From patchwork Tue Dec 19 21:05:42 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mike Snitzer X-Patchwork-Id: 10124365 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 100D36019C for ; Tue, 19 Dec 2017 21:06:15 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 01418294C6 for ; Tue, 19 Dec 2017 21:06:15 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id EA4A7295BA; Tue, 19 Dec 2017 21:06:14 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9B368294C6 for ; Tue, 19 Dec 2017 21:06:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752716AbdLSVGO (ORCPT ); Tue, 19 Dec 2017 16:06:14 -0500 Received: from mx1.redhat.com ([209.132.183.28]:34168 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752826AbdLSVGN (ORCPT ); Tue, 19 Dec 2017 16:06:13 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 91AB481DE2; Tue, 19 Dec 2017 21:06:13 +0000 (UTC) Received: from localhost (wlan-196-89.bos.redhat.com [10.16.196.89]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 02CA219652; Tue, 19 Dec 2017 21:06:10 +0000 (UTC) From: Mike Snitzer To: axboe@kernel.dk, hch@lst.de, emilne@redhat.com, james.smart@broadcom.com Cc: hare@suse.de, Bart.VanAssche@wdc.com, linux-block@vger.kernel.org, linux-nvme@lists.infradead.org, dm-devel@redhat.com Subject: [for-4.16 PATCH 1/5] block: establish request failover callback infrastructure Date: Tue, 19 Dec 2017 16:05:42 -0500 Message-Id: <20171219210546.65928-2-snitzer@redhat.com> In-Reply-To: <20171219210546.65928-1-snitzer@redhat.com> References: <20171219210546.65928-1-snitzer@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Tue, 19 Dec 2017 21:06:13 +0000 (UTC) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP If bio sets 'bi_failover_rq' callback it'll get transfered to the appropriate request's 'failover_rq' using blk_init_request_from_bio(). This callback is expected to use the blk_steal_bios() interface to transfer a request's bios back to a bio-based request_queue. This will be used by both NVMe multipath and DM multipath. Without it DM multipath cannot get access to NVMe-specific error handling that NVMe core provides in nvme_complete_rq(). Signed-off-by: Mike Snitzer --- block/blk-core.c | 2 ++ block/blk-mq.c | 1 + include/linux/blk_types.h | 4 ++++ include/linux/blkdev.h | 6 ++++++ 4 files changed, 13 insertions(+) diff --git a/block/blk-core.c b/block/blk-core.c index b8881750a3ac..95bdc4f2b11d 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1872,6 +1872,8 @@ void blk_init_request_from_bio(struct request *req, struct bio *bio) else req->ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 0); req->write_hint = bio->bi_write_hint; + if (bio->bi_failover_rq) + req->failover_rq = bio->bi_failover_rq; blk_rq_bio_prep(req->q, req, bio); } EXPORT_SYMBOL_GPL(blk_init_request_from_bio); diff --git a/block/blk-mq.c b/block/blk-mq.c index 11097477eeab..bb52f8283f07 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -320,6 +320,7 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data, rq->end_io = NULL; rq->end_io_data = NULL; + rq->failover_rq = NULL; rq->next_rq = NULL; data->ctx->rq_dispatched[op_is_sync(op)]++; diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index a1e628e032da..c3a952991814 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -18,6 +18,9 @@ struct io_context; struct cgroup_subsys_state; typedef void (bio_end_io_t) (struct bio *); +struct request; +typedef void (rq_failover_fn)(struct request *); + /* * Block error status values. See block/blk-core:blk_errors for the details. */ @@ -77,6 +80,7 @@ struct bio { atomic_t __bi_remaining; bio_end_io_t *bi_end_io; + rq_failover_fn *bi_failover_rq; void *bi_private; #ifdef CONFIG_BLK_CGROUP diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 8089ca17db9a..46bcd782debe 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -237,6 +237,12 @@ struct request { rq_end_io_fn *end_io; void *end_io_data; + /* + * callback to failover request's bios back to upper layer + * bio-based queue using blk_steal_bios(). + */ + rq_failover_fn *failover_rq; + /* for bidi */ struct request *next_rq; };