?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Btrfs: fix xattr loss after power failure
[linux/fpc-iii.git] / fs / btrfs / super.c
blob0628092b0b1bde633f9e2c0f6c339feda75013ec
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/buffer_head.h>
9 #include <linux/fs.h>
10 #include <linux/pagemap.h>
11 #include <linux/highmem.h>
12 #include <linux/time.h>
13 #include <linux/init.h>
14 #include <linux/seq_file.h>
15 #include <linux/string.h>
16 #include <linux/backing-dev.h>
17 #include <linux/mount.h>
18 #include <linux/mpage.h>
19 #include <linux/swap.h>
20 #include <linux/writeback.h>
21 #include <linux/statfs.h>
22 #include <linux/compat.h>
23 #include <linux/parser.h>
24 #include <linux/ctype.h>
25 #include <linux/namei.h>
26 #include <linux/miscdevice.h>
27 #include <linux/magic.h>
28 #include <linux/slab.h>
29 #include <linux/cleancache.h>
30 #include <linux/ratelimit.h>
31 #include <linux/crc32c.h>
32 #include <linux/btrfs.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 "print-tree.h"
39 #include "props.h"
40 #include "xattr.h"
41 #include "volumes.h"
42 #include "export.h"
43 #include "compression.h"
44 #include "rcu-string.h"
45 #include "dev-replace.h"
46 #include "free-space-cache.h"
47 #include "backref.h"
48 #include "tests/btrfs-tests.h"
49
50 #include "qgroup.h"
51 #define CREATE_TRACE_POINTS
52 #include <trace/events/btrfs.h>
53
54 static const struct super_operations btrfs_super_ops;
55
56 /*
57 * Types for mounting the default subvolume and a subvolume explicitly
58 * requested by subvol=/path. That way the callchain is straightforward and we
59 * don't have to play tricks with the mount options and recursive calls to
60 * btrfs_mount.
61 *
62 * The new btrfs_root_fs_type also servers as a tag for the bdev_holder.
63 */
64 static struct file_system_type btrfs_fs_type;
65 static struct file_system_type btrfs_root_fs_type;
66
67 static int btrfs_remount(struct super_block *sb, int *flags, char *data);
68
69 const char *btrfs_decode_error(int errno)
70 {
71 char *errstr = "unknown";
72
73 switch (errno) {
74 case -EIO:
75 errstr = "IO failure";
76 break;
77 case -ENOMEM:
78 errstr = "Out of memory";
79 break;
80 case -EROFS:
81 errstr = "Readonly filesystem";
82 break;
83 case -EEXIST:
84 errstr = "Object already exists";
85 break;
86 case -ENOSPC:
87 errstr = "No space left";
88 break;
89 case -ENOENT:
90 errstr = "No such entry";
91 break;
92 }
93
94 return errstr;
95 }
96
97 /*
98 * __btrfs_handle_fs_error decodes expected errors from the caller and
99 * invokes the approciate error response.
100 */
101 __cold
102 void __btrfs_handle_fs_error(struct btrfs_fs_info *fs_info, const char *function,
103 unsigned int line, int errno, const char *fmt, ...)
104 {
105 struct super_block *sb = fs_info->sb;
106 #ifdef CONFIG_PRINTK
107 const char *errstr;
108 #endif
109
110 /*
111 * Special case: if the error is EROFS, and we're already
112 * under SB_RDONLY, then it is safe here.
113 */
114 if (errno == -EROFS && sb_rdonly(sb))
115 return;
116
117 #ifdef CONFIG_PRINTK
118 errstr = btrfs_decode_error(errno);
119 if (fmt) {
120 struct va_format vaf;
121 va_list args;
122
123 va_start(args, fmt);
124 vaf.fmt = fmt;
125 vaf.va = &args;
126
127 pr_crit("BTRFS: error (device %s) in %s:%d: errno=%d %s (%pV)\n",
128 sb->s_id, function, line, errno, errstr, &vaf);
129 va_end(args);
130 } else {
131 pr_crit("BTRFS: error (device %s) in %s:%d: errno=%d %s\n",
132 sb->s_id, function, line, errno, errstr);
133 }
134 #endif
135
136 /*
137 * Today we only save the error info to memory. Long term we'll
138 * also send it down to the disk
139 */
140 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
141
142 /* Don't go through full error handling during mount */
143 if (!(sb->s_flags & SB_BORN))
144 return;
145
146 if (sb_rdonly(sb))
147 return;
148
149 /* btrfs handle error by forcing the filesystem readonly */
150 sb->s_flags |= SB_RDONLY;
151 btrfs_info(fs_info, "forced readonly");
152 /*
153 * Note that a running device replace operation is not canceled here
154 * although there is no way to update the progress. It would add the
155 * risk of a deadlock, therefore the canceling is omitted. The only
156 * penalty is that some I/O remains active until the procedure
157 * completes. The next time when the filesystem is mounted writeable
158 * again, the device replace operation continues.
159 */
160 }
161
162 #ifdef CONFIG_PRINTK
163 static const char * const logtypes[] = {
164 "emergency",
165 "alert",
166 "critical",
167 "error",
168 "warning",
169 "notice",
170 "info",
171 "debug",
172 };
173
174
175 /*
176 * Use one ratelimit state per log level so that a flood of less important
177 * messages doesn't cause more important ones to be dropped.
178 */
179 static struct ratelimit_state printk_limits[] = {
180 RATELIMIT_STATE_INIT(printk_limits[0], DEFAULT_RATELIMIT_INTERVAL, 100),
181 RATELIMIT_STATE_INIT(printk_limits[1], DEFAULT_RATELIMIT_INTERVAL, 100),
182 RATELIMIT_STATE_INIT(printk_limits[2], DEFAULT_RATELIMIT_INTERVAL, 100),
183 RATELIMIT_STATE_INIT(printk_limits[3], DEFAULT_RATELIMIT_INTERVAL, 100),
184 RATELIMIT_STATE_INIT(printk_limits[4], DEFAULT_RATELIMIT_INTERVAL, 100),
185 RATELIMIT_STATE_INIT(printk_limits[5], DEFAULT_RATELIMIT_INTERVAL, 100),
186 RATELIMIT_STATE_INIT(printk_limits[6], DEFAULT_RATELIMIT_INTERVAL, 100),
187 RATELIMIT_STATE_INIT(printk_limits[7], DEFAULT_RATELIMIT_INTERVAL, 100),
188 };
189
190 void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
191 {
192 char lvl[PRINTK_MAX_SINGLE_HEADER_LEN + 1] = "\0";
193 struct va_format vaf;
194 va_list args;
195 int kern_level;
196 const char *type = logtypes[4];
197 struct ratelimit_state *ratelimit = &printk_limits[4];
198
199 va_start(args, fmt);
200
201 while ((kern_level = printk_get_level(fmt)) != 0) {
202 size_t size = printk_skip_level(fmt) - fmt;
203
204 if (kern_level >= '0' && kern_level <= '7') {
205 memcpy(lvl, fmt, size);
206 lvl[size] = '\0';
207 type = logtypes[kern_level - '0'];
208 ratelimit = &printk_limits[kern_level - '0'];
209 }
210 fmt += size;
211 }
212
213 vaf.fmt = fmt;
214 vaf.va = &args;
215
216 if (__ratelimit(ratelimit))
217 printk("%sBTRFS %s (device %s): %pV\n", lvl, type,
218 fs_info ? fs_info->sb->s_id : "<unknown>", &vaf);
219
220 va_end(args);
221 }
222 #endif
223
224 /*
225 * We only mark the transaction aborted and then set the file system read-only.
226 * This will prevent new transactions from starting or trying to join this
227 * one.
228 *
229 * This means that error recovery at the call site is limited to freeing
230 * any local memory allocations and passing the error code up without
231 * further cleanup. The transaction should complete as it normally would
232 * in the call path but will return -EIO.
233 *
234 * We'll complete the cleanup in btrfs_end_transaction and
235 * btrfs_commit_transaction.
236 */
237 __cold
238 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
239 const char *function,
240 unsigned int line, int errno)
241 {
242 struct btrfs_fs_info *fs_info = trans->fs_info;
243
244 trans->aborted = errno;
245 /* Nothing used. The other threads that have joined this
246 * transaction may be able to continue. */
247 if (!trans->dirty && list_empty(&trans->new_bgs)) {
248 const char *errstr;
249
250 errstr = btrfs_decode_error(errno);
251 btrfs_warn(fs_info,
252 "%s:%d: Aborting unused transaction(%s).",
253 function, line, errstr);
254 return;
255 }
256 WRITE_ONCE(trans->transaction->aborted, errno);
257 /* Wake up anybody who may be waiting on this transaction */
258 wake_up(&fs_info->transaction_wait);
259 wake_up(&fs_info->transaction_blocked_wait);
260 __btrfs_handle_fs_error(fs_info, function, line, errno, NULL);
261 }
262 /*
263 * __btrfs_panic decodes unexpected, fatal errors from the caller,
264 * issues an alert, and either panics or BUGs, depending on mount options.
265 */
266 __cold
267 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
268 unsigned int line, int errno, const char *fmt, ...)
