From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A7E857E111; Mon, 8 Apr 2024 13:37:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712583445; cv=none; b=a7SD751ym+r7Rsa4T8at2sy0LFtGo+dvB/yhEo/E2g3rThROkaF2GtQlOdAfqsRa7wJm/4rYq1tZV3K4JPxgTJZetfcJJHOtj6S8uROYmmbjwI5P/FjBcxV4H/nFhoqDef0rymYtl0XC1ZkYt2lAbNsYva1QaBcOnPnObHodbYo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712583445; c=relaxed/simple; bh=jzSGQ0GvXL6bQhMZJeIupZn8NofFZE0yt5QVmHsORG4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=UKHDg1tB86xb4uTxt3fMNw8wVKKSlCRl5uFO60hf3JfP7/rXzDwt+zoX/SOc4sFVYXZgXardtwAi2THMlUaQEiwAwq+nARQjY9l/QHODZQtwYzVhnp9mIARnwuLtVUBbkFhe3rmaNQqOfLz5pCXNkfnb5FY84UdzCDCdP1hJMvA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=zjjGIFUC; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="zjjGIFUC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2DB59C433F1; Mon, 8 Apr 2024 13:37:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1712583445; bh=jzSGQ0GvXL6bQhMZJeIupZn8NofFZE0yt5QVmHsORG4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zjjGIFUCvtJDElt2Vb2+aad2xJ+fee4TXTCVRdEjyQ4VGoFt61M0neUdYNsbMm88e bJeL2VJ/wA/u3Yo8Zp44/jkIhj3biRFQFqdUTVz/JEx7kAIktv/8N8miZIbJN1oELX UkY4tFk1PgfTTELiWyVx/pDD5gj+iMxBQWrZ5cno= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, NeilBrown , Chuck Lever Subject: [PATCH 5.15 248/690] NFSD: simplify per-net file cache management Date: Mon, 8 Apr 2024 14:51:54 +0200 Message-ID: <20240408125408.604219954@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240408125359.506372836@linuxfoundation.org> References: <20240408125359.506372836@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: NeilBrown [ Upstream commit 1463b38e7cf34d4cc60f41daff459ad807b2e408 ] We currently have a 'laundrette' for closing cached files - a different work-item for each network-namespace. These 'laundrettes' (aka struct nfsd_fcache_disposal) are currently on a list, and are freed using rcu. The list is not necessary as we have a per-namespace structure (struct nfsd_net) which can hold a link to the nfsd_fcache_disposal. The use of kfree_rcu is also unnecessary as the cache is cleaned of all files associated with a given namespace, and no new files can be added, before the nfsd_fcache_disposal is freed. So add a '->fcache_disposal' link to nfsd_net, and discard the list management and rcu usage. Signed-off-by: NeilBrown Signed-off-by: Chuck Lever --- fs/nfsd/filecache.c | 76 +++++++++------------------------------------ fs/nfsd/netns.h | 2 ++ 2 files changed, 17 insertions(+), 61 deletions(-) diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c index fbc0628c599af..b99852b30308a 100644 --- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -44,12 +44,9 @@ struct nfsd_fcache_bucket { static DEFINE_PER_CPU(unsigned long, nfsd_file_cache_hits); struct nfsd_fcache_disposal { - struct list_head list; struct work_struct work; - struct net *net; spinlock_t lock; struct list_head freeme; - struct rcu_head rcu; }; static struct workqueue_struct *nfsd_filecache_wq __read_mostly; @@ -62,8 +59,6 @@ static long nfsd_file_lru_flags; static struct fsnotify_group *nfsd_file_fsnotify_group; static atomic_long_t nfsd_filecache_count; static struct delayed_work