diff --git a/[refs] b/[refs]
index a7ffaf34d762..bcb8bafaf995 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: cf481c20c476ad2c0febdace9ce23f5a4db19582
+refs/heads/master: 983bfb7db303cfde56ae5bbf4e0f2f46e38c9576
diff --git a/trunk/ipc/util.c b/trunk/ipc/util.c
index 3339177b336c..0f468c34e83c 100644
--- a/trunk/ipc/util.c
+++ b/trunk/ipc/util.c
@@ -688,10 +688,6 @@ void ipc64_perm_to_ipc_perm (struct ipc64_perm *in, struct ipc_perm *out)
  * Look for an id in the ipc ids idr and lock the associated ipc object.
  *
  * The ipc object is locked on exit.
- *
- * This is the routine that should be called when the rw_mutex is not already
- * held, i.e. idr tree not protected: it protects the idr tree in read mode
- * during the idr_find().
  */
 
 struct kern_ipc_perm *ipc_lock(struct ipc_ids *ids, int id)
@@ -699,18 +695,13 @@ struct kern_ipc_perm *ipc_lock(struct ipc_ids *ids, int id)
 	struct kern_ipc_perm *out;
 	int lid = ipcid_to_idx(id);
 
-	down_read(&ids->rw_mutex);
-
 	rcu_read_lock();
 	out = idr_find(&ids->ipcs_idr, lid);
 	if (out == NULL) {
 		rcu_read_unlock();
-		up_read(&ids->rw_mutex);
 		return ERR_PTR(-EINVAL);
 	}
 
-	up_read(&ids->rw_mutex);
-
 	spin_lock(&out->lock);
 	
 	/* ipc_rmid() may have already freed the ID while ipc_lock