runc update: support per-device weight and iops

This support was missing from runc, and thus the example from the
podman-update wasn't working.

To fix, introduce a function to either update or insert new weights and iops.

Add integration tests.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

Author: kolyshkin

tests/integration/cgroups.bats

@@ -174,17 +174,40 @@ function setup() {
 	runc run -d --console-socket "$CONSOLE_SOCKET" test_dev_weight
 	[ "$status" -eq 0 ]
 
-	# The loop device itself is no longer needed.
-	losetup -d "$dev"
-
 	if [ -v CGROUP_V2 ]; then
 		file="io.bfq.weight"
 	else
 		file="blkio.bfq.weight_device"
 	fi
-	weights=$(get_cgroup_value $file)
-	[[ "$weights" == *"default 333"* ]]
-	[[ "$weights" == *"$major:$minor 444"* ]]
+	weights1=$(get_cgroup_value $file)
+
+	# Check that runc update works.
+	runc update -r - test_dev_weight <<EOF
+{
+  "blockIO": {
+    "weight": 111,
+    "weightDevice": [
+      {
+        "major": $major,
+        "minor": $minor,
+        "weight": 222
+      }
+    ]
+  }
+}
+EOF
+	weights2=$(get_cgroup_value $file)
+
+	# The loop device itself is no longer needed.
+	losetup -d "$dev"
+
+	# Check original values.
+	grep '^default 333$' <<<"$weights1"
+	grep "^$major:$minor 444$" <<<"$weights1"
+	# Check updated values.
+	grep '^default 111$' <<<"$weights2"
+	grep "^$major:$minor 222$" <<<"$weights2"
+
 }
 
 @test "runc run (per-device multiple iops via unified)" {

tests/integration/helpers.bash

@@ -368,6 +368,22 @@ function check_cpu_weight() {
 	check_systemd_value "CPUWeight" "$weight"
 }
 
+function check_cgroup_dev_iops() {
+	local dev=$1 rbps=$2 wbps=$3 riops=$4 wiops=$5
+
+	if [ -v CGROUP_V2 ]; then
+		iops=$(get_cgroup_value "io.max")
+		printf "== io.max ==\n%s\n" "$iops"
+		grep "^$dev rbps=$rbps wbps=$wbps riops=$riops wiops=$wiops$" <<<"$iops"
+		return
+	fi
+
+	grep "^$dev ${rbps}$" <<<"$(get_cgroup_value blkio.throttle.read_bps_device)"
+	grep "^$dev ${wbps}$" <<<"$(get_cgroup_value blkio.throttle.write_bps_device)"
+	grep "^$dev ${riops}$" <<<"$(get_cgroup_value blkio.throttle.read_iops_device)"
+	grep "^$dev ${wiops}$" <<<"$(get_cgroup_value blkio.throttle.write_iops_device)"
+}
+
 # Helper function to set a resources limit
 function set_resources_limit() {
 	update_config '.linux.resources.pids.limit |= 100'

tests/integration/update.bats

@@ -892,3 +892,57 @@ EOF
 	runc update test_update --memory 1024
 	wait_for_container 10 1 test_update stopped
 }
+
+@test "update per-device iops/bps values" {
+	[ $EUID -ne 0 ] && requires rootless_cgroup
+
+	# We need a major number of any disk device. Usually those are partitioned,
+	# with the device itself having minor of 0, and partitions are 1, 2...
+	major=$(awk '$2 == 0 {print $1; exit}' /proc/partitions)
+	if [ "$major" = "0" ] || [ "$major" = "" ]; then
+		echo "=== /proc/partitions ==="
+		cat /proc/partitions
+		echo "==="
+		skip "can't get device major number from /proc/partitions (got $major)"
+	fi
+
+	runc run -d --console-socket "$CONSOLE_SOCKET" test_update
+	[ "$status" -eq 0 ]
+
+	runc update -r - test_update <<EOF
+{
+  "blockIO": {
+    "throttleReadBpsDevice": [
+      {
+        "major": $major,
+        "minor": 0,
+        "rate": 10485760
+      }
+    ],
+    "throttleWriteBpsDevice": [
+      {
+        "major": $major,
+        "minor": 0,
+        "rate": 9437184
+      }
+    ],
+    "throttleReadIOPSDevice": [
+      {
+        "major": $major,
+        "minor": 0,
+        "rate": 1000
+      }
+    ],
+    "throttleWriteIOPSDevice": [
+      {
+        "major": $major,
+        "minor": 0,
+        "rate": 900
+      }
+    ]
+  }
+}
+EOF
+	[ "$status" -eq 0 ]
+	check_cgroup_dev_iops "$major:0" 10485760 9437184 1000 900
+}

