Re: [PATCH v3 2/3] zram: fix deadlock with sysfs attribute usage and driver removal

From: Greg KH
Date: Tue Jun 22 2021 - 03:41:32 EST


On Mon, Jun 21, 2021 at 04:36:34PM -0700, Luis Chamberlain wrote:
> + ssize_t __ret; \
> + if (!try_module_get(THIS_MODULE)) \

try_module_get(THIS_MODULE) is always racy and probably does not do what
you want it to do. You always want to get/put module references from
code that is NOT the code calling these functions.

> + return -ENODEV; \
> + __ret = _name ## _store(dev, attr, buf, len); \
> + module_put(THIS_MODULE); \

This too is going to be racy.

While fun to poke at, I still think this is pointless.

greg k-h