On Mon, Jul 13, 2020 at 12:55:09PM +0100, Matthew Wilcox wrote: > On Mon, Jul 13, 2020 at 09:46:33AM +0200, Christoph Hellwig wrote: > > Failing to invalid the page cache means data in incoherent, which is > > a very bad state for the system. Always fall back to buffered I/O > > through the page cache if we can't invalidate mappings. > > Is that the right approach though? I don't have a full picture in my head, > but wouldn't we be better off marking these pages as !Uptodate and doing > the direct I/O? Isn't that a problem if e.g. pages are mapped into userspace and mlocked?
