[SRU][N:linux-bluefield][PATCH v1 3/5] net/mlx5: Fix return value when searching for existing flow group

[Stav Aviram]

From: Patrisious Haddad <phaddad at nvidia.com>

BugLink: https://bugs.launchpad.net/bugs/2126876

When attempting to add a rule to an existing flow group, if a matching
flow group exists but is not active, the error code returned should be
EAGAIN, so that the rule can be added to the matching flow group once
it is active, rather than ENOENT, which indicates that no matching
flow group was found.

Fixes: bd71b08ec2ee ("net/mlx5: Support multiple updates of steering rules in parallel")
Signed-off-by: Gavi Teitz <gavi at nvidia.com>
Signed-off-by: Roi Dayan <roid at nvidia.com>
Signed-off-by: Patrisious Haddad <phaddad at nvidia.com>
Reviewed-by: Tariq Toukan <tariqt at nvidia.com>
Signed-off-by: Mark Bloch <mbloch at nvidia.com>
Link: https://patch.msgid.link/20250610151514.1094735-4-mbloch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba at kernel.org>
(cherry picked from commit 8ec40e3f1f72bf8f8accf18020d487caa99f46a4)
Signed-off-by: Stav Aviram <saviram at nvidia.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/fs_core.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c b/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c
index 007007ef3e60..ad76a5b849bf 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c
@@ -1984,6 +1984,7 @@ try_add_to_existing_fg(struct mlx5_flow_table *ft,
 	struct mlx5_flow_handle *rule;
 	struct match_list *iter;
 	bool take_write = false;
+	bool try_again = false;
 	struct fs_fte *fte;
 	u64  version = 0;
 	int err;
@@ -2043,6 +2044,7 @@ try_add_to_existing_fg(struct mlx5_flow_table *ft,
 		nested_down_write_ref_node(&g->node, FS_LOCK_PARENT);
 
 		if (!g->node.active) {
+			try_again = true;
 			up_write_ref_node(&g->node, false);
 			continue;
 		}
@@ -2064,7 +2066,8 @@ try_add_to_existing_fg(struct mlx5_flow_table *ft,
 			tree_put_node(&fte->node, false);
 		return rule;
 	}
-	rule = ERR_PTR(-ENOENT);
+	err = try_again ? -EAGAIN : -ENOENT;
+	rule = ERR_PTR(err);
 out:
 	kmem_cache_free(steering->ftes_cache, fte);
 	return rule;
-- 
2.38.1