tree 606f85fe946ba1fdc759da76c0acca9afc62df3b
parent a910b12352f5ddee712c3423c31fbb8b312dde88
author Lars Ellenberg <lars.ellenberg@linbit.com> 1398703402 +0200
committer Jens Axboe <axboe@fb.com> 1398887214 -0600

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>