[PATCH] blk: avoid divide-by-zero with zero granularity

[Li Feng]

If the physical_block_size and io_min is less than a sector, the
'granularity >> SECTOR_SHIFT' will be zero.

Signed-off-by: Li Feng <fen...@smartx.com>
---
 include/linux/blkdev.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index f94ee3089e01..4d029e95adb4 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1485,6 +1485,10 @@ static inline int queue_alignment_offset(const struct 
request_queue *q)
 static inline int queue_limit_alignment_offset(struct queue_limits *lim, 
sector_t sector)
 {
        unsigned int granularity = max(lim->physical_block_size, lim->io_min);
+       granularity = granularity >> SECTOR_SHIFT;
+       if (!granularity)
+               return 0;
+
        unsigned int alignment = sector_div(sector, granularity >> SECTOR_SHIFT)
                << SECTOR_SHIFT;
 
-- 
2.29.2