lock: Make some cleanup and moving the code around. (#2718)

This patch just avoids lot of ifs and inverts some logic.

cmd/benchmark-utils_test.go

@@ -235,7 +235,7 @@ func runGetObjectBenchmark(b *testing.B, obj ObjectLayer, objSize int) {
 func getRandomByte() []byte {
 	const letterBytes = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
 	// seeding the random number generator.
-	rand.Seed(time.Now().UnixNano())
+	rand.Seed(time.Now().UTC().UnixNano())
 	var b byte
 	// pick a character randomly.
 	b = letterBytes[rand.Intn(len(letterBytes))]

cmd/control-lock-main.go

@@ -83,7 +83,7 @@ func generateSystemLockResponse() (SystemLockState, error) {
 			opsState.LockOrigin = nsMutex.debugLockMap[param].lockInfo[opsID].lockOrigin
 			opsState.LockType = nsMutex.debugLockMap[param].lockInfo[opsID].lockType
 			opsState.Status = nsMutex.debugLockMap[param].lockInfo[opsID].status
-			opsState.StatusSince = time.Now().Sub(nsMutex.debugLockMap[param].lockInfo[opsID].since).String()
+			opsState.StatusSince = time.Now().UTC().Sub(nsMutex.debugLockMap[param].lockInfo[opsID].since).String()
 
 			volLockInfo.LockDetailsOnObject = append(volLockInfo.LockDetailsOnObject, opsState)
 		}

cmd/erasure-readfile_test.go

@@ -435,7 +435,7 @@ func TestErasureReadFileRandomOffsetLength(t *testing.T) {
 	}
 
 	// To generate random offset/length.
-	r := rand.New(rand.NewSource(time.Now().UnixNano()))
+	r := rand.New(rand.NewSource(time.Now().UTC().UnixNano()))
 
 	// create pool buffer which will be used by erasureReadFile for
 	// reading from disks and erasure decoding.

cmd/fs-v1-multipart-common_test.go

@@ -118,7 +118,7 @@ func TestFSWriteUploadJSON(t *testing.T) {
 	obj.MakeBucket(bucketName)
 	uploadID, err := obj.NewMultipartUpload(bucketName, objectName, nil)
 
-	if err := fs.writeUploadJSON(bucketName, objectName, uploadID, time.Now()); err != nil {
+	if err := fs.writeUploadJSON(bucketName, objectName, uploadID, time.Now().UTC()); err != nil {
 		t.Fatal("Unexpected err: ", err)
 	}
 
@@ -127,7 +127,7 @@ func TestFSWriteUploadJSON(t *testing.T) {
 	for i := 1; i <= 3; i++ {
 		naughty := newNaughtyDisk(fsStorage, map[int]error{i: errFaultyDisk}, nil)
 		fs.storage = naughty
-		if err := fs.writeUploadJSON(bucketName, objectName, uploadID, time.Now()); errorCause(err) != errFaultyDisk {
+		if err := fs.writeUploadJSON(bucketName, objectName, uploadID, time.Now().UTC()); errorCause(err) != errFaultyDisk {
 			t.Fatal("Unexpected err: ", err)
 		}
 	}

cmd/leak-detect_test.go

@@ -57,7 +57,7 @@ func (initialSnapShot LeakDetect) DetectLeak(t TestErrHandler) {
 	}
 	// Loop, waiting for goroutines to shut down.
 	// Wait up to 5 seconds, but finish as quickly as possible.
-	deadline := time.Now().Add(leakDetectDeadline * time.Second)
+	deadline := time.Now().UTC().Add(leakDetectDeadline * time.Second)
 	for {
 		// get sack snapshot of relevant go routines.
 		leaked := initialSnapShot.CompareCurrentSnapshot()
@@ -66,7 +66,7 @@ func (initialSnapShot LeakDetect) DetectLeak(t TestErrHandler) {
 			return
 		}
 		// wait a test again will deadline.
-		if time.Now().Before(deadline) {
+		if time.Now().UTC().Before(deadline) {
 			time.Sleep(leakDetectPauseTimeMs * time.Millisecond)
 			continue
 		}

