struct_ops: fix to remove unused struct members

`wID` should be resolved in createMap()

Signed-off-by: shun159 <[email protected]>

Author: shun159

map.go

@@ -575,6 +575,10 @@ func (spec *MapSpec) createMap(inner *sys.FD) (_ *Map, err error) {
 			}
 
 			userStructType, s, modBtfObjId, err := findStructByNameWithPrefix(s, userStType)
+			if err != nil {
+				return nil, fmt.Errorf("lookup struct type: %w", err)
+			}
+
 			btfValueTypeId, err := s.TypeID(userStructType)
 			if err != nil {
 				return nil, fmt.Errorf("lookup type_id: %w", err)

prog.go

@@ -397,14 +397,14 @@ func newProgramWithOptions(spec *ProgramSpec, opts ProgramOptions, c *btf.Cache)
 
 	if spec.Type == StructOps {
 		if meta, ok := spec.Instructions[0].Metadata.Get(structOpsProgMetaKey{}).(*structOpsProgMeta); ok {
-			attr.AttachBtfId = sys.TypeID(meta.AttachBtfId)
-			attr.ExpectedAttachType = meta.AttachType
+			attr.AttachBtfId = sys.TypeID(meta.attachBtfId)
+			attr.ExpectedAttachType = meta.attachType
 
 			var modH *btf.Handle
-			if meta.ModBtfObjID != 0 {
-				h, err := btf.NewHandleFromID(btf.ID(meta.ModBtfObjID))
+			if meta.modBtfObjID != 0 {
+				h, err := btf.NewHandleFromID(btf.ID(meta.modBtfObjID))
 				if err != nil {
-					return nil, fmt.Errorf("open module BTF handle (id=%d): %w", meta.ModBtfObjID, err)
+					return nil, fmt.Errorf("open module BTF handle (id=%d): %w", meta.modBtfObjID, err)
 				}
 				modH = h
 				attr.AttachBtfObjFd = uint32(h.FD())

struct_ops.go

@@ -14,9 +14,9 @@ const structOpsValuePrefix = "bpf_struct_ops_"
 // TODO: Doc
 type structOpsProgMetaKey struct{}
 type structOpsProgMeta struct {
-	AttachBtfId btf.TypeID
-	AttachType  sys.AttachType
-	ModBtfObjID uint32
+	attachBtfId btf.TypeID
+	attachType  sys.AttachType
+	modBtfObjID uint32
 }
 
 // structOpsKernTypes holds information about kernel types related to struct_ops
@@ -28,8 +28,6 @@ type structOpsKernTypes struct {
 	typeID btf.TypeID
 	// The wrapper struct type that contains the target struct
 	valueType *btf.Struct
-	// The BTF type ID of the wrapper struct
-	valueTypeID btf.TypeID
 	// The member within ValueType that holds the target struct
 	dataMember *btf.Member
 	// mod_btf
@@ -69,8 +67,7 @@ type structOpsMeta struct {
 	funcs []structOpsFunc
 	// used for represent a data for the user struct
 	// e.g. struct tcp_congestion_ops in bpf_prog's btf format */
-	data        []byte
-	modBtfObjId btf.ID
+	data []byte
 }
 
 // extractStructOpsMeta returns the *structops.Meta embedded in a MapSpec’s Contents
@@ -221,18 +218,11 @@ func findStructOpsKernTypes(userStructType *btf.Struct) (*structOpsKernTypes, er
 		return nil, fmt.Errorf("type ID of %s: %w", kType.TypeName(), err)
 	}
 
-	// 5. type-ID of wrapper
-	wID, err := s.TypeID(wType)
-	if err != nil {
-		return nil, fmt.Errorf("type ID of %s: %w", wType.TypeName(), err)
-	}
-
 	return &structOpsKernTypes{
 		spec:        s,
 		typ:         kType,
 		typeID:      kID,
 		valueType:   wType,
-		valueTypeID: wID,
 		dataMember:  dataMem,
 		modBtfObjId: uint32(modID),
 	}, nil
@@ -416,9 +406,9 @@ func (sl *structOpsLoader) copyDataMember(
 		sl.stOpsProgsToMap[ps.Name] = ms.Name
 
 		ps.Instructions[0].Metadata.Set(structOpsProgMetaKey{}, &structOpsProgMeta{
-			AttachBtfId: kern.typeID,
-			AttachType:  attachType,
-			ModBtfObjID: kern.modBtfObjId,
+			attachBtfId: kern.typeID,
+			attachType:  attachType,
+			modBtfObjID: kern.modBtfObjId,
 		})
 	}