269 {
270 char *s_id = "<unknown>";
271 const char *errstr;
272 struct va_format vaf = { .fmt = fmt };
273 va_list args;
274
275 if (fs_info)
276 s_id = fs_info->sb->s_id;
277
278 va_start(args, fmt);
279 vaf.va = &args;
280
281 errstr = btrfs_decode_error(errno);
282 if (fs_info && (btrfs_test_opt(fs_info, PANIC_ON_FATAL_ERROR)))
283 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
284 s_id, function, line, &vaf, errno, errstr);
285
286 btrfs_crit(fs_info, "panic in %s:%d: %pV (errno=%d %s)",
287 function, line, &vaf, errno, errstr);
288 va_end(args);
289 /* Caller calls BUG() */
290 }
291
292 static void btrfs_put_super(struct super_block *sb)
293 {
294 close_ctree(btrfs_sb(sb));
295 }
296
297 enum {
298 Opt_acl, Opt_noacl,
299 Opt_clear_cache,
300 Opt_commit_interval,
301 Opt_compress,
302 Opt_compress_force,
303 Opt_compress_force_type,
304 Opt_compress_type,
305 Opt_degraded,
306 Opt_device,
307 Opt_fatal_errors,
308 Opt_flushoncommit, Opt_noflushoncommit,
309 Opt_inode_cache, Opt_noinode_cache,
310 Opt_max_inline,
311 Opt_barrier, Opt_nobarrier,
312 Opt_datacow, Opt_nodatacow,
313 Opt_datasum, Opt_nodatasum,
314 Opt_defrag, Opt_nodefrag,
315 Opt_discard, Opt_nodiscard,
316 Opt_nologreplay,
317 Opt_norecovery,
318 Opt_ratio,
319 Opt_rescan_uuid_tree,
320 Opt_skip_balance,
321 Opt_space_cache, Opt_no_space_cache,
322 Opt_space_cache_version,
323 Opt_ssd, Opt_nossd,
324 Opt_ssd_spread, Opt_nossd_spread,
325 Opt_subvol,
326 Opt_subvolid,
327 Opt_thread_pool,
328 Opt_treelog, Opt_notreelog,
329 Opt_usebackuproot,
330 Opt_user_subvol_rm_allowed,
331
332 /* Deprecated options */
333 Opt_alloc_start,
334 Opt_recovery,
335 Opt_subvolrootid,
336
337 /* Debugging options */
338 Opt_check_integrity,
339 Opt_check_integrity_including_extent_data,
340 Opt_check_integrity_print_mask,
341 Opt_enospc_debug, Opt_noenospc_debug,
342 #ifdef CONFIG_BTRFS_DEBUG
343 Opt_fragment_data, Opt_fragment_metadata, Opt_fragment_all,
344 #endif
345 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
346 Opt_ref_verify,
347 #endif
348 Opt_err,
349 };
350
351 static const match_table_t tokens = {
352 {Opt_acl, "acl"},
353 {Opt_noacl, "noacl"},
354 {Opt_clear_cache, "clear_cache"},
355 {Opt_commit_interval, "commit=%u"},
356 {Opt_compress, "compress"},
357 {Opt_compress_type, "compress=%s"},
358 {Opt_compress_force, "compress-force"},
359 {Opt_compress_force_type, "compress-force=%s"},
360 {Opt_degraded, "degraded"},
361 {Opt_device, "device=%s"},
362 {Opt_fatal_errors, "fatal_errors=%s"},
363 {Opt_flushoncommit, "flushoncommit"},
364 {Opt_noflushoncommit, "noflushoncommit"},
365 {Opt_inode_cache, "inode_cache"},
366 {Opt_noinode_cache, "noinode_cache"},
367 {Opt_max_inline, "max_inline=%s"},
368 {Opt_barrier, "barrier"},
369 {Opt_nobarrier, "nobarrier"},
370 {Opt_datacow, "datacow"},
371 {Opt_nodatacow, "nodatacow"},
372 {Opt_datasum, "datasum"},
373 {Opt_nodatasum, "nodatasum"},
374 {Opt_defrag, "autodefrag"},
375 {Opt_nodefrag, "noautodefrag"},
376 {Opt_discard, "discard"},
377 {Opt_nodiscard, "nodiscard"},
378 {Opt_nologreplay, "nologreplay"},
379 {Opt_norecovery, "norecovery"},
380 {Opt_ratio, "metadata_ratio=%u"},
381 {Opt_rescan_uuid_tree, "rescan_uuid_tree"},
382 {Opt_skip_balance, "skip_balance"},
383 {Opt_space_cache, "space_cache"},
384 {Opt_no_space_cache, "nospace_cache"},
385 {Opt_space_cache_version, "space_cache=%s"},
386 {Opt_ssd, "ssd"},
387 {Opt_nossd, "nossd"},
388 {Opt_ssd_spread, "ssd_spread"},
389 {Opt_nossd_spread, "nossd_spread"},
390 {Opt_subvol, "subvol=%s"},
391 {Opt_subvolid, "subvolid=%s"},
392 {Opt_thread_pool, "thread_pool=%u"},
393 {Opt_treelog, "treelog"},
394 {Opt_notreelog, "notreelog"},
395 {Opt_usebackuproot, "usebackuproot"},
396 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
397
398 /* Deprecated options */
399 {Opt_alloc_start, "alloc_start=%s"},
400 {Opt_recovery, "recovery"},
401 {Opt_subvolrootid, "subvolrootid=%d"},
402
403 /* Debugging options */
404 {Opt_check_integrity, "check_int"},
405 {Opt_check_integrity_including_extent_data, "check_int_data"},
406 {Opt_check_integrity_print_mask, "check_int_print_mask=%u"},
407 {Opt_enospc_debug, "enospc_debug"},
408 {Opt_noenospc_debug, "noenospc_debug"},
409 #ifdef CONFIG_BTRFS_DEBUG
410 {Opt_fragment_data, "fragment=data"},
411 {Opt_fragment_metadata, "fragment=metadata"},
412 {Opt_fragment_all, "fragment=all"},
413 #endif
414 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
415 {Opt_ref_verify, "ref_verify"},
416 #endif
417 {Opt_err, NULL},
418 };
419
420 /*
421 * Regular mount options parser. Everything that is needed only when
422 * reading in a new superblock is parsed here.
423 * XXX JDM: This needs to be cleaned up for remount.
424 */
425 int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
426 unsigned long new_flags)
427 {
428 substring_t args[MAX_OPT_ARGS];
429 char *p, *num;
430 u64 cache_gen;
431 int intarg;
432 int ret = 0;
433 char *compress_type;
434 bool compress_force = false;
435 enum btrfs_compression_type saved_compress_type;
436 bool saved_compress_force;
437 int no_compress = 0;
438
439 cache_gen = btrfs_super_cache_generation(info->super_copy);
440 if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE))
441 btrfs_set_opt(info->mount_opt, FREE_SPACE_TREE);
442 else if (cache_gen)
443 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
444
445 /*
446 * Even the options are empty, we still need to do extra check
447 * against new flags
448 */
449 if (!options)
450 goto check;
451
452 while ((p = strsep(&options, ",")) != NULL) {
453 int token;
454 if (!*p)
455 continue;
456
457 token = match_token(p, tokens, args);
458 switch (token) {
459 case Opt_degraded:
460 btrfs_info(info, "allowing degraded mounts");
461 btrfs_set_opt(info->mount_opt, DEGRADED);
462 break;
463 case Opt_subvol:
464 case Opt_subvolid:
465 case Opt_subvolrootid:
466 case Opt_device:
467 /*
468 * These are parsed by btrfs_parse_subvol_options
469 * and btrfs_parse_early_options
470 * and can be happily ignored here.
471 */
472 break;
473 case Opt_nodatasum:
474 btrfs_set_and_info(info, NODATASUM,
475 "setting nodatasum");
476 break;
477 case Opt_datasum:
478 if (btrfs_test_opt(info, NODATASUM)) {
479 if (btrfs_test_opt(info, NODATACOW))
480 btrfs_info(info,
481 "setting datasum, datacow enabled");
482 else
483 btrfs_info(info, "setting datasum");
484 }
485 btrfs_clear_opt(info->mount_opt, NODATACOW);
486 btrfs_clear_opt(info->mount_opt, NODATASUM);
487 break;
488 case Opt_nodatacow:
489 if (!btrfs_test_opt(info, NODATACOW)) {
490 if (!btrfs_test_opt(info, COMPRESS) ||
491 !btrfs_test_opt(info, FORCE_COMPRESS)) {
492 btrfs_info(info,
493 "setting nodatacow, compression disabled");
494 } else {
495 btrfs_info(info, "setting nodatacow");
496 }
497 }
498 btrfs_clear_opt(info->mount_opt, COMPRESS);
499 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
500 btrfs_set_opt(info->mount_opt, NODATACOW);
501 btrfs_set_opt(info->mount_opt, NODATASUM);
502 break;
503 case Opt_datacow:
504 btrfs_clear_and_info(info, NODATACOW,
505 "setting datacow");
506 break;
507 case Opt_compress_force:
508 case Opt_compress_force_type:
509 compress_force = true;
510 /* Fallthrough */
511 case Opt_compress:
512 case Opt_compress_type:
513 saved_compress_type = btrfs_test_opt(info,
514 COMPRESS) ?
515 info->compress_type : BTRFS_COMPRESS_NONE;
516 saved_compress_force =
517 btrfs_test_opt(info, FORCE_COMPRESS);
518 if (token == Opt_compress ||
519 token == Opt_compress_force ||
520 strncmp(args[0].from, "zlib", 4) == 0) {
521 compress_type = "zlib";
522
523 info->compress_type = BTRFS_COMPRESS_ZLIB;
524 info->compress_level = BTRFS_ZLIB_DEFAULT_LEVEL;
525 /*
526 * args[0] contains uninitialized data since
527 * for these tokens we don't expect any
528 * parameter.
529 */
530 if (token != Opt_compress &&
531 token != Opt_compress_force)
532 info->compress_level =
533 btrfs_compress_str2level(args[0].from);
534 btrfs_set_opt(info->mount_opt, COMPRESS);
535 btrfs_clear_opt(info->mount_opt, NODATACOW);
536 btrfs_clear_opt(info->mount_opt, NODATASUM);
537 no_compress = 0;
538 } else if (strncmp(args[0].from, "lzo", 3) == 0) {
539 compress_type = "lzo";
540 info->compress_type = BTRFS_COMPRESS_LZO;
541 btrfs_set_opt(info->mount_opt, COMPRESS);
542 btrfs_clear_opt(info->mount_opt, NODATACOW);
543 btrfs_clear_opt(info->mount_opt, NODATASUM);
544 btrfs_set_fs_incompat(info, COMPRESS_LZO);
545 no_compress = 0;
546 } else if (strcmp(args[0].from, "zstd") == 0) {
547 compress_type = "zstd";
548 info->compress_type = BTRFS_COMPRESS_ZSTD;
549 btrfs_set_opt(info->mount_opt, COMPRESS);
550 btrfs_clear_opt(info->mount_opt, NODATACOW);
551 btrfs_clear_opt(info->mount_opt, NODATASUM);
552 btrfs_set_fs_incompat(info, COMPRESS_ZSTD);
553 no_compress = 0;
554 } else if (strncmp(args[0].from, "no", 2) == 0) {
555 compress_type = "no";
556 btrfs_clear_opt(info->mount_opt, COMPRESS);
557 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
558 compress_force = false;
559 no_compress++;
560 } else {
561 ret = -EINVAL;
562 goto out;
563 }
564
565 if (compress_force) {
566 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
567 } else {
568 /*
569 * If we remount from compress-force=xxx to
570 * compress=xxx, we need clear FORCE_COMPRESS
571 * flag, otherwise, there is no way for users
572 * to disable forcible compression separately.
