Loading...
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 "compat.h"
44#include "delayed-inode.h"
45#include "ctree.h"
46#include "disk-io.h"
47#include "transaction.h"
48#include "btrfs_inode.h"
49#include "ioctl.h"
50#include "print-tree.h"
51#include "xattr.h"
52#include "volumes.h"
53#include "version.h"
54#include "export.h"
55#include "compression.h"
56
57#define CREATE_TRACE_POINTS
58#include <trace/events/btrfs.h>
59
60static const struct super_operations btrfs_super_ops;
61
62static const char *btrfs_decode_error(struct btrfs_fs_info *fs_info, int errno,
63 char nbuf[16])
64{
65 char *errstr = NULL;
66
67 switch (errno) {
68 case -EIO:
69 errstr = "IO failure";
70 break;
71 case -ENOMEM:
72 errstr = "Out of memory";
73 break;
74 case -EROFS:
75 errstr = "Readonly filesystem";
76 break;
77 default:
78 if (nbuf) {
79 if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
80 errstr = nbuf;
81 }
82 break;
83 }
84
85 return errstr;
86}
87
88static void __save_error_info(struct btrfs_fs_info *fs_info)
89{
90 /*
91 * today we only save the error info into ram. Long term we'll
92 * also send it down to the disk
93 */
94 fs_info->fs_state = BTRFS_SUPER_FLAG_ERROR;
95}
96
97/* NOTE:
98 * We move write_super stuff at umount in order to avoid deadlock
99 * for umount hold all lock.
100 */
101static void save_error_info(struct btrfs_fs_info *fs_info)
102{
103 __save_error_info(fs_info);
104}
105
106/* btrfs handle error by forcing the filesystem readonly */
107static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
108{
109 struct super_block *sb = fs_info->sb;
110
111 if (sb->s_flags & MS_RDONLY)
112 return;
113
114 if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
115 sb->s_flags |= MS_RDONLY;
116 printk(KERN_INFO "btrfs is forced readonly\n");
117 }
118}
119
120/*
121 * __btrfs_std_error decodes expected errors from the caller and
122 * invokes the approciate error response.
123 */
124void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
125 unsigned int line, int errno)
126{
127 struct super_block *sb = fs_info->sb;
128 char nbuf[16];
129 const char *errstr;
130
131 /*
132 * Special case: if the error is EROFS, and we're already
133 * under MS_RDONLY, then it is safe here.
134 */
135 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
136 return;
137
138 errstr = btrfs_decode_error(fs_info, errno, nbuf);
139 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: %s\n",
140 sb->s_id, function, line, errstr);
141 save_error_info(fs_info);
142
143 btrfs_handle_error(fs_info);
144}
145
146static void btrfs_put_super(struct super_block *sb)
147{
148 struct btrfs_root *root = btrfs_sb(sb);
149 int ret;
150
151 ret = close_ctree(root);
152 sb->s_fs_info = NULL;
153
154 (void)ret; /* FIXME: need to fix VFS to return error? */
155}
156
157enum {
158 Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
159 Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
160 Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
161 Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
162 Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
163 Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
164 Opt_enospc_debug, Opt_subvolrootid, Opt_defrag,
165 Opt_inode_cache, Opt_err,
166};
167
168static match_table_t tokens = {
169 {Opt_degraded, "degraded"},
170 {Opt_subvol, "subvol=%s"},
171 {Opt_subvolid, "subvolid=%d"},
172 {Opt_device, "device=%s"},
173 {Opt_nodatasum, "nodatasum"},
174 {Opt_nodatacow, "nodatacow"},
175 {Opt_nobarrier, "nobarrier"},
176 {Opt_max_inline, "max_inline=%s"},
177 {Opt_alloc_start, "alloc_start=%s"},
178 {Opt_thread_pool, "thread_pool=%d"},
179 {Opt_compress, "compress"},
180 {Opt_compress_type, "compress=%s"},
181 {Opt_compress_force, "compress-force"},
182 {Opt_compress_force_type, "compress-force=%s"},
183 {Opt_ssd, "ssd"},
184 {Opt_ssd_spread, "ssd_spread"},
185 {Opt_nossd, "nossd"},
186 {Opt_noacl, "noacl"},
187 {Opt_notreelog, "notreelog"},
188 {Opt_flushoncommit, "flushoncommit"},
189 {Opt_ratio, "metadata_ratio=%d"},
190 {Opt_discard, "discard"},
191 {Opt_space_cache, "space_cache"},
192 {Opt_clear_cache, "clear_cache"},
193 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
194 {Opt_enospc_debug, "enospc_debug"},
195 {Opt_subvolrootid, "subvolrootid=%d"},
196 {Opt_defrag, "autodefrag"},
197 {Opt_inode_cache, "inode_cache"},
198 {Opt_err, NULL},
199};
200
201/*
202 * Regular mount options parser. Everything that is needed only when
203 * reading in a new superblock is parsed here.
204 */
205int btrfs_parse_options(struct btrfs_root *root, char *options)
206{
207 struct btrfs_fs_info *info = root->fs_info;
208 substring_t args[MAX_OPT_ARGS];
209 char *p, *num, *orig;
210 int intarg;
211 int ret = 0;
212 char *compress_type;
213 bool compress_force = false;
214
215 if (!options)
216 return 0;
217
218 /*
219 * strsep changes the string, duplicate it because parse_options
220 * gets called twice
221 */
222 options = kstrdup(options, GFP_NOFS);
223 if (!options)
224 return -ENOMEM;
225
226 orig = options;
227
228 while ((p = strsep(&options, ",")) != NULL) {
229 int token;
230 if (!*p)
231 continue;
232
233 token = match_token(p, tokens, args);
234 switch (token) {
235 case Opt_degraded:
236 printk(KERN_INFO "btrfs: allowing degraded mounts\n");
237 btrfs_set_opt(info->mount_opt, DEGRADED);
238 break;
239 case Opt_subvol:
240 case Opt_subvolid:
241 case Opt_subvolrootid:
242 case Opt_device:
243 /*
244 * These are parsed by btrfs_parse_early_options
245 * and can be happily ignored here.
246 */
247 break;
248 case Opt_nodatasum:
249 printk(KERN_INFO "btrfs: setting nodatasum\n");
250 btrfs_set_opt(info->mount_opt, NODATASUM);
251 break;
252 case Opt_nodatacow:
253 printk(KERN_INFO "btrfs: setting nodatacow\n");
254 btrfs_set_opt(info->mount_opt, NODATACOW);
255 btrfs_set_opt(info->mount_opt, NODATASUM);
256 break;
257 case Opt_compress_force:
258 case Opt_compress_force_type:
259 compress_force = true;
260 case Opt_compress:
261 case Opt_compress_type:
262 if (token == Opt_compress ||
263 token == Opt_compress_force ||
264 strcmp(args[0].from, "zlib") == 0) {
265 compress_type = "zlib";
266 info->compress_type = BTRFS_COMPRESS_ZLIB;
267 } else if (strcmp(args[0].from, "lzo") == 0) {
268 compress_type = "lzo";
269 info->compress_type = BTRFS_COMPRESS_LZO;
270 } else {
271 ret = -EINVAL;
272 goto out;
273 }
274
275 btrfs_set_opt(info->mount_opt, COMPRESS);
276 if (compress_force) {
277 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
278 pr_info("btrfs: force %s compression\n",
279 compress_type);
280 } else
281 pr_info("btrfs: use %s compression\n",
282 compress_type);
283 break;
284 case Opt_ssd:
285 printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
286 btrfs_set_opt(info->mount_opt, SSD);
287 break;
288 case Opt_ssd_spread:
289 printk(KERN_INFO "btrfs: use spread ssd "
290 "allocation scheme\n");
291 btrfs_set_opt(info->mount_opt, SSD);
292 btrfs_set_opt(info->mount_opt, SSD_SPREAD);
293 break;
294 case Opt_nossd:
295 printk(KERN_INFO "btrfs: not using ssd allocation "
296 "scheme\n");
297 btrfs_set_opt(info->mount_opt, NOSSD);
298 btrfs_clear_opt(info->mount_opt, SSD);
299 btrfs_clear_opt(info->mount_opt, SSD_SPREAD);
300 break;
301 case Opt_nobarrier:
302 printk(KERN_INFO "btrfs: turning off barriers\n");
303 btrfs_set_opt(info->mount_opt, NOBARRIER);
304 break;
305 case Opt_thread_pool:
306 intarg = 0;
307 match_int(&args[0], &intarg);
308 if (intarg) {
309 info->thread_pool_size = intarg;
310 printk(KERN_INFO "btrfs: thread pool %d\n",
311 info->thread_pool_size);
312 }
313 break;
314 case Opt_max_inline:
315 num = match_strdup(&args[0]);
316 if (num) {
317 info->max_inline = memparse(num, NULL);
318 kfree(num);
319
320 if (info->max_inline) {
321 info->max_inline = max_t(u64,
322 info->max_inline,
323 root->sectorsize);
324 }
325 printk(KERN_INFO "btrfs: max_inline at %llu\n",
326 (unsigned long long)info->max_inline);
327 }
328 break;
329 case Opt_alloc_start:
330 num = match_strdup(&args[0]);
331 if (num) {
332 info->alloc_start = memparse(num, NULL);
333 kfree(num);
334 printk(KERN_INFO
335 "btrfs: allocations start at %llu\n",
336 (unsigned long long)info->alloc_start);
337 }
338 break;
339 case Opt_noacl:
340 root->fs_info->sb->s_flags &= ~MS_POSIXACL;
341 break;
342 case Opt_notreelog:
343 printk(KERN_INFO "btrfs: disabling tree log\n");
344 btrfs_set_opt(info->mount_opt, NOTREELOG);
345 break;
346 case Opt_flushoncommit:
347 printk(KERN_INFO "btrfs: turning on flush-on-commit\n");
348 btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT);
349 break;
350 case Opt_ratio:
351 intarg = 0;
352 match_int(&args[0], &intarg);
353 if (intarg) {
354 info->metadata_ratio = intarg;
355 printk(KERN_INFO "btrfs: metadata ratio %d\n",
356 info->metadata_ratio);
357 }
358 break;
359 case Opt_discard:
360 btrfs_set_opt(info->mount_opt, DISCARD);
361 break;
362 case Opt_space_cache:
363 printk(KERN_INFO "btrfs: enabling disk space caching\n");
364 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
365 break;
366 case Opt_inode_cache:
367 printk(KERN_INFO "btrfs: enabling inode map caching\n");
368 btrfs_set_opt(info->mount_opt, INODE_MAP_CACHE);
369 break;
370 case Opt_clear_cache:
371 printk(KERN_INFO "btrfs: force clearing of disk cache\n");
372 btrfs_set_opt(info->mount_opt, CLEAR_CACHE);
373 break;
374 case Opt_user_subvol_rm_allowed:
375 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
376 break;
377 case Opt_enospc_debug:
378 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
379 break;
380 case Opt_defrag:
381 printk(KERN_INFO "btrfs: enabling auto defrag");
382 btrfs_set_opt(info->mount_opt, AUTO_DEFRAG);
383 break;
384 case Opt_err:
385 printk(KERN_INFO "btrfs: unrecognized mount option "
386 "'%s'\n", p);
387 ret = -EINVAL;
388 goto out;
389 default:
390 break;
391 }
392 }
393out:
394 kfree(orig);
395 return ret;
396}
397
398/*
399 * Parse mount options that are required early in the mount process.
400 *
401 * All other options will be parsed on much later in the mount process and
402 * only when we need to allocate a new super block.
403 */
404static int btrfs_parse_early_options(const char *options, fmode_t flags,
405 void *holder, char **subvol_name, u64 *subvol_objectid,
406 u64 *subvol_rootid, struct btrfs_fs_devices **fs_devices)
407{
408 substring_t args[MAX_OPT_ARGS];
409 char *opts, *orig, *p;
410 int error = 0;
411 int intarg;
412
413 if (!options)
414 goto out;
415
416 /*
417 * strsep changes the string, duplicate it because parse_options
418 * gets called twice
419 */
420 opts = kstrdup(options, GFP_KERNEL);
421 if (!opts)
422 return -ENOMEM;
423 orig = opts;
424
425 while ((p = strsep(&opts, ",")) != NULL) {
426 int token;
427 if (!*p)
428 continue;
429
430 token = match_token(p, tokens, args);
431 switch (token) {
432 case Opt_subvol:
433 *subvol_name = match_strdup(&args[0]);
434 break;
435 case Opt_subvolid:
436 intarg = 0;
437 error = match_int(&args[0], &intarg);
438 if (!error) {
439 /* we want the original fs_tree */
440 if (!intarg)
441 *subvol_objectid =
442 BTRFS_FS_TREE_OBJECTID;
443 else
444 *subvol_objectid = intarg;
445 }
446 break;
447 case Opt_subvolrootid:
448 intarg = 0;
449 error = match_int(&args[0], &intarg);
450 if (!error) {
451 /* we want the original fs_tree */
452 if (!intarg)
453 *subvol_rootid =
454 BTRFS_FS_TREE_OBJECTID;
455 else
456 *subvol_rootid = intarg;
457 }
458 break;
459 case Opt_device:
460 error = btrfs_scan_one_device(match_strdup(&args[0]),
461 flags, holder, fs_devices);
462 if (error)
463 goto out_free_opts;
464 break;
465 default:
466 break;
467 }
468 }
469
470 out_free_opts:
471 kfree(orig);
472 out:
473 /*
474 * If no subvolume name is specified we use the default one. Allocate
475 * a copy of the string "." here so that code later in the
476 * mount path doesn't care if it's the default volume or another one.
477 */
478 if (!*subvol_name) {
479 *subvol_name = kstrdup(".", GFP_KERNEL);
480 if (!*subvol_name)
481 return -ENOMEM;
482 }
483 return error;
484}
485
486static struct dentry *get_default_root(struct super_block *sb,
487 u64 subvol_objectid)
488{
489 struct btrfs_root *root = sb->s_fs_info;
490 struct btrfs_root *new_root;
491 struct btrfs_dir_item *di;
492 struct btrfs_path *path;
493 struct btrfs_key location;
494 struct inode *inode;
495 struct dentry *dentry;
496 u64 dir_id;
497 int new = 0;
498
499 /*
500 * We have a specific subvol we want to mount, just setup location and
501 * go look up the root.
502 */
503 if (subvol_objectid) {
504 location.objectid = subvol_objectid;
505 location.type = BTRFS_ROOT_ITEM_KEY;
506 location.offset = (u64)-1;
507 goto find_root;
508 }
509
510 path = btrfs_alloc_path();
511 if (!path)
512 return ERR_PTR(-ENOMEM);
513 path->leave_spinning = 1;
514
515 /*
516 * Find the "default" dir item which points to the root item that we
517 * will mount by default if we haven't been given a specific subvolume
518 * to mount.
519 */
520 dir_id = btrfs_super_root_dir(&root->fs_info->super_copy);
521 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
522 if (IS_ERR(di)) {
523 btrfs_free_path(path);
524 return ERR_CAST(di);
525 }
526 if (!di) {
527 /*
528 * Ok the default dir item isn't there. This is weird since
529 * it's always been there, but don't freak out, just try and
530 * mount to root most subvolume.
531 */
532 btrfs_free_path(path);
533 dir_id = BTRFS_FIRST_FREE_OBJECTID;
534 new_root = root->fs_info->fs_root;
535 goto setup_root;
536 }
537
538 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
539 btrfs_free_path(path);
540
541find_root:
542 new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
543 if (IS_ERR(new_root))
544 return ERR_CAST(new_root);
545
546 if (btrfs_root_refs(&new_root->root_item) == 0)
547 return ERR_PTR(-ENOENT);
548
549 dir_id = btrfs_root_dirid(&new_root->root_item);
550setup_root:
551 location.objectid = dir_id;
552 location.type = BTRFS_INODE_ITEM_KEY;
553 location.offset = 0;
554
555 inode = btrfs_iget(sb, &location, new_root, &new);
556 if (IS_ERR(inode))
557 return ERR_CAST(inode);
558
559 /*
560 * If we're just mounting the root most subvol put the inode and return
561 * a reference to the dentry. We will have already gotten a reference
562 * to the inode in btrfs_fill_super so we're good to go.
563 */
564 if (!new && sb->s_root->d_inode == inode) {
565 iput(inode);
566 return dget(sb->s_root);
567 }
568
569 if (new) {
570 const struct qstr name = { .name = "/", .len = 1 };
571
572 /*
573 * New inode, we need to make the dentry a sibling of s_root so
574 * everything gets cleaned up properly on unmount.
575 */
576 dentry = d_alloc(sb->s_root, &name);
577 if (!dentry) {
578 iput(inode);
579 return ERR_PTR(-ENOMEM);
580 }
581 d_splice_alias(inode, dentry);
582 } else {
583 /*
584 * We found the inode in cache, just find a dentry for it and
585 * put the reference to the inode we just got.
