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Merge tag 'riscv-for-linus-4.15-rc2_cleanups' of git://git.kernel.org/pub/scm/linux...
[linux/fpc-iii.git] / fs / btrfs / super.c
blob3a4dce1536455416a4f609f99ec416b61811f592
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/blkdev.h>
20 #include <linux/module.h>
21 #include <linux/buffer_head.h>
22 #include <linux/fs.h>
23 #include <linux/pagemap.h>
24 #include <linux/highmem.h>
25 #include <linux/time.h>
26 #include <linux/init.h>
27 #include <linux/seq_file.h>
28 #include <linux/string.h>
29 #include <linux/backing-dev.h>
30 #include <linux/mount.h>
31 #include <linux/mpage.h>
32 #include <linux/swap.h>
33 #include <linux/writeback.h>
34 #include <linux/statfs.h>
35 #include <linux/compat.h>
36 #include <linux/parser.h>
37 #include <linux/ctype.h>
38 #include <linux/namei.h>
39 #include <linux/miscdevice.h>
40 #include <linux/magic.h>
41 #include <linux/slab.h>
42 #include <linux/cleancache.h>
43 #include <linux/ratelimit.h>
44 #include <linux/btrfs.h>
45 #include "delayed-inode.h"
46 #include "ctree.h"
47 #include "disk-io.h"
48 #include "transaction.h"
49 #include "btrfs_inode.h"
50 #include "print-tree.h"
51 #include "hash.h"
52 #include "props.h"
53 #include "xattr.h"
54 #include "volumes.h"
55 #include "export.h"
56 #include "compression.h"
57 #include "rcu-string.h"
58 #include "dev-replace.h"
59 #include "free-space-cache.h"
60 #include "backref.h"
61 #include "tests/btrfs-tests.h"
62
63 #include "qgroup.h"
64 #include "backref.h"
65 #define CREATE_TRACE_POINTS
66 #include <trace/events/btrfs.h>
67
68 static const struct super_operations btrfs_super_ops;
69 static struct file_system_type btrfs_fs_type;
70
71 static int btrfs_remount(struct super_block *sb, int *flags, char *data);
72
73 const char *btrfs_decode_error(int errno)
74 {
75 char *errstr = "unknown";
76
77 switch (errno) {
78 case -EIO:
79 errstr = "IO failure";
80 break;
81 case -ENOMEM:
82 errstr = "Out of memory";
83 break;
84 case -EROFS:
85 errstr = "Readonly filesystem";
86 break;
87 case -EEXIST:
88 errstr = "Object already exists";
89 break;
90 case -ENOSPC:
91 errstr = "No space left";
92 break;
93 case -ENOENT:
94 errstr = "No such entry";
95 break;
96 }
97
98 return errstr;
99 }
100
101 /* btrfs handle error by forcing the filesystem readonly */
102 static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
103 {
104 struct super_block *sb = fs_info->sb;
105
106 if (sb_rdonly(sb))
107 return;
108
109 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
110 sb->s_flags |= SB_RDONLY;
111 btrfs_info(fs_info, "forced readonly");
112 /*
113 * Note that a running device replace operation is not
114 * canceled here although there is no way to update
115 * the progress. It would add the risk of a deadlock,
116 * therefore the canceling is omitted. The only penalty
117 * is that some I/O remains active until the procedure
118 * completes. The next time when the filesystem is
119 * mounted writeable again, the device replace
120 * operation continues.
121 */
122 }
123 }
124
125 /*
126 * __btrfs_handle_fs_error decodes expected errors from the caller and
127 * invokes the approciate error response.
128 */
129 __cold
130 void __btrfs_handle_fs_error(struct btrfs_fs_info *fs_info, const char *function,
131 unsigned int line, int errno, const char *fmt, ...)
132 {
133 struct super_block *sb = fs_info->sb;
134 #ifdef CONFIG_PRINTK
135 const char *errstr;
136 #endif
137
138 /*
139 * Special case: if the error is EROFS, and we're already
140 * under SB_RDONLY, then it is safe here.
141 */
142 if (errno == -EROFS && sb_rdonly(sb))
143 return;
144
145 #ifdef CONFIG_PRINTK
146 errstr = btrfs_decode_error(errno);
147 if (fmt) {
148 struct va_format vaf;
149 va_list args;
150
151 va_start(args, fmt);
152 vaf.fmt = fmt;
153 vaf.va = &args;
154
155 pr_crit("BTRFS: error (device %s) in %s:%d: errno=%d %s (%pV)\n",
156 sb->s_id, function, line, errno, errstr, &vaf);
157 va_end(args);
158 } else {
159 pr_crit("BTRFS: error (device %s) in %s:%d: errno=%d %s\n",
160 sb->s_id, function, line, errno, errstr);
161 }
162 #endif
163
164 /*
165 * Today we only save the error info to memory. Long term we'll
166 * also send it down to the disk
167 */
168 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
169
170 /* Don't go through full error handling during mount */
171 if (sb->s_flags & SB_BORN)
172 btrfs_handle_error(fs_info);
173 }
174
175 #ifdef CONFIG_PRINTK
176 static const char * const logtypes[] = {
177 "emergency",
178 "alert",
179 "critical",
180 "error",
181 "warning",
182 "notice",
183 "info",
184 "debug",
185 };
186
187
188 /*
189 * Use one ratelimit state per log level so that a flood of less important
190 * messages doesn't cause more important ones to be dropped.
191 */
192 static struct ratelimit_state printk_limits[] = {
193 RATELIMIT_STATE_INIT(printk_limits[0], DEFAULT_RATELIMIT_INTERVAL, 100),
194 RATELIMIT_STATE_INIT(printk_limits[1], DEFAULT_RATELIMIT_INTERVAL, 100),
195 RATELIMIT_STATE_INIT(printk_limits[2], DEFAULT_RATELIMIT_INTERVAL, 100),
196 RATELIMIT_STATE_INIT(printk_limits[3], DEFAULT_RATELIMIT_INTERVAL, 100),
197 RATELIMIT_STATE_INIT(printk_limits[4], DEFAULT_RATELIMIT_INTERVAL, 100),
198 RATELIMIT_STATE_INIT(printk_limits[5], DEFAULT_RATELIMIT_INTERVAL, 100),
199 RATELIMIT_STATE_INIT(printk_limits[6], DEFAULT_RATELIMIT_INTERVAL, 100),
200 RATELIMIT_STATE_INIT(printk_limits[7], DEFAULT_RATELIMIT_INTERVAL, 100),
201 };
202
203 void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
204 {
205 char lvl[PRINTK_MAX_SINGLE_HEADER_LEN + 1] = "\0";
206 struct va_format vaf;
207 va_list args;
208 int kern_level;
209 const char *type = logtypes[4];
210 struct ratelimit_state *ratelimit = &printk_limits[4];
211
212 va_start(args, fmt);
213
214 while ((kern_level = printk_get_level(fmt)) != 0) {
215 size_t size = printk_skip_level(fmt) - fmt;
216
217 if (kern_level >= '0' && kern_level <= '7') {
218 memcpy(lvl, fmt, size);
219 lvl[size] = '\0';
220 type = logtypes[kern_level - '0'];
221 ratelimit = &printk_limits[kern_level - '0'];
222 }
223 fmt += size;
224 }
225
226 vaf.fmt = fmt;
227 vaf.va = &args;
228
229 if (__ratelimit(ratelimit))
230 printk("%sBTRFS %s (device %s): %pV\n", lvl, type,
231 fs_info ? fs_info->sb->s_id : "<unknown>", &vaf);
232
233 va_end(args);
234 }
235 #endif
236
237 /*
238 * We only mark the transaction aborted and then set the file system read-only.
239 * This will prevent new transactions from starting or trying to join this
240 * one.
241 *
242 * This means that error recovery at the call site is limited to freeing
243 * any local memory allocations and passing the error code up without
244 * further cleanup. The transaction should complete as it normally would
245 * in the call path but will return -EIO.
246 *
247 * We'll complete the cleanup in btrfs_end_transaction and
248 * btrfs_commit_transaction.
249 */
250 __cold
251 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
252 const char *function,
253 unsigned int line, int errno)
254 {
255 struct btrfs_fs_info *fs_info = trans->fs_info;
256
257 trans->aborted = errno;
258 /* Nothing used. The other threads that have joined this
259 * transaction may be able to continue. */
260 if (!trans->dirty && list_empty(&trans->new_bgs)) {
261 const char *errstr;
262
263 errstr = btrfs_decode_error(errno);
264 btrfs_warn(fs_info,
265 "%s:%d: Aborting unused transaction(%s).",
266 function, line, errstr);
267 return;
268 }
269 WRITE_ONCE(trans->transaction->aborted, errno);
270 /* Wake up anybody who may be waiting on this transaction */
271 wake_up(&fs_info->transaction_wait);
272 wake_up(&fs_info->transaction_blocked_wait);
273 __btrfs_handle_fs_error(fs_info, function, line, errno, NULL);
274 }
275 /*
276 * __btrfs_panic decodes unexpected, fatal errors from the caller,
277 * issues an alert, and either panics or BUGs, depending on mount options.
278 */
279 __cold
280 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
281 unsigned int line, int errno, const char *fmt, ...)
