From patchwork Fri Aug 4 15:05:22 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Petr Pavlu X-Patchwork-Id: 13341999 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 996ACC04A94 for ; Fri, 4 Aug 2023 15:06:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229591AbjHDPGe (ORCPT ); Fri, 4 Aug 2023 11:06:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46010 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231873AbjHDPGP (ORCPT ); Fri, 4 Aug 2023 11:06:15 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0D3634C00; Fri, 4 Aug 2023 08:06:09 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 95CE41F8B4; Fri, 4 Aug 2023 15:06:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1691161567; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=XsSun1+YJlfBM79bwQX5XcjtxYEu+EP0gv5ElS+bbJk=; b=YTYH5IoYf36CHrfJN/titJnr6JubWgizZfXYp8u93hmKunMAbKKnoUDW/xUHSBhvF3FoKj otBRhiOMh8dnJjQoX6NTuxgmPpXRuiCs3JRx9cTzys8mrFrn7jmLQnj02UctbVI0+Fx9ht mnNvkOMuLnC99ZkbeB5IDyTcQ8XuPPk= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 60517133B5; Fri, 4 Aug 2023 15:06:07 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id aLC3Ft8TzWRwSQAAMHmgww (envelope-from ); Fri, 04 Aug 2023 15:06:07 +0000 From: Petr Pavlu To: tariqt@nvidia.com, yishaih@nvidia.com, leon@kernel.org Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, jgg@ziepe.ca, netdev@vger.kernel.org, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, Petr Pavlu Subject: [PATCH net-next 05/10] mlx4: Move the bond work to the core driver Date: Fri, 4 Aug 2023 17:05:22 +0200 Message-Id: <20230804150527.6117-6-petr.pavlu@suse.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20230804150527.6117-1-petr.pavlu@suse.com> References: <20230804150527.6117-1-petr.pavlu@suse.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org Function mlx4_en_queue_bond_work() is used in mlx4_en to start a bond reconfiguration. It gathers data about a new port map setting, takes a reference on the netdev that triggered the change and queues a work object on mlx4_en_priv.mdev.workqueue to perform the operation. The scheduled work is mlx4_en_bond_work() which calls mlx4_bond()/mlx4_unbond() and consequently mlx4_do_bond(). At the same time, function mlx4_change_port_types() in mlx4_core might be invoked to change the port type configuration. As part of its logic, it re-registers the whole device by calling mlx4_unregister_device(), followed by mlx4_register_device(). The two operations can result in concurrent access to the data about currently active interfaces on the device. Functions mlx4_register_device() and mlx4_unregister_device() lock the intf_mutex to gain exclusive access to this data. The current implementation of mlx4_do_bond() doesn't do that which could result in an unexpected behavior. An updated version of mlx4_do_bond() for use with an auxiliary bus goes and locks the intf_mutex when accessing a new auxiliary device array. However, doing so can then result in the following deadlock: * A two-port mlx4 device is configured as an Ethernet bond. * One of the ports is changed from eth to ib, for instance, by writing into a mlx4_port sysfs attribute file. * mlx4_change_port_types() is called to update port types. It invokes mlx4_unregister_device() to unregister the device which locks the intf_mutex and starts removing all associated interfaces. * Function mlx4_en_remove() gets invoked and starts destroying its first netdev. This triggers mlx4_en_netdev_event() which recognizes that the configured bond is broken. It runs mlx4_en_queue_bond_work() which takes a reference on the netdev. Removing the netdev now cannot proceed until the work is completed. * Work function mlx4_en_bond_work() gets scheduled. It calls mlx4_unbond() -> mlx4_do_bond(). The latter function tries to lock the intf_mutex but that is not possible because it is held already by mlx4_unregister_device(). This particular case could be possibly solved by unregistering the mlx4_en_netdev_event() notifier in