From: Leon Romanovsky <leonro@xxxxxxxxxxxx>
Systemd triggers the following warning during IPoIB device load:
mlx5_core 0000:00:0c.0 ib0: "systemd-udevd" wants to know my dev_id.
Should it look at dev_port instead?
See Documentation/ABI/testing/sysfs-class-net for more info.
This is caused due to user space attempt to differentiate old systems
without dev_port and new systems with dev_port. In case dev_port will
be zero, the systemd will try to read dev_id instead.
There is no need to print a warning in such case, because it is valid
situation and it is needed to ensure systemd compatibility with old
kernels.
Link: https://github.com/systemd/systemd/blob/master/src/udev/udev-builtin-net_id.c#L358
Cc: <stable@xxxxxxxxxxxxxxx> # 4.19
Fixes: f6350da41dc7 ("IB/ipoib: Log sysfs 'dev_id' accesses from userspace")
Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxxxx>
---
drivers/infiniband/ulp/ipoib/ipoib_main.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
index 48eda16db1a7..34e6495aa8c5 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -2402,7 +2402,17 @@ static ssize_t dev_id_show(struct device *dev,
{
struct net_device *ndev = to_net_dev(dev);
- if (ndev->dev_id == ndev->dev_port)
+ /*
+ * ndev->dev_port will be equal to 0 in old kernel prior to commit
+ * 9b8b2a323008 ("IB/ipoib: Use dev_port to expose network interface port numbers")
+ * Zero was chosen as special case for user space applications to fallback
+ * and query dev_id to check if it has different value or not.
+ *
+ * Don't pring warning in such scenario.
+ *
+ * https://github.com/systemd/systemd/blob/master/src/udev/udev-builtin-net_id.c#L358
+ */
+ if (ndev->dev_port && ndev->dev_id == ndev->dev_port)
netdev_info_once(ndev,
"\"%s\" wants to know my dev_id. Should it look at dev_port instead? See Documentation/ABI/testing/sysfs-class-net for more info.\n",
current->comm);
--
2.20.1
