On Tue, Nov 22, 2016 at 08:32:51AM +1100, Dave Chinner wrote: > > This means that reproducing the race condition is going to be > machine dependent regardless of how the test is written. > > In cases like this for XFS, we tend towards adding a debug sysfs > file to introduce a delay into the code that allows the race to be > triggered reliably. The delay is only included in CONFIG_XFS_DEBUG=y > builds, and the test is conditional on the sysfs file being present. > > e.g. xfs/051 uses a log recovery delay to allow us to reliably > trigger IO errors in the middle of log recovery and hence exercise > the IO error failure paths in the middle of recovery. This made an > extremely unreliable reproducer into a test case that triggered > reliably on every machine the test is run on.... > > Can something like this be done in this case? > I'd really rather not do something like that just for this test, which is really just testing that the kernel does inode_lock()/inode_unlock() in fscrypt_process_policy(). It would be more worthwhile if the testing-only kernel code would help expose many race conditions, not just this one particular race in this particular ioctl. So if you don't want to have the C version of this test in xfstests, I think it should just be dropped from the series. Eric -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