573 */
574 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
575 }
576 if ((btrfs_test_opt(info, COMPRESS) &&
577 (info->compress_type != saved_compress_type ||
578 compress_force != saved_compress_force)) ||
579 (!btrfs_test_opt(info, COMPRESS) &&
580 no_compress == 1)) {
581 btrfs_info(info, "%s %s compression, level %d",
582 (compress_force) ? "force" : "use",
583 compress_type, info->compress_level);
584 }
585 compress_force = false;
586 break;
587 case Opt_ssd:
588 btrfs_set_and_info(info, SSD,
589 "enabling ssd optimizations");
590 btrfs_clear_opt(info->mount_opt, NOSSD);
591 break;
592 case Opt_ssd_spread:
593 btrfs_set_and_info(info, SSD,
594 "enabling ssd optimizations");
595 btrfs_set_and_info(info, SSD_SPREAD,
596 "using spread ssd allocation scheme");
597 btrfs_clear_opt(info->mount_opt, NOSSD);
598 break;
599 case Opt_nossd:
600 btrfs_set_opt(info->mount_opt, NOSSD);
601 btrfs_clear_and_info(info, SSD,
602 "not using ssd optimizations");
603 /* Fallthrough */
604 case Opt_nossd_spread:
605 btrfs_clear_and_info(info, SSD_SPREAD,
606 "not using spread ssd allocation scheme");
607 break;
608 case Opt_barrier:
609 btrfs_clear_and_info(info, NOBARRIER,
610 "turning on barriers");
611 break;
612 case Opt_nobarrier:
613 btrfs_set_and_info(info, NOBARRIER,
614 "turning off barriers");
615 break;
616 case Opt_thread_pool:
617 ret = match_int(&args[0], &intarg);
618 if (ret) {
619 goto out;
620 } else if (intarg == 0) {
621 ret = -EINVAL;
622 goto out;
623 }
624 info->thread_pool_size = intarg;
625 break;
626 case Opt_max_inline:
627 num = match_strdup(&args[0]);
628 if (num) {
629 info->max_inline = memparse(num, NULL);
630 kfree(num);
631
632 if (info->max_inline) {
633 info->max_inline = min_t(u64,
634 info->max_inline,
635 info->sectorsize);
636 }
637 btrfs_info(info, "max_inline at %llu",
638 info->max_inline);
639 } else {
640 ret = -ENOMEM;
641 goto out;
642 }
643 break;
644 case Opt_alloc_start:
645 btrfs_info(info,
646 "option alloc_start is obsolete, ignored");
647 break;
648 case Opt_acl:
649 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
650 info->sb->s_flags |= SB_POSIXACL;
651 break;
652 #else
653 btrfs_err(info, "support for ACL not compiled in!");
654 ret = -EINVAL;
655 goto out;
656 #endif
657 case Opt_noacl:
658 info->sb->s_flags &= ~SB_POSIXACL;
659 break;
660 case Opt_notreelog:
661 btrfs_set_and_info(info, NOTREELOG,
662 "disabling tree log");
663 break;
664 case Opt_treelog:
665 btrfs_clear_and_info(info, NOTREELOG,
666 "enabling tree log");
667 break;
668 case Opt_norecovery:
669 case Opt_nologreplay:
670 btrfs_set_and_info(info, NOLOGREPLAY,
671 "disabling log replay at mount time");
672 break;
673 case Opt_flushoncommit:
674 btrfs_set_and_info(info, FLUSHONCOMMIT,
675 "turning on flush-on-commit");
676 break;
677 case Opt_noflushoncommit:
678 btrfs_clear_and_info(info, FLUSHONCOMMIT,
679 "turning off flush-on-commit");
680 break;
681 case Opt_ratio:
682 ret = match_int(&args[0], &intarg);
683 if (ret)
684 goto out;
685 info->metadata_ratio = intarg;
686 btrfs_info(info, "metadata ratio %u",
687 info->metadata_ratio);
688 break;
689 case Opt_discard:
690 btrfs_set_and_info(info, DISCARD,
691 "turning on discard");
692 break;
693 case Opt_nodiscard:
694 btrfs_clear_and_info(info, DISCARD,
695 "turning off discard");
696 break;
697 case Opt_space_cache:
698 case Opt_space_cache_version:
699 if (token == Opt_space_cache ||
700 strcmp(args[0].from, "v1") == 0) {
701 btrfs_clear_opt(info->mount_opt,
702 FREE_SPACE_TREE);
703 btrfs_set_and_info(info, SPACE_CACHE,
704 "enabling disk space caching");
705 } else if (strcmp(args[0].from, "v2") == 0) {
706 btrfs_clear_opt(info->mount_opt,
707 SPACE_CACHE);
708 btrfs_set_and_info(info, FREE_SPACE_TREE,
709 "enabling free space tree");
710 } else {
711 ret = -EINVAL;
712 goto out;
713 }
714 break;
715 case Opt_rescan_uuid_tree:
716 btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE);
717 break;
718 case Opt_no_space_cache:
719 if (btrfs_test_opt(info, SPACE_CACHE)) {
720 btrfs_clear_and_info(info, SPACE_CACHE,
721 "disabling disk space caching");
722 }
723 if (btrfs_test_opt(info, FREE_SPACE_TREE)) {
724 btrfs_clear_and_info(info, FREE_SPACE_TREE,
725 "disabling free space tree");
726 }
727 break;
728 case Opt_inode_cache:
729 btrfs_set_pending_and_info(info, INODE_MAP_CACHE,
730 "enabling inode map caching");
731 break;
732 case Opt_noinode_cache:
733 btrfs_clear_pending_and_info(info, INODE_MAP_CACHE,
734 "disabling inode map caching");
735 break;
736 case Opt_clear_cache:
737 btrfs_set_and_info(info, CLEAR_CACHE,
738 "force clearing of disk cache");
739 break;
740 case Opt_user_subvol_rm_allowed:
741 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
742 break;
743 case Opt_enospc_debug:
744 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
745 break;
746 case Opt_noenospc_debug:
747 btrfs_clear_opt(info->mount_opt, ENOSPC_DEBUG);
748 break;
749 case Opt_defrag:
750 btrfs_set_and_info(info, AUTO_DEFRAG,
751 "enabling auto defrag");
752 break;
753 case Opt_nodefrag:
754 btrfs_clear_and_info(info, AUTO_DEFRAG,
755 "disabling auto defrag");
756 break;
757 case Opt_recovery:
758 btrfs_warn(info,
759 "'recovery' is deprecated, use 'usebackuproot' instead");
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_early_options(const char *options, fmode_t flags,
886 void *holder, struct btrfs_fs_devices **fs_devices)
887 {
888 substring_t args[MAX_OPT_ARGS];
889 char *device_name, *opts, *orig, *p;
890 int error = 0;
891
892 if (!options)
893 return 0;
894
895 /*
896 * strsep changes the string, duplicate it because btrfs_parse_options
897 * gets called later
898 */
899 opts = kstrdup(options, GFP_KERNEL);
900 if (!opts)
901 return -ENOMEM;
902 orig = opts;
903
904 while ((p = strsep(&opts, ",")) != NULL) {
905 int token;
906
907 if (!*p)
908 continue;
909
910 token = match_token(p, tokens, args);
911 if (token == Opt_device) {
912 device_name = match_strdup(&args[0]);
913 if (!device_name) {
914 error = -ENOMEM;
915 goto out;
916 }
917 error = btrfs_scan_one_device(device_name,
918 flags, holder, fs_devices);
919 kfree(device_name);
920 if (error)
921 goto out;
922 }
923 }
924
925 out:
926 kfree(orig);
927 return error;
928 }
929
930 /*
931 * Parse mount options that are related to subvolume id
932 *
933 * The value is later passed to mount_subvol()
934 */
935 static int btrfs_parse_subvol_options(const char *options, fmode_t flags,
936 char **subvol_name, u64 *subvol_objectid)
937 {
938 substring_t args[MAX_OPT_ARGS];
939 char *opts, *orig, *p;
940 int error = 0;
941 u64 subvolid;
942
943 if (!options)
944 return 0;
945
946 /*
947 * strsep changes the string, duplicate it because
948 * btrfs_parse_early_options gets called later
949 */
950 opts = kstrdup(options, GFP_KERNEL);
951 if (!opts)
952 return -ENOMEM;
953 orig = opts;
954
955 while ((p = strsep(&opts, ",")) != NULL) {
956 int token;
957 if (!*p)
958 continue;
959
960 token = match_token(p, tokens, args);
961 switch (token) {
962 case Opt_subvol:
963 kfree(*subvol_name);
964 *subvol_name = match_strdup(&args[0]);
965 if (!*subvol_name) {
966 error = -ENOMEM;
967 goto out;
968 }
969 break;
970 case Opt_subvolid:
971 error = match_u64(&args[0], &subvolid);
972 if (error)
973 goto out;
974
975 /* we want the original fs_tree */
976 if (subvolid == 0)
977 subvolid = BTRFS_FS_TREE_OBJECTID;
978
979 *subvol_objectid = subvolid;
980 break;
981 case Opt_subvolrootid:
982 pr_warn("BTRFS: 'subvolrootid' mount option is deprecated and has no effect\n");
983 break;
984 default:
985 break;
986 }
987 }
988
989 out:
990 kfree(orig);
991 return error;
992 }
993
994 static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info,
995 u64 subvol_objectid)
996 {
997 struct btrfs_root *root = fs_info->tree_root;
998 struct btrfs_root *fs_root;
999 struct btrfs_root_ref *root_ref;
1000 struct btrfs_inode_ref *inode_ref;
1001 struct btrfs_key key;
1002 struct btrfs_path *path = NULL;
1003 char *name = NULL, *ptr;
1004 u64 dirid;
1005 int len;
1006 int ret;
1007
1008 path = btrfs_alloc_path();
1009 if (!path) {
1010 ret = -ENOMEM;
1011 goto err;
1012 }
1013 path->leave_spinning = 1;
1014
1015 name = kmalloc(PATH_MAX, GFP_KERNEL);
1016 if (!name) {
1017 ret = -ENOMEM;
1018 goto err;
1019 }
1020 ptr = name + PATH_MAX - 1;
1021 ptr[0] = '\0';
1022
1023 /*
1024 * Walk up the subvolume trees in the tree of tree roots by root
1025 * backrefs until we hit the top-level subvolume.
