Re: [Qemu-devel] [PATCH] hostmem-file: add a property 'notrunc' to avoid data corruption

[Eduardo Habkost]

On Tue, Oct 25, 2016 at 02:42:41PM +0800, Haozhong Zhang wrote:
> On 10/24/16 11:10 -0200, Eduardo Habkost wrote:
> > On Thu, Oct 20, 2016 at 03:55:22PM +0200, Kevin Wolf wrote:
> > > Am 20.10.2016 um 14:34 hat Igor Mammedov geschrieben:
> > > > >  #ifdef __linux__
> > > > > +static uint64_t get_file_size(const char *path, Error **errp)
> > > > Maybe QEMU laredy has an utility to do it that could be shared,
> > > > CCing block maintainers.
> > > 
> > > We have quite a bit of code for determining the right size of a file
> > > (including block devices) on different platforms and devices. See the
> > > .bdrv_getlength implementations in raw-posix.c and raw-win32.c.
> > > 
> > > However, none of them are made for consumption outside the block layer.
> > 
> > There's a patch on qemu-devel archives from 2015:
> >  Subject [PATCH v7 11/35] util: introduce qemu_file_getlength()
> > it could be reused here.
> > 
> 
> My new version patches
> (https://lists.nongnu.org/archive/html/qemu-devel/2016-10/msg05519.html)
> use the same approach to get the file size except that I didn't make
> it a common function. I'll move it to a common function in the next
> version.

I think we can move it into a common function in a follow-up
series. This way the discussion about where to put the common
function (and what we should do on non-posix hosts) won't hold
this series.

-- 
Eduardo