1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2007 Oracle. All rights reserved.
4 */
5
6 #include <linux/blkdev.h>
7 #include <linux/module.h>
8 #include <linux/fs.h>
9 #include <linux/pagemap.h>
10 #include <linux/highmem.h>
11 #include <linux/time.h>
12 #include <linux/init.h>
13 #include <linux/seq_file.h>
14 #include <linux/string.h>
15 #include <linux/backing-dev.h>
16 #include <linux/mount.h>
17 #include <linux/writeback.h>
18 #include <linux/statfs.h>
19 #include <linux/compat.h>
20 #include <linux/parser.h>
21 #include <linux/ctype.h>
22 #include <linux/namei.h>
23 #include <linux/miscdevice.h>
24 #include <linux/magic.h>
25 #include <linux/slab.h>
26 #include <linux/cleancache.h>
27 #include <linux/ratelimit.h>
28 #include <linux/crc32c.h>
29 #include <linux/btrfs.h>
30 #include "delayed-inode.h"
31 #include "ctree.h"
32 #include "disk-io.h"
33 #include "transaction.h"
34 #include "btrfs_inode.h"
35 #include "print-tree.h"
36 #include "props.h"
37 #include "xattr.h"
38 #include "volumes.h"
39 #include "export.h"
40 #include "compression.h"
41 #include "rcu-string.h"
42 #include "dev-replace.h"
43 #include "free-space-cache.h"
44 #include "backref.h"
45 #include "space-info.h"
46 #include "sysfs.h"
47 #include "tests/btrfs-tests.h"
48 #include "block-group.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
btrfs_decode_error(int errno)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 appropriate error response.
100 */
101 __cold
__btrfs_handle_fs_error(struct btrfs_fs_info * fs_info,const char * function,unsigned int line,int errno,const char * fmt,...)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 writable
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
btrfs_printk(const struct btrfs_fs_info * fs_info,const char * fmt,...)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
__btrfs_abort_transaction(struct btrfs_trans_handle * trans,const char * function,unsigned int line,int errno)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
__btrfs_panic(struct btrfs_fs_info * fs_info,const char * function,unsigned int line,int errno,const char * fmt,...)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
btrfs_put_super(struct super_block * sb)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_subvol_empty,
327 Opt_subvolid,
328 Opt_thread_pool,
329 Opt_treelog, Opt_notreelog,
330 Opt_usebackuproot,
331 Opt_user_subvol_rm_allowed,
332
333 /* Deprecated options */
334 Opt_alloc_start,
335 Opt_recovery,
336 Opt_subvolrootid,
337
338 /* Debugging options */
339 Opt_check_integrity,
340 Opt_check_integrity_including_extent_data,
341 Opt_check_integrity_print_mask,
342 Opt_enospc_debug, Opt_noenospc_debug,
343 #ifdef CONFIG_BTRFS_DEBUG
344 Opt_fragment_data, Opt_fragment_metadata, Opt_fragment_all,
345 #endif
346 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
347 Opt_ref_verify,
348 #endif
349 Opt_err,
350 };
351
352 static const match_table_t tokens = {
353 {Opt_acl, "acl"},
354 {Opt_noacl, "noacl"},
355 {Opt_clear_cache, "clear_cache"},
356 {Opt_commit_interval, "commit=%u"},
357 {Opt_compress, "compress"},
358 {Opt_compress_type, "compress=%s"},
359 {Opt_compress_force, "compress-force"},
360 {Opt_compress_force_type, "compress-force=%s"},
361 {Opt_degraded, "degraded"},
362 {Opt_device, "device=%s"},
363 {Opt_fatal_errors, "fatal_errors=%s"},
364 {Opt_flushoncommit, "flushoncommit"},
365 {Opt_noflushoncommit, "noflushoncommit"},
366 {Opt_inode_cache, "inode_cache"},
367 {Opt_noinode_cache, "noinode_cache"},
368 {Opt_max_inline, "max_inline=%s"},
369 {Opt_barrier, "barrier"},
370 {Opt_nobarrier, "nobarrier"},
371 {Opt_datacow, "datacow"},
372 {Opt_nodatacow, "nodatacow"},
373 {Opt_datasum, "datasum"},
374 {Opt_nodatasum, "nodatasum"},
375 {Opt_defrag, "autodefrag"},
376 {Opt_nodefrag, "noautodefrag"},
377 {Opt_discard, "discard"},
378 {Opt_nodiscard, "nodiscard"},
379 {Opt_nologreplay, "nologreplay"},
380 {Opt_norecovery, "norecovery"},
381 {Opt_ratio, "metadata_ratio=%u"},
382 {Opt_rescan_uuid_tree, "rescan_uuid_tree"},
383 {Opt_skip_balance, "skip_balance"},
384 {Opt_space_cache, "space_cache"},
385 {Opt_no_space_cache, "nospace_cache"},
386 {Opt_space_cache_version, "space_cache=%s"},
387 {Opt_ssd, "ssd"},
388 {Opt_nossd, "nossd"},
389 {Opt_ssd_spread, "ssd_spread"},
390 {Opt_nossd_spread, "nossd_spread"},
391 {Opt_subvol, "subvol=%s"},
392 {Opt_subvol_empty, "subvol="},
393 {Opt_subvolid, "subvolid=%s"},
394 {Opt_thread_pool, "thread_pool=%u"},
395 {Opt_treelog, "treelog"},
396 {Opt_notreelog, "notreelog"},
397 {Opt_usebackuproot, "usebackuproot"},
398 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
399
400 /* Deprecated options */
401 {Opt_alloc_start, "alloc_start=%s"},
402 {Opt_recovery, "recovery"},
403 {Opt_subvolrootid, "subvolrootid=%d"},
404
405 /* Debugging options */
406 {Opt_check_integrity, "check_int"},
407 {Opt_check_integrity_including_extent_data, "check_int_data"},
408 {Opt_check_integrity_print_mask, "check_int_print_mask=%u"},
409 {Opt_enospc_debug, "enospc_debug"},
410 {Opt_noenospc_debug, "noenospc_debug"},
411 #ifdef CONFIG_BTRFS_DEBUG
412 {Opt_fragment_data, "fragment=data"},
413 {Opt_fragment_metadata, "fragment=metadata"},
414 {Opt_fragment_all, "fragment=all"},
415 #endif
416 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
417 {Opt_ref_verify, "ref_verify"},
418 #endif
419 {Opt_err, NULL},
420 };
421
422 /*
423 * Regular mount options parser. Everything that is needed only when
424 * reading in a new superblock is parsed here.
425 * XXX JDM: This needs to be cleaned up for remount.
426 */
btrfs_parse_options(struct btrfs_fs_info * info,char * options,unsigned long new_flags)427 int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
428 unsigned long new_flags)
429 {
430 substring_t args[MAX_OPT_ARGS];
431 char *p, *num;
432 u64 cache_gen;
433 int intarg;
434 int ret = 0;
435 char *compress_type;
436 bool compress_force = false;
437 enum btrfs_compression_type saved_compress_type;
438 bool saved_compress_force;
439 int no_compress = 0;
440
441 cache_gen = btrfs_super_cache_generation(info->super_copy);
442 if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE))
443 btrfs_set_opt(info->mount_opt, FREE_SPACE_TREE);
444 else if (cache_gen)
445 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
446
447 /*
448 * Even the options are empty, we still need to do extra check
449 * against new flags
450 */
451 if (!options)
452 goto check;
453
454 while ((p = strsep(&options, ",")) != NULL) {
455 int token;
456 if (!*p)
457 continue;
458
459 token = match_token(p, tokens, args);
460 switch (token) {
461 case Opt_degraded:
462 btrfs_info(info, "allowing degraded mounts");
463 btrfs_set_opt(info->mount_opt, DEGRADED);
464 break;
465 case Opt_subvol:
466 case Opt_subvol_empty:
467 case Opt_subvolid:
468 case Opt_subvolrootid:
469 case Opt_device:
470 /*
471 * These are parsed by btrfs_parse_subvol_options or
472 * btrfs_parse_device_options and can be ignored here.
473 */
474 break;
475 case Opt_nodatasum:
476 btrfs_set_and_info(info, NODATASUM,
477 "setting nodatasum");
478 break;
479 case Opt_datasum:
480 if (btrfs_test_opt(info, NODATASUM)) {
481 if (btrfs_test_opt(info, NODATACOW))
482 btrfs_info(info,
483 "setting datasum, datacow enabled");
484 else
485 btrfs_info(info, "setting datasum");
486 }
487 btrfs_clear_opt(info->mount_opt, NODATACOW);
488 btrfs_clear_opt(info->mount_opt, NODATASUM);
489 break;
490 case Opt_nodatacow:
491 if (!btrfs_test_opt(info, NODATACOW)) {
492 if (!btrfs_test_opt(info, COMPRESS) ||
493 !btrfs_test_opt(info, FORCE_COMPRESS)) {
494 btrfs_info(info,
495 "setting nodatacow, compression disabled");
496 } else {
497 btrfs_info(info, "setting nodatacow");
498 }
499 }
500 btrfs_clear_opt(info->mount_opt, COMPRESS);
501 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
502 btrfs_set_opt(info->mount_opt, NODATACOW);
503 btrfs_set_opt(info->mount_opt, NODATASUM);
504 break;
505 case Opt_datacow:
506 btrfs_clear_and_info(info, NODATACOW,
507 "setting datacow");
508 break;
509 case Opt_compress_force:
510 case Opt_compress_force_type:
511 compress_force = true;
512 /* Fallthrough */
513 case Opt_compress:
514 case Opt_compress_type:
515 saved_compress_type = btrfs_test_opt(info,
516 COMPRESS) ?
517 info->compress_type : BTRFS_COMPRESS_NONE;
518 saved_compress_force =
519 btrfs_test_opt(info, FORCE_COMPRESS);
520 if (token == Opt_compress ||
521 token == Opt_compress_force ||
522 strncmp(args[0].from, "zlib", 4) == 0) {
523 compress_type = "zlib";
524
525 info->compress_type = BTRFS_COMPRESS_ZLIB;
526 info->compress_level = BTRFS_ZLIB_DEFAULT_LEVEL;
527 /*
528 * args[0] contains uninitialized data since
529 * for these tokens we don't expect any
530 * parameter.
