[PATCH] scsi: ufs: Fix divide zero case in ufshcd_map_queues()

From: Jinyoung CHOI
Date: Mon Feb 14 2022 - 16:18:15 EST


Before calling blk_mq_map_queues(), the mq_map and nr_queues belonging
to "struct blk_mq_queue_map" must be a vaild value.

If nr_queues is set to 0, the system may encounter the "divide zero"
depending on the type of architecture.

blk_mq_map_queues() -> queue_index()

Signed-off-by: Jinyoung Choi <j-young.choi@xxxxxxxxxxx>
---
drivers/scsi/ufs/ufshcd.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 41d85b69fa50..36c5ca62ae0c 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -2674,21 +2674,21 @@ static int ufshcd_map_queues(struct Scsi_Host *shost)
for (i = 0; i < shost->nr_maps; i++) {
struct blk_mq_queue_map *map = &shost->tag_set.map[i];

switch (i) {
case HCTX_TYPE_DEFAULT:
case HCTX_TYPE_POLL:
map->nr_queues = 1;
break;
case HCTX_TYPE_READ:
map->nr_queues = 0;
- break;
+ continue;
default:
WARN_ON_ONCE(true);
}
map->queue_offset = 0;
ret = blk_mq_map_queues(map);
WARN_ON_ONCE(ret);
}

return 0;
}
--
2.25.1