drbd: RCU for disk_conf

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

1 files changed, 16 insertions, 9 deletions

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index e37244485d72..de6afa75dec6 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -866,6 +866,7 @@ int drbd_send_sync_param(struct drbd_conf *mdev)
         const int apv = mdev->tconn->agreed_pro_version;
         enum drbd_packet cmd;
         struct net_conf *nc;
+        struct disk_conf *dc;
 
         sock = &mdev->tconn->data;
         p = drbd_prepare_command(mdev, sock);
@@ -887,11 +888,12 @@ int drbd_send_sync_param(struct drbd_conf *mdev)
         memset(p->verify_alg, 0, 2 * SHARED_SECRET_MAX);
 
         if (get_ldev(mdev)) {
-                p->rate = cpu_to_be32(mdev->ldev->dc.resync_rate);
-                p->c_plan_ahead = cpu_to_be32(mdev->ldev->dc.c_plan_ahead);
-                p->c_delay_target = cpu_to_be32(mdev->ldev->dc.c_delay_target);
-                p->c_fill_target = cpu_to_be32(mdev->ldev->dc.c_fill_target);
-                p->c_max_rate = cpu_to_be32(mdev->ldev->dc.c_max_rate);
+                dc = rcu_dereference(mdev->ldev->disk_conf);
+                p->rate = cpu_to_be32(dc->resync_rate);
+                p->c_plan_ahead = cpu_to_be32(dc->c_plan_ahead);
+                p->c_delay_target = cpu_to_be32(dc->c_delay_target);
+                p->c_fill_target = cpu_to_be32(dc->c_fill_target);
+                p->c_max_rate = cpu_to_be32(dc->c_max_rate);
                 put_ldev(mdev);
         } else {
                 p->rate = cpu_to_be32(DRBD_RATE_DEF);
@@ -1056,7 +1058,9 @@ int drbd_send_sizes(struct drbd_conf *mdev, int trigger_reply, enum dds_flags fl
         if (get_ldev_if_state(mdev, D_NEGOTIATING)) {
                 D_ASSERT(mdev->ldev->backing_bdev);
                 d_size = drbd_get_max_capacity(mdev->ldev);
-                u_size = mdev->ldev->dc.disk_size;
+                rcu_read_lock();
+                u_size = rcu_dereference(mdev->ldev->disk_conf)->disk_size;
+                rcu_read_unlock();
                 q_order_type = drbd_queue_order_type(mdev);
                 max_bio_size = queue_max_hw_sectors(mdev->ldev->backing_bdev->bd_disk->queue) << 9;
                 max_bio_size = min_t(int, max_bio_size, DRBD_MAX_BIO_SIZE);
@@ -2889,7 +2893,6 @@ int drbd_md_read(struct drbd_conf *mdev, struct drbd_backing_dev *bdev)
         for (i = UI_CURRENT; i < UI_SIZE; i++)
                 bdev->md.uuid[i] = be64_to_cpu(buffer->uuid[i]);
         bdev->md.flags = be32_to_cpu(buffer->flags);
-        bdev->dc.al_extents = be32_to_cpu(buffer->al_nr_extents);
         bdev->md.device_uuid = be64_to_cpu(buffer->device_uuid);
 
         spin_lock_irq(&mdev->tconn->req_lock);
@@ -2901,8 +2904,12 @@ int drbd_md_read(struct drbd_conf *mdev, struct drbd_backing_dev *bdev)
         }
         spin_unlock_irq(&mdev->tconn->req_lock);
 
-        if (bdev->dc.al_extents < 7)
-                bdev->dc.al_extents = 127;
+        mutex_lock(&mdev->tconn->conf_update);
+        /* This blocks wants to be get removed... */
+        bdev->disk_conf->al_extents = be32_to_cpu(buffer->al_nr_extents);
+        if (bdev->disk_conf->al_extents < DRBD_AL_EXTENTS_MIN)
+                bdev->disk_conf->al_extents = DRBD_AL_EXTENTS_DEF;
+        mutex_unlock(&mdev->tconn->conf_update);
 
  err:
         mutex_unlock(&mdev->md_io_mutex);