On Sun, Oct 12, 2014 at 05:37:37AM +0100, Al Viro wrote: > > Gets clumsy in set_root_rcu() - you do *not* want it to bugger nd->inode > when done by follow_dotdot_rcu(), so we'd need either some indication which > caller it is, or something like struct inode **inode in argument list, > with NULL passed from follow_dotdot_rcu(), while path_init() would give > it &nd->inode... > > Doable, but unpleasant. And the price of that check is trivial - after all, > in case we *don't* bugger off immediately, we have that ->d_seq in cache - > we'd fetched it just before. Or set_root_rcu() can be hand-inlined, like the AT_FDCWD case. Then the only caller of set_root_rcu() would be follow_dotdot_rcu(), and the unnecessary __read_seqcount_begin() could be removed. (Probably gcc can't optimize it out currently, because of the ACCESS_ONCE().) -- 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
