4 * Copyright (C) 1991, 1992 Linus Torvalds
6 * super.c contains code to handle: - mount structures
8 * - filesystem drivers list
10 * - umount system call
13 * GK 2/5/95 - Changed to support mounting the root fs via NFS
15 * Added kerneld support: Jacques Gelinas and Bjorn Ekwall
16 * Added change_root: Werner Almesberger & Hans Lermen, Feb '96
17 * Added options to /proc/mounts:
18 * Torbjörn Lindh (torbjorn.lindh@gopta.se), April 14, 1996.
19 * Added devfs support: Richard Gooch <rgooch@atnf.csiro.au>, 13-JAN-1998
20 * Heavily rewritten for 'one fs - one tree' dcache architecture. AV, Mar 2000
23 #include <linux/module.h>
24 #include <linux/slab.h>
25 #include <linux/acct.h>
26 #include <linux/blkdev.h>
27 #include <linux/mount.h>
28 #include <linux/security.h>
29 #include <linux/writeback.h> /* for the emergency remount stuff */
30 #include <linux/idr.h>
31 #include <linux/mutex.h>
32 #include <linux/backing-dev.h>
33 #include <linux/rculist_bl.h>
34 #include <linux/cleancache.h>
38 LIST_HEAD(super_blocks);
39 DEFINE_SPINLOCK(sb_lock);
42 * alloc_super - create new superblock
43 * @type: filesystem type superblock should belong to
45 * Allocates and initializes a new &struct super_block. alloc_super()
46 * returns a pointer new superblock or %NULL if allocation had failed.
48 static struct super_block *alloc_super(struct file_system_type *type)
50 struct super_block *s = kzalloc(sizeof(struct super_block), GFP_USER);
51 static const struct super_operations default_op;
54 if (security_sb_alloc(s)) {
60 s->s_files = alloc_percpu(struct list_head);
69 for_each_possible_cpu(i)
70 INIT_LIST_HEAD(per_cpu_ptr(s->s_files, i));
73 INIT_LIST_HEAD(&s->s_files);
75 s->s_bdi = &default_backing_dev_info;
76 INIT_LIST_HEAD(&s->s_instances);
77 INIT_HLIST_BL_HEAD(&s->s_anon);
78 INIT_LIST_HEAD(&s->s_inodes);
79 INIT_LIST_HEAD(&s->s_dentry_lru);
80 init_rwsem(&s->s_umount);
81 mutex_init(&s->s_lock);
82 lockdep_set_class(&s->s_umount, &type->s_umount_key);
84 * The locking rules for s_lock are up to the
85 * filesystem. For example ext3fs has different
86 * lock ordering than usbfs:
88 lockdep_set_class(&s->s_lock, &type->s_lock_key);
90 * sget() can have s_umount recursion.
92 * When it cannot find a suitable sb, it allocates a new
93 * one (this one), and tries again to find a suitable old
96 * In case that succeeds, it will acquire the s_umount
97 * lock of the old one. Since these are clearly distrinct
98 * locks, and this object isn't exposed yet, there's no
101 * Annotate this by putting this lock in a different
104 down_write_nested(&s->s_umount, SINGLE_DEPTH_NESTING);
106 atomic_set(&s->s_active, 1);
107 mutex_init(&s->s_vfs_rename_mutex);
108 lockdep_set_class(&s->s_vfs_rename_mutex, &type->s_vfs_rename_key);
109 mutex_init(&s->s_dquot.dqio_mutex);
110 mutex_init(&s->s_dquot.dqonoff_mutex);
111 init_rwsem(&s->s_dquot.dqptr_sem);
112 init_waitqueue_head(&s->s_wait_unfrozen);
113 s->s_maxbytes = MAX_NON_LFS;
114 s->s_op = &default_op;
115 s->s_time_gran = 1000000000;
116 s->cleancache_poolid = -1;
123 * destroy_super - frees a superblock
124 * @s: superblock to free
126 * Frees a superblock.
128 static inline void destroy_super(struct super_block *s)
131 free_percpu(s->s_files);
139 /* Superblock refcounting */
142 * Drop a superblock's refcount. The caller must hold sb_lock.
