]> www.infradead.org Git - users/dwmw2/linux.git/commitdiff
drbd: Pass a peer device to the resync and online verify functions
authorChristoph Böhmwalder <christoph.boehmwalder@linbit.com>
Thu, 30 Mar 2023 10:27:44 +0000 (12:27 +0200)
committerJens Axboe <axboe@kernel.dk>
Sun, 2 Apr 2023 02:27:55 +0000 (20:27 -0600)
Originally-from: Andreas Grünbacher <agruen@linbit.com>
Signed-off-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Link: https://lore.kernel.org/r/20230330102744.2128122-2-christoph.boehmwalder@linbit.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
drivers/block/drbd/drbd_actlog.c
drivers/block/drbd/drbd_int.h
drivers/block/drbd/drbd_receiver.c
drivers/block/drbd/drbd_req.c
drivers/block/drbd/drbd_state.c
drivers/block/drbd/drbd_worker.c

index 429255876800458d796d6953f85b6df5e1ac7311..64b3a1c76f03d703e69e8bcc0749fc4d947439b1 100644 (file)
@@ -735,8 +735,9 @@ static bool update_rs_extent(struct drbd_device *device,
        return false;
 }
 
-void drbd_advance_rs_marks(struct drbd_device *device, unsigned long still_to_go)
+void drbd_advance_rs_marks(struct drbd_peer_device *peer_device, unsigned long still_to_go)
 {
+       struct drbd_device *device = peer_device->device;
        unsigned long now = jiffies;
        unsigned long last = device->rs_mark_time[device->rs_last_mark];
        int next = (device->rs_last_mark + 1) % DRBD_SYNC_MARKS;
@@ -819,7 +820,7 @@ static int update_sync_bits(struct drbd_device *device,
                if (mode == SET_IN_SYNC) {
                        unsigned long still_to_go = drbd_bm_total_weight(device);
                        bool rs_is_done = (still_to_go <= device->rs_failed);
-                       drbd_advance_rs_marks(device, still_to_go);
+                       drbd_advance_rs_marks(first_peer_device(device), still_to_go);
                        if (cleared || rs_is_done)
                                maybe_schedule_on_disk_bitmap_update(device, rs_is_done);
                } else if (mode == RECORD_RS_FAILED)
@@ -843,10 +844,11 @@ static bool plausible_request_size(int size)
  * called by worker on C_SYNC_TARGET and receiver on SyncSource.
  *
  */
-int __drbd_change_sync(struct drbd_device *device, sector_t sector, int size,
+int __drbd_change_sync(struct drbd_peer_device *peer_device, sector_t sector, int size,
                enum update_sync_bits_mode mode)
 {
        /* Is called from worker and receiver context _only_ */
+       struct drbd_device *device = peer_device->device;
        unsigned long sbnr, ebnr, lbnr;
        unsigned long count = 0;
        sector_t esector, nr_sectors;
@@ -1009,14 +1011,15 @@ retry:
  * tries to set it to BME_LOCKED. Returns 0 upon success, and -EAGAIN
  * if there is still application IO going on in this area.
  */
-int drbd_try_rs_begin_io(struct drbd_device *device, sector_t sector)
+int drbd_try_rs_begin_io(struct drbd_peer_device *peer_device, sector_t sector)
 {
+       struct drbd_device *device = peer_device->device;
        unsigned int enr = BM_SECT_TO_EXT(sector);
        const unsigned int al_enr = enr*AL_EXT_PER_BM_SECT;
        struct lc_element *e;
        struct bm_extent *bm_ext;
        int i;
-       bool throttle = drbd_rs_should_slow_down(device, sector, true);
+       bool throttle = drbd_rs_should_slow_down(peer_device, sector, true);
 
        /* If we need to throttle, a half-locked (only marked BME_NO_WRITES,
         * not yet BME_LOCKED) extent needs to be kicked out explicitly if we
index 97c091990bf6e03da495b987dee5e8189dde139d..a30a5ed811bea8e9f4486d004a9159f9a2a3cb9c 100644 (file)
@@ -1433,21 +1433,24 @@ void drbd_resync_after_changed(struct drbd_device *device);
 extern void drbd_start_resync(struct drbd_device *device, enum drbd_conns side);
 extern void resume_next_sg(struct drbd_device *device);
 extern void suspend_other_sg(struct drbd_device *device);
-extern int drbd_resync_finished(struct drbd_device *device);
+extern int drbd_resync_finished(struct drbd_peer_device *peer_device);
 /* maybe rather drbd_main.c ? */
 extern void *drbd_md_get_buffer(struct drbd_device *device, const char *intent);
 extern void drbd_md_put_buffer(struct drbd_device *device);
 extern int drbd_md_sync_page_io(struct drbd_device *device,
                struct drbd_backing_dev *bdev, sector_t sector, enum req_op op);
-extern void drbd_ov_out_of_sync_found(struct drbd_device *, sector_t, int);
+extern void drbd_ov_out_of_sync_found(struct drbd_peer_device *peer_device,
+               sector_t sector, int size);
 extern void wait_until_done_or_force_detached(struct drbd_device *device,
                struct drbd_backing_dev *bdev, unsigned int *done);
-extern void drbd_rs_controller_reset(struct drbd_device *device);
+extern void drbd_rs_controller_reset(struct drbd_peer_device *peer_device);
 
