On Mon, Nov 20, 2017 at 08:18:29AM -0800, Matthew Wilcox wrote: > On Fri, Nov 17, 2017 at 11:39:25AM -0800, Darrick J. Wong wrote: > > If two programs simultaneously try to write to the same part of a file > > via direct IO and buffered IO, there's a chance that the post-diowrite > > pagecache invalidation will fail on the dirty page. When this happens, > > the dio write succeeded, which means that the page cache is no longer > > coherent with the disk! > > This seems like a good opportunity to talk about what I've been working > on for solving this problem. The XArray is going to introduce a set > of entries which can be stored to locations in the page cache that I'm > calling 'wait entries'. What's this XArray thing you speak of? Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx
