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"
63 #define CREATE_TRACE_POINTS
64 #include <trace/events/btrfs.h>
66 static const struct super_operations btrfs_super_ops;
67 static struct file_system_type btrfs_fs_type;
69 static int btrfs_remount(struct super_block *sb, int *flags, char *data);
71 static const char *btrfs_decode_error(int errno)
73 char *errstr = "unknown";
77 errstr = "IO failure";
80 errstr = "Out of memory";
83 errstr = "Readonly filesystem";
86 errstr = "Object already exists";
89 errstr = "No space left";
92 errstr = "No such entry";
99 static void save_error_info(struct btrfs_fs_info *fs_info)
102 * today we only save the error info into ram. Long term we'll
103 * also send it down to the disk
105 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
108 /* btrfs handle error by forcing the filesystem readonly */
109 static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
111 struct super_block *sb = fs_info->sb;
113 if (sb->s_flags & MS_RDONLY)
116 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
117 sb->s_flags |= MS_RDONLY;
118 btrfs_info(fs_info, "forced readonly");
120 * Note that a running device replace operation is not
121 * canceled here although there is no way to update
122 * the progress. It would add the risk of a deadlock,
123 * therefore the canceling is ommited. The only penalty
124 * is that some I/O remains active until the procedure
125 * completes. The next time when the filesystem is
126 * mounted writeable again, the device replace
127 * operation continues.
134 * __btrfs_std_error decodes expected errors from the caller and
135 * invokes the approciate error response.
137 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
138 unsigned int line, int errno, const char *fmt, ...)
140 struct super_block *sb = fs_info->sb;
144 * Special case: if the error is EROFS, and we're already
145 * under MS_RDONLY, then it is safe here.
147 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
150 errstr = btrfs_decode_error(errno);
152 struct va_format vaf;
160 "BTRFS: error (device %s) in %s:%d: errno=%d %s (%pV)\n",
161 sb->s_id, function, line, errno, errstr, &vaf);
164 printk(KERN_CRIT "BTRFS: error (device %s) in %s:%d: errno=%d %s\n",
165 sb->s_id, function, line, errno, errstr);
168 /* Don't go through full error handling during mount */
169 save_error_info(fs_info);
170 if (sb->s_flags & MS_BORN)
171 btrfs_handle_error(fs_info);
174 static const char * const logtypes[] = {
185 void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
187 struct super_block *sb = fs_info->sb;
189 struct va_format vaf;
191 const char *type = logtypes[4];
196 kern_level = printk_get_level(fmt);
198 size_t size = printk_skip_level(fmt) - fmt;
199 memcpy(lvl, fmt, size);
202 type = logtypes[kern_level - '0'];
209 printk("%sBTRFS %s (device %s): %pV\n", lvl, type, sb->s_id, &vaf);
216 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
217 unsigned int line, int errno, const char *fmt, ...)
219 struct super_block *sb = fs_info->sb;
222 * Special case: if the error is EROFS, and we're already
223 * under MS_RDONLY, then it is safe here.
225 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
228 /* Don't go through full error handling during mount */
229 if (sb->s_flags & MS_BORN) {
230 save_error_info(fs_info);
231 btrfs_handle_error(fs_info);
237 * We only mark the transaction aborted and then set the file system read-only.
238 * This will prevent new transactions from starting or trying to join this
241 * This means that error recovery at the call site is limited to freeing
242 * any local memory allocations and passing the error code up without
243 * further cleanup. The transaction should complete as it normally would
244 * in the call path but will return -EIO.
246 * We'll complete the cleanup in btrfs_end_transaction and
247 * btrfs_commit_transaction.
249 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
250 struct btrfs_root *root, const char *function,
251 unsigned int line, int errno)
254 * Report first abort since mount
256 if (!test_and_set_bit(BTRFS_FS_STATE_TRANS_ABORTED,
257 &root->fs_info->fs_state)) {
258 WARN(1, KERN_DEBUG "BTRFS: Transaction aborted (error %d)\n",
261 trans->aborted = errno;
262 /* Nothing used. The other threads that have joined this
263 * transaction may be able to continue. */
264 if (!trans->blocks_used) {
267 errstr = btrfs_decode_error(errno);
268 btrfs_warn(root->fs_info,
269 "%s:%d: Aborting unused transaction(%s).",
270 function, line, errstr);
273 ACCESS_ONCE(trans->transaction->aborted) = errno;
274 /* Wake up anybody who may be waiting on this transaction */
275 wake_up(&root->fs_info->transaction_wait);
276 wake_up(&root->fs_info->transaction_blocked_wait);
277 __btrfs_std_error(root->fs_info, function, line, errno, NULL);
280 * __btrfs_panic decodes unexpected, fatal errors from the caller,
281 * issues an alert, and either panics or BUGs, depending on mount options.
283 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
284 unsigned int line, int errno, const char *fmt, ...)
286 char *s_id = "<unknown>";
288 struct va_format vaf = { .fmt = fmt };
292 s_id = fs_info->sb->s_id;
297 errstr = btrfs_decode_error(errno);
298 if (fs_info && (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR))
299 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
300 s_id, function, line, &vaf, errno, errstr);
302 btrfs_crit(fs_info, "panic in %s:%d: %pV (errno=%d %s)",
303 function, line, &vaf, errno, errstr);
305 /* Caller calls BUG() */
308 static void btrfs_put_super(struct super_block *sb)
310 (void)close_ctree(btrfs_sb(sb)->tree_root);
311 /* FIXME: need to fix VFS to return error? */
312 /* AV: return it _where_? ->put_super() can be triggered by any number
313 * of async events, up to and including delivery of SIGKILL to the
314 * last process that kept it busy. Or segfault in the aforementioned
315 * process... Whom would you report that to?
