Re: [PATCH v2] nbd: Don't use workqueue to handle recv work

[Yongji Xie]

On Fri, Feb 18, 2022 at 11:21 PM Josef Bacik <josef@xxxxxxxxxxxxxx> wrote:
>
> On Tue, Feb 15, 2022 at 09:17:37PM +0800, Yongji Xie wrote:
> > Ping again.
> >
> > Hi Josef, could you take a look?
>
> Sorry Yongji this got lost.  Again in the reconnect case we're still setting up
> a long running thread, so it's not like it'll happen during a normal reclaim
> path thing, it'll be acted upon by userspace.  Thanks,
>

During creating this long running thread, we might trigger memory
reclaim since workqueue will use GFP_KERNEL allocation for it. Then a
deadlock can occur if the memory reclaim happens to hit the page cache
on this reconnecting nbd device.

Thanks,
Yongji