blob: d7e3372230b0dc682e760894c06c65a0cd662c70 [file] [log] [blame]
// Copyright 2020 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package ld
import (
"syscall"
"unsafe"
)
func (out *OutBuf) fallocate(size uint64) error {
stat, err := out.f.Stat()
if err != nil {
return err
}
// F_PEOFPOSMODE allocates from the end of the file, so we want the size difference.
// Apparently, it uses the end of the allocation, instead of the logical end of the
// the file.
cursize := uint64(stat.Sys().(*syscall.Stat_t).Blocks * 512) // allocated size
if size <= cursize {
return nil
}
store := &syscall.Fstore_t{
Flags: syscall.F_ALLOCATEALL,
Posmode: syscall.F_PEOFPOSMODE,
Offset: 0,
Length: int64(size - cursize),
}
_, _, errno := syscall.Syscall(syscall.SYS_FCNTL, uintptr(out.f.Fd()), syscall.F_PREALLOCATE, uintptr(unsafe.Pointer(store)))
if errno != 0 {
return errno
}
return nil
}