diff options
| author | Sergey Vojtovich <svoj@mariadb.org> | 2019-03-07 13:43:53 +0400 |
|---|---|---|
| committer | Sergey Vojtovich <svoj@mariadb.org> | 2019-03-11 22:46:12 +0400 |
| commit | 149b75476837fb96c28739d5368e977e39fd671b (patch) | |
| tree | bcd2f7f80870032d0e3fcff82b472f4a7a3537f8 /sql/sql_table.cc | |
| parent | 0a0eed80164dac0d3bfb7dcc57eb416cfba89386 (diff) | |
| download | mariadb-git-149b75476837fb96c28739d5368e977e39fd671b.tar.gz | |
MDEV-17595 - ALTER TABLE ADD FOREIGN KEY crash
ALTER TABLE ... ADD FOREIGN KEY may trigger assertion failure when
it has LOCK=EXCLUSIVE clause or concurrent FLUSH TABLES is being
executed.
In both cases being altered table is marked as flushed, which forces
subsequent attempt to open parent table to re-open. Which in turn is
not allowed while transaction is running.
Rather than opening parent table, just take appropriate MDL lock.
Also removed table_already_fk_prelocked() check: MDL itself has much
better methods to handle duplicate locks. E.g. the former won't acquire
MDL_SHARED_NO_WRITE if it already has MDL_SHARED_READ.
Diffstat (limited to 'sql/sql_table.cc')
| -rw-r--r-- | sql/sql_table.cc | 20 |
1 files changed, 8 insertions, 12 deletions
diff --git a/sql/sql_table.cc b/sql/sql_table.cc index 8a4c6e025fb..3b4ba72b1f1 100644 --- a/sql/sql_table.cc +++ b/sql/sql_table.cc @@ -9074,6 +9074,8 @@ bool mysql_alter_table(THD *thd,char *new_db, char *new_name, new_table->file->get_foreign_key_list(thd, &fk_list); while ((fk= fk_list_it++)) { + MDL_request mdl_request; + if (lower_case_table_names) { char buf[NAME_LEN]; @@ -9085,20 +9087,14 @@ bool mysql_alter_table(THD *thd,char *new_db, char *new_name, len = my_casedn_str(files_charset_info, buf); thd->make_lex_string(fk->referenced_table, buf, len); } - if (table_already_fk_prelocked(table_list, fk->referenced_db, - fk->referenced_table, TL_READ_NO_INSERT)) - continue; - TABLE_LIST *tl= (TABLE_LIST *) thd->alloc(sizeof(TABLE_LIST)); - tl->init_one_table_for_prelocking(fk->referenced_db->str, fk->referenced_db->length, - fk->referenced_table->str, fk->referenced_table->length, - NULL, TL_READ_NO_INSERT, false, NULL, 0, - &thd->lex->query_tables_last); + mdl_request.init(MDL_key::TABLE, + fk->referenced_db->str, fk->referenced_table->str, + MDL_SHARED_NO_WRITE, MDL_TRANSACTION); + if (thd->mdl_context.acquire_lock(&mdl_request, + thd->variables.lock_wait_timeout)) + goto err_new_table_cleanup; } - - if (open_tables(thd, &table_list->next_global, &tables_opened, 0, - &alter_prelocking_strategy)) - goto err_new_table_cleanup; } } /* |