586 */
587 dentry = d_find_alias(inode);
588 iput(inode);
589 }
590
591 return dentry;
592}
593
594static int btrfs_fill_super(struct super_block *sb,
595 struct btrfs_fs_devices *fs_devices,
596 void *data, int silent)
597{
598 struct inode *inode;
599 struct dentry *root_dentry;
600 struct btrfs_root *tree_root;
601 struct btrfs_key key;
602 int err;
603
604 sb->s_maxbytes = MAX_LFS_FILESIZE;
605 sb->s_magic = BTRFS_SUPER_MAGIC;
606 sb->s_op = &btrfs_super_ops;
607 sb->s_d_op = &btrfs_dentry_operations;
608 sb->s_export_op = &btrfs_export_ops;
609 sb->s_xattr = btrfs_xattr_handlers;
610 sb->s_time_gran = 1;
611#ifdef CONFIG_BTRFS_FS_POSIX_ACL
612 sb->s_flags |= MS_POSIXACL;
613#endif
614
615 tree_root = open_ctree(sb, fs_devices, (char *)data);
616
617 if (IS_ERR(tree_root)) {
618 printk("btrfs: open_ctree failed\n");
619 return PTR_ERR(tree_root);
620 }
621 sb->s_fs_info = tree_root;
622
623 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
624 key.type = BTRFS_INODE_ITEM_KEY;
625 key.offset = 0;
626 inode = btrfs_iget(sb, &key, tree_root->fs_info->fs_root, NULL);
627 if (IS_ERR(inode)) {
628 err = PTR_ERR(inode);
629 goto fail_close;
630 }
631
632 root_dentry = d_alloc_root(inode);
633 if (!root_dentry) {
634 iput(inode);
635 err = -ENOMEM;
636 goto fail_close;
637 }
638
639 sb->s_root = root_dentry;
640
641 save_mount_options(sb, data);
642 cleancache_init_fs(sb);
643 return 0;
644
645fail_close:
646 close_ctree(tree_root);
647 return err;
648}
649
650int btrfs_sync_fs(struct super_block *sb, int wait)
651{
652 struct btrfs_trans_handle *trans;
653 struct btrfs_root *root = btrfs_sb(sb);
654 int ret;
655
656 trace_btrfs_sync_fs(wait);
657
658 if (!wait) {
659 filemap_flush(root->fs_info->btree_inode->i_mapping);
660 return 0;
661 }
662
663 btrfs_start_delalloc_inodes(root, 0);
664 btrfs_wait_ordered_extents(root, 0, 0);
665
666 trans = btrfs_start_transaction(root, 0);
667 if (IS_ERR(trans))
668 return PTR_ERR(trans);
669 ret = btrfs_commit_transaction(trans, root);
670 return ret;
671}
672
673static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
674{
675 struct btrfs_root *root = btrfs_sb(vfs->mnt_sb);
676 struct btrfs_fs_info *info = root->fs_info;
677 char *compress_type;
678
679 if (btrfs_test_opt(root, DEGRADED))
680 seq_puts(seq, ",degraded");
681 if (btrfs_test_opt(root, NODATASUM))
682 seq_puts(seq, ",nodatasum");
683 if (btrfs_test_opt(root, NODATACOW))
684 seq_puts(seq, ",nodatacow");
685 if (btrfs_test_opt(root, NOBARRIER))
686 seq_puts(seq, ",nobarrier");
687 if (info->max_inline != 8192 * 1024)
688 seq_printf(seq, ",max_inline=%llu",
689 (unsigned long long)info->max_inline);
690 if (info->alloc_start != 0)
691 seq_printf(seq, ",alloc_start=%llu",
692 (unsigned long long)info->alloc_start);
693 if (info->thread_pool_size != min_t(unsigned long,
694 num_online_cpus() + 2, 8))
695 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
696 if (btrfs_test_opt(root, COMPRESS)) {
697 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
698 compress_type = "zlib";
699 else
700 compress_type = "lzo";
701 if (btrfs_test_opt(root, FORCE_COMPRESS))
702 seq_printf(seq, ",compress-force=%s", compress_type);
703 else
704 seq_printf(seq, ",compress=%s", compress_type);
705 }
706 if (btrfs_test_opt(root, NOSSD))
707 seq_puts(seq, ",nossd");
708 if (btrfs_test_opt(root, SSD_SPREAD))
709 seq_puts(seq, ",ssd_spread");
710 else if (btrfs_test_opt(root, SSD))
711 seq_puts(seq, ",ssd");
712 if (btrfs_test_opt(root, NOTREELOG))
713 seq_puts(seq, ",notreelog");
714 if (btrfs_test_opt(root, FLUSHONCOMMIT))
715 seq_puts(seq, ",flushoncommit");
716 if (btrfs_test_opt(root, DISCARD))
717 seq_puts(seq, ",discard");
718 if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
719 seq_puts(seq, ",noacl");
720 if (btrfs_test_opt(root, SPACE_CACHE))
721 seq_puts(seq, ",space_cache");
722 if (btrfs_test_opt(root, CLEAR_CACHE))
723 seq_puts(seq, ",clear_cache");
724 if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
725 seq_puts(seq, ",user_subvol_rm_allowed");
726 if (btrfs_test_opt(root, ENOSPC_DEBUG))
727 seq_puts(seq, ",enospc_debug");
728 if (btrfs_test_opt(root, AUTO_DEFRAG))
729 seq_puts(seq, ",autodefrag");
730 if (btrfs_test_opt(root, INODE_MAP_CACHE))
731 seq_puts(seq, ",inode_cache");
732 return 0;
733}
734
735static int btrfs_test_super(struct super_block *s, void *data)
736{
737 struct btrfs_root *test_root = data;
738 struct btrfs_root *root = btrfs_sb(s);
739
740 /*
741 * If this super block is going away, return false as it
742 * can't match as an existing super block.
743 */
744 if (!atomic_read(&s->s_active))
745 return 0;
746 return root->fs_info->fs_devices == test_root->fs_info->fs_devices;
747}
748
749static int btrfs_set_super(struct super_block *s, void *data)
750{
751 s->s_fs_info = data;
752
753 return set_anon_super(s, data);
754}
755
756
757/*
758 * Find a superblock for the given device / mount point.
759 *
760 * Note: This is based on get_sb_bdev from fs/super.c with a few additions
761 * for multiple device setup. Make sure to keep it in sync.
762 */
763static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
764 const char *device_name, void *data)
765{
766 struct block_device *bdev = NULL;
767 struct super_block *s;
768 struct dentry *root;
769 struct btrfs_fs_devices *fs_devices = NULL;
770 struct btrfs_root *tree_root = NULL;
771 struct btrfs_fs_info *fs_info = NULL;
772 fmode_t mode = FMODE_READ;
773 char *subvol_name = NULL;
774 u64 subvol_objectid = 0;
775 u64 subvol_rootid = 0;
776 int error = 0;
777
778 if (!(flags & MS_RDONLY))
779 mode |= FMODE_WRITE;
780
781 error = btrfs_parse_early_options(data, mode, fs_type,
782 &subvol_name, &subvol_objectid,
783 &subvol_rootid, &fs_devices);
784 if (error)
785 return ERR_PTR(error);
786
787 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
788 if (error)
789 goto error_free_subvol_name;
790
791 error = btrfs_open_devices(fs_devices, mode, fs_type);
792 if (error)
793 goto error_free_subvol_name;
794
795 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
796 error = -EACCES;
797 goto error_close_devices;
798 }
799
800 /*
801 * Setup a dummy root and fs_info for test/set super. This is because
802 * we don't actually fill this stuff out until open_ctree, but we need
803 * it for searching for existing supers, so this lets us do that and
804 * then open_ctree will properly initialize everything later.
805 */
806 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
807 tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
808 if (!fs_info || !tree_root) {
809 error = -ENOMEM;
810 goto error_close_devices;
811 }
812 fs_info->tree_root = tree_root;
813 fs_info->fs_devices = fs_devices;
814 tree_root->fs_info = fs_info;
815
816 bdev = fs_devices->latest_bdev;
817 s = sget(fs_type, btrfs_test_super, btrfs_set_super, tree_root);
818 if (IS_ERR(s))
819 goto error_s;
820
821 if (s->s_root) {
822 if ((flags ^ s->s_flags) & MS_RDONLY) {
823 deactivate_locked_super(s);
824 error = -EBUSY;
825 goto error_close_devices;
826 }
827
828 btrfs_close_devices(fs_devices);
829 kfree(fs_info);
830 kfree(tree_root);
831 } else {
832 char b[BDEVNAME_SIZE];
833
834 s->s_flags = flags | MS_NOSEC;
835 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
836 error = btrfs_fill_super(s, fs_devices, data,
837 flags & MS_SILENT ? 1 : 0);
838 if (error) {
839 deactivate_locked_super(s);
840 goto error_free_subvol_name;
841 }
842
843 btrfs_sb(s)->fs_info->bdev_holder = fs_type;
844 s->s_flags |= MS_ACTIVE;
845 }
846
847 /* if they gave us a subvolume name bind mount into that */
848 if (strcmp(subvol_name, ".")) {
849 struct dentry *new_root;
850
851 root = get_default_root(s, subvol_rootid);
852 if (IS_ERR(root)) {
853 error = PTR_ERR(root);
854 deactivate_locked_super(s);
855 goto error_free_subvol_name;
856 }
857
858 mutex_lock(&root->d_inode->i_mutex);
859 new_root = lookup_one_len(subvol_name, root,
860 strlen(subvol_name));
861 mutex_unlock(&root->d_inode->i_mutex);
862
863 if (IS_ERR(new_root)) {
864 dput(root);
865 deactivate_locked_super(s);
866 error = PTR_ERR(new_root);
867 goto error_free_subvol_name;
868 }
869 if (!new_root->d_inode) {
870 dput(root);
871 dput(new_root);
872 deactivate_locked_super(s);
873 error = -ENXIO;
874 goto error_free_subvol_name;
875 }
876 dput(root);
877 root = new_root;
878 } else {
879 root = get_default_root(s, subvol_objectid);
880 if (IS_ERR(root)) {
881 error = PTR_ERR(root);
882 deactivate_locked_super(s);
883 goto error_free_subvol_name;
884 }
885 }
886
887 kfree(subvol_name);
888 return root;
889
890error_s:
891 error = PTR_ERR(s);
892error_close_devices:
893 btrfs_close_devices(fs_devices);
894 kfree(fs_info);
895 kfree(tree_root);
896error_free_subvol_name:
897 kfree(subvol_name);
898 return ERR_PTR(error);
899}
900
901static int btrfs_remount(struct super_block *sb, int *flags, char *data)
902{
903 struct btrfs_root *root = btrfs_sb(sb);
904 int ret;
905
906 ret = btrfs_parse_options(root, data);
907 if (ret)
908 return -EINVAL;
909
910 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
911 return 0;
912
913 if (*flags & MS_RDONLY) {
914 sb->s_flags |= MS_RDONLY;
915
916 ret = btrfs_commit_super(root);
917 WARN_ON(ret);
918 } else {
919 if (root->fs_info->fs_devices->rw_devices == 0)
920 return -EACCES;
921
922 if (btrfs_super_log_root(&root->fs_info->super_copy) != 0)
923 return -EINVAL;
924
925 ret = btrfs_cleanup_fs_roots(root->fs_info);
926 WARN_ON(ret);
927
928 /* recover relocation */
929 ret = btrfs_recover_relocation(root);
930 WARN_ON(ret);
931
932 sb->s_flags &= ~MS_RDONLY;
933 }
934
935 return 0;
936}
937
938/* Used to sort the devices by max_avail(descending sort) */
939static int btrfs_cmp_device_free_bytes(const void *dev_info1,
940 const void *dev_info2)
941{
942 if (((struct btrfs_device_info *)dev_info1)->max_avail >
943 ((struct btrfs_device_info *)dev_info2)->max_avail)
944 return -1;
945 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
946 ((struct btrfs_device_info *)dev_info2)->max_avail)
947 return 1;
948 else
949 return 0;
950}
951
952/*
953 * sort the devices by max_avail, in which max free extent size of each device
954 * is stored.(Descending Sort)
955 */
956static inline void btrfs_descending_sort_devices(
957 struct btrfs_device_info *devices,
958 size_t nr_devices)
959{
960 sort(devices, nr_devices, sizeof(struct btrfs_device_info),
961 btrfs_cmp_device_free_bytes, NULL);
962}
963
964/*
965 * The helper to calc the free space on the devices that can be used to store
966 * file data.
967 */
968static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
969{
970 struct btrfs_fs_info *fs_info = root->fs_info;
971 struct btrfs_device_info *devices_info;
972 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
973 struct btrfs_device *device;
974 u64 skip_space;
975 u64 type;
976 u64 avail_space;
977 u64 used_space;
978 u64 min_stripe_size;
979 int min_stripes = 1;
980 int i = 0, nr_devices;
981 int ret;
982
983 nr_devices = fs_info->fs_devices->rw_devices;
984 BUG_ON(!nr_devices);
985
986 devices_info = kmalloc(sizeof(*devices_info) * nr_devices,
987 GFP_NOFS);
988 if (!devices_info)
989 return -ENOMEM;
990
991 /* calc min stripe number for data space alloction */
992 type = btrfs_get_alloc_profile(root, 1);
993 if (type & BTRFS_BLOCK_GROUP_RAID0)
994 min_stripes = 2;
995 else if (type & BTRFS_BLOCK_GROUP_RAID1)
996 min_stripes = 2;
997 else if (type & BTRFS_BLOCK_GROUP_RAID10)
998 min_stripes = 4;
999
1000 if (type & BTRFS_BLOCK_GROUP_DUP)
1001 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1002 else
1003 min_stripe_size = BTRFS_STRIPE_LEN;
1004
1005 list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
1006 if (!device->in_fs_metadata)
1007 continue;
1008
1009 avail_space = device->total_bytes - device->bytes_used;
1010
1011 /* align with stripe_len */
1012 do_div(avail_space, BTRFS_STRIPE_LEN);
1013 avail_space *= BTRFS_STRIPE_LEN;
1014
1015 /*
1016 * In order to avoid overwritting the superblock on the drive,
1017 * btrfs starts at an offset of at least 1MB when doing chunk
1018 * allocation.
1019 */
1020 skip_space = 1024 * 1024;
1021
1022 /* user can set the offset in fs_info->alloc_start. */
1023 if (fs_info->alloc_start + BTRFS_STRIPE_LEN <=
1024 device->total_bytes)
1025 skip_space = max(fs_info->alloc_start, skip_space);
1026
1027 /*
1028 * btrfs can not use the free space in [0, skip_space - 1],
1029 * we must subtract it from the total. In order to implement
1030 * it, we account the used space in this range first.
1031 */
1032 ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1,
1033 &used_space);
1034 if (ret) {
1035 kfree(devices_info);
1036 return ret;
1037 }
1038
1039 /* calc the free space in [0, skip_space - 1] */
1040 skip_space -= used_space;
1041
1042 /*
1043 * we can use the free space in [0, skip_space - 1], subtract
1044 * it from the total.
