Implement lookup for . and ..

* procfs.c (procfs_lookup): Keep track of the parent directory,
  implement the lookup of the dot-directories.  (procfs_cleanup):
  Release the reference to the parent node, if applicable.
* procfs.h: Add a comment about the parent reference.
* netfs.c (netfs_attempt_lookup): Lock the looked up node after
  the directory has been unlocked, in case they are the same.

1 files changed, 2 insertions, 1 deletions

diff --git a/netfs.c b/netfs.c
index 58665085..6b105f91 100644
--- a/netfs.c
+++ b/netfs.c
@@ -151,10 +151,11 @@ error_t netfs_attempt_lookup (struct iouser *user, struct node *dir,
   error_t err;
 
   err = procfs_lookup (dir, name, np);
+  mutex_unlock (&dir->lock);
+
   if (! err)
     mutex_lock (&(*np)->lock);
 
-  mutex_unlock (&dir->lock);
   return err;
 }