2 * Copyright (C) 2007 Oracle. All rights reserved.
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.
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.
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.
19 #include <linux/blkdev.h>
20 #include <linux/module.h>
21 #include <linux/buffer_head.h>
23 #include <linux/pagemap.h>
24 #include <linux/highmem.h>
25 #include <linux/time.h>
26 #include <linux/init.h>
27 #include <linux/seq_file.h>
28 #include <linux/string.h>
29 #include <linux/backing-dev.h>
30 #include <linux/mount.h>
31 #include <linux/mpage.h>
32 #include <linux/swap.h>
33 #include <linux/writeback.h>
34 #include <linux/statfs.h>
35 #include <linux/compat.h>
36 #include <linux/parser.h>
37 #include <linux/ctype.h>
38 #include <linux/namei.h>
39 #include <linux/miscdevice.h>
40 #include <linux/magic.h>
41 #include <linux/slab.h>
42 #include <linux/cleancache.h>
43 #include <linux/ratelimit.h>
44 #include <linux/btrfs.h>
45 #include "delayed-inode.h"
48 #include "transaction.h"
49 #include "btrfs_inode.h"
50 #include "print-tree.h"
56 #include "compression.h"
57 #include "rcu-string.h"
58 #include "dev-replace.h"
59 #include "free-space-cache.h"
61 #include "tests/btrfs-tests.h"
64 #define CREATE_TRACE_POINTS
65 #include <trace/events/btrfs.h>
67 static const struct super_operations btrfs_super_ops;
68 static struct file_system_type btrfs_fs_type;
70 static int btrfs_remount(struct super_block *sb, int *flags, char *data);
72 static const char *btrfs_decode_error(int errno)
74 char *errstr = "unknown";
78 errstr = "IO failure";
81 errstr = "Out of memory";
84 errstr = "Readonly filesystem";
87 errstr = "Object already exists";
90 errstr = "No space left";
93 errstr = "No such entry";
100 static void save_error_info(struct btrfs_fs_info *fs_info)
103 * today we only save the error info into ram. Long term we'll
104 * also send it down to the disk
106 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
109 /* btrfs handle error by forcing the filesystem readonly */
110 static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
112 struct super_block *sb = fs_info->sb;
114 if (sb->s_flags & MS_RDONLY)
117 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
118 sb->s_flags |= MS_RDONLY;
119 btrfs_info(fs_info, "forced readonly");
121 * Note that a running device replace operation is not
122 * canceled here although there is no way to update
123 * the progress. It would add the risk of a deadlock,
124 * therefore the canceling is ommited. The only penalty
125 * is that some I/O remains active until the procedure
126 * completes. The next time when the filesystem is
127 * mounted writeable again, the device replace
128 * operation continues.
135 * __btrfs_std_error decodes expected errors from the caller and
136 * invokes the approciate error response.
139 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
140 unsigned int line, int errno, const char *fmt, ...)
142 struct super_block *sb = fs_info->sb;
146 * Special case: if the error is EROFS, and we're already
147 * under MS_RDONLY, then it is safe here.
149 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
152 errstr = btrfs_decode_error(errno);
154 struct va_format vaf;
162 "BTRFS: error (device %s) in %s:%d: errno=%d %s (%pV)\n",
163 sb->s_id, function, line, errno, errstr, &vaf);
166 printk(KERN_CRIT "BTRFS: error (device %s) in %s:%d: errno=%d %s\n",
167 sb->s_id, function, line, errno, errstr);
170 /* Don't go through full error handling during mount */
171 save_error_info(fs_info);
172 if (sb->s_flags & MS_BORN)
173 btrfs_handle_error(fs_info);
176 static const char * const logtypes[] = {
187 void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
189 struct super_block *sb = fs_info->sb;
191 struct va_format vaf;
193 const char *type = logtypes[4];
198 kern_level = printk_get_level(fmt);
200 size_t size = printk_skip_level(fmt) - fmt;
201 memcpy(lvl, fmt, size);
204 type = logtypes[kern_level - '0'];
211 printk("%sBTRFS %s (device %s): %pV\n", lvl, type, sb->s_id, &vaf);
218 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
219 unsigned int line, int errno, const char *fmt, ...)
221 struct super_block *sb = fs_info->sb;
224 * Special case: if the error is EROFS, and we're already
225 * under MS_RDONLY, then it is safe here.
227 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
230 /* Don't go through full error handling during mount */
231 if (sb->s_flags & MS_BORN) {
232 save_error_info(fs_info);
233 btrfs_handle_error(fs_info);
239 * We only mark the transaction aborted and then set the file system read-only.
240 * This will prevent new transactions from starting or trying to join this
243 * This means that error recovery at the call site is limited to freeing
244 * any local memory allocations and passing the error code up without
245 * further cleanup. The transaction should complete as it normally would
246 * in the call path but will return -EIO.
248 * We'll complete the cleanup in btrfs_end_transaction and
249 * btrfs_commit_transaction.
252 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
253 struct btrfs_root *root, const char *function,
254 unsigned int line, int errno)
256 trans->aborted = errno;
257 /* Nothing used. The other threads that have joined this
258 * transaction may be able to continue. */
259 if (!trans->blocks_used && list_empty(&trans->new_bgs)) {
262 errstr = btrfs_decode_error(errno);
263 btrfs_warn(root->fs_info,
264 "%s:%d: Aborting unused transaction(%s).",
265 function, line, errstr);
268 ACCESS_ONCE(trans->transaction->aborted) = errno;
269 /* Wake up anybody who may be waiting on this transaction */
270 wake_up(&root->fs_info->transaction_wait);
271 wake_up(&root->fs_info->transaction_blocked_wait);
272 __btrfs_std_error(root->fs_info, function, line, errno, NULL);
275 * __btrfs_panic decodes unexpected, fatal errors from the caller,
276 * issues an alert, and either panics or BUGs, depending on mount options.
279 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
280 unsigned int line, int errno, const char *fmt, ...)