320 Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
321 Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
322 Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
323 Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
324 Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
325 Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
326 Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_inode_cache,
327 Opt_no_space_cache, Opt_recovery, Opt_skip_balance,
328 Opt_check_integrity, Opt_check_integrity_including_extent_data,
329 Opt_check_integrity_print_mask, Opt_fatal_errors, Opt_rescan_uuid_tree,
330 Opt_commit_interval, Opt_barrier, Opt_nodefrag, Opt_nodiscard,
331 Opt_noenospc_debug, Opt_noflushoncommit, Opt_acl, Opt_datacow,
332 Opt_datasum, Opt_treelog, Opt_noinode_cache,
336 static match_table_t tokens = {
337 {Opt_degraded, "degraded"},
338 {Opt_subvol, "subvol=%s"},
339 {Opt_subvolid, "subvolid=%s"},
340 {Opt_device, "device=%s"},
341 {Opt_nodatasum, "nodatasum"},
342 {Opt_datasum, "datasum"},
343 {Opt_nodatacow, "nodatacow"},
344 {Opt_datacow, "datacow"},
345 {Opt_nobarrier, "nobarrier"},
346 {Opt_barrier, "barrier"},
347 {Opt_max_inline, "max_inline=%s"},
348 {Opt_alloc_start, "alloc_start=%s"},
349 {Opt_thread_pool, "thread_pool=%d"},
350 {Opt_compress, "compress"},
351 {Opt_compress_type, "compress=%s"},
352 {Opt_compress_force, "compress-force"},
353 {Opt_compress_force_type, "compress-force=%s"},
355 {Opt_ssd_spread, "ssd_spread"},
356 {Opt_nossd, "nossd"},
358 {Opt_noacl, "noacl"},
359 {Opt_notreelog, "notreelog"},
360 {Opt_treelog, "treelog"},
361 {Opt_flushoncommit, "flushoncommit"},
362 {Opt_noflushoncommit, "noflushoncommit"},
363 {Opt_ratio, "metadata_ratio=%d"},
364 {Opt_discard, "discard"},
365 {Opt_nodiscard, "nodiscard"},
366 {Opt_space_cache, "space_cache"},
367 {Opt_clear_cache, "clear_cache"},
368 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
369 {Opt_enospc_debug, "enospc_debug"},
370 {Opt_noenospc_debug, "noenospc_debug"},
371 {Opt_subvolrootid, "subvolrootid=%d"},
372 {Opt_defrag, "autodefrag"},
373 {Opt_nodefrag, "noautodefrag"},
374 {Opt_inode_cache, "inode_cache"},
375 {Opt_noinode_cache, "noinode_cache"},
376 {Opt_no_space_cache, "nospace_cache"},
377 {Opt_recovery, "recovery"},
378 {Opt_skip_balance, "skip_balance"},
379 {Opt_check_integrity, "check_int"},
380 {Opt_check_integrity_including_extent_data, "check_int_data"},
381 {Opt_check_integrity_print_mask, "check_int_print_mask=%d"},
382 {Opt_rescan_uuid_tree, "rescan_uuid_tree"},
383 {Opt_fatal_errors, "fatal_errors=%s"},
384 {Opt_commit_interval, "commit=%d"},
389 * Regular mount options parser. Everything that is needed only when
390 * reading in a new superblock is parsed here.
391 * XXX JDM: This needs to be cleaned up for remount.
393 int btrfs_parse_options(struct btrfs_root *root, char *options)
395 struct btrfs_fs_info *info = root->fs_info;
396 substring_t args[MAX_OPT_ARGS];
397 char *p, *num, *orig = NULL;
402 bool compress_force = false;
403 bool compress = false;
405 cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
407 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
413 * strsep changes the string, duplicate it because parse_options
416 options = kstrdup(options, GFP_NOFS);
422 while ((p = strsep(&options, ",")) != NULL) {
427 token = match_token(p, tokens, args);
430 btrfs_info(root->fs_info, "allowing degraded mounts");
431 btrfs_set_opt(info->mount_opt, DEGRADED);
435 case Opt_subvolrootid:
438 * These are parsed by btrfs_parse_early_options
439 * and can be happily ignored here.
443 btrfs_set_and_info(root, NODATASUM,
444 "setting nodatasum");
447 if (btrfs_test_opt(root, NODATASUM)) {
448 if (btrfs_test_opt(root, NODATACOW))
449 btrfs_info(root->fs_info, "setting datasum, datacow enabled");
451 btrfs_info(root->fs_info, "setting datasum");
453 btrfs_clear_opt(info->mount_opt, NODATACOW);
454 btrfs_clear_opt(info->mount_opt, NODATASUM);
457 if (!btrfs_test_opt(root, NODATACOW)) {
458 if (!btrfs_test_opt(root, COMPRESS) ||
459 !btrfs_test_opt(root, FORCE_COMPRESS)) {
460 btrfs_info(root->fs_info,
461 "setting nodatacow, compression disabled");
463 btrfs_info(root->fs_info, "setting nodatacow");
466 btrfs_clear_opt(info->mount_opt, COMPRESS);
467 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
468 btrfs_set_opt(info->mount_opt, NODATACOW);
469 btrfs_set_opt(info->mount_opt, NODATASUM);
472 btrfs_clear_and_info(root, NODATACOW,
475 case Opt_compress_force:
476 case Opt_compress_force_type:
477 compress_force = true;
480 case Opt_compress_type:
482 if (token == Opt_compress ||
483 token == Opt_compress_force ||
484 strcmp(args[0].from, "zlib") == 0) {
485 compress_type = "zlib";
486 info->compress_type = BTRFS_COMPRESS_ZLIB;
487 btrfs_set_opt(info->mount_opt, COMPRESS);
488 btrfs_clear_opt(info->mount_opt, NODATACOW);
489 btrfs_clear_opt(info->mount_opt, NODATASUM);
490 } else if (strcmp(args[0].from, "lzo") == 0) {
491 compress_type = "lzo";
492 info->compress_type = BTRFS_COMPRESS_LZO;
493 btrfs_set_opt(info->mount_opt, COMPRESS);
494 btrfs_clear_opt(info->mount_opt, NODATACOW);
495 btrfs_clear_opt(info->mount_opt, NODATASUM);
496 btrfs_set_fs_incompat(info, COMPRESS_LZO);
497 } else if (strncmp(args[0].from, "no", 2) == 0) {
498 compress_type = "no";
499 btrfs_clear_opt(info->mount_opt, COMPRESS);
500 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
501 compress_force = false;
507 if (compress_force) {
508 btrfs_set_and_info(root, FORCE_COMPRESS,
509 "force %s compression",
511 } else if (compress) {
512 if (!btrfs_test_opt(root, COMPRESS))
513 btrfs_info(root->fs_info,
514 "btrfs: use %s compression",
519 btrfs_set_and_info(root, SSD,
520 "use ssd allocation scheme");
523 btrfs_set_and_info(root, SSD_SPREAD,
524 "use spread ssd allocation scheme");
525 btrfs_set_opt(info->mount_opt, SSD);
528 btrfs_set_and_info(root, NOSSD,
529 "not using ssd allocation scheme");
530 btrfs_clear_opt(info->mount_opt, SSD);
533 btrfs_clear_and_info(root, NOBARRIER,
534 "turning on barriers");
