MDEV-18309: InnoDB reports bogus errors about missing #sql-*.ibd on startup

This is a follow-up to MDEV-18733. As part of that fix, we made
dict_check_sys_tables() skip tables that would be dropped by
row_mysql_drop_garbage_tables().

DICT_ERR_IGNORE_DROP: A new mode where the file should not be attempted
to be opened.

dict_load_tablespace(): Do not try to load the tablespace if
DICT_ERR_IGNORE_DROP has been specified.

row_mysql_drop_garbage_tables(): Pass the DICT_ERR_IGNORE_DROP mode.

fil_space_for_table_exists_in_mem(): Remove a parameter.
The only caller that passed print_error_if_does_not_exist=true
was row_drop_single_table_tablespace().

mysql-test/suite/innodb/t/drop_table_background.test

@@ -3,6 +3,8 @@
 # Embedded server does not support restarting
 --source include/not_embedded.inc
 
+let $MYSQLD_DATADIR=`select @@datadir`;
+
 CREATE TABLE t(c0 SERIAL, c1 INT, c2 INT, c3 INT, c4 INT,
 KEY(c1), KEY(c2), KEY(c2,c1),
 KEY(c3), KEY(c3,c1), KEY(c3,c2), KEY(c3,c2,c1),
@@ -32,7 +34,9 @@ CREATE TABLE target (PRIMARY KEY(c1)) ENGINE=InnoDB SELECT * FROM t;
 --error ER_NO_SUCH_TABLE
 SELECT * from target;
 DROP TABLE t;
---source include/restart_mysqld.inc
+--source include/shutdown_mysqld.inc
+--remove_files_wildcard $MYSQLD_DATADIR/test #sql-*.ibd
+--source include/start_mysqld.inc
 CREATE TABLE t (a INT) ENGINE=InnoDB;
 DROP TABLE t;
 --error ER_BAD_TABLE_ERROR

storage/innobase/dict/dict0load.cc

@@ -1449,8 +1449,7 @@ static ulint dict_check_sys_tables()
 		/* Now that we have the proper name for this tablespace,
 		look to see if it is already in the tablespace cache. */
 		if (fil_space_for_table_exists_in_mem(
-			    space_id, table_name.m_name,
-			    false, NULL, flags)) {
+			    space_id, table_name.m_name, NULL, flags)) {
 			/* Recovery can open a datafile that does not
 			match SYS_DATAFILES.  If they don't match, update
 			SYS_DATAFILES. */
@@ -2845,7 +2844,12 @@ dict_load_tablespace(
 
 	/* The tablespace may already be open. */
 	if (fil_space_for_table_exists_in_mem(
-		    table->space, space_name, false, heap, table->flags)) {
+		    table->space, space_name, heap, table->flags)) {
+		return;
+	}
+
+	if (ignore_err == DICT_ERR_IGNORE_DROP) {
+		table->file_unreadable = true;
 		return;
 	}
 

storage/innobase/fil/fil0fil.cc

@@ -4540,9 +4540,6 @@ memory cache. Note that if we have not done a crash recovery at the database
 startup, there may be many tablespaces which are not yet in the memory cache.
 @param[in]	id		Tablespace ID
 @param[in]	name		Tablespace name used in fil_space_create().
-@param[in]	print_error_if_does_not_exist
-				Print detailed error information to the
-error log if a matching tablespace is not found from memory.
 @param[in]	heap		Heap memory
 @param[in]	table_flags	table flags
 @return true if a matching tablespace exists in the memory cache */
@@ -4550,11 +4547,9 @@ bool
 fil_space_for_table_exists_in_mem(
 	ulint		id,
 	const char*	name,
-	bool		print_error_if_does_not_exist,
 	mem_heap_t*	heap,
 	ulint		table_flags)
 {
-	fil_space_t*	fnamespace;
 	fil_space_t*	space;
 
 	const ulint	expected_flags = dict_tf_to_fsp_flags(table_flags);
@@ -4568,58 +4563,10 @@ fil_space_for_table_exists_in_mem(
 	/* Look if there is a space with the same name; the name is the
 	directory path from the datadir to the file */
 
