fixup: do not generate keys with the same lsn

Author: dutow

contrib/pg_tde/src/access/pg_tde_xlog_smgr.c

@@ -267,7 +267,7 @@ TDEXLogSmgrInitWrite(bool encrypt_xlog)
 	if(keys == NULL)
 	{
 		/* TODO cache is empty, try to preread keys from disk */
-		//keys = pg_tde_fetch_wal_keys(start);
+		keys = pg_tde_fetch_wal_keys(start);
 	}
 
 	elog(WARNING, "keyloading %p", keys);
@@ -362,9 +362,9 @@ tdeheap_xlog_seg_write(int fd, const void *buf, size_t count, off_t offset,
 					   TimeLineID tli, XLogSegNo segno, int segSize)
 {
 	#ifdef FRONTEND
-	bool recoveryInProgress = false;
+	bool crashRecovery = false;
 	#else
-	bool recoveryInProgress = RecoveryInProgress();
+	bool crashRecovery = GetRecoveryState() == RECOVERY_STATE_CRASH;
 	#endif
 
 	WalLocation loc = {.tli = tli};
@@ -384,27 +384,15 @@ tdeheap_xlog_seg_write(int fd, const void *buf, size_t count, off_t offset,
 
 	if (EncryptionKey.type != WAL_KEY_TYPE_INVALID && !lastKeyUsable)
 	{
-		if(!recoveryInProgress || EncryptionKey.type == WAL_KEY_TYPE_UNENCRYPTED) {
-			// TODO: detect if we have conflicting later keys in case of unencrypted, and error out
-		pg_tde_wal_last_key_set_location(loc);
-		EncryptionKey.wal_start = loc;
-		TDEXLogSetEncKeyLocation(EncryptionKey.wal_start);
-		lastKeyUsable = true;
-		elog(WARNING, "Keyset1");
-		} else {
-			#ifndef FRONTEND
-			WALKeyCacheRec *last_key = pg_tde_get_last_wal_key();
-			if(last_key && GetRecoveryState() != RECOVERY_STATE_CRASH) {
-				if (last_key->start.lsn < loc.lsn) {
-					elog(WARNING, "Keyset2");
-					// If we progressed at least one more page, it is safe to switch keys
-					pg_tde_wal_last_key_set_location(loc);
-					EncryptionKey.wal_start = loc;
-					TDEXLogSetEncKeyLocation(EncryptionKey.wal_start);
-					lastKeyUsable = true;
-				}
+		WALKeyCacheRec *last_key = pg_tde_get_last_wal_key();
+		if(!crashRecovery || EncryptionKey.type == WAL_KEY_TYPE_UNENCRYPTED) {
+			if (last_key == NULL || last_key->start.lsn < loc.lsn) {
+				elog(WARNING, "Keyset2");
+				pg_tde_wal_last_key_set_location(loc);
+				EncryptionKey.wal_start = loc;
+				TDEXLogSetEncKeyLocation(EncryptionKey.wal_start);
+				lastKeyUsable = true;
 			}
-			#endif
 		}
 	}
 
@@ -454,12 +442,14 @@ TDEXLogCryptBuffer(const void *buf, void *out_buf, size_t count, off_t offset,
 	WalLocation data_end = {.tli = tli};
 	WalLocation data_start = {.tli = tli};
 
-	if (!keys)
+	if (keys == NULL)
 	{
 		WalLocation start = {.tli = 1,.lsn = 0};
 
 		/* cache is empty, try to read keys from disk */
-		keys = pg_tde_fetch_wal_keys(start);
+		pg_tde_fetch_wal_keys(start);
+
+		keys = pg_tde_get_wal_cache_keys();
 	}
 
 	/*