537 btrfs_set_and_info(root, NOBARRIER,
538 "turning off barriers");
540 case Opt_thread_pool:
541 ret = match_int(&args[0], &intarg);
544 } else if (intarg > 0) {
545 info->thread_pool_size = intarg;
552 num = match_strdup(&args[0]);
554 info->max_inline = memparse(num, NULL);
557 if (info->max_inline) {
558 info->max_inline = min_t(u64,
562 btrfs_info(root->fs_info, "max_inline at %llu",
569 case Opt_alloc_start:
570 num = match_strdup(&args[0]);
572 mutex_lock(&info->chunk_mutex);
573 info->alloc_start = memparse(num, NULL);
574 mutex_unlock(&info->chunk_mutex);
576 btrfs_info(root->fs_info, "allocations start at %llu",
584 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
585 root->fs_info->sb->s_flags |= MS_POSIXACL;
588 btrfs_err(root->fs_info,
589 "support for ACL not compiled in!");
594 root->fs_info->sb->s_flags &= ~MS_POSIXACL;
597 btrfs_set_and_info(root, NOTREELOG,
598 "disabling tree log");
601 btrfs_clear_and_info(root, NOTREELOG,
602 "enabling tree log");
604 case Opt_flushoncommit:
605 btrfs_set_and_info(root, FLUSHONCOMMIT,
606 "turning on flush-on-commit");
608 case Opt_noflushoncommit:
609 btrfs_clear_and_info(root, FLUSHONCOMMIT,
610 "turning off flush-on-commit");
613 ret = match_int(&args[0], &intarg);
616 } else if (intarg >= 0) {
617 info->metadata_ratio = intarg;
618 btrfs_info(root->fs_info, "metadata ratio %d",
619 info->metadata_ratio);
626 btrfs_set_and_info(root, DISCARD,
627 "turning on discard");
630 btrfs_clear_and_info(root, DISCARD,
631 "turning off discard");
633 case Opt_space_cache:
634 btrfs_set_and_info(root, SPACE_CACHE,
635 "enabling disk space caching");
637 case Opt_rescan_uuid_tree:
638 btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE);
640 case Opt_no_space_cache:
641 btrfs_clear_and_info(root, SPACE_CACHE,
642 "disabling disk space caching");
644 case Opt_inode_cache:
645 btrfs_set_and_info(root, CHANGE_INODE_CACHE,
646 "enabling inode map caching");
648 case Opt_noinode_cache:
649 btrfs_clear_and_info(root, CHANGE_INODE_CACHE,
650 "disabling inode map caching");
652 case Opt_clear_cache:
653 btrfs_set_and_info(root, CLEAR_CACHE,
654 "force clearing of disk cache");
656 case Opt_user_subvol_rm_allowed:
657 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
659 case Opt_enospc_debug:
660 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
662 case Opt_noenospc_debug:
663 btrfs_clear_opt(info->mount_opt, ENOSPC_DEBUG);
666 btrfs_set_and_info(root, AUTO_DEFRAG,
667 "enabling auto defrag");
670 btrfs_clear_and_info(root, AUTO_DEFRAG,
671 "disabling auto defrag");
674 btrfs_info(root->fs_info, "enabling auto recovery");
675 btrfs_set_opt(info->mount_opt, RECOVERY);
677 case Opt_skip_balance:
678 btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
680 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
681 case Opt_check_integrity_including_extent_data:
682 btrfs_info(root->fs_info,
683 "enabling check integrity including extent data");
684 btrfs_set_opt(info->mount_opt,
685 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
686 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
688 case Opt_check_integrity:
689 btrfs_info(root->fs_info, "enabling check integrity");
690 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
692 case Opt_check_integrity_print_mask:
693 ret = match_int(&args[0], &intarg);
696 } else if (intarg >= 0) {
697 info->check_integrity_print_mask = intarg;
698 btrfs_info(root->fs_info, "check_integrity_print_mask 0x%x",
699 info->check_integrity_print_mask);
706 case Opt_check_integrity_including_extent_data:
707 case Opt_check_integrity:
708 case Opt_check_integrity_print_mask:
709 btrfs_err(root->fs_info,
710 "support for check_integrity* not compiled in!");
714 case Opt_fatal_errors:
715 if (strcmp(args[0].from, "panic") == 0)
716 btrfs_set_opt(info->mount_opt,
717 PANIC_ON_FATAL_ERROR);
718 else if (strcmp(args[0].from, "bug") == 0)
719 btrfs_clear_opt(info->mount_opt,
720 PANIC_ON_FATAL_ERROR);
726 case Opt_commit_interval:
728 ret = match_int(&args[0], &intarg);
730 btrfs_err(root->fs_info, "invalid commit interval");
736 btrfs_warn(root->fs_info, "excessive commit interval %d",
739 info->commit_interval = intarg;
741 btrfs_info(root->fs_info, "using default commit interval %ds",
742 BTRFS_DEFAULT_COMMIT_INTERVAL);
743 info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
747 btrfs_info(root->fs_info, "unrecognized mount option '%s'", p);
755 if (!ret && btrfs_test_opt(root, SPACE_CACHE))
756 btrfs_info(root->fs_info, "disk space caching is enabled");
762 * Parse mount options that are required early in the mount process.
764 * All other options will be parsed on much later in the mount process and
765 * only when we need to allocate a new super block.
767 static int btrfs_parse_early_options(const char *options, fmode_t flags,
768 void *holder, char **subvol_name, u64 *subvol_objectid,
769 struct btrfs_fs_devices **fs_devices)
771 substring_t args[MAX_OPT_ARGS];
772 char *device_name, *opts, *orig, *p;
780 * strsep changes the string, duplicate it because parse_options
783 opts = kstrdup(options, GFP_KERNEL);
788 while ((p = strsep(&opts, ",")) != NULL) {
793 token = match_token(p, tokens, args);
797 *subvol_name = match_strdup(&args[0]);
804 num = match_strdup(&args[0]);
806 *subvol_objectid = memparse(num, NULL);
808 /* we want the original fs_tree */
809 if (!*subvol_objectid)
811 BTRFS_FS_TREE_OBJECTID;
817 case Opt_subvolrootid:
819 "BTRFS: 'subvolrootid' mount option is deprecated and has "
823 device_name = match_strdup(&args[0]);
828 error = btrfs_scan_one_device(device_name,
829 flags, holder, fs_devices);
844 static struct dentry *get_default_root(struct super_block *sb,
847 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
848 struct btrfs_root *root = fs_info->tree_root;
849 struct btrfs_root *new_root;
850 struct btrfs_dir_item *di;
851 struct btrfs_path *path;
852 struct btrfs_key location;
858 * We have a specific subvol we want to mount, just setup location and
859 * go look up the root.
