daemon: sortMounts: move to container.SortMounts

Move the utility to the container package, which is where the Mount
type is defined, and to allow re-use of the utility both inside the
container package and the daemon package.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

daemon/container/mounts.go

@@ -0,0 +1,34 @@
+package container
+
+import (
+	"cmp"
+	"os"
+	"path/filepath"
+	"slices"
+	"strings"
+)
+
+// compareMountPaths compares mount paths by depth so that parent paths sort
+// before paths beneath them.
+func compareMountPaths(a, b string) int {
+	a = filepath.Clean(a)
+	b = filepath.Clean(b)
+
+	aParts := strings.Count(a, string(os.PathSeparator))
+	bParts := strings.Count(b, string(os.PathSeparator))
+	if c := cmp.Compare(aParts, bParts); c != 0 {
+		return c
+	}
+	return cmp.Compare(a, b)
+}
+
+// SortMounts sorts mounts by destination depth so that parent mounts are
+// applied before mounts beneath them. Mounts at the same depth are sorted
+// by destination to produce a deterministic order.
+//
+// For example, /etc must be mounted before /etc/resolv.conf.
+func SortMounts(m []Mount) {
+	slices.SortStableFunc(m, func(a, b Mount) int {
+		return compareMountPaths(a.Destination, b.Destination)
+	})
+}

daemon/container/mounts_test.go

@@ -1,4 +1,4 @@
-package daemon
+package container_test
 
 import (
 	"testing"
@@ -81,7 +81,7 @@ func TestSortMounts(t *testing.T) {
 
 	for _, tc := range tests {
 		t.Run(tc.name, func(t *testing.T) {
-			sortMounts(tc.mounts)
+			container.SortMounts(tc.mounts)
 			assert.DeepEqual(t, tc.expected, tc.mounts)
 		})
 	}

daemon/oci_linux.go

@@ -479,7 +479,7 @@ var (
 // withMounts sets the container's mounts
 func withMounts(daemon *Daemon, daemonCfg *configStore, c *container.Container, mounts []container.Mount) coci.SpecOpts {
 	return func(ctx context.Context, _ coci.Client, _ *containers.Container, s *coci.Spec) error {
-		sortMounts(mounts)
+		container.SortMounts(mounts)
 
 		userMounts := make(map[string]struct{})
 		for _, m := range mounts {

daemon/volumes.go

@@ -1,15 +1,10 @@
 package daemon
 
 import (
-	"cmp"
 	"context"
 	"crypto/sha256"
 	"encoding/hex"
 	"maps"
-	"os"
-	"path/filepath"
-	"slices"
-	"strings"
 	"time"
 
 	"github.com/containerd/log"
@@ -28,31 +23,6 @@ import (
 
 var _ volume.LiveRestorer = (*volumeWrapper)(nil)
 
-// compareMountPaths compares mount paths by depth so that parent paths sort
-// before paths beneath them.
-func compareMountPaths(a, b string) int {
-	a = filepath.Clean(a)
-	b = filepath.Clean(b)
-
-	aParts := strings.Count(a, string(os.PathSeparator))
-	bParts := strings.Count(b, string(os.PathSeparator))
-	if c := cmp.Compare(aParts, bParts); c != 0 {
-		return c
-	}
-	return cmp.Compare(a, b)
-}
-
-// sortMounts sorts mounts by destination depth so that parent mounts are
-// applied before mounts beneath them. Mounts at the same depth are sorted
-// by destination to produce a deterministic order.
-//
-// For example, /etc must be mounted before /etc/resolv.conf.
-func sortMounts(m []container.Mount) {
-	slices.SortStableFunc(m, func(a, b container.Mount) int {
-		return compareMountPaths(a.Destination, b.Destination)
-	})
-}
-
 // registerMountPoints initializes the container mount points with the configured volumes and bind mounts.
 // It follows the next sequence to decide what to mount in each final destination:
 //

daemon/volumes_unix.go

@@ -103,7 +103,7 @@ func (daemon *Daemon) setupMounts(ctx context.Context, c *container.Container) (
 		}
 	}
 
-	sortMounts(mounts)
+	container.SortMounts(mounts)
 	netMounts := c.NetworkMounts()
 	// if we are going to mount any of the network files from container
 	// metadata, the ownership must be set properly for potential container

daemon/volumes_windows.go

@@ -48,7 +48,7 @@ func (daemon *Daemon) setupMounts(ctx context.Context, c *container.Container) (
 		})
 	}
 
-	sortMounts(mnts)
+	container.SortMounts(mnts)
 	return mnts, mntCleanups.Release(), nil
 }