When updating uuid, update the bitmap as well - external bitmaps

Signed-off-by: Neil Brown <neilb@suse.de>

Assemble.c

@@ -308,6 +308,10 @@ int Assemble(struct supertype *st, char *mddev, int mdfd,
 					devname);
 			if (dfd >= 0)
 				close(dfd);
+
+			if (strcmp(update, "uuid")==0 &&
+			    ident->bitmap_fd)
+				bitmap_update_uuid(ident->bitmap_fd, info.uuid);
 		}
 
 		if (verbose > 0)

ChangeLog

@@ -12,6 +12,8 @@ Changes Prior to this release
 	mode and auto-flag
     -   --detail checks if array has been started or not and includes that
 	in report.
+    -   When using --update=uuid on an array with a bitmap, update the
+	bitmap's uuid too.
 
 Changes Prior to 2.4.1 release
     -   Honour --write-mostly when adding to an array without persistent

bitmap.c

@@ -398,3 +398,17 @@ out:
 		unlink(filename); /* possibly corrupted, better get rid of it */
 	return rv;
 }
+
+void bitmap_update_uuid(int fd, int *uuid)
+{
+	struct bitmap_super_s bm;
+	lseek(fd, 0, 0);
+	if (read(fd, &bm, sizeof(bm)) != sizeof(bm))
+		return;
+	if (bm.magic != __cpu_to_le32(BITMAP_MAGIC))
+		return;
+	memcpy(bm.uuid, uuid, 16);
+	lseek(fd, 0, 0);
+	write(fd, &bm, sizeof(bm));
+	lseek(fd, 0, 0);
+}

mdadm.h

@@ -361,6 +361,7 @@ extern int CreateBitmap(char *filename, int force, char uuid[16],
 			unsigned long long array_size,
 			int major);
 extern int ExamineBitmap(char *filename, int brief, struct supertype *st);
+extern void bitmap_update_uuid(int fd, int *uuid);
 
 extern int md_get_version(int fd);
 extern int get_linux_version(void);