3 files changed, 25 insertions, 7 deletions

diff --git a/drivers/scsi/pmcraid.c b/drivers/scsi/pmcraid.c
index bd6f743d87a7..892ea6161376 100644
--- a/drivers/scsi/pmcraid.c
+++ b/drivers/scsi/pmcraid.c
@@ -1404,11 +1404,22 @@ enum {
 };
 #define PMCRAID_AEN_CMD_MAX (__PMCRAID_AEN_CMD_MAX - 1)
 
+static struct genl_multicast_group pmcraid_mcgrps[] = {
+        { .name = "events", /* not really used - see ID discussion below */ },
+};
+
 static struct genl_family pmcraid_event_family = {
-        .id = GENL_ID_GENERATE,
+        /*
+         * Due to prior multicast group abuse (the code having assumed that
+         * the family ID can be used as a multicast group ID) we need to
+         * statically allocate a family (and thus group) ID.
+         */
+        .id = GENL_ID_PMCRAID,
         .name = "pmcraid",
         .version = 1,
-        .maxattr = PMCRAID_AEN_ATTR_MAX
+        .maxattr = PMCRAID_AEN_ATTR_MAX,
+        .mcgrps = pmcraid_mcgrps,
+        .n_mcgrps = ARRAY_SIZE(pmcraid_mcgrps),
 };
 
 /**
@@ -1511,9 +1522,8 @@ static int pmcraid_notify_aen(
                 return result;
         }
 
-        result =
-                genlmsg_multicast(&pmcraid_event_family, skb, 0,
-                                  pmcraid_event_family.id, GFP_ATOMIC);
+        result = genlmsg_multicast(&pmcraid_event_family, skb,
+                                   0, 0, GFP_ATOMIC);
 
         /* If there are no listeners, genlmsg_multicast may return non-zero
          * value.
diff --git a/include/uapi/linux/genetlink.h b/include/uapi/linux/genetlink.h
index 1af72d8228e0..c3363ba1ae05 100644
--- a/include/uapi/linux/genetlink.h
+++ b/include/uapi/linux/genetlink.h
@@ -28,6 +28,7 @@ struct genlmsghdr {
 #define GENL_ID_GENERATE        0
 #define GENL_ID_CTRL            NLMSG_MIN_TYPE
 #define GENL_ID_VFS_DQUOT       (NLMSG_MIN_TYPE + 1)
+#define GENL_ID_PMCRAID         (NLMSG_MIN_TYPE + 2)
 
 /**************************************************************************
  * Controller
diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index 803206e82450..713671ae45af 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -74,9 +74,12 @@ static struct list_head family_ht[GENL_FAM_TAB_SIZE];
  * Bit 17 is marked as already used since the VFS quota code
  * also abused this API and relied on family == group ID, we
  * cater to that by giving it a static family and group ID.
+ * Bit 18 is marked as already used since the PMCRAID driver
+ * did the same thing as the VFS quota code (maybe copied?)
  */
 static unsigned long mc_group_start = 0x3 | BIT(GENL_ID_CTRL) |
-                                      BIT(GENL_ID_VFS_DQUOT);
+                                      BIT(GENL_ID_VFS_DQUOT) |
+                                      BIT(GENL_ID_PMCRAID);
 static unsigned long *mc_groups = &mc_group_start;
 static unsigned long mc_groups_longs = 1;
 
@@ -139,6 +142,7 @@ static u16 genl_generate_id(void)
 
         for (i = 0; i <= GENL_MAX_ID - GENL_MIN_ID; i++) {
                 if (id_gen_idx != GENL_ID_VFS_DQUOT &&
+                    id_gen_idx != GENL_ID_PMCRAID &&
                     !genl_family_find_byid(id_gen_idx))
                         return id_gen_idx;
                 if (++id_gen_idx > GENL_MAX_ID)
@@ -236,9 +240,12 @@ static int genl_validate_assign_mc_groups(struct genl_family *family)
         } else if (strcmp(family->name, "NET_DM") == 0) {
                 first_id = 1;
                 BUG_ON(n_groups != 1);
-        } else if (strcmp(family->name, "VFS_DQUOT") == 0) {
+        } else if (family->id == GENL_ID_VFS_DQUOT) {
                 first_id = GENL_ID_VFS_DQUOT;
                 BUG_ON(n_groups != 1);
+        } else if (family->id == GENL_ID_PMCRAID) {
+                first_id = GENL_ID_PMCRAID;
+                BUG_ON(n_groups != 1);
         } else {
                 groups_allocated = true;
                 err = genl_allocate_reserve_groups(n_groups, &first_id);