On Wed, 2010-12-01 at 08:14 -0500, Rik van Riel wrote: > On 11/30/2010 11:29 PM, Trond Myklebust wrote: > > > I'm not worried about other readdir calls invalidating the page. My > > concern is rather about the VM memory reclaimers ejecting the page from > > the page cache, and calling nfs_readdir_clear_array while we're > > referencing the page. > > Wait, if nfs_readdir_clear_array can clear the page while > somebody else has a refcount to it, what good is the > refcount? Hi Rik This is readdir, so there should normally be only one process accessing the page. If that process locks it (we don't have mmap() to worry about, so page locking is reasonable here) then the scheme is safe. Note that we do clear Pg_uptodate under the page lock in the latest version of the releasepage method (patches to be published later today after I finish testing). > Why is your .releasepage modifying the data on the page, > instead of just the metadata in the struct page? We want to be able to free up the data that is referenced by the array on the page before the page itself is freed. Cheers Trond -- Trond Myklebust Linux NFS client maintainer NetApp Trond.Myklebust@xxxxxxxxxx www.netapp.com -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
