drbd: Refcounting for mdev objects

Preparing removal of drbd_cfg_rwsem

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_int.h b/drivers/block/drbd/drbd_int.h
index 3f377e2..8bc604e 100644 (file)
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -867,6 +867,7 @@ struct drbd_tconn {                 /* is a resource from the config file */
 struct drbd_conf {
        struct drbd_tconn *tconn;
        int vnr;                        /* volume number within the connection */
+       struct kref kref;
 
        /* things that are stored as / read from meta data on disk */
        unsigned long flags;
@@ -1373,7 +1374,7 @@ extern rwlock_t global_state_lock;
 
 extern int conn_lowest_minor(struct drbd_tconn *tconn);
 enum drbd_ret_code conn_new_minor(struct drbd_tconn *tconn, unsigned int minor, int vnr);
-extern void drbd_delete_device(struct drbd_conf *mdev);
+extern void drbd_minor_destroy(struct kref *kref);
 
 struct drbd_tconn *conn_create(const char *name);
 extern void conn_destroy(struct kref *kref);

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 240319c..8da0e99 100644 (file)
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -2052,7 +2052,6 @@ void drbd_init_set_defaults(struct drbd_conf *mdev)
        init_waitqueue_head(&mdev->al_wait);
        init_waitqueue_head(&mdev->seq_wait);
 
-       /* mdev->tconn->agreed_pro_version gets initialized in drbd_connect() */
        mdev->write_ordering = WO_bdev_flush;
        mdev->resync_wenr = LC_FREE;
        mdev->peer_max_bio_size = DRBD_MAX_BIO_SIZE_SAFE;
@@ -2272,21 +2271,16 @@ static void drbd_release_all_peer_reqs(struct drbd_conf *mdev)
 }
 
 /* caution. no locking. */
-void drbd_delete_device(struct drbd_conf *mdev)
+void drbd_minor_destroy(struct kref *kref)
 {
+       struct drbd_conf *mdev = container_of(kref, struct drbd_conf, kref);
        struct drbd_tconn *tconn = mdev->tconn;
 
-       idr_remove(&mdev->tconn->volumes, mdev->vnr);
-       idr_remove(&minors, mdev_to_minor(mdev));
-       synchronize_rcu();
-
        /* paranoia asserts */
        D_ASSERT(mdev->open_cnt == 0);
        D_ASSERT(list_empty(&mdev->tconn->data.work.q));
        /* end paranoia asserts */
 
-       del_gendisk(mdev->vdisk);
-
        /* cleanup stuff that may have been allocated during
         * device (re-)configuration or state changes */
 
@@ -2320,6 +2314,7 @@ static void drbd_cleanup(void)
 {
        unsigned int i;
        struct drbd_conf *mdev;
+       struct drbd_tconn *tconn, *tmp;
 
        unregister_reboot_notifier(&drbd_notifier);
 
@@ -2337,8 +2332,19 @@ static void drbd_cleanup(void)
        drbd_genl_unregister();
 
        down_write(&drbd_cfg_rwsem);
-       idr_for_each_entry(&minors, mdev, i)
-               drbd_delete_device(mdev);
+       idr_for_each_entry(&minors, mdev, i) {
+               idr_remove(&minors, mdev_to_minor(mdev));
+               idr_remove(&mdev->tconn->volumes, mdev->vnr);
+               del_gendisk(mdev->vdisk);
+               synchronize_rcu();
+               kref_put(&mdev->kref, &drbd_minor_destroy);
+       }
+
+       list_for_each_entry_safe(tconn, tmp, &drbd_tconns, all_tconn) {
+               list_del(&tconn->all_tconn);
+               synchronize_rcu();
+               kref_put(&tconn->kref, &conn_destroy);
+       }
        up_write(&drbd_cfg_rwsem);
 
        drbd_destroy_mempools();
@@ -2625,6 +2631,7 @@ enum drbd_ret_code conn_new_minor(struct drbd_tconn *tconn, unsigned int minor,
                goto out_idr_remove_vol;
        }
        add_disk(disk);
+       kref_init(&mdev->kref); /* one ref for both idrs and the the add_disk */
 
        /* inherit the connection state */
        mdev->state.conn = tconn->cstate;

diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index 4a946a8..5747bc6 100644 (file)
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -1065,7 +1065,7 @@ static void conn_reconfig_done(struct drbd_tconn *tconn)
        spin_unlock_irq(&tconn->req_lock);
        if (stop_threads) {
                /* asender is implicitly stopped by receiver
-                * in drbd_disconnect() */
+                * in conn_disconnect() */
                drbd_thread_stop(&tconn->receiver);
                drbd_thread_stop(&tconn->worker);
        }
@@ -3033,7 +3033,11 @@ static enum drbd_ret_code adm_delete_minor(struct drbd_conf *mdev)
             * we may want to delete a minor from a live replication group.
             */
            mdev->state.role == R_SECONDARY) {
-               drbd_delete_device(mdev);
+               idr_remove(&mdev->tconn->volumes, mdev->vnr);
+               idr_remove(&minors, mdev_to_minor(mdev));
+               del_gendisk(mdev->vdisk);
+               synchronize_rcu();
+               kref_put(&mdev->kref, &drbd_minor_destroy);
                return NO_ERROR;
        } else
                return ERR_MINOR_CONFIGURED;

diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index b4858bb..7156e53 100644 (file)
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -844,7 +844,7 @@ int drbd_connected(int vnr, void *p, void *data)
  *     no point in trying again, please go standalone.
  *  -2 We do not have a network config...
  */
-static int drbd_connect(struct drbd_tconn *tconn)
+static int conn_connect(struct drbd_tconn *tconn)
 {
        struct socket *sock, *msock;
        struct net_conf *nc;
@@ -878,7 +878,7 @@ static int drbd_connect(struct drbd_tconn *tconn)
                                tconn->meta.socket = s;
                                send_first_packet(tconn, &tconn->meta, P_INITIAL_META);
                        } else {
-                               conn_err(tconn, "Logic error in drbd_connect()\n");
+                               conn_err(tconn, "Logic error in conn_connect()\n");
                                goto out_release_sockets;
                        }
                }
@@ -4240,7 +4240,7 @@ void conn_flush_workqueue(struct drbd_tconn *tconn)
        wait_for_completion(&barr.done);
 }
 
-static void drbd_disconnect(struct drbd_tconn *tconn)
+static void conn_disconnect(struct drbd_tconn *tconn)
 {
        enum drbd_conns oc;
        int rv = SS_UNKNOWN_ERROR;
@@ -4636,9 +4636,9 @@ int drbdd_init(struct drbd_thread *thi)
        conn_info(tconn, "receiver (re)started\n");
 
        do {
-               h = drbd_connect(tconn);
+               h = conn_connect(tconn);
                if (h == 0) {
-                       drbd_disconnect(tconn);
+                       conn_disconnect(tconn);
                        schedule_timeout_interruptible(HZ);
                }
                if (h == -1) {
@@ -4650,7 +4650,7 @@ int drbdd_init(struct drbd_thread *thi)
        if (h > 0)
                drbdd(tconn);
 
-       drbd_disconnect(tconn);
+       conn_disconnect(tconn);
 
        conn_info(tconn, "receiver terminated\n");
        return 0;