fix: order volume config by the requested size

This fixes an issue like that:

* the system disk is say 10GiB
* STATE is fixed 100 MiB always
* EPHEMERAL is configured to be min 6 GiB, max 100 GiB

As the EPHEMERAL/STATE provisioning order was not defined, EPHEMERAL
might be created first, occupying whole disk and leaving no space left
for STATE.

Signed-off-by: Andrey Smirnov <andrey.smirnov@siderolabs.com>

.github/workflows/ci.yaml

@@ -1,6 +1,6 @@
 # THIS FILE WAS AUTOMATICALLY GENERATED, PLEASE DO NOT EDIT.
 #
-# Generated on 2024-12-06T17:21:12Z by kres 1ebe796.
+# Generated on 2024-12-11T13:30:10Z by kres 8183c20.
 
 name: default
 concurrency:
@@ -2074,6 +2074,7 @@ jobs:
           GITHUB_STEP_NAME: ${{ github.job}}-e2e-controlplane-port
           IMAGE_REGISTRY: registry.dev.siderolabs.io
           SHORT_INTEGRATION_TEST: "yes"
+          WITH_CONFIG_PATCH: '@hack/test/patches/ephemeral-min-max.yaml'
           WITH_CONTROL_PLANE_PORT: "443"
         run: |
           sudo -E make e2e-qemu

.github/workflows/integration-misc-0-cron.yaml

@@ -1,6 +1,6 @@
 # THIS FILE WAS AUTOMATICALLY GENERATED, PLEASE DO NOT EDIT.
 #
-# Generated on 2024-11-28T13:53:18Z by kres 232fe63.
+# Generated on 2024-12-11T13:30:10Z by kres 8183c20.
 
 name: integration-misc-0-cron
 concurrency:
@@ -99,6 +99,7 @@ jobs:
           GITHUB_STEP_NAME: ${{ github.job}}-e2e-controlplane-port
           IMAGE_REGISTRY: registry.dev.siderolabs.io
           SHORT_INTEGRATION_TEST: "yes"
+          WITH_CONFIG_PATCH: '@hack/test/patches/ephemeral-min-max.yaml'
           WITH_CONTROL_PLANE_PORT: "443"
         run: |
           sudo -E make e2e-qemu

.kres.yaml

@@ -683,6 +683,7 @@ spec:
             SHORT_INTEGRATION_TEST: yes
             WITH_CONTROL_PLANE_PORT: 443
             IMAGE_REGISTRY: registry.dev.siderolabs.io
+            WITH_CONFIG_PATCH: "@hack/test/patches/ephemeral-min-max.yaml"
         - name: save-talos-logs
           conditions:
             - always

hack/test/patches/ephemeral-min-max.yaml

@@ -0,0 +1,8 @@
+apiVersion: v1alpha1
+kind: VolumeConfig
+name: EPHEMERAL
+provisioning:
+  diskSelector:
+    match: system_disk
+  minSize: 4GB
+  maxSize: 100GB

internal/app/machined/pkg/controllers/block/internal/volumes/volumes.go

@@ -8,6 +8,7 @@ package volumes
 import (
 	"cmp"
 	"context"
+	"math"
 
 	"github.com/siderolabs/gen/optional"
 
@@ -18,11 +19,29 @@ import (
 
 // CompareVolumeConfigs compares two volume configs in the proposed order of provisioning.
 func CompareVolumeConfigs(a, b *block.VolumeConfig) int {
+	// first, sort by wave, smaller wave first
 	if c := cmp.Compare(a.TypedSpec().Provisioning.Wave, b.TypedSpec().Provisioning.Wave); c != 0 {
 		return c
 	}
 
