From b090f85ff72bc8e20597005914b5f622ed0bff9a Mon Sep 17 00:00:00 2001
From: Mark Callaghan <mcallaghan@fb.com>
Date: Wed, 9 Feb 2011 12:12:20 -0800
Subject: [PATCH] s

---
 storage/innodb_plugin/fil/fil0fil.c     |   28 ++++++++++++++++++++++++++++
 storage/innodb_plugin/include/fil0fil.h |    5 +++++
 2 files changed, 33 insertions(+), 0 deletions(-)

diff --git a/storage/innodb_plugin/fil/fil0fil.c b/storage/innodb_plugin/fil/fil0fil.c
index 1a21d9a..e50a6ae 100644
--- a/storage/innodb_plugin/fil/fil0fil.c
+++ b/storage/innodb_plugin/fil/fil0fil.c
@@ -1074,6 +1074,9 @@ try_again:
 
 	rw_lock_create(&space->latch, SYNC_FSP);
 
+	pthread_cond_init(&space->extend_cond, NULL);
+	space->extend_in_progress = FALSE;
+
 	HASH_INSERT(fil_space_t, hash, fil_system->spaces, id, space);
 
 	HASH_INSERT(fil_space_t, name_hash, fil_system->name_hash,
@@ -1222,6 +1225,9 @@ fil_space_free(
 
 	rw_lock_free(&(space->latch));
 
+	pthread_cond_destroy(&(space->extend_cond));
+	ut_ad(space->extend_in_progress == FALSE);
+
 	mem_free(space->name);
 	mem_free(space);
 
@@ -4217,6 +4223,17 @@ fil_extend_space_to_desired_size(
 
 	fil_node_prepare_for_io(node, fil_system, space);
 
+	/* Wait until another thread is not extending this space because when
+	disk IO is done below fil_system->mutex will be released. This must be
+	done after fil_node_prepare_for_io increments n_pending to prevent
+	others from dropping or renaming the tablespace after this briefly
+	drops fil_system->mutex while IO is in progress. */
+
+	while (space->extend_in_progress) {
+		pthread_cond_wait(&space->extend_cond, &fil_system->mutex);
+	}
+	space->extend_in_progress = TRUE;
+
 	start_page_no = space->size;
 	file_start_page_no = space->size - node->size;
 
@@ -4236,6 +4253,10 @@ fil_extend_space_to_desired_size(
 		offset_low  = ((start_page_no - file_start_page_no)
 			       % (4096 * ((1024 * 1024) / page_size)))
 			* page_size;
+
+		/* Don't stall others -- see http://bugs.mysql.com/56433 */
+		mutex_exit(&fil_system->mutex);
+
 #ifdef UNIV_HOTBACKUP
 		success = os_file_write(node->name, node->handle, buf,
 					offset_low, offset_high,
@@ -4247,6 +4268,9 @@ fil_extend_space_to_desired_size(
 				 page_size * n_pages,
 				 NULL, NULL, &space->io_perf2, NULL);
 #endif
+
+		mutex_enter(&fil_system->mutex);
+
 		if (success) {
 			node->size += n_pages;
 			space->size += n_pages;
@@ -4291,6 +4315,10 @@ fil_extend_space_to_desired_size(
 	/*
 	printf("Extended %s to %lu, actual size %lu pages\n", space->name,
 	size_after_extend, *actual_size); */
+
+	space->extend_in_progress = FALSE;
+	pthread_cond_broadcast(&space->extend_cond);
+
 	mutex_exit(&fil_system->mutex);
 
 	fil_flush(space_id, FLUSH_FROM_OTHER);
diff --git a/storage/innodb_plugin/include/fil0fil.h b/storage/innodb_plugin/include/fil0fil.h
index bef44f7..8f4c8f2 100644
--- a/storage/innodb_plugin/include/fil0fil.h
+++ b/storage/innodb_plugin/include/fil0fil.h
@@ -253,6 +253,9 @@ struct fil_space_struct {
 #ifndef UNIV_HOTBACKUP
 	rw_lock_t	latch;	/*!< latch protecting the file space storage
 				allocation */
+	pthread_cond_t	extend_cond;
+				/*!< When file is being extended wait on this
+				until extend_in_progress is FALSE */
 #endif /* !UNIV_HOTBACKUP */
 	UT_LIST_NODE_T(fil_space_t) unflushed_spaces;
 				/*!< list of spaces with at least one unflushed
@@ -263,6 +266,8 @@ struct fil_space_struct {
 				/*!< list of all spaces */
 	os_io_perf2_t	io_perf2;/*!< per tablespace IO perf counters */
 	ulint		magic_n;/*!< FIL_SPACE_MAGIC_N */
+	ibool		extend_in_progress;
+				/*!< TRUE when file is being extended */
 };
 
 /** Value of fil_space_struct::magic_n */
-- 
1.7.3.2.146.gca209