[PATCH rdma-next] RDMA/ipoib: Allow user space differentiate between valid dev_port

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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




[Index of Archives]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Photo]     [Yosemite News]     [Yosemite Photos]     [Linux Kernel]     [Linux SCSI]     [XFree86]

  Powered by Linux