1538 ret = 0;
1539 if (!sb_rdonly(sb) && (fc->sb_flags &
1540 ret = btrfs_remount_ro(fs_inf
1541 else if (sb_rdonly(sb) && !(fc->sb_fl
1542 ret = btrfs_remount_rw(fs_inf
1543 if (ret)
1544 goto restore;
1545
1546 /*
1547 * If we set the mask during the para
1548 * remount. Here we can set the mask
1549 * appropriately.
1550 */
1551 if ((fc->sb_flags & SB_POSIXACL) != (
1552 fc->sb_flags_mask |= SB_POSIX
1553
1554 btrfs_emit_options(fs_info, &old_ctx)
1555 wake_up_process(fs_info->transaction_
1556 btrfs_remount_cleanup(fs_info, old_ct
1557 btrfs_clear_oneshot_options(fs_info);
1558 clear_bit(BTRFS_FS_STATE_REMOUNTING,
1559
1560 return 0;
1561 restore:
1562 btrfs_ctx_to_info(fs_info, &old_ctx);
1563 btrfs_remount_cleanup(fs_info, old_ct
1564 clear_bit(BTRFS_FS_STATE_REMOUNTING,
1565 return ret;
1566 }
1567
1568 /* Used to sort the devices by max_avail(desc
1569 static int btrfs_cmp_device_free_bytes(const
1570 {
1571 const struct btrfs_device_info *dev_i
1572 const struct btrfs_device_info *dev_i
1573
1574 if (dev_info1->max_avail > dev_info2-
1575 return -1;
1576 else if (dev_info1->max_avail < dev_i
1577 return 1;
1578 return 0;
1579 }
1580
1581 /*
1582 * sort the devices by max_avail, in which ma
1583 * is stored.(Descending Sort)
1584 */
1585 static inline void btrfs_descending_sort_devi
1586 struc
1587 size_
1588 {
1589 sort(devices, nr_devices, sizeof(stru
1590 btrfs_cmp_device_free_bytes, NUL
1591 }
1592
1593 /*
1594 * The helper to calc the free space on the d
1595 * file data.
1596 */
1597 static inline int btrfs_calc_avail_data_space
1598
1599 {
1600 struct btrfs_device_info *devices_inf
1601 struct btrfs_fs_devices *fs_devices =
1602 struct btrfs_device *device;
1603 u64 type;
1604 u64 avail_space;
1605 u64 min_stripe_size;
1606 int num_stripes = 1;
1607 int i = 0, nr_devices;
1608 const struct btrfs_raid_attr *rattr;
1609
1610 /*
1611 * We aren't under the device list lo
1612 * enough for our purposes.
1613 */
1614 nr_devices = fs_info->fs_devices->ope
1615 if (!nr_devices) {
1616 smp_mb();
1617 nr_devices = fs_info->fs_devi
1618 ASSERT(nr_devices);
1619 if (!nr_devices) {
1620 *free_bytes = 0;
1621 return 0;
1622 }
1623 }
1624
1625 devices_info = kmalloc_array(nr_devic
1626 GFP_KERNEL);
1627 if (!devices_info)
1628 return -ENOMEM;
1629
1630 /* calc min stripe number for data sp
1631 type = btrfs_data_alloc_profile(fs_in
1632 rattr = &btrfs_raid_array[btrfs_bg_fl
1633
1634 if (type & BTRFS_BLOCK_GROUP_RAID0)
1635 num_stripes = nr_devices;
1636 else if (type & BTRFS_BLOCK_GROUP_RAI
1637 num_stripes = rattr->ncopies;
1638 else if (type & BTRFS_BLOCK_GROUP_RAI
1639 num_stripes = 4;
1640
1641 /* Adjust for more than 1 stripe per
1642 min_stripe_size = rattr->dev_stripes
1643
1644 rcu_read_lock();
1645 list_for_each_entry_rcu(device, &fs_d
1646 if (!test_bit(BTRFS_DEV_STATE
1647
1648 !device->bdev ||
1649 test_bit(BTRFS_DEV_STATE_
1650 continue;
1651
1652 if (i >= nr_devices)
1653 break;
1654
1655 avail_space = device->total_b
1656
1657 /* align with stripe_len */
1658 avail_space = rounddown(avail
1659
1660 /*
1661 * Ensure we have at least mi
1662 * reserved space on the devi
1663 */
1664 if (avail_space <= BTRFS_DEVI
1665 continue;
1666
1667 avail_space -= BTRFS_DEVICE_R
1668
1669 devices_info[i].dev = device;
1670 devices_info[i].max_avail = a
1671
1672 i++;
1673 }
1674 rcu_read_unlock();
1675
1676 nr_devices = i;
1677
1678 btrfs_descending_sort_devices(devices
1679
1680 i = nr_devices - 1;
1681 avail_space = 0;
1682 while (nr_devices >= rattr->devs_min)
1683 num_stripes = min(num_stripes
1684
1685 if (devices_info[i].max_avail
1686 int j;
1687 u64 alloc_size;
1688
1689 avail_space += device
1690 alloc_size = devices_
1691 for (j = i + 1 - num_
1692 devices_info[
1693 }
1694 i--;
1695 nr_devices--;
1696 }
1697
1698 kfree(devices_info);
1699 *free_bytes = avail_space;
1700 return 0;
1701 }
1702
1703 /*
1704 * Calculate numbers for 'df', pessimistic in
1705 *
1706 * If there's a redundant raid level at DATA
1707 * multiplier to scale the sizes.
