[disk] darwin i386: add definition for darwin/386

and change to use Statfs. it is same as freebsd/openbsd.

disk/disk_darwin.go

@@ -22,7 +22,7 @@ func PartitionsWithContext(ctx context.Context, all bool) ([]PartitionStat, erro
 	if err != nil {
 		return ret, err
 	}
-	fs := make([]Statfs_t, count)
+	fs := make([]Statfs, count)
 	_, err = Getfsstat(fs, MntWait)
 	for _, stat := range fs {
 		opts := "rw"
@@ -92,16 +92,16 @@ func PartitionsWithContext(ctx context.Context, all bool) ([]PartitionStat, erro
 	return ret, nil
 }
 
-func Getfsstat(buf []Statfs_t, flags int) (n int, err error) {
+func Getfsstat(buf []Statfs, flags int) (n int, err error) {
 	return GetfsstatWithContext(context.Background(), buf, flags)
 }
 
-func GetfsstatWithContext(ctx context.Context, buf []Statfs_t, flags int) (n int, err error) {
+func GetfsstatWithContext(ctx context.Context, buf []Statfs, flags int) (n int, err error) {
 	var _p0 unsafe.Pointer
 	var bufsize uintptr
 	if len(buf) > 0 {
 		_p0 = unsafe.Pointer(&buf[0])
-		bufsize = unsafe.Sizeof(Statfs_t{}) * uintptr(len(buf))
+		bufsize = unsafe.Sizeof(Statfs{}) * uintptr(len(buf))
 	}
 	r0, _, e1 := unix.Syscall(SYS_GETFSSTAT64, uintptr(_p0), bufsize, uintptr(flags))
 	n = int(r0)

disk/disk_darwin_386.go

@@ -0,0 +1,59 @@
+// +build darwin
+// +build 386
+
+package disk
+
+const (
+	MntWait    = 1
+	MfsNameLen = 15 /* length of fs type name, not inc. nul */
+	MNameLen   = 90 /* length of buffer for returned name */
+
+	MFSTYPENAMELEN = 16 /* length of fs type name including null */
+	MAXPATHLEN     = 1024
+	MNAMELEN       = MAXPATHLEN
+
+	SYS_GETFSSTAT64 = 347
+)
+
+type Fsid struct{ val [2]int32 } /* file system id type */
+type uid_t int32
+
+// sys/mount.h
+const (
+	MntReadOnly     = 0x00000001 /* read only filesystem */
+	MntSynchronous  = 0x00000002 /* filesystem written synchronously */
+	MntNoExec       = 0x00000004 /* can't exec from filesystem */
+	MntNoSuid       = 0x00000008 /* don't honor setuid bits on fs */
+	MntUnion        = 0x00000020 /* union with underlying filesystem */
+	MntAsync        = 0x00000040 /* filesystem written asynchronously */
+	MntSuidDir      = 0x00100000 /* special handling of SUID on dirs */
+	MntSoftDep      = 0x00200000 /* soft updates being done */
+	MntNoSymFollow  = 0x00400000 /* do not follow symlinks */
+	MntGEOMJournal  = 0x02000000 /* GEOM journal support enabled */
+	MntMultilabel   = 0x04000000 /* MAC support for individual objects */
+	MntACLs         = 0x08000000 /* ACL support enabled */
+	MntNoATime      = 0x10000000 /* disable update of file access time */
+	MntClusterRead  = 0x40000000 /* disable cluster read */
+	MntClusterWrite = 0x80000000 /* disable cluster write */
+	MntNFS4ACLs     = 0x00000010
+)
+
+// https://github.com/golang/go/blob/master/src/syscall/ztypes_darwin_386.go#L82
+type Statfs struct {
+	Bsize       uint32
+	Iosize      int32
+	Blocks      uint64
+	Bfree       uint64
+	Bavail      uint64
+	Files       uint64
+	Ffree       uint64
+	Fsid        Fsid
+	Owner       uint32
+	Type        uint32
+	Flags       uint32
+	Fssubtype   uint32
+	Fstypename  [16]int8
+	Mntonname   [1024]int8
+	Mntfromname [1024]int8
+	Reserved    [8]uint32
+}

disk/disk_darwin_amd64.go

@@ -38,7 +38,7 @@ const (
 	MntNFS4ACLs     = 0x00000010
 )
 
-type Statfs_t struct {
+type Statfs struct {
 	Bsize       uint32
 	Iosize      int32
 	Blocks      uint64

disk/disk_darwin_arm64.go

@@ -38,7 +38,7 @@ const (
 	MntNFS4ACLs     = 0x00000010
 )
 
-type Statfs_t struct {
+type Statfs struct {
 	Bsize       uint32
 	Iosize      int32
 	Blocks      uint64