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/raid5.c b/drivers/md/raid5.c
index 002f33b1ae0..8c4e6149dae 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -4604,7 +4604,7 @@ abort:
 static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
 {
         raid5_conf_t *conf = mddev->private;
-        int found = 0;
+        int err = -EEXIST;
         int disk;
         struct disk_info *p;
         int first = 0;
@@ -4612,7 +4612,7 @@ static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
 
         if (mddev->degraded > conf->max_degraded)
                 /* no point adding a device */
-                return 0;
+                return -EINVAL;
 
         if (rdev->raid_disk >= 0)
                 first = last = rdev->raid_disk;
@@ -4631,14 +4631,14 @@ static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
                 if ((p=conf->disks + disk)->rdev == NULL) {
                         clear_bit(In_sync, &rdev->flags);
                         rdev->raid_disk = disk;
-                        found = 1;
+                        err = 0;
                         if (rdev->saved_raid_disk != disk)
                                 conf->fullsync = 1;
                         rcu_assign_pointer(p->rdev, rdev);
                         break;
                 }
         print_raid5_conf(conf);
-        return found;
+        return err;
 }
 
 static int raid5_resize(mddev_t *mddev, sector_t sectors)
@@ -4739,7 +4739,7 @@ static int raid5_start_reshape(mddev_t *mddev)
         rdev_for_each(rdev, rtmp, mddev)
                 if (rdev->raid_disk < 0 &&
                     !test_bit(Faulty, &rdev->flags)) {
-                        if (raid5_add_disk(mddev, rdev)) {
+                        if (raid5_add_disk(mddev, rdev) == 0) {
                                 char nm[20];
                                 set_bit(In_sync, &rdev->flags);
                                 added_devices++;