From 6827cabfbb63779b5304f32d3ef720f07f1c721c Mon Sep 17 00:00:00 2001
From: Chris Lu <chris.lu@gmail.com>
Date: Fri, 6 Dec 2019 06:59:57 -0800
Subject: [PATCH] volume: dataFileAccessLock change to RW Lock

---
 weed/storage/volume.go            | 30 +++++++++++++++---------------
 weed/storage/volume_backup.go     |  4 ++--
 weed/storage/volume_read_write.go |  4 ++--
 3 files changed, 19 insertions(+), 19 deletions(-)

diff --git a/weed/storage/volume.go b/weed/storage/volume.go
index f93651982..7edcacebd 100644
--- a/weed/storage/volume.go
+++ b/weed/storage/volume.go
@@ -30,7 +30,7 @@ type Volume struct {
 
 	SuperBlock
 
-	dataFileAccessLock    sync.Mutex
+	dataFileAccessLock    sync.RWMutex
 	lastModifiedTsSeconds uint64 //unix time in seconds
 	lastAppendAtNs        uint64 //unix time in nanoseconds
 
@@ -72,8 +72,8 @@ func (v *Volume) Version() needle.Version {
 }
 
 func (v *Volume) FileStat() (datSize uint64, idxSize uint64, modTime time.Time) {
-	v.dataFileAccessLock.Lock()
-	defer v.dataFileAccessLock.Unlock()
+	v.dataFileAccessLock.RLock()
+	defer v.dataFileAccessLock.RUnlock()
 
 	if v.DataBackend == nil {
 		return
@@ -88,8 +88,8 @@ func (v *Volume) FileStat() (datSize uint64, idxSize uint64, modTime time.Time)
 }
 
 func (v *Volume) ContentSize() uint64 {
-	v.dataFileAccessLock.Lock()
-	defer v.dataFileAccessLock.Unlock()
+	v.dataFileAccessLock.RLock()
+	defer v.dataFileAccessLock.RUnlock()
 	if v.nm == nil {
 		return 0
 	}
@@ -97,8 +97,8 @@ func (v *Volume) ContentSize() uint64 {
 }
 
 func (v *Volume) DeletedSize() uint64 {
-	v.dataFileAccessLock.Lock()
-	defer v.dataFileAccessLock.Unlock()
+	v.dataFileAccessLock.RLock()
+	defer v.dataFileAccessLock.RUnlock()
 	if v.nm == nil {
 		return 0
 	}
@@ -106,8 +106,8 @@ func (v *Volume) DeletedSize() uint64 {
 }
 
 func (v *Volume) FileCount() uint64 {
-	v.dataFileAccessLock.Lock()
-	defer v.dataFileAccessLock.Unlock()
+	v.dataFileAccessLock.RLock()
+	defer v.dataFileAccessLock.RUnlock()
 	if v.nm == nil {
 		return 0
 	}
@@ -115,8 +115,8 @@ func (v *Volume) FileCount() uint64 {
 }
 
 func (v *Volume) DeletedCount() uint64 {
-	v.dataFileAccessLock.Lock()
-	defer v.dataFileAccessLock.Unlock()
+	v.dataFileAccessLock.RLock()
+	defer v.dataFileAccessLock.RUnlock()
 	if v.nm == nil {
 		return 0
 	}
@@ -124,8 +124,8 @@ func (v *Volume) DeletedCount() uint64 {
 }
 
 func (v *Volume) MaxFileKey() types.NeedleId {
-	v.dataFileAccessLock.Lock()
-	defer v.dataFileAccessLock.Unlock()
+	v.dataFileAccessLock.RLock()
+	defer v.dataFileAccessLock.RUnlock()
 	if v.nm == nil {
 		return 0
 	}
@@ -133,8 +133,8 @@ func (v *Volume) MaxFileKey() types.NeedleId {
 }
 
 func (v *Volume) IndexFileSize() uint64 {
-	v.dataFileAccessLock.Lock()
-	defer v.dataFileAccessLock.Unlock()
+	v.dataFileAccessLock.RLock()
+	defer v.dataFileAccessLock.RUnlock()
 	if v.nm == nil {
 		return 0
 	}
diff --git a/weed/storage/volume_backup.go b/weed/storage/volume_backup.go
index fe0506917..efe1345c6 100644
--- a/weed/storage/volume_backup.go
+++ b/weed/storage/volume_backup.go
@@ -15,8 +15,8 @@ import (
 )
 
 func (v *Volume) GetVolumeSyncStatus() *volume_server_pb.VolumeSyncStatusResponse {
-	v.dataFileAccessLock.Lock()
-	defer v.dataFileAccessLock.Unlock()
+	v.dataFileAccessLock.RLock()
+	defer v.dataFileAccessLock.RUnlock()
 
 	var syncStatus = &volume_server_pb.VolumeSyncStatusResponse{}
 	if datSize, _, err := v.DataBackend.GetStat(); err == nil {
diff --git a/weed/storage/volume_read_write.go b/weed/storage/volume_read_write.go
index c1758c18b..f5cdd0944 100644
--- a/weed/storage/volume_read_write.go
+++ b/weed/storage/volume_read_write.go
@@ -136,8 +136,8 @@ func (v *Volume) deleteNeedle(n *needle.Needle) (uint32, error) {
 
 // read fills in Needle content by looking up n.Id from NeedleMapper
 func (v *Volume) readNeedle(n *needle.Needle) (int, error) {
-	v.dataFileAccessLock.Lock()
-	defer v.dataFileAccessLock.Unlock()
+	v.dataFileAccessLock.RLock()
+	defer v.dataFileAccessLock.RUnlock()
 
 	nv, ok := v.nm.Get(n.Id)
 	if !ok || nv.Offset.IsZero() {