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 8E987C433EF for ; Tue, 15 Mar 2022 17:21:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237488AbiCORWM (ORCPT ); Tue, 15 Mar 2022 13:22:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42444 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350516AbiCORWE (ORCPT ); Tue, 15 Mar 2022 13:22:04 -0400 Received: from fieldses.org (fieldses.org [IPv6:2600:3c00:e000:2f7::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BDD385880F; Tue, 15 Mar 2022 10:20:51 -0700 (PDT) Received: by fieldses.org (Postfix, from userid 2815) id 1EC6C6A84; Tue, 15 Mar 2022 13:20:51 -0400 (EDT) DKIM-Filter: OpenDKIM Filter v2.11.0 fieldses.org 1EC6C6A84 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fieldses.org; s=default; t=1647364851; bh=nMdUSnDfJGUkkshZG+wCco5fLanizJJTvgIT15m762s=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=q+yRz4wipkaDWxm6N9up/EmnOZqr+Nwm/cs0aCcQtbJsiubKwLlzHroBRaElXCwSh 6Y7iRU+RS+YDdh3hrpqn9Vjv0iytNh6J/iWn/w2eBIydgv3p3Rm9I4ovcFnaKgertP k/WVaZLvksv+BzktkxicNPYF+U+/uI3QCU/GWCfU= Date: Tue, 15 Mar 2022 13:20:51 -0400 From: "J. Bruce Fields" To: dai.ngo@oracle.com 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 v16 03/11] NFSD: Add lm_lock_expired call out Message-ID: <20220315172051.GD19168@fieldses.org> References: <1647051215-2873-1-git-send-email-dai.ngo@oracle.com> <1647051215-2873-4-git-send-email-dai.ngo@oracle.com> <20220315150245.GA19168@fieldses.org> <1e1ff6a1-86cf-99d4-13ad-45352e58fe73@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1e1ff6a1-86cf-99d4-13ad-45352e58fe73@oracle.com> User-Agent: Mutt/1.5.21 (2010-09-15) Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Tue, Mar 15, 2022 at 09:26:46AM -0700, dai.ngo@oracle.com wrote: > > On 3/15/22 8:02 AM, J. Bruce Fields wrote: > >On Fri, Mar 11, 2022 at 06:13:27PM -0800, Dai Ngo wrote: > >>Add callout function nfsd4_lm_lock_expired for lm_lock_expired. > >>If lock request has conflict with courtesy client then expire the > >>courtesy client and return no conflict to caller. > >> > >>Signed-off-by: Dai Ngo > >>--- > >> fs/nfsd/nfs4state.c | 37 +++++++++++++++++++++++++++++++++++++ > >> 1 file changed, 37 insertions(+) > >> > >>diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c > >>index a65d59510681..583ac807e98d 100644 > >>--- a/fs/nfsd/nfs4state.c > >>+++ b/fs/nfsd/nfs4state.c > >>@@ -6578,10 +6578,47 @@ nfsd4_lm_notify(struct file_lock *fl) > >> } > >> } > >>+/** > >>+ * nfsd4_lm_lock_expired - check if lock conflict can be resolved. > >>+ * > >>+ * @fl: pointer to file_lock with a potential conflict > >>+ * Return values: > >>+ * %false: real conflict, lock conflict can not be resolved. > >>+ * %true: no conflict, lock conflict was resolved. > >>+ * > >>+ * Note that this function is called while the flc_lock is held. > >>+ */ > >>+static bool > >>+nfsd4_lm_lock_expired(struct file_lock *fl) > >>+{ > >>+ struct nfs4_lockowner *lo; > >>+ struct nfs4_client *clp; > >>+ bool rc = false; > >>+ > >>+ if (!fl) > >>+ return false; > >>+ lo = (struct nfs4_lockowner *)fl->fl_owner; > >>+ clp = lo->lo_owner.so_client; > >>+ > >>+ /* need to sync with courtesy client trying to reconnect */ > >>+ spin_lock(&clp->cl_cs_lock); > >>+ if (test_bit(NFSD4_CLIENT_EXPIRED, &clp->cl_flags)) > >>+ rc = true; > >>+ else { > >>+ if (test_bit(NFSD4_CLIENT_COURTESY, &clp->cl_flags)) { > >>+ set_bit(NFSD4_CLIENT_EXPIRED, &clp->cl_flags); > >>+ rc = true; > >>+ } > >>+ } > >I'd prefer: > > > > if (test_bit(NFSD4_CLIENT_COURTESY, &clp->cl_flags)) > > set_bit(NFSD4_CLIENT_EXPIRED, &clp->cl_flags); > > we also need to set rc to true here. No, the next line does it because we set the EXPIRED bit. --b. > > > if (test_bit(NFSD4_CLIENT_EXPIRED, &clp->cl_flags)) > > rc = true; > > With v16 we need to check for NFSD4_CLIENT_EXPIRED first then > NFSD4_CLIENT_COURTESY because both flags can be set. In the > next patch version, we will clear NFSD4_CLIENT_COURTESY when > setting NFSD4_CLIENT_EXPIRED so the order of check does not > matter. > > > > >Same result, but more compact and straightforward, I think. > > Chuck wants to replace the bits used for courtesy client in > cl_flags with a separate u8 field so it does not have to use > bit operation to set/test. > > -Dai > > > > >--b. > > > >>+ spin_unlock(&clp->cl_cs_lock); > >>+ return rc; > >>+} > >>+ > >> static const struct lock_manager_operations nfsd_posix_mng_ops = { > >> .lm_notify = nfsd4_lm_notify, > >> .lm_get_owner = nfsd4_lm_get_owner, > >> .lm_put_owner = nfsd4_lm_put_owner, > >>+ .lm_lock_expired = nfsd4_lm_lock_expired, > >> }; > >> static inline void > >>-- > >>2.9.5