[src/trunk]: src/sys/kern Change the operations vector before changing the mo...

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

details:   https://anonhg.NetBSD.org/src/rev/46e3b058b1c4
branches:  trunk
changeset: 822652:46e3b058b1c4
user:      hannken <hannken%NetBSD.org@localhost>
date:      Thu Mar 30 09:15:51 2017 +0000

description:
Change the operations vector before changing the mount.

Vnode operations enter the mount before using the vector.

diffstat:

 sys/kern/vfs_vnode.c |  21 +++++++++++++--------
 1 files changed, 13 insertions(+), 8 deletions(-)

diffs (51 lines):

diff -r e2ada1b3cce8 -r 46e3b058b1c4 sys/kern/vfs_vnode.c
--- a/sys/kern/vfs_vnode.c      Thu Mar 30 09:14:59 2017 +0000
+++ b/sys/kern/vfs_vnode.c      Thu Mar 30 09:15:51 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: vfs_vnode.c,v 1.79 2017/03/30 09:14:59 hannken Exp $   */
+/*     $NetBSD: vfs_vnode.c,v 1.80 2017/03/30 09:15:51 hannken Exp $   */
 
 /*-
  * Copyright (c) 1997-2011 The NetBSD Foundation, Inc.
@@ -156,7 +156,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_vnode.c,v 1.79 2017/03/30 09:14:59 hannken Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_vnode.c,v 1.80 2017/03/30 09:15:51 hannken Exp $");
 
 #include <sys/param.h>
 #include <sys/kernel.h>
@@ -1556,11 +1556,6 @@
        /* Purge name cache. */
        cache_purge(vp);
 
-       /* Move to dead mount. */
-       vp->v_vflag &= ~VV_ROOT;
-       atomic_inc_uint(&dead_rootmount->mnt_refcnt);
-       vfs_insmntque(vp, dead_rootmount);
-
        /* Remove from vnode cache. */
        hash = vcache_hash(&vip->vi_key);
        mutex_enter(&vcache_lock);
@@ -1578,9 +1573,19 @@
        VSTATE_CHANGE(vp, VS_RECLAIMING, VS_RECLAIMED);
        vp->v_tag = VT_NON;
        KNOTE(&vp->v_klist, NOTE_REVOKE);
+       mutex_exit(vp->v_interlock);
 
+       /*
+        * Move to dead mount.  Must be after changing the operations
+        * vector as vnode operations enter the mount before using the
+        * operations vector.  See sys/kern/vnode_if.c.
+        */
+       vp->v_vflag &= ~VV_ROOT;
+       atomic_inc_uint(&dead_rootmount->mnt_refcnt);
+       vfs_insmntque(vp, dead_rootmount);
+
+       mutex_enter(vp->v_interlock);
        fstrans_done(mp);
-
        KASSERT((vp->v_iflag & VI_ONWORKLST) == 0);
 }