NFS: Sillyrename: in the case of a race, check aliases are really positive

In nfs_do_call_unlink() we check that we haven't raced, and that lookup()
hasn't created an aliased dentry to our sillydeleted dentry. If somebody
has deleted the file on the server and the lookup() resulted in a negative
dentry, then ignore...

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/fs/nfs/unlink.c b/fs/nfs/unlink.c
index c5fa6d8001f1..431981d0265f 100644
--- a/fs/nfs/unlink.c
+++ b/fs/nfs/unlink.c
@@ -130,13 +130,15 @@ static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct n
         alias = d_lookup(parent, &data->args.name);
         if (alias != NULL) {
                 int ret = 0;
+
                 /*
                  * Hey, we raced with lookup... See if we need to transfer
                  * the sillyrename information to the aliased dentry.
                  */
                 nfs_free_dname(data);
                 spin_lock(&alias->d_lock);
-                if (!(alias->d_flags & DCACHE_NFSFS_RENAMED)) {
+                if (alias->d_inode != NULL &&
+                    !(alias->d_flags & DCACHE_NFSFS_RENAMED)) {
                         alias->d_fsdata = data;
                         alias->d_flags |= DCACHE_NFSFS_RENAMED;
                         ret = 1;