rationalise return value for ->hot_add_disk method.

For all array types but linear, ->hot_add_disk returns 1 on
success, 0 on failure.
For linear, it returns 0 on success and -errno on failure.

This doesn't cause a functional problem because the ->hot_add_disk
function of linear is used quite differently to the others.
However it is confusing.

So convert all to return 0 for success or -errno on failure
and fix call sites to match.

Signed-off-by: Neil Brown <neilb@suse.de>

1 files changed, 5 insertions, 5 deletions

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 50ad8d2ae0e8..df08a9fa3a1f 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1113,7 +1113,7 @@ static int raid10_spare_active(mddev_t *mddev)
 static int raid10_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
 {
         conf_t *conf = mddev->private;
-        int found = 0;
+        int err = -EEXIST;
         int mirror;
         mirror_info_t *p;
         int first = 0;
@@ -1123,9 +1123,9 @@ static int raid10_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
                 /* only hot-add to in-sync arrays, as recovery is
                  * very different from resync
                  */
-                return 0;
+                return -EBUSY;
         if (!enough(conf))
-                return 0;
+                return -EINVAL;
 
         if (rdev->raid_disk)
                 first = last = rdev->raid_disk;
@@ -1151,7 +1151,7 @@ static int raid10_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
 
                         p->head_position = 0;
                         rdev->raid_disk = mirror;
-                        found = 1;
+                        err = 0;
                         if (rdev->saved_raid_disk != mirror)
                                 conf->fullsync = 1;
                         rcu_assign_pointer(p->rdev, rdev);
@@ -1159,7 +1159,7 @@ static int raid10_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
                 }
 
         print_conf(conf);
-        return found;
+        return err;
 }
 
 static int raid10_remove_disk(mddev_t *mddev, int number)