diff options
Diffstat (limited to 'fs/super.c')
| -rw-r--r-- | fs/super.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/fs/super.c b/fs/super.c index e5d9765ff5f4..fe5a7b3a1134 100644 --- a/fs/super.c +++ b/fs/super.c @@ -634,6 +634,28 @@ rescan: EXPORT_SYMBOL(get_super); /** + * get_super_thawed - get thawed superblock of a device + * @bdev: device to get the superblock for + * + * Scans the superblock list and finds the superblock of the file system + * mounted on the device. The superblock is returned once it is thawed + * (or immediately if it was not frozen). %NULL is returned if no match + * is found. + */ +struct super_block *get_super_thawed(struct block_device *bdev) +{ + while (1) { + struct super_block *s = get_super(bdev); + if (!s || s->s_frozen == SB_UNFROZEN) + return s; + up_read(&s->s_umount); + vfs_check_frozen(s, SB_FREEZE_WRITE); + put_super(s); + } +} +EXPORT_SYMBOL(get_super_thawed); + +/** * get_active_super - get an active reference to the superblock of a device * @bdev: device to get the superblock for * @@ -1186,6 +1208,8 @@ int freeze_super(struct super_block *sb) printk(KERN_ERR "VFS:Filesystem freeze failed\n"); sb->s_frozen = SB_UNFROZEN; + smp_wmb(); + wake_up(&sb->s_wait_unfrozen); deactivate_locked_super(sb); return ret; } |