From patchwork Fri Aug 17 10:22:04 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Javier_Gonz=C3=A1lez?= X-Patchwork-Id: 10568591 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 03AF41390 for ; Fri, 17 Aug 2018 10:22:19 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E72152B311 for ; Fri, 17 Aug 2018 10:22:18 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DB3DE2B32D; Fri, 17 Aug 2018 10:22:18 +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=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,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 CC7122B311 for ; Fri, 17 Aug 2018 10:22:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726329AbeHQNZJ (ORCPT ); Fri, 17 Aug 2018 09:25:09 -0400 Received: from mail-ed1-f68.google.com ([209.85.208.68]:41811 "EHLO mail-ed1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726319AbeHQNZI (ORCPT ); Fri, 17 Aug 2018 09:25:08 -0400 Received: by mail-ed1-f68.google.com with SMTP id s24-v6so4249821edr.8 for ; Fri, 17 Aug 2018 03:22:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=javigon-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=hVfKH5fxvtMI2nn+wFotQVSEFmCc6QzAd/OwPbB5mRw=; b=JXdXzh8BY0BBYk/N95Ue2lFimLeZbiZtnJhSYmgiqG1RK+gd4TDjOAfJ3v88QfKZR9 dKJKVxx4xbqvt4gpGwlnTvVG0shMGNrP7yRIM4kl8BoBUdHCSdhifETV/q/jaF/3cavQ JtEhBGuC2QC3Csv/GRRVkLYGB8ZARIpAo1dOWG0fYO5iYDHJM7OKmZKuqEOxGr0S6enl QPZ+aD5t0pu1GH4d1GKmf+tJUc7wSwCChDrqqxjjprkmeH+b0xu/Wha48q4fbEuaX5FO nHidHosrb+ewj8TpsiYyVkinaO/ffPcogmRCfCPqXGjaEhS5n6+cl2BOzbhX4QedHnZ1 Z0Ng== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=hVfKH5fxvtMI2nn+wFotQVSEFmCc6QzAd/OwPbB5mRw=; b=PWwlRZpaFXWyBHQwGJO87Oov9ql/NWHWFuoJ3yz+N5wuE8Cm1IyRC8wRJOZAzgOW63 u1Yk/PADiQ2JHd+XtHstMtMvch9UtVNyWo8fqoDkfAx46jKAuoWZA3j80dYE/8ViuL6L d01VcNDdv11R7kigNPAGYjMRb7uWD9oo+CE2AZZLFDkyyb2mLwKtBTZBNdNBrJ4zENJJ xVFAZbzgi7lMuna9mTthNtndlz5I39fBw4byqKm6kTLWfIuKyrIYM9VCgJmJxb0wjH7i 2tgqR1WrPC4YztimJIzrLsLBhQtrgrGrAAt/BIZVsKzTQzOzUCy5UsHaJbpCn7SDEu4H mCIg== X-Gm-Message-State: AOUpUlFBMbyHYRQYsl4Ry5l3At6wWdeXgh8F2D+nYoAeb42HAUlS8kG/ 7fK8goVbCI23bkYbrgGMIddTIw== X-Google-Smtp-Source: AA+uWPyC8zB7npyLzfk7pvWueOlYH2QW4gUan7PivalZYCETiqS6A8z7HLtq8hJ2moDitj2j7oIFUg== X-Received: by 2002:a50:c082:: with SMTP id k2-v6mr40353218edf.294.1534501335088; Fri, 17 Aug 2018 03:22:15 -0700 (PDT) Received: from ch-wrk-javier.cnexlabs.com (6164211-cl69.boa.fiberby.dk. [193.106.164.211]) by smtp.gmail.com with ESMTPSA id q26-v6sm2217865eda.35.2018.08.17.03.22.14 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 17 Aug 2018 03:22:14 -0700 (PDT) From: " =?utf-8?q?Javier_Gonz=C3=A1lez?= " X-Google-Original-From: =?utf-8?q?Javier_Gonz=C3=A1lez?= To: mb@lightnvm.io Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, =?utf-8?q?Jav?= =?utf-8?q?ier_Gonz=C3=A1lez?= Subject: [PATCH] lightnvm: pblk: fix race condition on metadata I/O Date: Fri, 17 Aug 2018 12:22:04 +0200 Message-Id: <1534501324-13693-1-git-send-email-javier@cnexlabs.com> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 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 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 on 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 --- 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 508c63701eda..df99c45778d4 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))