141 lines
3.0 KiB
Go
141 lines
3.0 KiB
Go
/*
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Copyright 2017 The GoStor Authors All rights reserved.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package backingstore
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import (
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"fmt"
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"io"
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"os"
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log "github.com/sirupsen/logrus"
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"github.com/gostor/gotgt/pkg/api"
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"github.com/gostor/gotgt/pkg/scsi"
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"github.com/gostor/gotgt/pkg/util"
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)
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const (
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FileBackingStorage = "file"
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)
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func init() {
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scsi.RegisterBackingStore(FileBackingStorage, new)
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}
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type FileBackingStore struct {
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scsi.BaseBackingStore
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file *os.File
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}
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func new() (api.BackingStore, error) {
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return &FileBackingStore{
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BaseBackingStore: scsi.BaseBackingStore{
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Name: FileBackingStorage,
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DataSize: 0,
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OflagsSupported: 0,
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},
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}, nil
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}
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func (bs *FileBackingStore) Open(dev *api.SCSILu, path string) error {
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var mode os.FileMode
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finfo, err := os.Stat(path)
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if err != nil {
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return err
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} else {
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// determine file type
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mode = finfo.Mode()
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}
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f, err := os.OpenFile(path, os.O_RDWR, os.ModePerm)
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if err == nil {
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// block device filesize needs to be treated differently
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if (mode & os.ModeDevice) != 0 {
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pos, err := f.Seek(0, io.SeekEnd)
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if err != nil {
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return err
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}
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bs.DataSize = uint64(pos)
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} else {
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if finfo == nil {
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log.Infof("finfo is nil")
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}
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bs.DataSize = uint64(finfo.Size())
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}
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}
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bs.file = f
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return err
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}
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func (bs *FileBackingStore) Close(dev *api.SCSILu) error {
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return bs.file.Close()
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}
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func (bs *FileBackingStore) Init(dev *api.SCSILu, Opts string) error {
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return nil
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}
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func (bs *FileBackingStore) Exit(dev *api.SCSILu) error {
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return nil
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}
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func (bs *FileBackingStore) Size(dev *api.SCSILu) uint64 {
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return bs.DataSize
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}
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func (bs *FileBackingStore) Read(offset, tl int64) ([]byte, error) {
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if bs.file == nil {
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return nil, fmt.Errorf("Backend store is nil")
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}
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tmpbuf := make([]byte, tl)
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length, err := bs.file.ReadAt(tmpbuf, offset)
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if err != nil {
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return nil, err
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}
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if length != len(tmpbuf) {
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return nil, fmt.Errorf("read is not same length of length")
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}
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return tmpbuf, nil
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}
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func (bs *FileBackingStore) Write(wbuf []byte, offset int64) error {
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length, err := bs.file.WriteAt(wbuf, offset)
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if err != nil {
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log.Error(err)
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return err
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}
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if length != len(wbuf) {
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return fmt.Errorf("write is not same length of length")
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}
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return nil
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}
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func (bs *FileBackingStore) DataSync(offset, tl int64) error {
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return util.Fdatasync(bs.file)
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}
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func (bs *FileBackingStore) DataAdvise(offset, length int64, advise uint32) error {
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return util.Fadvise(bs.file, offset, length, advise)
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}
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func (bs *FileBackingStore) Unmap([]api.UnmapBlockDescriptor) error {
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return nil
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}
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