531 */
532 if (token != Opt_compress &&
533 token != Opt_compress_force)
534 info->compress_level =
535 btrfs_compress_str2level(
536 BTRFS_COMPRESS_ZLIB,
537 args[0].from + 4);
538 btrfs_set_opt(info->mount_opt, COMPRESS);
539 btrfs_clear_opt(info->mount_opt, NODATACOW);
540 btrfs_clear_opt(info->mount_opt, NODATASUM);
541 no_compress = 0;
542 } else if (strncmp(args[0].from, "lzo", 3) == 0) {
543 compress_type = "lzo";
544 info->compress_type = BTRFS_COMPRESS_LZO;
545 btrfs_set_opt(info->mount_opt, COMPRESS);
546 btrfs_clear_opt(info->mount_opt, NODATACOW);
547 btrfs_clear_opt(info->mount_opt, NODATASUM);
548 btrfs_set_fs_incompat(info, COMPRESS_LZO);
549 no_compress = 0;
550 } else if (strncmp(args[0].from, "zstd", 4) == 0) {
551 compress_type = "zstd";
552 info->compress_type = BTRFS_COMPRESS_ZSTD;
553 info->compress_level =
554 btrfs_compress_str2level(
555 BTRFS_COMPRESS_ZSTD,
556 args[0].from + 4);
557 btrfs_set_opt(info->mount_opt, COMPRESS);
558 btrfs_clear_opt(info->mount_opt, NODATACOW);
559 btrfs_clear_opt(info->mount_opt, NODATASUM);
560 btrfs_set_fs_incompat(info, COMPRESS_ZSTD);
561 no_compress = 0;
562 } else if (strncmp(args[0].from, "no", 2) == 0) {
563 compress_type = "no";
564 btrfs_clear_opt(info->mount_opt, COMPRESS);
565 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
566 compress_force = false;
567 no_compress++;
568 } else {
569 ret = -EINVAL;
570 goto out;
571 }
572
573 if (compress_force) {
574 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
575 } else {
576 /*
577 * If we remount from compress-force=xxx to
578 * compress=xxx, we need clear FORCE_COMPRESS
579 * flag, otherwise, there is no way for users
580 * to disable forcible compression separately.
581 */
582 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
583 }
584 if ((btrfs_test_opt(info, COMPRESS) &&
585 (info->compress_type != saved_compress_type ||
586 compress_force != saved_compress_force)) ||
587 (!btrfs_test_opt(info, COMPRESS) &&
588 no_compress == 1)) {
589 btrfs_info(info, "%s %s compression, level %d",
590 (compress_force) ? "force" : "use",
591 compress_type, info->compress_level);
592 }
593 compress_force = false;
594 break;
595 case Opt_ssd:
596 btrfs_set_and_info(info, SSD,
597 "enabling ssd optimizations");
598 btrfs_clear_opt(info->mount_opt, NOSSD);
599 break;
600 case Opt_ssd_spread:
601 btrfs_set_and_info(info, SSD,
602 "enabling ssd optimizations");
603 btrfs_set_and_info(info, SSD_SPREAD,
604 "using spread ssd allocation scheme");
605 btrfs_clear_opt(info->mount_opt, NOSSD);
606 break;
607 case Opt_nossd:
608 btrfs_set_opt(info->mount_opt, NOSSD);
609 btrfs_clear_and_info(info, SSD,
610 "not using ssd optimizations");
611 /* Fallthrough */
612 case Opt_nossd_spread:
613 btrfs_clear_and_info(info, SSD_SPREAD,
614 "not using spread ssd allocation scheme");
615 break;
616 case Opt_barrier:
617 btrfs_clear_and_info(info, NOBARRIER,
618 "turning on barriers");
619 break;
620 case Opt_nobarrier:
621 btrfs_set_and_info(info, NOBARRIER,
622 "turning off barriers");
623 break;
624 case Opt_thread_pool:
625 ret = match_int(&args[0], &intarg);
626 if (ret) {
627 goto out;
628 } else if (intarg == 0) {
629 ret = -EINVAL;
630 goto out;
631 }
632 info->thread_pool_size = intarg;
633 break;
634 case Opt_max_inline:
635 num = match_strdup(&args[0]);
636 if (num) {
637 info->max_inline = memparse(num, NULL);
638 kfree(num);
639
640 if (info->max_inline) {
641 info->max_inline = min_t(u64,
642 info->max_inline,
643 info->sectorsize);
644 }
645 btrfs_info(info, "max_inline at %llu",
646 info->max_inline);
647 } else {
648 ret = -ENOMEM;
649 goto out;
650 }
651 break;
652 case Opt_alloc_start:
653 btrfs_info(info,
654 "option alloc_start is obsolete, ignored");
655 break;
656 case Opt_acl:
657 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
658 info->sb->s_flags |= SB_POSIXACL;
659 break;
660 #else
661 btrfs_err(info, "support for ACL not compiled in!");
662 ret = -EINVAL;
663 goto out;
664 #endif
665 case Opt_noacl:
666 info->sb->s_flags &= ~SB_POSIXACL;
667 break;
668 case Opt_notreelog:
669 btrfs_set_and_info(info, NOTREELOG,
670 "disabling tree log");
671 break;
672 case Opt_treelog:
673 btrfs_clear_and_info(info, NOTREELOG,
674 "enabling tree log");
675 break;
676 case Opt_norecovery:
677 case Opt_nologreplay:
678 btrfs_set_and_info(info, NOLOGREPLAY,
679 "disabling log replay at mount time");
680 break;
681 case Opt_flushoncommit:
682 btrfs_set_and_info(info, FLUSHONCOMMIT,
683 "turning on flush-on-commit");
684 break;
685 case Opt_noflushoncommit:
686 btrfs_clear_and_info(info, FLUSHONCOMMIT,
687 "turning off flush-on-commit");
688 break;
689 case Opt_ratio:
690 ret = match_int(&args[0], &intarg);
691 if (ret)
692 goto out;
693 info->metadata_ratio = intarg;
694 btrfs_info(info, "metadata ratio %u",
695 info->metadata_ratio);
696 break;
697 case Opt_discard:
698 btrfs_set_and_info(info, DISCARD,
699 "turning on discard");
700 break;
701 case Opt_nodiscard:
702 btrfs_clear_and_info(info, DISCARD,
703 "turning off discard");
704 break;
705 case Opt_space_cache:
706 case Opt_space_cache_version:
707 if (token == Opt_space_cache ||
708 strcmp(args[0].from, "v1") == 0) {
709 btrfs_clear_opt(info->mount_opt,
710 FREE_SPACE_TREE);
711 btrfs_set_and_info(info, SPACE_CACHE,
712 "enabling disk space caching");
713 } else if (strcmp(args[0].from, "v2") == 0) {
714 btrfs_clear_opt(info->mount_opt,
715 SPACE_CACHE);
716 btrfs_set_and_info(info, FREE_SPACE_TREE,
717 "enabling free space tree");
718 } else {
719 ret = -EINVAL;
720 goto out;
721 }
722 break;
723 case Opt_rescan_uuid_tree:
724 btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE);
725 break;
726 case Opt_no_space_cache:
727 if (btrfs_test_opt(info, SPACE_CACHE)) {
728 btrfs_clear_and_info(info, SPACE_CACHE,
729 "disabling disk space caching");
730 }
731 if (btrfs_test_opt(info, FREE_SPACE_TREE)) {
732 btrfs_clear_and_info(info, FREE_SPACE_TREE,
733 "disabling free space tree");
734 }
735 break;
736 case Opt_inode_cache:
737 btrfs_set_pending_and_info(info, INODE_MAP_CACHE,
738 "enabling inode map caching");
739 break;
740 case Opt_noinode_cache:
741 btrfs_clear_pending_and_info(info, INODE_MAP_CACHE,
742 "disabling inode map caching");
743 break;
744 case Opt_clear_cache:
745 btrfs_set_and_info(info, CLEAR_CACHE,
746 "force clearing of disk cache");
747 break;
748 case Opt_user_subvol_rm_allowed:
749 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
750 break;
751 case Opt_enospc_debug:
752 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
753 break;
754 case Opt_noenospc_debug:
755 btrfs_clear_opt(info->mount_opt, ENOSPC_DEBUG);
756 break;
757 case Opt_defrag:
758 btrfs_set_and_info(info, AUTO_DEFRAG,
759 "enabling auto defrag");
760 break;
761 case Opt_nodefrag:
762 btrfs_clear_and_info(info, AUTO_DEFRAG,
763 "disabling auto defrag");
764 break;
765 case Opt_recovery:
766 btrfs_warn(info,
767 "'recovery' is deprecated, use 'usebackuproot' instead");
768 /* fall through */
769 case Opt_usebackuproot:
770 btrfs_info(info,
771 "trying to use backup root at mount time");
772 btrfs_set_opt(info->mount_opt, USEBACKUPROOT);
773 break;
774 case Opt_skip_balance:
775 btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
776 break;
777 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
778 case Opt_check_integrity_including_extent_data:
779 btrfs_info(info,
780 "enabling check integrity including extent data");
781 btrfs_set_opt(info->mount_opt,
782 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
783 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
784 break;
785 case Opt_check_integrity:
786 btrfs_info(info, "enabling check integrity");
787 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
788 break;
789 case Opt_check_integrity_print_mask:
790 ret = match_int(&args[0], &intarg);
791 if (ret)
792 goto out;
793 info->check_integrity_print_mask = intarg;
794 btrfs_info(info, "check_integrity_print_mask 0x%x",
795 info->check_integrity_print_mask);
796 break;
797 #else
798 case Opt_check_integrity_including_extent_data:
799 case Opt_check_integrity:
800 case Opt_check_integrity_print_mask:
801 btrfs_err(info,
802 "support for check_integrity* not compiled in!");
803 ret = -EINVAL;
804 goto out;
805 #endif
806 case Opt_fatal_errors:
807 if (strcmp(args[0].from, "panic") == 0)
808 btrfs_set_opt(info->mount_opt,
809 PANIC_ON_FATAL_ERROR);
810 else if (strcmp(args[0].from, "bug") == 0)
811 btrfs_clear_opt(info->mount_opt,
812 PANIC_ON_FATAL_ERROR);
813 else {
814 ret = -EINVAL;
815 goto out;
816 }
817 break;
818 case Opt_commit_interval:
819 intarg = 0;
820 ret = match_int(&args[0], &intarg);
821 if (ret)
822 goto out;
823 if (intarg == 0) {
824 btrfs_info(info,
825 "using default commit interval %us",
826 BTRFS_DEFAULT_COMMIT_INTERVAL);
827 intarg = BTRFS_DEFAULT_COMMIT_INTERVAL;
828 } else if (intarg > 300) {
829 btrfs_warn(info, "excessive commit interval %d",
830 intarg);
831 }
832 info->commit_interval = intarg;
833 break;
834 #ifdef CONFIG_BTRFS_DEBUG
835 case Opt_fragment_all:
836 btrfs_info(info, "fragmenting all space");
837 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA);
838 btrfs_set_opt(info->mount_opt, FRAGMENT_METADATA);
839 break;
840 case Opt_fragment_metadata:
841 btrfs_info(info, "fragmenting metadata");
842 btrfs_set_opt(info->mount_opt,
843 FRAGMENT_METADATA);
844 break;
845 case Opt_fragment_data:
846 btrfs_info(info, "fragmenting data");
847 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA);
848 break;
849 #endif
850 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
851 case Opt_ref_verify:
852 btrfs_info(info, "doing ref verification");
853 btrfs_set_opt(info->mount_opt, REF_VERIFY);
854 break;
855 #endif
856 case Opt_err:
857 btrfs_info(info, "unrecognized mount option '%s'", p);
858 ret = -EINVAL;
859 goto out;
860 default:
861 break;
862 }
863 }
864 check:
865 /*
866 * Extra check for current option against current flag
867 */
868 if (btrfs_test_opt(info, NOLOGREPLAY) && !(new_flags & SB_RDONLY)) {
869 btrfs_err(info,
870 "nologreplay must be used with ro mount option");
871 ret = -EINVAL;
872 }
873 out:
874 if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE) &&
875 !btrfs_test_opt(info, FREE_SPACE_TREE) &&
876 !btrfs_test_opt(info, CLEAR_CACHE)) {
877 btrfs_err(info, "cannot disable free space tree");
878 ret = -EINVAL;
879
880 }
881 if (!ret && btrfs_test_opt(info, SPACE_CACHE))
882 btrfs_info(info, "disk space caching is enabled");
883 if (!ret && btrfs_test_opt(info, FREE_SPACE_TREE))
884 btrfs_info(info, "using free space tree");
885 return ret;
886 }
887
888 /*
889 * Parse mount options that are required early in the mount process.