144 void __put_super(struct super_block *sb)
146 if (!--sb->s_count) {
147 list_del_init(&sb->s_list);
153 * put_super - drop a temporary reference to superblock
154 * @sb: superblock in question
156 * Drops a temporary reference, frees superblock if there's no
159 void put_super(struct super_block *sb)
163 spin_unlock(&sb_lock);
168 * deactivate_locked_super - drop an active reference to superblock
169 * @s: superblock to deactivate
171 * Drops an active reference to superblock, converting it into a temprory
172 * one if there is no other active references left. In that case we
173 * tell fs driver to shut it down and drop the temporary reference we
176 * Caller holds exclusive lock on superblock; that lock is released.
178 void deactivate_locked_super(struct super_block *s)
180 struct file_system_type *fs = s->s_type;
181 if (atomic_dec_and_test(&s->s_active)) {
182 cleancache_flush_fs(s);
185 * We need to call rcu_barrier so all the delayed rcu free
186 * inodes are flushed before we release the fs module.
192 up_write(&s->s_umount);
196 EXPORT_SYMBOL(deactivate_locked_super);
199 * deactivate_super - drop an active reference to superblock
200 * @s: superblock to deactivate
202 * Variant of deactivate_locked_super(), except that superblock is *not*
203 * locked by caller. If we are going to drop the final active reference,
204 * lock will be acquired prior to that.
206 void deactivate_super(struct super_block *s)
208 if (!atomic_add_unless(&s->s_active, -1, 1)) {
209 down_write(&s->s_umount);
210 deactivate_locked_super(s);
214 EXPORT_SYMBOL(deactivate_super);
217 * grab_super - acquire an active reference
218 * @s: reference we are trying to make active
220 * Tries to acquire an active reference. grab_super() is used when we
221 * had just found a superblock in super_blocks or fs_type->fs_supers
222 * and want to turn it into a full-blown active reference. grab_super()
223 * is called with sb_lock held and drops it. Returns 1 in case of
224 * success, 0 if we had failed (superblock contents was already dead or
225 * dying when grab_super() had been called).
227 static int grab_super(struct super_block *s) __releases(sb_lock)
229 if (atomic_inc_not_zero(&s->s_active)) {
230 spin_unlock(&sb_lock);
233 /* it's going away */
235 spin_unlock(&sb_lock);
236 /* wait for it to die */
237 down_write(&s->s_umount);
238 up_write(&s->s_umount);
244 * Superblock locking. We really ought to get rid of these two.
246 void lock_super(struct super_block * sb)
249 mutex_lock(&sb->s_lock);
252 void unlock_super(struct super_block * sb)
255 mutex_unlock(&sb->s_lock);
258 EXPORT_SYMBOL(lock_super);
259 EXPORT_SYMBOL(unlock_super);
262 * generic_shutdown_super - common helper for ->kill_sb()
263 * @sb: superblock to kill
265 * generic_shutdown_super() does all fs-independent work on superblock
266 * shutdown. Typical ->kill_sb() should pick all fs-specific objects
267 * that need destruction out of superblock, call generic_shutdown_super()
268 * and release aforementioned objects. Note: dentries and inodes _are_
269 * taken care of and do not need specific handling.
271 * Upon calling this function, the filesystem may no longer alter or
272 * rearrange the set of dentries belonging to this super_block, nor may it
273 * change the attachments of dentries to inodes.
275 void generic_shutdown_super(struct super_block *sb)
277 const struct super_operations *sop = sb->s_op;
281 shrink_dcache_for_umount(sb);
284 sb->s_flags &= ~MS_ACTIVE;
286 fsnotify_unmount_inodes(&sb->s_inodes);
293 if (!list_empty(&sb->s_inodes)) {
294 printk("VFS: Busy inodes after unmount of %s. "
295 "Self-destruct in 5 seconds. Have a nice day...\n",
301 /* should be initialized for __put_super_and_need_restart() */
302 list_del_init(&sb->s_instances);
303 spin_unlock(&sb_lock);
304 up_write(&sb->s_umount);
307 EXPORT_SYMBOL(generic_shutdown_super);
310 * sget - find or create a superblock
311 * @type: filesystem type superblock should belong to
312 * @test: comparison callback
313 * @set: setup callback
314 * @data: argument to each of them
316 struct super_block *sget(struct file_system_type *type,
317 int (*test)(struct super_block *,void *),
318 int (*set)(struct super_block *,void *),
321 struct super_block *s = NULL;
322 struct super_block *old;
328 list_for_each_entry(old, &type->fs_supers, s_instances) {
329 if (!test(old, data))
331 if (!grab_super(old))
334 up_write(&s->s_umount);
338 down_write(&old->s_umount);
339 if (unlikely(!(old->s_flags & MS_BORN))) {
340 deactivate_locked_super(old);
347 spin_unlock(&sb_lock);
348 s = alloc_super(type);
350 return ERR_PTR(-ENOMEM);
356 spin_unlock(&sb_lock);
357 up_write(&s->s_umount);
362 strlcpy(s->s_id, type->name, sizeof(s->s_id));
363 list_add_tail(&s->s_list, &super_blocks);
364 list_add(&s->s_instances, &type->fs_supers);
365 spin_unlock(&sb_lock);
366 get_filesystem(type);
372 void drop_super(struct super_block *sb)
374 up_read(&sb->s_umount);
378 EXPORT_SYMBOL(drop_super);
381 * sync_supers - helper for periodic superblock writeback
383 * Call the write_super method if present on all dirty superblocks in
384 * the system. This is for the periodic writeback used by most older
385 * filesystems. For data integrity superblock writeback use
386 * sync_filesystems() instead.
