block: fix a race between del_gendisk and BLKRRPART

When BLKRRPART is called concurrently with del_gendisk, the partitions rescan can create a stale partition that will never be be cleaned up. Fix this by checking the the disk is up before rescanning partitions while under bd_mutex. Signed-off-by: Gulam Mohamed <[email protected]> [hch: split from a larger patch] Signed-off-by: Christoph Hellwig <[email protected]> Reviewed-by: Ming Lei <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jens Axboe <[email protected]>
multipath-tcp · May 20, 2021 · bc6a385 · bc6a385
1 parent 6c60ff0
commit bc6a385
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/fs/block_dev.c b/fs/block_dev.c
@@ -1244,6 +1244,9 @@ int bdev_disk_changed(struct block_device *bdev, bool invalidate)
 
 	lockdep_assert_held(&bdev->bd_mutex);
 
+	if (!(disk->flags & GENHD_FL_UP))
+		return -ENXIO;
+
 rescan:
 	if (bdev->bd_part_count)
 		return -EBUSY;