From patchwork Tue Jul 23 13:51:36 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Chapman X-Patchwork-Id: 13740078 X-Patchwork-Delegate: kuba@kernel.org Received: from mail.katalix.com (mail.katalix.com [3.9.82.81]) by smtp.subspace.kernel.org (Postfix) with ESMTP id BE19615380A for ; Tue, 23 Jul 2024 13:51:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=3.9.82.81 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721742715; cv=none; b=MBPjJyIyvETM5TTGMISfqn7MIMBC8wGQu21j2JF2gQmhcvJy+cNcIQeH3r2kxyHYK3PG6eC46OzmMf4jXdN4nidDidZDGYniDZq3OEDhZ9RbUBxn0bds7r7wijRchpgl+dGzQOTsUTsPn82FxrXp6oMAjy8BTDnKcMTaDekmVfQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721742715; c=relaxed/simple; bh=T6hLeXX7Sgkm5cr8ehfdSKVlUfoZynlwUDoVtbhDoqc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=QkwiqX1m/bSC0kgchn+iLrr/3PqOt44qNGnojc+hJJUw5aVLr81cm8u8JwA8RSX6KE9O+z+GEv0mwKsHzYG774O84be4GvcjCDc9/TsLTgwkjmVDvo6w5OO9Vr0aCvAYBVvD62FwP4Y/MDZSQXgozN6ezGF/85/9M990irz6zd8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=katalix.com; spf=pass smtp.mailfrom=katalix.com; dkim=pass (2048-bit key) header.d=katalix.com header.i=@katalix.com header.b=FEGWyXTh; arc=none smtp.client-ip=3.9.82.81 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=katalix.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=katalix.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=katalix.com header.i=@katalix.com header.b="FEGWyXTh" Received: from katalix.com (unknown [IPv6:2a02:8010:6359:1:47:b279:6330:ae0d]) (Authenticated sender: james) by mail.katalix.com (Postfix) with ESMTPSA id 1754B7DCEF; Tue, 23 Jul 2024 14:51:46 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=katalix.com; s=mail; t=1721742706; bh=T6hLeXX7Sgkm5cr8ehfdSKVlUfoZynlwUDoVtbhDoqc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:From; z=From:=20James=20Chapman=20|To:=20netdev@vge r.kernel.org|Cc:=20davem@davemloft.net,=0D=0A=09edumazet@google.co m,=0D=0A=09kuba@kernel.org,=0D=0A=09pabeni@redhat.com,=0D=0A=09dsa hern@kernel.org,=0D=0A=09tparkin@katalix.com|Subject:=20[RFC=20PAT CH=2008/15]=20l2tp:=20delete=20sessions=20using=20work=20queue|Dat e:=20Tue,=2023=20Jul=202024=2014:51:36=20+0100|Message-Id:=20<3017 b6e6df2c9591eb2e487b6e23fe509411f1c0.1721733730.git.jchapman@katal ix.com>|In-Reply-To:=20 |References:=20|MIME-Ve rsion:=201.0; b=FEGWyXThopLIeRfiLLp8s9gau+Ib+njkrMYbCf1ZRfErHLwUO6HouZPbyhXxsjZig hBz6gZuUO0QKq2iYVv/3DlBIp6fh3ed2uWIE6ZQm39WpOqIqiDJy8ynsUnGO0dAT+t nOjRjbhH/IOY3naJQtSSF8RUF2XDAyrnRFdsHtbQWvMYOmDRSYIXdcJmY1cXTxKQ8p IzSCfIjTYaHsXPeUehGSc38mhBycYSRbI8PyReYmyiSeOljiURMjwRLrZy03rvextg FN6REOT2MJzTHphw7QSkej1dTVNVxdj/7u/n5ScrbWST5DPh4e5B+Qjiam3V3JxW6i GdgNXczFQWwpQ== From: James Chapman To: netdev@vger.kernel.org Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, dsahern@kernel.org, tparkin@katalix.com Subject: [RFC PATCH 08/15] l2tp: delete sessions using work queue Date: Tue, 23 Jul 2024 14:51:36 +0100 Message-Id: <3017b6e6df2c9591eb2e487b6e23fe509411f1c0.1721733730.git.jchapman@katalix.