From: Ted Ts'o Subject: Re: [PATCH 2/2] ext4: fix ext4_da_block_invalidatepages() to handle page range properly Date: Sat, 26 Feb 2011 13:54:19 -0500 Message-ID: <20110226185419.GF2924@thunk.org> References: <1298064699-17987-1-git-send-email-curtw@google.com> <1298064699-17987-2-git-send-email-curtw@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-ext4@vger.kernel.org To: Curt Wohlgemuth Return-path: Received: from li9-11.members.linode.com ([67.18.176.11]:51937 "EHLO test.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752477Ab1BZSyV (ORCPT ); Sat, 26 Feb 2011 13:54:21 -0500 Content-Disposition: inline In-Reply-To: <1298064699-17987-2-git-send-email-curtw@google.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Fri, Feb 18, 2011 at 01:31:39PM -0800, Curt Wohlgemuth wrote: > If ext4_da_block_invalidatepages() is called because of a > failure from ext4_map_blocks() in mpage_da_map_and_submit(), > it's supposed to clean up -- including unlock -- all the > pages in the mpd structure. But these values may not match > up, even on a system in which block size == page size: > > mpd->b_blocknr != mpd->first_page > mpd->b_size != (mpd->next_page - mpd->first_page) > > ext4_da_block_invalidatepages() has been using b_blocknr and > b_size; this patch changes it to use first_page and > next_page. > > Tested: I injected a small number (5%) of failures in > ext4_map_blocks() in the case that the flags contain > EXT4_GET_BLOCKS_DELALLOC_RESERVE, and ran fsstress on this > kernel. Without this patch, I got hung tasks every time. > With this patch, I see no hangs in many runs of fsstress. > > Signed-off-by: Curt Wohlgemuth Thanks, added to the ext4 patch queue. - Ted