From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759634Ab0JVTGG (ORCPT ); Fri, 22 Oct 2010 15:06:06 -0400 Received: from kroah.org ([198.145.64.141]:34323 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759457Ab0JVS4w (ORCPT ); Fri, 22 Oct 2010 14:56:52 -0400 X-Mailbox-Line: From gregkh@clark.site Fri Oct 22 11:52:33 2010 Message-Id: <20101022185233.921638761@clark.site> User-Agent: quilt/0.48-11.2 Date: Fri, 22 Oct 2010 11:51:47 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Johannes Weiner , Alex Elder Subject: [073/103] xfs: properly account for reclaimed inodes In-Reply-To: <20101022185455.GA9114@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.35-stable review patch. If anyone has any objections, please let us know. ------------------ From: Johannes Weiner commit 081003fff467ea0e727f66d5d435b4f473a789b3 upstream. When marking an inode reclaimable, a per-AG counter is increased, the inode is tagged reclaimable in its per-AG tree, and, when this is the first reclaimable inode in the AG, the AG entry in the per-mount tree is also tagged. When an inode is finally reclaimed, however, it is only deleted from the per-AG tree. Neither the counter is decreased, nor is the parent tree's AG entry untagged properly. Since the tags in the per-mount tree are not cleared, the inode shrinker iterates over all AGs that have had reclaimable inodes at one point in time. The counters on the other hand signal an increasing amount of slab objects to reclaim. Since "70e60ce xfs: convert inode shrinker to per-filesystem context" this is not a real issue anymore because the shrinker bails out after one iteration. But the problem was observable on a machine running v2.6.34, where the reclaimable work increased and each process going into direct reclaim eventually got stuck on the xfs inode shrinking path, trying to scan several million objects. Fix this by properly unwinding the reclaimable-state tracking of an inode when it is reclaimed. Signed-off-by: Johannes Weiner Reviewed-by: Dave Chinner Signed-off-by: Alex Elder Signed-off-by: Greg Kroah-Hartman --- fs/xfs/linux-2.6/xfs_sync.c | 16 ++++++++++++---- fs/xfs/linux-2.6/xfs_sync.h | 1 + fs/xfs/xfs_iget.c | 1 + 3 files changed, 14 insertions(+), 4 deletions(-) --- a/fs/xfs/linux-2.6/xfs_sync.c +++ b/fs/xfs/linux-2.6/xfs_sync.c @@ -711,13 +711,10 @@ xfs_inode_set_reclaim_tag( } void -__xfs_inode_clear_reclaim_tag( - xfs_mount_t *mp, +__xfs_inode_clear_reclaim( xfs_perag_t *pag, xfs_inode_t *ip) { - radix_tree_tag_clear(&pag->pag_ici_root, - XFS_INO_TO_AGINO(mp, ip->i_ino), XFS_ICI_RECLAIM_TAG); pag->pag_ici_reclaimable--; if (!pag->pag_ici_reclaimable) { /* clear the reclaim tag from the perag radix tree */ @@ -731,6 +728,17 @@ __xfs_inode_clear_reclaim_tag( } } +void +__xfs_inode_clear_reclaim_tag( + xfs_mount_t *mp, + xfs_perag_t *pag, + xfs_inode_t *ip) +{ + radix_tree_tag_clear(&pag->pag_ici_root, + XFS_INO_TO_AGINO(mp, ip->i_ino), XFS_ICI_RECLAIM_TAG); + __xfs_inode_clear_reclaim(pag, ip); +} + /* * Inodes in different states need to be treated differently, and the return * value of xfs_iflush is not sufficient to get this right. The following table --- a/fs/xfs/linux-2.6/xfs_sync.h +++ b/fs/xfs/linux-2.6/xfs_sync.h @@ -47,6 +47,7 @@ int xfs_reclaim_inodes(struct xfs_mount void xfs_inode_set_reclaim_tag(struct xfs_inode *ip); void __xfs_inode_set_reclaim_tag(struct xfs_perag *pag, struct xfs_inode *ip); +void __xfs_inode_clear_reclaim(struct xfs_perag *pag, struct xfs_inode *ip); void __xfs_inode_clear_reclaim_tag(struct xfs_mount *mp, struct xfs_perag *pag, struct xfs_inode *ip); --- a/fs/xfs/xfs_iget.c +++ b/fs/xfs/xfs_iget.c @@ -492,6 +492,7 @@ xfs_ireclaim( write_lock(&pag->pag_ici_lock); if (!radix_tree_delete(&pag->pag_ici_root, agino)) ASSERT(0); + __xfs_inode_clear_reclaim(pag, ip); write_unlock(&pag->pag_ici_lock); xfs_perag_put(pag);