1708 *
1709 * Unused device space usage is based on simu
1710 * algorithm that respects the device sizes a
1711 * a close approximation of the actual use bu
1712 * change the result (like a new metadata chu
1713 *
1714 * If metadata is exhausted, f_bavail will be
1715 */
1716 static int btrfs_statfs(struct dentry *dentry
1717 {
1718 struct btrfs_fs_info *fs_info = btrfs
1719 struct btrfs_super_block *disk_super
1720 struct btrfs_space_info *found;
1721 u64 total_used = 0;
1722 u64 total_free_data = 0;
1723 u64 total_free_meta = 0;
1724 u32 bits = fs_info->sectorsize_bits;
1725 __be32 *fsid = (__be32 *)fs_info->fs_
1726 unsigned factor = 1;
1727 struct btrfs_block_rsv *block_rsv = &
1728 int ret;
1729 u64 thresh = 0;
1730 int mixed = 0;
1731
1732 list_for_each_entry(found, &fs_info->
1733 if (found->flags & BTRFS_BLOC
1734 int i;
1735
1736 total_free_data += fo
1737 total_free_data -=
1738 btrfs_account
1739
1740 for (i = 0; i < BTRFS
1741 if (!list_emp
1742 facto
1743
1744 }
1745 }
1746
1747 /*
1748 * Metadata in mixed block gr
1749 */
1750 if (!mixed && found->flags &
1751 if (found->flags & BT
1752 mixed = 1;
1753 else
1754 total_free_me
1755 found
1756 }
1757
1758 total_used += found->disk_use
1759 }
1760
1761 buf->f_blocks = div_u64(btrfs_super_t
1762 buf->f_blocks >>= bits;
1763 buf->f_bfree = buf->f_blocks - (div_u
1764
1765 /* Account global block reserve as us
1766 spin_lock(&block_rsv->lock);
1767 /* Mixed block groups accounting is n
1768 if (buf->f_bfree >= block_rsv->size >
1769 buf->f_bfree -= block_rsv->si
1770 else
1771 buf->f_bfree = 0;
1772 spin_unlock(&block_rsv->lock);
1773
1774 buf->f_bavail = div_u64(total_free_da
1775 ret = btrfs_calc_avail_data_space(fs_
1776 if (ret)
1777 return ret;
1778 buf->f_bavail += div_u64(total_free_d
1779 buf->f_bavail = buf->f_bavail >> bits
1780
1781 /*
1782 * We calculate the remaining metadat
1783 * this is (supposedly) smaller than
1784 * does not hold in practice, the exh
1785 * some positive delta. So we apply s
1786 * delta to a 4M threshold. (Practic
1787 *
1788 * We probably cannot calculate the e
1789 * depends on the internal reservatio
1790 * operations, so some operations tha
1791 * succeed even if the Avail is zero.
1792 * way around.
1793 */
1794 thresh = SZ_4M;
1795
1796 /*
1797 * We only want to claim there's no a
1798 * allocate chunks for our metadata p
1799 * not fit in the free metadata space
1800 * still can allocate chunks and thus
1801 * calculated f_bavail.
