[lxc-devel] [PATCH 2/3] execute: bind init.lxc.static into container

[Serge Hallyn]

Quoting Dwight Engen (dwight.engen at oracle.com):
> On Tue, 13 May 2014 11:46:00 +0000
> Serge Hallyn <serge.hallyn at ubuntu.com> wrote:
> 
> > Quoting Serge Hallyn (serge.hallyn at ubuntu.com):
> > > Quoting Dwight Engen (dwight.engen at oracle.com):
> > > > On Mon, 12 May 2014 18:04:00 +0000
> > > > Serge Hallyn <serge.hallyn at ubuntu.com> wrote:
> > > > 
> > > > > Signed-off-by: Serge Hallyn <serge.hallyn at ubuntu.com>
> > > > > ---
> > > > >  src/lxc/conf.c | 58
> > > > > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1
> > > > > file changed, 58 insertions(+)
> > > > > 
> > > > > diff --git a/src/lxc/conf.c b/src/lxc/conf.c
> > > > > index 7427a94..0580f46 100644
> > > > > --- a/src/lxc/conf.c
> > > > > +++ b/src/lxc/conf.c
> > > > > @@ -3811,6 +3811,61 @@ static void remount_all_slave(void)
> > > > >  		free(line);
> > > > >  }
> > > > >  
> > > > > +void lxc_execute_bind_init(struct lxc_conf *conf)
> > > > > +{
> > > > > +	int ret;
> > > > > +	char path[PATH_MAX], destpath[PATH_MAX];
> > > > > +
> > > > > +	ret = snprintf(path, PATH_MAX, SBINDIR
> > > > > "/init.lxc.static");
> > > > > +	if (ret < 0 || ret >= PATH_MAX) {
> > > > > +		WARN("Path name too long searching for
> > > > > lxc.init.static");
> > > > > +		return;
> > > > > +	}
> > > > > +
> > > > > +	if (!file_exists(path)) {
> > > > > +		INFO("%s does not exist on host", path);
> > > > > +		return;
> > > > > +	}
> > > > > +
> > > > > +	ret = snprintf(destpath, PATH_MAX, "%s%s",
> > > > > conf->rootfs.mount, path);
> > > > > +	if (ret < 0 || ret >= PATH_MAX) {
> > > > > +		WARN("Path name too long for container's
> > > > > lxc.init.static");
> > > > > +		return;
> > > > > +	}
> > > > > +
> > > > > +	if (!file_exists(destpath)) {
> > > > > +		FILE *pathfile;
> > > > > +		char *pathdirname = strdup(path);
> > > > > +
> > > > > +		if (!pathdirname) {
> > > > > +			SYSERROR("Out of memory binding
> > > > > lxc.init.static into container");
> > > > > +			return;
> > > > > +		}
> > > > > +		pathdirname = dirname(pathdirname);
> > > > > +		ret = mkdir_p(pathdirname, 0755);
> > > > > +		free(pathdirname);
> > > > > +		if (ret < 0) {
> > > > > +			/*
> > > > > +			 * this can fail just due to read-only
> > > > > bind mounts.  Trust
> > > > > +			 * that the user knows what they want,
> > > > > log and proceed
> > > > > +			 */
> > > > > +			WARN("Failed to create %s in
> > > > > container", SBINDIR);
> > > > > +			return;
> > > > > +		}
> > > > > +		pathfile = fopen(destpath, "wb");
> > > 
> > > Thanks for taking a look,
> > > 
> > > > Hi Serge, are you sure you want to truncate destpath in case it
> > > > exists? Maybe you want "ab"?
> > > 
> > > This only happens in the !file_exists(destpath) case though, so it
> > > really shouldn't be possible absent a weird race.
> > 
> > I guess it might be worth changing.  I copy/pasted this code from the
> > file=create case in conf.c, so I think we should fix it in both places
> > with one separate patch.
> 
> Hey, when I try to build this I get:
> 
> conf.c: In function 'lxc_execute_bind_init':
> conf.c:3824:2: error: implicit declaration of function 'file_exists' [-Werror=implicit-function-declaration]
>   if (!file_exists(path)) {
> 
> it looks like file_exists() isn't declared in any header and is static to lxccontainer.c?

Sorry, yeah I'd forgotten, this patch depends on my qcow2 patch which moves
that fn.  So we can either wait for that patch or I can break the qcow2 one
up.