From nobody Sat Feb 7 07:25:04 2026 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 51CE0284880 for ; Fri, 21 Nov 2025 01:59:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763690372; cv=none; b=GqHpTO6s2i3+ScFmwjD9AgYr5ajkxprvHChUTmfTuCkpxt5nKVekf4+DfUHOug+9L6XxZuqvl17tvo3WpE9d8iI1ToeQc7ket+5GsO3N31NaN37tZ+ctMwVlVt+s1Rjf2UEA4TyqqXMn6wfyj30Ix28JMJCI8KXReVU8Bx2/U7I= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763690372; c=relaxed/simple; bh=2sEs+ptW36m+FbqKF4ySBIhs1E5oCnMNQ3hLz1W9yQo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=IZC2neZ8vNujGfR6fL73O3V5CPAMU9E4w83ATvJLfwmYrJdmHg7nkdMsBC3/GGNt4FpVrJsqNC2TEg0O6rCOfy7dCmVOzADFLTcqiSxUbgIdndPHDPIh2/Zpr6a1QHNjukRbfwcKmqKQVG3HLRz6utAtYUWa8vWLPzcF2VTF15w= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=fVjUPYD2; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="fVjUPYD2" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1763690370; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=yzFM7RscsZAkx5obOZIu/ddnHKngMYodVSIc+DQ/QEg=; b=fVjUPYD2xv3acB+5Bld8sNE1VuWRQYt21TQQ8CQWT1kJgCudHxj4XMTPdVUpw4JIujLaIr cIvoNk+lfcaWRur6WB7y5uWSmkBSsIvipSVuyb1UwEooAvU+3ZKjiwnP7x689kE1LGkkH1 xRzmCZQb3IAqDiRyIABpMHDo0RyBh6c= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-635-8CSPvGiLNzedJsKOTZQ5Xg-1; Thu, 20 Nov 2025 20:59:23 -0500 X-MC-Unique: 8CSPvGiLNzedJsKOTZQ5Xg-1 X-Mimecast-MFC-AGG-ID: 8CSPvGiLNzedJsKOTZQ5Xg_1763690362 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 50EDA195609F; Fri, 21 Nov 2025 01:59:21 +0000 (UTC) Received: from localhost (unknown [10.72.116.211]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 0D33D1956045; Fri, 21 Nov 2025 01:59:19 +0000 (UTC) From: Ming Lei To: Jens Axboe , linux-block@vger.kernel.org Cc: Caleb Sander Mateos , Uday Shankar , Stefani Seibold , Andrew Morton , linux-kernel@vger.kernel.org, Ming Lei Subject: [PATCH V4 04/27] ublk: refactor auto buffer register in ublk_dispatch_req() Date: Fri, 21 Nov 2025 09:58:26 +0800 Message-ID: <20251121015851.3672073-5-ming.lei@redhat.com> In-Reply-To: <20251121015851.3672073-1-ming.lei@redhat.com> References: <20251121015851.3672073-1-ming.lei@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Content-Type: text/plain; charset="utf-8" Refactor auto buffer register code and prepare for supporting batch IO feature, and the main motivation is to put 'ublk_io' operation code together, so that per-io lock can be applied for the code block. The key changes are: - Rename ublk_auto_buf_reg() as ublk_do_auto_buf_reg() - Introduce an enum `auto_buf_reg_res` to represent the result of the buffer registration attempt (FAIL, FALLBACK, OK). - Split the existing `ublk_do_auto_buf_reg` function into two: - `__ublk_do_auto_buf_reg`: Performs the actual buffer registration and returns the `auto_buf_reg_res` status. - `ublk_do_auto_buf_reg`: A wrapper that calls the internal function and handles the I/O preparation based on the result. - Introduce `ublk_prep_auto_buf_reg_io` to encapsulate the logic for preparing the I/O for completion after buffer registration. - Pass the `tag` directly to `ublk_auto_buf_reg_fallback` to avoid recalculating it. This refactoring makes the control flow clearer and isolates the different stages of the auto buffer registration process. Reviewed-by: Caleb Sander Mateos Signed-off-by: Ming Lei --- drivers/block/ublk_drv.c | 64 +++++++++++++++++++++++++++------------- 