vendor: update c/common

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

vendor/github.com/opencontainers/cgroups/fs/pids.go

@@ -0,0 +1,61 @@
+package fs
+
+import (
+	"math"
+	"strconv"
+
+	"github.com/opencontainers/cgroups"
+	"github.com/opencontainers/cgroups/fscommon"
+)
+
+type PidsGroup struct{}
+
+func (s *PidsGroup) Name() string {
+	return "pids"
+}
+
+func (s *PidsGroup) Apply(path string, _ *cgroups.Resources, pid int) error {
+	return apply(path, pid)
+}
+
+func (s *PidsGroup) Set(path string, r *cgroups.Resources) error {
+	if r.PidsLimit != 0 {
+		// "max" is the fallback value.
+		limit := "max"
+
+		if r.PidsLimit > 0 {
+			limit = strconv.FormatInt(r.PidsLimit, 10)
+		}
+
+		if err := cgroups.WriteFile(path, "pids.max", limit); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (s *PidsGroup) GetStats(path string, stats *cgroups.Stats) error {
+	if !cgroups.PathExists(path) {
+		return nil
+	}
+	current, err := fscommon.GetCgroupParamUint(path, "pids.current")
+	if err != nil {
+		return err
+	}
+
+	max, err := fscommon.GetCgroupParamUint(path, "pids.max")
+	if err != nil {
+		return err
+	}
+	// If no limit is set, read from pids.max returns "max", which is
+	// converted to MaxUint64 by GetCgroupParamUint. Historically, we
+	// represent "no limit" for pids as 0, thus this conversion.
+	if max == math.MaxUint64 {
+		max = 0
+	}
+
+	stats.PidsStats.Current = current
+	stats.PidsStats.Limit = max
+	return nil
+}