1026 */
1027 while (subvol_objectid != BTRFS_FS_TREE_OBJECTID) {
1028 key.objectid = subvol_objectid;
1029 key.type = BTRFS_ROOT_BACKREF_KEY;
1030 key.offset = (u64)-1;
1031
1032 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1033 if (ret < 0) {
1034 goto err;
1035 } else if (ret > 0) {
1036 ret = btrfs_previous_item(root, path, subvol_objectid,
1037 BTRFS_ROOT_BACKREF_KEY);
1038 if (ret < 0) {
1039 goto err;
1040 } else if (ret > 0) {
1041 ret = -ENOENT;
1042 goto err;
1043 }
1044 }
1045
1046 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1047 subvol_objectid = key.offset;
1048
1049 root_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
1050 struct btrfs_root_ref);
1051 len = btrfs_root_ref_name_len(path->nodes[0], root_ref);
1052 ptr -= len + 1;
1053 if (ptr < name) {
1054 ret = -ENAMETOOLONG;
1055 goto err;
1056 }
1057 read_extent_buffer(path->nodes[0], ptr + 1,
1058 (unsigned long)(root_ref + 1), len);
1059 ptr[0] = '/';
1060 dirid = btrfs_root_ref_dirid(path->nodes[0], root_ref);
1061 btrfs_release_path(path);
1062
1063 key.objectid = subvol_objectid;
1064 key.type = BTRFS_ROOT_ITEM_KEY;
1065 key.offset = (u64)-1;
1066 fs_root = btrfs_read_fs_root_no_name(fs_info, &key);
1067 if (IS_ERR(fs_root)) {
1068 ret = PTR_ERR(fs_root);
1069 goto err;
1070 }
1071
1072 /*
1073 * Walk up the filesystem tree by inode refs until we hit the
1074 * root directory.
1075 */
1076 while (dirid != BTRFS_FIRST_FREE_OBJECTID) {
1077 key.objectid = dirid;
1078 key.type = BTRFS_INODE_REF_KEY;
1079 key.offset = (u64)-1;
1080
1081 ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0);
1082 if (ret < 0) {
1083 goto err;
1084 } else if (ret > 0) {
1085 ret = btrfs_previous_item(fs_root, path, dirid,
1086 BTRFS_INODE_REF_KEY);
1087 if (ret < 0) {
1088 goto err;
1089 } else if (ret > 0) {
1090 ret = -ENOENT;
1091 goto err;
1092 }
1093 }
1094
1095 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1096 dirid = key.offset;
1097
1098 inode_ref = btrfs_item_ptr(path->nodes[0],
1099 path->slots[0],
1100 struct btrfs_inode_ref);
1101 len = btrfs_inode_ref_name_len(path->nodes[0],
1102 inode_ref);
1103 ptr -= len + 1;
1104 if (ptr < name) {
1105 ret = -ENAMETOOLONG;
1106 goto err;
1107 }
1108 read_extent_buffer(path->nodes[0], ptr + 1,
1109 (unsigned long)(inode_ref + 1), len);
1110 ptr[0] = '/';
1111 btrfs_release_path(path);
1112 }
1113 }
1114
1115 btrfs_free_path(path);
1116 if (ptr == name + PATH_MAX - 1) {
1117 name[0] = '/';
1118 name[1] = '\0';
1119 } else {
1120 memmove(name, ptr, name + PATH_MAX - ptr);
1121 }
1122 return name;
1123
1124 err:
1125 btrfs_free_path(path);
1126 kfree(name);
1127 return ERR_PTR(ret);
1128 }
1129
1130 static int get_default_subvol_objectid(struct btrfs_fs_info *fs_info, u64 *objectid)
1131 {
1132 struct btrfs_root *root = fs_info->tree_root;
1133 struct btrfs_dir_item *di;
1134 struct btrfs_path *path;
1135 struct btrfs_key location;
1136 u64 dir_id;
1137
1138 path = btrfs_alloc_path();
1139 if (!path)
1140 return -ENOMEM;
1141 path->leave_spinning = 1;
1142
1143 /*
1144 * Find the "default" dir item which points to the root item that we
1145 * will mount by default if we haven't been given a specific subvolume
1146 * to mount.
1147 */
1148 dir_id = btrfs_super_root_dir(fs_info->super_copy);
1149 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
1150 if (IS_ERR(di)) {
1151 btrfs_free_path(path);
1152 return PTR_ERR(di);
1153 }
1154 if (!di) {
1155 /*
1156 * Ok the default dir item isn't there. This is weird since
1157 * it's always been there, but don't freak out, just try and
1158 * mount the top-level subvolume.
1159 */
1160 btrfs_free_path(path);
1161 *objectid = BTRFS_FS_TREE_OBJECTID;
1162 return 0;
1163 }
1164
1165 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
1166 btrfs_free_path(path);
1167 *objectid = location.objectid;
1168 return 0;
1169 }
1170
1171 static int btrfs_fill_super(struct super_block *sb,
1172 struct btrfs_fs_devices *fs_devices,
1173 void *data)
1174 {
1175 struct inode *inode;
1176 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1177 struct btrfs_key key;
1178 int err;
1179
1180 sb->s_maxbytes = MAX_LFS_FILESIZE;
1181 sb->s_magic = BTRFS_SUPER_MAGIC;
1182 sb->s_op = &btrfs_super_ops;
1183 sb->s_d_op = &btrfs_dentry_operations;
1184 sb->s_export_op = &btrfs_export_ops;
1185 sb->s_xattr = btrfs_xattr_handlers;
1186 sb->s_time_gran = 1;
1187 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
1188 sb->s_flags |= SB_POSIXACL;
1189 #endif
1190 sb->s_flags |= SB_I_VERSION;
1191 sb->s_iflags |= SB_I_CGROUPWB;
1192
1193 err = super_setup_bdi(sb);
1194 if (err) {
1195 btrfs_err(fs_info, "super_setup_bdi failed");
1196 return err;
1197 }
1198
1199 err = open_ctree(sb, fs_devices, (char *)data);
1200 if (err) {
1201 btrfs_err(fs_info, "open_ctree failed");
1202 return err;
1203 }
1204
1205 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
1206 key.type = BTRFS_INODE_ITEM_KEY;
1207 key.offset = 0;
1208 inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
1209 if (IS_ERR(inode)) {
1210 err = PTR_ERR(inode);
1211 goto fail_close;
1212 }
1213
1214 sb->s_root = d_make_root(inode);
1215 if (!sb->s_root) {
1216 err = -ENOMEM;
1217 goto fail_close;
1218 }
1219
1220 cleancache_init_fs(sb);
1221 sb->s_flags |= SB_ACTIVE;
1222 return 0;
1223
1224 fail_close:
1225 close_ctree(fs_info);
1226 return err;
1227 }
1228
1229 int btrfs_sync_fs(struct super_block *sb, int wait)
1230 {
1231 struct btrfs_trans_handle *trans;
1232 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1233 struct btrfs_root *root = fs_info->tree_root;
1234
1235 trace_btrfs_sync_fs(fs_info, wait);
1236
1237 if (!wait) {
1238 filemap_flush(fs_info->btree_inode->i_mapping);
1239 return 0;
1240 }
1241
1242 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
1243
1244 trans = btrfs_attach_transaction_barrier(root);
1245 if (IS_ERR(trans)) {
1246 /* no transaction, don't bother */
1247 if (PTR_ERR(trans) == -ENOENT) {
1248 /*
1249 * Exit unless we have some pending changes
1250 * that need to go through commit
1251 */
1252 if (fs_info->pending_changes == 0)
1253 return 0;
1254 /*
1255 * A non-blocking test if the fs is frozen. We must not
1256 * start a new transaction here otherwise a deadlock
1257 * happens. The pending operations are delayed to the
1258 * next commit after thawing.