282 {
283 char *s_id = "<unknown>";
284 const char *errstr;
285 struct va_format vaf = { .fmt = fmt };
286 va_list args;
287
288 if (fs_info)
289 s_id = fs_info->sb->s_id;
290
291 va_start(args, fmt);
292 vaf.va = &args;
293
294 errstr = btrfs_decode_error(errno);
295 if (fs_info && (btrfs_test_opt(fs_info, PANIC_ON_FATAL_ERROR)))
296 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
297 s_id, function, line, &vaf, errno, errstr);
298
299 btrfs_crit(fs_info, "panic in %s:%d: %pV (errno=%d %s)",
300 function, line, &vaf, errno, errstr);
301 va_end(args);
302 /* Caller calls BUG() */
303 }
304
305 static void btrfs_put_super(struct super_block *sb)
306 {
307 close_ctree(btrfs_sb(sb));
308 }
309
310 enum {
311 Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
312 Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
313 Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
314 Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
315 Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
316 Opt_space_cache, Opt_space_cache_version, Opt_clear_cache,
317 Opt_user_subvol_rm_allowed, Opt_enospc_debug, Opt_subvolrootid,
318 Opt_defrag, Opt_inode_cache, Opt_no_space_cache, Opt_recovery,
319 Opt_skip_balance, Opt_check_integrity,
320 Opt_check_integrity_including_extent_data,
321 Opt_check_integrity_print_mask, Opt_fatal_errors, Opt_rescan_uuid_tree,
322 Opt_commit_interval, Opt_barrier, Opt_nodefrag, Opt_nodiscard,
323 Opt_noenospc_debug, Opt_noflushoncommit, Opt_acl, Opt_datacow,
324 Opt_datasum, Opt_treelog, Opt_noinode_cache, Opt_usebackuproot,
325 Opt_nologreplay, Opt_norecovery,
326 #ifdef CONFIG_BTRFS_DEBUG
327 Opt_fragment_data, Opt_fragment_metadata, Opt_fragment_all,
328 #endif
329 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
330 Opt_ref_verify,
331 #endif
332 Opt_err,
333 };
334
335 static const match_table_t tokens = {
336 {Opt_degraded, "degraded"},
337 {Opt_subvol, "subvol=%s"},
338 {Opt_subvolid, "subvolid=%s"},
339 {Opt_device, "device=%s"},
340 {Opt_nodatasum, "nodatasum"},
341 {Opt_datasum, "datasum"},
342 {Opt_nodatacow, "nodatacow"},
343 {Opt_datacow, "datacow"},
344 {Opt_nobarrier, "nobarrier"},
345 {Opt_barrier, "barrier"},
346 {Opt_max_inline, "max_inline=%s"},
347 {Opt_alloc_start, "alloc_start=%s"},
348 {Opt_thread_pool, "thread_pool=%d"},
349 {Opt_compress, "compress"},
350 {Opt_compress_type, "compress=%s"},
351 {Opt_compress_force, "compress-force"},
352 {Opt_compress_force_type, "compress-force=%s"},
353 {Opt_ssd, "ssd"},
354 {Opt_ssd_spread, "ssd_spread"},
355 {Opt_nossd, "nossd"},
356 {Opt_acl, "acl"},
357 {Opt_noacl, "noacl"},
358 {Opt_notreelog, "notreelog"},
359 {Opt_treelog, "treelog"},
360 {Opt_nologreplay, "nologreplay"},
361 {Opt_norecovery, "norecovery"},
362 {Opt_flushoncommit, "flushoncommit"},
363 {Opt_noflushoncommit, "noflushoncommit"},
364 {Opt_ratio, "metadata_ratio=%d"},
365 {Opt_discard, "discard"},
366 {Opt_nodiscard, "nodiscard"},
367 {Opt_space_cache, "space_cache"},
368 {Opt_space_cache_version, "space_cache=%s"},
369 {Opt_clear_cache, "clear_cache"},
370 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
371 {Opt_enospc_debug, "enospc_debug"},
372 {Opt_noenospc_debug, "noenospc_debug"},
373 {Opt_subvolrootid, "subvolrootid=%d"},
374 {Opt_defrag, "autodefrag"},
375 {Opt_nodefrag, "noautodefrag"},
376 {Opt_inode_cache, "inode_cache"},
377 {Opt_noinode_cache, "noinode_cache"},
378 {Opt_no_space_cache, "nospace_cache"},
379 {Opt_recovery, "recovery"}, /* deprecated */
380 {Opt_usebackuproot, "usebackuproot"},
381 {Opt_skip_balance, "skip_balance"},
382 {Opt_check_integrity, "check_int"},
383 {Opt_check_integrity_including_extent_data, "check_int_data"},
384 {Opt_check_integrity_print_mask, "check_int_print_mask=%d"},
385 {Opt_rescan_uuid_tree, "rescan_uuid_tree"},
386 {Opt_fatal_errors, "fatal_errors=%s"},
387 {Opt_commit_interval, "commit=%d"},
388 #ifdef CONFIG_BTRFS_DEBUG
389 {Opt_fragment_data, "fragment=data"},
390 {Opt_fragment_metadata, "fragment=metadata"},
391 {Opt_fragment_all, "fragment=all"},
392 #endif
393 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
394 {Opt_ref_verify, "ref_verify"},
395 #endif
396 {Opt_err, NULL},
397 };
398
399 /*
400 * Regular mount options parser. Everything that is needed only when
401 * reading in a new superblock is parsed here.
402 * XXX JDM: This needs to be cleaned up for remount.
403 */
404 int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
405 unsigned long new_flags)
406 {
407 substring_t args[MAX_OPT_ARGS];
408 char *p, *num, *orig = NULL;
409 u64 cache_gen;
410 int intarg;
411 int ret = 0;
412 char *compress_type;
413 bool compress_force = false;
414 enum btrfs_compression_type saved_compress_type;
415 bool saved_compress_force;
416 int no_compress = 0;
417
418 cache_gen = btrfs_super_cache_generation(info->super_copy);
419 if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE))
420 btrfs_set_opt(info->mount_opt, FREE_SPACE_TREE);
421 else if (cache_gen)
422 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
423
424 /*
425 * Even the options are empty, we still need to do extra check
426 * against new flags
427 */
428 if (!options)
429 goto check;
430
431 /*
432 * strsep changes the string, duplicate it because parse_options
433 * gets called twice
434 */
435 options = kstrdup(options, GFP_KERNEL);
436 if (!options)
437 return -ENOMEM;
438
439 orig = options;
440
441 while ((p = strsep(&options, ",")) != NULL) {
442 int token;
443 if (!*p)
444 continue;
445
446 token = match_token(p, tokens, args);
447 switch (token) {
448 case Opt_degraded:
449 btrfs_info(info, "allowing degraded mounts");
450 btrfs_set_opt(info->mount_opt, DEGRADED);
451 break;
452 case Opt_subvol:
453 case Opt_subvolid:
454 case Opt_subvolrootid:
455 case Opt_device:
456 /*
457 * These are parsed by btrfs_parse_early_options
458 * and can be happily ignored here.
459 */
460 break;
461 case Opt_nodatasum:
462 btrfs_set_and_info(info, NODATASUM,
463 "setting nodatasum");
464 break;
465 case Opt_datasum:
466 if (btrfs_test_opt(info, NODATASUM)) {
467 if (btrfs_test_opt(info, NODATACOW))
468 btrfs_info(info,
469 "setting datasum, datacow enabled");
470 else
471 btrfs_info(info, "setting datasum");
472 }
473 btrfs_clear_opt(info->mount_opt, NODATACOW);
474 btrfs_clear_opt(info->mount_opt, NODATASUM);
475 break;
476 case Opt_nodatacow:
477 if (!btrfs_test_opt(info, NODATACOW)) {
478 if (!btrfs_test_opt(info, COMPRESS) ||
479 !btrfs_test_opt(info, FORCE_COMPRESS)) {
480 btrfs_info(info,
481 "setting nodatacow, compression disabled");
482 } else {
483 btrfs_info(info, "setting nodatacow");
484 }
485 }
486 btrfs_clear_opt(info->mount_opt, COMPRESS);
487 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
488 btrfs_set_opt(info->mount_opt, NODATACOW);
489 btrfs_set_opt(info->mount_opt, NODATASUM);
490 break;
491 case Opt_datacow:
492 btrfs_clear_and_info(info, NODATACOW,
493 "setting datacow");
494 break;
495 case Opt_compress_force:
496 case Opt_compress_force_type:
497 compress_force = true;
498 /* Fallthrough */
499 case Opt_compress:
500 case Opt_compress_type:
501 saved_compress_type = btrfs_test_opt(info,
502 COMPRESS) ?
503 info->compress_type : BTRFS_COMPRESS_NONE;
504 saved_compress_force =
505 btrfs_test_opt(info, FORCE_COMPRESS);
506 if (token == Opt_compress ||
507 token == Opt_compress_force ||
508 strncmp(args[0].from, "zlib", 4) == 0) {
509 compress_type = "zlib";
510
511 info->compress_type = BTRFS_COMPRESS_ZLIB;
512 info->compress_level = BTRFS_ZLIB_DEFAULT_LEVEL;
513 /*
514 * args[0] contains uninitialized data since
515 * for these tokens we don't expect any
516 * parameter.
517 */
518 if (token != Opt_compress &&
519 token != Opt_compress_force)
520 info->compress_level =
521 btrfs_compress_str2level(args[0].from);
522 btrfs_set_opt(info->mount_opt, COMPRESS);
523 btrfs_clear_opt(info->mount_opt, NODATACOW);
524 btrfs_clear_opt(info->mount_opt, NODATASUM);
525 no_compress = 0;
526 } else if (strncmp(args[0].from, "lzo", 3) == 0) {
527 compress_type = "lzo";
528 info->compress_type = BTRFS_COMPRESS_LZO;
529 btrfs_set_opt(info->mount_opt, COMPRESS);
530 btrfs_clear_opt(info->mount_opt, NODATACOW);
531 btrfs_clear_opt(info->mount_opt, NODATASUM);
532 btrfs_set_fs_incompat(info, COMPRESS_LZO);
533 no_compress = 0;
534 } else if (strcmp(args[0].from, "zstd") == 0) {
535 compress_type = "zstd";
536 info->compress_type = BTRFS_COMPRESS_ZSTD;
537 btrfs_set_opt(info->mount_opt, COMPRESS);
538 btrfs_clear_opt(info->mount_opt, NODATACOW);
539 btrfs_clear_opt(info->mount_opt, NODATASUM);
540 btrfs_set_fs_incompat(info, COMPRESS_ZSTD);
541 no_compress = 0;
542 } else if (strncmp(args[0].from, "no", 2) == 0) {
543 compress_type = "no";
544 btrfs_clear_opt(info->mount_opt, COMPRESS);
545 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
546 compress_force = false;
547 no_compress++;
548 } else {
549 ret = -EINVAL;
550 goto out;
551 }
552
553 if (compress_force) {
554 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
555 } else {
556 /*
557 * If we remount from compress-force=xxx to
558 * compress=xxx, we need clear FORCE_COMPRESS
559 * flag, otherwise, there is no way for users
560 * to disable forcible compression separately.
