From patchwork Wed Jun 22 14:13:19 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever X-Patchwork-Id: 12890801 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 4710ACCA47D for ; Wed, 22 Jun 2022 14:15:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1358084AbiFVOPf (ORCPT ); Wed, 22 Jun 2022 10:15:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35560 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1358170AbiFVONX (ORCPT ); Wed, 22 Jun 2022 10:13:23 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CF2163917E; Wed, 22 Jun 2022 07:13:21 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 47ABD61BDC; Wed, 22 Jun 2022 14:13:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4DA88C3411B; Wed, 22 Jun 2022 14:13:20 +0000 (UTC) Subject: [PATCH RFC 05/30] NFSD: Add nfsd_file_lru_dispose_list() helper From: Chuck Lever To: linux-nfs@vger.kernel.org, netdev@vger.kernel.org Cc: david@fromorbit.com, tgraf@suug.ch, jlayton@redhat.com Date: Wed, 22 Jun 2022 10:13:19 -0400 Message-ID: <165590719916.75778.4838226317826208480.stgit@manet.1015granger.net> In-Reply-To: <165590626293.75778.9843437418112335153.stgit@manet.1015granger.net> References: <165590626293.75778.9843437418112335153.stgit@manet.1015granger.net> User-Agent: StGit/1.5.dev2+g9ce680a5 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org Refactor the invariant part of nfsd_file_lru_walk_list() into a separate helper function. Signed-off-by: Chuck Lever --- fs/nfsd/filecache.c | 29 ++++++++++++++++++++++------- 1 file changed, 22 insertions(+), 7 deletions(-) diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c index 6f48528c6284..763a08196dcd 100644 --- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -457,11 +457,31 @@ nfsd_file_lru_cb(struct list_head *item, struct list_lru_one *lru, return LRU_SKIP; } +/* + * Unhash items on @dispose immediately, then queue them on the + * disposal workqueue to finish releasing them in the background. + * + * cel: Note that between the time list_lru_shrink_walk runs and + * now, these items are in the hash table but marked unhashed. + * Why release these outside of lru_cb ? There's no lock ordering + * problem since lru_cb currently takes no lock. + */ +static void nfsd_file_gc_dispose_list(struct list_head *dispose) +{ + struct nfsd_file *nf; + + list_for_each_entry(nf, dispose, nf_lru) { + spin_lock(&nfsd_file_hashtbl[nf->nf_hashval].nfb_lock); + nfsd_file_do_unhash(nf); + spin_unlock(&nfsd_file_hashtbl[nf->nf_hashval].nfb_lock); + } + nfsd_file_dispose_list_delayed(dispose); +} + static unsigned long nfsd_file_lru_walk_list(struct shrink_control *sc) { LIST_HEAD(head); - struct nfsd_file *nf; unsigned long ret; if (sc) @@ -471,12 +491,7 @@ nfsd_file_lru_walk_list(struct shrink_control *sc) ret = list_lru_walk(&nfsd_file_lru, nfsd_file_lru_cb, &head, LONG_MAX); - list_for_each_entry(nf, &head, nf_lru) { - spin_lock(&nfsd_file_hashtbl[nf->nf_hashval].nfb_lock); - nfsd_file_do_unhash(nf); - spin_unlock(&nfsd_file_hashtbl[nf->nf_hashval].nfb_lock); - } - nfsd_file_dispose_list_delayed(&head); + nfsd_file_gc_dispose_list(&head); return ret; }