-static inline void ov_out_of_sync_print(struct drbd_device *device)
+static inline void ov_out_of_sync_print(struct drbd_peer_device *peer_device)
 {
+       struct drbd_device *device = peer_device->device;
+
        if (device->ov_last_oos_size) {
-               drbd_err(device, "Out of sync: start=%llu, size=%lu (sectors)\n",
+               drbd_err(peer_device, "Out of sync: start=%llu, size=%lu (sectors)\n",
                     (unsigned long long)device->ov_last_oos_start,
                     (unsigned long)device->ov_last_oos_size);
        }
@@ -1486,7 +1489,7 @@ extern int drbd_ack_receiver(struct drbd_thread *thi);
 extern void drbd_send_ping_wf(struct work_struct *ws);
 extern void drbd_send_acks_wf(struct work_struct *ws);
 extern bool drbd_rs_c_min_rate_throttle(struct drbd_device *device);
-extern bool drbd_rs_should_slow_down(struct drbd_device *device, sector_t sector,
+extern bool drbd_rs_should_slow_down(struct drbd_peer_device *peer_device, sector_t sector,
                bool throttle_if_app_is_waiting);
 extern int drbd_submit_peer_request(struct drbd_peer_request *peer_req);
 extern int drbd_free_peer_reqs(struct drbd_device *, struct list_head *);
@@ -1542,22 +1545,22 @@ extern void drbd_al_begin_io(struct drbd_device *device, struct drbd_interval *i
 extern void drbd_al_complete_io(struct drbd_device *device, struct drbd_interval *i);
 extern void drbd_rs_complete_io(struct drbd_device *device, sector_t sector);
 extern int drbd_rs_begin_io(struct drbd_device *device, sector_t sector);
-extern int drbd_try_rs_begin_io(struct drbd_device *device, sector_t sector);
+extern int drbd_try_rs_begin_io(struct drbd_peer_device *peer_device, sector_t sector);
 extern void drbd_rs_cancel_all(struct drbd_device *device);
 extern int drbd_rs_del_all(struct drbd_device *device);
-extern void drbd_rs_failed_io(struct drbd_device *device,
+extern void drbd_rs_failed_io(struct drbd_peer_device *peer_device,
                sector_t sector, int size);
-extern void drbd_advance_rs_marks(struct drbd_device *device, unsigned long still_to_go);
+extern void drbd_advance_rs_marks(struct drbd_peer_device *peer_device, unsigned long still_to_go);
 
 enum update_sync_bits_mode { RECORD_RS_FAILED, SET_OUT_OF_SYNC, SET_IN_SYNC };
-extern int __drbd_change_sync(struct drbd_device *device, sector_t sector, int size,
+extern int __drbd_change_sync(struct drbd_peer_device *peer_device, sector_t sector, int size,
                enum update_sync_bits_mode mode);
-#define drbd_set_in_sync(device, sector, size) \
-       __drbd_change_sync(device, sector, size, SET_IN_SYNC)
-#define drbd_set_out_of_sync(device, sector, size) \
-       __drbd_change_sync(device, sector, size, SET_OUT_OF_SYNC)
-#define drbd_rs_failed_io(device, sector, size) \
-       __drbd_change_sync(device, sector, size, RECORD_RS_FAILED)
+#define drbd_set_in_sync(peer_device, sector, size) \
+       __drbd_change_sync(peer_device, sector, size, SET_IN_SYNC)
+#define drbd_set_out_of_sync(peer_device, sector, size) \
+       __drbd_change_sync(peer_device, sector, size, SET_OUT_OF_SYNC)
+#define drbd_rs_failed_io(peer_device, sector, size) \
+       __drbd_change_sync(peer_device, sector, size, RECORD_RS_FAILED)
 extern void drbd_al_shrink(struct drbd_device *device);
 extern int drbd_al_initialize(struct drbd_device *, void *);
 
@@ -1945,15 +1948,16 @@ static inline int __dec_ap_pending(struct drbd_device *device)
  * C_SYNC_SOURCE sends P_RS_DATA_REPLY   (and expects P_WRITE_ACK with ID_SYNCER)
  *                                        (or P_NEG_ACK with ID_SYNCER)
  */
-static inline void inc_rs_pending(struct drbd_device *device)
+static inline void inc_rs_pending(struct drbd_peer_device *peer_device)
 {
-       atomic_inc(&device->rs_pending_cnt);
+       atomic_inc(&peer_device->device->rs_pending_cnt);
 }
 
