From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E699AC4332F for ; Mon, 2 May 2022 16:01:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1386212AbiEBQFP (ORCPT ); Mon, 2 May 2022 12:05:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42784 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1386147AbiEBQEr (ORCPT ); Mon, 2 May 2022 12:04:47 -0400 Received: from fieldses.org (fieldses.org [IPv6:2600:3c00:e000:2f7::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5C050BE12; Mon, 2 May 2022 09:00:59 -0700 (PDT) Received: by fieldses.org (Postfix, from userid 2815) id 470FB6214; Mon, 2 May 2022 12:00:58 -0400 (EDT) DKIM-Filter: OpenDKIM Filter v2.11.0 fieldses.org 470FB6214 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fieldses.org; s=default; t=1651507258; bh=MgexYy/qSvZKhZG5OaGDKjaf+0dL78kNEUaZBzH7cTc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=MA4TVwilAIpU1e7Q5brjWFgbjw26KJ/iLL2YCf+tzucg8Y6BmHBeJrI9KjWIM+byc whod/pbRa4jGf1hk2mi1ZauH5nNCuPHpYU5RoPqhhGblOxUHK6W4pN3g1YM30CwNsV LN412usz7OmtOn9nSNyQcIvs9NQEKlclBHCqzVqo= Date: Mon, 2 May 2022 12:00:58 -0400 From: "J. Bruce Fields" To: Dai Ngo Cc: chuck.lever@oracle.com, jlayton@redhat.com, viro@zeniv.linux.org.uk, linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH RFC v24 6/7] NFSD: add support for lock conflict to courteous server Message-ID: <20220502160058.GF30550@fieldses.org> References: <1651426696-15509-1-git-send-email-dai.ngo@oracle.com> <1651426696-15509-7-git-send-email-dai.ngo@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1651426696-15509-7-git-send-email-dai.ngo@oracle.com> User-Agent: Mutt/1.5.21 (2010-09-15) Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Sun, May 01, 2022 at 10:38:15AM -0700, Dai Ngo wrote: > This patch allows expired client with lock state to be in COURTESY > state. Lock conflict with COURTESY client is resolved by the fs/lock > code using the lm_lock_expirable and lm_expire_lock callback in the > struct lock_manager_operations. > > If conflict client is in COURTESY state, set it to EXPIRABLE and > schedule the laundromat to run immediately to expire the client. The > callback lm_expire_lock waits for the laundromat to flush its work > queue before returning to caller. Reviewed-by: J. Bruce Fields (These searches over hash tables that we're adding in a few places are inefficient, but I'm assuming it won't matter. And I don't have a better idea off the top of my head. So I'm fine with just doing this instead of optimizing prematurely.) --b. > > Signed-off-by: Dai Ngo > --- > fs/nfsd/nfs4state.c | 70 +++++++++++++++++++++++++++++++++++++++++------------ > 1 file changed, 54 insertions(+), 16 deletions(-) > > diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c > index f369142da79f..4ab7dda44f38 100644 > --- a/fs/nfsd/nfs4state.c > +++ b/fs/nfsd/nfs4state.c > @@ -5715,39 +5715,51 @@ static void nfsd4_ssc_expire_umount(struct nfsd_net *nn) > } > #endif > > +/* Check if any lock belonging to this lockowner has any blockers */ > static bool > -nfs4_has_any_locks(struct nfs4_client *clp) > +nfs4_lockowner_has_blockers(struct nfs4_lockowner *lo) > +{ > + struct file_lock_context *ctx; > + struct nfs4_ol_stateid *stp; > + struct nfs4_file *nf; > + > + list_for_each_entry(stp, &lo->lo_owner.so_stateids, st_perstateowner) { > + nf = stp->st_stid.sc_file; > + ctx = nf->fi_inode->i_flctx; > + if (!ctx) > + continue; > + if (locks_owner_has_blockers(ctx, lo)) > + return true; > + } > + return false; > +} > + > +static bool > +nfs4_anylock_blockers(struct nfs4_client *clp) > { > int i; > struct nfs4_stateowner *so; > + struct nfs4_lockowner *lo; > > + if (atomic_read(&clp->cl_delegs_in_recall)) > + return true; > spin_lock(&clp->cl_lock); > for (i = 0; i < OWNER_HASH_SIZE; i++) { > list_for_each_entry(so, &clp->cl_ownerstr_hashtbl[i], > so_strhash) { > if (so->so_is_open_owner) > continue; > - spin_unlock(&clp->cl_lock); > - return true; > + lo = lockowner(so); > + if (nfs4_lockowner_has_blockers(lo)) { > + spin_unlock(&clp->cl_lock); > + return true; > + } > } > } > spin_unlock(&clp->cl_lock); > return false; > } > > -/* > - * place holder for now, no check for lock blockers yet > - */ > -static bool > -nfs4_anylock_blockers(struct nfs4_client *clp) > -{ > - if (atomic_read(&clp->cl_delegs_in_recall) || > - !list_empty(&clp->async_copies) || > - nfs4_has_any_locks(clp)) > - return true; > - return false; > -} > - > static void > nfs4_get_client_reaplist(struct nfsd_net *nn, struct list_head *reaplist, > struct laundry_time *lt) > @@ -6712,6 +6724,29 @@ nfsd4_lm_put_owner(fl_owner_t owner) > nfs4_put_stateowner(&lo->lo_owner); > } > > +/* return pointer to struct nfs4_client if client is expirable */ > +static bool > +nfsd4_lm_lock_expirable(struct file_lock *cfl) > +{ > + struct nfs4_lockowner *lo = (struct nfs4_lockowner *)cfl->fl_owner; > + struct nfs4_client *clp = lo->lo_owner.so_client; > + struct nfsd_net *nn; > + > + if (try_to_expire_client(clp)) { > + nn = net_generic(clp->net, nfsd_net_id); > + mod_delayed_work(laundry_wq, &nn->laundromat_work, 0); > + return true; > + } > + return false; > +} > + > +/* schedule laundromat to run immediately and wait for it to complete */ > +static void > +nfsd4_lm_expire_lock(void) > +{ > + flush_workqueue(laundry_wq); > +} > + > static void > nfsd4_lm_notify(struct file_lock *fl) > { > @@ -6738,9 +6773,12 @@ nfsd4_lm_notify(struct file_lock *fl) > } > > static const struct lock_manager_operations nfsd_posix_mng_ops = { > + .lm_mod_owner = THIS_MODULE, > .lm_notify = nfsd4_lm_notify, > .lm_get_owner = nfsd4_lm_get_owner, > .lm_put_owner = nfsd4_lm_put_owner, > + .lm_lock_expirable = nfsd4_lm_lock_expirable, > + .lm_expire_lock = nfsd4_lm_expire_lock, > }; > > static inline void > -- > 2.9.5