[dm-devel] [PATCH] kobject: provide kobject_put_wait to fix module unload race

[Greg Kroah-Hartman]

On Sat, Jan 04, 2014 at 01:14:14PM -0500, Jeff Mahoney wrote:
> On 1/4/14, 1:06 PM, Mikulas Patocka wrote:
> > Hi
> > 
> > I noticed that Jeff Mahoney added a new structure kobj_completion, defined 
> > in include/linux/kobj_completion.h to the kernel 3.13-rc1 in the patch 
> > eee031649707db3c9920d9498f8d03819b74fc23. In the current upstream kernel, 
> > this interface is still unused.
> > 
> > However, converting the drivers to use kobj_completion is not trivial 
> > (note that all users of the original kobject interface are buggy - so all 
> > of them need to be converted).
> > 
> > I came up with a simpler patch to achieve the same purpose - this patch 
> > makes fixing the drivers easy - the driver is fixed just by replacing 
> > "kobject_put" with "kobject_put_wait" in the unload routine.
> > 
> > I'd like to ask if you could revert 
> > eee031649707db3c9920d9498f8d03819b74fc23 (no code uses it) and replace it 
> > with this patch.
> 
> I have no objections to reverting it. There were concerns from Al Viro
> that it'd be tough to get right by callers and I had assumed it got
> dropped after that. I had planned on using it in my btrfs sysfs exports
> patchset but came up with a better way.

Ok, thanks, I'll revert it for 3.14.

greg k-h