[src/trunk]: src/sys/nfs VOP_GETATTR() needs a shared lock at least.

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

details:   https://anonhg.NetBSD.org/src/rev/f66eb51d3d92
branches:  trunk
changeset: 770581:f66eb51d3d92
user:      hannken <hannken%NetBSD.org@localhost>
date:      Mon Oct 24 11:43:30 2011 +0000

description:
VOP_GETATTR() needs a shared lock at least.

As nfs_kqpoll() ignores the return value from VOP_GETATTR() initialize
the attrributes to zero -- nfs_kqfilter() does the same.

diffstat:

 sys/nfs/nfs_kq.c     |  9 +++++++--
 sys/nfs/nfs_vfsops.c |  6 ++++--
 2 files changed, 11 insertions(+), 4 deletions(-)

diffs (67 lines):

diff -r 11bb20c58762 -r f66eb51d3d92 sys/nfs/nfs_kq.c
--- a/sys/nfs/nfs_kq.c  Mon Oct 24 07:33:26 2011 +0000
+++ b/sys/nfs/nfs_kq.c  Mon Oct 24 11:43:30 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: nfs_kq.c,v 1.24 2011/06/12 03:35:59 rmind Exp $        */
+/*     $NetBSD: nfs_kq.c,v 1.25 2011/10/24 11:43:30 hannken Exp $      */
 
 /*-
  * Copyright (c) 2002, 2008 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: nfs_kq.c,v 1.24 2011/06/12 03:35:59 rmind Exp $");
+__KERNEL_RCSID(0, "$NetBSD: nfs_kq.c,v 1.25 2011/10/24 11:43:30 hannken Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -138,7 +138,10 @@
                        /* save v_size, nfs_getattr() updates it */
                        osize = ke->vp->v_size;
 
+                       memset(&attr, 0, sizeof(attr));
+                       vn_lock(ke->vp, LK_SHARED | LK_RETRY);
                        (void) VOP_GETATTR(ke->vp, &attr, l->l_cred);
+                       VOP_UNLOCK(ke->vp);
 
                        /* following is a bit fragile, but about best
                         * we can get */
@@ -318,7 +321,9 @@
         * held. This is likely cheap due to attrcache, so do it now.
         */
        memset(&attr, 0, sizeof(attr));
+       vn_lock(vp, LK_SHARED | LK_RETRY);
        (void) VOP_GETATTR(vp, &attr, l->l_cred);
+       VOP_UNLOCK(vp);
 
        mutex_enter(&nfskq_lock);
 
diff -r 11bb20c58762 -r f66eb51d3d92 sys/nfs/nfs_vfsops.c
--- a/sys/nfs/nfs_vfsops.c      Mon Oct 24 07:33:26 2011 +0000
+++ b/sys/nfs/nfs_vfsops.c      Mon Oct 24 11:43:30 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: nfs_vfsops.c,v 1.219 2011/10/07 09:35:06 hannken Exp $ */
+/*     $NetBSD: nfs_vfsops.c,v 1.220 2011/10/24 11:43:30 hannken Exp $ */
 
 /*
  * Copyright (c) 1989, 1993, 1995
@@ -35,7 +35,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: nfs_vfsops.c,v 1.219 2011/10/07 09:35:06 hannken Exp $");
+__KERNEL_RCSID(0, "$NetBSD: nfs_vfsops.c,v 1.220 2011/10/24 11:43:30 hannken Exp $");
 
 #if defined(_KERNEL_OPT)
 #include "opt_nfs.h"
@@ -387,7 +387,9 @@
        vfs_unbusy(mp, false, NULL);
 
        /* Get root attributes (for the time). */
+       vn_lock(vp, LK_SHARED | LK_RETRY);
        error = VOP_GETATTR(vp, &attr, l->l_cred);
+       VOP_UNLOCK(vp);
        if (error)
                panic("nfs_mountroot: getattr for root");
        n = attr.va_atime.tv_sec;