MDEV-37520 Failure to detect corruption during backups of Aria table

Fixed the following issues:
- aria_read_index() and aria_read_data(), used by mariabackup, checked
  the wrong status from maria_page_crc_check().
- Both functions did infinite retries if crc did not match.
- Wrong usage of ma_check_if_zero() in maria_page_crc_check()

Author: Thirunarayanan Balathandayuthapani <thiru@mariadb.com>

Author: montywi

extra/mariabackup/aria_backup_client.cc

@@ -399,21 +399,19 @@ bool Table::copy(ds_ctxt_t *ds, bool is_index, unsigned thread_num) {
 
 		for (ulonglong block= 0 ; ; block++) {
 			size_t length = m_cap.block_size;
-			if (is_index) {
-				if ((error= aria_read_index(
-							partition.m_index_file, &m_cap, block, copy_buffer) ==
-							HA_ERR_END_OF_FILE))
-					break;
-			} else {
-				if ((error= aria_read_data(
-							partition.m_data_file, &m_cap, block, copy_buffer, &length) ==
-							HA_ERR_END_OF_FILE))
-					break;
-			}
-			if (error) {
-				msg(thread_num, "error: aria_read %s failed:  %d",
-					is_index ? "index" : "data", error);
-				goto err;
+			if (is_index)
+                          error= aria_read_index(partition.m_index_file, &m_cap,
+                                                       block, copy_buffer);
+                        else
+                          error= aria_read_data(partition.m_data_file, &m_cap,
+                                                block, copy_buffer, &length);
+			if (error)
+                        {
+                          if (error == HA_ERR_END_OF_FILE)
+                            break;
+                          msg(thread_num, "error: aria_read %s failed:  %d",
+                              is_index ? "index" : "data", error);
+                          goto err;
 			}
 			xtrabackup_io_throttling();
 			if ((error = ds_write(dst_file, copy_buffer, length))) {

mysql-test/suite/mariabackup/aria_log_rotate_during_backup.test

@@ -34,11 +34,11 @@ CREATE TABLE test.t1(id INT, txt LONGTEXT) ENGINE=Aria;
 --source include/aria_log_control_load.inc
 CALL display_aria_log_control(@aria_log_control);
 
-
+let $backuplog= $MYSQLTEST_VARDIR/tmp/backup.log;
 --echo # Running --backup
 --let after_scanning_log_files=CALL test.populate_t1
 --disable_result_log
---exec $XTRABACKUP --defaults-file=$MYSQLTEST_VARDIR/my.cnf  --backup --parallel=10  --target-dir=$targetdir  --dbug=+d,mariabackup_events 2>&1
+--exec $XTRABACKUP --defaults-file=$MYSQLTEST_VARDIR/my.cnf  --backup --target-dir=$targetdir  --dbug=+d,mariabackup_events > $backuplog
 --let after_scanning_log_files=
 --enable_result_log
 
@@ -77,6 +77,7 @@ CALL display_aria_log_control(@aria_log_control);
 SELECT id, LENGTH(txt) FROM t1 ORDER BY id;
 DROP TABLE t1;
 rmdir $targetdir;
+remove_file $backuplog;
 
 DROP PROCEDURE populate_t1;
 DROP PROCEDURE display_aria_log_control;

storage/maria/ma_backup.c

@@ -202,11 +202,11 @@ int aria_read_index(File kfile, ARIA_TABLE_CAPABILITIES *cap, ulonglong block,
       error= maria_page_crc_check(buffer, block, &share,
                                   MARIA_NO_CRC_NORMAL_PAGE,
                                   (int) length);
-      if (error != HA_ERR_WRONG_CRC)
+      if (error == 0 || my_errno != HA_ERR_WRONG_CRC)
         DBUG_RETURN(error);
     }
     my_sleep(100000);                              /* Sleep 0.1 seconds */
-  } while (retry < MAX_RETRY);
+  } while (retry++ < MAX_RETRY);
   DBUG_RETURN(HA_ERR_WRONG_CRC);
 }
 
@@ -264,15 +264,18 @@ int aria_read_data(File dfile, ARIA_TABLE_CAPABILITIES *cap, ulonglong block,
 
     if (length == cap->block_size)
     {
-      error= maria_page_crc_check(buffer, block, &share,
+      if (!_ma_check_if_zero(buffer, share.block_size - CRC_SIZE))
+       error= 0;
+      else
+        error= maria_page_crc_check(buffer, block, &share,
                                   ((block % cap->bitmap_pages_covered) == 0 ?
                                    MARIA_NO_CRC_BITMAP_PAGE :
                                    MARIA_NO_CRC_NORMAL_PAGE),
                                   share.block_size - CRC_SIZE);
-      if (error != HA_ERR_WRONG_CRC)
+     if (error == 0 || my_errno != HA_ERR_WRONG_CRC)
         DBUG_RETURN(error);
     }
     my_sleep(100000);                              /* Sleep 0.1 seconds */
-  } while (retry < MAX_RETRY);
+  } while (retry++ < MAX_RETRY);
     DBUG_RETURN(HA_ERR_WRONG_CRC);
 }

storage/maria/ma_pagecrc.c

@@ -103,7 +103,7 @@ my_bool maria_page_crc_check(uchar *page,
       the CRC will be corrected at next write)
     */
     if (no_crc_val == MARIA_NO_CRC_BITMAP_PAGE &&
-        crc == 0 && _ma_check_if_zero(page, data_length))
+        crc == 0 && !_ma_check_if_zero(page, data_length))
     {
       DBUG_PRINT("warning", ("Found bitmap page that was not initialized"));
       DBUG_RETURN(0);