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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/drbd/drbd_nl.c | |
| parent | 44a4d551846b8c61aa430b9432c1fcdf88444708 (diff) | |
| download | lwn-70df70927b75eb86f12b14167c398b99dc3a56e4.tar.gz lwn-70df70927b75eb86f12b14167c398b99dc3a56e4.zip | |
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/drbd/drbd_nl.c')
| -rw-r--r-- | drivers/block/drbd/drbd_nl.c | 10 |
1 files changed, 9 insertions, 1 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); |