Fix parsing of blkio files

Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)

cgroups/fs/blkio.go

@@ -3,8 +3,11 @@ package fs
 import (
 	"bufio"
 	"fmt"
+	"io/ioutil"
 	"os"
 	"path/filepath"
+	"strconv"
+	"strings"
 
 	"github.com/dotcloud/docker/pkg/cgroups"
 )
@@ -58,10 +61,9 @@ func (s *blkioGroup) Stats(d *data) (map[string]float64, error) {
 	var (
 		paramData = make(map[string]float64)
 		params    = []string{
-			"sectors",
+			"io_service_bytes_recursive",
-			"io_service_bytes",
+			"io_serviced_recursive",
-			"io_serviced",
+			"io_queued_recursive",
-			"io_queued",
 		}
 	)
 
@@ -70,6 +72,12 @@ func (s *blkioGroup) Stats(d *data) (map[string]float64, error) {
 		return nil, err
 	}
 
+	k, v, err := s.getSectors(path)
+	if err != nil {
+		return nil, err
+	}
+	paramData[fmt.Sprintf("blkio.sectors_recursive:%s", k)] = v
+
 	for _, param := range params {
 		f, err := os.Open(filepath.Join(path, fmt.Sprintf("blkio.%s", param)))
 		if err != nil {
@@ -79,12 +87,35 @@ func (s *blkioGroup) Stats(d *data) (map[string]float64, error) {
 
 		sc := bufio.NewScanner(f)
 		for sc.Scan() {
-			_, v, err := getCgroupParamKeyValue(sc.Text())
+			// format: dev type amount
+			fields := strings.Fields(sc.Text())
+			switch len(fields) {
+			case 3:
+				v, err := strconv.ParseFloat(fields[2], 64)
 				if err != nil {
 					return nil, err
 				}
-			paramData[param] = v
+				paramData[fmt.Sprintf("%s:%s:%s", param, fields[0], fields[1])] = v
+			case 2:
+				// this is the total line, skip
+			default:
+				return nil, ErrNotValidFormat
+			}
 		}
 	}
 	return paramData, nil
 }
+
+func (s *blkioGroup) getSectors(path string) (string, float64, error) {
+	f, err := os.Open(filepath.Join(path, "blkio.sectors_recursive"))
+	if err != nil {
+		return "", 0, err
+	}
+	defer f.Close()
+
+	data, err := ioutil.ReadAll(f)
+	if err != nil {
+		return "", 0, err
+	}
+	return getCgroupParamKeyValue(string(data))
+}

cgroups/fs/utils.go

@@ -7,7 +7,10 @@ import (
 	"strings"
 )
 
-var ErrNotSupportStat = errors.New("stats are not supported for subsystem")
+var (
+	ErrNotSupportStat = errors.New("stats are not supported for subsystem")
+	ErrNotValidFormat = errors.New("line is not a valid key value format")
+)
 
 // Parses a cgroup param and returns as name, value
 //  i.e. "io_service_bytes 1234" will return as io_service_bytes, 1234
@@ -21,6 +24,6 @@ func getCgroupParamKeyValue(t string) (string, float64, error) {
 		}
 		return parts[0], value, nil
 	default:
-		return "", 0.0, fmt.Errorf("Unable to parse cgroup param: not enough parts; expected 2")
+		return "", 0.0, ErrNotValidFormat
 	}
 }