Hello, this is my first attempt at DAX page fault locking rewrite. It is mostly just a dump of current status of my git tree so that people can see where I'm going before weekend. It should be complete but so far it is only compile tested. The basic idea is that we use a bit in an exceptional radix tree entry as a lock bit and use it similarly to how page lock is used for normal faults. That way we fix races between hole instantiation and read faults of the same index. For now I have disabled PMD faults since there the issues with page fault locking are even worse. I think we will need something like Matthew's multi-order radix tree to fix the races for PMD faults but I want to have a look at those once locking for normal pages is working. In the end I have decided to implement the bit locking directly in the DAX code. Originally I was thinking we could provide something generic directly in the radix tree code but the functions DAX needs are rather specific. Maybe someone else will have a good idea how to distill some generally useful functions out of what I've implemented for DAX but for now I didn't bother with that. Honza -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
