On Wed, 2007-11-14 at 22:22 +0100, Nick Piggin wrote: > On Wed, Nov 14, 2007 at 09:01:39PM +0100, Peter Zijlstra wrote: > > Normal locking order is: > > > > i_mutex > > mmap_sem > > > > However NFS's ->mmap hook, which is called under mmap_sem, can take i_mutex. > > Avoid this potential deadlock by doing the work that requires i_mutex from > > the new ->mmap_prepare(). > > > > [ Is this sufficient, or does it introduce a race? ] > > Seems like an OK patchset in my opinion. I don't know much about NFS > unfortunately, but I wonder what prevents the condition fixed by > nfs_revalidate_mapping from happening again while the mmap is active...? As the changelog might have suggested, I'm not overly sure of the nfs requirements myself. I think it just does a best effort at getting the pages coherent with other clients, and then hopes for the best. I'll let Trond enlighten us further before I make an utter fool of myself :-) - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
