Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753913Ab3IJRbz (ORCPT ); Tue, 10 Sep 2013 13:31:55 -0400 Received: from mail-pa0-f49.google.com ([209.85.220.49]:45104 "EHLO mail-pa0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752945Ab3IJRbx (ORCPT ); Tue, 10 Sep 2013 13:31:53 -0400 From: ycbzzjlby@gmail.com To: neilb@suse.de Cc: linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org, Bian Yu Subject: [PATCH] raid5: Retry R5_ReadNoMerge flag when hit a read error. Date: Sun, 1 Sep 2013 20:13:02 -0400 Message-Id: <1378080782-9971-1-git-send-email-ycbzzjlby@gmail.com> X-Mailer: git-send-email 1.7.1 Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1635 Lines: 53 From: Bian Yu Because of block layer merge, one bio fails will cause other bios which belongs to the same request fails, so raid5_end_read_request will record all these bios as badblocks. If retry request with R5_ReadNoMerge flag to avoid bios merge, badblocks can only record sector which is bad exactly. test: hdparm --yes-i-know-what-i-am-doing --make-bad-sector 300000 /dev/sdb mdadm -C /dev/md0 -l5 -n3 /dev/sd[bcd] --assume-clean mdadm /dev/md0 -f /dev/sdd mdadm /dev/md0 -r /dev/sdd mdadm --zero-superblock /dev/sdd mdadm /dev/md0 -a /dev/sdd 1. Without this patch: cat /sys/block/md0/md/rd*/bad_blocks 299776 256 299776 256 2. With this patch: cat /sys/block/md0/md/rd*/bad_blocks 300000 8 300000 8 Signed-off-by: Bian Yu --- drivers/md/raid5.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index ff1aecf..ee8c280 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -1924,6 +1924,9 @@ static void raid5_end_read_request(struct bio * bi, int error) mdname(conf->mddev), bdn); else retry = 1; + if (set_bad && test_bit(In_sync, &rdev->flags) + && !test_bit(R5_ReadNoMerge, &sh->dev[i].flags)) + retry = 1; if (retry) if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags)) { set_bit(R5_ReadError, &sh->dev[i].flags); -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/