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author | Leon Romanovsky <leonro@mellanox.com> | 2019-05-06 14:23:04 +0300 |
---|---|---|
committer | Jason Gunthorpe <jgg@mellanox.com> | 2019-05-07 16:13:23 -0300 |
commit | b79656ed44c6865e17bcd93472ec39488bcc4984 (patch) | |
tree | 403a47c6404c47141bb42351fd62d2e8572a199f | |
parent | ba7d8117f3cca8eb70d579fde3f9ec8cd6a28f39 (diff) | |
download | lwn-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.c | 13 |
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); |