Merge pull request #85 from datomia/fix-pool-leak

Fix memory leak

pkg/port/iscsit/iscsid.go

@@ -27,7 +27,6 @@ import (
 	"github.com/gostor/gotgt/pkg/config"
 	"github.com/gostor/gotgt/pkg/scsi"
 	"github.com/gostor/gotgt/pkg/util"
-	"github.com/gostor/gotgt/pkg/util/pool"
 	log "github.com/sirupsen/logrus"
 )
 
@@ -283,7 +282,7 @@ func (s *ISCSITargetDriver) rxHandler(conn *iscsiConnection) {
 				return
 			}
 			dl := ((cmd.DataLen + DataPadding - 1) / DataPadding) * DataPadding
-			cmd.RawData = pool.NewBuffer(dl)
+			cmd.RawData = make([]byte, int(dl))
 			length := 0
 			for length < dl {
 				l, err := conn.readData(cmd.RawData[length:])
@@ -608,7 +607,7 @@ func (s *ISCSITargetDriver) scsiCommandHandler(conn *iscsiConnection) (err error
 				}
 				scmd.OutSDBBuffer = &api.SCSIDataBuffer{
 					Length: uint32(blen),
-					Buffer: pool.NewBuffer(blen),
+					Buffer: make([]byte, blen),
 				}
 			}
 			log.Debugf("SCSI write, R2T count: %d, unsol Count: %d, offset: %d", task.r2tCount, task.unsolCount, task.offset)
@@ -621,7 +620,9 @@ func (s *ISCSITargetDriver) scsiCommandHandler(conn *iscsiConnection) (err error
 				// prepare to receive more data
 				conn.session.ExpCmdSN += 1
 				task.state = taskPending
+				conn.session.PendingTasksMutex.Lock()
 				conn.session.PendingTasks.Push(task)
+				conn.session.PendingTasksMutex.Unlock()
 				conn.rxTask = task
 				if conn.session.SessionParam[ISCSI_PARAM_INITIAL_R2T_EN].Value == 1 {
 					iscsiExecR2T(conn)
@@ -636,7 +637,7 @@ func (s *ISCSITargetDriver) scsiCommandHandler(conn *iscsiConnection) (err error
 		} else if scmd.InSDBBuffer == nil {
 			scmd.InSDBBuffer = &api.SCSIDataBuffer{
 				Length: uint32(req.ExpectedDataLen),
-				Buffer: pool.NewBuffer(int(req.ExpectedDataLen)),
+				Buffer: make([]byte, int(req.ExpectedDataLen)),
 			}
 		}
 		task.offset = 0
@@ -664,12 +665,9 @@ func (s *ISCSITargetDriver) scsiCommandHandler(conn *iscsiConnection) (err error
 		}
 	case OpSCSIOut:
 		log.Debugf("iSCSI Data-out processing...")
-		var task *iscsiTask
-		for _, t := range conn.session.PendingTasks {
-			if t.tag == conn.req.TaskTag {
-				task = t
-			}
-		}
+		conn.session.PendingTasksMutex.RLock()
+		task := conn.session.PendingTasks.GetByTag(conn.req.TaskTag)
+		conn.session.PendingTasksMutex.RUnlock()
 		if task == nil {
 			err = fmt.Errorf("Cannot find iSCSI task with tag[%v]", conn.req.TaskTag)
 			log.Error(err)
@@ -705,6 +703,9 @@ func (s *ISCSITargetDriver) scsiCommandHandler(conn *iscsiConnection) (err error
 		} else {
 			conn.buildRespPackage(OpSCSIResp, task)
 			conn.rxTask = nil
+			conn.session.PendingTasksMutex.Lock()
+			conn.session.PendingTasks.RemoveByTag(conn.req.TaskTag)
+			conn.session.PendingTasksMutex.Unlock()
 		}
 	case OpNoopOut:
 		iscsiExecNoopOut(conn)
@@ -745,11 +746,12 @@ func (s *ISCSITargetDriver) iscsiTaskQueueHandler(task *iscsiTask) error {
 		if err := s.iscsiExecTask(task); err != nil {
 			log.Error(err)
 		}
-		if len(sess.PendingTasks) == 0 {
+		sess.PendingTasksMutex.Lock()
+		if sess.PendingTasks.Len() == 0 {
+			sess.PendingTasksMutex.Unlock()
 			return nil
 		}
-		sess.PendingTasksMutex.Lock()
-		task = sess.PendingTasks.Pop().(*iscsiTask)
+		task = sess.PendingTasks.Pop()
 		cmd = task.cmd
 		if cmd.CmdSN != cmdsn {
 			sess.PendingTasks.Push(task)
@@ -796,15 +798,8 @@ func (s *ISCSITargetDriver) iscsiExecTask(task *iscsiTask) error {
 		sess := task.conn.session
 		switch cmd.TaskFunc {
 		case ISCSI_TM_FUNC_ABORT_TASK:
-			var stask *iscsiTask
 			sess.PendingTasksMutex.Lock()
-			for i, t := range sess.PendingTasks {
-				if cmd.ReferencedTaskTag == t.tag {
-					stask = sess.PendingTasks[i]
-					sess.PendingTasks = append(sess.PendingTasks[:i], sess.PendingTasks[i+1:]...)
-					break
-				}
-			}
+			stask := sess.PendingTasks.RemoveByTag(cmd.ReferencedTaskTag)
 			sess.PendingTasksMutex.Unlock()
 			if stask == nil {
 				task.result = ISCSI_TMF_RSP_NO_TASK

