drbd: Iterate over all connections

in drbd_adm_down(), drbd_create_device() and drbd_set_role()

Signed-off-by: Andreas Gruenbacher <agruen@linbit.com>
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>

2 files changed, 70 insertions, 53 deletions

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index b00a8d74f6cb..54df98fa2881 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -2661,9 +2661,9 @@ static int init_submitter(struct drbd_device *device)
 
 enum drbd_ret_code drbd_create_device(struct drbd_resource *resource, unsigned int minor, int vnr)
 {
-        struct drbd_connection *connection = first_connection(resource);
+        struct drbd_connection *connection;
         struct drbd_device *device;
-        struct drbd_peer_device *peer_device;
+        struct drbd_peer_device *peer_device, *tmp_peer_device;
         struct gendisk *disk;
         struct request_queue *q;
         int id;
@@ -2679,18 +2679,8 @@ enum drbd_ret_code drbd_create_device(struct drbd_resource *resource, unsigned i
                 return ERR_NOMEM;
         kref_init(&device->kref);
 
-        peer_device = kzalloc(sizeof(struct drbd_peer_device), GFP_KERNEL);
-        if (!peer_device)
-                goto out_no_peer_device;
-
-        INIT_LIST_HEAD(&device->peer_devices);
-        list_add(&peer_device->peer_devices, &device->peer_devices);
         kref_get(&resource->kref);
         device->resource = resource;
-        kref_get(&connection->kref);
-        peer_device->connection = connection;
-        peer_device->device = device;
-
         device->minor = minor;
         device->vnr = vnr;
 
@@ -2761,15 +2751,27 @@ enum drbd_ret_code drbd_create_device(struct drbd_resource *resource, unsigned i
         }
         kref_get(&device->kref);
 
-        id = idr_alloc(&connection->peer_devices, peer_device, vnr, vnr + 1, GFP_KERNEL);
-        if (id < 0) {
-                if (id == -ENOSPC) {
-                        err = ERR_INVALID_REQUEST;
-                        drbd_msg_put_info("requested volume exists already");
+        INIT_LIST_HEAD(&device->peer_devices);
+        for_each_connection(connection, resource) {
+                peer_device = kzalloc(sizeof(struct drbd_peer_device), GFP_KERNEL);
+                if (!peer_device)
+                        goto out_idr_remove_from_resource;
+                peer_device->connection = connection;
+                peer_device->device = device;
+
+                list_add(&peer_device->peer_devices, &device->peer_devices);
+                kref_get(&device->kref);
+
+                id = idr_alloc(&connection->peer_devices, peer_device, vnr, vnr + 1, GFP_KERNEL);
+                if (id < 0) {
+                        if (id == -ENOSPC) {
+                                err = ERR_INVALID_REQUEST;
+                                drbd_msg_put_info("requested volume exists already");
+                        }
+                        goto out_idr_remove_from_resource;
                 }
-                goto out_idr_remove_from_resource;
+                kref_get(&connection->kref);
         }
-        kref_get(&device->kref);
 
         if (init_submitter(device)) {
                 err = ERR_NOMEM;
@@ -2780,7 +2782,7 @@ enum drbd_ret_code drbd_create_device(struct drbd_resource *resource, unsigned i
         add_disk(disk);
 
         /* inherit the connection state */
-        device->state.conn = connection->cstate;
+        device->state.conn = first_connection(resource)->cstate;
         if (device->state.conn == C_WF_REPORT_PARAMS)
                 drbd_connected(device);
 
@@ -2789,6 +2791,17 @@ enum drbd_ret_code drbd_create_device(struct drbd_resource *resource, unsigned i
 out_idr_remove_vol:
         idr_remove(&connection->peer_devices, vnr);
 out_idr_remove_from_resource:
+        for_each_connection(connection, resource) {
+                peer_device = idr_find(&connection->peer_devices, vnr);
+                if (peer_device) {
+                        idr_remove(&connection->peer_devices, vnr);
+                        kref_put(&connection->kref, drbd_destroy_connection);
+                }
+        }
+        for_each_peer_device_safe(peer_device, tmp_peer_device, device) {
+                list_del(&peer_device->peer_devices);
+                kfree(peer_device);
+        }
         idr_remove(&resource->devices, vnr);
 out_idr_remove_minor:
         idr_remove(&drbd_devices, minor);
@@ -2802,9 +2815,7 @@ out_no_io_page:
 out_no_disk:
         blk_cleanup_queue(q);
 out_no_q:
-        kref_put(&connection->kref, drbd_destroy_connection);
         kref_put(&resource->kref, drbd_destroy_resource);
-out_no_peer_device:
         kfree(device);
         return err;
 }
diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index 33bc23fc55bb..8ebcf88b0c1b 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -560,8 +560,16 @@ drbd_set_role(struct drbd_device *device, enum drbd_role new_role, int force)
         int forced = 0;
         union drbd_state mask, val;
 
