Remove update_private

This fields doesn't work any more as ->getinfo_super clears the info
structure at an awkward time.  So get rid of it and do it differently.

The issue is that the metadata handler cannot tell if the uuid it has
was randomly generated or explicitly requested, except on the first
call.
And we don't want to accept explicit requests for IMSM.
So when it was auto-generated, make it look distinctive by having the
same int copied in all 4 positions.  If someone requests a uuid like
that, I guess they get away with it.

Reported-by: Adam Kwolek <adam.kwolek@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>

3 files changed, 21 insertions, 24 deletions

diff --git a/Assemble.c b/Assemble.c
index fac2bad6..74fb6a32 100644
--- a/Assemble.c
+++ b/Assemble.c
@@ -706,7 +706,6 @@ int Assemble(struct supertype *st, char *mddev,
 	bitmap_done = 0;
 #endif
 	/* Ok, no bad inconsistancy, we can try updating etc */
-	content->update_private = NULL;
 	devices = malloc(num_devs * sizeof(*devices));
 	devmap = calloc(num_devs * content->array.raid_disks, 1);
 	for (tmpdev = devlist; tmpdev; tmpdev=tmpdev->next) if (tmpdev->used == 1) {
@@ -891,8 +890,6 @@ int Assemble(struct supertype *st, char *mddev,
 		}
 		devcnt++;
 	}
-	free(content->update_private);
-	content->update_private = NULL;
 
 	if (devcnt == 0) {
 		fprintf(stderr, Name ": no devices found for %s\n",
diff --git a/mdadm.h b/mdadm.h
index 1351d420..4f3533f8 100644
--- a/mdadm.h
+++ b/mdadm.h
@@ -217,11 +217,6 @@ struct mdinfo {
 	unsigned long		cache_size; /* size of raid456 stripe cache*/
 	int			mismatch_cnt;
 	char			text_version[50];
-	void 			*update_private; /* for passing metadata-format
-						  * specific update data
-						  * between successive calls to
-						  * update_super()
-						  */
 
 	int container_member; /* for assembling external-metatdata arrays
 			       * This is to be used internally by metadata
diff --git a/super-intel.c b/super-intel.c
index e1073efb..9074485a 100644
--- a/super-intel.c
+++ b/super-intel.c
@@ -2791,25 +2791,30 @@ static int update_super_imsm(struct supertype *st, struct mdinfo *info,
 
 	mpb = super->anchor;
 
-	if (strcmp(update, "uuid") == 0 && uuid_set && !info->update_private)
-		rv = -1;
-	else if (strcmp(update, "uuid") == 0 && uuid_set && info->update_private) {
-		mpb->orig_family_num = *((__u32 *) info->update_private);
-		rv = 0;
-	} else if (strcmp(update, "uuid") == 0) {
-		__u32 *new_family = malloc(sizeof(*new_family));
-
-		/* update orig_family_number with the incoming random
-		 * data, report the new effective uuid, and store the
-		 * new orig_family_num for future updates.
+	if (strcmp(update, "uuid") == 0) {
+		/* We take this to mean that the family_num should be updated.
+		 * However that is much smaller than the uuid so we cannot really
+		 * allow an explicit uuid to be given.  And it is hard to reliably
+		 * know if one was.
+		 * So if !uuid_set we know the current uuid is random and just used
+		 * the first 'int' and copy it to the other 3 positions.
+		 * Otherwise we require the 4 'int's to be the same as would be the
+		 * case if we are using a random uuid.  So an explicit uuid will be
+		 * accepted as long as all for ints are the same... which shouldn't hurt
 		 */
-		if (new_family) {
-			memcpy(&mpb->orig_family_num, info->uuid, sizeof(__u32));
-			uuid_from_super_imsm(st, info->uuid);
-			*new_family = mpb->orig_family_num;
-			info->update_private = new_family;
+		if (!uuid_set) {
+			info->uuid[1] = info->uuid[2] = info->uuid[3] = info->uuid[0];
 			rv = 0;
+		} else {
+			if (info->uuid[0] != info->uuid[1] ||
+			    info->uuid[1] != info->uuid[2] ||
+			    info->uuid[2] != info->uuid[3])
+				rv = -1;
+			else
+				rv = 0;
 		}
+		if (rv == 0)
+			mpb->orig_family_num = info->uuid[0];
 	} else if (strcmp(update, "assemble") == 0)
 		rv = 0;
 	else