On Fri, Oct 22, 2010 at 01:34:44PM +1100, Nick Piggin wrote: > On Fri, Oct 22, 2010 at 03:20:10AM +0100, Al Viro wrote: > > On Fri, Oct 22, 2010 at 11:45:40AM +1100, Nick Piggin wrote: > > majority already checks for I_FREEING/I_WILL_FREE, refusing to pick such > > inodes. It's not an accidental subtle property of the code, it's bloody > > fundamental. > > I didn't miss that, and I agree that at the point of my initial lock > break up, the locking is "wrong". Whether you correct it by changing > the lock ordering or by using RCU to do lookups is something I want to > debate further. > > I think it is natural to be able to lock the inode and have it lock the > icache state. Importantly, to be able to manipulate the icache state in any number of steps, under a consistent lock. Exactly like we have with inode_lock today. Stepping away from that, adding code to handle new concurrencies, before inode_lock is able to be lifted is just wrong. The locking in my lock break patch is ugly and wrong, yes. But it is always an intermediate step. I want to argue that with RCU inode work *anyway*, there is not much point to reducing the strength of the i_lock property because locking can be cleaned up nicely and still keep i_lock ~= inode_lock (for a single inode). -- 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