-        if (new_role == R_PRIMARY)
-                request_ping(first_peer_device(device)->connection); /* Detect a dead peer ASAP */
+        if (new_role == R_PRIMARY) {
+                struct drbd_connection *connection;
+
+                /* Detect dead peers as soon as possible.  */
+
+                rcu_read_lock();
+                for_each_connection(connection, device->resource)
+                        request_ping(connection);
+                rcu_read_unlock();
+        }
 
         mutex_lock(device->state_mutex);
 
@@ -3387,8 +3395,10 @@ out:
 
 int drbd_adm_down(struct sk_buff *skb, struct genl_info *info)
 {
+        struct drbd_resource *resource;
+        struct drbd_connection *connection;
+        struct drbd_device *device;
         int retcode; /* enum drbd_ret_code rsp. enum drbd_state_rv */
-        struct drbd_peer_device *peer_device;
         unsigned i;
 
         retcode = drbd_adm_prepare(skb, info, DRBD_ADM_NEED_RESOURCE);
@@ -3397,24 +3407,29 @@ int drbd_adm_down(struct sk_buff *skb, struct genl_info *info)
         if (retcode != NO_ERROR)
                 goto out;
 
+        resource = adm_ctx.resource;
         /* demote */
-        idr_for_each_entry(&adm_ctx.connection->peer_devices, peer_device, i) {
-                retcode = drbd_set_role(peer_device->device, R_SECONDARY, 0);
+        for_each_connection(connection, resource) {
+                struct drbd_peer_device *peer_device;
+
+                idr_for_each_entry(&connection->peer_devices, peer_device, i) {
+                        retcode = drbd_set_role(peer_device->device, R_SECONDARY, 0);
+                        if (retcode < SS_SUCCESS) {
+                                drbd_msg_put_info("failed to demote");
+                                goto out;
+                        }
+                }
+
+                retcode = conn_try_disconnect(connection, 0);
                 if (retcode < SS_SUCCESS) {
-                        drbd_msg_put_info("failed to demote");
+                        drbd_msg_put_info("failed to disconnect");
                         goto out;
                 }
         }
 
-        retcode = conn_try_disconnect(adm_ctx.connection, 0);
-        if (retcode < SS_SUCCESS) {
-                drbd_msg_put_info("failed to disconnect");
-                goto out;
-        }
-
         /* detach */
-        idr_for_each_entry(&adm_ctx.connection->peer_devices, peer_device, i) {
-                retcode = adm_detach(peer_device->device, 0);
+        idr_for_each_entry(&resource->devices, device, i) {
+                retcode = adm_detach(device, 0);
                 if (retcode < SS_SUCCESS || retcode > NO_ERROR) {
                         drbd_msg_put_info("failed to detach");
                         goto out;
@@ -3424,13 +3439,14 @@ int drbd_adm_down(struct sk_buff *skb, struct genl_info *info)
         /* If we reach this, all volumes (of this connection) are Secondary,
          * Disconnected, Diskless, aka Unconfigured. Make sure all threads have
          * actually stopped, state handling only does drbd_thread_stop_nowait(). */
-        drbd_thread_stop(&adm_ctx.connection->worker);
+        for_each_connection(connection, resource)
+                drbd_thread_stop(&connection->worker);
 
         /* Now, nothing can fail anymore */
 
         /* delete volumes */
-        idr_for_each_entry(&adm_ctx.connection->peer_devices, peer_device, i) {
-                retcode = adm_del_minor(peer_device->device);
+        idr_for_each_entry(&resource->devices, device, i) {
+                retcode = adm_del_minor(device);
                 if (retcode != NO_ERROR) {
                         /* "can not happen" */
                         drbd_msg_put_info("failed to delete volume");
@@ -3438,21 +3454,11 @@ int drbd_adm_down(struct sk_buff *skb, struct genl_info *info)
                 }
         }
 
-        /* delete connection */
-        if (conn_lowest_minor(adm_ctx.connection) < 0) {
-                struct drbd_resource *resource = adm_ctx.connection->resource;
-
-                list_del_rcu(&resource->resources);
-                synchronize_rcu();
-                drbd_free_resource(resource);
+        list_del_rcu(&resource->resources);
+        synchronize_rcu();
+        drbd_free_resource(resource);
+        retcode = NO_ERROR;
 
-                retcode = NO_ERROR;
-        } else {
-                /* "can not happen" */
-                retcode = ERR_RES_IN_USE;
-                drbd_msg_put_info("failed to delete connection");
-        }
-        goto out;
 out:
         drbd_adm_finish(info, retcode);
         return 0;