1802 */
1803 if (!mixed && block_rsv->space_info->
1804 (total_free_meta < thresh || tota
1805 buf->f_bavail = 0;
1806
1807 buf->f_type = BTRFS_SUPER_MAGIC;
1808 buf->f_bsize = fs_info->sectorsize;
1809 buf->f_namelen = BTRFS_NAME_LEN;
1810
1811 /* We treat it as constant endianness
1812 because we want the fsid to come o
1813 on a big-endian or little-endian h
1814 buf->f_fsid.val[0] = be32_to_cpu(fsid
1815 buf->f_fsid.val[1] = be32_to_cpu(fsid
1816 /* Mask in the root object ID too, to
1817 buf->f_fsid.val[0] ^= btrfs_root_id(B
1818 buf->f_fsid.val[1] ^= btrfs_root_id(B
1819
1820 return 0;
1821 }
1822
1823 static int btrfs_fc_test_super(struct super_b
1824 {
1825 struct btrfs_fs_info *p = fc->s_fs_in
1826 struct btrfs_fs_info *fs_info = btrfs
1827
1828 return fs_info->fs_devices == p->fs_d
1829 }
1830
1831 static int btrfs_get_tree_super(struct fs_con
1832 {
1833 struct btrfs_fs_info *fs_info = fc->s
1834 struct btrfs_fs_context *ctx = fc->fs
1835 struct btrfs_fs_devices *fs_devices =
1836 struct block_device *bdev;
1837 struct btrfs_device *device;
1838 struct super_block *sb;
1839 blk_mode_t mode = btrfs_open_mode(fc)
1840 int ret;
1841
1842 btrfs_ctx_to_info(fs_info, ctx);
1843 mutex_lock(&uuid_mutex);
1844
1845 /*
1846 * With 'true' passed to btrfs_scan_o
1847 * either a valid device or an error.
1848 */
1849 device = btrfs_scan_one_device(fc->so
1850 ASSERT(device != NULL);
1851 if (IS_ERR(device)) {
1852 mutex_unlock(&uuid_mutex);
1853 return PTR_ERR(device);
1854 }
1855
1856 fs_devices = device->fs_devices;
1857 fs_info->fs_devices = fs_devices;
1858
1859 ret = btrfs_open_devices(fs_devices,
1860 mutex_unlock(&uuid_mutex);
1861 if (ret)
1862 return ret;
1863
1864 if (!(fc->sb_flags & SB_RDONLY) && fs
1865 ret = -EACCES;
1866 goto error;
1867 }
1868
1869 bdev = fs_devices->latest_dev->bdev;
1870
1871 /*
1872 * From now on the error handling is
1873 *
1874 * If successful, this will transfer
1875 * and fc->s_fs_info will be NULL. H
1876 * super, we'll still have fc->s_fs_i
1877 * completely out it'll be cleaned up
1878 * otherwise it's tied to the lifetim
1879 */
1880 sb = sget_fc(fc, btrfs_fc_test_super,
1881 if (IS_ERR(sb)) {
1882 ret = PTR_ERR(sb);
1883 goto error;
1884 }
1885
1886 set_device_specific_options(fs_info);
1887
1888 if (sb->s_root) {
1889 btrfs_close_devices(fs_device
1890 if ((fc->sb_flags ^ sb->s_fla
1891 ret = -EBUSY;
1892 } else {
1893 snprintf(sb->s_id, sizeof(sb-
1894 shrinker_debugfs_rename(sb->s
1895 btrfs_sb(sb)->bdev_holder = &
1896 ret = btrfs_fill_super(sb, fs
1897 }
1898
1899 if (ret) {
1900 deactivate_locked_super(sb);
1901 return ret;
1902 }
1903
1904 btrfs_clear_oneshot_options(fs_info);
1905
1906 fc->root = dget(sb->s_root);
1907 return 0;
1908
1909 error:
1910 btrfs_close_devices(fs_devices);
1911 return ret;
1912 }
1913
1914 /*
1915 * Ever since commit 0723a0473fb4 ("btrfs: al
1916 * with different ro/rw options") the followi
1917 *
1918 * (i) mount /dev/sda3 -o subvol=foo,r
1919 * (ii) mount /dev/sda3 -o subvol=bar,r
1920 *
1921 * which looks nice and innocent but is actua
1922 * a long comment.
1923 *
1924 * On another filesystem a subvolume mount is
1925 *
1926 * (iii) # create rw superblock + initia
1927 * mount -t xfs /dev/sdb /opt/
1928 *
1929 * # create ro bind mount
1930 * mount --bind -o ro /opt/foo /mn
1931 *
1932 * # unmount initial mount
1933 * umount /opt
1934 *
1935 * Of course, there's some special subvolume
1936 * sb->s_root dentry is really swapped after
1937 * it's very close and will help us understan
1938 *
1939 * The old mount API didn't cleanly distingui
1940 * and a superblock being made ro. The only
1941 * either object was by passing ms_rdonly. If
1942 * mount(2) such as:
1943 *
1944 * mount("/dev/sdb", "/mnt", "xfs", ms_r
1945 *
1946 * the MS_RDONLY flag being specified had two
1947 *
1948 * (1) MNT_READONLY was raised -> the resulti
1949 * @mnt->mnt_flags |= MNT_READONLY raised
1950 *
1951 * (2) MS_RDONLY was passed to the filesystem
1952 * made the superblock ro. Note, how SB_R
1953 * ms_rdonly and is raised whenever MS_RD
1954 *
1955 * Creating a subtree mount via (iii) ends up
1956 * subtree mounted ro.
