On Fri, Jun 29, 2012 at 3:34 PM, Markus Armbruster <arm...@redhat.com> wrote: > 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 <arm...@redhat.com> > --- > block/vvfat.c | 7 ++++--- > 1 files changed, 4 insertions(+), 3 deletions(-) > > diff --git a/block/vvfat.c b/block/vvfat.c > index 0fd3367..62745b5 100644 > --- a/block/vvfat.c > +++ b/block/vvfat.c > @@ -394,11 +394,12 @@ static void init_mbr(BDRVVVFATState* s) > > /* 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);
Spaces around '-'. Thanks for fixing the other cases, BTW. > + 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, > -- > 1.7.6.5 > >