388 * Note: check the dirty flag before waiting, so we don't
389 * hold up the sync while mounting a device. (The newly
390 * mounted device won't need syncing.)
392 void sync_supers(void)
394 struct super_block *sb, *p = NULL;
397 list_for_each_entry(sb, &super_blocks, s_list) {
398 if (list_empty(&sb->s_instances))
400 if (sb->s_op->write_super && sb->s_dirt) {
402 spin_unlock(&sb_lock);
404 down_read(&sb->s_umount);
405 if (sb->s_root && sb->s_dirt)
406 sb->s_op->write_super(sb);
407 up_read(&sb->s_umount);
417 spin_unlock(&sb_lock);
421 * iterate_supers - call function for all active superblocks
422 * @f: function to call
423 * @arg: argument to pass to it
425 * Scans the superblock list and calls given function, passing it
426 * locked superblock and given argument.
428 void iterate_supers(void (*f)(struct super_block *, void *), void *arg)
430 struct super_block *sb, *p = NULL;
433 list_for_each_entry(sb, &super_blocks, s_list) {
434 if (list_empty(&sb->s_instances))
437 spin_unlock(&sb_lock);
439 down_read(&sb->s_umount);
442 up_read(&sb->s_umount);
451 spin_unlock(&sb_lock);
455 * iterate_supers_type - call function for superblocks of given type
457 * @f: function to call
458 * @arg: argument to pass to it
460 * Scans the superblock list and calls given function, passing it
461 * locked superblock and given argument.
463 void iterate_supers_type(struct file_system_type *type,
464 void (*f)(struct super_block *, void *), void *arg)
466 struct super_block *sb, *p = NULL;
469 list_for_each_entry(sb, &type->fs_supers, s_instances) {
471 spin_unlock(&sb_lock);
473 down_read(&sb->s_umount);
476 up_read(&sb->s_umount);
485 spin_unlock(&sb_lock);
488 EXPORT_SYMBOL(iterate_supers_type);
491 * get_super - get the superblock of a device
492 * @bdev: device to get the superblock for
494 * Scans the superblock list and finds the superblock of the file system
495 * mounted on the device given. %NULL is returned if no match is found.
498 struct super_block *get_super(struct block_device *bdev)
500 struct super_block *sb;
507 list_for_each_entry(sb, &super_blocks, s_list) {
508 if (list_empty(&sb->s_instances))
510 if (sb->s_bdev == bdev) {
512 spin_unlock(&sb_lock);
513 down_read(&sb->s_umount);
517 up_read(&sb->s_umount);
518 /* nope, got unmounted */
524 spin_unlock(&sb_lock);
528 EXPORT_SYMBOL(get_super);
531 * get_active_super - get an active reference to the superblock of a device
532 * @bdev: device to get the superblock for
534 * Scans the superblock list and finds the superblock of the file system
535 * mounted on the device given. Returns the superblock with an active
536 * reference or %NULL if none was found.
