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authorLeon Romanovsky <leonro@mellanox.com>2019-05-06 14:23:04 +0300
committerJason Gunthorpe <jgg@mellanox.com>2019-05-07 16:13:23 -0300
commitb79656ed44c6865e17bcd93472ec39488bcc4984 (patch)
tree403a47c6404c47141bb42351fd62d2e8572a199f
parentba7d8117f3cca8eb70d579fde3f9ec8cd6a28f39 (diff)
downloadlwn-b79656ed44c6865e17bcd93472ec39488bcc4984.tar.gz
lwn-b79656ed44c6865e17bcd93472ec39488bcc4984.zip
RDMA/ipoib: Allow user space differentiate between valid dev_port
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@vger.kernel.org> # 4.19 Fixes: f6350da41dc7 ("IB/ipoib: Log sysfs 'dev_id' accesses from userspace") Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
-rw-r--r--drivers/infiniband/ulp/ipoib/ipoib_main.c13
1 files changed, 12 insertions, 1 deletions
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
index 48eda16db1a7..9b5e11d3fb85 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -2402,7 +2402,18 @@ 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 print 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);