282 char *s_id = "<unknown>";
284 struct va_format vaf = { .fmt = fmt };
288 s_id = fs_info->sb->s_id;
293 errstr = btrfs_decode_error(errno);
294 if (fs_info && (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR))
295 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
296 s_id, function, line, &vaf, errno, errstr);
298 btrfs_crit(fs_info, "panic in %s:%d: %pV (errno=%d %s)",
299 function, line, &vaf, errno, errstr);
301 /* Caller calls BUG() */
304 static void btrfs_put_super(struct super_block *sb)
306 close_ctree(btrfs_sb(sb)->tree_root);
310 Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
311 Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
312 Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
313 Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
314 Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
315 Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
316 Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_inode_cache,
317 Opt_no_space_cache, Opt_recovery, Opt_skip_balance,
318 Opt_check_integrity, Opt_check_integrity_including_extent_data,
319 Opt_check_integrity_print_mask, Opt_fatal_errors, Opt_rescan_uuid_tree,
320 Opt_commit_interval, Opt_barrier, Opt_nodefrag, Opt_nodiscard,
321 Opt_noenospc_debug, Opt_noflushoncommit, Opt_acl, Opt_datacow,
322 Opt_datasum, Opt_treelog, Opt_noinode_cache,
326 static match_table_t tokens = {
327 {Opt_degraded, "degraded"},
328 {Opt_subvol, "subvol=%s"},
329 {Opt_subvolid, "subvolid=%s"},
330 {Opt_device, "device=%s"},
331 {Opt_nodatasum, "nodatasum"},
332 {Opt_datasum, "datasum"},
333 {Opt_nodatacow, "nodatacow"},
334 {Opt_datacow, "datacow"},
335 {Opt_nobarrier, "nobarrier"},
336 {Opt_barrier, "barrier"},
337 {Opt_max_inline, "max_inline=%s"},
338 {Opt_alloc_start, "alloc_start=%s"},
339 {Opt_thread_pool, "thread_pool=%d"},
340 {Opt_compress, "compress"},
341 {Opt_compress_type, "compress=%s"},
342 {Opt_compress_force, "compress-force"},
343 {Opt_compress_force_type, "compress-force=%s"},
345 {Opt_ssd_spread, "ssd_spread"},
346 {Opt_nossd, "nossd"},
348 {Opt_noacl, "noacl"},
349 {Opt_notreelog, "notreelog"},
350 {Opt_treelog, "treelog"},
351 {Opt_flushoncommit, "flushoncommit"},
352 {Opt_noflushoncommit, "noflushoncommit"},
353 {Opt_ratio, "metadata_ratio=%d"},
354 {Opt_discard, "discard"},
355 {Opt_nodiscard, "nodiscard"},
356 {Opt_space_cache, "space_cache"},
357 {Opt_clear_cache, "clear_cache"},
358 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
359 {Opt_enospc_debug, "enospc_debug"},
360 {Opt_noenospc_debug, "noenospc_debug"},
361 {Opt_subvolrootid, "subvolrootid=%d"},
362 {Opt_defrag, "autodefrag"},
363 {Opt_nodefrag, "noautodefrag"},
364 {Opt_inode_cache, "inode_cache"},
365 {Opt_noinode_cache, "noinode_cache"},
366 {Opt_no_space_cache, "nospace_cache"},
367 {Opt_recovery, "recovery"},
368 {Opt_skip_balance, "skip_balance"},
369 {Opt_check_integrity, "check_int"},
370 {Opt_check_integrity_including_extent_data, "check_int_data"},
371 {Opt_check_integrity_print_mask, "check_int_print_mask=%d"},
372 {Opt_rescan_uuid_tree, "rescan_uuid_tree"},
373 {Opt_fatal_errors, "fatal_errors=%s"},
374 {Opt_commit_interval, "commit=%d"},
379 * Regular mount options parser. Everything that is needed only when
380 * reading in a new superblock is parsed here.
381 * XXX JDM: This needs to be cleaned up for remount.
383 int btrfs_parse_options(struct btrfs_root *root, char *options)
385 struct btrfs_fs_info *info = root->fs_info;
386 substring_t args[MAX_OPT_ARGS];
387 char *p, *num, *orig = NULL;
392 bool compress_force = false;
394 cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
396 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
402 * strsep changes the string, duplicate it because parse_options
405 options = kstrdup(options, GFP_NOFS);
411 while ((p = strsep(&options, ",")) != NULL) {
416 token = match_token(p, tokens, args);
419 btrfs_info(root->fs_info, "allowing degraded mounts");
420 btrfs_set_opt(info->mount_opt, DEGRADED);
424 case Opt_subvolrootid:
427 * These are parsed by btrfs_parse_early_options
428 * and can be happily ignored here.
432 btrfs_set_and_info(root, NODATASUM,
433 "setting nodatasum");
436 if (btrfs_test_opt(root, NODATASUM)) {
437 if (btrfs_test_opt(root, NODATACOW))
438 btrfs_info(root->fs_info, "setting datasum, datacow enabled");
440 btrfs_info(root->fs_info, "setting datasum");
442 btrfs_clear_opt(info->mount_opt, NODATACOW);
443 btrfs_clear_opt(info->mount_opt, NODATASUM);
446 if (!btrfs_test_opt(root, NODATACOW)) {
447 if (!btrfs_test_opt(root, COMPRESS) ||
448 !btrfs_test_opt(root, FORCE_COMPRESS)) {
449 btrfs_info(root->fs_info,
450 "setting nodatacow, compression disabled");
452 btrfs_info(root->fs_info, "setting nodatacow");
455 btrfs_clear_opt(info->mount_opt, COMPRESS);
456 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
457 btrfs_set_opt(info->mount_opt, NODATACOW);
458 btrfs_set_opt(info->mount_opt, NODATASUM);
461 btrfs_clear_and_info(root, NODATACOW,
464 case Opt_compress_force:
465 case Opt_compress_force_type:
466 compress_force = true;
469 case Opt_compress_type:
470 if (token == Opt_compress ||
471 token == Opt_compress_force ||
472 strcmp(args[0].from, "zlib") == 0) {
473 compress_type = "zlib";
474 info->compress_type = BTRFS_COMPRESS_ZLIB;
475 btrfs_set_opt(info->mount_opt, COMPRESS);
476 btrfs_clear_opt(info->mount_opt, NODATACOW);
477 btrfs_clear_opt(info->mount_opt, NODATASUM);
478 } else if (strcmp(args[0].from, "lzo") == 0) {
479 compress_type = "lzo";
480 info->compress_type = BTRFS_COMPRESS_LZO;
481 btrfs_set_opt(info->mount_opt, COMPRESS);
482 btrfs_clear_opt(info->mount_opt, NODATACOW);
483 btrfs_clear_opt(info->mount_opt, NODATASUM);
484 btrfs_set_fs_incompat(info, COMPRESS_LZO);
485 } else if (strncmp(args[0].from, "no", 2) == 0) {
486 compress_type = "no";
487 btrfs_clear_opt(info->mount_opt, COMPRESS);
488 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
489 compress_force = false;
495 if (compress_force) {
496 btrfs_set_and_info(root, FORCE_COMPRESS,
497 "force %s compression",
500 if (!btrfs_test_opt(root, COMPRESS))
501 btrfs_info(root->fs_info,
502 "btrfs: use %s compression",
505 * If we remount from compress-force=xxx to
506 * compress=xxx, we need clear FORCE_COMPRESS
507 * flag, otherwise, there is no way for users
508 * to disable forcible compression separately.
