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Date: Mon, 31 Oct 2016 15:21:59 -0200
From: Eduardo Habkost <ehabkost@redhat.com>
Message-ID: <20161031172159.GC2919@thinpad.lan.raisama.net>
References: <20161027042300.5929-1-haozhong.zhang@intel.com>
	<20161027042300.5929-2-haozhong.zhang@intel.com>
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Subject: Re: [Qemu-devel] [PATCH v2 1/3] exec.c: do not truncate non-empty
 memory backend file
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To: qemu-devel@nongnu.org, Igor Mammedov <imammedo@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>, Peter Crosthwaite <crosthwaite.peter@gmail.com>, Richard Henderson <rth@twiddle.net>

On Fri, Oct 28, 2016 at 10:07:40AM +0800, Haozhong Zhang wrote:
> On 10/27/16 12:31 -0200, Eduardo Habkost wrote:
> > On Thu, Oct 27, 2016 at 12:22:58PM +0800, Haozhong Zhang wrote:
> > > For '-object memory-backend-file,mem-path=foo,size=xyz', if the size of
> > > file 'foo' does not match the given size 'xyz', the current QEMU will
> > > truncate the file to the given size, which may corrupt the existing data
> > > in that file. To avoid such data corruption, this patch disables
> > > truncating non-empty backend files.
> > > 
> > > Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
> > 
> > Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
> > 
> > But I would add comment near the get_file_size() call to indicate
> > that not stopping on get_file_size() errors is on purpose and not
> > a mistake.
> > 
> 
> I'll add comments in the next version.
> 

The patch was applied to machine-next and will be in my next pull
request. The comment can be sent as a follow-up patch.

-- 
Eduardo