Re: [BUG report] Deadlock in xen-blkfront upon device hot-unplug

[Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>]

Christoph Hellwig <hch@xxxxxx> writes:

> On Thu, Jul 15, 2021 at 03:17:37PM +0200, Vitaly Kuznetsov wrote:
>> Christoph Hellwig <hch@xxxxxx> writes:
>> 
>> > On Thu, Jul 15, 2021 at 11:16:30AM +0200, Vitaly Kuznetsov wrote:
>> >> I'm observing a deadlock every time I try to unplug a xen-blkfront
>> >> device. With 5.14-rc1+ the deadlock looks like:
>> >
>> > I did actually stumble over this a few days ago just from code
>> > inspection.  Below is what I come up with, can you give it a spin?
>> 
>> This eliminates the deadlock, thanks! Unfortunately, this reveals the
>> same issue I observed when I just dropped taking the mutex from
>> blkfront_closing():
>
> Yeah, this still left too much cruft in blkfront_closing.  Can you
> try this version instead?
>

This one seems to work fine for me! Feel free to throw

Tested-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>

in. Thanks a lot!

-- 
Vitaly