1259 */
1260 if (sb_start_write_trylock(sb))
1261 sb_end_write(sb);
1262 else
1263 return 0;
1264 trans = btrfs_start_transaction(root, 0);
1265 }
1266 if (IS_ERR(trans))
1267 return PTR_ERR(trans);
1268 }
1269 return btrfs_commit_transaction(trans);
1270 }
1271
1272 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
1273 {
1274 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
1275 const char *compress_type;
1276
1277 if (btrfs_test_opt(info, DEGRADED))
1278 seq_puts(seq, ",degraded");
1279 if (btrfs_test_opt(info, NODATASUM))
1280 seq_puts(seq, ",nodatasum");
1281 if (btrfs_test_opt(info, NODATACOW))
1282 seq_puts(seq, ",nodatacow");
1283 if (btrfs_test_opt(info, NOBARRIER))
1284 seq_puts(seq, ",nobarrier");
1285 if (info->max_inline != BTRFS_DEFAULT_MAX_INLINE)
1286 seq_printf(seq, ",max_inline=%llu", info->max_inline);
1287 if (info->thread_pool_size != min_t(unsigned long,
1288 num_online_cpus() + 2, 8))
1289 seq_printf(seq, ",thread_pool=%u", info->thread_pool_size);
1290 if (btrfs_test_opt(info, COMPRESS)) {
1291 compress_type = btrfs_compress_type2str(info->compress_type);
1292 if (btrfs_test_opt(info, FORCE_COMPRESS))
1293 seq_printf(seq, ",compress-force=%s", compress_type);
1294 else
1295 seq_printf(seq, ",compress=%s", compress_type);
1296 if (info->compress_level)
1297 seq_printf(seq, ":%d", info->compress_level);
1298 }
1299 if (btrfs_test_opt(info, NOSSD))
1300 seq_puts(seq, ",nossd");
1301 if (btrfs_test_opt(info, SSD_SPREAD))
1302 seq_puts(seq, ",ssd_spread");
1303 else if (btrfs_test_opt(info, SSD))
1304 seq_puts(seq, ",ssd");
1305 if (btrfs_test_opt(info, NOTREELOG))
1306 seq_puts(seq, ",notreelog");
1307 if (btrfs_test_opt(info, NOLOGREPLAY))
1308 seq_puts(seq, ",nologreplay");
1309 if (btrfs_test_opt(info, FLUSHONCOMMIT))
1310 seq_puts(seq, ",flushoncommit");
1311 if (btrfs_test_opt(info, DISCARD))
1312 seq_puts(seq, ",discard");
1313 if (!(info->sb->s_flags & SB_POSIXACL))
1314 seq_puts(seq, ",noacl");
1315 if (btrfs_test_opt(info, SPACE_CACHE))
1316 seq_puts(seq, ",space_cache");
1317 else if (btrfs_test_opt(info, FREE_SPACE_TREE))
1318 seq_puts(seq, ",space_cache=v2");
1319 else
1320 seq_puts(seq, ",nospace_cache");
1321 if (btrfs_test_opt(info, RESCAN_UUID_TREE))
1322 seq_puts(seq, ",rescan_uuid_tree");
1323 if (btrfs_test_opt(info, CLEAR_CACHE))
1324 seq_puts(seq, ",clear_cache");
1325 if (btrfs_test_opt(info, USER_SUBVOL_RM_ALLOWED))
1326 seq_puts(seq, ",user_subvol_rm_allowed");
1327 if (btrfs_test_opt(info, ENOSPC_DEBUG))
1328 seq_puts(seq, ",enospc_debug");
1329 if (btrfs_test_opt(info, AUTO_DEFRAG))
1330 seq_puts(seq, ",autodefrag");
1331 if (btrfs_test_opt(info, INODE_MAP_CACHE))
1332 seq_puts(seq, ",inode_cache");
1333 if (btrfs_test_opt(info, SKIP_BALANCE))
1334 seq_puts(seq, ",skip_balance");
1335 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1336 if (btrfs_test_opt(info, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA))
1337 seq_puts(seq, ",check_int_data");
1338 else if (btrfs_test_opt(info, CHECK_INTEGRITY))
1339 seq_puts(seq, ",check_int");
1340 if (info->check_integrity_print_mask)
1341 seq_printf(seq, ",check_int_print_mask=%d",
1342 info->check_integrity_print_mask);
1343 #endif
1344 if (info->metadata_ratio)
1345 seq_printf(seq, ",metadata_ratio=%u", info->metadata_ratio);
1346 if (btrfs_test_opt(info, PANIC_ON_FATAL_ERROR))
1347 seq_puts(seq, ",fatal_errors=panic");
1348 if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL)
1349 seq_printf(seq, ",commit=%u", info->commit_interval);
1350 #ifdef CONFIG_BTRFS_DEBUG
1351 if (btrfs_test_opt(info, FRAGMENT_DATA))
1352 seq_puts(seq, ",fragment=data");
1353 if (btrfs_test_opt(info, FRAGMENT_METADATA))
1354 seq_puts(seq, ",fragment=metadata");
1355 #endif
1356 if (btrfs_test_opt(info, REF_VERIFY))
1357 seq_puts(seq, ",ref_verify");
1358 seq_printf(seq, ",subvolid=%llu",
1359 BTRFS_I(d_inode(dentry))->root->root_key.objectid);
1360 seq_puts(seq, ",subvol=");
1361 seq_dentry(seq, dentry, " \t\n\\");
1362 return 0;
1363 }
1364
1365 static int btrfs_test_super(struct super_block *s, void *data)
1366 {
1367 struct btrfs_fs_info *p = data;
1368 struct btrfs_fs_info *fs_info = btrfs_sb(s);
1369
1370 return fs_info->fs_devices == p->fs_devices;
1371 }
1372
1373 static int btrfs_set_super(struct super_block *s, void *data)
1374 {
1375 int err = set_anon_super(s, data);
1376 if (!err)
1377 s->s_fs_info = data;
1378 return err;
1379 }
1380
1381 /*
1382 * subvolumes are identified by ino 256
1383 */
1384 static inline int is_subvolume_inode(struct inode *inode)
1385 {
1386 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
1387 return 1;
1388 return 0;
1389 }
1390
1391 static struct dentry *mount_subvol(const char *subvol_name, u64 subvol_objectid,
1392 const char *device_name, struct vfsmount *mnt)
1393 {
1394 struct dentry *root;
1395 int ret;
1396
1397 if (!subvol_name) {
1398 if (!subvol_objectid) {
1399 ret = get_default_subvol_objectid(btrfs_sb(mnt->mnt_sb),
1400 &subvol_objectid);
1401 if (ret) {
1402 root = ERR_PTR(ret);
1403 goto out;
1404 }
1405 }
1406 subvol_name = get_subvol_name_from_objectid(btrfs_sb(mnt->mnt_sb),
1407 subvol_objectid);
1408 if (IS_ERR(subvol_name)) {
1409 root = ERR_CAST(subvol_name);
1410 subvol_name = NULL;
1411 goto out;
1412 }
1413
1414 }
1415
1416 root = mount_subtree(mnt, subvol_name);
1417 /* mount_subtree() drops our reference on the vfsmount. */
1418 mnt = NULL;
1419
1420 if (!IS_ERR(root)) {
1421 struct super_block *s = root->d_sb;
1422 struct btrfs_fs_info *fs_info = btrfs_sb(s);
1423 struct inode *root_inode = d_inode(root);
1424 u64 root_objectid = BTRFS_I(root_inode)->root->root_key.objectid;
1425
1426 ret = 0;
1427 if (!is_subvolume_inode(root_inode)) {
1428 btrfs_err(fs_info, "'%s' is not a valid subvolume",
1429 subvol_name);
1430 ret = -EINVAL;
1431 }
1432 if (subvol_objectid && root_objectid != subvol_objectid) {
1433 /*
1434 * This will also catch a race condition where a
1435 * subvolume which was passed by ID is renamed and
1436 * another subvolume is renamed over the old location.
1437 */
1438 btrfs_err(fs_info,
1439 "subvol '%s' does not match subvolid %llu",
1440 subvol_name, subvol_objectid);
1441 ret = -EINVAL;
1442 }
1443 if (ret) {
1444 dput(root);
1445 root = ERR_PTR(ret);
1446 deactivate_locked_super(s);
1447 }
1448 }
1449
1450 out:
1451 mntput(mnt);
1452 kfree(subvol_name);
1453 return root;
1454 }
1455
1456 static int parse_security_options(char *orig_opts,
1457 struct security_mnt_opts *sec_opts)
1458 {
1459 char *secdata = NULL;
1460 int ret = 0;
1461
1462 secdata = alloc_secdata();
1463 if (!secdata)
1464 return -ENOMEM;
1465 ret = security_sb_copy_data(orig_opts, secdata);
1466 if (ret) {
1467 free_secdata(secdata);
1468 return ret;
1469 }
1470 ret = security_sb_parse_opts_str(secdata, sec_opts);
1471 free_secdata(secdata);
1472 return ret;
1473 }
1474
1475 static int setup_security_options(struct btrfs_fs_info *fs_info,
1476 struct super_block *sb,
1477 struct security_mnt_opts *sec_opts)
1478 {
1479 int ret = 0;
1480
1481 /*
1482 * Call security_sb_set_mnt_opts() to check whether new sec_opts
1483 * is valid.
1484 */
1485 ret = security_sb_set_mnt_opts(sb, sec_opts, 0, NULL);
1486 if (ret)
1487 return ret;
1488
1489 #ifdef CONFIG_SECURITY
1490 if (!fs_info->security_opts.num_mnt_opts) {
1491 /* first time security setup, copy sec_opts to fs_info */
1492 memcpy(&fs_info->security_opts, sec_opts, sizeof(*sec_opts));
1493 } else {
1494 /*
1495 * Since SELinux (the only one supporting security_mnt_opts)
1496 * does NOT support changing context during remount/mount of
1497 * the same sb, this must be the same or part of the same
1498 * security options, just free it.
1499 */
1500 security_free_mnt_opts(sec_opts);
1501 }
1502 #endif
1503 return ret;
1504 }
1505
1506 /*
1507 * Find a superblock for the given device / mount point.
1508 *
1509 * Note: This is based on mount_bdev from fs/super.c with a few additions
1510 * for multiple device setup. Make sure to keep it in sync.
1511 */
1512 static struct dentry *btrfs_mount_root(struct file_system_type *fs_type,
1513 int flags, const char *device_name, void *data)
1514 {
1515 struct block_device *bdev = NULL;
1516 struct super_block *s;
1517 struct btrfs_fs_devices *fs_devices = NULL;
1518 struct btrfs_fs_info *fs_info = NULL;
1519 struct security_mnt_opts new_sec_opts;
1520 fmode_t mode = FMODE_READ;
1521 int error = 0;
1522
1523 if (!(flags & SB_RDONLY))
1524 mode |= FMODE_WRITE;
1525
1526 error = btrfs_parse_early_options(data, mode, fs_type,
1527 &fs_devices);
1528 if (error) {
1529 return ERR_PTR(error);
1530 }
1531
1532 security_init_mnt_opts(&new_sec_opts);
1533 if (data) {
1534 error = parse_security_options(data, &new_sec_opts);
1535 if (error)
1536 return ERR_PTR(error);
1537 }
1538
1539 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
1540 if (error)
1541 goto error_sec_opts;
1542
1543 /*
1544 * Setup a dummy root and fs_info for test/set super. This is because
1545 * we don't actually fill this stuff out until open_ctree, but we need
1546 * it for searching for existing supers, so this lets us do that and
1547 * then open_ctree will properly initialize everything later.
1548 */
1549 fs_info = kvzalloc(sizeof(struct btrfs_fs_info), GFP_KERNEL);
1550 if (!fs_info) {
1551 error = -ENOMEM;
1552 goto error_sec_opts;
1553 }
1554
1555 fs_info->fs_devices = fs_devices;
1556
1557 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL);
1558 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL);
1559 security_init_mnt_opts(&fs_info->security_opts);
1560 if (!fs_info->super_copy || !fs_info->super_for_commit) {
1561 error = -ENOMEM;
1562 goto error_fs_info;
1563 }
1564
1565 error = btrfs_open_devices(fs_devices, mode, fs_type);
1566 if (error)
1567 goto error_fs_info;
1568
1569 if (!(flags & SB_RDONLY) && fs_devices->rw_devices == 0) {
1570 error = -EACCES;
1571 goto error_close_devices;
1572 }
1573
1574 bdev = fs_devices->latest_bdev;
1575 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | SB_NOSEC,
1576 fs_info);
1577 if (IS_ERR(s)) {
1578 error = PTR_ERR(s);
1579 goto error_close_devices;
1580 }
1581
1582 if (s->s_root) {
1583 btrfs_close_devices(fs_devices);
1584 free_fs_info(fs_info);
1585 if ((flags ^ s->s_flags) & SB_RDONLY)
1586 error = -EBUSY;
1587 } else {
1588 snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev);
1589 btrfs_sb(s)->bdev_holder = fs_type;
1590 error = btrfs_fill_super(s, fs_devices, data);
1591 }
1592 if (error) {
1593 deactivate_locked_super(s);
1594 goto error_sec_opts;
1595 }
1596
1597 fs_info = btrfs_sb(s);
1598 error = setup_security_options(fs_info, s, &new_sec_opts);
1599 if (error) {
1600 deactivate_locked_super(s);
1601 goto error_sec_opts;
1602 }
1603
1604 return dget(s->s_root);
1605
1606 error_close_devices:
1607 btrfs_close_devices(fs_devices);
1608 error_fs_info:
1609 free_fs_info(fs_info);
1610 error_sec_opts:
1611 security_free_mnt_opts(&new_sec_opts);
1612 return ERR_PTR(error);
1613 }
1614
1615 /*
1616 * Mount function which is called by VFS layer.
