From 70df70927b75eb86f12b14167c398b99dc3a56e4 Mon Sep 17 00:00:00 2001 From: Lars Ellenberg Date: Fri, 20 Dec 2013 11:17:02 +0100 Subject: drbd: allow write-ordering policy to be bumped up again Previously, once you disabled flushes as a means of enforcing write-ordering, you'd need to detach/re-attach to enable them again. Allow drbdsetup disk-options to re-enable previously disabled write-ordering policy options at runtime. While at it fix RCU in drbd_bump_write_ordering() max_allowed_wo() uses rcu_dereference, therefore it must be called within rcu_read_lock()/rcu_read_unlock() Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg --- drivers/block/drbd/drbd_receiver.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'drivers/block/drbd/drbd_receiver.c') diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c index bb1434d..8d8a6b7 100644 --- a/drivers/block/drbd/drbd_receiver.c +++ b/drivers/block/drbd/drbd_receiver.c @@ -1290,7 +1290,8 @@ void drbd_bump_write_ordering(struct drbd_resource *resource, struct drbd_backin }; pwo = resource->write_ordering; - wo = min(pwo, wo); + if (wo != WO_bdev_flush) + wo = min(pwo, wo); rcu_read_lock(); idr_for_each_entry(&resource->devices, device, vnr) { if (get_ldev(device)) { @@ -1300,11 +1301,12 @@ void drbd_bump_write_ordering(struct drbd_resource *resource, struct drbd_backin put_ldev(device); } } - rcu_read_unlock(); if (bdev) wo = max_allowed_wo(bdev, wo); + rcu_read_unlock(); + resource->write_ordering = wo; if (pwo != resource->write_ordering || wo == WO_bdev_flush) drbd_info(resource, "Method to ensure write ordering: %s\n", write_ordering_str[resource->write_ordering]); -- cgit v1.1