Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756567Ab3CDDpx (ORCPT ); Sun, 3 Mar 2013 22:45:53 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:33209 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757481Ab3CDDo4 (ORCPT ); Sun, 3 Mar 2013 22:44:56 -0500 Message-Id: <20130304033709.644909876@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Mon, 04 Mar 2013 03:37:28 +0000 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: akpm@linux-foundation.org, Niu Yawei , Niu Yawei , "Theodore Tso" Subject: [ 021/153] ext4: fix race in ext4_mb_add_n_trim() In-Reply-To: <20130304033707.648729212@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:a11:96ff:fec6:70c4 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1628 Lines: 51 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Niu Yawei commit f1167009711032b0d747ec89a632a626c901a1ad upstream. In ext4_mb_add_n_trim(), lg_prealloc_lock should be taken when changing the lg_prealloc_list. Signed-off-by: Niu Yawei Signed-off-by: "Theodore Ts'o" Signed-off-by: Ben Hutchings --- fs/ext4/mballoc.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4178,7 +4178,7 @@ static void ext4_mb_add_n_trim(struct ex /* The max size of hash table is PREALLOC_TB_SIZE */ order = PREALLOC_TB_SIZE - 1; /* Add the prealloc space to lg */ - rcu_read_lock(); + spin_lock(&lg->lg_prealloc_lock); list_for_each_entry_rcu(tmp_pa, &lg->lg_prealloc_list[order], pa_inode_list) { spin_lock(&tmp_pa->pa_lock); @@ -4202,12 +4202,12 @@ static void ext4_mb_add_n_trim(struct ex if (!added) list_add_tail_rcu(&pa->pa_inode_list, &lg->lg_prealloc_list[order]); - rcu_read_unlock(); + spin_unlock(&lg->lg_prealloc_lock); /* Now trim the list to be not more than 8 elements */ if (lg_prealloc_count > 8) { ext4_mb_discard_lg_preallocations(sb, lg, - order, lg_prealloc_count); + order, lg_prealloc_count); return; } return ; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/