diff mbox series

[net,1/7] net/mlx5: E-switch, unload IB representors when unloading ETH representors

Message ID 20241107183527.676877-2-tariqt@nvidia.com (mailing list archive)
State Accepted
Commit 1220965d619178713844ef365beb9d9b88267e13
Delegated to: Netdev Maintainers
Headers show
Series mlx5 misc fixes 2024-11-07 | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 3 this patch: 3
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers fail 1 blamed authors not CCed: michaelgur@nvidia.com; 2 maintainers not CCed: linux-rdma@vger.kernel.org michaelgur@nvidia.com
netdev/build_clang success Errors and warnings before: 3 this patch: 3
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 4 this patch: 4
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 12 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-11-11--21-00 (tests: 787)

Commit Message

Tariq Toukan Nov. 7, 2024, 6:35 p.m. UTC 
From: Chiara Meiohas <cmeiohas@nvidia.com>

IB representors depend on ETH representors, so the IB representors
should not exist without the ETH ones. When unloading the ETH
representors, the corresponding IB representors should be also
unloaded.

The commit 8d159eb2117b ("RDMA/mlx5: Use IB set_netdev and get_netdev functions")
introduced the use of the ib_device_set_netdev API in IB
repsresentors. ib_device_set_netdev() increments the refcount of
the representor's netdev when loading an IB representor and
decrements it when unloading.
Without the unloading of the IB representor, the refcount of the
representor's netdev remains greater than 0, preventing it from
being unregistered.
The patch uncovered an underlying bug where the eth representor is
unloaded, without unloading the IB representor.

This issue happened when using multiport E-switch and rebooting,
causing the shutdown to hang when unloading the ETH representor
because the refcount of the representor's netdevice was greater than 0.

Call trace:
unregister_netdevice: waiting for eth3 to become free. Usage count = 2
ref_tracker: eth%d@00000000661d60f7 has 1/1 users at
	ib_device_set_netdev+0x160/0x2d0 [ib_core]
	mlx5_ib_vport_rep_load+0x104/0x3f0 [mlx5_ib]
	mlx5_eswitch_reload_ib_reps+0xfc/0x110 [mlx5_core]
	mlx5_mpesw_work+0x236/0x330 [mlx5_core]
	process_one_work+0x169/0x320
	worker_thread+0x288/0x3a0
	kthread+0xb8/0xe0
	ret_from_fork+0x2d/0x50
	ret_from_fork_asm+0x11/0x20

Fixes: 8d159eb2117b ("RDMA/mlx5: Use IB set_netdev and get_netdev functions")
Signed-off-by: Chiara Meiohas <cmeiohas@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c b/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c
index f24f91d213f2..8cf61ae8b89d 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c
@@ -2527,8 +2527,11 @@  static void __esw_offloads_unload_rep(struct mlx5_eswitch *esw,
 				      struct mlx5_eswitch_rep *rep, u8 rep_type)
 {
 	if (atomic_cmpxchg(&rep->rep_data[rep_type].state,
-			   REP_LOADED, REP_REGISTERED) == REP_LOADED)
+			   REP_LOADED, REP_REGISTERED) == REP_LOADED) {
+		if (rep_type == REP_ETH)
+			__esw_offloads_unload_rep(esw, rep, REP_IB);
 		esw->offloads.rep_ops[rep_type]->unload(rep);
+	}
 }
 
 static void __unload_reps_all_vport(struct mlx5_eswitch *esw, u8 rep_type)