On Tue, Aug 12, 2014 at 03:39:02PM +0300, Alex Lyakas wrote: > Then I set up the following Device Mapper target onto /dev/vde: > dmsetup create VDE --table "0 41943040 linear-custom /dev/vde 0" > I am attaching the code (and Makefile) of dm-linear-custom target. > It is exact copy of dm-linear, except that it has a module > parameter. With the parameter set to 0, this is an identity mapping > onto /dev/vde. If the parameter is set to non-0, all WRITE bios are > failed with ENOSPC. There is a workqueue to fail them in a different > context (not sure if really needed, but that's what our "real" > custom > block device does). FWIW, now I've looked at the dm module, this could easily be added to the dm-flakey driver by adding a "queue_write_error" option to it (i.e. similar to the current drop_writes and corrupt_bio_byte options). If we add the code there, then we could add a debug-only XFS sysfs variable to trigger the log recovery sleep, and then use dm-flakey to queue and error out writes. That gives us a reproducable xfstest for this condition. Brian, does that sound like a reasonable plan to you? Thanks for describing the method you've been using to reproduce the bug so clearly, Alex. Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
