From: zhangdongmao <dmzhang@suse.com>
To: Brassow Jonathan <jbrassow@redhat.com>,
device-mapper development <dm-devel@redhat.com>
Subject: Re: [PATCH] convert dm_ulog_request data to little endian
Date: Wed, 20 Aug 2014 11:19:02 +0800 [thread overview]
Message-ID: <53F413A6.2000409@suse.com> (raw)
In-Reply-To: <589E3349-24C0-4CBD-AA99-6F537BCDAAFB@redhat.com>
于 2014年08月20日 08:58, Brassow Jonathan 写道:
> This seems odd to me. I don't understand why you would get a bug. Do you have a mixed-architecture cluster? Some x86-64 and the s390? Otherwise, all operations should be in a format that is understood (unless there is a bug).
>
> Also, you don't really need to translate the structure just to go to userspace. Only the process that communicates between (potentially different architectures of) machines needs to do that. That process is cmirrord and the code that should translate for that daemon is in lvm2/daemons/cmirrord/compat.c.
>
> There could be a bug, but unless I'm not understanding right, we shouldn't need to switch endian in the kernel.
>
> brassow
>
I think this is because cmirrord always assume the network package is
little-endian.(see compat.c: v5_endian_from_network) .
So if cmirrord is running on S390, kernel will send package in its
native endian(big endian), this is why data is broken.
There might have two solutions:
1. cmirrord always use native endian.
2. kernel always send little endian data.
--
dm-devel mailing list
dm-devel@redhat.com
https://www.redhat.com/mailman/listinfo/dm-devel
next prev parent reply other threads:[~2014-08-20 3:19 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-08 0:56 [PATCH] convert dm_ulog_request data to little endian Dongmao Zhang
2014-08-11 3:15 ` Mike Snitzer
2014-08-11 14:03 ` Mikulas Patocka
2014-08-21 6:00 ` Brassow Jonathan
2014-08-21 11:08 ` zhangdongmao
2014-08-20 0:58 ` [PATCH] " Brassow Jonathan
2014-08-20 3:19 ` zhangdongmao [this message]
2014-08-20 4:20 ` Brassow Jonathan
2014-08-21 5:07 ` zhangdongmao
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=53F413A6.2000409@suse.com \
--to=dmzhang@suse.com \
--cc=dm-devel@redhat.com \
--cc=jbrassow@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.