1 // Copyright 2016 The etcd Authors 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 //go:build linux 16 // +build linux 17 18 package fileutil 19 20 import ( 21 "os" 22 "syscall" 23 ) 24 25 func preallocExtend(f *os.File, sizeInBytes int64) error { 26 // use mode = 0 to change size 27 err := syscall.Fallocate(int(f.Fd()), 0, 0, sizeInBytes) 28 if err != nil { 29 errno, ok := err.(syscall.Errno) 30 // not supported; fallback 31 // fallocate EINTRs frequently in some environments; fallback 32 if ok && (errno == syscall.ENOTSUP || errno == syscall.EINTR) { 33 return preallocExtendTrunc(f, sizeInBytes) 34 } 35 } 36 return err 37 } 38 39 func preallocFixed(f *os.File, sizeInBytes int64) error { 40 // use mode = 1 to keep size; see FALLOC_FL_KEEP_SIZE 41 err := syscall.Fallocate(int(f.Fd()), 1, 0, sizeInBytes) 42 if err != nil { 43 errno, ok := err.(syscall.Errno) 44 // treat not supported as nil error 45 if ok && errno == syscall.ENOTSUP { 46 return nil 47 } 48 } 49 return err 50 } 51