561 */
562 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
563 }
564 if ((btrfs_test_opt(info, COMPRESS) &&
565 (info->compress_type != saved_compress_type ||
566 compress_force != saved_compress_force)) ||
567 (!btrfs_test_opt(info, COMPRESS) &&
568 no_compress == 1)) {
569 btrfs_info(info, "%s %s compression, level %d",
570 (compress_force) ? "force" : "use",
571 compress_type, info->compress_level);
572 }
573 compress_force = false;
574 break;
575 case Opt_ssd:
576 btrfs_set_and_info(info, SSD,
577 "enabling ssd optimizations");
578 btrfs_clear_opt(info->mount_opt, NOSSD);
579 break;
580 case Opt_ssd_spread:
581 btrfs_set_and_info(info, SSD,
582 "enabling ssd optimizations");
583 btrfs_set_and_info(info, SSD_SPREAD,
584 "using spread ssd allocation scheme");
585 btrfs_clear_opt(info->mount_opt, NOSSD);
586 break;
587 case Opt_nossd:
588 btrfs_set_opt(info->mount_opt, NOSSD);
589 btrfs_clear_and_info(info, SSD,
590 "not using ssd optimizations");
591 btrfs_clear_and_info(info, SSD_SPREAD,
592 "not using spread ssd allocation scheme");
593 break;
594 case Opt_barrier:
595 btrfs_clear_and_info(info, NOBARRIER,
596 "turning on barriers");
597 break;
598 case Opt_nobarrier:
599 btrfs_set_and_info(info, NOBARRIER,
600 "turning off barriers");
601 break;
602 case Opt_thread_pool:
603 ret = match_int(&args[0], &intarg);
604 if (ret) {
605 goto out;
606 } else if (intarg > 0) {
607 info->thread_pool_size = intarg;
608 } else {
609 ret = -EINVAL;
610 goto out;
611 }
612 break;
613 case Opt_max_inline:
614 num = match_strdup(&args[0]);
615 if (num) {
616 info->max_inline = memparse(num, NULL);
617 kfree(num);
618
619 if (info->max_inline) {
620 info->max_inline = min_t(u64,
621 info->max_inline,
622 info->sectorsize);
623 }
624 btrfs_info(info, "max_inline at %llu",
625 info->max_inline);
626 } else {
627 ret = -ENOMEM;
628 goto out;
629 }
630 break;
631 case Opt_alloc_start:
632 btrfs_info(info,
633 "option alloc_start is obsolete, ignored");
634 break;
635 case Opt_acl:
636 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
637 info->sb->s_flags |= SB_POSIXACL;
638 break;
639 #else
640 btrfs_err(info, "support for ACL not compiled in!");
641 ret = -EINVAL;
642 goto out;
643 #endif
644 case Opt_noacl:
645 info->sb->s_flags &= ~SB_POSIXACL;
646 break;
647 case Opt_notreelog:
648 btrfs_set_and_info(info, NOTREELOG,
649 "disabling tree log");
650 break;
651 case Opt_treelog:
652 btrfs_clear_and_info(info, NOTREELOG,
653 "enabling tree log");
654 break;
655 case Opt_norecovery:
656 case Opt_nologreplay:
657 btrfs_set_and_info(info, NOLOGREPLAY,
658 "disabling log replay at mount time");
659 break;
660 case Opt_flushoncommit:
661 btrfs_set_and_info(info, FLUSHONCOMMIT,
662 "turning on flush-on-commit");
663 break;
664 case Opt_noflushoncommit:
665 btrfs_clear_and_info(info, FLUSHONCOMMIT,
666 "turning off flush-on-commit");
667 break;
668 case Opt_ratio:
669 ret = match_int(&args[0], &intarg);
670 if (ret) {
671 goto out;
672 } else if (intarg >= 0) {
673 info->metadata_ratio = intarg;
674 btrfs_info(info, "metadata ratio %d",
675 info->metadata_ratio);
676 } else {
677 ret = -EINVAL;
678 goto out;
679 }
680 break;
681 case Opt_discard:
682 btrfs_set_and_info(info, DISCARD,
683 "turning on discard");
684 break;
685 case Opt_nodiscard:
686 btrfs_clear_and_info(info, DISCARD,
687 "turning off discard");
688 break;
689 case Opt_space_cache:
690 case Opt_space_cache_version:
691 if (token == Opt_space_cache ||
692 strcmp(args[0].from, "v1") == 0) {
693 btrfs_clear_opt(info->mount_opt,
694 FREE_SPACE_TREE);
695 btrfs_set_and_info(info, SPACE_CACHE,
696 "enabling disk space caching");
697 } else if (strcmp(args[0].from, "v2") == 0) {
698 btrfs_clear_opt(info->mount_opt,
699 SPACE_CACHE);
700 btrfs_set_and_info(info, FREE_SPACE_TREE,
701 "enabling free space tree");
702 } else {
703 ret = -EINVAL;
704 goto out;
705 }
706 break;
707 case Opt_rescan_uuid_tree:
708 btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE);
709 break;
710 case Opt_no_space_cache:
711 if (btrfs_test_opt(info, SPACE_CACHE)) {
712 btrfs_clear_and_info(info, SPACE_CACHE,
713 "disabling disk space caching");
714 }
715 if (btrfs_test_opt(info, FREE_SPACE_TREE)) {
716 btrfs_clear_and_info(info, FREE_SPACE_TREE,
717 "disabling free space tree");
718 }
719 break;
720 case Opt_inode_cache:
721 btrfs_set_pending_and_info(info, INODE_MAP_CACHE,
722 "enabling inode map caching");
723 break;
724 case Opt_noinode_cache:
725 btrfs_clear_pending_and_info(info, INODE_MAP_CACHE,
726 "disabling inode map caching");
727 break;
728 case Opt_clear_cache:
729 btrfs_set_and_info(info, CLEAR_CACHE,
730 "force clearing of disk cache");
731 break;
732 case Opt_user_subvol_rm_allowed:
733 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
734 break;
735 case Opt_enospc_debug:
736 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
737 break;
738 case Opt_noenospc_debug:
739 btrfs_clear_opt(info->mount_opt, ENOSPC_DEBUG);
740 break;
741 case Opt_defrag:
742 btrfs_set_and_info(info, AUTO_DEFRAG,
743 "enabling auto defrag");
744 break;
745 case Opt_nodefrag:
746 btrfs_clear_and_info(info, AUTO_DEFRAG,
747 "disabling auto defrag");
748 break;
749 case Opt_recovery:
750 btrfs_warn(info,
751 "'recovery' is deprecated, use 'usebackuproot' instead");
752 case Opt_usebackuproot:
753 btrfs_info(info,
754 "trying to use backup root at mount time");
755 btrfs_set_opt(info->mount_opt, USEBACKUPROOT);
756 break;
757 case Opt_skip_balance:
758 btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
759 break;
760 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
761 case Opt_check_integrity_including_extent_data:
762 btrfs_info(info,
763 "enabling check integrity including extent data");
764 btrfs_set_opt(info->mount_opt,
765 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
766 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
767 break;
768 case Opt_check_integrity:
769 btrfs_info(info, "enabling check integrity");
770 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
771 break;
772 case Opt_check_integrity_print_mask:
773 ret = match_int(&args[0], &intarg);
774 if (ret) {
775 goto out;
776 } else if (intarg >= 0) {
777 info->check_integrity_print_mask = intarg;
778 btrfs_info(info,
779 "check_integrity_print_mask 0x%x",
780 info->check_integrity_print_mask);
781 } else {
782 ret = -EINVAL;
783 goto out;
784 }
785 break;
786 #else
787 case Opt_check_integrity_including_extent_data:
788 case Opt_check_integrity:
789 case Opt_check_integrity_print_mask:
790 btrfs_err(info,
791 "support for check_integrity* not compiled in!");
792 ret = -EINVAL;
793 goto out;
794 #endif
795 case Opt_fatal_errors:
796 if (strcmp(args[0].from, "panic") == 0)
797 btrfs_set_opt(info->mount_opt,
798 PANIC_ON_FATAL_ERROR);
799 else if (strcmp(args[0].from, "bug") == 0)
800 btrfs_clear_opt(info->mount_opt,
801 PANIC_ON_FATAL_ERROR);
802 else {
803 ret = -EINVAL;
804 goto out;
805 }
806 break;
807 case Opt_commit_interval:
808 intarg = 0;
809 ret = match_int(&args[0], &intarg);
810 if (ret < 0) {
811 btrfs_err(info, "invalid commit interval");
812 ret = -EINVAL;
813 goto out;
814 }
815 if (intarg > 0) {
816 if (intarg > 300) {
817 btrfs_warn(info,
818 "excessive commit interval %d",
819 intarg);
820 }
821 info->commit_interval = intarg;
822 } else {
823 btrfs_info(info,
824 "using default commit interval %ds",
825 BTRFS_DEFAULT_COMMIT_INTERVAL);
826 info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
827 }
828 break;
829 #ifdef CONFIG_BTRFS_DEBUG
830 case Opt_fragment_all:
831 btrfs_info(info, "fragmenting all space");
832 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA);
833 btrfs_set_opt(info->mount_opt, FRAGMENT_METADATA);
834 break;
835 case Opt_fragment_metadata:
836 btrfs_info(info, "fragmenting metadata");
837 btrfs_set_opt(info->mount_opt,
838 FRAGMENT_METADATA);
839 break;
840 case Opt_fragment_data:
841 btrfs_info(info, "fragmenting data");
842 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA);
843 break;
844 #endif
845 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
846 case Opt_ref_verify:
847 btrfs_info(info, "doing ref verification");
848 btrfs_set_opt(info->mount_opt, REF_VERIFY);
849 break;
850 #endif
851 case Opt_err:
852 btrfs_info(info, "unrecognized mount option '%s'", p);
853 ret = -EINVAL;
854 goto out;
855 default:
856 break;
857 }
858 }
859 check:
860 /*
861 * Extra check for current option against current flag
862 */
863 if (btrfs_test_opt(info, NOLOGREPLAY) && !(new_flags & SB_RDONLY)) {
864 btrfs_err(info,
865 "nologreplay must be used with ro mount option");
866 ret = -EINVAL;
867 }
868 out:
869 if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE) &&
870 !btrfs_test_opt(info, FREE_SPACE_TREE) &&
871 !btrfs_test_opt(info, CLEAR_CACHE)) {
872 btrfs_err(info, "cannot disable free space tree");
873 ret = -EINVAL;
874
875 }
876 if (!ret && btrfs_test_opt(info, SPACE_CACHE))
877 btrfs_info(info, "disk space caching is enabled");
878 if (!ret && btrfs_test_opt(info, FREE_SPACE_TREE))
879 btrfs_info(info, "using free space tree");
880 kfree(orig);
881 return ret;
882 }
883
884 /*
885 * Parse mount options that are required early in the mount process.
886 *
887 * All other options will be parsed on much later in the mount process and
888 * only when we need to allocate a new super block.
