On 5/15/08, Matthew Wilcox <matthew@xxxxxx> wrote: > On Thu, May 15, 2008 at 05:01:01PM +0800, Dave Young wrote: >> > The classes are different here, first sdev_class, then sg_sysfs_class > > Oh ... right. I misread scsi_register_interface as > class_register_interface. > >> Greg, what about using mutex_lock_nested to silence lockdep? They are >> the only usage of class->mutex out of class.c > > I don't see how we prove that, for example, you can never take the > sg_sysfs_class mutex and then take the sdev_class mutex. Sorry for my delay. AFAIK, there's no this kind of use. > > There aren't /that/ many classes in the kernel (my laptop has 33 in > /sys/class). How about we make each (sysfs) class its own (lockdep) > class? That way we let lockdep do its job rather than telling it "nah, > you're all right, this is good". > > I don't have a copy of the sem->mutex conversion to hand, but I imagine > you want to do something like: > > - Add a struct lock_class_key to struct class > - In drivers/base/class.c use __mutex_init instead of mutex_init > > I think that should be enough ... Yes, it's safer than mutex_lock_nested. If you all have no objection I can do the fix like this. Thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
