Patch "blk-mq: don't call io sched's .requeue_request when requeueing rq to ->dispatch" has been added to the 4.15-stable tree

Patch "blk-mq: don't call io sched's .requeue_request when requeueing rq to ->dispatch" has been added to the 4.15-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    blk-mq: don't call io sched's .requeue_request when requeueing rq to ->dispatch

to the 4.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     blk-mq-don-t-call-io-sched-s-.requeue_request-when-requeueing-rq-to-dispatch.patch
and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 105976f517791aed3b11f8f53b308a2069d42055 Mon Sep 17 00:00:00 2001
From: Ming Lei <ming.lei@redhat.com>
Date: Fri, 23 Feb 2018 23:36:56 +0800
Subject: blk-mq: don't call io sched's .requeue_request when requeueing rq to ->dispatch

From: Ming Lei <ming.lei@redhat.com>

commit 105976f517791aed3b11f8f53b308a2069d42055 upstream.

__blk_mq_requeue_request() covers two cases:

- one is that the requeued request is added to hctx->dispatch, such as
blk_mq_dispatch_rq_list()

- another case is that the request is requeued to io scheduler, such as
blk_mq_requeue_request().

We should call io sched's .requeue_request callback only for the 2nd
case.

Cc: Paolo Valente <paolo.valente@linaro.org>
Cc: Omar Sandoval <osandov@fb.com>
Fixes: bd166ef183c2 ("blk-mq-sched: add framework for MQ capable IO schedulers")
Cc: stable@vger.kernel.org
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Acked-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 block/blk-mq.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -655,7 +655,6 @@ static void __blk_mq_requeue_request(str
 
 	trace_block_rq_requeue(q, rq);
 	wbt_requeue(q->rq_wb, &rq->issue_stat);
-	blk_mq_sched_requeue_request(rq);
 
 	if (test_and_clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) {
 		if (q->dma_drain_size && blk_rq_bytes(rq))
@@ -667,6 +666,9 @@ void blk_mq_requeue_request(struct reque
 {
 	__blk_mq_requeue_request(rq);
 
+	/* this request will be re-inserted to io scheduler queue */
+	blk_mq_sched_requeue_request(rq);
+
 	BUG_ON(blk_queued_rq(rq));
 	blk_mq_add_to_requeue_list(rq, true, kick_requeue_list);
 }


Patches currently in stable-queue which might be from ming.lei@redhat.com are

queue-4.15/block-pass-inclusive-lend-parameter-to-truncate_inode_pages_range.patch
queue-4.15/blk-mq-don-t-call-io-sched-s-.requeue_request-when-requeueing-rq-to-dispatch.patch
queue-4.15/block-kyber-fix-domain-token-leak-during-requeue.patch