538 struct super_block *get_active_super(struct block_device *bdev)
540 struct super_block *sb;
547 list_for_each_entry(sb, &super_blocks, s_list) {
548 if (list_empty(&sb->s_instances))
550 if (sb->s_bdev == bdev) {
551 if (grab_super(sb)) /* drops sb_lock */
557 spin_unlock(&sb_lock);
561 struct super_block *user_get_super(dev_t dev)
563 struct super_block *sb;
567 list_for_each_entry(sb, &super_blocks, s_list) {
568 if (list_empty(&sb->s_instances))
570 if (sb->s_dev == dev) {
572 spin_unlock(&sb_lock);
573 down_read(&sb->s_umount);
577 up_read(&sb->s_umount);
578 /* nope, got unmounted */
584 spin_unlock(&sb_lock);
589 * do_remount_sb - asks filesystem to change mount options.
590 * @sb: superblock in question
591 * @flags: numeric part of options
592 * @data: the rest of options
593 * @force: whether or not to force the change
595 * Alters the mount options of a mounted file system.
597 int do_remount_sb(struct super_block *sb, int flags, void *data, int force)
602 if (sb->s_frozen != SB_UNFROZEN)
606 if (!(flags & MS_RDONLY) && bdev_read_only(sb->s_bdev))
610 if (flags & MS_RDONLY)
612 shrink_dcache_sb(sb);
615 remount_ro = (flags & MS_RDONLY) && !(sb->s_flags & MS_RDONLY);
617 /* If we are remounting RDONLY and current sb is read/write,
618 make sure there are no rw files opened */
622 else if (!fs_may_remount_ro(sb))
626 if (sb->s_op->remount_fs) {
627 retval = sb->s_op->remount_fs(sb, &flags, data);
631 sb->s_flags = (sb->s_flags & ~MS_RMT_MASK) | (flags & MS_RMT_MASK);
634 * Some filesystems modify their metadata via some other path than the
635 * bdev buffer cache (eg. use a private mapping, or directories in
636 * pagecache, etc). Also file data modifications go via their own
637 * mappings. So If we try to mount readonly then copy the filesystem
638 * from bdev, we could get stale data, so invalidate it to give a best
639 * effort at coherency.
641 if (remount_ro && sb->s_bdev)
642 invalidate_bdev(sb->s_bdev);
646 static void do_emergency_remount(struct work_struct *work)
648 struct super_block *sb, *p = NULL;
651 list_for_each_entry(sb, &super_blocks, s_list) {
652 if (list_empty(&sb->s_instances))
655 spin_unlock(&sb_lock);
656 down_write(&sb->s_umount);
657 if (sb->s_root && sb->s_bdev && !(sb->s_flags & MS_RDONLY)) {
659 * What lock protects sb->s_flags??
661 do_remount_sb(sb, MS_RDONLY, NULL, 1);
663 up_write(&sb->s_umount);
671 spin_unlock(&sb_lock);
673 printk("Emergency Remount complete\n");
676 void emergency_remount(void)
678 struct work_struct *work;
680 work = kmalloc(sizeof(*work), GFP_ATOMIC);
682 INIT_WORK(work, do_emergency_remount);
688 * Unnamed block devices are dummy devices used by virtual
689 * filesystems which don't use real block-devices. -- jrs
692 static DEFINE_IDA(unnamed_dev_ida);
693 static DEFINE_SPINLOCK(unnamed_dev_lock);/* protects the above */
694 static int unnamed_dev_start = 0; /* don't bother trying below it */
696 int set_anon_super(struct super_block *s, void *data)
702 if (ida_pre_get(&unnamed_dev_ida, GFP_ATOMIC) == 0)
704 spin_lock(&unnamed_dev_lock);