-#define dec_rs_pending(device) ((void)expect((device), __dec_rs_pending(device) >= 0))
-static inline int __dec_rs_pending(struct drbd_device *device)
+#define dec_rs_pending(peer_device) \
+       ((void)expect((peer_device), __dec_rs_pending(peer_device) >= 0))
+static inline int __dec_rs_pending(struct drbd_peer_device *peer_device)
 {
-       return atomic_dec_return(&device->rs_pending_cnt);
+       return atomic_dec_return(&peer_device->device->rs_pending_cnt);
 }
 
 /* counts how many answers we still need to send to the peer.
index 856c0e3a66300464e1ef70986a8402bd7606d62c..e54404c632e72d98c987a7b023a474b8eb51fe81 100644 (file)
@@ -2044,11 +2044,11 @@ static int e_end_resync_block(struct drbd_work *w, int unused)
        D_ASSERT(device, drbd_interval_empty(&peer_req->i));
 
        if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) {
-               drbd_set_in_sync(device, sector, peer_req->i.size);
+               drbd_set_in_sync(peer_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(device, sector, peer_req->i.size);
+               drbd_rs_failed_io(peer_device, sector, peer_req->i.size);
 
                err  = drbd_send_ack(peer_device, P_NEG_ACK, peer_req);
        }
@@ -2067,7 +2067,7 @@ static int recv_resync_read(struct drbd_peer_device *peer_device, sector_t secto
        if (!peer_req)
                goto fail;
 
-       dec_rs_pending(device);
+       dec_rs_pending(peer_device);
 
        inc_unacked(device);
        /* corresponding dec_unacked() in e_end_resync_block()
@@ -2220,7 +2220,7 @@ static int e_end_block(struct drbd_work *w, int cancel)
                                P_RS_WRITE_ACK : P_WRITE_ACK;
                        err = drbd_send_ack(peer_device, pcmd, peer_req);
                        if (pcmd == P_RS_WRITE_ACK)
-                               drbd_set_in_sync(device, sector, peer_req->i.size);
+                               drbd_set_in_sync(peer_device, sector, peer_req->i.size);
                } else {
                        err = drbd_send_ack(peer_device, P_NEG_ACK, peer_req);
                        /* we expect it to be marked out of sync anyways...
@@ -2691,7 +2691,7 @@ static int receive_Data(struct drbd_connection *connection, struct packet_info *
 
        if (device->state.pdsk < D_INCONSISTENT) {
                /* In case we have the only disk of the cluster, */
-               drbd_set_out_of_sync(device, peer_req->i.sector, peer_req->i.size);
+               drbd_set_out_of_sync(peer_device, peer_req->i.sector, peer_req->i.size);
                peer_req->flags &= ~EE_MAY_SET_IN_SYNC;
                drbd_al_begin_io(device, &peer_req->i);
                peer_req->flags |= EE_CALL_AL_COMPLETE_IO;
@@ -2730,9 +2730,10 @@ 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.
  */
-bool drbd_rs_should_slow_down(struct drbd_device *device, sector_t sector,
+bool drbd_rs_should_slow_down(struct drbd_peer_device *peer_device, sector_t sector,
                bool throttle_if_app_is_waiting)
 {
+       struct drbd_device *device = peer_device->device;
        struct lc_element *tmp;
        bool throttle = drbd_rs_c_min_rate_throttle(device);
 
@@ -2844,7 +2845,7 @@ static int receive_DataRequest(struct drbd_connection *connection, struct packet
                        break;
                case P_OV_REPLY:
                        verb = 0;
-                       dec_rs_pending(device);
+                       dec_rs_pending(peer_device);
                        drbd_send_ack_ex(peer_device, P_OV_RESULT, sector, size, ID_IN_SYNC);
                        break;
                default:
@@ -2915,7 +2916,7 @@ static int receive_DataRequest(struct drbd_connection *connection, struct packet
                        /* track progress, we may need to throttle */
                        atomic_add(size >> 9, &device->rs_sect_in);
                        peer_req->w.cb = w_e_end_ov_reply;
-                       dec_rs_pending(device);
+                       dec_rs_pending(peer_device);
                        /* drbd_rs_begin_io done when we sent this request,
                         * but accounting still needs to be done. */
                        goto submit_for_resync;
@@ -2978,7 +2979,7 @@ static int receive_DataRequest(struct drbd_connection *connection, struct packet
 
        update_receiver_timing_details(connection, drbd_rs_should_slow_down);
        if (device->state.peer != R_PRIMARY
-       && drbd_rs_should_slow_down(device, sector, false))
+       && drbd_rs_should_slow_down(peer_device, sector, false))
                schedule_timeout_uninterruptible(HZ/10);
        update_receiver_timing_details(connection, drbd_rs_begin_io);
        if (drbd_rs_begin_io(device, sector))
@@ -4450,7 +4451,7 @@ static int receive_state(struct drbd_connection *connection, struct packet_info
                else if (os.conn >= C_SYNC_SOURCE &&
                         peer_state.conn == C_CONNECTED) {
                        if (drbd_bm_total_weight(device) <= device->rs_failed)
-                               drbd_resync_finished(device);
+                               drbd_resync_finished(peer_device);
                        return 0;
                }
        }
@@ -4458,8 +4459,8 @@ static int receive_state(struct drbd_connection *connection, struct packet_info
        /* 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(device);
-               drbd_resync_finished(device);
+               ov_out_of_sync_print(peer_device);
+               drbd_resync_finished(peer_device);
                return 0;
        }
 
