source: branches/fc15-dev/server/common/patches/openafs-0006-linux-2.6.38-Make-d_revalidate-RCU-walk-aware.patch @ 1898

From 7bcd8c5884683a38cbe04faa631bda15b38a492b Mon Sep 17 00:00:00 2001
From: Marc Dionne <marc.c.dionne@gmail.com>
Date: Tue, 25 Jan 2011 18:18:56 -0500
Subject: [PATCH 6/8] linux: 2.6.38: Make d_revalidate RCU-walk aware

Signal to the vfs that we don't support path RCU walk in
d_revalidate.  It will call back in non-RCU mode.

Reviewed-on: http://gerrit.openafs.org/3759
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
(cherry picked from commit 52556d50298e4a636f07e9a3cf0b6557c882c82d)

Change-Id: Id346ca87a1a064ab7d66140156cb8eb48a888566
Signed-off-by: Anders Kaseorg <andersk@mit.edu>
Reviewed-on: http://gerrit.openafs.org/3995
Reviewed-by: Simon Wilkinson <sxw@inf.ed.ac.uk>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Marc Dionne <marc.c.dionne@gmail.com>
Reviewed-by: Russ Allbery <rra@stanford.edu>
Reviewed-on: http://gerrit.openafs.org/4042
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>
---
 src/afs/LINUX/osi_vnodeops.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/src/afs/LINUX/osi_vnodeops.c b/src/afs/LINUX/osi_vnodeops.c
index 03294b2..e2a3e28 100644
--- a/src/afs/LINUX/osi_vnodeops.c
+++ b/src/afs/LINUX/osi_vnodeops.c
@@ -865,10 +865,16 @@ afs_linux_dentry_revalidate(struct dentry *dp)
     int valid;
     struct afs_fakestat_state fakestate;
 
+#ifdef LOOKUP_RCU
+    /* We don't support RCU path walking */
+    if (nd->flags & LOOKUP_RCU)
+       return -ECHILD;
+#endif
 #ifdef AFS_LINUX24_ENV
     lock_kernel();
 #endif
     AFS_GLOCK();
+
     afs_InitFakeStat(&fakestate);
 
     if (dp->d_inode) {
-- 
1.7.3.4