510 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
514 btrfs_set_and_info(root, SSD,
515 "use ssd allocation scheme");
518 btrfs_set_and_info(root, SSD_SPREAD,
519 "use spread ssd allocation scheme");
520 btrfs_set_opt(info->mount_opt, SSD);
523 btrfs_set_and_info(root, NOSSD,
524 "not using ssd allocation scheme");
525 btrfs_clear_opt(info->mount_opt, SSD);
528 btrfs_clear_and_info(root, NOBARRIER,
529 "turning on barriers");
532 btrfs_set_and_info(root, NOBARRIER,
533 "turning off barriers");
535 case Opt_thread_pool:
536 ret = match_int(&args[0], &intarg);
539 } else if (intarg > 0) {
540 info->thread_pool_size = intarg;
547 num = match_strdup(&args[0]);
549 info->max_inline = memparse(num, NULL);
552 if (info->max_inline) {
553 info->max_inline = min_t(u64,
557 btrfs_info(root->fs_info, "max_inline at %llu",
564 case Opt_alloc_start:
565 num = match_strdup(&args[0]);
567 mutex_lock(&info->chunk_mutex);
568 info->alloc_start = memparse(num, NULL);
569 mutex_unlock(&info->chunk_mutex);
571 btrfs_info(root->fs_info, "allocations start at %llu",
579 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
580 root->fs_info->sb->s_flags |= MS_POSIXACL;
583 btrfs_err(root->fs_info,
584 "support for ACL not compiled in!");
589 root->fs_info->sb->s_flags &= ~MS_POSIXACL;
592 btrfs_set_and_info(root, NOTREELOG,
593 "disabling tree log");
596 btrfs_clear_and_info(root, NOTREELOG,
597 "enabling tree log");
599 case Opt_flushoncommit:
600 btrfs_set_and_info(root, FLUSHONCOMMIT,
601 "turning on flush-on-commit");
603 case Opt_noflushoncommit:
604 btrfs_clear_and_info(root, FLUSHONCOMMIT,
605 "turning off flush-on-commit");
608 ret = match_int(&args[0], &intarg);
611 } else if (intarg >= 0) {
612 info->metadata_ratio = intarg;
613 btrfs_info(root->fs_info, "metadata ratio %d",
614 info->metadata_ratio);
621 btrfs_set_and_info(root, DISCARD,
622 "turning on discard");
625 btrfs_clear_and_info(root, DISCARD,
626 "turning off discard");
628 case Opt_space_cache:
629 btrfs_set_and_info(root, SPACE_CACHE,
630 "enabling disk space caching");
632 case Opt_rescan_uuid_tree:
633 btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE);
635 case Opt_no_space_cache:
636 btrfs_clear_and_info(root, SPACE_CACHE,
637 "disabling disk space caching");
639 case Opt_inode_cache:
640 btrfs_set_pending_and_info(info, INODE_MAP_CACHE,
641 "enabling inode map caching");
643 case Opt_noinode_cache:
644 btrfs_clear_pending_and_info(info, INODE_MAP_CACHE,
645 "disabling inode map caching");
647 case Opt_clear_cache:
648 btrfs_set_and_info(root, CLEAR_CACHE,
649 "force clearing of disk cache");
651 case Opt_user_subvol_rm_allowed:
652 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
654 case Opt_enospc_debug:
655 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
657 case Opt_noenospc_debug:
658 btrfs_clear_opt(info->mount_opt, ENOSPC_DEBUG);
661 btrfs_set_and_info(root, AUTO_DEFRAG,
662 "enabling auto defrag");
665 btrfs_clear_and_info(root, AUTO_DEFRAG,
666 "disabling auto defrag");
669 btrfs_info(root->fs_info, "enabling auto recovery");
670 btrfs_set_opt(info->mount_opt, RECOVERY);
672 case Opt_skip_balance:
673 btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
675 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
676 case Opt_check_integrity_including_extent_data:
677 btrfs_info(root->fs_info,
678 "enabling check integrity including extent data");
679 btrfs_set_opt(info->mount_opt,
680 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
681 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
683 case Opt_check_integrity:
684 btrfs_info(root->fs_info, "enabling check integrity");
685 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
687 case Opt_check_integrity_print_mask:
688 ret = match_int(&args[0], &intarg);
691 } else if (intarg >= 0) {
692 info->check_integrity_print_mask = intarg;
693 btrfs_info(root->fs_info, "check_integrity_print_mask 0x%x",
694 info->check_integrity_print_mask);
701 case Opt_check_integrity_including_extent_data:
702 case Opt_check_integrity:
703 case Opt_check_integrity_print_mask:
704 btrfs_err(root->fs_info,
705 "support for check_integrity* not compiled in!");
709 case Opt_fatal_errors:
710 if (strcmp(args[0].from, "panic") == 0)
711 btrfs_set_opt(info->mount_opt,
712 PANIC_ON_FATAL_ERROR);
713 else if (strcmp(args[0].from, "bug") == 0)
714 btrfs_clear_opt(info->mount_opt,
715 PANIC_ON_FATAL_ERROR);
721 case Opt_commit_interval:
723 ret = match_int(&args[0], &intarg);
725 btrfs_err(root->fs_info, "invalid commit interval");
731 btrfs_warn(root->fs_info, "excessive commit interval %d",
734 info->commit_interval = intarg;
736 btrfs_info(root->fs_info, "using default commit interval %ds",
737 BTRFS_DEFAULT_COMMIT_INTERVAL);
738 info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
742 btrfs_info(root->fs_info, "unrecognized mount option '%s'", p);
750 if (!ret && btrfs_test_opt(root, SPACE_CACHE))
751 btrfs_info(root->fs_info, "disk space caching is enabled");
757 * Parse mount options that are required early in the mount process.
759 * All other options will be parsed on much later in the mount process and
760 * only when we need to allocate a new super block.
762 static int btrfs_parse_early_options(const char *options, fmode_t flags,
763 void *holder, char **subvol_name, u64 *subvol_objectid,
764 struct btrfs_fs_devices **fs_devices)
766 substring_t args[MAX_OPT_ARGS];
767 char *device_name, *opts, *orig, *p;
775 * strsep changes the string, duplicate it because parse_options
778 opts = kstrdup(options, GFP_KERNEL);
783 while ((p = strsep(&opts, ",")) != NULL) {
788 token = match_token(p, tokens, args);
792 *subvol_name = match_strdup(&args[0]);
799 num = match_strdup(&args[0]);
801 *subvol_objectid = memparse(num, NULL);
803 /* we want the original fs_tree */
804 if (!*subvol_objectid)
806 BTRFS_FS_TREE_OBJECTID;
812 case Opt_subvolrootid:
814 "BTRFS: 'subvolrootid' mount option is deprecated and has "
818 device_name = match_strdup(&args[0]);
823 error = btrfs_scan_one_device(device_name,
824 flags, holder, fs_devices);
839 static struct dentry *get_default_root(struct super_block *sb,
842 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
843 struct btrfs_root *root = fs_info->tree_root;
844 struct btrfs_root *new_root;
845 struct btrfs_dir_item *di;
846 struct btrfs_path *path;
847 struct btrfs_key location;
853 * We have a specific subvol we want to mount, just setup location and
854 * go look up the root.
856 if (subvol_objectid) {
857 location.objectid = subvol_objectid;
858 location.type = BTRFS_ROOT_ITEM_KEY;
859 location.offset = (u64)-1;
863 path = btrfs_alloc_path();
865 return ERR_PTR(-ENOMEM);
866 path->leave_spinning = 1;
869 * Find the "default" dir item which points to the root item that we
870 * will mount by default if we haven't been given a specific subvolume
873 dir_id = btrfs_super_root_dir(fs_info->super_copy);
874 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
876 btrfs_free_path(path);
881 * Ok the default dir item isn't there. This is weird since
882 * it's always been there, but don't freak out, just try and
883 * mount to root most subvolume.
