[PATCH 2/4] block: check virt boundary in bio_will_gap()

From: Ming Lei
Date: Mon Feb 15 2016 - 02:02:35 EST


In the following patch, the way for figuring out
the last bvec will be changed with a bit cost introduced,
so return immediately if the queue doesn't have virt
boundary limit. Actually most of devices have not
this limit.

Cc: Sagi Grimberg <sagig@xxxxxxxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxxxxx>
---
include/linux/blkdev.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 4571ef1..b8ff6a3 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1388,7 +1388,7 @@ static inline bool bvec_gap_to_prev(struct request_queue *q,
static inline bool bio_will_gap(struct request_queue *q, struct bio *prev,
struct bio *next)
{
- if (!bio_has_data(prev))
+ if (!bio_has_data(prev) || !queue_virt_boundary(q))
return false;

return bvec_gap_to_prev(q, &prev->bi_io_vec[prev->bi_vcnt - 1],
--
1.9.1