On Wed, Aug 03, 2016 at 09:40:26AM +1000, Dave Chinner wrote: > From: Dave Chinner <dchinner@xxxxxxxxxx> > > When we do DAX IO, we try to invalidate the entire page cache held > on the file. This is incorrect as it will trash the entire mapping > tree that now tracks dirty state in exceptional entries in the radix > tree slots. > > What we are trying to do is remove cached pages (e.g from reads > into holes) that sit in the radix tree over the range we are about > to write to. Hence we should just limit the invalidation to the > range we are about to overwrite. Looks fine (for a broad defintion of "fine"): Reviewed-by: Christoph Hellwig <hch@xxxxxx> > + * XXX: This is racy against mmap, and there's nothing we can do about > + * it. dax_do_io() should really do this invalidation internally as > + * it will know if we've allocated over a holei for this specific IO and > + * if so it needs to update the mapping tree and invalidate existing > + * PTEs over the newly allocated range. Remove this invalidation when > + * dax_do_io() is fixed up. FYI, I've got a basically working version of an iomap based DAX I/O path (still fails a few corner cases), and I'll see if I can add that to it. _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
