On Mon, Sep 08, 2014 at 10:38:07AM +0200, Johannes Berg wrote: > On Fri, 2014-09-05 at 15:13 -0700, Greg Kroah-Hartman wrote: > > > > + /* > > > + * this seems racy, but I don't see a notifier or such on > > > + * a struct device to know when it goes away? > > > + */ > > > + if (devcd->failing_dev->kobj.sd) > > > + sysfs_delete_link(&devcd->failing_dev->kobj, &dev->kobj, > > > + "dev_coredump"); > > > > What is this link? It should "just go away" if this: > > > > > + put_device(devcd->failing_dev); > > > > was the last put_device() call on the failing_dev, right? So you > > shouldn't need to make this call to sysfs_delete_link(). > > I looked at this again, and it's the other way around. This is the link > that Daniel requested, from the original device to the one that's being > freed. For whatever reason though, symlinks don't automatically go away > when freed: > > (with a test patch that makes "mac80211-hwsim" crash whenever we have > radar) > > # echo 1 > /sys/kernel/debug/ieee80211/phy0/hwsim/dfs_simulate_radar > # ls /sys/class/devcoredump/ > devcd1 > # ls /sys/class/devcoredump/devcd1/ > data failing_device/ power/ subsystem/ uevent > # ls -l /sys/class/mac80211_hwsim/hwsim0/dev_coredump > lrwxrwxrwx 1 root root 0 Sep 8 08:34 /sys/class/mac80211_hwsim/hwsim0/dev_coredump -> ../../devcoredump/devcd1 > # echo > /sys/class/devcoredump/devcd1/data > # ls /sys/class/devcoredump/ > # ls -l /sys/class/mac80211_hwsim/hwsim0/dev_coredump > lrwxrwxrwx 1 root root 0 Sep 8 08:34 /sys/class/mac80211_hwsim/hwsim0/dev_coredump -> ../../devcoredump/devcd1 > > (but the link is now dead) > > Maybe I'm creating the links in the wrong way so they don't > automatically get removed when the struct device is released? No, you are correct, sorry for the noise, I thought the symlink was the other way around for some reason. greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
