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,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 A5C0DC5DF60 for ; Fri, 8 Nov 2019 12:00:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 766A421848 for ; Fri, 8 Nov 2019 12:00:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573214444; bh=66ajkt9iM6MDmOPzzY+y7AnWo/Vg7+hhgie9nPB1eoI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=P9UG9hqW/RtLACWFScZM/MnG92ZlIb/9YMsdGsBGMEIsxkhozO00UoLpW+gztlaXJ YdPrT3DUQXr9flLsBj9COqaab0wjXTtPBehqMqSkw4TD6zY28iQfiiiVV+bWM3GIvY fY05Th1Ig6G9c++2fhao7ixsFuWLNQlQLo67F6BY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390566AbfKHLns (ORCPT ); Fri, 8 Nov 2019 06:43:48 -0500 Received: from mail.kernel.org ([198.145.29.99]:58098 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390498AbfKHLnf (ORCPT ); Fri, 8 Nov 2019 06:43:35 -0500 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 E58B7222D1; Fri, 8 Nov 2019 11:43:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573213414; bh=66ajkt9iM6MDmOPzzY+y7AnWo/Vg7+hhgie9nPB1eoI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Hmj5zx5bGZKPJ7L4vczycPv80RtVsL+drE8g5srLX6HGeCq0BaYsriuSqmNao3L7Y M0GZjmw8Bp5X6g8/FLFEXz7qA1wjYOG1S9+aET2PgUP1B2DgZXdwRa7By0gDvrEqPY 5c+MUOPT/i1R2kZ+u0tKBMvd49KeUTxhIcNVDrUQ= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Bob Peterson , Sasha Levin , cluster-devel@redhat.com Subject: [PATCH AUTOSEL 4.14 017/103] gfs2: Don't set GFS2_RDF_UPTODATE when the lvb is updated Date: Fri, 8 Nov 2019 06:41:42 -0500 Message-Id: <20191108114310.14363-17-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191108114310.14363-1-sashal@kernel.org> References: <20191108114310.14363-1-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: Bob Peterson [ Upstream commit 4f36cb36c9d14340bb200d2ad9117b03ce992cfe ] The GFS2_RDF_UPTODATE flag in the rgrp is used to determine when a rgrp buffer is valid. It's cleared when the glock is invalidated, signifying that the buffer data is now invalid. But before this patch, function update_rgrp_lvb was setting the flag when it determined it had a valid lvb. But that's an invalid assumption: just because you have a valid lvb doesn't mean you have valid buffers. After all, another node may have made the lvb valid, and this node just fetched it from the glock via dlm. Consider this scenario: 1. The file system is mounted with RGRPLVB option. 2. In gfs2_inplace_reserve it locks the rgrp glock EX, but thanks to GL_SKIP, it skips the gfs2_rgrp_bh_get. 3. Since loops == 0 and the allocation target (ap->target) is bigger than the largest known chunk of blocks in the rgrp (rs->rs_rbm.rgd->rd_extfail_pt) it skips that rgrp and bypasses the call to gfs2_rgrp_bh_get there as well. 4. update_rgrp_lvb sees the lvb MAGIC number is valid, so bypasses gfs2_rgrp_bh_get, but it still sets sets GFS2_RDF_UPTODATE due to this invalid assumption. 5. The next time update_rgrp_lvb is called, it sees the bit is set and just returns 0, assuming both the lvb and rgrp are both uptodate. But since this is a smaller allocation, or space has been freed by another node, thus adjusting the lvb values, it decides to use the rgrp for allocations, with invalid rd_free due to the fact it was never updated. This patch changes update_rgrp_lvb so it doesn't set the UPTODATE flag anymore. That way, it has no choice but to fetch the latest values. Signed-off-by: Bob Peterson Signed-off-by: Sasha Levin --- fs/gfs2/rgrp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c index b0eee90738ff4..0d72baae51509 100644 --- a/fs/gfs2/rgrp.c +++ b/fs/gfs2/rgrp.c @@ -1201,7 +1201,7 @@ static int update_rgrp_lvb(struct gfs2_rgrpd *rgd) rl_flags = be32_to_cpu(rgd->rd_rgl->rl_flags); rl_flags &= ~GFS2_RDF_MASK; rgd->rd_flags &= GFS2_RDF_MASK; - rgd->rd_flags |= (rl_flags | GFS2_RDF_UPTODATE | GFS2_RDF_CHECK); + rgd->rd_flags |= (rl_flags | GFS2_RDF_CHECK); if (rgd->rd_rgl->rl_unlinked == 0) rgd->rd_flags &= ~GFS2_RDF_CHECK; rgd->rd_free = be32_to_cpu(rgd->rd_rgl->rl_free); -- 2.20.1