cmd/lock-rpc-server-common.go

@@ -0,0 +1,85 @@
+/*
+ * Minio Cloud Storage, (C) 2016 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 cmd
+
+import (
+	"errors"
+	"time"
+)
+
+// Similar to removeEntry but only removes an entry only if the lock entry exists in map.
+func (l *lockServer) removeEntryIfExists(nlrip nameLockRequesterInfoPair) {
+	// Check if entry is still in map (could have been removed altogether by 'concurrent' (R)Unlock of last entry)
+	if lri, ok := l.lockMap[nlrip.name]; ok {
+		if !l.removeEntry(nlrip.name, nlrip.lri.uid, &lri) {
+			// Remove failed, in case it is a:
+			if nlrip.lri.writer {
+				// Writer: this should never happen as the whole (mapped) entry should have been deleted
+				errorIf(errors.New(""), "Lock maintenance failed to remove entry for write lock (should never happen)", nlrip.name, nlrip.lri.uid, lri)
+			} // Reader: this can happen if multiple read locks were active and
+			// the one we are looking for has been released concurrently (so it is fine).
+		} // Removal went okay, all is fine.
+	}
+}
+
+// removeEntry either, based on the uid of the lock message, removes a single entry from the
+// lockRequesterInfo array or the whole array from the map (in case of a write lock or last read lock)
+func (l *lockServer) removeEntry(name, uid string, lri *[]lockRequesterInfo) bool {
+	// Find correct entry to remove based on uid.
+	for index, entry := range *lri {
+		if entry.uid == uid {
+			if len(*lri) == 1 {
+				// Remove the (last) lock.
+				delete(l.lockMap, name)
+			} else {
+				// Remove the appropriate read lock.
+				*lri = append((*lri)[:index], (*lri)[index+1:]...)
+				l.lockMap[name] = *lri
+			}
+			return true
+		}
+	}
+	// None found return false, perhaps entry removed in previous run.
+	return false
+}
+
+// Validate lock args.
+func (l *lockServer) validateLockArgs(args *LockArgs) error {
+	if !l.timestamp.Equal(args.Timestamp) {
+		return errInvalidTimestamp
+	}
+	if !isRPCTokenValid(args.Token) {
+		return errInvalidToken
+	}
+	return nil
+}
+
+// getLongLivedLocks returns locks that are older than a certain time and
+// have not been 'checked' for validity too soon enough
+func getLongLivedLocks(m map[string][]lockRequesterInfo, interval time.Duration) []nameLockRequesterInfoPair {
+	rslt := []nameLockRequesterInfoPair{}
+	for name, lriArray := range m {
+		for idx := range lriArray {
+			// Check whether enough time has gone by since last check
+			if time.Since(lriArray[idx].timeLastCheck) >= interval {
+				rslt = append(rslt, nameLockRequesterInfoPair{name: name, lri: lriArray[idx]})
+				lriArray[idx].timeLastCheck = time.Now().UTC()
+			}
+		}
+	}
+	return rslt
+}