1045 */
1046 if (avail_space && avail_space >= skip_space)
1047 avail_space -= skip_space;
1048 else
1049 avail_space = 0;
1050
1051 if (avail_space < min_stripe_size)
1052 continue;
1053
1054 devices_info[i].dev = device;
1055 devices_info[i].max_avail = avail_space;
1056
1057 i++;
1058 }
1059
1060 nr_devices = i;
1061
1062 btrfs_descending_sort_devices(devices_info, nr_devices);
1063
1064 i = nr_devices - 1;
1065 avail_space = 0;
1066 while (nr_devices >= min_stripes) {
1067 if (devices_info[i].max_avail >= min_stripe_size) {
1068 int j;
1069 u64 alloc_size;
1070
1071 avail_space += devices_info[i].max_avail * min_stripes;
1072 alloc_size = devices_info[i].max_avail;
1073 for (j = i + 1 - min_stripes; j <= i; j++)
1074 devices_info[j].max_avail -= alloc_size;
1075 }
1076 i--;
1077 nr_devices--;
1078 }
1079
1080 kfree(devices_info);
1081 *free_bytes = avail_space;
1082 return 0;
1083}
1084
1085static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
1086{
1087 struct btrfs_root *root = btrfs_sb(dentry->d_sb);
1088 struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
1089 struct list_head *head = &root->fs_info->space_info;
1090 struct btrfs_space_info *found;
1091 u64 total_used = 0;
1092 u64 total_free_data = 0;
1093 int bits = dentry->d_sb->s_blocksize_bits;
1094 __be32 *fsid = (__be32 *)root->fs_info->fsid;
1095 int ret;
1096
1097 /* holding chunk_muext to avoid allocating new chunks */
1098 mutex_lock(&root->fs_info->chunk_mutex);
1099 rcu_read_lock();
1100 list_for_each_entry_rcu(found, head, list) {
1101 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
1102 total_free_data += found->disk_total - found->disk_used;
1103 total_free_data -=
1104 btrfs_account_ro_block_groups_free_space(found);
1105 }
1106
1107 total_used += found->disk_used;
1108 }
1109 rcu_read_unlock();
1110
1111 buf->f_namelen = BTRFS_NAME_LEN;
1112 buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
1113 buf->f_bfree = buf->f_blocks - (total_used >> bits);
1114 buf->f_bsize = dentry->d_sb->s_blocksize;
1115 buf->f_type = BTRFS_SUPER_MAGIC;
1116 buf->f_bavail = total_free_data;
1117 ret = btrfs_calc_avail_data_space(root, &total_free_data);
1118 if (ret) {
1119 mutex_unlock(&root->fs_info->chunk_mutex);
1120 return ret;
1121 }
1122 buf->f_bavail += total_free_data;
1123 buf->f_bavail = buf->f_bavail >> bits;
1124 mutex_unlock(&root->fs_info->chunk_mutex);
1125
1126 /* We treat it as constant endianness (it doesn't matter _which_)
1127 because we want the fsid to come out the same whether mounted
1128 on a big-endian or little-endian host */
1129 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
1130 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
1131 /* Mask in the root object ID too, to disambiguate subvols */
1132 buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32;
1133 buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid;
1134
1135 return 0;
1136}
1137
1138static struct file_system_type btrfs_fs_type = {
1139 .owner = THIS_MODULE,
1140 .name = "btrfs",
1141 .mount = btrfs_mount,
1142 .kill_sb = kill_anon_super,
1143 .fs_flags = FS_REQUIRES_DEV,
1144};
1145
1146/*
1147 * used by btrfsctl to scan devices when no FS is mounted
1148 */
1149static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
1150 unsigned long arg)
1151{
1152 struct btrfs_ioctl_vol_args *vol;
1153 struct btrfs_fs_devices *fs_devices;
1154 int ret = -ENOTTY;
1155
1156 if (!capable(CAP_SYS_ADMIN))
1157 return -EPERM;
1158
1159 vol = memdup_user((void __user *)arg, sizeof(*vol));
1160 if (IS_ERR(vol))
1161 return PTR_ERR(vol);
1162
1163 switch (cmd) {
1164 case BTRFS_IOC_SCAN_DEV:
1165 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1166 &btrfs_fs_type, &fs_devices);
1167 break;
1168 }
1169
1170 kfree(vol);
1171 return ret;
1172}
1173
1174static int btrfs_freeze(struct super_block *sb)
1175{
1176 struct btrfs_root *root = btrfs_sb(sb);
1177 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1178 mutex_lock(&root->fs_info->cleaner_mutex);
1179 return 0;
1180}
1181
1182static int btrfs_unfreeze(struct super_block *sb)
1183{
1184 struct btrfs_root *root = btrfs_sb(sb);
1185 mutex_unlock(&root->fs_info->cleaner_mutex);
1186 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1187 return 0;
1188}
1189
1190static const struct super_operations btrfs_super_ops = {
1191 .drop_inode = btrfs_drop_inode,
1192 .evict_inode = btrfs_evict_inode,
1193 .put_super = btrfs_put_super,
1194 .sync_fs = btrfs_sync_fs,
1195 .show_options = btrfs_show_options,
1196 .write_inode = btrfs_write_inode,
1197 .dirty_inode = btrfs_dirty_inode,
1198 .alloc_inode = btrfs_alloc_inode,
1199 .destroy_inode = btrfs_destroy_inode,
1200 .statfs = btrfs_statfs,
1201 .remount_fs = btrfs_remount,
1202 .freeze_fs = btrfs_freeze,
1203 .unfreeze_fs = btrfs_unfreeze,
1204};
1205
1206static const struct file_operations btrfs_ctl_fops = {
1207 .unlocked_ioctl = btrfs_control_ioctl,
1208 .compat_ioctl = btrfs_control_ioctl,
1209 .owner = THIS_MODULE,
1210 .llseek = noop_llseek,
1211};
1212
1213static struct miscdevice btrfs_misc = {
1214 .minor = BTRFS_MINOR,
1215 .name = "btrfs-control",
1216 .fops = &btrfs_ctl_fops
1217};
1218
1219MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
1220MODULE_ALIAS("devname:btrfs-control");
1221
1222static int btrfs_interface_init(void)
1223{
1224 return misc_register(&btrfs_misc);
1225}
1226
1227static void btrfs_interface_exit(void)
1228{
1229 if (misc_deregister(&btrfs_misc) < 0)
1230 printk(KERN_INFO "misc_deregister failed for control device");
1231}
1232
1233static int __init init_btrfs_fs(void)
1234{
1235 int err;
1236
1237 err = btrfs_init_sysfs();
1238 if (err)
1239 return err;
1240
1241 err = btrfs_init_compress();
1242 if (err)
1243 goto free_sysfs;
1244
1245 err = btrfs_init_cachep();
1246 if (err)
1247 goto free_compress;
1248
1249 err = extent_io_init();
1250 if (err)
1251 goto free_cachep;
1252
1253 err = extent_map_init();
1254 if (err)
1255 goto free_extent_io;
1256
1257 err = btrfs_delayed_inode_init();
1258 if (err)
1259 goto free_extent_map;
1260
1261 err = btrfs_interface_init();
1262 if (err)
1263 goto free_delayed_inode;
1264
1265 err = register_filesystem(&btrfs_fs_type);
1266 if (err)
1267 goto unregister_ioctl;
1268
1269 printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION);
1270 return 0;
1271
1272unregister_ioctl:
1273 btrfs_interface_exit();
1274free_delayed_inode:
1275 btrfs_delayed_inode_exit();
1276free_extent_map:
1277 extent_map_exit();
1278free_extent_io:
1279 extent_io_exit();
1280free_cachep:
1281 btrfs_destroy_cachep();
1282free_compress:
1283 btrfs_exit_compress();
1284free_sysfs:
1285 btrfs_exit_sysfs();
1286 return err;
1287}
1288
1289static void __exit exit_btrfs_fs(void)
1290{
1291 btrfs_destroy_cachep();
1292 btrfs_delayed_inode_exit();
1293 extent_map_exit();
1294 extent_io_exit();
1295 btrfs_interface_exit();
1296 unregister_filesystem(&btrfs_fs_type);
1297 btrfs_exit_sysfs();
1298 btrfs_cleanup_fs_uuids();
1299 btrfs_exit_compress();
1300}
1301
1302module_init(init_btrfs_fs)
1303module_exit(exit_btrfs_fs)
1304
1305MODULE_LICENSE("GPL");
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 "zoned.h"
48#include "tests/btrfs-tests.h"
49#include "block-group.h"
50#include "discard.h"
51#include "qgroup.h"
52#define CREATE_TRACE_POINTS
53#include <trace/events/btrfs.h>
54
55static const struct super_operations btrfs_super_ops;
56
57/*
58 * Types for mounting the default subvolume and a subvolume explicitly
59 * requested by subvol=/path. That way the callchain is straightforward and we
60 * don't have to play tricks with the mount options and recursive calls to
61 * btrfs_mount.
62 *
63 * The new btrfs_root_fs_type also servers as a tag for the bdev_holder.
64 */
65static struct file_system_type btrfs_fs_type;
66static struct file_system_type btrfs_root_fs_type;
67
68static int btrfs_remount(struct super_block *sb, int *flags, char *data);
69
70/*
71 * Generally the error codes correspond to their respective errors, but there
72 * are a few special cases.
73 *
74 * EUCLEAN: Any sort of corruption that we encounter. The tree-checker for
75 * instance will return EUCLEAN if any of the blocks are corrupted in
76 * a way that is problematic. We want to reserve EUCLEAN for these
77 * sort of corruptions.
78 *
79 * EROFS: If we check BTRFS_FS_STATE_ERROR and fail out with a return error, we
80 * need to use EROFS for this case. We will have no idea of the
81 * original failure, that will have been reported at the time we tripped
82 * over the error. Each subsequent error that doesn't have any context
83 * of the original error should use EROFS when handling BTRFS_FS_STATE_ERROR.
84 */
85const char * __attribute_const__ btrfs_decode_error(int errno)
86{
87 char *errstr = "unknown";
88
89 switch (errno) {
90 case -ENOENT: /* -2 */
91 errstr = "No such entry";
92 break;
93 case -EIO: /* -5 */
94 errstr = "IO failure";
95 break;
96 case -ENOMEM: /* -12*/
97 errstr = "Out of memory";
98 break;
99 case -EEXIST: /* -17 */
100 errstr = "Object already exists";
101 break;
102 case -ENOSPC: /* -28 */
103 errstr = "No space left";
104 break;
105 case -EROFS: /* -30 */
106 errstr = "Readonly filesystem";
107 break;
108 case -EOPNOTSUPP: /* -95 */
109 errstr = "Operation not supported";
110 break;
111 case -EUCLEAN: /* -117 */
112 errstr = "Filesystem corrupted";
113 break;
114 case -EDQUOT: /* -122 */
115 errstr = "Quota exceeded";
116 break;
117 }
118
119 return errstr;
120}
121
122/*
123 * __btrfs_handle_fs_error decodes expected errors from the caller and
124 * invokes the appropriate error response.
125 */
126__cold
127void __btrfs_handle_fs_error(struct btrfs_fs_info *fs_info, const char *function,
128 unsigned int line, int errno, const char *fmt, ...)
129{
130 struct super_block *sb = fs_info->sb;
131#ifdef CONFIG_PRINTK
132 const char *errstr;
133#endif
134
135 /*
136 * Special case: if the error is EROFS, and we're already
137 * under SB_RDONLY, then it is safe here.
138 */
139 if (errno == -EROFS && sb_rdonly(sb))
140 return;
141
142#ifdef CONFIG_PRINTK
143 errstr = btrfs_decode_error(errno);
144 if (fmt) {
145 struct va_format vaf;
146 va_list args;
147
148 va_start(args, fmt);
149 vaf.fmt = fmt;
150 vaf.va = &args;
151
152 pr_crit("BTRFS: error (device %s) in %s:%d: errno=%d %s (%pV)\n",
153 sb->s_id, function, line, errno, errstr, &vaf);
154 va_end(args);
155 } else {
156 pr_crit("BTRFS: error (device %s) in %s:%d: errno=%d %s\n",
157 sb->s_id, function, line, errno, errstr);
158 }
159#endif
160
161 /*
162 * Today we only save the error info to memory. Long term we'll
163 * also send it down to the disk
164 */
165 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
166
167 /* Don't go through full error handling during mount */
168 if (!(sb->s_flags & SB_BORN))
169 return;
170
171 if (sb_rdonly(sb))
172 return;
173
174 btrfs_discard_stop(fs_info);
175
176 /* btrfs handle error by forcing the filesystem readonly */
177 btrfs_set_sb_rdonly(sb);
178 btrfs_info(fs_info, "forced readonly");
179 /*
180 * Note that a running device replace operation is not canceled here
181 * although there is no way to update the progress. It would add the
182 * risk of a deadlock, therefore the canceling is omitted. The only
183 * penalty is that some I/O remains active until the procedure
184 * completes. The next time when the filesystem is mounted writable
185 * again, the device replace operation continues.
186 */
187}
188
189#ifdef CONFIG_PRINTK
190static const char * const logtypes[] = {
191 "emergency",
192 "alert",
193 "critical",
194 "error",
195 "warning",
196 "notice",
197 "info",
198 "debug",
199};
200
201
202/*
203 * Use one ratelimit state per log level so that a flood of less important
204 * messages doesn't cause more important ones to be dropped.
205 */
206static struct ratelimit_state printk_limits[] = {
207 RATELIMIT_STATE_INIT(printk_limits[0], DEFAULT_RATELIMIT_INTERVAL, 100),
208 RATELIMIT_STATE_INIT(printk_limits[1], DEFAULT_RATELIMIT_INTERVAL, 100),
209 RATELIMIT_STATE_INIT(printk_limits[2], DEFAULT_RATELIMIT_INTERVAL, 100),
210 RATELIMIT_STATE_INIT(printk_limits[3], DEFAULT_RATELIMIT_INTERVAL, 100),
211 RATELIMIT_STATE_INIT(printk_limits[4], DEFAULT_RATELIMIT_INTERVAL, 100),
212 RATELIMIT_STATE_INIT(printk_limits[5], DEFAULT_RATELIMIT_INTERVAL, 100),
213 RATELIMIT_STATE_INIT(printk_limits[6], DEFAULT_RATELIMIT_INTERVAL, 100),
214 RATELIMIT_STATE_INIT(printk_limits[7], DEFAULT_RATELIMIT_INTERVAL, 100),
215};
216
217void __cold btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
218{
219 char lvl[PRINTK_MAX_SINGLE_HEADER_LEN + 1] = "\0";
220 struct va_format vaf;
221 va_list args;
222 int kern_level;
223 const char *type = logtypes[4];
224 struct ratelimit_state *ratelimit = &printk_limits[4];
225
226 va_start(args, fmt);
227
228 while ((kern_level = printk_get_level(fmt)) != 0) {
229 size_t size = printk_skip_level(fmt) - fmt;
230
231 if (kern_level >= '0' && kern_level <= '7') {
232 memcpy(lvl, fmt, size);
233 lvl[size] = '\0';
234 type = logtypes[kern_level - '0'];
235 ratelimit = &printk_limits[kern_level - '0'];
236 }
237 fmt += size;
238 }
239
240 vaf.fmt = fmt;
241 vaf.va = &args;
242
243 if (__ratelimit(ratelimit)) {
244 if (fs_info)
245 printk("%sBTRFS %s (device %s): %pV\n", lvl, type,
246 fs_info->sb->s_id, &vaf);
247 else
248 printk("%sBTRFS %s: %pV\n", lvl, type, &vaf);
249 }
250
251 va_end(args);
252}
253#endif
254
255#if BITS_PER_LONG == 32
256void __cold btrfs_warn_32bit_limit(struct btrfs_fs_info *fs_info)
257{
258 if (!test_and_set_bit(BTRFS_FS_32BIT_WARN, &fs_info->flags)) {
259 btrfs_warn(fs_info, "reaching 32bit limit for logical addresses");
260 btrfs_warn(fs_info,
261"due to page cache limit on 32bit systems, btrfs can't access metadata at or beyond %lluT",
262 BTRFS_32BIT_MAX_FILE_SIZE >> 40);
263 btrfs_warn(fs_info,
264 "please consider upgrading to 64bit kernel/hardware");
265 }
266}
267
268void __cold btrfs_err_32bit_limit(struct btrfs_fs_info *fs_info)
269{
270 if (!test_and_set_bit(BTRFS_FS_32BIT_ERROR, &fs_info->flags)) {
271 btrfs_err(fs_info, "reached 32bit limit for logical addresses");
272 btrfs_err(fs_info,
273"due to page cache limit on 32bit systems, metadata beyond %lluT can't be accessed",
274 BTRFS_32BIT_MAX_FILE_SIZE >> 40);
275 btrfs_err(fs_info,
276 "please consider upgrading to 64bit kernel/hardware");
277 }
278}
279#endif
280
281/*
282 * We only mark the transaction aborted and then set the file system read-only.
283 * This will prevent new transactions from starting or trying to join this
284 * one.
285 *
286 * This means that error recovery at the call site is limited to freeing
287 * any local memory allocations and passing the error code up without
288 * further cleanup. The transaction should complete as it normally would
289 * in the call path but will return -EIO.
290 *
291 * We'll complete the cleanup in btrfs_end_transaction and
292 * btrfs_commit_transaction.
293 */
294__cold
295void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
296 const char *function,
297 unsigned int line, int errno)
298{
299 struct btrfs_fs_info *fs_info = trans->fs_info;
300
301 WRITE_ONCE(trans->aborted, errno);
302 WRITE_ONCE(trans->transaction->aborted, errno);
303 /* Wake up anybody who may be waiting on this transaction */
304 wake_up(&fs_info->transaction_wait);
305 wake_up(&fs_info->transaction_blocked_wait);
306 __btrfs_handle_fs_error(fs_info, function, line, errno, NULL);
307}
308/*
309 * __btrfs_panic decodes unexpected, fatal errors from the caller,
310 * issues an alert, and either panics or BUGs, depending on mount options.
311 */
312__cold
313void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
314 unsigned int line, int errno, const char *fmt, ...)
