Re: Port to 6.14-stable - ublk: fix race between io_uring_cmd_complete_in_task and ublk_cancel_cmd

[Ming Lei <ming.lei@redhat.com>]

On Tue, May 06, 2025 at 04:16:25PM +0300, Jared Holzman wrote:
> On 06/05/2025 5:13, Ming Lei wrote:
> > On Mon, May 05, 2025 at 07:06:37PM +0300, Jared Holzman wrote:
> >> Hi Ming,
> >>
> >> I'm attempting to back port the fix for this issue to the 6.14-stable branch.
> >>
> >> Greg Kroah-Hartman has already applied d6aa0c178bf8 - "ublk: call ublk_dispatch_req() for handling UBLK_U_IO_NEED_GET_DATA",
> >> but was unable to apply f40139fde527 cleanly.
> >>
> >> I created the patch below. It applies and compiles, but when I rerun the scenario I get several hung tasks waiting on the ub->mutex
> >> which is being held by the following task:
> > 
> > Hi Jared,
> > 
> > You need to pull in the following patchset too:
> > 
> > https://lore.kernel.org/linux-block/20250416035444.99569-1-ming.lei@redhat.com/
> > 
> > which avoids ub->mutex in error handling code path.
> > 
> > I just picked them in the following tree:
> > 
> > https://github.com/ming1/linux/commits/linux-6.14.y/
> > 
> > Please test and see if they work for you.
> > 
> > 
> > Thanks,
> > Ming
> > 
> 
> Hi Ming,
> 
> Tested. It works great!
> 
> Will you be sending a pull request to Greg or should I send him the patches?

Hi Jared,

Please make a PR and send to Greg since I didn't test & verify it on 6.14-y
tree yet.

And please Cc me, I will give one double review.


Thanks,
Ming