cmd/lock-rpc-server-common_test.go

@@ -0,0 +1,84 @@
+/*
+ * Minio Cloud Storage, (C) 2016 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 cmd
+
+import (
+	"reflect"
+	"testing"
+	"time"
+)
+
+// Tests function returning long lived locks.
+func TestGetLongLivedLocks(t *testing.T) {
+	ut := time.Now().UTC()
+	// Collection of test cases for verifying returning valid long lived locks.
+	testCases := []struct {
+		lockMap      map[string][]lockRequesterInfo
+		lockInterval time.Duration
+		expectedNSLR []nameLockRequesterInfoPair
+	}{
+		// Testcase - 1 validates long lived locks, returns empty list.
+		{
+			lockMap: map[string][]lockRequesterInfo{
+				"test": {{
+					writer:        true,
+					node:          "10.1.10.21",
+					rpcPath:       "/lock/mnt/disk1",
+					uid:           "10000112",
+					timestamp:     ut,
+					timeLastCheck: ut,
+				}},
+			},
+			lockInterval: 1 * time.Minute,
+			expectedNSLR: []nameLockRequesterInfoPair{},
+		},
+		// Testcase - 2 validates long lived locks, returns at least one list.
+		{
+			lockMap: map[string][]lockRequesterInfo{
+				"test": {{
+					writer:        true,
+					node:          "10.1.10.21",
+					rpcPath:       "/lock/mnt/disk1",
+					uid:           "10000112",
+					timestamp:     ut,
+					timeLastCheck: ut.Add(-2 * time.Minute),
+				}},
+			},
+			lockInterval: 1 * time.Minute,
+			expectedNSLR: []nameLockRequesterInfoPair{
+				{
+					name: "test",
+					lri: lockRequesterInfo{
+						writer:        true,
+						node:          "10.1.10.21",
+						rpcPath:       "/lock/mnt/disk1",
+						uid:           "10000112",
+						timestamp:     ut,
+						timeLastCheck: ut.Add(-2 * time.Minute),
+					},
+				},
+			},
+		},
+	}
+	// Validates all test cases here.
+	for i, testCase := range testCases {
+		nsLR := getLongLivedLocks(testCase.lockMap, testCase.lockInterval)
+		if !reflect.DeepEqual(testCase.expectedNSLR, nsLR) {
+			t.Errorf("Test %d: Expected %#v, got %#v", i+1, testCase.expectedNSLR, nsLR)
+		}
+	}
+}

cmd/lock-rpc-server.go

@@ -73,17 +73,68 @@ type lockServer struct {
 	rpcPath string
 	mutex   sync.Mutex
 	lockMap map[string][]lockRequesterInfo
-	timestamp time.Time // Timestamp set at the time of initialization. Resets naturally on minio server restart.
+	// Timestamp set at the time of initialization. Resets naturally on minio server restart.
+	timestamp time.Time
 }
 
-func (l *lockServer) verifyArgs(args *LockArgs) error {
-	if !l.timestamp.Equal(args.Timestamp) {
-		return errInvalidTimestamp
+// Initialize distributed name space lock.
+func initDistributedNSLock(mux *router.Router, serverConfig serverCmdConfig) {
+	lockServers := newLockServers(serverConfig)
+	registerStorageLockers(mux, lockServers)
+}
+
+// Create one lock server for every local storage rpc server.
+func newLockServers(serverConfig serverCmdConfig) (lockServers []*lockServer) {
+	// Initialize posix storage API.
+	exports := serverConfig.disks
+	ignoredExports := serverConfig.ignoredDisks
+
+	// Save ignored disks in a map
+	skipDisks := make(map[string]bool)
+	for _, ignoredExport := range ignoredExports {
+		skipDisks[ignoredExport] = true
 	}
-	if !isRPCTokenValid(args.Token) {
-		return errInvalidToken
+	for _, export := range exports {
+		if skipDisks[export] {
+			continue
+		}
+		// Not local storage move to the next node.
+		if !isLocalStorage(export) {
+			continue
+		}
+		if idx := strings.LastIndex(export, ":"); idx != -1 {
+			export = export[idx+1:]
+		}
+		// Create handler for lock RPCs
+		locker := &lockServer{
+			rpcPath:   export,
+			mutex:     sync.Mutex{},
+			lockMap:   make(map[string][]lockRequesterInfo),
+			timestamp: time.Now().UTC(),
+		}
+
+		// Start loop for stale lock maintenance
+		go func() {
+			// Start with random sleep time, so as to avoid "synchronous checks" between servers
+			time.Sleep(time.Duration(rand.Float64() * float64(lockMaintenanceLoop)))
+			for {
+				time.Sleep(lockMaintenanceLoop)
+				locker.lockMaintenance(lockCheckValidityInterval)
+			}
+		}()
+		lockServers = append(lockServers, locker)
+	}
+	return lockServers
+}
+
+// registerStorageLockers - register locker rpc handlers for net/rpc library clients
+func registerStorageLockers(mux *router.Router, lockServers []*lockServer) {
+	for _, lockServer := range lockServers {
+		lockRPCServer := rpc.NewServer()
+		lockRPCServer.RegisterName("Dsync", lockServer)
+		lockRouter := mux.PathPrefix(reservedBucket).Subrouter()
+		lockRouter.Path(path.Join("/lock", lockServer.rpcPath)).Handler(lockRPCServer)
 	}
-	return nil
 }
 
