md: provide appropriate return value for spare_active functions.

md_check_recovery expects ->spare_active to return 'true' if any
spares were activated, but none of them do, so the consequent change
in 'degraded' is not notified through sysfs.

So count the number of spares activated, subtract it from 'degraded'
just once, and return it.
Reported-by: Adrian Drzewiecki <adriand@vmware.com>
Signed-off-by: NeilBrown <neilb@suse.de>

drivers/md/raid1.c

@@ -1120,6 +1120,8 @@ static int raid1_spare_active(mddev_t *mddev)
 {
 	int i;
 	conf_t *conf = mddev->private;
+	int count = 0;
+	unsigned long flags;
 
 	/*
 	 * Find all failed disks within the RAID1 configuration 
@@ -1131,16 +1133,16 @@ static int raid1_spare_active(mddev_t *mddev)
 		if (rdev
 		    && !test_bit(Faulty, &rdev->flags)
 		    && !test_and_set_bit(In_sync, &rdev->flags)) {
-			unsigned long flags;
-			spin_lock_irqsave(&conf->device_lock, flags);
-			mddev->degraded--;
-			spin_unlock_irqrestore(&conf->device_lock, flags);
+			count++;
 			sysfs_notify_dirent(rdev->sysfs_state);
 		}
 	}
+	spin_lock_irqsave(&conf->device_lock, flags);
+	mddev->degraded -= count;
+	spin_unlock_irqrestore(&conf->device_lock, flags);
 
 	print_conf(conf);
-	return 0;
+	return count;
 }
 
 

drivers/md/raid10.c

@@ -1116,6 +1116,8 @@ static int raid10_spare_active(mddev_t *mddev)
 	int i;
 	conf_t *conf = mddev->private;
 	mirror_info_t *tmp;
+	int count = 0;
+	unsigned long flags;
 
 	/*
 	 * Find all non-in_sync disks within the RAID10 configuration
@@ -1126,16 +1128,16 @@ static int raid10_spare_active(mddev_t *mddev)
 		if (tmp->rdev
 		    && !test_bit(Faulty, &tmp->rdev->flags)
 		    && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
-			unsigned long flags;
-			spin_lock_irqsave(&conf->device_lock, flags);
-			mddev->degraded--;
-			spin_unlock_irqrestore(&conf->device_lock, flags);
+			count++;
 			sysfs_notify_dirent(tmp->rdev->sysfs_state);
 		}
 	}
+	spin_lock_irqsave(&conf->device_lock, flags);
+	mddev->degraded -= count;
+	spin_unlock_irqrestore(&conf->device_lock, flags);
 
 	print_conf(conf);
-	return 0;
+	return count;
 }
 
 

drivers/md/raid5.c

@@ -5330,6 +5330,8 @@ static int raid5_spare_active(mddev_t *mddev)
 	int i;
 	raid5_conf_t *conf = mddev->private;
 	struct disk_info *tmp;
+	int count = 0;
+	unsigned long flags;
 
 	for (i = 0; i < conf->raid_disks; i++) {
 		tmp = conf->disks + i;
@@ -5337,15 +5339,15 @@ static int raid5_spare_active(mddev_t *mddev)
 		    && tmp->rdev->recovery_offset == MaxSector
 		    && !test_bit(Faulty, &tmp->rdev->flags)
 		    && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
-			unsigned long flags;
-			spin_lock_irqsave(&conf->device_lock, flags);
-			mddev->degraded--;
-			spin_unlock_irqrestore(&conf->device_lock, flags);
+			count++;
 			sysfs_notify_dirent(tmp->rdev->sysfs_state);
 		}
 	}
+	spin_lock_irqsave(&conf->device_lock, flags);
+	mddev->degraded -= count;
+	spin_unlock_irqrestore(&conf->device_lock, flags);
 	print_raid5_conf(conf);
-	return 0;
+	return count;
 }
 
 static int raid5_remove_disk(mddev_t *mddev, int number)