On Thu, Oct 06, 2016 at 04:12:56PM +0800, Qu Wenruo wrote: > Hi, > > Just as the title says, for some case(OK, btrfs again) we need to > catch a file system in special timing. > > In this specific case, we need to grab a btrfs image undergoing > balancing, just before the balance finished. > > Although we can use flakey to drop all write, we still don't have > method to catch the timing of the that transaction. > > > On the other hand, we can tweak our local kernel, adding > msleep()/message and dump the disk during the sleep. > And the image I dumped can easily trigger btrfs kernel and user-space bug. > > So I'm wondering if I can just upload a zipped raw image as part of > the test case? Preferably not. We've managed to avoid pre-built images in xfstests for 15 years, so there'd have to be a really good reason to start doing this, especially as once we open that floodgate we'll end up with everyone wanting to do this and it will blow out the size of the repository in now time. If the issue is just timing or being unable to trigger an error at the right time, this is what error injection frameworks or debug-only sysfs hooks are for. The XFS kernel code has both, xfstests use both, and they pretty much do away with the need for custom binary filesystem images for such testing... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe fstests" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
