Bug#915666: linux: data corruption with blk-mq

[Christoph Anton Mitterer <calestyo@scientia.net>]

For those reading along, Jens Axboe gave a summary on how to
check whether one's affected or not:

Quoting from: https://bugzilla.kernel.org/show_bug.cgi?id=201685#c294
> scsi_mod.use_blk_mq=0 will do the trick, as will just ensuring that you have
> a scheduler for your device. Eg for sda, check:
> 
> # cat /sys/block/sda/queue/scheduler
> bfq [mq-deadline] none
> 
> As long as that doesn't say [none], you are fine as well. Also note that
> this seems to require a special circumstance of timing and devices to even
> be possible in the first place. But I would recommend ensuring that one of
> the above two conditions are true, and I'd further recommend just using
> mq-deadline (or bfq or kyber, whatever is your preference) instead of
> turning scsi-mq off.
> 
> Once you've ensured that after a fresh boot, I'd double check by running
> fsck on the file systems hosted by a SCSI/SATA device.


It seems that all my own systems (with blk-mq) run with [mq-deadline]
out of the box.
Maybe Debian maintainers can tell whether this is the default (since
long) so people can easier find out whether they need to check their
data for corruptions.



Cheers,
Chris.