MDEV-17845 Extreme high open file limit used

SHOW STATUS LIKE 'Open_files' was showing 18446744073709551615

my_file_opened used statistic_increment/statistic_decrement,
so one-off errors were normal and expected. But they confused
monitoring tools, so let's move my_file_opened to use atomics.

1 files changed, 3 insertions, 6 deletions

diff --git a/mysys/my_open.c b/mysys/my_open.c
index 92e46610100..aa3b0448cdb 100644
--- a/mysys/my_open.c
+++ b/mysys/my_open.c
@@ -105,7 +105,7 @@ int my_close(File fd, myf MyFlags)
   {
     my_free(name);
   }
-  statistic_decrement(my_file_opened, &THR_LOCK_open);
+  thread_safe_decrement32(&my_file_opened);
   DBUG_RETURN(err);
 } /* my_close */
 
@@ -133,13 +133,10 @@ File my_register_filename(File fd, const char *FileName, enum file_type
   DBUG_ENTER("my_register_filename");
   if ((int) fd >= MY_FILE_MIN)
   {
+    thread_safe_increment32(&my_file_opened);
     if ((uint) fd >= my_file_limit)
-    {
-      statistic_increment(my_file_opened,&THR_LOCK_open);
-      DBUG_RETURN(fd);				/* safeguard */
-    }
+      DBUG_RETURN(fd);
     my_file_info[fd].name = (char*) my_strdup(FileName, MyFlags);
-    statistic_increment(my_file_opened,&THR_LOCK_open);
     statistic_increment(my_file_total_opened,&THR_LOCK_open);
     my_file_info[fd].type = type_of_file;
     DBUG_PRINT("exit",("fd: %d",fd));