minio/pkg/lock/lock_solaris.go
Harshavardhana 075b8903d7 fs: Add safe locking semantics for format.json (#4523)
This patch also reverts previous changes which were
merged for migration to the newer disk format. We will
be bringing these changes in subsequent releases. But
we wish to add protection in this release such that
future release migrations are protected.

Revert "fs: Migration should handle bucketConfigs as regular objects. (#4482)"
This reverts commit 976870a391.

Revert "fs: Migrate object metadata to objects directory. (#4195)"
This reverts commit 76f4f20609.
2017-06-12 17:40:28 -07:00

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 = ErrLocked
}
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)
}