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| author | Sergei Golubchik <serg@mariadb.org> | 2018-07-19 01:03:14 +0200 |
|---|---|---|
| committer | Sergei Golubchik <serg@mariadb.org> | 2018-09-04 09:49:53 +0200 |
| commit | 9180e8666b8e31239d2e2075b703fb8bc8effc13 (patch) | |
| tree | aa9a4dce29f11c49e2e161d88432f18bba6028ff /sql/table.h | |
| parent | e81f101dac5c8514c362732a3b9dbc2f896390a6 (diff) | |
| download | mariadb-git-9180e8666b8e31239d2e2075b703fb8bc8effc13.tar.gz | |
MDEV-16465 Invalid (old?) table or database name or hang in ha_innobase::delete_table and log semaphore wait upon concurrent DDL with foreign keys
ALTER TABLE locks the table with TL_READ_NO_INSERT, to prevent the
source table modifications while it's being copied. But there's an
indirect way of modifying a table, via cascade FK actions.
After previous commits, an attempt to modify an FK parent table
will cause FK children to be prelocked, so the table-being-altered
cannot be modified by a cascade FK action, because ALTER holds a
lock and prelocking will wait.
But if a new FK is being added by this very ALTER, then the target
table is not locked yet (it's a temporary table). So, we have to
lock FK parents explicitly.
Diffstat (limited to 'sql/table.h')
| -rw-r--r-- | sql/table.h | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/sql/table.h b/sql/table.h index 23f97ed18d0..4a1552f8c0d 100644 --- a/sql/table.h +++ b/sql/table.h @@ -1695,6 +1695,14 @@ struct TABLE_LIST const char *alias_arg, enum thr_lock_type lock_type_arg) { + enum enum_mdl_type mdl_type; + if (lock_type_arg >= TL_WRITE_ALLOW_WRITE) + mdl_type= MDL_SHARED_WRITE; + else if (lock_type_arg == TL_READ_NO_INSERT) + mdl_type= MDL_SHARED_NO_WRITE; + else + mdl_type= MDL_SHARED_READ; + bzero((char*) this, sizeof(*this)); db= (char*) db_name_arg; db_length= db_length_arg; @@ -1702,10 +1710,7 @@ struct TABLE_LIST table_name_length= table_name_length_arg; alias= (char*) (alias_arg ? alias_arg : table_name_arg); lock_type= lock_type_arg; - mdl_request.init(MDL_key::TABLE, db, table_name, - (lock_type >= TL_WRITE_ALLOW_WRITE) ? - MDL_SHARED_WRITE : MDL_SHARED_READ, - MDL_TRANSACTION); + mdl_request.init(MDL_key::TABLE, db, table_name, mdl_type, MDL_TRANSACTION); } inline void init_one_table_for_prelocking(const char *db_name_arg, |