Hotfix 2487 (#2892)

* update.
Signed-off-by: NTinkerrr <linxiaojun.cn@outlook.com>

* update.
Signed-off-by: NTinkerrr <xiaojun.lin@zilliz.com>

* add fd check
Signed-off-by: NTinkerrr <xiaojun.lin@zilliz.com>

* fix
Signed-off-by: NTinkerrr <xiaojun.lin@zilliz.com>

CHANGELOG.md

@@ -23,6 +23,7 @@ Please mark all change in change log and use the issue from GitHub
 -   \#2774 Server down during loading data
 -   \#2776 Fix too many data copies during creating IVF index
 -   \#2813 To implemente RNSG IP
+-   \#2487 HotFix release lock failed on NAS
 
 ## Feature
 

core/src/server/init/InstanceLockCheck.cpp

@@ -23,6 +23,12 @@
 namespace milvus {
 namespace server {
 
+InstanceLockCheck*
+InstanceLockCheck::GetInstance() {
+    static InstanceLockCheck lk;
+    return &lk;
+}
+
 Status
 InstanceLockCheck::Check(const std::string& path) {
     std::string lock_path = path + "/lock";
@@ -37,6 +43,7 @@ InstanceLockCheck::Check(const std::string& path) {
         msg += "Could not open file: " + lock_path + ", " + strerror(errno);
         return Status(SERVER_UNEXPECTED_ERROR, msg);
     }
+    InstanceLockCheck::GetInstance()->lk_path = lock_path;
 
     // Acquire a write lock
     struct flock fl;
@@ -66,5 +73,21 @@ InstanceLockCheck::Check(const std::string& path) {
     return Status::OK();
 }
 
+void
+InstanceLockCheck::Release() {
+    auto fd = open(InstanceLockCheck::GetInstance()->lk_path.c_str(), O_RDWR | O_CREAT | O_NOFOLLOW, 0640);
+    if (fd < 0) {
+        std::string msg;
+        if (errno == EROFS) {
+            // Not using locking for read-only lock file
+            msg += "Lock file is read-only.";
+        }
+        msg += "Could not open file for release: " + InstanceLockCheck::GetInstance()->lk_path + ", " + strerror(errno);
+        LOG_SERVER_ERROR_ << msg;
+        return;
+    }
+    close(fd);
+}
+
 }  // namespace server
 }  // namespace milvus

core/src/server/init/InstanceLockCheck.h

@@ -21,6 +21,15 @@ class InstanceLockCheck {
  public:
     static Status
     Check(const std::string& path);
+
+    static void
+    Release();
+
+    static InstanceLockCheck*
+    GetInstance();
+
+ public:
+    std::string lk_path;
 };  // InstanceLockCheck
 
 }  // namespace server

core/src/utils/SignalUtil.cpp

@@ -11,6 +11,7 @@
 
 #include "utils/SignalUtil.h"
 #include "src/server/Server.h"
+#include "src/server/init/InstanceLockCheck.h"
 #include "utils/Log.h"
 
 #include <execinfo.h>
@@ -22,6 +23,8 @@ namespace server {
 
 void
 SignalUtil::HandleSignal(int signum) {
+    InstanceLockCheck::Release();
+    LOG_SERVER_INFO_ << "Release lock!" << signum;
     switch (signum) {
         case SIGINT:
         case SIGUSR2: {