From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756838AbYHYVXK (ORCPT ); Mon, 25 Aug 2008 17:23:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753883AbYHYVWz (ORCPT ); Mon, 25 Aug 2008 17:22:55 -0400 Received: from nlpi025.sbcis.sbc.com ([207.115.36.54]:15182 "EHLO nlpi025.prodigy.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753152AbYHYVWy (ORCPT ); Mon, 25 Aug 2008 17:22:54 -0400 Message-Id: <20080825212053.255444022@quilx.com> References: <20080825212035.861870487@quilx.com> User-Agent: quilt/0.46-1 Date: Mon, 25 Aug 2008 14:20:36 -0700 From: Christoph Lameter To: Pekka Enberg CC: akpm@linux-foundation.org, Christoph Lameter Cc: linux-kernel@vger.kernel.org CC: linux-fsdevel@vger.kernel.org Cc: Mel Gorman Cc: andi@firstfloor.org Cc: Rik van Riel Cc: mpm@selenic.com Cc: Dave Chinner Subject: [patch 1/3] dentries: Always use list_del_init() when removing a dentry from the lru Content-Disposition: inline; filename=consitent Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The patch restores what commit 4a0962abd187df29b7d1378b2f372a55667d54c0 already implemented. The feature was subsequently clobbered by commit da3bbdd4632c0171406b2677e31494afa5bde2f8 Before this patch some execution path use list_del() instead of list_del_init() which results in inconsitencies in the state of d_lru when the object is freed. The performance of list_del_init() and list_del() is the same. So lets just have one dentry removal function named dentry_lru_del() that always does a list_del_init(). The result of this patch is that dentry->d_lru is now always empty when a dentry is freed. The dentry defragmentation patch depends on a defined state of a dentry on free. Signed-off-by: Christoph Lameter Index: linux-next/fs/dcache.c =================================================================== --- linux-next.orig/fs/dcache.c 2008-08-25 15:44:58.000000000 -0500 +++ linux-next/fs/dcache.c 2008-08-25 15:45:59.000000000 -0500 @@ -141,15 +141,6 @@ static void dentry_lru_del(struct dentry *dentry) { if (!list_empty(&dentry->d_lru)) { - list_del(&dentry->d_lru); - dentry->d_sb->s_nr_dentry_unused--; - dentry_stat.nr_unused--; - } -} - -static void dentry_lru_del_init(struct dentry *dentry) -{ - if (likely(!list_empty(&dentry->d_lru))) { list_del_init(&dentry->d_lru); dentry->d_sb->s_nr_dentry_unused--; dentry_stat.nr_unused--; @@ -316,7 +307,7 @@ static inline struct dentry * __dget_locked(struct dentry *dentry) { atomic_inc(&dentry->d_count); - dentry_lru_del_init(dentry); + dentry_lru_del(dentry); return dentry; } @@ -432,7 +423,7 @@ if (dentry->d_op && dentry->d_op->d_delete) dentry->d_op->d_delete(dentry); - dentry_lru_del_init(dentry); + dentry_lru_del(dentry); __d_drop(dentry); dentry = d_kill(dentry); spin_lock(&dcache_lock); @@ -492,7 +483,7 @@ } while (!list_empty(&tmp)) { dentry = list_entry(tmp.prev, struct dentry, d_lru); - dentry_lru_del_init(dentry); + dentry_lru_del(dentry); spin_lock(&dentry->d_lock); /* * We found an inuse dentry which was not removed from @@ -621,7 +612,7 @@ /* detach this root from the system */ spin_lock(&dcache_lock); - dentry_lru_del_init(dentry); + dentry_lru_del(dentry); __d_drop(dentry); spin_unlock(&dcache_lock); @@ -635,7 +626,7 @@ spin_lock(&dcache_lock); list_for_each_entry(loop, &dentry->d_subdirs, d_u.d_child) { - dentry_lru_del_init(loop); + dentry_lru_del(loop); __d_drop(loop); cond_resched_lock(&dcache_lock); } @@ -817,7 +808,7 @@ struct dentry *dentry = list_entry(tmp, struct dentry, d_u.d_child); next = tmp->next; - dentry_lru_del_init(dentry); + dentry_lru_del(dentry); /* * move only zero ref count dentries to the end * of the unused list for prune_dcache --