890 *
891 * All other options will be parsed on much later in the mount process and
892 * only when we need to allocate a new super block.
893 */
btrfs_parse_device_options(const char * options,fmode_t flags,void * holder)894 static int btrfs_parse_device_options(const char *options, fmode_t flags,
895 void *holder)
896 {
897 substring_t args[MAX_OPT_ARGS];
898 char *device_name, *opts, *orig, *p;
899 struct btrfs_device *device = NULL;
900 int error = 0;
901
902 lockdep_assert_held(&uuid_mutex);
903
904 if (!options)
905 return 0;
906
907 /*
908 * strsep changes the string, duplicate it because btrfs_parse_options
909 * gets called later
910 */
911 opts = kstrdup(options, GFP_KERNEL);
912 if (!opts)
913 return -ENOMEM;
914 orig = opts;
915
916 while ((p = strsep(&opts, ",")) != NULL) {
917 int token;
918
919 if (!*p)
920 continue;
921
922 token = match_token(p, tokens, args);
923 if (token == Opt_device) {
924 device_name = match_strdup(&args[0]);
925 if (!device_name) {
926 error = -ENOMEM;
927 goto out;
928 }
929 device = btrfs_scan_one_device(device_name, flags,
930 holder);
931 kfree(device_name);
932 if (IS_ERR(device)) {
933 error = PTR_ERR(device);
934 goto out;
935 }
936 }
937 }
938
939 out:
940 kfree(orig);
941 return error;
942 }
943
944 /*
945 * Parse mount options that are related to subvolume id
946 *
947 * The value is later passed to mount_subvol()
948 */
btrfs_parse_subvol_options(const char * options,char ** subvol_name,u64 * subvol_objectid)949 static int btrfs_parse_subvol_options(const char *options, char **subvol_name,
950 u64 *subvol_objectid)
951 {
952 substring_t args[MAX_OPT_ARGS];
953 char *opts, *orig, *p;
954 int error = 0;
955 u64 subvolid;
956
957 if (!options)
958 return 0;
959
960 /*
961 * strsep changes the string, duplicate it because
962 * btrfs_parse_device_options gets called later
963 */
964 opts = kstrdup(options, GFP_KERNEL);
965 if (!opts)
966 return -ENOMEM;
967 orig = opts;
968
969 while ((p = strsep(&opts, ",")) != NULL) {
970 int token;
971 if (!*p)
972 continue;
973
974 token = match_token(p, tokens, args);
975 switch (token) {
976 case Opt_subvol:
977 kfree(*subvol_name);
978 *subvol_name = match_strdup(&args[0]);
979 if (!*subvol_name) {
980 error = -ENOMEM;
981 goto out;
982 }
983 break;
984 case Opt_subvolid:
985 error = match_u64(&args[0], &subvolid);
986 if (error)
987 goto out;
988
989 /* we want the original fs_tree */
990 if (subvolid == 0)
991 subvolid = BTRFS_FS_TREE_OBJECTID;
992
993 *subvol_objectid = subvolid;
994 break;
995 case Opt_subvolrootid:
996 pr_warn("BTRFS: 'subvolrootid' mount option is deprecated and has no effect\n");
997 break;
998 default:
999 break;
1000 }
1001 }
1002
1003 out:
1004 kfree(orig);
1005 return error;
1006 }
1007
get_subvol_name_from_objectid(struct btrfs_fs_info * fs_info,u64 subvol_objectid)1008 static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info,
1009 u64 subvol_objectid)
1010 {
1011 struct btrfs_root *root = fs_info->tree_root;
1012 struct btrfs_root *fs_root;
1013 struct btrfs_root_ref *root_ref;
1014 struct btrfs_inode_ref *inode_ref;
1015 struct btrfs_key key;
1016 struct btrfs_path *path = NULL;
1017 char *name = NULL, *ptr;
1018 u64 dirid;
1019 int len;
1020 int ret;
1021
1022 path = btrfs_alloc_path();
1023 if (!path) {
1024 ret = -ENOMEM;
1025 goto err;
1026 }
1027 path->leave_spinning = 1;
1028
1029 name = kmalloc(PATH_MAX, GFP_KERNEL);
1030 if (!name) {
1031 ret = -ENOMEM;
1032 goto err;
1033 }
1034 ptr = name + PATH_MAX - 1;
1035 ptr[0] = '\0';
1036
1037 /*
1038 * Walk up the subvolume trees in the tree of tree roots by root
1039 * backrefs until we hit the top-level subvolume.
1040 */
1041 while (subvol_objectid != BTRFS_FS_TREE_OBJECTID) {
1042 key.objectid = subvol_objectid;
1043 key.type = BTRFS_ROOT_BACKREF_KEY;
1044 key.offset = (u64)-1;
1045
1046 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1047 if (ret < 0) {
1048 goto err;
1049 } else if (ret > 0) {
1050 ret = btrfs_previous_item(root, path, subvol_objectid,
1051 BTRFS_ROOT_BACKREF_KEY);
1052 if (ret < 0) {
1053 goto err;
1054 } else if (ret > 0) {
1055 ret = -ENOENT;
1056 goto err;
1057 }
1058 }
1059
1060 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1061 subvol_objectid = key.offset;
1062
1063 root_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
1064 struct btrfs_root_ref);
1065 len = btrfs_root_ref_name_len(path->nodes[0], root_ref);
1066 ptr -= len + 1;
1067 if (ptr < name) {
1068 ret = -ENAMETOOLONG;
1069 goto err;
1070 }
1071 read_extent_buffer(path->nodes[0], ptr + 1,
1072 (unsigned long)(root_ref + 1), len);
1073 ptr[0] = '/';
1074 dirid = btrfs_root_ref_dirid(path->nodes[0], root_ref);
1075 btrfs_release_path(path);
1076
1077 key.objectid = subvol_objectid;
1078 key.type = BTRFS_ROOT_ITEM_KEY;
1079 key.offset = (u64)-1;
1080 fs_root = btrfs_read_fs_root_no_name(fs_info, &key);
1081 if (IS_ERR(fs_root)) {
1082 ret = PTR_ERR(fs_root);
1083 goto err;
1084 }
1085
1086 /*
1087 * Walk up the filesystem tree by inode refs until we hit the
1088 * root directory.