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org X-Patchwork-State: RFC When a tunnel is closed, l2tp_tunnel_closeall closes all sessions in the tunnel. Move the work of deleting each session to the work queue so that sessions are deleted using the same codepath whether they are closed by user API request or their parent tunnel is closing. This also avoids the locking dance in l2tp_tunnel_closeall where the tunnel's session list lock was unlocked and relocked in the loop. In l2tp_exit_net, use drain_workqueue instead of flush_workqueue because the processing of tunnel_delete work may queue session_delete work items which must also be processed. --- net/l2tp/l2tp_core.c | 36 ++++++++++++++++++++---------------- net/l2tp/l2tp_core.h | 1 + 2 files changed, 21 insertions(+), 16 deletions(-) diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index a01dd891639b..f6ae18c180bf 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -1282,18 +1282,8 @@ static void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel) spin_lock_bh(&tunnel->list_lock); tunnel->acpt_newsess = false; - for (;;) { - session = list_first_entry_or_null(&tunnel->session_list, - struct l2tp_session, list); - if (!session) - break; - l2tp_session_inc_refcount(session); - list_del_init(&session->list); - spin_unlock_bh(&tunnel->list_lock); + list_for_each_entry(session, &tunnel->session_list, list) l2tp_session_delete(session); - spin_lock_bh(&tunnel->list_lock); - l2tp_session_dec_refcount(session); - } spin_unlock_bh(&tunnel->list_lock); } @@ -1631,18 +1621,31 @@ EXPORT_SYMBOL_GPL(l2tp_tunnel_delete); void l2tp_session_delete(struct l2tp_session *session) { - if (test_and_set_bit(0, &session->dead)) - return; + if (!test_and_set_bit(0, &session->dead)) { + trace_delete_session(session); + l2tp_session_inc_refcount(session); + queue_work(l2tp_wq, &session->del_work); + } +} +EXPORT_SYMBOL_GPL(l2tp_session_delete); + +/* Workqueue session deletion function */ +static void l2tp_session_del_work(struct work_struct *work) +{ + struct l2tp_session *session = container_of(work, struct l2tp_session, + del_work); - trace_delete_session(session); l2tp_session_unhash(session); l2tp_session_queue_purge(session); if (session->session_close) (*session->session_close)(session); + /* drop initial ref */ + l2tp_session_dec_refcount(session); + + /* drop workqueue ref */ l2tp_session_dec_refcount(session); } -EXPORT_SYMBOL_GPL(l2tp_session_delete); /* We come here whenever a session's send_seq, cookie_len or * l2specific_type parameters are set. @@ -1694,6 +1697,7 @@ struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunn INIT_HLIST_NODE(&session->hlist); INIT_LIST_HEAD(&session->clist); INIT_LIST_HEAD(&session->list); + INIT_WORK(&session->del_work, l2tp_session_del_work); if (cfg) { session->pwtype = cfg->pw_type; @@ -1751,7 +1755,7 @@ static __net_exit void l2tp_exit_net(struct net *net) rcu_read_unlock_bh(); if (l2tp_wq) - flush_workqueue(l2tp_wq); + drain_workqueue(l2tp_wq); rcu_barrier(); idr_destroy(&pn->l2tp_v2_session_idr); diff --git a/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h index 6c62d02a0ae6..8d7a589ccd2a 100644 --- a/net/l2tp/l2tp_core.h +++ b/net/l2tp/l2tp_core.h @@ -102,6 +102,7 @@ struct l2tp_session { int reorder_skip; /* set if skip to next nr */ enum l2tp_pwtype pwtype; struct l2tp_stats stats; + struct work_struct del_work; /* Session receive handler for data packets. * Each pseudowire implementation should implement this callback in order to