From patchwork Wed Mar 1 00:06:55 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Uday Shankar X-Patchwork-Id: 13155365 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A15F6C64EC7 for ; Wed, 1 Mar 2023 00:07:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229496AbjCAAHU (ORCPT ); Tue, 28 Feb 2023 19:07:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47614 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229437AbjCAAHT (ORCPT ); Tue, 28 Feb 2023 19:07:19 -0500 Received: from mail-oa1-x61.google.com (mail-oa1-x61.google.com [IPv6:2001:4860:4864:20::61]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7E7DE2A6C2 for ; Tue, 28 Feb 2023 16:07:17 -0800 (PST) Received: by mail-oa1-x61.google.com with SMTP id 586e51a60fabf-1720433ba75so12754417fac.5 for ; Tue, 28 Feb 2023 16:07:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=purestorage.com; s=google2022; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=QOMQhF/sH9JXA0O/3+AXuQxVnIBs73dSZjVTlEU+U2Y=; b=WfwqX0VfYm63/bsSajmHVDKt0x6T4xjQ2JIxTqRbRitYqu5qqkT1WQ1Q+N8KZYe53E Er8ohR3y8Al6Ncc/U729Y9aAjNnhogYJj2HNC6xSusk8dXHlpZY7AOvpfGZIpLN4x4Ad D7eUcO6o4OPC6vsJ8MCPDCj9HhmSWUSrac7YtBDq4M1PwFo1eGwGLQRuLcY3suXlozmm eXvw54cr2vu8mJJwtaLeoLxfX8zapo9nmYA9NH9FrkOvif2EC/hlkqMxcoZmhTMJl2M2 Kxtmdi05Twp6kXJtt2iyY2pBgXg3QIkEfj8C24A/BNccrl3Fx+22mY+gNp7oqocEkV0T Pyfg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=QOMQhF/sH9JXA0O/3+AXuQxVnIBs73dSZjVTlEU+U2Y=; b=U/P6o5PvYavcn6VrmSVLfEssyC6qS1LM8E8sMTp9rJMacrdw2N8AI9trKV9IWBy36G fAZDqtFnBnSwC/zHt+lO4gDeA4IwYt0WEOwmSW3FIJ3W7guv0DabukTXX6HC3q9MO+v2 4DxxKphV3twJnoXPi/gCwXwLpNZ3X+1ioNJH9JrQ2JLtqhvIpix0qIDY0GCRIUcGhLT4 uvc8LdfkCqyklfRIoWFrfu4/qSZY6UOvOALD19nTQhDXDh3dRJ+wY7IJTh4EjyDndjOh oDeg/brFir7nomCFayDgsjVGeST17qVQiEUk5gY7BWk+06YbbRSVIBOtvpCtGuDtmLIL RjYA== X-Gm-Message-State: AO0yUKWKPJYIrdreIxhU98QyCbnMlsJAz18Wd/PukOoYahd71jPAMOBW RJzoeqoVnxL5Uk3oxOZdTVPVdBp4BA8J7hUM0ilF2CoZRI8nWoDWW6fOpPJkJ5gsgQ== X-Google-Smtp-Source: AK7set83EGGEx4Gtvz8XTLvtgE3w2Y6/DJ78cVT0IPvfAU2EunoiFrSo2mkWCWfJ5m1B6SfYuwyFaebXUk7m X-Received: by 2002:a05:6870:17aa:b0:172:4d65:d176 with SMTP id r42-20020a05687017aa00b001724d65d176mr2230426oae.11.1677629236781; Tue, 28 Feb 2023 16:07:16 -0800 (PST) Received: from c7-smtp.dev.purestorage.com ([2620:125:9007:320:7:32:106:0]) by smtp-relay.gmail.com with ESMTPS id z22-20020a05687042d600b001727c3968d1sm45584oah.38.2023.02.28.16.07.16 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 28 Feb 2023 16:07:16 -0800 (PST) X-Relaying-Domain: purestorage.com Received: from dev-ushankar.dev.purestorage.com (dev5.dev.purestorage.com [IPv6:2620:125:9007:640:7:70:36:0]) by c7-smtp.dev.purestorage.com (Postfix) with ESMTP id 98152220F7; Tue, 28 Feb 2023 17:07:15 -0700 (MST) Received: by dev-ushankar.dev.purestorage.com (Postfix, from userid 1557716368) id 930C4E4021C; Tue, 28 Feb 2023 17:07:15 -0700 (MST) From: Uday Shankar To: Jens Axboe , Alasdair Kergon , Mike Snitzer , Christoph Hellwig , Keith Busch Cc: linux-block@vger.kernel.org, dm-devel@redhat.com, Uday Shankar , kernel test robot Subject: [PATCH v3] blk-mq: enforce op-specific segment limits in blk_insert_cloned_request Date: Tue, 28 Feb 2023 17:06:55 -0700 Message-Id: <20230301000655.48112-1-ushankar@purestorage.