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 X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 10A1BC3A5A8 for ; Tue, 3 Sep 2019 16:31:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DADCF238F7 for ; Tue, 3 Sep 2019 16:31:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567528300; bh=dyrfv+WP+eThW7h6SeQXXHb7vB1kv65ppMyTfn8KQow=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=kLE15B2MIj3DA6S3l1KXxNPxmFgFO4EdOIjI0m6S5yfMHFcWtnUj4jQBwC6UUX/XK ba6r8sQDI1v74xAatgi5mwLe4A5XNlmLO9GE45wnAxLlxLeGmuFsnZGZFXRgUEN0hX GAjfTQRPCf/qbBLStC7IUOmmWzI7c6oBheOkKWuc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731087AbfICQ2S (ORCPT ); Tue, 3 Sep 2019 12:28:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:50100 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731080AbfICQ2R (ORCPT ); Tue, 3 Sep 2019 12:28:17 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1EFA3238C6; Tue, 3 Sep 2019 16:28:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567528096; bh=dyrfv+WP+eThW7h6SeQXXHb7vB1kv65ppMyTfn8KQow=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1iZbDcN0rFadrEOo41N4z2PB+gL7ULkZePJJNhx3OIgeCG9phzPT+1wkyM8BsxQmy nWceNAjZ7oT8/i5b5oeEH6KTCKl83FMzBt302hR1oTLWXxj0xCvIfngiOJ7xGgNM+U B2HcG90eaRfTH/dqvY7f719Kc8N2Obk64eDdNnSc= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Yufen Yu , stable@vger.kernl.org, Mike Snitzer , Sasha Levin Subject: [PATCH AUTOSEL 4.19 105/167] dm mpath: fix missing call of path selector type->end_io Date: Tue, 3 Sep 2019 12:24:17 -0400 Message-Id: <20190903162519.7136-105-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190903162519.7136-1-sashal@kernel.org> References: <20190903162519.7136-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Yufen Yu [ Upstream commit 5de719e3d01b4abe0de0d7b857148a880ff2a90b ] After commit 396eaf21ee17 ("blk-mq: improve DM's blk-mq IO merging via blk_insert_cloned_request feedback"), map_request() will requeue the tio when issued clone request return BLK_STS_RESOURCE or BLK_STS_DEV_RESOURCE. Thus, if device driver status is error, a tio may be requeued multiple times until the return value is not DM_MAPIO_REQUEUE. That means type->start_io may be called multiple times, while type->end_io is only called when IO complete. In fact, even without commit 396eaf21ee17, setup_clone() failure can also cause tio requeue and associated missed call to type->end_io. The service-time path selector selects path based on in_flight_size, which is increased by st_start_io() and decreased by st_end_io(). Missed calls to st_end_io() can lead to in_flight_size count error and will cause the selector to make the wrong choice. In addition, queue-length path selector will also be affected. To fix the problem, call type->end_io in ->release_clone_rq before tio requeue. map_info is passed to ->release_clone_rq() for map_request() error path that result in requeue. Fixes: 396eaf21ee17 ("blk-mq: improve DM's blk-mq IO merging via blk_insert_cloned_request feedback") Cc: stable@vger.kernl.org Signed-off-by: Yufen Yu Signed-off-by: Mike Snitzer Signed-off-by: Sasha Levin --- drivers/md/dm-mpath.c | 17 ++++++++++++++++- drivers/md/dm-rq.c | 8 ++++---- drivers/md/dm-target.c | 3 ++- include/linux/device-mapper.h | 3 ++- 4 files changed, 24 insertions(+), 7 deletions(-) diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index baa966e2778c0..481e54ded9dc7 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -554,8 +554,23 @@ static int multipath_clone_and_map(struct dm_target *ti, struct request *rq, return DM_MAPIO_REMAPPED; } -static void multipath_release_clone(struct request *clone) +static void multipath_release_clone(struct request *clone, + union map_info *map_context) { + if (unlikely(map_context)) { + /* + * non-NULL map_context means caller is still map + * method; must undo multipath_clone_and_map() + */ + struct dm_mpath_io *mpio = get_mpio(map_context); + struct pgpath *pgpath = mpio->pgpath; + + if (pgpath && pgpath->pg->ps.type->end_io) + pgpath->pg->ps.type->end_io(&pgpath->pg->ps, + &pgpath->path, + mpio->nr_bytes); + } + blk_put_request(clone); } diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c index 264b84e274aac..17c6a73c536c6 100644 --- a/drivers/md/dm-rq.c +++ b/drivers/md/dm-rq.c @@ -219,7 +219,7 @@ static void dm_end_request(struct request *clone, blk_status_t error) struct request *rq = tio->orig; blk_rq_unprep_clone(clone); - tio->ti->type->release_clone_rq(clone); + tio->ti->type->release_clone_rq(clone, NULL); rq_end_stats(md, rq); if (!rq->q->mq_ops) @@ -270,7 +270,7 @@ static void dm_requeue_original_request(struct dm_rq_target_io *tio, bool delay_ rq_end_stats(md, rq); if (tio->clone) { blk_rq_unprep_clone(tio->clone); - tio->ti->type->release_clone_rq(tio->clone); + tio->ti->type->release_clone_rq(tio->clone, NULL); } if (!rq->q->mq_ops) @@ -495,7 +495,7 @@ static int map_request(struct dm_rq_target_io *tio) case DM_MAPIO_REMAPPED: if (setup_clone(clone, rq, tio, GFP_ATOMIC)) { /* -ENOMEM */ - ti->type->release_clone_rq(clone); + ti->type->release_clone_rq(clone, &tio->info); return DM_MAPIO_REQUEUE; } @@ -505,7 +505,7 @@ static int map_request(struct dm_rq_target_io *tio) ret = dm_dispatch_clone_request(clone, rq); if (ret == BLK_STS_RESOURCE || ret == BLK_STS_DEV_RESOURCE) { blk_rq_unprep_clone(clone); - tio->ti->type->release_clone_rq(clone); + tio->ti->type->release_clone_rq(clone, &tio->info); tio->clone = NULL; if (!rq->q->mq_ops) r = DM_MAPIO_DELAY_REQUEUE; diff --git a/drivers/md/dm-target.c b/drivers/md/dm-target.c index 314d17ca64668..64dd0b34fcf49 100644 --- a/drivers/md/dm-target.c +++ b/drivers/md/dm-target.c @@ -136,7 +136,8 @@ static int io_err_clone_and_map_rq(struct dm_target *ti, struct request *rq, return DM_MAPIO_KILL; } -static void io_err_release_clone_rq(struct request *clone) +static void io_err_release_clone_rq(struct request *clone, + union map_info *map_context) { } diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index bef2e36c01b4b..91f9f95ad5066 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -62,7 +62,8 @@ typedef int (*dm_clone_and_map_request_fn) (struct dm_target *ti, struct request *rq, union map_info *map_context, struct request **clone); -typedef void (*dm_release_clone_request_fn) (struct request *clone); +typedef void (*dm_release_clone_request_fn) (struct request *clone, + union map_info *map_context); /* * Returns: -- 2.20.1