bugfix: remove my_delete_with_symlink()

it was race condition prone. instead use either a pair of my_delete()
calls with already resolved paths, or a safe high-level function
my_handler_delete_with_symlink(), like MyISAM and Aria already do.

1 files changed, 30 insertions, 27 deletions

diff --git a/storage/maria/ma_create.c b/storage/maria/ma_create.c
index 28c3491730f..3e96ffea335 100644
--- a/storage/maria/ma_create.c
+++ b/storage/maria/ma_create.c
@@ -52,7 +52,8 @@ int maria_create(const char *name, enum data_file_type datafile_type,
        unique_key_parts,fulltext_keys,offset, not_block_record_extra_length;
   uint max_field_lengths, extra_header_size, column_nr;
   ulong reclength, real_reclength,min_pack_length;
-  char filename[FN_REFLEN], linkname[FN_REFLEN], *linkname_ptr;
+  char kfilename[FN_REFLEN], klinkname[FN_REFLEN], *klinkname_ptr;
+  char dfilename[FN_REFLEN], dlinkname[FN_REFLEN], *dlinkname_ptr;
   ulong pack_reclength;
   ulonglong tot_length,max_rows, tmp;
   enum en_fieldtype type;
@@ -805,19 +806,19 @@ int maria_create(const char *name, enum data_file_type datafile_type,
       /* chop off the table name, tempory tables use generated name */
       if ((path= strrchr(ci->index_file_name, FN_LIBCHAR)))
         *path= '\0';
-      fn_format(filename, name, ci->index_file_name, MARIA_NAME_IEXT,
+      fn_format(kfilename, name, ci->index_file_name, MARIA_NAME_IEXT,
                 MY_REPLACE_DIR | MY_UNPACK_FILENAME |
                 MY_RETURN_REAL_PATH | MY_APPEND_EXT);
     }
     else
     {
-      fn_format(filename, ci->index_file_name, "", MARIA_NAME_IEXT,
+      fn_format(kfilename, ci->index_file_name, "", MARIA_NAME_IEXT,
                 MY_UNPACK_FILENAME | MY_RETURN_REAL_PATH |
                 (have_iext ? MY_REPLACE_EXT : MY_APPEND_EXT));
     }
-    fn_format(linkname, name, "", MARIA_NAME_IEXT,
+    fn_format(klinkname, name, "", MARIA_NAME_IEXT,
               MY_UNPACK_FILENAME|MY_APPEND_EXT);
-    linkname_ptr= linkname;
+    klinkname_ptr= klinkname;
     /*
       Don't create the table if the link or file exists to ensure that one
       doesn't accidently destroy another table.
@@ -831,10 +832,10 @@ int maria_create(const char *name, enum data_file_type datafile_type,
   {
     char *iext= strrchr(name, '.');
     int have_iext= iext && !strcmp(iext, MARIA_NAME_IEXT);
-    fn_format(filename, name, "", MARIA_NAME_IEXT,
+    fn_format(kfilename, name, "", MARIA_NAME_IEXT,
               MY_UNPACK_FILENAME | MY_RETURN_REAL_PATH |
               (have_iext ? MY_REPLACE_EXT : MY_APPEND_EXT));
-    linkname_ptr= NullS;
+    klinkname_ptr= NullS;
     /*
       Replace the current file.
       Don't sync dir now if the data file has the same path.
@@ -854,7 +855,7 @@ int maria_create(const char *name, enum data_file_type datafile_type,
     NOTE: The filename is compared against unique_file_name of every
     open table. Hence we need a real path here.
   */
-  if (_ma_test_if_reopen(filename))
+  if (_ma_test_if_reopen(kfilename))
   {
     my_printf_error(HA_ERR_TABLE_EXIST, "Aria table '%s' is in use "
                     "(most likely by a MERGE table). Try FLUSH TABLES.",
@@ -863,8 +864,8 @@ int maria_create(const char *name, enum data_file_type datafile_type,
     goto err;
   }
 