1089 */
1090 while (dirid != BTRFS_FIRST_FREE_OBJECTID) {
1091 key.objectid = dirid;
1092 key.type = BTRFS_INODE_REF_KEY;
1093 key.offset = (u64)-1;
1094
1095 ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0);
1096 if (ret < 0) {
1097 goto err;
1098 } else if (ret > 0) {
1099 ret = btrfs_previous_item(fs_root, path, dirid,
1100 BTRFS_INODE_REF_KEY);
1101 if (ret < 0) {
1102 goto err;
1103 } else if (ret > 0) {
1104 ret = -ENOENT;
1105 goto err;
1106 }
1107 }
1108
1109 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1110 dirid = key.offset;
1111
1112 inode_ref = btrfs_item_ptr(path->nodes[0],
1113 path->slots[0],
1114 struct btrfs_inode_ref);
1115 len = btrfs_inode_ref_name_len(path->nodes[0],
1116 inode_ref);
1117 ptr -= len + 1;
1118 if (ptr < name) {
1119 ret = -ENAMETOOLONG;
1120 goto err;
1121 }
1122 read_extent_buffer(path->nodes[0], ptr + 1,
1123 (unsigned long)(inode_ref + 1), len);
1124 ptr[0] = '/';
1125 btrfs_release_path(path);
1126 }
1127 }
1128
1129 btrfs_free_path(path);
1130 if (ptr == name + PATH_MAX - 1) {
1131 name[0] = '/';
1132 name[1] = '\0';
1133 } else {
1134 memmove(name, ptr, name + PATH_MAX - ptr);
1135 }
1136 return name;
1137
1138 err:
1139 btrfs_free_path(path);
1140 kfree(name);
1141 return ERR_PTR(ret);
1142 }
1143
get_default_subvol_objectid(struct btrfs_fs_info * fs_info,u64 * objectid)1144 static int get_default_subvol_objectid(struct btrfs_fs_info *fs_info, u64 *objectid)
1145 {
1146 struct btrfs_root *root = fs_info->tree_root;
1147 struct btrfs_dir_item *di;
1148 struct btrfs_path *path;
1149 struct btrfs_key location;
1150 u64 dir_id;
1151
1152 path = btrfs_alloc_path();
1153 if (!path)
1154 return -ENOMEM;
1155 path->leave_spinning = 1;
1156
1157 /*
1158 * Find the "default" dir item which points to the root item that we
1159 * will mount by default if we haven't been given a specific subvolume
1160 * to mount.
1161 */
1162 dir_id = btrfs_super_root_dir(fs_info->super_copy);
1163 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
1164 if (IS_ERR(di)) {
1165 btrfs_free_path(path);
1166 return PTR_ERR(di);
1167 }
1168 if (!di) {
1169 /*
1170 * Ok the default dir item isn't there. This is weird since
1171 * it's always been there, but don't freak out, just try and
1172 * mount the top-level subvolume.
1173 */
1174 btrfs_free_path(path);
1175 *objectid = BTRFS_FS_TREE_OBJECTID;
1176 return 0;
1177 }
1178
1179 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
1180 btrfs_free_path(path);
1181 *objectid = location.objectid;
1182 return 0;
1183 }
1184
btrfs_fill_super(struct super_block * sb,struct btrfs_fs_devices * fs_devices,void * data)1185 static int btrfs_fill_super(struct super_block *sb,
1186 struct btrfs_fs_devices *fs_devices,
1187 void *data)
1188 {
1189 struct inode *inode;
1190 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1191 struct btrfs_key key;
1192 int err;
1193
1194 sb->s_maxbytes = MAX_LFS_FILESIZE;
1195 sb->s_magic = BTRFS_SUPER_MAGIC;
1196 sb->s_op = &btrfs_super_ops;
1197 sb->s_d_op = &btrfs_dentry_operations;
1198 sb->s_export_op = &btrfs_export_ops;
1199 sb->s_xattr = btrfs_xattr_handlers;
1200 sb->s_time_gran = 1;
1201 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
1202 sb->s_flags |= SB_POSIXACL;
1203 #endif
1204 sb->s_flags |= SB_I_VERSION;
1205 sb->s_iflags |= SB_I_CGROUPWB;
1206
1207 err = super_setup_bdi(sb);
1208 if (err) {
1209 btrfs_err(fs_info, "super_setup_bdi failed");
1210 return err;
1211 }
1212
1213 err = open_ctree(sb, fs_devices, (char *)data);
1214 if (err) {
1215 btrfs_err(fs_info, "open_ctree failed");
1216 return err;
1217 }
1218
1219 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
1220 key.type = BTRFS_INODE_ITEM_KEY;
1221 key.offset = 0;
1222 inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
1223 if (IS_ERR(inode)) {
1224 err = PTR_ERR(inode);
1225 goto fail_close;
1226 }
1227
1228 sb->s_root = d_make_root(inode);
1229 if (!sb->s_root) {
1230 err = -ENOMEM;
1231 goto fail_close;
1232 }
1233
1234 cleancache_init_fs(sb);
1235 sb->s_flags |= SB_ACTIVE;
1236 return 0;
1237
1238 fail_close:
1239 close_ctree(fs_info);
1240 return err;
1241 }
1242
btrfs_sync_fs(struct super_block * sb,int wait)1243 int btrfs_sync_fs(struct super_block *sb, int wait)
1244 {
1245 struct btrfs_trans_handle *trans;
1246 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1247 struct btrfs_root *root = fs_info->tree_root;
1248
1249 trace_btrfs_sync_fs(fs_info, wait);
1250
1251 if (!wait) {
1252 filemap_flush(fs_info->btree_inode->i_mapping);
1253 return 0;
1254 }
1255
1256 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
1257
1258 trans = btrfs_attach_transaction_barrier(root);
1259 if (IS_ERR(trans)) {
1260 /* no transaction, don't bother */
1261 if (PTR_ERR(trans) == -ENOENT) {
1262 /*
1263 * Exit unless we have some pending changes
1264 * that need to go through commit
1265 */
1266 if (fs_info->pending_changes == 0)
1267 return 0;
1268 /*
1269 * A non-blocking test if the fs is frozen. We must not
1270 * start a new transaction here otherwise a deadlock
1271 * happens. The pending operations are delayed to the
1272 * next commit after thawing.
1273 */
1274 if (sb_start_write_trylock(sb))
1275 sb_end_write(sb);
1276 else
1277 return 0;
1278 trans = btrfs_start_transaction(root, 0);
1279 }
1280 if (IS_ERR(trans))
1281 return PTR_ERR(trans);
1282 }
1283 return btrfs_commit_transaction(trans);
1284 }
1285
btrfs_show_options(struct seq_file * seq,struct dentry * dentry)1286 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
1287 {
1288 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
1289 const char *compress_type;
1290
1291 if (btrfs_test_opt(info, DEGRADED))
1292 seq_puts(seq, ",degraded");
1293 if (btrfs_test_opt(info, NODATASUM))
1294 seq_puts(seq, ",nodatasum");
1295 if (btrfs_test_opt(info, NODATACOW))
1296 seq_puts(seq, ",nodatacow");
1297 if (btrfs_test_opt(info, NOBARRIER))
1298 seq_puts(seq, ",nobarrier");
1299 if (info->max_inline != BTRFS_DEFAULT_MAX_INLINE)
1300 seq_printf(seq, ",max_inline=%llu", info->max_inline);
1301 if (info->thread_pool_size != min_t(unsigned long,
1302 num_online_cpus() + 2, 8))
1303 seq_printf(seq, ",thread_pool=%u", info->thread_pool_size);
1304 if (btrfs_test_opt(info, COMPRESS)) {
1305 compress_type = btrfs_compress_type2str(info->compress_type);
1306 if (btrfs_test_opt(info, FORCE_COMPRESS))
1307 seq_printf(seq, ",compress-force=%s", compress_type);
1308 else
1309 seq_printf(seq, ",compress=%s", compress_type);
1310 if (info->compress_level)
1311 seq_printf(seq, ":%d", info->compress_level);
1312 }
1313 if (btrfs_test_opt(info, NOSSD))
1314 seq_puts(seq, ",nossd");
1315 if (btrfs_test_opt(info, SSD_SPREAD))
1316 seq_puts(seq, ",ssd_spread");
1317 else if (btrfs_test_opt(info, SSD))
1318 seq_puts(seq, ",ssd");
1319 if (btrfs_test_opt(info, NOTREELOG))
1320 seq_puts(seq, ",notreelog");
1321 if (btrfs_test_opt(info, NOLOGREPLAY))
1322 seq_puts(seq, ",nologreplay");
1323 if (btrfs_test_opt(info, FLUSHONCOMMIT))
1324 seq_puts(seq, ",flushoncommit");
1325 if (btrfs_test_opt(info, DISCARD))
1326 seq_puts(seq, ",discard");
1327 if (!(info->sb->s_flags & SB_POSIXACL))
1328 seq_puts(seq, ",noacl");
1329 if (btrfs_test_opt(info, SPACE_CACHE))
1330 seq_puts(seq, ",space_cache");
1331 else if (btrfs_test_opt(info, FREE_SPACE_TREE))
1332 seq_puts(seq, ",space_cache=v2");
1333 else
1334 seq_puts(seq, ",nospace_cache");
1335 if (btrfs_test_opt(info, RESCAN_UUID_TREE))
1336 seq_puts(seq, ",rescan_uuid_tree");
1337 if (btrfs_test_opt(info, CLEAR_CACHE))
1338 seq_puts(seq, ",clear_cache");
1339 if (btrfs_test_opt(info, USER_SUBVOL_RM_ALLOWED))
1340 seq_puts(seq, ",user_subvol_rm_allowed");
1341 if (btrfs_test_opt(info, ENOSPC_DEBUG))
1342 seq_puts(seq, ",enospc_debug");
1343 if (btrfs_test_opt(info, AUTO_DEFRAG))
1344 seq_puts(seq, ",autodefrag");
1345 if (btrfs_test_opt(info, INODE_MAP_CACHE))
1346 seq_puts(seq, ",inode_cache");
1347 if (btrfs_test_opt(info, SKIP_BALANCE))
1348 seq_puts(seq, ",skip_balance");
1349 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1350 if (btrfs_test_opt(info, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA))