315{
316 char *s_id = "<unknown>";
317 const char *errstr;
318 struct va_format vaf = { .fmt = fmt };
319 va_list args;
320
321 if (fs_info)
322 s_id = fs_info->sb->s_id;
323
324 va_start(args, fmt);
325 vaf.va = &args;
326
327 errstr = btrfs_decode_error(errno);
328 if (fs_info && (btrfs_test_opt(fs_info, PANIC_ON_FATAL_ERROR)))
329 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
330 s_id, function, line, &vaf, errno, errstr);
331
332 btrfs_crit(fs_info, "panic in %s:%d: %pV (errno=%d %s)",
333 function, line, &vaf, errno, errstr);
334 va_end(args);
335 /* Caller calls BUG() */
336}
337
338static void btrfs_put_super(struct super_block *sb)
339{
340 close_ctree(btrfs_sb(sb));
341}
342
343enum {
344 Opt_acl, Opt_noacl,
345 Opt_clear_cache,
346 Opt_commit_interval,
347 Opt_compress,
348 Opt_compress_force,
349 Opt_compress_force_type,
350 Opt_compress_type,
351 Opt_degraded,
352 Opt_device,
353 Opt_fatal_errors,
354 Opt_flushoncommit, Opt_noflushoncommit,
355 Opt_max_inline,
356 Opt_barrier, Opt_nobarrier,
357 Opt_datacow, Opt_nodatacow,
358 Opt_datasum, Opt_nodatasum,
359 Opt_defrag, Opt_nodefrag,
360 Opt_discard, Opt_nodiscard,
361 Opt_discard_mode,
362 Opt_norecovery,
363 Opt_ratio,
364 Opt_rescan_uuid_tree,
365 Opt_skip_balance,
366 Opt_space_cache, Opt_no_space_cache,
367 Opt_space_cache_version,
368 Opt_ssd, Opt_nossd,
369 Opt_ssd_spread, Opt_nossd_spread,
370 Opt_subvol,
371 Opt_subvol_empty,
372 Opt_subvolid,
373 Opt_thread_pool,
374 Opt_treelog, Opt_notreelog,
375 Opt_user_subvol_rm_allowed,
376
377 /* Rescue options */
378 Opt_rescue,
379 Opt_usebackuproot,
380 Opt_nologreplay,
381 Opt_ignorebadroots,
382 Opt_ignoredatacsums,
383 Opt_rescue_all,
384
385 /* Deprecated options */
386 Opt_recovery,
387 Opt_inode_cache, Opt_noinode_cache,
388
389 /* Debugging options */
390 Opt_check_integrity,
391 Opt_check_integrity_including_extent_data,
392 Opt_check_integrity_print_mask,
393 Opt_enospc_debug, Opt_noenospc_debug,
394#ifdef CONFIG_BTRFS_DEBUG
395 Opt_fragment_data, Opt_fragment_metadata, Opt_fragment_all,
396#endif
397#ifdef CONFIG_BTRFS_FS_REF_VERIFY
398 Opt_ref_verify,
399#endif
400 Opt_err,
401};
402
403static const match_table_t tokens = {
404 {Opt_acl, "acl"},
405 {Opt_noacl, "noacl"},
406 {Opt_clear_cache, "clear_cache"},
407 {Opt_commit_interval, "commit=%u"},
408 {Opt_compress, "compress"},
409 {Opt_compress_type, "compress=%s"},
410 {Opt_compress_force, "compress-force"},
411 {Opt_compress_force_type, "compress-force=%s"},
412 {Opt_degraded, "degraded"},
413 {Opt_device, "device=%s"},
414 {Opt_fatal_errors, "fatal_errors=%s"},
415 {Opt_flushoncommit, "flushoncommit"},
416 {Opt_noflushoncommit, "noflushoncommit"},
417 {Opt_inode_cache, "inode_cache"},
418 {Opt_noinode_cache, "noinode_cache"},
419 {Opt_max_inline, "max_inline=%s"},
420 {Opt_barrier, "barrier"},
421 {Opt_nobarrier, "nobarrier"},
422 {Opt_datacow, "datacow"},
423 {Opt_nodatacow, "nodatacow"},
424 {Opt_datasum, "datasum"},
425 {Opt_nodatasum, "nodatasum"},
426 {Opt_defrag, "autodefrag"},
427 {Opt_nodefrag, "noautodefrag"},
428 {Opt_discard, "discard"},
429 {Opt_discard_mode, "discard=%s"},
430 {Opt_nodiscard, "nodiscard"},
431 {Opt_norecovery, "norecovery"},
432 {Opt_ratio, "metadata_ratio=%u"},
433 {Opt_rescan_uuid_tree, "rescan_uuid_tree"},
434 {Opt_skip_balance, "skip_balance"},
435 {Opt_space_cache, "space_cache"},
436 {Opt_no_space_cache, "nospace_cache"},
437 {Opt_space_cache_version, "space_cache=%s"},
438 {Opt_ssd, "ssd"},
439 {Opt_nossd, "nossd"},
440 {Opt_ssd_spread, "ssd_spread"},
441 {Opt_nossd_spread, "nossd_spread"},
442 {Opt_subvol, "subvol=%s"},
443 {Opt_subvol_empty, "subvol="},
444 {Opt_subvolid, "subvolid=%s"},
445 {Opt_thread_pool, "thread_pool=%u"},
446 {Opt_treelog, "treelog"},
447 {Opt_notreelog, "notreelog"},
448 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
449
450 /* Rescue options */
451 {Opt_rescue, "rescue=%s"},
452 /* Deprecated, with alias rescue=nologreplay */
453 {Opt_nologreplay, "nologreplay"},
454 /* Deprecated, with alias rescue=usebackuproot */
455 {Opt_usebackuproot, "usebackuproot"},
456
457 /* Deprecated options */
458 {Opt_recovery, "recovery"},
459
460 /* Debugging options */
461 {Opt_check_integrity, "check_int"},
462 {Opt_check_integrity_including_extent_data, "check_int_data"},
463 {Opt_check_integrity_print_mask, "check_int_print_mask=%u"},
464 {Opt_enospc_debug, "enospc_debug"},
465 {Opt_noenospc_debug, "noenospc_debug"},
466#ifdef CONFIG_BTRFS_DEBUG
467 {Opt_fragment_data, "fragment=data"},
468 {Opt_fragment_metadata, "fragment=metadata"},
469 {Opt_fragment_all, "fragment=all"},
470#endif
471#ifdef CONFIG_BTRFS_FS_REF_VERIFY
472 {Opt_ref_verify, "ref_verify"},
473#endif
474 {Opt_err, NULL},
475};
476
477static const match_table_t rescue_tokens = {
478 {Opt_usebackuproot, "usebackuproot"},
479 {Opt_nologreplay, "nologreplay"},
480 {Opt_ignorebadroots, "ignorebadroots"},
481 {Opt_ignorebadroots, "ibadroots"},
482 {Opt_ignoredatacsums, "ignoredatacsums"},
483 {Opt_ignoredatacsums, "idatacsums"},
484 {Opt_rescue_all, "all"},
485 {Opt_err, NULL},
486};
487
488static bool check_ro_option(struct btrfs_fs_info *fs_info, unsigned long opt,
489 const char *opt_name)
490{
491 if (fs_info->mount_opt & opt) {
492 btrfs_err(fs_info, "%s must be used with ro mount option",
493 opt_name);
494 return true;
495 }
496 return false;
497}
498
499static int parse_rescue_options(struct btrfs_fs_info *info, const char *options)
500{
501 char *opts;
502 char *orig;
503 char *p;
504 substring_t args[MAX_OPT_ARGS];
505 int ret = 0;
506
507 opts = kstrdup(options, GFP_KERNEL);
508 if (!opts)
509 return -ENOMEM;
510 orig = opts;
511
512 while ((p = strsep(&opts, ":")) != NULL) {
513 int token;
514
515 if (!*p)
516 continue;
517 token = match_token(p, rescue_tokens, args);
518 switch (token){
519 case Opt_usebackuproot:
520 btrfs_info(info,
521 "trying to use backup root at mount time");
522 btrfs_set_opt(info->mount_opt, USEBACKUPROOT);
523 break;
524 case Opt_nologreplay:
525 btrfs_set_and_info(info, NOLOGREPLAY,
526 "disabling log replay at mount time");
527 break;
528 case Opt_ignorebadroots:
529 btrfs_set_and_info(info, IGNOREBADROOTS,
530 "ignoring bad roots");
531 break;
532 case Opt_ignoredatacsums:
533 btrfs_set_and_info(info, IGNOREDATACSUMS,
534 "ignoring data csums");
535 break;
536 case Opt_rescue_all:
537 btrfs_info(info, "enabling all of the rescue options");
538 btrfs_set_and_info(info, IGNOREDATACSUMS,
539 "ignoring data csums");
540 btrfs_set_and_info(info, IGNOREBADROOTS,
541 "ignoring bad roots");
542 btrfs_set_and_info(info, NOLOGREPLAY,
543 "disabling log replay at mount time");
544 break;
545 case Opt_err:
546 btrfs_info(info, "unrecognized rescue option '%s'", p);
547 ret = -EINVAL;
548 goto out;
549 default:
550 break;
551 }
552
553 }
554out:
555 kfree(orig);
556 return ret;
557}
558
559/*
560 * Regular mount options parser. Everything that is needed only when
561 * reading in a new superblock is parsed here.
562 * XXX JDM: This needs to be cleaned up for remount.
563 */
564int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
565 unsigned long new_flags)
566{
567 substring_t args[MAX_OPT_ARGS];
568 char *p, *num;
569 int intarg;
570 int ret = 0;
571 char *compress_type;
572 bool compress_force = false;
573 enum btrfs_compression_type saved_compress_type;
574 int saved_compress_level;
575 bool saved_compress_force;
576 int no_compress = 0;
577
578 if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE))
579 btrfs_set_opt(info->mount_opt, FREE_SPACE_TREE);
580 else if (btrfs_free_space_cache_v1_active(info)) {
581 if (btrfs_is_zoned(info)) {
582 btrfs_info(info,
583 "zoned: clearing existing space cache");
584 btrfs_set_super_cache_generation(info->super_copy, 0);
585 } else {
586 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
587 }
588 }
589
590 /*
591 * Even the options are empty, we still need to do extra check
592 * against new flags
593 */
594 if (!options)
595 goto check;
596
597 while ((p = strsep(&options, ",")) != NULL) {
598 int token;
599 if (!*p)
600 continue;
601
602 token = match_token(p, tokens, args);
603 switch (token) {
604 case Opt_degraded:
605 btrfs_info(info, "allowing degraded mounts");
606 btrfs_set_opt(info->mount_opt, DEGRADED);
607 break;
608 case Opt_subvol:
609 case Opt_subvol_empty:
610 case Opt_subvolid:
611 case Opt_device:
612 /*
613 * These are parsed by btrfs_parse_subvol_options or
614 * btrfs_parse_device_options and can be ignored here.
615 */
616 break;
617 case Opt_nodatasum:
618 btrfs_set_and_info(info, NODATASUM,
619 "setting nodatasum");
620 break;
621 case Opt_datasum:
622 if (btrfs_test_opt(info, NODATASUM)) {
623 if (btrfs_test_opt(info, NODATACOW))
624 btrfs_info(info,
625 "setting datasum, datacow enabled");
626 else
627 btrfs_info(info, "setting datasum");
628 }
629 btrfs_clear_opt(info->mount_opt, NODATACOW);
630 btrfs_clear_opt(info->mount_opt, NODATASUM);
631 break;
632 case Opt_nodatacow:
633 if (!btrfs_test_opt(info, NODATACOW)) {
634 if (!btrfs_test_opt(info, COMPRESS) ||
635 !btrfs_test_opt(info, FORCE_COMPRESS)) {
636 btrfs_info(info,
637 "setting nodatacow, compression disabled");
638 } else {
639 btrfs_info(info, "setting nodatacow");
640 }
641 }
642 btrfs_clear_opt(info->mount_opt, COMPRESS);
643 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
644 btrfs_set_opt(info->mount_opt, NODATACOW);
645 btrfs_set_opt(info->mount_opt, NODATASUM);
646 break;
647 case Opt_datacow:
648 btrfs_clear_and_info(info, NODATACOW,
649 "setting datacow");
650 break;
651 case Opt_compress_force:
652 case Opt_compress_force_type:
653 compress_force = true;
654 fallthrough;
655 case Opt_compress:
656 case Opt_compress_type:
657 saved_compress_type = btrfs_test_opt(info,
658 COMPRESS) ?
659 info->compress_type : BTRFS_COMPRESS_NONE;
660 saved_compress_force =
661 btrfs_test_opt(info, FORCE_COMPRESS);
662 saved_compress_level = info->compress_level;
663 if (token == Opt_compress ||
664 token == Opt_compress_force ||
665 strncmp(args[0].from, "zlib", 4) == 0) {
666 compress_type = "zlib";
667
668 info->compress_type = BTRFS_COMPRESS_ZLIB;
669 info->compress_level = BTRFS_ZLIB_DEFAULT_LEVEL;
670 /*
671 * args[0] contains uninitialized data since
672 * for these tokens we don't expect any
673 * parameter.
674 */
675 if (token != Opt_compress &&
676 token != Opt_compress_force)
677 info->compress_level =
678 btrfs_compress_str2level(
679 BTRFS_COMPRESS_ZLIB,
680 args[0].from + 4);
681 btrfs_set_opt(info->mount_opt, COMPRESS);
682 btrfs_clear_opt(info->mount_opt, NODATACOW);
683 btrfs_clear_opt(info->mount_opt, NODATASUM);
684 no_compress = 0;
685 } else if (strncmp(args[0].from, "lzo", 3) == 0) {
686 compress_type = "lzo";
687 info->compress_type = BTRFS_COMPRESS_LZO;
688 info->compress_level = 0;
689 btrfs_set_opt(info->mount_opt, COMPRESS);
690 btrfs_clear_opt(info->mount_opt, NODATACOW);
691 btrfs_clear_opt(info->mount_opt, NODATASUM);
692 btrfs_set_fs_incompat(info, COMPRESS_LZO);
693 no_compress = 0;
694 } else if (strncmp(args[0].from, "zstd", 4) == 0) {
695 compress_type = "zstd";
696 info->compress_type = BTRFS_COMPRESS_ZSTD;
697 info->compress_level =
698 btrfs_compress_str2level(
699 BTRFS_COMPRESS_ZSTD,
700 args[0].from + 4);
701 btrfs_set_opt(info->mount_opt, COMPRESS);
702 btrfs_clear_opt(info->mount_opt, NODATACOW);
703 btrfs_clear_opt(info->mount_opt, NODATASUM);
704 btrfs_set_fs_incompat(info, COMPRESS_ZSTD);
705 no_compress = 0;
706 } else if (strncmp(args[0].from, "no", 2) == 0) {
707 compress_type = "no";
708 info->compress_level = 0;
709 info->compress_type = 0;
710 btrfs_clear_opt(info->mount_opt, COMPRESS);
711 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
712 compress_force = false;
713 no_compress++;
714 } else {
715 ret = -EINVAL;
716 goto out;
717 }
718
719 if (compress_force) {
720 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
721 } else {
722 /*
723 * If we remount from compress-force=xxx to
724 * compress=xxx, we need clear FORCE_COMPRESS
725 * flag, otherwise, there is no way for users
726 * to disable forcible compression separately.