mlx4_en_remove() earlier, but it seems better to decouple mlx4_en more and break this reference order. Avoid then this scenario by recognizing that the bond reconfiguration operates only on a mlx4_dev. The logic to queue and execute the bond work can be moved into the mlx4_core driver. Only a reference on the respective mlx4_dev object is needed to be taken during the work's lifetime. This removes a call from mlx4_en that can directly result in needing to lock the intf_mutex, it remains a privilege of the core driver. Signed-off-by: Petr Pavlu Tested-by: Leon Romanovsky Reviewed-by: Leon Romanovsky --- .../net/ethernet/mellanox/mlx4/en_netdev.c | 62 +----------------- drivers/net/ethernet/mellanox/mlx4/main.c | 65 +++++++++++++++++-- drivers/net/ethernet/mellanox/mlx4/mlx4.h | 5 ++ include/linux/mlx4/device.h | 13 ++++ include/linux/mlx4/driver.h | 19 ------ 5 files changed, 77 insertions(+), 87 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c index 7066c426b95c..33bbcced8105 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c @@ -2894,63 +2894,6 @@ static const struct xdp_metadata_ops mlx4_xdp_metadata_ops = { .xmo_rx_hash = mlx4_en_xdp_rx_hash, }; -struct mlx4_en_bond { - struct work_struct work; - struct mlx4_en_priv *priv; - int is_bonded; - struct mlx4_port_map port_map; -}; - -static void mlx4_en_bond_work(struct work_struct *work) -{ - struct mlx4_en_bond *bond = container_of(work, - struct mlx4_en_bond, - work); - int err = 0; - struct mlx4_dev *dev = bond->priv->mdev->dev; - - if (bond->is_bonded) { - if (!mlx4_is_bonded(dev)) { - err = mlx4_bond(dev); - if (err) - en_err(bond->priv, "Fail to bond device\n"); - } - if (!err) { - err = mlx4_port_map_set(dev, &bond->port_map); - if (err) - en_err(bond->priv, "Fail to set port map [%d][%d]: %d\n", - bond->port_map.port1, - bond->port_map.port2, - err); - } - } else if (mlx4_is_bonded(dev)) { - err = mlx4_unbond(dev); - if (err) - en_err(bond->priv, "Fail to unbond device\n"); - } - dev_put(bond->priv->dev); - kfree(bond); -} - -static int mlx4_en_queue_bond_work(struct mlx4_en_priv *priv, int is_bonded, - u8 v2p_p1, u8 v2p_p2) -{ - struct mlx4_en_bond *bond; - - bond = kzalloc(sizeof(*bond), GFP_ATOMIC); - if (!bond) - return -ENOMEM; - - INIT_WORK(&bond->work, mlx4_en_bond_work); - bond->priv = priv; - bond->is_bonded = is_bonded; - bond->port_map.port1 = v2p_p1; - bond->port_map.port2 = v2p_p2; - dev_hold(priv->dev); - queue_work(priv->mdev->workqueue, &bond->work); - return 0; -} - int mlx4_en_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) { @@ -2960,7 +2903,6 @@ int mlx4_en_netdev_event(struct notifier_block *this, struct mlx4_dev *dev; int i, num_eth_ports = 0; bool do_bond = true; - struct mlx4_en_priv *priv; u8 v2p_port1 = 0; u8 v2p_port2 = 0; @@ -2995,7 +2937,6 @@ int mlx4_en_netdev_event(struct notifier_block *this, if ((do_bond && (event != NETDEV_BONDING_INFO)) || !port) return NOTIFY_DONE; - priv = netdev_priv(ndev); if (do_bond) { struct netdev_notifier_bonding_info *notifier_info = ptr; struct netdev_bonding_info *bonding_info = @@ -3062,8 +3003,7 @@ int mlx4_en_netdev_event(struct notifier_block *this, } } - mlx4_en_queue_bond_work(priv, do_bond, - v2p_port1, v2p_port2); + mlx4_queue_bond_work(dev, do_bond, v2p_port1, v2p_port2); return NOTIFY_DONE; } diff --git a/drivers/net/ethernet/mellanox/mlx4/main.c b/drivers/net/ethernet/mellanox/mlx4/main.c index 5f3ba8385e23..0ed490b99163 100644 --- a/drivers/net/ethernet/mellanox/mlx4/main.c +++ b/drivers/net/ethernet/mellanox/mlx4/main.c @@ -1441,7 +1441,7 @@ static int mlx4_mf_unbond(struct mlx4_dev *dev) return ret; } -int mlx4_bond(struct mlx4_dev *dev) +static int mlx4_bond(struct mlx4_dev *dev) { int ret = 0; struct mlx4_priv *priv = mlx4_priv(dev); @@ -1467,9 +1467,8 @@ int mlx4_bond(struct mlx4_dev *dev) return ret; } -EXPORT_SYMBOL_GPL(mlx4_bond); -int mlx4_unbond(struct mlx4_dev *dev) +static int mlx4_unbond(struct mlx4_dev *dev) { int ret = 0; struct mlx4_priv *priv = mlx4_priv(dev); @@ -1496,10 +1495,8 @@ int mlx4_unbond(struct mlx4_dev *dev) return ret; } -EXPORT_SYMBOL_GPL(mlx4_unbond); - -int mlx4_port_map_set(struct mlx4_dev *dev, struct mlx4_port_map *v2p) +static int mlx4_port_map_set(struct mlx4_dev *dev, struct mlx4_port_map *v2p) { u8 port1 = v2p->port1; u8 port2 = v2p->port2; @@ -1541,7 +1538,61 @@ int mlx4_port_map_set(struct mlx4_dev *dev, struct mlx4_port_map *v2p) mutex_unlock(&priv->bond_mutex); return err; } -EXPORT_SYMBOL_GPL(mlx4_port_map_set); + +struct mlx4_bond { + struct work_struct work; + struct mlx4_dev *dev; + int is_bonded; + struct mlx4_port_map port_map; +}; + +static void mlx4_bond_work(struct work_struct *work) +{ + struct mlx4_bond *bond = container_of(work, struct mlx4_bond, work); + int err = 0; + + if (bond->is_bonded) { + if (!mlx4_is_bonded(bond->dev)) { + err = mlx4_bond(bond->dev); + if (err) + mlx4_err(bond->dev, "Fail to bond device\n"); + } + if (!err) { + err = mlx4_port_map_set(bond->dev, &bond->port_map); + if (err) + mlx4_err(bond->dev, + "Fail to set port map [%d][%d]: %d\n", + bond->port_map.port1, + bond->port_map.port2, err); + } + } else if (mlx4_is_bonded(bond->dev)) { + err = mlx4_unbond(bond->dev); + if (err) + mlx4_err(bond->dev, "Fail to unbond device\n"); + } + put_device(&bond->dev->persist->pdev->dev); + kfree(bond); +} + +int mlx4_queue_bond_work(struct mlx4_dev *dev, int is_bonded, u8 v2p_p1, + u8 v2p_p2) +{ + struct mlx4_bond *bond; + + bond = kzalloc(sizeof(*bond), GFP_ATOMIC); + if (!bond) + return -ENOMEM; + + INIT_WORK(&bond->work, mlx4_bond_work); + get_device(&dev->persist->pdev->dev); + bond->dev = dev; + bond->is_bonded = is_bonded; + bond->port_map.port1 = v2p_p1; + bond->port_map.port2 = v2p_p2; + queue_work(mlx4_wq, &bond->work); + return 0; +} +EXPORT_SYMBOL(mlx4_queue_bond_work); static int mlx4_load_fw(struct mlx4_dev *dev) { diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4.h b/drivers/net/ethernet/mellanox/mlx4/mlx4.h index 10f12e4992f1..ece9acb6a869 100644 --- a/drivers/net/ethernet/mellanox/mlx4/mlx4.h +++ b/drivers/net/ethernet/mellanox/mlx4/mlx4.h @@ -863,6 +863,11 @@ struct mlx4_steer { struct list_head steer_entries[MLX4_NUM_STEERS]; }; +struct mlx4_port_map { + u8 port1; + u8 port2; +}; + enum { MLX4_PCI_DEV_IS_VF = 1 << 0, MLX4_PCI_DEV_FORCE_SENSE_PORT = 1 << 1, diff --git a/include/linux/mlx4/device.h b/include/linux/mlx4/device.h index 6646634a0b9d..049d8a4b044d 100644 --- a/include/linux/mlx4/device.h +++ b/include/linux/mlx4/device.h @@ -1087,6 +1087,19 @@ static inline void *mlx4_buf_offset(struct mlx4_buf *buf, int offset) (offset & (PAGE_SIZE - 1)); } +static inline int mlx4_is_bonded(struct mlx4_dev *dev) +{ + return !!(dev->flags & MLX4_FLAG_BONDED); +} + +static inline int mlx4_is_mf_bonded(struct mlx4_dev *dev) +{ + return (mlx4_is_bonded(dev) && mlx4_is_mfunc(dev)); +} + +int mlx4_queue_bond_work(struct mlx4_dev *dev, int is_bonded, u8 v2p_p1, + u8 v2p_p2); + int mlx4_pd_alloc(struct mlx4_dev *dev, u32 *pdn); void mlx4_pd_free(struct mlx4_dev *dev, u32 pdn); int mlx4_xrcd_alloc(struct mlx4_dev *dev, u32 *xrcdn); diff --git a/include/linux/mlx4/driver.h b/include/linux/mlx4/driver.h index 0f8c9ba4c574..781d5a0c2faa 100644 --- a/include/linux/mlx4/driver.h +++ b/include/linux/mlx4/driver.h @@ -66,25 +66,6 @@ struct mlx4_interface { int mlx4_register_interface(struct mlx4_interface *intf); void mlx4_unregister_interface(struct mlx4_interface *intf); -int mlx4_bond(struct mlx4_dev *dev); -int mlx4_unbond(struct mlx4_dev *dev); -static inline int mlx4_is_bonded(struct mlx4_dev *dev) -{ - return !!(dev->flags & MLX4_FLAG_BONDED); -} - -static inline int mlx4_is_mf_bonded(struct mlx4_dev *dev) -{ - return (mlx4_is_bonded(dev) && mlx4_is_mfunc(dev)); -} - -struct mlx4_port_map { - u8 port1; - u8 port2; -}; - -int mlx4_port_map_set(struct mlx4_dev *dev, struct mlx4_port_map *v2p); - int mlx4_register_event_notifier(struct mlx4_dev *dev, struct notifier_block *nb); int mlx4_unregister_event_notifier(struct mlx4_dev *dev,