Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
[linux.git] / drivers / block / drbd / drbd_receiver.c
index 1385714eccb705f30c3cbe29850701981732a330..68e3992e88381cd4974ebfa2da3400708ab4afa0 100644 (file)
@@ -44,6 +44,7 @@
 #include <linux/string.h>
 #include <linux/scatterlist.h>
 #include "drbd_int.h"
+#include "drbd_protocol.h"
 #include "drbd_req.h"
 
 #include "drbd_vli.h"
@@ -61,11 +62,11 @@ enum finish_epoch {
        FE_RECYCLED,
 };
 
-static int drbd_do_features(struct drbd_tconn *tconn);
-static int drbd_do_auth(struct drbd_tconn *tconn);
-static int drbd_disconnected(struct drbd_conf *mdev);
+static int drbd_do_features(struct drbd_connection *connection);
+static int drbd_do_auth(struct drbd_connection *connection);
+static int drbd_disconnected(struct drbd_peer_device *);
 
-static enum finish_epoch drbd_may_finish_epoch(struct drbd_tconn *, struct drbd_epoch *, enum epoch_event);
+static enum finish_epoch drbd_may_finish_epoch(struct drbd_connection *, struct drbd_epoch *, enum epoch_event);
 static int e_end_block(struct drbd_work *, int);
 
 
@@ -150,7 +151,7 @@ static void page_chain_add(struct page **head,
        *head = chain_first;
 }
 
-static struct page *__drbd_alloc_pages(struct drbd_conf *mdev,
+static struct page *__drbd_alloc_pages(struct drbd_device *device,
                                       unsigned int number)
 {
        struct page *page = NULL;
@@ -196,41 +197,39 @@ static struct page *__drbd_alloc_pages(struct drbd_conf *mdev,
        return NULL;
 }
 
-static void reclaim_finished_net_peer_reqs(struct drbd_conf *mdev,
+static void reclaim_finished_net_peer_reqs(struct drbd_device *device,
                                           struct list_head *to_be_freed)
 {
-       struct drbd_peer_request *peer_req;
-       struct list_head *le, *tle;
+       struct drbd_peer_request *peer_req, *tmp;
 
        /* The EEs are always appended to the end of the list. Since
           they are sent in order over the wire, they have to finish
           in order. As soon as we see the first not finished we can
           stop to examine the list... */
 
-       list_for_each_safe(le, tle, &mdev->net_ee) {
-               peer_req = list_entry(le, struct drbd_peer_request, w.list);
+       list_for_each_entry_safe(peer_req, tmp, &device->net_ee, w.list) {
                if (drbd_peer_req_has_active_page(peer_req))
                        break;
-               list_move(le, to_be_freed);
+               list_move(&peer_req->w.list, to_be_freed);
        }
 }
 
-static void drbd_kick_lo_and_reclaim_net(struct drbd_conf *mdev)
+static void drbd_kick_lo_and_reclaim_net(struct drbd_device *device)
 {
        LIST_HEAD(reclaimed);
        struct drbd_peer_request *peer_req, *t;
 
-       spin_lock_irq(&mdev->tconn->req_lock);
-       reclaim_finished_net_peer_reqs(mdev, &reclaimed);
-       spin_unlock_irq(&mdev->tconn->req_lock);
+       spin_lock_irq(&device->resource->req_lock);
+       reclaim_finished_net_peer_reqs(device, &reclaimed);
+       spin_unlock_irq(&device->resource->req_lock);
 
        list_for_each_entry_safe(peer_req, t, &reclaimed, w.list)
-               drbd_free_net_peer_req(mdev, peer_req);
+               drbd_free_net_peer_req(device, peer_req);
 }
 
 /**
  * drbd_alloc_pages() - Returns @number pages, retries forever (or until signalled)
- * @mdev:      DRBD device.
+ * @device:    DRBD device.
  * @number:    number of pages requested
  * @retry:     whether to retry, if not enough pages are available right now
  *
@@ -240,9 +239,10 @@ static void drbd_kick_lo_and_reclaim_net(struct drbd_conf *mdev)
  *
  * Returns a page chain linked via page->private.
  */
-struct page *drbd_alloc_pages(struct drbd_conf *mdev, unsigned int number,
+struct page *drbd_alloc_pages(struct drbd_peer_device *peer_device, unsigned int number,
                              bool retry)
 {
+       struct drbd_device *device = peer_device->device;
        struct page *page = NULL;
        struct net_conf *nc;
        DEFINE_WAIT(wait);
@@ -251,20 +251,20 @@ struct page *drbd_alloc_pages(struct drbd_conf *mdev, unsigned int number,
        /* Yes, we may run up to @number over max_buffers. If we
         * follow it strictly, the admin will get it wrong anyways. */
        rcu_read_lock();
-       nc = rcu_dereference(mdev->tconn->net_conf);
+       nc = rcu_dereference(peer_device->connection->net_conf);
        mxb = nc ? nc->max_buffers : 1000000;
        rcu_read_unlock();
 
-       if (atomic_read(&mdev->pp_in_use) < mxb)
-               page = __drbd_alloc_pages(mdev, number);
+       if (atomic_read(&device->pp_in_use) < mxb)
+               page = __drbd_alloc_pages(device, number);
 
        while (page == NULL) {
                prepare_to_wait(&drbd_pp_wait, &wait, TASK_INTERRUPTIBLE);
 
-               drbd_kick_lo_and_reclaim_net(mdev);
+               drbd_kick_lo_and_reclaim_net(device);
 
-               if (atomic_read(&mdev->pp_in_use) < mxb) {
-                       page = __drbd_alloc_pages(mdev, number);
+               if (atomic_read(&device->pp_in_use) < mxb) {
+                       page = __drbd_alloc_pages(device, number);
                        if (page)
                                break;
                }
@@ -273,7 +273,7 @@ struct page *drbd_alloc_pages(struct drbd_conf *mdev, unsigned int number,
                        break;
 
                if (signal_pending(current)) {
-                       dev_warn(DEV, "drbd_alloc_pages interrupted!\n");
+                       drbd_warn(device, "drbd_alloc_pages interrupted!\n");
                        break;
                }
 
@@ -282,17 +282,17 @@ struct page *drbd_alloc_pages(struct drbd_conf *mdev, unsigned int number,
        finish_wait(&drbd_pp_wait, &wait);
 
        if (page)
-               atomic_add(number, &mdev->pp_in_use);
+               atomic_add(number, &device->pp_in_use);
        return page;
 }
 
 /* Must not be used from irq, as that may deadlock: see drbd_alloc_pages.
- * Is also used from inside an other spin_lock_irq(&mdev->tconn->req_lock);
+ * Is also used from inside an other spin_lock_irq(&resource->req_lock);
  * Either links the page chain back to the global pool,
  * or returns all pages to the system. */
-static void drbd_free_pages(struct drbd_conf *mdev, struct page *page, int is_net)
+static void drbd_free_pages(struct drbd_device *device, struct page *page, int is_net)
 {
-       atomic_t *a = is_net ? &mdev->pp_in_use_by_net : &mdev->pp_in_use;
+       atomic_t *a = is_net ? &device->pp_in_use_by_net : &device->pp_in_use;
        int i;
 
        if (page == NULL)
@@ -310,7 +310,7 @@ static void drbd_free_pages(struct drbd_conf *mdev, struct page *page, int is_ne
        }
        i = atomic_sub_return(i, a);
        if (i < 0)
-               dev_warn(DEV, "ASSERTION FAILED: %s: %d < 0\n",
+               drbd_warn(device, "ASSERTION FAILED: %s: %d < 0\n",
                        is_net ? "pp_in_use_by_net" : "pp_in_use", i);
        wake_up(&drbd_pp_wait);
 }
@@ -330,25 +330,26 @@ You must not have the req_lock:
 */
 
 struct drbd_peer_request *
-drbd_alloc_peer_req(struct drbd_conf *mdev, u64 id, sector_t sector,
+drbd_alloc_peer_req(struct drbd_peer_device *peer_device, u64 id, sector_t sector,
                    unsigned int data_size, gfp_t gfp_mask) __must_hold(local)
 {
+       struct drbd_device *device = peer_device->device;
        struct drbd_peer_request *peer_req;
        struct page *page = NULL;
        unsigned nr_pages = (data_size + PAGE_SIZE -1) >> PAGE_SHIFT;
 
-       if (drbd_insert_fault(mdev, DRBD_FAULT_AL_EE))
+       if (drbd_insert_fault(device, DRBD_FAULT_AL_EE))
                return NULL;
 
        peer_req = mempool_alloc(drbd_ee_mempool, gfp_mask & ~__GFP_HIGHMEM);
        if (!peer_req) {
                if (!(gfp_mask & __GFP_NOWARN))
-                       dev_err(DEV, "%s: allocation failed\n", __func__);
+                       drbd_err(device, "%s: allocation failed\n", __func__);
                return NULL;
        }
 
        if (data_size) {
-               page = drbd_alloc_pages(mdev, nr_pages, (gfp_mask & __GFP_WAIT));
+               page = drbd_alloc_pages(peer_device, nr_pages, (gfp_mask & __GFP_WAIT));
                if (!page)
                        goto fail;
        }
@@ -360,7 +361,7 @@ drbd_alloc_peer_req(struct drbd_conf *mdev, u64 id, sector_t sector,
        peer_req->i.waiting = false;
 
        peer_req->epoch = NULL;
-       peer_req->w.mdev = mdev;
+       peer_req->peer_device = peer_device;
        peer_req->pages = page;
        atomic_set(&peer_req->pending_bios, 0);
        peer_req->flags = 0;
@@ -377,30 +378,30 @@ drbd_alloc_peer_req(struct drbd_conf *mdev, u64 id, sector_t sector,
        return NULL;
 }
 
-void __drbd_free_peer_req(struct drbd_conf *mdev, struct drbd_peer_request *peer_req,
+void __drbd_free_peer_req(struct drbd_device *device, struct drbd_peer_request *peer_req,
                       int is_net)
 {
        if (peer_req->flags & EE_HAS_DIGEST)
                kfree(peer_req->digest);
-       drbd_free_pages(mdev, peer_req->pages, is_net);
-       D_ASSERT(atomic_read(&peer_req->pending_bios) == 0);
-       D_ASSERT(drbd_interval_empty(&peer_req->i));
+       drbd_free_pages(device, peer_req->pages, is_net);
+       D_ASSERT(device, atomic_read(&peer_req->pending_bios) == 0);
+       D_ASSERT(device, drbd_interval_empty(&peer_req->i));
        mempool_free(peer_req, drbd_ee_mempool);
 }
 
-int drbd_free_peer_reqs(struct drbd_conf *mdev, struct list_head *list)
+int drbd_free_peer_reqs(struct drbd_device *device, struct list_head *list)
 {
        LIST_HEAD(work_list);
        struct drbd_peer_request *peer_req, *t;
        int count = 0;
-       int is_net = list == &mdev->net_ee;
+       int is_net = list == &device->net_ee;
 
-       spin_lock_irq(&mdev->tconn->req_lock);
+       spin_lock_irq(&device->resource->req_lock);
        list_splice_init(list, &work_list);
-       spin_unlock_irq(&mdev->tconn->req_lock);
+       spin_unlock_irq(&device->resource->req_lock);
 
        list_for_each_entry_safe(peer_req, t, &work_list, w.list) {
-               __drbd_free_peer_req(mdev, peer_req, is_net);
+               __drbd_free_peer_req(device, peer_req, is_net);
                count++;
        }
        return count;
@@ -409,20 +410,20 @@ int drbd_free_peer_reqs(struct drbd_conf *mdev, struct list_head *list)
 /*
  * See also comments in _req_mod(,BARRIER_ACKED) and receive_Barrier.
  */
-static int drbd_finish_peer_reqs(struct drbd_conf *mdev)
+static int drbd_finish_peer_reqs(struct drbd_device *device)
 {
        LIST_HEAD(work_list);
        LIST_HEAD(reclaimed);
        struct drbd_peer_request *peer_req, *t;
        int err = 0;
 
-       spin_lock_irq(&mdev->tconn->req_lock);
-       reclaim_finished_net_peer_reqs(mdev, &reclaimed);
-       list_splice_init(&mdev->done_ee, &work_list);
-       spin_unlock_irq(&mdev->tconn->req_lock);
+       spin_lock_irq(&device->resource->req_lock);
+       reclaim_finished_net_peer_reqs(device, &reclaimed);
+       list_splice_init(&device->done_ee, &work_list);
+       spin_unlock_irq(&device->resource->req_lock);
 
        list_for_each_entry_safe(peer_req, t, &reclaimed, w.list)
-               drbd_free_net_peer_req(mdev, peer_req);
+               drbd_free_net_peer_req(device, peer_req);
 
        /* possible callbacks here:
         * e_end_block, and e_end_resync_block, e_send_superseded.
@@ -435,14 +436,14 @@ static int drbd_finish_peer_reqs(struct drbd_conf *mdev)
                err2 = peer_req->w.cb(&peer_req->w, !!err);
                if (!err)
                        err = err2;
-               drbd_free_peer_req(mdev, peer_req);
+               drbd_free_peer_req(device, peer_req);
        }
-       wake_up(&mdev->ee_wait);
+       wake_up(&device->ee_wait);
 
        return err;
 }
 
-static void _drbd_wait_ee_list_empty(struct drbd_conf *mdev,
+static void _drbd_wait_ee_list_empty(struct drbd_device *device,
                                     struct list_head *head)
 {
        DEFINE_WAIT(wait);
@@ -450,20 +451,20 @@ static void _drbd_wait_ee_list_empty(struct drbd_conf *mdev,
        /* avoids spin_lock/unlock
         * and calling prepare_to_wait in the fast path */
        while (!list_empty(head)) {
-               prepare_to_wait(&mdev->ee_wait, &wait, TASK_UNINTERRUPTIBLE);
-               spin_unlock_irq(&mdev->tconn->req_lock);
+               prepare_to_wait(&device->ee_wait, &wait, TASK_UNINTERRUPTIBLE);
+               spin_unlock_irq(&device->resource->req_lock);
                io_schedule();
-               finish_wait(&mdev->ee_wait, &wait);
-               spin_lock_irq(&mdev->tconn->req_lock);
+               finish_wait(&device->ee_wait, &wait);
+               spin_lock_irq(&device->resource->req_lock);
        }
 }
 
-static void drbd_wait_ee_list_empty(struct drbd_conf *mdev,
+static void drbd_wait_ee_list_empty(struct drbd_device *device,
                                    struct list_head *head)
 {
-       spin_lock_irq(&mdev->tconn->req_lock);
-       _drbd_wait_ee_list_empty(mdev, head);
-       spin_unlock_irq(&mdev->tconn->req_lock);
+       spin_lock_irq(&device->resource->req_lock);
+       _drbd_wait_ee_list_empty(device, head);
+       spin_unlock_irq(&device->resource->req_lock);
 }
 
 static int drbd_recv_short(struct socket *sock, void *buf, size_t size, int flags)
@@ -478,44 +479,44 @@ static int drbd_recv_short(struct socket *sock, void *buf, size_t size, int flag
        return kernel_recvmsg(sock, &msg, &iov, 1, size, msg.msg_flags);
 }
 
-static int drbd_recv(struct drbd_tconn *tconn, void *buf, size_t size)
+static int drbd_recv(struct drbd_connection *connection, void *buf, size_t size)
 {
        int rv;
 
-       rv = drbd_recv_short(tconn->data.socket, buf, size, 0);
+       rv = drbd_recv_short(connection->data.socket, buf, size, 0);
 
        if (rv < 0) {
                if (rv == -ECONNRESET)
-                       conn_info(tconn, "sock was reset by peer\n");
+                       drbd_info(connection, "sock was reset by peer\n");
                else if (rv != -ERESTARTSYS)
-                       conn_err(tconn, "sock_recvmsg returned %d\n", rv);
+                       drbd_err(connection, "sock_recvmsg returned %d\n", rv);
        } else if (rv == 0) {
-               if (test_bit(DISCONNECT_SENT, &tconn->flags)) {
+               if (test_bit(DISCONNECT_SENT, &connection->flags)) {
                        long t;
                        rcu_read_lock();
-                       t = rcu_dereference(tconn->net_conf)->ping_timeo * HZ/10;
+                       t = rcu_dereference(connection->net_conf)->ping_timeo * HZ/10;
                        rcu_read_unlock();
 
-                       t = wait_event_timeout(tconn->ping_wait, tconn->cstate < C_WF_REPORT_PARAMS, t);
+                       t = wait_event_timeout(connection->ping_wait, connection->cstate < C_WF_REPORT_PARAMS, t);
 
                        if (t)
                                goto out;
                }
-               conn_info(tconn, "sock was shut down by peer\n");
+               drbd_info(connection, "sock was shut down by peer\n");
        }
 
        if (rv != size)
-               conn_request_state(tconn, NS(conn, C_BROKEN_PIPE), CS_HARD);
+               conn_request_state(connection, NS(conn, C_BROKEN_PIPE), CS_HARD);
 
 out:
        return rv;
 }
 
-static int drbd_recv_all(struct drbd_tconn *tconn, void *buf, size_t size)
+static int drbd_recv_all(struct drbd_connection *connection, void *buf, size_t size)
 {
        int err;
 
-       err = drbd_recv(tconn, buf, size);
+       err = drbd_recv(connection, buf, size);
        if (err != size) {
                if (err >= 0)
                        err = -EIO;
@@ -524,13 +525,13 @@ static int drbd_recv_all(struct drbd_tconn *tconn, void *buf, size_t size)
        return err;
 }
 
-static int drbd_recv_all_warn(struct drbd_tconn *tconn, void *buf, size_t size)
+static int drbd_recv_all_warn(struct drbd_connection *connection, void *buf, size_t size)
 {
        int err;
 
-       err = drbd_recv_all(tconn, buf, size);
+       err = drbd_recv_all(connection, buf, size);
        if (err && !signal_pending(current))
-               conn_warn(tconn, "short read (expected size %d)\n", (int)size);
+               drbd_warn(connection, "short read (expected size %d)\n", (int)size);
        return err;
 }
 
@@ -553,7 +554,7 @@ static void drbd_setbufsize(struct socket *sock, unsigned int snd,
        }
 }
 
-static struct socket *drbd_try_connect(struct drbd_tconn *tconn)
+static struct socket *drbd_try_connect(struct drbd_connection *connection)
 {
        const char *what;
        struct socket *sock;
@@ -565,7 +566,7 @@ static struct socket *drbd_try_connect(struct drbd_tconn *tconn)
        int disconnect_on_error = 1;
 
        rcu_read_lock();
-       nc = rcu_dereference(tconn->net_conf);
+       nc = rcu_dereference(connection->net_conf);
        if (!nc) {
                rcu_read_unlock();
                return NULL;
@@ -575,16 +576,16 @@ static struct socket *drbd_try_connect(struct drbd_tconn *tconn)
        connect_int = nc->connect_int;
        rcu_read_unlock();
 
-       my_addr_len = min_t(int, tconn->my_addr_len, sizeof(src_in6));
-       memcpy(&src_in6, &tconn->my_addr, my_addr_len);
+       my_addr_len = min_t(int, connection->my_addr_len, sizeof(src_in6));
+       memcpy(&src_in6, &connection->my_addr, my_addr_len);
 
-       if (((struct sockaddr *)&tconn->my_addr)->sa_family == AF_INET6)
+       if (((struct sockaddr *)&connection->my_addr)->sa_family == AF_INET6)
                src_in6.sin6_port = 0;
        else
                ((struct sockaddr_in *)&src_in6)->sin_port = 0; /* AF_INET & AF_SCI */
 
-       peer_addr_len = min_t(int, tconn->peer_addr_len, sizeof(src_in6));
-       memcpy(&peer_in6, &tconn->peer_addr, peer_addr_len);
+       peer_addr_len = min_t(int, connection->peer_addr_len, sizeof(src_in6));
+       memcpy(&peer_in6, &connection->peer_addr, peer_addr_len);
 
        what = "sock_create_kern";
        err = sock_create_kern(((struct sockaddr *)&src_in6)->sa_family,
@@ -632,17 +633,17 @@ out:
                        disconnect_on_error = 0;
                        break;
                default:
-                       conn_err(tconn, "%s failed, err = %d\n", what, err);
+                       drbd_err(connection, "%s failed, err = %d\n", what, err);
                }
                if (disconnect_on_error)
-                       conn_request_state(tconn, NS(conn, C_DISCONNECTING), CS_HARD);
+                       conn_request_state(connection, NS(conn, C_DISCONNECTING), CS_HARD);
        }
 
        return sock;
 }
 
 struct accept_wait_data {
-       struct drbd_tconn *tconn;
+       struct drbd_connection *connection;
        struct socket *s_listen;
        struct completion door_bell;
        void (*original_sk_state_change)(struct sock *sk);
@@ -660,7 +661,7 @@ static void drbd_incoming_connection(struct sock *sk)
        state_change(sk);
 }
 
-static int prepare_listen_socket(struct drbd_tconn *tconn, struct accept_wait_data *ad)
+static int prepare_listen_socket(struct drbd_connection *connection, struct accept_wait_data *ad)
 {
        int err, sndbuf_size, rcvbuf_size, my_addr_len;
        struct sockaddr_in6 my_addr;
@@ -669,7 +670,7 @@ static int prepare_listen_socket(struct drbd_tconn *tconn, struct accept_wait_da
        const char *what;
 
        rcu_read_lock();
-       nc = rcu_dereference(tconn->net_conf);
+       nc = rcu_dereference(connection->net_conf);
        if (!nc) {
                rcu_read_unlock();
                return -EIO;
@@ -678,8 +679,8 @@ static int prepare_listen_socket(struct drbd_tconn *tconn, struct accept_wait_da
        rcvbuf_size = nc->rcvbuf_size;
        rcu_read_unlock();
 
-       my_addr_len = min_t(int, tconn->my_addr_len, sizeof(struct sockaddr_in6));
-       memcpy(&my_addr, &tconn->my_addr, my_addr_len);
+       my_addr_len = min_t(int, connection->my_addr_len, sizeof(struct sockaddr_in6));
+       memcpy(&my_addr, &connection->my_addr, my_addr_len);
 
        what = "sock_create_kern";
        err = sock_create_kern(((struct sockaddr *)&my_addr)->sa_family,
@@ -715,8 +716,8 @@ out:
                sock_release(s_listen);
        if (err < 0) {
                if (err != -EAGAIN && err != -EINTR && err != -ERESTARTSYS) {
-                       conn_err(tconn, "%s failed, err = %d\n", what, err);
-                       conn_request_state(tconn, NS(conn, C_DISCONNECTING), CS_HARD);
+                       drbd_err(connection, "%s failed, err = %d\n", what, err);
+                       conn_request_state(connection, NS(conn, C_DISCONNECTING), CS_HARD);
                }
        }
 
@@ -731,14 +732,14 @@ static void unregister_state_change(struct sock *sk, struct accept_wait_data *ad
        write_unlock_bh(&sk->sk_callback_lock);
 }
 
-static struct socket *drbd_wait_for_connect(struct drbd_tconn *tconn, struct accept_wait_data *ad)
+static struct socket *drbd_wait_for_connect(struct drbd_connection *connection, struct accept_wait_data *ad)
 {
        int timeo, connect_int, err = 0;
        struct socket *s_estab = NULL;
        struct net_conf *nc;
 
        rcu_read_lock();
-       nc = rcu_dereference(tconn->net_conf);
+       nc = rcu_dereference(connection->net_conf);
        if (!nc) {
                rcu_read_unlock();
                return NULL;
@@ -757,8 +758,8 @@ static struct socket *drbd_wait_for_connect(struct drbd_tconn *tconn, struct acc
        err = kernel_accept(ad->s_listen, &s_estab, 0);
        if (err < 0) {
                if (err != -EAGAIN && err != -EINTR && err != -ERESTARTSYS) {
-                       conn_err(tconn, "accept failed, err = %d\n", err);
-                       conn_request_state(tconn, NS(conn, C_DISCONNECTING), CS_HARD);
+                       drbd_err(connection, "accept failed, err = %d\n", err);
+                       conn_request_state(connection, NS(conn, C_DISCONNECTING), CS_HARD);
                }
        }
 
@@ -768,29 +769,29 @@ static struct socket *drbd_wait_for_connect(struct drbd_tconn *tconn, struct acc
        return s_estab;
 }
 
-static int decode_header(struct drbd_tconn *, void *, struct packet_info *);
+static int decode_header(struct drbd_connection *, void *, struct packet_info *);
 
-static int send_first_packet(struct drbd_tconn *tconn, struct drbd_socket *sock,
+static int send_first_packet(struct drbd_connection *connection, struct drbd_socket *sock,
                             enum drbd_packet cmd)
 {
-       if (!conn_prepare_command(tconn, sock))
+       if (!conn_prepare_command(connection, sock))
                return -EIO;
-       return conn_send_command(tconn, sock, cmd, 0, NULL, 0);
+       return conn_send_command(connection, sock, cmd, 0, NULL, 0);
 }
 
-static int receive_first_packet(struct drbd_tconn *tconn, struct socket *sock)
+static int receive_first_packet(struct drbd_connection *connection, struct socket *sock)
 {
-       unsigned int header_size = drbd_header_size(tconn);
+       unsigned int header_size = drbd_header_size(connection);
        struct packet_info pi;
        int err;
 
-       err = drbd_recv_short(sock, tconn->data.rbuf, header_size, 0);
+       err = drbd_recv_short(sock, connection->data.rbuf, header_size, 0);
        if (err != header_size) {
                if (err >= 0)
                        err = -EIO;
                return err;
        }
-       err = decode_header(tconn, tconn->data.rbuf, &pi);
+       err = decode_header(connection, connection->data.rbuf, &pi);
        if (err)
                return err;
        return pi.cmd;
@@ -820,28 +821,29 @@ static int drbd_socket_okay(struct socket **sock)
 }
 /* Gets called if a connection is established, or if a new minor gets created
    in a connection */
-int drbd_connected(struct drbd_conf *mdev)
+int drbd_connected(struct drbd_peer_device *peer_device)
 {
+       struct drbd_device *device = peer_device->device;
        int err;
 
-       atomic_set(&mdev->packet_seq, 0);
-       mdev->peer_seq = 0;
+       atomic_set(&device->packet_seq, 0);
+       device->peer_seq = 0;
 
-       mdev->state_mutex = mdev->tconn->agreed_pro_version < 100 ?
-               &mdev->tconn->cstate_mutex :
-               &mdev->own_state_mutex;
+       device->state_mutex = peer_device->connection->agreed_pro_version < 100 ?
+               &peer_device->connection->cstate_mutex :
+               &device->own_state_mutex;
 
-       err = drbd_send_sync_param(mdev);
+       err = drbd_send_sync_param(peer_device);
        if (!err)
-               err = drbd_send_sizes(mdev, 0, 0);
+               err = drbd_send_sizes(peer_device, 0, 0);
        if (!err)
-               err = drbd_send_uuids(mdev);
+               err = drbd_send_uuids(peer_device);
        if (!err)
-               err = drbd_send_current_state(mdev);
-       clear_bit(USE_DEGR_WFC_T, &mdev->flags);
-       clear_bit(RESIZE_PENDING, &mdev->flags);
-       atomic_set(&mdev->ap_in_flight, 0);
-       mod_timer(&mdev->request_timer, jiffies + HZ); /* just start it here. */
+               err = drbd_send_current_state(peer_device);
+       clear_bit(USE_DEGR_WFC_T, &device->flags);
+       clear_bit(RESIZE_PENDING, &device->flags);
+       atomic_set(&device->ap_in_flight, 0);
+       mod_timer(&device->request_timer, jiffies + HZ); /* just start it here. */
        return err;
 }
 
@@ -853,59 +855,59 @@ int drbd_connected(struct drbd_conf *mdev)
  *     no point in trying again, please go standalone.
  *  -2 We do not have a network config...
  */
-static int conn_connect(struct drbd_tconn *tconn)
+static int conn_connect(struct drbd_connection *connection)
 {
        struct drbd_socket sock, msock;
-       struct drbd_conf *mdev;
+       struct drbd_peer_device *peer_device;
        struct net_conf *nc;
        int vnr, timeout, h, ok;
        bool discard_my_data;
        enum drbd_state_rv rv;
        struct accept_wait_data ad = {
-               .tconn = tconn,
+               .connection = connection,
                .door_bell = COMPLETION_INITIALIZER_ONSTACK(ad.door_bell),
        };
 
-       clear_bit(DISCONNECT_SENT, &tconn->flags);
-       if (conn_request_state(tconn, NS(conn, C_WF_CONNECTION), CS_VERBOSE) < SS_SUCCESS)
+       clear_bit(DISCONNECT_SENT, &connection->flags);
+       if (conn_request_state(connection, NS(conn, C_WF_CONNECTION), CS_VERBOSE) < SS_SUCCESS)
                return -2;
 
        mutex_init(&sock.mutex);
-       sock.sbuf = tconn->data.sbuf;
-       sock.rbuf = tconn->data.rbuf;
+       sock.sbuf = connection->data.sbuf;
+       sock.rbuf = connection->data.rbuf;
        sock.socket = NULL;
        mutex_init(&msock.mutex);
-       msock.sbuf = tconn->meta.sbuf;
-       msock.rbuf = tconn->meta.rbuf;
+       msock.sbuf = connection->meta.sbuf;
+       msock.rbuf = connection->meta.rbuf;
        msock.socket = NULL;
 
        /* Assume that the peer only understands protocol 80 until we know better.  */
-       tconn->agreed_pro_version = 80;
+       connection->agreed_pro_version = 80;
 
-       if (prepare_listen_socket(tconn, &ad))
+       if (prepare_listen_socket(connection, &ad))
                return 0;
 
        do {
                struct socket *s;
 
-               s = drbd_try_connect(tconn);
+               s = drbd_try_connect(connection);
                if (s) {
                        if (!sock.socket) {
                                sock.socket = s;
-                               send_first_packet(tconn, &sock, P_INITIAL_DATA);
+                               send_first_packet(connection, &sock, P_INITIAL_DATA);
                        } else if (!msock.socket) {
-                               clear_bit(RESOLVE_CONFLICTS, &tconn->flags);
+                               clear_bit(RESOLVE_CONFLICTS, &connection->flags);
                                msock.socket = s;
-                               send_first_packet(tconn, &msock, P_INITIAL_META);
+                               send_first_packet(connection, &msock, P_INITIAL_META);
                        } else {
-                               conn_err(tconn, "Logic error in conn_connect()\n");
+                               drbd_err(connection, "Logic error in conn_connect()\n");
                                goto out_release_sockets;
                        }
                }
 
                if (sock.socket && msock.socket) {
                        rcu_read_lock();
-                       nc = rcu_dereference(tconn->net_conf);
+                       nc = rcu_dereference(connection->net_conf);
                        timeout = nc->ping_timeo * HZ / 10;
                        rcu_read_unlock();
                        schedule_timeout_interruptible(timeout);
@@ -916,15 +918,15 @@ static int conn_connect(struct drbd_tconn *tconn)
                }
 
 retry:
-               s = drbd_wait_for_connect(tconn, &ad);
+               s = drbd_wait_for_connect(connection, &ad);
                if (s) {
-                       int fp = receive_first_packet(tconn, s);
+                       int fp = receive_first_packet(connection, s);
                        drbd_socket_okay(&sock.socket);
                        drbd_socket_okay(&msock.socket);
                        switch (fp) {
                        case P_INITIAL_DATA:
                                if (sock.socket) {
-                                       conn_warn(tconn, "initial packet S crossed\n");
+                                       drbd_warn(connection, "initial packet S crossed\n");
                                        sock_release(sock.socket);
                                        sock.socket = s;
                                        goto randomize;
@@ -932,9 +934,9 @@ retry:
                                sock.socket = s;
                                break;
                        case P_INITIAL_META:
-                               set_bit(RESOLVE_CONFLICTS, &tconn->flags);
+                               set_bit(RESOLVE_CONFLICTS, &connection->flags);
                                if (msock.socket) {
-                                       conn_warn(tconn, "initial packet M crossed\n");
+                                       drbd_warn(connection, "initial packet M crossed\n");
                                        sock_release(msock.socket);
                                        msock.socket = s;
                                        goto randomize;
@@ -942,7 +944,7 @@ retry:
                                msock.socket = s;
                                break;
                        default:
-                               conn_warn(tconn, "Error receiving initial packet\n");
+                               drbd_warn(connection, "Error receiving initial packet\n");
                                sock_release(s);
 randomize:
                                if (prandom_u32() & 1)
@@ -950,12 +952,12 @@ randomize:
                        }
                }
 
