Simplify the overly complex VXLOCK handling in spec_close.

The code only needs to know if the vnode is exclusive locked and this
can be done on entry of the function.
OK mpi@

diff --git a/sys/kern/spec_vnops.c b/sys/kern/spec_vnops.c
index 8d50c04..57474fb 100644 (file)
--- a/sys/kern/spec_vnops.c
+++ b/sys/kern/spec_vnops.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: spec_vnops.c,v 1.109 2022/08/14 01:58:27 jsg Exp $    */
+/*     $OpenBSD: spec_vnops.c,v 1.110 2022/11/09 18:12:47 claudio Exp $        */
 /*     $NetBSD: spec_vnops.c,v 1.29 1996/04/22 01:42:38 christos Exp $ */
 
 /*
@@ -465,8 +465,11 @@ spec_close(void *v)
        int mode, relock, xlocked, error;
        int clone = 0;
 
-       switch (vp->v_type) {
+       mtx_enter(&vnode_mtx);
+       xlocked = (vp->v_lflag & VXLOCK);
+       mtx_leave(&vnode_mtx);
 
+       switch (vp->v_type) {
        case VCHR:
                /*
                 * Hack: a tty device that is a controlling terminal
@@ -490,9 +493,6 @@ spec_close(void *v)
                         * of forcibly closing the device, otherwise we only
                         * close on last reference.
                         */
-                       mtx_enter(&vnode_mtx);
-                       xlocked = (vp->v_lflag & VXLOCK);
-                       mtx_leave(&vnode_mtx);
                        if (vcount(vp) > 1 && !xlocked)
                                return (0);
                }
@@ -508,9 +508,6 @@ spec_close(void *v)
                 * that, we must lock the vnode. If we are coming from
                 * vclean(), the vnode is already locked.
                 */
-               mtx_enter(&vnode_mtx);
-               xlocked = (vp->v_lflag & VXLOCK);
-               mtx_leave(&vnode_mtx);
                if (!xlocked)
                        vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
                error = vinvalbuf(vp, V_SAVE, ap->a_cred, p, 0, INFSLP);
@@ -527,9 +524,6 @@ spec_close(void *v)
                 * sum of the reference counts on all the aliased
                 * vnodes descends to one, we are on last close.
                 */
-               mtx_enter(&vnode_mtx);
-               xlocked = (vp->v_lflag & VXLOCK);
-               mtx_leave(&vnode_mtx);
                if (vcount(vp) > 1 && !xlocked)
                        return (0);
                devclose = bdevsw[major(dev)].d_close;
@@ -541,9 +535,6 @@ spec_close(void *v)
        }
 
        /* release lock if held and this isn't coming from vclean() */
-       mtx_enter(&vnode_mtx);
-       xlocked = (vp->v_lflag & VXLOCK);
-       mtx_leave(&vnode_mtx);
        relock = VOP_ISLOCKED(vp) && !xlocked;
        if (relock)
                VOP_UNLOCK(vp);