[PATCH] lockdep: remove lock_key approach to managing nested bd_mutex locks

The extra call to get_gendisk is not good.  It causes a ->probe and possible
module load before it is really appropriate to do this.

Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 528cf053ce967e99dbddd419ebc91b04d68d229a..36c38f48a4edaf9ff80c0cd434886649d80b3101 100644 (file)
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -355,14 +355,10 @@ static int bdev_set(struct inode *inode, void *data)
 
 static LIST_HEAD(all_bdevs);
 
-static struct lock_class_key bdev_part_lock_key;
-
 struct block_device *bdget(dev_t dev)
 {
        struct block_device *bdev;
        struct inode *inode;
-       struct gendisk *disk;
-       int part = 0;
 
        inode = iget5_locked(bd_mnt->mnt_sb, hash(dev),
                        bdev_test, bdev_set, &dev);
@@ -388,11 +384,6 @@ struct block_device *bdget(dev_t dev)
                list_add(&bdev->bd_list, &all_bdevs);
                spin_unlock(&bdev_lock);
                unlock_new_inode(inode);
-               mutex_init(&bdev->bd_mutex);
-               disk = get_gendisk(dev, &part);
-               if (part)
-                       lockdep_set_class(&bdev->bd_mutex, &bdev_part_lock_key);
-               put_disk(disk);
        }
        return bdev;
 }