705 error = ida_get_new_above(&unnamed_dev_ida, unnamed_dev_start, &dev);
707 unnamed_dev_start = dev + 1;
708 spin_unlock(&unnamed_dev_lock);
709 if (error == -EAGAIN)
710 /* We raced and lost with another CPU. */
715 if ((dev & MAX_ID_MASK) == (1 << MINORBITS)) {
716 spin_lock(&unnamed_dev_lock);
717 ida_remove(&unnamed_dev_ida, dev);
718 if (unnamed_dev_start > dev)
719 unnamed_dev_start = dev;
720 spin_unlock(&unnamed_dev_lock);
723 s->s_dev = MKDEV(0, dev & MINORMASK);
724 s->s_bdi = &noop_backing_dev_info;
728 EXPORT_SYMBOL(set_anon_super);
730 void kill_anon_super(struct super_block *sb)
732 int slot = MINOR(sb->s_dev);
734 generic_shutdown_super(sb);
735 spin_lock(&unnamed_dev_lock);
736 ida_remove(&unnamed_dev_ida, slot);
737 if (slot < unnamed_dev_start)
738 unnamed_dev_start = slot;
739 spin_unlock(&unnamed_dev_lock);
742 EXPORT_SYMBOL(kill_anon_super);
744 void kill_litter_super(struct super_block *sb)
747 d_genocide(sb->s_root);
751 EXPORT_SYMBOL(kill_litter_super);
753 static int ns_test_super(struct super_block *sb, void *data)
755 return sb->s_fs_info == data;
758 static int ns_set_super(struct super_block *sb, void *data)
760 sb->s_fs_info = data;
761 return set_anon_super(sb, NULL);
764 struct dentry *mount_ns(struct file_system_type *fs_type, int flags,
765 void *data, int (*fill_super)(struct super_block *, void *, int))
767 struct super_block *sb;
769 sb = sget(fs_type, ns_test_super, ns_set_super, data);
776 err = fill_super(sb, data, flags & MS_SILENT ? 1 : 0);
778 deactivate_locked_super(sb);
782 sb->s_flags |= MS_ACTIVE;
785 return dget(sb->s_root);
788 EXPORT_SYMBOL(mount_ns);
791 static int set_bdev_super(struct super_block *s, void *data)
794 s->s_dev = s->s_bdev->bd_dev;
797 * We set the bdi here to the queue backing, file systems can
798 * overwrite this in ->fill_super()
800 s->s_bdi = &bdev_get_queue(s->s_bdev)->backing_dev_info;
804 static int test_bdev_super(struct super_block *s, void *data)
806 return (void *)s->s_bdev == data;
809 struct dentry *mount_bdev(struct file_system_type *fs_type,
810 int flags, const char *dev_name, void *data,
811 int (*fill_super)(struct super_block *, void *, int))
813 struct block_device *bdev;
814 struct super_block *s;
815 fmode_t mode = FMODE_READ | FMODE_EXCL;
818 if (!(flags & MS_RDONLY))
821 bdev = blkdev_get_by_path(dev_name, mode, fs_type);
823 return ERR_CAST(bdev);
826 * once the super is inserted into the list by sget, s_umount
827 * will protect the lockfs code from trying to start a snapshot
828 * while we are mounting
830 mutex_lock(&bdev->bd_fsfreeze_mutex);
831 if (bdev->bd_fsfreeze_count > 0) {
832 mutex_unlock(&bdev->bd_fsfreeze_mutex);
836 s = sget(fs_type, test_bdev_super, set_bdev_super, bdev);
837 mutex_unlock(&bdev->bd_fsfreeze_mutex);
842 if ((flags ^ s->s_flags) & MS_RDONLY) {
843 deactivate_locked_super(s);
849 * s_umount nests inside bd_mutex during
850 * __invalidate_device(). blkdev_put() acquires
851 * bd_mutex and can't be called under s_umount. Drop
852 * s_umount temporarily. This is safe as we're
853 * holding an active reference.