1617 *
1618 * In order to allow mounting a subvolume directly, btrfs uses mount_subtree()
1619 * which needs vfsmount* of device's root (/). This means device's root has to
1620 * be mounted internally in any case.
1621 *
1622 * Operation flow:
1623 * 1. Parse subvol id related options for later use in mount_subvol().
1624 *
1625 * 2. Mount device's root (/) by calling vfs_kern_mount().
1626 *
1627 * NOTE: vfs_kern_mount() is used by VFS to call btrfs_mount() in the
1628 * first place. In order to avoid calling btrfs_mount() again, we use
1629 * different file_system_type which is not registered to VFS by
1630 * register_filesystem() (btrfs_root_fs_type). As a result,
1631 * btrfs_mount_root() is called. The return value will be used by
1632 * mount_subtree() in mount_subvol().
1633 *
1634 * 3. Call mount_subvol() to get the dentry of subvolume. Since there is
1635 * "btrfs subvolume set-default", mount_subvol() is called always.
1636 */
1637 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1638 const char *device_name, void *data)
1639 {
1640 struct vfsmount *mnt_root;
1641 struct dentry *root;
1642 fmode_t mode = FMODE_READ;
1643 char *subvol_name = NULL;
1644 u64 subvol_objectid = 0;
1645 int error = 0;
1646
1647 if (!(flags & SB_RDONLY))
1648 mode |= FMODE_WRITE;
1649
1650 error = btrfs_parse_subvol_options(data, mode,
1651 &subvol_name, &subvol_objectid);
1652 if (error) {
1653 kfree(subvol_name);
1654 return ERR_PTR(error);
1655 }
1656
1657 /* mount device's root (/) */
1658 mnt_root = vfs_kern_mount(&btrfs_root_fs_type, flags, device_name, data);
1659 if (PTR_ERR_OR_ZERO(mnt_root) == -EBUSY) {
1660 if (flags & SB_RDONLY) {
1661 mnt_root = vfs_kern_mount(&btrfs_root_fs_type,
1662 flags & ~SB_RDONLY, device_name, data);
1663 } else {
1664 mnt_root = vfs_kern_mount(&btrfs_root_fs_type,
1665 flags | SB_RDONLY, device_name, data);
1666 if (IS_ERR(mnt_root)) {
1667 root = ERR_CAST(mnt_root);
1668 goto out;
1669 }
1670
1671 down_write(&mnt_root->mnt_sb->s_umount);
1672 error = btrfs_remount(mnt_root->mnt_sb, &flags, NULL);
1673 up_write(&mnt_root->mnt_sb->s_umount);
1674 if (error < 0) {
1675 root = ERR_PTR(error);
1676 mntput(mnt_root);
1677 goto out;
1678 }
1679 }
1680 }
1681 if (IS_ERR(mnt_root)) {
1682 root = ERR_CAST(mnt_root);
1683 goto out;
1684 }
1685
1686 /* mount_subvol() will free subvol_name and mnt_root */
1687 root = mount_subvol(subvol_name, subvol_objectid, device_name, mnt_root);
1688
1689 out:
1690 return root;
1691 }
1692
1693 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1694 u32 new_pool_size, u32 old_pool_size)
1695 {
1696 if (new_pool_size == old_pool_size)
1697 return;
1698
1699 fs_info->thread_pool_size = new_pool_size;
1700
1701 btrfs_info(fs_info, "resize thread pool %d -> %d",
1702 old_pool_size, new_pool_size);
1703
1704 btrfs_workqueue_set_max(fs_info->workers, new_pool_size);
1705 btrfs_workqueue_set_max(fs_info->delalloc_workers, new_pool_size);
1706 btrfs_workqueue_set_max(fs_info->submit_workers, new_pool_size);
1707 btrfs_workqueue_set_max(fs_info->caching_workers, new_pool_size);
1708 btrfs_workqueue_set_max(fs_info->endio_workers, new_pool_size);
1709 btrfs_workqueue_set_max(fs_info->endio_meta_workers, new_pool_size);
1710 btrfs_workqueue_set_max(fs_info->endio_meta_write_workers,
1711 new_pool_size);
1712 btrfs_workqueue_set_max(fs_info->endio_write_workers, new_pool_size);
1713 btrfs_workqueue_set_max(fs_info->endio_freespace_worker, new_pool_size);
1714 btrfs_workqueue_set_max(fs_info->delayed_workers, new_pool_size);
1715 btrfs_workqueue_set_max(fs_info->readahead_workers, new_pool_size);
1716 btrfs_workqueue_set_max(fs_info->scrub_wr_completion_workers,
1717 new_pool_size);
1718 }
1719
1720 static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info)
1721 {
1722 set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1723 }
1724
1725 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
1726 unsigned long old_opts, int flags)
1727 {
1728 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1729 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1730 (flags & SB_RDONLY))) {
1731 /* wait for any defraggers to finish */
1732 wait_event(fs_info->transaction_wait,
1733 (atomic_read(&fs_info->defrag_running) == 0));
1734 if (flags & SB_RDONLY)
1735 sync_filesystem(fs_info->sb);
1736 }
1737 }
1738
1739 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1740 unsigned long old_opts)
1741 {
1742 /*
1743 * We need to cleanup all defragable inodes if the autodefragment is
1744 * close or the filesystem is read only.
1745 */
1746 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1747 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) || sb_rdonly(fs_info->sb))) {
1748 btrfs_cleanup_defrag_inodes(fs_info);
1749 }
1750
1751 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1752 }
1753
1754 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1755 {
1756 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1757 struct btrfs_root *root = fs_info->tree_root;
1758 unsigned old_flags = sb->s_flags;
1759 unsigned long old_opts = fs_info->mount_opt;
1760 unsigned long old_compress_type = fs_info->compress_type;
1761 u64 old_max_inline = fs_info->max_inline;
1762 u32 old_thread_pool_size = fs_info->thread_pool_size;
1763 u32 old_metadata_ratio = fs_info->metadata_ratio;
1764 int ret;
1765
1766 sync_filesystem(sb);
1767 btrfs_remount_prepare(fs_info);
1768
1769 if (data) {
1770 struct security_mnt_opts new_sec_opts;
1771
1772 security_init_mnt_opts(&new_sec_opts);
1773 ret = parse_security_options(data, &new_sec_opts);
1774 if (ret)
1775 goto restore;
1776 ret = setup_security_options(fs_info, sb,
1777 &new_sec_opts);
1778 if (ret) {
1779 security_free_mnt_opts(&new_sec_opts);
1780 goto restore;
1781 }
1782 }
1783
1784 ret = btrfs_parse_options(fs_info, data, *flags);
1785 if (ret) {
1786 ret = -EINVAL;
1787 goto restore;
1788 }
1789
1790 btrfs_remount_begin(fs_info, old_opts, *flags);
1791 btrfs_resize_thread_pool(fs_info,
1792 fs_info->thread_pool_size, old_thread_pool_size);
1793
1794 if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1795 goto out;
1796
1797 if (*flags & SB_RDONLY) {
1798 /*
1799 * this also happens on 'umount -rf' or on shutdown, when
1800 * the filesystem is busy.
1801 */
1802 cancel_work_sync(&fs_info->async_reclaim_work);
1803
1804 /* wait for the uuid_scan task to finish */
1805 down(&fs_info->uuid_tree_rescan_sem);
1806 /* avoid complains from lockdep et al. */
1807 up(&fs_info->uuid_tree_rescan_sem);
1808
1809 sb->s_flags |= SB_RDONLY;
1810
1811 /*
1812 * Setting SB_RDONLY will put the cleaner thread to
1813 * sleep at the next loop if it's already active.
1814 * If it's already asleep, we'll leave unused block
1815 * groups on disk until we're mounted read-write again
1816 * unless we clean them up here.
1817 */
1818 btrfs_delete_unused_bgs(fs_info);
1819
1820 btrfs_dev_replace_suspend_for_unmount(fs_info);
1821 btrfs_scrub_cancel(fs_info);
1822 btrfs_pause_balance(fs_info);
1823
1824 ret = btrfs_commit_super(fs_info);
1825 if (ret)
1826 goto restore;
1827 } else {
1828 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
1829 btrfs_err(fs_info,
1830 "Remounting read-write after error is not allowed");
1831 ret = -EINVAL;
1832 goto restore;
1833 }
1834 if (fs_info->fs_devices->rw_devices == 0) {
1835 ret = -EACCES;
1836 goto restore;
1837 }
1838
1839 if (!btrfs_check_rw_degradable(fs_info, NULL)) {
1840 btrfs_warn(fs_info,
1841 "too many missing devices, writeable remount is not allowed");
1842 ret = -EACCES;
1843 goto restore;
1844 }
1845
1846 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1847 ret = -EINVAL;
1848 goto restore;
1849 }
1850
1851 ret = btrfs_cleanup_fs_roots(fs_info);
1852 if (ret)
1853 goto restore;
1854
1855 /* recover relocation */
1856 mutex_lock(&fs_info->cleaner_mutex);
1857 ret = btrfs_recover_relocation(root);
1858 mutex_unlock(&fs_info->cleaner_mutex);
1859 if (ret)
1860 goto restore;
1861
1862 ret = btrfs_resume_balance_async(fs_info);
1863 if (ret)
1864 goto restore;
1865
1866 ret = btrfs_resume_dev_replace_async(fs_info);
1867 if (ret) {
1868 btrfs_warn(fs_info, "failed to resume dev_replace");
1869 goto restore;
1870 }
1871
1872 btrfs_qgroup_rescan_resume(fs_info);
1873
1874 if (!fs_info->uuid_root) {
1875 btrfs_info(fs_info, "creating UUID tree");
1876 ret = btrfs_create_uuid_tree(fs_info);
1877 if (ret) {
1878 btrfs_warn(fs_info,
1879 "failed to create the UUID tree %d",
1880 ret);
1881 goto restore;
1882 }
1883 }
1884 sb->s_flags &= ~SB_RDONLY;
1885
1886 set_bit(BTRFS_FS_OPEN, &fs_info->flags);
1887 }
1888 out:
1889 wake_up_process(fs_info->transaction_kthread);
1890 btrfs_remount_cleanup(fs_info, old_opts);
1891 return 0;
1892
1893 restore:
1894 /* We've hit an error - don't reset SB_RDONLY */
1895 if (sb_rdonly(sb))
1896 old_flags |= SB_RDONLY;
1897 sb->s_flags = old_flags;
1898 fs_info->mount_opt = old_opts;
1899 fs_info->compress_type = old_compress_type;
1900 fs_info->max_inline = old_max_inline;
1901 btrfs_resize_thread_pool(fs_info,
1902 old_thread_pool_size, fs_info->thread_pool_size);
1903 fs_info->metadata_ratio = old_metadata_ratio;
1904 btrfs_remount_cleanup(fs_info, old_opts);
1905 return ret;
1906 }
1907
1908 /* Used to sort the devices by max_avail(descending sort) */
1909 static int btrfs_cmp_device_free_bytes(const void *dev_info1,
1910 const void *dev_info2)
1911 {
1912 if (((struct btrfs_device_info *)dev_info1)->max_avail >
1913 ((struct btrfs_device_info *)dev_info2)->max_avail)
1914 return -1;
1915 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1916 ((struct btrfs_device_info *)dev_info2)->max_avail)
1917 return 1;
1918 else
1919 return 0;
1920 }
1921
1922 /*
1923 * sort the devices by max_avail, in which max free extent size of each device
1924 * is stored.(Descending Sort)
1925 */
1926 static inline void btrfs_descending_sort_devices(
1927 struct btrfs_device_info *devices,
1928 size_t nr_devices)
1929 {
1930 sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1931 btrfs_cmp_device_free_bytes, NULL);
1932 }
1933
1934 /*
1935 * The helper to calc the free space on the devices that can be used to store
1936 * file data.
