NFS: Fix an Oops in nfs_setattr()

It looks like nfs_setattr() and nfs_rename() also need to test whether the
target is a regular file before calling nfs_wb_all()...

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 93d046c..44aa9b7 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -341,8 +341,10 @@
 	lock_kernel();
 	nfs_begin_data_update(inode);
 	/* Write all dirty data */
-	filemap_write_and_wait(inode->i_mapping);
-	nfs_wb_all(inode);
+	if (S_ISREG(inode->i_mode)) {
+		filemap_write_and_wait(inode->i_mapping);
+		nfs_wb_all(inode);
+	}
 	/*
 	 * Return any delegations if we're going to change ACLs
 	 */