On Tue, Jun 26, 2012 at 12:07:17AM -0600, Miao Xie wrote: > The 209th case of xfstests failed because of the race between aio and dio. The > detail reason is following: > Task1 Task2 Btrfs-worker > invalidate pages > read pages > do direct io > invalidate pages fail* > finish ordered io > read data from > pages > This just papers over the problem and makes DIO touch page cache which it shouldn't be doing if it's working properly, so NAK. We need to figure out why exactly my patch didn't work, since it should be working. The write should be doing lock_extent setup ordered extent unlock_extent and the read should be doing lock_extent check for ordered extent if there is one unlock and wait and then loop do read unlock_extent there should be no room for races in here. The patch I sent earlier should have caught if we had done a read between the invalidate and the locking and should be invalidating the range again and then checking. If this isn't working then something else is going sideways and we really need to figure out what it is rather than just working around the issue, as it will likely bite us in a different way later. Thanks, Josef -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