update.go

@@ -273,6 +273,25 @@ other options are ignored.
 		if r.BlockIO.Weight != nil {
 			config.Cgroups.Resources.BlkioWeight = *r.BlockIO.Weight
 		}
+		if r.BlockIO.LeafWeight != nil {
+			config.Cgroups.Resources.BlkioLeafWeight = *r.BlockIO.LeafWeight
+		}
+		// For devices, we either update an existing one, or insert a new one.
+		for _, wd := range r.BlockIO.WeightDevice {
+			config.Cgroups.Resources.BlkioWeightDevice = upsertWeightDevice(config.Cgroups.Resources.BlkioWeightDevice, wd)
+		}
+		for _, td := range r.BlockIO.ThrottleReadBpsDevice {
+			config.Cgroups.Resources.BlkioThrottleReadBpsDevice = upsertThrottleDevice(config.Cgroups.Resources.BlkioThrottleReadBpsDevice, td)
+		}
+		for _, td := range r.BlockIO.ThrottleWriteBpsDevice {
+			config.Cgroups.Resources.BlkioThrottleWriteBpsDevice = upsertThrottleDevice(config.Cgroups.Resources.BlkioThrottleWriteBpsDevice, td)
+		}
+		for _, td := range r.BlockIO.ThrottleReadIOPSDevice {
+			config.Cgroups.Resources.BlkioThrottleReadIOPSDevice = upsertThrottleDevice(config.Cgroups.Resources.BlkioThrottleReadIOPSDevice, td)
+		}
+		for _, td := range r.BlockIO.ThrottleWriteIOPSDevice {
+			config.Cgroups.Resources.BlkioThrottleWriteIOPSDevice = upsertThrottleDevice(config.Cgroups.Resources.BlkioThrottleWriteIOPSDevice, td)
+		}
 
 		// Setting CPU quota and period independently does not make much sense,
 		// but historically runc allowed it and this needs to be supported
@@ -381,3 +400,41 @@ other options are ignored.
 		return container.Set(config)
 	},
 }
+
+func upsertWeightDevice(devices []*cgroups.WeightDevice, wd specs.LinuxWeightDevice) []*cgroups.WeightDevice {
+	for i, dev := range devices {
+		if dev.Major != wd.Major || dev.Minor != wd.Minor {
+			continue
+		}
+		// Update weights for existing device.
+		if wd.Weight != nil {
+			devices[i].Weight = *wd.Weight
+		}
+		if wd.LeafWeight != nil {
+			devices[i].LeafWeight = *wd.LeafWeight
+		}
+		return devices
+	}
+
+	// New device -- append it.
+	var weight, leafWeight uint16
+	if wd.Weight != nil {
+		weight = *wd.Weight
+	}
+	if wd.LeafWeight != nil {
+		leafWeight = *wd.LeafWeight
+	}
+
+	return append(devices, cgroups.NewWeightDevice(wd.Major, wd.Minor, weight, leafWeight))
+}
+
+func upsertThrottleDevice(devices []*cgroups.ThrottleDevice, td specs.LinuxThrottleDevice) []*cgroups.ThrottleDevice {
+	for i, dev := range devices {
+		if dev.Major == td.Major && dev.Minor == td.Minor {
+			devices[i].Rate = td.Rate
+			return devices
+		}
+	}
+
+	return append(devices, cgroups.NewThrottleDevice(td.Major, td.Minor, td.Rate))
+}