-               if (tconn->cstate <= C_DISCONNECTING)
+               if (connection->cstate <= C_DISCONNECTING)
                        goto out_release_sockets;
                if (signal_pending(current)) {
                        flush_signals(current);
                        smp_rmb();
-                       if (get_t_state(&tconn->receiver) == EXITING)
+                       if (get_t_state(&connection->receiver) == EXITING)
                                goto out_release_sockets;
                }
 
@@ -976,12 +978,12 @@ randomize:
        msock.socket->sk->sk_priority = TC_PRIO_INTERACTIVE;
 
        /* NOT YET ...
-        * sock.socket->sk->sk_sndtimeo = tconn->net_conf->timeout*HZ/10;
+        * sock.socket->sk->sk_sndtimeo = connection->net_conf->timeout*HZ/10;
         * sock.socket->sk->sk_rcvtimeo = MAX_SCHEDULE_TIMEOUT;
         * first set it to the P_CONNECTION_FEATURES timeout,
         * which we set to 4x the configured ping_timeout. */
        rcu_read_lock();
-       nc = rcu_dereference(tconn->net_conf);
+       nc = rcu_dereference(connection->net_conf);
 
        sock.socket->sk->sk_sndtimeo =
        sock.socket->sk->sk_rcvtimeo = nc->ping_timeo*4*HZ/10;
@@ -998,37 +1000,38 @@ randomize:
        drbd_tcp_nodelay(sock.socket);
        drbd_tcp_nodelay(msock.socket);
 
-       tconn->data.socket = sock.socket;
-       tconn->meta.socket = msock.socket;
-       tconn->last_received = jiffies;
+       connection->data.socket = sock.socket;
+       connection->meta.socket = msock.socket;
+       connection->last_received = jiffies;
 
-       h = drbd_do_features(tconn);
+       h = drbd_do_features(connection);
        if (h <= 0)
                return h;
 
-       if (tconn->cram_hmac_tfm) {
-               /* drbd_request_state(mdev, NS(conn, WFAuth)); */
-               switch (drbd_do_auth(tconn)) {
+       if (connection->cram_hmac_tfm) {
+               /* drbd_request_state(device, NS(conn, WFAuth)); */
+               switch (drbd_do_auth(connection)) {
                case -1:
-                       conn_err(tconn, "Authentication of peer failed\n");
+                       drbd_err(connection, "Authentication of peer failed\n");
                        return -1;
                case 0:
-                       conn_err(tconn, "Authentication of peer failed, trying again.\n");
+                       drbd_err(connection, "Authentication of peer failed, trying again.\n");
                        return 0;
                }
        }
 
-       tconn->data.socket->sk->sk_sndtimeo = timeout;
-       tconn->data.socket->sk->sk_rcvtimeo = MAX_SCHEDULE_TIMEOUT;
+       connection->data.socket->sk->sk_sndtimeo = timeout;
+       connection->data.socket->sk->sk_rcvtimeo = MAX_SCHEDULE_TIMEOUT;
 
-       if (drbd_send_protocol(tconn) == -EOPNOTSUPP)
+       if (drbd_send_protocol(connection) == -EOPNOTSUPP)
                return -1;
 
-       set_bit(STATE_SENT, &tconn->flags);
+       set_bit(STATE_SENT, &connection->flags);
 
        rcu_read_lock();
-       idr_for_each_entry(&tconn->volumes, mdev, vnr) {
-               kref_get(&mdev->kref);
+       idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
+               struct drbd_device *device = peer_device->device;
+               kref_get(&device->kref);
                rcu_read_unlock();
 
                /* Prevent a race between resync-handshake and
@@ -1038,35 +1041,35 @@ randomize:
                 * drbd_set_role() is finished, and any incoming drbd_set_role
                 * will see the STATE_SENT flag, and wait for it to be cleared.
                 */
-               mutex_lock(mdev->state_mutex);
-               mutex_unlock(mdev->state_mutex);
+               mutex_lock(device->state_mutex);
+               mutex_unlock(device->state_mutex);
 
                if (discard_my_data)
-                       set_bit(DISCARD_MY_DATA, &mdev->flags);
+                       set_bit(DISCARD_MY_DATA, &device->flags);
                else
-                       clear_bit(DISCARD_MY_DATA, &mdev->flags);
+                       clear_bit(DISCARD_MY_DATA, &device->flags);
 
-               drbd_connected(mdev);
-               kref_put(&mdev->kref, &drbd_minor_destroy);
+               drbd_connected(peer_device);
+               kref_put(&device->kref, drbd_destroy_device);
                rcu_read_lock();
        }
        rcu_read_unlock();
 
-       rv = conn_request_state(tconn, NS(conn, C_WF_REPORT_PARAMS), CS_VERBOSE);
-       if (rv < SS_SUCCESS || tconn->cstate != C_WF_REPORT_PARAMS) {
-               clear_bit(STATE_SENT, &tconn->flags);
+       rv = conn_request_state(connection, NS(conn, C_WF_REPORT_PARAMS), CS_VERBOSE);
+       if (rv < SS_SUCCESS || connection->cstate != C_WF_REPORT_PARAMS) {
+               clear_bit(STATE_SENT, &connection->flags);
                return 0;
        }
 
-       drbd_thread_start(&tconn->asender);
+       drbd_thread_start(&connection->asender);
 
-       mutex_lock(&tconn->conf_update);
+       mutex_lock(&connection->resource->conf_update);
        /* The discard_my_data flag is a single-shot modifier to the next
         * connection attempt, the handshake of which is now well underway.
         * No need for rcu style copying of the whole struct
         * just to clear a single value. */
-       tconn->net_conf->discard_my_data = 0;
-       mutex_unlock(&tconn->conf_update);
+       connection->net_conf->discard_my_data = 0;
+       mutex_unlock(&connection->resource->conf_update);
 
        return h;
 
@@ -1080,15 +1083,15 @@ out_release_sockets:
        return -1;
 }
 
-static int decode_header(struct drbd_tconn *tconn, void *header, struct packet_info *pi)
+static int decode_header(struct drbd_connection *connection, void *header, struct packet_info *pi)
 {
-       unsigned int header_size = drbd_header_size(tconn);
+       unsigned int header_size = drbd_header_size(connection);
 
        if (header_size == sizeof(struct p_header100) &&
            *(__be32 *)header == cpu_to_be32(DRBD_MAGIC_100)) {
                struct p_header100 *h = header;
                if (h->pad != 0) {
-                       conn_err(tconn, "Header padding is not zero\n");
+                       drbd_err(connection, "Header padding is not zero\n");
                        return -EINVAL;
                }
                pi->vnr = be16_to_cpu(h->volume);
@@ -1107,55 +1110,57 @@ static int decode_header(struct drbd_tconn *tconn, void *header, struct packet_i
                pi->size = be16_to_cpu(h->length);
                pi->vnr = 0;
        } else {
-               conn_err(tconn, "Wrong magic value 0x%08x in protocol version %d\n",
+               drbd_err(connection, "Wrong magic value 0x%08x in protocol version %d\n",
                         be32_to_cpu(*(__be32 *)header),
-                        tconn->agreed_pro_version);
+                        connection->agreed_pro_version);
                return -EINVAL;
        }
        pi->data = header + header_size;
        return 0;
 }
 
-static int drbd_recv_header(struct drbd_tconn *tconn, struct packet_info *pi)
+static int drbd_recv_header(struct drbd_connection *connection, struct packet_info *pi)
 {
-       void *buffer = tconn->data.rbuf;
+       void *buffer = connection->data.rbuf;
        int err;
 
-       err = drbd_recv_all_warn(tconn, buffer, drbd_header_size(tconn));
+       err = drbd_recv_all_warn(connection, buffer, drbd_header_size(connection));
        if (err)
                return err;
 
-       err = decode_header(tconn, buffer, pi);
-       tconn->last_received = jiffies;
+       err = decode_header(connection, buffer, pi);
+       connection->last_received = jiffies;
 
        return err;
 }
 
-static void drbd_flush(struct drbd_tconn *tconn)
+static void drbd_flush(struct drbd_connection *connection)
 {
        int rv;
-       struct drbd_conf *mdev;
+       struct drbd_peer_device *peer_device;
        int vnr;
 
-       if (tconn->write_ordering >= WO_bdev_flush) {
+       if (connection->write_ordering >= WO_bdev_flush) {
                rcu_read_lock();
-               idr_for_each_entry(&tconn->volumes, mdev, vnr) {
-                       if (!get_ldev(mdev))
+               idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
+                       struct drbd_device *device = peer_device->device;
+
+                       if (!get_ldev(device))
                                continue;
-                       kref_get(&mdev->kref);
+                       kref_get(&device->kref);
                        rcu_read_unlock();
 
-                       rv = blkdev_issue_flush(mdev->ldev->backing_bdev,
+                       rv = blkdev_issue_flush(device->ldev->backing_bdev,
                                        GFP_NOIO, NULL);
                        if (rv) {
-                               dev_info(DEV, "local disk flush failed with status %d\n", rv);
+                               drbd_info(device, "local disk flush failed with status %d\n", rv);
                                /* would rather check on EOPNOTSUPP, but that is not reliable.
                                 * don't try again for ANY return value != 0
                                 * if (rv == -EOPNOTSUPP) */
-                               drbd_bump_write_ordering(tconn, WO_drain_io);
+                               drbd_bump_write_ordering(connection, WO_drain_io);
                        }
-                       put_ldev(mdev);
-                       kref_put(&mdev->kref, &drbd_minor_destroy);
+                       put_ldev(device);
+                       kref_put(&device->kref, drbd_destroy_device);
 
                        rcu_read_lock();
                        if (rv)
@@ -1167,11 +1172,11 @@ static void drbd_flush(struct drbd_tconn *tconn)
 
 /**
  * drbd_may_finish_epoch() - Applies an epoch_event to the epoch's state, eventually finishes it.
- * @mdev:      DRBD device.
+ * @device:    DRBD device.
  * @epoch:     Epoch object.
  * @ev:                Epoch event.
  */
-static enum finish_epoch drbd_may_finish_epoch(struct drbd_tconn *tconn,
+static enum finish_epoch drbd_may_finish_epoch(struct drbd_connection *connection,
                                               struct drbd_epoch *epoch,
                                               enum epoch_event ev)
 {
@@ -1179,7 +1184,7 @@ static enum finish_epoch drbd_may_finish_epoch(struct drbd_tconn *tconn,
        struct drbd_epoch *next_epoch;
        enum finish_epoch rv = FE_STILL_LIVE;
 
-       spin_lock(&tconn->epoch_lock);
+       spin_lock(&connection->epoch_lock);
        do {
                next_epoch = NULL;
 
@@ -1201,22 +1206,22 @@ static enum finish_epoch drbd_may_finish_epoch(struct drbd_tconn *tconn,
                    atomic_read(&epoch->active) == 0 &&
                    (test_bit(DE_HAVE_BARRIER_NUMBER, &epoch->flags) || ev & EV_CLEANUP)) {
                        if (!(ev & EV_CLEANUP)) {
-                               spin_unlock(&tconn->epoch_lock);
-                               drbd_send_b_ack(epoch->tconn, epoch->barrier_nr, epoch_size);
-                               spin_lock(&tconn->epoch_lock);
+                               spin_unlock(&connection->epoch_lock);
+                               drbd_send_b_ack(epoch->connection, epoch->barrier_nr, epoch_size);
+                               spin_lock(&connection->epoch_lock);
                        }
 #if 0
                        /* FIXME: dec unacked on connection, once we have
                         * something to count pending connection packets in. */
                        if (test_bit(DE_HAVE_BARRIER_NUMBER, &epoch->flags))
-                               dec_unacked(epoch->tconn);
+                               dec_unacked(epoch->connection);
 #endif
 
-                       if (tconn->current_epoch != epoch) {
+                       if (connection->current_epoch != epoch) {
                                next_epoch = list_entry(epoch->list.next, struct drbd_epoch, list);
                                list_del(&epoch->list);
                                ev = EV_BECAME_LAST | (ev & EV_CLEANUP);
-                               tconn->epochs--;
+                               connection->epochs--;
                                kfree(epoch);
 
                                if (rv == FE_STILL_LIVE)
@@ -1236,20 +1241,20 @@ static enum finish_epoch drbd_may_finish_epoch(struct drbd_tconn *tconn,
                epoch = next_epoch;
        } while (1);
 
-       spin_unlock(&tconn->epoch_lock);
+       spin_unlock(&connection->epoch_lock);
 
        return rv;
 }
 
 /**
  * drbd_bump_write_ordering() - Fall back to an other write ordering method
- * @tconn:     DRBD connection.
+ * @connection:        DRBD connection.
  * @wo:                Write ordering method to try.
  */
-void drbd_bump_write_ordering(struct drbd_tconn *tconn, enum write_ordering_e wo)
+void drbd_bump_write_ordering(struct drbd_connection *connection, enum write_ordering_e wo)
 {
        struct disk_conf *dc;
-       struct drbd_conf *mdev;
+       struct drbd_peer_device *peer_device;
        enum write_ordering_e pwo;
        int vnr;
        static char *write_ordering_str[] = {
@@ -1258,29 +1263,31 @@ void drbd_bump_write_ordering(struct drbd_tconn *tconn, enum write_ordering_e wo
                [WO_bdev_flush] = "flush",
        };
 
-       pwo = tconn->write_ordering;
+       pwo = connection->write_ordering;
        wo = min(pwo, wo);
        rcu_read_lock();
-       idr_for_each_entry(&tconn->volumes, mdev, vnr) {
-               if (!get_ldev_if_state(mdev, D_ATTACHING))
+       idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
+               struct drbd_device *device = peer_device->device;
+
+               if (!get_ldev_if_state(device, D_ATTACHING))
                        continue;
-               dc = rcu_dereference(mdev->ldev->disk_conf);
+               dc = rcu_dereference(device->ldev->disk_conf);
 
                if (wo == WO_bdev_flush && !dc->disk_flushes)
                        wo = WO_drain_io;
                if (wo == WO_drain_io && !dc->disk_drain)
                        wo = WO_none;
-               put_ldev(mdev);
+               put_ldev(device);
        }
        rcu_read_unlock();
-       tconn->write_ordering = wo;
-       if (pwo != tconn->write_ordering || wo == WO_bdev_flush)
-               conn_info(tconn, "Method to ensure write ordering: %s\n", write_ordering_str[tconn->write_ordering]);
+       connection->write_ordering = wo;
+       if (pwo != connection->write_ordering || wo == WO_bdev_flush)
+               drbd_info(connection, "Method to ensure write ordering: %s\n", write_ordering_str[connection->write_ordering]);
 }
 
 /**
  * drbd_submit_peer_request()
- * @mdev:      DRBD device.
+ * @device:    DRBD device.
  * @peer_req:  peer request
  * @rw:                flag field, see bio->bi_rw
  *
@@ -1295,7 +1302,7 @@ void drbd_bump_write_ordering(struct drbd_tconn *tconn, enum write_ordering_e wo
  *  on certain Xen deployments.
  */
 /* TODO allocate from our own bio_set. */
-int drbd_submit_peer_request(struct drbd_conf *mdev,
+int drbd_submit_peer_request(struct drbd_device *device,
                             struct drbd_peer_request *peer_req,
                             const unsigned rw, const int fault_type)
 {
@@ -1319,12 +1326,12 @@ int drbd_submit_peer_request(struct drbd_conf *mdev,
 next_bio:
        bio = bio_alloc(GFP_NOIO, nr_pages);
        if (!bio) {
-               dev_err(DEV, "submit_ee: Allocation of a bio failed\n");
+               drbd_err(device, "submit_ee: Allocation of a bio failed\n");
                goto fail;
        }
        /* > peer_req->i.sector, unless this is the first bio */
        bio->bi_iter.bi_sector = sector;
-       bio->bi_bdev = mdev->ldev->backing_bdev;
+       bio->bi_bdev = device->ldev->backing_bdev;
        bio->bi_rw = rw;
        bio->bi_private = peer_req;
        bio->bi_end_io = drbd_peer_request_endio;
@@ -1340,7 +1347,7 @@ next_bio:
                         * But in case it fails anyways,
                         * we deal with it, and complain (below). */
                        if (bio->bi_vcnt == 0) {
-                               dev_err(DEV,
+                               drbd_err(device,
                                        "bio_add_page failed for len=%u, "
                                        "bi_vcnt=0 (bi_sector=%llu)\n",
                                        len, (uint64_t)bio->bi_iter.bi_sector);
@@ -1353,8 +1360,8 @@ next_bio:
                sector += len >> 9;
                --nr_pages;
        }
-       D_ASSERT(page == NULL);
-       D_ASSERT(ds == 0);
+       D_ASSERT(device, page == NULL);
+       D_ASSERT(device, ds == 0);
 
        atomic_set(&peer_req->pending_bios, n_bios);
        do {
@@ -1362,7 +1369,7 @@ next_bio:
                bios = bios->bi_next;
                bio->bi_next = NULL;
 
-               drbd_generic_make_request(mdev, fault_type, bio);
+               drbd_generic_make_request(device, fault_type, bio);
        } while (bios);
        return 0;
 
@@ -1375,36 +1382,44 @@ fail:
        return err;
 }
 
-static void drbd_remove_epoch_entry_interval(struct drbd_conf *mdev,
+static void drbd_remove_epoch_entry_interval(struct drbd_device *device,
                                             struct drbd_peer_request *peer_req)
 {
        struct drbd_interval *i = &peer_req->i;
 
-       drbd_remove_interval(&mdev->write_requests, i);
+       drbd_remove_interval(&device->write_requests, i);
        drbd_clear_interval(i);
 
        /* Wake up any processes waiting for this peer request to complete.  */
        if (i->waiting)
-               wake_up(&mdev->misc_wait);
+               wake_up(&device->misc_wait);
 }
 
-void conn_wait_active_ee_empty(struct drbd_tconn *tconn)
+static void conn_wait_active_ee_empty(struct drbd_connection *connection)
 {
-       struct drbd_conf *mdev;
+       struct drbd_peer_device *peer_device;
        int vnr;
 
        rcu_read_lock();
-       idr_for_each_entry(&tconn->volumes, mdev, vnr) {
-               kref_get(&mdev->kref);
+       idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
+               struct drbd_device *device = peer_device->device;
+
+               kref_get(&device->kref);
                rcu_read_unlock();
-               drbd_wait_ee_list_empty(mdev, &mdev->active_ee);
-               kref_put(&mdev->kref, &drbd_minor_destroy);
+               drbd_wait_ee_list_empty(device, &device->active_ee);
+               kref_put(&device->kref, drbd_destroy_device);
                rcu_read_lock();
        }
        rcu_read_unlock();
 }
 
-static int receive_Barrier(struct drbd_tconn *tconn, struct packet_info *pi)
+static struct drbd_peer_device *
+conn_peer_device(struct drbd_connection *connection, int volume_number)
+{
+       return idr_find(&connection->peer_devices, volume_number);
+}
+
+static int receive_Barrier(struct drbd_connection *connection, struct packet_info *pi)
 {
        int rv;
        struct p_barrier *p = pi->data;
@@ -1413,16 +1428,16 @@ static int receive_Barrier(struct drbd_tconn *tconn, struct packet_info *pi)
        /* FIXME these are unacked on connection,
         * not a specific (peer)device.
         */
-       tconn->current_epoch->barrier_nr = p->barrier;
-       tconn->current_epoch->tconn = tconn;
-       rv = drbd_may_finish_epoch(tconn, tconn->current_epoch, EV_GOT_BARRIER_NR);
+       connection->current_epoch->barrier_nr = p->barrier;
+       connection->current_epoch->connection = connection;
+       rv = drbd_may_finish_epoch(connection, connection->current_epoch, EV_GOT_BARRIER_NR);
 
        /* P_BARRIER_ACK may imply that the corresponding extent is dropped from
         * the activity log, which means it would not be resynced in case the
         * R_PRIMARY crashes now.
         * Therefore we must send the barrier_ack after the barrier request was
         * completed. */
-       switch (tconn->write_ordering) {
+       switch (connection->write_ordering) {
        case WO_none:
                if (rv == FE_RECYCLED)
                        return 0;
@@ -1433,15 +1448,15 @@ static int receive_Barrier(struct drbd_tconn *tconn, struct packet_info *pi)
                if (epoch)
                        break;
                else
-                       conn_warn(tconn, "Allocation of an epoch failed, slowing down\n");
+                       drbd_warn(connection, "Allocation of an epoch failed, slowing down\n");
                        /* Fall through */
 
        case WO_bdev_flush:
        case WO_drain_io:
-               conn_wait_active_ee_empty(tconn);
-               drbd_flush(tconn);
+               conn_wait_active_ee_empty(connection);
+               drbd_flush(connection);
 
-               if (atomic_read(&tconn->current_epoch->epoch_size)) {
+               if (atomic_read(&connection->current_epoch->epoch_size)) {
                        epoch = kmalloc(sizeof(struct drbd_epoch), GFP_NOIO);
                        if (epoch)
                                break;
@@ -1449,7 +1464,7 @@ static int receive_Barrier(struct drbd_tconn *tconn, struct packet_info *pi)
 
                return 0;
        default:
-               conn_err(tconn, "Strangeness in tconn->write_ordering %d\n", tconn->write_ordering);
+               drbd_err(connection, "Strangeness in connection->write_ordering %d\n", connection->write_ordering);
                return -EIO;
        }
 
@@ -1457,16 +1472,16 @@ static int receive_Barrier(struct drbd_tconn *tconn, struct packet_info *pi)
        atomic_set(&epoch->epoch_size, 0);
        atomic_set(&epoch->active, 0);
 
-       spin_lock(&tconn->epoch_lock);
-       if (atomic_read(&tconn->current_epoch->epoch_size)) {
-               list_add(&epoch->list, &tconn->current_epoch->list);
-               tconn->current_epoch = epoch;
-               tconn->epochs++;
+       spin_lock(&connection->epoch_lock);
+       if (atomic_read(&connection->current_epoch->epoch_size)) {
+               list_add(&epoch->list, &connection->current_epoch->list);
+               connection->current_epoch = epoch;
+               connection->epochs++;
        } else {
                /* The current_epoch got recycled while we allocated this one... */
                kfree(epoch);
        }
-       spin_unlock(&tconn->epoch_lock);
+       spin_unlock(&connection->epoch_lock);
 
        return 0;
 }
@@ -1474,25 +1489,26 @@ static int receive_Barrier(struct drbd_tconn *tconn, struct packet_info *pi)
 /* used from receive_RSDataReply (recv_resync_read)
  * and from receive_Data */
 static struct drbd_peer_request *
-read_in_block(struct drbd_conf *mdev, u64 id, sector_t sector,
+read_in_block(struct drbd_peer_device *peer_device, u64 id, sector_t sector,
              int data_size) __must_hold(local)
 {
-       const sector_t capacity = drbd_get_capacity(mdev->this_bdev);
+       struct drbd_device *device = peer_device->device;
+       const sector_t capacity = drbd_get_capacity(device->this_bdev);
        struct drbd_peer_request *peer_req;
        struct page *page;
        int dgs, ds, err;
-       void *dig_in = mdev->tconn->int_dig_in;
-       void *dig_vv = mdev->tconn->int_dig_vv;
+       void *dig_in = peer_device->connection->int_dig_in;
+       void *dig_vv = peer_device->connection->int_dig_vv;
        unsigned long *data;
 
        dgs = 0;
-       if (mdev->tconn->peer_integrity_tfm) {
-               dgs = crypto_hash_digestsize(mdev->tconn->peer_integrity_tfm);
+       if (peer_device->connection->peer_integrity_tfm) {
+               dgs = crypto_hash_digestsize(peer_device->connection->peer_integrity_tfm);
                /*
                 * FIXME: Receive the incoming digest into the receive buffer
                 *        here, together with its struct p_data?
                 */
-               err = drbd_recv_all_warn(mdev->tconn, dig_in, dgs);
+               err = drbd_recv_all_warn(peer_device->connection, dig_in, dgs);
                if (err)
                        return NULL;
                data_size -= dgs;
@@ -1506,7 +1522,7 @@ read_in_block(struct drbd_conf *mdev, u64 id, sector_t sector,
        /* even though we trust out peer,
         * we sometimes have to double check. */
        if (sector + (data_size>>9) > capacity) {
-               dev_err(DEV, "request from peer beyond end of local disk: "
+               drbd_err(device, "request from peer beyond end of local disk: "
                        "capacity: %llus < sector: %llus + size: %u\n",
                        (unsigned long long)capacity,
                        (unsigned long long)sector, data_size);
@@ -1516,7 +1532,7 @@ read_in_block(struct drbd_conf *mdev, u64 id, sector_t sector,
        /* GFP_NOIO, because we must not cause arbitrary write-out: in a DRBD
         * "criss-cross" setup, that might cause write-out on some other DRBD,
         * which in turn might block on the other node at this very place.  */
-       peer_req = drbd_alloc_peer_req(mdev, id, sector, data_size, GFP_NOIO);
+       peer_req = drbd_alloc_peer_req(peer_device, id, sector, data_size, GFP_NOIO);
        if (!peer_req)
                return NULL;
 
@@ -1528,36 +1544,36 @@ read_in_block(struct drbd_conf *mdev, u64 id, sector_t sector,
        page_chain_for_each(page) {
                unsigned len = min_t(int, ds, PAGE_SIZE);
                data = kmap(page);
-               err = drbd_recv_all_warn(mdev->tconn, data, len);
-               if (drbd_insert_fault(mdev, DRBD_FAULT_RECEIVE)) {
-                       dev_err(DEV, "Fault injection: Corrupting data on receive\n");
+               err = drbd_recv_all_warn(peer_device->connection, data, len);
+               if (drbd_insert_fault(device, DRBD_FAULT_RECEIVE)) {
+                       drbd_err(device, "Fault injection: Corrupting data on receive\n");
                        data[0] = data[0] ^ (unsigned long)-1;
                }
                kunmap(page);
                if (err) {
-                       drbd_free_peer_req(mdev, peer_req);
+                       drbd_free_peer_req(device, peer_req);
                        return NULL;
                }
                ds -= len;
        }
 
        if (dgs) {
-               drbd_csum_ee(mdev, mdev->tconn->peer_integrity_tfm, peer_req, dig_vv);
+               drbd_csum_ee(peer_device->connection->peer_integrity_tfm, peer_req, dig_vv);
                if (memcmp(dig_in, dig_vv, dgs)) {
-                       dev_err(DEV, "Digest integrity check FAILED: %llus +%u\n",
+                       drbd_err(device, "Digest integrity check FAILED: %llus +%u\n",
                                (unsigned long long)sector, data_size);
-                       drbd_free_peer_req(mdev, peer_req);
+                       drbd_free_peer_req(device, peer_req);
                        return NULL;
                }
        }
-       mdev->recv_cnt += data_size>>9;
+       device->recv_cnt += data_size>>9;
        return peer_req;
 }
 
 /* drbd_drain_block() just takes a data block
  * out of the socket input buffer, and discards it.
  */
-static int drbd_drain_block(struct drbd_conf *mdev, int data_size)
+static int drbd_drain_block(struct drbd_peer_device *peer_device, int data_size)
 {
        struct page *page;
        int err = 0;
@@ -1566,36 +1582,36 @@ static int drbd_drain_block(struct drbd_conf *mdev, int data_size)
        if (!data_size)
                return 0;
 
-       page = drbd_alloc_pages(mdev, 1, 1);
+       page = drbd_alloc_pages(peer_device, 1, 1);
 
        data = kmap(page);
        while (data_size) {
                unsigned int len = min_t(int, data_size, PAGE_SIZE);
 
-               err = drbd_recv_all_warn(mdev->tconn, data, len);
+               err = drbd_recv_all_warn(peer_device->connection, data, len);
                if (err)
                        break;
                data_size -= len;
        }
        kunmap(page);
-       drbd_free_pages(mdev, page, 0);
+       drbd_free_pages(peer_device->device, page, 0);
        return err;
 }
 
-static int recv_dless_read(struct drbd_conf *mdev, struct drbd_request *req,
+static int recv_dless_read(struct drbd_peer_device *peer_device, struct drbd_request *req,
                           sector_t sector, int data_size)
 {
        struct bio_vec bvec;
        struct bvec_iter iter;
        struct bio *bio;
        int dgs, err, expect;
-       void *dig_in = mdev->tconn->int_dig_in;
-       void *dig_vv = mdev->tconn->int_dig_vv;
+       void *dig_in = peer_device->connection->int_dig_in;
+       void *dig_vv = peer_device->connection->int_dig_vv;
 
        dgs = 0;
-       if (mdev->tconn->peer_integrity_tfm) {
-               dgs = crypto_hash_digestsize(mdev->tconn->peer_integrity_tfm);
-               err = drbd_recv_all_warn(mdev->tconn, dig_in, dgs);
+       if (peer_device->connection->peer_integrity_tfm) {
+               dgs = crypto_hash_digestsize(peer_device->connection->peer_integrity_tfm);
+               err = drbd_recv_all_warn(peer_device->connection, dig_in, dgs);
                if (err)
                        return err;
                data_size -= dgs;
@@ -1603,15 +1619,15 @@ static int recv_dless_read(struct drbd_conf *mdev, struct drbd_request *req,
 
        /* optimistically update recv_cnt.  if receiving fails below,
         * we disconnect anyways, and counters will be reset. */
-       mdev->recv_cnt += data_size>>9;
+       peer_device->device->recv_cnt += data_size>>9;
 
        bio = req->master_bio;
-       D_ASSERT(sector == bio->bi_iter.bi_sector);
+       D_ASSERT(peer_device->device, sector == bio->bi_iter.bi_sector);
 
        bio_for_each_segment(bvec, bio, iter) {
                void *mapped = kmap(bvec.bv_page) + bvec.bv_offset;
                expect = min_t(int, data_size, bvec.bv_len);
-               err = drbd_recv_all_warn(mdev->tconn, mapped, expect);
+               err = drbd_recv_all_warn(peer_device->connection, mapped, expect);
                kunmap(bvec.bv_page);
                if (err)
                        return err;
@@ -1619,14 +1635,14 @@ static int recv_dless_read(struct drbd_conf *mdev, struct drbd_request *req,
        }
 
        if (dgs) {
-               drbd_csum_bio(mdev, mdev->tconn->peer_integrity_tfm, bio, dig_vv);
+               drbd_csum_bio(peer_device->connection->peer_integrity_tfm, bio, dig_vv);
                if (memcmp(dig_in, dig_vv, dgs)) {
-                       dev_err(DEV, "Digest integrity check FAILED. Broken NICs?\n");
+                       drbd_err(peer_device, "Digest integrity check FAILED. Broken NICs?\n");
                        return -EINVAL;
                }
        }
 
-       D_ASSERT(data_size == 0);
+       D_ASSERT(peer_device->device, data_size == 0);
        return 0;
 }
 
@@ -1638,64 +1654,67 @@ static int e_end_resync_block(struct drbd_work *w, int unused)
 {
        struct drbd_peer_request *peer_req =
                container_of(w, struct drbd_peer_request, w);
-       struct drbd_conf *mdev = w->mdev;
+       struct drbd_peer_device *peer_device = peer_req->peer_device;
+       struct drbd_device *device = peer_device->device;
        sector_t sector = peer_req->i.sector;
        int err;
 
-       D_ASSERT(drbd_interval_empty(&peer_req->i));
+       D_ASSERT(device, drbd_interval_empty(&peer_req->i));
 
        if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) {
-               drbd_set_in_sync(mdev, sector, peer_req->i.size);
-               err = drbd_send_ack(mdev, P_RS_WRITE_ACK, peer_req);
+               drbd_set_in_sync(device, sector, peer_req->i.size);
+               err = drbd_send_ack(peer_device, P_RS_WRITE_ACK, peer_req);
        } else {
                /* Record failure to sync */
-               drbd_rs_failed_io(mdev, sector, peer_req->i.size);
+               drbd_rs_failed_io(device, sector, peer_req->i.size);
 
-               err  = drbd_send_ack(mdev, P_NEG_ACK, peer_req);
+               err  = drbd_send_ack(peer_device, P_NEG_ACK, peer_req);
        }
-       dec_unacked(mdev);
+       dec_unacked(device);
 
        return err;
 }
 
-static int recv_resync_read(struct drbd_conf *mdev, sector_t sector, int data_size) __releases(local)
+static int recv_resync_read(struct drbd_peer_device *peer_device, sector_t sector,
+                           int data_size) __releases(local)
 {
+       struct drbd_device *device = peer_device->device;
        struct drbd_peer_request *peer_req;
 
-       peer_req = read_in_block(mdev, ID_SYNCER, sector, data_size);
+       peer_req = read_in_block(peer_device, ID_SYNCER, sector, data_size);
        if (!peer_req)
                goto fail;
 
-       dec_rs_pending(mdev);
+       dec_rs_pending(device);
 
-       inc_unacked(mdev);
+       inc_unacked(device);
        /* corresponding dec_unacked() in e_end_resync_block()
         * respective _drbd_clear_done_ee */
 
        peer_req->w.cb = e_end_resync_block;
 
