drbd: Silenced compiler warnings

Since version 4.6.1 gcc warns about variables that get
a value assigned, but which are never read later on.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

drivers/block/drbd/drbd_actlog.c

@@ -264,8 +264,7 @@ void drbd_al_begin_io(struct drbd_conf *mdev, struct drbd_interval *i)
 		/* Double check: it may have been committed by someone else,
 		 * while we have been waiting for the lock. */
 		if (mdev->act_log->pending_changes) {
-			int err;
-			err = al_write_transaction(mdev);
+			al_write_transaction(mdev);
 			mdev->al_writ_cnt++;
 
 			spin_lock_irq(&mdev->al_lock);
@@ -290,7 +289,6 @@ void drbd_al_complete_io(struct drbd_conf *mdev, struct drbd_interval *i)
 	unsigned enr;
 	struct lc_element *extent;
 	unsigned long flags;
-	bool wake = false;
 
 	spin_lock_irqsave(&mdev->al_lock, flags);
 
@@ -300,8 +298,7 @@ void drbd_al_complete_io(struct drbd_conf *mdev, struct drbd_interval *i)
 			dev_err(DEV, "al_complete_io() called on inactive extent %u\n", enr);
 			continue;
 		}
-		if (lc_put(mdev->act_log, extent) == 0)
-			wake = true;
+		lc_put(mdev->act_log, extent);
 	}
 	spin_unlock_irqrestore(&mdev->al_lock, flags);
 	wake_up(&mdev->al_wait);
@@ -730,7 +727,7 @@ void __drbd_set_in_sync(struct drbd_conf *mdev, sector_t sector, int size,
 int __drbd_set_out_of_sync(struct drbd_conf *mdev, sector_t sector, int size,
 			    const char *file, const unsigned int line)
 {
-	unsigned long sbnr, ebnr, lbnr, flags;
+	unsigned long sbnr, ebnr, flags;
 	sector_t esector, nr_sectors;
 	unsigned int enr, count = 0;
 	struct lc_element *e;
@@ -752,8 +749,6 @@ int __drbd_set_out_of_sync(struct drbd_conf *mdev, sector_t sector, int size,
 	if (!expect(esector < nr_sectors))
 		esector = nr_sectors - 1;
 
-	lbnr = BM_SECT_TO_BIT(nr_sectors-1);
-
 	/* we set it out of sync,
 	 * we do not need to round anything here */
 	sbnr = BM_SECT_TO_BIT(sector);

drivers/block/drbd/drbd_receiver.c

@@ -4324,7 +4324,7 @@ static void conn_disconnect(struct drbd_tconn *tconn)
 {
 	struct drbd_conf *mdev;
 	enum drbd_conns oc;
-	int vnr, rv = SS_UNKNOWN_ERROR;
+	int vnr;
 
 	if (tconn->cstate == C_STANDALONE)
 		return;
@@ -4351,7 +4351,7 @@ static void conn_disconnect(struct drbd_tconn *tconn)
 	spin_lock_irq(&tconn->req_lock);
 	oc = tconn->cstate;
 	if (oc >= C_UNCONNECTED)
-		rv = _conn_request_state(tconn, NS(conn, C_UNCONNECTED), CS_VERBOSE);
+		_conn_request_state(tconn, NS(conn, C_UNCONNECTED), CS_VERBOSE);
 
 	spin_unlock_irq(&tconn->req_lock);
 
@@ -4361,7 +4361,6 @@ static void conn_disconnect(struct drbd_tconn *tconn)
 
 static int drbd_disconnected(struct drbd_conf *mdev)
 {
-	enum drbd_fencing_p fp;
 	unsigned int i;
 
 	/* wait for current activity to cease. */
@@ -4405,14 +4404,6 @@ static int drbd_disconnected(struct drbd_conf *mdev)
 
 	drbd_md_sync(mdev);
 
-	fp = FP_DONT_CARE;
-	if (get_ldev(mdev)) {
-		rcu_read_lock();
-		fp = rcu_dereference(mdev->ldev->disk_conf)->fencing;
-		rcu_read_unlock();
-		put_ldev(mdev);
-	}
-
 	/* serialize with bitmap writeout triggered by the state change,
 	 * if any. */
 	wait_event(mdev->misc_wait, !test_bit(BITMAP_IO, &mdev->flags));

drivers/block/drbd/drbd_req.c

@@ -39,6 +39,8 @@ static void _drbd_start_io_acct(struct drbd_conf *mdev, struct drbd_request *req
 	cpu = part_stat_lock();
 	part_stat_inc(cpu, &mdev->vdisk->part0, ios[rw]);
 	part_stat_add(cpu, &mdev->vdisk->part0, sectors[rw], bio_sectors(bio));
+	(void) cpu; /* The macro invocations above want the cpu argument, I do not like
+		       the compiler warning about cpu only assigned but never used... */
 	part_inc_in_flight(&mdev->vdisk->part0, rw);
 	part_stat_unlock();
 }

drivers/block/drbd/drbd_state.c

@@ -1143,7 +1143,6 @@ int drbd_bitmap_io_from_worker(struct drbd_conf *mdev,
 static void after_state_ch(struct drbd_conf *mdev, union drbd_state os,
 			   union drbd_state ns, enum chg_state_flags flags)
 {
-	enum drbd_fencing_p fp;
 	struct sib_info sib;
 
 	sib.sib_reason = SIB_STATE_CHANGE;
@@ -1156,14 +1155,6 @@ static void after_state_ch(struct drbd_conf *mdev, union drbd_state os,
 			mdev->p_uuid[UI_FLAGS] &= ~((u64)2);
 	}
 
-	fp = FP_DONT_CARE;
-	if (get_ldev(mdev)) {
-		rcu_read_lock();
-		fp = rcu_dereference(mdev->ldev->disk_conf)->fencing;
-		rcu_read_unlock();
-		put_ldev(mdev);
-	}
-
 	/* Inform userspace about the change... */
 	drbd_bcast_event(mdev, &sib);