Don't attempt to create or read bitmaps where the metadata doesn't support it.

In particular, if the relevant bitmap method is NULL, don't try to
call it, print an error instead.

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

1 files changed, 6 insertions, 2 deletions

diff --git a/bitmap.c b/bitmap.c
index 088e37d..beef2dc 100644
--- a/bitmap.c
+++ b/bitmap.c
@@ -227,9 +227,13 @@ bitmap_info_t *bitmap_file_read(char *filename, int brief, struct supertype **st
 		if (!st) {
 			/* just look at device... */
 			lseek(fd, 0, 0);
-		} else {
+		} else if (!st->ss->locate_bitmap) {
+			fprintf(stderr, Name ": No bitmap possible with %s metadata\n",
+				st->ss->name);
+			return NULL;
+		} else
 			st->ss->locate_bitmap(st, fd);
-		}
+
 		ioctl(fd, BLKFLSBUF, 0); /* make sure we read current data */
 		*stp = st;
 	} else {