1957 *
1958 * But consider the effect on the old mount A
1959 * which combines the distinct step in (iii)
1960 *
1961 * By issuing (i) both the mount and the supe
1962 * is issued the superblock is ro and thus ev
1963 * rw it wouldn't help. Hence, btrfs needed t
1964 * to rw for (ii) which it did using an inter
1965 *
1966 * IOW, subvolume mounting was inherently com
1967 * MS_RDONLY in mount(2). Note, this ambiguit
1968 * "ro" to MS_RDONLY. IOW, in both (i) and (i
1969 * passed by mount(8) to mount(2).
1970 *
1971 * Enter the new mount API. The new mount API
1972 * and making a superblock ro.
1973 *
1974 * (3) To turn a mount ro the MOUNT_ATTR_ONLY
1975 * fsmount() or mount_setattr() this is a
1976 * specific mount or mount tree that is n
1977 *
1978 * (4) To turn a superblock ro the "ro" flag
1979 * fsconfig(FSCONFIG_SET_FLAG, "ro"). Thi
1980 * in fc->sb_flags.
1981 *
1982 * But, currently the util-linux mount comman
1983 * API and is still setting fsconfig(FSCONFIG
1984 * btrfs or not, setting the whole super bloc
1985 * work with different options work we need t
1986 */
1987 static struct vfsmount *btrfs_reconfigure_for
1988 {
1989 struct vfsmount *mnt;
1990 int ret;
1991 const bool ro2rw = !(fc->sb_flags & S
1992
1993 /*
1994 * We got an EBUSY because our SB_RDO
1995 * super block, so invert our setting
1996 * can get our vfsmount.
1997 */
1998 if (ro2rw)
1999 fc->sb_flags |= SB_RDONLY;
2000 else
2001 fc->sb_flags &= ~SB_RDONLY;
2002
2003 mnt = fc_mount(fc);
2004 if (IS_ERR(mnt))
2005 return mnt;
2006
2007 if (!ro2rw)
2008 return mnt;
2009
2010 /* We need to convert to rw, call rec
2011 fc->sb_flags &= ~SB_RDONLY;
2012 down_write(&mnt->mnt_sb->s_umount);
2013 ret = btrfs_reconfigure(fc);
2014 up_write(&mnt->mnt_sb->s_umount);
2015 if (ret) {
2016 mntput(mnt);
2017 return ERR_PTR(ret);
2018 }
2019 return mnt;
2020 }
2021
2022 static int btrfs_get_tree_subvol(struct fs_co
2023 {
2024 struct btrfs_fs_info *fs_info = NULL;
2025 struct btrfs_fs_context *ctx = fc->fs
2026 struct fs_context *dup_fc;
2027 struct dentry *dentry;
2028 struct vfsmount *mnt;
2029
2030 /*
2031 * Setup a dummy root and fs_info for
2032 * we don't actually fill this stuff
2033 * then open_ctree will properly init
2034 * settings later. btrfs_init_fs_inf
2035 * of the fs_info (locks and such) to
2036 * superblock with our given fs_devic
2037 */
2038 fs_info = kvzalloc(sizeof(struct btrf
2039 if (!fs_info)
2040 return -ENOMEM;
2041
2042 fs_info->super_copy = kzalloc(BTRFS_S
2043 fs_info->super_for_commit = kzalloc(B
2044 if (!fs_info->super_copy || !fs_info-
2045 btrfs_free_fs_info(fs_info);
2046 return -ENOMEM;
2047 }
2048 btrfs_init_fs_info(fs_info);
2049
2050 dup_fc = vfs_dup_fs_context(fc);
2051 if (IS_ERR(dup_fc)) {
2052 btrfs_free_fs_info(fs_info);
2053 return PTR_ERR(dup_fc);
2054 }
2055
2056 /*
2057 * When we do the sget_fc this gets t
2058 * need to set it on the dup_fc as th
2059 */
2060 dup_fc->s_fs_info = fs_info;
2061
2062 /*
2063 * We'll do the security settings in
2064 * loop, they were duplicated into du
2065 * here.