1351 seq_puts(seq, ",check_int_data");
1352 else if (btrfs_test_opt(info, CHECK_INTEGRITY))
1353 seq_puts(seq, ",check_int");
1354 if (info->check_integrity_print_mask)
1355 seq_printf(seq, ",check_int_print_mask=%d",
1356 info->check_integrity_print_mask);
1357 #endif
1358 if (info->metadata_ratio)
1359 seq_printf(seq, ",metadata_ratio=%u", info->metadata_ratio);
1360 if (btrfs_test_opt(info, PANIC_ON_FATAL_ERROR))
1361 seq_puts(seq, ",fatal_errors=panic");
1362 if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL)
1363 seq_printf(seq, ",commit=%u", info->commit_interval);
1364 #ifdef CONFIG_BTRFS_DEBUG
1365 if (btrfs_test_opt(info, FRAGMENT_DATA))
1366 seq_puts(seq, ",fragment=data");
1367 if (btrfs_test_opt(info, FRAGMENT_METADATA))
1368 seq_puts(seq, ",fragment=metadata");
1369 #endif
1370 if (btrfs_test_opt(info, REF_VERIFY))
1371 seq_puts(seq, ",ref_verify");
1372 seq_printf(seq, ",subvolid=%llu",
1373 BTRFS_I(d_inode(dentry))->root->root_key.objectid);
1374 seq_puts(seq, ",subvol=");
1375 seq_dentry(seq, dentry, " \t\n\\");
1376 return 0;
1377 }
1378
btrfs_test_super(struct super_block * s,void * data)1379 static int btrfs_test_super(struct super_block *s, void *data)
1380 {
1381 struct btrfs_fs_info *p = data;
1382 struct btrfs_fs_info *fs_info = btrfs_sb(s);
1383
1384 return fs_info->fs_devices == p->fs_devices;
1385 }
1386
btrfs_set_super(struct super_block * s,void * data)1387 static int btrfs_set_super(struct super_block *s, void *data)
1388 {
1389 int err = set_anon_super(s, data);
1390 if (!err)
1391 s->s_fs_info = data;
1392 return err;
1393 }
1394
1395 /*
1396 * subvolumes are identified by ino 256
1397 */
is_subvolume_inode(struct inode * inode)1398 static inline int is_subvolume_inode(struct inode *inode)
1399 {
1400 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
1401 return 1;
1402 return 0;
1403 }
1404
mount_subvol(const char * subvol_name,u64 subvol_objectid,struct vfsmount * mnt)1405 static struct dentry *mount_subvol(const char *subvol_name, u64 subvol_objectid,
1406 struct vfsmount *mnt)
1407 {
1408 struct dentry *root;
1409 int ret;
1410
1411 if (!subvol_name) {
1412 if (!subvol_objectid) {
1413 ret = get_default_subvol_objectid(btrfs_sb(mnt->mnt_sb),
1414 &subvol_objectid);
1415 if (ret) {
1416 root = ERR_PTR(ret);
1417 goto out;
1418 }
1419 }
1420 subvol_name = get_subvol_name_from_objectid(btrfs_sb(mnt->mnt_sb),
1421 subvol_objectid);
1422 if (IS_ERR(subvol_name)) {
1423 root = ERR_CAST(subvol_name);
1424 subvol_name = NULL;
1425 goto out;
1426 }
1427
1428 }
1429
1430 root = mount_subtree(mnt, subvol_name);
1431 /* mount_subtree() drops our reference on the vfsmount. */
1432 mnt = NULL;
1433
1434 if (!IS_ERR(root)) {
1435 struct super_block *s = root->d_sb;
1436 struct btrfs_fs_info *fs_info = btrfs_sb(s);
1437 struct inode *root_inode = d_inode(root);
1438 u64 root_objectid = BTRFS_I(root_inode)->root->root_key.objectid;
1439
1440 ret = 0;
1441 if (!is_subvolume_inode(root_inode)) {
1442 btrfs_err(fs_info, "'%s' is not a valid subvolume",
1443 subvol_name);
1444 ret = -EINVAL;
1445 }
1446 if (subvol_objectid && root_objectid != subvol_objectid) {
1447 /*
1448 * This will also catch a race condition where a
1449 * subvolume which was passed by ID is renamed and
1450 * another subvolume is renamed over the old location.
1451 */
1452 btrfs_err(fs_info,
1453 "subvol '%s' does not match subvolid %llu",
1454 subvol_name, subvol_objectid);
1455 ret = -EINVAL;
1456 }
1457 if (ret) {
1458 dput(root);
1459 root = ERR_PTR(ret);
1460 deactivate_locked_super(s);
1461 }
1462 }
1463
1464 out:
1465 mntput(mnt);
1466 kfree(subvol_name);
1467 return root;
1468 }
1469
1470 /*
1471 * Find a superblock for the given device / mount point.
1472 *
1473 * Note: This is based on mount_bdev from fs/super.c with a few additions
1474 * for multiple device setup. Make sure to keep it in sync.
1475 */
btrfs_mount_root(struct file_system_type * fs_type,int flags,const char * device_name,void * data)1476 static struct dentry *btrfs_mount_root(struct file_system_type *fs_type,
1477 int flags, const char *device_name, void *data)
1478 {
1479 struct block_device *bdev = NULL;
1480 struct super_block *s;
1481 struct btrfs_device *device = NULL;
1482 struct btrfs_fs_devices *fs_devices = NULL;
1483 struct btrfs_fs_info *fs_info = NULL;
1484 void *new_sec_opts = NULL;
1485 fmode_t mode = FMODE_READ;
1486 int error = 0;
1487
1488 if (!(flags & SB_RDONLY))
1489 mode |= FMODE_WRITE;
1490
1491 if (data) {
1492 error = security_sb_eat_lsm_opts(data, &new_sec_opts);
1493 if (error)
1494 return ERR_PTR(error);
1495 }
1496
1497 /*
1498 * Setup a dummy root and fs_info for test/set super. This is because
1499 * we don't actually fill this stuff out until open_ctree, but we need
1500 * it for searching for existing supers, so this lets us do that and
1501 * then open_ctree will properly initialize everything later.
1502 */
1503 fs_info = kvzalloc(sizeof(struct btrfs_fs_info), GFP_KERNEL);
1504 if (!fs_info) {
1505 error = -ENOMEM;
1506 goto error_sec_opts;
1507 }
1508
1509 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL);
1510 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL);
1511 if (!fs_info->super_copy || !fs_info->super_for_commit) {
1512 error = -ENOMEM;
1513 goto error_fs_info;
1514 }
1515
1516 mutex_lock(&uuid_mutex);
1517 error = btrfs_parse_device_options(data, mode, fs_type);
1518 if (error) {
1519 mutex_unlock(&uuid_mutex);
1520 goto error_fs_info;
1521 }
1522
1523 device = btrfs_scan_one_device(device_name, mode, fs_type);
1524 if (IS_ERR(device)) {
1525 mutex_unlock(&uuid_mutex);
1526 error = PTR_ERR(device);
1527 goto error_fs_info;
1528 }
1529
1530 fs_devices = device->fs_devices;
1531 fs_info->fs_devices = fs_devices;
1532
1533 error = btrfs_open_devices(fs_devices, mode, fs_type);
1534 mutex_unlock(&uuid_mutex);
1535 if (error)
1536 goto error_fs_info;
1537
1538 if (!(flags & SB_RDONLY) && fs_devices->rw_devices == 0) {
1539 error = -EACCES;
1540 goto error_close_devices;
1541 }
1542
1543 bdev = fs_devices->latest_bdev;
1544 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | SB_NOSEC,
1545 fs_info);
1546 if (IS_ERR(s)) {
1547 error = PTR_ERR(s);
1548 goto error_close_devices;
1549 }
1550
1551 if (s->s_root) {
1552 btrfs_close_devices(fs_devices);
1553 free_fs_info(fs_info);
1554 if ((flags ^ s->s_flags) & SB_RDONLY)
1555 error = -EBUSY;
1556 } else {
1557 snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev);
1558 btrfs_sb(s)->bdev_holder = fs_type;
1559 if (!strstr(crc32c_impl(), "generic"))
1560 set_bit(BTRFS_FS_CSUM_IMPL_FAST, &fs_info->flags);
1561 error = btrfs_fill_super(s, fs_devices, data);
1562 }
1563 if (!error)
1564 error = security_sb_set_mnt_opts(s, new_sec_opts, 0, NULL);
1565 security_free_mnt_opts(&new_sec_opts);
1566 if (error) {
1567 deactivate_locked_super(s);
1568 return ERR_PTR(error);
1569 }
1570
1571 return dget(s->s_root);
1572
1573 error_close_devices:
1574 btrfs_close_devices(fs_devices);
1575 error_fs_info:
1576 free_fs_info(fs_info);
1577 error_sec_opts:
1578 security_free_mnt_opts(&new_sec_opts);
1579 return ERR_PTR(error);
1580 }
1581
1582 /*
1583 * Mount function which is called by VFS layer.
1584 *
1585 * In order to allow mounting a subvolume directly, btrfs uses mount_subtree()
1586 * which needs vfsmount* of device's root (/). This means device's root has to
1587 * be mounted internally in any case.
1588 *
1589 * Operation flow:
1590 * 1. Parse subvol id related options for later use in mount_subvol().
1591 *
1592 * 2. Mount device's root (/) by calling vfs_kern_mount().
1593 *
1594 * NOTE: vfs_kern_mount() is used by VFS to call btrfs_mount() in the
1595 * first place. In order to avoid calling btrfs_mount() again, we use
1596 * different file_system_type which is not registered to VFS by
1597 * register_filesystem() (btrfs_root_fs_type). As a result,
1598 * btrfs_mount_root() is called. The return value will be used by
1599 * mount_subtree() in mount_subvol().
1600 *
1601 * 3. Call mount_subvol() to get the dentry of subvolume. Since there is
1602 * "btrfs subvolume set-default", mount_subvol() is called always.