1937 */
1938 static int btrfs_calc_avail_data_space(struct btrfs_fs_info *fs_info,
1939 u64 *free_bytes)
1940 {
1941 struct btrfs_device_info *devices_info;
1942 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1943 struct btrfs_device *device;
1944 u64 skip_space;
1945 u64 type;
1946 u64 avail_space;
1947 u64 min_stripe_size;
1948 int min_stripes = 1, num_stripes = 1;
1949 int i = 0, nr_devices;
1950
1951 /*
1952 * We aren't under the device list lock, so this is racy-ish, but good
1953 * enough for our purposes.
1954 */
1955 nr_devices = fs_info->fs_devices->open_devices;
1956 if (!nr_devices) {
1957 smp_mb();
1958 nr_devices = fs_info->fs_devices->open_devices;
1959 ASSERT(nr_devices);
1960 if (!nr_devices) {
1961 *free_bytes = 0;
1962 return 0;
1963 }
1964 }
1965
1966 devices_info = kmalloc_array(nr_devices, sizeof(*devices_info),
1967 GFP_KERNEL);
1968 if (!devices_info)
1969 return -ENOMEM;
1970
1971 /* calc min stripe number for data space allocation */
1972 type = btrfs_data_alloc_profile(fs_info);
1973 if (type & BTRFS_BLOCK_GROUP_RAID0) {
1974 min_stripes = 2;
1975 num_stripes = nr_devices;
1976 } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
1977 min_stripes = 2;
1978 num_stripes = 2;
1979 } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
1980 min_stripes = 4;
1981 num_stripes = 4;
1982 }
1983
1984 if (type & BTRFS_BLOCK_GROUP_DUP)
1985 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1986 else
1987 min_stripe_size = BTRFS_STRIPE_LEN;
1988
1989 rcu_read_lock();
1990 list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
1991 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
1992 &device->dev_state) ||
1993 !device->bdev ||
1994 test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state))
1995 continue;
1996
1997 if (i >= nr_devices)
1998 break;
1999
2000 avail_space = device->total_bytes - device->bytes_used;
2001
2002 /* align with stripe_len */
2003 avail_space = div_u64(avail_space, BTRFS_STRIPE_LEN);
2004 avail_space *= BTRFS_STRIPE_LEN;
2005
2006 /*
2007 * In order to avoid overwriting the superblock on the drive,
2008 * btrfs starts at an offset of at least 1MB when doing chunk
2009 * allocation.
2010 */
2011 skip_space = SZ_1M;
2012
2013 /*
2014 * we can use the free space in [0, skip_space - 1], subtract
2015 * it from the total.
2016 */
2017 if (avail_space && avail_space >= skip_space)
2018 avail_space -= skip_space;
2019 else
2020 avail_space = 0;
2021
2022 if (avail_space < min_stripe_size)
2023 continue;
2024
2025 devices_info[i].dev = device;
2026 devices_info[i].max_avail = avail_space;
2027
2028 i++;
2029 }
2030 rcu_read_unlock();
2031
2032 nr_devices = i;
2033
2034 btrfs_descending_sort_devices(devices_info, nr_devices);
2035
2036 i = nr_devices - 1;
2037 avail_space = 0;
2038 while (nr_devices >= min_stripes) {
2039 if (num_stripes > nr_devices)
2040 num_stripes = nr_devices;
2041
2042 if (devices_info[i].max_avail >= min_stripe_size) {
2043 int j;
2044 u64 alloc_size;
2045
2046 avail_space += devices_info[i].max_avail * num_stripes;
2047 alloc_size = devices_info[i].max_avail;
2048 for (j = i + 1 - num_stripes; j <= i; j++)
2049 devices_info[j].max_avail -= alloc_size;
2050 }
2051 i--;
2052 nr_devices--;
2053 }
2054
2055 kfree(devices_info);
2056 *free_bytes = avail_space;
2057 return 0;
2058 }
2059
2060 /*
2061 * Calculate numbers for 'df', pessimistic in case of mixed raid profiles.
2062 *
2063 * If there's a redundant raid level at DATA block groups, use the respective
2064 * multiplier to scale the sizes.
2065 *
2066 * Unused device space usage is based on simulating the chunk allocator
2067 * algorithm that respects the device sizes and order of allocations. This is
2068 * a close approximation of the actual use but there are other factors that may
2069 * change the result (like a new metadata chunk).
2070 *
2071 * If metadata is exhausted, f_bavail will be 0.
2072 */
2073 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
2074 {
2075 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
2076 struct btrfs_super_block *disk_super = fs_info->super_copy;
2077 struct list_head *head = &fs_info->space_info;
2078 struct btrfs_space_info *found;
2079 u64 total_used = 0;
2080 u64 total_free_data = 0;
2081 u64 total_free_meta = 0;
2082 int bits = dentry->d_sb->s_blocksize_bits;
2083 __be32 *fsid = (__be32 *)fs_info->fsid;
2084 unsigned factor = 1;
2085 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
2086 int ret;
2087 u64 thresh = 0;
2088 int mixed = 0;
2089
2090 rcu_read_lock();
2091 list_for_each_entry_rcu(found, head, list) {
2092 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
2093 int i;
2094
2095 total_free_data += found->disk_total - found->disk_used;
2096 total_free_data -=
2097 btrfs_account_ro_block_groups_free_space(found);
2098
2099 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
2100 if (!list_empty(&found->block_groups[i])) {
2101 switch (i) {
2102 case BTRFS_RAID_DUP:
2103 case BTRFS_RAID_RAID1:
2104 case BTRFS_RAID_RAID10:
2105 factor = 2;
2106 }
2107 }
2108 }
2109 }
2110
2111 /*
2112 * Metadata in mixed block goup profiles are accounted in data
2113 */
2114 if (!mixed && found->flags & BTRFS_BLOCK_GROUP_METADATA) {
2115 if (found->flags & BTRFS_BLOCK_GROUP_DATA)
2116 mixed = 1;
2117 else
2118 total_free_meta += found->disk_total -
2119 found->disk_used;
2120 }
2121
2122 total_used += found->disk_used;
2123 }
2124
2125 rcu_read_unlock();
2126
2127 buf->f_blocks = div_u64(btrfs_super_total_bytes(disk_super), factor);
2128 buf->f_blocks >>= bits;
2129 buf->f_bfree = buf->f_blocks - (div_u64(total_used, factor) >> bits);
2130
2131 /* Account global block reserve as used, it's in logical size already */
2132 spin_lock(&block_rsv->lock);
2133 /* Mixed block groups accounting is not byte-accurate, avoid overflow */
2134 if (buf->f_bfree >= block_rsv->size >> bits)
2135 buf->f_bfree -= block_rsv->size >> bits;
2136 else
2137 buf->f_bfree = 0;
2138 spin_unlock(&block_rsv->lock);
2139
2140 buf->f_bavail = div_u64(total_free_data, factor);
2141 ret = btrfs_calc_avail_data_space(fs_info, &total_free_data);
2142 if (ret)
2143 return ret;
2144 buf->f_bavail += div_u64(total_free_data, factor);
2145 buf->f_bavail = buf->f_bavail >> bits;
2146
2147 /*
2148 * We calculate the remaining metadata space minus global reserve. If
2149 * this is (supposedly) smaller than zero, there's no space. But this
2150 * does not hold in practice, the exhausted state happens where's still
2151 * some positive delta. So we apply some guesswork and compare the
2152 * delta to a 4M threshold. (Practically observed delta was ~2M.)
2153 *
2154 * We probably cannot calculate the exact threshold value because this
2155 * depends on the internal reservations requested by various
2156 * operations, so some operations that consume a few metadata will
2157 * succeed even if the Avail is zero. But this is better than the other
2158 * way around.
