Hi guys, I'm a bit late the party, but: On Sun, 17 Oct 2010, Dave Chinner wrote: > On Sun, Oct 17, 2010 at 04:13:10PM +1100, Nick Piggin wrote: > > On Sun, Oct 17, 2010 at 03:35:14PM +1100, Nick Piggin wrote: > > > On Sun, Oct 17, 2010 at 03:13:13PM +1100, Dave Chinner wrote: > > > > On Sun, Oct 17, 2010 at 01:49:23PM +1100, Nick Piggin wrote: > > > > > On Sat, Oct 16, 2010 at 09:30:47PM -0400, Christoph Hellwig wrote: > > > > > > > * inode->i_lock is *always* the innermost lock. > > > > > > > * > > > > > > > + * inode->i_lock is *always* the innermost lock. > > > > > > > + * > > > > > > > > > > > > No need to repeat, we got it.. > > > > > > > > > > Except that I didn't see where you fixed all the places where it is > > > > > *not* the innermost lock. Like for example places that take dcache_lock > > > > > inside i_lock. > > > > > > > > I can't find any code outside of ceph where the dcache_lock is used > > > > within 200 lines of code of the inode->i_lock. The ceph code is not > > > > nesting them, though. > > > > > > You mustn't have looked very hard? From ceph: > > > > > > spin_unlock(&dcache_lock); > > > spin_unlock(&inode->i_lock); > > > > > > (and yes, acquisition side does go in i_lock->dcache_lock order) > > Sorry, easy to miss with a quick grep when the locks are taken in > different functions. > > Anyway, this one looks difficult to fix without knowing something > about Ceph and wtf it is doing there. It's one to punt to the > maintainer to solve as it's not critical to this patch set. I took a look at this code and was able to remove the i_lock -> dcache_lock nesting. To be honest, I'm not sure why I did it that way in the first place. The only point (now) where i_lock is used/needed is while checking the ceph inode flags, and that's done without holding dcache_lock (presumably soon to be d_lock). The patch is 622386be in the for-next branch of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client.git Anyway, hope this helps! sage -- 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
