353f2d3a6e
Looks like if we follow pattern such as ``` _ = rlk ``` Go can potentially kick in GC and close the fd when the reference is lost, only speculation is that the cause here is `SetFinalizer` which is set on `os.close()` internally in `os` stdlib. This is unexpected and unsual endeavour for Go, but we have to make sure the reference is never lost and always dies with the server. Fixes #4530
101 lines
2.5 KiB
Go
101 lines
2.5 KiB
Go
// +build solaris
|
|
|
|
/*
|
|
* Minio Cloud Storage, (C) 2017 Minio, Inc.
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
package lock
|
|
|
|
import (
|
|
"fmt"
|
|
"os"
|
|
"syscall"
|
|
)
|
|
|
|
// lockedOpenFile is an internal function.
|
|
func lockedOpenFile(path string, flag int, perm os.FileMode, rlockType int) (*LockedFile, error) {
|
|
var lockType int16
|
|
switch flag {
|
|
case syscall.O_RDONLY:
|
|
lockType = syscall.F_RDLCK
|
|
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.F_WRLCK
|
|
default:
|
|
return nil, fmt.Errorf("Unsupported flag (%d)", flag)
|
|
}
|
|
|
|
var lock = syscall.Flock_t{
|
|
Start: 0,
|
|
Len: 0,
|
|
Pid: 0,
|
|
Type: lockType,
|
|
Whence: 0,
|
|
}
|
|
|
|
f, err := os.OpenFile(path, flag, perm)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if err = syscall.FcntlFlock(f.Fd(), rlockType, &lock); err != nil {
|
|
f.Close()
|
|
if err == syscall.EAGAIN {
|
|
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{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.F_SETLK)
|
|
}
|
|
|
|
// 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, syscall.F_SETLKW)
|
|
}
|