From: David Miller <davem@xxxxxxxxxxxxx> Date: Thu, 18 Nov 2010 12:51:23 -0800 (PST) > 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. In fact the conflicts of your patch set are even more pervasive, since all dcache hash traversals are essentially RCU protected instead of dcache_lock protected right now. This makes it very difficult to test or analyze your patches for those of us on mainline or similar. -- 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
