drbd: Replace conn_get_by_name() with drbd_find_resource()

So far, connections and resources always come in pairs, but in the future with
multiple connections per resource, the names will stick with the resources.

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

3 files changed, 30 insertions, 20 deletions

diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index 73a7a6e8f715..1bca8ec5f65b 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -1211,9 +1211,9 @@ extern void drbd_free_resource(struct drbd_resource *resource);
 extern int set_resource_options(struct drbd_connection *connection, struct res_opts *res_opts);
 extern struct drbd_connection *conn_create(const char *name, struct res_opts *res_opts);
 extern void drbd_destroy_connection(struct kref *kref);
-struct drbd_connection *conn_get_by_name(const char *name);
 extern struct drbd_connection *conn_get_by_addrs(void *my_addr, int my_addr_len,
                                             void *peer_addr, int peer_addr_len);
+extern struct drbd_resource *drbd_find_resource(const char *name);
 extern void drbd_destroy_resource(struct kref *kref);
 extern void conn_free_crypto(struct drbd_connection *connection);
 
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 92479bdc3e78..2be5355dede2 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -2405,9 +2405,8 @@ static void drbd_init_workqueue(struct drbd_work_queue* wq)
         init_waitqueue_head(&wq->q_wait);
 }
 
-struct drbd_connection *conn_get_by_name(const char *name)
+struct drbd_resource *drbd_find_resource(const char *name)
 {
-        struct drbd_connection *connection;
         struct drbd_resource *resource;
 
         if (!name || !name[0])
@@ -2416,15 +2415,14 @@ struct drbd_connection *conn_get_by_name(const char *name)
         rcu_read_lock();
         for_each_resource_rcu(resource, &drbd_resources) {
                 if (!strcmp(resource->name, name)) {
-                        connection = first_connection(resource);
-                        kref_get(&connection->kref);
+                        kref_get(&resource->kref);
                         goto found;
                 }
         }
-        connection = NULL;
+        resource = NULL;
 found:
         rcu_read_unlock();
-        return connection;
+        return resource;
 }
 
 struct drbd_connection *conn_get_by_addrs(void *my_addr, int my_addr_len,
diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index bbd63e9f51d8..cbf745c7bc2f 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -104,6 +104,7 @@ static struct drbd_config_context {
         struct drbd_genlmsghdr *reply_dh;
         /* resolved from attributes, if possible */
         struct drbd_device *device;
+        struct drbd_resource *resource;
         struct drbd_connection *connection;
 } adm_ctx;
 
@@ -213,13 +214,19 @@ static int drbd_adm_prepare(struct sk_buff *skb, struct genl_info *info,
 
         adm_ctx.minor = d_in->minor;
         adm_ctx.device = minor_to_device(d_in->minor);
-        adm_ctx.connection = conn_get_by_name(adm_ctx.resource_name);
+        if (adm_ctx.resource_name) {
+                adm_ctx.resource = drbd_find_resource(adm_ctx.resource_name);
+                if (adm_ctx.resource) {
+                        adm_ctx.connection = first_connection(adm_ctx.resource);
+                        kref_get(&adm_ctx.connection->kref);
+                }
+        }
 
         if (!adm_ctx.device && (flags & DRBD_ADM_NEED_MINOR)) {
                 drbd_msg_put_info("unknown minor");
                 return ERR_MINOR_INVALID;
         }
-        if (!adm_ctx.connection && (flags & DRBD_ADM_NEED_RESOURCE)) {
+        if (!adm_ctx.resource && (flags & DRBD_ADM_NEED_RESOURCE)) {
                 drbd_msg_put_info("unknown resource");
                 if (adm_ctx.resource_name)
                         return ERR_RES_NOT_KNOWN;
@@ -247,10 +254,10 @@ static int drbd_adm_prepare(struct sk_buff *skb, struct genl_info *info,
         }
 
         /* some more paranoia, if the request was over-determined */
-        if (adm_ctx.device && adm_ctx.connection &&
-            first_peer_device(adm_ctx.device)->connection != adm_ctx.connection) {
-                pr_warning("request: minor=%u, resource=%s; but that minor belongs to connection %s\n",
-                                adm_ctx.minor, adm_ctx.resource_name,
+        if (adm_ctx.device && adm_ctx.resource &&
+            adm_ctx.device->resource != adm_ctx.resource) {
+                pr_warning("request: minor=%u, resource=%s; but that minor belongs to resource %s\n",
+                                adm_ctx.minor, adm_ctx.resource->name,
                                 adm_ctx.device->resource->name);
                 drbd_msg_put_info("minor exists in different resource");
                 return ERR_INVALID_REQUEST;
@@ -280,6 +287,10 @@ static int drbd_adm_finish(struct genl_info *info, int retcode)
                 kref_put(&adm_ctx.connection->kref, drbd_destroy_connection);
                 adm_ctx.connection = NULL;
         }
+        if (adm_ctx.resource) {
+                kref_put(&adm_ctx.resource->kref, drbd_destroy_resource);
+                adm_ctx.resource = NULL;
+        }
 
         if (!adm_ctx.reply_skb)
                 return -ENOMEM;
@@ -3034,7 +3045,7 @@ int drbd_adm_get_status_all(struct sk_buff *skb, struct netlink_callback *cb)
         const unsigned hdrlen = GENL_HDRLEN + GENL_MAGIC_FAMILY_HDRSZ;
         struct nlattr *nla;
         const char *resource_name;
-        struct drbd_connection *connection;
+        struct drbd_resource *resource;
         int maxtype;
 
         /* Is this a followup call? */
@@ -3063,18 +3074,19 @@ int drbd_adm_get_status_all(struct sk_buff *skb, struct netlink_callback *cb)
         if (!nla)
                 return -EINVAL;
         resource_name = nla_data(nla);
-        connection = conn_get_by_name(resource_name);
-
-        if (!connection)
+        if (!*resource_name)
+                return -ENODEV;
+        resource = drbd_find_resource(resource_name);
+        if (!resource)
                 return -ENODEV;
 
-        kref_put(&connection->kref, drbd_destroy_connection); /* get_one_status() (re)validates connection by itself */
+        kref_put(&resource->kref, drbd_destroy_resource); /* get_one_status() revalidates the resource */
 
         /* prime iterators, and set "filter" mode mark:
          * only dump this connection. */
-        cb->args[0] = (long)connection;
+        cb->args[0] = (long)resource;
         /* cb->args[1] = 0; passed in this way. */
-        cb->args[2] = (long)connection;
+        cb->args[2] = (long)resource;
 
 dump:
         return get_one_status(skb, cb);