vvfat: Fix partition table
Unless parameter ":floppy:" is given, vvfat creates a virtual image
with DOS MBR defining a single partition which holds the FAT file
system. The size of the virtual image depends on the width of the
FAT: 32 MiB (CHS 64, 16, 63) for 12 bit FAT, 504 MiB (CHS 1024, 16,
63) for 16 and 32 bit FAT, leaving (64*16-1)*63 = 64449 and
(1024*16-1)*64 = 1032129 sectors for the partition.
However, it screws up the end of the partition in the MBR:
FAT width param. start CHS end CHS start LBA size
:32: 0,1,1 1023,14,63 63 1032065
:16: 0,1,1 1023,14,55 63 1032057
:12: 0,1,1 63,14,55 63 64377
The actual FAT file system nevertheless assumes the partition has
1032129 or 64449 sectors. Oops.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/block/vvfat.c b/block/vvfat.c
index 0fd3367..e2b83a2 100644
--- a/block/vvfat.c
+++ b/block/vvfat.c
@@ -394,11 +394,12 @@
/* LBA is used when partition is outside the CHS geometry */
lba = sector2CHS(s->bs, &partition->start_CHS, s->first_sectors_number-1);
- lba|= sector2CHS(s->bs, &partition->end_CHS, s->sector_count);
+ lba |= sector2CHS(s->bs, &partition->end_CHS, s->bs->total_sectors - 1);
/*LBA partitions are identified only by start/length_sector_long not by CHS*/
- partition->start_sector_long =cpu_to_le32(s->first_sectors_number-1);
- partition->length_sector_long=cpu_to_le32(s->sector_count - s->first_sectors_number+1);
+ partition->start_sector_long = cpu_to_le32(s->first_sectors_number - 1);
+ partition->length_sector_long = cpu_to_le32(s->bs->total_sectors
+ - s->first_sectors_number + 1);
/* FAT12/FAT16/FAT32 */
/* DOS uses different types when partition is LBA,
