[dm-devel] Propagating queue/rotational up the stack

[Phillip Susi <psusi cfl rr com>]

I am running my root fs on an lvm lv situated on a pv built on an SSD,
and have noticed that ureadahead is optimizing for rotational disks
instead of SSD.  This is because the dm-0 block device's
queue/rotational entry in sysfs reports 1 instead of 0.  It seems that
this should be set to match the value of the underlying pv.  Would this
be possible and if so, would it be very difficult?