From 0a5668f5128c731a346abf41afdc6fed33164ffc Mon Sep 17 00:00:00 2001 From: Varun Gupta Date: Fri, 15 May 2020 02:37:16 +0530 Subject: [PATCH] MDEV-22556: Incorrect result for window function when using encrypt-tmp-files=ON The issue here is that end_of_file for encrypted temporary IO_CACHE (used by filesort) is updated using lseek. Encryption adds storage overhead and hides it from the caller by recalculating offsets and lengths. Two different IO_CACHE cannot possibly modify the same file because the encryption key is randomly generated and stored in the IO_CACHE. So when the tempfiles are encrypted DO NOT use lseek to change end_of_file. Further observations about updating end_of_file using lseek 1) The end_of_file update is only used for binlog index files 2) The whole point is to update file length when the file was modified via a different file descriptor. 3) The temporary IO_CACHE files can never be modified via a different file descriptor. 4) For encrypted temporary IO_CACHE, end_of_file should not be updated with lseek --- .../encryption/r/tempfiles_encrypted.result | 18 +++++++++++++++ .../encryption/t/tempfiles_encrypted.opt | 1 + .../encryption/t/tempfiles_encrypted.test | 23 +++++++++++++++++++ mysys/mf_iocache.c | 7 ++++-- 4 files changed, 47 insertions(+), 2 deletions(-) create mode 100644 mysql-test/suite/encryption/r/tempfiles_encrypted.result create mode 100644 mysql-test/suite/encryption/t/tempfiles_encrypted.opt create mode 100644 mysql-test/suite/encryption/t/tempfiles_encrypted.test diff --git a/mysql-test/suite/encryption/r/tempfiles_encrypted.result b/mysql-test/suite/encryption/r/tempfiles_encrypted.result new file mode 100644 index 00000000000..d08cb33e0fc --- /dev/null +++ b/mysql-test/suite/encryption/r/tempfiles_encrypted.result @@ -0,0 +1,18 @@ +# +# Tests when the temporary files are encrypted +# +select @@encrypt_tmp_files; +@@encrypt_tmp_files +1 +# +# MDEV-22556: Incorrect result for window function when using encrypt-tmp-files=ON +# +set @save_sort_buffer_size=@@sort_buffer_size; +set sort_buffer_size= 2000; +create table t1( a DECIMAL(12,0) DEFAULT NULL, b VARCHAR(20) DEFAULT NULL, c DECIMAL(12,0) DEFAULT NULL)engine=INNODB; +insert into t1 select seq, seq, seq from seq_1_to_5000; +select count(*) from (select a, b, c, ROW_NUMBER() OVER (PARTITION BY a) FROM t1)q; +count(*) +5000 +set @@sort_buffer_size=@save_sort_buffer_size; +drop table t1; diff --git a/mysql-test/suite/encryption/t/tempfiles_encrypted.opt b/mysql-test/suite/encryption/t/tempfiles_encrypted.opt new file mode 100644 index 00000000000..81877a8d1c5 --- /dev/null +++ b/mysql-test/suite/encryption/t/tempfiles_encrypted.opt @@ -0,0 +1 @@ +--encrypt-tmp_files=ON diff --git a/mysql-test/suite/encryption/t/tempfiles_encrypted.test b/mysql-test/suite/encryption/t/tempfiles_encrypted.test new file mode 100644 index 00000000000..96b981c1c06 --- /dev/null +++ b/mysql-test/suite/encryption/t/tempfiles_encrypted.test @@ -0,0 +1,23 @@ +--echo # +--echo # Tests when the temporary files are encrypted +--echo # + +source include/have_file_key_management_plugin.inc; +source include/have_sequence.inc; +source include/have_innodb.inc; + +select @@encrypt_tmp_files; + +--echo # +--echo # MDEV-22556: Incorrect result for window function when using encrypt-tmp-files=ON +--echo # + +set @save_sort_buffer_size=@@sort_buffer_size; +set sort_buffer_size= 2000; +create table t1( a DECIMAL(12,0) DEFAULT NULL, b VARCHAR(20) DEFAULT NULL, c DECIMAL(12,0) DEFAULT NULL)engine=INNODB; +insert into t1 select seq, seq, seq from seq_1_to_5000; +select count(*) from (select a, b, c, ROW_NUMBER() OVER (PARTITION BY a) FROM t1)q; + +set @@sort_buffer_size=@save_sort_buffer_size; + +drop table t1; diff --git a/mysys/mf_iocache.c b/mysys/mf_iocache.c index 54b89007b4c..51e8fe1a02f 100644 --- a/mysys/mf_iocache.c +++ b/mysys/mf_iocache.c @@ -504,8 +504,11 @@ my_bool reinit_io_cache(IO_CACHE *info, enum cache_type type, if (info->type == WRITE_CACHE) info->end_of_file= my_b_tell(info); else - info->end_of_file= mysql_file_seek(info->file, 0L, MY_SEEK_END, - MYF(0)); + { + if (!(info->myflags & MY_ENCRYPT)) + info->end_of_file= mysql_file_seek(info->file, 0L, + MY_SEEK_END, MYF(0)); + } } /* flush cache if we want to reuse it */ if (!clear_cache && my_b_flush_io_cache(info,1))