861 if (subvol_objectid) {
862 location.objectid = subvol_objectid;
863 location.type = BTRFS_ROOT_ITEM_KEY;
864 location.offset = (u64)-1;
868 path = btrfs_alloc_path();
870 return ERR_PTR(-ENOMEM);
871 path->leave_spinning = 1;
874 * Find the "default" dir item which points to the root item that we
875 * will mount by default if we haven't been given a specific subvolume
878 dir_id = btrfs_super_root_dir(fs_info->super_copy);
879 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
881 btrfs_free_path(path);
886 * Ok the default dir item isn't there. This is weird since
887 * it's always been there, but don't freak out, just try and
888 * mount to root most subvolume.
890 btrfs_free_path(path);
891 dir_id = BTRFS_FIRST_FREE_OBJECTID;
892 new_root = fs_info->fs_root;
896 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
897 btrfs_free_path(path);
900 new_root = btrfs_read_fs_root_no_name(fs_info, &location);
901 if (IS_ERR(new_root))
902 return ERR_CAST(new_root);
904 dir_id = btrfs_root_dirid(&new_root->root_item);
906 location.objectid = dir_id;
907 location.type = BTRFS_INODE_ITEM_KEY;
910 inode = btrfs_iget(sb, &location, new_root, &new);
912 return ERR_CAST(inode);
915 * If we're just mounting the root most subvol put the inode and return
916 * a reference to the dentry. We will have already gotten a reference
917 * to the inode in btrfs_fill_super so we're good to go.
919 if (!new && sb->s_root->d_inode == inode) {
921 return dget(sb->s_root);
924 return d_obtain_root(inode);
927 static int btrfs_fill_super(struct super_block *sb,
928 struct btrfs_fs_devices *fs_devices,
929 void *data, int silent)
932 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
933 struct btrfs_key key;
936 sb->s_maxbytes = MAX_LFS_FILESIZE;
937 sb->s_magic = BTRFS_SUPER_MAGIC;
938 sb->s_op = &btrfs_super_ops;
939 sb->s_d_op = &btrfs_dentry_operations;
940 sb->s_export_op = &btrfs_export_ops;
941 sb->s_xattr = btrfs_xattr_handlers;
943 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
944 sb->s_flags |= MS_POSIXACL;
946 sb->s_flags |= MS_I_VERSION;
947 err = open_ctree(sb, fs_devices, (char *)data);
949 printk(KERN_ERR "BTRFS: open_ctree failed\n");
953 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
954 key.type = BTRFS_INODE_ITEM_KEY;
956 inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
958 err = PTR_ERR(inode);
962 sb->s_root = d_make_root(inode);
968 save_mount_options(sb, data);
969 cleancache_init_fs(sb);
970 sb->s_flags |= MS_ACTIVE;
974 close_ctree(fs_info->tree_root);
978 int btrfs_sync_fs(struct super_block *sb, int wait)
980 struct btrfs_trans_handle *trans;
981 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
982 struct btrfs_root *root = fs_info->tree_root;
984 trace_btrfs_sync_fs(wait);
987 filemap_flush(fs_info->btree_inode->i_mapping);
991 btrfs_wait_ordered_roots(fs_info, -1);
993 trans = btrfs_attach_transaction_barrier(root);
995 /* no transaction, don't bother */
996 if (PTR_ERR(trans) == -ENOENT)
998 return PTR_ERR(trans);
1000 return btrfs_commit_transaction(trans, root);
1003 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
1005 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
1006 struct btrfs_root *root = info->tree_root;
1007 char *compress_type;
1009 if (btrfs_test_opt(root, DEGRADED))
1010 seq_puts(seq, ",degraded");
1011 if (btrfs_test_opt(root, NODATASUM))
1012 seq_puts(seq, ",nodatasum");
1013 if (btrfs_test_opt(root, NODATACOW))
1014 seq_puts(seq, ",nodatacow");
1015 if (btrfs_test_opt(root, NOBARRIER))
1016 seq_puts(seq, ",nobarrier");
1017 if (info->max_inline != 8192 * 1024)
1018 seq_printf(seq, ",max_inline=%llu", info->max_inline);
1019 if (info->alloc_start != 0)
1020 seq_printf(seq, ",alloc_start=%llu", info->alloc_start);
1021 if (info->thread_pool_size != min_t(unsigned long,
1022 num_online_cpus() + 2, 8))
1023 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
1024 if (btrfs_test_opt(root, COMPRESS)) {
1025 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
1026 compress_type = "zlib";
1028 compress_type = "lzo";
1029 if (btrfs_test_opt(root, FORCE_COMPRESS))
1030 seq_printf(seq, ",compress-force=%s", compress_type);
1032 seq_printf(seq, ",compress=%s", compress_type);
1034 if (btrfs_test_opt(root, NOSSD))
1035 seq_puts(seq, ",nossd");
1036 if (btrfs_test_opt(root, SSD_SPREAD))
1037 seq_puts(seq, ",ssd_spread");
1038 else if (btrfs_test_opt(root, SSD))
1039 seq_puts(seq, ",ssd");
1040 if (btrfs_test_opt(root, NOTREELOG))
1041 seq_puts(seq, ",notreelog");
1042 if (btrfs_test_opt(root, FLUSHONCOMMIT))
1043 seq_puts(seq, ",flushoncommit");
1044 if (btrfs_test_opt(root, DISCARD))
1045 seq_puts(seq, ",discard");
1046 if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
1047 seq_puts(seq, ",noacl");
1048 if (btrfs_test_opt(root, SPACE_CACHE))
1049 seq_puts(seq, ",space_cache");
1051 seq_puts(seq, ",nospace_cache");
1052 if (btrfs_test_opt(root, RESCAN_UUID_TREE))
1053 seq_puts(seq, ",rescan_uuid_tree");
