On Thu, Aug 02, 2012 at 12:57:44AM -0700, Joel Becker wrote: > On Tue, Jul 31, 2012 at 06:33:23PM -0400, J. Bruce Fields wrote: > > From: "J. Bruce Fields" <bfields@xxxxxxxxxx> > > > > XXX: I don't understand this code, but I also can't see how it can be > > right as is: a dentry marked DCACHE_DISCONNECTED can in fact be a > > fully-connected member of the dcache. Is IS_ROOT() the right check > > instead? > > > > Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx> > > NAK. DISCONNECTED is cleared when the dentry is materialized. Are you sure? ocfs2 uses d_splice_alias in its lookup method, which doesn't clear DISCONNECTED. (d_materialise_unique does something similar to d_splice_alias and also clears DISCONNECTED. However, I'm almost certain that's a bug in d_materialise_unique. The export code connects a looked-up-by-filehandle directory by doing lookups in parents one step at a time up to the root, only clearing DISCONNECTED once we know that the dentry is connected all the way up to the root. Clearing DISCONNECTED as soon as a single dentry is connected to parents will lead to bugs.) > Here's the context. When an ocfs2 dentry is discoverable via the tree > (lookup or splicing an alias), we hold a cluster lock (the "dentry > lock"). This is why we override d_move(), to make sure that state is > kept sane. That way, other nodes can communicate unlink to this node. Alas, I'm not following you. I'll stare at some of the code and try to understand.... > They notify our node via the locking system, which does a > d_delete()+dput(), which sets DISCONNECTED. When the dentry gets its > final put, we can properly accept an empty lock. So you also depend on d_kill setting DISCONNECTED, huh. --b. -- 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
