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/drivers/block/drbd/drbd_actlog.c b/drivers/block/drbd/drbd_actlog.c
index 6608076..28c73ca 100644
--- a/drivers/block/drbd/drbd_actlog.c
+++ b/drivers/block/drbd/drbd_actlog.c
@@ -659,6 +659,27 @@
wake_up(&mdev->al_wait);
}
+int drbd_initialize_al(struct drbd_conf *mdev, void *buffer)
+{
+ struct al_transaction_on_disk *al = buffer;
+ struct drbd_md *md = &mdev->ldev->md;
+ sector_t al_base = md->md_offset + md->al_offset;
+ int al_size_4k = md->al_stripes * md->al_stripe_size_4k;
+ int i;
+
+ memset(al, 0, 4096);
+ al->magic = cpu_to_be32(DRBD_AL_MAGIC);
+ al->transaction_type = cpu_to_be16(AL_TR_INITIALIZED);
+ al->crc32c = cpu_to_be32(crc32c(0, al, 4096));
+
+ for (i = 0; i < al_size_4k; i++) {
+ int err = drbd_md_sync_page_io(mdev, mdev->ldev, al_base + i * 8, WRITE);
+ if (err)
+ return err;
+ }
+ return 0;
+}
+
static int w_update_odbm(struct drbd_work *w, int unused)
{
struct update_odbm_work *udw = container_of(w, struct update_odbm_work, w);