From 4074565a6b8197e153a6a3c29c46854c160c5e03 Mon Sep 17 00:00:00 2001
From: "A.Unger" <zyxancf@gmail.com>
Date: Thu, 30 Jul 2020 10:06:29 +0200
Subject: [PATCH 1/2] use global mutex

---
 pkg/service/v0/accounts.go | 9 +++++----
 pkg/service/v0/groups.go   | 7 ++-----
 2 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/pkg/service/v0/accounts.go b/pkg/service/v0/accounts.go
index 6a3e8ec..f8a8f28 100644
--- a/pkg/service/v0/accounts.go
+++ b/pkg/service/v0/accounts.go
@@ -32,6 +32,9 @@ import (
 	_ "github.com/tredoe/osutil/user/crypt/sha512_crypt"
 )
 
+// M synchronizes access to account files to readers and writers
+var M sync.RWMutex
+
 func (s Service) indexAccounts(path string) (err error) {
 	var f *os.File
 	if f, err = os.Open(path); err != nil {
@@ -85,8 +88,6 @@ func (s Service) loadAccount(id string, a *proto.Account) (err error) {
 	return
 }
 
-var accountMutex sync.Mutex
-
 func (s Service) writeAccount(a *proto.Account) (err error) {
 
 	// leave only the group id
@@ -99,8 +100,8 @@ func (s Service) writeAccount(a *proto.Account) (err error) {
 
 	path := filepath.Join(s.Config.Server.AccountsDataPath, "accounts", a.Id)
 
-	accountMutex.Lock()
-	defer accountMutex.Unlock()
+	M.Lock()
+	defer M.Unlock()
 	if err = ioutil.WriteFile(path, bytes, 0600); err != nil {
 		return merrors.InternalServerError(s.id, "could not write account: %v", err.Error())
 	}
diff --git a/pkg/service/v0/groups.go b/pkg/service/v0/groups.go
index 150dc7d..5d8b887 100644
--- a/pkg/service/v0/groups.go
+++ b/pkg/service/v0/groups.go
@@ -6,7 +6,6 @@ import (
 	"io/ioutil"
 	"os"
 	"path/filepath"
-	"sync"
 
 	"github.com/CiscoM31/godata"
 	"github.com/blevesearch/bleve"
@@ -67,8 +66,6 @@ func (s Service) loadGroup(id string, g *proto.Group) (err error) {
 	return
 }
 
-var groupMutex sync.Mutex
-
 func (s Service) writeGroup(g *proto.Group) (err error) {
 
 	// leave only the member id
@@ -81,8 +78,8 @@ func (s Service) writeGroup(g *proto.Group) (err error) {
 
 	path := filepath.Join(s.Config.Server.AccountsDataPath, "groups", g.Id)
 
-	groupMutex.Lock()
-	defer groupMutex.Unlock()
+	M.Lock()
+	defer M.Unlock()
 	if err = ioutil.WriteFile(path, bytes, 0600); err != nil {
 		return merrors.InternalServerError(s.id, "could not write group: %v", err.Error())
 	}

From c432f296ebbebf4c23ae80c4fac1d25baef29414 Mon Sep 17 00:00:00 2001
From: "A.Unger" <zyxancf@gmail.com>
Date: Thu, 30 Jul 2020 10:10:52 +0200
Subject: [PATCH 2/2] set lock on read

---
 pkg/service/v0/accounts.go | 11 +++++++----
 pkg/service/v0/groups.go   | 10 ++++++++--
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/pkg/service/v0/accounts.go b/pkg/service/v0/accounts.go
index f8a8f28..18d0429 100644
--- a/pkg/service/v0/accounts.go
+++ b/pkg/service/v0/accounts.go
@@ -32,8 +32,8 @@ import (
 	_ "github.com/tredoe/osutil/user/crypt/sha512_crypt"
 )
 
-// M synchronizes access to account files to readers and writers
-var M sync.RWMutex
+// accLock mutually exclude readers from writers on account files
+var accLock sync.RWMutex
 
 func (s Service) indexAccounts(path string) (err error) {
 	var f *os.File
@@ -77,6 +77,9 @@ var authQuery = regexp.MustCompile(`^login eq '(.*)' and password eq '(.*)'$`) /
 func (s Service) loadAccount(id string, a *proto.Account) (err error) {
 	path := filepath.Join(s.Config.Server.AccountsDataPath, "accounts", id)
 
+	accLock.Lock()
+	defer accLock.Unlock()
+
 	var data []byte
 	if data, err = ioutil.ReadFile(path); err != nil {
 		return merrors.NotFound(s.id, "could not read account: %v", err.Error())
@@ -100,8 +103,8 @@ func (s Service) writeAccount(a *proto.Account) (err error) {
 
 	path := filepath.Join(s.Config.Server.AccountsDataPath, "accounts", a.Id)
 
-	M.Lock()
-	defer M.Unlock()
+	accLock.Lock()
+	defer accLock.Unlock()
 	if err = ioutil.WriteFile(path, bytes, 0600); err != nil {
 		return merrors.InternalServerError(s.id, "could not write account: %v", err.Error())
 	}
diff --git a/pkg/service/v0/groups.go b/pkg/service/v0/groups.go
index 5d8b887..63ca4a0 100644
--- a/pkg/service/v0/groups.go
+++ b/pkg/service/v0/groups.go
@@ -6,6 +6,7 @@ import (
 	"io/ioutil"
 	"os"
 	"path/filepath"
+	"sync"
 
 	"github.com/CiscoM31/godata"
 	"github.com/blevesearch/bleve"
@@ -35,6 +36,9 @@ func (s Service) indexGroups(path string) (err error) {
 	return
 }
 
+// accLock mutually exclude readers from writers on group files
+var groupLock sync.RWMutex
+
 func (s Service) indexGroup(id string) error {
 	g := &proto.BleveGroup{
 		BleveType: "group",
@@ -54,6 +58,8 @@ func (s Service) indexGroup(id string) error {
 func (s Service) loadGroup(id string, g *proto.Group) (err error) {
 	path := filepath.Join(s.Config.Server.AccountsDataPath, "groups", id)
 
+	groupLock.Lock()
+	defer groupLock.Unlock()
 	var data []byte
 	if data, err = ioutil.ReadFile(path); err != nil {
 		return merrors.NotFound(s.id, "could not read group: %v", err.Error())
@@ -78,8 +84,8 @@ func (s Service) writeGroup(g *proto.Group) (err error) {
 
 	path := filepath.Join(s.Config.Server.AccountsDataPath, "groups", g.Id)
 
-	M.Lock()
-	defer M.Unlock()
+	groupLock.Lock()
+	defer groupLock.Unlock()
 	if err = ioutil.WriteFile(path, bytes, 0600); err != nil {
 		return merrors.InternalServerError(s.id, "could not write group: %v", err.Error())
 	}