drbd: transfer log epoch numbers are now per resource

cherry-picked from drbd 9 devel branch.

In preparation of multiple connections, the "barrier number" or
"epoch number" needs to be tracked per-resource, not per connection.
The sequence number space will not be reset anymore.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

1 files changed, 3 insertions, 6 deletions

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 843d0af68f96..bfe6975ef94c 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -208,7 +208,7 @@ static int tl_init(struct drbd_tconn *tconn)
         INIT_LIST_HEAD(&b->requests);
         INIT_LIST_HEAD(&b->w.list);
         b->next = NULL;
-        b->br_number = 4711;
+        b->br_number = atomic_inc_return(&tconn->current_tle_nr);
         b->n_writes = 0;
         b->w.cb = NULL; /* if this is != NULL, we need to dec_ap_pending in tl_clear */
 
@@ -241,16 +241,13 @@ static void tl_cleanup(struct drbd_tconn *tconn)
  */
 void _tl_add_barrier(struct drbd_tconn *tconn, struct drbd_tl_epoch *new)
 {
-        struct drbd_tl_epoch *newest_before;
-
         INIT_LIST_HEAD(&new->requests);
         INIT_LIST_HEAD(&new->w.list);
         new->w.cb = NULL; /* if this is != NULL, we need to dec_ap_pending in tl_clear */
         new->next = NULL;
         new->n_writes = 0;
 
-        newest_before = tconn->newest_tle;
-        new->br_number = newest_before->br_number+1;
+        new->br_number = atomic_inc_return(&tconn->current_tle_nr);
         if (tconn->newest_tle != new) {
                 tconn->newest_tle->next = new;
                 tconn->newest_tle = new;
@@ -406,7 +403,7 @@ void _tl_restart(struct drbd_tconn *tconn, enum drbd_req_event what)
                                 list_splice(&carry_reads, &b->requests);
                                 INIT_LIST_HEAD(&b->w.list);
                                 b->w.cb = NULL;
-                                b->br_number = net_random();
+                                b->br_number = atomic_inc_return(&tconn->current_tle_nr);
                                 b->n_writes = 0;
 
                                 *pn = b;