885 btrfs_free_path(path);
886 dir_id = BTRFS_FIRST_FREE_OBJECTID;
887 new_root = fs_info->fs_root;
891 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
892 btrfs_free_path(path);
895 new_root = btrfs_read_fs_root_no_name(fs_info, &location);
896 if (IS_ERR(new_root))
897 return ERR_CAST(new_root);
899 if (!(sb->s_flags & MS_RDONLY)) {
901 down_read(&fs_info->cleanup_work_sem);
902 ret = btrfs_orphan_cleanup(new_root);
903 up_read(&fs_info->cleanup_work_sem);
908 dir_id = btrfs_root_dirid(&new_root->root_item);
910 location.objectid = dir_id;
911 location.type = BTRFS_INODE_ITEM_KEY;
914 inode = btrfs_iget(sb, &location, new_root, &new);
916 return ERR_CAST(inode);
919 * If we're just mounting the root most subvol put the inode and return
920 * a reference to the dentry. We will have already gotten a reference
921 * to the inode in btrfs_fill_super so we're good to go.
923 if (!new && d_inode(sb->s_root) == inode) {
925 return dget(sb->s_root);
928 return d_obtain_root(inode);
931 static int btrfs_fill_super(struct super_block *sb,
932 struct btrfs_fs_devices *fs_devices,
933 void *data, int silent)
936 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
937 struct btrfs_key key;
940 sb->s_maxbytes = MAX_LFS_FILESIZE;
941 sb->s_magic = BTRFS_SUPER_MAGIC;
942 sb->s_op = &btrfs_super_ops;
943 sb->s_d_op = &btrfs_dentry_operations;
944 sb->s_export_op = &btrfs_export_ops;
945 sb->s_xattr = btrfs_xattr_handlers;
947 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
948 sb->s_flags |= MS_POSIXACL;
950 sb->s_flags |= MS_I_VERSION;
951 err = open_ctree(sb, fs_devices, (char *)data);
953 printk(KERN_ERR "BTRFS: open_ctree failed\n");
957 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
958 key.type = BTRFS_INODE_ITEM_KEY;
960 inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
962 err = PTR_ERR(inode);
966 sb->s_root = d_make_root(inode);
972 save_mount_options(sb, data);
973 cleancache_init_fs(sb);
974 sb->s_flags |= MS_ACTIVE;
978 close_ctree(fs_info->tree_root);
982 int btrfs_sync_fs(struct super_block *sb, int wait)
984 struct btrfs_trans_handle *trans;
985 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
986 struct btrfs_root *root = fs_info->tree_root;
988 trace_btrfs_sync_fs(wait);
991 filemap_flush(fs_info->btree_inode->i_mapping);
995 btrfs_wait_ordered_roots(fs_info, -1);
997 trans = btrfs_attach_transaction_barrier(root);
999 /* no transaction, don't bother */
1000 if (PTR_ERR(trans) == -ENOENT) {
1002 * Exit unless we have some pending changes
1003 * that need to go through commit
1005 if (fs_info->pending_changes == 0)
1008 * A non-blocking test if the fs is frozen. We must not
1009 * start a new transaction here otherwise a deadlock
1010 * happens. The pending operations are delayed to the
1011 * next commit after thawing.
1013 if (__sb_start_write(sb, SB_FREEZE_WRITE, false))
1014 __sb_end_write(sb, SB_FREEZE_WRITE);
1017 trans = btrfs_start_transaction(root, 0);
1020 return PTR_ERR(trans);
1022 return btrfs_commit_transaction(trans, root);
1025 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
1027 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
1028 struct btrfs_root *root = info->tree_root;
1029 char *compress_type;
1031 if (btrfs_test_opt(root, DEGRADED))
1032 seq_puts(seq, ",degraded");
1033 if (btrfs_test_opt(root, NODATASUM))
1034 seq_puts(seq, ",nodatasum");
1035 if (btrfs_test_opt(root, NODATACOW))
1036 seq_puts(seq, ",nodatacow");
1037 if (btrfs_test_opt(root, NOBARRIER))
1038 seq_puts(seq, ",nobarrier");
1039 if (info->max_inline != BTRFS_DEFAULT_MAX_INLINE)
1040 seq_printf(seq, ",max_inline=%llu", info->max_inline);
1041 if (info->alloc_start != 0)
1042 seq_printf(seq, ",alloc_start=%llu", info->alloc_start);
1043 if (info->thread_pool_size != min_t(unsigned long,
1044 num_online_cpus() + 2, 8))
1045 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
1046 if (btrfs_test_opt(root, COMPRESS)) {
1047 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
1048 compress_type = "zlib";
1050 compress_type = "lzo";
1051 if (btrfs_test_opt(root, FORCE_COMPRESS))
1052 seq_printf(seq, ",compress-force=%s", compress_type);
1054 seq_printf(seq, ",compress=%s", compress_type);
1056 if (btrfs_test_opt(root, NOSSD))
1057 seq_puts(seq, ",nossd");
1058 if (btrfs_test_opt(root, SSD_SPREAD))
1059 seq_puts(seq, ",ssd_spread");
1060 else if (btrfs_test_opt(root, SSD))
1061 seq_puts(seq, ",ssd");
1062 if (btrfs_test_opt(root, NOTREELOG))
1063 seq_puts(seq, ",notreelog");
1064 if (btrfs_test_opt(root, FLUSHONCOMMIT))
1065 seq_puts(seq, ",flushoncommit");
1066 if (btrfs_test_opt(root, DISCARD))
1067 seq_puts(seq, ",discard");
1068 if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
1069 seq_puts(seq, ",noacl");
1070 if (btrfs_test_opt(root, SPACE_CACHE))
1071 seq_puts(seq, ",space_cache");
1073 seq_puts(seq, ",nospace_cache");
1074 if (btrfs_test_opt(root, RESCAN_UUID_TREE))
1075 seq_puts(seq, ",rescan_uuid_tree");
1076 if (btrfs_test_opt(root, CLEAR_CACHE))
1077 seq_puts(seq, ",clear_cache");
1078 if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
1079 seq_puts(seq, ",user_subvol_rm_allowed");
1080 if (btrfs_test_opt(root, ENOSPC_DEBUG))
1081 seq_puts(seq, ",enospc_debug");
1082 if (btrfs_test_opt(root, AUTO_DEFRAG))
1083 seq_puts(seq, ",autodefrag");
1084 if (btrfs_test_opt(root, INODE_MAP_CACHE))
1085 seq_puts(seq, ",inode_cache");
1086 if (btrfs_test_opt(root, SKIP_BALANCE))
1087 seq_puts(seq, ",skip_balance");
1088 if (btrfs_test_opt(root, RECOVERY))
1089 seq_puts(seq, ",recovery");
1090 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1091 if (btrfs_test_opt(root, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA))
1092 seq_puts(seq, ",check_int_data");
1093 else if (btrfs_test_opt(root, CHECK_INTEGRITY))
1094 seq_puts(seq, ",check_int");
1095 if (info->check_integrity_print_mask)
1096 seq_printf(seq, ",check_int_print_mask=%d",
1097 info->check_integrity_print_mask);
1099 if (info->metadata_ratio)
1100 seq_printf(seq, ",metadata_ratio=%d",
1101 info->metadata_ratio);
1102 if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR))
1103 seq_puts(seq, ",fatal_errors=panic");
1104 if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL)
1105 seq_printf(seq, ",commit=%d", info->commit_interval);
1109 static int btrfs_test_super(struct super_block *s, void *data)
1111 struct btrfs_fs_info *p = data;
1112 struct btrfs_fs_info *fs_info = btrfs_sb(s);
1114 return fs_info->fs_devices == p->fs_devices;
1117 static int btrfs_set_super(struct super_block *s, void *data)
1119 int err = set_anon_super(s, data);
1121 s->s_fs_info = data;
1126 * subvolumes are identified by ino 256
1128 static inline int is_subvolume_inode(struct inode *inode)
1130 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
1136 * This will strip out the subvol=%s argument for an argument string and add
1137 * subvolid=0 to make sure we get the actual tree root for path walking to the
1140 static char *setup_root_args(char *args)
1142 unsigned len = strlen(args) + 2 + 1;
1143 char *src, *dst, *buf;
1146 * We need the same args as before, but with this substitution:
1147 * s!subvol=[^,]+!subvolid=0!
