This is a note to let you know that I've just added the patch titled net/mlx5e: Add refcount to VXLAN structure to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-mlx5e-add-refcount-to-vxlan-structure.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Sun Dec 31 11:13:15 CET 2017 From: Gal Pressman <galp@xxxxxxxxxxxx> Date: Sun, 3 Dec 2017 13:58:50 +0200 Subject: net/mlx5e: Add refcount to VXLAN structure From: Gal Pressman <galp@xxxxxxxxxxxx> [ Upstream commit 23f4cc2cd9ed92570647220aca60d0197d8c1fa9 ] A refcount mechanism must be implemented in order to prevent unwanted scenarios such as: - Open an IPv4 VXLAN interface - Open an IPv6 VXLAN interface (different socket) - Remove one of the interfaces With current implementation, the UDP port will be removed from our VXLAN database and turn off the offloads for the other interface, which is still active. The reference count mechanism will only allow UDP port removals once all consumers are gone. Fixes: b3f63c3d5e2c ("net/mlx5e: Add netdev support for VXLAN tunneling") Signed-off-by: Gal Pressman <galp@xxxxxxxxxxxx> Signed-off-by: Saeed Mahameed <saeedm@xxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/mellanox/mlx5/core/vxlan.c | 50 ++++++++++++------------ drivers/net/ethernet/mellanox/mlx5/core/vxlan.h | 1 2 files changed, 28 insertions(+), 23 deletions(-) --- a/drivers/net/ethernet/mellanox/mlx5/core/vxlan.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/vxlan.c @@ -88,8 +88,11 @@ static void mlx5e_vxlan_add_port(struct struct mlx5e_vxlan *vxlan; int err; - if (mlx5e_vxlan_lookup_port(priv, port)) + vxlan = mlx5e_vxlan_lookup_port(priv, port); + if (vxlan) { + atomic_inc(&vxlan->refcount); goto free_work; + } if (mlx5e_vxlan_core_add_port_cmd(priv->mdev, port)) goto free_work; @@ -99,6 +102,7 @@ static void mlx5e_vxlan_add_port(struct goto err_delete_port; vxlan->udp_port = port; + atomic_set(&vxlan->refcount, 1); spin_lock_bh(&vxlan_db->lock); err = radix_tree_insert(&vxlan_db->tree, vxlan->udp_port, vxlan); @@ -116,32 +120,33 @@ free_work: kfree(vxlan_work); } -static void __mlx5e_vxlan_core_del_port(struct mlx5e_priv *priv, u16 port) +static void mlx5e_vxlan_del_port(struct work_struct *work) { + struct mlx5e_vxlan_work *vxlan_work = + container_of(work, struct mlx5e_vxlan_work, work); + struct mlx5e_priv *priv = vxlan_work->priv; struct mlx5e_vxlan_db *vxlan_db = &priv->vxlan; + u16 port = vxlan_work->port; struct mlx5e_vxlan *vxlan; + bool remove = false; spin_lock_bh(&vxlan_db->lock); - vxlan = radix_tree_delete(&vxlan_db->tree, port); - spin_unlock_bh(&vxlan_db->lock); - + vxlan = radix_tree_lookup(&vxlan_db->tree, port); if (!vxlan) - return; - - mlx5e_vxlan_core_del_port_cmd(priv->mdev, vxlan->udp_port); - - kfree(vxlan); -} + goto out_unlock; -static void mlx5e_vxlan_del_port(struct work_struct *work) -{ - struct mlx5e_vxlan_work *vxlan_work = - container_of(work, struct mlx5e_vxlan_work, work); - struct mlx5e_priv *priv = vxlan_work->priv; - u16 port = vxlan_work->port; + if (atomic_dec_and_test(&vxlan->refcount)) { + radix_tree_delete(&vxlan_db->tree, port); + remove = true; + } - __mlx5e_vxlan_core_del_port(priv, port); +out_unlock: + spin_unlock_bh(&vxlan_db->lock); + if (remove) { + mlx5e_vxlan_core_del_port_cmd(priv->mdev, port); + kfree(vxlan); + } kfree(vxlan_work); } @@ -171,12 +176,11 @@ void mlx5e_vxlan_cleanup(struct mlx5e_pr struct mlx5e_vxlan *vxlan; unsigned int port = 0; - spin_lock_bh(&vxlan_db->lock); + /* Lockless since we are the only radix-tree consumers, wq is disabled */ while (radix_tree_gang_lookup(&vxlan_db->tree, (void **)&vxlan, port, 1)) { port = vxlan->udp_port; - spin_unlock_bh(&vxlan_db->lock); - __mlx5e_vxlan_core_del_port(priv, (u16)port); - spin_lock_bh(&vxlan_db->lock); + radix_tree_delete(&vxlan_db->tree, port); + mlx5e_vxlan_core_del_port_cmd(priv->mdev, port); + kfree(vxlan); } - spin_unlock_bh(&vxlan_db->lock); } --- a/drivers/net/ethernet/mellanox/mlx5/core/vxlan.h +++ b/drivers/net/ethernet/mellanox/mlx5/core/vxlan.h @@ -36,6 +36,7 @@ #include "en.h" struct mlx5e_vxlan { + atomic_t refcount; u16 udp_port; }; Patches currently in stable-queue which might be from galp@xxxxxxxxxxxx are queue-4.9/net-mlx5e-fix-possible-deadlock-of-vxlan-lock.patch queue-4.9/net-mlx5e-prevent-possible-races-in-vxlan-control-flow.patch queue-4.9/net-mlx5e-add-refcount-to-vxlan-structure.patch queue-4.9/net-mlx5e-fix-features-check-of-ipv6-traffic.patch