1054 if (btrfs_test_opt(root, CLEAR_CACHE))
1055 seq_puts(seq, ",clear_cache");
1056 if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
1057 seq_puts(seq, ",user_subvol_rm_allowed");
1058 if (btrfs_test_opt(root, ENOSPC_DEBUG))
1059 seq_puts(seq, ",enospc_debug");
1060 if (btrfs_test_opt(root, AUTO_DEFRAG))
1061 seq_puts(seq, ",autodefrag");
1062 if (btrfs_test_opt(root, INODE_MAP_CACHE))
1063 seq_puts(seq, ",inode_cache");
1064 if (btrfs_test_opt(root, SKIP_BALANCE))
1065 seq_puts(seq, ",skip_balance");
1066 if (btrfs_test_opt(root, RECOVERY))
1067 seq_puts(seq, ",recovery");
1068 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1069 if (btrfs_test_opt(root, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA))
1070 seq_puts(seq, ",check_int_data");
1071 else if (btrfs_test_opt(root, CHECK_INTEGRITY))
1072 seq_puts(seq, ",check_int");
1073 if (info->check_integrity_print_mask)
1074 seq_printf(seq, ",check_int_print_mask=%d",
1075 info->check_integrity_print_mask);
1077 if (info->metadata_ratio)
1078 seq_printf(seq, ",metadata_ratio=%d",
1079 info->metadata_ratio);
1080 if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR))
1081 seq_puts(seq, ",fatal_errors=panic");
1082 if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL)
1083 seq_printf(seq, ",commit=%d", info->commit_interval);
1087 static int btrfs_test_super(struct super_block *s, void *data)
1089 struct btrfs_fs_info *p = data;
1090 struct btrfs_fs_info *fs_info = btrfs_sb(s);
1092 return fs_info->fs_devices == p->fs_devices;
1095 static int btrfs_set_super(struct super_block *s, void *data)
1097 int err = set_anon_super(s, data);
1099 s->s_fs_info = data;
1104 * subvolumes are identified by ino 256
1106 static inline int is_subvolume_inode(struct inode *inode)
1108 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
1114 * This will strip out the subvol=%s argument for an argument string and add
1115 * subvolid=0 to make sure we get the actual tree root for path walking to the
1118 static char *setup_root_args(char *args)
1120 unsigned len = strlen(args) + 2 + 1;
1121 char *src, *dst, *buf;
1124 * We need the same args as before, but with this substitution:
1125 * s!subvol=[^,]+!subvolid=0!
1127 * Since the replacement string is up to 2 bytes longer than the
1128 * original, allocate strlen(args) + 2 + 1 bytes.
1131 src = strstr(args, "subvol=");
1132 /* This shouldn't happen, but just in case.. */
1136 buf = dst = kmalloc(len, GFP_NOFS);
1141 * If the subvol= arg is not at the start of the string,
1142 * copy whatever precedes it into buf.
1147 dst += strlen(args);
1150 strcpy(dst, "subvolid=0");
1151 dst += strlen("subvolid=0");
1154 * If there is a "," after the original subvol=... string,
1155 * copy that suffix into our buffer. Otherwise, we're done.
1157 src = strchr(src, ',');
1164 static struct dentry *mount_subvol(const char *subvol_name, int flags,
1165 const char *device_name, char *data)
1167 struct dentry *root;
1168 struct vfsmount *mnt;
1171 newargs = setup_root_args(data);
1173 return ERR_PTR(-ENOMEM);
1174 mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name,
1177 if (PTR_RET(mnt) == -EBUSY) {
1178 if (flags & MS_RDONLY) {
1179 mnt = vfs_kern_mount(&btrfs_fs_type, flags & ~MS_RDONLY, device_name,
1183 mnt = vfs_kern_mount(&btrfs_fs_type, flags | MS_RDONLY, device_name,
1187 return ERR_CAST(mnt);
1190 r = btrfs_remount(mnt->mnt_sb, &flags, NULL);
1192 /* FIXME: release vfsmount mnt ??*/
1202 return ERR_CAST(mnt);
1204 root = mount_subtree(mnt, subvol_name);
1206 if (!IS_ERR(root) && !is_subvolume_inode(root->d_inode)) {
1207 struct super_block *s = root->d_sb;
1209 root = ERR_PTR(-EINVAL);
1210 deactivate_locked_super(s);
1211 printk(KERN_ERR "BTRFS: '%s' is not a valid subvolume\n",
1219 * Find a superblock for the given device / mount point.
1221 * Note: This is based on get_sb_bdev from fs/super.c with a few additions
1222 * for multiple device setup. Make sure to keep it in sync.
1224 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1225 const char *device_name, void *data)
1227 struct block_device *bdev = NULL;
1228 struct super_block *s;
1229 struct dentry *root;
1230 struct btrfs_fs_devices *fs_devices = NULL;
1231 struct btrfs_fs_info *fs_info = NULL;
1232 fmode_t mode = FMODE_READ;
1233 char *subvol_name = NULL;
1234 u64 subvol_objectid = 0;
1237 if (!(flags & MS_RDONLY))
1238 mode |= FMODE_WRITE;
1240 error = btrfs_parse_early_options(data, mode, fs_type,
1241 &subvol_name, &subvol_objectid,
1245 return ERR_PTR(error);
1249 root = mount_subvol(subvol_name, flags, device_name, data);
1254 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
1256 return ERR_PTR(error);
1259 * Setup a dummy root and fs_info for test/set super. This is because
1260 * we don't actually fill this stuff out until open_ctree, but we need
1261 * it for searching for existing supers, so this lets us do that and
1262 * then open_ctree will properly initialize everything later.
