[libvirt] [PATCH 2/3] Auto-add a root <filesystem> element to LXC containers on startup

[Daniel P. Berrange]

On Wed, Apr 03, 2013 at 11:17:30AM -0600, Eric Blake wrote:
> On 04/03/2013 10:02 AM, Daniel P. Berrange wrote:
> > From: "Daniel P. Berrange" <berrange at redhat.com>
> > 
> > Currently the LXC container code has two codepaths, depending on
> > whether there is a <filesystem> element with a target path of '/'.
> > If we automatically add a <filesystem> device with src=/ and dst=/,
> > for any container which has not specified a root filesystem, then
> > we only need one codepath for setting up the filesystem.
> > 
> > Signed-off-by: Daniel P. Berrange <berrange at redhat.com>
> > ---
> >  src/lxc/lxc_container.c | 113 +++---------------------------------------------
> >  src/lxc/lxc_process.c   |  38 ++++++++++++++++
> >  2 files changed, 44 insertions(+), 107 deletions(-)
> 
> Nice cleanup!
> 
> > +++ b/src/lxc/lxc_process.c
> > @@ -981,6 +981,41 @@ virLXCProcessReadLogOutput(virDomainObjPtr vm,
> >      return ret;
> >  }
> >  
> > +
> > +static int
> > +virLXCProcessEnsureRootFS(virDomainObjPtr vm)
> > +{
> > +    virDomainFSDefPtr root = virDomainGetRootFilesystem(vm->def);
> > +
> > +    if (root)
> > +        return 0;
> > +
> > +    if (VIR_ALLOC(root) < 0)
> > +        goto no_memory;
> > +
> > +    root->type = VIR_DOMAIN_FS_TYPE_MOUNT;
> > +
> > +    if (!(root->src = strdup("/")) ||
> > +        !(root->dst = strdup("/")))
> > +        goto no_memory;
> 
> Might be a fun merge conflict, depending on whether this or VIR_STRDUP
> gets merged first. :)
> 
> > +
> > +    if (VIR_EXPAND_N(vm->def->fss,
> > +                     vm->def->nfss, 1) < 0)
> > +        goto no_memory;
> > +
> > +    memmove(vm->def->fss + 1,
> > +            vm->def->fss,
> > +            vm->def->nfss * sizeof(virDomainFSDefPtr));
> > +    vm->def->fss[0] = root;
> 
> Instead of VIR_EXPAND_N/memmove, you should use VIR_INSERT_ELEMENT.
> 
> I like the concept of the patch, but I'm debating whether to ack this or
> require a v2 just so we make sure the VIR_INSERT_ELEMENT usage is correct.

I'll repost it


Daniel
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