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 64A38C3A5A6 for ; Thu, 29 Aug 2019 10:54:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3016E23405 for ; Thu, 29 Aug 2019 10:54:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567076097; bh=7b65reXVFw1RYJf9RpdWTCouvQR5rD8v4dzt/bdk5c4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=tgIFZEPsjdjSm+E8ldfkn0hle7aQm0V66+JWrz9EZq+JI5R1phbvCHTjxIF0x/Uzk BkBxKFS6iSm2iL4idISVqkRmdWGZtcHyEh7oMJiwuhFwfxlQlw0IBqV3YsZQ8lUnSm gcp037AV4wGBsSiOS/xvmt1NgasiHyHGnKh5c8H4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727883AbfH2KuX (ORCPT ); Thu, 29 Aug 2019 06:50:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:57448 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727620AbfH2KuQ (ORCPT ); Thu, 29 Aug 2019 06:50:16 -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 4E741233A1; Thu, 29 Aug 2019 10:50:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567075816; bh=7b65reXVFw1RYJf9RpdWTCouvQR5rD8v4dzt/bdk5c4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QdjDp6vWV38lSL1T69GDy39+vlL/saIIo+hCmC+Yt1KUW0ooSiXGsBX9b27xx2ZUL oLSg5jiOPTjL65s86Py1ZRyt0fM2uDqac+MW/mXLgab8PTxhNc8fJ3ZIije3+SBCoP BoNwOLQuRrT+PB08lym4qqiRysmv2jOWPRGt0Zp8= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Liu Bo , Jens Axboe , Sasha Levin , linux-block@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 05/29] Blk-iolatency: warn on negative inflight IO counter Date: Thu, 29 Aug 2019 06:49:45 -0400 Message-Id: <20190829105009.2265-5-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190829105009.2265-1-sashal@kernel.org> References: <20190829105009.2265-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Liu Bo [ Upstream commit 391f552af213985d3d324c60004475759a7030c5 ] This is to catch any unexpected negative value of inflight IO counter. Signed-off-by: Liu Bo Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- block/blk-iolatency.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c index f4f7c73fb8284..84ecdab41b691 100644 --- a/block/blk-iolatency.c +++ b/block/blk-iolatency.c @@ -560,6 +560,7 @@ static void blkcg_iolatency_done_bio(struct rq_qos *rqos, struct bio *bio) u64 now = ktime_to_ns(ktime_get()); bool issue_as_root = bio_issue_as_root_blkg(bio); bool enabled = false; + int inflight = 0; blkg = bio->bi_blkg; if (!blkg) @@ -585,7 +586,8 @@ static void blkcg_iolatency_done_bio(struct rq_qos *rqos, struct bio *bio) } rqw = &iolat->rq_wait; - atomic_dec(&rqw->inflight); + inflight = atomic_dec_return(&rqw->inflight); + WARN_ON_ONCE(inflight < 0); if (iolat->min_lat_nsec == 0) goto next; iolatency_record_time(iolat, &bio->bi_issue, now, -- 2.20.1