[src/trunk]: src/sys/kern reassignbuf(), brelvp(): VI_WRMAPDIRTY is always cl...

[ad <ad%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/49c37aa67501
branches:  trunk
changeset: 969799:49c37aa67501
user:      ad <ad%NetBSD.org@localhost>
date:      Sun Mar 01 21:39:07 2020 +0000

description:
reassignbuf(), brelvp(): VI_WRMAPDIRTY is always clear if the object has no
pages, so assert that instead of trying to clear it.

diffstat:

 sys/kern/vfs_subr.c |  19 ++++---------------
 1 files changed, 4 insertions(+), 15 deletions(-)

diffs (47 lines):

diff -r f13b8ee56f21 -r 49c37aa67501 sys/kern/vfs_subr.c
--- a/sys/kern/vfs_subr.c       Sun Mar 01 21:37:26 2020 +0000
+++ b/sys/kern/vfs_subr.c       Sun Mar 01 21:39:07 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: vfs_subr.c,v 1.482 2020/02/27 22:12:54 ad Exp $        */
+/*     $NetBSD: vfs_subr.c,v 1.483 2020/03/01 21:39:07 ad Exp $        */
 
 /*-
  * Copyright (c) 1997, 1998, 2004, 2005, 2007, 2008, 2019, 2020
@@ -69,7 +69,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_subr.c,v 1.482 2020/02/27 22:12:54 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_subr.c,v 1.483 2020/03/01 21:39:07 ad Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_ddb.h"
@@ -423,12 +423,7 @@
 
        if ((vp->v_iflag & (VI_ONWORKLST | VI_PAGES)) == VI_ONWORKLST &&
            LIST_FIRST(&vp->v_dirtyblkhd) == NULL) {
-               /*
-                * Okay to clear VI_WRMAPDIRTY without the uvm_object locked
-                * here, because new pages can't be inserted without first
-                * taking v_interlock (which is held here).
-                */
-               vp->v_iflag &= ~VI_WRMAPDIRTY;
+               KASSERT((vp->v_iflag & VI_WRMAPDIRTY) == 0);
                vn_syncer_remove_from_worklist(vp);
        }
 
@@ -469,13 +464,7 @@
                if ((vp->v_iflag & (VI_ONWORKLST | VI_PAGES)) ==
                    VI_ONWORKLST &&
                    LIST_FIRST(&vp->v_dirtyblkhd) == NULL) {
-                       /*
-                        * Okay to clear VI_WRMAPDIRTY without the
-                        * uvm_object locked here, because new pages can't
-                        * be inserted without first taking v_interlock
-                        * (which is held here).
-                        */
-                       vp->v_iflag &= ~VI_WRMAPDIRTY;
+                       KASSERT((vp->v_iflag & VI_WRMAPDIRTY) == 0);
                        vn_syncer_remove_from_worklist(vp);
                }
        } else {