On Thu, Nov 18, 2010 at 12:51:23PM -0800, David Miller wrote: > From: Nick Piggin <npiggin@xxxxxxxxx> > Date: Wed, 17 Nov 2010 01:09:01 +1100 > > > d_validate has been broken for a long time. > > > > kmem_ptr_validate does not guarantee that a pointer can be dereferenced > > if it can go away at any time. Even rcu_read_lock doesn't help, because > > the pointer might be queued in RCU callbacks but not executed yet. > > > > So the parent cannot be checked, nor the name hashed. The dentry pointer > > can not be touched until it can be verified under lock. Hashing simply > > cannot be used. > > > > Instead, verify the parent/child relationship by traversing parent's > > d_child list. It's slow, but only ncpfs and the destaged smbfs care > > about it, at this point. > > > > Signed-off-by: Nick Piggin <npiggin@xxxxxxxxx> > > This won't apply because is conflicts with Christoph Hellwig's > RCU conversion of d_validate(). > > Which is a change that went in more than a month ago. Sorry yeah I had a local revert that I didn't send out, otherwise it should be a vanilla upstream kernel. > Thus I'd really appreciate if you mentioned what tree your patches are > against in your "0/N" posting, always. Try to remember. I'll put some time into polishing up a git tree and submitting the more interesting patches as well, this weekend. Thanks, Nick -- 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
