Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:13427 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757682Ab0ENRig (ORCPT ); Fri, 14 May 2010 13:38:36 -0400 Date: Fri, 14 May 2010 13:38:19 -0400 From: Jeff Layton To: Trond Myklebust Cc: Mi Jinlong , NFSv3 list , linux-fsdevel@vger.kernel.org, ebiederm@xmission.com, adobriyan@gmail.com, viro@ZenIV.linux.org.uk, jamie@shareable.org Subject: Re: [PATCH] VFS: Unlink should revoke all outstanding leases on file Message-ID: <20100514133819.5e383485@tlielax.poochiereds.net> In-Reply-To: <1273857471.4732.7.camel@localhost.localdomain> References: <4BED195F.3070504@cn.fujitsu.com> <20100514055844.109d2fdc@tlielax.poochiereds.net> <1273857471.4732.7.camel@localhost.localdomain> Content-Type: text/plain; charset=US-ASCII Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 On Fri, 14 May 2010 13:17:51 -0400 Trond Myklebust wrote: > On Fri, 2010-05-14 at 05:58 -0400, Jeff Layton wrote: > > On Fri, 14 May 2010 17:35:27 +0800 > > Mi Jinlong wrote: > > > > > After client get one file's READ delegation through NFSv4, > > > server delete this file but don't reclaim the delegation. > > > > > > This patch add break_lease at may_delete, which can reclaim delegations. > > > > > > --- > > > fs/namei.c | 2 +- > > > 1 files changed, 1 insertions(+), 1 deletions(-) > > > > > > diff --git a/fs/namei.c b/fs/namei.c > > > index 16df727..17bafc1 100644 > > > --- a/fs/namei.c > > > +++ b/fs/namei.c > > > @@ -1338,7 +1338,7 @@ static int may_delete(struct inode *dir,struct dentry *victim,int isdir) > > > return -ENOENT; > > > if (victim->d_flags & DCACHE_NFSFS_RENAMED) > > > return -EBUSY; > > > - return 0; > > > + return break_lease(victim->d_inode, FMODE_WRITE); > > > } > > > > > > /* Check whether we can create an object with dentry child in directory > > > > This doesn't look right to me. > > > > The fcntl(2) manpage basically says that leases should be broken if the > > file is opened for read or write, or is truncated. unlinks don't seem > > to fall into either category... > > > > Breaking the lease in this case is certainly a requirement for NFSv4 > delegations. I've no idea what the CIFS oplock requirements are... > Heh, probably "undefined". Windows generally doesn't allow you to delete open files at all. I don't think samba will really care too much either way. I suppose it could hurt performance in situations where you had a file that was hardlinked and deleted a hardlink that was "unrelated" to the dentry being held open...but that's pretty clearly a corner case at best. At the risk of being lazy and not checking for myself...what in the NFSv4 spec mandates this? -- Jeff Layton