From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757017Ab2AJXMd (ORCPT ); Tue, 10 Jan 2012 18:12:33 -0500 Received: from cantor2.suse.de ([195.135.220.15]:52617 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934201Ab2AJXCU (ORCPT ); Tue, 10 Jan 2012 18:02:20 -0500 X-Mailbox-Line: From gregkh@clark.kroah.org Tue Jan 10 13:56:03 2012 Message-Id: <20120110215603.282928038@clark.kroah.org> User-Agent: quilt/0.50-25.1 Date: Tue, 10 Jan 2012 13:55:23 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Boaz Harrosh Subject: [20/49] ore: fix BUG_ON, too few sgs when reading In-Reply-To: <20120110215609.GA22505@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Boaz Harrosh commit 361aba569f55dd159b850489a3538253afbb3973 upstream. When reading RAID5 files, in rare cases, we calculated too few sg segments. There should be two extra for the beginning and end partial units. Also "too few sg segments" should not be a BUG_ON there is all the mechanics in place to handle it, as a short read. So just return -ENOMEM and the rest of the code will gracefully split the IO. Signed-off-by: Boaz Harrosh Signed-off-by: Greg Kroah-Hartman --- fs/exofs/ore.c | 2 +- fs/exofs/ore_raid.c | 6 +++++- 2 files changed, 6 insertions(+), 2 deletions(-) --- a/fs/exofs/ore.c +++ b/fs/exofs/ore.c @@ -266,7 +266,7 @@ int ore_get_rw_state(struct ore_layout /* first/last seg is split */ num_raid_units += layout->group_width; - sgs_per_dev = div_u64(num_raid_units, data_devs); + sgs_per_dev = div_u64(num_raid_units, data_devs) + 2; } else { /* For Writes add parity pages array. */ max_par_pages = num_raid_units * pages_in_unit * --- a/fs/exofs/ore_raid.c +++ b/fs/exofs/ore_raid.c @@ -551,7 +551,11 @@ int _ore_add_parity_unit(struct ore_io_s unsigned cur_len) { if (ios->reading) { - BUG_ON(per_dev->cur_sg >= ios->sgs_per_dev); + if (per_dev->cur_sg >= ios->sgs_per_dev) { + ORE_DBGMSG("cur_sg(%d) >= sgs_per_dev(%d)\n" , + per_dev->cur_sg, ios->sgs_per_dev); + return -ENOMEM; + } _ore_add_sg_seg(per_dev, cur_len, true); } else { struct __stripe_pages_2d *sp2d = ios->sp2d;