1 files changed, 76 insertions, 51 deletions

diff --git a/storage/innobase/fil/fil0fil.cc b/storage/innobase/fil/fil0fil.cc
index 4c6ed9807f6..2e6835fe0c0 100644
--- a/storage/innobase/fil/fil0fil.cc
+++ b/storage/innobase/fil/fil0fil.cc
@@ -194,16 +194,18 @@ struct fil_space_struct {
 				.ibd file of tablespace and want to
 				stop temporarily posting of new i/o
 				requests on the file */
-	ibool		stop_ibuf_merges;
+	ibool		stop_new_ops;
 				/*!< we set this TRUE when we start
-				deleting a single-table tablespace */
-	ibool		is_being_deleted;
-				/*!< this is set to TRUE when we start
-				deleting a single-table tablespace and its
-				file; when this flag is set no further i/o
-				or flush requests can be placed on this space,
-				though there may be such requests still being
-				processed on this space */
+				deleting a single-table tablespace.
+				When this is set following new ops
+				are not allowed:
+				* read IO request
+				* ibuf merge
+				* file flush
+				Note that we can still possibly have
+				new write operations because we don't
+				check this flag when doing flush
+				batches. */
 	ulint		purpose;/*!< FIL_TABLESPACE, FIL_LOG, or
 				FIL_ARCH_LOG */
 	UT_LIST_BASE_NODE_T(fil_node_t) chain;
@@ -220,12 +222,13 @@ struct fil_space_struct {
 	ulint		n_pending_flushes; /*!< this is positive when flushing
 				the tablespace to disk; dropping of the
 				tablespace is forbidden if this is positive */
-	ulint		n_pending_ibuf_merges;/*!< this is positive
-				when merging insert buffer entries to
-				a page so that we may need to access
-				the ibuf bitmap page in the
-				tablespade: dropping of the tablespace
-				is forbidden if this is positive */
+	ulint		n_pending_ops;/*!< this is positive when we
+				have pending operations against this
+				tablespace. The pending operations can
+				be ibuf merges or lock validation code
+				trying to read a block.
+				Dropping of the tablespace is forbidden
+				if this is positive */
 	hash_node_t	hash;	/*!< hash chain node */
 	hash_node_t	name_hash;/*!< hash chain the name_hash table */
 #ifndef UNIV_HOTBACKUP
@@ -1928,13 +1931,12 @@ fil_read_first_page(
 
 #ifndef UNIV_HOTBACKUP
 /*******************************************************************//**
-Increments the count of pending insert buffer page merges, if space is not
-being deleted.
-@return	TRUE if being deleted, and ibuf merges should be skipped */
+Increments the count of pending operation, if space is not being deleted.
+@return	TRUE if being deleted, and operation should be skipped */
 UNIV_INTERN
 ibool
-fil_inc_pending_ibuf_merges(
-/*========================*/
+fil_inc_pending_ops(
+/*================*/
 	ulint	id)	/*!< in: space id */
 {
 	fil_space_t*	space;
@@ -1945,18 +1947,18 @@ fil_inc_pending_ibuf_merges(
 
 	if (space == NULL) {
 		fprintf(stderr,
-			"InnoDB: Error: trying to do ibuf merge to a"
+			"InnoDB: Error: trying to do an operation on a"
 			" dropped tablespace %lu\n",
 			(ulong) id);
 	}
 
-	if (space == NULL || space->stop_ibuf_merges) {
+	if (space == NULL || space->stop_new_ops) {
 		mutex_exit(&fil_system->mutex);
 
 		return(TRUE);
 	}
 
-	space->n_pending_ibuf_merges++;
+	space->n_pending_ops++;
 
 	mutex_exit(&fil_system->mutex);
 
@@ -1964,11 +1966,11 @@ fil_inc_pending_ibuf_merges(
 }
 
 /*******************************************************************//**
-Decrements the count of pending insert buffer page merges. */
+Decrements the count of pending operations. */
 UNIV_INTERN
 void
-fil_decr_pending_ibuf_merges(
-/*=========================*/
+fil_decr_pending_ops(
+/*=================*/
 	ulint	id)	/*!< in: space id */
 {
 	fil_space_t*	space;
@@ -1979,13 +1981,13 @@ fil_decr_pending_ibuf_merges(
 
 	if (space == NULL) {
 		fprintf(stderr,
-			"InnoDB: Error: decrementing ibuf merge of a"
-			" dropped tablespace %lu\n",
+			"InnoDB: Error: decrementing pending operation"
+			" of a dropped tablespace %lu\n",
 			(ulong) id);
 	}
 
 	if (space != NULL) {
-		space->n_pending_ibuf_merges--;
+		space->n_pending_ops--;
 	}
 
 	mutex_exit(&fil_system->mutex);
@@ -2181,7 +2183,6 @@ fil_op_log_parse_or_replay(
 	}
 	*/
 	if (!space_id) {
-
 		return(ptr);
 	}
 
@@ -2276,15 +2277,15 @@ fil_delete_tablespace(
 	char*		path;
 
 	ut_a(id != 0);
-stop_ibuf_merges:
+stop_new_ops:
 	mutex_enter(&fil_system->mutex);
 
 	space = fil_space_get_by_id(id);
 
 	if (space != NULL) {
-		space->stop_ibuf_merges = TRUE;
+		space->stop_new_ops = TRUE;
 
