Re: [bug] kernel panic when running ublk selftest on next-20250321

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

On Fri, Mar 21, 2025 at 08:40:57AM -0600, Jens Axboe wrote:
> On 3/21/25 8:40 AM, Pavel Begunkov wrote:
> > On 3/21/25 14:33, Ming Lei wrote:
> >> Hello,
> >>
> >> When running ublk selftest on today's next tree, the following kernel
> >> panic is triggered immediately:
> > 
> > Jens already stumbled on that one, it's likely because the
> > cached structure is not zeroed on alloc. I believe the
> > troubled patch is removed from the tree for now.
> 
> Yep, ran into the same thing this morning, and yep the two last patches
> in that series got dropped until this is resolved. Ming, if you use my
> current for-next branch, it should all be good again.

Yeah, looks everything is good after reverting the following two patches:

Revert "io_uring/cmd: add iovec cache for commands"
Revert "io_uring/cmd: introduce io_uring_cmd_import_fixed_vec"

BTW I feel io_uring_cmd_import_fixed_vec is useful for using ublk
zc to write stacking target, plain readv/writev works just
fine without zc.




thanks,
Ming