From: "kedacomkernel" <kedacomkernel@gmail.com>
To: NeilBrown <neilb@suse.de>
Cc: linux-raid <linux-raid@vger.kernel.org>
Subject: Re: Re: md/raid1:Fix a logic bug in fix_sync_read_error().
Date: Thu, 5 Apr 2012 10:23:47 +0800 [thread overview]
Message-ID: <201204051023442812453@gmail.com> (raw)
In-Reply-To: 201203311037586565381@gmail.com
>>That is correct, and that is how it should be.
>>If we get a read error, then try again and get a successful read, then there
>>is nothing more that we need to do. No need to write or anything.
>>So: current code is correct.
>>Thanks,
>>NeilBrown
Sorry Neil,I don't understand what's your mean?
I think this function is want to do something like follow when all sync_read failed.
1:want to read partly by PAGE_SIZE from all read devices.
2:if read success and write write to other and read back, in order to repair those disks.
for example :
disk A,B ,read 64k from 0 to 128 sector.
supposed: disk A read failed because sector 0-7 was bad sector.
disk B read failed because sector 8-15 was bad sector.
by this function,we can fix sector 0-7 of A and sector 8-15 of B.
Is ok?
If B is read_disk,so read 0-7 is ok and want to write it to A.But becasue the code ,do not write to disk A.
------------------
kedacomkernel
2012-04-05
-------------------------------------------------------------
发件人:NeilBrown
发送日期:2012-04-02 10:05:34
收件人:kedacomkernel
抄送:linux-raid
主题:Re: md/raid1:Fix a logic bug in fix_sync_read_error().
On Sat, 31 Mar 2012 10:38:01 +0800 "kedacomkernel" <kedacomkernel@gmail.com>
wrote:
> >From 0fe15c8e1bd5e46234d37573f3322312d8da325d Mon Sep 17 00:00:00 2001
> From: majianpeng <majianpeng@gmail.com>
> Date: Sat, 31 Mar 2012 10:27:33 +0800
> Subject: [PATCH] md/raid1:Fix a logic bug in fix_sync_read_error().
> If d==read_disk && success == 1 and then break, so d =
> read_disk. When exec this judgement: >>start = d; >>/*
> write it back and re-read */ >>while (d !=
> r1_bio->read_disk) { Because d == read_disk,so write and
> re-add did not exec.
That is correct, and that is how it should be.
If we get a read error, then try again and get a successful read, then there
is nothing more that we need to do. No need to write or anything.
So: current code is correct.
Thanks,
NeilBrown
>
>
> Signed-off-by: majianpeng <majianpeng@gmail.com>
> ---
> drivers/md/raid1.c | 1 -
> 1 files changed, 0 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
> index 4a40a20..3a133ff 100644
> --- a/drivers/md/raid1.c
> +++ b/drivers/md/raid1.c
> @@ -1618,7 +1618,6 @@ static int fix_sync_read_error(struct r1bio *r1_bio)
> bio->bi_io_vec[idx].bv_page,
> READ, false)) {
> success = 1;
> - break;
> }
> }
> d++;
next prev parent reply other threads:[~2012-04-05 2:23 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-31 2:38 md/raid1:Fix a logic bug in fix_sync_read_error() kedacomkernel
2012-04-02 2:05 ` NeilBrown
2012-04-05 2:23 ` kedacomkernel [this message]
2012-04-05 3:36 ` NeilBrown
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