tree c0c50ab6ac43e9c762199bfd94c787f43a8e0896
parent 97658cdd3af7d01461874c93b89afa4a2465e7c6
author NeilBrown <neilb@suse.de> 1303115143 +1000
committer NeilBrown <neilb@suse.de> 1303115143 +1000

md: incorporate new plugging into raid5.

In raid5 plugging is used for 2 things:
 1/ collecting writes that require a bitmap update
 2/ collecting writes in the hope that we can create full
    stripes - or at least more-full.

We now release these different sets of stripes when plug_cnt
is zero.

Also in make_request, we call mddev_check_plug to hopefully increase
plug_cnt, and wake up the thread at the end if plugging wasn't
achieved for some reason.

Signed-off-by: NeilBrown <neilb@suse.de>