Return-Path: Received: from bombadil.infradead.org ([198.137.202.9]:56387 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932893AbbD0MvW (ORCPT ); Mon, 27 Apr 2015 08:51:22 -0400 From: Christoph Hellwig To: "J. Bruce Fields" Cc: linux-nfs@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH 1/2] nfsd/blocklayout: pretend we can send deviceid notifications Date: Mon, 27 Apr 2015 14:50:13 +0200 Message-Id: <1430139014-28013-2-git-send-email-hch@lst.de> In-Reply-To: <1430139014-28013-1-git-send-email-hch@lst.de> References: <1430139014-28013-1-git-send-email-hch@lst.de> Sender: linux-nfs-owner@vger.kernel.org List-ID: Commit df52699e4fcef ("NFSv4.1: Don't cache deviceids that have no notifications") causes the Linux NFS client stop caching deviceid unless a server pretends to support deviceid notifications. While this behavior is stupid and the language around this area in rfc5661 is a mess carified by an errata that I submittted, Trond insists on this behavior. Not caching deviceids degrades block layout performance massively as a GETDEVICEINFO is fairly expensive. So add this hack to make the Linux client happy again. Cc: stable@vger.kernel.org Signed-off-by: Christoph Hellwig --- fs/nfsd/blocklayout.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/fs/nfsd/blocklayout.c b/fs/nfsd/blocklayout.c index 03d647b..cdefaa3 100644 --- a/fs/nfsd/blocklayout.c +++ b/fs/nfsd/blocklayout.c @@ -181,6 +181,17 @@ nfsd4_block_proc_layoutcommit(struct inode *inode, } const struct nfsd4_layout_ops bl_layout_ops = { + /* + * Pretend that we send notification to the client. This is a blatant + * lie to force recent Linux clients to cache our device IDs. + * We rarely ever change the device ID, so the harm of leaking deviceids + * for a while isn't too bad. Unfortunately RFC5661 is a complete mess + * in this regard, but I filed errata 4119 for this a while ago, and + * hopefully the Linux client will eventually start caching deviceids + * without this again. + */ + .notify_types = + NOTIFY_DEVICEID4_DELETE | NOTIFY_DEVICEID4_CHANGE, .proc_getdeviceinfo = nfsd4_block_proc_getdeviceinfo, .encode_getdeviceinfo = nfsd4_block_encode_getdeviceinfo, .proc_layoutget = nfsd4_block_proc_layoutget, -- 1.9.1