[LSF/MM?BFP TOPIC] Block-layer device resets

[Hannes Reinecke <hare@suse.de>]

Hi all,

We are currently working on implementing cross-controller resets for
NVMe, which requires to send a command to the target which then should
terminate all commands on a given controller.
While we could easily terminate the controller, the specification
also requires us to terminate all outstanding commands.
Which then recurses into my all-time favourite topic on how to
abort outstanding commands from the fs/bio layer.

However, here we don't have to dissect/match to individual commands,
but rather have to abort everything, which seems rather easier.s

So I would like to fathom whether such a thing is feasible/reasonable
(I think so, obviously, and can think of several other use-cases, too,
qemu springs to mind here ...) and discuss possible implementations
(set 'req->deadline' to zero for all pending commands?).
Or maybe we can do such a thing already and I'm just not aware of it...

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
hare@suse.de                                +49 911 74053 688
SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg
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