From f9264280d68dcbca2f9312c7d8620b2bcc9d0694 Mon Sep 17 00:00:00 2001 From: Sergei Golubchik Date: Fri, 12 May 2017 14:27:49 +0200 Subject: [PATCH] MDEV-12761 Error return from external_lock make the server crash bunch of bugs when external_lock() fails on unlock: * mi_lock_database() used mi_mark_crashed() under share->intern_lock, but mi_mark_crashed() itself locks this mutex. * handler::close() required table to be unlocked, but failed external_lock didn't count as unlock * mysql_unlock_tables() ignored all unlock errors, but they still set the error status in stmt_da. --- mysql-test/r/myisam_debug.result | 12 ++++++++++++ mysql-test/t/myisam_debug.test | 13 +++++++++++++ sql/handler.cc | 2 +- sql/lock.cc | 3 +++ storage/myisam/mi_locking.c | 20 +++++++++----------- 5 files changed, 38 insertions(+), 12 deletions(-) diff --git a/mysql-test/r/myisam_debug.result b/mysql-test/r/myisam_debug.result index 36a8fe6c724..77de991bafd 100644 --- a/mysql-test/r/myisam_debug.result +++ b/mysql-test/r/myisam_debug.result @@ -27,3 +27,15 @@ CHECK TABLE t1; Table Op Msg_type Msg_text test.t1 check status OK DROP TABLE t1,t2; +call mtr.add_suppression('Incorrect key file for table'); +create table t1 (a int, index(a)); +lock tables t1 write; +insert t1 values (1),(2),(1); +set @old_dbug=@@debug_dbug; +set debug_dbug='+d,mi_lock_database_failure'; +unlock tables; +Warnings: +Error 126 Incorrect key file for table './test/t1.MYI'; try to repair it +Error 1015 Can't lock file (errno: 22 "Invalid argument") +set debug_dbug=@old_dbug; +drop table t1; diff --git a/mysql-test/t/myisam_debug.test b/mysql-test/t/myisam_debug.test index 5b5d006bd22..57d423d88c9 100644 --- a/mysql-test/t/myisam_debug.test +++ b/mysql-test/t/myisam_debug.test @@ -59,3 +59,16 @@ KILL QUERY @thread_id; CHECK TABLE t1; DROP TABLE t1,t2; DISCONNECT insertConn; + +# +# MDEV-12761 Error return from external_lock make the server crash +# +call mtr.add_suppression('Incorrect key file for table'); +create table t1 (a int, index(a)); +lock tables t1 write; +insert t1 values (1),(2),(1); +set @old_dbug=@@debug_dbug; +set debug_dbug='+d,mi_lock_database_failure'; +unlock tables; +set debug_dbug=@old_dbug; +drop table t1; diff --git a/sql/handler.cc b/sql/handler.cc index fc70ed5affc..e51f17f1712 100644 --- a/sql/handler.cc +++ b/sql/handler.cc @@ -5944,7 +5944,7 @@ int handler::ha_external_lock(THD *thd, int lock_type) MYSQL_TABLE_LOCK_WAIT(m_psi, PSI_TABLE_EXTERNAL_LOCK, lock_type, { error= external_lock(thd, lock_type); }) - if (error == 0) + if (error == 0 || lock_type == F_UNLCK) { m_lock_type= lock_type; cached_table_flags= table_flags(); diff --git a/sql/lock.cc b/sql/lock.cc index 614341fcc43..29afcc8f578 100644 --- a/sql/lock.cc +++ b/sql/lock.cc @@ -380,12 +380,15 @@ static int lock_external(THD *thd, TABLE **tables, uint count) void mysql_unlock_tables(THD *thd, MYSQL_LOCK *sql_lock, bool free_lock) { DBUG_ENTER("mysql_unlock_tables"); + bool errors= thd->is_error(); if (sql_lock->table_count) unlock_external(thd, sql_lock->table, sql_lock->table_count); if (sql_lock->lock_count) thr_multi_unlock(sql_lock->locks, sql_lock->lock_count, 0); if (free_lock) my_free(sql_lock); + if (!errors) + thd->clear_error(); DBUG_VOID_RETURN; } diff --git a/storage/myisam/mi_locking.c b/storage/myisam/mi_locking.c index 531b800c63e..1921926463e 100644 --- a/storage/myisam/mi_locking.c +++ b/storage/myisam/mi_locking.c @@ -29,7 +29,7 @@ static void mi_update_status_with_lock(MI_INFO *info); int mi_lock_database(MI_INFO *info, int lock_type) { - int error; + int error, mark_crashed= 0; uint count; MYISAM_SHARE *share=info->s; DBUG_ENTER("mi_lock_database"); @@ -52,6 +52,7 @@ int mi_lock_database(MI_INFO *info, int lock_type) } error= 0; + DBUG_EXECUTE_IF ("mi_lock_database_failure", error= EINVAL;); mysql_mutex_lock(&share->intern_lock); if (share->kfile >= 0) /* May only be false on windows */ { @@ -75,17 +76,15 @@ int mi_lock_database(MI_INFO *info, int lock_type) &share->dirty_part_map, FLUSH_KEEP)) { - error=my_errno; + mark_crashed= error=my_errno; mi_print_error(info->s, HA_ERR_CRASHED); - mi_mark_crashed(info); /* Mark that table must be checked */ } if (info->opt_flag & (READ_CACHE_USED | WRITE_CACHE_USED)) { if (end_io_cache(&info->rec_cache)) { - error=my_errno; + mark_crashed= error=my_errno; mi_print_error(info->s, HA_ERR_CRASHED); - mi_mark_crashed(info); } } if (!count) @@ -110,22 +109,19 @@ int mi_lock_database(MI_INFO *info, int lock_type) share->state.unique= info->last_unique= info->this_unique; share->state.update_count= info->last_loop= ++info->this_loop; if (mi_state_info_write(share->kfile, &share->state, 1)) - error=my_errno; + mark_crashed= error=my_errno; share->changed=0; if (myisam_flush) { if (mysql_file_sync(share->kfile, MYF(0))) - error= my_errno; + mark_crashed= error= my_errno; if (mysql_file_sync(info->dfile, MYF(0))) - error= my_errno; + mark_crashed= error= my_errno; } else share->not_flushed=1; if (error) - { mi_print_error(info->s, HA_ERR_CRASHED); - mi_mark_crashed(info); - } } if (info->lock_type != F_EXTRA_LCK) { @@ -260,6 +256,8 @@ int mi_lock_database(MI_INFO *info, int lock_type) } #endif mysql_mutex_unlock(&share->intern_lock); + if (mark_crashed) + mi_mark_crashed(info); DBUG_RETURN(error); } /* mi_lock_database */