block: fix wrong mode for blkdev_put() from disk_scan_partitions()

If disk_scan_partitions() is called with 'FMODE_EXCL',
blkdev_get_by_dev() will be called without 'FMODE_EXCL', however, follow
blkdev_put() is still called with 'FMODE_EXCL', which will cause
'bd_holders' counter to leak.

Fix the problem by using the right mode for blkdev_put().

Reported-by: [email protected]
Link: https://lore.kernel.org/lkml/[email protected]/T/
Tested-by: Julian Ruess <[email protected]>
Fixes: e5cfefa ("block: fix scan partition for exclusively open device again")
Signed-off-by: Yu Kuai <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

Author: YuKuai-huawei

block/genhd.c

@@ -385,7 +385,7 @@ int disk_scan_partitions(struct gendisk *disk, fmode_t mode)
 	if (IS_ERR(bdev))
 		ret =  PTR_ERR(bdev);
 	else
-		blkdev_put(bdev, mode);
+		blkdev_put(bdev, mode & ~FMODE_EXCL);
 
 	if (!(mode & FMODE_EXCL))
 		bd_abort_claiming(disk->part0, disk_scan_partitions);