How to prevent a module from unloading when in used

[Greg KH]

On Mon, Jul 21, 2014 at 10:20:48AM +0530, Chetan Nanda wrote:
> On Mon, Jul 21, 2014 at 9:52 AM, Greg KH <greg at kroah.com> wrote:
> 
> > On Mon, Jul 21, 2014 at 09:09:02AM +0530, Chetan Nanda wrote:
> > > I try to debug the hang when unloading of driver. I am using kernel v3.10
> > > and it hangs in 'wait_for_zero_refcount'.
> > > I checked that this function has been removed in kernel 3.13.
> > > But I am not able to find the patch for this change.
> > >
> > > Is there an easy way to find the patch which cause removal of wait from
> > > module unloading in v3.13.
> >
> > You have the full git tree, it should be very easy to find, you don't
> > need help from me.
> >
> > Hi Greg,
> 
> Thanks for your mail,
> 
> I have found a thread with the discussion and a patch for removing the
> wait_for_zero_refcount from module unloading, But not able to find this
> patch being merged on v3.13. (have checked all patches between 3.12 and
> 3.13)
> http://www.gossamer-threads.com/lists/linux/kernel/1783584?do=post_view_threaded#1783584

This email tells you the exact name of the patch to search for, and the
files in which it modifies, making it even easier to search for it.

How are you searching the git log that you are not seeing this patch,
which ended up being in the 3.13-rc1 kernel release?

Finding the git commit id is an exercise left for the reader...

greg k-h