1264 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
1266 return ERR_PTR(-ENOMEM);
1268 fs_info->fs_devices = fs_devices;
1270 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1271 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1272 if (!fs_info->super_copy || !fs_info->super_for_commit) {
1277 error = btrfs_open_devices(fs_devices, mode, fs_type);
1281 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
1283 goto error_close_devices;
1286 bdev = fs_devices->latest_bdev;
1287 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | MS_NOSEC,
1291 goto error_close_devices;
1295 btrfs_close_devices(fs_devices);
1296 free_fs_info(fs_info);
1297 if ((flags ^ s->s_flags) & MS_RDONLY)
1300 char b[BDEVNAME_SIZE];
1302 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
1303 btrfs_sb(s)->bdev_holder = fs_type;
1304 error = btrfs_fill_super(s, fs_devices, data,
1305 flags & MS_SILENT ? 1 : 0);
1308 root = !error ? get_default_root(s, subvol_objectid) : ERR_PTR(error);
1310 deactivate_locked_super(s);
1314 error_close_devices:
1315 btrfs_close_devices(fs_devices);
1317 free_fs_info(fs_info);
1318 return ERR_PTR(error);
1321 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1322 int new_pool_size, int old_pool_size)
1324 if (new_pool_size == old_pool_size)
1327 fs_info->thread_pool_size = new_pool_size;
1329 btrfs_info(fs_info, "resize thread pool %d -> %d",
1330 old_pool_size, new_pool_size);
1332 btrfs_workqueue_set_max(fs_info->workers, new_pool_size);
1333 btrfs_workqueue_set_max(fs_info->delalloc_workers, new_pool_size);
1334 btrfs_workqueue_set_max(fs_info->submit_workers, new_pool_size);
1335 btrfs_workqueue_set_max(fs_info->caching_workers, new_pool_size);
1336 btrfs_workqueue_set_max(fs_info->endio_workers, new_pool_size);
1337 btrfs_workqueue_set_max(fs_info->endio_meta_workers, new_pool_size);
1338 btrfs_workqueue_set_max(fs_info->endio_meta_write_workers,
1340 btrfs_workqueue_set_max(fs_info->endio_write_workers, new_pool_size);
1341 btrfs_workqueue_set_max(fs_info->endio_freespace_worker, new_pool_size);
1342 btrfs_workqueue_set_max(fs_info->delayed_workers, new_pool_size);
1343 btrfs_workqueue_set_max(fs_info->readahead_workers, new_pool_size);
1344 btrfs_workqueue_set_max(fs_info->scrub_wr_completion_workers,
1348 static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info)
1350 set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1353 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
1354 unsigned long old_opts, int flags)
1356 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1357 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1358 (flags & MS_RDONLY))) {
1359 /* wait for any defraggers to finish */
1360 wait_event(fs_info->transaction_wait,
1361 (atomic_read(&fs_info->defrag_running) == 0));
1362 if (flags & MS_RDONLY)
1363 sync_filesystem(fs_info->sb);
1367 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1368 unsigned long old_opts)
1371 * We need cleanup all defragable inodes if the autodefragment is
1372 * close or the fs is R/O.
1374 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1375 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1376 (fs_info->sb->s_flags & MS_RDONLY))) {
1377 btrfs_cleanup_defrag_inodes(fs_info);
1380 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1383 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1385 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1386 struct btrfs_root *root = fs_info->tree_root;
1387 unsigned old_flags = sb->s_flags;
1388 unsigned long old_opts = fs_info->mount_opt;
1389 unsigned long old_compress_type = fs_info->compress_type;
1390 u64 old_max_inline = fs_info->max_inline;
1391 u64 old_alloc_start = fs_info->alloc_start;
1392 int old_thread_pool_size = fs_info->thread_pool_size;
1393 unsigned int old_metadata_ratio = fs_info->metadata_ratio;
1396 sync_filesystem(sb);
1397 btrfs_remount_prepare(fs_info);
1399 ret = btrfs_parse_options(root, data);
1405 btrfs_remount_begin(fs_info, old_opts, *flags);
1406 btrfs_resize_thread_pool(fs_info,
1407 fs_info->thread_pool_size, old_thread_pool_size);
1409 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1412 if (*flags & MS_RDONLY) {
1414 * this also happens on 'umount -rf' or on shutdown, when
1415 * the filesystem is busy.
1417 cancel_work_sync(&fs_info->async_reclaim_work);
1419 /* wait for the uuid_scan task to finish */
1420 down(&fs_info->uuid_tree_rescan_sem);
1421 /* avoid complains from lockdep et al. */
1422 up(&fs_info->uuid_tree_rescan_sem);
1424 sb->s_flags |= MS_RDONLY;
1426 btrfs_dev_replace_suspend_for_unmount(fs_info);
1427 btrfs_scrub_cancel(fs_info);
1428 btrfs_pause_balance(fs_info);
1430 ret = btrfs_commit_super(root);
1434 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) {
1436 "Remounting read-write after error is not allowed");
1440 if (fs_info->fs_devices->rw_devices == 0) {
1445 if (fs_info->fs_devices->missing_devices >
1446 fs_info->num_tolerated_disk_barrier_failures &&
1447 !(*flags & MS_RDONLY)) {
1449 "too many missing devices, writeable remount is not allowed");
1454 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1459 ret = btrfs_cleanup_fs_roots(fs_info);
1463 /* recover relocation */
1464 mutex_lock(&fs_info->cleaner_mutex);
1465 ret = btrfs_recover_relocation(root);
1466 mutex_unlock(&fs_info->cleaner_mutex);
1470 ret = btrfs_resume_balance_async(fs_info);
1474 ret = btrfs_resume_dev_replace_async(fs_info);
1476 btrfs_warn(fs_info, "failed to resume dev_replace");
1480 if (!fs_info->uuid_root) {
1481 btrfs_info(fs_info, "creating UUID tree");
1482 ret = btrfs_create_uuid_tree(fs_info);
1484 btrfs_warn(fs_info, "failed to create the UUID tree %d", ret);
1488 sb->s_flags &= ~MS_RDONLY;
1491 wake_up_process(fs_info->transaction_kthread);
1492 btrfs_remount_cleanup(fs_info, old_opts);
1496 /* We've hit an error - don't reset MS_RDONLY */
1497 if (sb->s_flags & MS_RDONLY)
1498 old_flags |= MS_RDONLY;
1499 sb->s_flags = old_flags;
1500 fs_info->mount_opt = old_opts;
1501 fs_info->compress_type = old_compress_type;
1502 fs_info->max_inline = old_max_inline;
1503 mutex_lock(&fs_info->chunk_mutex);