-       spin_lock_irq(&mdev->tconn->req_lock);
-       list_add(&peer_req->w.list, &mdev->sync_ee);
-       spin_unlock_irq(&mdev->tconn->req_lock);
+       spin_lock_irq(&device->resource->req_lock);
+       list_add(&peer_req->w.list, &device->sync_ee);
+       spin_unlock_irq(&device->resource->req_lock);
 
-       atomic_add(data_size >> 9, &mdev->rs_sect_ev);
-       if (drbd_submit_peer_request(mdev, peer_req, WRITE, DRBD_FAULT_RS_WR) == 0)
+       atomic_add(data_size >> 9, &device->rs_sect_ev);
+       if (drbd_submit_peer_request(device, peer_req, WRITE, DRBD_FAULT_RS_WR) == 0)
                return 0;
 
        /* don't care for the reason here */
-       dev_err(DEV, "submit failed, triggering re-connect\n");
-       spin_lock_irq(&mdev->tconn->req_lock);
+       drbd_err(device, "submit failed, triggering re-connect\n");
+       spin_lock_irq(&device->resource->req_lock);
        list_del(&peer_req->w.list);
-       spin_unlock_irq(&mdev->tconn->req_lock);
+       spin_unlock_irq(&device->resource->req_lock);
 
-       drbd_free_peer_req(mdev, peer_req);
+       drbd_free_peer_req(device, peer_req);
 fail:
-       put_ldev(mdev);
+       put_ldev(device);
        return -EIO;
 }
 
 static struct drbd_request *
-find_request(struct drbd_conf *mdev, struct rb_root *root, u64 id,
+find_request(struct drbd_device *device, struct rb_root *root, u64 id,
             sector_t sector, bool missing_ok, const char *func)
 {
        struct drbd_request *req;
@@ -1705,36 +1724,38 @@ find_request(struct drbd_conf *mdev, struct rb_root *root, u64 id,
        if (drbd_contains_interval(root, sector, &req->i) && req->i.local)
                return req;
        if (!missing_ok) {
-               dev_err(DEV, "%s: failed to find request 0x%lx, sector %llus\n", func,
+               drbd_err(device, "%s: failed to find request 0x%lx, sector %llus\n", func,
                        (unsigned long)id, (unsigned long long)sector);
        }
        return NULL;
 }
 
-static int receive_DataReply(struct drbd_tconn *tconn, struct packet_info *pi)
+static int receive_DataReply(struct drbd_connection *connection, struct packet_info *pi)
 {
-       struct drbd_conf *mdev;
+       struct drbd_peer_device *peer_device;
+       struct drbd_device *device;
        struct drbd_request *req;
        sector_t sector;
        int err;
        struct p_data *p = pi->data;
 
-       mdev = vnr_to_mdev(tconn, pi->vnr);
-       if (!mdev)
+       peer_device = conn_peer_device(connection, pi->vnr);
+       if (!peer_device)
                return -EIO;
+       device = peer_device->device;
 
        sector = be64_to_cpu(p->sector);
 
-       spin_lock_irq(&mdev->tconn->req_lock);
-       req = find_request(mdev, &mdev->read_requests, p->block_id, sector, false, __func__);
-       spin_unlock_irq(&mdev->tconn->req_lock);
+       spin_lock_irq(&device->resource->req_lock);
+       req = find_request(device, &device->read_requests, p->block_id, sector, false, __func__);
+       spin_unlock_irq(&device->resource->req_lock);
        if (unlikely(!req))
                return -EIO;
 
        /* hlist_del(&req->collision) is done in _req_may_be_done, to avoid
         * special casing it there for the various failure cases.
         * still no race with drbd_fail_pending_reads */
-       err = recv_dless_read(mdev, req, sector, pi->size);
+       err = recv_dless_read(peer_device, req, sector, pi->size);
        if (!err)
                req_mod(req, DATA_RECEIVED);
        /* else: nothing. handled from drbd_disconnect...
@@ -1744,46 +1765,48 @@ static int receive_DataReply(struct drbd_tconn *tconn, struct packet_info *pi)
        return err;
 }
 
-static int receive_RSDataReply(struct drbd_tconn *tconn, struct packet_info *pi)
+static int receive_RSDataReply(struct drbd_connection *connection, struct packet_info *pi)
 {
-       struct drbd_conf *mdev;
+       struct drbd_peer_device *peer_device;
+       struct drbd_device *device;
        sector_t sector;
        int err;
        struct p_data *p = pi->data;
 
-       mdev = vnr_to_mdev(tconn, pi->vnr);
-       if (!mdev)
+       peer_device = conn_peer_device(connection, pi->vnr);
+       if (!peer_device)
                return -EIO;
+       device = peer_device->device;
 
        sector = be64_to_cpu(p->sector);
-       D_ASSERT(p->block_id == ID_SYNCER);
+       D_ASSERT(device, p->block_id == ID_SYNCER);
 
-       if (get_ldev(mdev)) {
+       if (get_ldev(device)) {
                /* data is submitted to disk within recv_resync_read.
                 * corresponding put_ldev done below on error,
                 * or in drbd_peer_request_endio. */
-               err = recv_resync_read(mdev, sector, pi->size);
+               err = recv_resync_read(peer_device, sector, pi->size);
        } else {
                if (__ratelimit(&drbd_ratelimit_state))
-                       dev_err(DEV, "Can not write resync data to local disk.\n");
+                       drbd_err(device, "Can not write resync data to local disk.\n");
 
-               err = drbd_drain_block(mdev, pi->size);
+               err = drbd_drain_block(peer_device, pi->size);
 
-               drbd_send_ack_dp(mdev, P_NEG_ACK, p, pi->size);
+               drbd_send_ack_dp(peer_device, P_NEG_ACK, p, pi->size);
        }
 
-       atomic_add(pi->size >> 9, &mdev->rs_sect_in);
+       atomic_add(pi->size >> 9, &device->rs_sect_in);
 
        return err;
 }
 
-static void restart_conflicting_writes(struct drbd_conf *mdev,
+static void restart_conflicting_writes(struct drbd_device *device,
                                       sector_t sector, int size)
 {
        struct drbd_interval *i;
        struct drbd_request *req;
 
-       drbd_for_each_overlap(i, &mdev->write_requests, sector, size) {
+       drbd_for_each_overlap(i, &device->write_requests, sector, size) {
                if (!i->local)
                        continue;
                req = container_of(i, struct drbd_request, i);
@@ -1803,52 +1826,53 @@ static int e_end_block(struct drbd_work *w, int cancel)
 {
        struct drbd_peer_request *peer_req =
                container_of(w, struct drbd_peer_request, w);
-       struct drbd_conf *mdev = w->mdev;
+       struct drbd_peer_device *peer_device = peer_req->peer_device;
+       struct drbd_device *device = peer_device->device;
        sector_t sector = peer_req->i.sector;
        int err = 0, pcmd;
 
        if (peer_req->flags & EE_SEND_WRITE_ACK) {
                if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) {
-                       pcmd = (mdev->state.conn >= C_SYNC_SOURCE &&
-                               mdev->state.conn <= C_PAUSED_SYNC_T &&
+                       pcmd = (device->state.conn >= C_SYNC_SOURCE &&
+                               device->state.conn <= C_PAUSED_SYNC_T &&
                                peer_req->flags & EE_MAY_SET_IN_SYNC) ?
                                P_RS_WRITE_ACK : P_WRITE_ACK;
-                       err = drbd_send_ack(mdev, pcmd, peer_req);
+                       err = drbd_send_ack(peer_device, pcmd, peer_req);
                        if (pcmd == P_RS_WRITE_ACK)
-                               drbd_set_in_sync(mdev, sector, peer_req->i.size);
+                               drbd_set_in_sync(device, sector, peer_req->i.size);
                } else {
-                       err = drbd_send_ack(mdev, P_NEG_ACK, peer_req);
+                       err = drbd_send_ack(peer_device, P_NEG_ACK, peer_req);
                        /* we expect it to be marked out of sync anyways...
                         * maybe assert this?  */
                }
-               dec_unacked(mdev);
+               dec_unacked(device);
        }
        /* we delete from the conflict detection hash _after_ we sent out the
         * P_WRITE_ACK / P_NEG_ACK, to get the sequence number right.  */
        if (peer_req->flags & EE_IN_INTERVAL_TREE) {
-               spin_lock_irq(&mdev->tconn->req_lock);
-               D_ASSERT(!drbd_interval_empty(&peer_req->i));
-               drbd_remove_epoch_entry_interval(mdev, peer_req);
+               spin_lock_irq(&device->resource->req_lock);
+               D_ASSERT(device, !drbd_interval_empty(&peer_req->i));
+               drbd_remove_epoch_entry_interval(device, peer_req);
                if (peer_req->flags & EE_RESTART_REQUESTS)
-                       restart_conflicting_writes(mdev, sector, peer_req->i.size);
-               spin_unlock_irq(&mdev->tconn->req_lock);
+                       restart_conflicting_writes(device, sector, peer_req->i.size);
+               spin_unlock_irq(&device->resource->req_lock);
        } else
-               D_ASSERT(drbd_interval_empty(&peer_req->i));
+               D_ASSERT(device, drbd_interval_empty(&peer_req->i));
 
-       drbd_may_finish_epoch(mdev->tconn, peer_req->epoch, EV_PUT + (cancel ? EV_CLEANUP : 0));
+       drbd_may_finish_epoch(first_peer_device(device)->connection, peer_req->epoch, EV_PUT + (cancel ? EV_CLEANUP : 0));
 
        return err;
 }
 
 static int e_send_ack(struct drbd_work *w, enum drbd_packet ack)
 {
-       struct drbd_conf *mdev = w->mdev;
        struct drbd_peer_request *peer_req =
                container_of(w, struct drbd_peer_request, w);
+       struct drbd_peer_device *peer_device = peer_req->peer_device;
        int err;
 
-       err = drbd_send_ack(mdev, ack, peer_req);
-       dec_unacked(mdev);
+       err = drbd_send_ack(peer_device, ack, peer_req);
+       dec_unacked(peer_device->device);
 
        return err;
 }
@@ -1860,9 +1884,11 @@ static int e_send_superseded(struct drbd_work *w, int unused)
 
 static int e_send_retry_write(struct drbd_work *w, int unused)
 {
-       struct drbd_tconn *tconn = w->mdev->tconn;
+       struct drbd_peer_request *peer_req =
+               container_of(w, struct drbd_peer_request, w);
+       struct drbd_connection *connection = peer_req->peer_device->connection;
 
-       return e_send_ack(w, tconn->agreed_pro_version >= 100 ?
+       return e_send_ack(w, connection->agreed_pro_version >= 100 ?
                             P_RETRY_WRITE : P_SUPERSEDED);
 }
 
@@ -1881,18 +1907,19 @@ static u32 seq_max(u32 a, u32 b)
        return seq_greater(a, b) ? a : b;
 }
 
-static void update_peer_seq(struct drbd_conf *mdev, unsigned int peer_seq)
+static void update_peer_seq(struct drbd_peer_device *peer_device, unsigned int peer_seq)
 {
+       struct drbd_device *device = peer_device->device;
        unsigned int newest_peer_seq;
 
-       if (test_bit(RESOLVE_CONFLICTS, &mdev->tconn->flags)) {
-               spin_lock(&mdev->peer_seq_lock);
-               newest_peer_seq = seq_max(mdev->peer_seq, peer_seq);
-               mdev->peer_seq = newest_peer_seq;
-               spin_unlock(&mdev->peer_seq_lock);
-               /* wake up only if we actually changed mdev->peer_seq */
+       if (test_bit(RESOLVE_CONFLICTS, &peer_device->connection->flags)) {
+               spin_lock(&device->peer_seq_lock);
+               newest_peer_seq = seq_max(device->peer_seq, peer_seq);
+               device->peer_seq = newest_peer_seq;
+               spin_unlock(&device->peer_seq_lock);
+               /* wake up only if we actually changed device->peer_seq */
                if (peer_seq == newest_peer_seq)
-                       wake_up(&mdev->seq_wait);
+                       wake_up(&device->seq_wait);
        }
 }
 
@@ -1902,20 +1929,20 @@ static inline int overlaps(sector_t s1, int l1, sector_t s2, int l2)
 }
 
 /* maybe change sync_ee into interval trees as well? */
-static bool overlapping_resync_write(struct drbd_conf *mdev, struct drbd_peer_request *peer_req)
+static bool overlapping_resync_write(struct drbd_device *device, struct drbd_peer_request *peer_req)
 {
        struct drbd_peer_request *rs_req;
        bool rv = 0;
 
-       spin_lock_irq(&mdev->tconn->req_lock);
-       list_for_each_entry(rs_req, &mdev->sync_ee, w.list) {
+       spin_lock_irq(&device->resource->req_lock);
+       list_for_each_entry(rs_req, &device->sync_ee, w.list) {
                if (overlaps(peer_req->i.sector, peer_req->i.size,
                             rs_req->i.sector, rs_req->i.size)) {
                        rv = 1;
                        break;
                }
        }
-       spin_unlock_irq(&mdev->tconn->req_lock);
+       spin_unlock_irq(&device->resource->req_lock);
 
        return rv;
 }
@@ -1929,9 +1956,9 @@ static bool overlapping_resync_write(struct drbd_conf *mdev, struct drbd_peer_re
  *
  * Note: we don't care for Ack packets overtaking P_DATA packets.
  *
- * In case packet_seq is larger than mdev->peer_seq number, there are
+ * In case packet_seq is larger than device->peer_seq number, there are
  * outstanding packets on the msock. We wait for them to arrive.
- * In case we are the logically next packet, we update mdev->peer_seq
+ * In case we are the logically next packet, we update device->peer_seq
  * ourselves. Correctly handles 32bit wrap around.
  *
  * Assume we have a 10 GBit connection, that is about 1<<30 byte per second,
@@ -1941,19 +1968,20 @@ static bool overlapping_resync_write(struct drbd_conf *mdev, struct drbd_peer_re
  *
  * returns 0 if we may process the packet,
  * -ERESTARTSYS if we were interrupted (by disconnect signal). */
-static int wait_for_and_update_peer_seq(struct drbd_conf *mdev, const u32 peer_seq)
+static int wait_for_and_update_peer_seq(struct drbd_peer_device *peer_device, const u32 peer_seq)
 {
+       struct drbd_device *device = peer_device->device;
        DEFINE_WAIT(wait);
        long timeout;
        int ret = 0, tp;
 
-       if (!test_bit(RESOLVE_CONFLICTS, &mdev->tconn->flags))
+       if (!test_bit(RESOLVE_CONFLICTS, &peer_device->connection->flags))
                return 0;
 
-       spin_lock(&mdev->peer_seq_lock);
+       spin_lock(&device->peer_seq_lock);
        for (;;) {
-               if (!seq_greater(peer_seq - 1, mdev->peer_seq)) {
-                       mdev->peer_seq = seq_max(mdev->peer_seq, peer_seq);
+               if (!seq_greater(peer_seq - 1, device->peer_seq)) {
+                       device->peer_seq = seq_max(device->peer_seq, peer_seq);
                        break;
                }
 
@@ -1963,35 +1991,35 @@ static int wait_for_and_update_peer_seq(struct drbd_conf *mdev, const u32 peer_s
                }
 
                rcu_read_lock();
-               tp = rcu_dereference(mdev->tconn->net_conf)->two_primaries;
+               tp = rcu_dereference(first_peer_device(device)->connection->net_conf)->two_primaries;
                rcu_read_unlock();
 
                if (!tp)
                        break;
 
                /* Only need to wait if two_primaries is enabled */
-               prepare_to_wait(&mdev->seq_wait, &wait, TASK_INTERRUPTIBLE);
-               spin_unlock(&mdev->peer_seq_lock);
+               prepare_to_wait(&device->seq_wait, &wait, TASK_INTERRUPTIBLE);
+               spin_unlock(&device->peer_seq_lock);
                rcu_read_lock();
-               timeout = rcu_dereference(mdev->tconn->net_conf)->ping_timeo*HZ/10;
+               timeout = rcu_dereference(peer_device->connection->net_conf)->ping_timeo*HZ/10;
                rcu_read_unlock();
                timeout = schedule_timeout(timeout);
-               spin_lock(&mdev->peer_seq_lock);
+               spin_lock(&device->peer_seq_lock);
                if (!timeout) {
                        ret = -ETIMEDOUT;
-                       dev_err(DEV, "Timed out waiting for missing ack packets; disconnecting\n");
+                       drbd_err(device, "Timed out waiting for missing ack packets; disconnecting\n");
                        break;
                }
        }
-       spin_unlock(&mdev->peer_seq_lock);
-       finish_wait(&mdev->seq_wait, &wait);
+       spin_unlock(&device->peer_seq_lock);
+       finish_wait(&device->seq_wait, &wait);
        return ret;
 }
 
 /* see also bio_flags_to_wire()
  * DRBD_REQ_*, because we need to semantically map the flags to data packet
  * flags and back. We may replicate to other kernel versions. */
-static unsigned long wire_flags_to_bio(struct drbd_conf *mdev, u32 dpf)
+static unsigned long wire_flags_to_bio(u32 dpf)
 {
        return  (dpf & DP_RW_SYNC ? REQ_SYNC : 0) |
                (dpf & DP_FUA ? REQ_FUA : 0) |
@@ -1999,13 +2027,13 @@ static unsigned long wire_flags_to_bio(struct drbd_conf *mdev, u32 dpf)
                (dpf & DP_DISCARD ? REQ_DISCARD : 0);
 }
 
-static void fail_postponed_requests(struct drbd_conf *mdev, sector_t sector,
+static void fail_postponed_requests(struct drbd_device *device, sector_t sector,
                                    unsigned int size)
 {
        struct drbd_interval *i;
 
     repeat:
-       drbd_for_each_overlap(i, &mdev->write_requests, sector, size) {
+       drbd_for_each_overlap(i, &device->write_requests, sector, size) {
                struct drbd_request *req;
                struct bio_and_error m;
 
@@ -2016,19 +2044,19 @@ static void fail_postponed_requests(struct drbd_conf *mdev, sector_t sector,
                        continue;
                req->rq_state &= ~RQ_POSTPONED;
                __req_mod(req, NEG_ACKED, &m);
-               spin_unlock_irq(&mdev->tconn->req_lock);
+               spin_unlock_irq(&device->resource->req_lock);
                if (m.bio)
-                       complete_master_bio(mdev, &m);
-               spin_lock_irq(&mdev->tconn->req_lock);
+                       complete_master_bio(device, &m);
+               spin_lock_irq(&device->resource->req_lock);
                goto repeat;
        }
 }
 
-static int handle_write_conflicts(struct drbd_conf *mdev,
+static int handle_write_conflicts(struct drbd_device *device,
                                  struct drbd_peer_request *peer_req)
 {
-       struct drbd_tconn *tconn = mdev->tconn;
-       bool resolve_conflicts = test_bit(RESOLVE_CONFLICTS, &tconn->flags);
+       struct drbd_connection *connection = peer_req->peer_device->connection;
+       bool resolve_conflicts = test_bit(RESOLVE_CONFLICTS, &connection->flags);
        sector_t sector = peer_req->i.sector;
        const unsigned int size = peer_req->i.size;
        struct drbd_interval *i;
@@ -2039,10 +2067,10 @@ static int handle_write_conflicts(struct drbd_conf *mdev,
         * Inserting the peer request into the write_requests tree will prevent
         * new conflicting local requests from being added.
         */
-       drbd_insert_interval(&mdev->write_requests, &peer_req->i);
+       drbd_insert_interval(&device->write_requests, &peer_req->i);
 
     repeat:
-       drbd_for_each_overlap(i, &mdev->write_requests, sector, size) {
+       drbd_for_each_overlap(i, &device->write_requests, sector, size) {
                if (i == &peer_req->i)
                        continue;
 
@@ -2052,7 +2080,7 @@ static int handle_write_conflicts(struct drbd_conf *mdev,
                         * should not happen in a two-node setup.  Wait for the
                         * earlier peer request to complete.
                         */
-                       err = drbd_wait_misc(mdev, i);
+                       err = drbd_wait_misc(device, i);
                        if (err)
                                goto out;
                        goto repeat;
@@ -2070,18 +2098,18 @@ static int handle_write_conflicts(struct drbd_conf *mdev,
                                       (i->size >> 9) >= sector + (size >> 9);
 
                        if (!equal)
-                               dev_alert(DEV, "Concurrent writes detected: "
+                               drbd_alert(device, "Concurrent writes detected: "
                                               "local=%llus +%u, remote=%llus +%u, "
                                               "assuming %s came first\n",
                                          (unsigned long long)i->sector, i->size,
                                          (unsigned long long)sector, size,
                                          superseded ? "local" : "remote");
 
-                       inc_unacked(mdev);
+                       inc_unacked(device);
                        peer_req->w.cb = superseded ? e_send_superseded :
                                                   e_send_retry_write;
-                       list_add_tail(&peer_req->w.list, &mdev->done_ee);
-                       wake_asender(mdev->tconn);
+                       list_add_tail(&peer_req->w.list, &device->done_ee);
+                       wake_asender(connection);
 
                        err = -ENOENT;
                        goto out;
@@ -2090,7 +2118,7 @@ static int handle_write_conflicts(struct drbd_conf *mdev,
                                container_of(i, struct drbd_request, i);
 
                        if (!equal)
-                               dev_alert(DEV, "Concurrent writes detected: "
+                               drbd_alert(device, "Concurrent writes detected: "
                                               "local=%llus +%u, remote=%llus +%u\n",
                                          (unsigned long long)i->sector, i->size,
                                          (unsigned long long)sector, size);
@@ -2108,12 +2136,10 @@ static int handle_write_conflicts(struct drbd_conf *mdev,
                                 * request to finish locally before submitting
                                 * the conflicting peer request.
                                 */
-                               err = drbd_wait_misc(mdev, &req->i);
+                               err = drbd_wait_misc(device, &req->i);
                                if (err) {
-                                       _conn_request_state(mdev->tconn,
-                                                           NS(conn, C_TIMEOUT),
-                                                           CS_HARD);
-                                       fail_postponed_requests(mdev, sector, size);
+                                       _conn_request_state(connection, NS(conn, C_TIMEOUT), CS_HARD);
+                                       fail_postponed_requests(device, sector, size);
                                        goto out;
                                }
                                goto repeat;
@@ -2129,14 +2155,15 @@ static int handle_write_conflicts(struct drbd_conf *mdev,
 
     out:
        if (err)
-               drbd_remove_epoch_entry_interval(mdev, peer_req);
+               drbd_remove_epoch_entry_interval(device, peer_req);
        return err;
 }
 
 /* mirrored write */
-static int receive_Data(struct drbd_tconn *tconn, struct packet_info *pi)
+static int receive_Data(struct drbd_connection *connection, struct packet_info *pi)
 {
-       struct drbd_conf *mdev;
+       struct drbd_peer_device *peer_device;
+       struct drbd_device *device;
        sector_t sector;
        struct drbd_peer_request *peer_req;
        struct p_data *p = pi->data;
@@ -2145,17 +2172,18 @@ static int receive_Data(struct drbd_tconn *tconn, struct packet_info *pi)
        u32 dp_flags;
        int err, tp;
 
-       mdev = vnr_to_mdev(tconn, pi->vnr);
-       if (!mdev)
+       peer_device = conn_peer_device(connection, pi->vnr);
+       if (!peer_device)
                return -EIO;
+       device = peer_device->device;
 
-       if (!get_ldev(mdev)) {
+       if (!get_ldev(device)) {
                int err2;
 
-               err = wait_for_and_update_peer_seq(mdev, peer_seq);
-               drbd_send_ack_dp(mdev, P_NEG_ACK, p, pi->size);
-               atomic_inc(&tconn->current_epoch->epoch_size);
-               err2 = drbd_drain_block(mdev, pi->size);
+               err = wait_for_and_update_peer_seq(peer_device, peer_seq);
+               drbd_send_ack_dp(peer_device, P_NEG_ACK, p, pi->size);
+               atomic_inc(&connection->current_epoch->epoch_size);
+               err2 = drbd_drain_block(peer_device, pi->size);
                if (!err)
                        err = err2;
                return err;
@@ -2168,61 +2196,61 @@ static int receive_Data(struct drbd_tconn *tconn, struct packet_info *pi)
         */
 
        sector = be64_to_cpu(p->sector);
-       peer_req = read_in_block(mdev, p->block_id, sector, pi->size);
+       peer_req = read_in_block(peer_device, p->block_id, sector, pi->size);
        if (!peer_req) {
-               put_ldev(mdev);
+               put_ldev(device);
                return -EIO;
        }
 
        peer_req->w.cb = e_end_block;
 
        dp_flags = be32_to_cpu(p->dp_flags);
-       rw |= wire_flags_to_bio(mdev, dp_flags);
+       rw |= wire_flags_to_bio(dp_flags);
        if (peer_req->pages == NULL) {
-               D_ASSERT(peer_req->i.size == 0);
-               D_ASSERT(dp_flags & DP_FLUSH);
+               D_ASSERT(device, peer_req->i.size == 0);
+               D_ASSERT(device, dp_flags & DP_FLUSH);
        }
 
        if (dp_flags & DP_MAY_SET_IN_SYNC)
                peer_req->flags |= EE_MAY_SET_IN_SYNC;
 
-       spin_lock(&tconn->epoch_lock);
-       peer_req->epoch = tconn->current_epoch;
+       spin_lock(&connection->epoch_lock);
+       peer_req->epoch = connection->current_epoch;
        atomic_inc(&peer_req->epoch->epoch_size);
        atomic_inc(&peer_req->epoch->active);
-       spin_unlock(&tconn->epoch_lock);
+       spin_unlock(&connection->epoch_lock);
 
        rcu_read_lock();
-       tp = rcu_dereference(mdev->tconn->net_conf)->two_primaries;
+       tp = rcu_dereference(peer_device->connection->net_conf)->two_primaries;
        rcu_read_unlock();
        if (tp) {
                peer_req->flags |= EE_IN_INTERVAL_TREE;
-               err = wait_for_and_update_peer_seq(mdev, peer_seq);
+               err = wait_for_and_update_peer_seq(peer_device, peer_seq);
                if (err)
                        goto out_interrupted;
-               spin_lock_irq(&mdev->tconn->req_lock);
-               err = handle_write_conflicts(mdev, peer_req);
+               spin_lock_irq(&device->resource->req_lock);
+               err = handle_write_conflicts(device, peer_req);
                if (err) {
-                       spin_unlock_irq(&mdev->tconn->req_lock);
+                       spin_unlock_irq(&device->resource->req_lock);
                        if (err == -ENOENT) {
-                               put_ldev(mdev);
+                               put_ldev(device);
                                return 0;
                        }
                        goto out_interrupted;
                }
        } else {
-               update_peer_seq(mdev, peer_seq);
-               spin_lock_irq(&mdev->tconn->req_lock);
+               update_peer_seq(peer_device, peer_seq);
+               spin_lock_irq(&device->resource->req_lock);
        }
-       list_add(&peer_req->w.list, &mdev->active_ee);
-       spin_unlock_irq(&mdev->tconn->req_lock);
+       list_add(&peer_req->w.list, &device->active_ee);
+       spin_unlock_irq(&device->resource->req_lock);
 
-       if (mdev->state.conn == C_SYNC_TARGET)
-               wait_event(mdev->ee_wait, !overlapping_resync_write(mdev, peer_req));
+       if (device->state.conn == C_SYNC_TARGET)
+               wait_event(device->ee_wait, !overlapping_resync_write(device, peer_req));
 
-       if (mdev->tconn->agreed_pro_version < 100) {
+       if (peer_device->connection->agreed_pro_version < 100) {
                rcu_read_lock();
-               switch (rcu_dereference(mdev->tconn->net_conf)->wire_protocol) {
+               switch (rcu_dereference(peer_device->connection->net_conf)->wire_protocol) {
                case DRBD_PROT_C:
                        dp_flags |= DP_SEND_WRITE_ACK;
                        break;
@@ -2235,7 +2263,7 @@ static int receive_Data(struct drbd_tconn *tconn, struct packet_info *pi)
 
        if (dp_flags & DP_SEND_WRITE_ACK) {
                peer_req->flags |= EE_SEND_WRITE_ACK;
-               inc_unacked(mdev);
+               inc_unacked(device);
                /* corresponding dec_unacked() in e_end_block()
                 * respective _drbd_clear_done_ee */
        }
@@ -2243,34 +2271,34 @@ static int receive_Data(struct drbd_tconn *tconn, struct packet_info *pi)
        if (dp_flags & DP_SEND_RECEIVE_ACK) {
                /* I really don't like it that the receiver thread
                 * sends on the msock, but anyways */
-               drbd_send_ack(mdev, P_RECV_ACK, peer_req);
+               drbd_send_ack(first_peer_device(device), P_RECV_ACK, peer_req);
        }
 
-       if (mdev->state.pdsk < D_INCONSISTENT) {
+       if (device->state.pdsk < D_INCONSISTENT) {
                /* In case we have the only disk of the cluster, */
-               drbd_set_out_of_sync(mdev, peer_req->i.sector, peer_req->i.size);
+               drbd_set_out_of_sync(device, peer_req->i.sector, peer_req->i.size);
                peer_req->flags |= EE_CALL_AL_COMPLETE_IO;
                peer_req->flags &= ~EE_MAY_SET_IN_SYNC;
-               drbd_al_begin_io(mdev, &peer_req->i, true);
+               drbd_al_begin_io(device, &peer_req->i, true);
        }
 
-       err = drbd_submit_peer_request(mdev, peer_req, rw, DRBD_FAULT_DT_WR);
+       err = drbd_submit_peer_request(device, peer_req, rw, DRBD_FAULT_DT_WR);
        if (!err)
                return 0;
 
        /* don't care for the reason here */
-       dev_err(DEV, "submit failed, triggering re-connect\n");
-       spin_lock_irq(&mdev->tconn->req_lock);
+       drbd_err(device, "submit failed, triggering re-connect\n");
+       spin_lock_irq(&device->resource->req_lock);
        list_del(&peer_req->w.list);
-       drbd_remove_epoch_entry_interval(mdev, peer_req);
-       spin_unlock_irq(&mdev->tconn->req_lock);
+       drbd_remove_epoch_entry_interval(device, peer_req);
+       spin_unlock_irq(&device->resource->req_lock);
        if (peer_req->flags & EE_CALL_AL_COMPLETE_IO)
-               drbd_al_complete_io(mdev, &peer_req->i);
+               drbd_al_complete_io(device, &peer_req->i);
 
 out_interrupted:
-       drbd_may_finish_epoch(tconn, peer_req->epoch, EV_PUT + EV_CLEANUP);
-       put_ldev(mdev);
-       drbd_free_peer_req(mdev, peer_req);
+       drbd_may_finish_epoch(connection, peer_req->epoch, EV_PUT + EV_CLEANUP);
+       put_ldev(device);
+       drbd_free_peer_req(device, peer_req);
        return err;
 }
 
@@ -2285,9 +2313,9 @@ out_interrupted:
  * The current sync rate used here uses only the most recent two step marks,
  * to have a short time average so we can react faster.
  */
-int drbd_rs_should_slow_down(struct drbd_conf *mdev, sector_t sector)
+int drbd_rs_should_slow_down(struct drbd_device *device, sector_t sector)
 {
-       struct gendisk *disk = mdev->ldev->backing_bdev->bd_contains->bd_disk;
+       struct gendisk *disk = device->ldev->backing_bdev->bd_contains->bd_disk;
        unsigned long db, dt, dbdt;
        struct lc_element *tmp;
        int curr_events;
@@ -2295,48 +2323,48 @@ int drbd_rs_should_slow_down(struct drbd_conf *mdev, sector_t sector)
        unsigned int c_min_rate;
 
        rcu_read_lock();
-       c_min_rate = rcu_dereference(mdev->ldev->disk_conf)->c_min_rate;
+       c_min_rate = rcu_dereference(device->ldev->disk_conf)->c_min_rate;
        rcu_read_unlock();
 
        /* feature disabled? */
        if (c_min_rate == 0)
                return 0;
 
-       spin_lock_irq(&mdev->al_lock);
-       tmp = lc_find(mdev->resync, BM_SECT_TO_EXT(sector));
+       spin_lock_irq(&device->al_lock);
+       tmp = lc_find(device->resync, BM_SECT_TO_EXT(sector));
        if (tmp) {
                struct bm_extent *bm_ext = lc_entry(tmp, struct bm_extent, lce);
                if (test_bit(BME_PRIORITY, &bm_ext->flags)) {
-                       spin_unlock_irq(&mdev->al_lock);
+                       spin_unlock_irq(&device->al_lock);
                        return 0;
                }
                /* Do not slow down if app IO is already waiting for this extent */
        }
-       spin_unlock_irq(&mdev->al_lock);
+       spin_unlock_irq(&device->al_lock);
 
        curr_events = (int)part_stat_read(&disk->part0, sectors[0]) +
                      (int)part_stat_read(&disk->part0, sectors[1]) -
-                       atomic_read(&mdev->rs_sect_ev);
+                       atomic_read(&device->rs_sect_ev);
 
