NFSv4: Don't invalidate inode attributes on delegation return

There is no need to declare attributes such as the ctime, mtime and
block size invalid when we're just returning a delegation, so it is
inappropriate to call nfs_post_op_update_inode_force_wcc().
Instead, just call nfs_refresh_inode() after faking up the change
attribute. We know that the GETATTR op occurs before the DELEGRETURN, so
we are safe when doing this.

Fixes: 0bc2c9b4 ("NFSv4: Don't discard the attributes returned by asynchronous DELEGRETURN")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

fs/nfs/nfs4proc.c

@@ -363,6 +363,14 @@ static void nfs4_setup_readdir(u64 cookie, __be32 *verifier, struct dentry *dent
 	kunmap_atomic(start);
 }
 
+static void nfs4_fattr_set_prechange(struct nfs_fattr *fattr, u64 version)
+{
+	if (!(fattr->valid & NFS_ATTR_FATTR_PRECHANGE)) {
+		fattr->pre_change_attr = version;
+		fattr->valid |= NFS_ATTR_FATTR_PRECHANGE;
+	}
+}
+
 static void nfs4_test_and_free_stateid(struct nfs_server *server,
 		nfs4_stateid *stateid,
 		const struct cred *cred)
@@ -6553,7 +6561,9 @@ static void nfs4_delegreturn_release(void *calldata)
 		pnfs_roc_release(&data->lr.arg, &data->lr.res,
 				 data->res.lr_ret);
 	if (inode) {
-		nfs_post_op_update_inode_force_wcc(inode, &data->fattr);
+		nfs4_fattr_set_prechange(&data->fattr,
+					 inode_peek_iversion_raw(inode));
+		nfs_refresh_inode(inode, &data->fattr);
 		nfs_iput_and_deactive(inode);
 	}
 	kfree(calldata);