2066 */
2067 security_free_mnt_opts(&fc->security)
2068 fc->security = NULL;
2069
2070 mnt = fc_mount(dup_fc);
2071 if (PTR_ERR_OR_ZERO(mnt) == -EBUSY)
2072 mnt = btrfs_reconfigure_for_m
2073 put_fs_context(dup_fc);
2074 if (IS_ERR(mnt))
2075 return PTR_ERR(mnt);
2076
2077 /*
2078 * This free's ->subvol_name, because
2079 * allocate a buffer to hold the subv
2080 * reference to it here.
2081 */
2082 dentry = mount_subvol(ctx->subvol_nam
2083 ctx->subvol_name = NULL;
2084 if (IS_ERR(dentry))
2085 return PTR_ERR(dentry);
2086
2087 fc->root = dentry;
2088 return 0;
2089 }
2090
2091 static int btrfs_get_tree(struct fs_context *
2092 {
2093 /*
2094 * Since we use mount_subtree to moun
2095 * have to do mounts in two steps.
2096 *
2097 * First pass through we call btrfs_g
2098 * wrapper around fc_mount() to call
2099 * we'll call btrfs_get_tree_super().
2100 * everything to open the devices and
2101 * with a fully constructed vfsmount
2102 * from there we can do our mount_sub
2103 * whichever subvol we're mounting an
2104 * appropriate dentry for the subvol.
2105 */
2106 if (fc->s_fs_info)
2107 return btrfs_get_tree_super(f
2108 return btrfs_get_tree_subvol(fc);
2109 }
2110
2111 static void btrfs_kill_super(struct super_blo
2112 {
2113 struct btrfs_fs_info *fs_info = btrfs
2114 kill_anon_super(sb);
2115 btrfs_free_fs_info(fs_info);
2116 }
2117
2118 static void btrfs_free_fs_context(struct fs_c
2119 {
2120 struct btrfs_fs_context *ctx = fc->fs
2121 struct btrfs_fs_info *fs_info = fc->s
2122
2123 if (fs_info)
2124 btrfs_free_fs_info(fs_info);
2125
2126 if (ctx && refcount_dec_and_test(&ctx
2127 kfree(ctx->subvol_name);
2128 kfree(ctx);
2129 }
2130 }
2131
2132 static int btrfs_dup_fs_context(struct fs_con
2133 {
2134 struct btrfs_fs_context *ctx = src_fc
2135
2136 /*
2137 * Give a ref to our ctx to this dup,
2138 * our original fc so we can have the
2139 *
2140 * We unset ->source in the original
2141 * mounting, and then once we free th
2142 * need to make sure we're only point
2143 */
2144 refcount_inc(&ctx->refs);
2145 fc->fs_private = ctx;
2146 fc->source = src_fc->source;
2147 src_fc->source = NULL;
2148 return 0;
2149 }
2150
2151 static const struct fs_context_operations btr
2152 .parse_param = btrfs_parse_param,
2153 .reconfigure = btrfs_reconfigure,
2154 .get_tree = btrfs_get_tree,
2155 .dup = btrfs_dup_fs_contex
2156 .free = btrfs_free_fs_conte
2157 };
2158
2159 static int btrfs_init_fs_context(struct fs_co
2160 {
2161 struct btrfs_fs_context *ctx;
2162
2163 ctx = kzalloc(sizeof(struct btrfs_fs_
2164 if (!ctx)
2165 return -ENOMEM;
2166
2167 refcount_set(&ctx->refs, 1);
2168 fc->fs_private = ctx;
2169 fc->ops = &btrfs_fs_context_ops;
2170
2171 if (fc->purpose == FS_CONTEXT_FOR_REC
2172 btrfs_info_to_ctx(btrfs_sb(fc
2173 } else {
2174 ctx->thread_pool_size =
2175 min_t(unsigned long,
2176 ctx->max_inline = BTRFS_DEFAU
2177 ctx->commit_interval = BTRFS_
2178 }
2179
2180 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
2181 fc->sb_flags |= SB_POSIXACL;
2182 #endif
2183 fc->sb_flags |= SB_I_VERSION;
2184
2185 return 0;
2186 }
2187
2188 static struct file_system_type btrfs_fs_type
2189 .owner = THIS_MODULE
2190 .name = "btrfs",
2191 .init_fs_context = btrfs_init_
2192 .parameters = btrfs_fs_pa
2193 .kill_sb = btrfs_kill_
2194 .fs_flags = FS_REQUIRES
2195 };
2196
2197 MODULE_ALIAS_FS("btrfs");
2198
2199 static int btrfs_control_open(struct inode *i
2200 {
2201 /*
2202 * The control file's private_data is
2203 * transaction when it is started and
2204 * track of whether a transaction is
2205 */
2206 file->private_data = NULL;
2207 return 0;
2208 }
2209
2210 /*
2211 * Used by /dev/btrfs-control for devices ioc
2212 */
2213 static long btrfs_control_ioctl(struct file *
2214 unsigned long
2215 {
2216 struct btrfs_ioctl_vol_args *vol;
2217 struct btrfs_device *device = NULL;
2218 dev_t devt = 0;
2219 int ret = -ENOTTY;
2220
2221 if (!capable(CAP_SYS_ADMIN))
2222 return -EPERM;
2223
2224 vol = memdup_user((void __user *)arg,
2225 if (IS_ERR(vol))
2226 return PTR_ERR(vol);
2227 ret = btrfs_check_ioctl_vol_args_path
2228 if (ret < 0)
2229 goto out;
2230
2231 switch (cmd) {
2232 case BTRFS_IOC_SCAN_DEV:
2233 mutex_lock(&uuid_mutex);
2234 /*
2235 * Scanning outside of mount
2236 * into 0 error code.
