[lxc-devel] [PATCH] make cgmanager follow lxc.cgroup.use

[Stéphane Graber]

On Fri, May 01, 2015 at 03:09:41PM +0000, Serge Hallyn wrote:
> Signed-off-by: Serge Hallyn <serge.hallyn at ubuntu.com>

Acked-by: Stéphane Graber <stgraber at ubuntu.com>

> ---
>  src/lxc/cgmanager.c | 82 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 82 insertions(+)
> 
> diff --git a/src/lxc/cgmanager.c b/src/lxc/cgmanager.c
> index c8d0745..c58f2e5 100644
> --- a/src/lxc/cgmanager.c
> +++ b/src/lxc/cgmanager.c
> @@ -1093,6 +1093,76 @@ static void cull_user_controllers(void)
>  	}
>  }
>  
> +static bool in_comma_list(const char *inword, const char *cgroup_use)
> +{
> +	char *e;
> +	size_t inlen = strlen(inword), len;
> +
> +	do {
> +		e = strchr(cgroup_use, ',');
> +		len = e ? e - cgroup_use : strlen(cgroup_use);
> +		if (len == inlen && strncmp(inword, cgroup_use, len) == 0)
> +			return true;
> +		cgroup_use = e + 1;
> +	} while (e);
> +
> +	return false;
> +}
> +
> +static bool in_subsystem_list(const char *c)
> +{
> +	int i;
> +
> +	for (i = 0; i < nr_subsystems; i++) {
> +		if (strcmp(c, subsystems[i]) == 0)
> +			return true;
> +	}
> +
> +	return false;
> +}
> +
> +/*
> + * If /etc/lxc/lxc.conf specifies lxc.cgroup.use = "freezer,memory",
> + * then clear out any other subsystems, and make sure that freezer
> + * and memory are both enabled
> + */
> +static bool verify_and_prune(const char *cgroup_use)
> +{
> +	const char *p;
> +	char *e;
> +	int i, j;
> +
> +	for (p = cgroup_use; p && *p; p = e + 1) {
> +		e = strchr(p, ',');
> +		if (e)
> +			*e = '\0';
> +
> +		if (!in_subsystem_list(p)) {
> +			ERROR("Controller %s required by lxc.cgroup.use but not available\n", p);
> +			return false;
> +		}
> +
> +		if (e)
> +			*e = ',';
> +		if (!e)
> +			break;
> +	}
> +
> +	for (i = 0; i < nr_subsystems;) {
> +		if (in_comma_list(subsystems[i], cgroup_use)) {
> +			i++;
> +			continue;
> +		}
> +		free(subsystems[i]);
> +		for (j = i;  j < nr_subsystems-1; j++)
> +			subsystems[j] = subsystems[j+1];
> +		subsystems[nr_subsystems-1] = NULL;
> +		nr_subsystems--;
> +	}
> +
> +	return true;
> +}
> +
>  static bool collect_subsytems(void)
>  {
>  	char *line = NULL;
> @@ -1154,6 +1224,18 @@ static bool collect_subsytems(void)
>  		return false;
>  	}
>  
> +	/* make sure that cgroup.use can be and is honored */
> +	const char *cgroup_use = lxc_global_config_value("lxc.cgroup.use");
> +	if (!cgroup_use && errno != 0)
> +		goto out_good;
> +	if (cgroup_use) {
> +		if (!verify_and_prune(cgroup_use))
> +			goto out_free;
> +		subsystems_inone[0] = NIH_MUST( strdup(cgroup_use) );
> +		cgm_all_controllers_same = false;
> +	}
> +
> +out_good:
>  	return true;
>  
>  out_free:
> -- 
> 2.1.4
> 
> _______________________________________________
> lxc-devel mailing list
> lxc-devel at lists.linuxcontainers.org
> http://lists.linuxcontainers.org/listinfo/lxc-devel

-- 
Stéphane Graber
Ubuntu developer
http://www.ubuntu.com
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