1603 */
btrfs_mount(struct file_system_type * fs_type,int flags,const char * device_name,void * data)1604 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1605 const char *device_name, void *data)
1606 {
1607 struct vfsmount *mnt_root;
1608 struct dentry *root;
1609 char *subvol_name = NULL;
1610 u64 subvol_objectid = 0;
1611 int error = 0;
1612
1613 error = btrfs_parse_subvol_options(data, &subvol_name,
1614 &subvol_objectid);
1615 if (error) {
1616 kfree(subvol_name);
1617 return ERR_PTR(error);
1618 }
1619
1620 /* mount device's root (/) */
1621 mnt_root = vfs_kern_mount(&btrfs_root_fs_type, flags, device_name, data);
1622 if (PTR_ERR_OR_ZERO(mnt_root) == -EBUSY) {
1623 if (flags & SB_RDONLY) {
1624 mnt_root = vfs_kern_mount(&btrfs_root_fs_type,
1625 flags & ~SB_RDONLY, device_name, data);
1626 } else {
1627 mnt_root = vfs_kern_mount(&btrfs_root_fs_type,
1628 flags | SB_RDONLY, device_name, data);
1629 if (IS_ERR(mnt_root)) {
1630 root = ERR_CAST(mnt_root);
1631 kfree(subvol_name);
1632 goto out;
1633 }
1634
1635 down_write(&mnt_root->mnt_sb->s_umount);
1636 error = btrfs_remount(mnt_root->mnt_sb, &flags, NULL);
1637 up_write(&mnt_root->mnt_sb->s_umount);
1638 if (error < 0) {
1639 root = ERR_PTR(error);
1640 mntput(mnt_root);
1641 kfree(subvol_name);
1642 goto out;
1643 }
1644 }
1645 }
1646 if (IS_ERR(mnt_root)) {
1647 root = ERR_CAST(mnt_root);
1648 kfree(subvol_name);
1649 goto out;
1650 }
1651
1652 /* mount_subvol() will free subvol_name and mnt_root */
1653 root = mount_subvol(subvol_name, subvol_objectid, mnt_root);
1654
1655 out:
1656 return root;
1657 }
1658
btrfs_resize_thread_pool(struct btrfs_fs_info * fs_info,u32 new_pool_size,u32 old_pool_size)1659 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1660 u32 new_pool_size, u32 old_pool_size)
1661 {
1662 if (new_pool_size == old_pool_size)
1663 return;
1664
1665 fs_info->thread_pool_size = new_pool_size;
1666
1667 btrfs_info(fs_info, "resize thread pool %d -> %d",
1668 old_pool_size, new_pool_size);
1669
1670 btrfs_workqueue_set_max(fs_info->workers, new_pool_size);
1671 btrfs_workqueue_set_max(fs_info->delalloc_workers, new_pool_size);
1672 btrfs_workqueue_set_max(fs_info->submit_workers, new_pool_size);
1673 btrfs_workqueue_set_max(fs_info->caching_workers, new_pool_size);
1674 btrfs_workqueue_set_max(fs_info->endio_workers, new_pool_size);
1675 btrfs_workqueue_set_max(fs_info->endio_meta_workers, new_pool_size);
1676 btrfs_workqueue_set_max(fs_info->endio_meta_write_workers,
1677 new_pool_size);
1678 btrfs_workqueue_set_max(fs_info->endio_write_workers, new_pool_size);
1679 btrfs_workqueue_set_max(fs_info->endio_freespace_worker, new_pool_size);
1680 btrfs_workqueue_set_max(fs_info->delayed_workers, new_pool_size);
1681 btrfs_workqueue_set_max(fs_info->readahead_workers, new_pool_size);
1682 btrfs_workqueue_set_max(fs_info->scrub_wr_completion_workers,
1683 new_pool_size);
1684 }
1685
btrfs_remount_prepare(struct btrfs_fs_info * fs_info)1686 static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info)
1687 {
1688 set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1689 }
1690
btrfs_remount_begin(struct btrfs_fs_info * fs_info,unsigned long old_opts,int flags)1691 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
1692 unsigned long old_opts, int flags)
1693 {
1694 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1695 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1696 (flags & SB_RDONLY))) {
1697 /* wait for any defraggers to finish */
1698 wait_event(fs_info->transaction_wait,
1699 (atomic_read(&fs_info->defrag_running) == 0));
1700 if (flags & SB_RDONLY)
1701 sync_filesystem(fs_info->sb);
1702 }
1703 }
1704
btrfs_remount_cleanup(struct btrfs_fs_info * fs_info,unsigned long old_opts)1705 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1706 unsigned long old_opts)
1707 {
1708 /*
1709 * We need to cleanup all defragable inodes if the autodefragment is
1710 * close or the filesystem is read only.
1711 */
1712 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1713 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) || sb_rdonly(fs_info->sb))) {
1714 btrfs_cleanup_defrag_inodes(fs_info);
1715 }
1716
1717 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1718 }
1719
btrfs_remount(struct super_block * sb,int * flags,char * data)1720 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1721 {
1722 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1723 struct btrfs_root *root = fs_info->tree_root;
1724 unsigned old_flags = sb->s_flags;
1725 unsigned long old_opts = fs_info->mount_opt;
1726 unsigned long old_compress_type = fs_info->compress_type;
1727 u64 old_max_inline = fs_info->max_inline;
1728 u32 old_thread_pool_size = fs_info->thread_pool_size;
1729 u32 old_metadata_ratio = fs_info->metadata_ratio;
1730 int ret;
1731
1732 sync_filesystem(sb);
1733 btrfs_remount_prepare(fs_info);
1734
1735 if (data) {
1736 void *new_sec_opts = NULL;
1737
1738 ret = security_sb_eat_lsm_opts(data, &new_sec_opts);
1739 if (!ret)
1740 ret = security_sb_remount(sb, new_sec_opts);
1741 security_free_mnt_opts(&new_sec_opts);
1742 if (ret)
1743 goto restore;
1744 }
1745
1746 ret = btrfs_parse_options(fs_info, data, *flags);
1747 if (ret)
1748 goto restore;
1749
1750 btrfs_remount_begin(fs_info, old_opts, *flags);
1751 btrfs_resize_thread_pool(fs_info,
1752 fs_info->thread_pool_size, old_thread_pool_size);
1753
1754 if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1755 goto out;
1756
1757 if (*flags & SB_RDONLY) {
1758 /*
1759 * this also happens on 'umount -rf' or on shutdown, when
1760 * the filesystem is busy.
1761 */
1762 cancel_work_sync(&fs_info->async_reclaim_work);
1763
1764 /* wait for the uuid_scan task to finish */
1765 down(&fs_info->uuid_tree_rescan_sem);
1766 /* avoid complains from lockdep et al. */
1767 up(&fs_info->uuid_tree_rescan_sem);
1768
1769 sb->s_flags |= SB_RDONLY;
1770
1771 /*
1772 * Setting SB_RDONLY will put the cleaner thread to
1773 * sleep at the next loop if it's already active.
1774 * If it's already asleep, we'll leave unused block
1775 * groups on disk until we're mounted read-write again
1776 * unless we clean them up here.
1777 */
1778 btrfs_delete_unused_bgs(fs_info);
1779
1780 btrfs_dev_replace_suspend_for_unmount(fs_info);
1781 btrfs_scrub_cancel(fs_info);
1782 btrfs_pause_balance(fs_info);
1783
1784 ret = btrfs_commit_super(fs_info);
1785 if (ret)
1786 goto restore;
1787 } else {
1788 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
1789 btrfs_err(fs_info,
1790 "Remounting read-write after error is not allowed");
1791 ret = -EINVAL;
1792 goto restore;
1793 }
1794 if (fs_info->fs_devices->rw_devices == 0) {
1795 ret = -EACCES;
1796 goto restore;
1797 }
1798
1799 if (!btrfs_check_rw_degradable(fs_info, NULL)) {
1800 btrfs_warn(fs_info,
1801 "too many missing devices, writable remount is not allowed");
1802 ret = -EACCES;
1803 goto restore;
1804 }
1805
1806 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1807 ret = -EINVAL;
1808 goto restore;
1809 }
1810
1811 ret = btrfs_cleanup_fs_roots(fs_info);
1812 if (ret)
1813 goto restore;
1814
1815 /* recover relocation */
1816 mutex_lock(&fs_info->cleaner_mutex);
1817 ret = btrfs_recover_relocation(root);
1818 mutex_unlock(&fs_info->cleaner_mutex);
1819 if (ret)
1820 goto restore;
1821
1822 ret = btrfs_resume_balance_async(fs_info);
1823 if (ret)
1824 goto restore;
1825
1826 ret = btrfs_resume_dev_replace_async(fs_info);
1827 if (ret) {
1828 btrfs_warn(fs_info, "failed to resume dev_replace");
1829 goto restore;
1830 }
1831
1832 btrfs_qgroup_rescan_resume(fs_info);
1833
1834 if (!fs_info->uuid_root) {
1835 btrfs_info(fs_info, "creating UUID tree");
1836 ret = btrfs_create_uuid_tree(fs_info);
1837 if (ret) {
1838 btrfs_warn(fs_info,
1839 "failed to create the UUID tree %d",
1840 ret);
1841 goto restore;
1842 }
1843 }
1844 sb->s_flags &= ~SB_RDONLY;
1845
1846 set_bit(BTRFS_FS_OPEN, &fs_info->flags);
1847 }
1848 out:
1849 wake_up_process(fs_info->transaction_kthread);
1850 btrfs_remount_cleanup(fs_info, old_opts);
1851 return 0;
1852
1853 restore:
1854 /* We've hit an error - don't reset SB_RDONLY */
1855 if (sb_rdonly(sb))
1856 old_flags |= SB_RDONLY;
1857 sb->s_flags = old_flags;
1858 fs_info->mount_opt = old_opts;
1859 fs_info->compress_type = old_compress_type;
1860 fs_info->max_inline = old_max_inline;
1861 btrfs_resize_thread_pool(fs_info,
1862 old_thread_pool_size, fs_info->thread_pool_size);
1863 fs_info->metadata_ratio = old_metadata_ratio;
1864 btrfs_remount_cleanup(fs_info, old_opts);
1865 return ret;
1866 }
1867
1868 /* Used to sort the devices by max_avail(descending sort) */
btrfs_cmp_device_free_bytes(const void * dev_info1,const void * dev_info2)1869 static inline int btrfs_cmp_device_free_bytes(const void *dev_info1,
1870 const void *dev_info2)
1871 {
1872 if (((struct btrfs_device_info *)dev_info1)->max_avail >
1873 ((struct btrfs_device_info *)dev_info2)->max_avail)
1874 return -1;
1875 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1876 ((struct btrfs_device_info *)dev_info2)->max_avail)
1877 return 1;
1878 else
1879 return 0;
1880 }
1881
1882 /*
1883 * sort the devices by max_avail, in which max free extent size of each device
1884 * is stored.(Descending Sort)
1885 */
btrfs_descending_sort_devices(struct btrfs_device_info * devices,size_t nr_devices)1886 static inline void btrfs_descending_sort_devices(
1887 struct btrfs_device_info *devices,
1888 size_t nr_devices)
1889 {
1890 sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1891 btrfs_cmp_device_free_bytes, NULL);
1892 }
1893
1894 /*
1895 * The helper to calc the free space on the devices that can be used to store
1896 * file data.
