From: Jan Kara Subject: [PATCH 04/11] ocfs2: Fix possible deadlock in ocfs2_write_dquot() Date: Fri, 16 Jan 2009 19:08:12 +0100 Message-ID: <1232129299-22018-5-git-send-email-jack@suse.cz> References: <1232129299-22018-1-git-send-email-jack@suse.cz> <1232129299-22018-2-git-send-email-jack@suse.cz> <1232129299-22018-3-git-send-email-jack@suse.cz> <1232129299-22018-4-git-send-email-jack@suse.cz> Cc: linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, Jan Kara To: linux-kernel@vger.kernel.org Return-path: Received: from styx.suse.cz ([82.119.242.94]:47978 "EHLO mail.suse.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1761813AbZAPSIW (ORCPT ); Fri, 16 Jan 2009 13:08:22 -0500 In-Reply-To: <1232129299-22018-4-git-send-email-jack@suse.cz> Sender: linux-ext4-owner@vger.kernel.org List-ID: It could happen that some limit has been set via quotactl() and in parallel ->mark_dirty() is called from another thread doing e.g. dquot_alloc_space(). In such case ocfs2_write_dquot() must not try to sync the dquot because that needs global quota lock but that ranks above transaction start. Signed-off-by: Jan Kara Acked-by: Mark Fasheh --- fs/ocfs2/quota_global.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-) diff --git a/fs/ocfs2/quota_global.c b/fs/ocfs2/quota_global.c index f4efa89..1ed0f7c 100644 --- a/fs/ocfs2/quota_global.c +++ b/fs/ocfs2/quota_global.c @@ -754,7 +754,9 @@ static int ocfs2_mark_dquot_dirty(struct dquot *dquot) if (dquot->dq_flags & mask) sync = 1; spin_unlock(&dq_data_lock); - if (!sync) { + /* This is a slight hack but we can't afford getting global quota + * lock if we already have a transaction started. */ + if (!sync || journal_current_handle()) { status = ocfs2_write_dquot(dquot); goto out; } -- 1.6.0.2