From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EC000C433EF for ; Tue, 26 Oct 2021 07:31:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C69E7610C7 for ; Tue, 26 Oct 2021 07:31:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232736AbhJZHeS (ORCPT ); Tue, 26 Oct 2021 03:34:18 -0400 Received: from verein.lst.de ([213.95.11.211]:60757 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232626AbhJZHeR (ORCPT ); Tue, 26 Oct 2021 03:34:17 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id 47F4F6732D; Tue, 26 Oct 2021 09:31:52 +0200 (CEST) Date: Tue, 26 Oct 2021 09:31:52 +0200 From: Christoph Hellwig To: Ming Lei Cc: Jens Axboe , linux-block@vger.kernel.org, Christoph Hellwig Subject: Re: [PATCH 2/8] loop: remove always true check Message-ID: <20211026073152.GB31967@lst.de> References: <20211025094437.2837701-1-ming.lei@redhat.com> <20211025094437.2837701-3-ming.lei@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211025094437.2837701-3-ming.lei@redhat.com> User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org lo_complete_rq is still a complete mess. I'd suggest something like this instead: diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 8f140d6374356..1648d30a8cb4a 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -517,40 +517,37 @@ static void lo_flush_dcache_for_read(struct request *rq) static void lo_complete_rq(struct request *rq) { struct loop_cmd *cmd = blk_mq_rq_to_pdu(rq); - blk_status_t ret = BLK_STS_OK; + + if (cmd->ret < 0) { + blk_mq_end_request(rq, errno_to_blk_status(cmd->ret)); + return; + } /* Kernel wrote to our pages, call flush_dcache_page */ if (req_op(rq) == REQ_OP_READ && !cmd->use_aio && cmd->ret >= 0) lo_flush_dcache_for_read(rq); - if (!cmd->use_aio || cmd->ret < 0 || cmd->ret == blk_rq_bytes(rq) || - req_op(rq) != REQ_OP_READ) { - if (cmd->ret < 0) - ret = errno_to_blk_status(cmd->ret); - goto end_io; - } - /* - * Short READ - if we got some data, advance our request and - * retry it. If we got no data, end the rest with EIO. + * Short READ - if we got some data, advance our request and retry it. + * If we got no data, end the rest with EIO. */ - if (cmd->ret) { - blk_update_request(rq, BLK_STS_OK, cmd->ret); - cmd->ret = 0; - blk_mq_requeue_request(rq, true); - } else { - if (cmd->use_aio) { - struct bio *bio = rq->bio; + if (req_op(rq) == REQ_OP_READ && cmd->use_aio && + cmd->ret != blk_rq_bytes(rq)) { + if (cmd->ret) { + blk_update_request(rq, BLK_STS_OK, cmd->ret); + cmd->ret = 0; + blk_mq_requeue_request(rq, true); + } else { + struct bio *bio; - while (bio) { + for (bio = rq->bio; bio; bio = bio->bi_next) zero_fill_bio(bio); - bio = bio->bi_next; - } + blk_mq_end_request(rq, BLK_STS_IOERR); } - ret = BLK_STS_IOERR; -end_io: - blk_mq_end_request(rq, ret); + return; } + + blk_mq_end_request(rq, BLK_STS_OK); } static void lo_rw_aio_do_completion(struct loop_cmd *cmd)