889 */
890 static int btrfs_parse_early_options(const char *options, fmode_t flags,
891 void *holder, char **subvol_name, u64 *subvol_objectid,
892 struct btrfs_fs_devices **fs_devices)
893 {
894 substring_t args[MAX_OPT_ARGS];
895 char *device_name, *opts, *orig, *p;
896 char *num = NULL;
897 int error = 0;
898
899 if (!options)
900 return 0;
901
902 /*
903 * strsep changes the string, duplicate it because parse_options
904 * gets called twice
905 */
906 opts = kstrdup(options, GFP_KERNEL);
907 if (!opts)
908 return -ENOMEM;
909 orig = opts;
910
911 while ((p = strsep(&opts, ",")) != NULL) {
912 int token;
913 if (!*p)
914 continue;
915
916 token = match_token(p, tokens, args);
917 switch (token) {
918 case Opt_subvol:
919 kfree(*subvol_name);
920 *subvol_name = match_strdup(&args[0]);
921 if (!*subvol_name) {
922 error = -ENOMEM;
923 goto out;
924 }
925 break;
926 case Opt_subvolid:
927 num = match_strdup(&args[0]);
928 if (num) {
929 *subvol_objectid = memparse(num, NULL);
930 kfree(num);
931 /* we want the original fs_tree */
932 if (!*subvol_objectid)
933 *subvol_objectid =
934 BTRFS_FS_TREE_OBJECTID;
935 } else {
936 error = -EINVAL;
937 goto out;
938 }
939 break;
940 case Opt_subvolrootid:
941 pr_warn("BTRFS: 'subvolrootid' mount option is deprecated and has no effect\n");
942 break;
943 case Opt_device:
944 device_name = match_strdup(&args[0]);
945 if (!device_name) {
946 error = -ENOMEM;
947 goto out;
948 }
949 error = btrfs_scan_one_device(device_name,
950 flags, holder, fs_devices);
951 kfree(device_name);
952 if (error)
953 goto out;
954 break;
955 default:
956 break;
957 }
958 }
959
960 out:
961 kfree(orig);
962 return error;
963 }
964
965 static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info,
966 u64 subvol_objectid)
967 {
968 struct btrfs_root *root = fs_info->tree_root;
969 struct btrfs_root *fs_root;
970 struct btrfs_root_ref *root_ref;
971 struct btrfs_inode_ref *inode_ref;
972 struct btrfs_key key;
973 struct btrfs_path *path = NULL;
974 char *name = NULL, *ptr;
975 u64 dirid;
976 int len;
977 int ret;
978
979 path = btrfs_alloc_path();
980 if (!path) {
981 ret = -ENOMEM;
982 goto err;
983 }
984 path->leave_spinning = 1;
985
986 name = kmalloc(PATH_MAX, GFP_KERNEL);
987 if (!name) {
988 ret = -ENOMEM;
989 goto err;
990 }
991 ptr = name + PATH_MAX - 1;
992 ptr[0] = '\0';
993
994 /*
995 * Walk up the subvolume trees in the tree of tree roots by root
996 * backrefs until we hit the top-level subvolume.
997 */
998 while (subvol_objectid != BTRFS_FS_TREE_OBJECTID) {
999 key.objectid = subvol_objectid;
1000 key.type = BTRFS_ROOT_BACKREF_KEY;
1001 key.offset = (u64)-1;
1002
1003 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1004 if (ret < 0) {
1005 goto err;
1006 } else if (ret > 0) {
1007 ret = btrfs_previous_item(root, path, subvol_objectid,
1008 BTRFS_ROOT_BACKREF_KEY);
1009 if (ret < 0) {
1010 goto err;
1011 } else if (ret > 0) {
1012 ret = -ENOENT;
1013 goto err;
1014 }
1015 }
1016
1017 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1018 subvol_objectid = key.offset;
1019
1020 root_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
1021 struct btrfs_root_ref);
1022 len = btrfs_root_ref_name_len(path->nodes[0], root_ref);
1023 ptr -= len + 1;
1024 if (ptr < name) {
1025 ret = -ENAMETOOLONG;
1026 goto err;
1027 }
1028 read_extent_buffer(path->nodes[0], ptr + 1,
1029 (unsigned long)(root_ref + 1), len);
1030 ptr[0] = '/';
1031 dirid = btrfs_root_ref_dirid(path->nodes[0], root_ref);
1032 btrfs_release_path(path);
1033
1034 key.objectid = subvol_objectid;
1035 key.type = BTRFS_ROOT_ITEM_KEY;
1036 key.offset = (u64)-1;
1037 fs_root = btrfs_read_fs_root_no_name(fs_info, &key);
1038 if (IS_ERR(fs_root)) {
1039 ret = PTR_ERR(fs_root);
1040 goto err;
1041 }
1042
1043 /*
1044 * Walk up the filesystem tree by inode refs until we hit the
1045 * root directory.
1046 */
1047 while (dirid != BTRFS_FIRST_FREE_OBJECTID) {
1048 key.objectid = dirid;
1049 key.type = BTRFS_INODE_REF_KEY;
1050 key.offset = (u64)-1;
1051
1052 ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0);
1053 if (ret < 0) {
1054 goto err;
1055 } else if (ret > 0) {
1056 ret = btrfs_previous_item(fs_root, path, dirid,
1057 BTRFS_INODE_REF_KEY);
1058 if (ret < 0) {
1059 goto err;
1060 } else if (ret > 0) {
1061 ret = -ENOENT;
1062 goto err;
1063 }
1064 }
1065
1066 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1067 dirid = key.offset;
1068
1069 inode_ref = btrfs_item_ptr(path->nodes[0],
1070 path->slots[0],
1071 struct btrfs_inode_ref);
1072 len = btrfs_inode_ref_name_len(path->nodes[0],
1073 inode_ref);
1074 ptr -= len + 1;
1075 if (ptr < name) {
1076 ret = -ENAMETOOLONG;
1077 goto err;
1078 }
1079 read_extent_buffer(path->nodes[0], ptr + 1,
1080 (unsigned long)(inode_ref + 1), len);
1081 ptr[0] = '/';
1082 btrfs_release_path(path);
1083 }
1084 }
1085
1086 btrfs_free_path(path);
1087 if (ptr == name + PATH_MAX - 1) {
1088 name[0] = '/';
1089 name[1] = '\0';
1090 } else {
1091 memmove(name, ptr, name + PATH_MAX - ptr);
1092 }
1093 return name;
1094
1095 err:
1096 btrfs_free_path(path);
1097 kfree(name);
1098 return ERR_PTR(ret);
1099 }
1100
1101 static int get_default_subvol_objectid(struct btrfs_fs_info *fs_info, u64 *objectid)
1102 {
1103 struct btrfs_root *root = fs_info->tree_root;
1104 struct btrfs_dir_item *di;
1105 struct btrfs_path *path;
1106 struct btrfs_key location;
1107 u64 dir_id;
1108
1109 path = btrfs_alloc_path();
1110 if (!path)
1111 return -ENOMEM;
1112 path->leave_spinning = 1;
1113
1114 /*
1115 * Find the "default" dir item which points to the root item that we
1116 * will mount by default if we haven't been given a specific subvolume
1117 * to mount.
1118 */
1119 dir_id = btrfs_super_root_dir(fs_info->super_copy);
1120 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
1121 if (IS_ERR(di)) {
1122 btrfs_free_path(path);
1123 return PTR_ERR(di);
1124 }
1125 if (!di) {
1126 /*
1127 * Ok the default dir item isn't there. This is weird since
1128 * it's always been there, but don't freak out, just try and
1129 * mount the top-level subvolume.
1130 */
1131 btrfs_free_path(path);
1132 *objectid = BTRFS_FS_TREE_OBJECTID;
1133 return 0;
1134 }
1135
1136 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
1137 btrfs_free_path(path);
1138 *objectid = location.objectid;
1139 return 0;
1140 }
1141
1142 static int btrfs_fill_super(struct super_block *sb,
1143 struct btrfs_fs_devices *fs_devices,
1144 void *data)
1145 {
1146 struct inode *inode;
1147 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1148 struct btrfs_key key;
1149 int err;
1150
1151 sb->s_maxbytes = MAX_LFS_FILESIZE;
1152 sb->s_magic = BTRFS_SUPER_MAGIC;
1153 sb->s_op = &btrfs_super_ops;
1154 sb->s_d_op = &btrfs_dentry_operations;
1155 sb->s_export_op = &btrfs_export_ops;
1156 sb->s_xattr = btrfs_xattr_handlers;
1157 sb->s_time_gran = 1;
1158 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
1159 sb->s_flags |= SB_POSIXACL;
1160 #endif
1161 sb->s_flags |= SB_I_VERSION;
1162 sb->s_iflags |= SB_I_CGROUPWB;
1163
1164 err = super_setup_bdi(sb);
1165 if (err) {
1166 btrfs_err(fs_info, "super_setup_bdi failed");
1167 return err;
1168 }
1169
1170 err = open_ctree(sb, fs_devices, (char *)data);
1171 if (err) {
1172 btrfs_err(fs_info, "open_ctree failed");
1173 return err;
1174 }
1175
1176 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
1177 key.type = BTRFS_INODE_ITEM_KEY;
1178 key.offset = 0;
1179 inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
1180 if (IS_ERR(inode)) {
1181 err = PTR_ERR(inode);
1182 goto fail_close;
1183 }
1184
1185 sb->s_root = d_make_root(inode);
1186 if (!sb->s_root) {
1187 err = -ENOMEM;
1188 goto fail_close;
1189 }
1190
1191 cleancache_init_fs(sb);
1192 sb->s_flags |= SB_ACTIVE;
1193 return 0;
1194
1195 fail_close:
1196 close_ctree(fs_info);
1197 return err;
1198 }
1199
1200 int btrfs_sync_fs(struct super_block *sb, int wait)
1201 {
1202 struct btrfs_trans_handle *trans;
1203 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1204 struct btrfs_root *root = fs_info->tree_root;
1205
1206 trace_btrfs_sync_fs(fs_info, wait);
1207
1208 if (!wait) {
1209 filemap_flush(fs_info->btree_inode->i_mapping);
1210 return 0;
1211 }
1212
1213 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
1214
1215 trans = btrfs_attach_transaction_barrier(root);
1216 if (IS_ERR(trans)) {
1217 /* no transaction, don't bother */
1218 if (PTR_ERR(trans) == -ENOENT) {
1219 /*
1220 * Exit unless we have some pending changes
1221 * that need to go through commit
1222 */
1223 if (fs_info->pending_changes == 0)
1224 return 0;
1225 /*
1226 * A non-blocking test if the fs is frozen. We must not
1227 * start a new transaction here otherwise a deadlock
1228 * happens. The pending operations are delayed to the
1229 * next commit after thawing.
