From 9155311648dfbcd2c5688dc8d06031a3b9b8e82b Mon Sep 17 00:00:00 2001
From: Dattaprasad Govekar <dattaprasad.govekar@seagate.com>
Date: Tue, 16 Aug 2022 18:51:45 +0530
Subject: [PATCH] motr_gc: [CORTX-32689] Validate GC for simple object delete
 API (#393)

- Fix issues in locking mechanism.

Signed-off-by: Dattaprasad Govekar <dattaprasad.govekar@seagate.com>

Signed-off-by: Dattaprasad Govekar <dattaprasad.govekar@seagate.com>
---
 src/rgw/motr/gc/gc.cc               | 12 ++++++++++--
 src/rgw/motr/sync/motr_sync_impl.cc |  9 +++++++--
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/src/rgw/motr/gc/gc.cc b/src/rgw/motr/gc/gc.cc
index 576c4ede41c4e..20f4251e268e9 100644
--- a/src/rgw/motr/gc/gc.cc
+++ b/src/rgw/motr/gc/gc.cc
@@ -136,6 +136,7 @@ int MotrGC::initialize() {
       ldout(cct, 0) << "ERROR: GC index creation failed with rc: " << rc << dendl;
       break;
     }
+    if (rc == -EEXIST) rc = 0;
     index_names.push_back(iname);
   }
   // Get the max count of objects to be deleted in 1 processing cycle
@@ -356,19 +357,26 @@ int MotrGC::get_locked_gc_index(uint32_t& rand_ind,
                                 uint32_t& lease_duration) {
   int rc = -1;
   uint32_t new_index = 0;
+  std::shared_ptr<MotrSync>& gc_lock = get_lock_instance();
+
   // attempt to lock GC starting with passed in index
   for (uint32_t ind = 0; ind < max_indices; ind++) {
     new_index = (ind + rand_ind) % max_indices;
-    // try locking index
-    std::shared_ptr<MotrSync>& gc_lock = get_lock_instance();
     if (gc_lock) {
       std::chrono::milliseconds lease_timeout{lease_duration * 1000};
       auto tv = ceph::to_timeval(lease_timeout);
       utime_t gc_lease_duration;
       gc_lease_duration.set_from_timeval(&tv);
       std::string iname = index_names[new_index];
+      // try locking index
       rc = gc_lock->lock(iname, MotrLockType::EXCLUSIVE,
                          gc_lease_duration, caller_id);
+      if (rc < 0) {
+        ldout(cct, 10) << "Failed to acquire lock: GC Queue =["<< iname << "]" 
+          << "caller_id =[" << caller_id << "]" << "rc = " << rc << dendl;
+      } else {
+        ldout(cct, 10) << "Acquired lock for GC Queue =["<<  iname << "]" << dendl;
+      }
     }
     if (rc == 0)
       break;
diff --git a/src/rgw/motr/sync/motr_sync_impl.cc b/src/rgw/motr/sync/motr_sync_impl.cc
index 831f6c7a11b4e..67e18f96f6844 100644
--- a/src/rgw/motr/sync/motr_sync_impl.cc
+++ b/src/rgw/motr/sync/motr_sync_impl.cc
@@ -89,13 +89,16 @@ int MotrLock::unlock(const std::string& lock_name,
 int MotrKVLockProvider::initialize(const DoutPrefixProvider* dpp,
                                    rgw::sal::MotrStore* _s,
                                    const std::string& lock_index_name) {
+  int rc = 0;
   _dpp = dpp;
   _store = _s;
   _lock_index = lock_index_name;
   if (!_store || lock_index_name.empty()) {
     return -EINVAL;
   }
-  return _store->create_motr_idx_by_name(lock_index_name);
+  rc = _store->create_motr_idx_by_name(lock_index_name);
+  if (rc == -EEXIST) rc = 0;
+  return rc;  
 }
 
 int MotrLock::check_lock(const std::string& lock_name,
@@ -193,7 +196,9 @@ std::shared_ptr<MotrSync> g_motr_lock;
 std::shared_ptr<MotrSync>& get_lock_instance(
     std::unique_ptr<MotrLockProvider>& lock_provider) {
   static bool initialize = false;
-  if (!initialize && !lock_provider) {
+  std::mutex lock;
+  std::lock_guard l(lock);
+  if (!initialize && lock_provider) {
     g_motr_lock = std::make_shared<MotrLock>();
     g_motr_lock->initialize(lock_provider);
     initialize = true;