1149 * Since the replacement string is up to 2 bytes longer than the
1150 * original, allocate strlen(args) + 2 + 1 bytes.
1153 src = strstr(args, "subvol=");
1154 /* This shouldn't happen, but just in case.. */
1158 buf = dst = kmalloc(len, GFP_NOFS);
1163 * If the subvol= arg is not at the start of the string,
1164 * copy whatever precedes it into buf.
1169 dst += strlen(args);
1172 strcpy(dst, "subvolid=0");
1173 dst += strlen("subvolid=0");
1176 * If there is a "," after the original subvol=... string,
1177 * copy that suffix into our buffer. Otherwise, we're done.
1179 src = strchr(src, ',');
1186 static struct dentry *mount_subvol(const char *subvol_name, int flags,
1187 const char *device_name, char *data)
1189 struct dentry *root;
1190 struct vfsmount *mnt;
1193 newargs = setup_root_args(data);
1195 return ERR_PTR(-ENOMEM);
1196 mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name,
1199 if (PTR_RET(mnt) == -EBUSY) {
1200 if (flags & MS_RDONLY) {
1201 mnt = vfs_kern_mount(&btrfs_fs_type, flags & ~MS_RDONLY, device_name,
1205 mnt = vfs_kern_mount(&btrfs_fs_type, flags | MS_RDONLY, device_name,
1209 return ERR_CAST(mnt);
1212 down_write(&mnt->mnt_sb->s_umount);
1213 r = btrfs_remount(mnt->mnt_sb, &flags, NULL);
1214 up_write(&mnt->mnt_sb->s_umount);
1216 /* FIXME: release vfsmount mnt ??*/
1226 return ERR_CAST(mnt);
1228 root = mount_subtree(mnt, subvol_name);
1230 if (!IS_ERR(root) && !is_subvolume_inode(d_inode(root))) {
1231 struct super_block *s = root->d_sb;
1233 root = ERR_PTR(-EINVAL);
1234 deactivate_locked_super(s);
1235 printk(KERN_ERR "BTRFS: '%s' is not a valid subvolume\n",
1242 static int parse_security_options(char *orig_opts,
1243 struct security_mnt_opts *sec_opts)
1245 char *secdata = NULL;
1248 secdata = alloc_secdata();
1251 ret = security_sb_copy_data(orig_opts, secdata);
1253 free_secdata(secdata);
1256 ret = security_sb_parse_opts_str(secdata, sec_opts);
1257 free_secdata(secdata);
1261 static int setup_security_options(struct btrfs_fs_info *fs_info,
1262 struct super_block *sb,
1263 struct security_mnt_opts *sec_opts)
1268 * Call security_sb_set_mnt_opts() to check whether new sec_opts
1271 ret = security_sb_set_mnt_opts(sb, sec_opts, 0, NULL);
1275 #ifdef CONFIG_SECURITY
1276 if (!fs_info->security_opts.num_mnt_opts) {
1277 /* first time security setup, copy sec_opts to fs_info */
1278 memcpy(&fs_info->security_opts, sec_opts, sizeof(*sec_opts));
1281 * Since SELinux(the only one supports security_mnt_opts) does
1282 * NOT support changing context during remount/mount same sb,
1283 * This must be the same or part of the same security options,
1286 security_free_mnt_opts(sec_opts);
1293 * Find a superblock for the given device / mount point.
1295 * Note: This is based on get_sb_bdev from fs/super.c with a few additions
1296 * for multiple device setup. Make sure to keep it in sync.
1298 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1299 const char *device_name, void *data)
1301 struct block_device *bdev = NULL;
1302 struct super_block *s;
1303 struct dentry *root;
1304 struct btrfs_fs_devices *fs_devices = NULL;
1305 struct btrfs_fs_info *fs_info = NULL;
1306 struct security_mnt_opts new_sec_opts;
1307 fmode_t mode = FMODE_READ;
1308 char *subvol_name = NULL;
1309 u64 subvol_objectid = 0;
1312 if (!(flags & MS_RDONLY))
1313 mode |= FMODE_WRITE;
1315 error = btrfs_parse_early_options(data, mode, fs_type,
1316 &subvol_name, &subvol_objectid,
1320 return ERR_PTR(error);
1324 root = mount_subvol(subvol_name, flags, device_name, data);
1329 security_init_mnt_opts(&new_sec_opts);
1331 error = parse_security_options(data, &new_sec_opts);
1333 return ERR_PTR(error);
1336 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
1338 goto error_sec_opts;
1341 * Setup a dummy root and fs_info for test/set super. This is because
1342 * we don't actually fill this stuff out until open_ctree, but we need
1343 * it for searching for existing supers, so this lets us do that and
1344 * then open_ctree will properly initialize everything later.
