drbd: Add drbd_thread->resource and make drbd_thread->connection optional

In the drbd_thread "infrastructure" functions, only use the resource instead of
the connection.  Make the connection field of drbd_thread optional.  This will
allow to introduce threads which are not associated with a connection.

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

diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index b3f46fb4dda3199258f52fb1de8ceff429a64bc3..e7093d4291f1a850326ab2f17d6cb52ff15d0250 100644 (file)
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -263,6 +263,7 @@ struct drbd_thread {
        struct completion stop;
        enum drbd_thread_state t_state;
        int (*function) (struct drbd_thread *);
+       struct drbd_resource *resource;
        struct drbd_connection *connection;
        int reset_cpu_mask;
        const char *name;

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 232cd570d3aeaefb4b2e3f2772fa19036a285f5d..331e5cc1227ddfed1d7d78467de86d186f6d4f45 100644 (file)
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -322,13 +322,13 @@ void tl_abort_disk_io(struct drbd_device *device)
 static int drbd_thread_setup(void *arg)
 {
        struct drbd_thread *thi = (struct drbd_thread *) arg;
-       struct drbd_connection *connection = thi->connection;
+       struct drbd_resource *resource = thi->resource;
        unsigned long flags;
        int retval;
 
        snprintf(current->comm, sizeof(current->comm), "drbd_%c_%s",
                 thi->name[0],
-                thi->connection->resource->name);
+                resource->name);
 
 restart:
        retval = thi->function(thi);
@@ -346,7 +346,7 @@ restart:
         */
 
        if (thi->t_state == RESTARTING) {
-               drbd_info(connection, "Restarting %s thread\n", thi->name);
+               drbd_info(resource, "Restarting %s thread\n", thi->name);
                thi->t_state = RUNNING;
                spin_unlock_irqrestore(&thi->t_lock, flags);
                goto restart;
@@ -358,29 +358,32 @@ restart:
        complete_all(&thi->stop);
        spin_unlock_irqrestore(&thi->t_lock, flags);
 
-       drbd_info(connection, "Terminating %s\n", current->comm);
+       drbd_info(resource, "Terminating %s\n", current->comm);
 
        /* Release mod reference taken when thread was started */
 
-       kref_put(&connection->kref, drbd_destroy_connection);
+       if (thi->connection)
+               kref_put(&thi->connection->kref, drbd_destroy_connection);
+       kref_put(&resource->kref, drbd_destroy_resource);
        module_put(THIS_MODULE);
        return retval;
 }
 
-static void drbd_thread_init(struct drbd_connection *connection, struct drbd_thread *thi,
+static void drbd_thread_init(struct drbd_resource *resource, struct drbd_thread *thi,
                             int (*func) (struct drbd_thread *), const char *name)
 {
        spin_lock_init(&thi->t_lock);
        thi->task    = NULL;
        thi->t_state = NONE;
        thi->function = func;
-       thi->connection = connection;
+       thi->resource = resource;
+       thi->connection = NULL;
        thi->name = name;
 }
 
 int drbd_thread_start(struct drbd_thread *thi)
 {
-       struct drbd_connection *connection = thi->connection;
+       struct drbd_resource *resource = thi->resource;
        struct task_struct *nt;
        unsigned long flags;
 
@@ -390,17 +393,19 @@ int drbd_thread_start(struct drbd_thread *thi)
 
        switch (thi->t_state) {
        case NONE:
-               drbd_info(connection, "Starting %s thread (from %s [%d])\n",
+               drbd_info(resource, "Starting %s thread (from %s [%d])\n",
                         thi->name, current->comm, current->pid);
 
                /* Get ref on module for thread - this is released when thread exits */
                if (!try_module_get(THIS_MODULE)) {
-                       drbd_err(connection, "Failed to get module reference in drbd_thread_start\n");
+                       drbd_err(resource, "Failed to get module reference in drbd_thread_start\n");
                        spin_unlock_irqrestore(&thi->t_lock, flags);
                        return false;
                }
 
-               kref_get(&thi->connection->kref);
+               kref_get(&resource->kref);
+               if (thi->connection)
+                       kref_get(&thi->connection->kref);
 
                init_completion(&thi->stop);
                thi->reset_cpu_mask = 1;
@@ -409,12 +414,14 @@ int drbd_thread_start(struct drbd_thread *thi)
                flush_signals(current); /* otherw. may get -ERESTARTNOINTR */
 
                nt = kthread_create(drbd_thread_setup, (void *) thi,
-                                   "drbd_%c_%s", thi->name[0], thi->connection->resource->name);
+                                   "drbd_%c_%s", thi->name[0], thi->resource->name);
 
                if (IS_ERR(nt)) {
-                       drbd_err(connection, "Couldn't start thread\n");
+                       drbd_err(resource, "Couldn't start thread\n");
 
-                       kref_put(&connection->kref, drbd_destroy_connection);
+                       if (thi->connection)
+                               kref_put(&thi->connection->kref, drbd_destroy_connection);
+                       kref_put(&resource->kref, drbd_destroy_resource);
                        module_put(THIS_MODULE);
                        return false;
                }
@@ -426,7 +433,7 @@ int drbd_thread_start(struct drbd_thread *thi)
                break;
        case EXITING:
                thi->t_state = RESTARTING;
-               drbd_info(connection, "Restarting %s thread (from %s [%d])\n",
+               drbd_info(resource, "Restarting %s thread (from %s [%d])\n",
                                thi->name, current->comm, current->pid);
                /* fall through */
        case RUNNING:
@@ -536,12 +543,13 @@ static void drbd_calc_cpu_mask(cpumask_var_t *cpu_mask)
  */
 void drbd_thread_current_set_cpu(struct drbd_thread *thi)
 {
+       struct drbd_resource *resource = thi->resource;
        struct task_struct *p = current;
 
        if (!thi->reset_cpu_mask)
                return;
        thi->reset_cpu_mask = 0;
-       set_cpus_allowed_ptr(p, thi->connection->resource->cpu_mask);
+       set_cpus_allowed_ptr(p, resource->cpu_mask);
 }
 #else
 #define drbd_calc_cpu_mask(A) ({})
@@ -2616,9 +2624,12 @@ struct drbd_connection *conn_create(const char *name, struct res_opts *res_opts)
        mutex_init(&connection->data.mutex);
        mutex_init(&connection->meta.mutex);
 
-       drbd_thread_init(connection, &connection->receiver, drbd_receiver, "receiver");
-       drbd_thread_init(connection, &connection->worker, drbd_worker, "worker");
-       drbd_thread_init(connection, &connection->asender, drbd_asender, "asender");
+       drbd_thread_init(resource, &connection->receiver, drbd_receiver, "receiver");
+       connection->receiver.connection = connection;
+       drbd_thread_init(resource, &connection->worker, drbd_worker, "worker");
+       connection->worker.connection = connection;
+       drbd_thread_init(resource, &connection->asender, drbd_asender, "asender");
+       connection->asender.connection = connection;
 
        kref_init(&connection->kref);