-       if (!mdev->rs_last_events || curr_events - mdev->rs_last_events > 64) {
+       if (!device->rs_last_events || curr_events - device->rs_last_events > 64) {
                unsigned long rs_left;
                int i;
 
-               mdev->rs_last_events = curr_events;
+               device->rs_last_events = curr_events;
 
                /* sync speed average over the last 2*DRBD_SYNC_MARK_STEP,
                 * approx. */
-               i = (mdev->rs_last_mark + DRBD_SYNC_MARKS-1) % DRBD_SYNC_MARKS;
+               i = (device->rs_last_mark + DRBD_SYNC_MARKS-1) % DRBD_SYNC_MARKS;
 
-               if (mdev->state.conn == C_VERIFY_S || mdev->state.conn == C_VERIFY_T)
-                       rs_left = mdev->ov_left;
+               if (device->state.conn == C_VERIFY_S || device->state.conn == C_VERIFY_T)
+                       rs_left = device->ov_left;
                else
-                       rs_left = drbd_bm_total_weight(mdev) - mdev->rs_failed;
+                       rs_left = drbd_bm_total_weight(device) - device->rs_failed;
 
-               dt = ((long)jiffies - (long)mdev->rs_mark_time[i]) / HZ;
+               dt = ((long)jiffies - (long)device->rs_mark_time[i]) / HZ;
                if (!dt)
                        dt++;
-               db = mdev->rs_mark_left[i] - rs_left;
+               db = device->rs_mark_left[i] - rs_left;
                dbdt = Bit2KB(db/dt);
 
                if (dbdt > c_min_rate)
@@ -2346,9 +2374,10 @@ int drbd_rs_should_slow_down(struct drbd_conf *mdev, sector_t sector)
 }
 
 
-static int receive_DataRequest(struct drbd_tconn *tconn, struct packet_info *pi)
+static int receive_DataRequest(struct drbd_connection *connection, struct packet_info *pi)
 {
-       struct drbd_conf *mdev;
+       struct drbd_peer_device *peer_device;
+       struct drbd_device *device;
        sector_t sector;
        sector_t capacity;
        struct drbd_peer_request *peer_req;
@@ -2357,58 +2386,59 @@ static int receive_DataRequest(struct drbd_tconn *tconn, struct packet_info *pi)
        unsigned int fault_type;
        struct p_block_req *p = pi->data;
 
-       mdev = vnr_to_mdev(tconn, pi->vnr);
-       if (!mdev)
+       peer_device = conn_peer_device(connection, pi->vnr);
+       if (!peer_device)
                return -EIO;
-       capacity = drbd_get_capacity(mdev->this_bdev);
+       device = peer_device->device;
+       capacity = drbd_get_capacity(device->this_bdev);
 
        sector = be64_to_cpu(p->sector);
        size   = be32_to_cpu(p->blksize);
 
        if (size <= 0 || !IS_ALIGNED(size, 512) || size > DRBD_MAX_BIO_SIZE) {
-               dev_err(DEV, "%s:%d: sector: %llus, size: %u\n", __FILE__, __LINE__,
+               drbd_err(device, "%s:%d: sector: %llus, size: %u\n", __FILE__, __LINE__,
                                (unsigned long long)sector, size);
                return -EINVAL;
        }
        if (sector + (size>>9) > capacity) {
-               dev_err(DEV, "%s:%d: sector: %llus, size: %u\n", __FILE__, __LINE__,
+               drbd_err(device, "%s:%d: sector: %llus, size: %u\n", __FILE__, __LINE__,
                                (unsigned long long)sector, size);
                return -EINVAL;
        }
 
-       if (!get_ldev_if_state(mdev, D_UP_TO_DATE)) {
+       if (!get_ldev_if_state(device, D_UP_TO_DATE)) {
                verb = 1;
                switch (pi->cmd) {
                case P_DATA_REQUEST:
-                       drbd_send_ack_rp(mdev, P_NEG_DREPLY, p);
+                       drbd_send_ack_rp(peer_device, P_NEG_DREPLY, p);
                        break;
                case P_RS_DATA_REQUEST:
                case P_CSUM_RS_REQUEST:
                case P_OV_REQUEST:
-                       drbd_send_ack_rp(mdev, P_NEG_RS_DREPLY , p);
+                       drbd_send_ack_rp(peer_device, P_NEG_RS_DREPLY , p);
                        break;
                case P_OV_REPLY:
                        verb = 0;
-                       dec_rs_pending(mdev);
-                       drbd_send_ack_ex(mdev, P_OV_RESULT, sector, size, ID_IN_SYNC);
+                       dec_rs_pending(device);
+                       drbd_send_ack_ex(peer_device, P_OV_RESULT, sector, size, ID_IN_SYNC);
                        break;
                default:
                        BUG();
                }
                if (verb && __ratelimit(&drbd_ratelimit_state))
-                       dev_err(DEV, "Can not satisfy peer's read request, "
+                       drbd_err(device, "Can not satisfy peer's read request, "
                            "no local data.\n");
 
                /* drain possibly payload */
-               return drbd_drain_block(mdev, pi->size);
+               return drbd_drain_block(peer_device, pi->size);
        }
 
        /* GFP_NOIO, because we must not cause arbitrary write-out: in a DRBD
         * "criss-cross" setup, that might cause write-out on some other DRBD,
         * which in turn might block on the other node at this very place.  */
-       peer_req = drbd_alloc_peer_req(mdev, p->block_id, sector, size, GFP_NOIO);
+       peer_req = drbd_alloc_peer_req(peer_device, p->block_id, sector, size, GFP_NOIO);
        if (!peer_req) {
-               put_ldev(mdev);
+               put_ldev(device);
                return -ENOMEM;
        }
 
@@ -2423,7 +2453,7 @@ static int receive_DataRequest(struct drbd_tconn *tconn, struct packet_info *pi)
                peer_req->w.cb = w_e_end_rsdata_req;
                fault_type = DRBD_FAULT_RS_RD;
                /* used in the sector offset progress display */
-               mdev->bm_resync_fo = BM_SECT_TO_BIT(sector);
+               device->bm_resync_fo = BM_SECT_TO_BIT(sector);
                break;
 
        case P_OV_REPLY:
@@ -2439,19 +2469,19 @@ static int receive_DataRequest(struct drbd_tconn *tconn, struct packet_info *pi)
                peer_req->digest = di;
                peer_req->flags |= EE_HAS_DIGEST;
 
-               if (drbd_recv_all(mdev->tconn, di->digest, pi->size))
+               if (drbd_recv_all(peer_device->connection, di->digest, pi->size))
                        goto out_free_e;
 
                if (pi->cmd == P_CSUM_RS_REQUEST) {
-                       D_ASSERT(mdev->tconn->agreed_pro_version >= 89);
+                       D_ASSERT(device, peer_device->connection->agreed_pro_version >= 89);
                        peer_req->w.cb = w_e_end_csum_rs_req;
                        /* used in the sector offset progress display */
-                       mdev->bm_resync_fo = BM_SECT_TO_BIT(sector);
+                       device->bm_resync_fo = BM_SECT_TO_BIT(sector);
                } else if (pi->cmd == P_OV_REPLY) {
                        /* track progress, we may need to throttle */
-                       atomic_add(size >> 9, &mdev->rs_sect_in);
+                       atomic_add(size >> 9, &device->rs_sect_in);
                        peer_req->w.cb = w_e_end_ov_reply;
-                       dec_rs_pending(mdev);
+                       dec_rs_pending(device);
                        /* drbd_rs_begin_io done when we sent this request,
                         * but accounting still needs to be done. */
                        goto submit_for_resync;
@@ -2459,19 +2489,19 @@ static int receive_DataRequest(struct drbd_tconn *tconn, struct packet_info *pi)
                break;
 
        case P_OV_REQUEST:
-               if (mdev->ov_start_sector == ~(sector_t)0 &&
-                   mdev->tconn->agreed_pro_version >= 90) {
+               if (device->ov_start_sector == ~(sector_t)0 &&
+                   peer_device->connection->agreed_pro_version >= 90) {
                        unsigned long now = jiffies;
                        int i;
-                       mdev->ov_start_sector = sector;
-                       mdev->ov_position = sector;
-                       mdev->ov_left = drbd_bm_bits(mdev) - BM_SECT_TO_BIT(sector);
-                       mdev->rs_total = mdev->ov_left;
+                       device->ov_start_sector = sector;
+                       device->ov_position = sector;
+                       device->ov_left = drbd_bm_bits(device) - BM_SECT_TO_BIT(sector);
+                       device->rs_total = device->ov_left;
                        for (i = 0; i < DRBD_SYNC_MARKS; i++) {
-                               mdev->rs_mark_left[i] = mdev->ov_left;
-                               mdev->rs_mark_time[i] = now;
+                               device->rs_mark_left[i] = device->ov_left;
+                               device->rs_mark_time[i] = now;
                        }
-                       dev_info(DEV, "Online Verify start sector: %llu\n",
+                       drbd_info(device, "Online Verify start sector: %llu\n",
                                        (unsigned long long)sector);
                }
                peer_req->w.cb = w_e_end_ov_req;
@@ -2504,57 +2534,61 @@ static int receive_DataRequest(struct drbd_tconn *tconn, struct packet_info *pi)
         * we would also throttle its application reads.
         * In that case, throttling is done on the SyncTarget only.
         */
-       if (mdev->state.peer != R_PRIMARY && drbd_rs_should_slow_down(mdev, sector))
+       if (device->state.peer != R_PRIMARY && drbd_rs_should_slow_down(device, sector))
                schedule_timeout_uninterruptible(HZ/10);
-       if (drbd_rs_begin_io(mdev, sector))
+       if (drbd_rs_begin_io(device, sector))
                goto out_free_e;
 
 submit_for_resync:
-       atomic_add(size >> 9, &mdev->rs_sect_ev);
+       atomic_add(size >> 9, &device->rs_sect_ev);
 
 submit:
-       inc_unacked(mdev);
-       spin_lock_irq(&mdev->tconn->req_lock);
-       list_add_tail(&peer_req->w.list, &mdev->read_ee);
-       spin_unlock_irq(&mdev->tconn->req_lock);
+       inc_unacked(device);
+       spin_lock_irq(&device->resource->req_lock);
+       list_add_tail(&peer_req->w.list, &device->read_ee);
+       spin_unlock_irq(&device->resource->req_lock);
 
-       if (drbd_submit_peer_request(mdev, peer_req, READ, fault_type) == 0)
+       if (drbd_submit_peer_request(device, peer_req, READ, fault_type) == 0)
                return 0;
 
        /* don't care for the reason here */
-       dev_err(DEV, "submit failed, triggering re-connect\n");
-       spin_lock_irq(&mdev->tconn->req_lock);
+       drbd_err(device, "submit failed, triggering re-connect\n");
+       spin_lock_irq(&device->resource->req_lock);
        list_del(&peer_req->w.list);
-       spin_unlock_irq(&mdev->tconn->req_lock);
+       spin_unlock_irq(&device->resource->req_lock);
        /* no drbd_rs_complete_io(), we are dropping the connection anyways */
 
 out_free_e:
-       put_ldev(mdev);
-       drbd_free_peer_req(mdev, peer_req);
+       put_ldev(device);
+       drbd_free_peer_req(device, peer_req);
        return -EIO;
 }
 
-static int drbd_asb_recover_0p(struct drbd_conf *mdev) __must_hold(local)
+/**
+ * drbd_asb_recover_0p  -  Recover after split-brain with no remaining primaries
+ */
+static int drbd_asb_recover_0p(struct drbd_peer_device *peer_device) __must_hold(local)
 {
+       struct drbd_device *device = peer_device->device;
        int self, peer, rv = -100;
        unsigned long ch_self, ch_peer;
        enum drbd_after_sb_p after_sb_0p;
 
-       self = mdev->ldev->md.uuid[UI_BITMAP] & 1;
-       peer = mdev->p_uuid[UI_BITMAP] & 1;
+       self = device->ldev->md.uuid[UI_BITMAP] & 1;
+       peer = device->p_uuid[UI_BITMAP] & 1;
 
-       ch_peer = mdev->p_uuid[UI_SIZE];
-       ch_self = mdev->comm_bm_set;
+       ch_peer = device->p_uuid[UI_SIZE];
+       ch_self = device->comm_bm_set;
 
        rcu_read_lock();
-       after_sb_0p = rcu_dereference(mdev->tconn->net_conf)->after_sb_0p;
+       after_sb_0p = rcu_dereference(peer_device->connection->net_conf)->after_sb_0p;
        rcu_read_unlock();
        switch (after_sb_0p) {
        case ASB_CONSENSUS:
        case ASB_DISCARD_SECONDARY:
        case ASB_CALL_HELPER:
        case ASB_VIOLENTLY:
-               dev_err(DEV, "Configuration error.\n");
+               drbd_err(device, "Configuration error.\n");
                break;
        case ASB_DISCONNECT:
                break;
@@ -2578,11 +2612,11 @@ static int drbd_asb_recover_0p(struct drbd_conf *mdev) __must_hold(local)
                        break;
                }
                /* Else fall through to one of the other strategies... */
-               dev_warn(DEV, "Discard younger/older primary did not find a decision\n"
+               drbd_warn(device, "Discard younger/older primary did not find a decision\n"
                     "Using discard-least-changes instead\n");
        case ASB_DISCARD_ZERO_CHG:
                if (ch_peer == 0 && ch_self == 0) {
-                       rv = test_bit(RESOLVE_CONFLICTS, &mdev->tconn->flags)
+                       rv = test_bit(RESOLVE_CONFLICTS, &peer_device->connection->flags)
                                ? -1 : 1;
                        break;
                } else {
@@ -2598,7 +2632,7 @@ static int drbd_asb_recover_0p(struct drbd_conf *mdev) __must_hold(local)
                        rv =  1;
                else /* ( ch_self == ch_peer ) */
                     /* Well, then use something else. */
-                       rv = test_bit(RESOLVE_CONFLICTS, &mdev->tconn->flags)
+                       rv = test_bit(RESOLVE_CONFLICTS, &peer_device->connection->flags)
                                ? -1 : 1;
                break;
        case ASB_DISCARD_LOCAL:
@@ -2611,13 +2645,17 @@ static int drbd_asb_recover_0p(struct drbd_conf *mdev) __must_hold(local)
        return rv;
 }
 
-static int drbd_asb_recover_1p(struct drbd_conf *mdev) __must_hold(local)
+/**
+ * drbd_asb_recover_1p  -  Recover after split-brain with one remaining primary
+ */
+static int drbd_asb_recover_1p(struct drbd_peer_device *peer_device) __must_hold(local)
 {
+       struct drbd_device *device = peer_device->device;
        int hg, rv = -100;
        enum drbd_after_sb_p after_sb_1p;
 
        rcu_read_lock();
-       after_sb_1p = rcu_dereference(mdev->tconn->net_conf)->after_sb_1p;
+       after_sb_1p = rcu_dereference(peer_device->connection->net_conf)->after_sb_1p;
        rcu_read_unlock();
        switch (after_sb_1p) {
        case ASB_DISCARD_YOUNGER_PRI:
@@ -2626,35 +2664,35 @@ static int drbd_asb_recover_1p(struct drbd_conf *mdev) __must_hold(local)
        case ASB_DISCARD_LOCAL:
        case ASB_DISCARD_REMOTE:
        case ASB_DISCARD_ZERO_CHG:
-               dev_err(DEV, "Configuration error.\n");
+               drbd_err(device, "Configuration error.\n");
                break;
        case ASB_DISCONNECT:
                break;
        case ASB_CONSENSUS:
-               hg = drbd_asb_recover_0p(mdev);
-               if (hg == -1 && mdev->state.role == R_SECONDARY)
+               hg = drbd_asb_recover_0p(peer_device);
+               if (hg == -1 && device->state.role == R_SECONDARY)
                        rv = hg;
-               if (hg == 1  && mdev->state.role == R_PRIMARY)
+               if (hg == 1  && device->state.role == R_PRIMARY)
                        rv = hg;
                break;
        case ASB_VIOLENTLY:
-               rv = drbd_asb_recover_0p(mdev);
+               rv = drbd_asb_recover_0p(peer_device);
                break;
        case ASB_DISCARD_SECONDARY:
-               return mdev->state.role == R_PRIMARY ? 1 : -1;
+               return device->state.role == R_PRIMARY ? 1 : -1;
        case ASB_CALL_HELPER:
-               hg = drbd_asb_recover_0p(mdev);
-               if (hg == -1 && mdev->state.role == R_PRIMARY) {
+               hg = drbd_asb_recover_0p(peer_device);
+               if (hg == -1 && device->state.role == R_PRIMARY) {
                        enum drbd_state_rv rv2;
 
                         /* drbd_change_state() does not sleep while in SS_IN_TRANSIENT_STATE,
                          * we might be here in C_WF_REPORT_PARAMS which is transient.
                          * we do not need to wait for the after state change work either. */
-                       rv2 = drbd_change_state(mdev, CS_VERBOSE, NS(role, R_SECONDARY));
+                       rv2 = drbd_change_state(device, CS_VERBOSE, NS(role, R_SECONDARY));
                        if (rv2 != SS_SUCCESS) {
-                               drbd_khelper(mdev, "pri-lost-after-sb");
+                               drbd_khelper(device, "pri-lost-after-sb");
                        } else {
-                               dev_warn(DEV, "Successfully gave up primary role.\n");
+                               drbd_warn(device, "Successfully gave up primary role.\n");
                                rv = hg;
                        }
                } else
@@ -2664,13 +2702,17 @@ static int drbd_asb_recover_1p(struct drbd_conf *mdev) __must_hold(local)
        return rv;
 }
 
-static int drbd_asb_recover_2p(struct drbd_conf *mdev) __must_hold(local)
+/**
+ * drbd_asb_recover_2p  -  Recover after split-brain with two remaining primaries
+ */
+static int drbd_asb_recover_2p(struct drbd_peer_device *peer_device) __must_hold(local)
 {
+       struct drbd_device *device = peer_device->device;
        int hg, rv = -100;
        enum drbd_after_sb_p after_sb_2p;
 
        rcu_read_lock();
-       after_sb_2p = rcu_dereference(mdev->tconn->net_conf)->after_sb_2p;
+       after_sb_2p = rcu_dereference(peer_device->connection->net_conf)->after_sb_2p;
        rcu_read_unlock();
        switch (after_sb_2p) {
        case ASB_DISCARD_YOUNGER_PRI:
@@ -2681,26 +2723,26 @@ static int drbd_asb_recover_2p(struct drbd_conf *mdev) __must_hold(local)
        case ASB_CONSENSUS:
        case ASB_DISCARD_SECONDARY:
        case ASB_DISCARD_ZERO_CHG:
-               dev_err(DEV, "Configuration error.\n");
+               drbd_err(device, "Configuration error.\n");
                break;
        case ASB_VIOLENTLY:
-               rv = drbd_asb_recover_0p(mdev);
+               rv = drbd_asb_recover_0p(peer_device);
                break;
        case ASB_DISCONNECT:
                break;
        case ASB_CALL_HELPER:
-               hg = drbd_asb_recover_0p(mdev);
+               hg = drbd_asb_recover_0p(peer_device);
                if (hg == -1) {
                        enum drbd_state_rv rv2;
 
                         /* drbd_change_state() does not sleep while in SS_IN_TRANSIENT_STATE,
                          * we might be here in C_WF_REPORT_PARAMS which is transient.
                          * we do not need to wait for the after state change work either. */
-                       rv2 = drbd_change_state(mdev, CS_VERBOSE, NS(role, R_SECONDARY));
+                       rv2 = drbd_change_state(device, CS_VERBOSE, NS(role, R_SECONDARY));
                        if (rv2 != SS_SUCCESS) {
-                               drbd_khelper(mdev, "pri-lost-after-sb");
+                               drbd_khelper(device, "pri-lost-after-sb");
                        } else {
-                               dev_warn(DEV, "Successfully gave up primary role.\n");
+                               drbd_warn(device, "Successfully gave up primary role.\n");
                                rv = hg;
                        }
                } else
@@ -2710,14 +2752,14 @@ static int drbd_asb_recover_2p(struct drbd_conf *mdev) __must_hold(local)
        return rv;
 }
 
-static void drbd_uuid_dump(struct drbd_conf *mdev, char *text, u64 *uuid,
+static void drbd_uuid_dump(struct drbd_device *device, char *text, u64 *uuid,
                           u64 bits, u64 flags)
 {
        if (!uuid) {
-               dev_info(DEV, "%s uuid info vanished while I was looking!\n", text);
+               drbd_info(device, "%s uuid info vanished while I was looking!\n", text);
                return;
        }
-       dev_info(DEV, "%s %016llX:%016llX:%016llX:%016llX bits:%llu flags:%llX\n",
+       drbd_info(device, "%s %016llX:%016llX:%016llX:%016llX bits:%llu flags:%llX\n",
             text,
             (unsigned long long)uuid[UI_CURRENT],
             (unsigned long long)uuid[UI_BITMAP],
@@ -2739,13 +2781,13 @@ static void drbd_uuid_dump(struct drbd_conf *mdev, char *text, u64 *uuid,
 -1091   requires proto 91
 -1096   requires proto 96
  */
-static int drbd_uuid_compare(struct drbd_conf *mdev, int *rule_nr) __must_hold(local)
+static int drbd_uuid_compare(struct drbd_device *device, int *rule_nr) __must_hold(local)
 {
        u64 self, peer;
        int i, j;
 
-       self = mdev->ldev->md.uuid[UI_CURRENT] & ~((u64)1);
-       peer = mdev->p_uuid[UI_CURRENT] & ~((u64)1);
+       self = device->ldev->md.uuid[UI_CURRENT] & ~((u64)1);
+       peer = device->p_uuid[UI_CURRENT] & ~((u64)1);
 
        *rule_nr = 10;
        if (self == UUID_JUST_CREATED && peer == UUID_JUST_CREATED)
@@ -2764,46 +2806,46 @@ static int drbd_uuid_compare(struct drbd_conf *mdev, int *rule_nr) __must_hold(l
        if (self == peer) {
                int rct, dc; /* roles at crash time */
 
-               if (mdev->p_uuid[UI_BITMAP] == (u64)0 && mdev->ldev->md.uuid[UI_BITMAP] != (u64)0) {
+               if (device->p_uuid[UI_BITMAP] == (u64)0 && device->ldev->md.uuid[UI_BITMAP] != (u64)0) {
 
-                       if (mdev->tconn->agreed_pro_version < 91)
+                       if (first_peer_device(device)->connection->agreed_pro_version < 91)
                                return -1091;
 
-                       if ((mdev->ldev->md.uuid[UI_BITMAP] & ~((u64)1)) == (mdev->p_uuid[UI_HISTORY_START] & ~((u64)1)) &&
-                           (mdev->ldev->md.uuid[UI_HISTORY_START] & ~((u64)1)) == (mdev->p_uuid[UI_HISTORY_START + 1] & ~((u64)1))) {
-                               dev_info(DEV, "was SyncSource, missed the resync finished event, corrected myself:\n");
-                               drbd_uuid_move_history(mdev);
-                               mdev->ldev->md.uuid[UI_HISTORY_START] = mdev->ldev->md.uuid[UI_BITMAP];
-                               mdev->ldev->md.uuid[UI_BITMAP] = 0;
+                       if ((device->ldev->md.uuid[UI_BITMAP] & ~((u64)1)) == (device->p_uuid[UI_HISTORY_START] & ~((u64)1)) &&
+                           (device->ldev->md.uuid[UI_HISTORY_START] & ~((u64)1)) == (device->p_uuid[UI_HISTORY_START + 1] & ~((u64)1))) {
+                               drbd_info(device, "was SyncSource, missed the resync finished event, corrected myself:\n");
+                               drbd_uuid_move_history(device);
+                               device->ldev->md.uuid[UI_HISTORY_START] = device->ldev->md.uuid[UI_BITMAP];
+                               device->ldev->md.uuid[UI_BITMAP] = 0;
 
-                               drbd_uuid_dump(mdev, "self", mdev->ldev->md.uuid,
-                                              mdev->state.disk >= D_NEGOTIATING ? drbd_bm_total_weight(mdev) : 0, 0);
+                               drbd_uuid_dump(device, "self", device->ldev->md.uuid,
+                                              device->state.disk >= D_NEGOTIATING ? drbd_bm_total_weight(device) : 0, 0);
                                *rule_nr = 34;
                        } else {
-                               dev_info(DEV, "was SyncSource (peer failed to write sync_uuid)\n");
+                               drbd_info(device, "was SyncSource (peer failed to write sync_uuid)\n");
                                *rule_nr = 36;
                        }
 
                        return 1;
                }
 
-               if (mdev->ldev->md.uuid[UI_BITMAP] == (u64)0 && mdev->p_uuid[UI_BITMAP] != (u64)0) {
+               if (device->ldev->md.uuid[UI_BITMAP] == (u64)0 && device->p_uuid[UI_BITMAP] != (u64)0) {
 
-                       if (mdev->tconn->agreed_pro_version < 91)
+                       if (first_peer_device(device)->connection->agreed_pro_version < 91)
                                return -1091;
 
-                       if ((mdev->ldev->md.uuid[UI_HISTORY_START] & ~((u64)1)) == (mdev->p_uuid[UI_BITMAP] & ~((u64)1)) &&
-                           (mdev->ldev->md.uuid[UI_HISTORY_START + 1] & ~((u64)1)) == (mdev->p_uuid[UI_HISTORY_START] & ~((u64)1))) {
-                               dev_info(DEV, "was SyncTarget, peer missed the resync finished event, corrected peer:\n");
+                       if ((device->ldev->md.uuid[UI_HISTORY_START] & ~((u64)1)) == (device->p_uuid[UI_BITMAP] & ~((u64)1)) &&
+                           (device->ldev->md.uuid[UI_HISTORY_START + 1] & ~((u64)1)) == (device->p_uuid[UI_HISTORY_START] & ~((u64)1))) {
+                               drbd_info(device, "was SyncTarget, peer missed the resync finished event, corrected peer:\n");
 
-                               mdev->p_uuid[UI_HISTORY_START + 1] = mdev->p_uuid[UI_HISTORY_START];
-                               mdev->p_uuid[UI_HISTORY_START] = mdev->p_uuid[UI_BITMAP];
-                               mdev->p_uuid[UI_BITMAP] = 0UL;
+                               device->p_uuid[UI_HISTORY_START + 1] = device->p_uuid[UI_HISTORY_START];
+                               device->p_uuid[UI_HISTORY_START] = device->p_uuid[UI_BITMAP];
+                               device->p_uuid[UI_BITMAP] = 0UL;
 
-                               drbd_uuid_dump(mdev, "peer", mdev->p_uuid, mdev->p_uuid[UI_SIZE], mdev->p_uuid[UI_FLAGS]);
+                               drbd_uuid_dump(device, "peer", device->p_uuid, device->p_uuid[UI_SIZE], device->p_uuid[UI_FLAGS]);
                                *rule_nr = 35;
                        } else {
-                               dev_info(DEV, "was SyncTarget (failed to write sync_uuid)\n");
+                               drbd_info(device, "was SyncTarget (failed to write sync_uuid)\n");
                                *rule_nr = 37;
                        }
 
@@ -2811,8 +2853,8 @@ static int drbd_uuid_compare(struct drbd_conf *mdev, int *rule_nr) __must_hold(l
                }
 
                /* Common power [off|failure] */
-               rct = (test_bit(CRASHED_PRIMARY, &mdev->flags) ? 1 : 0) +
-                       (mdev->p_uuid[UI_FLAGS] & 2);
+               rct = (test_bit(CRASHED_PRIMARY, &device->flags) ? 1 : 0) +
+                       (device->p_uuid[UI_FLAGS] & 2);
                /* lowest bit is set when we were primary,
                 * next bit (weight 2) is set when peer was primary */
                *rule_nr = 40;
@@ -2822,72 +2864,72 @@ static int drbd_uuid_compare(struct drbd_conf *mdev, int *rule_nr) __must_hold(l
                case 1: /*  self_pri && !peer_pri */ return 1;
                case 2: /* !self_pri &&  peer_pri */ return -1;
                case 3: /*  self_pri &&  peer_pri */
-                       dc = test_bit(RESOLVE_CONFLICTS, &mdev->tconn->flags);
+                       dc = test_bit(RESOLVE_CONFLICTS, &first_peer_device(device)->connection->flags);
                        return dc ? -1 : 1;
                }
        }
 
        *rule_nr = 50;
-       peer = mdev->p_uuid[UI_BITMAP] & ~((u64)1);
+       peer = device->p_uuid[UI_BITMAP] & ~((u64)1);
        if (self == peer)
                return -1;
 
        *rule_nr = 51;
-       peer = mdev->p_uuid[UI_HISTORY_START] & ~((u64)1);
+       peer = device->p_uuid[UI_HISTORY_START] & ~((u64)1);
        if (self == peer) {
-               if (mdev->tconn->agreed_pro_version < 96 ?
-                   (mdev->ldev->md.uuid[UI_HISTORY_START] & ~((u64)1)) ==
-                   (mdev->p_uuid[UI_HISTORY_START + 1] & ~((u64)1)) :
-                   peer + UUID_NEW_BM_OFFSET == (mdev->p_uuid[UI_BITMAP] & ~((u64)1))) {
+               if (first_peer_device(device)->connection->agreed_pro_version < 96 ?
+                   (device->ldev->md.uuid[UI_HISTORY_START] & ~((u64)1)) ==
+                   (device->p_uuid[UI_HISTORY_START + 1] & ~((u64)1)) :
+                   peer + UUID_NEW_BM_OFFSET == (device->p_uuid[UI_BITMAP] & ~((u64)1))) {
                        /* The last P_SYNC_UUID did not get though. Undo the last start of
                           resync as sync source modifications of the peer's UUIDs. */
 
-                       if (mdev->tconn->agreed_pro_version < 91)
+                       if (first_peer_device(device)->connection->agreed_pro_version < 91)
                                return -1091;
 
-                       mdev->p_uuid[UI_BITMAP] = mdev->p_uuid[UI_HISTORY_START];
-                       mdev->p_uuid[UI_HISTORY_START] = mdev->p_uuid[UI_HISTORY_START + 1];
+                       device->p_uuid[UI_BITMAP] = device->p_uuid[UI_HISTORY_START];
+                       device->p_uuid[UI_HISTORY_START] = device->p_uuid[UI_HISTORY_START + 1];
 
-                       dev_info(DEV, "Lost last syncUUID packet, corrected:\n");
-                       drbd_uuid_dump(mdev, "peer", mdev->p_uuid, mdev->p_uuid[UI_SIZE], mdev->p_uuid[UI_FLAGS]);
+                       drbd_info(device, "Lost last syncUUID packet, corrected:\n");
+                       drbd_uuid_dump(device, "peer", device->p_uuid, device->p_uuid[UI_SIZE], device->p_uuid[UI_FLAGS]);
 
                        return -1;
                }
        }
 
        *rule_nr = 60;
-       self = mdev->ldev->md.uuid[UI_CURRENT] & ~((u64)1);
+       self = device->ldev->md.uuid[UI_CURRENT] & ~((u64)1);
        for (i = UI_HISTORY_START; i <= UI_HISTORY_END; i++) {
-               peer = mdev->p_uuid[i] & ~((u64)1);
+               peer = device->p_uuid[i] & ~((u64)1);
                if (self == peer)
                        return -2;
        }
 
        *rule_nr = 70;
-       self = mdev->ldev->md.uuid[UI_BITMAP] & ~((u64)1);
-       peer = mdev->p_uuid[UI_CURRENT] & ~((u64)1);
+       self = device->ldev->md.uuid[UI_BITMAP] & ~((u64)1);
+       peer = device->p_uuid[UI_CURRENT] & ~((u64)1);
        if (self == peer)
                return 1;
 
        *rule_nr = 71;
-       self = mdev->ldev->md.uuid[UI_HISTORY_START] & ~((u64)1);
+       self = device->ldev->md.uuid[UI_HISTORY_START] & ~((u64)1);
        if (self == peer) {
-               if (mdev->tconn->agreed_pro_version < 96 ?
-                   (mdev->ldev->md.uuid[UI_HISTORY_START + 1] & ~((u64)1)) ==
-                   (mdev->p_uuid[UI_HISTORY_START] & ~((u64)1)) :
-                   self + UUID_NEW_BM_OFFSET == (mdev->ldev->md.uuid[UI_BITMAP] & ~((u64)1))) {
+               if (first_peer_device(device)->connection->agreed_pro_version < 96 ?
+                   (device->ldev->md.uuid[UI_HISTORY_START + 1] & ~((u64)1)) ==
+                   (device->p_uuid[UI_HISTORY_START] & ~((u64)1)) :
+                   self + UUID_NEW_BM_OFFSET == (device->ldev->md.uuid[UI_BITMAP] & ~((u64)1))) {
                        /* The last P_SYNC_UUID did not get though. Undo the last start of
                           resync as sync source modifications of our UUIDs. */
 
