From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DF874BA32 for ; Tue, 7 Mar 2023 17:11:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 45BFBC433EF; Tue, 7 Mar 2023 17:11:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678209085; bh=x615Eig+2u2KTTZ4IJAVCKtXMpVU2WTJvZyHG95cn0I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Yi7vxUwleJ7xMFzsju6NPx4ZEAGl/gqGeBdqpjgpTRfJ1FeK3X2jze89ioTEvu7lL GITBHuGSMiV11U+0+G1fsnY5Rn60oFNifusU8QF7tGeZuUESqZlbWLeZ+zwwE5dDWA K7Jfk6sDuo7DAtYUi++0uYD81av3YZlyVbuWurBQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Christoph Hellwig , Kemeng Shi , Jens Axboe , Sasha Levin Subject: [PATCH 6.2 0106/1001] blk-mq: avoid sleep in blk_mq_alloc_request_hctx Date: Tue, 7 Mar 2023 17:47:58 +0100 Message-Id: <20230307170026.733142946@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230307170022.094103862@linuxfoundation.org> References: <20230307170022.094103862@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Kemeng Shi [ Upstream commit 6ee858a3d3270a68902d66bb47c151a83622535c ] Commit 1f5bd336b9150 ("blk-mq: add blk_mq_alloc_request_hctx") add blk_mq_alloc_request_hctx to send commands to a specific queue. If BLK_MQ_REQ_NOWAIT is not set in tag allocation, we may change to different hctx after sleep and get tag from unexpected hctx. So BLK_MQ_REQ_NOWAIT must be set in flags for blk_mq_alloc_request_hctx. After commit 600c3b0cea784 ("blk-mq: open code __blk_mq_alloc_request in blk_mq_alloc_request_hctx"), blk_mq_alloc_request_hctx return -EINVAL if both BLK_MQ_REQ_NOWAIT and BLK_MQ_REQ_RESERVED are not set instead of if BLK_MQ_REQ_NOWAIT is not set. So if BLK_MQ_REQ_NOWAIT is not set and BLK_MQ_REQ_RESERVED is set, blk_mq_alloc_request_hctx could alloc tag from unexpected hctx. I guess what we need here is that return -EINVAL if either BLK_MQ_REQ_NOWAIT or BLK_MQ_REQ_RESERVED is not set. Currently both BLK_MQ_REQ_NOWAIT and BLK_MQ_REQ_RESERVED will be set if specific hctx is needed in nvme_auth_submit, nvmf_connect_io_queue and nvmf_connect_admin_queue. Fix the potential BLK_MQ_REQ_NOWAIT missed case in future. Fixes: 600c3b0cea78 ("blk-mq: open code __blk_mq_alloc_request in blk_mq_alloc_request_hctx") Reviewed-by: Christoph Hellwig Signed-off-by: Kemeng Shi Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- block/blk-mq.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 9c8dc70020bc9..dc29a7c82bb82 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -658,7 +658,8 @@ struct request *blk_mq_alloc_request_hctx(struct request_queue *q, * allocator for this for the rare use case of a command tied to * a specific queue. */ - if (WARN_ON_ONCE(!(flags & (BLK_MQ_REQ_NOWAIT | BLK_MQ_REQ_RESERVED)))) + if (WARN_ON_ONCE(!(flags & BLK_MQ_REQ_NOWAIT)) || + WARN_ON_ONCE(!(flags & BLK_MQ_REQ_RESERVED))) return ERR_PTR(-EINVAL); if (hctx_idx >= q->nr_hw_queues) -- 2.39.2