BUG#11753923-SQL THREAD CRASHES ON DISK FULL

Problem:If Disk becomes full while writing into the binlog,
then the server instance hangs till someone frees the space.
After user frees up the disk space, mysql server crashes
with an assert (m_status != DA_EMPTY)

Analysis: wait_for_free_space is being called in an
infinite loop i.e., server instance will hang until
someone frees up the space. So there is no need to
set status bit in diagnostic area.

Fix: Replace my_error/my_printf_error with
sql_print_warning() which prints the warning in error log.

include/my_sys.h:
  Provision to call sql_print_warning from mysys files
mysys/errors.c:
  Replace my_error/my_printf_error with
  sql_print_warning() which prints the warning in error log.
mysys/my_error.c:
  implementation of my_printf_warning
mysys/my_write.c:
  Adding logic to break infinite loop in the simulation
sql/mysqld.cc:
  Provision to call sql_print_warning from mysys files

3 files changed, 44 insertions, 6 deletions

diff --git a/mysys/errors.c b/mysys/errors.c
index 4e93f872a55..1199df2f2be 100644
--- a/mysys/errors.c
+++ b/mysys/errors.c
@@ -101,16 +101,28 @@ void init_glob_errs()
 }
 #endif
 
+/*
+ We cannot call my_error/my_printf_error here in this function.
+  Those functions will set status variable in diagnostic area
+  and there is no provision to reset them back.
+  Here we are waiting for free space and will wait forever till
+  space is created. So just giving warning in the error file
+  should be enough.
+*/
 void wait_for_free_space(const char *filename, int errors)
 {
-  if (errors == 0)
-    my_error(EE_DISK_FULL,MYF(ME_BELL | ME_NOREFRESH),
-             filename,my_errno,MY_WAIT_FOR_USER_TO_FIX_PANIC);
   if (!(errors % MY_WAIT_GIVE_USER_A_MESSAGE))
-    my_printf_error(EE_DISK_FULL,
-                    "Retry in %d secs. Message reprinted in %d secs",
-                    MYF(ME_BELL | ME_NOREFRESH),
+  {
+    my_printf_warning(EE(EE_DISK_FULL),
+             filename,my_errno,MY_WAIT_FOR_USER_TO_FIX_PANIC);
+    my_printf_warning("Retry in %d secs. Message reprinted in %d secs",
                     MY_WAIT_FOR_USER_TO_FIX_PANIC,
                     MY_WAIT_GIVE_USER_A_MESSAGE * MY_WAIT_FOR_USER_TO_FIX_PANIC );
+  }
+  DBUG_EXECUTE_IF("simulate_file_write_error_once",
+                 {
+                   VOID(sleep(1));
+                   return;
+                 });
   VOID(sleep(MY_WAIT_FOR_USER_TO_FIX_PANIC));
 }
diff --git a/mysys/my_error.c b/mysys/my_error.c
index 20d8438a712..5167598bfae 100644
--- a/mysys/my_error.c
+++ b/mysys/my_error.c
@@ -129,6 +129,28 @@ int my_printf_error(uint error, const char *format, myf MyFlags, ...)
 }
 
 /*
+  Warning as printf
+
+  SYNOPSIS
+    my_printf_warning()
+      format>   Format string
+      ...>      variable list
+*/
+void(*sql_print_warning_hook)(const char *format,...);
+void my_printf_warning(const char *format, ...)
+{
+  va_list args;
+  char wbuff[ERRMSGSIZE];
+  DBUG_ENTER("my_printf_warning");
+  DBUG_PRINT("my", ("Format: %s", format));
+  va_start(args,format);
+  (void) my_vsnprintf (wbuff, sizeof(wbuff), format, args);
+  va_end(args);
+  (*sql_print_warning_hook)(wbuff);
+  DBUG_VOID_RETURN;
+}
+
+/*
   Give message using error_handler_hook
 
   SYNOPSIS
diff --git a/mysys/my_write.c b/mysys/my_write.c
index b545ab776b0..d0a59a605b6 100644
--- a/mysys/my_write.c
+++ b/mysys/my_write.c
@@ -36,6 +36,8 @@ size_t my_write(int Filedes, const uchar *Buffer, size_t Count, myf MyFlags)
   if (unlikely(!Count))
     DBUG_RETURN(0);
   
+  DBUG_EXECUTE_IF ("simulate_file_write_error_once",
+                   { DBUG_SET("+d,simulate_file_write_error");});
   for (;;)
   {
     writenbytes= write(Filedes, Buffer, Count);
@@ -69,6 +71,8 @@ size_t my_write(int Filedes, const uchar *Buffer, size_t Count, myf MyFlags)
     {
       wait_for_free_space(my_filename(Filedes), errors);
       errors++;
+      DBUG_EXECUTE_IF("simulate_file_write_error_once",
+                      { DBUG_SET("-d,simulate_file_write_error");});
       continue;
     }