check is data_checksums are enabled in postgres instance

Author: alubennikova

src/backup.c

@@ -52,6 +52,7 @@ static pthread_mutex_t start_stream_mut = PTHREAD_MUTEX_INITIALIZER;
 static pthread_t stream_thread;
 
 static int is_ptrack_enable = false;
+bool is_checksum_enabled = false;
 
 /* Backup connections */
 static PGconn *backup_conn = NULL;
@@ -108,6 +109,7 @@ static void	remote_copy_file(PGconn *conn, pgFile* file);
 static void pg_ptrack_clear(void);
 static bool pg_ptrack_support(void);
 static bool pg_ptrack_enable(void);
+static bool pg_checksum_enable(void);
 static bool pg_is_in_recovery(void);
 static bool pg_ptrack_get_and_clear_db(Oid dbOid, Oid tblspcOid);
 static char *pg_ptrack_get_and_clear(Oid tablespace_oid,
@@ -772,6 +774,9 @@ do_backup(time_t start_time)
 	/* TODO fix it for remote backup*/
 	if (!is_remote_backup)
 		current.checksum_version = get_data_checksum_version(true);
+
+	is_checksum_enabled = pg_checksum_enable();
+	
 	StrNCpy(current.server_version, server_version_str,
 			sizeof(current.server_version));
 	current.stream = stream_wal;
@@ -1094,6 +1099,23 @@ pg_ptrack_enable(void)
 	return true;
 }
 
+/* Check if ptrack is enabled in target instance */
+static bool
+pg_checksum_enable(void)
+{
+	PGresult   *res_db;
+
+	res_db = pgut_execute(backup_conn, "show data_checksums", 0, NULL, true);
+
+	if (strcmp(PQgetvalue(res_db, 0, 0), "on") != 0)
+	{
+		PQclear(res_db);
+		return false;
+	}
+	PQclear(res_db);
+	return true;
+}
+
 /* Check if target instance is replica */
 static bool
 pg_is_in_recovery(void)
@@ -2683,31 +2705,6 @@ pg_ptrack_get_block(Oid dbOid,
 	params[2] = palloc(64);
 	params[3] = palloc(64);
 
-// 	sprintf(params[0], "%i", dbOid);
-// 	res_db = pgut_execute(backup_conn,
-// 							"SELECT datname FROM pg_database WHERE oid=$1",
-// 							1, (const char **) params, true);
-// 	/*
-// 	 * If database is not found, it's not an error.
-// 	 * It could have been deleted.
-// 	 */
-// 	if (PQntuples(res_db) != 1 || PQnfields(res_db) != 1)
-// 	{
-// 		//elog(LOG, "Database with oid %d is not found", dbOid);
-// 		return NULL;
-// 	}
-// 
-// 	dbname = PQgetvalue(res_db, 0, 0);
-// 	if (strcmp(dbname, "template0") == 0)
-// 	{
-// 		/*
-// 		 * There is no way to connect to the template0 database.
-// 		 * But it's totally OK, since files there can never be changed.
-// 		 */
-// 		return NULL;
-// 	}
-// 	tmp_conn = pgut_connect(dbname);
-
 	/*
 	 * Use backup_conn, cause we can do it from any database.
 	 */
@@ -2739,9 +2736,6 @@ pg_ptrack_get_block(Oid dbOid,
 	result = (char *) PQunescapeBytea((unsigned char *) PQgetvalue(res, 0, 0),
 									  result_size);
 
-// 	pgut_disconnect(tmp_conn);
-// 	PQclear(res_db);
-
 	PQclear(res);
 	pfree(params[0]);
 	pfree(params[1]);

src/data.c

@@ -190,7 +190,7 @@ read_page_from_file(pgFile *file, BlockNumber blknum,
 	}
 
 	/* Verify checksum */
-	if(current.checksum_version)
+	if(current.checksum_version && is_checksum_enabled)
 	{
 		/*
 		 * If checksum is wrong, sleep a bit and then try again
@@ -269,8 +269,7 @@ backup_data_page(pgFile *file, XLogRecPtr prev_backup_start_lsn,
 		}
 	}
 
-	if ((!page_is_valid)
-		 || (backup_mode == BACKUP_MODE_DIFF_PTRACK))
+	if (backup_mode == BACKUP_MODE_DIFF_PTRACK)
 	{
 		size_t page_size = 0;
 		PageHeader phdr = (PageHeader) page;
@@ -298,7 +297,8 @@ backup_data_page(pgFile *file, XLogRecPtr prev_backup_start_lsn,
 			 * We must set checksum here, because it is outdated
 			 * in the block recieved from shared buffers.
 			 */
-			((PageHeader) page)->pd_checksum = pg_checksum_page(page, absolute_blknum);
+			if (is_checksum_enabled)
+				((PageHeader) page)->pd_checksum = pg_checksum_page(page, absolute_blknum);
 		}
 	}
 

src/pg_probackup.h

@@ -283,6 +283,8 @@ extern const char *master_port;
 extern const char *master_user;
 extern uint32	replica_timeout;
 
+extern bool is_checksum_enabled;
+
 /* delete options */
 extern bool		delete_wal;
 extern bool		delete_expired;