pkg/port/iscsit/session.go

@@ -273,12 +273,12 @@ func (tq taskQueue) Swap(i, j int) {
 	tq[i], tq[j] = tq[j], tq[i]
 }
 
-func (tq *taskQueue) Push(x interface{}) {
-	item := x.(*iscsiTask)
+func (tq *taskQueue) Push(x *iscsiTask) {
+	item := x
 	*tq = append(*tq, item)
 }
 
-func (tq *taskQueue) Pop() interface{} {
+func (tq *taskQueue) Pop() *iscsiTask {
 	old := *tq
 	n := len(old)
 	item := old[n-1]
@@ -286,6 +286,26 @@ func (tq *taskQueue) Pop() interface{} {
 	return item
 }
 
+func (tq taskQueue) GetByTag(tag uint32) *iscsiTask {
+	for _, t := range tq {
+		if t.tag == tag {
+			return t
+		}
+	}
+	return nil
+}
+
+func (tq *taskQueue) RemoveByTag(tag uint32) *iscsiTask {
+	old := *tq
+	for i, t := range old {
+		if t.tag == tag {
+			*tq = append(old[:i], old[i+1:]...)
+			return t
+		}
+	}
+	return nil
+}
+
 func (s *ISCSITargetDriver) LookupISCSISession(tgtName string, iniName string, isid uint64, tsih uint16, tpgt uint16) *ISCSISession {
 	var (
 		tgt  *ISCSITarget

pkg/scsi/backingstore.go

@@ -23,7 +23,6 @@ import (
 
 	"github.com/gostor/gotgt/pkg/api"
 	"github.com/gostor/gotgt/pkg/util"
-	"github.com/gostor/gotgt/pkg/util/pool"
 	log "github.com/sirupsen/logrus"
 )
 
@@ -110,7 +109,7 @@ func bsPerformCommand(bs api.BackingStore, cmd *api.SCSICommand) (err error, key
 		// TODO
 		break
 	case api.READ_6, api.READ_10, api.READ_12, api.READ_16:
-		rbuf = pool.NewBuffer(int(tl))
+		rbuf = make([]byte, int(tl))
 		rbuf, err = bs.Read(int64(offset), tl)
 		if err != nil && err != io.EOF {
 			key = MEDIUM_ERROR
@@ -179,7 +178,7 @@ write:
 	}
 verify:
 	if doVerify {
-		rbuf = pool.NewBuffer(int(tl))
+		rbuf = make([]byte, int(tl))
 		rbuf, err = bs.Read(int64(offset), tl)
 		if err != nil {
 			key = MEDIUM_ERROR

pkg/util/pool/pool.go

@@ -1,34 +0,0 @@
-/*
-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 pool provides memory pool for buffer.
-package pool
-
-import "sync"
-
-var bytePool sync.Pool = sync.Pool{}
-
-func NewBuffer(size int) []byte {
-	bytePool.New = func() interface{} {
-		return make([]byte, size)
-	}
-
-	return bytePool.Get().([]byte)
-}
-
-func ReleaseBuffer(b []byte) {
-	bytePool.Put(b)
-}