1230 */
1231 if (sb_start_write_trylock(sb))
1232 sb_end_write(sb);
1233 else
1234 return 0;
1235 trans = btrfs_start_transaction(root, 0);
1236 }
1237 if (IS_ERR(trans))
1238 return PTR_ERR(trans);
1239 }
1240 return btrfs_commit_transaction(trans);
1241 }
1242
1243 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
1244 {
1245 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
1246 char *compress_type;
1247
1248 if (btrfs_test_opt(info, DEGRADED))
1249 seq_puts(seq, ",degraded");
1250 if (btrfs_test_opt(info, NODATASUM))
1251 seq_puts(seq, ",nodatasum");
1252 if (btrfs_test_opt(info, NODATACOW))
1253 seq_puts(seq, ",nodatacow");
1254 if (btrfs_test_opt(info, NOBARRIER))
1255 seq_puts(seq, ",nobarrier");
1256 if (info->max_inline != BTRFS_DEFAULT_MAX_INLINE)
1257 seq_printf(seq, ",max_inline=%llu", info->max_inline);
1258 if (info->thread_pool_size != min_t(unsigned long,
1259 num_online_cpus() + 2, 8))
1260 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
1261 if (btrfs_test_opt(info, COMPRESS)) {
1262 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
1263 compress_type = "zlib";
1264 else if (info->compress_type == BTRFS_COMPRESS_LZO)
1265 compress_type = "lzo";
1266 else
1267 compress_type = "zstd";
1268 if (btrfs_test_opt(info, FORCE_COMPRESS))
1269 seq_printf(seq, ",compress-force=%s", compress_type);
1270 else
1271 seq_printf(seq, ",compress=%s", compress_type);
1272 if (info->compress_level)
1273 seq_printf(seq, ":%d", info->compress_level);
1274 }
1275 if (btrfs_test_opt(info, NOSSD))
1276 seq_puts(seq, ",nossd");
1277 if (btrfs_test_opt(info, SSD_SPREAD))
1278 seq_puts(seq, ",ssd_spread");
1279 else if (btrfs_test_opt(info, SSD))
1280 seq_puts(seq, ",ssd");
1281 if (btrfs_test_opt(info, NOTREELOG))
1282 seq_puts(seq, ",notreelog");
1283 if (btrfs_test_opt(info, NOLOGREPLAY))
1284 seq_puts(seq, ",nologreplay");
1285 if (btrfs_test_opt(info, FLUSHONCOMMIT))
1286 seq_puts(seq, ",flushoncommit");
1287 if (btrfs_test_opt(info, DISCARD))
1288 seq_puts(seq, ",discard");
1289 if (!(info->sb->s_flags & SB_POSIXACL))
1290 seq_puts(seq, ",noacl");
1291 if (btrfs_test_opt(info, SPACE_CACHE))
1292 seq_puts(seq, ",space_cache");
1293 else if (btrfs_test_opt(info, FREE_SPACE_TREE))
1294 seq_puts(seq, ",space_cache=v2");
1295 else
1296 seq_puts(seq, ",nospace_cache");
1297 if (btrfs_test_opt(info, RESCAN_UUID_TREE))
1298 seq_puts(seq, ",rescan_uuid_tree");
1299 if (btrfs_test_opt(info, CLEAR_CACHE))
1300 seq_puts(seq, ",clear_cache");
1301 if (btrfs_test_opt(info, USER_SUBVOL_RM_ALLOWED))
1302 seq_puts(seq, ",user_subvol_rm_allowed");
1303 if (btrfs_test_opt(info, ENOSPC_DEBUG))
1304 seq_puts(seq, ",enospc_debug");
1305 if (btrfs_test_opt(info, AUTO_DEFRAG))
1306 seq_puts(seq, ",autodefrag");
1307 if (btrfs_test_opt(info, INODE_MAP_CACHE))
1308 seq_puts(seq, ",inode_cache");
1309 if (btrfs_test_opt(info, SKIP_BALANCE))
1310 seq_puts(seq, ",skip_balance");
1311 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1312 if (btrfs_test_opt(info, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA))
1313 seq_puts(seq, ",check_int_data");
1314 else if (btrfs_test_opt(info, CHECK_INTEGRITY))
1315 seq_puts(seq, ",check_int");
1316 if (info->check_integrity_print_mask)
1317 seq_printf(seq, ",check_int_print_mask=%d",
1318 info->check_integrity_print_mask);
1319 #endif
1320 if (info->metadata_ratio)
1321 seq_printf(seq, ",metadata_ratio=%d",
1322 info->metadata_ratio);
1323 if (btrfs_test_opt(info, PANIC_ON_FATAL_ERROR))
1324 seq_puts(seq, ",fatal_errors=panic");
1325 if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL)
1326 seq_printf(seq, ",commit=%d", info->commit_interval);
1327 #ifdef CONFIG_BTRFS_DEBUG
1328 if (btrfs_test_opt(info, FRAGMENT_DATA))
1329 seq_puts(seq, ",fragment=data");
1330 if (btrfs_test_opt(info, FRAGMENT_METADATA))
1331 seq_puts(seq, ",fragment=metadata");
1332 #endif
1333 if (btrfs_test_opt(info, REF_VERIFY))
1334 seq_puts(seq, ",ref_verify");
1335 seq_printf(seq, ",subvolid=%llu",
1336 BTRFS_I(d_inode(dentry))->root->root_key.objectid);
1337 seq_puts(seq, ",subvol=");
1338 seq_dentry(seq, dentry, " \t\n\\");
1339 return 0;
1340 }
1341
1342 static int btrfs_test_super(struct super_block *s, void *data)
1343 {
1344 struct btrfs_fs_info *p = data;
1345 struct btrfs_fs_info *fs_info = btrfs_sb(s);
1346
1347 return fs_info->fs_devices == p->fs_devices;
1348 }
1349
1350 static int btrfs_set_super(struct super_block *s, void *data)
1351 {
1352 int err = set_anon_super(s, data);
1353 if (!err)
1354 s->s_fs_info = data;
1355 return err;
1356 }
1357
1358 /*
1359 * subvolumes are identified by ino 256
1360 */
1361 static inline int is_subvolume_inode(struct inode *inode)
1362 {
1363 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
1364 return 1;
1365 return 0;
1366 }
1367
1368 /*
1369 * This will add subvolid=0 to the argument string while removing any subvol=
1370 * and subvolid= arguments to make sure we get the top-level root for path
1371 * walking to the subvol we want.
1372 */
1373 static char *setup_root_args(char *args)
1374 {
1375 char *buf, *dst, *sep;
1376
1377 if (!args)
1378 return kstrdup("subvolid=0", GFP_KERNEL);
1379
1380 /* The worst case is that we add ",subvolid=0" to the end. */
1381 buf = dst = kmalloc(strlen(args) + strlen(",subvolid=0") + 1,
1382 GFP_KERNEL);
1383 if (!buf)
1384 return NULL;
1385
1386 while (1) {
1387 sep = strchrnul(args, ',');
1388 if (!strstarts(args, "subvol=") &&
1389 !strstarts(args, "subvolid=")) {
1390 memcpy(dst, args, sep - args);
1391 dst += sep - args;
1392 *dst++ = ',';
1393 }
1394 if (*sep)
1395 args = sep + 1;
1396 else
1397 break;
1398 }
1399 strcpy(dst, "subvolid=0");
1400
1401 return buf;
1402 }
1403
1404 static struct dentry *mount_subvol(const char *subvol_name, u64 subvol_objectid,
1405 int flags, const char *device_name,
1406 char *data)
1407 {
1408 struct dentry *root;
1409 struct vfsmount *mnt = NULL;
1410 char *newargs;
1411 int ret;
1412
1413 newargs = setup_root_args(data);
1414 if (!newargs) {
1415 root = ERR_PTR(-ENOMEM);
1416 goto out;
1417 }
1418
1419 mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name, newargs);
1420 if (PTR_ERR_OR_ZERO(mnt) == -EBUSY) {
1421 if (flags & SB_RDONLY) {
1422 mnt = vfs_kern_mount(&btrfs_fs_type, flags & ~SB_RDONLY,
1423 device_name, newargs);
1424 } else {
1425 mnt = vfs_kern_mount(&btrfs_fs_type, flags | SB_RDONLY,
1426 device_name, newargs);
1427 if (IS_ERR(mnt)) {
1428 root = ERR_CAST(mnt);
1429 mnt = NULL;
1430 goto out;
1431 }
1432
1433 down_write(&mnt->mnt_sb->s_umount);
1434 ret = btrfs_remount(mnt->mnt_sb, &flags, NULL);
1435 up_write(&mnt->mnt_sb->s_umount);
1436 if (ret < 0) {
1437 root = ERR_PTR(ret);
1438 goto out;
1439 }
1440 }
1441 }
1442 if (IS_ERR(mnt)) {
1443 root = ERR_CAST(mnt);
1444 mnt = NULL;
1445 goto out;
1446 }
1447
1448 if (!subvol_name) {
1449 if (!subvol_objectid) {
1450 ret = get_default_subvol_objectid(btrfs_sb(mnt->mnt_sb),
1451 &subvol_objectid);
1452 if (ret) {
1453 root = ERR_PTR(ret);
1454 goto out;
1455 }
1456 }
1457 subvol_name = get_subvol_name_from_objectid(btrfs_sb(mnt->mnt_sb),
1458 subvol_objectid);
1459 if (IS_ERR(subvol_name)) {
1460 root = ERR_CAST(subvol_name);
1461 subvol_name = NULL;
1462 goto out;
1463 }
1464
1465 }
1466
1467 root = mount_subtree(mnt, subvol_name);
1468 /* mount_subtree() drops our reference on the vfsmount. */
1469 mnt = NULL;
1470
1471 if (!IS_ERR(root)) {
1472 struct super_block *s = root->d_sb;
1473 struct btrfs_fs_info *fs_info = btrfs_sb(s);
1474 struct inode *root_inode = d_inode(root);
1475 u64 root_objectid = BTRFS_I(root_inode)->root->root_key.objectid;
1476
1477 ret = 0;
1478 if (!is_subvolume_inode(root_inode)) {
1479 btrfs_err(fs_info, "'%s' is not a valid subvolume",
1480 subvol_name);
1481 ret = -EINVAL;
1482 }
1483 if (subvol_objectid && root_objectid != subvol_objectid) {
1484 /*
1485 * This will also catch a race condition where a
1486 * subvolume which was passed by ID is renamed and
1487 * another subvolume is renamed over the old location.
1488 */
1489 btrfs_err(fs_info,
1490 "subvol '%s' does not match subvolid %llu",
1491 subvol_name, subvol_objectid);
1492 ret = -EINVAL;
1493 }
1494 if (ret) {
1495 dput(root);
1496 root = ERR_PTR(ret);
1497 deactivate_locked_super(s);
1498 }
1499 }
1500
1501 out:
1502 mntput(mnt);
1503 kfree(newargs);
1504 kfree(subvol_name);
1505 return root;
1506 }
1507
1508 static int parse_security_options(char *orig_opts,
1509 struct security_mnt_opts *sec_opts)
1510 {
1511 char *secdata = NULL;
1512 int ret = 0;
1513
1514 secdata = alloc_secdata();
1515 if (!secdata)
1516 return -ENOMEM;
1517 ret = security_sb_copy_data(orig_opts, secdata);
1518 if (ret) {
1519 free_secdata(secdata);
1520 return ret;
1521 }
1522 ret = security_sb_parse_opts_str(secdata, sec_opts);
1523 free_secdata(secdata);
1524 return ret;
1525 }
1526
1527 static int setup_security_options(struct btrfs_fs_info *fs_info,
1528 struct super_block *sb,
1529 struct security_mnt_opts *sec_opts)
1530 {
1531 int ret = 0;
1532
1533 /*
1534 * Call security_sb_set_mnt_opts() to check whether new sec_opts
1535 * is valid.
