drbd: Allow online change of al-stripes and al-stripe-size
Allow to change the AL layout with an resize operation. For that
the reisze command gets two new fields: al_stripes and al_stripe_size.
In order to make the operation crash save:
1) Lock out all IO and MD-IO
2) Write the super block with MDF_PRIMARY_IND clear
3) write the bitmap to the new location (all zeros, since
we allow only while connected)
4) Initialize the new AL-area
5) Write the super block with the restored MDF_PRIMARY_IND.
6) Unfreeze all IO
Since the AL-layout has no influence on the protocol, this operation
needs to be beforemed on both sides of a resource (if intended).
Signed-off-by: Andreas Gruenbacher <agruen@linbit.com>
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/include/linux/drbd_genl.h b/include/linux/drbd_genl.h
index d0d8fac..e8c4457 100644
--- a/include/linux/drbd_genl.h
+++ b/include/linux/drbd_genl.h
@@ -181,6 +181,8 @@
__u64_field(1, DRBD_GENLA_F_MANDATORY, resize_size)
__flg_field(2, DRBD_GENLA_F_MANDATORY, resize_force)
__flg_field(3, DRBD_GENLA_F_MANDATORY, no_resync)
+ __u32_field_def(4, 0 /* OPTIONAL */, al_stripes, DRBD_AL_STRIPES_DEF)
+ __u32_field_def(5, 0 /* OPTIONAL */, al_stripe_size, DRBD_AL_STRIPE_SIZE_DEF)
)
GENL_struct(DRBD_NLA_STATE_INFO, 8, state_info,