tree a3509f442e6fc75ca9304757ffa3dce4918ef55e
parent 26be34dc3a46be983352dd89683db374b0cb73fa
author NeilBrown <neilb@suse.de> 1159863354 -0700
committer Linus Torvalds <torvalds@g5.osdl.org> 1159887858 -0700

[PATCH] md: define ->congested_fn for raid1, raid10, and multipath

raid1, raid10 and multipath don't report their 'congested' status through
bdi_*_congested, but should.

This patch adds the appropriate functions which just check the 'congested'
status of all active members (with appropriate locking).

raid1 read_balance should be modified to prefer devices where
bdi_read_congested returns false.  Then we could use the '&' branch rather
than the '|' branch.  However that should would need some benchmarking first
to make sure it is actually a good idea.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>