 ///  Distributed lock handlers
@@ -110,12 +161,21 @@ func (l *lockServer) LoginHandler(args *RPCLoginArgs, reply *RPCLoginReply) erro
 func (l *lockServer) Lock(args *LockArgs, reply *bool) error {
 	l.mutex.Lock()
 	defer l.mutex.Unlock()
-	if err := l.verifyArgs(args); err != nil {
+	if err := l.validateLockArgs(args); err != nil {
 		return err
 	}
 	_, *reply = l.lockMap[args.Name]
 	if !*reply { // No locks held on the given name, so claim write lock
-		l.lockMap[args.Name] = []lockRequesterInfo{{writer: true, node: args.Node, rpcPath: args.RPCPath, uid: args.UID, timestamp: time.Now(), timeLastCheck: time.Now()}}
+		l.lockMap[args.Name] = []lockRequesterInfo{
+			{
+				writer:        true,
+				node:          args.Node,
+				rpcPath:       args.RPCPath,
+				uid:           args.UID,
+				timestamp:     time.Now().UTC(),
+				timeLastCheck: time.Now().UTC(),
+			},
+		}
 	}
 	*reply = !*reply // Negate *reply to return true when lock is granted or false otherwise
 	return nil
@@ -125,39 +185,44 @@ func (l *lockServer) Lock(args *LockArgs, reply *bool) error {
 func (l *lockServer) Unlock(args *LockArgs, reply *bool) error {
 	l.mutex.Lock()
 	defer l.mutex.Unlock()
-	if err := l.verifyArgs(args); err != nil {
+	if err := l.validateLockArgs(args); err != nil {
 		return err
 	}
 	var lri []lockRequesterInfo
-	lri, *reply = l.lockMap[args.Name]
-	if !*reply { // No lock is held on the given name
+	if lri, *reply = l.lockMap[args.Name]; !*reply { // No lock is held on the given name
 		return fmt.Errorf("Unlock attempted on an unlocked entity: %s", args.Name)
 	}
 	if *reply = isWriteLock(lri); !*reply { // Unless it is a write lock
 		return fmt.Errorf("Unlock attempted on a read locked entity: %s (%d read locks active)", args.Name, len(lri))
 	}
-	if l.removeEntry(args.Name, args.UID, &lri) {
-		return nil
-	}
+	if !l.removeEntry(args.Name, args.UID, &lri) {
 		return fmt.Errorf("Unlock unable to find corresponding lock for uid: %s", args.UID)
+	}
+	return nil
 }
 
