From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753468Ab2KFWWA (ORCPT ); Tue, 6 Nov 2012 17:22:00 -0500 Received: from [93.179.225.50] ([93.179.225.50]:39237 "EHLO shrek.podlesie.net" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752735Ab2KFWUV (ORCPT ); Tue, 6 Nov 2012 17:20:21 -0500 From: Krzysztof Mazur To: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Chas Williams - CONTRACTOR , David Woodhouse , davem@davemloft.net, Krzysztof Mazur Subject: [PATCH v3 2/7] atm: add owner of push() callback to atmvcc Date: Tue, 6 Nov 2012 23:16:57 +0100 Message-Id: <1352240222-363-3-git-send-email-krzysiek@podlesie.net> X-Mailer: git-send-email 1.8.0.233.g54991f2 In-Reply-To: <1352240222-363-1-git-send-email-krzysiek@podlesie.net> References: <1352240222-363-1-git-send-email-krzysiek@podlesie.net> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The atm is using atmvcc->push(vcc, NULL) callback to notify protocol that vcc will be closed and protocol must detach from it. This callback is usually used by protocol to decrement module usage count by module_put(), but it leaves small window then module is still used after module_put(). Now the owner of push() callback is kept in atmvcc and module_put(atmvcc->owner) is called after the protocol is detached from vcc. Signed-off-by: Krzysztof Mazur --- include/linux/atmdev.h | 1 + net/atm/common.c | 2 ++ 2 files changed, 3 insertions(+) diff --git a/include/linux/atmdev.h b/include/linux/atmdev.h index 06fd4bb..31c16c6 100644 --- a/include/linux/atmdev.h +++ b/include/linux/atmdev.h @@ -315,6 +315,7 @@ struct atm_vcc { void *dev_data; /* per-device data */ void *proto_data; /* per-protocol data */ struct k_atm_aal_stats *stats; /* pointer to AAL stats group */ + struct module *owner; /* owner of ->push function */ /* SVC part --- may move later ------------------------------------- */ short itf; /* interface number */ struct sockaddr_atmsvc local; diff --git a/net/atm/common.c b/net/atm/common.c index a0e4411..ea952b2 100644 --- a/net/atm/common.c +++ b/net/atm/common.c @@ -156,6 +156,7 @@ int vcc_create(struct net *net, struct socket *sock, int protocol, int family) atomic_set(&sk->sk_rmem_alloc, 0); vcc->push = NULL; vcc->pop = NULL; + vcc->owner = NULL; vcc->push_oam = NULL; vcc->vpi = vcc->vci = 0; /* no VCI/VPI yet */ vcc->atm_options = vcc->aal_options = 0; @@ -173,6 +174,7 @@ static void vcc_destroy_socket(struct sock *sk) if (vcc->dev) { if (vcc->push) vcc->push(vcc, NULL); /* atmarpd has no push */ + module_put(vcc->owner); if (vcc->dev->ops->close) vcc->dev->ops->close(vcc); -- 1.8.0.233.g54991f2