On Tue, 2012-10-23 at 11:55 -0700, Thomas Pedersen wrote: > mesh_plink_alloc() was being called with the RCU read lock held, which > triggered warnings because various things inside this function must > sleep. It doesn't make much sense to hold an RCU lock on a pointer we > don't yet have anyway, so do rcu_read_unlock() if allocating and relock > on insertion.
I'm not going to apply this, the locking in mesh_plink.c is *already* a mess with the spinlock being unlocked in so many places. Adding a random rcu being possibly dropped in the middle won't help it at all. That may be safe today, but it's in no way obvious. Dropping a lock in the middle of a function when it was acquired by the caller is always a *really* bad idea. To fix the issue right now, you can simply change GFP_KERNEL to GFP_ATOMIC in mesh_plink_alloc(). If that's not good enough in the long term, I'd really like to see code cleanups to make all the locking easier to follow. johannes _______________________________________________ Devel mailing list [email protected] http://lists.open80211s.org/cgi-bin/mailman/listinfo/devel