-	fnamespace = fil_space_get_by_name(name);
-	bool valid = space && !((space->flags ^ expected_flags)
-				& ~FSP_FLAGS_MEM_MASK);
+	const bool valid = space
+		&& !((space->flags ^ expected_flags) & ~FSP_FLAGS_MEM_MASK)
+		&& space == fil_space_get_by_name(name);
 
-	if (!space) {
-	} else if (!valid || space == fnamespace) {
-		/* Found with the same file name, or got a flag mismatch. */
-		goto func_exit;
-	}
-
-	if (!print_error_if_does_not_exist) {
-		valid = false;
-		goto func_exit;
-	}
-
-	if (space == NULL) {
-		if (fnamespace == NULL) {
-			if (print_error_if_does_not_exist) {
-				fil_report_missing_tablespace(name, id);
-			}
-		} else {
-			ib::error() << "Table " << name << " in InnoDB data"
-				" dictionary has tablespace id " << id
-				<< ", but a tablespace with that id does not"
-				" exist. There is a tablespace of name "
-				<< fnamespace->name << " and id "
-				<< fnamespace->id << ", though. Have you"
-				" deleted or moved .ibd files?";
-		}
-error_exit:
-		ib::info() << TROUBLESHOOT_DATADICT_MSG;
-		valid = false;
-		goto func_exit;
-	}
-
-	if (0 != strcmp(space->name, name)) {
-
-		ib::error() << "Table " << name << " in InnoDB data dictionary"
-			" has tablespace id " << id << ", but the tablespace"
-			" with that id has name " << space->name << "."
-			" Have you deleted or moved .ibd files?";
-
-		if (fnamespace != NULL) {
-			ib::error() << "There is a tablespace with the right"
-				" name: " << fnamespace->name << ", but its id"
-				" is " << fnamespace->id << ".";
-		}
-
-		goto error_exit;
-	}
-
-func_exit:
 	if (valid) {
 		/* Adjust the flags that are in FSP_FLAGS_MEM_MASK.
 		FSP_SPACE_FLAGS will not be written back here. */

storage/innobase/include/dict0types.h

@@ -70,7 +70,10 @@ enum dict_err_ignore_t {
 					Silently load a missing
 					tablespace, and do not load
 					incomplete index definitions. */
-	DICT_ERR_IGNORE_ALL = 0xFFFF	/*!< ignore all errors */
+	/** ignore all errors above */
+	DICT_ERR_IGNORE_ALL = 15,
+	/** prepare to drop the table; do not attempt to load tablespace */
+	DICT_ERR_IGNORE_DROP = 31
 };
 
 /** Quiescing states for flushing tables to disk. */

storage/innobase/include/fil0fil.h

@@ -1162,9 +1162,6 @@ memory cache. Note that if we have not done a crash recovery at the database
 startup, there may be many tablespaces which are not yet in the memory cache.
 @param[in]	id		Tablespace ID
 @param[in]	name		Tablespace name used in fil_space_create().
-@param[in]	print_error_if_does_not_exist
-				Print detailed error information to the
-error log if a matching tablespace is not found from memory.
 @param[in]	heap		Heap memory
 @param[in]	table_flags	table flags
 @return true if a matching tablespace exists in the memory cache */
@@ -1172,7 +1169,6 @@ bool
 fil_space_for_table_exists_in_mem(
 	ulint		id,
 	const char*	name,
-	bool		print_error_if_does_not_exist,
 	mem_heap_t*	heap,
 	ulint		table_flags);
 

storage/innobase/row/row0mysql.cc

@@ -2675,7 +2675,7 @@ row_mysql_drop_garbage_tables()
 			btr_pcur_commit_specify_mtr(&pcur, &mtr);
 
 			if (dict_load_table(table_name, true,
-					    DICT_ERR_IGNORE_ALL)) {
+					    DICT_ERR_IGNORE_DROP)) {
 				row_drop_table_for_mysql(
 					table_name, trx,
 					SQLCOM_DROP_TABLE);
@@ -3231,7 +3231,7 @@ row_drop_single_table_tablespace(
 
 	/* If the tablespace is not in the cache, just delete the file. */
 	if (!fil_space_for_table_exists_in_mem(
-		    space_id, tablename, true, NULL, table_flags)) {
+		    space_id, tablename, NULL, table_flags)) {
 
 		/* Force a delete of any discarded or temporary files. */
 		fil_delete_file(filepath);