@@ -4937,7 +4938,7 @@ static int receive_out_of_sync(struct drbd_connection *connection, struct packet
                                drbd_conn_str(device->state.conn));
        }
 
-       drbd_set_out_of_sync(device, be64_to_cpu(p->sector), be32_to_cpu(p->blksize));
+       drbd_set_out_of_sync(peer_device, be64_to_cpu(p->sector), be32_to_cpu(p->blksize));
 
        return 0;
 }
@@ -4958,7 +4959,7 @@ static int receive_rs_deallocated(struct drbd_connection *connection, struct pac
        sector = be64_to_cpu(p->sector);
        size = be32_to_cpu(p->blksize);
 
-       dec_rs_pending(device);
+       dec_rs_pending(peer_device);
 
        if (get_ldev(device)) {
                struct drbd_peer_request *peer_req;
@@ -5650,12 +5651,12 @@ static int got_IsInSync(struct drbd_connection *connection, struct packet_info *
 
        if (get_ldev(device)) {
                drbd_rs_complete_io(device, sector);
-               drbd_set_in_sync(device, sector, blksize);
+               drbd_set_in_sync(peer_device, sector, blksize);
                /* rs_same_csums is supposed to count in units of BM_BLOCK_SIZE */
                device->rs_same_csum += (blksize >> BM_BLOCK_SHIFT);
                put_ldev(device);
        }
-       dec_rs_pending(device);
+       dec_rs_pending(peer_device);
        atomic_add(blksize >> 9, &device->rs_sect_in);
 
        return 0;
@@ -5701,8 +5702,8 @@ static int got_BlockAck(struct drbd_connection *connection, struct packet_info *
        update_peer_seq(peer_device, be32_to_cpu(p->seq_num));
 
        if (p->block_id == ID_SYNCER) {
-               drbd_set_in_sync(device, sector, blksize);
-               dec_rs_pending(device);
+               drbd_set_in_sync(peer_device, sector, blksize);
+               dec_rs_pending(peer_device);
                return 0;
        }
        switch (pi->cmd) {
@@ -5747,8 +5748,8 @@ static int got_NegAck(struct drbd_connection *connection, struct packet_info *pi
        update_peer_seq(peer_device, be32_to_cpu(p->seq_num));
 
        if (p->block_id == ID_SYNCER) {
-               dec_rs_pending(device);
-               drbd_rs_failed_io(device, sector, size);
+               dec_rs_pending(peer_device);
+               drbd_rs_failed_io(peer_device, sector, size);
                return 0;
        }
 
@@ -5761,7 +5762,7 @@ static int got_NegAck(struct drbd_connection *connection, 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(device, sector, size);
+               drbd_set_out_of_sync(peer_device, sector, size);
        }
        return 0;
 }
@@ -5806,13 +5807,13 @@ static int got_NegRSDReply(struct drbd_connection *connection, struct packet_inf
 
        update_peer_seq(peer_device, be32_to_cpu(p->seq_num));
 
-       dec_rs_pending(device);
+       dec_rs_pending(peer_device);
 
        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(device, sector, size);
+                       drbd_rs_failed_io(peer_device, sector, size);
                        break;
                case P_RS_CANCEL:
                        break;
@@ -5869,21 +5870,21 @@ static int got_OVResult(struct drbd_connection *connection, struct packet_info *
        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(device, sector, size);
+               drbd_ov_out_of_sync_found(peer_device, sector, size);
        else
-               ov_out_of_sync_print(device);
+               ov_out_of_sync_print(peer_device);
 
        if (!get_ldev(device))
                return 0;
 
        drbd_rs_complete_io(device, sector);
-       dec_rs_pending(device);
+       dec_rs_pending(peer_device);
 
        --device->ov_left;
 
        /* let's advance progress step marks only for every other megabyte */
        if ((device->ov_left & 0x200) == 0x200)
-               drbd_advance_rs_marks(device, device->ov_left);
+               drbd_advance_rs_marks(peer_device, device->ov_left);
 
