Assertion `!thd || thd->locked_tables_mode || !thd->mdl_context.has_locks() || thd->handler_tables_hash.records || thd->ull_hash.records || thd->global_read_lock.is_acquired() || thd->current_backup_stage != BACKUP_FINISHED' failed in reload_acl_and_cache

BACKUP LOCK x;

RESET QUERY CACHE;

mysqld: /data/src/10.4/sql/sql_reload.cc:219: bool reload_acl_and_cache(THD*, long long unsigned int, TABLE_LIST*, int*): Assertion `!thd || thd->locked_tables_mode || !thd->mdl_context.has_locks() || thd->handler_tables_hash.records || thd->ull_hash.records || thd->global_read_lock.is_acquired() || thd->current_backup_stage != BACKUP_FINISHED' failed.

200322  2:28:51 [ERROR] mysqld got signal 6 ;

#6  0x00007fdb455e9e67 in __assert_fail_base (fmt=<optimized out>, assertion=assertion@entry=0x5634d95cde38 "!thd || thd->locked_tables_mode || !thd->mdl_context.has_locks() || thd->handler_tables_hash.records || thd->ull_hash.records || thd->global_read_lock.is_acquired() || thd->current_backup_stage != BAC"..., file=file@entry=0x5634d95cde10 "/data/src/10.4/sql/sql_reload.cc", line=line@entry=219, function=function@entry=0x5634d95cdfa0 <reload_acl_and_cache(THD*, unsigned long long, TABLE_LIST*, int*)::__PRETTY_FUNCTION__> "bool reload_acl_and_cache(THD*, long long unsigned int, TABLE_LIST*, int*)") at assert.c:92

#7  0x00007fdb455e9f12 in __GI___assert_fail (assertion=0x5634d95cde38 "!thd || thd->locked_tables_mode || !thd->mdl_context.has_locks() || thd->handler_tables_hash.records || thd->ull_hash.records || thd->global_read_lock.is_acquired() || thd->current_backup_stage != BAC"..., file=0x5634d95cde10 "/data/src/10.4/sql/sql_reload.cc", line=219, function=0x5634d95cdfa0 <reload_acl_and_cache(THD*, unsigned long long, TABLE_LIST*, int*)::__PRETTY_FUNCTION__> "bool reload_acl_and_cache(THD*, long long unsigned int, TABLE_LIST*, int*)") at assert.c:101

#8  0x00005634d8a2fcbb in reload_acl_and_cache (thd=0x7fdb24000af0, options=65536, tables=0x0, write_to_binlog=0x7fdb3b766900) at /data/src/10.4/sql/sql_reload.cc:213

#9  0x00005634d887600d in mysql_execute_command (thd=0x7fdb24000af0) at /data/src/10.4/sql/sql_parse.cc:5460

#10 0x00005634d887e287 in mysql_parse (thd=0x7fdb24000af0, rawbuf=0x7fdb24013198 "RESET QUERY CACHE", length=17, parser_state=0x7fdb3b767160, is_com_multi=false, is_next_command=false) at /data/src/10.4/sql/sql_parse.cc:7900

#11 0x00005634d886946a in dispatch_command (command=COM_QUERY, thd=0x7fdb24000af0, packet=0x7fdb24136341 "RESET QUERY CACHE", packet_length=17, is_com_multi=false, is_next_command=false) at /data/src/10.4/sql/sql_parse.cc:1842

#12 0x00005634d8867af7 in do_command (thd=0x7fdb24000af0) at /data/src/10.4/sql/sql_parse.cc:1360

#13 0x00005634d89f0f7d in do_handle_one_connection (connect=0x5634dcba88d0) at /data/src/10.4/sql/sql_connect.cc:1412

#14 0x00005634d89f0ccc in handle_one_connection (arg=0x5634dcba88d0) at /data/src/10.4/sql/sql_connect.cc:1316

#15 0x00005634d93f93df in pfs_spawn_thread (arg=0x5634dcabc250) at /data/src/10.4/storage/perfschema/pfs.cc:1869

#16 0x00007fdb475724a4 in start_thread (arg=0x7fdb3b768700) at pthread_create.c:456

#17 0x00007fdb456a6d0f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97