On Fri, Jan 23, 2015 at 10:42:47AM -0800, James Bottomley wrote: > To that point, Rusty's patch just keeps the status quo in the new > module_refcount() environment, so it's the quick bandaid. > > I think the use case you're worrying about is what happens if someone > tries to use a device after module removal begins executing but before > the device has been deleted (say by opening it)? We'll exit the device > removal routines and then kill the module, because after the module code > gets to ->exit(), nothing re-checks the module refcount, so the host > module will get free'd while we're still using the device. > > The fix for this seems to be to differentiate between special uses of > scsi_get_device, which are allowed to get the device in the module exit > routines and ordinary uses which aren't. Something like this? (the > patch isn't complete, but you get the idea). Yes, that's exactly what I worry about. But you're right, the patch doesn't make anything worse compared to the 3.18 and earlier status quo. So I think I'm fine with the __module_get patch (which I assume will go through the module tree as well?), and I'll get back to my series to unwind our bandaids back to the start for the proper fix. -- 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
