Add option to disable multipath and other fixes

Signed-off-by: Utkarsh Mani Tripathi <utkarsh.tripathi@mayadata.io>

pkg/port/iscsit/cmd.go

@@ -371,7 +371,6 @@ func (m *ISCSICommand) dataInBytes() []byte {
 	copy(buf[36:], util.MarshalUint32(m.DataSN))
 	copy(buf[40:], util.MarshalUint32(m.BufferOffset))
 	copy(buf[44:], util.MarshalUint32(m.Resid))
-	copy(buf[48:], m.RawData[m.BufferOffset:m.BufferOffset+uint32(m.DataLen)])
 	if m.ExpectedDataLen != 0 {
 		copy(buf[48:], m.RawData[m.BufferOffset:m.BufferOffset+uint32(m.DataLen)])
 	}

pkg/port/iscsit/iscsid.go

@@ -55,7 +55,6 @@ type ISCSITargetDriver struct {
 	TSIHPoolMutex     sync.Mutex
 	isClientConnected bool
 	enableStats       bool
-	SCSIIOCount       map[int]int64
 	mu                *sync.RWMutex
 	l                 net.Listener
 	state             uint8
@@ -77,8 +76,8 @@ func NewISCSITargetDriver(base *scsi.SCSITargetService) (scsi.SCSITargetDriver,
 	}
 
 	if EnableStats {
-		driver.SCSIIOCount = map[int]int64{}
 		driver.enableStats = true
+		driver.TargetStats.SCSIIOCount = map[int]int64{}
 	}
 	return driver, nil
 }
@@ -631,10 +630,12 @@ func (s *ISCSITargetDriver) scsiCommandHandler(conn *iscsiConnection) (err error
 	switch req.OpCode {
 	case OpSCSICmd:
 		log.Debugf("SCSI Command processing...")
-		if _, ok := s.SCSIIOCount[(int)(req.CDB[0])]; ok != false {
-			s.SCSIIOCount[(int)(req.CDB[0])] += 1
-		} else {
-			s.SCSIIOCount[(int)(req.CDB[0])] = 1
+		if s.enableStats {
+			if _, ok := s.TargetStats.SCSIIOCount[(int)(req.CDB[0])]; ok != false {
+				s.TargetStats.SCSIIOCount[(int)(req.CDB[0])] += 1
+			} else {
+				s.TargetStats.SCSIIOCount[(int)(req.CDB[0])] = 1
+			}
 		}
 		scmd := &api.SCSICommand{
 			ITNexusID:       conn.session.ITNexus.ID,

pkg/scsi/backingstore.go

@@ -125,12 +125,12 @@ func bsPerformCommand(bs api.BackingStore, cmd *api.SCSICommand) (err error, key
 			bs.DataAdvise(int64(offset), int64(length), util.POSIX_FADV_NOREUSE)
 		}
 		cmd.InSDBBuffer.Resid = uint32(length)
-		copy(cmd.InSDBBuffer.Buffer, rbuf)
 		if cmd.InSDBBuffer.Length < uint32(length) {
 			key = ILLEGAL_REQUEST
 			asc = ASC_INVALID_FIELD_IN_CDB
 			goto sense
 		}
+		copy(cmd.InSDBBuffer.Buffer, rbuf)
 	case api.PRE_FETCH_10, api.PRE_FETCH_16:
 		err = bs.DataAdvise(int64(offset), tl, util.POSIX_FADV_WILLNEED)
 		if err != nil {

pkg/scsi/backingstore/remote/remote.go

@@ -113,6 +113,6 @@ func (bs *RemBackingStore) DataSync(offset, length int64) (err error) {
 }
 
 func (bs *RemBackingStore) Unmap(bd []api.UnmapBlockDescriptor) (err error) {
-	_, err = bs.RemBs.Unmap(int64(bd[0].Offset), int64(bd[0].TL))
+	//_, err = bs.RemBs.Unmap(int64(bd[0].Offset), int64(bd[0].TL))
 	return
 }

pkg/scsi/spc.go

@@ -28,6 +28,10 @@ import (
 	log "github.com/sirupsen/logrus"
 )
 
+var (
+	EnableMultipath = true
+)
+
 func SPCIllegalOp(host int, cmd *api.SCSICommand) api.SAMStat {
 	BuildSenseData(cmd, ILLEGAL_REQUEST, ASC_INVALID_OP_CODE)
 	return api.SAMStatCheckCondition
@@ -325,7 +329,11 @@ func SPCInquiry(host int, cmd *api.SCSICommand) api.SAMStat {
 		}
 		//byte 5
 		//SCCS(0) AAC(0) TPGS(0) 3PC(0) PROTECT(0)
-		addBuf.WriteByte(INQUIRY_TPGS_IMPLICIT)
+		if EnableMultipath {
+			addBuf.WriteByte(INQUIRY_TPGS_IMPLICIT)
+		} else {
+			addBuf.WriteByte(INQUIRY_TPGS_NO)
+		}
 		//byte 6
 		//ENCSERV(0) VS(0) MULTIP(0) ADDR16(0)
 		addBuf.WriteByte(0x00)