727 */
728 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
729 }
730 if (no_compress == 1) {
731 btrfs_info(info, "use no compression");
732 } else if ((info->compress_type != saved_compress_type) ||
733 (compress_force != saved_compress_force) ||
734 (info->compress_level != saved_compress_level)) {
735 btrfs_info(info, "%s %s compression, level %d",
736 (compress_force) ? "force" : "use",
737 compress_type, info->compress_level);
738 }
739 compress_force = false;
740 break;
741 case Opt_ssd:
742 btrfs_set_and_info(info, SSD,
743 "enabling ssd optimizations");
744 btrfs_clear_opt(info->mount_opt, NOSSD);
745 break;
746 case Opt_ssd_spread:
747 btrfs_set_and_info(info, SSD,
748 "enabling ssd optimizations");
749 btrfs_set_and_info(info, SSD_SPREAD,
750 "using spread ssd allocation scheme");
751 btrfs_clear_opt(info->mount_opt, NOSSD);
752 break;
753 case Opt_nossd:
754 btrfs_set_opt(info->mount_opt, NOSSD);
755 btrfs_clear_and_info(info, SSD,
756 "not using ssd optimizations");
757 fallthrough;
758 case Opt_nossd_spread:
759 btrfs_clear_and_info(info, SSD_SPREAD,
760 "not using spread ssd allocation scheme");
761 break;
762 case Opt_barrier:
763 btrfs_clear_and_info(info, NOBARRIER,
764 "turning on barriers");
765 break;
766 case Opt_nobarrier:
767 btrfs_set_and_info(info, NOBARRIER,
768 "turning off barriers");
769 break;
770 case Opt_thread_pool:
771 ret = match_int(&args[0], &intarg);
772 if (ret) {
773 goto out;
774 } else if (intarg == 0) {
775 ret = -EINVAL;
776 goto out;
777 }
778 info->thread_pool_size = intarg;
779 break;
780 case Opt_max_inline:
781 num = match_strdup(&args[0]);
782 if (num) {
783 info->max_inline = memparse(num, NULL);
784 kfree(num);
785
786 if (info->max_inline) {
787 info->max_inline = min_t(u64,
788 info->max_inline,
789 info->sectorsize);
790 }
791 btrfs_info(info, "max_inline at %llu",
792 info->max_inline);
793 } else {
794 ret = -ENOMEM;
795 goto out;
796 }
797 break;
798 case Opt_acl:
799#ifdef CONFIG_BTRFS_FS_POSIX_ACL
800 info->sb->s_flags |= SB_POSIXACL;
801 break;
802#else
803 btrfs_err(info, "support for ACL not compiled in!");
804 ret = -EINVAL;
805 goto out;
806#endif
807 case Opt_noacl:
808 info->sb->s_flags &= ~SB_POSIXACL;
809 break;
810 case Opt_notreelog:
811 btrfs_set_and_info(info, NOTREELOG,
812 "disabling tree log");
813 break;
814 case Opt_treelog:
815 btrfs_clear_and_info(info, NOTREELOG,
816 "enabling tree log");
817 break;
818 case Opt_norecovery:
819 case Opt_nologreplay:
820 btrfs_warn(info,
821 "'nologreplay' is deprecated, use 'rescue=nologreplay' instead");
822 btrfs_set_and_info(info, NOLOGREPLAY,
823 "disabling log replay at mount time");
824 break;
825 case Opt_flushoncommit:
826 btrfs_set_and_info(info, FLUSHONCOMMIT,
827 "turning on flush-on-commit");
828 break;
829 case Opt_noflushoncommit:
830 btrfs_clear_and_info(info, FLUSHONCOMMIT,
831 "turning off flush-on-commit");
832 break;
833 case Opt_ratio:
834 ret = match_int(&args[0], &intarg);
835 if (ret)
836 goto out;
837 info->metadata_ratio = intarg;
838 btrfs_info(info, "metadata ratio %u",
839 info->metadata_ratio);
840 break;
841 case Opt_discard:
842 case Opt_discard_mode:
843 if (token == Opt_discard ||
844 strcmp(args[0].from, "sync") == 0) {
845 btrfs_clear_opt(info->mount_opt, DISCARD_ASYNC);
846 btrfs_set_and_info(info, DISCARD_SYNC,
847 "turning on sync discard");
848 } else if (strcmp(args[0].from, "async") == 0) {
849 btrfs_clear_opt(info->mount_opt, DISCARD_SYNC);
850 btrfs_set_and_info(info, DISCARD_ASYNC,
851 "turning on async discard");
852 } else {
853 ret = -EINVAL;
854 goto out;
855 }
856 break;
857 case Opt_nodiscard:
858 btrfs_clear_and_info(info, DISCARD_SYNC,
859 "turning off discard");
860 btrfs_clear_and_info(info, DISCARD_ASYNC,
861 "turning off async discard");
862 break;
863 case Opt_space_cache:
864 case Opt_space_cache_version:
865 if (token == Opt_space_cache ||
866 strcmp(args[0].from, "v1") == 0) {
867 btrfs_clear_opt(info->mount_opt,
868 FREE_SPACE_TREE);
869 btrfs_set_and_info(info, SPACE_CACHE,
870 "enabling disk space caching");
871 } else if (strcmp(args[0].from, "v2") == 0) {
872 btrfs_clear_opt(info->mount_opt,
873 SPACE_CACHE);
874 btrfs_set_and_info(info, FREE_SPACE_TREE,
875 "enabling free space tree");
876 } else {
877 ret = -EINVAL;
878 goto out;
879 }
880 break;
881 case Opt_rescan_uuid_tree:
882 btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE);
883 break;
884 case Opt_no_space_cache:
885 if (btrfs_test_opt(info, SPACE_CACHE)) {
886 btrfs_clear_and_info(info, SPACE_CACHE,
887 "disabling disk space caching");
888 }
889 if (btrfs_test_opt(info, FREE_SPACE_TREE)) {
890 btrfs_clear_and_info(info, FREE_SPACE_TREE,
891 "disabling free space tree");
892 }
893 break;
894 case Opt_inode_cache:
895 case Opt_noinode_cache:
896 btrfs_warn(info,
897 "the 'inode_cache' option is deprecated and has no effect since 5.11");
898 break;
899 case Opt_clear_cache:
900 btrfs_set_and_info(info, CLEAR_CACHE,
901 "force clearing of disk cache");
902 break;
903 case Opt_user_subvol_rm_allowed:
904 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
905 break;
906 case Opt_enospc_debug:
907 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
908 break;
909 case Opt_noenospc_debug:
910 btrfs_clear_opt(info->mount_opt, ENOSPC_DEBUG);
911 break;
912 case Opt_defrag:
913 btrfs_set_and_info(info, AUTO_DEFRAG,
914 "enabling auto defrag");
915 break;
916 case Opt_nodefrag:
917 btrfs_clear_and_info(info, AUTO_DEFRAG,
918 "disabling auto defrag");
919 break;
920 case Opt_recovery:
921 case Opt_usebackuproot:
922 btrfs_warn(info,
923 "'%s' is deprecated, use 'rescue=usebackuproot' instead",
924 token == Opt_recovery ? "recovery" :
925 "usebackuproot");
926 btrfs_info(info,
927 "trying to use backup root at mount time");
928 btrfs_set_opt(info->mount_opt, USEBACKUPROOT);
929 break;
930 case Opt_skip_balance:
931 btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
932 break;
933#ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
934 case Opt_check_integrity_including_extent_data:
935 btrfs_info(info,
936 "enabling check integrity including extent data");
937 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY_DATA);
938 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
939 break;
940 case Opt_check_integrity:
941 btrfs_info(info, "enabling check integrity");
942 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
943 break;
944 case Opt_check_integrity_print_mask:
945 ret = match_int(&args[0], &intarg);
946 if (ret)
947 goto out;
948 info->check_integrity_print_mask = intarg;
949 btrfs_info(info, "check_integrity_print_mask 0x%x",
950 info->check_integrity_print_mask);
951 break;
952#else
953 case Opt_check_integrity_including_extent_data:
954 case Opt_check_integrity:
955 case Opt_check_integrity_print_mask:
956 btrfs_err(info,
957 "support for check_integrity* not compiled in!");
958 ret = -EINVAL;
959 goto out;
960#endif
961 case Opt_fatal_errors:
962 if (strcmp(args[0].from, "panic") == 0)
963 btrfs_set_opt(info->mount_opt,
964 PANIC_ON_FATAL_ERROR);
965 else if (strcmp(args[0].from, "bug") == 0)
966 btrfs_clear_opt(info->mount_opt,
967 PANIC_ON_FATAL_ERROR);
968 else {
969 ret = -EINVAL;
970 goto out;
971 }
972 break;
973 case Opt_commit_interval:
974 intarg = 0;
975 ret = match_int(&args[0], &intarg);
976 if (ret)
977 goto out;
978 if (intarg == 0) {
979 btrfs_info(info,
980 "using default commit interval %us",
981 BTRFS_DEFAULT_COMMIT_INTERVAL);
982 intarg = BTRFS_DEFAULT_COMMIT_INTERVAL;
983 } else if (intarg > 300) {
984 btrfs_warn(info, "excessive commit interval %d",
985 intarg);
986 }
987 info->commit_interval = intarg;
988 break;
989 case Opt_rescue:
990 ret = parse_rescue_options(info, args[0].from);
991 if (ret < 0)
992 goto out;
993 break;
994#ifdef CONFIG_BTRFS_DEBUG
995 case Opt_fragment_all:
996 btrfs_info(info, "fragmenting all space");
997 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA);
998 btrfs_set_opt(info->mount_opt, FRAGMENT_METADATA);
999 break;
1000 case Opt_fragment_metadata:
1001 btrfs_info(info, "fragmenting metadata");
1002 btrfs_set_opt(info->mount_opt,
1003 FRAGMENT_METADATA);
1004 break;
1005 case Opt_fragment_data:
1006 btrfs_info(info, "fragmenting data");
1007 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA);
1008 break;
1009#endif
1010#ifdef CONFIG_BTRFS_FS_REF_VERIFY
1011 case Opt_ref_verify:
1012 btrfs_info(info, "doing ref verification");
1013 btrfs_set_opt(info->mount_opt, REF_VERIFY);
1014 break;
1015#endif
1016 case Opt_err:
1017 btrfs_err(info, "unrecognized mount option '%s'", p);
1018 ret = -EINVAL;
1019 goto out;
1020 default:
1021 break;
1022 }
1023 }
1024check:
1025 /* We're read-only, don't have to check. */
1026 if (new_flags & SB_RDONLY)
1027 goto out;
1028
1029 if (check_ro_option(info, BTRFS_MOUNT_NOLOGREPLAY, "nologreplay") ||
1030 check_ro_option(info, BTRFS_MOUNT_IGNOREBADROOTS, "ignorebadroots") ||
1031 check_ro_option(info, BTRFS_MOUNT_IGNOREDATACSUMS, "ignoredatacsums"))
1032 ret = -EINVAL;
1033out:
1034 if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE) &&
1035 !btrfs_test_opt(info, FREE_SPACE_TREE) &&
1036 !btrfs_test_opt(info, CLEAR_CACHE)) {
1037 btrfs_err(info, "cannot disable free space tree");
1038 ret = -EINVAL;
1039
1040 }
1041 if (!ret)
1042 ret = btrfs_check_mountopts_zoned(info);
1043 if (!ret && btrfs_test_opt(info, SPACE_CACHE))
1044 btrfs_info(info, "disk space caching is enabled");
1045 if (!ret && btrfs_test_opt(info, FREE_SPACE_TREE))
1046 btrfs_info(info, "using free space tree");
1047 return ret;
1048}
1049
1050/*
1051 * Parse mount options that are required early in the mount process.
1052 *
1053 * All other options will be parsed on much later in the mount process and
1054 * only when we need to allocate a new super block.
1055 */
1056static int btrfs_parse_device_options(const char *options, fmode_t flags,
1057 void *holder)
1058{
1059 substring_t args[MAX_OPT_ARGS];
1060 char *device_name, *opts, *orig, *p;
1061 struct btrfs_device *device = NULL;
1062 int error = 0;
1063
1064 lockdep_assert_held(&uuid_mutex);
1065
1066 if (!options)
1067 return 0;
1068
1069 /*
1070 * strsep changes the string, duplicate it because btrfs_parse_options
1071 * gets called later
1072 */
1073 opts = kstrdup(options, GFP_KERNEL);
1074 if (!opts)
1075 return -ENOMEM;
1076 orig = opts;
1077
1078 while ((p = strsep(&opts, ",")) != NULL) {
1079 int token;
1080
1081 if (!*p)
1082 continue;
1083
1084 token = match_token(p, tokens, args);
1085 if (token == Opt_device) {
1086 device_name = match_strdup(&args[0]);
1087 if (!device_name) {
1088 error = -ENOMEM;
1089 goto out;
1090 }
1091 device = btrfs_scan_one_device(device_name, flags,
1092 holder);
1093 kfree(device_name);
1094 if (IS_ERR(device)) {
1095 error = PTR_ERR(device);
1096 goto out;
1097 }
1098 }
1099 }
1100
1101out:
1102 kfree(orig);
1103 return error;
1104}
1105
1106/*
1107 * Parse mount options that are related to subvolume id
1108 *
1109 * The value is later passed to mount_subvol()
1110 */
1111static int btrfs_parse_subvol_options(const char *options, char **subvol_name,
1112 u64 *subvol_objectid)
1113{
1114 substring_t args[MAX_OPT_ARGS];
1115 char *opts, *orig, *p;
1116 int error = 0;
1117 u64 subvolid;
1118
1119 if (!options)
1120 return 0;
1121
1122 /*
1123 * strsep changes the string, duplicate it because
1124 * btrfs_parse_device_options gets called later
1125 */
1126 opts = kstrdup(options, GFP_KERNEL);
1127 if (!opts)
1128 return -ENOMEM;
1129 orig = opts;
1130
1131 while ((p = strsep(&opts, ",")) != NULL) {
1132 int token;
1133 if (!*p)
1134 continue;
1135
1136 token = match_token(p, tokens, args);
1137 switch (token) {
1138 case Opt_subvol:
1139 kfree(*subvol_name);
1140 *subvol_name = match_strdup(&args[0]);
1141 if (!*subvol_name) {
1142 error = -ENOMEM;
1143 goto out;
1144 }
1145 break;
1146 case Opt_subvolid:
1147 error = match_u64(&args[0], &subvolid);
1148 if (error)
1149 goto out;
1150
1151 /* we want the original fs_tree */
1152 if (subvolid == 0)
1153 subvolid = BTRFS_FS_TREE_OBJECTID;
1154
1155 *subvol_objectid = subvolid;
1156 break;
1157 default:
1158 break;
1159 }
1160 }
1161
1162out:
1163 kfree(orig);
1164 return error;
1165}
1166
1167char *btrfs_get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info,
1168 u64 subvol_objectid)
1169{
1170 struct btrfs_root *root = fs_info->tree_root;
1171 struct btrfs_root *fs_root = NULL;
1172 struct btrfs_root_ref *root_ref;
1173 struct btrfs_inode_ref *inode_ref;
1174 struct btrfs_key key;
1175 struct btrfs_path *path = NULL;
1176 char *name = NULL, *ptr;
1177 u64 dirid;
1178 int len;
1179 int ret;
1180
1181 path = btrfs_alloc_path();
1182 if (!path) {
1183 ret = -ENOMEM;
1184 goto err;
1185 }
1186
1187 name = kmalloc(PATH_MAX, GFP_KERNEL);
1188 if (!name) {
1189 ret = -ENOMEM;
1190 goto err;
1191 }
1192 ptr = name + PATH_MAX - 1;
1193 ptr[0] = '\0';
1194
1195 /*
1196 * Walk up the subvolume trees in the tree of tree roots by root
1197 * backrefs until we hit the top-level subvolume.
1198 */
1199 while (subvol_objectid != BTRFS_FS_TREE_OBJECTID) {
1200 key.objectid = subvol_objectid;
1201 key.type = BTRFS_ROOT_BACKREF_KEY;
1202 key.offset = (u64)-1;
1203
1204 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1205 if (ret < 0) {
1206 goto err;
1207 } else if (ret > 0) {
1208 ret = btrfs_previous_item(root, path, subvol_objectid,
1209 BTRFS_ROOT_BACKREF_KEY);
1210 if (ret < 0) {
1211 goto err;
1212 } else if (ret > 0) {
1213 ret = -ENOENT;
1214 goto err;
1215 }
1216 }
1217
1218 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1219 subvol_objectid = key.offset;
1220
1221 root_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
1222 struct btrfs_root_ref);
1223 len = btrfs_root_ref_name_len(path->nodes[0], root_ref);
1224 ptr -= len + 1;
1225 if (ptr < name) {
1226 ret = -ENAMETOOLONG;
1227 goto err;
1228 }
1229 read_extent_buffer(path->nodes[0], ptr + 1,
1230 (unsigned long)(root_ref + 1), len);
1231 ptr[0] = '/';
1232 dirid = btrfs_root_ref_dirid(path->nodes[0], root_ref);
1233 btrfs_release_path(path);
1234
1235 fs_root = btrfs_get_fs_root(fs_info, subvol_objectid, true);
1236 if (IS_ERR(fs_root)) {
1237 ret = PTR_ERR(fs_root);
1238 fs_root = NULL;
1239 goto err;
1240 }
1241
1242 /*
1243 * Walk up the filesystem tree by inode refs until we hit the
1244 * root directory.
1245 */
1246 while (dirid != BTRFS_FIRST_FREE_OBJECTID) {
1247 key.objectid = dirid;
1248 key.type = BTRFS_INODE_REF_KEY;
1249 key.offset = (u64)-1;
1250
1251 ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0);
1252 if (ret < 0) {
1253 goto err;
1254 } else if (ret > 0) {
1255 ret = btrfs_previous_item(fs_root, path, dirid,
1256 BTRFS_INODE_REF_KEY);
1257 if (ret < 0) {
1258 goto err;
1259 } else if (ret > 0) {
1260 ret = -ENOENT;
1261 goto err;
1262 }
1263 }
1264
1265 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1266 dirid = key.offset;
1267
1268 inode_ref = btrfs_item_ptr(path->nodes[0],
1269 path->slots[0],
1270 struct btrfs_inode_ref);
1271 len = btrfs_inode_ref_name_len(path->nodes[0],
1272 inode_ref);
1273 ptr -= len + 1;
1274 if (ptr < name) {
1275 ret = -ENAMETOOLONG;
1276 goto err;
1277 }
1278 read_extent_buffer(path->nodes[0], ptr + 1,
1279 (unsigned long)(inode_ref + 1), len);
1280 ptr[0] = '/';
1281 btrfs_release_path(path);
1282 }
1283 btrfs_put_root(fs_root);
1284 fs_root = NULL;
1285 }
1286
1287 btrfs_free_path(path);
1288 if (ptr == name + PATH_MAX - 1) {
1289 name[0] = '/';
1290 name[1] = '\0';
1291 } else {
1292 memmove(name, ptr, name + PATH_MAX - ptr);
1293 }
1294 return name;
1295
1296err:
1297 btrfs_put_root(fs_root);
1298 btrfs_free_path(path);
1299 kfree(name);
1300 return ERR_PTR(ret);
1301}
1302
1303static int get_default_subvol_objectid(struct btrfs_fs_info *fs_info, u64 *objectid)
1304{
1305 struct btrfs_root *root = fs_info->tree_root;
1306 struct btrfs_dir_item *di;
1307 struct btrfs_path *path;
1308 struct btrfs_key location;
1309 u64 dir_id;
1310
1311 path = btrfs_alloc_path();
1312 if (!path)
1313 return -ENOMEM;
1314
1315 /*
1316 * Find the "default" dir item which points to the root item that we
1317 * will mount by default if we haven't been given a specific subvolume
1318 * to mount.
1319 */
1320 dir_id = btrfs_super_root_dir(fs_info->super_copy);
1321 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
1322 if (IS_ERR(di)) {
1323 btrfs_free_path(path);
1324 return PTR_ERR(di);
1325 }
1326 if (!di) {
1327 /*
1328 * Ok the default dir item isn't there. This is weird since
1329 * it's always been there, but don't freak out, just try and
1330 * mount the top-level subvolume.
