vvfat: do not fail if the disk has spare sectors

If the number of "faked sectors" + the number of sectors that are
part of a cluster does not sum up to the total number of sectors,
qemu-img convert fails.  Read these spare sectors as all zeros.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

diff --git a/block/vvfat.c b/block/vvfat.c
index 75d0dc0..9f851b0 100644 (file)
--- a/block/vvfat.c
+++ b/block/vvfat.c
@@ -1245,7 +1245,7 @@ static int vvfat_read(BlockDriverState *bs, int64_t sector_num,
     int i;
 
     for(i=0;i<nb_sectors;i++,sector_num++) {
-       if (sector_num >= s->sector_count)
+       if (sector_num >= bs->total_sectors)
           return -1;
        if (s->qcow) {
            int n;
@@ -1271,7 +1271,7 @@ DLOG(fprintf(stderr, "sector %d not allocated\n", (int)sector_num));
            uint32_t sector=sector_num-s->faked_sectors,
            sector_offset_in_cluster=(sector%s->sectors_per_cluster),
            cluster_num=sector/s->sectors_per_cluster;
-           if(read_cluster(s, cluster_num) != 0) {
+           if(cluster_num > s->cluster_count || read_cluster(s, cluster_num) != 0) {
                /* LATER TODO: strict: return -1; */
                memset(buf+i*0x200,0,0x200);
                continue;