1897 */
btrfs_calc_avail_data_space(struct btrfs_fs_info * fs_info,u64 * free_bytes)1898 static inline int btrfs_calc_avail_data_space(struct btrfs_fs_info *fs_info,
1899 u64 *free_bytes)
1900 {
1901 struct btrfs_device_info *devices_info;
1902 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1903 struct btrfs_device *device;
1904 u64 type;
1905 u64 avail_space;
1906 u64 min_stripe_size;
1907 int num_stripes = 1;
1908 int i = 0, nr_devices;
1909 const struct btrfs_raid_attr *rattr;
1910
1911 /*
1912 * We aren't under the device list lock, so this is racy-ish, but good
1913 * enough for our purposes.
1914 */
1915 nr_devices = fs_info->fs_devices->open_devices;
1916 if (!nr_devices) {
1917 smp_mb();
1918 nr_devices = fs_info->fs_devices->open_devices;
1919 ASSERT(nr_devices);
1920 if (!nr_devices) {
1921 *free_bytes = 0;
1922 return 0;
1923 }
1924 }
1925
1926 devices_info = kmalloc_array(nr_devices, sizeof(*devices_info),
1927 GFP_KERNEL);
1928 if (!devices_info)
1929 return -ENOMEM;
1930
1931 /* calc min stripe number for data space allocation */
1932 type = btrfs_data_alloc_profile(fs_info);
1933 rattr = &btrfs_raid_array[btrfs_bg_flags_to_raid_index(type)];
1934
1935 if (type & BTRFS_BLOCK_GROUP_RAID0)
1936 num_stripes = nr_devices;
1937 else if (type & BTRFS_BLOCK_GROUP_RAID1)
1938 num_stripes = 2;
1939 else if (type & BTRFS_BLOCK_GROUP_RAID10)
1940 num_stripes = 4;
1941
1942 /* Adjust for more than 1 stripe per device */
1943 min_stripe_size = rattr->dev_stripes * BTRFS_STRIPE_LEN;
1944
1945 rcu_read_lock();
1946 list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
1947 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
1948 &device->dev_state) ||
1949 !device->bdev ||
1950 test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state))
1951 continue;
1952
1953 if (i >= nr_devices)
1954 break;
1955
1956 avail_space = device->total_bytes - device->bytes_used;
1957
1958 /* align with stripe_len */
1959 avail_space = rounddown(avail_space, BTRFS_STRIPE_LEN);
1960
1961 /*
1962 * In order to avoid overwriting the superblock on the drive,
1963 * btrfs starts at an offset of at least 1MB when doing chunk
1964 * allocation.
1965 *
1966 * This ensures we have at least min_stripe_size free space
1967 * after excluding 1MB.
1968 */
1969 if (avail_space <= SZ_1M + min_stripe_size)
1970 continue;
1971
1972 avail_space -= SZ_1M;
1973
1974 devices_info[i].dev = device;
1975 devices_info[i].max_avail = avail_space;
1976
1977 i++;
1978 }
1979 rcu_read_unlock();
1980
1981 nr_devices = i;
1982
1983 btrfs_descending_sort_devices(devices_info, nr_devices);
1984
1985 i = nr_devices - 1;
1986 avail_space = 0;
1987 while (nr_devices >= rattr->devs_min) {
1988 num_stripes = min(num_stripes, nr_devices);
1989
1990 if (devices_info[i].max_avail >= min_stripe_size) {
1991 int j;
1992 u64 alloc_size;
1993
1994 avail_space += devices_info[i].max_avail * num_stripes;
1995 alloc_size = devices_info[i].max_avail;
1996 for (j = i + 1 - num_stripes; j <= i; j++)
1997 devices_info[j].max_avail -= alloc_size;
1998 }
1999 i--;
2000 nr_devices--;
2001 }
2002
2003 kfree(devices_info);
2004 *free_bytes = avail_space;
2005 return 0;
2006 }
2007
2008 /*
2009 * Calculate numbers for 'df', pessimistic in case of mixed raid profiles.
2010 *
2011 * If there's a redundant raid level at DATA block groups, use the respective
2012 * multiplier to scale the sizes.
2013 *
2014 * Unused device space usage is based on simulating the chunk allocator
2015 * algorithm that respects the device sizes and order of allocations. This is
2016 * a close approximation of the actual use but there are other factors that may
2017 * change the result (like a new metadata chunk).
2018 *
2019 * If metadata is exhausted, f_bavail will be 0.
2020 */
btrfs_statfs(struct dentry * dentry,struct kstatfs * buf)2021 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
2022 {
2023 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
2024 struct btrfs_super_block *disk_super = fs_info->super_copy;
2025 struct list_head *head = &fs_info->space_info;
2026 struct btrfs_space_info *found;
2027 u64 total_used = 0;
2028 u64 total_free_data = 0;
2029 u64 total_free_meta = 0;
2030 int bits = dentry->d_sb->s_blocksize_bits;
2031 __be32 *fsid = (__be32 *)fs_info->fs_devices->fsid;
2032 unsigned factor = 1;
2033 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
2034 int ret;
2035 u64 thresh = 0;
2036 int mixed = 0;
2037
2038 rcu_read_lock();
2039 list_for_each_entry_rcu(found, head, list) {
2040 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
2041 int i;
2042
2043 total_free_data += found->disk_total - found->disk_used;
2044 total_free_data -=
2045 btrfs_account_ro_block_groups_free_space(found);
2046
2047 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
2048 if (!list_empty(&found->block_groups[i]))
2049 factor = btrfs_bg_type_to_factor(
2050 btrfs_raid_array[i].bg_flag);
2051 }
2052 }
2053
2054 /*
2055 * Metadata in mixed block goup profiles are accounted in data
2056 */
2057 if (!mixed && found->flags & BTRFS_BLOCK_GROUP_METADATA) {
2058 if (found->flags & BTRFS_BLOCK_GROUP_DATA)
2059 mixed = 1;
2060 else
2061 total_free_meta += found->disk_total -
2062 found->disk_used;
2063 }
2064
2065 total_used += found->disk_used;
2066 }
2067
2068 rcu_read_unlock();
2069
2070 buf->f_blocks = div_u64(btrfs_super_total_bytes(disk_super), factor);
2071 buf->f_blocks >>= bits;
2072 buf->f_bfree = buf->f_blocks - (div_u64(total_used, factor) >> bits);
2073
2074 /* Account global block reserve as used, it's in logical size already */
2075 spin_lock(&block_rsv->lock);
2076 /* Mixed block groups accounting is not byte-accurate, avoid overflow */
2077 if (buf->f_bfree >= block_rsv->size >> bits)
2078 buf->f_bfree -= block_rsv->size >> bits;
2079 else
2080 buf->f_bfree = 0;
2081 spin_unlock(&block_rsv->lock);
2082
2083 buf->f_bavail = div_u64(total_free_data, factor);
2084 ret = btrfs_calc_avail_data_space(fs_info, &total_free_data);
2085 if (ret)
2086 return ret;
2087 buf->f_bavail += div_u64(total_free_data, factor);
2088 buf->f_bavail = buf->f_bavail >> bits;
2089
2090 /*
2091 * We calculate the remaining metadata space minus global reserve. If
2092 * this is (supposedly) smaller than zero, there's no space. But this
2093 * does not hold in practice, the exhausted state happens where's still
2094 * some positive delta. So we apply some guesswork and compare the
2095 * delta to a 4M threshold. (Practically observed delta was ~2M.)
2096 *
2097 * We probably cannot calculate the exact threshold value because this
2098 * depends on the internal reservations requested by various
2099 * operations, so some operations that consume a few metadata will
2100 * succeed even if the Avail is zero. But this is better than the other
2101 * way around.
2102 */
2103 thresh = SZ_4M;
2104
2105 if (!mixed && total_free_meta - thresh < block_rsv->size)
2106 buf->f_bavail = 0;
2107
2108 buf->f_type = BTRFS_SUPER_MAGIC;
2109 buf->f_bsize = dentry->d_sb->s_blocksize;
2110 buf->f_namelen = BTRFS_NAME_LEN;
2111
2112 /* We treat it as constant endianness (it doesn't matter _which_)
2113 because we want the fsid to come out the same whether mounted
2114 on a big-endian or little-endian host */
2115 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
2116 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
2117 /* Mask in the root object ID too, to disambiguate subvols */
2118 buf->f_fsid.val[0] ^=
2119 BTRFS_I(d_inode(dentry))->root->root_key.objectid >> 32;
2120 buf->f_fsid.val[1] ^=
2121 BTRFS_I(d_inode(dentry))->root->root_key.objectid;
2122
2123 return 0;
2124 }
2125
btrfs_kill_super(struct super_block * sb)2126 static void btrfs_kill_super(struct super_block *sb)
2127 {
2128 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2129 kill_anon_super(sb);
2130 free_fs_info(fs_info);
2131 }
2132
2133 static struct file_system_type btrfs_fs_type = {
2134 .owner = THIS_MODULE,
2135 .name = "btrfs",
2136 .mount = btrfs_mount,
2137 .kill_sb = btrfs_kill_super,
2138 .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA,
2139 };
2140
2141 static struct file_system_type btrfs_root_fs_type = {
2142 .owner = THIS_MODULE,
2143 .name = "btrfs",
2144 .mount = btrfs_mount_root,
2145 .kill_sb = btrfs_kill_super,
2146 .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA,
2147 };
2148
2149 MODULE_ALIAS_FS("btrfs");
2150
btrfs_control_open(struct inode * inode,struct file * file)2151 static int btrfs_control_open(struct inode *inode, struct file *file)
2152 {
2153 /*
2154 * The control file's private_data is used to hold the
2155 * transaction when it is started and is used to keep
2156 * track of whether a transaction is already in progress.
