[libvirt] [PATCH 22/53] vircgroup: introduce virCgroupV2GetBlkioIoServiced

[Michal Privoznik]

On 10/02/2018 10:44 AM, Pavel Hrdina wrote:
> Signed-off-by: Pavel Hrdina <phrdina at redhat.com>
> ---
>  src/util/vircgroupv2.c | 66 ++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 66 insertions(+)
> 
> diff --git a/src/util/vircgroupv2.c b/src/util/vircgroupv2.c
> index 3e2cd16335..30c400f129 100644
> --- a/src/util/vircgroupv2.c
> +++ b/src/util/vircgroupv2.c
> @@ -592,6 +592,71 @@ virCgroupV2GetBlkioWeight(virCgroupPtr group,
>  }
>  
>  
> +static int
> +virCgroupV2GetBlkioIoServiced(virCgroupPtr group,
> +                              long long *bytes_read,
> +                              long long *bytes_write,
> +                              long long *requests_read,
> +                              long long *requests_write)
> +{
> +    long long stats_val;
> +    VIR_AUTOFREE(char *) str1 = NULL;
> +    char *p1;
> +    size_t i;
> +
> +    const char *value_names[] = {
> +        "rbytes=",
> +        "wbytes=",
> +        "rios=",
> +        "wios=",
> +    };
> +    long long *value_ptrs[] = {
> +        bytes_read,
> +        bytes_write,
> +        requests_read,
> +        requests_write
> +    };
> +
> +    *bytes_read = 0;
> +    *bytes_write = 0;
> +    *requests_read = 0;
> +    *requests_write = 0;
> +
> +    if (virCgroupGetValueStr(group,
> +                             VIR_CGROUP_CONTROLLER_BLKIO,
> +                             "io.stat", &str1) < 0) {
> +        return -1;
> +    }
> +
> +    /* sum up all entries of the same kind, from all devices */
> +    for (i = 0; i < ARRAY_CARDINALITY(value_names); i++) {
> +        p1 = str1;
> +
> +        while ((p1 = strstr(p1, value_names[i]))) {
> +            p1 += strlen(value_names[i]);
> +            if (virStrToLong_ll(p1, &p1, 10, &stats_val) < 0) {

Rather unusual use, we tend to use two different pointers. Perhaps s/p1/p/?

> +                virReportError(VIR_ERR_INTERNAL_ERROR,
> +                               _("Cannot parse byte %sstat '%s'"),
> +                               value_names[i],
> +                               p1);

What do you expect to be printed out here? Because IIUC this will print
the incorrect string + the rest of the file. Also, "%sstat" will print
"rwbytes=stat". I'd put a space after %s at least.

> +                return -1;
> +            }
> +
> +            if (stats_val < 0 ||
> +                (stats_val > 0 && *value_ptrs[i] > (LLONG_MAX - stats_val))) {
> +                virReportError(VIR_ERR_OVERFLOW,
> +                               _("Sum of byte %sstat overflows"),
> +                               value_names[i]);
> +                return -1;
> +            }
> +            *value_ptrs[i] += stats_val;
> +        }
> +    }
> +
> +    return 0;
> +}
> +
> +
>  virCgroupBackend virCgroupV2Backend = {
>      .type = VIR_CGROUP_BACKEND_TYPE_V2,
>  
> @@ -616,6 +681,7 @@ virCgroupBackend virCgroupV2Backend = {
>  
>      .setBlkioWeight = virCgroupV2SetBlkioWeight,
>      .getBlkioWeight = virCgroupV2GetBlkioWeight,
> +    .getBlkioIoServiced = virCgroupV2GetBlkioIoServiced,
>  };
>  
>  
> 

Michal