 // RLock - rpc handler for read lock operation.
 func (l *lockServer) RLock(args *LockArgs, reply *bool) error {
 	l.mutex.Lock()
 	defer l.mutex.Unlock()
-	if err := l.verifyArgs(args); err != nil {
+	if err := l.validateLockArgs(args); err != nil {
 		return err
 	}
-	var lri []lockRequesterInfo
-	lri, *reply = l.lockMap[args.Name]
-	if !*reply { // No locks held on the given name, so claim (first) read lock
-		l.lockMap[args.Name] = []lockRequesterInfo{{writer: false, node: args.Node, rpcPath: args.RPCPath, uid: args.UID, timestamp: time.Now(), timeLastCheck: time.Now()}}
-		*reply = true
-	} else {
-		if *reply = !isWriteLock(lri); *reply { // Unless there is a write lock
-			l.lockMap[args.Name] = append(l.lockMap[args.Name], lockRequesterInfo{writer: false, node: args.Node, rpcPath: args.RPCPath, uid: args.UID, timestamp: time.Now(), timeLastCheck: time.Now()})
+	lrInfo := lockRequesterInfo{
+		writer:        false,
+		node:          args.Node,
+		rpcPath:       args.RPCPath,
+		uid:           args.UID,
+		timestamp:     time.Now().UTC(),
+		timeLastCheck: time.Now().UTC(),
 	}
+	if lri, ok := l.lockMap[args.Name]; ok {
+		if *reply = !isWriteLock(lri); *reply { // Unless there is a write lock
+			l.lockMap[args.Name] = append(l.lockMap[args.Name], lrInfo)
+		}
+	} else { // No locks held on the given name, so claim (first) read lock
+		l.lockMap[args.Name] = []lockRequesterInfo{lrInfo}
+		*reply = true
 	}
 	return nil
 }
@@ -166,7 +231,7 @@ func (l *lockServer) RLock(args *LockArgs, reply *bool) error {
 func (l *lockServer) RUnlock(args *LockArgs, reply *bool) error {
 	l.mutex.Lock()
 	defer l.mutex.Unlock()
-	if err := l.verifyArgs(args); err != nil {
+	if err := l.validateLockArgs(args); err != nil {
 		return err
 	}
 	var lri []lockRequesterInfo
@@ -176,49 +241,33 @@ func (l *lockServer) RUnlock(args *LockArgs, reply *bool) error {
 	if *reply = !isWriteLock(lri); !*reply { // A write-lock is held, cannot release a read lock
 		return fmt.Errorf("RUnlock attempted on a write locked entity: %s", args.Name)
 	}
-	if l.removeEntry(args.Name, args.UID, &lri) {
-		return nil
-	}
+	if !l.removeEntry(args.Name, args.UID, &lri) {
 		return fmt.Errorf("RUnlock unable to find corresponding read lock for uid: %s", args.UID)
+	}
+	return nil
 }
 
-// Active - rpc handler for active lock status.
-func (l *lockServer) Active(args *LockArgs, reply *bool) error {
+// Expired - rpc handler for expired lock status.
+func (l *lockServer) Expired(args *LockArgs, reply *bool) error {
 	l.mutex.Lock()
 	defer l.mutex.Unlock()
-	if err := l.verifyArgs(args); err != nil {
+	if err := l.validateLockArgs(args); err != nil {
 		return err
 	}
-	var lri []lockRequesterInfo
-	if lri, *reply = l.lockMap[args.Name]; !*reply {
-		return nil // No lock is held on the given name so return false
-	}
+	// Lock found, proceed to verify if belongs to given uid.
+	if lri, ok := l.lockMap[args.Name]; ok {
 		// Check whether uid is still active
 		for _, entry := range lri {
-		if *reply = entry.uid == args.UID; *reply {
-			return nil // When uid found return true
+			if entry.uid == args.UID {
+				*reply = false // When uid found, lock is still active so return not expired.
+				return nil     // When uid found *reply is set to true.
 			}
 		}
-	return nil // None found so return false
-}
-
-// removeEntry either, based on the uid of the lock message, removes a single entry from the
-// lockRequesterInfo array or the whole array from the map (in case of a write lock or last read lock)
-func (l *lockServer) removeEntry(name, uid string, lri *[]lockRequesterInfo) bool {
-	// Find correct entry to remove based on uid
-	for index, entry := range *lri {
-		if entry.uid == uid {
-			if len(*lri) == 1 {
-				delete(l.lockMap, name) // Remove the (last) lock
-			} else {
-				// Remove the appropriate read lock
-				*lri = append((*lri)[:index], (*lri)[index+1:]...)
-				l.lockMap[name] = *lri
 	}
-			return true
-		}
-	}
-	return false
+	// When we get here lock is no longer active due to either args.Name
+	// being absent from map or uid not found for given args.Name
+	*reply = true
+	return nil
 }
 
 // nameLockRequesterInfoPair is a helper type for lock maintenance
@@ -227,132 +276,41 @@ type nameLockRequesterInfoPair struct {
 	lri  lockRequesterInfo
 }
 
