On Thu, 2018-09-06 at 16:03 +0300, Leon Romanovsky wrote: > On Thu, Sep 06, 2018 at 10:04:33AM +0300, Arseny Maslennikov wrote: > > On Wed, Sep 05, 2018 at 04:50:35PM +0300, Leon Romanovsky wrote: > > > On Mon, Sep 03, 2018 at 07:13:16PM +0300, Arseny Maslennikov wrote: > > > > Signed-off-by: Arseny Maslennikov <ar@xxxxxxxxx> > > > > --- > > > > drivers/infiniband/ulp/ipoib/ipoib_main.c | 38 +++++++++++++++++++++++ > > > > 1 file changed, 38 insertions(+) > > > > > > > > diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c > > > > index 30f840f874b3..7386e5bde3d3 100644 > > > > --- a/drivers/infiniband/ulp/ipoib/ipoib_main.c > > > > +++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c > > > > @@ -2386,6 +2386,42 @@ int ipoib_add_pkey_attr(struct net_device *dev) > > > > return device_create_file(&dev->dev, &dev_attr_pkey); > > > > } > > > > > > > > +/* > > > > + * We erroneously exposed the iface's port number in the dev_id > > > > + * sysfs field long after dev_port was introduced for that purpose[1], > > > > + * and we need to stop everyone from relying on that. > > > > + * Let's overload the shower routine for the dev_id file here > > > > + * to gently bring the issue up. > > > > + * > > > > + * [1] https://www.spinics.net/lists/netdev/msg272123.html > > > > + */ > > > > +static ssize_t dev_id_show(struct device *dev, > > > > + struct device_attribute *attr, char *buf) > > > > +{ > > > > + struct net_device *ndev = to_net_dev(dev); > > > > + ssize_t ret = -EINVAL; > > > > + > > > > + if (ndev->dev_id == ndev->dev_port) { > > > > + netdev_info_once(ndev, > > > > + "\"%s\" wants to know my dev_id. " > > > > + "Should it look at dev_port instead?\n", > > > > + current->comm); > > > > + netdev_info_once(ndev, > > > > + "See Documentation/ABI/testing/sysfs-class-net for more info.\n"); > > > > + } > > > > + > > > > + ret = sprintf(buf, "%#x\n", ndev->dev_id); > > > > + > > > > + return ret; > > > > +} > > > > +static DEVICE_ATTR_RO(dev_id); > > > > + > > > > > > I don't see this field among exposed by IPoIB, why should we expose it now? > > > > > > > To deviate from standard netdev behaviour, which only prints the > > field out. Doug wanted this to also print a deprecation message, and > > netdev (obviously) does not do that. See below. > > > > > > +int ipoib_intercept_dev_id_attr(struct net_device *dev) > > > > +{ > > > > + device_remove_file(&dev->dev, &dev_attr_dev_id); > > > > + return device_create_file(&dev->dev, &dev_attr_dev_id); > > > > > > Why isn't enough to rely on netdev code? > > > > > > > Netdev code relies on macros around a *static* function 'netdev_show', > > which is defined in net/core/net-sysfs.c; it is not listed in any header > > files, and the macros aren't as well. This all leads me to believe it > > was not really meant to be used from outside net/core/net-sysfs. > > > > The only way we could use any netdev code here is to set up our own > > handler (again), printk() a message, then call netdev_show — but we have > > no access to it. > > > > Of course, it also may be that I'm terribly missing a clue. > > Thanks, > > IMHO, the end result of adequate Doug's request is a little bit too much. > I don't think that it justifies such remove->create construction. > > Personal opinion. I agree with you that the end result is kinda bulky, *but*, we will need to know if there are things using the old dev_id before we can remove it. In particular, I'm concerned the IPoIB handling code of NetworkManager uses it. It's worth the cost I think. -- Doug Ledford <dledford@xxxxxxxxxx> GPG KeyID: B826A3330E572FDD Key fingerprint = AE6B 1BDA 122B 23B4 265B 1274 B826 A333 0E57 2FDD
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