dm: introduce num_flush_requests
authorMikulas Patocka <mpatocka@redhat.com>
Mon, 22 Jun 2009 09:12:20 +0000 (10:12 +0100)
committerAlasdair G Kergon <agk@redhat.com>
Mon, 22 Jun 2009 09:12:20 +0000 (10:12 +0100)
commitf9ab94cee313746573b2d693bc2afb807ebb0998
tree150155f364db0f26c7217e1f92d31344aa67a3f0
parent27eaa14975d8b53f0bad422e53cdf8e5f6dd44ec
dm: introduce num_flush_requests

Introduce num_flush_requests for a target to set to say how many flush
instructions (empty barriers) it wants to receive.  These are sent by
__clone_and_map_empty_barrier with map_info->flush_request going from 0
to (num_flush_requests - 1).

Old targets without flush support won't receive any flush requests.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
drivers/md/dm.c
include/linux/device-mapper.h