2 files changed, 8 insertions, 1 deletions

diff --git a/block/ioctl.c b/block/ioctl.c
index e3f5eb9882cf..e06dbe9bc858 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -82,7 +82,7 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user
                         fsync_bdev(bdevp);
                         invalidate_bdev(bdevp, 0);
 
-                        mutex_lock(&bdev->bd_mutex);
+                        mutex_lock_nested(&bdev->bd_mutex, 1);
                         delete_partition(disk, part);
                         mutex_unlock(&bdev->bd_mutex);
                         mutex_unlock(&bdevp->bd_mutex);
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 0c59b703e9d5..575076c018f4 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1101,6 +1101,13 @@ static int __blkdev_get(struct block_device *bdev, mode_t mode, unsigned flags,
                         int for_part);
 static int __blkdev_put(struct block_device *bdev, int for_part);
 
+/*
+ * bd_mutex locking:
+ *
+ *  mutex_lock(part->bd_mutex)
+ *    mutex_lock_nested(whole->bd_mutex, 1)
+ */
+
 static int do_open(struct block_device *bdev, struct file *file, int for_part)
 {
         struct module *owner = NULL;