[PATCH 6.1 454/473] ice: fix accounting if a VLAN already exists

Greg Kroah-Hartman
2024-06-06T14:20:33Z

From: Jacob Keller <jacob.e.keller@intel.com>

[ Upstream commit 82617b9a04649e83ee8731918aeadbb6e6d7cbc7 ]

The ice_vsi_add_vlan() function is used to add a VLAN filter for the target
VSI. This function prepares a filter in the switch table for the given VSI.
If it succeeds, the vsi->num_vlan counter is incremented.

It is not considered an error to add a VLAN which already exists in the
switch table, so the function explicitly checks and ignores -EEXIST. The
vsi->num_vlan counter is still incremented.

This seems incorrect, as it means we can double-count in the case where the
same VLAN is added twice by the caller. The actual table will have one less
filter than the count.

The ice_vsi_del_vlan() function similarly checks and handles the -ENOENT
condition for when deleting a filter that doesn't exist. This flow only
decrements the vsi->num_vlan if it actually deleted a filter.

The vsi->num_vlan counter is used only in a few places, primarily related
to tracking the number of non-zero VLANs. If the vsi->num_vlans gets out of
sync, then ice_vsi_num_non_zero_vlans() will incorrectly report more VLANs
than are present, and ice_vsi_has_non_zero_vlans() could return true
potentially in cases where there are only VLAN 0 filters left.

Fix this by only incrementing the vsi->num_vlan in the case where we
actually added an entry, and not in the case where the entry already
existed.

Fixes: a1ffafb0b4a4 ("ice: Support configuring the device to Double VLAN Mode")
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240523-net-2024-05-23-intel-net-fixes-v1-2-17a923e0bb5f@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/intel/ice/ice_vsi_vlan_lib.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_vsi_vlan_lib.c b/drivers/net/ethernet/intel/ice/ice_vsi_vlan_lib.c
index 239266e9d5f12..80c16e04f6702 100644
--- a/drivers/net/ethernet/intel/ice/ice_vsi_vlan_lib.c
+++ b/drivers/net/ethernet/intel/ice/ice_vsi_vlan_lib.c
@@ -45,14 +45,15 @@ int ice_vsi_add_vlan(struct ice_vsi *vsi, struct ice_vlan *vlan)
return -EINVAL;

err = ice_fltr_add_vlan(vsi, vlan);
- if (err && err != -EEXIST) {
+ if (!err)
+ vsi->num_vlan++;
+ else if (err == -EEXIST)
+ err = 0;
+ else
dev_err(ice_pf_to_dev(vsi->back), "Failure Adding VLAN %d on VSI %i, status %d\n",
vlan->vid, vsi->vsi_num, err);
- return err;
- }

- vsi->num_vlan++;
- return 0;
+ return err;
}

/**
--
2.43.0