From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932391Ab2AXCpm (ORCPT ); Mon, 23 Jan 2012 21:45:42 -0500 Received: from cantor2.suse.de ([195.135.220.15]:50290 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932368Ab2AXCpi (ORCPT ); Mon, 23 Jan 2012 21:45:38 -0500 X-Mailbox-Line: From gregkh@clark.kroah.org Mon Jan 23 18:39:27 2012 Message-Id: <20120124023927.399359476@clark.kroah.org> User-Agent: quilt/0.50-11.1 Date: Mon, 23 Jan 2012 18:34:19 -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, NeilBrown Subject: [039/129] md/raid1: perform bad-block tests for WriteMostly devices too. In-Reply-To: <20120124024041.GA18422@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. ------------------ Content-Length: 1469 Lines: 46 From: NeilBrown commit 307729c8bc5b5a41361af8af95906eee7552acb1 upstream. We normally try to avoid reading from write-mostly devices, but when we do we really have to check for bad blocks and be sure not to try reading them. With the current code, best_good_sectors might not get set and that causes zero-length read requests to be send down which is very confusing. This bug was introduced in commit d2eb35acfdccbe2 and so the patch is suitable for 3.1.x and 3.2.x Reported-and-tested-by: Michał Mirosław Reported-and-tested-by: Art -kwaak- van Breemen Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman --- drivers/md/raid1.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -525,8 +525,17 @@ static int read_balance(struct r1conf *c if (test_bit(WriteMostly, &rdev->flags)) { /* Don't balance among write-mostly, just * use the first as a last resort */ - if (best_disk < 0) + if (best_disk < 0) { + if (is_badblock(rdev, this_sector, sectors, + &first_bad, &bad_sectors)) { + if (first_bad < this_sector) + /* Cannot use this */ + continue; + best_good_sectors = first_bad - this_sector; + } else + best_good_sectors = sectors; best_disk = disk; + } continue; } /* This is a reasonable device to use. It might