From patchwork Fri Jul 1 14:30:41 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miquel Raynal X-Patchwork-Id: 12903446 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 A350BCCA47B for ; Fri, 1 Jul 2022 14:36:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231844AbiGAOgQ (ORCPT ); Fri, 1 Jul 2022 10:36:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55072 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231891AbiGAOfl (ORCPT ); Fri, 1 Jul 2022 10:35:41 -0400 Received: from relay9-d.mail.gandi.net (relay9-d.mail.gandi.net [IPv6:2001:4b98:dc4:8::229]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A7DD96B805; Fri, 1 Jul 2022 07:31:15 -0700 (PDT) Received: (Authenticated sender: miquel.raynal@bootlin.com) by mail.gandi.net (Postfix) with ESMTPSA id 8D8CEFF80F; Fri, 1 Jul 2022 14:31:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1656685874; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ocxbWdcl4mMHYc5HbDE1q7HijgptxH2Rs9Qwuibjyhw=; b=LyHNtG6ZHrhA8PXgjwRqnyS57ab7XUGHcr6GUi4xHG8fiyxNLJAgYHH2DBRIipE0L9vurs 3r43OP4cTbgclWrxrF7+BInF0cj7twwWXmTJkPO0cq14N22ZzxSG+u0Z5jcY7yPAiqmb2O lyHNfRE/pBsB6MX0yAB/nw7rIykonZ7fUml9pGYebFmIEE+S2xhLIObUmZuqHoHYyxlV9y suaJtc2qgOPwqd4lwfZCZUDLw6A0qXPQbNJZwMoixckmRerhokgzPnbqJ6dQwmpfhZeuLI vIYng1SBhQydlC+GTDfwwZ/qb5NPKeSezU5ZWn2EyhA5QdeIOAqggUoOJzjDDw== From: Miquel Raynal To: Alexander Aring , Stefan Schmidt , linux-wpan@vger.kernel.org Cc: "David S. Miller" , Jakub Kicinski , Paolo Abeni , Eric Dumazet , netdev@vger.kernel.org, David Girault , Romuald Despres , Frederic Blain , Nicolas Schodet , Thomas Petazzoni , Miquel Raynal Subject: [PATCH wpan-next 09/20] net: mac802154: Introduce a global device lock Date: Fri, 1 Jul 2022 16:30:41 +0200 Message-Id: <20220701143052.1267509-10-miquel.raynal@bootlin.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220701143052.1267509-1-miquel.raynal@bootlin.com> References: <20220701143052.1267509-1-miquel.raynal@bootlin.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wpan@vger.kernel.org The purpose of this device lock is to prevent the removal of the device while an asynchronous MLME operation happens. The RTNL works well for that but in a later series having the RTNL taken here will be problematic and will cause lockdep to warn us about a circular dependency. We don't really need the RTNL here, just a serialization over this operation. Replace the RTNL calls with this new lock. Signed-off-by: Miquel Raynal --- net/mac802154/ieee802154_i.h | 2 ++ net/mac802154/iface.c | 4 ++++ net/mac802154/main.c | 1 + net/mac802154/tx.c | 12 ++++++------ 4 files changed, 13 insertions(+), 6 deletions(-) diff --git a/net/mac802154/ieee802154_i.h b/net/mac802154/ieee802154_i.h index 010365a6364e..b8775bcc9003 100644 --- a/net/mac802154/ieee802154_i.h +++ b/net/mac802154/ieee802154_i.h @@ -29,7 +29,9 @@ struct ieee802154_local { /* ieee802154 phy */ struct wpan_phy *phy; + /* Open/close counter and lock */ int open_count; + struct mutex device_lock; /* As in mac80211 slaves list is modified: * 1) under the RTNL diff --git a/net/mac802154/iface.c b/net/mac802154/iface.c index 7ac0c5685d3f..7715e17d9ba1 100644 --- a/net/mac802154/iface.c +++ b/net/mac802154/iface.c @@ -315,11 +315,15 @@ static int mac802154_slave_close(struct net_device *dev) ASSERT_RTNL(); + mutex_lock(&local->device_lock); + netif_stop_queue(dev); local->open_count--; clear_bit(SDATA_STATE_RUNNING, &sdata->state); + mutex_unlock(&local->device_lock); + if (!local->open_count) ieee802154_stop_device(local); diff --git a/net/mac802154/main.c b/net/mac802154/main.c index a2da9d4c5273..e5fb7ed73663 100644 --- a/net/mac802154/main.c +++ b/net/mac802154/main.c @@ -90,6 +90,7 @@ ieee802154_alloc_hw(size_t priv_data_len, const struct ieee802154_ops *ops) INIT_LIST_HEAD(&local->interfaces); mutex_init(&local->iflist_mtx); + mutex_init(&local->device_lock); tasklet_setup(&local->tasklet, ieee802154_tasklet_handler); diff --git a/net/mac802154/tx.c b/net/mac802154/tx.c index 9d8d43cf1e64..fb555797f326 100644 --- a/net/mac802154/tx.c +++ b/net/mac802154/tx.c @@ -143,14 +143,14 @@ int ieee802154_mlme_tx(struct ieee802154_local *local, { int ret; - /* Avoid possible calls to ->ndo_stop() when we asynchronously perform - * MLME transmissions. + /* Serialize possible calls to ->ndo_stop() when we asynchronously + * perform MLME transmissions. */ - rtnl_lock(); + mutex_lock(&local->device_lock); /* Ensure the device was not stopped, otherwise error out */ if (!local->open_count) { - rtnl_unlock(); + mutex_unlock(&local->device_lock); return -ENETDOWN; } @@ -158,14 +158,14 @@ int ieee802154_mlme_tx(struct ieee802154_local *local, * net interface expects this cannot happen. */ if (WARN_ON_ONCE(!netif_running(sdata->dev))) { - rtnl_unlock(); + mutex_unlock(&local->device_lock); return -ENETDOWN; } ieee802154_tx(local, skb); ret = ieee802154_sync_queue(local); - rtnl_unlock(); + mutex_unlock(&local->device_lock); return ret; }