-                       if (mdev->tconn->agreed_pro_version < 91)
+                       if (first_peer_device(device)->connection->agreed_pro_version < 91)
                                return -1091;
 
-                       __drbd_uuid_set(mdev, UI_BITMAP, mdev->ldev->md.uuid[UI_HISTORY_START]);
-                       __drbd_uuid_set(mdev, UI_HISTORY_START, mdev->ldev->md.uuid[UI_HISTORY_START + 1]);
+                       __drbd_uuid_set(device, UI_BITMAP, device->ldev->md.uuid[UI_HISTORY_START]);
+                       __drbd_uuid_set(device, UI_HISTORY_START, device->ldev->md.uuid[UI_HISTORY_START + 1]);
 
-                       dev_info(DEV, "Last syncUUID did not get through, corrected:\n");
-                       drbd_uuid_dump(mdev, "self", mdev->ldev->md.uuid,
-                                      mdev->state.disk >= D_NEGOTIATING ? drbd_bm_total_weight(mdev) : 0, 0);
+                       drbd_info(device, "Last syncUUID did not get through, corrected:\n");
+                       drbd_uuid_dump(device, "self", device->ldev->md.uuid,
+                                      device->state.disk >= D_NEGOTIATING ? drbd_bm_total_weight(device) : 0, 0);
 
                        return 1;
                }
@@ -2895,24 +2937,24 @@ static int drbd_uuid_compare(struct drbd_conf *mdev, int *rule_nr) __must_hold(l
 
 
        *rule_nr = 80;
-       peer = mdev->p_uuid[UI_CURRENT] & ~((u64)1);
+       peer = device->p_uuid[UI_CURRENT] & ~((u64)1);
        for (i = UI_HISTORY_START; i <= UI_HISTORY_END; i++) {
-               self = mdev->ldev->md.uuid[i] & ~((u64)1);
+               self = device->ldev->md.uuid[i] & ~((u64)1);
                if (self == peer)
                        return 2;
        }
 
        *rule_nr = 90;
-       self = mdev->ldev->md.uuid[UI_BITMAP] & ~((u64)1);
-       peer = mdev->p_uuid[UI_BITMAP] & ~((u64)1);
+       self = device->ldev->md.uuid[UI_BITMAP] & ~((u64)1);
+       peer = device->p_uuid[UI_BITMAP] & ~((u64)1);
        if (self == peer && self != ((u64)0))
                return 100;
 
        *rule_nr = 100;
        for (i = UI_HISTORY_START; i <= UI_HISTORY_END; i++) {
-               self = mdev->ldev->md.uuid[i] & ~((u64)1);
+               self = device->ldev->md.uuid[i] & ~((u64)1);
                for (j = UI_HISTORY_START; j <= UI_HISTORY_END; j++) {
-                       peer = mdev->p_uuid[j] & ~((u64)1);
+                       peer = device->p_uuid[j] & ~((u64)1);
                        if (self == peer)
                                return -100;
                }
@@ -2924,36 +2966,38 @@ static int drbd_uuid_compare(struct drbd_conf *mdev, int *rule_nr) __must_hold(l
 /* drbd_sync_handshake() returns the new conn state on success, or
    CONN_MASK (-1) on failure.
  */
-static enum drbd_conns drbd_sync_handshake(struct drbd_conf *mdev, enum drbd_role peer_role,
+static enum drbd_conns drbd_sync_handshake(struct drbd_peer_device *peer_device,
+                                          enum drbd_role peer_role,
                                           enum drbd_disk_state peer_disk) __must_hold(local)
 {
+       struct drbd_device *device = peer_device->device;
        enum drbd_conns rv = C_MASK;
        enum drbd_disk_state mydisk;
        struct net_conf *nc;
        int hg, rule_nr, rr_conflict, tentative;
 
-       mydisk = mdev->state.disk;
+       mydisk = device->state.disk;
        if (mydisk == D_NEGOTIATING)
-               mydisk = mdev->new_state_tmp.disk;
+               mydisk = device->new_state_tmp.disk;
 
-       dev_info(DEV, "drbd_sync_handshake:\n");
+       drbd_info(device, "drbd_sync_handshake:\n");
 
-       spin_lock_irq(&mdev->ldev->md.uuid_lock);
-       drbd_uuid_dump(mdev, "self", mdev->ldev->md.uuid, mdev->comm_bm_set, 0);
-       drbd_uuid_dump(mdev, "peer", mdev->p_uuid,
-                      mdev->p_uuid[UI_SIZE], mdev->p_uuid[UI_FLAGS]);
+       spin_lock_irq(&device->ldev->md.uuid_lock);
+       drbd_uuid_dump(device, "self", device->ldev->md.uuid, device->comm_bm_set, 0);
+       drbd_uuid_dump(device, "peer", device->p_uuid,
+                      device->p_uuid[UI_SIZE], device->p_uuid[UI_FLAGS]);
 
-       hg = drbd_uuid_compare(mdev, &rule_nr);
-       spin_unlock_irq(&mdev->ldev->md.uuid_lock);
+       hg = drbd_uuid_compare(device, &rule_nr);
+       spin_unlock_irq(&device->ldev->md.uuid_lock);
 
-       dev_info(DEV, "uuid_compare()=%d by rule %d\n", hg, rule_nr);
+       drbd_info(device, "uuid_compare()=%d by rule %d\n", hg, rule_nr);
 
        if (hg == -1000) {
-               dev_alert(DEV, "Unrelated data, aborting!\n");
+               drbd_alert(device, "Unrelated data, aborting!\n");
                return C_MASK;
        }
        if (hg < -1000) {
-               dev_alert(DEV, "To resolve this both sides have to support at least protocol %d\n", -hg - 1000);
+               drbd_alert(device, "To resolve this both sides have to support at least protocol %d\n", -hg - 1000);
                return C_MASK;
        }
 
@@ -2963,38 +3007,38 @@ static enum drbd_conns drbd_sync_handshake(struct drbd_conf *mdev, enum drbd_rol
                hg = mydisk > D_INCONSISTENT ? 1 : -1;
                if (f)
                        hg = hg*2;
-               dev_info(DEV, "Becoming sync %s due to disk states.\n",
+               drbd_info(device, "Becoming sync %s due to disk states.\n",
                     hg > 0 ? "source" : "target");
        }
 
        if (abs(hg) == 100)
-               drbd_khelper(mdev, "initial-split-brain");
+               drbd_khelper(device, "initial-split-brain");
 
        rcu_read_lock();
-       nc = rcu_dereference(mdev->tconn->net_conf);
+       nc = rcu_dereference(peer_device->connection->net_conf);
 
        if (hg == 100 || (hg == -100 && nc->always_asbp)) {
-               int pcount = (mdev->state.role == R_PRIMARY)
+               int pcount = (device->state.role == R_PRIMARY)
                           + (peer_role == R_PRIMARY);
                int forced = (hg == -100);
 
                switch (pcount) {
                case 0:
-                       hg = drbd_asb_recover_0p(mdev);
+                       hg = drbd_asb_recover_0p(peer_device);
                        break;
                case 1:
-                       hg = drbd_asb_recover_1p(mdev);
+                       hg = drbd_asb_recover_1p(peer_device);
                        break;
                case 2:
-                       hg = drbd_asb_recover_2p(mdev);
+                       hg = drbd_asb_recover_2p(peer_device);
                        break;
                }
                if (abs(hg) < 100) {
-                       dev_warn(DEV, "Split-Brain detected, %d primaries, "
+                       drbd_warn(device, "Split-Brain detected, %d primaries, "
                             "automatically solved. Sync from %s node\n",
                             pcount, (hg < 0) ? "peer" : "this");
                        if (forced) {
-                               dev_warn(DEV, "Doing a full sync, since"
+                               drbd_warn(device, "Doing a full sync, since"
                                     " UUIDs where ambiguous.\n");
                                hg = hg*2;
                        }
@@ -3002,13 +3046,13 @@ static enum drbd_conns drbd_sync_handshake(struct drbd_conf *mdev, enum drbd_rol
        }
 
        if (hg == -100) {
-               if (test_bit(DISCARD_MY_DATA, &mdev->flags) && !(mdev->p_uuid[UI_FLAGS]&1))
+               if (test_bit(DISCARD_MY_DATA, &device->flags) && !(device->p_uuid[UI_FLAGS]&1))
                        hg = -1;
-               if (!test_bit(DISCARD_MY_DATA, &mdev->flags) && (mdev->p_uuid[UI_FLAGS]&1))
+               if (!test_bit(DISCARD_MY_DATA, &device->flags) && (device->p_uuid[UI_FLAGS]&1))
                        hg = 1;
 
                if (abs(hg) < 100)
-                       dev_warn(DEV, "Split-Brain detected, manually solved. "
+                       drbd_warn(device, "Split-Brain detected, manually solved. "
                             "Sync from %s node\n",
                             (hg < 0) ? "peer" : "this");
        }
@@ -3021,44 +3065,44 @@ static enum drbd_conns drbd_sync_handshake(struct drbd_conf *mdev, enum drbd_rol
                 * after an attempted attach on a diskless node.
                 * We just refuse to attach -- well, we drop the "connection"
                 * to that disk, in a way... */
-               dev_alert(DEV, "Split-Brain detected but unresolved, dropping connection!\n");
-               drbd_khelper(mdev, "split-brain");
+               drbd_alert(device, "Split-Brain detected but unresolved, dropping connection!\n");
+               drbd_khelper(device, "split-brain");
                return C_MASK;
        }
 
        if (hg > 0 && mydisk <= D_INCONSISTENT) {
-               dev_err(DEV, "I shall become SyncSource, but I am inconsistent!\n");
+               drbd_err(device, "I shall become SyncSource, but I am inconsistent!\n");
                return C_MASK;
        }
 
        if (hg < 0 && /* by intention we do not use mydisk here. */
-           mdev->state.role == R_PRIMARY && mdev->state.disk >= D_CONSISTENT) {
+           device->state.role == R_PRIMARY && device->state.disk >= D_CONSISTENT) {
                switch (rr_conflict) {
                case ASB_CALL_HELPER:
-                       drbd_khelper(mdev, "pri-lost");
+                       drbd_khelper(device, "pri-lost");
                        /* fall through */
                case ASB_DISCONNECT:
-                       dev_err(DEV, "I shall become SyncTarget, but I am primary!\n");
+                       drbd_err(device, "I shall become SyncTarget, but I am primary!\n");
                        return C_MASK;
                case ASB_VIOLENTLY:
-                       dev_warn(DEV, "Becoming SyncTarget, violating the stable-data"
+                       drbd_warn(device, "Becoming SyncTarget, violating the stable-data"
                             "assumption\n");
                }
        }
 
-       if (tentative || test_bit(CONN_DRY_RUN, &mdev->tconn->flags)) {
+       if (tentative || test_bit(CONN_DRY_RUN, &peer_device->connection->flags)) {
                if (hg == 0)
-                       dev_info(DEV, "dry-run connect: No resync, would become Connected immediately.\n");
+                       drbd_info(device, "dry-run connect: No resync, would become Connected immediately.\n");
                else
-                       dev_info(DEV, "dry-run connect: Would become %s, doing a %s resync.",
+                       drbd_info(device, "dry-run connect: Would become %s, doing a %s resync.",
                                 drbd_conn_str(hg > 0 ? C_SYNC_SOURCE : C_SYNC_TARGET),
                                 abs(hg) >= 2 ? "full" : "bit-map based");
                return C_MASK;
        }
 
        if (abs(hg) >= 2) {
-               dev_info(DEV, "Writing the whole bitmap, full sync required after drbd_sync_handshake.\n");
-               if (drbd_bitmap_io(mdev, &drbd_bmio_set_n_write, "set_n_write from sync_handshake",
+               drbd_info(device, "Writing the whole bitmap, full sync required after drbd_sync_handshake.\n");
+               if (drbd_bitmap_io(device, &drbd_bmio_set_n_write, "set_n_write from sync_handshake",
                                        BM_LOCKED_SET_ALLOWED))
                        return C_MASK;
        }
@@ -3069,9 +3113,9 @@ static enum drbd_conns drbd_sync_handshake(struct drbd_conf *mdev, enum drbd_rol
                rv = C_WF_BITMAP_T;
        } else {
                rv = C_CONNECTED;
-               if (drbd_bm_total_weight(mdev)) {
-                       dev_info(DEV, "No resync, but %lu bits in bitmap!\n",
-                            drbd_bm_total_weight(mdev));
+               if (drbd_bm_total_weight(device)) {
+                       drbd_info(device, "No resync, but %lu bits in bitmap!\n",
+                            drbd_bm_total_weight(device));
                }
        }
 
@@ -3092,7 +3136,7 @@ static enum drbd_after_sb_p convert_after_sb(enum drbd_after_sb_p peer)
        return peer;
 }
 
-static int receive_protocol(struct drbd_tconn *tconn, struct packet_info *pi)
+static int receive_protocol(struct drbd_connection *connection, struct packet_info *pi)
 {
        struct p_protocol *p = pi->data;
        enum drbd_after_sb_p p_after_sb_0p, p_after_sb_1p, p_after_sb_2p;
@@ -3110,58 +3154,58 @@ static int receive_protocol(struct drbd_tconn *tconn, struct packet_info *pi)
        cf              = be32_to_cpu(p->conn_flags);
        p_discard_my_data = cf & CF_DISCARD_MY_DATA;
 
-       if (tconn->agreed_pro_version >= 87) {
+       if (connection->agreed_pro_version >= 87) {
                int err;
 
                if (pi->size > sizeof(integrity_alg))
                        return -EIO;
-               err = drbd_recv_all(tconn, integrity_alg, pi->size);
+               err = drbd_recv_all(connection, integrity_alg, pi->size);
                if (err)
                        return err;
                integrity_alg[SHARED_SECRET_MAX - 1] = 0;
        }
 
        if (pi->cmd != P_PROTOCOL_UPDATE) {
-               clear_bit(CONN_DRY_RUN, &tconn->flags);
+               clear_bit(CONN_DRY_RUN, &connection->flags);
 
                if (cf & CF_DRY_RUN)
-                       set_bit(CONN_DRY_RUN, &tconn->flags);
+                       set_bit(CONN_DRY_RUN, &connection->flags);
 
                rcu_read_lock();
-               nc = rcu_dereference(tconn->net_conf);
+               nc = rcu_dereference(connection->net_conf);
 
                if (p_proto != nc->wire_protocol) {
-                       conn_err(tconn, "incompatible %s settings\n", "protocol");
+                       drbd_err(connection, "incompatible %s settings\n", "protocol");
                        goto disconnect_rcu_unlock;
                }
 
                if (convert_after_sb(p_after_sb_0p) != nc->after_sb_0p) {
-                       conn_err(tconn, "incompatible %s settings\n", "after-sb-0pri");
+                       drbd_err(connection, "incompatible %s settings\n", "after-sb-0pri");
                        goto disconnect_rcu_unlock;
                }
 
                if (convert_after_sb(p_after_sb_1p) != nc->after_sb_1p) {
-                       conn_err(tconn, "incompatible %s settings\n", "after-sb-1pri");
+                       drbd_err(connection, "incompatible %s settings\n", "after-sb-1pri");
                        goto disconnect_rcu_unlock;
                }
 
                if (convert_after_sb(p_after_sb_2p) != nc->after_sb_2p) {
-                       conn_err(tconn, "incompatible %s settings\n", "after-sb-2pri");
+                       drbd_err(connection, "incompatible %s settings\n", "after-sb-2pri");
                        goto disconnect_rcu_unlock;
                }
 
                if (p_discard_my_data && nc->discard_my_data) {
-                       conn_err(tconn, "incompatible %s settings\n", "discard-my-data");
+                       drbd_err(connection, "incompatible %s settings\n", "discard-my-data");
                        goto disconnect_rcu_unlock;
                }
 
                if (p_two_primaries != nc->two_primaries) {
-                       conn_err(tconn, "incompatible %s settings\n", "allow-two-primaries");
+                       drbd_err(connection, "incompatible %s settings\n", "allow-two-primaries");
                        goto disconnect_rcu_unlock;
                }
 
                if (strcmp(integrity_alg, nc->integrity_alg)) {
-                       conn_err(tconn, "incompatible %s settings\n", "data-integrity-alg");
+                       drbd_err(connection, "incompatible %s settings\n", "data-integrity-alg");
                        goto disconnect_rcu_unlock;
                }
 
@@ -3182,7 +3226,7 @@ static int receive_protocol(struct drbd_tconn *tconn, struct packet_info *pi)
 
                peer_integrity_tfm = crypto_alloc_hash(integrity_alg, 0, CRYPTO_ALG_ASYNC);
                if (!peer_integrity_tfm) {
-                       conn_err(tconn, "peer data-integrity-alg %s not supported\n",
+                       drbd_err(connection, "peer data-integrity-alg %s not supported\n",
                                 integrity_alg);
                        goto disconnect;
                }
@@ -3191,20 +3235,20 @@ static int receive_protocol(struct drbd_tconn *tconn, struct packet_info *pi)
                int_dig_in = kmalloc(hash_size, GFP_KERNEL);
                int_dig_vv = kmalloc(hash_size, GFP_KERNEL);
                if (!(int_dig_in && int_dig_vv)) {
-                       conn_err(tconn, "Allocation of buffers for data integrity checking failed\n");
+                       drbd_err(connection, "Allocation of buffers for data integrity checking failed\n");
                        goto disconnect;
                }
        }
 
        new_net_conf = kmalloc(sizeof(struct net_conf), GFP_KERNEL);
        if (!new_net_conf) {
-               conn_err(tconn, "Allocation of new net_conf failed\n");
+               drbd_err(connection, "Allocation of new net_conf failed\n");
                goto disconnect;
        }
 
-       mutex_lock(&tconn->data.mutex);
-       mutex_lock(&tconn->conf_update);
-       old_net_conf = tconn->net_conf;
+       mutex_lock(&connection->data.mutex);
+       mutex_lock(&connection->resource->conf_update);
+       old_net_conf = connection->net_conf;
        *new_net_conf = *old_net_conf;
 
        new_net_conf->wire_protocol = p_proto;
@@ -3213,19 +3257,19 @@ static int receive_protocol(struct drbd_tconn *tconn, struct packet_info *pi)
        new_net_conf->after_sb_2p = convert_after_sb(p_after_sb_2p);
        new_net_conf->two_primaries = p_two_primaries;
 
-       rcu_assign_pointer(tconn->net_conf, new_net_conf);
-       mutex_unlock(&tconn->conf_update);
-       mutex_unlock(&tconn->data.mutex);
+       rcu_assign_pointer(connection->net_conf, new_net_conf);
+       mutex_unlock(&connection->resource->conf_update);
+       mutex_unlock(&connection->data.mutex);
 
-       crypto_free_hash(tconn->peer_integrity_tfm);
-       kfree(tconn->int_dig_in);
-       kfree(tconn->int_dig_vv);
-       tconn->peer_integrity_tfm = peer_integrity_tfm;
-       tconn->int_dig_in = int_dig_in;
-       tconn->int_dig_vv = int_dig_vv;
+       crypto_free_hash(connection->peer_integrity_tfm);
+       kfree(connection->int_dig_in);
+       kfree(connection->int_dig_vv);
+       connection->peer_integrity_tfm = peer_integrity_tfm;
+       connection->int_dig_in = int_dig_in;
+       connection->int_dig_vv = int_dig_vv;
 
        if (strcmp(old_net_conf->integrity_alg, integrity_alg))
-               conn_info(tconn, "peer data-integrity-alg: %s\n",
+               drbd_info(connection, "peer data-integrity-alg: %s\n",
                          integrity_alg[0] ? integrity_alg : "(none)");
 
        synchronize_rcu();
@@ -3238,7 +3282,7 @@ disconnect:
        crypto_free_hash(peer_integrity_tfm);
        kfree(int_dig_in);
        kfree(int_dig_vv);
-       conn_request_state(tconn, NS(conn, C_DISCONNECTING), CS_HARD);
+       conn_request_state(connection, NS(conn, C_DISCONNECTING), CS_HARD);
        return -EIO;
 }
 
@@ -3247,7 +3291,8 @@ disconnect:
  * return: NULL (alg name was "")
  *         ERR_PTR(error) if something goes wrong
  *         or the crypto hash ptr, if it worked out ok. */
-struct crypto_hash *drbd_crypto_alloc_digest_safe(const struct drbd_conf *mdev,
+static
+struct crypto_hash *drbd_crypto_alloc_digest_safe(const struct drbd_device *device,
                const char *alg, const char *name)
 {
        struct crypto_hash *tfm;
@@ -3257,21 +3302,21 @@ struct crypto_hash *drbd_crypto_alloc_digest_safe(const struct drbd_conf *mdev,
 
        tfm = crypto_alloc_hash(alg, 0, CRYPTO_ALG_ASYNC);
        if (IS_ERR(tfm)) {
-               dev_err(DEV, "Can not allocate \"%s\" as %s (reason: %ld)\n",
+               drbd_err(device, "Can not allocate \"%s\" as %s (reason: %ld)\n",
                        alg, name, PTR_ERR(tfm));
                return tfm;
        }
        return tfm;
 }
 
-static int ignore_remaining_packet(struct drbd_tconn *tconn, struct packet_info *pi)
+static int ignore_remaining_packet(struct drbd_connection *connection, struct packet_info *pi)
 {
-       void *buffer = tconn->data.rbuf;
+       void *buffer = connection->data.rbuf;
        int size = pi->size;
 
        while (size) {
                int s = min_t(int, size, DRBD_SOCKET_BUFFER_SIZE);
-               s = drbd_recv(tconn, buffer, s);
+               s = drbd_recv(connection, buffer, s);
                if (s <= 0) {
                        if (s < 0)
                                return s;
@@ -3295,30 +3340,32 @@ static int ignore_remaining_packet(struct drbd_tconn *tconn, struct packet_info
  *
  * (We can also end up here if drbd is misconfigured.)
  */
-static int config_unknown_volume(struct drbd_tconn *tconn, struct packet_info *pi)
+static int config_unknown_volume(struct drbd_connection *connection, struct packet_info *pi)
 {
-       conn_warn(tconn, "%s packet received for volume %u, which is not configured locally\n",
+       drbd_warn(connection, "%s packet received for volume %u, which is not configured locally\n",
                  cmdname(pi->cmd), pi->vnr);
-       return ignore_remaining_packet(tconn, pi);
+       return ignore_remaining_packet(connection, pi);
 }
 
-static int receive_SyncParam(struct drbd_tconn *tconn, struct packet_info *pi)
+static int receive_SyncParam(struct drbd_connection *connection, struct packet_info *pi)
 {
-       struct drbd_conf *mdev;
+       struct drbd_peer_device *peer_device;
+       struct drbd_device *device;
        struct p_rs_param_95 *p;
        unsigned int header_size, data_size, exp_max_sz;
        struct crypto_hash *verify_tfm = NULL;
        struct crypto_hash *csums_tfm = NULL;
        struct net_conf *old_net_conf, *new_net_conf = NULL;
        struct disk_conf *old_disk_conf = NULL, *new_disk_conf = NULL;
-       const int apv = tconn->agreed_pro_version;
+       const int apv = connection->agreed_pro_version;
        struct fifo_buffer *old_plan = NULL, *new_plan = NULL;
        int fifo_size = 0;
        int err;
 
-       mdev = vnr_to_mdev(tconn, pi->vnr);
-       if (!mdev)
-               return config_unknown_volume(tconn, pi);
+       peer_device = conn_peer_device(connection, pi->vnr);
+       if (!peer_device)
+               return config_unknown_volume(connection, pi);
+       device = peer_device->device;
 
        exp_max_sz  = apv <= 87 ? sizeof(struct p_rs_param)
                    : apv == 88 ? sizeof(struct p_rs_param)
@@ -3327,7 +3374,7 @@ static int receive_SyncParam(struct drbd_tconn *tconn, struct packet_info *pi)
                    : /* apv >= 95 */ sizeof(struct p_rs_param_95);
 
        if (pi->size > exp_max_sz) {
-               dev_err(DEV, "SyncParam packet too long: received %u, expected <= %u bytes\n",
+               drbd_err(device, "SyncParam packet too long: received %u, expected <= %u bytes\n",
                    pi->size, exp_max_sz);
                return -EIO;
        }
@@ -3338,33 +3385,33 @@ static int receive_SyncParam(struct drbd_tconn *tconn, struct packet_info *pi)
        } else if (apv <= 94) {
                header_size = sizeof(struct p_rs_param_89);
                data_size = pi->size - header_size;
-               D_ASSERT(data_size == 0);
+               D_ASSERT(device, data_size == 0);
        } else {
                header_size = sizeof(struct p_rs_param_95);
                data_size = pi->size - header_size;
-               D_ASSERT(data_size == 0);
+               D_ASSERT(device, data_size == 0);
        }
 
        /* initialize verify_alg and csums_alg */
        p = pi->data;
        memset(p->verify_alg, 0, 2 * SHARED_SECRET_MAX);
 
-       err = drbd_recv_all(mdev->tconn, p, header_size);
+       err = drbd_recv_all(peer_device->connection, p, header_size);
        if (err)
                return err;
 
-       mutex_lock(&mdev->tconn->conf_update);
-       old_net_conf = mdev->tconn->net_conf;
-       if (get_ldev(mdev)) {
+       mutex_lock(&connection->resource->conf_update);
+       old_net_conf = peer_device->connection->net_conf;
+       if (get_ldev(device)) {
                new_disk_conf = kzalloc(sizeof(struct disk_conf), GFP_KERNEL);
                if (!new_disk_conf) {
-                       put_ldev(mdev);
-                       mutex_unlock(&mdev->tconn->conf_update);
-                       dev_err(DEV, "Allocation of new disk_conf failed\n");
+                       put_ldev(device);
+                       mutex_unlock(&connection->resource->conf_update);
+                       drbd_err(device, "Allocation of new disk_conf failed\n");
                        return -ENOMEM;
                }
 
-               old_disk_conf = mdev->ldev->disk_conf;
+               old_disk_conf = device->ldev->disk_conf;
                *new_disk_conf = *old_disk_conf;
 
                new_disk_conf->resync_rate = be32_to_cpu(p->resync_rate);
@@ -3373,37 +3420,37 @@ static int receive_SyncParam(struct drbd_tconn *tconn, struct packet_info *pi)
        if (apv >= 88) {
                if (apv == 88) {
                        if (data_size > SHARED_SECRET_MAX || data_size == 0) {
-                               dev_err(DEV, "verify-alg of wrong size, "
+                               drbd_err(device, "verify-alg of wrong size, "
                                        "peer wants %u, accepting only up to %u byte\n",
                                        data_size, SHARED_SECRET_MAX);
                                err = -EIO;
                                goto reconnect;
                        }
 
-                       err = drbd_recv_all(mdev->tconn, p->verify_alg, data_size);
+                       err = drbd_recv_all(peer_device->connection, p->verify_alg, data_size);
                        if (err)
                                goto reconnect;
                        /* we expect NUL terminated string */
                        /* but just in case someone tries to be evil */
-                       D_ASSERT(p->verify_alg[data_size-1] == 0);
+                       D_ASSERT(device, p->verify_alg[data_size-1] == 0);
                        p->verify_alg[data_size-1] = 0;
 
                } else /* apv >= 89 */ {
                        /* we still expect NUL terminated strings */
                        /* but just in case someone tries to be evil */
-                       D_ASSERT(p->verify_alg[SHARED_SECRET_MAX-1] == 0);
-                       D_ASSERT(p->csums_alg[SHARED_SECRET_MAX-1] == 0);
+                       D_ASSERT(device, p->verify_alg[SHARED_SECRET_MAX-1] == 0);
+                       D_ASSERT(device, p->csums_alg[SHARED_SECRET_MAX-1] == 0);
                        p->verify_alg[SHARED_SECRET_MAX-1] = 0;
                        p->csums_alg[SHARED_SECRET_MAX-1] = 0;
                }
 
                if (strcmp(old_net_conf->verify_alg, p->verify_alg)) {
-                       if (mdev->state.conn == C_WF_REPORT_PARAMS) {
-                               dev_err(DEV, "Different verify-alg settings. me=\"%s\" peer=\"%s\"\n",
+                       if (device->state.conn == C_WF_REPORT_PARAMS) {
+                               drbd_err(device, "Different verify-alg settings. me=\"%s\" peer=\"%s\"\n",
                                    old_net_conf->verify_alg, p->verify_alg);
                                goto disconnect;
                        }
-                       verify_tfm = drbd_crypto_alloc_digest_safe(mdev,
+                       verify_tfm = drbd_crypto_alloc_digest_safe(device,
                                        p->verify_alg, "verify-alg");
                        if (IS_ERR(verify_tfm)) {
                                verify_tfm = NULL;
@@ -3412,12 +3459,12 @@ static int receive_SyncParam(struct drbd_tconn *tconn, struct packet_info *pi)
                }
 
                if (apv >= 89 && strcmp(old_net_conf->csums_alg, p->csums_alg)) {
-                       if (mdev->state.conn == C_WF_REPORT_PARAMS) {
-                               dev_err(DEV, "Different csums-alg settings. me=\"%s\" peer=\"%s\"\n",
+                       if (device->state.conn == C_WF_REPORT_PARAMS) {
+                               drbd_err(device, "Different csums-alg settings. me=\"%s\" peer=\"%s\"\n",
                                    old_net_conf->csums_alg, p->csums_alg);
                                goto disconnect;
                        }
-                       csums_tfm = drbd_crypto_alloc_digest_safe(mdev,
+                       csums_tfm = drbd_crypto_alloc_digest_safe(device,
                                        p->csums_alg, "csums-alg");
                        if (IS_ERR(csums_tfm)) {
                                csums_tfm = NULL;
@@ -3432,11 +3479,11 @@ static int receive_SyncParam(struct drbd_tconn *tconn, struct packet_info *pi)
                        new_disk_conf->c_max_rate = be32_to_cpu(p->c_max_rate);
 
                        fifo_size = (new_disk_conf->c_plan_ahead * 10 * SLEEP_TIME) / HZ;
-                       if (fifo_size != mdev->rs_plan_s->size) {
+                       if (fifo_size != device->rs_plan_s->size) {
                                new_plan = fifo_alloc(fifo_size);
                                if (!new_plan) {
-                                       dev_err(DEV, "kmalloc of fifo_buffer failed");
-                                       put_ldev(mdev);
+                                       drbd_err(device, "kmalloc of fifo_buffer failed");
+                                       put_ldev(device);
                                        goto disconnect;
                                }
                        }
@@ -3445,7 +3492,7 @@ static int receive_SyncParam(struct drbd_tconn *tconn, struct packet_info *pi)
                if (verify_tfm || csums_tfm) {
                        new_net_conf = kzalloc(sizeof(struct net_conf), GFP_KERNEL);
                        if (!new_net_conf) {
-                               dev_err(DEV, "Allocation of new net_conf failed\n");
+                               drbd_err(device, "Allocation of new net_conf failed\n");
                                goto disconnect;
                        }
 
@@ -3454,32 +3501,32 @@ static int receive_SyncParam(struct drbd_tconn *tconn, struct packet_info *pi)
                        if (verify_tfm) {
                                strcpy(new_net_conf->verify_alg, p->verify_alg);
                                new_net_conf->verify_alg_len = strlen(p->verify_alg) + 1;
-                               crypto_free_hash(mdev->tconn->verify_tfm);
-                               mdev->tconn->verify_tfm = verify_tfm;
-                               dev_info(DEV, "using verify-alg: \"%s\"\n", p->verify_alg);
+                               crypto_free_hash(peer_device->connection->verify_tfm);
+                               peer_device->connection->verify_tfm = verify_tfm;
+                               drbd_info(device, "using verify-alg: \"%s\"\n", p->verify_alg);
                        }
                        if (csums_tfm) {
                                strcpy(new_net_conf->csums_alg, p->csums_alg);
                                new_net_conf->csums_alg_len = strlen(p->csums_alg) + 1;
-                               crypto_free_hash(mdev->tconn->csums_tfm);
-                               mdev->tconn->csums_tfm = csums_tfm;
-                               dev_info(DEV, "using csums-alg: \"%s\"\n", p->csums_alg);
+                               crypto_free_hash(peer_device->connection->csums_tfm);
+                               peer_device->connection->csums_tfm = csums_tfm;
+                               drbd_info(device, "using csums-alg: \"%s\"\n", p->csums_alg);
                        }
-                       rcu_assign_pointer(tconn->net_conf, new_net_conf);
+                       rcu_assign_pointer(connection->net_conf, new_net_conf);
                }
        }
 
        if (new_disk_conf) {
-               rcu_assign_pointer(mdev->ldev->disk_conf, new_disk_conf);
-               put_ldev(mdev);
+               rcu_assign_pointer(device->ldev->disk_conf, new_disk_conf);
+               put_ldev(device);
        }
 
        if (new_plan) {
-               old_plan = mdev->rs_plan_s;
-               rcu_assign_pointer(mdev->rs_plan_s, new_plan);
+               old_plan = device->rs_plan_s;
+               rcu_assign_pointer(device->rs_plan_s, new_plan);
        }
 
