On Mon, Nov 21, 2016 at 03:41:06PM -0800, Eric Biggers wrote: > 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. OK. > 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. If there's no other alternative, a test written in C is better than nothing. Thanks! -Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- 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
