mirror of
https://github.com/minio/minio.git
synced 2024-12-27 23:55:56 -05:00
102 lines
2.7 KiB
Go
102 lines
2.7 KiB
Go
// +build !windows,!plan9,!solaris
|
|
|
|
// Copyright (c) 2015-2021 MinIO, Inc.
|
|
//
|
|
// This file is part of MinIO Object Storage stack
|
|
//
|
|
// This program is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU Affero General Public License as published by
|
|
// the Free Software Foundation, either version 3 of the License, or
|
|
// (at your option) any later version.
|
|
//
|
|
// This program is distributed in the hope that it will be useful
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU Affero General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU Affero General Public License
|
|
// along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
package lock
|
|
|
|
import (
|
|
"os"
|
|
"syscall"
|
|
)
|
|
|
|
// Internal function implements support for both
|
|
// blocking and non blocking lock type.
|
|
func lockedOpenFile(path string, flag int, perm os.FileMode, lockType int) (*LockedFile, error) {
|
|
switch flag {
|
|
case syscall.O_RDONLY:
|
|
lockType |= syscall.LOCK_SH
|
|
case syscall.O_WRONLY:
|
|
fallthrough
|
|
case syscall.O_RDWR:
|
|
fallthrough
|
|
case syscall.O_WRONLY | syscall.O_CREAT:
|
|
fallthrough
|
|
case syscall.O_RDWR | syscall.O_CREAT:
|
|
lockType |= syscall.LOCK_EX
|
|
default:
|
|
return nil, &os.PathError{
|
|
Op: "open",
|
|
Path: path,
|
|
Err: syscall.EINVAL,
|
|
}
|
|
}
|
|
|
|
f, err := os.OpenFile(path, flag|syscall.O_SYNC, perm)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if err = syscall.Flock(int(f.Fd()), lockType); err != nil {
|
|
f.Close()
|
|
if err == syscall.EWOULDBLOCK {
|
|
err = ErrAlreadyLocked
|
|
}
|
|
return nil, err
|
|
}
|
|
|
|
st, err := os.Stat(path)
|
|
if err != nil {
|
|
f.Close()
|
|
return nil, err
|
|
}
|
|
|
|
if st.IsDir() {
|
|
f.Close()
|
|
return nil, &os.PathError{
|
|
Op: "open",
|
|
Path: path,
|
|
Err: syscall.EISDIR,
|
|
}
|
|
}
|
|
|
|
return &LockedFile{File: f}, nil
|
|
}
|
|
|
|
// TryLockedOpenFile - tries a new write lock, functionality
|
|
// it is similar to LockedOpenFile with with syscall.LOCK_EX
|
|
// mode but along with syscall.LOCK_NB such that the function
|
|
// doesn't wait forever but instead returns if it cannot
|
|
// acquire a write lock.
|
|
func TryLockedOpenFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
|
|
return lockedOpenFile(path, flag, perm, syscall.LOCK_NB)
|
|
}
|
|
|
|
// LockedOpenFile - initializes a new lock and protects
|
|
// the file from concurrent access across mount points.
|
|
// This implementation doesn't support all the open
|
|
// flags and shouldn't be considered as replacement
|
|
// for os.OpenFile().
|
|
func LockedOpenFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
|
|
return lockedOpenFile(path, flag, perm, 0)
|
|
}
|
|
|
|
// Open - Call os.OpenFile
|
|
func Open(path string, flag int, perm os.FileMode) (*os.File, error) {
|
|
return os.OpenFile(path, flag, perm)
|
|
}
|