1536 */
1537 ret = security_sb_set_mnt_opts(sb, sec_opts, 0, NULL);
1538 if (ret)
1539 return ret;
1540
1541 #ifdef CONFIG_SECURITY
1542 if (!fs_info->security_opts.num_mnt_opts) {
1543 /* first time security setup, copy sec_opts to fs_info */
1544 memcpy(&fs_info->security_opts, sec_opts, sizeof(*sec_opts));
1545 } else {
1546 /*
1547 * Since SELinux (the only one supporting security_mnt_opts)
1548 * does NOT support changing context during remount/mount of
1549 * the same sb, this must be the same or part of the same
1550 * security options, just free it.
1551 */
1552 security_free_mnt_opts(sec_opts);
1553 }
1554 #endif
1555 return ret;
1556 }
1557
1558 /*
1559 * Find a superblock for the given device / mount point.
1560 *
1561 * Note: This is based on get_sb_bdev from fs/super.c with a few additions
1562 * for multiple device setup. Make sure to keep it in sync.
1563 */
1564 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1565 const char *device_name, void *data)
1566 {
1567 struct block_device *bdev = NULL;
1568 struct super_block *s;
1569 struct btrfs_fs_devices *fs_devices = NULL;
1570 struct btrfs_fs_info *fs_info = NULL;
1571 struct security_mnt_opts new_sec_opts;
1572 fmode_t mode = FMODE_READ;
1573 char *subvol_name = NULL;
1574 u64 subvol_objectid = 0;
1575 int error = 0;
1576
1577 if (!(flags & SB_RDONLY))
1578 mode |= FMODE_WRITE;
1579
1580 error = btrfs_parse_early_options(data, mode, fs_type,
1581 &subvol_name, &subvol_objectid,
1582 &fs_devices);
1583 if (error) {
1584 kfree(subvol_name);
1585 return ERR_PTR(error);
1586 }
1587
1588 if (subvol_name || subvol_objectid != BTRFS_FS_TREE_OBJECTID) {
1589 /* mount_subvol() will free subvol_name. */
1590 return mount_subvol(subvol_name, subvol_objectid, flags,
1591 device_name, data);
1592 }
1593
1594 security_init_mnt_opts(&new_sec_opts);
1595 if (data) {
1596 error = parse_security_options(data, &new_sec_opts);
1597 if (error)
1598 return ERR_PTR(error);
1599 }
1600
1601 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
1602 if (error)
1603 goto error_sec_opts;
1604
1605 /*
1606 * Setup a dummy root and fs_info for test/set super. This is because
1607 * we don't actually fill this stuff out until open_ctree, but we need
1608 * it for searching for existing supers, so this lets us do that and
1609 * then open_ctree will properly initialize everything later.
1610 */
1611 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_KERNEL);
1612 if (!fs_info) {
1613 error = -ENOMEM;
1614 goto error_sec_opts;
1615 }
1616
1617 fs_info->fs_devices = fs_devices;
1618
1619 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL);
1620 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL);
1621 security_init_mnt_opts(&fs_info->security_opts);
1622 if (!fs_info->super_copy || !fs_info->super_for_commit) {
1623 error = -ENOMEM;
1624 goto error_fs_info;
1625 }
1626
1627 error = btrfs_open_devices(fs_devices, mode, fs_type);
1628 if (error)
1629 goto error_fs_info;
1630
1631 if (!(flags & SB_RDONLY) && fs_devices->rw_devices == 0) {
1632 error = -EACCES;
1633 goto error_close_devices;
1634 }
1635
1636 bdev = fs_devices->latest_bdev;
1637 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | SB_NOSEC,
1638 fs_info);
1639 if (IS_ERR(s)) {
1640 error = PTR_ERR(s);
1641 goto error_close_devices;
1642 }
1643
1644 if (s->s_root) {
1645 btrfs_close_devices(fs_devices);
1646 free_fs_info(fs_info);
1647 if ((flags ^ s->s_flags) & SB_RDONLY)
1648 error = -EBUSY;
1649 } else {
1650 snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev);
1651 btrfs_sb(s)->bdev_holder = fs_type;
1652 error = btrfs_fill_super(s, fs_devices, data);
1653 }
1654 if (error) {
1655 deactivate_locked_super(s);
1656 goto error_sec_opts;
1657 }
1658
1659 fs_info = btrfs_sb(s);
1660 error = setup_security_options(fs_info, s, &new_sec_opts);
1661 if (error) {
1662 deactivate_locked_super(s);
1663 goto error_sec_opts;
1664 }
1665
1666 return dget(s->s_root);
1667
1668 error_close_devices:
1669 btrfs_close_devices(fs_devices);
1670 error_fs_info:
1671 free_fs_info(fs_info);
1672 error_sec_opts:
1673 security_free_mnt_opts(&new_sec_opts);
1674 return ERR_PTR(error);
1675 }
1676
1677 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1678 int new_pool_size, int old_pool_size)
1679 {
1680 if (new_pool_size == old_pool_size)
1681 return;
1682
1683 fs_info->thread_pool_size = new_pool_size;
1684
1685 btrfs_info(fs_info, "resize thread pool %d -> %d",
1686 old_pool_size, new_pool_size);
1687
1688 btrfs_workqueue_set_max(fs_info->workers, new_pool_size);
1689 btrfs_workqueue_set_max(fs_info->delalloc_workers, new_pool_size);
1690 btrfs_workqueue_set_max(fs_info->submit_workers, new_pool_size);
1691 btrfs_workqueue_set_max(fs_info->caching_workers, new_pool_size);
1692 btrfs_workqueue_set_max(fs_info->endio_workers, new_pool_size);
1693 btrfs_workqueue_set_max(fs_info->endio_meta_workers, new_pool_size);
1694 btrfs_workqueue_set_max(fs_info->endio_meta_write_workers,
1695 new_pool_size);
1696 btrfs_workqueue_set_max(fs_info->endio_write_workers, new_pool_size);
1697 btrfs_workqueue_set_max(fs_info->endio_freespace_worker, new_pool_size);
1698 btrfs_workqueue_set_max(fs_info->delayed_workers, new_pool_size);
1699 btrfs_workqueue_set_max(fs_info->readahead_workers, new_pool_size);
1700 btrfs_workqueue_set_max(fs_info->scrub_wr_completion_workers,
1701 new_pool_size);
1702 }
1703
1704 static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info)
1705 {
1706 set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1707 }
1708
1709 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
1710 unsigned long old_opts, int flags)
1711 {
1712 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1713 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1714 (flags & SB_RDONLY))) {
1715 /* wait for any defraggers to finish */
1716 wait_event(fs_info->transaction_wait,
1717 (atomic_read(&fs_info->defrag_running) == 0));
1718 if (flags & SB_RDONLY)
1719 sync_filesystem(fs_info->sb);
1720 }
1721 }
1722
1723 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1724 unsigned long old_opts)
1725 {
1726 /*
1727 * We need to cleanup all defragable inodes if the autodefragment is
1728 * close or the filesystem is read only.
1729 */
1730 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1731 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) || sb_rdonly(fs_info->sb))) {
1732 btrfs_cleanup_defrag_inodes(fs_info);
1733 }
1734
1735 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1736 }
1737
1738 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1739 {
1740 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1741 struct btrfs_root *root = fs_info->tree_root;
1742 unsigned old_flags = sb->s_flags;
1743 unsigned long old_opts = fs_info->mount_opt;
1744 unsigned long old_compress_type = fs_info->compress_type;
1745 u64 old_max_inline = fs_info->max_inline;
1746 int old_thread_pool_size = fs_info->thread_pool_size;
1747 unsigned int old_metadata_ratio = fs_info->metadata_ratio;
1748 int ret;
1749
1750 sync_filesystem(sb);
1751 btrfs_remount_prepare(fs_info);
1752
1753 if (data) {
1754 struct security_mnt_opts new_sec_opts;
1755
1756 security_init_mnt_opts(&new_sec_opts);
1757 ret = parse_security_options(data, &new_sec_opts);
1758 if (ret)
1759 goto restore;
1760 ret = setup_security_options(fs_info, sb,
1761 &new_sec_opts);
1762 if (ret) {
1763 security_free_mnt_opts(&new_sec_opts);
1764 goto restore;
1765 }
1766 }
1767
1768 ret = btrfs_parse_options(fs_info, data, *flags);
1769 if (ret) {
1770 ret = -EINVAL;
1771 goto restore;
1772 }
1773
1774 btrfs_remount_begin(fs_info, old_opts, *flags);
1775 btrfs_resize_thread_pool(fs_info,
1776 fs_info->thread_pool_size, old_thread_pool_size);
1777
1778 if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1779 goto out;
1780
1781 if (*flags & SB_RDONLY) {
1782 /*
1783 * this also happens on 'umount -rf' or on shutdown, when
1784 * the filesystem is busy.
1785 */
1786 cancel_work_sync(&fs_info->async_reclaim_work);
1787
1788 /* wait for the uuid_scan task to finish */
1789 down(&fs_info->uuid_tree_rescan_sem);
1790 /* avoid complains from lockdep et al. */
1791 up(&fs_info->uuid_tree_rescan_sem);
1792
1793 sb->s_flags |= SB_RDONLY;
1794
1795 /*
1796 * Setting SB_RDONLY will put the cleaner thread to
1797 * sleep at the next loop if it's already active.
1798 * If it's already asleep, we'll leave unused block
1799 * groups on disk until we're mounted read-write again
1800 * unless we clean them up here.