855 up_write(&s->s_umount);
856 blkdev_put(bdev, mode);
857 down_write(&s->s_umount);
859 char b[BDEVNAME_SIZE];
861 s->s_flags = flags | MS_NOSEC;
863 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
864 sb_set_blocksize(s, block_size(bdev));
865 error = fill_super(s, data, flags & MS_SILENT ? 1 : 0);
867 deactivate_locked_super(s);
871 s->s_flags |= MS_ACTIVE;
875 return dget(s->s_root);
880 blkdev_put(bdev, mode);
882 return ERR_PTR(error);
884 EXPORT_SYMBOL(mount_bdev);
886 void kill_block_super(struct super_block *sb)
888 struct block_device *bdev = sb->s_bdev;
889 fmode_t mode = sb->s_mode;
891 bdev->bd_super = NULL;
892 generic_shutdown_super(sb);
894 WARN_ON_ONCE(!(mode & FMODE_EXCL));
895 blkdev_put(bdev, mode | FMODE_EXCL);
898 EXPORT_SYMBOL(kill_block_super);
901 struct dentry *mount_nodev(struct file_system_type *fs_type,
902 int flags, void *data,
903 int (*fill_super)(struct super_block *, void *, int))
906 struct super_block *s = sget(fs_type, NULL, set_anon_super, NULL);
913 error = fill_super(s, data, flags & MS_SILENT ? 1 : 0);
915 deactivate_locked_super(s);
916 return ERR_PTR(error);
918 s->s_flags |= MS_ACTIVE;
919 return dget(s->s_root);
921 EXPORT_SYMBOL(mount_nodev);
923 static int compare_single(struct super_block *s, void *p)
928 struct dentry *mount_single(struct file_system_type *fs_type,
929 int flags, void *data,
930 int (*fill_super)(struct super_block *, void *, int))
932 struct super_block *s;
935 s = sget(fs_type, compare_single, set_anon_super, NULL);
940 error = fill_super(s, data, flags & MS_SILENT ? 1 : 0);
942 deactivate_locked_super(s);
943 return ERR_PTR(error);
945 s->s_flags |= MS_ACTIVE;
947 do_remount_sb(s, flags, data, 0);
949 return dget(s->s_root);
951 EXPORT_SYMBOL(mount_single);
954 mount_fs(struct file_system_type *type, int flags, const char *name, void *data)
957 struct super_block *sb;
958 char *secdata = NULL;
961 if (data && !(type->fs_flags & FS_BINARY_MOUNTDATA)) {
962 secdata = alloc_secdata();
966 error = security_sb_copy_data(data, secdata);
968 goto out_free_secdata;
971 root = type->mount(type, flags, name, data);
973 error = PTR_ERR(root);
974 goto out_free_secdata;
979 WARN_ON(sb->s_bdi == &default_backing_dev_info);
980 sb->s_flags |= MS_BORN;
982 error = security_sb_kern_mount(sb, flags, secdata);
987 * filesystems should never set s_maxbytes larger than MAX_LFS_FILESIZE
988 * but s_maxbytes was an unsigned long long for many releases. Throw
989 * this warning for a little while to try and catch filesystems that
992 WARN((sb->s_maxbytes < 0), "%s set sb->s_maxbytes to "
993 "negative value (%lld)\n", type->name, sb->s_maxbytes);
995 up_write(&sb->s_umount);
996 free_secdata(secdata);
1000 deactivate_locked_super(sb);
1002 free_secdata(secdata);
1004 return ERR_PTR(error);
1008 * freeze_super - lock the filesystem and force it into a consistent state
1009 * @sb: the super to lock
1011 * Syncs the super to make sure the filesystem is consistent and calls the fs's
1012 * freeze_fs. Subsequent calls to this without first thawing the fs will return
1015 int freeze_super(struct super_block *sb)
1019 atomic_inc(&sb->s_active);
1020 down_write(&sb->s_umount);
1022 deactivate_locked_super(sb);
1026 if (sb->s_flags & MS_RDONLY) {
1027 sb->s_frozen = SB_FREEZE_TRANS;
1029 up_write(&sb->s_umount);
1033 sb->s_frozen = SB_FREEZE_WRITE;
1036 sync_filesystem(sb);
1038 sb->s_frozen = SB_FREEZE_TRANS;
1041 sync_blockdev(sb->s_bdev);
1042 if (sb->s_op->freeze_fs) {
1043 ret = sb->s_op->freeze_fs(sb);
1046 "VFS:Filesystem freeze failed\n");
1047 sb->s_frozen = SB_UNFROZEN;
1048 deactivate_locked_super(sb);
1052 up_write(&sb->s_umount);
1055 EXPORT_SYMBOL(freeze_super);
1058 * thaw_super -- unlock filesystem
1059 * @sb: the super to thaw
1061 * Unlocks the filesystem and marks it writeable again after freeze_super().
1063 int thaw_super(struct super_block *sb)
1067 down_write(&sb->s_umount);
1068 if (sb->s_frozen == SB_UNFROZEN) {
1069 up_write(&sb->s_umount);
1073 if (sb->s_flags & MS_RDONLY)
1076 if (sb->s_op->unfreeze_fs) {
1077 error = sb->s_op->unfreeze_fs(sb);
1080 "VFS:Filesystem thaw failed\n");
1081 sb->s_frozen = SB_FREEZE_TRANS;
1082 up_write(&sb->s_umount);
1088 sb->s_frozen = SB_UNFROZEN;
1090 wake_up(&sb->s_wait_unfrozen);
1091 deactivate_locked_super(sb);
1095 EXPORT_SYMBOL(thaw_super);