fs: export fs_holder_ops

Export fs_holder_ops so that file systems that open additional block
devices can use it as well.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Message-Id: <20230802154131.2221419-9-hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>

fs/super.c

@@ -1244,9 +1244,10 @@ static void fs_mark_dead(struct block_device *bdev)
 	up_read(&sb->s_umount);
 }
 
-static const struct blk_holder_ops fs_holder_ops = {
+const struct blk_holder_ops fs_holder_ops = {
 	.mark_dead		= fs_mark_dead,
 };
+EXPORT_SYMBOL_GPL(fs_holder_ops);
 
 static int set_bdev_super(struct super_block *s, void *data)
 {

include/linux/blkdev.h

@@ -1464,6 +1464,8 @@ struct blk_holder_ops {
 	void (*mark_dead)(struct block_device *bdev);
 };
 
+extern const struct blk_holder_ops fs_holder_ops;
+
 /*
  * Return the correct open flags for blkdev_get_by_* for super block flags
  * as stored in sb->s_flags.