-// getLongLivedLocks returns locks that are older than a certain time and
-// have not been 'checked' for validity too soon enough
-func getLongLivedLocks(m map[string][]lockRequesterInfo, interval time.Duration) []nameLockRequesterInfoPair {
-
-	rslt := []nameLockRequesterInfoPair{}
-
-	for name, lriArray := range m {
-
-		for idx := range lriArray {
-			// Check whether enough time has gone by since last check
-			if time.Since(lriArray[idx].timeLastCheck) >= interval {
-				rslt = append(rslt, nameLockRequesterInfoPair{name: name, lri: lriArray[idx]})
-				lriArray[idx].timeLastCheck = time.Now()
-			}
-		}
-	}
-
-	return rslt
-}
-
 // lockMaintenance loops over locks that have been active for some time and checks back
 // with the original server whether it is still alive or not
+//
+// Following logic inside ignores the errors generated for Dsync.Active operation.
+// - server at client down
+// - some network error (and server is up normally)
+//
+// We will ignore the error, and we will retry later to get a resolve on this lock
 func (l *lockServer) lockMaintenance(interval time.Duration) {
-
 	l.mutex.Lock()
-	// get list of locks to check
+	// Get list of long lived locks to check for staleness.
 	nlripLongLived := getLongLivedLocks(l.lockMap, interval)
 	l.mutex.Unlock()
 
+	// Validate if long lived locks are indeed clean.
 	for _, nlrip := range nlripLongLived {
-
+		// Initialize client based on the long live locks.
 		c := newClient(nlrip.lri.node, nlrip.lri.rpcPath)
 
-		var active bool
+		var expired bool
 
 		// Call back to original server verify whether the lock is still active (based on name & uid)
-		if err := c.Call("Dsync.Active", &LockArgs{Name: nlrip.name, UID: nlrip.lri.uid}, &active); err != nil {
-			// We failed to connect back to the server that originated the lock, this can either be due to
-			// - server at client down
-			// - some network error (and server is up normally)
-			//
-			// We will ignore the error, and we will retry later to get resolve on this lock
-			c.Close()
-		} else {
-			c.Close()
+		c.Call("Dsync.Expired", &LockArgs{
+			Name: nlrip.name,
+			UID:  nlrip.lri.uid,
+		}, &expired)
+		c.Close() // Close the connection regardless of the call response.
 
-			if !active { // The lock is no longer active at server that originated the lock
-				// so remove the lock from the map
+		// For successful response, verify if lock is indeed active or stale.
+		if expired {
+			// The lock is no longer active at server that originated the lock
+			// So remove the lock from the map.
 			l.mutex.Lock()
-				// Check if entry is still in map (could have been removed altogether by 'concurrent' (R)Unlock of last entry)
-				if lri, ok := l.lockMap[nlrip.name]; ok {
-					if !l.removeEntry(nlrip.name, nlrip.lri.uid, &lri) {
-						// Remove failed, in case it is a:
-						if nlrip.lri.writer {
-							// Writer: this should never happen as the whole (mapped) entry should have been deleted
-							log.Errorln("Lock maintenance failed to remove entry for write lock (should never happen)", nlrip.name, nlrip.lri, lri)
-						} else {
-							// Reader: this can happen if multiple read locks were active and the one we are looking for
-							// has been released concurrently (so it is fine)
-						}
-					} else {
-						// remove went okay, all is fine
-					}
-				}
+			l.removeEntryIfExists(nlrip) // Purge the stale entry if it exists.
 			l.mutex.Unlock()
 		}
 	}
-	}
-}
-
-// Initialize distributed lock.
-func initDistributedNSLock(mux *router.Router, serverConfig serverCmdConfig) {
-	lockServers := newLockServers(serverConfig)
-	registerStorageLockers(mux, lockServers)
-}
-
-// Create one lock server for every local storage rpc server.
-func newLockServers(serverConfig serverCmdConfig) (lockServers []*lockServer) {
-	// Initialize posix storage API.
-	exports := serverConfig.disks
-	ignoredExports := serverConfig.ignoredDisks
-
-	// Save ignored disks in a map
-	skipDisks := make(map[string]bool)
-	for _, ignoredExport := range ignoredExports {
-		skipDisks[ignoredExport] = true
-	}
-	for _, export := range exports {
-		if skipDisks[export] {
-			continue
-		}
-		if isLocalStorage(export) {
-			if idx := strings.LastIndex(export, ":"); idx != -1 {
-				export = export[idx+1:]
-			}
-
-			// Create handler for lock RPCs
-			locker := &lockServer{
-				rpcPath:   export,
-				mutex:     sync.Mutex{},
-				lockMap:   make(map[string][]lockRequesterInfo),
-				timestamp: time.Now().UTC(),
-			}
-
-			// Start loop for stale lock maintenance
-			go func() {
-				// Start with random sleep time, so as to avoid "synchronous checks" between servers
-				time.Sleep(time.Duration(rand.Float64() * float64(lockMaintenanceLoop)))
-				for {
-					time.Sleep(lockMaintenanceLoop)
-					locker.lockMaintenance(lockCheckValidityInterval)
-				}
-			}()
-
-			lockServers = append(lockServers, locker)
-		}
-	}
-	return lockServers
-}
-
-// registerStorageLockers - register locker rpc handlers for net/rpc library clients
-func registerStorageLockers(mux *router.Router, lockServers []*lockServer) {
-	for _, lockServer := range lockServers {
-		lockRPCServer := rpc.NewServer()
-		lockRPCServer.RegisterName("Dsync", lockServer)
-		lockRouter := mux.PathPrefix(reservedBucket).Subrouter()
-		lockRouter.Path(path.Join("/lock", lockServer.rpcPath)).Handler(lockRPCServer)
-	}
 }