1801 */
1802 btrfs_delete_unused_bgs(fs_info);
1803
1804 btrfs_dev_replace_suspend_for_unmount(fs_info);
1805 btrfs_scrub_cancel(fs_info);
1806 btrfs_pause_balance(fs_info);
1807
1808 ret = btrfs_commit_super(fs_info);
1809 if (ret)
1810 goto restore;
1811 } else {
1812 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
1813 btrfs_err(fs_info,
1814 "Remounting read-write after error is not allowed");
1815 ret = -EINVAL;
1816 goto restore;
1817 }
1818 if (fs_info->fs_devices->rw_devices == 0) {
1819 ret = -EACCES;
1820 goto restore;
1821 }
1822
1823 if (!btrfs_check_rw_degradable(fs_info)) {
1824 btrfs_warn(fs_info,
1825 "too many missing devices, writeable remount is not allowed");
1826 ret = -EACCES;
1827 goto restore;
1828 }
1829
1830 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1831 ret = -EINVAL;
1832 goto restore;
1833 }
1834
1835 ret = btrfs_cleanup_fs_roots(fs_info);
1836 if (ret)
1837 goto restore;
1838
1839 /* recover relocation */
1840 mutex_lock(&fs_info->cleaner_mutex);
1841 ret = btrfs_recover_relocation(root);
1842 mutex_unlock(&fs_info->cleaner_mutex);
1843 if (ret)
1844 goto restore;
1845
1846 ret = btrfs_resume_balance_async(fs_info);
1847 if (ret)
1848 goto restore;
1849
1850 ret = btrfs_resume_dev_replace_async(fs_info);
1851 if (ret) {
1852 btrfs_warn(fs_info, "failed to resume dev_replace");
1853 goto restore;
1854 }
1855
1856 btrfs_qgroup_rescan_resume(fs_info);
1857
1858 if (!fs_info->uuid_root) {
1859 btrfs_info(fs_info, "creating UUID tree");
1860 ret = btrfs_create_uuid_tree(fs_info);
1861 if (ret) {
1862 btrfs_warn(fs_info,
1863 "failed to create the UUID tree %d",
1864 ret);
1865 goto restore;
1866 }
1867 }
1868 sb->s_flags &= ~SB_RDONLY;
1869
1870 set_bit(BTRFS_FS_OPEN, &fs_info->flags);
1871 }
1872 out:
1873 wake_up_process(fs_info->transaction_kthread);
1874 btrfs_remount_cleanup(fs_info, old_opts);
1875 return 0;
1876
1877 restore:
1878 /* We've hit an error - don't reset SB_RDONLY */
1879 if (sb_rdonly(sb))
1880 old_flags |= SB_RDONLY;
1881 sb->s_flags = old_flags;
1882 fs_info->mount_opt = old_opts;
1883 fs_info->compress_type = old_compress_type;
1884 fs_info->max_inline = old_max_inline;
1885 btrfs_resize_thread_pool(fs_info,
1886 old_thread_pool_size, fs_info->thread_pool_size);
1887 fs_info->metadata_ratio = old_metadata_ratio;
1888 btrfs_remount_cleanup(fs_info, old_opts);
1889 return ret;
1890 }
1891
1892 /* Used to sort the devices by max_avail(descending sort) */
1893 static int btrfs_cmp_device_free_bytes(const void *dev_info1,
1894 const void *dev_info2)
1895 {
1896 if (((struct btrfs_device_info *)dev_info1)->max_avail >
1897 ((struct btrfs_device_info *)dev_info2)->max_avail)
1898 return -1;
1899 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1900 ((struct btrfs_device_info *)dev_info2)->max_avail)
1901 return 1;
1902 else
1903 return 0;
1904 }
1905
1906 /*
1907 * sort the devices by max_avail, in which max free extent size of each device
1908 * is stored.(Descending Sort)
1909 */
1910 static inline void btrfs_descending_sort_devices(
1911 struct btrfs_device_info *devices,
1912 size_t nr_devices)
1913 {
1914 sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1915 btrfs_cmp_device_free_bytes, NULL);
1916 }
1917
1918 /*
1919 * The helper to calc the free space on the devices that can be used to store
1920 * file data.
1921 */
1922 static int btrfs_calc_avail_data_space(struct btrfs_fs_info *fs_info,
1923 u64 *free_bytes)
1924 {
1925 struct btrfs_device_info *devices_info;
1926 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1927 struct btrfs_device *device;
1928 u64 skip_space;
1929 u64 type;
1930 u64 avail_space;
1931 u64 min_stripe_size;
1932 int min_stripes = 1, num_stripes = 1;
1933 int i = 0, nr_devices;
1934
1935 /*
1936 * We aren't under the device list lock, so this is racy-ish, but good
1937 * enough for our purposes.
1938 */
1939 nr_devices = fs_info->fs_devices->open_devices;
1940 if (!nr_devices) {
1941 smp_mb();
1942 nr_devices = fs_info->fs_devices->open_devices;
1943 ASSERT(nr_devices);
1944 if (!nr_devices) {
1945 *free_bytes = 0;
1946 return 0;
1947 }
1948 }
1949
1950 devices_info = kmalloc_array(nr_devices, sizeof(*devices_info),
1951 GFP_KERNEL);
1952 if (!devices_info)
1953 return -ENOMEM;
1954
1955 /* calc min stripe number for data space allocation */
1956 type = btrfs_data_alloc_profile(fs_info);
1957 if (type & BTRFS_BLOCK_GROUP_RAID0) {
1958 min_stripes = 2;
1959 num_stripes = nr_devices;
1960 } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
1961 min_stripes = 2;
1962 num_stripes = 2;
1963 } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
1964 min_stripes = 4;
1965 num_stripes = 4;
1966 }
1967
1968 if (type & BTRFS_BLOCK_GROUP_DUP)
1969 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1970 else
1971 min_stripe_size = BTRFS_STRIPE_LEN;
1972
1973 rcu_read_lock();
1974 list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
1975 if (!device->in_fs_metadata || !device->bdev ||
1976 device->is_tgtdev_for_dev_replace)
1977 continue;
1978
1979 if (i >= nr_devices)
1980 break;
1981
1982 avail_space = device->total_bytes - device->bytes_used;
1983
1984 /* align with stripe_len */
1985 avail_space = div_u64(avail_space, BTRFS_STRIPE_LEN);
1986 avail_space *= BTRFS_STRIPE_LEN;
1987
1988 /*
1989 * In order to avoid overwriting the superblock on the drive,
1990 * btrfs starts at an offset of at least 1MB when doing chunk
1991 * allocation.
1992 */
1993 skip_space = SZ_1M;
1994
1995 /*
1996 * we can use the free space in [0, skip_space - 1], subtract
1997 * it from the total.
1998 */
1999 if (avail_space && avail_space >= skip_space)
2000 avail_space -= skip_space;
2001 else
2002 avail_space = 0;
2003
2004 if (avail_space < min_stripe_size)
2005 continue;
2006
2007 devices_info[i].dev = device;
2008 devices_info[i].max_avail = avail_space;
2009
2010 i++;
2011 }
2012 rcu_read_unlock();
2013
2014 nr_devices = i;
2015
2016 btrfs_descending_sort_devices(devices_info, nr_devices);
2017
2018 i = nr_devices - 1;
2019 avail_space = 0;
2020 while (nr_devices >= min_stripes) {
2021 if (num_stripes > nr_devices)
2022 num_stripes = nr_devices;
2023
2024 if (devices_info[i].max_avail >= min_stripe_size) {
2025 int j;
2026 u64 alloc_size;
2027
2028 avail_space += devices_info[i].max_avail * num_stripes;
2029 alloc_size = devices_info[i].max_avail;
2030 for (j = i + 1 - num_stripes; j <= i; j++)
2031 devices_info[j].max_avail -= alloc_size;
2032 }
2033 i--;
2034 nr_devices--;
2035 }
2036
2037 kfree(devices_info);
2038 *free_bytes = avail_space;
2039 return 0;
2040 }
2041
2042 /*
2043 * Calculate numbers for 'df', pessimistic in case of mixed raid profiles.
2044 *
2045 * If there's a redundant raid level at DATA block groups, use the respective
2046 * multiplier to scale the sizes.
2047 *
2048 * Unused device space usage is based on simulating the chunk allocator
2049 * algorithm that respects the device sizes and order of allocations. This is
2050 * a close approximation of the actual use but there are other factors that may
2051 * change the result (like a new metadata chunk).
2052 *
2053 * If metadata is exhausted, f_bavail will be 0.
2054 */
2055 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
2056 {
2057 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
2058 struct btrfs_super_block *disk_super = fs_info->super_copy;
2059 struct list_head *head = &fs_info->space_info;
2060 struct btrfs_space_info *found;
2061 u64 total_used = 0;
2062 u64 total_free_data = 0;
2063 u64 total_free_meta = 0;
2064 int bits = dentry->d_sb->s_blocksize_bits;
2065 __be32 *fsid = (__be32 *)fs_info->fsid;
2066 unsigned factor = 1;
2067 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
2068 int ret;
2069 u64 thresh = 0;
2070 int mixed = 0;
2071
2072 rcu_read_lock();
2073 list_for_each_entry_rcu(found, head, list) {
2074 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
2075 int i;
2076
2077 total_free_data += found->disk_total - found->disk_used;
2078 total_free_data -=
2079 btrfs_account_ro_block_groups_free_space(found);
2080
2081 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
2082 if (!list_empty(&found->block_groups[i])) {
2083 switch (i) {
2084 case BTRFS_RAID_DUP:
2085 case BTRFS_RAID_RAID1:
2086 case BTRFS_RAID_RAID10:
2087 factor = 2;
2088 }
2089 }
2090 }
2091 }
2092
2093 /*
2094 * Metadata in mixed block goup profiles are accounted in data
2095 */
2096 if (!mixed && found->flags & BTRFS_BLOCK_GROUP_METADATA) {
2097 if (found->flags & BTRFS_BLOCK_GROUP_DATA)
2098 mixed = 1;
2099 else
2100 total_free_meta += found->disk_total -
2101 found->disk_used;
2102 }
2103
2104 total_used += found->disk_used;
2105 }
2106
2107 rcu_read_unlock();
2108
2109 buf->f_blocks = div_u64(btrfs_super_total_bytes(disk_super), factor);
2110 buf->f_blocks >>= bits;
2111 buf->f_bfree = buf->f_blocks - (div_u64(total_used, factor) >> bits);
2112
2113 /* Account global block reserve as used, it's in logical size already */
2114 spin_lock(&block_rsv->lock);
2115 /* Mixed block groups accounting is not byte-accurate, avoid overflow */
2116 if (buf->f_bfree >= block_rsv->size >> bits)
2117 buf->f_bfree -= block_rsv->size >> bits;
2118 else
2119 buf->f_bfree = 0;
2120 spin_unlock(&block_rsv->lock);
2121
2122 buf->f_bavail = div_u64(total_free_data, factor);
2123 ret = btrfs_calc_avail_data_space(fs_info, &total_free_data);
2124 if (ret)
2125 return ret;
2126 buf->f_bavail += div_u64(total_free_data, factor);
2127 buf->f_bavail = buf->f_bavail >> bits;
2128
2129 /*
2130 * We calculate the remaining metadata space minus global reserve. If
2131 * this is (supposedly) smaller than zero, there's no space. But this
2132 * does not hold in practice, the exhausted state happens where's still
2133 * some positive delta. So we apply some guesswork and compare the
2134 * delta to a 4M threshold. (Practically observed delta was ~2M.)
2135 *
2136 * We probably cannot calculate the exact threshold value because this
2137 * depends on the internal reservations requested by various
2138 * operations, so some operations that consume a few metadata will
2139 * succeed even if the Avail is zero. But this is better than the other
2140 * way around.