1331 */
1332 btrfs_free_path(path);
1333 *objectid = BTRFS_FS_TREE_OBJECTID;
1334 return 0;
1335 }
1336
1337 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
1338 btrfs_free_path(path);
1339 *objectid = location.objectid;
1340 return 0;
1341}
1342
1343static int btrfs_fill_super(struct super_block *sb,
1344 struct btrfs_fs_devices *fs_devices,
1345 void *data)
1346{
1347 struct inode *inode;
1348 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1349 int err;
1350
1351 sb->s_maxbytes = MAX_LFS_FILESIZE;
1352 sb->s_magic = BTRFS_SUPER_MAGIC;
1353 sb->s_op = &btrfs_super_ops;
1354 sb->s_d_op = &btrfs_dentry_operations;
1355 sb->s_export_op = &btrfs_export_ops;
1356 sb->s_xattr = btrfs_xattr_handlers;
1357 sb->s_time_gran = 1;
1358#ifdef CONFIG_BTRFS_FS_POSIX_ACL
1359 sb->s_flags |= SB_POSIXACL;
1360#endif
1361 sb->s_flags |= SB_I_VERSION;
1362 sb->s_iflags |= SB_I_CGROUPWB;
1363
1364 err = super_setup_bdi(sb);
1365 if (err) {
1366 btrfs_err(fs_info, "super_setup_bdi failed");
1367 return err;
1368 }
1369
1370 err = open_ctree(sb, fs_devices, (char *)data);
1371 if (err) {
1372 btrfs_err(fs_info, "open_ctree failed");
1373 return err;
1374 }
1375
1376 inode = btrfs_iget(sb, BTRFS_FIRST_FREE_OBJECTID, fs_info->fs_root);
1377 if (IS_ERR(inode)) {
1378 err = PTR_ERR(inode);
1379 goto fail_close;
1380 }
1381
1382 sb->s_root = d_make_root(inode);
1383 if (!sb->s_root) {
1384 err = -ENOMEM;
1385 goto fail_close;
1386 }
1387
1388 cleancache_init_fs(sb);
1389 sb->s_flags |= SB_ACTIVE;
1390 return 0;
1391
1392fail_close:
1393 close_ctree(fs_info);
1394 return err;
1395}
1396
1397int btrfs_sync_fs(struct super_block *sb, int wait)
1398{
1399 struct btrfs_trans_handle *trans;
1400 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1401 struct btrfs_root *root = fs_info->tree_root;
1402
1403 trace_btrfs_sync_fs(fs_info, wait);
1404
1405 if (!wait) {
1406 filemap_flush(fs_info->btree_inode->i_mapping);
1407 return 0;
1408 }
1409
1410 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
1411
1412 trans = btrfs_attach_transaction_barrier(root);
1413 if (IS_ERR(trans)) {
1414 /* no transaction, don't bother */
1415 if (PTR_ERR(trans) == -ENOENT) {
1416 /*
1417 * Exit unless we have some pending changes
1418 * that need to go through commit
1419 */
1420 if (fs_info->pending_changes == 0)
1421 return 0;
1422 /*
1423 * A non-blocking test if the fs is frozen. We must not
1424 * start a new transaction here otherwise a deadlock
1425 * happens. The pending operations are delayed to the
1426 * next commit after thawing.
1427 */
1428 if (sb_start_write_trylock(sb))
1429 sb_end_write(sb);
1430 else
1431 return 0;
1432 trans = btrfs_start_transaction(root, 0);
1433 }
1434 if (IS_ERR(trans))
1435 return PTR_ERR(trans);
1436 }
1437 return btrfs_commit_transaction(trans);
1438}
1439
1440static void print_rescue_option(struct seq_file *seq, const char *s, bool *printed)
1441{
1442 seq_printf(seq, "%s%s", (*printed) ? ":" : ",rescue=", s);
1443 *printed = true;
1444}
1445
1446static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
1447{
1448 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
1449 const char *compress_type;
1450 const char *subvol_name;
1451 bool printed = false;
1452
1453 if (btrfs_test_opt(info, DEGRADED))
1454 seq_puts(seq, ",degraded");
1455 if (btrfs_test_opt(info, NODATASUM))
1456 seq_puts(seq, ",nodatasum");
1457 if (btrfs_test_opt(info, NODATACOW))
1458 seq_puts(seq, ",nodatacow");
1459 if (btrfs_test_opt(info, NOBARRIER))
1460 seq_puts(seq, ",nobarrier");
1461 if (info->max_inline != BTRFS_DEFAULT_MAX_INLINE)
1462 seq_printf(seq, ",max_inline=%llu", info->max_inline);
1463 if (info->thread_pool_size != min_t(unsigned long,
1464 num_online_cpus() + 2, 8))
1465 seq_printf(seq, ",thread_pool=%u", info->thread_pool_size);
1466 if (btrfs_test_opt(info, COMPRESS)) {
1467 compress_type = btrfs_compress_type2str(info->compress_type);
1468 if (btrfs_test_opt(info, FORCE_COMPRESS))
1469 seq_printf(seq, ",compress-force=%s", compress_type);
1470 else
1471 seq_printf(seq, ",compress=%s", compress_type);
1472 if (info->compress_level)
1473 seq_printf(seq, ":%d", info->compress_level);
1474 }
1475 if (btrfs_test_opt(info, NOSSD))
1476 seq_puts(seq, ",nossd");
1477 if (btrfs_test_opt(info, SSD_SPREAD))
1478 seq_puts(seq, ",ssd_spread");
1479 else if (btrfs_test_opt(info, SSD))
1480 seq_puts(seq, ",ssd");
1481 if (btrfs_test_opt(info, NOTREELOG))
1482 seq_puts(seq, ",notreelog");
1483 if (btrfs_test_opt(info, NOLOGREPLAY))
1484 print_rescue_option(seq, "nologreplay", &printed);
1485 if (btrfs_test_opt(info, USEBACKUPROOT))
1486 print_rescue_option(seq, "usebackuproot", &printed);
1487 if (btrfs_test_opt(info, IGNOREBADROOTS))
1488 print_rescue_option(seq, "ignorebadroots", &printed);
1489 if (btrfs_test_opt(info, IGNOREDATACSUMS))
1490 print_rescue_option(seq, "ignoredatacsums", &printed);
1491 if (btrfs_test_opt(info, FLUSHONCOMMIT))
1492 seq_puts(seq, ",flushoncommit");
1493 if (btrfs_test_opt(info, DISCARD_SYNC))
1494 seq_puts(seq, ",discard");
1495 if (btrfs_test_opt(info, DISCARD_ASYNC))
1496 seq_puts(seq, ",discard=async");
1497 if (!(info->sb->s_flags & SB_POSIXACL))
1498 seq_puts(seq, ",noacl");
1499 if (btrfs_free_space_cache_v1_active(info))
1500 seq_puts(seq, ",space_cache");
1501 else if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE))
1502 seq_puts(seq, ",space_cache=v2");
1503 else
1504 seq_puts(seq, ",nospace_cache");
1505 if (btrfs_test_opt(info, RESCAN_UUID_TREE))
1506 seq_puts(seq, ",rescan_uuid_tree");
1507 if (btrfs_test_opt(info, CLEAR_CACHE))
1508 seq_puts(seq, ",clear_cache");
1509 if (btrfs_test_opt(info, USER_SUBVOL_RM_ALLOWED))
1510 seq_puts(seq, ",user_subvol_rm_allowed");
1511 if (btrfs_test_opt(info, ENOSPC_DEBUG))
1512 seq_puts(seq, ",enospc_debug");
1513 if (btrfs_test_opt(info, AUTO_DEFRAG))
1514 seq_puts(seq, ",autodefrag");
1515 if (btrfs_test_opt(info, SKIP_BALANCE))
1516 seq_puts(seq, ",skip_balance");
1517#ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1518 if (btrfs_test_opt(info, CHECK_INTEGRITY_DATA))
1519 seq_puts(seq, ",check_int_data");
1520 else if (btrfs_test_opt(info, CHECK_INTEGRITY))
1521 seq_puts(seq, ",check_int");
1522 if (info->check_integrity_print_mask)
1523 seq_printf(seq, ",check_int_print_mask=%d",
1524 info->check_integrity_print_mask);
1525#endif
1526 if (info->metadata_ratio)
1527 seq_printf(seq, ",metadata_ratio=%u", info->metadata_ratio);
1528 if (btrfs_test_opt(info, PANIC_ON_FATAL_ERROR))
1529 seq_puts(seq, ",fatal_errors=panic");
1530 if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL)
1531 seq_printf(seq, ",commit=%u", info->commit_interval);
1532#ifdef CONFIG_BTRFS_DEBUG
1533 if (btrfs_test_opt(info, FRAGMENT_DATA))
1534 seq_puts(seq, ",fragment=data");
1535 if (btrfs_test_opt(info, FRAGMENT_METADATA))
1536 seq_puts(seq, ",fragment=metadata");
1537#endif
1538 if (btrfs_test_opt(info, REF_VERIFY))
1539 seq_puts(seq, ",ref_verify");
1540 seq_printf(seq, ",subvolid=%llu",
1541 BTRFS_I(d_inode(dentry))->root->root_key.objectid);
1542 subvol_name = btrfs_get_subvol_name_from_objectid(info,
1543 BTRFS_I(d_inode(dentry))->root->root_key.objectid);
1544 if (!IS_ERR(subvol_name)) {
1545 seq_puts(seq, ",subvol=");
1546 seq_escape(seq, subvol_name, " \t\n\\");
1547 kfree(subvol_name);
1548 }
1549 return 0;
1550}
1551
1552static int btrfs_test_super(struct super_block *s, void *data)
1553{
1554 struct btrfs_fs_info *p = data;
1555 struct btrfs_fs_info *fs_info = btrfs_sb(s);
1556
1557 return fs_info->fs_devices == p->fs_devices;
1558}
1559
1560static int btrfs_set_super(struct super_block *s, void *data)
1561{
1562 int err = set_anon_super(s, data);
1563 if (!err)
1564 s->s_fs_info = data;
1565 return err;
1566}
1567
1568/*
1569 * subvolumes are identified by ino 256
1570 */
1571static inline int is_subvolume_inode(struct inode *inode)
1572{
1573 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
1574 return 1;
1575 return 0;
1576}
1577
1578static struct dentry *mount_subvol(const char *subvol_name, u64 subvol_objectid,
1579 struct vfsmount *mnt)
1580{
1581 struct dentry *root;
1582 int ret;
1583
1584 if (!subvol_name) {
1585 if (!subvol_objectid) {
1586 ret = get_default_subvol_objectid(btrfs_sb(mnt->mnt_sb),
1587 &subvol_objectid);
1588 if (ret) {
1589 root = ERR_PTR(ret);
1590 goto out;
1591 }
1592 }
1593 subvol_name = btrfs_get_subvol_name_from_objectid(
1594 btrfs_sb(mnt->mnt_sb), subvol_objectid);
1595 if (IS_ERR(subvol_name)) {
1596 root = ERR_CAST(subvol_name);
1597 subvol_name = NULL;
1598 goto out;
1599 }
1600
1601 }
1602
1603 root = mount_subtree(mnt, subvol_name);
1604 /* mount_subtree() drops our reference on the vfsmount. */
1605 mnt = NULL;
1606
1607 if (!IS_ERR(root)) {
1608 struct super_block *s = root->d_sb;
1609 struct btrfs_fs_info *fs_info = btrfs_sb(s);
1610 struct inode *root_inode = d_inode(root);
1611 u64 root_objectid = BTRFS_I(root_inode)->root->root_key.objectid;
1612
1613 ret = 0;
1614 if (!is_subvolume_inode(root_inode)) {
1615 btrfs_err(fs_info, "'%s' is not a valid subvolume",
1616 subvol_name);
1617 ret = -EINVAL;
1618 }
1619 if (subvol_objectid && root_objectid != subvol_objectid) {
1620 /*
1621 * This will also catch a race condition where a
1622 * subvolume which was passed by ID is renamed and
1623 * another subvolume is renamed over the old location.
1624 */
1625 btrfs_err(fs_info,
1626 "subvol '%s' does not match subvolid %llu",
1627 subvol_name, subvol_objectid);
1628 ret = -EINVAL;
1629 }
1630 if (ret) {
1631 dput(root);
1632 root = ERR_PTR(ret);
1633 deactivate_locked_super(s);
1634 }
1635 }
1636
1637out:
1638 mntput(mnt);
1639 kfree(subvol_name);
1640 return root;
1641}
1642
1643/*
1644 * Find a superblock for the given device / mount point.
1645 *
1646 * Note: This is based on mount_bdev from fs/super.c with a few additions
1647 * for multiple device setup. Make sure to keep it in sync.
1648 */
1649static struct dentry *btrfs_mount_root(struct file_system_type *fs_type,
1650 int flags, const char *device_name, void *data)
1651{
1652 struct block_device *bdev = NULL;
1653 struct super_block *s;
1654 struct btrfs_device *device = NULL;
1655 struct btrfs_fs_devices *fs_devices = NULL;
1656 struct btrfs_fs_info *fs_info = NULL;
1657 void *new_sec_opts = NULL;
1658 fmode_t mode = FMODE_READ;
1659 int error = 0;
1660
1661 if (!(flags & SB_RDONLY))
1662 mode |= FMODE_WRITE;
1663
1664 if (data) {
1665 error = security_sb_eat_lsm_opts(data, &new_sec_opts);
1666 if (error)
1667 return ERR_PTR(error);
1668 }
1669
1670 /*
1671 * Setup a dummy root and fs_info for test/set super. This is because
1672 * we don't actually fill this stuff out until open_ctree, but we need
1673 * then open_ctree will properly initialize the file system specific
1674 * settings later. btrfs_init_fs_info initializes the static elements
1675 * of the fs_info (locks and such) to make cleanup easier if we find a
1676 * superblock with our given fs_devices later on at sget() time.
1677 */
1678 fs_info = kvzalloc(sizeof(struct btrfs_fs_info), GFP_KERNEL);
1679 if (!fs_info) {
1680 error = -ENOMEM;
1681 goto error_sec_opts;
1682 }
1683 btrfs_init_fs_info(fs_info);
1684
1685 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL);
1686 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL);
1687 if (!fs_info->super_copy || !fs_info->super_for_commit) {
1688 error = -ENOMEM;
1689 goto error_fs_info;
1690 }
1691
1692 mutex_lock(&uuid_mutex);
1693 error = btrfs_parse_device_options(data, mode, fs_type);
1694 if (error) {
1695 mutex_unlock(&uuid_mutex);
1696 goto error_fs_info;
1697 }
1698
1699 device = btrfs_scan_one_device(device_name, mode, fs_type);
1700 if (IS_ERR(device)) {
1701 mutex_unlock(&uuid_mutex);
1702 error = PTR_ERR(device);
1703 goto error_fs_info;
1704 }
1705
1706 fs_devices = device->fs_devices;
1707 fs_info->fs_devices = fs_devices;
1708
1709 error = btrfs_open_devices(fs_devices, mode, fs_type);
1710 mutex_unlock(&uuid_mutex);
1711 if (error)
1712 goto error_fs_info;
1713
1714 if (!(flags & SB_RDONLY) && fs_devices->rw_devices == 0) {
1715 error = -EACCES;
1716 goto error_close_devices;
1717 }
1718
1719 bdev = fs_devices->latest_bdev;
1720 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | SB_NOSEC,
1721 fs_info);
1722 if (IS_ERR(s)) {
1723 error = PTR_ERR(s);
1724 goto error_close_devices;
1725 }
1726
1727 if (s->s_root) {
1728 btrfs_close_devices(fs_devices);
1729 btrfs_free_fs_info(fs_info);
1730 if ((flags ^ s->s_flags) & SB_RDONLY)
1731 error = -EBUSY;
1732 } else {
1733 snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev);
1734 btrfs_sb(s)->bdev_holder = fs_type;
1735 if (!strstr(crc32c_impl(), "generic"))
1736 set_bit(BTRFS_FS_CSUM_IMPL_FAST, &fs_info->flags);
1737 error = btrfs_fill_super(s, fs_devices, data);
1738 }
1739 if (!error)
1740 error = security_sb_set_mnt_opts(s, new_sec_opts, 0, NULL);
1741 security_free_mnt_opts(&new_sec_opts);
1742 if (error) {
1743 deactivate_locked_super(s);
1744 return ERR_PTR(error);
1745 }
1746
1747 return dget(s->s_root);
1748
1749error_close_devices:
1750 btrfs_close_devices(fs_devices);
1751error_fs_info:
1752 btrfs_free_fs_info(fs_info);
1753error_sec_opts:
1754 security_free_mnt_opts(&new_sec_opts);
1755 return ERR_PTR(error);
1756}
1757
1758/*
1759 * Mount function which is called by VFS layer.
1760 *
1761 * In order to allow mounting a subvolume directly, btrfs uses mount_subtree()
1762 * which needs vfsmount* of device's root (/). This means device's root has to
1763 * be mounted internally in any case.
