On Fri, Oct 9, 2015 at 10:44 AM, Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> wrote: > > The issue is that revalidation may cause the dentry to be dropped in NFS > if, say, the client notes that the directory timestamps have changed. Ack. We've had this bug before, where we returned something else than -ENOCHLD while we were doing RCU lookups. See for example commit 97242f99a013 ("link_path_walk(): be careful when failing with ENOTDIR"). So in general, we should always (a) either verify all sequence points or (b) return -ENOCHLD to go into slow mode. The patch seems However, this thing was explicitly made to be this way by commit 766c4cbfacd8 ("namei: d_is_negative() should be checked before ->d_seq validation"), so while my gut feel is to consider this fix ObviouslyCorrect(tm), I will delay it a bit in the hope to get an ACK and comment from Al about the patch. Al? Linus -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html