1 file changed, 43 insertions(+), 21 deletions(-) diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index f1fa5ceacdf6..b36cd55eceb0 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -1168,17 +1168,37 @@ static inline void __ublk_abort_rq(struct ublk_queu= e *ubq, } =20 static void -ublk_auto_buf_reg_fallback(const struct ublk_queue *ubq, struct ublk_io *i= o) +ublk_auto_buf_reg_fallback(const struct ublk_queue *ubq, unsigned tag) { - unsigned tag =3D io - ubq->ios; struct ublksrv_io_desc *iod =3D ublk_get_iod(ubq, tag); =20 iod->op_flags |=3D UBLK_IO_F_NEED_REG_BUF; } =20 -static bool ublk_auto_buf_reg(const struct ublk_queue *ubq, struct request= *req, - struct ublk_io *io, struct io_uring_cmd *cmd, - unsigned int issue_flags) +enum auto_buf_reg_res { + AUTO_BUF_REG_FAIL, + AUTO_BUF_REG_FALLBACK, + AUTO_BUF_REG_OK, +}; + +static void ublk_prep_auto_buf_reg_io(const struct ublk_queue *ubq, + struct request *req, struct ublk_io *io, + struct io_uring_cmd *cmd, + enum auto_buf_reg_res res) +{ + if (res =3D=3D AUTO_BUF_REG_OK) { + io->task_registered_buffers =3D 1; + io->buf_ctx_handle =3D io_uring_cmd_ctx_handle(cmd); + io->flags |=3D UBLK_IO_FLAG_AUTO_BUF_REG; + } + ublk_init_req_ref(ubq, io); + __ublk_prep_compl_io_cmd(io, req); +} + +static enum auto_buf_reg_res +__ublk_do_auto_buf_reg(const struct ublk_queue *ubq, struct request *req, + struct ublk_io *io, struct io_uring_cmd *cmd, + unsigned int issue_flags) { int ret; =20 @@ -1186,29 +1206,27 @@ static bool ublk_auto_buf_reg(const struct ublk_que= ue *ubq, struct request *req, io->buf.auto_reg.index, issue_flags); if (ret) { if (io->buf.auto_reg.flags & UBLK_AUTO_BUF_REG_FALLBACK) { - ublk_auto_buf_reg_fallback(ubq, io); - return true; + ublk_auto_buf_reg_fallback(ubq, req->tag); + return AUTO_BUF_REG_FALLBACK; } blk_mq_end_request(req, BLK_STS_IOERR); - return false; + return AUTO_BUF_REG_FAIL; } =20 - io->task_registered_buffers =3D 1; - io->buf_ctx_handle =3D io_uring_cmd_ctx_handle(cmd); - io->flags |=3D UBLK_IO_FLAG_AUTO_BUF_REG; - return true; + return AUTO_BUF_REG_OK; } =20 -static bool ublk_prep_auto_buf_reg(struct ublk_queue *ubq, - struct request *req, struct ublk_io *io, - struct io_uring_cmd *cmd, - unsigned int issue_flags) +static void ublk_do_auto_buf_reg(const struct ublk_queue *ubq, struct requ= est *req, + struct ublk_io *io, struct io_uring_cmd *cmd, + unsigned int issue_flags) { - ublk_init_req_ref(ubq, io); - if (ublk_support_auto_buf_reg(ubq) && ublk_rq_has_data(req)) - return ublk_auto_buf_reg(ubq, req, io, cmd, issue_flags); + enum auto_buf_reg_res res =3D __ublk_do_auto_buf_reg(ubq, req, io, cmd, + issue_flags); =20 - return true; + if (res !=3D AUTO_BUF_REG_FAIL) { + ublk_prep_auto_buf_reg_io(ubq, req, io, cmd, res); + io_uring_cmd_done(cmd, UBLK_IO_RES_OK, issue_flags); + } } =20 static bool ublk_start_io(const struct ublk_queue *ubq, struct request *re= q, @@ -1281,8 +1299,12 @@ static void ublk_dispatch_req(struct ublk_queue *ubq, if (!ublk_start_io(ubq, req, io)) return; =20 - if (ublk_prep_auto_buf_reg(ubq, req, io, io->cmd, issue_flags)) + if (ublk_support_auto_buf_reg(ubq) && ublk_rq_has_data(req)) { + ublk_do_auto_buf_reg(ubq, req, io, io->cmd, issue_flags); + } else { + ublk_init_req_ref(ubq, io); ublk_complete_io_cmd(io, req, UBLK_IO_RES_OK, issue_flags); + } } =20 static void ublk_cmd_tw_cb(struct io_uring_cmd *cmd, --=20 2.47.0