drdb: use cpumask_var_t in struct drdb_conf

Any code which can be compiled on x86 should try to avoid cpumask_t
(or even struct cpumask) declarations; we are heading towards struct
cpumask being undefined if CONFIG_CPUMASK_OFFSTACK.

The code is the same for CONFIG_CPUMASK_OFFSTACK=n.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

drivers/block/drbd/drbd_int.h

@@ -1006,7 +1006,7 @@ struct drbd_conf {
 	spinlock_t peer_seq_lock;
 	unsigned int minor;
 	unsigned long comm_bm_set; /* communicated number of set bits. */
-	cpumask_t cpu_mask;
+	cpumask_var_t cpu_mask;
 	struct bm_io_work bm_io_work;
 	u64 ed_uuid; /* UUID of the exposed data */
 	struct mutex state_mutex;

drivers/block/drbd/drbd_main.c

@@ -1550,18 +1550,18 @@ void drbd_calc_cpu_mask(struct drbd_conf *mdev)
 	int ord, cpu;
 
 	/* user override. */
-	if (cpumask_weight(&mdev->cpu_mask))
+	if (cpumask_weight(mdev->cpu_mask))
 		return;
 
 	ord = mdev_to_minor(mdev) % cpumask_weight(cpu_online_mask);
 	for_each_online_cpu(cpu) {
 		if (ord-- == 0) {
-			cpumask_set_cpu(cpu, &mdev->cpu_mask);
+			cpumask_set_cpu(cpu, mdev->cpu_mask);
 			return;
 		}
 	}
 	/* should not be reached */
-	cpumask_setall(&mdev->cpu_mask);
+	cpumask_setall(mdev->cpu_mask);
 }
 
 /**
@@ -1584,7 +1584,7 @@ void drbd_thread_current_set_cpu(struct drbd_conf *mdev)
 	if (!thi->reset_cpu_mask)
 		return;
 	thi->reset_cpu_mask = 0;
-	set_cpus_allowed_ptr(p, &mdev->cpu_mask);
+	set_cpus_allowed_ptr(p, mdev->cpu_mask);
 }
 #endif
 
@@ -3001,6 +3001,8 @@ struct drbd_conf *drbd_new_device(unsigned int minor)
 	mdev = kzalloc(sizeof(struct drbd_conf), GFP_KERNEL);
 	if (!mdev)
 		return NULL;
+	if (!zalloc_cpumask_var(&mdev->cpu_mask, GFP_KERNEL))
+		goto out_no_cpumask;
 
 	mdev->minor = minor;
 
@@ -3079,6 +3081,8 @@ out_no_io_page:
 out_no_disk:
 	blk_cleanup_queue(q);
 out_no_q:
+	free_cpumask_var(mdev->cpu_mask);
+out_no_cpumask:
 	kfree(mdev);
 	return NULL;
 }
@@ -3095,6 +3099,7 @@ void drbd_free_mdev(struct drbd_conf *mdev)
 	__free_page(mdev->md_io_page);
 	put_disk(mdev->vdisk);
 	blk_cleanup_queue(mdev->rq_queue);
+	free_cpumask_var(mdev->cpu_mask);
 	kfree(mdev);
 }
 

drivers/block/drbd/drbd_nl.c

@@ -1657,8 +1657,8 @@ static int drbd_nl_syncer_conf(struct drbd_conf *mdev, struct drbd_nl_cfg_req *n
 	if (mdev->state.conn >= C_CONNECTED)
 		drbd_send_sync_param(mdev, &sc);
 
-	if (!cpumask_equal(&mdev->cpu_mask, new_cpu_mask)) {
-		cpumask_copy(&mdev->cpu_mask, new_cpu_mask);
+	if (!cpumask_equal(mdev->cpu_mask, new_cpu_mask)) {
+		cpumask_copy(mdev->cpu_mask, new_cpu_mask);
 		drbd_calc_cpu_mask(mdev);
 		mdev->receiver.reset_cpu_mask = 1;
 		mdev->asender.reset_cpu_mask = 1;