From: Bart Van Assche <bart.vanassche@wdc.com>
Date: Thu, 9 Nov 2017 10:49:55 -0800
Subject: [PATCH] block: Introduce BLK_MQ_REQ_PREEMPT
Git-commit: 1b6d65a0bfb5df2a6029c1430e99fcc5d96bb59a
Patch-mainline: v4.15-rc1
References: bsc#1104967,FATE#325924
Set RQF_PREEMPT if BLK_MQ_REQ_PREEMPT is passed to
blk_get_request_flags().
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Martin Steigerwald <martin@lichtvoll.de>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Hannes Reinecke <hare@suse.com>
---
block/blk-core.c | 4 +++-
block/blk-mq.c | 2 ++
include/linux/blk-mq.h | 1 +
3 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 0f7093dfc010..17eed16a6e04 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1263,6 +1263,8 @@ static struct request *__get_request(struct request_list *rl, unsigned int op,
blk_rq_set_rl(rq, rl);
rq->cmd_flags = op;
rq->rq_flags = rq_flags;
+ if (flags & BLK_MQ_REQ_PREEMPT)
+ rq->rq_flags |= RQF_PREEMPT;
/* init elvpriv */
if (rq_flags & RQF_ELVPRIV) {
@@ -1444,7 +1446,7 @@ struct request *blk_get_request_flags(struct request_queue *q, unsigned int op,
struct request *req;
WARN_ON_ONCE(op & REQ_NOWAIT);
- WARN_ON_ONCE(flags & ~BLK_MQ_REQ_NOWAIT);
+ WARN_ON_ONCE(flags & ~(BLK_MQ_REQ_NOWAIT | BLK_MQ_REQ_PREEMPT));
if (q->mq_ops) {
req = blk_mq_alloc_request(q, op, flags);
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 7173d4bd64af..e21876778cec 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -291,6 +291,8 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
rq->q = data->q;
rq->mq_ctx = data->ctx;
rq->cmd_flags = op;
+ if (data->flags & BLK_MQ_REQ_PREEMPT)
+ rq->rq_flags |= RQF_PREEMPT;
if (blk_queue_io_stat(data->q))
rq->rq_flags |= RQF_IO_STAT;
/* do not touch atomic flags, it needs atomic ops against the timer */
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 4ae987c2352c..82b56609736a 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -212,6 +212,7 @@ enum {
BLK_MQ_REQ_NOWAIT = (1 << 0), /* return when out of requests */
BLK_MQ_REQ_RESERVED = (1 << 1), /* allocate from reserved pool */
BLK_MQ_REQ_INTERNAL = (1 << 2), /* allocate internal/sched tag */
+ BLK_MQ_REQ_PREEMPT = (1 << 3), /* set RQF_PREEMPT */
};
struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op,
--
2.16.4