-	return cmpBool(a.TypedSpec().Provisioning.PartitionSpec.Grow, b.TypedSpec().Provisioning.PartitionSpec.Grow)
+	// prefer partitions which do not grow, as growing partitions may consume space needed by other partitions
+	if c := cmpBool(a.TypedSpec().Provisioning.PartitionSpec.Grow, b.TypedSpec().Provisioning.PartitionSpec.Grow); c != 0 {
+		return c
+	}
+
+	// prefer partitions with smaller sizes first
+	// e.g.: for a disk of size 1GiB, and following config with min-max requested sizes:
+	// 1. 100MiB - 200MiB
+	// 2. 300MiB - 2GiB
+	//
+	// if the order is 2-1, the second partition will grow to full disk size and will leave no space for the first partition,
+	// but if the order is 1-2, partition sizes will 200MiB and 800MiB respectively.
+	//
+	// we compare only max size, as it affects the resulting size of the partition
+	desiredSizeA := cmp.Or(a.TypedSpec().Provisioning.PartitionSpec.MaxSize, math.MaxUint64)
+	desiredSizeB := cmp.Or(b.TypedSpec().Provisioning.PartitionSpec.MaxSize, math.MaxUint64)
+
+	return cmp.Compare(desiredSizeA, desiredSizeB)
 }
 
 func cmpBool(a, b bool) int {

internal/app/machined/pkg/controllers/block/internal/volumes/volumes_test.go

@@ -0,0 +1,132 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+package volumes_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/siderolabs/talos/internal/app/machined/pkg/controllers/block/internal/volumes"
+	"github.com/siderolabs/talos/pkg/machinery/resources/block"
+)
+
+func TestCompareVolumeConfigs(t *testing.T) {
+	t.Parallel()
+
+	for _, test := range []struct {
+		name string
+
+		a *block.VolumeConfigSpec
+		b *block.VolumeConfigSpec
+
+		expected int
+	}{
+		{
+			name: "different wave",
+
+			a: &block.VolumeConfigSpec{
+				Provisioning: block.ProvisioningSpec{
+					Wave: block.WaveSystemDisk,
+				},
+			},
+			b: &block.VolumeConfigSpec{
+				Provisioning: block.ProvisioningSpec{
+					Wave: block.WaveUserDisks,
+				},
+			},
+
+			expected: -1,
+		},
+		{
+			name: "prefer grow",
+
+			a: &block.VolumeConfigSpec{
+				Provisioning: block.ProvisioningSpec{
+					Wave: block.WaveSystemDisk,
+					PartitionSpec: block.PartitionSpec{
+						Grow: true,
+					},
+				},
+			},
+			b: &block.VolumeConfigSpec{
+				Provisioning: block.ProvisioningSpec{
+					Wave: block.WaveSystemDisk,
+					PartitionSpec: block.PartitionSpec{
+						Grow: false,
+					},
+				},
+			},
+
+			expected: 1,
+		},
+		{
+			name: "prefer smaller size",
+
+			a: &block.VolumeConfigSpec{
+				Provisioning: block.ProvisioningSpec{
+					Wave: block.WaveSystemDisk,
+					PartitionSpec: block.PartitionSpec{
+						Grow:    false,
+						MinSize: 100,
+						MaxSize: 200,
+					},
+				},
+			},
+			b: &block.VolumeConfigSpec{
+				Provisioning: block.ProvisioningSpec{
+					Wave: block.WaveSystemDisk,
+					PartitionSpec: block.PartitionSpec{
+						Grow:    false,
+						MinSize: 150,
+						MaxSize: 1000,
+					},
+				},
+			},
+
+			expected: -1,
+		},
+		{
+			name: "prefer max size",
+
+			a: &block.VolumeConfigSpec{
+				Provisioning: block.ProvisioningSpec{
+					Wave: block.WaveSystemDisk,
+					PartitionSpec: block.PartitionSpec{
+						Grow:    false,
+						MinSize: 100,
+						MaxSize: 200,
+					},
+				},
+			},
+			b: &block.VolumeConfigSpec{
+				Provisioning: block.ProvisioningSpec{
+					Wave: block.WaveSystemDisk,
+					PartitionSpec: block.PartitionSpec{
+						Grow:    false,
+						MinSize: 50,
+						MaxSize: 0, // no limit
+					},
+				},
+			},
+
+			expected: -1,
+		},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			t.Parallel()
+
+			resA := block.NewVolumeConfig(block.NamespaceName, "A")
+			*resA.TypedSpec() = *test.a
+
+			resB := block.NewVolumeConfig(block.NamespaceName, "B")
+			*resB.TypedSpec() = *test.b
+
+			actual := volumes.CompareVolumeConfigs(resA, resB)
+
+			assert.Equal(t, test.expected, actual)
+		})
+	}
+}