runtime: config: linux: Edit BlockIO struct

`WeightDevice`, `ThrottleReadBpsDevice`, `ThrottleWriteBpsDevice`,
`ThrottleReadIOpsDevice`, `ThrottleWriteIOpsDevice` are now slices to
well defined structs to allow setting multiple devices in their respective
blkio file. By using a string to represents those values it wasn't possible
to set correct values when multiple devices were passed in the config
(either newline separated or comma separated).

Signed-off-by: Antonio Murdaca <runcom@linux.com>

Author: runcom

runtime-config-linux.md

@@ -146,45 +146,55 @@ The cgroups will be created if they don't exist.
 
 `cgroupsPath` can be used to either control the cgroups hierarchy for containers or to run a new process in an existing container.
 
-Optionally, cgroups limits can be specified via `resources`.
+You can configure a container's cgroups via the `resources` field of the Linux configuration.
+Do not specify `resources` unless limits have to be updated.
+For example, to run a new process in an existing container without updating limits, `resources` need not be specified.
+
+### Block IO Controller
 
 ```json
-    "resources": {
-        "disableOOMKiller": false,
-        "memory": {
-            "limit": 0,
-            "reservation": 0,
-            "swap": 0,
-            "kernel": 0,
-            "swappiness": -1
-        },
-        "cpu": {
-            "shares": 0,
-            "quota": 0,
-            "period": 0,
-            "realtimeRuntime": 0,
-            "realtimePeriod": 0,
-            "cpus": "",
-            "mems": ""
-        },
-        "blockIO": {
-            "blkioWeight": 0,
-            "blkioWeightDevice": "",
-            "blkioThrottleReadBpsDevice": "",
-            "blkioThrottleWriteBpsDevice": "",
-            "blkioThrottleReadIopsDevice": "",
-            "blkioThrottleWriteIopsDevice": ""
-        },
-        "hugepageLimits": null,
-        "network": {
-            "classId": "",
-            "priorities": null
-        }
-    }
+	"blockIO": {
+		"blkioWeight": 0,
+		"blkioLeafWeight": 0,
+		"blkioWeightDevice": [
+			{
+				"major": 8,
+				"minor": 0,
+				"weight": 500,
+				"leafWeight": 300
+			},
+			{
+				"major": 8,
+				"minor": 16,
+				"weight": 500
+			}
+		],
+		"blkioThrottleReadBpsDevice": [
+			{
+				"major": 8,
+				"minor": 0,
+				"rate": 600
+			}
+		],
+		"blkioThrottleWriteBpsDevice": null,
+		"blkioThrottleReadIopsDevice": null,
+		"blkioThrottleWriteIopsDevice": [
+			{
+				"major": 8,
+				"minor": 16,
+				"rate": 300
+			}
+		]
+	}
 ```
 
-Do not specify `resources` unless limits have to be updated.
-For example, to run a new process in an existing container without updating limits, `resources` need not be specified.
+* **blkioWeight** .
+* **blkioLeafWeight** .
+* **blkioWeightDevice** .
+* **blkioThrottleReadBpsDevice** .
+* **blkioThrottleWriteBpsDevice** .
+* **blkioThrottleReadIopsDevice** .
+* **blkioThrottleWriteIopsDevice** .
 
 ## Sysctl
 

runtime_config_linux.go

@@ -104,20 +104,46 @@ type InterfacePriority struct {
 	Priority int64 `json:"priority"`
 }
 
+// blockIODevice holds major:minor format supported in blkio cgroup
+type blockIODevice struct {
+	// Major is the device's major number.
+	Major int64 `json:"major"`
+	// Minor is the device's minor number.
+	Minor int64 `json:"minor"`
+}
+
+// WeightDevice struct holds a `major:minor weight` pair for blkioWeightDevice
+type WeightDevice struct {
+	blockIODevice
+	// Weight is the bandwidth rate for the device, range is from 10 to 1000
+	Weight uint16 `json:"weight"`
+	// LeafWeight is the bandwidth rate given to the device while competing with the cgroup's child cgroups, range is from 10 to 1000, cfq scheduler only
+	LeafWeight uint16 `json:"leafWeight"`
+}
+
+// ThrottleDevice struct holds a `major:minor rate_per_second` pair
+type ThrottleDevice struct {
+	blockIODevice
+	// Rate is the IO rate limit per cgroup per device
+	Rate uint64 `json:"rate"`
+}
+
 // BlockIO for Linux cgroup 'blkio' resource management
 type BlockIO struct {
 	// Specifies per cgroup weight, range is from 10 to 1000
-	Weight int64 `json:"blkioWeight"`
+	Weight uint16 `json:"blkioWeight"`
+	// Specifies tasks' weight in the given cgroup while competing with the cgroup's child cgroups, range is from 10 to 1000, cfq scheduler only
+	LeafWeight uint16 `json:"blkioLeafWeight"`
 	// Weight per cgroup per device, can override BlkioWeight
-	WeightDevice string `json:"blkioWeightDevice"`
+	WeightDevice []*WeightDevice `json:"blkioWeightDevice"`
 	// IO read rate limit per cgroup per device, bytes per second
-	ThrottleReadBpsDevice string `json:"blkioThrottleReadBpsDevice"`
-	// IO write rate limit per cgroup per divice, bytes per second
-	ThrottleWriteBpsDevice string `json:"blkioThrottleWriteBpsDevice"`
+	ThrottleReadBpsDevice []*ThrottleDevice `json:"blkioThrottleReadBpsDevice"`
+	// IO write rate limit per cgroup per device, bytes per second
+	ThrottleWriteBpsDevice []*ThrottleDevice `json:"blkioThrottleWriteBpsDevice"`
 	// IO read rate limit per cgroup per device, IO per second
-	ThrottleReadIOpsDevice string `json:"blkioThrottleReadIopsDevice"`
+	ThrottleReadIOpsDevice []*ThrottleDevice `json:"blkioThrottleReadIopsDevice"`
 	// IO write rate limit per cgroup per device, IO per second
-	ThrottleWriteIOpsDevice string `json:"blkioThrottleWriteIopsDevice"`
+	ThrottleWriteIOpsDevice []*ThrottleDevice `json:"blkioThrottleWriteIopsDevice"`
 }
 
 // Memory for Linux cgroup 'memory' resource management