1764 *
1765 * Operation flow:
1766 * 1. Parse subvol id related options for later use in mount_subvol().
1767 *
1768 * 2. Mount device's root (/) by calling vfs_kern_mount().
1769 *
1770 * NOTE: vfs_kern_mount() is used by VFS to call btrfs_mount() in the
1771 * first place. In order to avoid calling btrfs_mount() again, we use
1772 * different file_system_type which is not registered to VFS by
1773 * register_filesystem() (btrfs_root_fs_type). As a result,
1774 * btrfs_mount_root() is called. The return value will be used by
1775 * mount_subtree() in mount_subvol().
1776 *
1777 * 3. Call mount_subvol() to get the dentry of subvolume. Since there is
1778 * "btrfs subvolume set-default", mount_subvol() is called always.
1779 */
1780static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1781 const char *device_name, void *data)
1782{
1783 struct vfsmount *mnt_root;
1784 struct dentry *root;
1785 char *subvol_name = NULL;
1786 u64 subvol_objectid = 0;
1787 int error = 0;
1788
1789 error = btrfs_parse_subvol_options(data, &subvol_name,
1790 &subvol_objectid);
1791 if (error) {
1792 kfree(subvol_name);
1793 return ERR_PTR(error);
1794 }
1795
1796 /* mount device's root (/) */
1797 mnt_root = vfs_kern_mount(&btrfs_root_fs_type, flags, device_name, data);
1798 if (PTR_ERR_OR_ZERO(mnt_root) == -EBUSY) {
1799 if (flags & SB_RDONLY) {
1800 mnt_root = vfs_kern_mount(&btrfs_root_fs_type,
1801 flags & ~SB_RDONLY, device_name, data);
1802 } else {
1803 mnt_root = vfs_kern_mount(&btrfs_root_fs_type,
1804 flags | SB_RDONLY, device_name, data);
1805 if (IS_ERR(mnt_root)) {
1806 root = ERR_CAST(mnt_root);
1807 kfree(subvol_name);
1808 goto out;
1809 }
1810
1811 down_write(&mnt_root->mnt_sb->s_umount);
1812 error = btrfs_remount(mnt_root->mnt_sb, &flags, NULL);
1813 up_write(&mnt_root->mnt_sb->s_umount);
1814 if (error < 0) {
1815 root = ERR_PTR(error);
1816 mntput(mnt_root);
1817 kfree(subvol_name);
1818 goto out;
1819 }
1820 }
1821 }
1822 if (IS_ERR(mnt_root)) {
1823 root = ERR_CAST(mnt_root);
1824 kfree(subvol_name);
1825 goto out;
1826 }
1827
1828 /* mount_subvol() will free subvol_name and mnt_root */
1829 root = mount_subvol(subvol_name, subvol_objectid, mnt_root);
1830
1831out:
1832 return root;
1833}
1834
1835static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1836 u32 new_pool_size, u32 old_pool_size)
1837{
1838 if (new_pool_size == old_pool_size)
1839 return;
1840
1841 fs_info->thread_pool_size = new_pool_size;
1842
1843 btrfs_info(fs_info, "resize thread pool %d -> %d",
1844 old_pool_size, new_pool_size);
1845
1846 btrfs_workqueue_set_max(fs_info->workers, new_pool_size);
1847 btrfs_workqueue_set_max(fs_info->delalloc_workers, new_pool_size);
1848 btrfs_workqueue_set_max(fs_info->caching_workers, new_pool_size);
1849 btrfs_workqueue_set_max(fs_info->endio_workers, new_pool_size);
1850 btrfs_workqueue_set_max(fs_info->endio_meta_workers, new_pool_size);
1851 btrfs_workqueue_set_max(fs_info->endio_meta_write_workers,
1852 new_pool_size);
1853 btrfs_workqueue_set_max(fs_info->endio_write_workers, new_pool_size);
1854 btrfs_workqueue_set_max(fs_info->endio_freespace_worker, new_pool_size);
1855 btrfs_workqueue_set_max(fs_info->delayed_workers, new_pool_size);
1856 btrfs_workqueue_set_max(fs_info->readahead_workers, new_pool_size);
1857 btrfs_workqueue_set_max(fs_info->scrub_wr_completion_workers,
1858 new_pool_size);
1859}
1860
1861static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
1862 unsigned long old_opts, int flags)
1863{
1864 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1865 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1866 (flags & SB_RDONLY))) {
1867 /* wait for any defraggers to finish */
1868 wait_event(fs_info->transaction_wait,
1869 (atomic_read(&fs_info->defrag_running) == 0));
1870 if (flags & SB_RDONLY)
1871 sync_filesystem(fs_info->sb);
1872 }
1873}
1874
1875static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1876 unsigned long old_opts)
1877{
1878 const bool cache_opt = btrfs_test_opt(fs_info, SPACE_CACHE);
1879
1880 /*
1881 * We need to cleanup all defragable inodes if the autodefragment is
1882 * close or the filesystem is read only.
1883 */
1884 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1885 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) || sb_rdonly(fs_info->sb))) {
1886 btrfs_cleanup_defrag_inodes(fs_info);
1887 }
1888
1889 /* If we toggled discard async */
1890 if (!btrfs_raw_test_opt(old_opts, DISCARD_ASYNC) &&
1891 btrfs_test_opt(fs_info, DISCARD_ASYNC))
1892 btrfs_discard_resume(fs_info);
1893 else if (btrfs_raw_test_opt(old_opts, DISCARD_ASYNC) &&
1894 !btrfs_test_opt(fs_info, DISCARD_ASYNC))
1895 btrfs_discard_cleanup(fs_info);
1896
1897 /* If we toggled space cache */
1898 if (cache_opt != btrfs_free_space_cache_v1_active(fs_info))
1899 btrfs_set_free_space_cache_v1_active(fs_info, cache_opt);
1900}
1901
1902static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1903{
1904 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1905 unsigned old_flags = sb->s_flags;
1906 unsigned long old_opts = fs_info->mount_opt;
1907 unsigned long old_compress_type = fs_info->compress_type;
1908 u64 old_max_inline = fs_info->max_inline;
1909 u32 old_thread_pool_size = fs_info->thread_pool_size;
1910 u32 old_metadata_ratio = fs_info->metadata_ratio;
1911 int ret;
1912
1913 sync_filesystem(sb);
1914 set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1915
1916 if (data) {
1917 void *new_sec_opts = NULL;
1918
1919 ret = security_sb_eat_lsm_opts(data, &new_sec_opts);
1920 if (!ret)
1921 ret = security_sb_remount(sb, new_sec_opts);
1922 security_free_mnt_opts(&new_sec_opts);
1923 if (ret)
1924 goto restore;
1925 }
1926
1927 ret = btrfs_parse_options(fs_info, data, *flags);
1928 if (ret)
1929 goto restore;
1930
1931 btrfs_remount_begin(fs_info, old_opts, *flags);
1932 btrfs_resize_thread_pool(fs_info,
1933 fs_info->thread_pool_size, old_thread_pool_size);
1934
1935 if ((bool)btrfs_test_opt(fs_info, FREE_SPACE_TREE) !=
1936 (bool)btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE) &&
1937 (!sb_rdonly(sb) || (*flags & SB_RDONLY))) {
1938 btrfs_warn(fs_info,
1939 "remount supports changing free space tree only from ro to rw");
1940 /* Make sure free space cache options match the state on disk */
1941 if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
1942 btrfs_set_opt(fs_info->mount_opt, FREE_SPACE_TREE);
1943 btrfs_clear_opt(fs_info->mount_opt, SPACE_CACHE);
1944 }
1945 if (btrfs_free_space_cache_v1_active(fs_info)) {
1946 btrfs_clear_opt(fs_info->mount_opt, FREE_SPACE_TREE);
1947 btrfs_set_opt(fs_info->mount_opt, SPACE_CACHE);
1948 }
1949 }
1950
1951 if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1952 goto out;
1953
1954 if (*flags & SB_RDONLY) {
1955 /*
1956 * this also happens on 'umount -rf' or on shutdown, when
1957 * the filesystem is busy.
1958 */
1959 cancel_work_sync(&fs_info->async_reclaim_work);
1960 cancel_work_sync(&fs_info->async_data_reclaim_work);
1961
1962 btrfs_discard_cleanup(fs_info);
1963
1964 /* wait for the uuid_scan task to finish */
1965 down(&fs_info->uuid_tree_rescan_sem);
1966 /* avoid complains from lockdep et al. */
1967 up(&fs_info->uuid_tree_rescan_sem);
1968
1969 btrfs_set_sb_rdonly(sb);
1970
1971 /*
1972 * Setting SB_RDONLY will put the cleaner thread to
1973 * sleep at the next loop if it's already active.
1974 * If it's already asleep, we'll leave unused block
1975 * groups on disk until we're mounted read-write again
1976 * unless we clean them up here.
1977 */
1978 btrfs_delete_unused_bgs(fs_info);
1979
1980 /*
1981 * The cleaner task could be already running before we set the
1982 * flag BTRFS_FS_STATE_RO (and SB_RDONLY in the superblock).
1983 * We must make sure that after we finish the remount, i.e. after
1984 * we call btrfs_commit_super(), the cleaner can no longer start
1985 * a transaction - either because it was dropping a dead root,
1986 * running delayed iputs or deleting an unused block group (the
1987 * cleaner picked a block group from the list of unused block
1988 * groups before we were able to in the previous call to
1989 * btrfs_delete_unused_bgs()).
1990 */
1991 wait_on_bit(&fs_info->flags, BTRFS_FS_CLEANER_RUNNING,
1992 TASK_UNINTERRUPTIBLE);
1993
1994 /*
1995 * We've set the superblock to RO mode, so we might have made
1996 * the cleaner task sleep without running all pending delayed
1997 * iputs. Go through all the delayed iputs here, so that if an
1998 * unmount happens without remounting RW we don't end up at
1999 * finishing close_ctree() with a non-empty list of delayed
2000 * iputs.
2001 */
2002 btrfs_run_delayed_iputs(fs_info);
2003
2004 btrfs_dev_replace_suspend_for_unmount(fs_info);
2005 btrfs_scrub_cancel(fs_info);
2006 btrfs_pause_balance(fs_info);
2007
2008 /*
2009 * Pause the qgroup rescan worker if it is running. We don't want
2010 * it to be still running after we are in RO mode, as after that,
2011 * by the time we unmount, it might have left a transaction open,
2012 * so we would leak the transaction and/or crash.
2013 */
2014 btrfs_qgroup_wait_for_completion(fs_info, false);
2015
2016 ret = btrfs_commit_super(fs_info);
2017 if (ret)
2018 goto restore;
2019 } else {
2020 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
2021 btrfs_err(fs_info,
2022 "Remounting read-write after error is not allowed");
2023 ret = -EINVAL;
2024 goto restore;
2025 }
2026 if (fs_info->fs_devices->rw_devices == 0) {
2027 ret = -EACCES;
2028 goto restore;
2029 }
2030
2031 if (!btrfs_check_rw_degradable(fs_info, NULL)) {
2032 btrfs_warn(fs_info,
2033 "too many missing devices, writable remount is not allowed");
2034 ret = -EACCES;
2035 goto restore;
2036 }
2037
2038 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
2039 btrfs_warn(fs_info,
2040 "mount required to replay tree-log, cannot remount read-write");
2041 ret = -EINVAL;
2042 goto restore;
2043 }
2044 if (fs_info->sectorsize < PAGE_SIZE) {
2045 btrfs_warn(fs_info,
2046 "read-write mount is not yet allowed for sectorsize %u page size %lu",
2047 fs_info->sectorsize, PAGE_SIZE);
2048 ret = -EINVAL;
2049 goto restore;
2050 }
2051
2052 /*
2053 * NOTE: when remounting with a change that does writes, don't
2054 * put it anywhere above this point, as we are not sure to be
2055 * safe to write until we pass the above checks.
2056 */
2057 ret = btrfs_start_pre_rw_mount(fs_info);
2058 if (ret)
2059 goto restore;
2060
2061 btrfs_clear_sb_rdonly(sb);
2062
2063 set_bit(BTRFS_FS_OPEN, &fs_info->flags);
2064 }
2065out:
2066 /*
2067 * We need to set SB_I_VERSION here otherwise it'll get cleared by VFS,
2068 * since the absence of the flag means it can be toggled off by remount.
2069 */
2070 *flags |= SB_I_VERSION;
2071
2072 wake_up_process(fs_info->transaction_kthread);
2073 btrfs_remount_cleanup(fs_info, old_opts);
2074 btrfs_clear_oneshot_options(fs_info);
2075 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
2076
2077 return 0;
2078
2079restore:
2080 /* We've hit an error - don't reset SB_RDONLY */
2081 if (sb_rdonly(sb))
2082 old_flags |= SB_RDONLY;
2083 if (!(old_flags & SB_RDONLY))
2084 clear_bit(BTRFS_FS_STATE_RO, &fs_info->fs_state);
2085 sb->s_flags = old_flags;
2086 fs_info->mount_opt = old_opts;
2087 fs_info->compress_type = old_compress_type;
2088 fs_info->max_inline = old_max_inline;
2089 btrfs_resize_thread_pool(fs_info,
2090 old_thread_pool_size, fs_info->thread_pool_size);
2091 fs_info->metadata_ratio = old_metadata_ratio;
2092 btrfs_remount_cleanup(fs_info, old_opts);
2093 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
2094
2095 return ret;
2096}
2097
2098/* Used to sort the devices by max_avail(descending sort) */
2099static inline int btrfs_cmp_device_free_bytes(const void *dev_info1,
2100 const void *dev_info2)
2101{
2102 if (((struct btrfs_device_info *)dev_info1)->max_avail >
2103 ((struct btrfs_device_info *)dev_info2)->max_avail)
2104 return -1;
2105 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
2106 ((struct btrfs_device_info *)dev_info2)->max_avail)
2107 return 1;
2108 else
2109 return 0;
2110}
2111
2112/*
2113 * sort the devices by max_avail, in which max free extent size of each device
2114 * is stored.(Descending Sort)
2115 */
2116static inline void btrfs_descending_sort_devices(
2117 struct btrfs_device_info *devices,
2118 size_t nr_devices)
2119{
2120 sort(devices, nr_devices, sizeof(struct btrfs_device_info),
2121 btrfs_cmp_device_free_bytes, NULL);
2122}
2123
2124/*
2125 * The helper to calc the free space on the devices that can be used to store
2126 * file data.
2127 */
2128static inline int btrfs_calc_avail_data_space(struct btrfs_fs_info *fs_info,
2129 u64 *free_bytes)
2130{
2131 struct btrfs_device_info *devices_info;
2132 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
2133 struct btrfs_device *device;
2134 u64 type;
2135 u64 avail_space;
2136 u64 min_stripe_size;
2137 int num_stripes = 1;
2138 int i = 0, nr_devices;
2139 const struct btrfs_raid_attr *rattr;
2140
2141 /*
2142 * We aren't under the device list lock, so this is racy-ish, but good
2143 * enough for our purposes.
2144 */
2145 nr_devices = fs_info->fs_devices->open_devices;
2146 if (!nr_devices) {
2147 smp_mb();
2148 nr_devices = fs_info->fs_devices->open_devices;
2149 ASSERT(nr_devices);
2150 if (!nr_devices) {
2151 *free_bytes = 0;
2152 return 0;
2153 }
2154 }
2155
2156 devices_info = kmalloc_array(nr_devices, sizeof(*devices_info),
2157 GFP_KERNEL);
2158 if (!devices_info)
2159 return -ENOMEM;
2160
2161 /* calc min stripe number for data space allocation */
2162 type = btrfs_data_alloc_profile(fs_info);
2163 rattr = &btrfs_raid_array[btrfs_bg_flags_to_raid_index(type)];
2164
2165 if (type & BTRFS_BLOCK_GROUP_RAID0)
2166 num_stripes = nr_devices;
2167 else if (type & BTRFS_BLOCK_GROUP_RAID1)
2168 num_stripes = 2;
2169 else if (type & BTRFS_BLOCK_GROUP_RAID1C3)
2170 num_stripes = 3;
2171 else if (type & BTRFS_BLOCK_GROUP_RAID1C4)
2172 num_stripes = 4;
2173 else if (type & BTRFS_BLOCK_GROUP_RAID10)
2174 num_stripes = 4;
2175
2176 /* Adjust for more than 1 stripe per device */
2177 min_stripe_size = rattr->dev_stripes * BTRFS_STRIPE_LEN;
2178
2179 rcu_read_lock();
2180 list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
2181 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
2182 &device->dev_state) ||
2183 !device->bdev ||
2184 test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state))
2185 continue;
2186
2187 if (i >= nr_devices)
2188 break;
2189
2190 avail_space = device->total_bytes - device->bytes_used;
2191
2192 /* align with stripe_len */
2193 avail_space = rounddown(avail_space, BTRFS_STRIPE_LEN);
2194
2195 /*
2196 * In order to avoid overwriting the superblock on the drive,
2197 * btrfs starts at an offset of at least 1MB when doing chunk
2198 * allocation.
2199 *
2200 * This ensures we have at least min_stripe_size free space
2201 * after excluding 1MB.
