drbd: allow parallel promote/demote actions
authorLars Ellenberg <lars.ellenberg@linbit.com>
Mon, 28 Apr 2014 16:43:22 +0000 (18:43 +0200)
committerJens Axboe <axboe@fb.com>
Wed, 30 Apr 2014 19:46:54 +0000 (13:46 -0600)
commit9e276872fe1665ea158f0c6f40df13008fed2908
tree606f85fe946ba1fdc759da76c0acca9afc62df3b
parenta910b12352f5ddee712c3423c31fbb8b312dde88
drbd: allow parallel promote/demote actions

We plan to use genl_family->parallel_ops = true in the future,
but need to review all possible interactions first.

For now, only selectively drop genl_lock() in drbd_set_role(),
instead serializing on our own internal resource->conf_update mutex.

We now can be promoted/demoted on many resources in parallel,
which may significantly improve cluster failover times
when fencing is required.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
drivers/block/drbd/drbd_int.h
drivers/block/drbd/drbd_main.c
drivers/block/drbd/drbd_nl.c