-  if ((file= mysql_file_create_with_symlink(key_file_kfile, linkname_ptr,
-                                            filename, 0, create_mode,
+  if ((file= mysql_file_create_with_symlink(key_file_kfile, klinkname_ptr,
+                                            kfilename, 0, create_mode,
                                             MYF(MY_WME|create_flag))) < 0)
     goto err;
   errpos=1;
@@ -1118,30 +1119,30 @@ int maria_create(const char *name, enum data_file_type datafile_type,
         /* chop off the table name, tempory tables use generated name */
         if ((path= strrchr(ci->data_file_name, FN_LIBCHAR)))
           *path= '\0';
-        fn_format(filename, name, ci->data_file_name, MARIA_NAME_DEXT,
+        fn_format(dfilename, name, ci->data_file_name, MARIA_NAME_DEXT,
                   MY_REPLACE_DIR | MY_UNPACK_FILENAME | MY_APPEND_EXT);
       }
       else
       {
-        fn_format(filename, ci->data_file_name, "", MARIA_NAME_DEXT,
+        fn_format(dfilename, ci->data_file_name, "", MARIA_NAME_DEXT,
                   MY_UNPACK_FILENAME |
                   (have_dext ? MY_REPLACE_EXT : MY_APPEND_EXT));
       }
-      fn_format(linkname, name, "",MARIA_NAME_DEXT,
+      fn_format(dlinkname, name, "",MARIA_NAME_DEXT,
                 MY_UNPACK_FILENAME | MY_APPEND_EXT);
-      linkname_ptr= linkname;
+      dlinkname_ptr= dlinkname;
       create_flag=0;
     }
     else
     {
-      fn_format(filename,name,"", MARIA_NAME_DEXT,
+      fn_format(dfilename,name,"", MARIA_NAME_DEXT,
                 MY_UNPACK_FILENAME | MY_APPEND_EXT);
-      linkname_ptr= NullS;
+      dlinkname_ptr= NullS;
       create_flag= (flags & HA_CREATE_KEEP_FILES) ? 0 : MY_DELETE_OLD;
     }
     if ((dfile=
-         mysql_file_create_with_symlink(key_file_dfile, linkname_ptr,
-                                        filename, 0, create_mode,
+         mysql_file_create_with_symlink(key_file_dfile, dlinkname_ptr,
+                                        dfilename, 0, create_mode,
                                         MYF(MY_WME | create_flag | sync_dir))) < 0)
       goto err;
     errpos=3;
@@ -1189,19 +1190,21 @@ err_no_lock:
     mysql_file_close(dfile, MYF(0));
     /* fall through */
   case 2:
-  if (! (flags & HA_DONT_TOUCH_DATA))
-    mysql_file_delete_with_symlink(key_file_dfile,
-                                   fn_format(filename,name,"",MARIA_NAME_DEXT,
-                                     MY_UNPACK_FILENAME | MY_APPEND_EXT),
-			   sync_dir);
+    if (! (flags & HA_DONT_TOUCH_DATA))
+    {
+      mysql_file_delete(key_file_dfile, dfilename, MYF(sync_dir));
+      if (dlinkname_ptr)
+        mysql_file_delete(key_file_dfile, dlinkname_ptr, MYF(sync_dir));
+    }
     /* fall through */
   case 1:
     mysql_file_close(file, MYF(0));
     if (! (flags & HA_DONT_TOUCH_DATA))
-      mysql_file_delete_with_symlink(key_file_kfile,
-                                     fn_format(filename,name,"",MARIA_NAME_IEXT,
-                                       MY_UNPACK_FILENAME | MY_APPEND_EXT),
-			     sync_dir);
+    {
+      mysql_file_delete(key_file_kfile, kfilename, MYF(sync_dir));
+      if (klinkname_ptr)
+        mysql_file_delete(key_file_kfile, klinkname_ptr, MYF(sync_dir));
+    }
   }
   my_free(log_data);
   my_free(rec_per_key_part);