1 files changed, 39 insertions, 19 deletions

diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index 32517a0cbc62..85e2f4b56a06 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -483,7 +483,7 @@ struct drbd_backing_dev {
         struct block_device *backing_bdev;
         struct block_device *md_bdev;
         struct drbd_md md;
-        struct disk_conf *disk_conf; /* RCU, for updates: device->connection->conf_update */
+        struct disk_conf *disk_conf; /* RCU, for updates: first_peer_device(device)->connection->conf_update */
         sector_t known_size; /* last known size of that backing device */
 };
 
@@ -617,8 +617,14 @@ struct submit_worker {
         struct list_head writes;
 };
 
-struct drbd_device {
+struct drbd_peer_device {
+        struct list_head peer_devices;
+        struct drbd_device *device;
         struct drbd_connection *connection;
+};
+
+struct drbd_device {
+        struct list_head peer_devices;
         int vnr;                        /* volume number within the connection */
         struct kref kref;
 
@@ -744,7 +750,7 @@ struct drbd_device {
         struct bm_io_work bm_io_work;
         u64 ed_uuid; /* UUID of the exposed data */
         struct mutex own_state_mutex;
-        struct mutex *state_mutex; /* either own_state_mutex or device->connection->cstate_mutex */
+        struct mutex *state_mutex; /* either own_state_mutex or first_peer_device(device)->connection->cstate_mutex */
         char congestion_reason;  /* Why we where congested... */
         atomic_t rs_sect_in; /* for incoming resync data rate, SyncTarget */
         atomic_t rs_sect_ev; /* for submitted resync data rate, both */
@@ -768,6 +774,20 @@ static inline struct drbd_device *minor_to_device(unsigned int minor)
         return (struct drbd_device *)idr_find(&minors, minor);
 }
 
+static inline struct drbd_peer_device *first_peer_device(struct drbd_device *device)
+{
+        return list_first_entry(&device->peer_devices, struct drbd_peer_device, peer_devices);
+}
+
+#define for_each_peer_device(peer_device, device) \
+        list_for_each_entry(peer_device, &device->peer_devices, peer_devices)
+
+#define for_each_peer_device_rcu(peer_device, device) \
+        list_for_each_entry_rcu(peer_device, &device->peer_devices, peer_devices)
+
+#define for_each_peer_device_safe(peer_device, tmp, device) \
+        list_for_each_entry_safe(peer_device, tmp, &device->peer_devices, peer_devices)
+
 static inline unsigned int device_to_minor(struct drbd_device *device)
 {
         return device->minor;
@@ -1154,7 +1174,7 @@ extern struct bio *bio_alloc_drbd(gfp_t gfp_mask);
 extern rwlock_t global_state_lock;
 
 extern int conn_lowest_minor(struct drbd_connection *connection);
-enum drbd_ret_code conn_new_minor(struct drbd_connection *connection, unsigned int minor, int vnr);
+enum drbd_ret_code drbd_create_minor(struct drbd_connection *connection, unsigned int minor, int vnr);
 extern void drbd_minor_destroy(struct kref *kref);
 
 extern int set_resource_options(struct drbd_connection *connection, struct res_opts *res_opts);
@@ -1275,7 +1295,7 @@ extern void conn_flush_workqueue(struct drbd_connection *connection);
 extern int drbd_connected(struct drbd_device *device);
 static inline void drbd_flush_workqueue(struct drbd_device *device)
 {
-        conn_flush_workqueue(device->connection);
+        conn_flush_workqueue(first_peer_device(device)->connection);
 }
 
