diff --git a/core/snapshots/snapshotter.go b/core/snapshots/snapshotter.go
index 5cae7aae37..cb94e12110 100644
--- a/core/snapshots/snapshotter.go
+++ b/core/snapshots/snapshotter.go
@@ -39,6 +39,15 @@ const (
 	LabelSnapshotUIDMapping = "containerd.io/snapshot/uidmapping"
 	// LabelSnapshotGIDMapping is the label used for GID mappings
 	LabelSnapshotGIDMapping = "containerd.io/snapshot/gidmapping"
+
+	// LabelSnapshotMaxSize is a hint to the snapshotter that the active
+	// snapshot's filesystem should be limited to the given size, in bytes
+	// (decimal int64 as a string). Snapshotters that back an active
+	// snapshot with a block image or support filesystem quotas should
+	// honor this value; those that cannot enforce a size may ignore it.
+	// Ignoring is not a failure — callers that require enforcement must
+	// pick a snapshotter that supports it.
+	LabelSnapshotMaxSize = "containerd.io/snapshot/max-size"
 )
 
 // Kind identifies the kind of snapshot.
diff --git a/plugins/snapshots/erofs/erofs.go b/plugins/snapshots/erofs/erofs.go
index 586d16583c..2f038706f2 100644
--- a/plugins/snapshots/erofs/erofs.go
+++ b/plugins/snapshots/erofs/erofs.go
@@ -22,6 +22,7 @@ import (
 	"os"
 	"path/filepath"
 	"runtime"
+	"strconv"
 
 	"github.com/containerd/continuity/fs"
 	"github.com/containerd/errdefs"
@@ -207,6 +208,25 @@ func (s *snapshotter) writablePath(id string) string {
 	return filepath.Join(s.root, "snapshots", id, "rwlayer.img")
 }
 
+// writableSize returns the size (in bytes) to allocate for this active
+// snapshot's writable block image. If the caller set the
+// LabelSnapshotMaxSize label, that value is used; otherwise the
+// snapshotter's configured default is used. Only consulted in block mode.
+func (s *snapshotter) writableSize(info snapshots.Info) int64 {
+	v, ok := info.Labels[snapshots.LabelSnapshotMaxSize]
+	if !ok {
+		return s.defaultWritable
+	}
+	size, err := strconv.ParseInt(v, 10, 64)
+	if err != nil || size <= 0 {
+		log.L.WithField("label", snapshots.LabelSnapshotMaxSize).
+			WithField("value", v).
+			Warn("invalid max-size label, falling back to default")
+		return s.defaultWritable
+	}
+	return size
+}
+
 // A committed layer blob generated by the EROFS differ
 func (s *snapshotter) layerBlobPath(id string) string {
 	return filepath.Join(s.root, "snapshots", id, "layer.erofs")
@@ -356,8 +376,7 @@ func (s *snapshotter) mounts(snap storage.Snapshot, info snapshots.Info) ([]moun
 					Type:   "mkfs/ext4",
 					Options: []string{
 						"X-containerd.mkfs.fs=ext4",
-						// TODO: Get size from snapshot labels
-						fmt.Sprintf("X-containerd.mkfs.size=%d", s.defaultWritable),
+						fmt.Sprintf("X-containerd.mkfs.size=%d", s.writableSize(info)),
 						// TODO: Add UUID
 						roFlag,
 						"loop",
@@ -398,8 +417,7 @@ func (s *snapshotter) mounts(snap storage.Snapshot, info snapshots.Info) ([]moun
 				Type:   "mkfs/ext4",
 				Options: []string{
 					"X-containerd.mkfs.fs=ext4",
-					// TODO: Get size from snapshot labels
-					fmt.Sprintf("X-containerd.mkfs.size=%d", s.defaultWritable),
+					fmt.Sprintf("X-containerd.mkfs.size=%d", s.writableSize(info)),
 					// TODO: Add UUID
 					"rw",
 					"loop",
diff --git a/plugins/snapshots/erofs/erofs_linux_test.go b/plugins/snapshots/erofs/erofs_linux_test.go
index 07e1600890..3c182d800d 100644
--- a/plugins/snapshots/erofs/erofs_linux_test.go
+++ b/plugins/snapshots/erofs/erofs_linux_test.go
@@ -113,6 +113,50 @@ func TestErofsWithQuota(t *testing.T) {
 	testsuite.SnapshotterSuite(t, "erofs", newSnapshotter(t, WithDefaultSize(16*1024*1024)))
 }
 
+// TestWritableSize exercises the LabelSnapshotMaxSize override that the
+// block-mode mkfs path passes to X-containerd.mkfs.size. Covers the
+// happy path (label overrides default), fallback cases (missing, empty,
+// malformed, non-positive), and that a valid label wins over a non-zero
+// configured default.
+func TestWritableSize(t *testing.T) {
+	const defaultSize = int64(16 * 1024 * 1024)
+	s := &snapshotter{defaultWritable: defaultSize}
+
+	for _, tc := range []struct {
+		name   string
+		labels map[string]string
+		want   int64
+	}{
+		{"unset", nil, defaultSize},
+		{"empty-map", map[string]string{}, defaultSize},
+		{"valid-overrides-default", map[string]string{snapshots.LabelSnapshotMaxSize: "268435456"}, 268435456},
+		{"empty-value-falls-back", map[string]string{snapshots.LabelSnapshotMaxSize: ""}, defaultSize},
+		{"non-numeric-falls-back", map[string]string{snapshots.LabelSnapshotMaxSize: "100MB"}, defaultSize},
+		{"zero-falls-back", map[string]string{snapshots.LabelSnapshotMaxSize: "0"}, defaultSize},
+		{"negative-falls-back", map[string]string{snapshots.LabelSnapshotMaxSize: "-1"}, defaultSize},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			got := s.writableSize(snapshots.Info{Labels: tc.labels})
+			assert.Equal(t, tc.want, got)
+		})
+	}
+
+	// Also verify behaviour when the snapshotter has no configured default:
+	// an unset/invalid label yields 0 (caller treats as "no size"), a valid
+	// label is respected.
+	t.Run("no-default-unset", func(t *testing.T) {
+		z := &snapshotter{defaultWritable: 0}
+		assert.Equal(t, int64(0), z.writableSize(snapshots.Info{}))
+	})
+	t.Run("no-default-with-label", func(t *testing.T) {
+		z := &snapshotter{defaultWritable: 0}
+		got := z.writableSize(snapshots.Info{Labels: map[string]string{
+			snapshots.LabelSnapshotMaxSize: "1048576",
+		}})
+		assert.Equal(t, int64(1048576), got)
+	})
+}
+
 func TestErofsFsverity(t *testing.T) {
 	testutil.RequiresRoot(t)
 	ctx := context.Background()