[dm-devel] dm: fix iterate_device sanity check

[Mike Snitzer]

On Tue, Feb 09 2021 at  2:06am -0500,
JeffleXu <jefflexu at linux.alibaba.com> wrote:

> 
> 
> On 2/9/21 1:29 PM, Mike Snitzer wrote:
> > 
> > Hi, please see these commits that I've staged in linux-next via:
> > https://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm.git/log/?h=for-next
> > 
> > 1141b9133777 dm table: fix iterate_devices based device capability checks
> > 0224c5e6fd07 dm table: fix DAX iterate_devices based device capability checks
> > 76b0e14be03f dm table: fix zoned iterate_devices based device capability checks
> > 55cdd7435e97 dm table: remove needless request_queue NULL pointer checks
> > 
> 
> Thanks. This series looks good to me.
> 
> I suddenly find that the semantics of patch 1 (1141b9133777 dm table:
> fix iterate_devices based device capability checks) is a little
> different with the original context.
> 
> -	if (blk_queue_add_random(q) && dm_table_all_devices_attribute(t,
> device_is_not_random))
> +	if (dm_table_any_dev_attr(t, device_is_not_random))
>  		blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, q);
> +	else
> +		blk_queue_flag_set(QUEUE_FLAG_ADD_RANDOM, q);
> 
> In the original context, QUEUE_FLAG_ADD_RANDOM will only be cleared, it
> won't be set, while it could be set after patch 1. But I could see no
> harm of setting QUEUE_FLAG_ADD_RANDOM flag though.
> 
> FYI. Currently only scsi devices are still using QUEUE_FLAG_ADD_RANDOM
> flag, as all non-rotational devices should not set this flag since
> commit b277da0a8a59 ("block: disable entropy contributions for nonrot
> devices").

I fixed it, thanks.

Mike