        if (device->ov_left == 0) {
                dw = kmalloc(sizeof(*dw), GFP_NOIO);
@@ -5893,8 +5894,8 @@ static int got_OVResult(struct drbd_connection *connection, struct packet_info *
                        drbd_queue_work(&peer_device->connection->sender_work, &dw->w);
                } else {
                        drbd_err(device, "kmalloc(dw) failed.");
-                       ov_out_of_sync_print(device);
-                       drbd_resync_finished(device);
+                       ov_out_of_sync_print(peer_device);
+                       drbd_resync_finished(peer_device);
                }
        }
        put_ldev(device);
index 528f29ebf3696d7c63670a9575d08385ca797e7f..380e6584a4ee7638e4bb61e189edd1c61f733391 100644 (file)
@@ -122,12 +122,13 @@ void drbd_req_destroy(struct kref *kref)
                 * before it even was submitted or sent.
                 * In that case we do not want to touch the bitmap at all.
                 */
+               struct drbd_peer_device *peer_device = first_peer_device(device);
                if ((s & (RQ_POSTPONED|RQ_LOCAL_MASK|RQ_NET_MASK)) != RQ_POSTPONED) {
                        if (!(s & RQ_NET_OK) || !(s & RQ_LOCAL_OK))
-                               drbd_set_out_of_sync(device, req->i.sector, req->i.size);
+                               drbd_set_out_of_sync(peer_device, req->i.sector, req->i.size);
 
                        if ((s & RQ_NET_OK) && (s & RQ_LOCAL_OK) && (s & RQ_NET_SIS))
-                               drbd_set_in_sync(device, req->i.sector, req->i.size);
+                               drbd_set_in_sync(peer_device, req->i.sector, req->i.size);
                }
 
                /* one might be tempted to move the drbd_al_complete_io
@@ -620,7 +621,7 @@ int __req_mod(struct drbd_request *req, enum drbd_req_event what,
                break;
 
        case READ_COMPLETED_WITH_ERROR:
-               drbd_set_out_of_sync(device, req->i.sector, req->i.size);
+               drbd_set_out_of_sync(peer_device, req->i.sector, req->i.size);
                drbd_report_io_error(device, req);
                __drbd_chk_io_error(device, DRBD_READ_ERROR);
                fallthrough;
@@ -1131,7 +1132,7 @@ static int drbd_process_write_request(struct drbd_request *req)
        if (remote) {
                _req_mod(req, TO_BE_SENT, peer_device);
                _req_mod(req, QUEUE_FOR_NET_WRITE, peer_device);
-       } else if (drbd_set_out_of_sync(device, req->i.sector, req->i.size))
+       } else if (drbd_set_out_of_sync(peer_device, req->i.sector, req->i.size))
                _req_mod(req, QUEUE_FOR_SEND_OOS, peer_device);
 
        return remote;
index c92dc6093b0aa3bd0bb2d8e1af98ce18310f5c80..563e67f1ead962e9f5ceb812d889194e4031923f 100644 (file)
@@ -1222,9 +1222,11 @@ void drbd_resume_al(struct drbd_device *device)
 }
 
 /* helper for _drbd_set_state */
-static void set_ov_position(struct drbd_device *device, enum drbd_conns cs)
+static void set_ov_position(struct drbd_peer_device *peer_device, enum drbd_conns cs)
 {
-       if (first_peer_device(device)->connection->agreed_pro_version < 90)
+       struct drbd_device *device = peer_device->device;
+
+       if (peer_device->connection->agreed_pro_version < 90)
                device->ov_start_sector = 0;
        device->rs_total = drbd_bm_bits(device);
        device->ov_position = 0;
@@ -1387,7 +1389,7 @@ _drbd_set_state(struct drbd_device *device, union drbd_state ns,
                unsigned long now = jiffies;
                int i;
 
-               set_ov_position(device, ns.conn);
+               set_ov_position(peer_device, ns.conn);
                device->rs_start = now;
                device->rs_last_sect_ev = 0;
                device->ov_last_oos_size = 0;
@@ -1398,7 +1400,7 @@ _drbd_set_state(struct drbd_device *device, union drbd_state ns,
                        device->rs_mark_time[i] = now;
                }
 
-               drbd_rs_controller_reset(device);
+               drbd_rs_controller_reset(peer_device);
 
                if (ns.conn == C_VERIFY_S) {
                        drbd_info(device, "Starting Online Verify from sector %llu\n",
index 6455edca7aa9f148748462c58dee83bd92deb2d2..4352a50fbb3f8fc966734a7d79e5cb0b311dcb68 100644 (file)
@@ -28,8 +28,8 @@
 #include "drbd_protocol.h"
 #include "drbd_req.h"
 
-static int make_ov_request(struct drbd_device *, int);
-static int make_resync_request(struct drbd_device *, int);
+static int make_ov_request(struct drbd_peer_device *, int);
+static int make_resync_request(struct drbd_peer_device *, int);
 
