From 29ece8b4354f8c5eaee798a3d8a1b356efee426f Mon Sep 17 00:00:00 2001
From: Yufen Yu <yuyufen@huawei.com>
Date: Mon, 18 Mar 2019 22:44:41 +0800
Subject: [PATCH] block: add BLK_MQ_POLL_CLASSIC for hybrid poll and return
EINVAL for unexpected value
For q->poll_nsec == -1, means doing classic poll, not hybrid poll.
We introduce a new flag BLK_MQ_POLL_CLASSIC to replace -1, which
may make code much easier to read.
Additionally, since val is an int obtained with kstrtoint(), val can be
a negative value other than -1, so return -EINVAL for that case.
Thanks to Damien Le Moal for some good suggestion.
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
block/blk-mq.c | 4 ++--
block/blk-sysfs.c | 12 +++++++-----
include/linux/blkdev.h | 3 +++
3 files changed, 12 insertions(+), 7 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index ea01c23b58a3d..76a3f78c566ab 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2856,7 +2856,7 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
/*
* Default to classic polling
*/
- q->poll_nsec = -1;
+ q->poll_nsec = BLK_MQ_POLL_CLASSIC;
blk_mq_init_cpu_queues(q, set->nr_hw_queues);
blk_mq_add_queue_tag_set(set, q);
@@ -3391,7 +3391,7 @@ static bool blk_mq_poll_hybrid(struct request_queue *q,
{
struct request *rq;
- if (q->poll_nsec == -1)
+ if (q->poll_nsec == BLK_MQ_POLL_CLASSIC)
return false;
if (!blk_qc_t_is_internal(cookie))
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 59685918167e5..422327089e0fd 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -360,8 +360,8 @@ static ssize_t queue_poll_delay_show(struct request_queue *q, char *page)
{
int val;
- if (q->poll_nsec == -1)
- val = -1;
+ if (q->poll_nsec == BLK_MQ_POLL_CLASSIC)
+ val = BLK_MQ_POLL_CLASSIC;
else
val = q->poll_nsec / 1000;
@@ -380,10 +380,12 @@ static ssize_t queue_poll_delay_store(struct request_queue *q, const char *page,
if (err < 0)
return err;
- if (val == -1)
- q->poll_nsec = -1;
- else
+ if (val == BLK_MQ_POLL_CLASSIC)
+ q->poll_nsec = BLK_MQ_POLL_CLASSIC;
+ else if (val >= 0)
q->poll_nsec = val * 1000;
+ else
+ return -EINVAL;
return count;
}
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 0de92b29f589c..5c58a3b2bf003 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -50,6 +50,9 @@ struct blk_stat_callback;
/* Must be consistent with blk_mq_poll_stats_bkt() */
#define BLK_MQ_POLL_STATS_BKTS 16
+/* Doing classic polling */
+#define BLK_MQ_POLL_CLASSIC -1
+
/*
* Maximum number of blkcg policies allowed to be registered concurrently.
* Defined here to simplify include dependency.
--
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