2157 */
2158 file->private_data = NULL;
2159 return 0;
2160 }
2161
2162 /*
2163 * used by btrfsctl to scan devices when no FS is mounted
2164 */
btrfs_control_ioctl(struct file * file,unsigned int cmd,unsigned long arg)2165 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
2166 unsigned long arg)
2167 {
2168 struct btrfs_ioctl_vol_args *vol;
2169 struct btrfs_device *device = NULL;
2170 int ret = -ENOTTY;
2171
2172 if (!capable(CAP_SYS_ADMIN))
2173 return -EPERM;
2174
2175 vol = memdup_user((void __user *)arg, sizeof(*vol));
2176 if (IS_ERR(vol))
2177 return PTR_ERR(vol);
2178 vol->name[BTRFS_PATH_NAME_MAX] = '\0';
2179
2180 switch (cmd) {
2181 case BTRFS_IOC_SCAN_DEV:
2182 mutex_lock(&uuid_mutex);
2183 device = btrfs_scan_one_device(vol->name, FMODE_READ,
2184 &btrfs_root_fs_type);
2185 ret = PTR_ERR_OR_ZERO(device);
2186 mutex_unlock(&uuid_mutex);
2187 break;
2188 case BTRFS_IOC_FORGET_DEV:
2189 ret = btrfs_forget_devices(vol->name);
2190 break;
2191 case BTRFS_IOC_DEVICES_READY:
2192 mutex_lock(&uuid_mutex);
2193 device = btrfs_scan_one_device(vol->name, FMODE_READ,
2194 &btrfs_root_fs_type);
2195 if (IS_ERR(device)) {
2196 mutex_unlock(&uuid_mutex);
2197 ret = PTR_ERR(device);
2198 break;
2199 }
2200 ret = !(device->fs_devices->num_devices ==
2201 device->fs_devices->total_devices);
2202 mutex_unlock(&uuid_mutex);
2203 break;
2204 case BTRFS_IOC_GET_SUPPORTED_FEATURES:
2205 ret = btrfs_ioctl_get_supported_features((void __user*)arg);
2206 break;
2207 }
2208
2209 kfree(vol);
2210 return ret;
2211 }
2212
btrfs_freeze(struct super_block * sb)2213 static int btrfs_freeze(struct super_block *sb)
2214 {
2215 struct btrfs_trans_handle *trans;
2216 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2217 struct btrfs_root *root = fs_info->tree_root;
2218
2219 set_bit(BTRFS_FS_FROZEN, &fs_info->flags);
2220 /*
2221 * We don't need a barrier here, we'll wait for any transaction that
2222 * could be in progress on other threads (and do delayed iputs that
2223 * we want to avoid on a frozen filesystem), or do the commit
2224 * ourselves.
2225 */
2226 trans = btrfs_attach_transaction_barrier(root);
2227 if (IS_ERR(trans)) {
2228 /* no transaction, don't bother */
2229 if (PTR_ERR(trans) == -ENOENT)
2230 return 0;
2231 return PTR_ERR(trans);
2232 }
2233 return btrfs_commit_transaction(trans);
2234 }
2235
btrfs_unfreeze(struct super_block * sb)2236 static int btrfs_unfreeze(struct super_block *sb)
2237 {
2238 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2239
2240 clear_bit(BTRFS_FS_FROZEN, &fs_info->flags);
2241 return 0;
2242 }
2243
btrfs_show_devname(struct seq_file * m,struct dentry * root)2244 static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
2245 {
2246 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
2247 struct btrfs_fs_devices *cur_devices;
2248 struct btrfs_device *dev, *first_dev = NULL;
2249 struct list_head *head;
2250
2251 /*
2252 * Lightweight locking of the devices. We should not need
2253 * device_list_mutex here as we only read the device data and the list
2254 * is protected by RCU. Even if a device is deleted during the list
2255 * traversals, we'll get valid data, the freeing callback will wait at
2256 * least until the rcu_read_unlock.
2257 */
2258 rcu_read_lock();
2259 cur_devices = fs_info->fs_devices;
2260 while (cur_devices) {
2261 head = &cur_devices->devices;
2262 list_for_each_entry_rcu(dev, head, dev_list) {
2263 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state))
2264 continue;
2265 if (!dev->name)
2266 continue;
2267 if (!first_dev || dev->devid < first_dev->devid)
2268 first_dev = dev;
2269 }
2270 cur_devices = cur_devices->seed;
2271 }
2272
2273 if (first_dev)
2274 seq_escape(m, rcu_str_deref(first_dev->name), " \t\n\\");
2275 else
2276 WARN_ON(1);
2277 rcu_read_unlock();
2278 return 0;
2279 }
2280
2281 static const struct super_operations btrfs_super_ops = {
2282 .drop_inode = btrfs_drop_inode,
2283 .evict_inode = btrfs_evict_inode,
2284 .put_super = btrfs_put_super,
2285 .sync_fs = btrfs_sync_fs,
2286 .show_options = btrfs_show_options,
2287 .show_devname = btrfs_show_devname,
2288 .alloc_inode = btrfs_alloc_inode,
2289 .destroy_inode = btrfs_destroy_inode,
2290 .free_inode = btrfs_free_inode,
2291 .statfs = btrfs_statfs,
2292 .remount_fs = btrfs_remount,
2293 .freeze_fs = btrfs_freeze,
2294 .unfreeze_fs = btrfs_unfreeze,
2295 };
2296
2297 static const struct file_operations btrfs_ctl_fops = {
2298 .open = btrfs_control_open,
2299 .unlocked_ioctl = btrfs_control_ioctl,
2300 .compat_ioctl = btrfs_control_ioctl,
2301 .owner = THIS_MODULE,
2302 .llseek = noop_llseek,
2303 };
2304
2305 static struct miscdevice btrfs_misc = {
2306 .minor = BTRFS_MINOR,
2307 .name = "btrfs-control",
2308 .fops = &btrfs_ctl_fops
2309 };
2310
2311 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
2312 MODULE_ALIAS("devname:btrfs-control");
2313
btrfs_interface_init(void)2314 static int __init btrfs_interface_init(void)
2315 {
2316 return misc_register(&btrfs_misc);
2317 }
2318
btrfs_interface_exit(void)2319 static __cold void btrfs_interface_exit(void)
2320 {
2321 misc_deregister(&btrfs_misc);
2322 }
2323
btrfs_print_mod_info(void)2324 static void __init btrfs_print_mod_info(void)
2325 {
2326 static const char options[] = ""
2327 #ifdef CONFIG_BTRFS_DEBUG
2328 ", debug=on"
2329 #endif
2330 #ifdef CONFIG_BTRFS_ASSERT
2331 ", assert=on"
2332 #endif
2333 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2334 ", integrity-checker=on"
2335 #endif
2336 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
2337 ", ref-verify=on"
2338 #endif
2339 ;
2340 pr_info("Btrfs loaded, crc32c=%s%s\n", crc32c_impl(), options);
2341 }
2342
init_btrfs_fs(void)2343 static int __init init_btrfs_fs(void)
2344 {
2345 int err;
2346
2347 btrfs_props_init();
2348
2349 err = btrfs_init_sysfs();
2350 if (err)
2351 return err;
2352
2353 btrfs_init_compress();
2354
2355 err = btrfs_init_cachep();
2356 if (err)
2357 goto free_compress;
2358
2359 err = extent_io_init();
2360 if (err)
2361 goto free_cachep;
2362
2363 err = extent_map_init();
2364 if (err)
2365 goto free_extent_io;
2366
2367 err = ordered_data_init();
2368 if (err)
2369 goto free_extent_map;
2370
2371 err = btrfs_delayed_inode_init();
2372 if (err)
2373 goto free_ordered_data;
2374
2375 err = btrfs_auto_defrag_init();
2376 if (err)
2377 goto free_delayed_inode;
2378
2379 err = btrfs_delayed_ref_init();
2380 if (err)
2381 goto free_auto_defrag;
2382
2383 err = btrfs_prelim_ref_init();
2384 if (err)
2385 goto free_delayed_ref;
2386
2387 err = btrfs_end_io_wq_init();
2388 if (err)
2389 goto free_prelim_ref;
2390
2391 err = btrfs_interface_init();
2392 if (err)
2393 goto free_end_io_wq;
2394
2395 btrfs_init_lockdep();
2396
2397 btrfs_print_mod_info();
2398
2399 err = btrfs_run_sanity_tests();
2400 if (err)
2401 goto unregister_ioctl;
2402
2403 err = register_filesystem(&btrfs_fs_type);
2404 if (err)
2405 goto unregister_ioctl;
2406
2407 return 0;
2408
2409 unregister_ioctl:
2410 btrfs_interface_exit();
2411 free_end_io_wq:
2412 btrfs_end_io_wq_exit();
2413 free_prelim_ref:
2414 btrfs_prelim_ref_exit();
2415 free_delayed_ref:
2416 btrfs_delayed_ref_exit();
2417 free_auto_defrag:
2418 btrfs_auto_defrag_exit();
2419 free_delayed_inode:
2420 btrfs_delayed_inode_exit();
2421 free_ordered_data:
2422 ordered_data_exit();
2423 free_extent_map:
2424 extent_map_exit();
2425 free_extent_io:
2426 extent_io_exit();
2427 free_cachep:
2428 btrfs_destroy_cachep();
2429 free_compress:
2430 btrfs_exit_compress();
2431 btrfs_exit_sysfs();
2432
2433 return err;
2434 }
2435
exit_btrfs_fs(void)2436 static void __exit exit_btrfs_fs(void)
2437 {
2438 btrfs_destroy_cachep();
2439 btrfs_delayed_ref_exit();
2440 btrfs_auto_defrag_exit();
2441 btrfs_delayed_inode_exit();
2442 btrfs_prelim_ref_exit();
2443 ordered_data_exit();
2444 extent_map_exit();
2445 extent_io_exit();
2446 btrfs_interface_exit();
2447 btrfs_end_io_wq_exit();
2448 unregister_filesystem(&btrfs_fs_type);
2449 btrfs_exit_sysfs();
2450 btrfs_cleanup_fs_uuids();
2451 btrfs_exit_compress();
2452 }
2453
2454 late_initcall(init_btrfs_fs);
2455 module_exit(exit_btrfs_fs)
2456
2457 MODULE_LICENSE("GPL");
2458 MODULE_SOFTDEP("pre: crc32c");
2459