-		if (space->n_pending_ibuf_merges == 0) {
+		if (space->n_pending_ops == 0) {
 			mutex_exit(&fil_system->mutex);
 
 			count = 0;
@@ -2298,9 +2299,10 @@ stop_ibuf_merges:
 				ut_print_filename(stderr, space->name);
 				fprintf(stderr, ",\n"
 					"InnoDB: but there are %lu pending"
-					" ibuf merges on it.\n"
+					" operations (most likely ibuf merges)"
+					" on it.\n"
 					"InnoDB: Loop %lu.\n",
-					(ulong) space->n_pending_ibuf_merges,
+					(ulong) space->n_pending_ops,
 					(ulong) count);
 			}
 
@@ -2309,7 +2311,7 @@ stop_ibuf_merges:
 			os_thread_sleep(20000);
 			count++;
 
-			goto stop_ibuf_merges;
+			goto stop_new_ops;
 		}
 	}
 
@@ -2334,10 +2336,8 @@ try_again:
 		return(FALSE);
 	}
 
-	ut_a(space);
-	ut_a(space->n_pending_ibuf_merges == 0);
-
-	space->is_being_deleted = TRUE;
+	ut_a(space->stop_new_ops);
+	ut_a(space->n_pending_ops == 0);
 
 	/* TODO: The following code must change when InnoDB supports
 	multiple datafiles per tablespace. */
@@ -2386,12 +2386,26 @@ try_again:
 	rw_lock_x_lock(&space->latch);
 
 #ifndef UNIV_HOTBACKUP
-	/* Invalidate in the buffer pool all pages belonging to the
-	tablespace. Since we have set space->is_being_deleted = TRUE, readahead
-	or ibuf merge can no longer read more pages of this tablespace to the
-	buffer pool. Thus we can clean the tablespace out of the buffer pool
-	completely and permanently. The flag is_being_deleted also prevents
-	fil_flush() from being applied to this tablespace. */
+	/* IMPORTANT: Because we have set space::stop_new_ops there
+	can't be any new ibuf merges, reads or flushes. We are here
+	because node::n_pending was zero above. However, it is still
+	possible to have pending read and write requests:
+
+	A read request can happen because the reader thread has
+	gone through the ::stop_new_ops check in buf_page_init_for_read()
+	before the flag was set and has not yet incremented ::n_pending
+	when we checked it above.
+
+	A write request can be issued any time because we don't check
+	the ::stop_new_ops flag when queueing a block for write.
+
+	We deal with pending write requests in the following function
+	where we'd minimally evict all dirty pages belonging to this
+	space from the flush_list. Not that if a block is IO-fixed
+	we'll wait for IO to complete.
+
+	To deal with potential read requests by checking the
+	::stop_new_ops flag in fil_io() */
 
 	buf_LRU_invalidate_tablespace(id);
 #endif
@@ -2399,6 +2413,15 @@ try_again:
 
 	mutex_enter(&fil_system->mutex);
 
+	/* Double check the sanity of pending ops after reacquiring
+	the fil_system::mutex. */
+	if (fil_space_get_by_id(id)) {
+		ut_a(space->n_pending_ops == 0);
+		ut_a(UT_LIST_GET_LEN(space->chain) == 1);
+		node = UT_LIST_GET_FIRST(space->chain);
+		ut_a(node->n_pending == 0);
+	}
+
 	success = fil_space_free(id, TRUE);
 
 	mutex_exit(&fil_system->mutex);
@@ -2456,7 +2479,7 @@ fil_tablespace_is_being_deleted(
 
 	ut_a(space != NULL);
 
-	is_being_deleted = space->is_being_deleted;
+	is_being_deleted = space->stop_new_ops;
 
 	mutex_exit(&fil_system->mutex);
 
@@ -3744,7 +3767,7 @@ fil_tablespace_deleted_or_being_deleted_in_mem(
 
 	space = fil_space_get_by_id(id);
 
-	if (space == NULL || space->is_being_deleted) {
+	if (space == NULL || space->stop_new_ops) {
 		mutex_exit(&fil_system->mutex);
 
 		return(TRUE);
@@ -4472,7 +4495,9 @@ fil_io(
 
 	space = fil_space_get_by_id(space_id);
 
-	if (!space) {
+	/* If we are deleting a tablespace we don't allow any read
+	operations on that. However, we do allow write operations. */
+	if (!space || (type == OS_FILE_READ && space->stop_new_ops)) {
 		mutex_exit(&fil_system->mutex);
 
 		ut_print_timestamp(stderr);
@@ -4691,7 +4716,7 @@ fil_flush(
 
 	space = fil_space_get_by_id(space_id);
 
-	if (!space || space->is_being_deleted) {
+	if (!space || space->stop_new_ops) {
 		mutex_exit(&fil_system->mutex);
 
 		return;
@@ -4823,7 +4848,7 @@ fil_flush_file_spaces(
 	     space;
 	     space = UT_LIST_GET_NEXT(unflushed_spaces, space)) {
 
-		if (space->purpose == purpose && !space->is_being_deleted) {
+		if (space->purpose == purpose && !space->stop_new_ops) {
 
 			space_ids[n_space_ids++] = space->id;
 		}