1504 fs_info->alloc_start = old_alloc_start;
1505 mutex_unlock(&fs_info->chunk_mutex);
1506 btrfs_resize_thread_pool(fs_info,
1507 old_thread_pool_size, fs_info->thread_pool_size);
1508 fs_info->metadata_ratio = old_metadata_ratio;
1509 btrfs_remount_cleanup(fs_info, old_opts);
1513 /* Used to sort the devices by max_avail(descending sort) */
1514 static int btrfs_cmp_device_free_bytes(const void *dev_info1,
1515 const void *dev_info2)
1517 if (((struct btrfs_device_info *)dev_info1)->max_avail >
1518 ((struct btrfs_device_info *)dev_info2)->max_avail)
1520 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1521 ((struct btrfs_device_info *)dev_info2)->max_avail)
1528 * sort the devices by max_avail, in which max free extent size of each device
1529 * is stored.(Descending Sort)
1531 static inline void btrfs_descending_sort_devices(
1532 struct btrfs_device_info *devices,
1535 sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1536 btrfs_cmp_device_free_bytes, NULL);
1540 * The helper to calc the free space on the devices that can be used to store
1543 static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
1545 struct btrfs_fs_info *fs_info = root->fs_info;
1546 struct btrfs_device_info *devices_info;
1547 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1548 struct btrfs_device *device;
1553 u64 min_stripe_size;
1554 int min_stripes = 1, num_stripes = 1;
1555 int i = 0, nr_devices;
1558 nr_devices = fs_info->fs_devices->open_devices;
1559 BUG_ON(!nr_devices);
1561 devices_info = kmalloc_array(nr_devices, sizeof(*devices_info),
1566 /* calc min stripe number for data space alloction */
1567 type = btrfs_get_alloc_profile(root, 1);
1568 if (type & BTRFS_BLOCK_GROUP_RAID0) {
1570 num_stripes = nr_devices;
1571 } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
1574 } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
1579 if (type & BTRFS_BLOCK_GROUP_DUP)
1580 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1582 min_stripe_size = BTRFS_STRIPE_LEN;
1584 list_for_each_entry(device, &fs_devices->devices, dev_list) {
1585 if (!device->in_fs_metadata || !device->bdev ||
1586 device->is_tgtdev_for_dev_replace)
1589 avail_space = device->total_bytes - device->bytes_used;
1591 /* align with stripe_len */
1592 do_div(avail_space, BTRFS_STRIPE_LEN);
1593 avail_space *= BTRFS_STRIPE_LEN;
1596 * In order to avoid overwritting the superblock on the drive,
1597 * btrfs starts at an offset of at least 1MB when doing chunk
1600 skip_space = 1024 * 1024;
1602 /* user can set the offset in fs_info->alloc_start. */
1603 if (fs_info->alloc_start + BTRFS_STRIPE_LEN <=
1604 device->total_bytes)
1605 skip_space = max(fs_info->alloc_start, skip_space);
1608 * btrfs can not use the free space in [0, skip_space - 1],
1609 * we must subtract it from the total. In order to implement
1610 * it, we account the used space in this range first.
1612 ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1,
1615 kfree(devices_info);
1619 /* calc the free space in [0, skip_space - 1] */
1620 skip_space -= used_space;
1623 * we can use the free space in [0, skip_space - 1], subtract
1624 * it from the total.
1626 if (avail_space && avail_space >= skip_space)
1627 avail_space -= skip_space;
1631 if (avail_space < min_stripe_size)
1634 devices_info[i].dev = device;
1635 devices_info[i].max_avail = avail_space;
1642 btrfs_descending_sort_devices(devices_info, nr_devices);
1646 while (nr_devices >= min_stripes) {
1647 if (num_stripes > nr_devices)
1648 num_stripes = nr_devices;
1650 if (devices_info[i].max_avail >= min_stripe_size) {
1654 avail_space += devices_info[i].max_avail * num_stripes;
1655 alloc_size = devices_info[i].max_avail;
1656 for (j = i + 1 - num_stripes; j <= i; j++)
1657 devices_info[j].max_avail -= alloc_size;
1663 kfree(devices_info);
1664 *free_bytes = avail_space;
1669 * Calculate numbers for 'df', pessimistic in case of mixed raid profiles.
1671 * If there's a redundant raid level at DATA block groups, use the respective
1672 * multiplier to scale the sizes.
1674 * Unused device space usage is based on simulating the chunk allocator
1675 * algorithm that respects the device sizes, order of allocations and the
1676 * 'alloc_start' value, this is a close approximation of the actual use but
1677 * there are other factors that may change the result (like a new metadata
1680 * FIXME: not accurate for mixed block groups, total and free/used are ok,
1681 * available appears slightly larger.
1683 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
1685 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
1686 struct btrfs_super_block *disk_super = fs_info->super_copy;
1687 struct list_head *head = &fs_info->space_info;
1688 struct btrfs_space_info *found;
1690 u64 total_free_data = 0;
1691 int bits = dentry->d_sb->s_blocksize_bits;
1692 __be32 *fsid = (__be32 *)fs_info->fsid;
1693 unsigned factor = 1;
1694 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
1697 /* holding chunk_muext to avoid allocating new chunks */
1698 mutex_lock(&fs_info->chunk_mutex);
1700 list_for_each_entry_rcu(found, head, list) {
1701 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
1704 total_free_data += found->disk_total - found->disk_used;
1706 btrfs_account_ro_block_groups_free_space(found);
1708 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
1709 if (!list_empty(&found->block_groups[i])) {
1711 case BTRFS_RAID_DUP:
1712 case BTRFS_RAID_RAID1:
1713 case BTRFS_RAID_RAID10:
1720 total_used += found->disk_used;
1725 buf->f_blocks = div_u64(btrfs_super_total_bytes(disk_super), factor);
1726 buf->f_blocks >>= bits;
1727 buf->f_bfree = buf->f_blocks - (div_u64(total_used, factor) >> bits);
1729 /* Account global block reserve as used, it's in logical size already */
1730 spin_lock(&block_rsv->lock);
1731 buf->f_bfree -= block_rsv->size >> bits;
1732 spin_unlock(&block_rsv->lock);
1734 buf->f_bavail = total_free_data;
1735 ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data);
1737 mutex_unlock(&fs_info->chunk_mutex);
1740 buf->f_bavail += div_u64(total_free_data, factor);