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org The block layer might merge together discard requests up until the max_discard_segments limit is hit, but blk_insert_cloned_request checks the segment count against max_segments regardless of the req op. This can result in errors like the following when discards are issued through a DM device and max_discard_segments exceeds max_segments for the queue of the chosen underlying device. blk_insert_cloned_request: over max segments limit. (256 > 129) Fix this by looking at the req_op and enforcing the appropriate segment limit - max_discard_segments for REQ_OP_DISCARDs and max_segments for everything else. Signed-off-by: Uday Shankar Reviewed-by: Keith Busch Reviewed-by: Ming Lei --- Changes v1-v2: - Fixed format specifier type mismatch Reported-by: kernel test robot Link: https://lore.kernel.org/oe-kbuild-all/202302162040.FaI25ul2-lkp@intel.com/ Changes v2-v3: - Refactor: move pre-existing blk_rq_get_max_segments to blk.h and use it instead of introducing a new function block/blk-merge.c | 7 ------- block/blk-mq.c | 7 ++++--- block/blk.h | 7 +++++++ 3 files changed, 11 insertions(+), 10 deletions(-) base-commit: bdc9c96cfce220e972136493f4c031f28ecb9f36 diff --git a/block/blk-merge.c b/block/blk-merge.c index 1ac782fdc..6460abdb2 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -587,13 +587,6 @@ int __blk_rq_map_sg(struct request_queue *q, struct request *rq, } EXPORT_SYMBOL(__blk_rq_map_sg); -static inline unsigned int blk_rq_get_max_segments(struct request *rq) -{ - if (req_op(rq) == REQ_OP_DISCARD) - return queue_max_discard_segments(rq->q); - return queue_max_segments(rq->q); -} - static inline unsigned int blk_rq_get_max_sectors(struct request *rq, sector_t offset) { diff --git a/block/blk-mq.c b/block/blk-mq.c index d3494a796..d0cb2ef18 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -3000,6 +3000,7 @@ blk_status_t blk_insert_cloned_request(struct request *rq) { struct request_queue *q = rq->q; unsigned int max_sectors = blk_queue_get_max_sectors(q, req_op(rq)); + unsigned int max_segments = blk_rq_get_max_segments(rq); blk_status_t ret; if (blk_rq_sectors(rq) > max_sectors) { @@ -3026,9 +3027,9 @@ blk_status_t blk_insert_cloned_request(struct request *rq) * original queue. */ rq->nr_phys_segments = blk_recalc_rq_segments(rq); - if (rq->nr_phys_segments > queue_max_segments(q)) { - printk(KERN_ERR "%s: over max segments limit. (%hu > %hu)\n", - __func__, rq->nr_phys_segments, queue_max_segments(q)); + if (rq->nr_phys_segments > max_segments) { + printk(KERN_ERR "%s: over max segments limit. (%u > %u)\n", + __func__, rq->nr_phys_segments, max_segments); return BLK_STS_IOERR; } diff --git a/block/blk.h b/block/blk.h index e835f21d4..cc4e8873d 100644 --- a/block/blk.h +++ b/block/blk.h @@ -156,6 +156,13 @@ static inline bool blk_discard_mergable(struct request *req) return false; } +static inline unsigned int blk_rq_get_max_segments(struct request *rq) +{ + if (req_op(rq) == REQ_OP_DISCARD) + return queue_max_discard_segments(rq->q); + return queue_max_segments(rq->q); +} + static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q, enum req_op op) {