From mboxrd@z Thu Jan 1 00:00:00 1970 From: Theodore Ts'o Subject: Re: [PATCH] ext4: take i_mutex in ext4_symlink to eliminate a warning from ext4_truncate Date: Wed, 27 Mar 2013 09:51:55 -0400 Message-ID: <20130327135155.GK5861@thunk.org> References: <1364390347-4360-1-git-send-email-wenqing.lz@taobao.com> <20130327134110.GI5861@thunk.org> <20130327140250.GA4316@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: linux-ext4@vger.kernel.org, Zheng Liu Return-path: Received: from li9-11.members.linode.com ([67.18.176.11]:56333 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750977Ab3C0Nv5 (ORCPT ); Wed, 27 Mar 2013 09:51:57 -0400 Content-Disposition: inline In-Reply-To: <20130327140250.GA4316@gmail.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: Ah, now I see. Thanks for sending the stack trace. On the failure path, we're calling the inline function ext4_truncate_filaed_write() and this is calling ext4_truncate(). But I'm now wondering if we need to take the i_data_sem mutex in ext4_truncate_failed_write(). Otherwise, couldn't we end up with problems where a failed write calls ext4_truncate() without i_data_sem(), and that races with something else --- say, a punch or truncate call to that same inode? - Ted