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Re: [Qemu-devel] [PATCH] raw-posix: add 'offset' and 'size' options
From: |
Daniel P. Berrange |
Subject: |
Re: [Qemu-devel] [PATCH] raw-posix: add 'offset' and 'size' options |
Date: |
Tue, 4 Oct 2016 10:15:10 +0100 |
User-agent: |
Mutt/1.7.0 (2016-08-17) |
On Tue, Oct 04, 2016 at 10:57:49AM +0200, Kevin Wolf wrote:
> Am 03.10.2016 um 13:07 hat Tomáš Golembiovský geschrieben:
> > > > > > + if (((bs->drv != &bdrv_file) || !bs->read_only) &&
> > > > >
> > > > > Why the check against bdrv_file ?
> > > >
> > > > To limit it only to files. Maybe there is better way to do that? The
> > > > devices have a nasty habit to change the size. Sure, this can happen to
> > > > file too, e.g. if somebody truncates the file outside QEMU. But that's
> > > > rather a bad behaviour. For devices changing the size may be perfectly
> > > > valid operation, e.g. replacing CD in drive or card in a card reader.
> > >
> > > The raw driver is usable over any storage backend (file, rbd, iscsi,
> > > etc, etc) and it is valid to want to use a offset/size parameter in
> > > combination with any of them. So we should not restrict it to just
> > > files.
>
> Just to clear up some confusion here: There are the file/host_device/...
> protocol drivers, which only access local files. These are implemented
> in raw-posix.c, i.e. the file that this patch is touching. raw-win32.c
> implements the same kind of file access for Windows.
This naming is constantly confusing - is there any appetite for renaming
those to 'file-posix.c' and 'file-win32.c', and raw_bsd.c to raw.c ?
Regards,
Daniel
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- [Qemu-devel] [PATCH] raw-posix: add 'offset' and 'size' options, Tomáš Golembiovský, 2016/10/02
- Re: [Qemu-devel] [PATCH] raw-posix: add 'offset' and 'size' options, Daniel P. Berrange, 2016/10/03
- Re: [Qemu-devel] [PATCH] raw-posix: add 'offset' and 'size' options, Tomáš Golembiovský, 2016/10/03
- Re: [Qemu-devel] [PATCH] raw-posix: add 'offset' and 'size' options, Daniel P. Berrange, 2016/10/03
- Re: [Qemu-devel] [PATCH] raw-posix: add 'offset' and 'size' options, Tomáš Golembiovský, 2016/10/03
- Re: [Qemu-devel] [PATCH] raw-posix: add 'offset' and 'size' options, Daniel P. Berrange, 2016/10/03
- Re: [Qemu-devel] [PATCH] raw-posix: add 'offset' and 'size' options, Kevin Wolf, 2016/10/04
- Re: [Qemu-devel] [PATCH] raw-posix: add 'offset' and 'size' options,
Daniel P. Berrange <=
- Re: [Qemu-devel] [PATCH] raw-posix: add 'offset' and 'size' options, Eric Blake, 2016/10/04
- Re: [Qemu-devel] [PATCH] raw-posix: add 'offset' and 'size' options, Tomáš Golembiovský, 2016/10/04
Re: [Qemu-devel] [PATCH] raw-posix: add 'offset' and 'size' options, Eric Blake, 2016/10/03
Re: [Qemu-devel] [PATCH] raw-posix: add 'offset' and 'size' options, Kevin Wolf, 2016/10/04