From patchwork Wed Mar 5 03:00:28 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 3770081 Return-Path: X-Original-To: patchwork-linux-nfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 7A7089F35F for ; Wed, 5 Mar 2014 03:01:55 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id B0CC720225 for ; Wed, 5 Mar 2014 03:01:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CE7652021C for ; Wed, 5 Mar 2014 03:01:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755911AbaCEDBw (ORCPT ); Tue, 4 Mar 2014 22:01:52 -0500 Received: from cantor2.suse.de ([195.135.220.15]:52099 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755165AbaCEDBw (ORCPT ); Tue, 4 Mar 2014 22:01:52 -0500 Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id AA176ACC3; Wed, 5 Mar 2014 03:01:51 +0000 (UTC) From: NeilBrown To: Trond Myklebust Date: Wed, 05 Mar 2014 14:00:28 +1100 Subject: [PATCH 5/8] NFS: teach nfs_do_access to understand MAY_NOT_BLOCK Cc: linux-nfs@vger.kernel.org Message-ID: <20140305030028.27421.27775.stgit@notabene.brown> In-Reply-To: <20140305025813.27421.23871.stgit@notabene.brown> References: <20140305025813.27421.23871.stgit@notabene.brown> User-Agent: StGit/0.16 MIME-Version: 1.0 Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP If MAY_NOT_BLOCK is set we return -ECHILD in preference to making a network call. This allows nfs_permission to call it in RCU-walk mode. Now nfs_permission() can often complete in RCU-walk mode with no error. Signed-off-by: NeilBrown --- fs/nfs/dir.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 36e12f545fd7..f3895325ac6a 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -2232,6 +2232,10 @@ static int nfs_do_access(struct inode *inode, struct rpc_cred *cred, int mask) if (status == 0) goto out_cached; + status = -ECHILD; + if (mask & MAY_NOT_BLOCK) + goto out; + /* Be clever: ask server to check for all possible rights */ cache.mask = MAY_EXEC | MAY_WRITE | MAY_READ; cache.cred = cred; @@ -2311,10 +2315,9 @@ force_lookup: cred = rpc_lookup_cred(mask & MAY_NOT_BLOCK); if (!IS_ERR(cred)) { - if (mask & MAY_NOT_BLOCK) - return -ECHILD; res = nfs_do_access(inode, cred, mask); - put_rpccred(cred); + if (!(mask & MAY_NOT_BLOCK)) + put_rpccred(cred); } else res = PTR_ERR(cred); out: