NFS: nfs_rename() should not have to flush out writebacks

We don't really support nfs servers that invalidate the file handle after a
rename, so precautions such as flushing out dirty data before renaming the
file are superfluous.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/dir.c

@@ -1652,16 +1652,7 @@ static int nfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 		}
 	}
 
-	/*
-	 * ... prune child dentries and writebacks if needed.
-	 */
-	if (atomic_read(&old_dentry->d_count) > 1) {
-		if (S_ISREG(old_inode->i_mode))
-			nfs_wb_all(old_inode);
-		shrink_dcache_parent(old_dentry);
-	}
 	nfs_inode_return_delegation(old_inode);
-
 	if (new_inode != NULL)
 		nfs_inode_return_delegation(new_inode);