From: "Richard W.M. Jones" <rjones@redhat.com>
To: Alex Bligh <alex@alex.org.uk>
Cc: Kevin Wolf <kwolf@redhat.com>, Kaveh Razavi <kaveh@cs.vu.nl>,
famz@redhat.com, qemu-devel@nongnu.org,
Stefan Hajnoczi <stefanha@redhat.com>
Subject: Re: [Qemu-devel] [PATCH] Introduce cache images for the QCOW2 format
Date: Wed, 14 Aug 2013 16:58:55 +0100 [thread overview]
Message-ID: <20130814155855.GA5784@redhat.com> (raw)
In-Reply-To: <F7EC3402-4216-4ED6-A844-BC1657D422BF@alex.org.uk>
On Wed, Aug 14, 2013 at 01:03:48PM +0100, Alex Bligh wrote:
>
> On 14 Aug 2013, at 12:52, Fam Zheng wrote:
>
> > Yes, this one sounds good to have. VMDK and VHDX have this kind of
> > backing file status validation.
>
> ... though I'd prefer something safer than looking at mtime, for
> instance a sequence number that is incremented prior to any
> bdrv_close if a write has been done since bdrv_open.
Yes, please not mtime. User-mode Linux COW files use mtime to check
this, and it causes no end of problems (eg. if the backing file is
copied from one place to another without using the magic incantations
to preserve file times).
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Fedora Windows cross-compiler. Compile Windows programs, test, and
build Windows installers. Over 100 libraries supported.
http://fedoraproject.org/wiki/MinGW
next prev parent reply other threads:[~2013-08-14 15:59 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-13 17:03 [Qemu-devel] [PATCH] Introduce cache images for the QCOW2 format Kaveh Razavi
2013-08-13 21:37 ` Eric Blake
2013-08-14 11:13 ` Kaveh Razavi
2013-08-13 22:53 ` Alex Bligh
2013-08-14 11:28 ` Kaveh Razavi
2013-08-14 11:52 ` Fam Zheng
2013-08-14 12:03 ` Alex Bligh
2013-08-14 15:58 ` Richard W.M. Jones [this message]
2013-08-15 0:53 ` Fam Zheng
2013-08-15 5:51 ` Alex Bligh
2013-08-14 11:57 ` Alex Bligh
2013-08-14 13:37 ` Kaveh Razavi
2013-08-13 23:16 ` Alex Bligh
2013-08-14 11:42 ` Kaveh Razavi
2013-08-14 12:02 ` Alex Bligh
2013-08-14 13:43 ` Kaveh Razavi
2013-08-14 13:50 ` Alex Bligh
2013-08-14 14:26 ` Kaveh Razavi
2013-08-14 15:02 ` Alex Bligh
2013-08-14 15:32 ` Kevin Wolf
2013-08-15 7:50 ` Wenchao Xia
2013-08-15 8:11 ` Stefan Hajnoczi
2013-08-14 9:29 ` Stefan Hajnoczi
2013-08-14 14:20 ` Kaveh Razavi
2013-08-15 8:32 ` Stefan Hajnoczi
2013-08-15 12:25 ` Kaveh Razavi
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