1346 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
1349 goto error_sec_opts;
1352 fs_info->fs_devices = fs_devices;
1354 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1355 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1356 security_init_mnt_opts(&fs_info->security_opts);
1357 if (!fs_info->super_copy || !fs_info->super_for_commit) {
1362 error = btrfs_open_devices(fs_devices, mode, fs_type);
1366 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
1368 goto error_close_devices;
1371 bdev = fs_devices->latest_bdev;
1372 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | MS_NOSEC,
1376 goto error_close_devices;
1380 btrfs_close_devices(fs_devices);
1381 free_fs_info(fs_info);
1382 if ((flags ^ s->s_flags) & MS_RDONLY)
1385 char b[BDEVNAME_SIZE];
1387 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
1388 btrfs_sb(s)->bdev_holder = fs_type;
1389 error = btrfs_fill_super(s, fs_devices, data,
1390 flags & MS_SILENT ? 1 : 0);
1393 root = !error ? get_default_root(s, subvol_objectid) : ERR_PTR(error);
1395 deactivate_locked_super(s);
1396 error = PTR_ERR(root);
1397 goto error_sec_opts;
1400 fs_info = btrfs_sb(s);
1401 error = setup_security_options(fs_info, s, &new_sec_opts);
1404 deactivate_locked_super(s);
1405 goto error_sec_opts;
1410 error_close_devices:
1411 btrfs_close_devices(fs_devices);
1413 free_fs_info(fs_info);
1415 security_free_mnt_opts(&new_sec_opts);
1416 return ERR_PTR(error);
1419 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1420 int new_pool_size, int old_pool_size)
1422 if (new_pool_size == old_pool_size)
1425 fs_info->thread_pool_size = new_pool_size;
1427 btrfs_info(fs_info, "resize thread pool %d -> %d",
1428 old_pool_size, new_pool_size);
1430 btrfs_workqueue_set_max(fs_info->workers, new_pool_size);
1431 btrfs_workqueue_set_max(fs_info->delalloc_workers, new_pool_size);
1432 btrfs_workqueue_set_max(fs_info->submit_workers, new_pool_size);
1433 btrfs_workqueue_set_max(fs_info->caching_workers, new_pool_size);
1434 btrfs_workqueue_set_max(fs_info->endio_workers, new_pool_size);
1435 btrfs_workqueue_set_max(fs_info->endio_meta_workers, new_pool_size);
1436 btrfs_workqueue_set_max(fs_info->endio_meta_write_workers,
1438 btrfs_workqueue_set_max(fs_info->endio_write_workers, new_pool_size);
1439 btrfs_workqueue_set_max(fs_info->endio_freespace_worker, new_pool_size);
1440 btrfs_workqueue_set_max(fs_info->delayed_workers, new_pool_size);
1441 btrfs_workqueue_set_max(fs_info->readahead_workers, new_pool_size);
1442 btrfs_workqueue_set_max(fs_info->scrub_wr_completion_workers,
1446 static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info)
1448 set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1451 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
1452 unsigned long old_opts, int flags)
1454 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1455 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1456 (flags & MS_RDONLY))) {
1457 /* wait for any defraggers to finish */
1458 wait_event(fs_info->transaction_wait,
1459 (atomic_read(&fs_info->defrag_running) == 0));
1460 if (flags & MS_RDONLY)
1461 sync_filesystem(fs_info->sb);
1465 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1466 unsigned long old_opts)
1469 * We need cleanup all defragable inodes if the autodefragment is
1470 * close or the fs is R/O.
1472 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1473 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1474 (fs_info->sb->s_flags & MS_RDONLY))) {
1475 btrfs_cleanup_defrag_inodes(fs_info);
1478 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1481 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1483 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1484 struct btrfs_root *root = fs_info->tree_root;
1485 unsigned old_flags = sb->s_flags;
1486 unsigned long old_opts = fs_info->mount_opt;
1487 unsigned long old_compress_type = fs_info->compress_type;
1488 u64 old_max_inline = fs_info->max_inline;
1489 u64 old_alloc_start = fs_info->alloc_start;
1490 int old_thread_pool_size = fs_info->thread_pool_size;
1491 unsigned int old_metadata_ratio = fs_info->metadata_ratio;
1494 sync_filesystem(sb);
1495 btrfs_remount_prepare(fs_info);
1498 struct security_mnt_opts new_sec_opts;
1500 security_init_mnt_opts(&new_sec_opts);
1501 ret = parse_security_options(data, &new_sec_opts);
1504 ret = setup_security_options(fs_info, sb,
1507 security_free_mnt_opts(&new_sec_opts);
1512 ret = btrfs_parse_options(root, data);
1518 btrfs_remount_begin(fs_info, old_opts, *flags);
1519 btrfs_resize_thread_pool(fs_info,
1520 fs_info->thread_pool_size, old_thread_pool_size);
1522 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1525 if (*flags & MS_RDONLY) {
1527 * this also happens on 'umount -rf' or on shutdown, when
1528 * the filesystem is busy.
1530 cancel_work_sync(&fs_info->async_reclaim_work);
1532 /* wait for the uuid_scan task to finish */
1533 down(&fs_info->uuid_tree_rescan_sem);
1534 /* avoid complains from lockdep et al. */
1535 up(&fs_info->uuid_tree_rescan_sem);
1537 sb->s_flags |= MS_RDONLY;
1539 btrfs_dev_replace_suspend_for_unmount(fs_info);
1540 btrfs_scrub_cancel(fs_info);
1541 btrfs_pause_balance(fs_info);
1543 ret = btrfs_commit_super(root);
1547 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) {
1549 "Remounting read-write after error is not allowed");
1553 if (fs_info->fs_devices->rw_devices == 0) {
1558 if (fs_info->fs_devices->missing_devices >
1559 fs_info->num_tolerated_disk_barrier_failures &&
1560 !(*flags & MS_RDONLY)) {
1562 "too many missing devices, writeable remount is not allowed");
1567 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1572 ret = btrfs_cleanup_fs_roots(fs_info);
1576 /* recover relocation */
1577 mutex_lock(&fs_info->cleaner_mutex);
1578 ret = btrfs_recover_relocation(root);
1579 mutex_unlock(&fs_info->cleaner_mutex);
1583 ret = btrfs_resume_balance_async(fs_info);
1587 ret = btrfs_resume_dev_replace_async(fs_info);
1589 btrfs_warn(fs_info, "failed to resume dev_replace");
1593 if (!fs_info->uuid_root) {
1594 btrfs_info(fs_info, "creating UUID tree");
1595 ret = btrfs_create_uuid_tree(fs_info);
1597 btrfs_warn(fs_info, "failed to create the UUID tree %d", ret);
1601 sb->s_flags &= ~MS_RDONLY;
1604 wake_up_process(fs_info->transaction_kthread);
1605 btrfs_remount_cleanup(fs_info, old_opts);
1609 /* We've hit an error - don't reset MS_RDONLY */
1610 if (sb->s_flags & MS_RDONLY)
1611 old_flags |= MS_RDONLY;
1612 sb->s_flags = old_flags;
1613 fs_info->mount_opt = old_opts;
1614 fs_info->compress_type = old_compress_type;
1615 fs_info->max_inline = old_max_inline;
1616 mutex_lock(&fs_info->chunk_mutex);
1617 fs_info->alloc_start = old_alloc_start;
1618 mutex_unlock(&fs_info->chunk_mutex);
1619 btrfs_resize_thread_pool(fs_info,
1620 old_thread_pool_size, fs_info->thread_pool_size);
1621 fs_info->metadata_ratio = old_metadata_ratio;
1622 btrfs_remount_cleanup(fs_info, old_opts);
1626 /* Used to sort the devices by max_avail(descending sort) */
1627 static int btrfs_cmp_device_free_bytes(const void *dev_info1,
1628 const void *dev_info2)
1630 if (((struct btrfs_device_info *)dev_info1)->max_avail >
1631 ((struct btrfs_device_info *)dev_info2)->max_avail)
1633 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1634 ((struct btrfs_device_info *)dev_info2)->max_avail)
1641 * sort the devices by max_avail, in which max free extent size of each device
1642 * is stored.(Descending Sort)
1644 static inline void btrfs_descending_sort_devices(
1645 struct btrfs_device_info *devices,
1648 sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1649 btrfs_cmp_device_free_bytes, NULL);
1653 * The helper to calc the free space on the devices that can be used to store
1656 static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
1658 struct btrfs_fs_info *fs_info = root->fs_info;
1659 struct btrfs_device_info *devices_info;
1660 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1661 struct btrfs_device *device;
1666 u64 min_stripe_size;
1667 int min_stripes = 1, num_stripes = 1;
1668 int i = 0, nr_devices;
1672 * We aren't under the device list lock, so this is racey-ish, but good
1673 * enough for our purposes.