1741 buf->f_bavail = buf->f_bavail >> bits;
1742 mutex_unlock(&fs_info->chunk_mutex);
1744 buf->f_type = BTRFS_SUPER_MAGIC;
1745 buf->f_bsize = dentry->d_sb->s_blocksize;
1746 buf->f_namelen = BTRFS_NAME_LEN;
1748 /* We treat it as constant endianness (it doesn't matter _which_)
1749 because we want the fsid to come out the same whether mounted
1750 on a big-endian or little-endian host */
1751 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
1752 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
1753 /* Mask in the root object ID too, to disambiguate subvols */
1754 buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32;
1755 buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid;
1760 static void btrfs_kill_super(struct super_block *sb)
1762 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1763 kill_anon_super(sb);
1764 free_fs_info(fs_info);
1767 static struct file_system_type btrfs_fs_type = {
1768 .owner = THIS_MODULE,
1770 .mount = btrfs_mount,
1771 .kill_sb = btrfs_kill_super,
1772 .fs_flags = FS_REQUIRES_DEV,
1774 MODULE_ALIAS_FS("btrfs");
1777 * used by btrfsctl to scan devices when no FS is mounted
1779 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
1782 struct btrfs_ioctl_vol_args *vol;
1783 struct btrfs_fs_devices *fs_devices;
1786 if (!capable(CAP_SYS_ADMIN))
1789 vol = memdup_user((void __user *)arg, sizeof(*vol));
1791 return PTR_ERR(vol);
1794 case BTRFS_IOC_SCAN_DEV:
1795 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1796 &btrfs_fs_type, &fs_devices);
1798 case BTRFS_IOC_DEVICES_READY:
1799 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1800 &btrfs_fs_type, &fs_devices);
1803 ret = !(fs_devices->num_devices == fs_devices->total_devices);
1811 static int btrfs_freeze(struct super_block *sb)
1813 struct btrfs_trans_handle *trans;
1814 struct btrfs_root *root = btrfs_sb(sb)->tree_root;
1816 trans = btrfs_attach_transaction_barrier(root);
1817 if (IS_ERR(trans)) {
1818 /* no transaction, don't bother */
1819 if (PTR_ERR(trans) == -ENOENT)
1821 return PTR_ERR(trans);
1823 return btrfs_commit_transaction(trans, root);
1826 static int btrfs_unfreeze(struct super_block *sb)
1831 static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
1833 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
1834 struct btrfs_fs_devices *cur_devices;
1835 struct btrfs_device *dev, *first_dev = NULL;
1836 struct list_head *head;
1837 struct rcu_string *name;
1839 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1840 cur_devices = fs_info->fs_devices;
1841 while (cur_devices) {
1842 head = &cur_devices->devices;
1843 list_for_each_entry(dev, head, dev_list) {
1848 if (!first_dev || dev->devid < first_dev->devid)
1851 cur_devices = cur_devices->seed;
1856 name = rcu_dereference(first_dev->name);
1857 seq_escape(m, name->str, " \t\n\\");
1862 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1866 static const struct super_operations btrfs_super_ops = {
1867 .drop_inode = btrfs_drop_inode,
1868 .evict_inode = btrfs_evict_inode,
1869 .put_super = btrfs_put_super,
1870 .sync_fs = btrfs_sync_fs,
1871 .show_options = btrfs_show_options,
1872 .show_devname = btrfs_show_devname,
1873 .write_inode = btrfs_write_inode,
1874 .alloc_inode = btrfs_alloc_inode,
1875 .destroy_inode = btrfs_destroy_inode,
1876 .statfs = btrfs_statfs,
1877 .remount_fs = btrfs_remount,
1878 .freeze_fs = btrfs_freeze,
1879 .unfreeze_fs = btrfs_unfreeze,
1882 static const struct file_operations btrfs_ctl_fops = {
1883 .unlocked_ioctl = btrfs_control_ioctl,
1884 .compat_ioctl = btrfs_control_ioctl,
1885 .owner = THIS_MODULE,
1886 .llseek = noop_llseek,
1889 static struct miscdevice btrfs_misc = {
1890 .minor = BTRFS_MINOR,
1891 .name = "btrfs-control",
1892 .fops = &btrfs_ctl_fops
1895 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
1896 MODULE_ALIAS("devname:btrfs-control");
1898 static int btrfs_interface_init(void)
1900 return misc_register(&btrfs_misc);
1903 static void btrfs_interface_exit(void)
1905 if (misc_deregister(&btrfs_misc) < 0)
1906 printk(KERN_INFO "BTRFS: misc_deregister failed for control device\n");
1909 static void btrfs_print_info(void)
1911 printk(KERN_INFO "Btrfs loaded"
1912 #ifdef CONFIG_BTRFS_DEBUG
1915 #ifdef CONFIG_BTRFS_ASSERT
1918 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1919 ", integrity-checker=on"
1924 static int btrfs_run_sanity_tests(void)
1928 ret = btrfs_init_test_fs();
1932 ret = btrfs_test_free_space_cache();
1935 ret = btrfs_test_extent_buffer_operations();
1938 ret = btrfs_test_extent_io();
1941 ret = btrfs_test_inodes();
1944 ret = btrfs_test_qgroups();
1946 btrfs_destroy_test_fs();
1950 static int __init init_btrfs_fs(void)
1954 err = btrfs_hash_init();
1960 err = btrfs_init_sysfs();
1964 btrfs_init_compress();
1966 err = btrfs_init_cachep();
1970 err = extent_io_init();
1974 err = extent_map_init();
1976 goto free_extent_io;
1978 err = ordered_data_init();
1980 goto free_extent_map;
1982 err = btrfs_delayed_inode_init();
1984 goto free_ordered_data;
1986 err = btrfs_auto_defrag_init();
1988 goto free_delayed_inode;
1990 err = btrfs_delayed_ref_init();
1992 goto free_auto_defrag;
1994 err = btrfs_prelim_ref_init();
1996 goto free_prelim_ref;
1998 err = btrfs_interface_init();
2000 goto free_delayed_ref;
2002 btrfs_init_lockdep();
2006 err = btrfs_run_sanity_tests();
2008 goto unregister_ioctl;
2010 err = register_filesystem(&btrfs_fs_type);
2012 goto unregister_ioctl;
2017 btrfs_interface_exit();
2019 btrfs_prelim_ref_exit();
2021 btrfs_delayed_ref_exit();
2023 btrfs_auto_defrag_exit();
2025 btrfs_delayed_inode_exit();
2027 ordered_data_exit();
2033 btrfs_destroy_cachep();
2035 btrfs_exit_compress();
2042 static void __exit exit_btrfs_fs(void)
2044 btrfs_destroy_cachep();
2045 btrfs_delayed_ref_exit();
2046 btrfs_auto_defrag_exit();
2047 btrfs_delayed_inode_exit();
2048 btrfs_prelim_ref_exit();
2049 ordered_data_exit();
2052 btrfs_interface_exit();
2053 unregister_filesystem(&btrfs_fs_type);
2055 btrfs_cleanup_fs_uuids();
2056 btrfs_exit_compress();
2060 late_initcall(init_btrfs_fs);
2061 module_exit(exit_btrfs_fs)
2063 MODULE_LICENSE("GPL");