nfsd_filecache_laundrette; -static DEFINE_SPINLOCK(laundrette_lock); -static LIST_HEAD(laundrettes); static void nfsd_file_gc(void); @@ -360,19 +355,13 @@ nfsd_file_list_remove_disposal(struct list_head *dst, static void nfsd_file_list_add_disposal(struct list_head *files, struct net *net) { - struct nfsd_fcache_disposal *l; + struct nfsd_net *nn = net_generic(net, nfsd_net_id); + struct nfsd_fcache_disposal *l = nn->fcache_disposal; - rcu_read_lock(); - list_for_each_entry_rcu(l, &laundrettes, list) { - if (l->net == net) { - spin_lock(&l->lock); - list_splice_tail_init(files, &l->freeme); - spin_unlock(&l->lock); - queue_work(nfsd_filecache_wq, &l->work); - break; - } - } - rcu_read_unlock(); + spin_lock(&l->lock); + list_splice_tail_init(files, &l->freeme); + spin_unlock(&l->lock); + queue_work(nfsd_filecache_wq, &l->work); } static void @@ -748,7 +737,7 @@ nfsd_file_cache_purge(struct net *net) } static struct nfsd_fcache_disposal * -nfsd_alloc_fcache_disposal(struct net *net) +nfsd_alloc_fcache_disposal(void) { struct nfsd_fcache_disposal *l; @@ -756,7 +745,6 @@ nfsd_alloc_fcache_disposal(struct net *net) if (!l) return NULL; INIT_WORK(&l->work, nfsd_file_delayed_close); - l->net = net; spin_lock_init(&l->lock); INIT_LIST_HEAD(&l->freeme); return l; @@ -765,61 +753,27 @@ nfsd_alloc_fcache_disposal(struct net *net) static void nfsd_free_fcache_disposal(struct nfsd_fcache_disposal *l) { - rcu_assign_pointer(l->net, NULL); cancel_work_sync(&l->work); nfsd_file_dispose_list(&l->freeme); - kfree_rcu(l, rcu); -} - -static void -nfsd_add_fcache_disposal(struct nfsd_fcache_disposal *l) -{ - spin_lock(&laundrette_lock); - list_add_tail_rcu(&l->list, &laundrettes); - spin_unlock(&laundrette_lock); -} - -static void -nfsd_del_fcache_disposal(struct nfsd_fcache_disposal *l) -{ - spin_lock(&laundrette_lock); - list_del_rcu(&l->list); - spin_unlock(&laundrette_lock); -} - -static int -nfsd_alloc_fcache_disposal_net(struct net *net) -{ - struct nfsd_fcache_disposal *l; - - l = nfsd_alloc_fcache_disposal(net); - if (!l) - return -ENOMEM; - nfsd_add_fcache_disposal(l); - return 0; + kfree(l); } static void nfsd_free_fcache_disposal_net(struct net *net) { - struct nfsd_fcache_disposal *l; + struct nfsd_net *nn = net_generic(net, nfsd_net_id); + struct nfsd_fcache_disposal *l = nn->fcache_disposal; - rcu_read_lock(); - list_for_each_entry_rcu(l, &laundrettes, list) { - if (l->net != net) - continue; - nfsd_del_fcache_disposal(l); - rcu_read_unlock(); - nfsd_free_fcache_disposal(l); - return; - } - rcu_read_unlock(); + nfsd_free_fcache_disposal(l); } int nfsd_file_cache_start_net(struct net *net) { - return nfsd_alloc_fcache_disposal_net(net); + struct nfsd_net *nn = net_generic(net, nfsd_net_id); + + nn->fcache_disposal = nfsd_alloc_fcache_disposal(); + return nn->fcache_disposal ? 0 : -ENOMEM; } void diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h index 021acdc0d03bb..9e8b77d2a3a47 100644 --- a/fs/nfsd/netns.h +++ b/fs/nfsd/netns.h @@ -185,6 +185,8 @@ struct nfsd_net { /* utsname taken from the process that starts the server */ char nfsd_name[UNX_MAXNODENAME+1]; + + struct nfsd_fcache_disposal *fcache_disposal; }; /* Simple check to find out if a given net was properly initialized */ -- 2.43.0