Failed to set O_DIRECT on xb_doublewrite when running MTR test cases

[Sveta Smirnova]

All MTR test fail with error:

==============================================================================

TEST RESULT TIME (ms) or COMMENT
--------------------------------------------------------------------------

worker[1] Using MTR_BUILD_THREAD 300, with reserved ports 13000..13009
main.alias [ fail ] Found warnings/errors in server log file!
        Test ended at 2017-03-02 15:49:41
line
2017-03-02T12:49:33.406293Z 0 [Warning] InnoDB: Failed to set O_DIRECT on file/home/sveta/build/ps-5.7/mysql-test/var/mysqld.1/data/xb_doublewrite;create: Invalid argument, continuing anyway. O_DIRECT is known to result in 'Invalid argument' on Linux on tmpfs, see MySQL Bug#26662.

FS: ecryptfs

Removing var directory before running test does not help.

How to repeat:

sveta@Thinkie:~/build/ps-5.7/mysql-test$ mount
...
/home/.ecryptfs/sveta/.Private on /home/sveta type ecryptfs (rw,nosuid,nodev,relatime,ecryptfs_fnek_sig=1fe38ac67150d26d,ecryptfs_sig=3da24c1114964df7,ecryptfs_cipher=aes,ecryptfs_key_bytes=16,ecryptfs_unlink_sigs)
gvfsd-fuse on /run/user/1000/gvfs type fuse.gvfsd-fuse (rw,nosuid,nodev,relatime,user_id=1000,group_id=1000)
sveta@Thinkie:~/build/ps-5.7/mysql-test$ rm -rf var
sveta@Thinkie:~/build/ps-5.7/mysql-test$ ls -l var
ls: cannot access 'var': No such file or directory
sveta@Thinkie:~/build/ps-5.7/mysql-test$ ./mtr alias
Logging: ./mtr alias
MySQL Version 5.7.17
Checking supported features...
 - SSL connections supported
 - binaries are debug compiled
Collecting tests...
Removing old var directory...
Creating var directory '/home/sveta/build/ps-5.7/mysql-test/var'...
Installing system database...
Using parallel: 1

==============================================================================

TEST RESULT TIME (ms) or COMMENT
--------------------------------------------------------------------------

worker[1] Using MTR_BUILD_THREAD 300, with reserved ports 13000..13009
main.alias [ fail ] Found warnings/errors in server log file!
        Test ended at 2017-03-02 15:55:01
line
2017-03-02T12:54:53.171057Z 0 [Warning] InnoDB: Failed to set O_DIRECT on file/home/sveta/build/ps-5.7/mysql-test/var/mysqld.1/data/xb_doublewrite;create: Invalid argument, continuing anyway. O_DIRECT is known to result in 'Invalid argument' on Linux on tmpfs, see MySQL Bug#26662.
^ Found warnings in /home/sveta/build/ps-5.7/mysql-test/var/log/mysqld.1.err
ok

 - the logfile can be found in '/home/sveta/build/ps-5.7/mysql-test/var/log/main.alias/alias.log'
--------------------------------------------------------------------------
The servers were restarted 0 times
Spent 0.000 of 32 seconds executing testcases
mysql-test-run: WARNING: Got errors/warnings while running tests, please examine '/home/sveta/build/ps-5.7/mysql-test/var/log/warnings' for details.

Completed: Failed 1/1 tests, 0.00% were successful.

Failing test(s): main.alias

The log files in var/log may give you some hint of what went wrong.

If you want to report this error, please read first the documentation
at http://dev.mysql.com/doc/mysql/en/mysql-test-suite.html

mysql-test-run: *** ERROR: there were failing test cases

[Sveta Smirnova (svetasmirnova)]

Not repeatable with version 5.6

[Laurynas Biveinis (laurynas-biveinis)]

Besides the warning message, this might result in reduced durability if innodb_flush_method=ALL_O_DIRECT, similar to bug 801989.

Parallel doublewrite O_DIRECT setting is unconditional and not dependent on innodb_flush_method. The fix would be:
- only for the doublewrite buffer, downgrade the message to Note severity;
- add check for os_file_set_nocache failure in parallel doublewrite create, save it in a flag, check it before flushing in buf_dblwr_flush_buffered_writes
- fix the incorrect comment added by bug 801989 fix in os_file_create_func re. fsync on parallel doublewrite (as it uses the simple os0file API)

[Laurynas Biveinis (laurynas-biveinis)]

Sveta, would you be able to test whether https://github.com/laurynas-biveinis/percona-server/tree/bug1669414 fixes the issue in your environment?

[Laurynas Biveinis (laurynas-biveinis)]

Sorry, the branch is not ready yet - will add a comment when it is

[Laurynas Biveinis (laurynas-biveinis)]

The branch is ready now

[Sveta Smirnova (svetasmirnova)]

I still see the warning

[Sveta Smirnova (svetasmirnova)]

Re-tested and confirm: bug is fixed.

[Laurynas Biveinis (laurynas-biveinis)]

https://github.com/percona/percona-server/pull/1826

[Shahriyar Rzayev (rzayev-sehriyar)]

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PS-1068