[libvirt] [PATCH 3/4] virt-host-validate: check for required cgroups

[Laine Stump]

On 10/07/2015 12:50 PM, Daniel P. Berrange wrote:
> Extend the virt-host-validate checks to see if the required
> cgroups are compiled into the kernel and that they are
> mounted on the system. The cgroups are all optional except
> for 3 that LXC mandates
>
> Signed-off-by: Daniel P. Berrange <berrange at redhat.com>
> ---
>   tools/virt-host-validate-common.c | 130 +++++++++++++++++++++++++++++++++++---
>   tools/virt-host-validate-common.h |   8 ++-
>   tools/virt-host-validate-lxc.c    |  30 +++++++++
>   tools/virt-host-validate-qemu.c   |  30 +++++++++
>   4 files changed, 188 insertions(+), 10 deletions(-)
>
> diff --git a/tools/virt-host-validate-common.c b/tools/virt-host-validate-common.c
> index d646a79..7e8d619 100644
> --- a/tools/virt-host-validate-common.c
> +++ b/tools/virt-host-validate-common.c
> @@ -26,6 +26,7 @@
>   #include <stdio.h>
>   #include <unistd.h>
>   #include <sys/utsname.h>
> +#include <mntent.h>
>   
>   #include "virutil.h"
>   #include "viralloc.h"
> @@ -104,14 +105,29 @@ static const char *failEscapeCodes[] = {
>   verify(ARRAY_CARDINALITY(failEscapeCodes) == VIR_HOST_VALIDATE_LAST);
>   
>   void virHostMsgFail(virHostValidateLevel level,
> -                    const char *hint)
> +                    const char *format,
> +                    ...)
>   {
> +    va_list args;
> +    char *msg;
> +
> +    if (quiet)
> +        return;
> +
> +    va_start(args, format);
> +    if (virVasprintf(&msg, format, args) < 0) {
> +        perror("malloc");
> +        abort();
> +    }
> +    va_end(args);
> +
>       if (virHostMsgWantEscape())
>           fprintf(stdout, "%s%s\033[0m (%s)\n",
> -                failEscapeCodes[level], _(failMessages[level]), hint);
> +                failEscapeCodes[level], _(failMessages[level]), msg);
>       else
>           fprintf(stdout, "%s (%s)\n",
> -                _(failMessages[level]), hint);
> +                _(failMessages[level]), msg);
> +    free(msg);
>   }
>   
>   
> @@ -123,7 +139,7 @@ int virHostValidateDeviceExists(const char *hvname,
>       virHostMsgCheck(hvname, "if device %s exists", dev_name);
>   
>       if (access(dev_name, F_OK) < 0) {
> -        virHostMsgFail(level, hint);
> +        virHostMsgFail(level, "%s", hint);
>           return -1;
>       }
>   
> @@ -140,7 +156,7 @@ int virHostValidateDeviceAccessible(const char *hvname,
>       virHostMsgCheck(hvname, "if device %s is accessible", dev_name);
>   
>       if (access(dev_name, R_OK|W_OK) < 0) {
> -        virHostMsgFail(level, hint);
> +        virHostMsgFail(level, "%s", hint);
>           return -1;
>       }
>   
> @@ -160,7 +176,7 @@ int virHostValidateNamespace(const char *hvname,
>       snprintf(nspath, sizeof(nspath), "/proc/self/ns/%s", ns_name);
>   
>       if (access(nspath, F_OK) < 0) {
> -        virHostMsgFail(level, hint);
> +        virHostMsgFail(level, "%s", hint);
>           return -1;
>       }
>   
> @@ -211,20 +227,116 @@ int virHostValidateLinuxKernel(const char *hvname,
>                       (version & 0xff));
>   
>       if (STRNEQ(uts.sysname, "Linux")) {
> -        virHostMsgFail(level, hint);
> +        virHostMsgFail(level, "%s", hint);
>           return -1;
>       }
>   
>       if (virParseVersionString(uts.release, &thisversion, true) < 0) {
> -        virHostMsgFail(level, hint);
> +        virHostMsgFail(level, "%s", hint);
>           return -1;
>       }
>   
>       if (thisversion < version) {
> -        virHostMsgFail(level, hint);
> +        virHostMsgFail(level, "%s", hint);
>           return -1;
>       } else {
>           virHostMsgPass();
>           return 0;
>       }
>   }
> +
> +
> +static int virHostValidateCGroupSupport(const char *hvname,
> +                                        const char *cg_name,
> +                                        virHostValidateLevel level,
> +                                        const char *config_name)
> +{
> +    virHostMsgCheck(hvname, "for cgroup '%s' controller support", cg_name);
> +    FILE *fp = fopen("/proc/self/cgroup", "r");
> +    size_t len = 0;
> +    char *line = NULL;
> +    ssize_t ret;
> +    bool matched = false;
> +
> +    if (!fp)
> +        goto error;
> +
> +    while ((ret = getline(&line, &len, fp)) >= 0 && !matched) {
> +        char *tmp = strstr(line, cg_name);
> +        if (!tmp)
> +            continue;
> +
> +        tmp += strlen(cg_name);
> +        if (*tmp != ',' &&
> +            *tmp != ':')
> +            continue;
> +
> +        matched = true;
> +    }
> +    free(line);
> +    fclose(fp);
> +    if (!matched)
> +        goto error;
> +
> +    virHostMsgPass();
> +    return 0;
> +
> + error:
> +    free(line);
> +    virHostMsgFail(level, "Enable CONFIG_%s in kernel Kconfig file", config_name);
> +    return -1;
> +}
> +
> +static int virHostValidateCGroupMount(const char *hvname,
> +                                      const char *cg_name,
> +                                      virHostValidateLevel level)
> +{
> +    virHostMsgCheck(hvname, "for cgroup '%s' controller mount-point", cg_name);
> +    FILE *fp = setmntent("/proc/mounts", "r");
> +    struct mntent *ent;
> +    bool matched = false;
> +
> +    if (!fp)
> +        goto error;
> +
> +    while ((ent = getmntent(fp)) && !matched) {

Oops, another make syntax-check fail:

tools/virt-host-validate-common.c:302: while ((ent = getmntent(fp)) && 
!matched) { maint.mk: use getmntent_r, not getmntent