From 0795e14ca0dd01d03fb7b804b9eaf3ef843e2ef1 Mon Sep 17 00:00:00 2001
From: unknown <ramil/ram@mysql.com/ramil.myoffice.izhnet.ru>
Date: Fri, 28 Mar 2008 19:16:52 +0400
Subject: [PATCH] Fix for bug #35392: Delete all statement does not execute
 properly after few delete statements

Problem: changing a file size might require that it must be
unmapped beforehand.

Fix: unmap the file before changing its size.


mysql-test/r/temp_table.result:
  Fix for bug #35392: Delete all statement does not execute properly
  after few delete statements
    - test result.
mysql-test/t/temp_table.test:
  Fix for bug #35392: Delete all statement does not execute properly
  after few delete statements
    - test case.
storage/myisam/mi_delete_all.c:
  Fix for bug #35392: Delete all statement does not execute properly
  after few delete statements
    - unmap file before changing its size as it's required
      by SetEndOfFile() function (see my_chsize()).
    - as no other threads allowed to perform concurrent inserts
      when delete_all is called, mmap_lock locking removed.
---
 mysql-test/r/temp_table.result | 11 +++++++++++
 mysql-test/t/temp_table.test   | 14 ++++++++++++++
 storage/myisam/mi_delete_all.c | 11 +++++++----
 3 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/mysql-test/r/temp_table.result b/mysql-test/r/temp_table.result
index 1c846700346..6df09463d02 100644
--- a/mysql-test/r/temp_table.result
+++ b/mysql-test/r/temp_table.result
@@ -184,3 +184,14 @@ select * from t1;
 a
 42
 drop table t1;
+CREATE TEMPORARY TABLE t1(a INT, b VARCHAR(20));
+INSERT INTO t1 VALUES(1, 'val1'), (2, 'val2'), (3, 'val3');
+DELETE FROM t1 WHERE a=1;
+SELECT count(*) FROM t1;
+count(*)
+2
+DELETE FROM t1;
+SELECT * FROM t1;
+a	b
+DROP TABLE t1;
+End of 5.1 tests
diff --git a/mysql-test/t/temp_table.test b/mysql-test/t/temp_table.test
index d1ad7ab8ffa..4ab8a982e63 100644
--- a/mysql-test/t/temp_table.test
+++ b/mysql-test/t/temp_table.test
@@ -191,3 +191,17 @@ truncate t1;
 insert into t1 values (42);
 select * from t1;
 drop table t1;
+
+#
+# Bug #35392: Delete all statement does not execute properly after 
+# few delete statements
+#
+CREATE TEMPORARY TABLE t1(a INT, b VARCHAR(20));
+INSERT INTO t1 VALUES(1, 'val1'), (2, 'val2'), (3, 'val3');
+DELETE FROM t1 WHERE a=1;
+SELECT count(*) FROM t1;
+DELETE FROM t1;
+SELECT * FROM t1;
+DROP TABLE t1;
+
+--echo End of 5.1 tests
diff --git a/storage/myisam/mi_delete_all.c b/storage/myisam/mi_delete_all.c
index dea0385cbca..e2bbb04ab3c 100644
--- a/storage/myisam/mi_delete_all.c
+++ b/storage/myisam/mi_delete_all.c
@@ -53,15 +53,18 @@ int mi_delete_all_rows(MI_INFO *info)
     since it was locked then there may be key blocks in the key cache
   */
   flush_key_blocks(share->key_cache, share->kfile, FLUSH_IGNORE_CHANGED);
+#ifdef HAVE_MMAP
+  if (share->file_map)
+    _mi_unmap_file(info);
+#endif
   if (my_chsize(info->dfile, 0, 0, MYF(MY_WME)) ||
       my_chsize(share->kfile, share->base.keystart, 0, MYF(MY_WME))  )
     goto err;
   VOID(_mi_writeinfo(info,WRITEINFO_UPDATE_KEYFILE));
 #ifdef HAVE_MMAP
-  /* Resize mmaped area */
-  rw_wrlock(&info->s->mmap_lock);
-  mi_remap_file(info, (my_off_t)0);
-  rw_unlock(&info->s->mmap_lock);
+  /* Map again */
+  if (share->file_map)
+    mi_dynmap_file(info, (my_off_t) 0);
 #endif
   allow_break();			/* Allow SIGHUP & SIGINT */
   DBUG_RETURN(0);