Port fix for bug #54311 from mysql-trunk-innodb to mysql-5.1-innodb codeline.

Bug #54311: Crash on CHECK PARTITION after concurrent LOAD DATA
and adaptive_hash_index=OFF

storage/innodb_plugin/ChangeLog

+2010-06-30	The InnoDB Team
+
+	* btr/btr0sea.c, ha/ha0ha.c, handler/ha_innodb.cc, include/btr0sea.h:
+	Fix Bug#54311 Crash on CHECK PARTITION after concurrent LOAD DATA
+	and adaptive_hash_index=OFF
+
 2010-06-29	The InnoDB Team
 	* row/row0row.c, row/row0undo.c, row/row0upd.c:
 	Fix Bug#54408 txn rollback after recovery: row0umod.c:673

storage/innodb_plugin/btr/btr0sea.c

@@ -46,6 +46,7 @@ Created 2/17/1996 Heikki Tuuri
 /** Flag: has the search system been enabled?
 Protected by btr_search_latch and btr_search_enabled_mutex. */
 UNIV_INTERN char		btr_search_enabled	= TRUE;
+UNIV_INTERN ibool		btr_search_fully_disabled = FALSE;
 
 /** Mutex protecting btr_search_enabled */
 static mutex_t			btr_search_enabled_mutex;
@@ -201,12 +202,19 @@ btr_search_disable(void)
 	mutex_enter(&btr_search_enabled_mutex);
 	rw_lock_x_lock(&btr_search_latch);
 
+	/* Disable access to hash index, also tell ha_insert_for_fold()
+	stop adding new nodes to hash index, but still allow updating
+	existing nodes */
 	btr_search_enabled = FALSE;
 
 	/* Clear all block->is_hashed flags and remove all entries
 	from btr_search_sys->hash_index. */
 	buf_pool_drop_hash_index();
 
+	/* hash index has been cleaned up, disallow any operation to
+	the hash index */
+	btr_search_fully_disabled = TRUE;
+
 	/* btr_search_enabled_mutex should guarantee this. */
 	ut_ad(!btr_search_enabled);
 
@@ -225,6 +233,7 @@ btr_search_enable(void)
 	rw_lock_x_lock(&btr_search_latch);
 
 	btr_search_enabled = TRUE;
+	btr_search_fully_disabled = FALSE;
 
 	rw_lock_x_unlock(&btr_search_latch);
 	mutex_exit(&btr_search_enabled_mutex);
@@ -1363,7 +1372,7 @@ btr_search_build_page_hash_index(
 
 	rw_lock_x_lock(&btr_search_latch);
 
-	if (UNIV_UNLIKELY(!btr_search_enabled)) {
+	if (UNIV_UNLIKELY(btr_search_fully_disabled)) {
 		goto exit_func;
 	}
 

storage/innodb_plugin/ha/ha0ha.c

@@ -31,9 +31,7 @@ Created 8/22/1994 Heikki Tuuri
 #ifdef UNIV_DEBUG
 # include "buf0buf.h"
 #endif /* UNIV_DEBUG */
-#ifdef UNIV_SYNC_DEBUG
-# include "btr0sea.h"
-#endif /* UNIV_SYNC_DEBUG */
+#include "btr0sea.h"
 #include "page0page.h"
 
 /*************************************************************//**
@@ -127,7 +125,8 @@ ha_clear(
 /*************************************************************//**
 Inserts an entry into a hash table. If an entry with the same fold number
 is found, its node is updated to point to the new data, and no new node
-is inserted.
+is inserted. If btr_search_enabled is set to FALSE, we will only allow
+updating existing nodes, but no new node is allowed to be added.
 @return	TRUE if succeed, FALSE if no more memory could be allocated */
 UNIV_INTERN
 ibool
@@ -174,6 +173,7 @@ ha_insert_for_fold_func(
 				prev_block->n_pointers--;
 				block->n_pointers++;
 			}
+			ut_ad(!btr_search_fully_disabled);
 # endif /* !UNIV_HOTBACKUP */
 
 			prev_node->block = block;
@@ -186,6 +186,13 @@ ha_insert_for_fold_func(
 		prev_node = prev_node->next;
 	}
 
+	/* We are in the process of disabling hash index, do not add
+	new chain node */
+	if (!btr_search_enabled) {
+		ut_ad(!btr_search_fully_disabled);
+		return(TRUE);
+	}
+
 	/* We have to allocate a new chain node */
 
 	node = mem_heap_alloc(hash_get_heap(table, fold), sizeof(ha_node_t));

storage/innodb_plugin/handler/ha_innodb.cc

@@ -2270,6 +2270,7 @@ innobase_change_buffering_inited_ok:
 	/* Get the current high water mark format. */
 	innobase_file_format_check = (char*) trx_sys_file_format_max_get();
 
+	btr_search_fully_disabled = (!btr_search_enabled);
 	DBUG_RETURN(FALSE);
 error:
 	DBUG_RETURN(TRUE);

storage/innodb_plugin/include/btr0sea.h

@@ -192,6 +192,12 @@ btr_search_validate(void);
 Protected by btr_search_latch and btr_search_enabled_mutex. */
 extern char	btr_search_enabled;
 
+/** Flag: whether the search system has completed its disabling process,
+It is set to TRUE right after buf_pool_drop_hash_index() in
+btr_search_disable(), indicating hash index entries are cleaned up.
+Protected by btr_search_latch and btr_search_enabled_mutex. */
+extern ibool	btr_search_fully_disabled;
+
 /** The search info struct in an index */
 struct btr_search_struct{
 	ulint	ref_count;	/*!< Number of blocks in this index tree