Re: [Qemu-block] [Qemu-devel] [RFC 0/2] Parse 'filename' option for RBD/iSCSI

[Richard W.M. Jones]

On Mon, Jun 12, 2017 at 12:05:12AM -0400, Jeff Cody wrote:
> We need to be able to parse the 'filename' option for both rbd and iscsi,
> because there may exist images in the wild that have json backing files,
> that specify the filename argument.
> 
> Marking the series as RFC at least partially for the precedence given to
> arguments; as written, these patches will give preference to the 'filename'
> parameter over passed options.

I tested this as follows:

(1) Prepare a test image.  By using the ‘qemu-img rebase -u’ option we
can set the formerly correct / now incorrect backing option to an
arbitrary json string of our choosing:

$ qemu-img create test.img -f qcow2 10M
$ qemu-img rebase -u -b 
'json:{"file.driver":"rbd","file.filename":"rbd:rbd/rbd.img:mon_host=127.0.0.0"}'
 test.img 

(2) With upstream qemu:

$ qemu-system-x86_64 -hda test.img 
qemu-system-x86_64: -hda test.img: Could not open backing file: Parameters 
'pool' and 'image' are required

(3) With upstream qemu + these two patches:

$ ~/d/qemu/x86_64-softmmu/qemu-system-x86_64 -hda test.img
[hangs and eventually reports a timeout because I don't really
have a Ceph server]

So I would say that these patches, superficially at least, do seem to
work.  Although I wasn't able to test them against a real Ceph server.

  Tested-by: Richard W.M. Jones <address@hidden>

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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