block: fix busy device checking in blk_drop_partitions again

The previous fix had an off by one in the bd_openers checking, counting
the callers blkdev_get.

Fixes: d3ef5536274f ("block: fix busy device checking in blk_drop_partitions")
Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Qian Cai <cai@lca.pw>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/partitions/core.c b/block/partitions/core.c
index 1a0a829..bc1ded1 100644 (file)
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -496,7 +496,7 @@ int blk_drop_partitions(struct gendisk *disk, struct block_device *bdev)
 
        if (!disk_part_scan_enabled(disk))
                return 0;
-       if (bdev->bd_part_count || bdev->bd_openers)
+       if (bdev->bd_part_count || bdev->bd_openers > 1)
                return -EBUSY;
        res = invalidate_partition(disk, 0);
        if (res)