-       mutex_unlock(&mdev->tconn->conf_update);
+       mutex_unlock(&connection->resource->conf_update);
        synchronize_rcu();
        if (new_net_conf)
                kfree(old_net_conf);
@@ -3490,30 +3537,30 @@ static int receive_SyncParam(struct drbd_tconn *tconn, struct packet_info *pi)
 
 reconnect:
        if (new_disk_conf) {
-               put_ldev(mdev);
+               put_ldev(device);
                kfree(new_disk_conf);
        }
-       mutex_unlock(&mdev->tconn->conf_update);
+       mutex_unlock(&connection->resource->conf_update);
        return -EIO;
 
 disconnect:
        kfree(new_plan);
        if (new_disk_conf) {
-               put_ldev(mdev);
+               put_ldev(device);
                kfree(new_disk_conf);
        }
-       mutex_unlock(&mdev->tconn->conf_update);
+       mutex_unlock(&connection->resource->conf_update);
        /* just for completeness: actually not needed,
         * as this is not reached if csums_tfm was ok. */
        crypto_free_hash(csums_tfm);
        /* but free the verify_tfm again, if csums_tfm did not work out */
        crypto_free_hash(verify_tfm);
-       conn_request_state(mdev->tconn, NS(conn, C_DISCONNECTING), CS_HARD);
+       conn_request_state(peer_device->connection, NS(conn, C_DISCONNECTING), CS_HARD);
        return -EIO;
 }
 
 /* warn if the arguments differ by more than 12.5% */
-static void warn_if_differ_considerably(struct drbd_conf *mdev,
+static void warn_if_differ_considerably(struct drbd_device *device,
        const char *s, sector_t a, sector_t b)
 {
        sector_t d;
@@ -3521,54 +3568,56 @@ static void warn_if_differ_considerably(struct drbd_conf *mdev,
                return;
        d = (a > b) ? (a - b) : (b - a);
        if (d > (a>>3) || d > (b>>3))
-               dev_warn(DEV, "Considerable difference in %s: %llus vs. %llus\n", s,
+               drbd_warn(device, "Considerable difference in %s: %llus vs. %llus\n", s,
                     (unsigned long long)a, (unsigned long long)b);
 }
 
-static int receive_sizes(struct drbd_tconn *tconn, struct packet_info *pi)
+static int receive_sizes(struct drbd_connection *connection, struct packet_info *pi)
 {
-       struct drbd_conf *mdev;
+       struct drbd_peer_device *peer_device;
+       struct drbd_device *device;
        struct p_sizes *p = pi->data;
        enum determine_dev_size dd = DS_UNCHANGED;
        sector_t p_size, p_usize, my_usize;
        int ldsc = 0; /* local disk size changed */
        enum dds_flags ddsf;
 
-       mdev = vnr_to_mdev(tconn, pi->vnr);
-       if (!mdev)
-               return config_unknown_volume(tconn, pi);
+       peer_device = conn_peer_device(connection, pi->vnr);
+       if (!peer_device)
+               return config_unknown_volume(connection, pi);
+       device = peer_device->device;
 
        p_size = be64_to_cpu(p->d_size);
        p_usize = be64_to_cpu(p->u_size);
 
        /* just store the peer's disk size for now.
         * we still need to figure out whether we accept that. */
-       mdev->p_size = p_size;
+       device->p_size = p_size;
 
-       if (get_ldev(mdev)) {
+       if (get_ldev(device)) {
                rcu_read_lock();
-               my_usize = rcu_dereference(mdev->ldev->disk_conf)->disk_size;
+               my_usize = rcu_dereference(device->ldev->disk_conf)->disk_size;
                rcu_read_unlock();
 
-               warn_if_differ_considerably(mdev, "lower level device sizes",
-                          p_size, drbd_get_max_capacity(mdev->ldev));
-               warn_if_differ_considerably(mdev, "user requested size",
+               warn_if_differ_considerably(device, "lower level device sizes",
+                          p_size, drbd_get_max_capacity(device->ldev));
+               warn_if_differ_considerably(device, "user requested size",
                                            p_usize, my_usize);
 
                /* if this is the first connect, or an otherwise expected
                 * param exchange, choose the minimum */
-               if (mdev->state.conn == C_WF_REPORT_PARAMS)
+               if (device->state.conn == C_WF_REPORT_PARAMS)
                        p_usize = min_not_zero(my_usize, p_usize);
 
                /* Never shrink a device with usable data during connect.
                   But allow online shrinking if we are connected. */
-               if (drbd_new_dev_size(mdev, mdev->ldev, p_usize, 0) <
-                   drbd_get_capacity(mdev->this_bdev) &&
-                   mdev->state.disk >= D_OUTDATED &&
-                   mdev->state.conn < C_CONNECTED) {
-                       dev_err(DEV, "The peer's disk size is too small!\n");
-                       conn_request_state(mdev->tconn, NS(conn, C_DISCONNECTING), CS_HARD);
-                       put_ldev(mdev);
+               if (drbd_new_dev_size(device, device->ldev, p_usize, 0) <
+                   drbd_get_capacity(device->this_bdev) &&
+                   device->state.disk >= D_OUTDATED &&
+                   device->state.conn < C_CONNECTED) {
+                       drbd_err(device, "The peer's disk size is too small!\n");
+                       conn_request_state(peer_device->connection, NS(conn, C_DISCONNECTING), CS_HARD);
+                       put_ldev(device);
                        return -EIO;
                }
 
@@ -3577,145 +3626,147 @@ static int receive_sizes(struct drbd_tconn *tconn, struct packet_info *pi)
 
                        new_disk_conf = kzalloc(sizeof(struct disk_conf), GFP_KERNEL);
                        if (!new_disk_conf) {
-                               dev_err(DEV, "Allocation of new disk_conf failed\n");
-                               put_ldev(mdev);
+                               drbd_err(device, "Allocation of new disk_conf failed\n");
+                               put_ldev(device);
                                return -ENOMEM;
                        }
 
-                       mutex_lock(&mdev->tconn->conf_update);
-                       old_disk_conf = mdev->ldev->disk_conf;
+                       mutex_lock(&connection->resource->conf_update);
+                       old_disk_conf = device->ldev->disk_conf;
                        *new_disk_conf = *old_disk_conf;
                        new_disk_conf->disk_size = p_usize;
 
-                       rcu_assign_pointer(mdev->ldev->disk_conf, new_disk_conf);
-                       mutex_unlock(&mdev->tconn->conf_update);
+                       rcu_assign_pointer(device->ldev->disk_conf, new_disk_conf);
+                       mutex_unlock(&connection->resource->conf_update);
                        synchronize_rcu();
                        kfree(old_disk_conf);
 
-                       dev_info(DEV, "Peer sets u_size to %lu sectors\n",
+                       drbd_info(device, "Peer sets u_size to %lu sectors\n",
                                 (unsigned long)my_usize);
                }
 
-               put_ldev(mdev);
+               put_ldev(device);
        }
 
        ddsf = be16_to_cpu(p->dds_flags);
-       if (get_ldev(mdev)) {
-               dd = drbd_determine_dev_size(mdev, ddsf, NULL);
-               put_ldev(mdev);
+       if (get_ldev(device)) {
+               dd = drbd_determine_dev_size(device, ddsf, NULL);
+               put_ldev(device);
                if (dd == DS_ERROR)
                        return -EIO;
-               drbd_md_sync(mdev);
+               drbd_md_sync(device);
        } else {
                /* I am diskless, need to accept the peer's size. */
-               drbd_set_my_capacity(mdev, p_size);
+               drbd_set_my_capacity(device, p_size);
        }
 
-       mdev->peer_max_bio_size = be32_to_cpu(p->max_bio_size);
-       drbd_reconsider_max_bio_size(mdev);
+       device->peer_max_bio_size = be32_to_cpu(p->max_bio_size);
+       drbd_reconsider_max_bio_size(device);
 
-       if (get_ldev(mdev)) {
-               if (mdev->ldev->known_size != drbd_get_capacity(mdev->ldev->backing_bdev)) {
-                       mdev->ldev->known_size = drbd_get_capacity(mdev->ldev->backing_bdev);
+       if (get_ldev(device)) {
+               if (device->ldev->known_size != drbd_get_capacity(device->ldev->backing_bdev)) {
+                       device->ldev->known_size = drbd_get_capacity(device->ldev->backing_bdev);
                        ldsc = 1;
                }
 
-               put_ldev(mdev);
+               put_ldev(device);
        }
 
-       if (mdev->state.conn > C_WF_REPORT_PARAMS) {
+       if (device->state.conn > C_WF_REPORT_PARAMS) {
                if (be64_to_cpu(p->c_size) !=
-                   drbd_get_capacity(mdev->this_bdev) || ldsc) {
+                   drbd_get_capacity(device->this_bdev) || ldsc) {
                        /* we have different sizes, probably peer
                         * needs to know my new size... */
-                       drbd_send_sizes(mdev, 0, ddsf);
+                       drbd_send_sizes(peer_device, 0, ddsf);
                }
-               if (test_and_clear_bit(RESIZE_PENDING, &mdev->flags) ||
-                   (dd == DS_GREW && mdev->state.conn == C_CONNECTED)) {
-                       if (mdev->state.pdsk >= D_INCONSISTENT &&
-                           mdev->state.disk >= D_INCONSISTENT) {
+               if (test_and_clear_bit(RESIZE_PENDING, &device->flags) ||
+                   (dd == DS_GREW && device->state.conn == C_CONNECTED)) {
+                       if (device->state.pdsk >= D_INCONSISTENT &&
+                           device->state.disk >= D_INCONSISTENT) {
                                if (ddsf & DDSF_NO_RESYNC)
-                                       dev_info(DEV, "Resync of new storage suppressed with --assume-clean\n");
+                                       drbd_info(device, "Resync of new storage suppressed with --assume-clean\n");
                                else
-                                       resync_after_online_grow(mdev);
+                                       resync_after_online_grow(device);
                        } else
-                               set_bit(RESYNC_AFTER_NEG, &mdev->flags);
+                               set_bit(RESYNC_AFTER_NEG, &device->flags);
                }
        }
 
        return 0;
 }
 
-static int receive_uuids(struct drbd_tconn *tconn, struct packet_info *pi)
+static int receive_uuids(struct drbd_connection *connection, struct packet_info *pi)
 {
-       struct drbd_conf *mdev;
+       struct drbd_peer_device *peer_device;
+       struct drbd_device *device;
        struct p_uuids *p = pi->data;
        u64 *p_uuid;
        int i, updated_uuids = 0;
 
-       mdev = vnr_to_mdev(tconn, pi->vnr);
-       if (!mdev)
-               return config_unknown_volume(tconn, pi);
+       peer_device = conn_peer_device(connection, pi->vnr);
+       if (!peer_device)
+               return config_unknown_volume(connection, pi);
+       device = peer_device->device;
 
        p_uuid = kmalloc(sizeof(u64)*UI_EXTENDED_SIZE, GFP_NOIO);
        if (!p_uuid) {
-               dev_err(DEV, "kmalloc of p_uuid failed\n");
+               drbd_err(device, "kmalloc of p_uuid failed\n");
                return false;
        }
 
        for (i = UI_CURRENT; i < UI_EXTENDED_SIZE; i++)
                p_uuid[i] = be64_to_cpu(p->uuid[i]);
 
-       kfree(mdev->p_uuid);
-       mdev->p_uuid = p_uuid;
+       kfree(device->p_uuid);
+       device->p_uuid = p_uuid;
 
-       if (mdev->state.conn < C_CONNECTED &&
-           mdev->state.disk < D_INCONSISTENT &&
-           mdev->state.role == R_PRIMARY &&
-           (mdev->ed_uuid & ~((u64)1)) != (p_uuid[UI_CURRENT] & ~((u64)1))) {
-               dev_err(DEV, "Can only connect to data with current UUID=%016llX\n",
-                   (unsigned long long)mdev->ed_uuid);
-               conn_request_state(mdev->tconn, NS(conn, C_DISCONNECTING), CS_HARD);
+       if (device->state.conn < C_CONNECTED &&
+           device->state.disk < D_INCONSISTENT &&
+           device->state.role == R_PRIMARY &&
+           (device->ed_uuid & ~((u64)1)) != (p_uuid[UI_CURRENT] & ~((u64)1))) {
+               drbd_err(device, "Can only connect to data with current UUID=%016llX\n",
+                   (unsigned long long)device->ed_uuid);
+               conn_request_state(peer_device->connection, NS(conn, C_DISCONNECTING), CS_HARD);
                return -EIO;
        }
 
-       if (get_ldev(mdev)) {
+       if (get_ldev(device)) {
                int skip_initial_sync =
-                       mdev->state.conn == C_CONNECTED &&
-                       mdev->tconn->agreed_pro_version >= 90 &&
-                       mdev->ldev->md.uuid[UI_CURRENT] == UUID_JUST_CREATED &&
+                       device->state.conn == C_CONNECTED &&
+                       peer_device->connection->agreed_pro_version >= 90 &&
+                       device->ldev->md.uuid[UI_CURRENT] == UUID_JUST_CREATED &&
                        (p_uuid[UI_FLAGS] & 8);
                if (skip_initial_sync) {
-                       dev_info(DEV, "Accepted new current UUID, preparing to skip initial sync\n");
-                       drbd_bitmap_io(mdev, &drbd_bmio_clear_n_write,
+                       drbd_info(device, "Accepted new current UUID, preparing to skip initial sync\n");
+                       drbd_bitmap_io(device, &drbd_bmio_clear_n_write,
                                        "clear_n_write from receive_uuids",
                                        BM_LOCKED_TEST_ALLOWED);
-                       _drbd_uuid_set(mdev, UI_CURRENT, p_uuid[UI_CURRENT]);
-                       _drbd_uuid_set(mdev, UI_BITMAP, 0);
-                       _drbd_set_state(_NS2(mdev, disk, D_UP_TO_DATE, pdsk, D_UP_TO_DATE),
+                       _drbd_uuid_set(device, UI_CURRENT, p_uuid[UI_CURRENT]);
+                       _drbd_uuid_set(device, UI_BITMAP, 0);
+                       _drbd_set_state(_NS2(device, disk, D_UP_TO_DATE, pdsk, D_UP_TO_DATE),
                                        CS_VERBOSE, NULL);
-                       drbd_md_sync(mdev);
+                       drbd_md_sync(device);
                        updated_uuids = 1;
                }
-               put_ldev(mdev);
-       } else if (mdev->state.disk < D_INCONSISTENT &&
-                  mdev->state.role == R_PRIMARY) {
+               put_ldev(device);
+       } else if (device->state.disk < D_INCONSISTENT &&
+                  device->state.role == R_PRIMARY) {
                /* I am a diskless primary, the peer just created a new current UUID
                   for me. */
-               updated_uuids = drbd_set_ed_uuid(mdev, p_uuid[UI_CURRENT]);
+               updated_uuids = drbd_set_ed_uuid(device, p_uuid[UI_CURRENT]);
        }
 
        /* Before we test for the disk state, we should wait until an eventually
           ongoing cluster wide state change is finished. That is important if
           we are primary and are detaching from our disk. We need to see the
           new disk state... */
-       mutex_lock(mdev->state_mutex);
-       mutex_unlock(mdev->state_mutex);
-       if (mdev->state.conn >= C_CONNECTED && mdev->state.disk < D_INCONSISTENT)
-               updated_uuids |= drbd_set_ed_uuid(mdev, p_uuid[UI_CURRENT]);
+       mutex_lock(device->state_mutex);
+       mutex_unlock(device->state_mutex);
+       if (device->state.conn >= C_CONNECTED && device->state.disk < D_INCONSISTENT)
+               updated_uuids |= drbd_set_ed_uuid(device, p_uuid[UI_CURRENT]);
 
        if (updated_uuids)
-               drbd_print_uuids(mdev, "receiver updated UUIDs to");
+               drbd_print_uuids(device, "receiver updated UUIDs to");
 
        return 0;
 }
@@ -3751,38 +3802,40 @@ static union drbd_state convert_state(union drbd_state ps)
        return ms;
 }
 
-static int receive_req_state(struct drbd_tconn *tconn, struct packet_info *pi)
+static int receive_req_state(struct drbd_connection *connection, struct packet_info *pi)
 {
-       struct drbd_conf *mdev;
+       struct drbd_peer_device *peer_device;
+       struct drbd_device *device;
        struct p_req_state *p = pi->data;
        union drbd_state mask, val;
        enum drbd_state_rv rv;
 
-       mdev = vnr_to_mdev(tconn, pi->vnr);
-       if (!mdev)
+       peer_device = conn_peer_device(connection, pi->vnr);
+       if (!peer_device)
                return -EIO;
+       device = peer_device->device;
 
        mask.i = be32_to_cpu(p->mask);
        val.i = be32_to_cpu(p->val);
 
-       if (test_bit(RESOLVE_CONFLICTS, &mdev->tconn->flags) &&
-           mutex_is_locked(mdev->state_mutex)) {
-               drbd_send_sr_reply(mdev, SS_CONCURRENT_ST_CHG);
+       if (test_bit(RESOLVE_CONFLICTS, &peer_device->connection->flags) &&
+           mutex_is_locked(device->state_mutex)) {
+               drbd_send_sr_reply(peer_device, SS_CONCURRENT_ST_CHG);
                return 0;
        }
 
        mask = convert_state(mask);
        val = convert_state(val);
 
-       rv = drbd_change_state(mdev, CS_VERBOSE, mask, val);
-       drbd_send_sr_reply(mdev, rv);
+       rv = drbd_change_state(device, CS_VERBOSE, mask, val);
+       drbd_send_sr_reply(peer_device, rv);
 
-       drbd_md_sync(mdev);
+       drbd_md_sync(device);
 
        return 0;
 }
 
-static int receive_req_conn_state(struct drbd_tconn *tconn, struct packet_info *pi)
+static int receive_req_conn_state(struct drbd_connection *connection, struct packet_info *pi)
 {
        struct p_req_state *p = pi->data;
        union drbd_state mask, val;
@@ -3791,46 +3844,48 @@ static int receive_req_conn_state(struct drbd_tconn *tconn, struct packet_info *
        mask.i = be32_to_cpu(p->mask);
        val.i = be32_to_cpu(p->val);
 
-       if (test_bit(RESOLVE_CONFLICTS, &tconn->flags) &&
-           mutex_is_locked(&tconn->cstate_mutex)) {
-               conn_send_sr_reply(tconn, SS_CONCURRENT_ST_CHG);
+       if (test_bit(RESOLVE_CONFLICTS, &connection->flags) &&
+           mutex_is_locked(&connection->cstate_mutex)) {
+               conn_send_sr_reply(connection, SS_CONCURRENT_ST_CHG);
                return 0;
        }
 
        mask = convert_state(mask);
        val = convert_state(val);
 
-       rv = conn_request_state(tconn, mask, val, CS_VERBOSE | CS_LOCAL_ONLY | CS_IGN_OUTD_FAIL);
-       conn_send_sr_reply(tconn, rv);
+       rv = conn_request_state(connection, mask, val, CS_VERBOSE | CS_LOCAL_ONLY | CS_IGN_OUTD_FAIL);
+       conn_send_sr_reply(connection, rv);
 
        return 0;
 }
 
-static int receive_state(struct drbd_tconn *tconn, struct packet_info *pi)
+static int receive_state(struct drbd_connection *connection, struct packet_info *pi)
 {
-       struct drbd_conf *mdev;
+       struct drbd_peer_device *peer_device;
+       struct drbd_device *device;
        struct p_state *p = pi->data;
        union drbd_state os, ns, peer_state;
        enum drbd_disk_state real_peer_disk;
        enum chg_state_flags cs_flags;
        int rv;
 
-       mdev = vnr_to_mdev(tconn, pi->vnr);
-       if (!mdev)
-               return config_unknown_volume(tconn, pi);
+       peer_device = conn_peer_device(connection, pi->vnr);
+       if (!peer_device)
+               return config_unknown_volume(connection, pi);
+       device = peer_device->device;
 
        peer_state.i = be32_to_cpu(p->state);
 
        real_peer_disk = peer_state.disk;
        if (peer_state.disk == D_NEGOTIATING) {
-               real_peer_disk = mdev->p_uuid[UI_FLAGS] & 4 ? D_INCONSISTENT : D_CONSISTENT;
-               dev_info(DEV, "real peer disk state = %s\n", drbd_disk_str(real_peer_disk));
+               real_peer_disk = device->p_uuid[UI_FLAGS] & 4 ? D_INCONSISTENT : D_CONSISTENT;
+               drbd_info(device, "real peer disk state = %s\n", drbd_disk_str(real_peer_disk));
        }
 
-       spin_lock_irq(&mdev->tconn->req_lock);
+       spin_lock_irq(&device->resource->req_lock);
  retry:
-       os = ns = drbd_read_state(mdev);
-       spin_unlock_irq(&mdev->tconn->req_lock);
+       os = ns = drbd_read_state(device);
+       spin_unlock_irq(&device->resource->req_lock);
 
        /* If some other part of the code (asender thread, timeout)
         * already decided to close the connection again,
@@ -3862,8 +3917,8 @@ static int receive_state(struct drbd_tconn *tconn, struct packet_info *pi)
                 * Maybe we should finish it up, too? */
                else if (os.conn >= C_SYNC_SOURCE &&
                         peer_state.conn == C_CONNECTED) {
-                       if (drbd_bm_total_weight(mdev) <= mdev->rs_failed)
-                               drbd_resync_finished(mdev);
+                       if (drbd_bm_total_weight(device) <= device->rs_failed)
+                               drbd_resync_finished(device);
                        return 0;
                }
        }
@@ -3871,8 +3926,8 @@ static int receive_state(struct drbd_tconn *tconn, struct packet_info *pi)
        /* explicit verify finished notification, stop sector reached. */
        if (os.conn == C_VERIFY_T && os.disk == D_UP_TO_DATE &&
            peer_state.conn == C_CONNECTED && real_peer_disk == D_UP_TO_DATE) {
-               ov_out_of_sync_print(mdev);
-               drbd_resync_finished(mdev);
+               ov_out_of_sync_print(device);
+               drbd_resync_finished(device);
                return 0;
        }
 
@@ -3891,8 +3946,8 @@ static int receive_state(struct drbd_tconn *tconn, struct packet_info *pi)
        if (peer_state.conn == C_AHEAD)
                ns.conn = C_BEHIND;
 
-       if (mdev->p_uuid && peer_state.disk >= D_NEGOTIATING &&
-           get_ldev_if_state(mdev, D_NEGOTIATING)) {
+       if (device->p_uuid && peer_state.disk >= D_NEGOTIATING &&
+           get_ldev_if_state(device, D_NEGOTIATING)) {
                int cr; /* consider resync */
 
                /* if we established a new connection */
@@ -3904,7 +3959,7 @@ static int receive_state(struct drbd_tconn *tconn, struct packet_info *pi)
                        os.disk == D_NEGOTIATING));
                /* if we have both been inconsistent, and the peer has been
                 * forced to be UpToDate with --overwrite-data */
-               cr |= test_bit(CONSIDER_RESYNC, &mdev->flags);
+               cr |= test_bit(CONSIDER_RESYNC, &device->flags);
                /* if we had been plain connected, and the admin requested to
                 * start a sync by "invalidate" or "invalidate-remote" */
                cr |= (os.conn == C_CONNECTED &&
@@ -3912,55 +3967,55 @@ static int receive_state(struct drbd_tconn *tconn, struct packet_info *pi)
                                 peer_state.conn <= C_WF_BITMAP_T));
 
                if (cr)
-                       ns.conn = drbd_sync_handshake(mdev, peer_state.role, real_peer_disk);
+                       ns.conn = drbd_sync_handshake(peer_device, peer_state.role, real_peer_disk);
 
-               put_ldev(mdev);
+               put_ldev(device);
                if (ns.conn == C_MASK) {
                        ns.conn = C_CONNECTED;
-                       if (mdev->state.disk == D_NEGOTIATING) {
-                               drbd_force_state(mdev, NS(disk, D_FAILED));
+                       if (device->state.disk == D_NEGOTIATING) {
+                               drbd_force_state(device, NS(disk, D_FAILED));
                        } else if (peer_state.disk == D_NEGOTIATING) {
-                               dev_err(DEV, "Disk attach process on the peer node was aborted.\n");
+                               drbd_err(device, "Disk attach process on the peer node was aborted.\n");
                                peer_state.disk = D_DISKLESS;
                                real_peer_disk = D_DISKLESS;
                        } else {
-                               if (test_and_clear_bit(CONN_DRY_RUN, &mdev->tconn->flags))
+                               if (test_and_clear_bit(CONN_DRY_RUN, &peer_device->connection->flags))
                                        return -EIO;
-                               D_ASSERT(os.conn == C_WF_REPORT_PARAMS);
-                               conn_request_state(mdev->tconn, NS(conn, C_DISCONNECTING), CS_HARD);
+                               D_ASSERT(device, os.conn == C_WF_REPORT_PARAMS);
+                               conn_request_state(peer_device->connection, NS(conn, C_DISCONNECTING), CS_HARD);
                                return -EIO;
                        }
                }
        }
 
-       spin_lock_irq(&mdev->tconn->req_lock);
-       if (os.i != drbd_read_state(mdev).i)
+       spin_lock_irq(&device->resource->req_lock);
+       if (os.i != drbd_read_state(device).i)
                goto retry;
-       clear_bit(CONSIDER_RESYNC, &mdev->flags);
+       clear_bit(CONSIDER_RESYNC, &device->flags);
        ns.peer = peer_state.role;
        ns.pdsk = real_peer_disk;
        ns.peer_isp = (peer_state.aftr_isp | peer_state.user_isp);
        if ((ns.conn == C_CONNECTED || ns.conn == C_WF_BITMAP_S) && ns.disk == D_NEGOTIATING)
-               ns.disk = mdev->new_state_tmp.disk;
+               ns.disk = device->new_state_tmp.disk;
        cs_flags = CS_VERBOSE + (os.conn < C_CONNECTED && ns.conn >= C_CONNECTED ? 0 : CS_HARD);
-       if (ns.pdsk == D_CONSISTENT && drbd_suspended(mdev) && ns.conn == C_CONNECTED && os.conn < C_CONNECTED &&
-           test_bit(NEW_CUR_UUID, &mdev->flags)) {
+       if (ns.pdsk == D_CONSISTENT && drbd_suspended(device) && ns.conn == C_CONNECTED && os.conn < C_CONNECTED &&
+           test_bit(NEW_CUR_UUID, &device->flags)) {
                /* Do not allow tl_restart(RESEND) for a rebooted peer. We can only allow this
                   for temporal network outages! */
-               spin_unlock_irq(&mdev->tconn->req_lock);
-               dev_err(DEV, "Aborting Connect, can not thaw IO with an only Consistent peer\n");
-               tl_clear(mdev->tconn);
-               drbd_uuid_new_current(mdev);
-               clear_bit(NEW_CUR_UUID, &mdev->flags);
-               conn_request_state(mdev->tconn, NS2(conn, C_PROTOCOL_ERROR, susp, 0), CS_HARD);
+               spin_unlock_irq(&device->resource->req_lock);
+               drbd_err(device, "Aborting Connect, can not thaw IO with an only Consistent peer\n");
+               tl_clear(peer_device->connection);
+               drbd_uuid_new_current(device);
+               clear_bit(NEW_CUR_UUID, &device->flags);
+               conn_request_state(peer_device->connection, NS2(conn, C_PROTOCOL_ERROR, susp, 0), CS_HARD);
                return -EIO;
        }
-       rv = _drbd_set_state(mdev, ns, cs_flags, NULL);
-       ns = drbd_read_state(mdev);
-       spin_unlock_irq(&mdev->tconn->req_lock);
+       rv = _drbd_set_state(device, ns, cs_flags, NULL);
+       ns = drbd_read_state(device);
+       spin_unlock_irq(&device->resource->req_lock);
 
        if (rv < SS_SUCCESS) {
-               conn_request_state(mdev->tconn, NS(conn, C_DISCONNECTING), CS_HARD);
+               conn_request_state(peer_device->connection, NS(conn, C_DISCONNECTING), CS_HARD);
                return -EIO;
        }
 
@@ -3970,47 +4025,49 @@ static int receive_state(struct drbd_tconn *tconn, struct packet_info *pi)
                        /* we want resync, peer has not yet decided to sync... */
                        /* Nowadays only used when forcing a node into primary role and
                           setting its disk to UpToDate with that */
-                       drbd_send_uuids(mdev);
-                       drbd_send_current_state(mdev);
+                       drbd_send_uuids(peer_device);
+                       drbd_send_current_state(peer_device);
                }
        }
 
-       clear_bit(DISCARD_MY_DATA, &mdev->flags);
+       clear_bit(DISCARD_MY_DATA, &device->flags);
 
-       drbd_md_sync(mdev); /* update connected indicator, la_size_sect, ... */
+       drbd_md_sync(device); /* update connected indicator, la_size_sect, ... */
 
        return 0;
 }
 
-static int receive_sync_uuid(struct drbd_tconn *tconn, struct packet_info *pi)
+static int receive_sync_uuid(struct drbd_connection *connection, struct packet_info *pi)
 {
-       struct drbd_conf *mdev;
+       struct drbd_peer_device *peer_device;
+       struct drbd_device *device;
        struct p_rs_uuid *p = pi->data;
 
-       mdev = vnr_to_mdev(tconn, pi->vnr);
-       if (!mdev)
+       peer_device = conn_peer_device(connection, pi->vnr);
+       if (!peer_device)
                return -EIO;
+       device = peer_device->device;
 
-       wait_event(mdev->misc_wait,
-                  mdev->state.conn == C_WF_SYNC_UUID ||
-                  mdev->state.conn == C_BEHIND ||
-                  mdev->state.conn < C_CONNECTED ||
-                  mdev->state.disk < D_NEGOTIATING);
+       wait_event(device->misc_wait,
+                  device->state.conn == C_WF_SYNC_UUID ||
+                  device->state.conn == C_BEHIND ||
+                  device->state.conn < C_CONNECTED ||
+                  device->state.disk < D_NEGOTIATING);
 
-       /* D_ASSERT( mdev->state.conn == C_WF_SYNC_UUID ); */
+       /* D_ASSERT(device,  device->state.conn == C_WF_SYNC_UUID ); */
 
        /* Here the _drbd_uuid_ functions are right, current should
           _not_ be rotated into the history */
-       if (get_ldev_if_state(mdev, D_NEGOTIATING)) {
-               _drbd_uuid_set(mdev, UI_CURRENT, be64_to_cpu(p->uuid));
-               _drbd_uuid_set(mdev, UI_BITMAP, 0UL);
+       if (get_ldev_if_state(device, D_NEGOTIATING)) {
+               _drbd_uuid_set(device, UI_CURRENT, be64_to_cpu(p->uuid));
+               _drbd_uuid_set(device, UI_BITMAP, 0UL);
 
-               drbd_print_uuids(mdev, "updated sync uuid");
-               drbd_start_resync(mdev, C_SYNC_TARGET);
+               drbd_print_uuids(device, "updated sync uuid");
+               drbd_start_resync(device, C_SYNC_TARGET);
 
-               put_ldev(mdev);
+               put_ldev(device);
        } else
-               dev_err(DEV, "Ignoring SyncUUID packet!\n");
+               drbd_err(device, "Ignoring SyncUUID packet!\n");
 
        return 0;
 }
@@ -4022,27 +4079,27 @@ static int receive_sync_uuid(struct drbd_tconn *tconn, struct packet_info *pi)
  * code upon failure.
  */
 static int
-receive_bitmap_plain(struct drbd_conf *mdev, unsigned int size,
+receive_bitmap_plain(struct drbd_peer_device *peer_device, unsigned int size,
                     unsigned long *p, struct bm_xfer_ctx *c)
 {
        unsigned int data_size = DRBD_SOCKET_BUFFER_SIZE -
-                                drbd_header_size(mdev->tconn);
+                                drbd_header_size(peer_device->connection);
        unsigned int num_words = min_t(size_t, data_size / sizeof(*p),
                                       c->bm_words - c->word_offset);
        unsigned int want = num_words * sizeof(*p);
        int err;
 
        if (want != size) {
-               dev_err(DEV, "%s:want (%u) != size (%u)\n", __func__, want, size);
+               drbd_err(peer_device, "%s:want (%u) != size (%u)\n", __func__, want, size);
                return -EIO;
        }
        if (want == 0)
                return 0;
-       err = drbd_recv_all(mdev->tconn, p, want);
+       err = drbd_recv_all(peer_device->connection, p, want);
        if (err)
                return err;
 
