6.8-stable review patch. If anyone has any objections, please let me know.
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From: Maher Sanalla msanalla@nvidia.com
[ Upstream commit 0f06228d4a2dcc1fca5b3ddb0eefa09c05b102c4 ]
On lag disable, the bond IB device along with all of its representors are destroyed, and then the slaves' representors get reloaded.
In case the slave IB representor load fails, the eswitch error flow unloads all representors, including ethernet representors, where the netdevs get detached and removed from lag bond. Such flow is inaccurate as the lag driver is not responsible for loading/unloading ethernet representors. Furthermore, the flow described above begins by holding lag lock to prevent bond changes during disable flow. However, when reaching the ethernet representors detachment from lag, the lag lock is required again, triggering the following deadlock:
Call trace: __switch_to+0xf4/0x148 __schedule+0x2c8/0x7d0 schedule+0x50/0xe0 schedule_preempt_disabled+0x18/0x28 __mutex_lock.isra.13+0x2b8/0x570 __mutex_lock_slowpath+0x1c/0x28 mutex_lock+0x4c/0x68 mlx5_lag_remove_netdev+0x3c/0x1a0 [mlx5_core] mlx5e_uplink_rep_disable+0x70/0xa0 [mlx5_core] mlx5e_detach_netdev+0x6c/0xb0 [mlx5_core] mlx5e_netdev_change_profile+0x44/0x138 [mlx5_core] mlx5e_netdev_attach_nic_profile+0x28/0x38 [mlx5_core] mlx5e_vport_rep_unload+0x184/0x1b8 [mlx5_core] mlx5_esw_offloads_rep_load+0xd8/0xe0 [mlx5_core] mlx5_eswitch_reload_reps+0x74/0xd0 [mlx5_core] mlx5_disable_lag+0x130/0x138 [mlx5_core] mlx5_lag_disable_change+0x6c/0x70 [mlx5_core] // hold ldev->lock mlx5_devlink_eswitch_mode_set+0xc0/0x410 [mlx5_core] devlink_nl_cmd_eswitch_set_doit+0xdc/0x180 genl_family_rcv_msg_doit.isra.17+0xe8/0x138 genl_rcv_msg+0xe4/0x220 netlink_rcv_skb+0x44/0x108 genl_rcv+0x40/0x58 netlink_unicast+0x198/0x268 netlink_sendmsg+0x1d4/0x418 sock_sendmsg+0x54/0x60 __sys_sendto+0xf4/0x120 __arm64_sys_sendto+0x30/0x40 el0_svc_common+0x8c/0x120 do_el0_svc+0x30/0xa0 el0_svc+0x20/0x30 el0_sync_handler+0x90/0xb8 el0_sync+0x160/0x180
Thus, upon lag enable/disable, load and unload only the IB representors of the slaves preventing the deadlock mentioned above.
While at it, refactor the mlx5_esw_offloads_rep_load() function to have a static helper method for its internal logic, in symmetry with the representor unload design.
Fixes: 598fe77df855 ("net/mlx5: Lag, Create shared FDB when in switchdev mode") Co-developed-by: Mark Bloch mbloch@nvidia.com Signed-off-by: Mark Bloch mbloch@nvidia.com Signed-off-by: Maher Sanalla msanalla@nvidia.com Signed-off-by: Tariq Toukan tariqt@nvidia.com Reviewed-by: Simon Horman horms@kernel.org Link: https://lore.kernel.org/r/20240509112951.590184-4-tariqt@nvidia.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- .../net/ethernet/mellanox/mlx5/core/eswitch.h | 4 +-- .../mellanox/mlx5/core/eswitch_offloads.c | 28 ++++++++++++------- .../net/ethernet/mellanox/mlx5/core/lag/lag.c | 6 ++-- .../ethernet/mellanox/mlx5/core/lag/mpesw.c | 4 +-- 4 files changed, 25 insertions(+), 17 deletions(-)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h index 349e28a6dd8df..ef55674876cb4 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h +++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h @@ -833,7 +833,7 @@ int mlx5_eswitch_offloads_single_fdb_add_one(struct mlx5_eswitch *master_esw, struct mlx5_eswitch *slave_esw, int max_slaves); void mlx5_eswitch_offloads_single_fdb_del_one(struct mlx5_eswitch *master_esw, struct mlx5_eswitch *slave_esw); -int mlx5_eswitch_reload_reps(struct mlx5_eswitch *esw); +int mlx5_eswitch_reload_ib_reps(struct mlx5_eswitch *esw);
bool mlx5_eswitch_block_encap(struct mlx5_core_dev *dev); void mlx5_eswitch_unblock_encap(struct mlx5_core_dev *dev); @@ -925,7 +925,7 @@ mlx5_eswitch_offloads_single_fdb_del_one(struct mlx5_eswitch *master_esw, static inline int mlx5_eswitch_get_npeers(struct mlx5_eswitch *esw) { return 0; }
static inline int -mlx5_eswitch_reload_reps(struct mlx5_eswitch *esw) +mlx5_eswitch_reload_ib_reps(struct mlx5_eswitch *esw) { return 0; } diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c b/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c index e3cce110e52fd..58529d1a98b37 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c @@ -2501,6 +2501,16 @@ void esw_offloads_cleanup(struct mlx5_eswitch *esw) esw_offloads_cleanup_reps(esw); }
