Le Thursday 19 Sep 2013 à 15:21:46 (+0200), Kevin Wolf a écrit : > Am 19.09.2013 um 14:55 hat Benoît Canet geschrieben: > > Le Thursday 19 Sep 2013 à 10:57:50 (+0200), Kevin Wolf a écrit : > > > Am 19.09.2013 um 10:26 hat Stefan Hajnoczi geschrieben: > > > > On Wed, Sep 18, 2013 at 05:05:27PM +0200, Benoît Canet wrote: > > > > > Le Tuesday 17 Sep 2013 à 14:44:13 (+0200), Stefan Hajnoczi a écrit : > > > > > > Hi Benoit, > > > > > > Kevin and I had a chance to chat face-to-face and we discussed what > > > > > > concrete changes are necessary to merge quorum (without solving all > > > > > > the > > > > > > other block layers problems at once). > > > > > > > > > > > > I think quorum could be merged relatively quickly (and without > > > > > > massive > > > > > > BlockFilter investments) by changing the following: > > > > > > > > > > > > 1. Defining children on the command-line > > > > > > > > > > > > Existing "filter" drivers use the protocol filename to embed their > > > > > > children, for example the blkverify driver. This is a big hack > > > > > > because > > > > > > we have no proper syntax or escaping for the embedded drive > > > > > > definitions > > > > > > in the file= option. > > > > > > > > > > > > This was one of the main arguments against merging quorum. Now that > > > > > > Kevin has implemented driver-specific open options (see > > > > > > block/qcow2.c:qcow2_runtime_opts), it is possible for the quorum > > > > > > driver > > > > > > to open children specific on the command-line: > > > > > > > > > > > > -drive if=none,file.driver=quorum,format=raw,\ > > > > > > file.children0.file=/nfs1/test.qcow2,\ > > > > > > file.children1.file=/nfs2/test.qcow2,\ > > > > > > file.children2.file=/nfs3/test.qcow2 > > > > > > By the way, I think he concrete syntax might have to be a bit different > > > so it can be mapped to QAPI for blockdev-add. I think we'll want to use > > > a JSON list for the children; a mapping to QDict and to the command line > > > is yet to be implemented I guess. > > > > Hi, > > > > Just to make sure I'll code the right thing; is the following correct ? > > > > -drive if=none,file.driver=quorum,format=raw,\ > > file.children=[/nfs1/test.qcow2, /nfs2/test.qcow2, > > /nfs3/test.qcow2], \ > > file.vote_threshold=2 > > I was thinking more along the lines of: > > -drive if=none,file.driver=quorum,format=raw,\ > file.children[0].file.filename=/nfs1/test.qcow2, \ > file.children[1].file.filename=/nfs2/test.qcow2, \ > file.children[1].file.cache.direct=on, \ > file.children[2].file.driver=nbd, \ > file.children[2].file.host=localhost, \ > file.vote_threshold=2 > > The exact syntax doesn't matter all that much as long as it can be > mapped to QAPI, but as you can see this allows specifying detailed > options even for the children. I think this is a requirement.
So does it mean that on top of your blockdev branch qemu_opts_to_qdict should do a little parsing of opt->name to regroup options of the same children together ? e.g: converting the incoming qoption into the qdict equivalent of: dict = { "driver": "quorum", "children[0]": "file.filename=/nfs1/test.qcow2", "children[1]": "file.filename=/nfs2/test.qcow2,file.cache.direct=on", "children[2]": "file.driver=nbd,file.host=localhost", "vote_threshold": 2 } Best regards Benoît