-       drbd_bm_merge_lel(mdev, c->word_offset, num_words, p);
+       drbd_bm_merge_lel(peer_device->device, c->word_offset, num_words, p);
 
        c->word_offset += num_words;
        c->bit_offset = c->word_offset * BITS_PER_LONG;
@@ -4074,7 +4131,7 @@ static int dcbp_get_pad_bits(struct p_compressed_bm *p)
  * code upon failure.
  */
 static int
-recv_bm_rle_bits(struct drbd_conf *mdev,
+recv_bm_rle_bits(struct drbd_peer_device *peer_device,
                struct p_compressed_bm *p,
                 struct bm_xfer_ctx *c,
                 unsigned int len)
@@ -4103,14 +4160,14 @@ recv_bm_rle_bits(struct drbd_conf *mdev,
                if (toggle) {
                        e = s + rl -1;
                        if (e >= c->bm_bits) {
-                               dev_err(DEV, "bitmap overflow (e:%lu) while decoding bm RLE packet\n", e);
+                               drbd_err(peer_device, "bitmap overflow (e:%lu) while decoding bm RLE packet\n", e);
                                return -EIO;
                        }
-                       _drbd_bm_set_bits(mdev, s, e);
+                       _drbd_bm_set_bits(peer_device->device, s, e);
                }
 
                if (have < bits) {
-                       dev_err(DEV, "bitmap decoding error: h:%d b:%d la:0x%08llx l:%u/%u\n",
+                       drbd_err(peer_device, "bitmap decoding error: h:%d b:%d la:0x%08llx l:%u/%u\n",
                                have, bits, look_ahead,
                                (unsigned int)(bs.cur.b - p->code),
                                (unsigned int)bs.buf_len);
@@ -4143,28 +4200,28 @@ recv_bm_rle_bits(struct drbd_conf *mdev,
  * code upon failure.
  */
 static int
-decode_bitmap_c(struct drbd_conf *mdev,
+decode_bitmap_c(struct drbd_peer_device *peer_device,
                struct p_compressed_bm *p,
                struct bm_xfer_ctx *c,
                unsigned int len)
 {
        if (dcbp_get_code(p) == RLE_VLI_Bits)
-               return recv_bm_rle_bits(mdev, p, c, len - sizeof(*p));
+               return recv_bm_rle_bits(peer_device, p, c, len - sizeof(*p));
 
        /* other variants had been implemented for evaluation,
         * but have been dropped as this one turned out to be "best"
         * during all our tests. */
 
-       dev_err(DEV, "receive_bitmap_c: unknown encoding %u\n", p->encoding);
-       conn_request_state(mdev->tconn, NS(conn, C_PROTOCOL_ERROR), CS_HARD);
+       drbd_err(peer_device, "receive_bitmap_c: unknown encoding %u\n", p->encoding);
+       conn_request_state(peer_device->connection, NS(conn, C_PROTOCOL_ERROR), CS_HARD);
        return -EIO;
 }
 
-void INFO_bm_xfer_stats(struct drbd_conf *mdev,
+void INFO_bm_xfer_stats(struct drbd_device *device,
                const char *direction, struct bm_xfer_ctx *c)
 {
        /* what would it take to transfer it "plaintext" */
-       unsigned int header_size = drbd_header_size(mdev->tconn);
+       unsigned int header_size = drbd_header_size(first_peer_device(device)->connection);
        unsigned int data_size = DRBD_SOCKET_BUFFER_SIZE - header_size;
        unsigned int plain =
                header_size * (DIV_ROUND_UP(c->bm_words, data_size) + 1) +
@@ -4188,7 +4245,7 @@ void INFO_bm_xfer_stats(struct drbd_conf *mdev,
                r = 1000;
 
        r = 1000 - r;
-       dev_info(DEV, "%s bitmap stats [Bytes(packets)]: plain %u(%u), RLE %u(%u), "
+       drbd_info(device, "%s bitmap stats [Bytes(packets)]: plain %u(%u), RLE %u(%u), "
             "total %u; compression: %u.%u%%\n",
                        direction,
                        c->bytes[1], c->packets[1],
@@ -4204,129 +4261,133 @@ void INFO_bm_xfer_stats(struct drbd_conf *mdev,
    in order to be agnostic to the 32 vs 64 bits issue.
 
    returns 0 on failure, 1 if we successfully received it. */
-static int receive_bitmap(struct drbd_tconn *tconn, struct packet_info *pi)
+static int receive_bitmap(struct drbd_connection *connection, struct packet_info *pi)
 {
-       struct drbd_conf *mdev;
+       struct drbd_peer_device *peer_device;
+       struct drbd_device *device;
        struct bm_xfer_ctx c;
        int err;
 
-       mdev = vnr_to_mdev(tconn, pi->vnr);
-       if (!mdev)
+       peer_device = conn_peer_device(connection, pi->vnr);
+       if (!peer_device)
                return -EIO;
+       device = peer_device->device;
 
-       drbd_bm_lock(mdev, "receive bitmap", BM_LOCKED_SET_ALLOWED);
+       drbd_bm_lock(device, "receive bitmap", BM_LOCKED_SET_ALLOWED);
        /* you are supposed to send additional out-of-sync information
         * if you actually set bits during this phase */
 
        c = (struct bm_xfer_ctx) {
-               .bm_bits = drbd_bm_bits(mdev),
-               .bm_words = drbd_bm_words(mdev),
+               .bm_bits = drbd_bm_bits(device),
+               .bm_words = drbd_bm_words(device),
        };
 
        for(;;) {
                if (pi->cmd == P_BITMAP)
-                       err = receive_bitmap_plain(mdev, pi->size, pi->data, &c);
+                       err = receive_bitmap_plain(peer_device, pi->size, pi->data, &c);
                else if (pi->cmd == P_COMPRESSED_BITMAP) {
                        /* MAYBE: sanity check that we speak proto >= 90,
                         * and the feature is enabled! */
                        struct p_compressed_bm *p = pi->data;
 
-                       if (pi->size > DRBD_SOCKET_BUFFER_SIZE - drbd_header_size(tconn)) {
-                               dev_err(DEV, "ReportCBitmap packet too large\n");
+                       if (pi->size > DRBD_SOCKET_BUFFER_SIZE - drbd_header_size(connection)) {
+                               drbd_err(device, "ReportCBitmap packet too large\n");
                                err = -EIO;
                                goto out;
                        }
                        if (pi->size <= sizeof(*p)) {
-                               dev_err(DEV, "ReportCBitmap packet too small (l:%u)\n", pi->size);
+                               drbd_err(device, "ReportCBitmap packet too small (l:%u)\n", pi->size);
                                err = -EIO;
                                goto out;
                        }
-                       err = drbd_recv_all(mdev->tconn, p, pi->size);
+                       err = drbd_recv_all(peer_device->connection, p, pi->size);
                        if (err)
                               goto out;
-                       err = decode_bitmap_c(mdev, p, &c, pi->size);
+                       err = decode_bitmap_c(peer_device, p, &c, pi->size);
                } else {
-                       dev_warn(DEV, "receive_bitmap: cmd neither ReportBitMap nor ReportCBitMap (is 0x%x)", pi->cmd);
+                       drbd_warn(device, "receive_bitmap: cmd neither ReportBitMap nor ReportCBitMap (is 0x%x)", pi->cmd);
                        err = -EIO;
                        goto out;
                }
 
                c.packets[pi->cmd == P_BITMAP]++;
-               c.bytes[pi->cmd == P_BITMAP] += drbd_header_size(tconn) + pi->size;
+               c.bytes[pi->cmd == P_BITMAP] += drbd_header_size(connection) + pi->size;
 
                if (err <= 0) {
                        if (err < 0)
                                goto out;
                        break;
                }
-               err = drbd_recv_header(mdev->tconn, pi);
+               err = drbd_recv_header(peer_device->connection, pi);
                if (err)
                        goto out;
        }
 
-       INFO_bm_xfer_stats(mdev, "receive", &c);
+       INFO_bm_xfer_stats(device, "receive", &c);
 
-       if (mdev->state.conn == C_WF_BITMAP_T) {
+       if (device->state.conn == C_WF_BITMAP_T) {
                enum drbd_state_rv rv;
 
-               err = drbd_send_bitmap(mdev);
+               err = drbd_send_bitmap(device);
                if (err)
                        goto out;
                /* Omit CS_ORDERED with this state transition to avoid deadlocks. */
-               rv = _drbd_request_state(mdev, NS(conn, C_WF_SYNC_UUID), CS_VERBOSE);
-               D_ASSERT(rv == SS_SUCCESS);
-       } else if (mdev->state.conn != C_WF_BITMAP_S) {
+               rv = _drbd_request_state(device, NS(conn, C_WF_SYNC_UUID), CS_VERBOSE);
+               D_ASSERT(device, rv == SS_SUCCESS);
+       } else if (device->state.conn != C_WF_BITMAP_S) {
                /* admin may have requested C_DISCONNECTING,
                 * other threads may have noticed network errors */
-               dev_info(DEV, "unexpected cstate (%s) in receive_bitmap\n",
-                   drbd_conn_str(mdev->state.conn));
+               drbd_info(device, "unexpected cstate (%s) in receive_bitmap\n",
+                   drbd_conn_str(device->state.conn));
        }
        err = 0;
 
  out:
-       drbd_bm_unlock(mdev);
-       if (!err && mdev->state.conn == C_WF_BITMAP_S)
-               drbd_start_resync(mdev, C_SYNC_SOURCE);
+       drbd_bm_unlock(device);
+       if (!err && device->state.conn == C_WF_BITMAP_S)
+               drbd_start_resync(device, C_SYNC_SOURCE);
        return err;
 }
 
-static int receive_skip(struct drbd_tconn *tconn, struct packet_info *pi)
+static int receive_skip(struct drbd_connection *connection, struct packet_info *pi)
 {
-       conn_warn(tconn, "skipping unknown optional packet type %d, l: %d!\n",
+       drbd_warn(connection, "skipping unknown optional packet type %d, l: %d!\n",
                 pi->cmd, pi->size);
 
-       return ignore_remaining_packet(tconn, pi);
+       return ignore_remaining_packet(connection, pi);
 }
 
-static int receive_UnplugRemote(struct drbd_tconn *tconn, struct packet_info *pi)
+static int receive_UnplugRemote(struct drbd_connection *connection, struct packet_info *pi)
 {
        /* Make sure we've acked all the TCP data associated
         * with the data requests being unplugged */
-       drbd_tcp_quickack(tconn->data.socket);
+       drbd_tcp_quickack(connection->data.socket);
 
        return 0;
 }
 
-static int receive_out_of_sync(struct drbd_tconn *tconn, struct packet_info *pi)
+static int receive_out_of_sync(struct drbd_connection *connection, struct packet_info *pi)
 {
-       struct drbd_conf *mdev;
+       struct drbd_peer_device *peer_device;
+       struct drbd_device *device;
        struct p_block_desc *p = pi->data;
 
-       mdev = vnr_to_mdev(tconn, pi->vnr);
-       if (!mdev)
+       peer_device = conn_peer_device(connection, pi->vnr);
+       if (!peer_device)
                return -EIO;
+       device = peer_device->device;
 
-       switch (mdev->state.conn) {
+       switch (device->state.conn) {
        case C_WF_SYNC_UUID:
        case C_WF_BITMAP_T:
        case C_BEHIND:
                        break;
        default:
-               dev_err(DEV, "ASSERT FAILED cstate = %s, expected: WFSyncUUID|WFBitMapT|Behind\n",
-                               drbd_conn_str(mdev->state.conn));
+               drbd_err(device, "ASSERT FAILED cstate = %s, expected: WFSyncUUID|WFBitMapT|Behind\n",
+                               drbd_conn_str(device->state.conn));
        }
 
-       drbd_set_out_of_sync(mdev, be64_to_cpu(p->sector), be32_to_cpu(p->blksize));
+       drbd_set_out_of_sync(device, be64_to_cpu(p->sector), be32_to_cpu(p->blksize));
 
        return 0;
 }
@@ -4334,7 +4395,7 @@ static int receive_out_of_sync(struct drbd_tconn *tconn, struct packet_info *pi)
 struct data_cmd {
        int expect_payload;
        size_t pkt_size;
-       int (*fn)(struct drbd_tconn *, struct packet_info *);
+       int (*fn)(struct drbd_connection *, struct packet_info *);
 };
 
 static struct data_cmd drbd_cmd_handler[] = {
@@ -4364,43 +4425,43 @@ static struct data_cmd drbd_cmd_handler[] = {
        [P_PROTOCOL_UPDATE] = { 1, sizeof(struct p_protocol), receive_protocol },
 };
 
-static void drbdd(struct drbd_tconn *tconn)
+static void drbdd(struct drbd_connection *connection)
 {
        struct packet_info pi;
        size_t shs; /* sub header size */
        int err;
 
-       while (get_t_state(&tconn->receiver) == RUNNING) {
+       while (get_t_state(&connection->receiver) == RUNNING) {
                struct data_cmd *cmd;
 
-               drbd_thread_current_set_cpu(&tconn->receiver);
-               if (drbd_recv_header(tconn, &pi))
+               drbd_thread_current_set_cpu(&connection->receiver);
+               if (drbd_recv_header(connection, &pi))
                        goto err_out;
 
                cmd = &drbd_cmd_handler[pi.cmd];
                if (unlikely(pi.cmd >= ARRAY_SIZE(drbd_cmd_handler) || !cmd->fn)) {
-                       conn_err(tconn, "Unexpected data packet %s (0x%04x)",
+                       drbd_err(connection, "Unexpected data packet %s (0x%04x)",
                                 cmdname(pi.cmd), pi.cmd);
                        goto err_out;
                }
 
                shs = cmd->pkt_size;
                if (pi.size > shs && !cmd->expect_payload) {
-                       conn_err(tconn, "No payload expected %s l:%d\n",
+                       drbd_err(connection, "No payload expected %s l:%d\n",
                                 cmdname(pi.cmd), pi.size);
                        goto err_out;
                }
 
                if (shs) {
-                       err = drbd_recv_all_warn(tconn, pi.data, shs);
+                       err = drbd_recv_all_warn(connection, pi.data, shs);
                        if (err)
                                goto err_out;
                        pi.size -= shs;
                }
 
-               err = cmd->fn(tconn, &pi);
+               err = cmd->fn(connection, &pi);
                if (err) {
-                       conn_err(tconn, "error receiving %s, e: %d l: %d!\n",
+                       drbd_err(connection, "error receiving %s, e: %d l: %d!\n",
                                 cmdname(pi.cmd), err, pi.size);
                        goto err_out;
                }
@@ -4408,27 +4469,16 @@ static void drbdd(struct drbd_tconn *tconn)
        return;
 
     err_out:
-       conn_request_state(tconn, NS(conn, C_PROTOCOL_ERROR), CS_HARD);
-}
-
-void conn_flush_workqueue(struct drbd_tconn *tconn)
-{
-       struct drbd_wq_barrier barr;
-
-       barr.w.cb = w_prev_work_done;
-       barr.w.tconn = tconn;
-       init_completion(&barr.done);
-       drbd_queue_work(&tconn->sender_work, &barr.w);
-       wait_for_completion(&barr.done);
+       conn_request_state(connection, NS(conn, C_PROTOCOL_ERROR), CS_HARD);
 }
 
-static void conn_disconnect(struct drbd_tconn *tconn)
+static void conn_disconnect(struct drbd_connection *connection)
 {
-       struct drbd_conf *mdev;
+       struct drbd_peer_device *peer_device;
        enum drbd_conns oc;
        int vnr;
 
-       if (tconn->cstate == C_STANDALONE)
+       if (connection->cstate == C_STANDALONE)
                return;
 
        /* We are about to start the cleanup after connection loss.
@@ -4436,54 +4486,56 @@ static void conn_disconnect(struct drbd_tconn *tconn)
         * Usually we should be in some network failure state already,
         * but just in case we are not, we fix it up here.
         */
-       conn_request_state(tconn, NS(conn, C_NETWORK_FAILURE), CS_HARD);
+       conn_request_state(connection, NS(conn, C_NETWORK_FAILURE), CS_HARD);
 
        /* asender does not clean up anything. it must not interfere, either */
-       drbd_thread_stop(&tconn->asender);
-       drbd_free_sock(tconn);
+       drbd_thread_stop(&connection->asender);
+       drbd_free_sock(connection);
 
        rcu_read_lock();
-       idr_for_each_entry(&tconn->volumes, mdev, vnr) {
-               kref_get(&mdev->kref);
+       idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
+               struct drbd_device *device = peer_device->device;
+               kref_get(&device->kref);
                rcu_read_unlock();
-               drbd_disconnected(mdev);
-               kref_put(&mdev->kref, &drbd_minor_destroy);
+               drbd_disconnected(peer_device);
+               kref_put(&device->kref, drbd_destroy_device);
                rcu_read_lock();
        }
        rcu_read_unlock();
 
-       if (!list_empty(&tconn->current_epoch->list))
-               conn_err(tconn, "ASSERTION FAILED: tconn->current_epoch->list not empty\n");
+       if (!list_empty(&connection->current_epoch->list))
+               drbd_err(connection, "ASSERTION FAILED: connection->current_epoch->list not empty\n");
        /* ok, no more ee's on the fly, it is safe to reset the epoch_size */
-       atomic_set(&tconn->current_epoch->epoch_size, 0);
-       tconn->send.seen_any_write_yet = false;
+       atomic_set(&connection->current_epoch->epoch_size, 0);
+       connection->send.seen_any_write_yet = false;
 
-       conn_info(tconn, "Connection closed\n");
+       drbd_info(connection, "Connection closed\n");
 
-       if (conn_highest_role(tconn) == R_PRIMARY && conn_highest_pdsk(tconn) >= D_UNKNOWN)
-               conn_try_outdate_peer_async(tconn);
+       if (conn_highest_role(connection) == R_PRIMARY && conn_highest_pdsk(connection) >= D_UNKNOWN)
+               conn_try_outdate_peer_async(connection);
 
-       spin_lock_irq(&tconn->req_lock);
-       oc = tconn->cstate;
+       spin_lock_irq(&connection->resource->req_lock);
+       oc = connection->cstate;
        if (oc >= C_UNCONNECTED)
-               _conn_request_state(tconn, NS(conn, C_UNCONNECTED), CS_VERBOSE);
+               _conn_request_state(connection, NS(conn, C_UNCONNECTED), CS_VERBOSE);
 
-       spin_unlock_irq(&tconn->req_lock);
+       spin_unlock_irq(&connection->resource->req_lock);
 
        if (oc == C_DISCONNECTING)
-               conn_request_state(tconn, NS(conn, C_STANDALONE), CS_VERBOSE | CS_HARD);
+               conn_request_state(connection, NS(conn, C_STANDALONE), CS_VERBOSE | CS_HARD);
 }
 
-static int drbd_disconnected(struct drbd_conf *mdev)
+static int drbd_disconnected(struct drbd_peer_device *peer_device)
 {
+       struct drbd_device *device = peer_device->device;
        unsigned int i;
 
        /* wait for current activity to cease. */
-       spin_lock_irq(&mdev->tconn->req_lock);
-       _drbd_wait_ee_list_empty(mdev, &mdev->active_ee);
-       _drbd_wait_ee_list_empty(mdev, &mdev->sync_ee);
-       _drbd_wait_ee_list_empty(mdev, &mdev->read_ee);
-       spin_unlock_irq(&mdev->tconn->req_lock);
+       spin_lock_irq(&device->resource->req_lock);
+       _drbd_wait_ee_list_empty(device, &device->active_ee);
+       _drbd_wait_ee_list_empty(device, &device->sync_ee);
+       _drbd_wait_ee_list_empty(device, &device->read_ee);
+       spin_unlock_irq(&device->resource->req_lock);
 
        /* We do not have data structures that would allow us to
         * get the rs_pending_cnt down to 0 again.
@@ -4495,42 +4547,42 @@ static int drbd_disconnected(struct drbd_conf *mdev)
         *  resync_LRU. The resync_LRU tracks the whole operation including
         *  the disk-IO, while the rs_pending_cnt only tracks the blocks
         *  on the fly. */
-       drbd_rs_cancel_all(mdev);
-       mdev->rs_total = 0;
-       mdev->rs_failed = 0;
-       atomic_set(&mdev->rs_pending_cnt, 0);
-       wake_up(&mdev->misc_wait);
+       drbd_rs_cancel_all(device);
+       device->rs_total = 0;
+       device->rs_failed = 0;
+       atomic_set(&device->rs_pending_cnt, 0);
+       wake_up(&device->misc_wait);
 
-       del_timer_sync(&mdev->resync_timer);
-       resync_timer_fn((unsigned long)mdev);
+       del_timer_sync(&device->resync_timer);
+       resync_timer_fn((unsigned long)device);
 
        /* wait for all w_e_end_data_req, w_e_end_rsdata_req, w_send_barrier,
         * w_make_resync_request etc. which may still be on the worker queue
         * to be "canceled" */
-       drbd_flush_workqueue(mdev);
+       drbd_flush_workqueue(&peer_device->connection->sender_work);
 
-       drbd_finish_peer_reqs(mdev);
+       drbd_finish_peer_reqs(device);
 
        /* This second workqueue flush is necessary, since drbd_finish_peer_reqs()
           might have issued a work again. The one before drbd_finish_peer_reqs() is
           necessary to reclain net_ee in drbd_finish_peer_reqs(). */
-       drbd_flush_workqueue(mdev);
+       drbd_flush_workqueue(&peer_device->connection->sender_work);
 
        /* need to do it again, drbd_finish_peer_reqs() may have populated it
         * again via drbd_try_clear_on_disk_bm(). */
-       drbd_rs_cancel_all(mdev);
+       drbd_rs_cancel_all(device);
 
-       kfree(mdev->p_uuid);
-       mdev->p_uuid = NULL;
+       kfree(device->p_uuid);
+       device->p_uuid = NULL;
 
-       if (!drbd_suspended(mdev))
-               tl_clear(mdev->tconn);
+       if (!drbd_suspended(device))
+               tl_clear(peer_device->connection);
 
-       drbd_md_sync(mdev);
+       drbd_md_sync(device);
 
        /* serialize with bitmap writeout triggered by the state change,
         * if any. */
-       wait_event(mdev->misc_wait, !test_bit(BITMAP_IO, &mdev->flags));
+       wait_event(device->misc_wait, !test_bit(BITMAP_IO, &device->flags));
 
        /* tcp_close and release of sendpage pages can be deferred.  I don't
         * want to use SO_LINGER, because apparently it can be deferred for
@@ -4539,20 +4591,20 @@ static int drbd_disconnected(struct drbd_conf *mdev)
         * Actually we don't care for exactly when the network stack does its
         * put_page(), but release our reference on these pages right here.
         */
-       i = drbd_free_peer_reqs(mdev, &mdev->net_ee);
+       i = drbd_free_peer_reqs(device, &device->net_ee);
        if (i)
-               dev_info(DEV, "net_ee not empty, killed %u entries\n", i);
-       i = atomic_read(&mdev->pp_in_use_by_net);
+               drbd_info(device, "net_ee not empty, killed %u entries\n", i);
+       i = atomic_read(&device->pp_in_use_by_net);
        if (i)
-               dev_info(DEV, "pp_in_use_by_net = %d, expected 0\n", i);
-       i = atomic_read(&mdev->pp_in_use);
+               drbd_info(device, "pp_in_use_by_net = %d, expected 0\n", i);
+       i = atomic_read(&device->pp_in_use);
        if (i)
-               dev_info(DEV, "pp_in_use = %d, expected 0\n", i);
+               drbd_info(device, "pp_in_use = %d, expected 0\n", i);
 
-       D_ASSERT(list_empty(&mdev->read_ee));
-       D_ASSERT(list_empty(&mdev->active_ee));
-       D_ASSERT(list_empty(&mdev->sync_ee));
-       D_ASSERT(list_empty(&mdev->done_ee));
+       D_ASSERT(device, list_empty(&device->read_ee));
+       D_ASSERT(device, list_empty(&device->active_ee));
+       D_ASSERT(device, list_empty(&device->sync_ee));
+       D_ASSERT(device, list_empty(&device->done_ee));
 
        return 0;
 }
@@ -4566,19 +4618,19 @@ static int drbd_disconnected(struct drbd_conf *mdev)
  *
  * for now, they are expected to be zero, but ignored.
  */
-static int drbd_send_features(struct drbd_tconn *tconn)
+static int drbd_send_features(struct drbd_connection *connection)
 {
        struct drbd_socket *sock;
        struct p_connection_features *p;
 
-       sock = &tconn->data;
-       p = conn_prepare_command(tconn, sock);
+       sock = &connection->data;
+       p = conn_prepare_command(connection, sock);
        if (!p)
                return -EIO;
        memset(p, 0, sizeof(*p));
        p->protocol_min = cpu_to_be32(PRO_VERSION_MIN);
        p->protocol_max = cpu_to_be32(PRO_VERSION_MAX);
-       return conn_send_command(tconn, sock, P_CONNECTION_FEATURES, sizeof(*p), NULL, 0);
+       return conn_send_command(connection, sock, P_CONNECTION_FEATURES, sizeof(*p), NULL, 0);
 }
 
 /*
@@ -4588,36 +4640,36 @@ static int drbd_send_features(struct drbd_tconn *tconn)
  *  -1 peer talks different language,
  *     no point in trying again, please go standalone.
  */
-static int drbd_do_features(struct drbd_tconn *tconn)
+static int drbd_do_features(struct drbd_connection *connection)
 {
-       /* ASSERT current == tconn->receiver ... */
+       /* ASSERT current == connection->receiver ... */
        struct p_connection_features *p;
        const int expect = sizeof(struct p_connection_features);
        struct packet_info pi;
        int err;
 
-       err = drbd_send_features(tconn);
+       err = drbd_send_features(connection);
        if (err)
                return 0;
 
-       err = drbd_recv_header(tconn, &pi);
+       err = drbd_recv_header(connection, &pi);
        if (err)
                return 0;
 
        if (pi.cmd != P_CONNECTION_FEATURES) {
-               conn_err(tconn, "expected ConnectionFeatures packet, received: %s (0x%04x)\n",
+               drbd_err(connection, "expected ConnectionFeatures packet, received: %s (0x%04x)\n",
                         cmdname(pi.cmd), pi.cmd);
                return -1;
        }
 
        if (pi.size != expect) {
-               conn_err(tconn, "expected ConnectionFeatures length: %u, received: %u\n",
+               drbd_err(connection, "expected ConnectionFeatures length: %u, received: %u\n",
                     expect, pi.size);
                return -1;
        }
 
        p = pi.data;
-       err = drbd_recv_all_warn(tconn, p, expect);
+       err = drbd_recv_all_warn(connection, p, expect);
        if (err)
                return 0;
 
@@ -4630,15 +4682,15 @@ static int drbd_do_features(struct drbd_tconn *tconn)
            PRO_VERSION_MIN > p->protocol_max)
                goto incompat;
 
-       tconn->agreed_pro_version = min_t(int, PRO_VERSION_MAX, p->protocol_max);
+       connection->agreed_pro_version = min_t(int, PRO_VERSION_MAX, p->protocol_max);
 
-       conn_info(tconn, "Handshake successful: "
-            "Agreed network protocol version %d\n", tconn->agreed_pro_version);
+       drbd_info(connection, "Handshake successful: "
+            "Agreed network protocol version %d\n", connection->agreed_pro_version);
 
        return 1;
 
  incompat:
-       conn_err(tconn, "incompatible DRBD dialects: "
+       drbd_err(connection, "incompatible DRBD dialects: "
            "I support %d-%d, peer supports %d-%d\n",
            PRO_VERSION_MIN, PRO_VERSION_MAX,
            p->protocol_min, p->protocol_max);
@@ -4646,10 +4698,10 @@ static int drbd_do_features(struct drbd_tconn *tconn)
 }
 
 #if !defined(CONFIG_CRYPTO_HMAC) && !defined(CONFIG_CRYPTO_HMAC_MODULE)
-static int drbd_do_auth(struct drbd_tconn *tconn)
+static int drbd_do_auth(struct drbd_connection *connection)
 {
-       conn_err(tconn, "This kernel was build without CONFIG_CRYPTO_HMAC.\n");
-       conn_err(tconn, "You need to disable 'cram-hmac-alg' in drbd.conf.\n");
+       drbd_err(connection, "This kernel was build without CONFIG_CRYPTO_HMAC.\n");
+       drbd_err(connection, "You need to disable 'cram-hmac-alg' in drbd.conf.\n");
        return -1;
 }
 #else
@@ -4661,7 +4713,7 @@ static int drbd_do_auth(struct drbd_tconn *tconn)
        -1 - auth failed, don't try again.
 */
 
-static int drbd_do_auth(struct drbd_tconn *tconn)
+static int drbd_do_auth(struct drbd_connection *connection)
 {
        struct drbd_socket *sock;
        char my_challenge[CHALLENGE_LEN];  /* 64 Bytes... */
@@ -4680,69 +4732,69 @@ static int drbd_do_auth(struct drbd_tconn *tconn)
        /* FIXME: Put the challenge/response into the preallocated socket buffer.  */
 
        rcu_read_lock();
-       nc = rcu_dereference(tconn->net_conf);
+       nc = rcu_dereference(connection->net_conf);
        key_len = strlen(nc->shared_secret);
        memcpy(secret, nc->shared_secret, key_len);
        rcu_read_unlock();
 
-       desc.tfm = tconn->cram_hmac_tfm;
+       desc.tfm = connection->cram_hmac_tfm;
        desc.flags = 0;
 
-       rv = crypto_hash_setkey(tconn->cram_hmac_tfm, (u8 *)secret, key_len);
+       rv = crypto_hash_setkey(connection->cram_hmac_tfm, (u8 *)secret, key_len);
        if (rv) {
-               conn_err(tconn, "crypto_hash_setkey() failed with %d\n", rv);
+               drbd_err(connection, "crypto_hash_setkey() failed with %d\n", rv);
                rv = -1;
                goto fail;
        }
 
        get_random_bytes(my_challenge, CHALLENGE_LEN);
 
-       sock = &tconn->data;
-       if (!conn_prepare_command(tconn, sock)) {
+       sock = &connection->data;
+       if (!conn_prepare_command(connection, sock)) {
                rv = 0;
                goto fail;
        }
-       rv = !conn_send_command(tconn, sock, P_AUTH_CHALLENGE, 0,
+       rv = !conn_send_command(connection, sock, P_AUTH_CHALLENGE, 0,
                                my_challenge, CHALLENGE_LEN);
        if (!rv)
                goto fail;
 
-       err = drbd_recv_header(tconn, &pi);
+       err = drbd_recv_header(connection, &pi);
        if (err) {
                rv = 0;
                goto fail;
        }
 
        if (pi.cmd != P_AUTH_CHALLENGE) {
-               conn_err(tconn, "expected AuthChallenge packet, received: %s (0x%04x)\n",
+               drbd_err(connection, "expected AuthChallenge packet, received: %s (0x%04x)\n",
                         cmdname(pi.cmd), pi.cmd);
                rv = 0;
                goto fail;
        }
 
        if (pi.size > CHALLENGE_LEN * 2) {
-               conn_err(tconn, "expected AuthChallenge payload too big.\n");
+               drbd_err(connection, "expected AuthChallenge payload too big.\n");
                rv = -1;
                goto fail;
        }
 
        peers_ch = kmalloc(pi.size, GFP_NOIO);
        if (peers_ch == NULL) {
-               conn_err(tconn, "kmalloc of peers_ch failed\n");
+               drbd_err(connection, "kmalloc of peers_ch failed\n");
                rv = -1;
                goto fail;
        }
 
-       err = drbd_recv_all_warn(tconn, peers_ch, pi.size);
+       err = drbd_recv_all_warn(connection, peers_ch, pi.size);
        if (err) {
                rv = 0;
                goto fail;
        }
 
