add missing unlock before returning in uvn_detach()

uvn_detach sets UVM_VNODE_RELKILL flag and wait for all async i/o to finish. but
uvm_vnp_terminate() could clear the flag and take over the vnode.

mpi@ noted that this code path is mostly dead code because there is no "async
I/O" (uvn_io() is always synchronous).

ok visa@ mpi@

diff --git a/sys/uvm/uvm_vnode.c b/sys/uvm/uvm_vnode.c
index c9e7dd6..3f3de38 100644 (file)
--- a/sys/uvm/uvm_vnode.c
+++ b/sys/uvm/uvm_vnode.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: uvm_vnode.c,v 1.121 2021/12/15 12:53:53 mpi Exp $     */
+/*     $OpenBSD: uvm_vnode.c,v 1.122 2022/04/19 15:30:52 semarie Exp $ */
 /*     $NetBSD: uvm_vnode.c,v 1.36 2000/11/24 20:34:01 chs Exp $       */
 
 /*
@@ -358,8 +358,10 @@ uvn_detach(struct uvm_object *uobj)
                    INFSLP);
        }
 
-       if ((uvn->u_flags & UVM_VNODE_RELKILL) == 0)
+       if ((uvn->u_flags & UVM_VNODE_RELKILL) == 0) {
+               rw_exit(uobj->vmobjlock);
                return;
+       }
 
        /*
         * kill object now.   note that we can't be on the sync q because