[PATCH net 1/2] net/mlx5: HWS, fix reformat pool creation race
flat view
WARM2d
SUPERSEDED
From: Alexandre Cassen <hidden>
Date: 2026-10-08 20:43:00
Also in:
linux-rdma
Subsystem:
mellanox mlx5 core vpi driver, networking drivers, the rest · Maintainers:
Saeed Mahameed, Leon Romanovsky, Tariq Toukan, Mark Bloch, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Revision v1 of 2 in this series.
Revisions (2)
- v1 current
- v2 [diff vs current]
mlx5_fs_get_pr_encap_pool() inserts a new pool when the lookup misses.
Two callers allocating the first reformat of a size at once both
create one and the second fails with -EBUSY. TC serializes these
allocations under encap_tbl_lock while RDMA flow actions on the FDB
don't.
Sashiko AI review of an earlier series spotted this issue.
Tested for regressions on ConnectX-7 with firmware 28.48.1000.
Fixes: aecd9d1020e3 ("net/mlx5: fs, add HWS packet reformat API function")
Signed-off-by: Alexandre Cassen <redacted>
---
.../mellanox/mlx5/core/steering/hws/fs_hws.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/steering/hws/fs_hws.c b/drivers/net/ethernet/mellanox/mlx5/core/steering/hws/fs_hws.c
index 5a172c572a68..66edb42268cb 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/steering/hws/fs_hws.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/steering/hws/fs_hws.c@@ -1228,7 +1228,7 @@ static struct mlx5_fs_pool * mlx5_fs_get_pr_encap_pool(struct mlx5_core_dev *dev, struct xarray *pr_pools, enum mlx5hws_action_type reformat_type, size_t size) { - struct mlx5_fs_pool *pr_pool; + struct mlx5_fs_pool *pr_pool, *old; unsigned long index = size; int err;
@@ -1242,13 +1242,14 @@ mlx5_fs_get_pr_encap_pool(struct mlx5_core_dev *dev, struct xarray *pr_pools, err = mlx5_fs_hws_pr_pool_init(pr_pool, dev, size, reformat_type); if (err) goto free_pr_pool; - err = xa_insert(pr_pools, index, pr_pool, GFP_KERNEL); - if (err) - goto cleanup_pr_pool; - return pr_pool; + old = xa_cmpxchg(pr_pools, index, NULL, pr_pool, GFP_KERNEL); + if (!old) + return pr_pool; -cleanup_pr_pool: mlx5_fs_hws_pr_pool_cleanup(pr_pool); + kfree(pr_pool); + return xa_is_err(old) ? ERR_PTR(xa_err(old)) : old; + free_pr_pool: kfree(pr_pool); return ERR_PTR(err);
--
2.43.0