165 lines
3.8 KiB
Go
165 lines
3.8 KiB
Go
/*
|
|
Copyright 2017 The GoStor Authors All rights reserved.
|
|
|
|
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 backingstore
|
|
|
|
import (
|
|
"fmt"
|
|
"io"
|
|
"os"
|
|
"strings"
|
|
|
|
log "github.com/sirupsen/logrus"
|
|
|
|
"github.com/gostor/gotgt/pkg/api"
|
|
"github.com/gostor/gotgt/pkg/scsi"
|
|
"github.com/gostor/gotgt/pkg/util"
|
|
)
|
|
|
|
const (
|
|
FileBackingStorage = "file"
|
|
)
|
|
|
|
func init() {
|
|
scsi.RegisterBackingStore(FileBackingStorage, new)
|
|
}
|
|
|
|
type FileBackingStore struct {
|
|
scsi.BaseBackingStore
|
|
file *os.File
|
|
}
|
|
|
|
func new() (api.BackingStore, error) {
|
|
return &FileBackingStore{
|
|
BaseBackingStore: scsi.BaseBackingStore{
|
|
Name: FileBackingStorage,
|
|
DataSize: 0,
|
|
OflagsSupported: 0,
|
|
},
|
|
}, nil
|
|
}
|
|
|
|
// parseStoragePath parses a storage path that may include backend type prefix
|
|
// Format: [backend_type:]path
|
|
// Examples:
|
|
// - /var/tmp/disk.img (default file backend)
|
|
// - file:/var/tmp/disk.img (explicit file backend)
|
|
// - iouring:/var/tmp/disk.img (io_uring backend on Linux 5.1+)
|
|
func parseStoragePath(path string) (backendType, filePath string) {
|
|
if idx := strings.Index(path, ":"); idx > 0 {
|
|
possibleType := path[:idx]
|
|
// Check if it's a known backend type
|
|
switch possibleType {
|
|
case "file", "iouring", "ceph", "null", "RemBs":
|
|
return possibleType, path[idx+1:]
|
|
}
|
|
}
|
|
// Default to file backend
|
|
return "file", path
|
|
}
|
|
|
|
func (bs *FileBackingStore) Open(dev *api.SCSILu, path string) error {
|
|
var mode os.FileMode
|
|
|
|
// Parse backend type and actual path
|
|
backendType, filePath := parseStoragePath(path)
|
|
_ = backendType // file backend ignores this
|
|
|
|
finfo, err := os.Stat(filePath)
|
|
if err != nil {
|
|
return err
|
|
} else {
|
|
// determine file type
|
|
mode = finfo.Mode()
|
|
}
|
|
|
|
f, err := os.OpenFile(filePath, os.O_RDWR, os.ModePerm)
|
|
|
|
if err == nil {
|
|
// block device filesize needs to be treated differently
|
|
if (mode & os.ModeDevice) != 0 {
|
|
pos, err := f.Seek(0, io.SeekEnd)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
bs.DataSize = uint64(pos)
|
|
} else {
|
|
if finfo == nil {
|
|
log.Infof("finfo is nil")
|
|
}
|
|
bs.DataSize = uint64(finfo.Size())
|
|
}
|
|
}
|
|
|
|
bs.file = f
|
|
return err
|
|
}
|
|
|
|
func (bs *FileBackingStore) Close(dev *api.SCSILu) error {
|
|
return bs.file.Close()
|
|
}
|
|
|
|
func (bs *FileBackingStore) Init(dev *api.SCSILu, Opts string) error {
|
|
return nil
|
|
}
|
|
|
|
func (bs *FileBackingStore) Exit(dev *api.SCSILu) error {
|
|
return nil
|
|
}
|
|
|
|
func (bs *FileBackingStore) Size(dev *api.SCSILu) uint64 {
|
|
return bs.DataSize
|
|
}
|
|
|
|
func (bs *FileBackingStore) Read(offset, tl int64) ([]byte, error) {
|
|
if bs.file == nil {
|
|
return nil, fmt.Errorf("Backend store is nil")
|
|
}
|
|
tmpbuf := make([]byte, tl)
|
|
length, err := bs.file.ReadAt(tmpbuf, offset)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
if length != len(tmpbuf) {
|
|
return nil, fmt.Errorf("read is not same length of length")
|
|
}
|
|
return tmpbuf, nil
|
|
}
|
|
|
|
func (bs *FileBackingStore) Write(wbuf []byte, offset int64) error {
|
|
length, err := bs.file.WriteAt(wbuf, offset)
|
|
if err != nil {
|
|
log.Error(err)
|
|
return err
|
|
}
|
|
if length != len(wbuf) {
|
|
return fmt.Errorf("write is not same length of length")
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (bs *FileBackingStore) DataSync(offset, tl int64) error {
|
|
return util.Fdatasync(bs.file)
|
|
}
|
|
|
|
func (bs *FileBackingStore) DataAdvise(offset, length int64, advise uint32) error {
|
|
return util.Fadvise(bs.file, offset, length, advise)
|
|
}
|
|
|
|
func (bs *FileBackingStore) Unmap([]api.UnmapBlockDescriptor) error {
|
|
return nil
|
|
}
|