vfs: Provide function to get superblock and wait for it to thaw
In quota code we need to find a superblock corresponding to a device and wait
for superblock to be unfrozen. However this waiting has to happen without
s_umount semaphore because that is required for superblock to thaw. So provide
a function in VFS for this to keep dances with s_umount where they belong.
[AV: implementation switched to saner variant]
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 386da09..69cd5bb 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2496,6 +2496,7 @@
extern void put_filesystem(struct file_system_type *fs);
extern struct file_system_type *get_fs_type(const char *name);
extern struct super_block *get_super(struct block_device *);
+extern struct super_block *get_super_thawed(struct block_device *);
extern struct super_block *get_active_super(struct block_device *bdev);
extern void drop_super(struct super_block *sb);
extern void iterate_supers(void (*)(struct super_block *, void *), void *);