+static int __esw_offloads_load_rep(struct mlx5_eswitch *esw, + struct mlx5_eswitch_rep *rep, u8 rep_type) +{ + if (atomic_cmpxchg(&rep->rep_data[rep_type].state, + REP_REGISTERED, REP_LOADED) == REP_REGISTERED) + return esw->offloads.rep_ops[rep_type]->load(esw->dev, rep); + + return 0; +} + static void __esw_offloads_unload_rep(struct mlx5_eswitch *esw, struct mlx5_eswitch_rep *rep, u8 rep_type) { @@ -2525,13 +2535,11 @@ static int mlx5_esw_offloads_rep_load(struct mlx5_eswitch *esw, u16 vport_num) int err;
rep = mlx5_eswitch_get_rep(esw, vport_num); - for (rep_type = 0; rep_type < NUM_REP_TYPES; rep_type++) - if (atomic_cmpxchg(&rep->rep_data[rep_type].state, - REP_REGISTERED, REP_LOADED) == REP_REGISTERED) { - err = esw->offloads.rep_ops[rep_type]->load(esw->dev, rep); - if (err) - goto err_reps; - } + for (rep_type = 0; rep_type < NUM_REP_TYPES; rep_type++) { + err = __esw_offloads_load_rep(esw, rep, rep_type); + if (err) + goto err_reps; + }
return 0;
@@ -3276,7 +3284,7 @@ static void esw_destroy_offloads_acl_tables(struct mlx5_eswitch *esw) esw_vport_destroy_offloads_acl_tables(esw, vport); }
-int mlx5_eswitch_reload_reps(struct mlx5_eswitch *esw) +int mlx5_eswitch_reload_ib_reps(struct mlx5_eswitch *esw) { struct mlx5_eswitch_rep *rep; unsigned long i; @@ -3289,13 +3297,13 @@ int mlx5_eswitch_reload_reps(struct mlx5_eswitch *esw) if (atomic_read(&rep->rep_data[REP_ETH].state) != REP_LOADED) return 0;
- ret = mlx5_esw_offloads_rep_load(esw, MLX5_VPORT_UPLINK); + ret = __esw_offloads_load_rep(esw, rep, REP_IB); if (ret) return ret;
mlx5_esw_for_each_rep(esw, i, rep) { if (atomic_read(&rep->rep_data[REP_ETH].state) == REP_LOADED) - mlx5_esw_offloads_rep_load(esw, rep->vport); + __esw_offloads_load_rep(esw, rep, REP_IB); }
return 0; diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lag/lag.c b/drivers/net/ethernet/mellanox/mlx5/core/lag/lag.c index 69d482f7c5a29..37598d116f3b8 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/lag/lag.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/lag/lag.c @@ -814,7 +814,7 @@ void mlx5_disable_lag(struct mlx5_lag *ldev) if (shared_fdb) for (i = 0; i < ldev->ports; i++) if (!(ldev->pf[i].dev->priv.flags & MLX5_PRIV_FLAGS_DISABLE_ALL_ADEV)) - mlx5_eswitch_reload_reps(ldev->pf[i].dev->priv.eswitch); + mlx5_eswitch_reload_ib_reps(ldev->pf[i].dev->priv.eswitch); }
static bool mlx5_shared_fdb_supported(struct mlx5_lag *ldev) @@ -922,7 +922,7 @@ static void mlx5_do_bond(struct mlx5_lag *ldev) mlx5_rescan_drivers_locked(dev0);
for (i = 0; i < ldev->ports; i++) { - err = mlx5_eswitch_reload_reps(ldev->pf[i].dev->priv.eswitch); + err = mlx5_eswitch_reload_ib_reps(ldev->pf[i].dev->priv.eswitch); if (err) break; } @@ -933,7 +933,7 @@ static void mlx5_do_bond(struct mlx5_lag *ldev) mlx5_deactivate_lag(ldev); mlx5_lag_add_devices(ldev); for (i = 0; i < ldev->ports; i++) - mlx5_eswitch_reload_reps(ldev->pf[i].dev->priv.eswitch); + mlx5_eswitch_reload_ib_reps(ldev->pf[i].dev->priv.eswitch); mlx5_core_err(dev0, "Failed to enable lag\n"); return; } diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lag/mpesw.c b/drivers/net/ethernet/mellanox/mlx5/core/lag/mpesw.c index 82889f30506ea..571ea26edd0ca 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/lag/mpesw.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/lag/mpesw.c @@ -99,7 +99,7 @@ static int enable_mpesw(struct mlx5_lag *ldev) dev0->priv.flags &= ~MLX5_PRIV_FLAGS_DISABLE_IB_ADEV; mlx5_rescan_drivers_locked(dev0); for (i = 0; i < ldev->ports; i++) { - err = mlx5_eswitch_reload_reps(ldev->pf[i].dev->priv.eswitch); + err = mlx5_eswitch_reload_ib_reps(ldev->pf[i].dev->priv.eswitch); if (err) goto err_rescan_drivers; } @@ -113,7 +113,7 @@ static int enable_mpesw(struct mlx5_lag *ldev) err_add_devices: mlx5_lag_add_devices(ldev); for (i = 0; i < ldev->ports; i++) - mlx5_eswitch_reload_reps(ldev->pf[i].dev->priv.eswitch); + mlx5_eswitch_reload_ib_reps(ldev->pf[i].dev->priv.eswitch); mlx5_mpesw_metadata_cleanup(ldev); return err; }