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| author | Lars Ellenberg <lars.ellenberg@linbit.com> | 2013-12-20 11:17:02 +0100 |
|---|---|---|
| committer | Philipp Reisner <philipp.reisner@linbit.com> | 2014-07-10 15:22:22 +0200 |
| commit | 70df70927b75eb86f12b14167c398b99dc3a56e4 (patch) | |
| tree | 81225e07ec255438893b727d99937ffa16cdc732 /drivers/block | |
| parent | 44a4d551846b8c61aa430b9432c1fcdf88444708 (diff) | |
| download | linux-70df70927b75eb86f12b14167c398b99dc3a56e4.tar.gz linux-70df70927b75eb86f12b14167c398b99dc3a56e4.tar.xz | |
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 <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/drbd/drbd_nl.c | 10 | ||||
| -rw-r--r-- | drivers/block/drbd/drbd_receiver.c | 6 |
2 files changed, 13 insertions, 3 deletions
diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c index 0bf8a6082bb8..66065e60fdbc 100644 --- a/drivers/block/drbd/drbd_nl.c +++ b/drivers/block/drbd/drbd_nl.c @@ -1294,6 +1294,13 @@ static unsigned int drbd_al_extents_max(struct drbd_backing_dev *bdev) return (al_size_4k - 1) * AL_CONTEXT_PER_TRANSACTION; } +static bool write_ordering_changed(struct disk_conf *a, struct disk_conf *b) +{ + return a->disk_barrier != b->disk_barrier || + a->disk_flushes != b->disk_flushes || + a->disk_drain != b->disk_drain; +} + int drbd_adm_disk_opts(struct sk_buff *skb, struct genl_info *info) { struct drbd_config_context adm_ctx; @@ -1400,7 +1407,8 @@ int drbd_adm_disk_opts(struct sk_buff *skb, struct genl_info *info) else set_bit(MD_NO_FUA, &device->flags); - drbd_bump_write_ordering(device->resource, NULL, WO_bdev_flush); + if (write_ordering_changed(old_disk_conf, new_disk_conf)) + drbd_bump_write_ordering(device->resource, NULL, WO_bdev_flush); drbd_md_sync(device); diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c index bb1434dfec8a..8d8a6b7f8f5d 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]); |