1675 nr_devices = fs_info->fs_devices->open_devices;
1678 nr_devices = fs_info->fs_devices->open_devices;
1686 devices_info = kmalloc_array(nr_devices, sizeof(*devices_info),
1691 /* calc min stripe number for data space alloction */
1692 type = btrfs_get_alloc_profile(root, 1);
1693 if (type & BTRFS_BLOCK_GROUP_RAID0) {
1695 num_stripes = nr_devices;
1696 } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
1699 } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
1704 if (type & BTRFS_BLOCK_GROUP_DUP)
1705 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1707 min_stripe_size = BTRFS_STRIPE_LEN;
1709 if (fs_info->alloc_start)
1710 mutex_lock(&fs_devices->device_list_mutex);
1712 list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
1713 if (!device->in_fs_metadata || !device->bdev ||
1714 device->is_tgtdev_for_dev_replace)
1717 if (i >= nr_devices)
1720 avail_space = device->total_bytes - device->bytes_used;
1722 /* align with stripe_len */
1723 avail_space = div_u64(avail_space, BTRFS_STRIPE_LEN);
1724 avail_space *= BTRFS_STRIPE_LEN;
1727 * In order to avoid overwritting the superblock on the drive,
1728 * btrfs starts at an offset of at least 1MB when doing chunk
1731 skip_space = 1024 * 1024;
1733 /* user can set the offset in fs_info->alloc_start. */
1734 if (fs_info->alloc_start &&
1735 fs_info->alloc_start + BTRFS_STRIPE_LEN <=
1736 device->total_bytes) {
1738 skip_space = max(fs_info->alloc_start, skip_space);
1741 * btrfs can not use the free space in
1742 * [0, skip_space - 1], we must subtract it from the
1743 * total. In order to implement it, we account the used
1744 * space in this range first.
1746 ret = btrfs_account_dev_extents_size(device, 0,
1750 kfree(devices_info);
1751 mutex_unlock(&fs_devices->device_list_mutex);
1757 /* calc the free space in [0, skip_space - 1] */
1758 skip_space -= used_space;
1762 * we can use the free space in [0, skip_space - 1], subtract
1763 * it from the total.
1765 if (avail_space && avail_space >= skip_space)
1766 avail_space -= skip_space;
1770 if (avail_space < min_stripe_size)
1773 devices_info[i].dev = device;
1774 devices_info[i].max_avail = avail_space;
1779 if (fs_info->alloc_start)
1780 mutex_unlock(&fs_devices->device_list_mutex);
1784 btrfs_descending_sort_devices(devices_info, nr_devices);
1788 while (nr_devices >= min_stripes) {
1789 if (num_stripes > nr_devices)
1790 num_stripes = nr_devices;
1792 if (devices_info[i].max_avail >= min_stripe_size) {
1796 avail_space += devices_info[i].max_avail * num_stripes;
1797 alloc_size = devices_info[i].max_avail;
1798 for (j = i + 1 - num_stripes; j <= i; j++)
1799 devices_info[j].max_avail -= alloc_size;
1805 kfree(devices_info);
1806 *free_bytes = avail_space;
1811 * Calculate numbers for 'df', pessimistic in case of mixed raid profiles.
1813 * If there's a redundant raid level at DATA block groups, use the respective
1814 * multiplier to scale the sizes.
1816 * Unused device space usage is based on simulating the chunk allocator
1817 * algorithm that respects the device sizes, order of allocations and the
1818 * 'alloc_start' value, this is a close approximation of the actual use but
1819 * there are other factors that may change the result (like a new metadata
1822 * FIXME: not accurate for mixed block groups, total and free/used are ok,
1823 * available appears slightly larger.
1825 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
1827 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
1828 struct btrfs_super_block *disk_super = fs_info->super_copy;
1829 struct list_head *head = &fs_info->space_info;
1830 struct btrfs_space_info *found;
1832 u64 total_free_data = 0;
1833 int bits = dentry->d_sb->s_blocksize_bits;
1834 __be32 *fsid = (__be32 *)fs_info->fsid;
1835 unsigned factor = 1;
1836 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
1840 * holding chunk_muext to avoid allocating new chunks, holding
1841 * device_list_mutex to avoid the device being removed
1844 list_for_each_entry_rcu(found, head, list) {
1845 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
1848 total_free_data += found->disk_total - found->disk_used;
1850 btrfs_account_ro_block_groups_free_space(found);
1852 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
1853 if (!list_empty(&found->block_groups[i])) {
1855 case BTRFS_RAID_DUP:
1856 case BTRFS_RAID_RAID1:
1857 case BTRFS_RAID_RAID10:
1864 total_used += found->disk_used;
1869 buf->f_blocks = div_u64(btrfs_super_total_bytes(disk_super), factor);
1870 buf->f_blocks >>= bits;
1871 buf->f_bfree = buf->f_blocks - (div_u64(total_used, factor) >> bits);
1873 /* Account global block reserve as used, it's in logical size already */
1874 spin_lock(&block_rsv->lock);
1875 buf->f_bfree -= block_rsv->size >> bits;
1876 spin_unlock(&block_rsv->lock);
1878 buf->f_bavail = div_u64(total_free_data, factor);
1879 ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data);
1882 buf->f_bavail += div_u64(total_free_data, factor);
1883 buf->f_bavail = buf->f_bavail >> bits;
1885 buf->f_type = BTRFS_SUPER_MAGIC;
1886 buf->f_bsize = dentry->d_sb->s_blocksize;
1887 buf->f_namelen = BTRFS_NAME_LEN;
1889 /* We treat it as constant endianness (it doesn't matter _which_)
1890 because we want the fsid to come out the same whether mounted
1891 on a big-endian or little-endian host */
1892 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
1893 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
1894 /* Mask in the root object ID too, to disambiguate subvols */
1895 buf->f_fsid.val[0] ^= BTRFS_I(d_inode(dentry))->root->objectid >> 32;
1896 buf->f_fsid.val[1] ^= BTRFS_I(d_inode(dentry))->root->objectid;
1901 static void btrfs_kill_super(struct super_block *sb)
1903 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1904 kill_anon_super(sb);
1905 free_fs_info(fs_info);
1908 static struct file_system_type btrfs_fs_type = {
1909 .owner = THIS_MODULE,
1911 .mount = btrfs_mount,
1912 .kill_sb = btrfs_kill_super,
1913 .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA,
1915 MODULE_ALIAS_FS("btrfs");
1917 static int btrfs_control_open(struct inode *inode, struct file *file)
1920 * The control file's private_data is used to hold the
1921 * transaction when it is started and is used to keep
1922 * track of whether a transaction is already in progress.