2202 */
2203 if (avail_space <= SZ_1M + min_stripe_size)
2204 continue;
2205
2206 avail_space -= SZ_1M;
2207
2208 devices_info[i].dev = device;
2209 devices_info[i].max_avail = avail_space;
2210
2211 i++;
2212 }
2213 rcu_read_unlock();
2214
2215 nr_devices = i;
2216
2217 btrfs_descending_sort_devices(devices_info, nr_devices);
2218
2219 i = nr_devices - 1;
2220 avail_space = 0;
2221 while (nr_devices >= rattr->devs_min) {
2222 num_stripes = min(num_stripes, nr_devices);
2223
2224 if (devices_info[i].max_avail >= min_stripe_size) {
2225 int j;
2226 u64 alloc_size;
2227
2228 avail_space += devices_info[i].max_avail * num_stripes;
2229 alloc_size = devices_info[i].max_avail;
2230 for (j = i + 1 - num_stripes; j <= i; j++)
2231 devices_info[j].max_avail -= alloc_size;
2232 }
2233 i--;
2234 nr_devices--;
2235 }
2236
2237 kfree(devices_info);
2238 *free_bytes = avail_space;
2239 return 0;
2240}
2241
2242/*
2243 * Calculate numbers for 'df', pessimistic in case of mixed raid profiles.
2244 *
2245 * If there's a redundant raid level at DATA block groups, use the respective
2246 * multiplier to scale the sizes.
2247 *
2248 * Unused device space usage is based on simulating the chunk allocator
2249 * algorithm that respects the device sizes and order of allocations. This is
2250 * a close approximation of the actual use but there are other factors that may
2251 * change the result (like a new metadata chunk).
2252 *
2253 * If metadata is exhausted, f_bavail will be 0.
2254 */
2255static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
2256{
2257 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
2258 struct btrfs_super_block *disk_super = fs_info->super_copy;
2259 struct btrfs_space_info *found;
2260 u64 total_used = 0;
2261 u64 total_free_data = 0;
2262 u64 total_free_meta = 0;
2263 u32 bits = fs_info->sectorsize_bits;
2264 __be32 *fsid = (__be32 *)fs_info->fs_devices->fsid;
2265 unsigned factor = 1;
2266 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
2267 int ret;
2268 u64 thresh = 0;
2269 int mixed = 0;
2270
2271 list_for_each_entry(found, &fs_info->space_info, list) {
2272 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
2273 int i;
2274
2275 total_free_data += found->disk_total - found->disk_used;
2276 total_free_data -=
2277 btrfs_account_ro_block_groups_free_space(found);
2278
2279 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
2280 if (!list_empty(&found->block_groups[i]))
2281 factor = btrfs_bg_type_to_factor(
2282 btrfs_raid_array[i].bg_flag);
2283 }
2284 }
2285
2286 /*
2287 * Metadata in mixed block goup profiles are accounted in data
2288 */
2289 if (!mixed && found->flags & BTRFS_BLOCK_GROUP_METADATA) {
2290 if (found->flags & BTRFS_BLOCK_GROUP_DATA)
2291 mixed = 1;
2292 else
2293 total_free_meta += found->disk_total -
2294 found->disk_used;
2295 }
2296
2297 total_used += found->disk_used;
2298 }
2299
2300 buf->f_blocks = div_u64(btrfs_super_total_bytes(disk_super), factor);
2301 buf->f_blocks >>= bits;
2302 buf->f_bfree = buf->f_blocks - (div_u64(total_used, factor) >> bits);
2303
2304 /* Account global block reserve as used, it's in logical size already */
2305 spin_lock(&block_rsv->lock);
2306 /* Mixed block groups accounting is not byte-accurate, avoid overflow */
2307 if (buf->f_bfree >= block_rsv->size >> bits)
2308 buf->f_bfree -= block_rsv->size >> bits;
2309 else
2310 buf->f_bfree = 0;
2311 spin_unlock(&block_rsv->lock);
2312
2313 buf->f_bavail = div_u64(total_free_data, factor);
2314 ret = btrfs_calc_avail_data_space(fs_info, &total_free_data);
2315 if (ret)
2316 return ret;
2317 buf->f_bavail += div_u64(total_free_data, factor);
2318 buf->f_bavail = buf->f_bavail >> bits;
2319
2320 /*
2321 * We calculate the remaining metadata space minus global reserve. If
2322 * this is (supposedly) smaller than zero, there's no space. But this
2323 * does not hold in practice, the exhausted state happens where's still
2324 * some positive delta. So we apply some guesswork and compare the
2325 * delta to a 4M threshold. (Practically observed delta was ~2M.)
2326 *
2327 * We probably cannot calculate the exact threshold value because this
2328 * depends on the internal reservations requested by various
2329 * operations, so some operations that consume a few metadata will
2330 * succeed even if the Avail is zero. But this is better than the other
2331 * way around.
2332 */
2333 thresh = SZ_4M;
2334
2335 /*
2336 * We only want to claim there's no available space if we can no longer
2337 * allocate chunks for our metadata profile and our global reserve will
2338 * not fit in the free metadata space. If we aren't ->full then we
2339 * still can allocate chunks and thus are fine using the currently
2340 * calculated f_bavail.
2341 */
2342 if (!mixed && block_rsv->space_info->full &&
2343 total_free_meta - thresh < block_rsv->size)
2344 buf->f_bavail = 0;
2345
2346 buf->f_type = BTRFS_SUPER_MAGIC;
2347 buf->f_bsize = dentry->d_sb->s_blocksize;
2348 buf->f_namelen = BTRFS_NAME_LEN;
2349
2350 /* We treat it as constant endianness (it doesn't matter _which_)
2351 because we want the fsid to come out the same whether mounted
2352 on a big-endian or little-endian host */
2353 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
2354 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
2355 /* Mask in the root object ID too, to disambiguate subvols */
2356 buf->f_fsid.val[0] ^=
2357 BTRFS_I(d_inode(dentry))->root->root_key.objectid >> 32;
2358 buf->f_fsid.val[1] ^=
2359 BTRFS_I(d_inode(dentry))->root->root_key.objectid;
2360
2361 return 0;
2362}
2363
2364static void btrfs_kill_super(struct super_block *sb)
2365{
2366 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2367 kill_anon_super(sb);
2368 btrfs_free_fs_info(fs_info);
2369}
2370
2371static struct file_system_type btrfs_fs_type = {
2372 .owner = THIS_MODULE,
2373 .name = "btrfs",
2374 .mount = btrfs_mount,
2375 .kill_sb = btrfs_kill_super,
2376 .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA,
2377};
2378
2379static struct file_system_type btrfs_root_fs_type = {
2380 .owner = THIS_MODULE,
2381 .name = "btrfs",
2382 .mount = btrfs_mount_root,
2383 .kill_sb = btrfs_kill_super,
2384 .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA,
2385};
2386
2387MODULE_ALIAS_FS("btrfs");
2388
2389static int btrfs_control_open(struct inode *inode, struct file *file)
2390{
2391 /*
2392 * The control file's private_data is used to hold the
2393 * transaction when it is started and is used to keep
2394 * track of whether a transaction is already in progress.
2395 */
2396 file->private_data = NULL;
2397 return 0;
2398}
2399
2400/*
2401 * Used by /dev/btrfs-control for devices ioctls.
2402 */
2403static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
2404 unsigned long arg)
2405{
2406 struct btrfs_ioctl_vol_args *vol;
2407 struct btrfs_device *device = NULL;
2408 int ret = -ENOTTY;
2409
2410 if (!capable(CAP_SYS_ADMIN))
2411 return -EPERM;
2412
2413 vol = memdup_user((void __user *)arg, sizeof(*vol));
2414 if (IS_ERR(vol))
2415 return PTR_ERR(vol);
2416 vol->name[BTRFS_PATH_NAME_MAX] = '\0';
2417
2418 switch (cmd) {
2419 case BTRFS_IOC_SCAN_DEV:
2420 mutex_lock(&uuid_mutex);
2421 device = btrfs_scan_one_device(vol->name, FMODE_READ,
2422 &btrfs_root_fs_type);
2423 ret = PTR_ERR_OR_ZERO(device);
2424 mutex_unlock(&uuid_mutex);
2425 break;
2426 case BTRFS_IOC_FORGET_DEV:
2427 ret = btrfs_forget_devices(vol->name);
2428 break;
2429 case BTRFS_IOC_DEVICES_READY:
2430 mutex_lock(&uuid_mutex);
2431 device = btrfs_scan_one_device(vol->name, FMODE_READ,
2432 &btrfs_root_fs_type);
2433 if (IS_ERR(device)) {
2434 mutex_unlock(&uuid_mutex);
2435 ret = PTR_ERR(device);
2436 break;
2437 }
2438 ret = !(device->fs_devices->num_devices ==
2439 device->fs_devices->total_devices);
2440 mutex_unlock(&uuid_mutex);
2441 break;
2442 case BTRFS_IOC_GET_SUPPORTED_FEATURES:
2443 ret = btrfs_ioctl_get_supported_features((void __user*)arg);
2444 break;
2445 }
2446
2447 kfree(vol);
2448 return ret;
2449}
2450
2451static int btrfs_freeze(struct super_block *sb)
2452{
2453 struct btrfs_trans_handle *trans;
2454 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2455 struct btrfs_root *root = fs_info->tree_root;
2456
2457 set_bit(BTRFS_FS_FROZEN, &fs_info->flags);
2458 /*
2459 * We don't need a barrier here, we'll wait for any transaction that
2460 * could be in progress on other threads (and do delayed iputs that
2461 * we want to avoid on a frozen filesystem), or do the commit
2462 * ourselves.
2463 */
2464 trans = btrfs_attach_transaction_barrier(root);
2465 if (IS_ERR(trans)) {
2466 /* no transaction, don't bother */
2467 if (PTR_ERR(trans) == -ENOENT)
2468 return 0;
2469 return PTR_ERR(trans);
2470 }
2471 return btrfs_commit_transaction(trans);
2472}
2473
2474static int btrfs_unfreeze(struct super_block *sb)
2475{
2476 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2477
2478 clear_bit(BTRFS_FS_FROZEN, &fs_info->flags);
2479 return 0;
2480}
2481
2482static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
2483{
2484 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
2485 struct btrfs_device *dev, *first_dev = NULL;
2486
2487 /*
2488 * Lightweight locking of the devices. We should not need
2489 * device_list_mutex here as we only read the device data and the list
2490 * is protected by RCU. Even if a device is deleted during the list
2491 * traversals, we'll get valid data, the freeing callback will wait at
2492 * least until the rcu_read_unlock.
2493 */
2494 rcu_read_lock();
2495 list_for_each_entry_rcu(dev, &fs_info->fs_devices->devices, dev_list) {
2496 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state))
2497 continue;
2498 if (!dev->name)
2499 continue;
2500 if (!first_dev || dev->devid < first_dev->devid)
2501 first_dev = dev;
2502 }
2503
2504 if (first_dev)
2505 seq_escape(m, rcu_str_deref(first_dev->name), " \t\n\\");
2506 else
2507 WARN_ON(1);
2508 rcu_read_unlock();
2509 return 0;
2510}
2511
2512static const struct super_operations btrfs_super_ops = {
2513 .drop_inode = btrfs_drop_inode,
2514 .evict_inode = btrfs_evict_inode,
2515 .put_super = btrfs_put_super,
2516 .sync_fs = btrfs_sync_fs,
2517 .show_options = btrfs_show_options,
2518 .show_devname = btrfs_show_devname,
2519 .alloc_inode = btrfs_alloc_inode,
2520 .destroy_inode = btrfs_destroy_inode,
2521 .free_inode = btrfs_free_inode,
2522 .statfs = btrfs_statfs,
2523 .remount_fs = btrfs_remount,
2524 .freeze_fs = btrfs_freeze,
2525 .unfreeze_fs = btrfs_unfreeze,
2526};
2527
2528static const struct file_operations btrfs_ctl_fops = {
2529 .open = btrfs_control_open,
2530 .unlocked_ioctl = btrfs_control_ioctl,
2531 .compat_ioctl = compat_ptr_ioctl,
2532 .owner = THIS_MODULE,
2533 .llseek = noop_llseek,
2534};
2535
2536static struct miscdevice btrfs_misc = {
2537 .minor = BTRFS_MINOR,
2538 .name = "btrfs-control",
2539 .fops = &btrfs_ctl_fops
2540};
2541
2542MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
2543MODULE_ALIAS("devname:btrfs-control");
2544
2545static int __init btrfs_interface_init(void)
2546{
2547 return misc_register(&btrfs_misc);
2548}
2549
2550static __cold void btrfs_interface_exit(void)
2551{
2552 misc_deregister(&btrfs_misc);
2553}
2554
2555static void __init btrfs_print_mod_info(void)
2556{
2557 static const char options[] = ""
2558#ifdef CONFIG_BTRFS_DEBUG
2559 ", debug=on"
2560#endif
2561#ifdef CONFIG_BTRFS_ASSERT
2562 ", assert=on"
2563#endif
2564#ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2565 ", integrity-checker=on"
2566#endif
2567#ifdef CONFIG_BTRFS_FS_REF_VERIFY
2568 ", ref-verify=on"
2569#endif
2570#ifdef CONFIG_BLK_DEV_ZONED
2571 ", zoned=yes"
2572#else
2573 ", zoned=no"
2574#endif
2575 ;
2576 pr_info("Btrfs loaded, crc32c=%s%s\n", crc32c_impl(), options);
2577}
2578
2579static int __init init_btrfs_fs(void)
2580{
2581 int err;
2582
2583 btrfs_props_init();
2584
2585 err = btrfs_init_sysfs();
2586 if (err)
2587 return err;
2588
2589 btrfs_init_compress();
2590
2591 err = btrfs_init_cachep();
2592 if (err)
2593 goto free_compress;
2594
2595 err = extent_io_init();
2596 if (err)
2597 goto free_cachep;
2598
2599 err = extent_state_cache_init();
2600 if (err)
2601 goto free_extent_io;
2602
2603 err = extent_map_init();
2604 if (err)
2605 goto free_extent_state_cache;
2606
2607 err = ordered_data_init();
2608 if (err)
2609 goto free_extent_map;
2610
2611 err = btrfs_delayed_inode_init();
2612 if (err)
2613 goto free_ordered_data;
2614
2615 err = btrfs_auto_defrag_init();
2616 if (err)
2617 goto free_delayed_inode;
2618
2619 err = btrfs_delayed_ref_init();
2620 if (err)
2621 goto free_auto_defrag;
2622
2623 err = btrfs_prelim_ref_init();
2624 if (err)
2625 goto free_delayed_ref;
2626
2627 err = btrfs_end_io_wq_init();
2628 if (err)
2629 goto free_prelim_ref;
2630
2631 err = btrfs_interface_init();
2632 if (err)
2633 goto free_end_io_wq;
2634
2635 btrfs_print_mod_info();
2636
2637 err = btrfs_run_sanity_tests();
2638 if (err)
2639 goto unregister_ioctl;
2640
2641 err = register_filesystem(&btrfs_fs_type);
2642 if (err)
2643 goto unregister_ioctl;
2644
2645 return 0;
2646
2647unregister_ioctl:
2648 btrfs_interface_exit();
2649free_end_io_wq:
2650 btrfs_end_io_wq_exit();
2651free_prelim_ref:
2652 btrfs_prelim_ref_exit();
2653free_delayed_ref:
2654 btrfs_delayed_ref_exit();
2655free_auto_defrag:
2656 btrfs_auto_defrag_exit();
2657free_delayed_inode:
2658 btrfs_delayed_inode_exit();
2659free_ordered_data:
2660 ordered_data_exit();
2661free_extent_map:
2662 extent_map_exit();
2663free_extent_state_cache:
2664 extent_state_cache_exit();
2665free_extent_io:
2666 extent_io_exit();
2667free_cachep:
2668 btrfs_destroy_cachep();
2669free_compress:
2670 btrfs_exit_compress();
2671 btrfs_exit_sysfs();
2672
2673 return err;
2674}
2675
2676static void __exit exit_btrfs_fs(void)
2677{
2678 btrfs_destroy_cachep();
2679 btrfs_delayed_ref_exit();
2680 btrfs_auto_defrag_exit();
2681 btrfs_delayed_inode_exit();
2682 btrfs_prelim_ref_exit();
2683 ordered_data_exit();
2684 extent_map_exit();
2685 extent_state_cache_exit();
2686 extent_io_exit();
2687 btrfs_interface_exit();
2688 btrfs_end_io_wq_exit();
2689 unregister_filesystem(&btrfs_fs_type);
2690 btrfs_exit_sysfs();
2691 btrfs_cleanup_fs_uuids();
2692 btrfs_exit_compress();
2693}
2694
2695late_initcall(init_btrfs_fs);
2696module_exit(exit_btrfs_fs)
2697
2698MODULE_LICENSE("GPL");
2699MODULE_SOFTDEP("pre: crc32c");
2700MODULE_SOFTDEP("pre: xxhash64");
2701MODULE_SOFTDEP("pre: sha256");
2702MODULE_SOFTDEP("pre: blake2b-256");