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, 3 insertions, 3 deletions

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index d32fc559ff05..f05d5983efb6 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1100,7 +1100,7 @@ static int raid1_spare_active(mddev_t *mddev)
 static int raid1_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
 {
         conf_t *conf = mddev->private;
-        int found = 0;
+        int err = -EEXIST;
         int mirror = 0;
         mirror_info_t *p;
         int first = 0;
@@ -1124,7 +1124,7 @@ static int raid1_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
 
                         p->head_position = 0;
                         rdev->raid_disk = mirror;
-                        found = 1;
+                        err = 0;
                         /* As all devices are equivalent, we don't need a full recovery
                          * if this was recently any drive of the array
                          */
@@ -1135,7 +1135,7 @@ static int raid1_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
                 }
 
         print_conf(conf);
-        return found;
+        return err;
 }
 
 static int raid1_remove_disk(mddev_t *mddev, int number)