-       resp_size = crypto_hash_digestsize(tconn->cram_hmac_tfm);
+       resp_size = crypto_hash_digestsize(connection->cram_hmac_tfm);
        response = kmalloc(resp_size, GFP_NOIO);
        if (response == NULL) {
-               conn_err(tconn, "kmalloc of response failed\n");
+               drbd_err(connection, "kmalloc of response failed\n");
                rv = -1;
                goto fail;
        }
@@ -4752,40 +4804,40 @@ static int drbd_do_auth(struct drbd_tconn *tconn)
 
        rv = crypto_hash_digest(&desc, &sg, sg.length, response);
        if (rv) {
-               conn_err(tconn, "crypto_hash_digest() failed with %d\n", rv);
+               drbd_err(connection, "crypto_hash_digest() failed with %d\n", rv);
                rv = -1;
                goto fail;
        }
 
-       if (!conn_prepare_command(tconn, sock)) {
+       if (!conn_prepare_command(connection, sock)) {
                rv = 0;
                goto fail;
        }
-       rv = !conn_send_command(tconn, sock, P_AUTH_RESPONSE, 0,
+       rv = !conn_send_command(connection, sock, P_AUTH_RESPONSE, 0,
                                response, resp_size);
        if (!rv)
                goto fail;
 
-       err = drbd_recv_header(tconn, &pi);
+       err = drbd_recv_header(connection, &pi);
        if (err) {
                rv = 0;
                goto fail;
        }
 
        if (pi.cmd != P_AUTH_RESPONSE) {
-               conn_err(tconn, "expected AuthResponse packet, received: %s (0x%04x)\n",
+               drbd_err(connection, "expected AuthResponse packet, received: %s (0x%04x)\n",
                         cmdname(pi.cmd), pi.cmd);
                rv = 0;
                goto fail;
        }
 
        if (pi.size != resp_size) {
-               conn_err(tconn, "expected AuthResponse payload of wrong size\n");
+               drbd_err(connection, "expected AuthResponse payload of wrong size\n");
                rv = 0;
                goto fail;
        }
 
-       err = drbd_recv_all_warn(tconn, response , resp_size);
+       err = drbd_recv_all_warn(connection, response , resp_size);
        if (err) {
                rv = 0;
                goto fail;
@@ -4793,7 +4845,7 @@ static int drbd_do_auth(struct drbd_tconn *tconn)
 
        right_response = kmalloc(resp_size, GFP_NOIO);
        if (right_response == NULL) {
-               conn_err(tconn, "kmalloc of right_response failed\n");
+               drbd_err(connection, "kmalloc of right_response failed\n");
                rv = -1;
                goto fail;
        }
@@ -4802,7 +4854,7 @@ static int drbd_do_auth(struct drbd_tconn *tconn)
 
        rv = crypto_hash_digest(&desc, &sg, sg.length, right_response);
        if (rv) {
-               conn_err(tconn, "crypto_hash_digest() failed with %d\n", rv);
+               drbd_err(connection, "crypto_hash_digest() failed with %d\n", rv);
                rv = -1;
                goto fail;
        }
@@ -4810,7 +4862,7 @@ static int drbd_do_auth(struct drbd_tconn *tconn)
        rv = !memcmp(response, right_response, resp_size);
 
        if (rv)
-               conn_info(tconn, "Peer authenticated using %d bytes HMAC\n",
+               drbd_info(connection, "Peer authenticated using %d bytes HMAC\n",
                     resp_size);
        else
                rv = -1;
@@ -4824,163 +4876,169 @@ static int drbd_do_auth(struct drbd_tconn *tconn)
 }
 #endif
 
-int drbdd_init(struct drbd_thread *thi)
+int drbd_receiver(struct drbd_thread *thi)
 {
-       struct drbd_tconn *tconn = thi->tconn;
+       struct drbd_connection *connection = thi->connection;
        int h;
 
-       conn_info(tconn, "receiver (re)started\n");
+       drbd_info(connection, "receiver (re)started\n");
 
        do {
-               h = conn_connect(tconn);
+               h = conn_connect(connection);
                if (h == 0) {
-                       conn_disconnect(tconn);
+                       conn_disconnect(connection);
                        schedule_timeout_interruptible(HZ);
                }
                if (h == -1) {
-                       conn_warn(tconn, "Discarding network configuration.\n");
-                       conn_request_state(tconn, NS(conn, C_DISCONNECTING), CS_HARD);
+                       drbd_warn(connection, "Discarding network configuration.\n");
+                       conn_request_state(connection, NS(conn, C_DISCONNECTING), CS_HARD);
                }
        } while (h == 0);
 
        if (h > 0)
-               drbdd(tconn);
+               drbdd(connection);
 
-       conn_disconnect(tconn);
+       conn_disconnect(connection);
 
-       conn_info(tconn, "receiver terminated\n");
+       drbd_info(connection, "receiver terminated\n");
        return 0;
 }
 
 /* ********* acknowledge sender ******** */
 
-static int got_conn_RqSReply(struct drbd_tconn *tconn, struct packet_info *pi)
+static int got_conn_RqSReply(struct drbd_connection *connection, struct packet_info *pi)
 {
        struct p_req_state_reply *p = pi->data;
        int retcode = be32_to_cpu(p->retcode);
 
        if (retcode >= SS_SUCCESS) {
-               set_bit(CONN_WD_ST_CHG_OKAY, &tconn->flags);
+               set_bit(CONN_WD_ST_CHG_OKAY, &connection->flags);
        } else {
-               set_bit(CONN_WD_ST_CHG_FAIL, &tconn->flags);
-               conn_err(tconn, "Requested state change failed by peer: %s (%d)\n",
+               set_bit(CONN_WD_ST_CHG_FAIL, &connection->flags);
+               drbd_err(connection, "Requested state change failed by peer: %s (%d)\n",
                         drbd_set_st_err_str(retcode), retcode);
        }
-       wake_up(&tconn->ping_wait);
+       wake_up(&connection->ping_wait);
 
        return 0;
 }
 
-static int got_RqSReply(struct drbd_tconn *tconn, struct packet_info *pi)
+static int got_RqSReply(struct drbd_connection *connection, struct packet_info *pi)
 {
-       struct drbd_conf *mdev;
+       struct drbd_peer_device *peer_device;
+       struct drbd_device *device;
        struct p_req_state_reply *p = pi->data;
        int retcode = be32_to_cpu(p->retcode);
 
-       mdev = vnr_to_mdev(tconn, pi->vnr);
-       if (!mdev)
+       peer_device = conn_peer_device(connection, pi->vnr);
+       if (!peer_device)
                return -EIO;
+       device = peer_device->device;
 
-       if (test_bit(CONN_WD_ST_CHG_REQ, &tconn->flags)) {
-               D_ASSERT(tconn->agreed_pro_version < 100);
-               return got_conn_RqSReply(tconn, pi);
+       if (test_bit(CONN_WD_ST_CHG_REQ, &connection->flags)) {
+               D_ASSERT(device, connection->agreed_pro_version < 100);
+               return got_conn_RqSReply(connection, pi);
        }
 
        if (retcode >= SS_SUCCESS) {
-               set_bit(CL_ST_CHG_SUCCESS, &mdev->flags);
+               set_bit(CL_ST_CHG_SUCCESS, &device->flags);
        } else {
-               set_bit(CL_ST_CHG_FAIL, &mdev->flags);
-               dev_err(DEV, "Requested state change failed by peer: %s (%d)\n",
+               set_bit(CL_ST_CHG_FAIL, &device->flags);
+               drbd_err(device, "Requested state change failed by peer: %s (%d)\n",
                        drbd_set_st_err_str(retcode), retcode);
        }
-       wake_up(&mdev->state_wait);
+       wake_up(&device->state_wait);
 
        return 0;
 }
 
-static int got_Ping(struct drbd_tconn *tconn, struct packet_info *pi)
+static int got_Ping(struct drbd_connection *connection, struct packet_info *pi)
 {
-       return drbd_send_ping_ack(tconn);
+       return drbd_send_ping_ack(connection);
 
 }
 
-static int got_PingAck(struct drbd_tconn *tconn, struct packet_info *pi)
+static int got_PingAck(struct drbd_connection *connection, struct packet_info *pi)
 {
        /* restore idle timeout */
-       tconn->meta.socket->sk->sk_rcvtimeo = tconn->net_conf->ping_int*HZ;
-       if (!test_and_set_bit(GOT_PING_ACK, &tconn->flags))
-               wake_up(&tconn->ping_wait);
+       connection->meta.socket->sk->sk_rcvtimeo = connection->net_conf->ping_int*HZ;
+       if (!test_and_set_bit(GOT_PING_ACK, &connection->flags))
+               wake_up(&connection->ping_wait);
 
        return 0;
 }
 
-static int got_IsInSync(struct drbd_tconn *tconn, struct packet_info *pi)
+static int got_IsInSync(struct drbd_connection *connection, struct packet_info *pi)
 {
-       struct drbd_conf *mdev;
+       struct drbd_peer_device *peer_device;
+       struct drbd_device *device;
        struct p_block_ack *p = pi->data;
        sector_t sector = be64_to_cpu(p->sector);
        int blksize = be32_to_cpu(p->blksize);
 
-       mdev = vnr_to_mdev(tconn, pi->vnr);
-       if (!mdev)
+       peer_device = conn_peer_device(connection, pi->vnr);
+       if (!peer_device)
                return -EIO;
+       device = peer_device->device;
 
-       D_ASSERT(mdev->tconn->agreed_pro_version >= 89);
+       D_ASSERT(device, peer_device->connection->agreed_pro_version >= 89);
 
-       update_peer_seq(mdev, be32_to_cpu(p->seq_num));
+       update_peer_seq(peer_device, be32_to_cpu(p->seq_num));
 
-       if (get_ldev(mdev)) {
-               drbd_rs_complete_io(mdev, sector);
-               drbd_set_in_sync(mdev, sector, blksize);
+       if (get_ldev(device)) {
+               drbd_rs_complete_io(device, sector);
+               drbd_set_in_sync(device, sector, blksize);
                /* rs_same_csums is supposed to count in units of BM_BLOCK_SIZE */
-               mdev->rs_same_csum += (blksize >> BM_BLOCK_SHIFT);
-               put_ldev(mdev);
+               device->rs_same_csum += (blksize >> BM_BLOCK_SHIFT);
+               put_ldev(device);
        }
-       dec_rs_pending(mdev);
-       atomic_add(blksize >> 9, &mdev->rs_sect_in);
+       dec_rs_pending(device);
+       atomic_add(blksize >> 9, &device->rs_sect_in);
 
        return 0;
 }
 
 static int
-validate_req_change_req_state(struct drbd_conf *mdev, u64 id, sector_t sector,
+validate_req_change_req_state(struct drbd_device *device, u64 id, sector_t sector,
                              struct rb_root *root, const char *func,
                              enum drbd_req_event what, bool missing_ok)
 {
        struct drbd_request *req;
        struct bio_and_error m;
 
-       spin_lock_irq(&mdev->tconn->req_lock);
-       req = find_request(mdev, root, id, sector, missing_ok, func);
+       spin_lock_irq(&device->resource->req_lock);
+       req = find_request(device, root, id, sector, missing_ok, func);
        if (unlikely(!req)) {
-               spin_unlock_irq(&mdev->tconn->req_lock);
+               spin_unlock_irq(&device->resource->req_lock);
                return -EIO;
        }
        __req_mod(req, what, &m);
-       spin_unlock_irq(&mdev->tconn->req_lock);
+       spin_unlock_irq(&device->resource->req_lock);
 
        if (m.bio)
-               complete_master_bio(mdev, &m);
+               complete_master_bio(device, &m);
        return 0;
 }
 
-static int got_BlockAck(struct drbd_tconn *tconn, struct packet_info *pi)
+static int got_BlockAck(struct drbd_connection *connection, struct packet_info *pi)
 {
-       struct drbd_conf *mdev;
+       struct drbd_peer_device *peer_device;
+       struct drbd_device *device;
        struct p_block_ack *p = pi->data;
        sector_t sector = be64_to_cpu(p->sector);
        int blksize = be32_to_cpu(p->blksize);
        enum drbd_req_event what;
 
-       mdev = vnr_to_mdev(tconn, pi->vnr);
-       if (!mdev)
+       peer_device = conn_peer_device(connection, pi->vnr);
+       if (!peer_device)
                return -EIO;
+       device = peer_device->device;
 
-       update_peer_seq(mdev, be32_to_cpu(p->seq_num));
+       update_peer_seq(peer_device, be32_to_cpu(p->seq_num));
 
        if (p->block_id == ID_SYNCER) {
-               drbd_set_in_sync(mdev, sector, blksize);
-               dec_rs_pending(mdev);
+               drbd_set_in_sync(device, sector, blksize);
+               dec_rs_pending(device);
                return 0;
        }
        switch (pi->cmd) {
@@ -5003,33 +5061,35 @@ static int got_BlockAck(struct drbd_tconn *tconn, struct packet_info *pi)
                BUG();
        }
 
-       return validate_req_change_req_state(mdev, p->block_id, sector,
-                                            &mdev->write_requests, __func__,
+       return validate_req_change_req_state(device, p->block_id, sector,
+                                            &device->write_requests, __func__,
                                             what, false);
 }
 
-static int got_NegAck(struct drbd_tconn *tconn, struct packet_info *pi)
+static int got_NegAck(struct drbd_connection *connection, struct packet_info *pi)
 {
-       struct drbd_conf *mdev;
+       struct drbd_peer_device *peer_device;
+       struct drbd_device *device;
        struct p_block_ack *p = pi->data;
        sector_t sector = be64_to_cpu(p->sector);
        int size = be32_to_cpu(p->blksize);
        int err;
 
-       mdev = vnr_to_mdev(tconn, pi->vnr);
-       if (!mdev)
+       peer_device = conn_peer_device(connection, pi->vnr);
+       if (!peer_device)
                return -EIO;
+       device = peer_device->device;
 
-       update_peer_seq(mdev, be32_to_cpu(p->seq_num));
+       update_peer_seq(peer_device, be32_to_cpu(p->seq_num));
 
        if (p->block_id == ID_SYNCER) {
-               dec_rs_pending(mdev);
-               drbd_rs_failed_io(mdev, sector, size);
+               dec_rs_pending(device);
+               drbd_rs_failed_io(device, sector, size);
                return 0;
        }
 
-       err = validate_req_change_req_state(mdev, p->block_id, sector,
-                                           &mdev->write_requests, __func__,
+       err = validate_req_change_req_state(device, p->block_id, sector,
+                                           &device->write_requests, __func__,
                                            NEG_ACKED, true);
        if (err) {
                /* Protocol A has no P_WRITE_ACKs, but has P_NEG_ACKs.
@@ -5037,80 +5097,86 @@ static int got_NegAck(struct drbd_tconn *tconn, struct packet_info *pi)
                   request is no longer in the collision hash. */
                /* In Protocol B we might already have got a P_RECV_ACK
                   but then get a P_NEG_ACK afterwards. */
-               drbd_set_out_of_sync(mdev, sector, size);
+               drbd_set_out_of_sync(device, sector, size);
        }
        return 0;
 }
 
-static int got_NegDReply(struct drbd_tconn *tconn, struct packet_info *pi)
+static int got_NegDReply(struct drbd_connection *connection, struct packet_info *pi)
 {
-       struct drbd_conf *mdev;
+       struct drbd_peer_device *peer_device;
+       struct drbd_device *device;
        struct p_block_ack *p = pi->data;
        sector_t sector = be64_to_cpu(p->sector);
 
-       mdev = vnr_to_mdev(tconn, pi->vnr);
-       if (!mdev)
+       peer_device = conn_peer_device(connection, pi->vnr);
+       if (!peer_device)
                return -EIO;
+       device = peer_device->device;
 
-       update_peer_seq(mdev, be32_to_cpu(p->seq_num));
+       update_peer_seq(peer_device, be32_to_cpu(p->seq_num));
 
-       dev_err(DEV, "Got NegDReply; Sector %llus, len %u.\n",
+       drbd_err(device, "Got NegDReply; Sector %llus, len %u.\n",
            (unsigned long long)sector, be32_to_cpu(p->blksize));
 
-       return validate_req_change_req_state(mdev, p->block_id, sector,
-                                            &mdev->read_requests, __func__,
+       return validate_req_change_req_state(device, p->block_id, sector,
+                                            &device->read_requests, __func__,
                                             NEG_ACKED, false);
 }
 
-static int got_NegRSDReply(struct drbd_tconn *tconn, struct packet_info *pi)
+static int got_NegRSDReply(struct drbd_connection *connection, struct packet_info *pi)
 {
-       struct drbd_conf *mdev;
+       struct drbd_peer_device *peer_device;
+       struct drbd_device *device;
        sector_t sector;
        int size;
        struct p_block_ack *p = pi->data;
 
-       mdev = vnr_to_mdev(tconn, pi->vnr);
-       if (!mdev)
+       peer_device = conn_peer_device(connection, pi->vnr);
+       if (!peer_device)
                return -EIO;
+       device = peer_device->device;
 
        sector = be64_to_cpu(p->sector);
        size = be32_to_cpu(p->blksize);
 
-       update_peer_seq(mdev, be32_to_cpu(p->seq_num));
+       update_peer_seq(peer_device, be32_to_cpu(p->seq_num));
 
-       dec_rs_pending(mdev);
+       dec_rs_pending(device);
 
-       if (get_ldev_if_state(mdev, D_FAILED)) {
-               drbd_rs_complete_io(mdev, sector);
+       if (get_ldev_if_state(device, D_FAILED)) {
+               drbd_rs_complete_io(device, sector);
                switch (pi->cmd) {
                case P_NEG_RS_DREPLY:
-                       drbd_rs_failed_io(mdev, sector, size);
+                       drbd_rs_failed_io(device, sector, size);
                case P_RS_CANCEL:
                        break;
                default:
                        BUG();
                }
-               put_ldev(mdev);
+               put_ldev(device);
        }
 
        return 0;
 }
 
-static int got_BarrierAck(struct drbd_tconn *tconn, struct packet_info *pi)
+static int got_BarrierAck(struct drbd_connection *connection, struct packet_info *pi)
 {
        struct p_barrier_ack *p = pi->data;
-       struct drbd_conf *mdev;
+       struct drbd_peer_device *peer_device;
        int vnr;
 
-       tl_release(tconn, p->barrier, be32_to_cpu(p->set_size));
+       tl_release(connection, p->barrier, be32_to_cpu(p->set_size));
 
        rcu_read_lock();
-       idr_for_each_entry(&tconn->volumes, mdev, vnr) {
-               if (mdev->state.conn == C_AHEAD &&
-                   atomic_read(&mdev->ap_in_flight) == 0 &&
-                   !test_and_set_bit(AHEAD_TO_SYNC_SOURCE, &mdev->flags)) {
-                       mdev->start_resync_timer.expires = jiffies + HZ;
-                       add_timer(&mdev->start_resync_timer);
+       idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
+               struct drbd_device *device = peer_device->device;
+
+               if (device->state.conn == C_AHEAD &&
+                   atomic_read(&device->ap_in_flight) == 0 &&
+                   !test_and_set_bit(AHEAD_TO_SYNC_SOURCE, &device->flags)) {
+                       device->start_resync_timer.expires = jiffies + HZ;
+                       add_timer(&device->start_resync_timer);
                }
        }
        rcu_read_unlock();
@@ -5118,90 +5184,94 @@ static int got_BarrierAck(struct drbd_tconn *tconn, struct packet_info *pi)
        return 0;
 }
 
-static int got_OVResult(struct drbd_tconn *tconn, struct packet_info *pi)
+static int got_OVResult(struct drbd_connection *connection, struct packet_info *pi)
 {
-       struct drbd_conf *mdev;
+       struct drbd_peer_device *peer_device;
+       struct drbd_device *device;
        struct p_block_ack *p = pi->data;
-       struct drbd_work *w;
+       struct drbd_device_work *dw;
        sector_t sector;
        int size;
 
-       mdev = vnr_to_mdev(tconn, pi->vnr);
-       if (!mdev)
+       peer_device = conn_peer_device(connection, pi->vnr);
+       if (!peer_device)
                return -EIO;
+       device = peer_device->device;
 
        sector = be64_to_cpu(p->sector);
        size = be32_to_cpu(p->blksize);
 
-       update_peer_seq(mdev, be32_to_cpu(p->seq_num));
+       update_peer_seq(peer_device, be32_to_cpu(p->seq_num));
 
        if (be64_to_cpu(p->block_id) == ID_OUT_OF_SYNC)
-               drbd_ov_out_of_sync_found(mdev, sector, size);
+               drbd_ov_out_of_sync_found(device, sector, size);
        else
-               ov_out_of_sync_print(mdev);
+               ov_out_of_sync_print(device);
 
-       if (!get_ldev(mdev))
+       if (!get_ldev(device))
                return 0;
 
-       drbd_rs_complete_io(mdev, sector);
-       dec_rs_pending(mdev);
+       drbd_rs_complete_io(device, sector);
+       dec_rs_pending(device);
 
-       --mdev->ov_left;
+       --device->ov_left;
 
        /* let's advance progress step marks only for every other megabyte */
-       if ((mdev->ov_left & 0x200) == 0x200)
-               drbd_advance_rs_marks(mdev, mdev->ov_left);
-
-       if (mdev->ov_left == 0) {
-               w = kmalloc(sizeof(*w), GFP_NOIO);
-               if (w) {
-                       w->cb = w_ov_finished;
-                       w->mdev = mdev;
-                       drbd_queue_work(&mdev->tconn->sender_work, w);
+       if ((device->ov_left & 0x200) == 0x200)
+               drbd_advance_rs_marks(device, device->ov_left);
+
+       if (device->ov_left == 0) {
+               dw = kmalloc(sizeof(*dw), GFP_NOIO);
+               if (dw) {
+                       dw->w.cb = w_ov_finished;
+                       dw->device = device;
+                       drbd_queue_work(&peer_device->connection->sender_work, &dw->w);
                } else {
-                       dev_err(DEV, "kmalloc(w) failed.");
-                       ov_out_of_sync_print(mdev);
-                       drbd_resync_finished(mdev);
+                       drbd_err(device, "kmalloc(dw) failed.");
+                       ov_out_of_sync_print(device);
+                       drbd_resync_finished(device);
                }
        }
-       put_ldev(mdev);
+       put_ldev(device);
        return 0;
 }
 
-static int got_skip(struct drbd_tconn *tconn, struct packet_info *pi)
+static int got_skip(struct drbd_connection *connection, struct packet_info *pi)
 {
        return 0;
 }
 
-static int tconn_finish_peer_reqs(struct drbd_tconn *tconn)
+static int connection_finish_peer_reqs(struct drbd_connection *connection)
 {
-       struct drbd_conf *mdev;
+       struct drbd_peer_device *peer_device;
        int vnr, not_empty = 0;
 
        do {
-               clear_bit(SIGNAL_ASENDER, &tconn->flags);
+               clear_bit(SIGNAL_ASENDER, &connection->flags);
                flush_signals(current);
 
                rcu_read_lock();
-               idr_for_each_entry(&tconn->volumes, mdev, vnr) {
-                       kref_get(&mdev->kref);
+               idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
+                       struct drbd_device *device = peer_device->device;
+                       kref_get(&device->kref);
                        rcu_read_unlock();
-                       if (drbd_finish_peer_reqs(mdev)) {
-                               kref_put(&mdev->kref, &drbd_minor_destroy);
+                       if (drbd_finish_peer_reqs(device)) {
+                               kref_put(&device->kref, drbd_destroy_device);
                                return 1;
                        }
-                       kref_put(&mdev->kref, &drbd_minor_destroy);
+                       kref_put(&device->kref, drbd_destroy_device);
                        rcu_read_lock();
                }
-               set_bit(SIGNAL_ASENDER, &tconn->flags);
+               set_bit(SIGNAL_ASENDER, &connection->flags);
 
-               spin_lock_irq(&tconn->req_lock);
-               idr_for_each_entry(&tconn->volumes, mdev, vnr) {
-                       not_empty = !list_empty(&mdev->done_ee);
+               spin_lock_irq(&connection->resource->req_lock);
+               idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
+                       struct drbd_device *device = peer_device->device;
+                       not_empty = !list_empty(&device->done_ee);
                        if (not_empty)
                                break;
                }
-               spin_unlock_irq(&tconn->req_lock);
+               spin_unlock_irq(&connection->resource->req_lock);
                rcu_read_unlock();
        } while (not_empty);
 
@@ -5210,7 +5280,7 @@ static int tconn_finish_peer_reqs(struct drbd_tconn *tconn)
 
 struct asender_cmd {
        size_t pkt_size;
-       int (*fn)(struct drbd_tconn *tconn, struct packet_info *);
+       int (*fn)(struct drbd_connection *connection, struct packet_info *);
 };
 
 static struct asender_cmd asender_tbl[] = {
@@ -5235,13 +5305,13 @@ static struct asender_cmd asender_tbl[] = {
 
 int drbd_asender(struct drbd_thread *thi)
 {
-       struct drbd_tconn *tconn = thi->tconn;
+       struct drbd_connection *connection = thi->connection;
        struct asender_cmd *cmd = NULL;
        struct packet_info pi;
        int rv;
-       void *buf    = tconn->meta.rbuf;
+       void *buf    = connection->meta.rbuf;
        int received = 0;
-       unsigned int header_size = drbd_header_size(tconn);
+       unsigned int header_size = drbd_header_size(connection);
        int expect   = header_size;
        bool ping_timeout_active = false;
        struct net_conf *nc;
@@ -5250,45 +5320,45 @@ int drbd_asender(struct drbd_thread *thi)
 
        rv = sched_setscheduler(current, SCHED_RR, &param);
        if (rv < 0)
-               conn_err(tconn, "drbd_asender: ERROR set priority, ret=%d\n", rv);
+               drbd_err(connection, "drbd_asender: ERROR set priority, ret=%d\n", rv);
 
        while (get_t_state(thi) == RUNNING) {
                drbd_thread_current_set_cpu(thi);
 
                rcu_read_lock();
-               nc = rcu_dereference(tconn->net_conf);
+               nc = rcu_dereference(connection->net_conf);
                ping_timeo = nc->ping_timeo;
                tcp_cork = nc->tcp_cork;
                ping_int = nc->ping_int;
                rcu_read_unlock();
 
-               if (test_and_clear_bit(SEND_PING, &tconn->flags)) {
-                       if (drbd_send_ping(tconn)) {
-                               conn_err(tconn, "drbd_send_ping has failed\n");
+               if (test_and_clear_bit(SEND_PING, &connection->flags)) {
+                       if (drbd_send_ping(connection)) {
+                               drbd_err(connection, "drbd_send_ping has failed\n");
                                goto reconnect;
                        }
-                       tconn->meta.socket->sk->sk_rcvtimeo = ping_timeo * HZ / 10;
+                       connection->meta.socket->sk->sk_rcvtimeo = ping_timeo * HZ / 10;
                        ping_timeout_active = true;
                }
 
                /* TODO: conditionally cork; it may hurt latency if we cork without
                   much to send */
                if (tcp_cork)
-                       drbd_tcp_cork(tconn->meta.socket);
-               if (tconn_finish_peer_reqs(tconn)) {
-                       conn_err(tconn, "tconn_finish_peer_reqs() failed\n");
+                       drbd_tcp_cork(connection->meta.socket);
+               if (connection_finish_peer_reqs(connection)) {
+                       drbd_err(connection, "connection_finish_peer_reqs() failed\n");
                        goto reconnect;
                }
                /* but unconditionally uncork unless disabled */
                if (tcp_cork)
-                       drbd_tcp_uncork(tconn->meta.socket);
+                       drbd_tcp_uncork(connection->meta.socket);
 
                /* short circuit, recv_msg would return EINTR anyways. */
                if (signal_pending(current))
                        continue;
 
-               rv = drbd_recv_short(tconn->meta.socket, buf, expect-received, 0);
-               clear_bit(SIGNAL_ASENDER, &tconn->flags);
+               rv = drbd_recv_short(connection->meta.socket, buf, expect-received, 0);
+               clear_bit(SIGNAL_ASENDER, &connection->flags);
 
                flush_signals(current);
 
@@ -5306,51 +5376,51 @@ int drbd_asender(struct drbd_thread *thi)
                        received += rv;
                        buf      += rv;
                } else if (rv == 0) {
-                       if (test_bit(DISCONNECT_SENT, &tconn->flags)) {
+                       if (test_bit(DISCONNECT_SENT, &connection->flags)) {
                                long t;
                                rcu_read_lock();
-                               t = rcu_dereference(tconn->net_conf)->ping_timeo * HZ/10;
+                               t = rcu_dereference(connection->net_conf)->ping_timeo * HZ/10;
                                rcu_read_unlock();
 
-                               t = wait_event_timeout(tconn->ping_wait,
-                                                      tconn->cstate < C_WF_REPORT_PARAMS,
+                               t = wait_event_timeout(connection->ping_wait,
+                                                      connection->cstate < C_WF_REPORT_PARAMS,
                                                       t);
                                if (t)
                                        break;
                        }
-                       conn_err(tconn, "meta connection shut down by peer.\n");
+                       drbd_err(connection, "meta connection shut down by peer.\n");
                        goto reconnect;
                } else if (rv == -EAGAIN) {
                        /* If the data socket received something meanwhile,
                         * that is good enough: peer is still alive. */
-                       if (time_after(tconn->last_received,
-                               jiffies - tconn->meta.socket->sk->sk_rcvtimeo))
+                       if (time_after(connection->last_received,
+                               jiffies - connection->meta.socket->sk->sk_rcvtimeo))
                                continue;
                        if (ping_timeout_active) {
-                               conn_err(tconn, "PingAck did not arrive in time.\n");
+                               drbd_err(connection, "PingAck did not arrive in time.\n");
                                goto reconnect;
                        }
-                       set_bit(SEND_PING, &tconn->flags);
+                       set_bit(SEND_PING, &connection->flags);
                        continue;
                } else if (rv == -EINTR) {
                        continue;
                } else {
-                       conn_err(tconn, "sock_recvmsg returned %d\n", rv);
+                       drbd_err(connection, "sock_recvmsg returned %d\n", rv);
                        goto reconnect;
                }
 
                if (received == expect && cmd == NULL) {
-                       if (decode_header(tconn, tconn->meta.rbuf, &pi))
+                       if (decode_header(connection, connection->meta.rbuf, &pi))
                                goto reconnect;
                        cmd = &asender_tbl[pi.cmd];
                        if (pi.cmd >= ARRAY_SIZE(asender_tbl) || !cmd->fn) {
-                               conn_err(tconn, "Unexpected meta packet %s (0x%04x)\n",
+                               drbd_err(connection, "Unexpected meta packet %s (0x%04x)\n",
                                         cmdname(pi.cmd), pi.cmd);
                                goto disconnect;
                        }
                        expect = header_size + cmd->pkt_size;
                        if (pi.size != expect - header_size) {
-                               conn_err(tconn, "Wrong packet size on meta (c: %d, l: %d)\n",
+                               drbd_err(connection, "Wrong packet size on meta (c: %d, l: %d)\n",
                                        pi.cmd, pi.size);
                                goto reconnect;
                        }
@@ -5358,21 +5428,21 @@ int drbd_asender(struct drbd_thread *thi)
                if (received == expect) {
                        bool err;
 
-                       err = cmd->fn(tconn, &pi);
+                       err = cmd->fn(connection, &pi);
                        if (err) {
-                               conn_err(tconn, "%pf failed\n", cmd->fn);
+                               drbd_err(connection, "%pf failed\n", cmd->fn);
                                goto reconnect;
                        }
 
-                       tconn->last_received = jiffies;
+                       connection->last_received = jiffies;
 
                        if (cmd == &asender_tbl[P_PING_ACK]) {
                                /* restore idle timeout */
-                               tconn->meta.socket->sk->sk_rcvtimeo = ping_int * HZ;
+                               connection->meta.socket->sk->sk_rcvtimeo = ping_int * HZ;
                                ping_timeout_active = false;
                        }
 
-                       buf      = tconn->meta.rbuf;
+                       buf      = connection->meta.rbuf;
                        received = 0;
                        expect   = header_size;
                        cmd      = NULL;
@@ -5381,16 +5451,16 @@ int drbd_asender(struct drbd_thread *thi)
 
        if (0) {
 reconnect:
-               conn_request_state(tconn, NS(conn, C_NETWORK_FAILURE), CS_HARD);
-               conn_md_sync(tconn);
+               conn_request_state(connection, NS(conn, C_NETWORK_FAILURE), CS_HARD);
+               conn_md_sync(connection);
        }
        if (0) {
 disconnect:
-               conn_request_state(tconn, NS(conn, C_DISCONNECTING), CS_HARD);
+               conn_request_state(connection, NS(conn, C_DISCONNECTING), CS_HARD);
        }
-       clear_bit(SIGNAL_ASENDER, &tconn->flags);
+       clear_bit(SIGNAL_ASENDER, &connection->flags);
 
-       conn_info(tconn, "asender terminated\n");
+       drbd_info(connection, "asender terminated\n");
 
        return 0;
 }