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Subject: Re: [PATCH RESEND v3 01/13] blk-mq: Change rqs check in
 blk_mq_free_rqs()
To:     John Garry <john.garry@huawei.com>, axboe@kernel.dk
Cc:     linux-kernel@vger.kernel.org, linux-block@vger.kernel.org,
        ming.lei@redhat.com, linux-scsi@vger.kernel.org
References: <1631545950-56586-1-git-send-email-john.garry@huawei.com>
 <1631545950-56586-2-git-send-email-john.garry@huawei.com>
From:   Hannes Reinecke <hare@suse.de>
Message-ID: <7a75a9e0-5467-e4fa-d059-8154f5568854@suse.de>
Date:   Tue, 14 Sep 2021 07:35:48 +0200
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On 9/13/21 5:12 PM, John Garry wrote:
> The original code in commit 24d2f90309b23 ("blk-mq: split out tag
> initialization, support shared tags") would check tags->rqs is non-NULL and
> then dereference tags->rqs[].
> 
> Then in commit 2af8cbe30531 ("blk-mq: split tag ->rqs[] into two"), we
> started to dereference tags->static_rqs[], but continued to check non-NULL
> tags->rqs.
> 
> Check tags->static_rqs as non-NULL instead, which is more logical.
> 
> Signed-off-by: John Garry <john.garry@huawei.com>
> Reviewed-by: Ming Lei <ming.lei@redhat.com>
> ---
>   block/blk-mq.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/block/blk-mq.c b/block/blk-mq.c
> index 108a352051be..2316ff27c1f5 100644
> --- a/block/blk-mq.c
> +++ b/block/blk-mq.c
> @@ -2340,7 +2340,7 @@ void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
>   {
>   	struct page *page;
>   
> -	if (tags->rqs && set->ops->exit_request) {
> +	if (tags->static_rqs && set->ops->exit_request) {
>   		int i;
>   
>   		for (i = 0; i < tags->nr_tags; i++) {
> 
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
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