k3s/vendor/go.etcd.io/etcd/pkg/fileutil/preallocate_darwin.go

66 lines
1.9 KiB
Go

// Copyright 2016 The etcd Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// +build darwin
package fileutil
import (
"os"
"syscall"
"unsafe"
)
func preallocExtend(f *os.File, sizeInBytes int64) error {
if err := preallocFixed(f, sizeInBytes); err != nil {
return err
}
return preallocExtendTrunc(f, sizeInBytes)
}
func preallocFixed(f *os.File, sizeInBytes int64) error {
// allocate all requested space or no space at all
// TODO: allocate contiguous space on disk with F_ALLOCATECONTIG flag
fstore := &syscall.Fstore_t{
Flags: syscall.F_ALLOCATEALL,
Posmode: syscall.F_PEOFPOSMODE,
Length: sizeInBytes}
p := unsafe.Pointer(fstore)
_, _, errno := syscall.Syscall(syscall.SYS_FCNTL, f.Fd(), uintptr(syscall.F_PREALLOCATE), uintptr(p))
if errno == 0 || errno == syscall.ENOTSUP {
return nil
}
// wrong argument to fallocate syscall
if errno == syscall.EINVAL {
// filesystem "st_blocks" are allocated in the units of
// "Allocation Block Size" (run "diskutil info /" command)
var stat syscall.Stat_t
syscall.Fstat(int(f.Fd()), &stat)
// syscall.Statfs_t.Bsize is "optimal transfer block size"
// and contains matching 4096 value when latest OS X kernel
// supports 4,096 KB filesystem block size
var statfs syscall.Statfs_t
syscall.Fstatfs(int(f.Fd()), &statfs)
blockSize := int64(statfs.Bsize)
if stat.Blocks*blockSize >= sizeInBytes {
// enough blocks are already allocated
return nil
}
}
return errno
}