cmd/namespace-lock.go

@@ -56,7 +56,6 @@ func initDsyncNodes(disks []string, port int) error {
 			}
 		}
 	}
-
 	return dsync.SetNodesWithClients(clnts, myNode)
 }
 
@@ -100,12 +99,14 @@ type nsLock struct {
 // Unlock, RLock and RUnlock.
 type nsLockMap struct {
 	// lock counter used for lock debugging.
-	globalLockCounter  int64                                   //total locks held.
-	blockedCounter     int64                                   // total operations blocked waiting for locks.
-	runningLockCounter int64                                   // total locks held but not released yet.
-	debugLockMap       map[nsParam]*debugLockInfoPerVolumePath // info for instrumentation on locks.
+	globalLockCounter  int64                                   // Total locks held.
+	blockedCounter     int64                                   // Total operations blocked waiting for locks.
+	runningLockCounter int64                                   // Total locks held but not released yet.
+	debugLockMap       map[nsParam]*debugLockInfoPerVolumePath // Info for instrumentation on locks.
 
-	isDist       bool // indicates whether the locking service is part of a distributed setup or not.
+	// Indicates whether the locking service is part
+	// of a distributed setup or not.
+	isDist       bool
 	lockMap      map[nsParam]*nsLock
 	lockMapMutex sync.Mutex
 }
@@ -132,13 +133,14 @@ func (n *nsLockMap) lock(volume, path string, lockOrigin, opsID string, readLock
 	nsLk.ref++ // Update ref count here to avoid multiple races.
 
 	if globalDebugLock {
-		// change the state of the lock to be  blocked for the given pair of <volume, path> and <OperationID> till the lock unblocks.
-		// The lock for accessing `nsMutex` is held inside the function itself.
-		err := n.statusNoneToBlocked(param, lockOrigin, opsID, readLock)
-		if err != nil {
+		// Change the state of the lock to be blocked for the given pair of <volume, path>
+		// and <OperationID> till the lock unblocks. The lock for accessing `nsMutex` is
+		// held inside the function itself.
+		if err := n.statusNoneToBlocked(param, lockOrigin, opsID, readLock); err != nil {
 			errorIf(err, "Failed to set lock state to blocked.")
 		}
 	}
+
 	// Unlock map before Locking NS which might block.
 	n.lockMapMutex.Unlock()
 
@@ -149,12 +151,12 @@ func (n *nsLockMap) lock(volume, path string, lockOrigin, opsID string, readLock
 		nsLk.Lock()
 	}
 
