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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Damien Le Moal <damien.lemoal@wdc.com>,
        Hannes Reinecke <hare@suse.de>, Jens Axboe <axboe@kernel.dk>
Subject: [PATCH 4.19 144/293] block: bfq: fix bfq_set_next_ioprio_data()
Date:   Mon, 20 Sep 2021 18:41:46 +0200
Message-Id: <20210920163938.210294242@linuxfoundation.org>
In-Reply-To: <20210920163933.258815435@linuxfoundation.org>
References: <20210920163933.258815435@linuxfoundation.org>
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From: Damien Le Moal <damien.lemoal@wdc.com>

commit a680dd72ec336b81511e3bff48efac6dbfa563e7 upstream.

For a request that has a priority level equal to or larger than
IOPRIO_BE_NR, bfq_set_next_ioprio_data() prints a critical warning but
defaults to setting the request new_ioprio field to IOPRIO_BE_NR. This
is not consistent with the warning and the allowed values for priority
levels. Fix this by setting the request new_ioprio field to
IOPRIO_BE_NR - 1, the lowest priority level allowed.

Cc: <stable@vger.kernel.org>
Fixes: aee69d78dec0 ("block, bfq: introduce the BFQ-v0 I/O scheduler as an extra scheduler")
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20210811033702.368488-2-damien.lemoal@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 block/bfq-iosched.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -4241,7 +4241,7 @@ bfq_set_next_ioprio_data(struct bfq_queu
 	if (bfqq->new_ioprio >= IOPRIO_BE_NR) {
 		pr_crit("bfq_set_next_ioprio_data: new_ioprio %d\n",
 			bfqq->new_ioprio);
-		bfqq->new_ioprio = IOPRIO_BE_NR;
+		bfqq->new_ioprio = IOPRIO_BE_NR - 1;
 	}
 
 	bfqq->entity.new_weight = bfq_ioprio_to_weight(bfqq->new_ioprio);