 /* Yes, there is kernel_setsockopt, but only since 2.6.18.
@@ -1421,9 +1441,9 @@ static inline union drbd_state drbd_read_state(struct drbd_device *device)
         union drbd_state rv;
 
         rv.i = device->state.i;
-        rv.susp = device->connection->susp;
-        rv.susp_nod = device->connection->susp_nod;
-        rv.susp_fen = device->connection->susp_fen;
+        rv.susp = first_peer_device(device)->connection->susp;
+        rv.susp_nod = first_peer_device(device)->connection->susp_nod;
+        rv.susp_fen = first_peer_device(device)->connection->susp_fen;
 
         return rv;
 }
@@ -1505,9 +1525,9 @@ static inline void drbd_chk_io_error_(struct drbd_device *device,
 {
         if (error) {
                 unsigned long flags;
-                spin_lock_irqsave(&device->connection->req_lock, flags);
+                spin_lock_irqsave(&first_peer_device(device)->connection->req_lock, flags);
                 __drbd_chk_io_error_(device, forcedetach, where);
-                spin_unlock_irqrestore(&device->connection->req_lock, flags);
+                spin_unlock_irqrestore(&first_peer_device(device)->connection->req_lock, flags);
         }
 }
 
@@ -1783,7 +1803,7 @@ static inline void put_ldev(struct drbd_device *device)
                 if (device->state.disk == D_FAILED) {
                         /* all application IO references gone. */
                         if (!test_and_set_bit(GO_DISKLESS, &device->flags))
-                                drbd_queue_work(&device->connection->sender_work, &device->go_diskless);
+                                drbd_queue_work(&first_peer_device(device)->connection->sender_work, &device->go_diskless);
                 }
                 wake_up(&device->misc_wait);
         }
@@ -1865,7 +1885,7 @@ static inline int drbd_get_max_buffers(struct drbd_device *device)
         int mxb;
 
         rcu_read_lock();
-        nc = rcu_dereference(device->connection->net_conf);
+        nc = rcu_dereference(first_peer_device(device)->connection->net_conf);
         mxb = nc ? nc->max_buffers : 1000000;  /* arbitrary limit on open requests */
         rcu_read_unlock();
 
@@ -1908,7 +1928,7 @@ static inline int drbd_state_is_stable(struct drbd_device *device)
 
                 /* Allow IO in BM exchange states with new protocols */
         case C_WF_BITMAP_S:
-                if (device->connection->agreed_pro_version < 96)
+                if (first_peer_device(device)->connection->agreed_pro_version < 96)
                         return 0;
                 break;
 
@@ -1944,7 +1964,7 @@ static inline int drbd_state_is_stable(struct drbd_device *device)
 
 static inline int drbd_suspended(struct drbd_device *device)
 {
-        struct drbd_connection *connection = device->connection;
+        struct drbd_connection *connection = first_peer_device(device)->connection;
 
         return connection->susp || connection->susp_fen || connection->susp_nod;
 }
@@ -1979,11 +1999,11 @@ static inline bool inc_ap_bio_cond(struct drbd_device *device)
 {
         bool rv = false;
 
-        spin_lock_irq(&device->connection->req_lock);
+        spin_lock_irq(&first_peer_device(device)->connection->req_lock);
         rv = may_inc_ap_bio(device);
         if (rv)
                 atomic_inc(&device->ap_bio_cnt);
-        spin_unlock_irq(&device->connection->req_lock);
+        spin_unlock_irq(&first_peer_device(device)->connection->req_lock);
 
         return rv;
 }
@@ -2010,7 +2030,7 @@ static inline void dec_ap_bio(struct drbd_device *device)
 
         if (ap_bio == 0 && test_bit(BITMAP_IO, &device->flags)) {
                 if (!test_and_set_bit(BITMAP_IO_QUEUED, &device->flags))
-                        drbd_queue_work(&device->connection->sender_work, &device->bm_io_work.w);
+                        drbd_queue_work(&first_peer_device(device)->connection->sender_work, &device->bm_io_work.w);
         }
 
         /* this currently does wake_up for every dec_ap_bio!
@@ -2022,8 +2042,8 @@ static inline void dec_ap_bio(struct drbd_device *device)
 
 static inline bool verify_can_do_stop_sector(struct drbd_device *device)
 {
-        return device->connection->agreed_pro_version >= 97 &&
-                device->connection->agreed_pro_version != 100;
+        return first_peer_device(device)->connection->agreed_pro_version >= 97 &&
+                first_peer_device(device)->connection->agreed_pro_version != 100;
 }
 
 static inline int drbd_set_ed_uuid(struct drbd_device *device, u64 val)