kernel/SOURCES/1562-net-mlx5-pagealloc-fix-reclaim-race-during-command-interface.patch

60 lines
2.4 KiB
Diff

From 0c5ea60367085f9ccb735f4c05ee9e35faebf640 Mon Sep 17 00:00:00 2001
From: Kamal Heib <kheib@redhat.com>
Date: Sun, 19 Apr 2026 18:24:30 -0400
Subject: [PATCH] net/mlx5: pagealloc: Fix reclaim race during command
interface teardown
JIRA: https://redhat.atlassian.net/browse/RHEL-169055
commit 79a0e32b32ac4e4f9e4bb22be97f371c8c116c88
Author: Shay Drory <shayd@nvidia.com>
Date: Mon Sep 29 00:02:08 2025 +0300
net/mlx5: pagealloc: Fix reclaim race during command interface teardown
The reclaim_pages_cmd() function sends a command to the firmware to
reclaim pages if the command interface is active.
A race condition can occur if the command interface goes down (e.g., due
to a PCI error) while the mlx5_cmd_do() call is in flight. In this
case, mlx5_cmd_do() will return an error. The original code would
propagate this error immediately, bypassing the software-based page
reclamation logic that is supposed to run when the command interface is
down.
Fix this by checking whether mlx5_cmd_do() returns -ENXIO, which mark
that command interface is down. If this is the case, fall through to
the software reclamation path. If the command failed for any another
reason, or finished successfully, return as before.
Fixes: b898ce7bccf1 ("net/mlx5: cmdif, Avoid skipping reclaim pages if FW is not accessible")
Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Kamal Heib <kheib@redhat.com>
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/pagealloc.c b/drivers/net/ethernet/mellanox/mlx5/core/pagealloc.c
index 9bc9bd83c232..cd68c4b2c0bf 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/pagealloc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/pagealloc.c
@@ -489,9 +489,12 @@ static int reclaim_pages_cmd(struct mlx5_core_dev *dev,
u32 func_id;
u32 npages;
u32 i = 0;
+ int err;
- if (!mlx5_cmd_is_down(dev))
- return mlx5_cmd_do(dev, in, in_size, out, out_size);
+ err = mlx5_cmd_do(dev, in, in_size, out, out_size);
+ /* If FW is gone (-ENXIO), proceed to forceful reclaim */
+ if (err != -ENXIO)
+ return err;
/* No hard feelings, we want our pages back! */
npages = MLX5_GET(manage_pages_in, in, input_num_entries);
--
2.50.1 (Apple Git-155)