github.com/containers/podman/v2@v2.2.2-0.20210501105131-c1e07d070c4c/pkg/cgroups/blkio.go (about) 1 package cgroups 2 3 import ( 4 "bufio" 5 "fmt" 6 "os" 7 "path/filepath" 8 "strconv" 9 "strings" 10 11 spec "github.com/opencontainers/runtime-spec/specs-go" 12 "github.com/pkg/errors" 13 ) 14 15 type blkioHandler struct { 16 } 17 18 func getBlkioHandler() *blkioHandler { 19 return &blkioHandler{} 20 } 21 22 // Apply set the specified constraints 23 func (c *blkioHandler) Apply(ctr *CgroupControl, res *spec.LinuxResources) error { 24 if res.BlockIO == nil { 25 return nil 26 } 27 return fmt.Errorf("blkio apply function not implemented yet") 28 } 29 30 // Create the cgroup 31 func (c *blkioHandler) Create(ctr *CgroupControl) (bool, error) { 32 if ctr.cgroup2 { 33 return false, nil 34 } 35 return ctr.createCgroupDirectory(Blkio) 36 } 37 38 // Destroy the cgroup 39 func (c *blkioHandler) Destroy(ctr *CgroupControl) error { 40 return rmDirRecursively(ctr.getCgroupv1Path(Blkio)) 41 } 42 43 // Stat fills a metrics structure with usage stats for the controller 44 func (c *blkioHandler) Stat(ctr *CgroupControl, m *Metrics) error { 45 var ioServiceBytesRecursive []BlkIOEntry 46 47 if ctr.cgroup2 { 48 // more details on the io.stat file format:X https://facebookmicrosites.github.io/cgroup2/docs/io-controller.html 49 values, err := readCgroup2MapFile(ctr, "io.stat") 50 if err != nil { 51 return err 52 } 53 for k, v := range values { 54 d := strings.Split(k, ":") 55 if len(d) != 2 { 56 continue 57 } 58 minor, err := strconv.ParseUint(d[0], 10, 0) 59 if err != nil { 60 return err 61 } 62 major, err := strconv.ParseUint(d[1], 10, 0) 63 if err != nil { 64 return err 65 } 66 67 for _, item := range v { 68 d := strings.Split(item, "=") 69 if len(d) != 2 { 70 continue 71 } 72 op := d[0] 73 74 // Accommodate the cgroup v1 naming 75 switch op { 76 case "rbytes": 77 op = "read" 78 case "wbytes": 79 op = "write" 80 } 81 82 value, err := strconv.ParseUint(d[1], 10, 0) 83 if err != nil { 84 return err 85 } 86 87 entry := BlkIOEntry{ 88 Op: op, 89 Major: major, 90 Minor: minor, 91 Value: value, 92 } 93 ioServiceBytesRecursive = append(ioServiceBytesRecursive, entry) 94 } 95 } 96 } else { 97 BlkioRoot := ctr.getCgroupv1Path(Blkio) 98 99 p := filepath.Join(BlkioRoot, "blkio.throttle.io_service_bytes_recursive") 100 f, err := os.Open(p) 101 if err != nil { 102 if os.IsNotExist(err) { 103 return nil 104 } 105 return errors.Wrapf(err, "open %s", p) 106 } 107 defer f.Close() 108 109 scanner := bufio.NewScanner(f) 110 for scanner.Scan() { 111 line := scanner.Text() 112 parts := strings.Fields(line) 113 if len(parts) < 3 { 114 continue 115 } 116 d := strings.Split(parts[0], ":") 117 if len(d) != 2 { 118 continue 119 } 120 minor, err := strconv.ParseUint(d[0], 10, 0) 121 if err != nil { 122 return err 123 } 124 major, err := strconv.ParseUint(d[1], 10, 0) 125 if err != nil { 126 return err 127 } 128 129 op := parts[1] 130 131 value, err := strconv.ParseUint(parts[2], 10, 0) 132 if err != nil { 133 return err 134 } 135 entry := BlkIOEntry{ 136 Op: op, 137 Major: major, 138 Minor: minor, 139 Value: value, 140 } 141 ioServiceBytesRecursive = append(ioServiceBytesRecursive, entry) 142 } 143 if err := scanner.Err(); err != nil { 144 return errors.Wrapf(err, "parse %s", p) 145 } 146 } 147 m.Blkio = BlkioMetrics{IoServiceBytesRecursive: ioServiceBytesRecursive} 148 return nil 149 }