 /* endio handlers:
  *   drbd_md_endio (defined here)
@@ -124,7 +124,7 @@ void drbd_endio_write_sec_final(struct drbd_peer_request *peer_req) __releases(l
                 * In case of a write error, send the neg ack anyways. */
                if (!__test_and_set_bit(__EE_SEND_WRITE_ACK, &peer_req->flags))
                        inc_unacked(device);
-               drbd_set_out_of_sync(device, peer_req->i.sector, peer_req->i.size);
+               drbd_set_out_of_sync(peer_device, peer_req->i.sector, peer_req->i.size);
        }
 
        spin_lock_irqsave(&device->resource->req_lock, flags);
@@ -363,7 +363,7 @@ static int w_e_send_csum(struct drbd_work *w, int cancel)
                 * drbd_alloc_pages due to pp_in_use > max_buffers. */
                drbd_free_peer_req(device, peer_req);
                peer_req = NULL;
-               inc_rs_pending(device);
+               inc_rs_pending(peer_device);
                err = drbd_send_drequest_csum(peer_device, sector, size,
                                              digest, digest_size,
                                              P_CSUM_RS_REQUEST);
@@ -430,10 +430,10 @@ int w_resync_timer(struct drbd_work *w, int cancel)
 
        switch (device->state.conn) {
        case C_VERIFY_S:
-               make_ov_request(device, cancel);
+               make_ov_request(first_peer_device(device), cancel);
                break;
        case C_SYNC_TARGET:
-               make_resync_request(device, cancel);
+               make_resync_request(first_peer_device(device), cancel);
                break;
        }
 
@@ -493,8 +493,9 @@ struct fifo_buffer *fifo_alloc(unsigned int fifo_size)
        return fb;
 }
 
-static int drbd_rs_controller(struct drbd_device *device, unsigned int sect_in)
+static int drbd_rs_controller(struct drbd_peer_device *peer_device, unsigned int sect_in)
 {
+       struct drbd_device *device = peer_device->device;
        struct disk_conf *dc;
        unsigned int want;     /* The number of sectors we want in-flight */
        int req_sect; /* Number of sectors to request in this turn */
@@ -545,8 +546,9 @@ static int drbd_rs_controller(struct drbd_device *device, unsigned int sect_in)
        return req_sect;
 }
 
-static int drbd_rs_number_requests(struct drbd_device *device)
+static int drbd_rs_number_requests(struct drbd_peer_device *peer_device)
 {
+       struct drbd_device *device = peer_device->device;
        unsigned int sect_in;  /* Number of sectors that came in since the last turn */
        int number, mxb;
 
@@ -556,7 +558,7 @@ static int drbd_rs_number_requests(struct drbd_device *device)
        rcu_read_lock();
        mxb = drbd_get_max_buffers(device) / 2;
        if (rcu_dereference(device->rs_plan_s)->size) {
-               number = drbd_rs_controller(device, sect_in) >> (BM_BLOCK_SHIFT - 9);
+               number = drbd_rs_controller(peer_device, sect_in) >> (BM_BLOCK_SHIFT - 9);
                device->c_sync_rate = number * HZ * (BM_BLOCK_SIZE / 1024) / SLEEP_TIME;
        } else {
                device->c_sync_rate = rcu_dereference(device->ldev->disk_conf)->resync_rate;
@@ -580,9 +582,9 @@ static int drbd_rs_number_requests(struct drbd_device *device)
        return number;
 }
 
-static int make_resync_request(struct drbd_device *const device, int cancel)
+static int make_resync_request(struct drbd_peer_device *const peer_device, int cancel)
 {
-       struct drbd_peer_device *const peer_device = first_peer_device(device);
+       struct drbd_device *const device = peer_device->device;
        struct drbd_connection *const connection = peer_device ? peer_device->connection : NULL;
        unsigned long bit;
        sector_t sector;
@@ -598,7 +600,7 @@ static int make_resync_request(struct drbd_device *const device, int cancel)
 
        if (device->rs_total == 0) {
                /* empty resync? */
-               drbd_resync_finished(device);
+               drbd_resync_finished(peer_device);
                return 0;
        }
 
@@ -618,7 +620,7 @@ static int make_resync_request(struct drbd_device *const device, int cancel)
        }
 
        max_bio_size = queue_max_hw_sectors(device->rq_queue) << 9;
-       number = drbd_rs_number_requests(device);
+       number = drbd_rs_number_requests(peer_device);
        if (number <= 0)
                goto requeue;
 
@@ -653,7 +655,7 @@ next_sector:
 
                sector = BM_BIT_TO_SECT(bit);
 
-               if (drbd_try_rs_begin_io(device, sector)) {
+               if (drbd_try_rs_begin_io(peer_device, sector)) {
                        device->bm_resync_fo = bit;
                        goto requeue;
                }
@@ -729,13 +731,13 @@ next_sector:
                } else {
                        int err;
 
-                       inc_rs_pending(device);
+                       inc_rs_pending(peer_device);
                        err = drbd_send_drequest(peer_device,
                                                 size == discard_granularity ? P_RS_THIN_REQ : P_RS_DATA_REQUEST,
                                                 sector, size, ID_SYNCER);
                        if (err) {
                                drbd_err(device, "drbd_send_drequest() failed, aborting...\n");
-                               dec_rs_pending(device);
+                               dec_rs_pending(peer_device);
                                put_ldev(device);
                                return err;
                        }
@@ -760,8 +762,9 @@ next_sector:
        return 0;
 }
 
