Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote: > commit e3db7691e9f3dff3289f64e3d98583e28afe03db > Author: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx> > Date: Wed Jan 10 23:15:39 2007 -0800 > > [PATCH] NFS: Fix race in nfs_release_page() >... > invalidate_inode_pages2() may find the dirty bit has been set on a page > owing to the fact that the page may still be mapped after it was locked. > Only after the call to unmap_mapping_range() are we sure that the page > can no longer be dirtied. Is that last sentence even true? It evicts folios from the TLB and/or pagetables, but it doesn't actually trim any mmap made - in which case, userspace is perfectly at liberty to regenerate and dirty the folio the moment the folio is removed from the page tables. Otherwise DIO-to/from-mmap will deadlock. > but my belief is that we should be able to get rid of it. I think you're probably correct. The best we can do, I think, is to preface any call to invalidate_inode_pages2() with a flush-and-wait over the same range. David
