On Tuesday May 29, psusi@cfl.rr.com wrote:

Neil Brown wrote:

quoted

 md/dm modules could keep count of requests as has been suggested
 (though that would be a fairly big change for raid0 as it currently
 doesn't know when a request completes - bi_endio goes directly to the
 filesystem). 

Are you sure?  I believe that dm handles bi_endio because it waits for 
all in progress bio to complete before switching tables.

I was taking about md/raid0, not dm-stripe.
md/raid0 (and md/linear) currently never know that a request has
completed.

NeilBrown