2159 */
2160 thresh = SZ_4M;
2161
2162 if (!mixed && total_free_meta - thresh < block_rsv->size)
2163 buf->f_bavail = 0;
2164
2165 buf->f_type = BTRFS_SUPER_MAGIC;
2166 buf->f_bsize = dentry->d_sb->s_blocksize;
2167 buf->f_namelen = BTRFS_NAME_LEN;
2168
2169 /* We treat it as constant endianness (it doesn't matter _which_)
2170 because we want the fsid to come out the same whether mounted
2171 on a big-endian or little-endian host */
2172 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
2173 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
2174 /* Mask in the root object ID too, to disambiguate subvols */
2175 buf->f_fsid.val[0] ^= BTRFS_I(d_inode(dentry))->root->objectid >> 32;
2176 buf->f_fsid.val[1] ^= BTRFS_I(d_inode(dentry))->root->objectid;
2177
2178 return 0;
2179 }
2180
2181 static void btrfs_kill_super(struct super_block *sb)
2182 {
2183 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2184 kill_anon_super(sb);
2185 free_fs_info(fs_info);
2186 }
2187
2188 static struct file_system_type btrfs_fs_type = {
2189 .owner = THIS_MODULE,
2190 .name = "btrfs",
2191 .mount = btrfs_mount,
2192 .kill_sb = btrfs_kill_super,
2193 .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA,
2194 };
2195
2196 static struct file_system_type btrfs_root_fs_type = {
2197 .owner = THIS_MODULE,
2198 .name = "btrfs",
2199 .mount = btrfs_mount_root,
2200 .kill_sb = btrfs_kill_super,
2201 .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA,
2202 };
2203
2204 MODULE_ALIAS_FS("btrfs");
2205
2206 static int btrfs_control_open(struct inode *inode, struct file *file)
2207 {
2208 /*
2209 * The control file's private_data is used to hold the
2210 * transaction when it is started and is used to keep
2211 * track of whether a transaction is already in progress.
2212 */
2213 file->private_data = NULL;
2214 return 0;
2215 }
2216
2217 /*
2218 * used by btrfsctl to scan devices when no FS is mounted
2219 */
2220 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
2221 unsigned long arg)
2222 {
2223 struct btrfs_ioctl_vol_args *vol;
2224 struct btrfs_fs_devices *fs_devices;
2225 int ret = -ENOTTY;
2226
2227 if (!capable(CAP_SYS_ADMIN))
2228 return -EPERM;
2229
2230 vol = memdup_user((void __user *)arg, sizeof(*vol));
2231 if (IS_ERR(vol))
2232 return PTR_ERR(vol);
2233
2234 switch (cmd) {
2235 case BTRFS_IOC_SCAN_DEV:
2236 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
2237 &btrfs_root_fs_type, &fs_devices);
2238 break;
2239 case BTRFS_IOC_DEVICES_READY:
2240 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
2241 &btrfs_root_fs_type, &fs_devices);
2242 if (ret)
2243 break;
2244 ret = !(fs_devices->num_devices == fs_devices->total_devices);
2245 break;
2246 case BTRFS_IOC_GET_SUPPORTED_FEATURES:
2247 ret = btrfs_ioctl_get_supported_features((void __user*)arg);
2248 break;
2249 }
2250
2251 kfree(vol);
2252 return ret;
2253 }
2254
2255 static int btrfs_freeze(struct super_block *sb)
2256 {
2257 struct btrfs_trans_handle *trans;
2258 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2259 struct btrfs_root *root = fs_info->tree_root;
2260
2261 set_bit(BTRFS_FS_FROZEN, &fs_info->flags);
2262 /*
2263 * We don't need a barrier here, we'll wait for any transaction that
2264 * could be in progress on other threads (and do delayed iputs that
2265 * we want to avoid on a frozen filesystem), or do the commit
2266 * ourselves.
2267 */
2268 trans = btrfs_attach_transaction_barrier(root);
2269 if (IS_ERR(trans)) {
2270 /* no transaction, don't bother */
2271 if (PTR_ERR(trans) == -ENOENT)
2272 return 0;
2273 return PTR_ERR(trans);
2274 }
2275 return btrfs_commit_transaction(trans);
2276 }
2277
2278 static int btrfs_unfreeze(struct super_block *sb)
2279 {
2280 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2281
2282 clear_bit(BTRFS_FS_FROZEN, &fs_info->flags);
2283 return 0;
2284 }
2285
2286 static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
2287 {
2288 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
2289 struct btrfs_fs_devices *cur_devices;
2290 struct btrfs_device *dev, *first_dev = NULL;
2291 struct list_head *head;
2292 struct rcu_string *name;
2293
2294 /*
2295 * Lightweight locking of the devices. We should not need
2296 * device_list_mutex here as we only read the device data and the list
2297 * is protected by RCU. Even if a device is deleted during the list
2298 * traversals, we'll get valid data, the freeing callback will wait at
2299 * least until until the rcu_read_unlock.
2300 */
2301 rcu_read_lock();
2302 cur_devices = fs_info->fs_devices;
2303 while (cur_devices) {
2304 head = &cur_devices->devices;
2305 list_for_each_entry_rcu(dev, head, dev_list) {
2306 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state))
2307 continue;
2308 if (!dev->name)
2309 continue;
2310 if (!first_dev || dev->devid < first_dev->devid)
2311 first_dev = dev;
2312 }
2313 cur_devices = cur_devices->seed;
2314 }
2315
2316 if (first_dev) {
2317 name = rcu_dereference(first_dev->name);
2318 seq_escape(m, name->str, " \t\n\\");
2319 } else {
2320 WARN_ON(1);
2321 }
2322 rcu_read_unlock();
2323 return 0;
2324 }
2325
2326 static const struct super_operations btrfs_super_ops = {
2327 .drop_inode = btrfs_drop_inode,
2328 .evict_inode = btrfs_evict_inode,
2329 .put_super = btrfs_put_super,
2330 .sync_fs = btrfs_sync_fs,
2331 .show_options = btrfs_show_options,
2332 .show_devname = btrfs_show_devname,
2333 .write_inode = btrfs_write_inode,
2334 .alloc_inode = btrfs_alloc_inode,
2335 .destroy_inode = btrfs_destroy_inode,
2336 .statfs = btrfs_statfs,
2337 .remount_fs = btrfs_remount,
2338 .freeze_fs = btrfs_freeze,
2339 .unfreeze_fs = btrfs_unfreeze,
2340 };
2341
2342 static const struct file_operations btrfs_ctl_fops = {
2343 .open = btrfs_control_open,
2344 .unlocked_ioctl = btrfs_control_ioctl,
2345 .compat_ioctl = btrfs_control_ioctl,
2346 .owner = THIS_MODULE,
2347 .llseek = noop_llseek,
2348 };
2349
2350 static struct miscdevice btrfs_misc = {
2351 .minor = BTRFS_MINOR,
2352 .name = "btrfs-control",
2353 .fops = &btrfs_ctl_fops
2354 };
2355
2356 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
2357 MODULE_ALIAS("devname:btrfs-control");
2358
2359 static int __init btrfs_interface_init(void)
2360 {
2361 return misc_register(&btrfs_misc);
2362 }
2363
2364 static __cold void btrfs_interface_exit(void)
2365 {
2366 misc_deregister(&btrfs_misc);
2367 }
2368
2369 static void __init btrfs_print_mod_info(void)
2370 {
2371 pr_info("Btrfs loaded, crc32c=%s"
2372 #ifdef CONFIG_BTRFS_DEBUG
2373 ", debug=on"
2374 #endif
2375 #ifdef CONFIG_BTRFS_ASSERT
2376 ", assert=on"
2377 #endif
2378 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2379 ", integrity-checker=on"
2380 #endif
2381 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
2382 ", ref-verify=on"
2383 #endif
2384 "\n",
2385 crc32c_impl());
2386 }
2387
2388 static int __init init_btrfs_fs(void)
2389 {
2390 int err;
2391
2392 btrfs_props_init();
2393
2394 err = btrfs_init_sysfs();
2395 if (err)
2396 return err;
2397
2398 btrfs_init_compress();
2399
2400 err = btrfs_init_cachep();
2401 if (err)
2402 goto free_compress;
2403
2404 err = extent_io_init();
2405 if (err)
2406 goto free_cachep;
2407
2408 err = extent_map_init();
2409 if (err)
2410 goto free_extent_io;
2411
2412 err = ordered_data_init();
2413 if (err)
2414 goto free_extent_map;
2415
2416 err = btrfs_delayed_inode_init();
2417 if (err)
2418 goto free_ordered_data;
2419
2420 err = btrfs_auto_defrag_init();
2421 if (err)
2422 goto free_delayed_inode;
2423
2424 err = btrfs_delayed_ref_init();
2425 if (err)
2426 goto free_auto_defrag;
2427
2428 err = btrfs_prelim_ref_init();
2429 if (err)
2430 goto free_delayed_ref;
2431
2432 err = btrfs_end_io_wq_init();
2433 if (err)
2434 goto free_prelim_ref;
2435
2436 err = btrfs_interface_init();
2437 if (err)
2438 goto free_end_io_wq;
2439
2440 btrfs_init_lockdep();
2441
2442 btrfs_print_mod_info();
2443
2444 err = btrfs_run_sanity_tests();
2445 if (err)
2446 goto unregister_ioctl;
2447
2448 err = register_filesystem(&btrfs_fs_type);
2449 if (err)
2450 goto unregister_ioctl;
2451
2452 return 0;
2453
2454 unregister_ioctl:
2455 btrfs_interface_exit();
2456 free_end_io_wq:
2457 btrfs_end_io_wq_exit();
2458 free_prelim_ref:
2459 btrfs_prelim_ref_exit();
2460 free_delayed_ref:
2461 btrfs_delayed_ref_exit();
2462 free_auto_defrag:
2463 btrfs_auto_defrag_exit();
2464 free_delayed_inode:
2465 btrfs_delayed_inode_exit();
2466 free_ordered_data:
2467 ordered_data_exit();
2468 free_extent_map:
2469 extent_map_exit();
2470 free_extent_io:
2471 extent_io_exit();
2472 free_cachep:
2473 btrfs_destroy_cachep();
2474 free_compress:
2475 btrfs_exit_compress();
2476 btrfs_exit_sysfs();
2477
2478 return err;
2479 }
2480
2481 static void __exit exit_btrfs_fs(void)
2482 {
2483 btrfs_destroy_cachep();
2484 btrfs_delayed_ref_exit();
2485 btrfs_auto_defrag_exit();
2486 btrfs_delayed_inode_exit();
2487 btrfs_prelim_ref_exit();
2488 ordered_data_exit();
2489 extent_map_exit();
2490 extent_io_exit();
2491 btrfs_interface_exit();
2492 btrfs_end_io_wq_exit();
2493 unregister_filesystem(&btrfs_fs_type);
2494 btrfs_exit_sysfs();
2495 btrfs_cleanup_fs_uuids();
2496 btrfs_exit_compress();
2497 }
2498
2499 late_initcall(init_btrfs_fs);
2500 module_exit(exit_btrfs_fs)
2501
2502 MODULE_LICENSE("GPL");
Linux with added FPC-III support