Re: [Qemu-devel] [PATCH][RFC] Handling ':' on filenames

[Eduardo Habkost <ehabkost@raisama.net>]

Excerpts from kvm_autotest's message of Dom Mar 08 08:28:31 -0300 2009:
> Eduardo Habkost wrote:
> > This patch fixes this issue:
> > 
> >   $ qemu-img create -f qcow2 /tmp/a:b 1G
> >   $ qemu-system-x86_64 -hda qcow2:/tmp/a:b
> >   qemu: could not open disk image /tmp/a:b
> >   $
> 
> This patch looks good to me with the following comments:
> 
> 1. I think the example above is wrong.
>     a. There is no protocol "qcow2"
>     b. We do not want to use "qcow2:/tmp/a:b" as filenames (been there).
>        We want to use -drive file=/tmp/a:b,format=qcow2 (and
>        similar "qemu-img info -f ").

Oops. Ignore that, I've pasted the wrong command-line. That was when I
was testing the behaviour of qemu when I specified other things before
the colon. The error appears when I do this:

 $ qemu-system-x86_64 -hda /tmp/a:b

>     c. But, without this patch, even when using appropriate -drive, we'd
>        still get the same result (could not open disk image).
>        Qemu considers "/tmp/a" to be a protocol, which does not exist,
>        so Qemu fails to open the image.
>        With this patch, Qemu opens the file successfully.
> 

Yes.

> > 
> > Based on a suggestion by Daniel Berrange.
> > 
> > However, this is still just a workaround. The semantics of filenames
> > containing colon characters (and how this can be escaped, avoided,
> > or worked around) are not very clear.
> > 
> > Going further, what if we stop using "protocol:filename" strings
> > internally, except where the user interface or external data really
> > requires this format?
> 
> 2. Do you mean something like adding a '-drive protocol=xxx' option ?

Where possible, yes.
-- 
Eduardo