From e9d598caae72203455d55f0b6753641bf841e41e Mon Sep 17 00:00:00 2001
From: Trond Myklebust <Trond.Myklebust@netapp.com>
Date: Wed, 12 Dec 2007 11:12:15 -0500
Subject: [PATCH] --- yaml --- r: 74962 b: refs/heads/master c:
 a10db50a4ae813fcb2f431f2fb039933c109a925 h: refs/heads/master v: v3

---
 [refs]                 |  2 +-
 trunk/fs/nfs/getroot.c | 11 +++++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index 7ef12cdd4d5e..df38d44d3e25 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: a5576cfa5cd8d8aa874bd4ee500dc8a2e7cbad18
+refs/heads/master: a10db50a4ae813fcb2f431f2fb039933c109a925
diff --git a/trunk/fs/nfs/getroot.c b/trunk/fs/nfs/getroot.c
index 0ee43843f4ec..e6242cdbaf91 100644
--- a/trunk/fs/nfs/getroot.c
+++ b/trunk/fs/nfs/getroot.c
@@ -57,6 +57,17 @@ static int nfs_superblock_set_dummy_root(struct super_block *sb, struct inode *i
 		}
 		/* Circumvent igrab(): we know the inode is not being freed */
 		atomic_inc(&inode->i_count);
+		/*
+		 * Ensure that this dentry is invisible to d_find_alias().
+		 * Otherwise, it may be spliced into the tree by
+		 * d_materialise_unique if a parent directory from the same
+		 * filesystem gets mounted at a later time.
+		 * This again causes shrink_dcache_for_umount_subtree() to
+		 * Oops, since the test for IS_ROOT() will fail.
+		 */
+		spin_lock(&dcache_lock);
+		list_del_init(&sb->s_root->d_alias);
+		spin_unlock(&dcache_lock);
 	}
 	return 0;
 }