On Fri, 30 Mar 2007 22:58:39 +0900, Tejun Heo <htejun@xxxxxxxxx> wrote: > It's a little bit more convoluted than that. Module reference count of > zero doesn't indicate that there is no one referencing the module. It > just means that the module can be unloaded. ie. There still can be any > number of kobjects with release function backed by the module but as > long as all of them can be deleted and released by module exit function, > the module is unloadable at that point. > > IOW, module reference count does not count number of objects depending > on the module. It counts the number of active usages of those objects. We must make sure that the module is never deleted while there may be calls to ->release functions - the exit function can only return when all ->release calls have returned. This can be guaranteed if we (1) don't allow the module to unload if there are outstanding kobjects (we may need a "self destruct" knob then) or (2) make sure the ->release functions are outside of the module (see, for example, drivers/s390/s390_rdev.c). (Gah, that stuff is always giving me headaches. Sorry if I'm not making sense...) - 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
