From 824f4facbdce7886b5916b1f2c05843c0b989266 Mon Sep 17 00:00:00 2001
From: Nick Piggin <npiggin@kernel.dk>
Date: Fri, 14 Jan 2011 02:35:53 +0000
Subject: [PATCH] --- yaml --- r: 230859 b: refs/heads/master c:
 bb20c18db6fbb5e6ba499c76473a487d35073467 h: refs/heads/master i:   230857:
 13beff45de54294179357ba6693324ffcdf850e2   230855:
 24c3131d604244bd9ecea2d0ceadb90aa4bf914b v: v3

---
 [refs]           |  2 +-
 trunk/fs/namei.c | 10 ++++++++++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index 076957b8bafc..cb7d3888a5f6 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: a82416da83722944d78d933301e32e7c5ad70edd
+refs/heads/master: bb20c18db6fbb5e6ba499c76473a487d35073467
diff --git a/trunk/fs/namei.c b/trunk/fs/namei.c
index 19433cdba011..0f02359ce685 100644
--- a/trunk/fs/namei.c
+++ b/trunk/fs/namei.c
@@ -583,6 +583,13 @@ void release_open_intent(struct nameidata *nd)
 		fput(nd->intent.open.file);
 }
 
+/*
+ * Call d_revalidate and handle filesystems that request rcu-walk
+ * to be dropped. This may be called and return in rcu-walk mode,
+ * regardless of success or error. If -ECHILD is returned, the caller
+ * must return -ECHILD back up the path walk stack so path walk may
+ * be restarted in ref-walk mode.
+ */
 static int d_revalidate(struct dentry *dentry, struct nameidata *nd)
 {
 	int status;
@@ -673,6 +680,9 @@ force_reval_path(struct path *path, struct nameidata *nd)
 		return 0;
 
 	if (!status) {
+		/* Don't d_invalidate in rcu-walk mode */
+		if (nameidata_drop_rcu(nd))
+			return -ECHILD;
 		d_invalidate(dentry);
 		status = -ESTALE;
 	}