From: Eric Blake <eblake@redhat.com>
To: Max Reitz <mreitz@redhat.com>, qemu-devel@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>, Stefan Hajnoczi <stefanha@redhat.com>
Subject: Re: [Qemu-devel] [PATCH] qcow2: Unset zero_beyond_eof in save_vmstate
Date: Mon, 21 Oct 2013 21:37:05 +0100 [thread overview]
Message-ID: <52659071.4070003@redhat.com> (raw)
In-Reply-To: <1382298755-21383-1-git-send-email-mreitz@redhat.com>
[-- Attachment #1: Type: text/plain, Size: 823 bytes --]
On 10/20/2013 08:52 PM, Max Reitz wrote:
> Saving the VM state is done using bdrv_pwrite. This function may perform
> a read-modify-write, which in this case results in data being read from
> beyond the end of the virtual disk. Since we are actually trying to
> access an area which is not a part of the virtual disk, zero_beyond_eof
> has to be set to false before performing the partial write, otherwise
> the VM state may become corrupted.
>
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> ---
> Follow-up to (depends on):
> - qcow2: Restore total_sectors value in save_vmstate
Reviewed-by: Eric Blake <eblake@redhat.com>
Do you have test cases that demonstrate the corruption pre-patch?
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 621 bytes --]
next prev parent reply other threads:[~2013-10-21 20:37 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-20 19:52 [Qemu-devel] [PATCH] qcow2: Unset zero_beyond_eof in save_vmstate Max Reitz
2013-10-21 20:37 ` Eric Blake [this message]
2013-10-23 17:07 ` Max Reitz
2013-10-23 18:27 ` Max Reitz
2013-10-24 9:52 ` Kevin Wolf
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=52659071.4070003@redhat.com \
--to=eblake@redhat.com \
--cc=kwolf@redhat.com \
--cc=mreitz@redhat.com \
--cc=qemu-devel@nongnu.org \
--cc=stefanha@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.