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?
johannes