1924 file->private_data = NULL;
1929 * used by btrfsctl to scan devices when no FS is mounted
1931 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
1934 struct btrfs_ioctl_vol_args *vol;
1935 struct btrfs_fs_devices *fs_devices;
1938 if (!capable(CAP_SYS_ADMIN))
1941 vol = memdup_user((void __user *)arg, sizeof(*vol));
1943 return PTR_ERR(vol);
1946 case BTRFS_IOC_SCAN_DEV:
1947 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1948 &btrfs_fs_type, &fs_devices);
1950 case BTRFS_IOC_DEVICES_READY:
1951 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1952 &btrfs_fs_type, &fs_devices);
1955 ret = !(fs_devices->num_devices == fs_devices->total_devices);
1963 static int btrfs_freeze(struct super_block *sb)
1965 struct btrfs_trans_handle *trans;
1966 struct btrfs_root *root = btrfs_sb(sb)->tree_root;
1968 trans = btrfs_attach_transaction_barrier(root);
1969 if (IS_ERR(trans)) {
1970 /* no transaction, don't bother */
1971 if (PTR_ERR(trans) == -ENOENT)
1973 return PTR_ERR(trans);
1975 return btrfs_commit_transaction(trans, root);
1978 static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
1980 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
1981 struct btrfs_fs_devices *cur_devices;
1982 struct btrfs_device *dev, *first_dev = NULL;
1983 struct list_head *head;
1984 struct rcu_string *name;
1986 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1987 cur_devices = fs_info->fs_devices;
1988 while (cur_devices) {
1989 head = &cur_devices->devices;
1990 list_for_each_entry(dev, head, dev_list) {
1995 if (!first_dev || dev->devid < first_dev->devid)
1998 cur_devices = cur_devices->seed;
2003 name = rcu_dereference(first_dev->name);
2004 seq_escape(m, name->str, " \t\n\\");
2009 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2013 static const struct super_operations btrfs_super_ops = {
2014 .drop_inode = btrfs_drop_inode,
2015 .evict_inode = btrfs_evict_inode,
2016 .put_super = btrfs_put_super,
2017 .sync_fs = btrfs_sync_fs,
2018 .show_options = btrfs_show_options,
2019 .show_devname = btrfs_show_devname,
2020 .write_inode = btrfs_write_inode,
2021 .alloc_inode = btrfs_alloc_inode,
2022 .destroy_inode = btrfs_destroy_inode,
2023 .statfs = btrfs_statfs,
2024 .remount_fs = btrfs_remount,
2025 .freeze_fs = btrfs_freeze,
2028 static const struct file_operations btrfs_ctl_fops = {
2029 .open = btrfs_control_open,
2030 .unlocked_ioctl = btrfs_control_ioctl,
2031 .compat_ioctl = btrfs_control_ioctl,
2032 .owner = THIS_MODULE,
2033 .llseek = noop_llseek,
2036 static struct miscdevice btrfs_misc = {
2037 .minor = BTRFS_MINOR,
2038 .name = "btrfs-control",
2039 .fops = &btrfs_ctl_fops
2042 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
2043 MODULE_ALIAS("devname:btrfs-control");
2045 static int btrfs_interface_init(void)
2047 return misc_register(&btrfs_misc);
2050 static void btrfs_interface_exit(void)
2052 if (misc_deregister(&btrfs_misc) < 0)
2053 printk(KERN_INFO "BTRFS: misc_deregister failed for control device\n");
2056 static void btrfs_print_info(void)
2058 printk(KERN_INFO "Btrfs loaded"
2059 #ifdef CONFIG_BTRFS_DEBUG
2062 #ifdef CONFIG_BTRFS_ASSERT
2065 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2066 ", integrity-checker=on"
2071 static int btrfs_run_sanity_tests(void)
2075 ret = btrfs_init_test_fs();
2079 ret = btrfs_test_free_space_cache();
2082 ret = btrfs_test_extent_buffer_operations();
2085 ret = btrfs_test_extent_io();
2088 ret = btrfs_test_inodes();
2091 ret = btrfs_test_qgroups();
2093 btrfs_destroy_test_fs();
2097 static int __init init_btrfs_fs(void)
2101 err = btrfs_hash_init();
2107 err = btrfs_init_sysfs();
2111 btrfs_init_compress();
2113 err = btrfs_init_cachep();
2117 err = extent_io_init();
2121 err = extent_map_init();
2123 goto free_extent_io;
2125 err = ordered_data_init();
2127 goto free_extent_map;
2129 err = btrfs_delayed_inode_init();
2131 goto free_ordered_data;
2133 err = btrfs_auto_defrag_init();
2135 goto free_delayed_inode;
2137 err = btrfs_delayed_ref_init();
2139 goto free_auto_defrag;
2141 err = btrfs_prelim_ref_init();
2143 goto free_delayed_ref;
2145 err = btrfs_end_io_wq_init();
2147 goto free_prelim_ref;
2149 err = btrfs_interface_init();
2151 goto free_end_io_wq;
2153 btrfs_init_lockdep();
2157 err = btrfs_run_sanity_tests();
2159 goto unregister_ioctl;
2161 err = register_filesystem(&btrfs_fs_type);
2163 goto unregister_ioctl;
2168 btrfs_interface_exit();
2170 btrfs_end_io_wq_exit();
2172 btrfs_prelim_ref_exit();
2174 btrfs_delayed_ref_exit();
2176 btrfs_auto_defrag_exit();
2178 btrfs_delayed_inode_exit();
2180 ordered_data_exit();
2186 btrfs_destroy_cachep();
2188 btrfs_exit_compress();
2195 static void __exit exit_btrfs_fs(void)
2197 btrfs_destroy_cachep();
2198 btrfs_delayed_ref_exit();
2199 btrfs_auto_defrag_exit();
2200 btrfs_delayed_inode_exit();
2201 btrfs_prelim_ref_exit();
2202 ordered_data_exit();
2205 btrfs_interface_exit();
2206 btrfs_end_io_wq_exit();
2207 unregister_filesystem(&btrfs_fs_type);
2209 btrfs_cleanup_fs_uuids();
2210 btrfs_exit_compress();
2214 late_initcall(init_btrfs_fs);
2215 module_exit(exit_btrfs_fs)
2217 MODULE_LICENSE("GPL");