From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753236AbaATMYL (ORCPT ); Mon, 20 Jan 2014 07:24:11 -0500 Received: from mx1.redhat.com ([209.132.183.28]:32802 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753016AbaATMYG (ORCPT ); Mon, 20 Jan 2014 07:24:06 -0500 From: Steven Whitehouse To: linux-kernel@vger.kernel.org, cluster-devel@redhat.com Cc: Bob Peterson , Steven Whitehouse Subject: [PATCH 02/24] GFS2: Drop inadequate rgrps from the reservation tree Date: Mon, 20 Jan 2014 12:23:25 +0000 Message-Id: <1390220627-1571-3-git-send-email-swhiteho@redhat.com> In-Reply-To: <1390220627-1571-1-git-send-email-swhiteho@redhat.com> References: <1390220627-1571-1-git-send-email-swhiteho@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Bob Peterson This is just basically a resend of a patch I posted earlier. It didn't change from its original, except in diff offsets, etc: This patch fixes a bug in the GFS2 block allocation code. The problem starts if a process already has a multi-block reservation, but for some reason, another process disqualifies it from further allocations. For example, the other process might set on the GFS2_RDF_ERROR bit. The process holding the reservation jumps to label skip_rgrp, but that label comes after the code that removes the reservation from the tree. Therefore, the no longer usable reservation is not removed from the rgrp's reservations tree; it's lost. Eventually, the lost reservation causes the count of reserved blocks to get off, and eventually that causes a BUG_ON(rs->rs_rbm.rgd->rd_reserved < rs->rs_free) to trigger. This patch moves the call to after label skip_rgrp so that the disqualified reservation is properly removed from the tree, thus keeping the rgrp rd_reserved count sane. Signed-off-by: Bob Peterson Signed-off-by: Steven Whitehouse diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c index 809fecd..1ccf89a 100644 --- a/fs/gfs2/rgrp.c +++ b/fs/gfs2/rgrp.c @@ -1944,15 +1944,16 @@ int gfs2_inplace_reserve(struct gfs2_inode *ip, const struct gfs2_alloc_parms *a return 0; } - /* Drop reservation, if we couldn't use reserved rgrp */ - if (gfs2_rs_active(rs)) - gfs2_rs_deltree(rs); check_rgrp: /* Check for unlinked inodes which can be reclaimed */ if (rs->rs_rbm.rgd->rd_flags & GFS2_RDF_CHECK) try_rgrp_unlink(rs->rs_rbm.rgd, &last_unlinked, ip->i_no_addr); skip_rgrp: + /* Drop reservation, if we couldn't use reserved rgrp */ + if (gfs2_rs_active(rs)) + gfs2_rs_deltree(rs); + /* Unlock rgrp if required */ if (!rg_locked) gfs2_glock_dq_uninit(&rs->rs_rgd_gh); -- 1.8.3.1