2237 */
2238 device = btrfs_scan_one_devic
2239 ret = PTR_ERR_OR_ZERO(device)
2240 mutex_unlock(&uuid_mutex);
2241 break;
2242 case BTRFS_IOC_FORGET_DEV:
2243 if (vol->name[0] != 0) {
2244 ret = lookup_bdev(vol
2245 if (ret)
2246 break;
2247 }
2248 ret = btrfs_forget_devices(de
2249 break;
2250 case BTRFS_IOC_DEVICES_READY:
2251 mutex_lock(&uuid_mutex);
2252 /*
2253 * Scanning outside of mount
2254 * into 0 error code.
2255 */
2256 device = btrfs_scan_one_devic
2257 if (IS_ERR_OR_NULL(device)) {
2258 mutex_unlock(&uuid_mu
2259 ret = PTR_ERR(device)
2260 break;
2261 }
2262 ret = !(device->fs_devices->n
2263 device->fs_devices->t
2264 mutex_unlock(&uuid_mutex);
2265 break;
2266 case BTRFS_IOC_GET_SUPPORTED_FEATURES
2267 ret = btrfs_ioctl_get_support
2268 break;
2269 }
2270
2271 out:
2272 kfree(vol);
2273 return ret;
2274 }
2275
2276 static int btrfs_freeze(struct super_block *s
2277 {
2278 struct btrfs_fs_info *fs_info = btrfs
2279
2280 set_bit(BTRFS_FS_FROZEN, &fs_info->fl
2281 /*
2282 * We don't need a barrier here, we'l
2283 * could be in progress on other thre
2284 * we want to avoid on a frozen files
2285 * ourselves.
2286 */
2287 return btrfs_commit_current_transacti
2288 }
2289
2290 static int check_dev_super(struct btrfs_devic
2291 {
2292 struct btrfs_fs_info *fs_info = dev->
2293 struct btrfs_super_block *sb;
2294 u64 last_trans;
2295 u16 csum_type;
2296 int ret = 0;
2297
2298 /* This should be called with fs stil
2299 ASSERT(test_bit(BTRFS_FS_FROZEN, &fs_
2300
2301 /* Missing dev, no need to check. */
2302 if (!dev->bdev)
2303 return 0;
2304
2305 /* Only need to check the primary sup
2306 sb = btrfs_read_dev_one_super(dev->bd
2307 if (IS_ERR(sb))
2308 return PTR_ERR(sb);
2309
2310 /* Verify the checksum. */
2311 csum_type = btrfs_super_csum_type(sb)
2312 if (csum_type != btrfs_super_csum_typ
2313 btrfs_err(fs_info, "csum type
2314 csum_type, btrfs_su
2315 ret = -EUCLEAN;
2316 goto out;
2317 }
2318
2319 if (btrfs_check_super_csum(fs_info, s
2320 btrfs_err(fs_info, "csum for
2321 ret = -EUCLEAN;
2322 goto out;
2323 }
2324
2325 /* Btrfs_validate_super() includes fs
2326 ret = btrfs_validate_super(fs_info, s
2327 if (ret < 0)
2328 goto out;
2329
2330 last_trans = btrfs_get_last_trans_com
2331 if (btrfs_super_generation(sb) != las
2332 btrfs_err(fs_info, "transid m
2333 btrfs_super_generat
2334 ret = -EUCLEAN;
2335 goto out;
2336 }
2337 out:
2338 btrfs_release_disk_super(sb);
2339 return ret;
2340 }
2341
2342 static int btrfs_unfreeze(struct super_block
2343 {
2344 struct btrfs_fs_info *fs_info = btrfs
2345 struct btrfs_device *device;
2346 int ret = 0;
2347
2348 /*
2349 * Make sure the fs is not changed by
2350 * modified by other OS).
