blk-mq: don't time out requests again that are in the timeout handler

From: Christoph Hellwig
Date: Wed Jun 13 2018 - 10:25:40 EST


Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
block/blk-mq.c | 4 ++++
include/linux/blkdev.h | 2 ++
2 files changed, 6 insertions(+)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index e9da5e6a8526..8a2895fed078 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -770,6 +770,7 @@ EXPORT_SYMBOL(blk_mq_tag_to_rq);

static void blk_mq_rq_timed_out(struct request *req, bool reserved)
{
+ req->rq_flags |= RQF_TIMED_OUT;
if (req->q->mq_ops->timeout) {
enum blk_eh_timer_return ret;

@@ -779,6 +780,7 @@ static void blk_mq_rq_timed_out(struct request *req, bool reserved)
WARN_ON_ONCE(ret != BLK_EH_RESET_TIMER);
}

+ req->rq_flags &= ~RQF_TIMED_OUT;
blk_add_timer(req);
}

@@ -788,6 +790,8 @@ static bool blk_mq_req_expired(struct request *rq, unsigned long *next)

if (blk_mq_rq_state(rq) != MQ_RQ_IN_FLIGHT)
return false;
+ if (rq->rq_flags & RQF_TIMED_OUT)
+ return false;

deadline = blk_rq_deadline(rq);
if (time_after_eq(jiffies, deadline))
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index bca3a92eb55f..fa6f11751430 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -127,6 +127,8 @@ typedef __u32 __bitwise req_flags_t;
#define RQF_ZONE_WRITE_LOCKED ((__force req_flags_t)(1 << 19))
/* already slept for hybrid poll */
#define RQF_MQ_POLL_SLEPT ((__force req_flags_t)(1 << 20))
+/* ->timeout has been called, don't expire again */
+#define RQF_TIMED_OUT ((__force req_flags_t)(1 << 21))

/* flags that prevent us from merging requests: */
#define RQF_NOMERGE_FLAGS \
--
2.17.1