[S390] memory hotplug: only unassign assigned increments

Make sure that only assigned storage increments are unassigned when
attaching a storage element.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/s390/char/sclp_cmd.c b/drivers/s390/char/sclp_cmd.c
index be55fb2b1b1..837e010299a 100644
--- a/drivers/s390/char/sclp_cmd.c
+++ b/drivers/s390/char/sclp_cmd.c
@@ -383,8 +383,10 @@ static int sclp_attach_storage(u8 id)
         switch (sccb->header.response_code) {
         case 0x0020:
                 set_bit(id, sclp_storage_ids);
-                for (i = 0; i < sccb->assigned; i++)
-                        sclp_unassign_storage(sccb->entries[i] >> 16);
+                for (i = 0; i < sccb->assigned; i++) {
+                        if (sccb->entries[i])
+                                sclp_unassign_storage(sccb->entries[i] >> 16);
+                }
                 break;
         default:
                 rc = -EIO;