drbd: Basic refcounting for drbd_tconn
References hold by:
* Each (running) drbd thread has a reference on tconn
* Each mdev has a referenc on tconn
* Beeing in the all_tconn list counts for one reference
* Each after_conn_state_chg_work has a reference to tconn
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index b9c103f..11427f5 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -509,6 +509,8 @@
conn_info(tconn, "Terminating %s\n", current->comm);
/* Release mod reference taken when thread was started */
+
+ kref_put(&tconn->kref, &conn_destroy);
module_put(THIS_MODULE);
return retval;
}
@@ -546,6 +548,8 @@
return false;
}
+ kref_get(&thi->tconn->kref);
+
init_completion(&thi->stop);
thi->reset_cpu_mask = 1;
thi->t_state = RUNNING;
@@ -558,6 +562,7 @@
if (IS_ERR(nt)) {
conn_err(tconn, "Couldn't start thread\n");
+ kref_put(&tconn->kref, &conn_destroy);
module_put(THIS_MODULE);
return false;
}
@@ -2237,6 +2242,8 @@
/* caution. no locking. */
void drbd_delete_device(struct drbd_conf *mdev)
{
+ struct drbd_tconn *tconn = mdev->tconn;
+
idr_remove(&mdev->tconn->volumes, mdev->vnr);
idr_remove(&minors, mdev_to_minor(mdev));
synchronize_rcu();
@@ -2272,6 +2279,8 @@
put_disk(mdev->vdisk);
blk_cleanup_queue(mdev->rq_queue);
kfree(mdev);
+
+ kref_put(&tconn->kref, &conn_destroy);
}
static void drbd_cleanup(void)
@@ -2409,7 +2418,7 @@
tconn->int_dig_vv = NULL;
}
-struct drbd_tconn *drbd_new_tconn(const char *name)
+struct drbd_tconn *conn_create(const char *name)
{
struct drbd_tconn *tconn;
@@ -2455,6 +2464,7 @@
};
down_write(&drbd_cfg_rwsem);
+ kref_init(&tconn->kref);
list_add_tail(&tconn->all_tconn, &drbd_tconns);
up_write(&drbd_cfg_rwsem);
@@ -2471,9 +2481,10 @@
return NULL;
}
-void drbd_free_tconn(struct drbd_tconn *tconn)
+void conn_destroy(struct kref *kref)
{
- list_del(&tconn->all_tconn);
+ struct drbd_tconn *tconn = container_of(kref, struct drbd_tconn, kref);
+
idr_destroy(&tconn->volumes);
free_cpumask_var(tconn->cpu_mask);
@@ -2503,7 +2514,9 @@
if (!mdev)
return ERR_NOMEM;
+ kref_get(&tconn->kref);
mdev->tconn = tconn;
+
mdev->minor = minor;
mdev->vnr = vnr;
@@ -2605,6 +2618,7 @@
blk_cleanup_queue(q);
out_no_q:
kfree(mdev);
+ kref_put(&tconn->kref, &conn_destroy);
return err;
}