disk: fix various bugs

disk/disk_netbsd.go

@@ -26,13 +26,12 @@ const (
 func PartitionsWithContext(ctx context.Context, all bool) ([]PartitionStat, error) {
 	var ret []PartitionStat
     
-    trap := 483 // SYS___getvfsstat90 syscall 
     flag := uint64(1) // ST_WAIT/MNT_WAIT, see sys/fstypes.h
 
     // get required buffer size
     emptyBufSize := 0
     r, _, err := unix.Syscall(
-        uintptr(unsafe.Pointer(&trap)), 
+        483, // SYS___getvfsstat90 syscall 
         uintptr(unsafe.Pointer(nil)),
         uintptr(unsafe.Pointer(&emptyBufSize)),
         uintptr(unsafe.Pointer(&flag)),
@@ -44,11 +43,11 @@ func PartitionsWithContext(ctx context.Context, all bool) ([]PartitionStat, erro
 
     // calculate the buffer size
     bufSize := sizeOfStatvfs * mountedFsCount
-    buf := make([]Statvfs, bufSize)
+    buf := make([]Statvfs, mountedFsCount)
 
     // request agian to get desired mount data
     _, _, err = unix.Syscall(
-        uintptr(unsafe.Pointer(&flag)),
+        483, // SYS___getvfsstat90 syscall 
         uintptr(unsafe.Pointer(&buf[0])),
         uintptr(unsafe.Pointer(&bufSize)),
         uintptr(unsafe.Pointer(&flag)),
@@ -104,12 +103,16 @@ func IOCountersWithContext(ctx context.Context, names ...string) (map[string]IOC
 
 func UsageWithContext(ctx context.Context, path string) (*UsageStat, error) {
     stat := Statvfs{}
-    trap := 485 // SYS___fstatvfs190, see sys/syscall.h
     flag := uint64(1) // ST_WAIT/MNT_WAIT, see sys/fstypes.h
 
+    _path, e := unix.BytePtrFromString(path)
+    if e != nil {
+        return nil, e
+    }
+
     _, _, err := unix.Syscall(
-        uintptr(unsafe.Pointer(&trap)),
+        484, // SYS___fstatvfs190, see sys/syscall.h
-        uintptr(unsafe.Pointer(&path)),
+        uintptr(unsafe.Pointer(_path)),
         uintptr(unsafe.Pointer(&stat)),
         uintptr(unsafe.Pointer(&flag)),
     )

disk/disk_netbsd_arm64.go

@@ -41,5 +41,5 @@ type (
 )
 
 type _Ctype_struct___0 struct {
-    FsidVal     [32]int32
+    FsidVal     [2]int32
 }