From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:36248 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754390AbdDOMko (ORCPT ); Sat, 15 Apr 2017 08:40:44 -0400 From: Ming Lei To: Jens Axboe , linux-block@vger.kernel.org Cc: Christoph Hellwig , Omar Sandoval , Jozef Mikovic , Ming Lei Subject: [PATCH 1/4] block: respect BLK_MQ_F_NO_SCHED Date: Sat, 15 Apr 2017 20:38:22 +0800 Message-Id: <20170415123825.32716-2-ming.lei@redhat.com> In-Reply-To: <20170415123825.32716-1-ming.lei@redhat.com> References: <20170415123825.32716-1-ming.lei@redhat.com> Sender: linux-block-owner@vger.kernel.org List-Id: linux-block@vger.kernel.org If one driver claims that it doesn't support io scheduler via BLK_MQ_F_NO_SCHED, we should not allow to change and show the availabe io schedulers. This patch adds check to enhance this behaviour. Signed-off-by: Ming Lei --- block/elevator.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/block/elevator.c b/block/elevator.c index dbeecf7be719..4d9084a14c10 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -1098,12 +1098,20 @@ int elevator_change(struct request_queue *q, const char *name) } EXPORT_SYMBOL(elevator_change); +static inline bool elv_support_iosched(struct request_queue *q) +{ + if (q->mq_ops && q->tag_set && (q->tag_set->flags & + BLK_MQ_F_NO_SCHED)) + return false; + return true; +} + ssize_t elv_iosched_store(struct request_queue *q, const char *name, size_t count) { int ret; - if (!(q->mq_ops || q->request_fn)) + if (!(q->mq_ops || q->request_fn) || !elv_support_iosched(q)) return count; ret = __elevator_change(q, name); @@ -1135,7 +1143,7 @@ ssize_t elv_iosched_show(struct request_queue *q, char *name) len += sprintf(name+len, "[%s] ", elv->elevator_name); continue; } - if (__e->uses_mq && q->mq_ops) + if (__e->uses_mq && q->mq_ops && elv_support_iosched(q)) len += sprintf(name+len, "%s ", __e->elevator_name); else if (!__e->uses_mq && !q->mq_ops) len += sprintf(name+len, "%s ", __e->elevator_name); -- 2.9.3