The size of the first level reference count table is given in terms of the

number of clusters it occupies. It's not the number of entries in the table,
as it is for the L1 cluster table.

For small images, the two are the same. With the unit tests based on small
images, this change has therefore no effect on the unit test.  For larger
images (like the FreeBSD 10.1-RELEASE image), this gives a discrepancy that
actually shows up when running "qemu-img check".

Bump the version number of mkimg.

While here, fix a white-space bug.

MFC after: 1 week

1 files changed, 5 insertions, 4 deletions

diff --git a/usr.bin/mkimg/qcow.c b/usr.bin/mkimg/qcow.c
index 5033286..a89761b 100644
--- a/usr.bin/mkimg/qcow.c
+++ b/usr.bin/mkimg/qcow.c
@@ -71,7 +71,7 @@ struct qcow_header {
 			uint32_t	l1_entries;
 			uint64_t	l1_offset;
 			uint64_t	refcnt_offset;
-			uint32_t	refcnt_entries;
+			uint32_t	refcnt_clstrs;
 			uint32_t	snapshot_count;
 			uint64_t	snapshot_offset;
 		} v2;
@@ -139,7 +139,7 @@ qcow_write(int fd, u_int version)
 	uint64_t n, imagesz, nclstrs, ofs, ofsflags;
 	lba_t blk, blkofs, blk_imgsz;
 	u_int l1clno, l2clno, rcclno;
-	u_int blk_clstrsz;
+	u_int blk_clstrsz, refcnt_clstrs;
 	u_int clstrsz, l1idx, l2idx;
 	int error;
 
@@ -199,14 +199,15 @@ qcow_write(int fd, u_int version)
 		be32enc(&hdr->u.v2.l1_entries, clstr_l2tbls);
 		be64enc(&hdr->u.v2.l1_offset, clstrsz * l1clno);
 		be64enc(&hdr->u.v2.refcnt_offset, clstrsz * rcclno);
-		be32enc(&hdr->u.v2.refcnt_entries, clstr_rcblks);
+		refcnt_clstrs = round_clstr(clstr_rcblks * 8) >> clstr_log2sz;
+		be32enc(&hdr->u.v2.refcnt_clstrs, refcnt_clstrs);
 		break;
 	default:
 		return (EDOOFUS);
 	}
 
 	if (sparse_write(fd, hdr, clstrsz) < 0) {
-                error = errno;
+		error = errno;
 		goto out;
 	}