2351 * If we found anything wrong, we mar
2352 *
2353 * And since the fs is frozen, no one
2354 * we don't need to hold device_list_
2355 */
2356 list_for_each_entry(device, &fs_info-
2357 ret = check_dev_super(device)
2358 if (ret < 0) {
2359 btrfs_handle_fs_error
2360 "super block
2361 device->devid
2362 break;
2363 }
2364 }
2365 clear_bit(BTRFS_FS_FROZEN, &fs_info->
2366
2367 /*
2368 * We still return 0, to allow VFS la
2369 * above checks failed. Since the fs
2370 * safe to continue, without causing
2371 */
2372 return 0;
2373 }
2374
2375 static int btrfs_show_devname(struct seq_file
2376 {
2377 struct btrfs_fs_info *fs_info = btrfs
2378
2379 /*
2380 * There should be always a valid poi
2381 * for a short moment in case it's be
2382 * the end of RCU grace period.
2383 */
2384 rcu_read_lock();
2385 seq_escape(m, btrfs_dev_name(fs_info-
2386 rcu_read_unlock();
2387
2388 return 0;
2389 }
2390
2391 static long btrfs_nr_cached_objects(struct su
2392 {
2393 struct btrfs_fs_info *fs_info = btrfs
2394 const s64 nr = percpu_counter_sum_pos
2395
2396 trace_btrfs_extent_map_shrinker_count
2397
2398 /*
2399 * Only report the real number for DE
2400 * serious performance degradation ca
2401 */
2402 if (IS_ENABLED(CONFIG_BTRFS_DEBUG))
2403 return nr;
2404 return 0;
2405 }
2406
2407 static long btrfs_free_cached_objects(struct
2408 {
2409 const long nr_to_scan = min_t(unsigne
2410 struct btrfs_fs_info *fs_info = btrfs
2411
2412 /*
2413 * We may be called from any task try
2414 * want to slow it down with scanning
2415 * also cause heavy lock contention i
2416 * here. Therefore only allow kswapd
2417 */
2418 if (!current_is_kswapd())
2419 return 0;
2420
2421 return btrfs_free_extent_maps(fs_info
2422 }
2423
2424 static const struct super_operations btrfs_su
2425 .drop_inode = btrfs_drop_inode,
2426 .evict_inode = btrfs_evict_inode,
2427 .put_super = btrfs_put_super,
2428 .sync_fs = btrfs_sync_fs,
2429 .show_options = btrfs_show_options,
2430 .show_devname = btrfs_show_devname,
2431 .alloc_inode = btrfs_alloc_inode,
2432 .destroy_inode = btrfs_destroy_inode
2433 .free_inode = btrfs_free_inode,
2434 .statfs = btrfs_statfs,
2435 .freeze_fs = btrfs_freeze,
2436 .unfreeze_fs = btrfs_unfreeze,
2437 .nr_cached_objects = btrfs_nr_cached_
2438 .free_cached_objects = btrfs_free_cac
2439 };
2440
2441 static const struct file_operations btrfs_ctl
2442 .open = btrfs_control_open,
2443 .unlocked_ioctl = btrfs_control_ioct
2444 .compat_ioctl = compat_ptr_ioctl,
2445 .owner = THIS_MODULE,
2446 .llseek = noop_llseek,
2447 };
2448
2449 static struct miscdevice btrfs_misc = {
2450 .minor = BTRFS_MINOR,
2451 .name = "btrfs-control",
2452 .fops = &btrfs_ctl_fops
2453 };
2454
2455 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
2456 MODULE_ALIAS("devname:btrfs-control");
2457
2458 static int __init btrfs_interface_init(void)
2459 {
2460 return misc_register(&btrfs_misc);
2461 }
2462
2463 static __cold void btrfs_interface_exit(void)
2464 {
2465 misc_deregister(&btrfs_misc);
2466 }
2467
2468 static int __init btrfs_print_mod_info(void)
2469 {
2470 static const char options[] = ""
2471 #ifdef CONFIG_BTRFS_DEBUG
2472 ", debug=on"
2473 #endif
2474 #ifdef CONFIG_BTRFS_ASSERT
2475 ", assert=on"
2476 #endif
2477 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
2478 ", ref-verify=on"
2479 #endif
2480 #ifdef CONFIG_BLK_DEV_ZONED
2481 ", zoned=yes"
2482 #else
2483 ", zoned=no"
2484 #endif