-static int make_ov_request(struct drbd_device *device, int cancel)
+static int make_ov_request(struct drbd_peer_device *peer_device, int cancel)
 {
+       struct drbd_device *device = peer_device->device;
        int number, i, size;
        sector_t sector;
        const sector_t capacity = get_capacity(device->vdisk);
@@ -770,7 +773,7 @@ static int make_ov_request(struct drbd_device *device, int cancel)
        if (unlikely(cancel))
                return 1;
 
-       number = drbd_rs_number_requests(device);
+       number = drbd_rs_number_requests(peer_device);
 
        sector = device->ov_position;
        for (i = 0; i < number; i++) {
@@ -788,7 +791,7 @@ static int make_ov_request(struct drbd_device *device, int cancel)
 
                size = BM_BLOCK_SIZE;
 
-               if (drbd_try_rs_begin_io(device, sector)) {
+               if (drbd_try_rs_begin_io(peer_device, sector)) {
                        device->ov_position = sector;
                        goto requeue;
                }
@@ -796,9 +799,9 @@ static int make_ov_request(struct drbd_device *device, int cancel)
                if (sector + (size>>9) > capacity)
                        size = (capacity-sector)<<9;
 
-               inc_rs_pending(device);
+               inc_rs_pending(peer_device);
                if (drbd_send_ov_request(first_peer_device(device), sector, size)) {
-                       dec_rs_pending(device);
+                       dec_rs_pending(peer_device);
                        return 0;
                }
                sector += BM_SECT_PER_BIT;
@@ -818,8 +821,8 @@ int w_ov_finished(struct drbd_work *w, int cancel)
                container_of(w, struct drbd_device_work, w);
        struct drbd_device *device = dw->device;
        kfree(dw);
-       ov_out_of_sync_print(device);
-       drbd_resync_finished(device);
+       ov_out_of_sync_print(first_peer_device(device));
+       drbd_resync_finished(first_peer_device(device));
 
        return 0;
 }
@@ -831,7 +834,7 @@ static int w_resync_finished(struct drbd_work *w, int cancel)
        struct drbd_device *device = dw->device;
        kfree(dw);
 
-       drbd_resync_finished(device);
+       drbd_resync_finished(first_peer_device(device));
 
        return 0;
 }
@@ -846,9 +849,10 @@ static void ping_peer(struct drbd_device *device)
                   test_bit(GOT_PING_ACK, &connection->flags) || device->state.conn < C_CONNECTED);
 }
 
-int drbd_resync_finished(struct drbd_device *device)
+int drbd_resync_finished(struct drbd_peer_device *peer_device)
 {
-       struct drbd_connection *connection = first_peer_device(device)->connection;
+       struct drbd_device *device = peer_device->device;
+       struct drbd_connection *connection = peer_device->connection;
        unsigned long db, dt, dbdt;
        unsigned long n_oos;
        union drbd_state os, ns;
@@ -1129,7 +1133,7 @@ int w_e_end_rsdata_req(struct drbd_work *w, int cancel)
                err = drbd_send_ack(peer_device, P_RS_CANCEL, peer_req);
        } else if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) {
                if (likely(device->state.pdsk >= D_INCONSISTENT)) {
-                       inc_rs_pending(device);
+                       inc_rs_pending(peer_device);
                        if (peer_req->flags & EE_RS_THIN_REQ && all_zero(peer_req))
                                err = drbd_send_rs_deallocated(peer_device, peer_req);
                        else
@@ -1148,7 +1152,7 @@ int w_e_end_rsdata_req(struct drbd_work *w, int cancel)
                err = drbd_send_ack(peer_device, P_NEG_RS_DREPLY, peer_req);
 
                /* update resync data with failure */
-               drbd_rs_failed_io(device, peer_req->i.sector, peer_req->i.size);
+               drbd_rs_failed_io(peer_device, peer_req->i.sector, peer_req->i.size);
        }
 
        dec_unacked(device);
@@ -1199,12 +1203,12 @@ int w_e_end_csum_rs_req(struct drbd_work *w, int cancel)
                }
 
                if (eq) {
-                       drbd_set_in_sync(device, peer_req->i.sector, peer_req->i.size);
+                       drbd_set_in_sync(peer_device, peer_req->i.sector, peer_req->i.size);
                        /* rs_same_csums unit is BM_BLOCK_SIZE */
                        device->rs_same_csum += peer_req->i.size >> BM_BLOCK_SHIFT;
                        err = drbd_send_ack(peer_device, P_RS_IS_IN_SYNC, peer_req);
                } else {
-                       inc_rs_pending(device);
+                       inc_rs_pending(peer_device);
                        peer_req->block_id = ID_SYNCER; /* By setting block_id, digest pointer becomes invalid! */
                        peer_req->flags &= ~EE_HAS_DIGEST; /* This peer request no longer has a digest pointer */
                        kfree(di);
@@ -1257,10 +1261,10 @@ int w_e_end_ov_req(struct drbd_work *w, int cancel)
         * drbd_alloc_pages due to pp_in_use > max_buffers. */
        drbd_free_peer_req(device, peer_req);
        peer_req = NULL;
-       inc_rs_pending(device);
+       inc_rs_pending(peer_device);
        err = drbd_send_drequest_csum(peer_device, sector, size, digest, digest_size, P_OV_REPLY);
        if (err)
-               dec_rs_pending(device);
+               dec_rs_pending(peer_device);
        kfree(digest);
 
