[S390] dasd: Add support for enhanced VM UID

When z/VM provides two virtual devices (minidisks) that reside on the
same real device, both will receive the configuration data from the
real device and thus get the same uid. To fix this problem, z/VM
provides an additional configuration data record that allows to
distinguish between minidisks.
z/VM APAR VM64273 needs be installed so this fix has an effect.

Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/s390/block/dasd_alias.c b/drivers/s390/block/dasd_alias.c
index 2d8df0b30538..20676cdef4a5 100644
--- a/drivers/s390/block/dasd_alias.c
+++ b/drivers/s390/block/dasd_alias.c
@@ -91,7 +91,8 @@ static struct alias_pav_group *_find_group(struct alias_lcu *lcu,
         else
                 search_unit_addr = uid->base_unit_addr;
         list_for_each_entry(pos, &lcu->grouplist, group) {
-                if (pos->uid.base_unit_addr == search_unit_addr)
+                if (pos->uid.base_unit_addr == search_unit_addr &&
+                    !strncmp(pos->uid.vduit, uid->vduit, sizeof(uid->vduit)))
                         return pos;
         };
         return NULL;
@@ -332,6 +333,7 @@ static int _add_device_to_lcu(struct alias_lcu *lcu,
                         group->uid.base_unit_addr = uid->real_unit_addr;
                 else
                         group->uid.base_unit_addr = uid->base_unit_addr;
+                memcpy(group->uid.vduit, uid->vduit, sizeof(uid->vduit));
                 INIT_LIST_HEAD(&group->group);
                 INIT_LIST_HEAD(&group->baselist);
                 INIT_LIST_HEAD(&group->aliaslist);