2485 #ifdef CONFIG_FS_VERITY
2486 ", fsverity=yes"
2487 #else
2488 ", fsverity=no"
2489 #endif
2490 ;
2491 pr_info("Btrfs loaded%s\n", options);
2492 return 0;
2493 }
2494
2495 static int register_btrfs(void)
2496 {
2497 return register_filesystem(&btrfs_fs_
2498 }
2499
2500 static void unregister_btrfs(void)
2501 {
2502 unregister_filesystem(&btrfs_fs_type)
2503 }
2504
2505 /* Helper structure for long init/exit functi
2506 struct init_sequence {
2507 int (*init_func)(void);
2508 /* Can be NULL if the init_func doesn
2509 void (*exit_func)(void);
2510 };
2511
2512 static const struct init_sequence mod_init_se
2513 {
2514 .init_func = btrfs_props_init
2515 .exit_func = NULL,
2516 }, {
2517 .init_func = btrfs_init_sysfs
2518 .exit_func = btrfs_exit_sysfs
2519 }, {
2520 .init_func = btrfs_init_compr
2521 .exit_func = btrfs_exit_compr
2522 }, {
2523 .init_func = btrfs_init_cache
2524 .exit_func = btrfs_destroy_ca
2525 }, {
2526 .init_func = btrfs_init_dio,
2527 .exit_func = btrfs_destroy_di
2528 }, {
2529 .init_func = btrfs_transactio
2530 .exit_func = btrfs_transactio
2531 }, {
2532 .init_func = btrfs_ctree_init
2533 .exit_func = btrfs_ctree_exit
2534 }, {
2535 .init_func = btrfs_free_space
2536 .exit_func = btrfs_free_space
2537 }, {
2538 .init_func = extent_state_ini
2539 .exit_func = extent_state_fre
2540 }, {
2541 .init_func = extent_buffer_in
2542 .exit_func = extent_buffer_fr
2543 }, {
2544 .init_func = btrfs_bioset_ini
2545 .exit_func = btrfs_bioset_exi
2546 }, {
2547 .init_func = extent_map_init,
2548 .exit_func = extent_map_exit,
2549 }, {
2550 .init_func = ordered_data_ini
2551 .exit_func = ordered_data_exi
2552 }, {
2553 .init_func = btrfs_delayed_in
2554 .exit_func = btrfs_delayed_in
2555 }, {
2556 .init_func = btrfs_auto_defra
2557 .exit_func = btrfs_auto_defra
2558 }, {
2559 .init_func = btrfs_delayed_re
2560 .exit_func = btrfs_delayed_re
2561 }, {
2562 .init_func = btrfs_prelim_ref
2563 .exit_func = btrfs_prelim_ref
2564 }, {
2565 .init_func = btrfs_interface_
2566 .exit_func = btrfs_interface_
2567 }, {
2568 .init_func = btrfs_print_mod_
2569 .exit_func = NULL,
2570 }, {
2571 .init_func = btrfs_run_sanity
2572 .exit_func = NULL,
2573 }, {
2574 .init_func = register_btrfs,
2575 .exit_func = unregister_btrfs
2576 }
2577 };
2578
2579 static bool mod_init_result[ARRAY_SIZE(mod_in
2580
2581 static __always_inline void btrfs_exit_btrfs_
2582 {
2583 int i;
2584
2585 for (i = ARRAY_SIZE(mod_init_seq) - 1
2586 if (!mod_init_result[i])
2587 continue;
2588 if (mod_init_seq[i].exit_func
2589 mod_init_seq[i].exit_
2590 mod_init_result[i] = false;
2591 }
2592 }
2593
2594 static void __exit exit_btrfs_fs(void)
2595 {
2596 btrfs_exit_btrfs_fs();
2597 btrfs_cleanup_fs_uuids();
2598 }
2599
2600 static int __init init_btrfs_fs(void)
2601 {
2602 int ret;
2603 int i;
2604
2605 for (i = 0; i < ARRAY_SIZE(mod_init_s
2606 ASSERT(!mod_init_result[i]);
2607 ret = mod_init_seq[i].init_fu
2608 if (ret < 0) {
2609 btrfs_exit_btrfs_fs()
2610 return ret;
2611 }
2612 mod_init_result[i] = true;
2613 }
2614 return 0;
2615 }
2616
2617 late_initcall(init_btrfs_fs);
2618 module_exit(exit_btrfs_fs)
2619
2620 MODULE_DESCRIPTION("B-Tree File System (BTRFS
2621 MODULE_LICENSE("GPL");
2622 MODULE_SOFTDEP("pre: crc32c");
2623 MODULE_SOFTDEP("pre: xxhash64");
2624 MODULE_SOFTDEP("pre: sha256");
2625 MODULE_SOFTDEP("pre: blake2b-256");
2626
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