From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ted Ts'o Subject: Re: [PATCH v4] ext4:Let ext4_ext_fiemap_cb() handle blocks before request range correctly. Date: Tue, 24 May 2011 11:42:12 -0400 Message-ID: <20110524154212.GA26055@thunk.org> References: <1306134178-9883-1-git-send-email-xiaoqiangnk@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-ext4@vger.kernel.org, lczerner@redhat.com, amir73il@gmail.com To: Yongqiang Yang Return-path: Received: from li9-11.members.linode.com ([67.18.176.11]:49998 "EHLO test.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750862Ab1EXPmQ (ORCPT ); Tue, 24 May 2011 11:42:16 -0400 Content-Disposition: inline In-Reply-To: <1306134178-9883-1-git-send-email-xiaoqiangnk@gmail.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Mon, May 23, 2011 at 03:02:58PM +0800, Yongqiang Yang wrote: > To get delayed-extent information, ext4_ext_fiemap_cb() looks up > pagecache, it thus collects information starting from a page's > head block. > > If blocksize < pagesize, the beginning blocks of a page may lies > before the request range. So ext4_ext_fiemap_cb() should proceed > ignoring them, because they has been handled before. If no mapped > buffer in the range is found in the 1st page, we need to look up > the 2nd page, otherwise delayed-extents after a hole will be ignored. > > Without this patch, xfstests 225 will hung on ext4 with 1K block. > > Reported-by: Amir Goldstein > Signed-off-by: Yongqiang Yang Thanks, added to the ext4 tree. - Ted