-	// check if lock debugging enabled.
+	// Check if lock debugging enabled.
 	if globalDebugLock {
 		// Changing the status of the operation from blocked to running.
-		// change the state of the lock to be  running (from blocked) for the given pair of <volume, path> and <OperationID>.
-		err := n.statusBlockedToRunning(param, lockOrigin, opsID, readLock)
-		if err != nil {
+		// change the state of the lock to be  running (from blocked) for
+		// the given pair of <volume, path> and <OperationID>.
+		if err := n.statusBlockedToRunning(param, lockOrigin, opsID, readLock); err != nil {
 			errorIf(err, "Failed to set the lock state to running.")
 		}
 	}
@@ -178,7 +180,7 @@ func (n *nsLockMap) unlock(volume, path, opsID string, readLock bool) {
 		}
 		if nsLk.ref != 0 {
 			nsLk.ref--
-			// locking debug enabled, delete the lock state entry for given operation ID.
+			// Locking debug enabled, delete the lock state entry for given operation ID.
 			if globalDebugLock {
 				err := n.deleteLockInfoEntryForOps(param, opsID)
 				if err != nil {
@@ -190,7 +192,7 @@ func (n *nsLockMap) unlock(volume, path, opsID string, readLock bool) {
 			// Remove from the map if there are no more references.
 			delete(n.lockMap, param)
 
-			// locking debug enabled, delete the lock state entry for given <volume, path> pair.
+			// Locking debug enabled, delete the lock state entry for given <volume, path> pair.
 			if globalDebugLock {
 				err := n.deleteLockInfoEntryForVolumePath(param)
 				if err != nil {
@@ -205,9 +207,10 @@ func (n *nsLockMap) unlock(volume, path, opsID string, readLock bool) {
 // allocated name space lock or initializing a new one.
 func (n *nsLockMap) Lock(volume, path, opsID string) {
 	var lockOrigin string
-	// lock debugging enabled. The caller information of the lock held has be obtained here before calling any other function.
+	// Lock debugging enabled. The caller information of the lock held has
+	// been obtained here before calling any other function.
 	if globalDebugLock {
-		// fetching the package, function name and the line number of the caller from the runtime.
+		// Fetching the package, function name and the line number of the caller from the runtime.
 		// here is an example https://play.golang.org/p/perrmNRI9_ .
 		pc, fn, line, success := runtime.Caller(1)
 		if !success {
@@ -229,10 +232,11 @@ func (n *nsLockMap) Unlock(volume, path, opsID string) {
 func (n *nsLockMap) RLock(volume, path, opsID string) {
 	var lockOrigin string
 	readLock := true
-	// lock debugging enabled. The caller information of the lock held has be obtained here before calling any other function.
+	// Lock debugging enabled. The caller information of the lock held has
+	// been obtained here before calling any other function.
 	if globalDebugLock {
-		// fetching the package, function name and the line number of the caller from the runtime.
-		// here is an example https://play.golang.org/p/perrmNRI9_ .
+		// Fetching the package, function name and the line number of the
+		// caller from the runtime. Here is an example https://play.golang.org/p/perrmNRI9_ .
 		pc, fn, line, success := runtime.Caller(1)
 		if !success {
 			errorIf(errors.New("Couldn't get caller info."), "Fetching caller info form runtime failed.")

cmd/server-mux_test.go

@@ -293,8 +293,8 @@ func generateTestCert(host string) error {
 		Subject: pkix.Name{
 			Organization: []string{"Minio Test Cert"},
 		},
-		NotBefore: time.Now(),
-		NotAfter:  time.Now().Add(time.Minute * 1),
+		NotBefore: time.Now().UTC(),
+		NotAfter:  time.Now().UTC().Add(time.Minute * 1),
 
 		KeyUsage:              x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
 		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},

cmd/signature-v4-parser_test.go

@@ -565,7 +565,7 @@ func TestParsePreSignV4(t *testing.T) {
 		return strconv.FormatInt(int64(expires), 10)
 	}
 	// used in expected preSignValues, preSignValues.Date is of type time.Time .
-	queryTime := time.Now()
+	queryTime := time.Now().UTC()
 
 	sampleTimeStr := time.Now().UTC().Format(yyyymmdd)