2141 */
2142 thresh = SZ_4M;
2143
2144 if (!mixed && total_free_meta - thresh < block_rsv->size)
2145 buf->f_bavail = 0;
2146
2147 buf->f_type = BTRFS_SUPER_MAGIC;
2148 buf->f_bsize = dentry->d_sb->s_blocksize;
2149 buf->f_namelen = BTRFS_NAME_LEN;
2150
2151 /* We treat it as constant endianness (it doesn't matter _which_)
2152 because we want the fsid to come out the same whether mounted
2153 on a big-endian or little-endian host */
2154 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
2155 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
2156 /* Mask in the root object ID too, to disambiguate subvols */
2157 buf->f_fsid.val[0] ^= BTRFS_I(d_inode(dentry))->root->objectid >> 32;
2158 buf->f_fsid.val[1] ^= BTRFS_I(d_inode(dentry))->root->objectid;
2159
2160 return 0;
2161 }
2162
2163 static void btrfs_kill_super(struct super_block *sb)
2164 {
2165 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2166 kill_anon_super(sb);
2167 free_fs_info(fs_info);
2168 }
2169
2170 static struct file_system_type btrfs_fs_type = {
2171 .owner = THIS_MODULE,
2172 .name = "btrfs",
2173 .mount = btrfs_mount,
2174 .kill_sb = btrfs_kill_super,
2175 .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA,
2176 };
2177 MODULE_ALIAS_FS("btrfs");
2178
2179 static int btrfs_control_open(struct inode *inode, struct file *file)
2180 {
2181 /*
2182 * The control file's private_data is used to hold the
2183 * transaction when it is started and is used to keep
2184 * track of whether a transaction is already in progress.
2185 */
2186 file->private_data = NULL;
2187 return 0;
2188 }
2189
2190 /*
2191 * used by btrfsctl to scan devices when no FS is mounted
2192 */
2193 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
2194 unsigned long arg)
2195 {
2196 struct btrfs_ioctl_vol_args *vol;
2197 struct btrfs_fs_devices *fs_devices;
2198 int ret = -ENOTTY;
2199
2200 if (!capable(CAP_SYS_ADMIN))
2201 return -EPERM;
2202
2203 vol = memdup_user((void __user *)arg, sizeof(*vol));
2204 if (IS_ERR(vol))
2205 return PTR_ERR(vol);
2206
2207 switch (cmd) {
2208 case BTRFS_IOC_SCAN_DEV:
2209 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
2210 &btrfs_fs_type, &fs_devices);
2211 break;
2212 case BTRFS_IOC_DEVICES_READY:
2213 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
2214 &btrfs_fs_type, &fs_devices);
2215 if (ret)
2216 break;
2217 ret = !(fs_devices->num_devices == fs_devices->total_devices);
2218 break;
2219 case BTRFS_IOC_GET_SUPPORTED_FEATURES:
2220 ret = btrfs_ioctl_get_supported_features((void __user*)arg);
2221 break;
2222 }
2223
2224 kfree(vol);
2225 return ret;
2226 }
2227
2228 static int btrfs_freeze(struct super_block *sb)
2229 {
2230 struct btrfs_trans_handle *trans;
2231 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2232 struct btrfs_root *root = fs_info->tree_root;
2233
2234 set_bit(BTRFS_FS_FROZEN, &fs_info->flags);
2235 /*
2236 * We don't need a barrier here, we'll wait for any transaction that
2237 * could be in progress on other threads (and do delayed iputs that
2238 * we want to avoid on a frozen filesystem), or do the commit
2239 * ourselves.
2240 */
2241 trans = btrfs_attach_transaction_barrier(root);
2242 if (IS_ERR(trans)) {
2243 /* no transaction, don't bother */
2244 if (PTR_ERR(trans) == -ENOENT)
2245 return 0;
2246 return PTR_ERR(trans);
2247 }
2248 return btrfs_commit_transaction(trans);
2249 }
2250
2251 static int btrfs_unfreeze(struct super_block *sb)
2252 {
2253 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2254
2255 clear_bit(BTRFS_FS_FROZEN, &fs_info->flags);
2256 return 0;
2257 }
2258
2259 static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
2260 {
2261 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
2262 struct btrfs_fs_devices *cur_devices;
2263 struct btrfs_device *dev, *first_dev = NULL;
2264 struct list_head *head;
2265 struct rcu_string *name;
2266
2267 mutex_lock(&fs_info->fs_devices->device_list_mutex);
2268 cur_devices = fs_info->fs_devices;
2269 while (cur_devices) {
2270 head = &cur_devices->devices;
2271 list_for_each_entry(dev, head, dev_list) {
2272 if (dev->missing)
2273 continue;
2274 if (!dev->name)
2275 continue;
2276 if (!first_dev || dev->devid < first_dev->devid)
2277 first_dev = dev;
2278 }
2279 cur_devices = cur_devices->seed;
2280 }
2281
2282 if (first_dev) {
2283 rcu_read_lock();
2284 name = rcu_dereference(first_dev->name);
2285 seq_escape(m, name->str, " \t\n\\");
2286 rcu_read_unlock();
2287 } else {
2288 WARN_ON(1);
2289 }
2290 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2291 return 0;
2292 }
2293
2294 static const struct super_operations btrfs_super_ops = {
2295 .drop_inode = btrfs_drop_inode,
2296 .evict_inode = btrfs_evict_inode,
2297 .put_super = btrfs_put_super,
2298 .sync_fs = btrfs_sync_fs,
2299 .show_options = btrfs_show_options,
2300 .show_devname = btrfs_show_devname,
2301 .write_inode = btrfs_write_inode,
2302 .alloc_inode = btrfs_alloc_inode,
2303 .destroy_inode = btrfs_destroy_inode,
2304 .statfs = btrfs_statfs,
2305 .remount_fs = btrfs_remount,
2306 .freeze_fs = btrfs_freeze,
2307 .unfreeze_fs = btrfs_unfreeze,
2308 };
2309
2310 static const struct file_operations btrfs_ctl_fops = {
2311 .open = btrfs_control_open,
2312 .unlocked_ioctl = btrfs_control_ioctl,
2313 .compat_ioctl = btrfs_control_ioctl,
2314 .owner = THIS_MODULE,
2315 .llseek = noop_llseek,
2316 };
2317
2318 static struct miscdevice btrfs_misc = {
2319 .minor = BTRFS_MINOR,
2320 .name = "btrfs-control",
2321 .fops = &btrfs_ctl_fops
2322 };
2323
2324 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
2325 MODULE_ALIAS("devname:btrfs-control");
2326
2327 static int btrfs_interface_init(void)
2328 {
2329 return misc_register(&btrfs_misc);
2330 }
2331
2332 static void btrfs_interface_exit(void)
2333 {
2334 misc_deregister(&btrfs_misc);
2335 }
2336
2337 static void btrfs_print_mod_info(void)
2338 {
2339 pr_info("Btrfs loaded, crc32c=%s"
2340 #ifdef CONFIG_BTRFS_DEBUG
2341 ", debug=on"
2342 #endif
2343 #ifdef CONFIG_BTRFS_ASSERT
2344 ", assert=on"
2345 #endif
2346 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2347 ", integrity-checker=on"
2348 #endif
2349 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
2350 ", ref-verify=on"
2351 #endif
2352 "\n",
2353 btrfs_crc32c_impl());
2354 }
2355
2356 static int __init init_btrfs_fs(void)
2357 {
2358 int err;
2359
2360 err = btrfs_hash_init();
2361 if (err)
2362 return err;
2363
2364 btrfs_props_init();
2365
2366 err = btrfs_init_sysfs();
2367 if (err)
2368 goto free_hash;
2369
2370 btrfs_init_compress();
2371
2372 err = btrfs_init_cachep();
2373 if (err)
2374 goto free_compress;
2375
2376 err = extent_io_init();
2377 if (err)
2378 goto free_cachep;
2379
2380 err = extent_map_init();
2381 if (err)
2382 goto free_extent_io;
2383
2384 err = ordered_data_init();
2385 if (err)
2386 goto free_extent_map;
2387
2388 err = btrfs_delayed_inode_init();
2389 if (err)
2390 goto free_ordered_data;
2391
2392 err = btrfs_auto_defrag_init();
2393 if (err)
2394 goto free_delayed_inode;
2395
2396 err = btrfs_delayed_ref_init();
2397 if (err)
2398 goto free_auto_defrag;
2399
2400 err = btrfs_prelim_ref_init();
2401 if (err)
2402 goto free_delayed_ref;
2403
2404 err = btrfs_end_io_wq_init();
2405 if (err)
2406 goto free_prelim_ref;
2407
2408 err = btrfs_interface_init();
2409 if (err)
2410 goto free_end_io_wq;
2411
2412 btrfs_init_lockdep();
2413
2414 btrfs_print_mod_info();
2415
2416 err = btrfs_run_sanity_tests();
2417 if (err)
2418 goto unregister_ioctl;
2419
2420 err = register_filesystem(&btrfs_fs_type);
2421 if (err)
2422 goto unregister_ioctl;
2423
2424 return 0;
2425
2426 unregister_ioctl:
2427 btrfs_interface_exit();
2428 free_end_io_wq:
2429 btrfs_end_io_wq_exit();
2430 free_prelim_ref:
2431 btrfs_prelim_ref_exit();
2432 free_delayed_ref:
2433 btrfs_delayed_ref_exit();
2434 free_auto_defrag:
2435 btrfs_auto_defrag_exit();
2436 free_delayed_inode:
2437 btrfs_delayed_inode_exit();
2438 free_ordered_data:
2439 ordered_data_exit();
2440 free_extent_map:
2441 extent_map_exit();
2442 free_extent_io:
2443 extent_io_exit();
2444 free_cachep:
2445 btrfs_destroy_cachep();
2446 free_compress:
2447 btrfs_exit_compress();
2448 btrfs_exit_sysfs();
2449 free_hash:
2450 btrfs_hash_exit();
2451 return err;
2452 }
2453
2454 static void __exit exit_btrfs_fs(void)
2455 {
2456 btrfs_destroy_cachep();
2457 btrfs_delayed_ref_exit();
2458 btrfs_auto_defrag_exit();
2459 btrfs_delayed_inode_exit();
2460 btrfs_prelim_ref_exit();
2461 ordered_data_exit();
2462 extent_map_exit();
2463 extent_io_exit();
2464 btrfs_interface_exit();
2465 btrfs_end_io_wq_exit();
2466 unregister_filesystem(&btrfs_fs_type);
2467 btrfs_exit_sysfs();
2468 btrfs_cleanup_fs_uuids();
2469 btrfs_exit_compress();
2470 btrfs_hash_exit();
2471 }
2472
2473 late_initcall(init_btrfs_fs);
2474 module_exit(exit_btrfs_fs)
2475
2476 MODULE_LICENSE("GPL");
Linux with added FPC-III support