Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-vc0-f174.google.com ([209.85.220.174]:46035 "EHLO mail-vc0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752389AbaHBOr2 (ORCPT ); Sat, 2 Aug 2014 10:47:28 -0400 Received: by mail-vc0-f174.google.com with SMTP id la4so8604839vcb.33 for ; Sat, 02 Aug 2014 07:47:28 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <53DCF3C0.6050201@gmail.com> References: <1406684083-19736-1-git-send-email-jlayton@primarydata.com> <1406684083-19736-32-git-send-email-jlayton@primarydata.com> <53DCBFDB.5060808@gmail.com> <53DCEAE8.70707@gmail.com> <53DCF3C0.6050201@gmail.com> Date: Sat, 2 Aug 2014 10:47:27 -0400 Message-ID: Subject: Re: [PATCH v3 31/38] nfsd: Move the open owner hash table into struct nfs4_client From: Trond Myklebust To: Kinglong Mee Cc: Jeff Layton , Bruce Fields , Linux NFS Mailing List , Christoph Hellwig Content-Type: text/plain; charset=UTF-8 Sender: linux-nfs-owner@vger.kernel.org List-ID: On Sat, Aug 2, 2014 at 10:20 AM, Kinglong Mee wrote: > On 8/2/2014 22:05, Trond Myklebust wrote: >> On Sat, Aug 2, 2014 at 9:43 AM, Kinglong Mee wrote: >>> On 8/2/2014 21:11, Trond Myklebust wrote: >>>> On Sat, Aug 2, 2014 at 6:39 AM, Kinglong Mee wrote: >>>>> On 7/30/2014 09:34, Jeff Layton wrote: >>>>>> From: Trond Myklebust >>>>>> >>>>>> Preparation for removing the client_mutex. >>>>>> >>>>>> Convert the open owner hash table into a per-client table and protect it >>>>>> using the nfs4_client->cl_lock spin lock. >>>>>> >>>>>> Signed-off-by: Trond Myklebust >>>>>> --- >>>>>> fs/nfsd/netns.h | 1 - >>>>>> fs/nfsd/nfs4state.c | 187 ++++++++++++++++++++++++---------------------------- >>>>>> fs/nfsd/state.h | 1 + >>>>>> 3 files changed, 86 insertions(+), 103 deletions(-) >>>>>> >>>>>> diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h >>>>>> index a71d14413d39..e1f479c162b5 100644 >>>>>> --- a/fs/nfsd/netns.h >>>>>> +++ b/fs/nfsd/netns.h >>>>>> @@ -63,7 +63,6 @@ struct nfsd_net { >>>>>> struct rb_root conf_name_tree; >>>>>> struct list_head *unconf_id_hashtbl; >>>>>> struct rb_root unconf_name_tree; >>>>>> - struct list_head *ownerstr_hashtbl; >>>>> >>>>> I send a patch "NFSD: Rervert "knfsd: locks: flag NFSv4-owned locks"" before, >>>>> http://comments.gmane.org/gmane.linux.nfs/64382 >>>>> >>>>> nfsd needs the hashtbl to find the lockowner for locking by owner from >>>>> fl->fl_owner stored in struct file_lock, but without nfs_client. >>>> >>>> Why? We're not currently doing that. >>> >>> Although not doing that right now, but there is a bug for getting the right ld_owner >>> in nfs4_set_lock_denied. >>> >>> If denying locks, vfs don't copy fl->fl_lmops to the returned file_lock, so that, >>> fl->fl_lmops always be NULL, nfsd never return the owner who holds the conflock. >>> >>> If we want fix this problem, needs finding the lockowner from struct file_lock. >> >> Do we really care enough about fixing nfs4_set_lock_denied enough to >> do so at the cost of reducing overall scalability of locking state? > > I just report this problem, don't think enough about the scalability. > >> We will always be faking up the clientid etc for local locks. Are >> there any clients out there that actually inspect the clientid on a >> result of NFS4ERR_DENIED and that will break if we give them a fake >> for non-local locks? > > Jeff has point the same problem of a non-nfs4_lockowner. > Maybe we should copy fl_lmops to conflock as before, nfsd can distinguish > the lockowner stored in struct file_lock by checking fl_lmops. > Alternatively, set a flag in fl_flags. Back in the days, we used to have a FL_NFSD, perhaps it is time to resurrect that? Cheers, Trond -- Trond Myklebust Linux NFS client maintainer, PrimaryData trond.myklebust@primarydata.com