Re: block: del_gendisk() vs blk_queue_enter() race condition

[Sergey Senozhatsky <senozhatsky@chromium.org>]

On (24/10/08 01:13), Christoph Hellwig wrote:
> On Tue, Oct 08, 2024 at 03:10:53PM +0900, Sergey Senozhatsky wrote:
> > cd->lock still falls a victim of
> > "blk_queue_enter() and blk_queue_start_drain() are both called under ->open_mutex"
> > thingy, which seems like a primary problem here.  No matter why
> > blk_queue_enter() sleeps, draining under ->open_mutex, given that what we
> > want to drain can hold ->open_mutex, sometimes isn't going to drain.
> 
> Yes. So I think we'll need to move __blk_mark_disk_dead out
> of ->open_mutex again

Right, we also need to make sure that we drain before we try to
lock ->open_mutex in gel_dendisk() for the first time.

> it also isn't protected when calling blk_mark_disk_dead, but we'll
> also need to stop the SCSI LLDs from submitting new commands from
> their ->relase routines.   Let me cook up a little series..

Thank you!