Re: Revealing unload_lock to everyone

Keith Owens
2002-02-01T01:03:27Z

On Thu, 31 Jan 2002 15:58:17 -0800,
Dave Hansen <haveblue@us.ibm.com> wrote:
>This came up in a conversation about ieee1394_core.c. In 2.5.3, the BKL
>is used to protect a module from being unloaded. The code looks like this:
>
> lock_kernel();
> read_lock(&ieee1394_chardevs_lock);
> file_ops = ieee1394_chardevs[blocknum].file_ops;
> module = ieee1394_chardevs[blocknum].module;
> read_unlock(&ieee1394_chardevs_lock);
> ...
> INCREF(module);
> unlock_kernel();
>
>
>The question is, how can we keep the module from being unloaded between
>the file_ops assignment, and the INCREF. Do we have a general purpose
>way, other than the BKL, to keep a module from being unloaded? There is
>unload_lock, but it is static to module.c. We can always make it
>global, but is there a better solution?

try_inc_mod_count().