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=-9.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 645A1ECDE44 for ; Wed, 31 Oct 2018 23:53:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2533920821 for ; Wed, 31 Oct 2018 23:53:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="1fDyhSjn" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2533920821 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727869AbeKAIyU (ORCPT ); Thu, 1 Nov 2018 04:54:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:52860 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727312AbeKAIGH (ORCPT ); Thu, 1 Nov 2018 04:06:07 -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 E34372085A; Wed, 31 Oct 2018 23:05:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1541027157; bh=aPI56e/X7Fen3qsq7FQyLmzMg0HBIEjJB7cM+v0IHpk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1fDyhSjnT+afS4T+tRBORMkcuFGQcXEilwFgPMdsjEZPabMrCZYUbzGQ/k3YJvsfn ICifSVnfh+S1IUhmAmP7RcmPN8DGmuILdUrNYIYjye+4LMnowrjLsh+YJDTxmVmshy mryZHga6pqq/jh2uQ05QV0AiTM+bD9BkQjjBdufY= From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: =?UTF-8?q?Javier=20Gonz=C3=A1lez?= , =?UTF-8?q?Javier=20Gonz=C3=A1lez?= , =?UTF-8?q?Matias=20Bj=C3=B8rling?= , Jens Axboe , Sasha Levin Subject: [PATCH AUTOSEL 4.19 016/146] lightnvm: pblk: fix race condition on metadata I/O Date: Wed, 31 Oct 2018 19:03:31 -0400 Message-Id: <20181031230541.28822-16-sashal@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181031230541.28822-1-sashal@kernel.org> References: <20181031230541.28822-1-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Javier González [ Upstream commit d8adaa3b86324c6186d0adf74bc256bdacfffdb6 ] In pblk, when a new line is allocated, metadata for the previously written line is scheduled. This is done through a fixed memory region that is shared through time and contexts across different lines and therefore protected by a lock. Unfortunately, this lock is not properly covering all the metadata used for sharing this memory regions, resulting in a race condition. This patch fixes this race condition by protecting this metadata properly. Fixes: dd2a43437337 ("lightnvm: pblk: sched. metadata on write thread") Signed-off-by: Javier González Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- drivers/lightnvm/pblk-write.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/lightnvm/pblk-write.c b/drivers/lightnvm/pblk-write.c index ee774a86cf1e..879227d584e7 100644 --- a/drivers/lightnvm/pblk-write.c +++ b/drivers/lightnvm/pblk-write.c @@ -417,12 +417,11 @@ int pblk_submit_meta_io(struct pblk *pblk, struct pblk_line *meta_line) rqd->ppa_list[i] = addr_to_gen_ppa(pblk, paddr, id); } + spin_lock(&l_mg->close_lock); emeta->mem += rq_len; - if (emeta->mem >= lm->emeta_len[0]) { - spin_lock(&l_mg->close_lock); + if (emeta->mem >= lm->emeta_len[0]) list_del(&meta_line->list); - spin_unlock(&l_mg->close_lock); - } + spin_unlock(&l_mg->close_lock); pblk_down_page(pblk, rqd->ppa_list, rqd->nr_ppas); @@ -491,14 +490,15 @@ static struct pblk_line *pblk_should_submit_meta_io(struct pblk *pblk, struct pblk_line *meta_line; spin_lock(&l_mg->close_lock); -retry: if (list_empty(&l_mg->emeta_list)) { spin_unlock(&l_mg->close_lock); return NULL; } meta_line = list_first_entry(&l_mg->emeta_list, struct pblk_line, list); - if (meta_line->emeta->mem >= lm->emeta_len[0]) - goto retry; + if (meta_line->emeta->mem >= lm->emeta_len[0]) { + spin_unlock(&l_mg->close_lock); + return NULL; + } spin_unlock(&l_mg->close_lock); if (!pblk_valid_meta_ppa(pblk, meta_line, data_rqd)) -- 2.17.1