 out:
@@ -1270,15 +1274,16 @@ out:
        return err;
 }
 
-void drbd_ov_out_of_sync_found(struct drbd_device *device, sector_t sector, int size)
+void drbd_ov_out_of_sync_found(struct drbd_peer_device *peer_device, sector_t sector, int size)
 {
+       struct drbd_device *device = peer_device->device;
        if (device->ov_last_oos_start + device->ov_last_oos_size == sector) {
                device->ov_last_oos_size += size>>9;
        } else {
                device->ov_last_oos_start = sector;
                device->ov_last_oos_size = size>>9;
        }
-       drbd_set_out_of_sync(device, sector, size);
+       drbd_set_out_of_sync(peer_device, sector, size);
 }
 
 int w_e_end_ov_reply(struct drbd_work *w, int cancel)
@@ -1328,9 +1333,9 @@ int w_e_end_ov_reply(struct drbd_work *w, int cancel)
         * drbd_alloc_pages due to pp_in_use > max_buffers. */
        drbd_free_peer_req(device, peer_req);
        if (!eq)
-               drbd_ov_out_of_sync_found(device, sector, size);
+               drbd_ov_out_of_sync_found(peer_device, sector, size);
        else
-               ov_out_of_sync_print(device);
+               ov_out_of_sync_print(peer_device);
 
        err = drbd_send_ack_ex(peer_device, P_OV_RESULT, sector, size,
                               eq ? ID_IN_SYNC : ID_OUT_OF_SYNC);
@@ -1341,14 +1346,14 @@ int w_e_end_ov_reply(struct drbd_work *w, int cancel)
 
        /* let's advance progress step marks only for every other megabyte */
        if ((device->ov_left & 0x200) == 0x200)
-               drbd_advance_rs_marks(device, device->ov_left);
+               drbd_advance_rs_marks(peer_device, device->ov_left);
 
        stop_sector_reached = verify_can_do_stop_sector(device) &&
                (sector + (size>>9)) >= device->ov_stop_sector;
 
        if (device->ov_left == 0 || stop_sector_reached) {
-               ov_out_of_sync_print(device);
-               drbd_resync_finished(device);
+               ov_out_of_sync_print(peer_device);
+               drbd_resync_finished(peer_device);
        }
 
        return err;
@@ -1668,8 +1673,9 @@ void drbd_resync_after_changed(struct drbd_device *device)
        } while (changed);
 }
 
-void drbd_rs_controller_reset(struct drbd_device *device)
+void drbd_rs_controller_reset(struct drbd_peer_device *peer_device)
 {
+       struct drbd_device *device = peer_device->device;
        struct gendisk *disk = device->ldev->backing_bdev->bd_disk;
        struct fifo_buffer *plan;
 
@@ -1891,10 +1897,10 @@ void drbd_start_resync(struct drbd_device *device, enum drbd_conns side)
                                rcu_read_unlock();
                                schedule_timeout_interruptible(timeo);
                        }
-                       drbd_resync_finished(device);
+                       drbd_resync_finished(peer_device);
                }
 
-               drbd_rs_controller_reset(device);
+               drbd_rs_controller_reset(peer_device);
                /* ns.conn may already be != device->state.conn,
                 * we may have been paused in between, or become paused until
                 * the timer triggers.
@@ -1909,8 +1915,9 @@ out:
        mutex_unlock(device->state_mutex);
 }
 
-static void update_on_disk_bitmap(struct drbd_device *device, bool resync_done)
+static void update_on_disk_bitmap(struct drbd_peer_device *peer_device, bool resync_done)
 {
+       struct drbd_device *device = peer_device->device;
        struct sib_info sib = { .sib_reason = SIB_SYNC_PROGRESS, };
        device->rs_last_bcast = jiffies;
 
@@ -1919,7 +1926,7 @@ static void update_on_disk_bitmap(struct drbd_device *device, bool resync_done)
 
        drbd_bm_write_lazy(device, 0);
        if (resync_done && is_sync_state(device->state.conn))
-               drbd_resync_finished(device);
+               drbd_resync_finished(peer_device);
 
        drbd_bcast_event(device, &sib);
        /* update timestamp, in case it took a while to write out stuff */
@@ -2018,7 +2025,7 @@ static void do_device_work(struct drbd_device *device, const unsigned long todo)
                do_md_sync(device);
        if (test_bit(RS_DONE, &todo) ||
            test_bit(RS_PROGRESS, &todo))
-               update_on_disk_bitmap(device, test_bit(RS_DONE, &todo));
+               update_on_disk_bitmap(first_peer_device(device), test_bit(RS_DONE, &todo));
        if (test_bit(GO_DISKLESS, &todo))
                go_diskless(device);
        if (test_bit(DESTROY_DISK, &todo))